WO2024084536A1 - Refrigeration cycle system - Google Patents
Refrigeration cycle system Download PDFInfo
- Publication number
- WO2024084536A1 WO2024084536A1 PCT/JP2022/038500 JP2022038500W WO2024084536A1 WO 2024084536 A1 WO2024084536 A1 WO 2024084536A1 JP 2022038500 W JP2022038500 W JP 2022038500W WO 2024084536 A1 WO2024084536 A1 WO 2024084536A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- heat
- heat medium
- heat exchanger
- differential pressure
- source side
- Prior art date
Links
- 238000005057 refrigeration Methods 0.000 title claims abstract description 175
- 238000001514 detection method Methods 0.000 claims abstract description 142
- 239000003507 refrigerant Substances 0.000 claims abstract description 90
- 230000008021 deposition Effects 0.000 claims abstract description 14
- 238000005259 measurement Methods 0.000 abstract description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 72
- 238000009825 accumulation Methods 0.000 description 25
- 238000010586 diagram Methods 0.000 description 12
- 238000000034 method Methods 0.000 description 12
- 230000006870 function Effects 0.000 description 11
- 239000008400 supply water Substances 0.000 description 8
- 230000007423 decrease Effects 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- 238000011144 upstream manufacturing Methods 0.000 description 4
- 230000009977 dual effect Effects 0.000 description 3
- 238000007689 inspection Methods 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 101000892301 Phomopsis amygdali Geranylgeranyl diphosphate synthase Proteins 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- 230000002528 anti-freeze Effects 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B1/00—Compression machines, plants or systems with non-reversible cycle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
Definitions
- This disclosure relates to a refrigeration cycle system that supplies a heat medium, such as water, that has exchanged heat with a refrigerant to a load device.
- a heat medium such as water
- Some refrigeration cycle systems include a refrigeration cycle device, which is a heat source machine equipped with a refrigerant circuit through which a refrigerant circulates, and in the refrigeration cycle device, a heat medium (e.g., water) in the heat medium circuit is heat exchanged with the refrigerant, and the heat medium after the heat exchange is supplied to a load device (e.g., an air conditioner).
- a heat medium e.g., water
- a load device e.g., an air conditioner
- the heat exchanger hereinafter also referred to as a water heat exchanger
- the refrigerant and the heat medium exchange heat is reduced in heat exchange efficiency due to the accumulation of scale in the heat medium flow path over time due to calcium components and the like contained in the heat medium.
- Patent Document 1 diagnoses the accumulation state of dirt based on the heat exchange efficiency between the refrigerant and the heat medium. Specifically, the refrigeration cycle system of Patent Document 1 calculates the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the water heat exchanger, and uses this temperature difference to diagnose the state of dirt accumulation in the water heat exchanger.
- the present disclosure has been made against the background of the above-mentioned problems, and provides a refrigeration cycle system that can determine the state of dirt accumulation in the heat medium flow path of a water heat exchanger (heat exchanger) more accurately than ever before.
- the first refrigeration cycle system includes a refrigerant circuit having a compressor and in which a refrigerant is circulated by the compressor, a heat medium circuit having a heat source side pump and in which a heat medium is circulated by the heat source side pump, a heat exchanger for exchanging heat between the refrigerant and the heat medium, and a system control device for controlling the heat source side pump, and the heat medium circuit includes a load device provided downstream of the heat exchanger and a bypass piping for bypassing the load device.
- a first pressure sensor is provided in the heat medium circuit and detects a pressure difference between before and after the heat exchanger.
- a detection unit and a second detection unit provided in the heat medium circuit for detecting a bypass differential pressure before and after the bypass piping determines the head of the heat source side pump from the differential pressure detected by the first detection unit and the rotation speed of the heat source side pump, calculates the bypass differential pressure before and after the bypass piping based on the differential pressure and the head, and determines the scale deposition state of the heat exchanger by comparing the difference between the calculated bypass differential pressure value and the actual measured value of the bypass differential pressure detected by the second detection unit with a difference value stored in advance.
- a second refrigeration cycle system includes a refrigerant circuit having a compressor and in which a refrigerant is circulated by the compressor, a heat medium circuit having a heat source side pump and in which a heat medium is circulated by the heat source side pump, a heat exchanger for exchanging heat between the refrigerant and the heat medium, and a system control device for controlling the heat source side pump, the heat medium circuit having a load device provided downstream of the heat exchanger and a bypass piping for bypassing the load device.
- the heat medium circuit includes a first detection unit provided in the heat medium circuit and detecting a pressure difference between before and after the heat exchanger, and a pump provided in the heat medium circuit and detecting a pressure difference between before and after the heat source side pump. and a second detection unit that detects the differential pressure.
- the system control device determines the head of the heat source side pump from the differential pressure detected by the first detection unit and the rotation speed of the heat source side pump, calculates the bypass differential pressure before and after the bypass piping based on the differential pressure and the head to obtain a first calculated value, calculates the bypass differential pressure before and after the bypass piping based on the differential pressure detected by the first detection unit and the pump differential pressure detected by the second detection unit to obtain a second calculated value, and determines the scale deposition state of the heat exchanger by comparing the difference between the first and second calculated values of the bypass differential pressure with a previously stored difference value.
- a third refrigeration cycle system includes a refrigerant circuit having a compressor and in which a refrigerant is circulated by the compressor, a heat medium circuit having a heat source side pump and a load side pump and in which a heat medium is circulated by the heat source side pump and the load side pump, a heat exchanger that exchanges heat between the refrigerant and the heat medium, and a system control device that controls the heat source side pump, the heat medium circuit having a load device provided downstream of the heat exchanger and a free bypass piping that bypasses the load device, the heat source side pump pressure-feeds the heat medium to the heat exchanger, and the load side pump pressure-feeds the heat medium to the load device.
- a first detection unit is provided in the heat medium circuit and detects the differential pressure before and after the heat exchanger
- a second detection unit is provided on the load side of the heat medium circuit and detects the load side flow rate of the heat medium.
- the system control device determines the head of the heat source side pump from the differential pressure detected by the first detection unit and the rotation speed of the heat source side pump, calculates the load side flow rate of the heat medium flowing on the load side of the heat medium circuit based on the differential pressure and the head, and determines the scale accumulation state of the heat exchanger by comparing the difference between the calculated value of the load side flow rate and the actual value of the load side flow rate detected by the second detection unit with a pre-stored difference value.
- a fourth refrigeration cycle system includes a refrigerant circuit having a compressor and in which a refrigerant is circulated by the compressor, a heat medium circuit having a heat source side pump and a load side pump and in which a heat medium is circulated by the heat source side pump and the load side pump, a heat exchanger that exchanges heat between the refrigerant and the heat medium, and a system control device that controls the heat source side pump, wherein the heat medium circuit has a load device provided downstream of the heat exchanger and a free bypass piping that bypasses the load device, the heat source side pump pressure-feeds the heat medium to the heat exchanger, and the load side pump pressure-feeds the heat medium to the load device.
- a pressure difference between the front and rear of the heat exchanger is detected by a pressure sensor provided in the heat medium circuit.
- the system control device includes a first detection unit that detects the pump pressure difference between before and after the heat source pump, and a second detection unit that is provided in the heat medium circuit and detects the pump pressure difference between before and after the heat source pump.
- the system control device determines the head of the heat source pump from the pressure difference detected by the first detection unit and the rotation speed of the heat source pump, calculates the load side flow rate of the heat medium flowing to the load side of the heat medium circuit based on the pressure difference and the head to obtain a first calculated value, calculates the load side flow rate of the heat medium flowing to the load side of the heat medium circuit based on the pressure difference detected by the first detection unit and the pump pressure difference detected by the second detection unit to obtain a second calculated value, and compares the difference between the first and second calculated values of the load side flow rate with a difference value stored in advance to determine the scale deposition state of the heat exchanger.
- the scale buildup state of the heat exchanger is determined by comparing the difference between the calculated and actual values of the bypass differential pressure (or load side flow rate) obtained by different methods using the first and second detection units provided in the heat medium circuit, or the difference between the first and second calculated values of the bypass differential pressure (or load side flow rate), with a pre-stored difference value.
- the first and second detection units are both provided in the heat medium circuit where scale buildup occurs, and therefore, by determining the scale buildup state of the heat exchanger based on these detection values, the scale buildup state of the heat exchanger can be determined more accurately with less influence from load fluctuations and fluctuations in operating conditions, compared to a conventional configuration in which the scale buildup state of the heat exchanger is determined based on the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the heat exchanger.
- FIG. 1 is a circuit diagram showing a schematic configuration of a refrigeration cycle system according to a first embodiment of the present disclosure.
- FIG. 2 is a circuit diagram showing an example of the configuration of the refrigeration cycle device of FIG. 1.
- FIG. 2 is a diagram showing the relationship between head loss and flow rate of the water heat exchanger of FIG. 1 .
- FIG. 2 is a diagram showing the head characteristics of the pump of FIG. 1 .
- 4 is a flowchart showing a scale accumulation determination process performed by the system control device of FIG. 1 .
- FIG. 3 is a circuit diagram showing a modified example of the refrigeration cycle device of FIG. 2 .
- FIG. 1 is a circuit diagram showing a schematic configuration of a refrigeration cycle system 10 according to a first embodiment of the present disclosure.
- Fig. 2 is a circuit diagram showing an example of the configuration of a refrigeration cycle device 20 of Fig. 1.
- solid white arrows indicate the direction in which a refrigerant flows
- dashed white arrows indicate the direction in which a heat medium flows.
- the schematic configuration of the refrigeration cycle system 10 will be described with reference to Figs. 1 and 2.
- the refrigeration cycle system 10 includes a refrigerant circuit 27 through which a refrigerant circulates, a heat medium circuit 40 through which a heat medium such as water circulates, and a water heat exchanger (hereinafter also referred to as heat exchanger 26) that exchanges heat between the refrigerant and the heat medium.
- a heat medium flowing through the heat medium circuit 40 is water, but other fluids such as antifreeze may also be used.
- the heat medium circuit 40 has a heat source side pump 30 that pressurizes the heat medium to the heat exchanger 26, and supplies the heat medium that has exchanged heat with the refrigerant in the heat exchanger 26 to a load device 70.
- the load device 70 is, for example, an air conditioner.
- the refrigeration cycle system 10 in FIG. 1 includes a plurality of refrigeration cycle devices 20 each equipped with a refrigerant circuit 27.
- the number of refrigeration cycle devices 20 included in the refrigeration cycle system 10 may be any number, for example, it may be one.
- the refrigeration cycle device 20 functions as a heat source device, for example, an air-cooled heat pump chiller.
- the refrigeration cycle device 20 is configured to include a part of the heat medium circuit 40.
- Each of the plurality of refrigeration cycle devices 20 has a heat source side branch pipe 40a described later in which a water heat exchanger (heat exchanger 26) and a heat source side pump 30 are provided. In the heat medium circuit 40, these plurality of heat source side branch pipes 40a are connected in parallel to each other and connected to the load side circuit portion.
- the refrigeration cycle system 10 is configured to exchange heat between the heat medium circulating in one heat medium circuit 40 and the refrigerant circulating in each refrigerant circuit 27 of the plurality of refrigeration cycle devices 20, and the heat generated in the plurality of refrigeration cycle devices 20 is supplied to one or more load devices 70 via the heat medium.
- the configuration of the heat medium circuit 40 will be described later.
- the refrigerant circuit 27 is formed by connecting the compressor 22, the air heat exchanger (heat exchanger 24), the pressure reducing device 25, and the water heat exchanger (heat exchanger 26) in a ring shape via refrigerant piping.
- the compressor 22 compresses the refrigerant and circulates it in the refrigerant circuit 27.
- the compressor 22 is, for example, an inverter compressor whose capacity, which is the amount of refrigerant sent out per unit time, is controlled by changing the operating frequency.
- the heat exchanger 24 is, for example, a fin-and-tube type heat exchanger, and exchanges heat between the air and the refrigerant.
- the fan 28 supplies outdoor air to the heat exchanger 24 to promote heat exchange by the heat exchanger 24.
- the amount of air sent to the heat exchanger 24 is controlled by controlling the rotation speed of the fan 28.
- the pressure reducing device 25 is, for example, an electronic expansion valve, and controls the pressure of the refrigerant flowing into the water heat exchanger (heat exchanger 26) by changing the opening degree.
- the pressure reducing device 25 reduces the pressure of the high-pressure refrigerant that flows out of the heat exchanger 24.
- the heat exchanger 26 exchanges heat between the heat medium circulating in the heat medium circuit 40 and the refrigerant flowing in the refrigerant circuit 27.
- the discharge side of the compressor 22 is connected to an air heat exchanger (heat exchanger 24), the heat exchanger 24 is connected to a pressure reducing device 25, the pressure reducing device 25 is connected to a water heat exchanger (heat exchanger 26), and the heat exchanger 26 is connected to the suction side of the compressor 22.
- the heat exchanger 24 functions as a condenser
- the water heat exchanger (heat exchanger 26) functions as an evaporator.
- the heat medium pumped by the heat source side pump 30 is cooled by the refrigerant decompressed by the pressure reducing device 25 of the refrigerant circuit 27.
- the heat medium and the refrigerant flow in parallel in the heat exchanger 26.
- the configuration of the refrigerant circuit 27 is not limited to this configuration.
- a flow switching device such as a four-way valve may be provided on the refrigerant discharge side of the compressor 22 to switch between a cooling operation in which the refrigerant flows through the compressor 22, heat exchanger 24, pressure reducing device 25, and heat exchanger 26 in that order, and a heating operation in which the refrigerant flows through the compressor 22, heat exchanger 26, pressure reducing device 25, and heat exchanger 24 in that order.
- the heat exchanger 24, which is the condenser is configured as an air heat exchanger
- the refrigeration cycle device 20 is air-cooled
- the heat exchanger 24 may be configured as a water heat exchanger
- the refrigeration cycle device 20 may be water-cooled.
- the refrigeration cycle device 20 also includes a control device 21 that controls the refrigerant circuit 27 and the heat source side pump 30. Specifically, the control device 21 controls the frequency of the compressor 22, the opening degree of the pressure reducing device 25, the rotation speed of the fan 28, and the frequency (i.e., the rotation speed) of the heat source side pump 30.
- the control device 21 is configured with hardware such as a circuit device that realizes its functions.
- the control device 21 has a memory that stores programs and a CPU (Central Processing Unit), and the functions of the control device 21 are realized by the CPU executing the programs.
- a CPU Central Processing Unit
- the refrigeration cycle device 20 also includes a heat exchanger differential pressure detection unit 31 that detects the differential pressure between the inlet and outlet sides of the heat medium in the water heat exchanger, i.e., the differential pressure before and after the heat exchanger 26 in the heat source side branch pipe 40a (hereinafter also referred to as the heat exchanger differential pressure).
- the heat exchanger differential pressure detection unit 31 is composed of, for example, a differential pressure gauge.
- the control device 21 of the refrigeration cycle device 20 is connected to the heat exchanger differential pressure detection unit 31, and the heat exchanger differential pressure ⁇ Phex(i) detected by the heat exchanger differential pressure detection unit 31 is input to the control device 21.
- the heat exchanger differential pressure detection unit 31 may be referred to as the first detection unit.
- the heat exchanger differential pressure detection unit 31 may be configured as two pressure sensors, each of which is attached before and after the heat exchanger 26, and the heat exchanger differential pressure ⁇ Phex(i) may be calculated in the control device 21.
- the configuration of the heat medium circuit 40 will be described below with reference to FIG. 1.
- two load devices 70 are provided in the load side circuit portion of the heat medium circuit 40. Any number of load devices 70 may be provided in the load side circuit portion in the refrigeration cycle system 10, for example, one, or three or more.
- the load device 70 is, for example, an air conditioner such as an air handling unit or a fan coil unit.
- the load device 70 has a load side heat exchanger (not shown) that exchanges heat between the air in the room and the heat medium circulating through the heat medium circuit 40.
- the load side circuit portion of the heat medium circuit 40 has a plurality of load side branch pipes 40b connected in parallel to each other, each of which is provided with a load device 70, and a second return side header pipe 42b to which each downstream end of the plurality of load side branch pipes 40b is connected.
- the load side circuit portion of the heat medium circuit 40 also has a junction pipe 40c that connects the second return side header pipe 42b and a first return side header pipe 42a described below.
- Each load side branch pipe 40b is provided with a load side expansion valve 71, which is, for example, a proportional two-way valve.
- the load side expansion valve 71 is provided on the side of the load side branch pipe 40b where the heat medium flows out from the load device 70, that is, between the load device 70 and the second return side header pipe 42b.
- the junction pipe 40c is also provided with a load side flow meter 73 that detects the flow rate of the heat medium flowing through the load side circuit portion of the heat medium circuit 40 (hereinafter also referred to as the load side flow rate).
- the load side flow meter 73 may be omitted.
- the heat source side circuit portion of the heat medium circuit 40 has a first return water side header pipe 42a connected to a second return water side header pipe 42b via a junction pipe 40c, a supply water side header pipe 41 to which the upstream ends of the multiple load side branch pipes 40b are connected, and multiple heat source side branch pipes 40a each equipped with a heat exchanger 26 and a heat source side pump 30.
- the downstream ends of the multiple heat source side branch pipes 40a are connected to the supply water side header pipe 41, and the upstream ends of the multiple heat source side branch pipes 40a are connected to the first return water side header pipe 42a.
- the first return water side header pipe 42a distributes the heat medium returning from the load side circuit portion to the multiple heat source side branch pipes 40a.
- Each heat source side pump 30 pressurizes the heat medium distributed by the first return water side header pipe 42a to the water heat exchanger (heat exchanger 26).
- the heat medium pressurized by the heat source side pump 30 to the heat exchanger 26 is cooled by heat exchange with the refrigerant of the refrigerant circuit 27 in the heat exchanger 26.
- the heat medium cooled in each of the multiple heat exchangers 26 flows into the supply water side header pipe 41.
- the supply water side header pipe 41 merges the heat medium cooled in each of the multiple refrigeration cycle devices 20 and flowing into the supply water side header pipe 41, and distributes and supplies it to the multiple load devices 70 provided downstream.
- the heat medium circuit 40 also has a bypass pipe 80 that bypasses the load side circuit portion (i.e., bypasses the multiple load devices 70).
- the bypass pipe 80 connects the supply water side header pipe 41 and the first return water side header pipe 42a that are provided before and after the multiple refrigeration cycle devices 20 in the heat medium circuit 40.
- the refrigeration cycle system 10 of the first embodiment shown in FIG. 1 employs a single pump system in which the heat source pump 30 is provided only in the heat source side circuit portion of the heat medium circuit 40, and no pump is provided in the load side circuit portion.
- the bypass piping 80 is provided with a bypass valve 81 that adjusts the flow rate of the heat medium flowing through the bypass piping 80.
- the differential pressure before and after the bypass piping 80 (hereinafter also referred to as the bypass differential pressure), that is, the differential pressure between the forward water header pipe 41 on the upstream side of the bypass piping 80 and the first return water header pipe 42a on the downstream side, is adjusted by the opening degree of the bypass valve 81.
- the refrigeration cycle system 10 of the first embodiment also includes a bypass differential pressure detection unit 90 that detects the bypass differential pressure before and after the bypass piping 80.
- the bypass differential pressure detection unit 90 is composed of, for example, a differential pressure gauge.
- the bypass differential pressure detection unit 90 may be referred to as the second detection unit.
- the refrigeration cycle system 10 includes a system control device 21a that controls the heat medium circuit 40.
- the system control device 21a is configured with hardware such as a circuit device that realizes its functions.
- the system control device 21a has a memory that stores programs and a CPU (Central Processing Unit), and the functions of the system control device 21a are realized by the CPU executing the programs.
- a CPU Central Processing Unit
- the system control device 21a is connected to the load side flow meter 73, the bypass differential pressure detection unit 90, and the bypass valve 81.
- the load side flow rate detected by the load side flow meter 73 and the bypass differential pressure detected by the bypass differential pressure detection unit 90 are input to the system control device 21a.
- the system control device 21a also outputs an instruction opening to the bypass valve 81.
- the inputs to and outputs from the system control device 21a as described above are input or output as current signals of, for example, DC 4 to 20 mA.
- the current of each current signal is a current corresponding to the load side flow rate, the bypass differential pressure, or the command opening of the bypass valve 81.
- bypass differential pressure detection unit 90 may be configured with two pressure sensors, with each pressure sensor attached before and after the bypass piping 80, i.e., to the forward water header pipe 41 and the first return water header pipe 42a, and the bypass differential pressure may be determined by the system control device 21a.
- the control device 21 of the refrigeration cycle device 20 is configured to cooperate with the control devices 21 of the other refrigeration cycle devices 20 to control the operation of the corresponding refrigerant circuit 27 and heat source side pump 30.
- one of the multiple refrigeration cycle devices 20 may be set as a representative device, and the control device 21 of this representative device may communicate with each of the control devices 21 of the refrigeration cycle devices 20 other than the representative device.
- the control device 21 of the representative device (the refrigeration cycle device 20 on the lower side in the figure) functions as the system control device 21a.
- the system control device 21a acquires the operating frequency Fp(i) of the heat source pump 30 and the differential pressure (heat exchanger differential pressure ⁇ Phex(i)) before and after the heat exchanger 26 from each refrigeration cycle device 20.
- the load side flow rate is input from the load side flow meter 73 to the system control device 21a
- the bypass differential pressure is input from the bypass differential pressure detection unit 90.
- the system control device 21a outputs an opening command to the bypass valve 81 according to the operating frequency Fp(i) of the multiple refrigeration cycle devices 20 acquired and the actual measurement value B of the bypass differential pressure.
- the bypass valve 81 adjusts the opening according to the opening command from the system control device 21a.
- the flow rate of the heat medium flowing from the supply water side header pipe 41 to the first return water side header pipe 42a via the bypass piping 80 is adjusted, and the difference between the flow rate of the heat medium flowing to each refrigeration cycle device 20, which is a heat source device, and the flow rate of the heat medium flowing to each load device 70 is adjusted.
- the pressure difference between the forward water header pipe 41 and the first return water header pipe 42a i.e., the bypass pressure difference
- the bypass pressure difference is detected by the bypass pressure difference detection unit 90.
- the system control device 21a judges the scale buildup state of the water heat exchanger (heat exchanger 26) based on the state of the heat medium circuit 40.
- the refrigeration cycle system 10 includes an alarm unit 99 that notifies the result of the scale buildup judgment by the system control device 21a.
- the alarm unit 99 is configured, for example, as an LCD display or a speaker, and displays the result of the scale buildup judgment. For example, an operator performing regular inspection can know the result of the scale buildup judgment of the heat exchanger 26 by checking the result displayed on the alarm unit 99. For example, when the system control device 21a judges that the amount of scale buildup in the heat exchanger 26 is equal to or greater than a certain amount, the alarm unit 99 may be configured to notify that fact, or that cleaning is required.
- FIG. 3 is a diagram showing the relationship between head loss and flow rate of the water heat exchanger (heat exchanger 26) in FIG. 1.
- FIG. 4 is a diagram showing the head characteristics of the pump (heat source side pump 30) in FIG. 1.
- FIG. 5 is a flowchart showing the scale buildup determination performed by the system control device 21a in FIG. 1. Below, with reference to FIGS. 3 to 5, an example of scale buildup determination performed by the system control device 21a in the refrigeration cycle system 10 employing a single pump system will be described.
- the system control device 21a determines the state of scale buildup in the heat exchanger 26 as the state of the heat medium circuit 40 using the detection value (heat exchanger differential pressure ⁇ Phex(i)) of the heat exchanger differential pressure detection unit 31 and the detection value (actual measured value B of the bypass differential pressure) of the bypass differential pressure detection unit 90.
- the horizontal axis indicates the flow rate [ m3 /h] of the heat medium flowing through the water heat exchanger (heat exchanger 26), and the vertical axis indicates the head loss [kPa] of the heat medium in the water heat exchanger (heat exchanger 26).
- the horizontal axis indicates the flow rate Vw of the heat medium that can be delivered by the heat source side pump 30, and the vertical axis indicates the head pressure P.
- the head pressure P is the amount of pressure increase of the heat medium by the heat source side pump 30, and corresponds to the pump head of the heat source side pump 30.
- FIG. 4 shows pump head curves C1, C2, and C3 that represent the relationship between the flow rate Vw of the heat medium and the head pressure P when the operating frequency Fp of the heat source side pump 30 is Fp1, Fp2, and Fp3 (Fp1 ⁇ Fp2 ⁇ Fp3).
- the head loss i.e., the pressure difference before and after the heat exchanger 26 increases.
- the system control device 21a calculates the bypass differential pressure using the heat exchanger differential pressure ⁇ Phex(i) detected by the heat exchanger differential pressure detection unit 31, and compares the difference Dab between the calculated bypass differential pressure value A and the actual measured bypass differential pressure value B detected by the bypass differential pressure detection unit 90 with a pre-stored difference value (for example, the difference Dab_0 between the calculated value A and the actual measured bypass differential pressure B obtained in an initial state such as during a test run).
- a pre-stored difference value for example, the difference Dab_0 between the calculated value A and the actual measured bypass differential pressure B obtained in an initial state such as during a test run.
- the system control device 21a determines that a certain amount or more of scale has accumulated in the heat exchanger 26, and notifies this fact via the notification unit 99.
- the characteristics of the heat exchanger 26 shown in FIG. 3 and the head characteristics of the heat source side pump 30 shown in FIG. 4 are stored in advance in the system control device 21a in the form of a table or formula so that the bypass differential pressure calculation value A can be calculated from the heat exchanger differential pressure ⁇ Phex(i) detected by the heat exchanger differential pressure detection unit 31.
- the relationship between the head loss in the heat exchanger 26 i.e., the heat exchanger differential pressure ⁇ Phex(i)
- the heat medium flow rate Vw is stored in the form of the following formula (1).
- f1( ⁇ Phex(i)) in formula (1) is a function of the heat exchanger differential pressure ⁇ Phex(i).
- the (i) in each parameter indicates the number of refrigeration cycle devices 20.
- the flow rate of the heat medium flowing through the heat exchanger 26 is the flow rate of the heat medium flowing through the heat source side pump 30, and is also the flow rate of the heat medium flowing through the refrigeration cycle device 20, which is the heat source machine.
- Vw(i) f1( ⁇ Phex(i)) ... (1)
- the relationship between the operating frequency Fp (i.e., rotation speed), flow rate Vw(i), and head pressure P (i.e., pump head ⁇ Pp(i)) of the heat source side pump 30 is stored in the form of the following formula (2).
- f2(Fp, Vw(i)) in formula (2) is a function of the operating frequency Fp and flow rate Vw(i) of the heat source side pump 30.
- the refrigeration cycle system 10 In a configuration in which the refrigeration cycle system 10 includes multiple refrigeration cycle devices 20 as shown in FIG. 1, the refrigeration cycle system 10 has the same number of heat exchanger differential pressure detection units 31 (see FIG. 2) as the number of refrigeration cycle devices 20.
- the system control device 21a uses the heat exchanger differential pressure ⁇ Phex(i) detected by the multiple heat exchanger differential pressure detection units 31 and the actual bypass differential pressure value B detected by one bypass differential pressure detection unit 90 to determine scale accumulation.
- the system control device 21a acquires the heat exchanger differential pressure ⁇ Phex(i) detected by the heat exchanger differential pressure detection unit 31 and the operation frequency Fp of the heat source side pump 30 from the control devices 21 of the multiple refrigeration cycle devices 20.
- the actual measurement value B of the bypass differential pressure is input from the bypass differential pressure detection unit 90 to the system control device 21a.
- the system control device 21a calculates the flow rate of the heat medium flowing in the heat exchanger 26, i.e., the flow rate Vw(i) of the heat medium flowing through the refrigeration cycle device 20, from the acquired heat exchanger differential pressure ⁇ Phex(i) using equation (1). Furthermore, the system control device 21a calculates the pump head ⁇ Pp(i) from the calculated flow rate Vw(i) and the acquired operation frequency Fp (i.e., the rotation speed) of the heat source side pump 30 using equation (2). The system control device 21a calculates the pump head ⁇ Pp(i) using equations (1) and (2) for each of the multiple refrigeration cycle devices 20.
- the system control device 21a calculates an average value of the differences between the pump head ⁇ Pp(i) and the heat exchanger differential pressure ⁇ Phex(i) in each refrigeration cycle device 20 using the following equation (3), and sets the calculated average value as the bypass differential pressure calculation value A.
- the calculated value A of the bypass differential pressure is the average of the pressure differences ( ⁇ Pp(i) - ⁇ Phex(i)) before and after the refrigeration cycle device 20 in the heat source side branch pipe 40a for all heat source side branch pipes 40a.
- the system control device 21a calculates the difference between the calculated value A of the bypass differential pressure obtained using formula (3), i.e., the bypass differential pressure calculated based on the state of the heat source side circuit part of the heat medium circuit 40, and the actual measured value B of the bypass differential pressure detected directly by the bypass differential pressure detection unit 90, and stores this as the initial state difference Dab_0.
- the system control device 21a acquires each heat exchanger differential pressure ⁇ Phex(i) and an actual measurement value B of the bypass differential pressure, calculates a calculated value A of the bypass differential pressure, and obtains a difference between the calculated value A and the actual measurement value B, as in the case of a test run. Then, during operation of the refrigeration cycle system 10 after the start of operation, the system control device 21a compares the difference obtained during operation with the difference obtained in the initial state to determine the scale buildup state for the multiple heat exchangers 26.
- the system control device 21a acquires the heat exchanger differential pressure ⁇ Phex(i) detected by the heat exchanger differential pressure detection unit 31 from each control device 21 of the multiple refrigeration cycle devices 20 (step S10).
- the system control device 21a also acquires the operating frequency Fp of the heat source side pump 30 from each control device 21 of the multiple refrigeration cycle devices 20.
- the system control device 21a also receives an actual measured value B of the bypass differential pressure from the bypass differential pressure detection unit 90.
- the system control device 21a calculates the flow rate Vw(i) of the heat medium flowing through the heat exchanger 26, i.e., the flow rate of the heat medium flowing through the refrigeration cycle device 20, for each refrigeration cycle device 20 from the acquired heat exchanger differential pressure ⁇ Phex(i) using formula (1) (step S11). Furthermore, the system control device 21a calculates the pump head ⁇ Pp(i) using formula (2) from the flow rate Vw(i) calculated in step S11 and the acquired operating frequency Fp of the heat source side pump 30 (step S12).
- the system control device 21a performs the calculations of steps S11 and S12 for each refrigeration cycle device 20, and obtains a bypass differential pressure calculation value A using formula (3) from the pump head ⁇ Pp(i) calculated in step S12 and the heat exchanger differential pressure ⁇ Phex(i) acquired in step S10 (step S13).
- the calculated value A of the bypass differential pressure obtained here reflects the state of the flow path of the heat medium in the heat exchangers 26 of the multiple refrigeration cycle devices 20 at this time.
- the head loss of the heat medium in the heat exchangers 26 i.e., the heat exchanger differential pressure ⁇ Phex(i)
- the flow rate [ m3 /h] increases and the head pressure P of the heat source side pump 30 (i.e., the pump head ⁇ Pp(i)) decreases. Therefore, when the amount of scale deposition increases, the pump head ⁇ Pp(i) decreases and the heat exchanger differential pressure ⁇ Phex(i) increases, so the calculated value A of the bypass differential pressure decreases.
- the system control device 21a calculates the difference Dab between the calculated value A of the bypass differential pressure calculated in step S13 and the actual measured value B of the bypass differential pressure input from the bypass differential pressure detection unit 90 (step S14). The system control device 21a then determines whether this difference Dab obtained during operation deviates from the pre-stored difference value (i.e., the difference Dab_0 obtained in the initial state) by a certain amount or more (step S15).
- step S15 If the difference Dab during operation deviates from the difference Dab_0 in the initial state by a certain amount or more (step S15; YES), the system control device 21a determines that a certain amount or more of scale has accumulated in the multiple heat exchangers 26 of the refrigeration cycle system 10 and notifies the fact by the notification unit 99 or the like (step S16).
- the difference Dab during operation deviates by a certain amount or more from the difference Dab_0 in the initial state
- the difference may be determined by the absolute value of the difference Dab_0 in the initial state subtracted from the difference during operation, regardless of whether the difference is positive or negative.
- the system control device 21a calculates the difference Dab between the calculated bypass differential pressure A and the measured value B, and compares the calculated difference Dab during operation with the initial state difference Dab_0 calculated and stored in advance during trial operation, and the state of scale buildup on the heat exchanger 26 over time can be determined based on the comparison result.
- the criteria for determining that a certain amount of scale has accumulated in the multiple heat exchangers 26 of the refrigeration cycle system 10 may be determined, for example, by learning the difference Dab and determining the difference Dab based on the learned difference Dab.
- the system control device 21a has a function for storing and learning the calculated value A, the measured value B, and the difference Dab between them.
- the system control device 21a learns the difference Dab in the process of operating the refrigeration cycle system 10 and determines the scale accumulation state based on the learned difference Dab.
- the method of determining the scale accumulation state of the heat exchanger 26 is not limited to the example shown in FIG. 5.
- the pump head ⁇ Pp(i) of the heat source pump 30 is calculated from the heat exchanger differential pressure ⁇ Phex(i) detected by the heat exchanger differential pressure detection unit 31, the bypass differential pressure is calculated based on the heat exchanger differential pressure ⁇ Phex(i) and the calculated pump head ⁇ Pp(i), and the scale accumulation state is determined based on the difference Dab between the calculated value A of the calculated bypass differential pressure and the actual measured value B of the bypass differential pressure detected by the bypass differential pressure detection unit 90.
- a method of determining the scale accumulation state by comparing a calculated value C obtained by a method different from the calculated value A instead of the actual measured value B with the calculated value A will be described.
- FIG. 6 is a circuit diagram showing a modified example of the refrigeration cycle device 20 in FIG. 2.
- the solid white arrows indicate the direction in which the refrigerant flows
- the dashed white arrows indicate the direction in which the heat transfer medium flows.
- the heat source side branch pipe 40a is provided with a heat exchanger differential pressure detection unit 31 that detects the differential pressure before and after the heat exchanger 26, and a pump differential pressure detection unit 32 that detects the pump differential pressure before and after the heat source side pump 30 (i.e., the pump head).
- the pump differential pressure detection unit 32 is, for example, a differential pressure gauge.
- the heat exchanger differential pressure detection unit 31 may be referred to as the first detection unit
- the pump differential pressure detection unit 32 may be referred to as the second detection unit. Note that instead of using a differential pressure gauge as the pump differential pressure detection unit 32, two pressure sensors provided before and after the heat source side pump 30 may be used.
- the system control device 21a calculates the bypass differential pressure using the following formula (4) to obtain the calculated value C.
- the pump head ⁇ Pp(i) which is a parameter of the calculated value A, is calculated from the heat exchanger differential pressure ⁇ Phex(i) detected by the heat exchanger differential pressure detection unit 31 using formulas (1) and (2), but ⁇ Pp_a(i) in formula (4) for calculating the calculated value C is the actual pump head value detected directly by the pump differential pressure detection unit 32.
- the system control device 21a calculates the bypass differential pressures A and C, respectively, and calculates the difference between them and stores it as the initial state difference Dac_0.
- the system control device 21a calculates the bypass differential pressures A and C, respectively, and calculates the difference Dac between them, and determines the scale accumulation state of the heat exchanger 26 by comparing the difference Dac during operation with the initial state difference Dac_0.
- the refrigeration cycle system 10 includes a refrigerant circuit 27 having a compressor 22 and a refrigerant circulating by the compressor 22, a heat medium circuit 40 having a heat source side pump 30 and a heat medium circulating by the heat source side pump 30, a heat exchanger 26 for exchanging heat between the refrigerant and the heat medium, and a system control device 21a for controlling the heat source side pump 30.
- the heat medium circuit 40 includes a load device 70 provided downstream of the heat exchanger 26 and a bypass piping 80 bypassing the load device 70.
- the refrigeration cycle system 10 also includes a first detection unit (heat exchanger differential pressure detection unit 31) provided in the heat medium circuit 40 for detecting a differential pressure before and after the heat exchanger 26, and a second detection unit (bypass differential pressure detection unit 90) provided in the heat medium circuit 40 for detecting a bypass differential pressure before and after the bypass piping 80.
- a first detection unit heat exchanger differential pressure detection unit 31
- a second detection unit bypass differential pressure detection unit 90
- the system control device 21a obtains the head ( ⁇ Pp(i)) of the heat source side pump 30 from the differential pressure (heat exchanger differential pressure ⁇ Phex(i)) detected by the first detection unit and the rotation speed (e.g., operating frequency Fp) of the heat source side pump 30, and calculates the bypass differential pressure before and after the bypass piping 80 based on the differential pressure (heat exchanger differential pressure ⁇ Phex(i)) and the head ( ⁇ Pp(i)).
- the system control device 21a compares the difference Dab between the calculated value A of the calculated bypass differential pressure and the actual measured value B of the bypass differential pressure detected by the second detection unit with a previously stored difference value (e.g., the difference Dab_0 in the initial state) to determine the scale deposition state of the heat exchanger 26.
- a previously stored difference value e.g., the difference Dab_0 in the initial state
- the scale buildup state of the heat exchanger 26 is determined by comparing the difference Dab between the calculated value A and the measured value B of the bypass differential pressure obtained by different methods using the first and second detection units provided in the heat medium circuit 40 with the difference value stored in advance.
- the configuration of the present disclosure which determines the scale buildup state of the heat exchanger 26 based on the difference Dab between the calculated value A and the measured value B of the bypass differential pressure obtained using these detection values (heat exchanger differential pressure ⁇ Phex(i) and the measured value B of the bypass differential pressure), can perform a more accurate determination that is less affected by load fluctuations and fluctuations in operating conditions than a conventional configuration in which the scale buildup state of the heat exchanger is determined based on the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the heat exchanger.
- the refrigeration cycle system 10 includes a refrigerant circuit 27 having a compressor 22 and circulating a refrigerant by the compressor 22, a heat medium circuit 40 having a heat source side pump 30 and circulating a heat medium by the heat source side pump 30, a heat exchanger 26 exchanging heat between the refrigerant and the heat medium, and a system control device 21a controlling the heat source side pump 30, and the heat medium circuit 40 includes a load device 70 provided downstream of the heat exchanger 26 and a bypass piping 80 bypassing the load device 70.
- the refrigeration cycle system 10 also includes a first detection unit (heat exchanger differential pressure detection unit 31) provided in the heat medium circuit 40 for detecting a differential pressure before and after the heat exchanger 26, and a second detection unit (pump differential pressure detection unit 32) provided in the heat medium circuit 40 for detecting a pump differential pressure before and after the heat source side pump 30.
- a first detection unit heat exchanger differential pressure detection unit 31
- a second detection unit pump differential pressure detection unit 32
- the system control device 21a determines the head ( ⁇ Pp(i)) of the heat source side pump 30 from the differential pressure (heat exchanger differential pressure ⁇ Phex(i)) detected by the first detection unit and the rotation speed (e.g., operating frequency Fp) of the heat source side pump 30, calculates the bypass differential pressure before and after the bypass piping based on the differential pressure (heat exchanger differential pressure ⁇ Phex(i)) and the head ( ⁇ Pp(i)) to obtain a first calculated value (calculated value A), and calculates the bypass differential pressure before and after the bypass piping 80 based on the differential pressure (heat exchanger differential pressure ⁇ Phex(i)) detected by the first detection unit and the pump differential pressure (actual measured head value ⁇ Pp_a(i)) detected by the second detection unit to obtain a second calculated value (calculated value C).
- the system control device 21a compares the difference Dac between the first calculated value (calculated value A) and the second calculated value (calculated value C) of the bypass differential pressure with a previously stored difference value (Dac_0 in the initial state) to determine the scale buildup state of the heat exchanger 26.
- the scale buildup state of the heat exchanger 26 is determined by comparing the difference Dac between the first calculated value (calculated value A) and the second calculated value (calculated value C) of the bypass differential pressure obtained by different methods using the first and second detection units provided in the heat medium circuit 40 with a pre-stored difference value (initial state difference Dac_0).
- the configuration of the present disclosure which determines the scale buildup state of the heat exchanger 26 based on the difference Dac between the first and second calculated values of the bypass differential pressure obtained using the detection values (heat exchanger differential pressure ⁇ Phex(i) and actual head value ⁇ Pp_a(i)), is less affected by load fluctuations and operating condition fluctuations and can perform more accurate determinations than the conventional configuration in which the scale buildup state of the heat exchanger is determined based on the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the heat exchanger.
- the system control device 21a also stores the difference Dac_0 calculated for the initial state when there is no scale in the heat exchanger 26 as a pre-stored difference value. Therefore, the scale accumulation judgment during operation can be performed using the initial state obtained by the configuration of the refrigeration cycle system, improving the accuracy of the judgment.
- the refrigeration cycle system 10 also includes a plurality of refrigeration cycle devices 20 each having a refrigerant circuit 27, a heat source side pump 30, and a heat exchanger 26, and the heat medium circuit 40 includes a plurality of heat source side branch pipes 40a in which the heat source side pumps 30 and heat exchangers 26 of each refrigeration cycle device 20 are provided, and the plurality of heat source side branch pipes 40a are connected in parallel to each other and connected to the load side.
- the scale accumulation state of the multiple heat exchangers 26 can be determined from the state of the heat medium circuit 40, just as in the case where the refrigeration cycle system 10 includes only one refrigeration cycle device 20.
- the refrigeration cycle system 10 also includes an alarm unit 99 having a display or a speaker.
- the system control device 21a is configured to notify the user by the alarm unit 99 that scale has accumulated when the difference Dab (or the difference Dac) deviates from a pre-stored difference value by a certain amount or more.
- an operator performing regular inspections can know when the amount of scale on the heat exchanger 26 exceeds a certain amount, and when notified, can take measures such as cleaning the heat exchanger 26, thereby preventing abnormalities such as clogging of the heat exchanger 26 due to scale or an extreme drop in heat exchange efficiency.
- Fig. 7 is a circuit diagram showing a schematic configuration of a refrigeration cycle system 110 according to a second embodiment of the present disclosure.
- the refrigeration cycle system 10 of the first embodiment employs a single pump system
- the refrigeration cycle system 110 of the second embodiment employs a dual pump system.
- the second detection unit used to determine the scale accumulation state is different from that in the first embodiment.
- the circuit configuration of the refrigeration cycle system 110 of the second embodiment will be described with reference to Fig. 7.
- the same parts as those in the first embodiment are denoted by the same reference numerals and description thereof will be omitted, and differences from the first embodiment will be mainly described.
- a pump is provided in each of the heat source side circuit portion and the load side circuit portion of the heat medium circuit 140.
- the pump provided in the heat source side circuit portion is referred to as the heat source side pump 30, and the pump provided in the load side circuit portion is referred to as the load side pump 144.
- the piping that bypasses the load side circuit portion in the heat medium circuit 140, i.e., that bypasses the multiple load devices 70, is a free bypass piping 180 that does not have a bypass valve 81 (see FIG. 1).
- the configuration of the heat source side circuit portion of the heat medium circuit 140 is the same as in the first embodiment shown in FIG. 1.
- the heat source side circuit portion has a plurality of heat source side branch pipes 140a, each of which is provided with a heat exchanger 26 and a heat source side pump 30, a first return water side header pipe 142a to which the upstream ends of the plurality of heat source side branch pipes 140a are connected, and a first supply water side header pipe 141a to which the downstream ends of the plurality of heat source side branch pipes 140a are connected.
- the load side circuit portion of the heat medium circuit 140 has a plurality of load side branch pipes 140b each provided with a load device 70 and a load side expansion valve 71, a second return water side header pipe 142b to which the downstream ends of the plurality of load side branch pipes 140b are connected, a junction pipe 140c connecting the second return water side header pipe 142b and the first return water side header pipe 142a on the heat source side, and a load side flow meter 73 provided on the junction pipe 140c.
- the forward water side header pipe 141 has a first forward water side header pipe 141a on the heat source side (refrigeration cycle device 20) side and a second forward water side header pipe 141b on the load device 70 side, and the first forward water side header pipe 141a and the second forward water side header pipe 141b are connected by a connection pipe 140d on which a load side pump 144 is provided.
- the refrigeration cycle system 10 is configured to distribute and circulate the heat medium cooled by four refrigeration cycle devices 20 to two load devices 70.
- the heat medium circuit 40 is configured to sequentially connect four heat source side branch pipes 40a, a first water supply side header pipe 141a, three connection pipes 140d, a second water supply side header pipe 141b, two load side branch pipes 140b, a second return water side header pipe 142b, a junction pipe 140c, and a first return water side header pipe 142a.
- Two of the three connection pipes 140d are provided with load side pumps 144 that pump the heat medium from the first water supply side header pipe 141a on the heat source side to the second water supply side header pipe 141b on the load side.
- the remaining one of the three connection pipes 140d is provided with a forward water expansion valve 145, which is, for example, a proportional two-way valve.
- the system control device 21a is connected to a load side flow meter 73, and the load side flow rate detected by the load side flow meter 73 is input to the system control device 21a.
- the load side pump 144 and the forward water expansion valve 145 are each connected to the system control device 21a, and the system control device 21a is configured to control the frequency of the load side pump 144 and the opening of the forward water expansion valve 145.
- the free bypass piping 180 connects the first forward water header pipe 141a and the first return water header pipe 142a, which are both ends of the circuit portion on the heat source side.
- the free bypass piping 180 allows the heat medium equivalent to the difference between the flow rates to bypass the two load devices 70 and circulate from the first forward water header pipe 141a to the first return water header pipe 142a.
- the system control device 121a determines the scale deposition state of the water heat exchanger (heat exchanger 26) based on the state of the heat medium circuit 140.
- the differential pressure before and after the heat exchanger 26 detected by the heat exchanger differential pressure detection unit 31 and the bypass differential pressure before and after the bypass piping 80 detected by the bypass differential pressure detection unit 90 are used as the state of the heat medium circuit 40
- the differential pressure before and after the heat exchanger 26 detected by the heat exchanger differential pressure detection unit 31 and the flow rate of the heat medium flowing on the load side detected by the load side flow meter 73 (hereinafter also referred to as the load side flow rate) are used as the state of the heat medium circuit 40. That is, in the second embodiment, the first detection unit is the heat exchanger differential pressure detection unit 31, and the second detection unit is the load side flow meter 73.
- the system control device 121a acquires the differential pressures (heat exchanger differential pressure ⁇ Phex(i)) across the heat exchanger 26 detected by the heat exchanger differential pressure detection units 31 from the control devices 21 of the multiple refrigeration cycle devices 20.
- the actual measured value FB of the load side flow rate detected by the load side flow meter 73 is input to the system control device 121a.
- the system control device 121a first calculates the bypass differential pressure calculation value A from the acquired multiple heat exchanger differential pressures ⁇ Phex(i) using equations (1) to (3). That is, the system control device 21a calculates the flow rate through the heat exchanger 26, i.e., the flow rate Vw(i) through the refrigeration cycle device 20, from the acquired heat exchanger differential pressures ⁇ Phex(i) using equation (1), calculates the pump head ⁇ Pp(i) from the flow rate Vw(i) using equation (2), and obtains the bypass differential pressure calculation value A from the pump head ⁇ Pp(i) and the heat exchanger differential pressure ⁇ Phex(i) using equation (3).
- the system control device 21a calculates the flow rate through the heat exchanger 26, i.e., the flow rate Vw(i) through the refrigeration cycle device 20, from the acquired heat exchanger differential pressures ⁇ Phex(i) using equation (1), calculates the pump head ⁇ Pp(i) from the flow rate Vw(i) using equation (2), and
- the system control device 121a uses the calculated bypass differential pressure A and the previously learned Cv value (hereafter referred to as Cv) of the free bypass piping 180 to calculate the bypass flow rate through the free bypass piping 180 from the following formula (5), thereby obtaining the calculated value BFa.
- the Cv value of the free bypass piping 180 is learned during the trial run and the learned Cv value is obtained.
- the Cv value of the free bypass piping 180 basically does not change except in special cases such as when a failure occurs, so the value learned during the trial run can be used after the start of operation.
- the system control device 121a uses the calculated bypass flow rate BFa and the flow rate Vw(i) of the heat medium flowing through each refrigeration cycle device 20 to determine the load side flow rate flowing through the load side from the following equation (6), obtaining a calculated value FA.
- the flow rate Vw(i) of the heat medium flowing through each refrigeration cycle device 20 is calculated by subtracting the calculated bypass flow rate BFa obtained from equation (5) from the total flow rate for all refrigeration cycle devices 20 in the refrigeration cycle system 10, thereby obtaining the calculated flow rate FA of the heat medium flowing through the load side.
- the system control device 21a calculates the difference between the calculated value FA of the load side flow rate obtained by equation (6), i.e., the load side flow rate obtained from the state of the circuit portion on the heat source side of the heat medium circuit 40, and the actual measured value FB of the load side flow rate detected by the load side flow meter 73, and stores the calculated difference as the initial state difference Dfab_0.
- the system control device 121a acquires each heat exchanger differential pressure ⁇ Phex(i) and the actual measured value FB of the load side flow rate, calculates a calculated value FA of the load side flow rate, and obtains a difference Dfab between the calculated value FA and the actual measured value FB, as in the case of the test run.
- the system control device 121a compares the difference Dfab obtained during operation with the difference Dfab_0 obtained during the test run to determine the scale buildup state for the multiple heat exchangers 26.
- FIG. 8 is a flow chart of the scale deposition determination performed by the system control device 121a of FIG. 7. Based on FIG. 8, the flow of the scale deposition determination performed by the system control device 121a during operation after the start of operation of the refrigeration cycle system 110 will be described.
- the system control device 121a acquires the heat exchanger differential pressure ⁇ Phex(i) detected by the heat exchanger differential pressure detection unit 31 (see FIG. 2) from the control devices 21 of the multiple refrigeration cycle devices 20 (step S20).
- the system control device 121a acquires the operating frequency Fp (i.e., the rotation speed) of the heat source side pump 30 from the control devices 21 of the multiple refrigeration cycle devices 20.
- the system control device 121a receives the flow rate of the heat medium flowing through the load side junction pipe 40c, i.e., the actual measured value FB of the load side flow rate, from the load side flow meter 73.
- the system control device 121a calculates the flow rate of the heat medium flowing through the heat exchanger 26 from the heat exchanger differential pressure ⁇ Phex(i) for each refrigeration cycle device 20, i.e., the flow rate Vw(i) of the heat medium flowing through the refrigeration cycle device 20, using formula (1) (step S21). Furthermore, the system control device 121a calculates the pump head ⁇ Pp(i) using formula (2) from the flow rate Vw(i) calculated in step S21 and the operating frequency Fp (i.e., the rotation speed) of the heat source side pump 30 obtained (step S22).
- the system control device 121a performs the calculations of steps S11 and S22 for each refrigeration cycle device 20, and obtains the bypass differential pressure calculation value A using formula (3) from the pump head ⁇ Pp(i) calculated in step S22 and the heat exchanger differential pressure ⁇ Phex(i) obtained in step S20 (step S23). Furthermore, the system control device 121a calculates the bypass flow rate using equation (5) from the calculated bypass differential pressure A and the previously learned Cv value of the free bypass piping 180, and obtains the calculated value BFa (step S23).
- the system control device 121a calculates the load side flow rate using equation (6) from the flow rate Vw(i) calculated in step S21 for each refrigeration cycle device 20 and the calculated bypass flow rate BFa calculated in step S23, and obtains the calculated value FA (step S24).
- the calculated load side flow rate FA obtained here reflects the state of the flow path of the heat medium in the heat exchangers 26 of the multiple refrigeration cycle devices 20 at this time.
- the head loss of the heat medium in the heat exchangers 26 i.e., the heat exchanger differential pressure ⁇ Phex(i)
- the flow rate [ m3 /h] increases and the head pressure P of the heat source side pump 30 (i.e., the pump head ⁇ Pp(i)) decreases. Therefore, when the amount of scale deposition increases, the pump head ⁇ Pp(i) decreases and the heat exchanger differential pressure ⁇ Phex(i) increases, so the calculated bypass differential pressure A decreases and the calculated load side flow rate FA increases.
- the system controller 121a calculates the difference Dfab between the calculated load side flow rate FA calculated in step S24 and the actual load side flow rate FB detected by the load side flow meter 73 (step S25). The system controller 121a then determines whether this difference Dfab obtained during operation deviates by a certain amount or more from the previously stored difference Dfab_0 (i.e., the difference Dfab_0 obtained in the initial state) (step S26).
- step S26 If the difference Dfab during operation deviates by a certain amount or more from the difference Dfab_0 in the initial state (step S26; YES), the system controller 121a determines that a certain amount or more of scale has accumulated in the multiple heat exchangers 26 of the refrigeration cycle system 110 and notifies the same via the notification unit 99 or the like (step S27).
- the difference Dfab during operation deviates from the difference Dfab_0 in the initial state by a certain amount or more, this can be determined by the absolute value of the difference Dfab during operation minus the difference Dfab_0 in the initial state, regardless of whether the difference is positive or negative.
- the system control device 21a calculates the difference Dfab between the calculated load side flow rate FA and the measured value FB, and compares the calculated difference Dfab during operation with the initial state difference Dfab_0 calculated and stored in advance during trial operation, and the state of scale buildup on the heat exchanger 26 over time can be determined based on the comparison result.
- the calculated value FC of the load side flow rate obtained by a method other than the calculated value FA can be used to determine the accumulation of scale.
- a heat exchanger differential pressure detection unit 31 and a pump differential pressure detection unit 32 are provided in the heat source side branch pipe 40a of each refrigeration cycle device 20, and the calculated value FC of the load side flow rate is obtained from equations (4) to (6) using these detection values.
- the system control device 121a calculates the difference Dfac between the calculated value FA of the load side flow rate obtained from equations (1) to (3), (5), and (6) and the calculated value FC of the load side flow rate.
- the refrigeration cycle system 110 includes a refrigerant circuit 27 having a compressor 22 and in which a refrigerant is circulated by the compressor 22, a heat medium circuit 40 having a heat source side pump 30 and a load side pump 144 and in which a heat medium is circulated by the heat source side pump 30 and the load side pump 144, a heat exchanger 26 that exchanges heat between the refrigerant and the heat medium, and a system control device 121a that controls the heat source side pump 30.
- the heat medium circuit 40 includes a load device 70 provided downstream of the heat exchanger 26, and a free bypass piping 180 that bypasses the load device 70.
- the heat source side pump 30 pumps the heat medium to the heat exchanger 26, and the load side pump 144 pumps the heat medium to the load device 70.
- the refrigeration cycle system 110 further includes a first detector (heat exchanger differential pressure detector 31) provided in the heat medium circuit 40 for detecting a pressure difference between before and after the heat exchanger 26, and a second detector (load side flow meter 73) provided on the load side of the heat medium circuit 40 for detecting a load side flow rate of the heat medium.
- the system control device 121a obtains the head ( ⁇ Pp(i)) of the heat source side pump 30 from the pressure difference (heat exchanger differential pressure ⁇ Phex(i)) detected by the first detector and the rotation speed (e.g., operating frequency Fp) of the heat source side pump 30, and calculates the load side flow rate of the heat medium flowing on the load side of the heat medium circuit 40 based on the pressure difference (heat exchanger differential pressure ⁇ Phex(i)) and the head ( ⁇ Pp(i)).
- the system control device 121a determines the scale buildup state of the heat exchanger 26 by comparing the difference Dfab between the calculated load side flow rate FA and the actual load side flow rate FB detected by the second detection unit with a pre-stored difference value (e.g., the difference Dfab_0 in the initial state).
- the difference Dfab between the calculated value A and the measured value B of the load side flow rate obtained by different methods using the first and second detection units provided in the heat medium circuit 40 is compared with the difference value stored in advance to determine the scale accumulation state of the heat exchanger 26.
- the configuration of the present disclosure which determines the scale accumulation state of the heat exchanger 26 based on the difference Dfab between the calculated value FA and the measured value FB of the load side flow rate obtained using these detection values (heat exchanger differential pressure ⁇ Phex(i) and the measured value FB of the load side flow rate), can perform a more accurate determination that is less affected by fluctuations in load and operating conditions than a conventional configuration in which the scale accumulation state of the heat exchanger is determined based on the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the heat exchanger.
- a modified example of the refrigeration cycle system 110 of the second embodiment includes a refrigerant circuit 27 having a compressor 22 and circulating a refrigerant by the compressor 22, a heat medium circuit 40 having a heat source side pump 30 and a load side pump 144 and circulating a heat medium by the heat source side pump 30 and the load side pump 144, a heat exchanger 26 that exchanges heat between the refrigerant and the heat medium, and a system control device 121a that controls the heat source side pump 30.
- the heat medium circuit 40 includes a load device 70 provided downstream of the heat exchanger 26, and a free bypass piping 180 that bypasses the load device 70.
- the heat source side pump 30 pumps the heat medium to the heat exchanger 26, and the load side pump 144 pumps the heat medium to the load device 70.
- the refrigeration cycle system 110 also includes a first detection unit (heat exchanger differential pressure detection unit 31) provided in the heat medium circuit 40 for detecting the differential pressure before and after the heat exchanger 26, and a second detection unit (pump differential pressure detection unit 32) provided in the heat medium circuit 40 for detecting the pump differential pressure before and after the heat source side pump 30.
- the system control device 121a determines the head ( ⁇ Pp(i)) of the heat source side pump 30 from the differential pressure (heat exchanger differential pressure ⁇ Phex(i)) detected by the first detection unit and the rotation speed (e.g., operating frequency Fp) of the heat source side pump 30, calculates the load side flow rate of the heat medium flowing on the load side of the heat medium circuit 40 based on the differential pressure (heat exchanger differential pressure ⁇ Phex(i)) and the head ( ⁇ Pp(i)) to obtain a first calculated value (calculated value FA), and calculates the load side flow rate of the heat medium flowing on the load side of the heat medium circuit 40 based on the differential pressure detected by the first detection unit and the pump differential pressure (actual measured head value ⁇ Pp_a(i)) detected by the second detection unit to obtain a second calculated value (calculated value FC).
- the system control device 121a determines the scale buildup state of the heat exchanger 26 by comparing the difference Dfac between the first and second calculated values of the load side flow rate with a previously stored difference value (the initial state difference Dfac_0).
- the difference Dfac between the first calculated value (calculated value FA) and the second calculated value (calculated value FC) of the load side flow rate obtained by different methods using the first and second detection units provided in the heat medium circuit 40 is compared with a pre-stored difference value (initial state difference Dfac_0) to determine the scale accumulation state of the heat exchanger 26.
- the configuration of the present disclosure which determines the scale accumulation state of the heat exchanger 26 based on the difference Dfac between the first and second calculated values of the load side flow rate obtained using the detection values (heat exchanger differential pressure ⁇ Phex(i) and actual head value ⁇ Pp_a(i)), is less affected by load fluctuations and fluctuations in operating conditions and can perform more accurate determinations than the conventional configuration in which the scale accumulation state of the heat exchanger is determined based on the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the heat exchanger.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Air Conditioning Control Device (AREA)
Abstract
The refrigeration cycle system comprises: a refrigerant circuit which has a compressor and through which a refrigerant is circulated by the compressor; a heat medium circuit which has a heat source side pump and through which a heat medium is circulated by the heat source side pump; a heat exchanger that exchanges heat between the refrigerant and the heat medium; and a system control device that controls the heat source side pump. The heat medium circuit has a load device provided on the downstream side of the heat exchanger, and a bypass piping that bypasses the load device. The refrigeration cycle system comprises a first detection unit that is provided to the heat medium circuit and that detects pressure difference before and after the heat exchanger, and a second detection unit that is provided to the heat medium circuit and that detects bypass pressure difference before and after the bypass piping. The system control device obtains the lift of the heat source side pump from the pressure difference detected by the first detection unit and the rotational speed of the heat source side pump, calculates the bypass pressure difference before and after the bypass piping on the basis of the pressure difference and the lift, and determines the deposition state of scales in the heat exchanger by comparing, with a pre-stored difference value, the difference between a calculation value of the calculated bypass pressure difference and an actual measurement of the bypass pressure difference detected by the second detection unit.
Description
本開示は、冷媒と熱交換した水等の熱媒体を負荷装置に供給する冷凍サイクルシステムに関する。
This disclosure relates to a refrigeration cycle system that supplies a heat medium, such as water, that has exchanged heat with a refrigerant to a load device.
冷凍サイクルシステムにおいて、冷媒が循環する冷媒回路を備えた熱源機である冷凍サイクル装置を備え、冷凍サイクル装置において熱媒体回路の熱媒体(例えば、水)を冷媒と熱交換させ、熱交換後の熱媒体を負荷装置(例えば、空調器)に供給するものがある。冷凍サイクルシステムにおいて、冷媒と熱媒体とが熱交換する熱交換器(以下、水熱交換器ともいう)は、熱媒体中に含まれるカルシウム成分等により経年的に熱媒体の流路にスケールが堆積することにより、熱交換効率が低下する。水熱交換器のスケール等の汚れが一定量以上になると、冷媒と熱媒体との熱交換が極端に阻害されて異常状態に至る場合もある。そこで、冷凍サイクルシステムにおいて、汚れの堆積状態を診断できるようにし、定期点検の作業者が診断結果に応じて洗浄を行うことで水熱交換器の詰まりの発生すなわち異常状態を未然に防止するものがある(例えば、特許文献1参照)。特許文献1の冷凍サイクルシステムは、冷媒と熱媒体との熱交換効率に基づき汚れの堆積状態を診断する。具体的には、特許文献1の冷凍サイクルシステムは、冷媒の飽和温度と、水熱交換器から流出する熱媒体の温度との温度差を算出し、この温度差を用いて、水熱交換器の汚れの堆積状態を診断する。
Some refrigeration cycle systems include a refrigeration cycle device, which is a heat source machine equipped with a refrigerant circuit through which a refrigerant circulates, and in the refrigeration cycle device, a heat medium (e.g., water) in the heat medium circuit is heat exchanged with the refrigerant, and the heat medium after the heat exchange is supplied to a load device (e.g., an air conditioner). In the refrigeration cycle system, the heat exchanger (hereinafter also referred to as a water heat exchanger) in which the refrigerant and the heat medium exchange heat is reduced in heat exchange efficiency due to the accumulation of scale in the heat medium flow path over time due to calcium components and the like contained in the heat medium. When the amount of dirt such as scale in the water heat exchanger exceeds a certain amount, the heat exchange between the refrigerant and the heat medium may be extremely hindered, leading to an abnormal state. Therefore, some refrigeration cycle systems are designed to be able to diagnose the accumulation state of dirt, and regular inspection workers clean the water heat exchanger according to the diagnosis results, thereby preventing clogging of the water heat exchanger, i.e., an abnormal state, from occurring (see, for example, Patent Document 1). The refrigeration cycle system of Patent Document 1 diagnoses the accumulation state of dirt based on the heat exchange efficiency between the refrigerant and the heat medium. Specifically, the refrigeration cycle system of Patent Document 1 calculates the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the water heat exchanger, and uses this temperature difference to diagnose the state of dirt accumulation in the water heat exchanger.
しかしながら、一般に冷媒は、冷媒回路を循環する間に状態変化、圧力変化、及び温度変化を伴う冷凍サイクルを繰り返すので、冷媒の飽和温度は、負荷変動及び運転条件の変動により変化し易い。したがって、特許文献1のように冷媒の飽和温度と水熱交換器から流出する熱媒体の温度との温度差を用いて水熱交換器の汚れの堆積状態を判定する構成では、負荷変動及び運転条件の変動による影響により判定精度に課題があった。
However, since the refrigerant generally repeats a refrigeration cycle involving changes in state, pressure, and temperature while circulating through the refrigerant circuit, the saturation temperature of the refrigerant is easily changed by fluctuations in load and operating conditions. Therefore, in a configuration such as that in Patent Document 1, which determines the state of dirt accumulation in the water heat exchanger using the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the water heat exchanger, there was an issue with the accuracy of the determination due to the effects of fluctuations in load and operating conditions.
本開示は、上記のような課題を背景としてなされたものであり、水熱交換器(熱交換器)の熱媒体の流路における汚れの堆積状態を、従来よりも正確に判定することができる冷凍サイクルシステムを提供するものである。
The present disclosure has been made against the background of the above-mentioned problems, and provides a refrigeration cycle system that can determine the state of dirt accumulation in the heat medium flow path of a water heat exchanger (heat exchanger) more accurately than ever before.
本開示に係る第1の冷凍サイクルシステムは、圧縮機を有し、前記圧縮機により冷媒が循環する冷媒回路と、熱源側ポンプを有し、前記熱源側ポンプにより熱媒体が循環する熱媒体回路と、前記冷媒と前記熱媒体との間で熱交換を行う熱交換器と、前記熱源側ポンプを制御するシステム制御装置と、を備え、前記熱媒体回路は、前記熱交換器の下流側に設けられる負荷装置と、前記負荷装置をバイパスするバイパス配管とを有したものである冷凍サイクルシステムにおいて、前記熱媒体回路に設けられ、前記熱交換器の前後の差圧を検出する第1検出部と、前記熱媒体回路に設けられ、前記バイパス配管の前後のバイパス差圧を検出する第2検出部と、を備え、前記システム制御装置は、前記第1検出部により検出された前記差圧と、前記熱源側ポンプの回転数から前記熱源側ポンプの揚程を求め、前記差圧及び前記揚程に基づき前記バイパス配管の前後の前記バイパス差圧を算出し、算出された前記バイパス差圧の計算値と、前記第2検出部により検出された前記バイパス差圧の実測値との差分を、予め記憶された差分値と比較することにより前記熱交換器のスケールの堆積状態を判定する。
The first refrigeration cycle system according to the present disclosure includes a refrigerant circuit having a compressor and in which a refrigerant is circulated by the compressor, a heat medium circuit having a heat source side pump and in which a heat medium is circulated by the heat source side pump, a heat exchanger for exchanging heat between the refrigerant and the heat medium, and a system control device for controlling the heat source side pump, and the heat medium circuit includes a load device provided downstream of the heat exchanger and a bypass piping for bypassing the load device. In the refrigeration cycle system, a first pressure sensor is provided in the heat medium circuit and detects a pressure difference between before and after the heat exchanger. A detection unit and a second detection unit provided in the heat medium circuit for detecting a bypass differential pressure before and after the bypass piping, the system control device determines the head of the heat source side pump from the differential pressure detected by the first detection unit and the rotation speed of the heat source side pump, calculates the bypass differential pressure before and after the bypass piping based on the differential pressure and the head, and determines the scale deposition state of the heat exchanger by comparing the difference between the calculated bypass differential pressure value and the actual measured value of the bypass differential pressure detected by the second detection unit with a difference value stored in advance.
また、本開示に係る第2の冷凍サイクルシステムは、圧縮機を有し、前記圧縮機により冷媒が循環する冷媒回路と、熱源側ポンプを有し、前記熱源側ポンプにより熱媒体が循環する熱媒体回路と、前記冷媒と前記熱媒体との間で熱交換を行う熱交換器と、前記熱源側ポンプを制御するシステム制御装置と、を備え、前記熱媒体回路は、前記熱交換器の下流側に設けられる負荷装置と、前記負荷装置をバイパスするバイパス配管とを有したものである冷凍サイクルシステムにおいて、前記熱媒体回路に設けられ、前記熱交換器の前後の差圧を検出する第1検出部と、前記熱媒体回路に設けられ、前記熱源側ポンプの前後のポンプ差圧を検出する第2検出部と、を備え、前記システム制御装置は、前記第1検出部により検出された前記差圧と、前記熱源側ポンプの回転数から前記熱源側ポンプの揚程を求め、前記差圧及び前記揚程に基づき前記バイパス配管の前後のバイパス差圧を算出して第1計算値を得るとともに、前記第1検出部により検出された前記差圧及び前記第2検出部により検出された前記ポンプ差圧に基づき前記バイパス配管の前後の前記バイパス差圧を算出して第2計算値を得、前記バイパス差圧の前記第1計算値と前記第2計算値との差分を、予め記憶された差分値と比較することにより前記熱交換器のスケールの堆積状態を判定する。
A second refrigeration cycle system according to the present disclosure includes a refrigerant circuit having a compressor and in which a refrigerant is circulated by the compressor, a heat medium circuit having a heat source side pump and in which a heat medium is circulated by the heat source side pump, a heat exchanger for exchanging heat between the refrigerant and the heat medium, and a system control device for controlling the heat source side pump, the heat medium circuit having a load device provided downstream of the heat exchanger and a bypass piping for bypassing the load device. In the refrigeration cycle system, the heat medium circuit includes a first detection unit provided in the heat medium circuit and detecting a pressure difference between before and after the heat exchanger, and a pump provided in the heat medium circuit and detecting a pressure difference between before and after the heat source side pump. and a second detection unit that detects the differential pressure. The system control device determines the head of the heat source side pump from the differential pressure detected by the first detection unit and the rotation speed of the heat source side pump, calculates the bypass differential pressure before and after the bypass piping based on the differential pressure and the head to obtain a first calculated value, calculates the bypass differential pressure before and after the bypass piping based on the differential pressure detected by the first detection unit and the pump differential pressure detected by the second detection unit to obtain a second calculated value, and determines the scale deposition state of the heat exchanger by comparing the difference between the first and second calculated values of the bypass differential pressure with a previously stored difference value.
また、本開示に係る第3の冷凍サイクルシステムは、圧縮機を有し、前記圧縮機により冷媒が循環する冷媒回路と、熱源側ポンプ及び負荷側ポンプを有し、前記熱源側ポンプ及び前記負荷側ポンプにより熱媒体が循環する熱媒体回路と、前記冷媒と前記熱媒体との間で熱交換を行う熱交換器と、前記熱源側ポンプを制御するシステム制御装置と、を備え、前記熱媒体回路は、前記熱交換器の下流側に設けられる負荷装置と、前記負荷装置をバイパスするフリーバイパス配管とを有したものであり、前記熱源側ポンプは、前記熱交換器に前記熱媒体を圧送するものであり、前記負荷側ポンプは、前記負荷装置に前記熱媒体を圧送するものである冷凍サイクルシステムにおいて、前記熱媒体回路に設けられ、前記熱交換器の前後の差圧を検出する第1検出部と、前記熱媒体回路の負荷側に設けられ、前記熱媒体の負荷側流量を検出する第2検出部と、備え、前記システム制御装置は、前記第1検出部により検出された前記差圧と、前記熱源側ポンプの回転数から前記熱源側ポンプの揚程を求め、前記差圧及び前記揚程に基づき前記熱媒体回路の負荷側に流れる前記熱媒体の前記負荷側流量を算出し、算出された前記負荷側流量の計算値と、前記第2検出部により検出された前記負荷側流量の実測値との差分を、予め記憶された差分値と比較することにより前記熱交換器のスケールの堆積状態を判定する。
A third refrigeration cycle system according to the present disclosure includes a refrigerant circuit having a compressor and in which a refrigerant is circulated by the compressor, a heat medium circuit having a heat source side pump and a load side pump and in which a heat medium is circulated by the heat source side pump and the load side pump, a heat exchanger that exchanges heat between the refrigerant and the heat medium, and a system control device that controls the heat source side pump, the heat medium circuit having a load device provided downstream of the heat exchanger and a free bypass piping that bypasses the load device, the heat source side pump pressure-feeds the heat medium to the heat exchanger, and the load side pump pressure-feeds the heat medium to the load device. In the cycle system, a first detection unit is provided in the heat medium circuit and detects the differential pressure before and after the heat exchanger, and a second detection unit is provided on the load side of the heat medium circuit and detects the load side flow rate of the heat medium. The system control device determines the head of the heat source side pump from the differential pressure detected by the first detection unit and the rotation speed of the heat source side pump, calculates the load side flow rate of the heat medium flowing on the load side of the heat medium circuit based on the differential pressure and the head, and determines the scale accumulation state of the heat exchanger by comparing the difference between the calculated value of the load side flow rate and the actual value of the load side flow rate detected by the second detection unit with a pre-stored difference value.
また、本開示に係る第4の冷凍サイクルシステムは、圧縮機を有し、前記圧縮機により冷媒が循環する冷媒回路と、熱源側ポンプ及び負荷側ポンプを有し、前記熱源側ポンプ及び前記負荷側ポンプにより熱媒体が循環する熱媒体回路と、前記冷媒と前記熱媒体との間で熱交換を行う熱交換器と、前記熱源側ポンプを制御するシステム制御装置と、を備え、前記熱媒体回路は、前記熱交換器の下流側に設けられる負荷装置と、前記負荷装置をバイパスするフリーバイパス配管とを有したものであり、前記熱源側ポンプは、前記熱交換器に前記熱媒体を圧送するものであり、前記負荷側ポンプは、前記負荷装置に前記熱媒体を圧送するものである冷凍サイクルシステムにおいて、前記熱媒体回路に設けられ、前記熱交換器の前後の差圧を検出する第1検出部と、前記熱媒体回路に設けられ、前記熱源側ポンプの前後のポンプ差圧を検出する第2検出部と、を備え、前記システム制御装置は、前記第1検出部により検出された前記差圧と、前記熱源側ポンプの回転数から前記熱源側ポンプの揚程を求め、前記差圧及び前記揚程に基づき前記熱媒体回路の負荷側に流れる前記熱媒体の負荷側流量を算出して第1計算値を得るとともに、前記第1検出部により検出された前記差圧及び前記第2検出部により検出された前記ポンプ差圧に基づき前記熱媒体回路の負荷側に流れる前記熱媒体の前記負荷側流量を算出して第2計算値を得、前記負荷側流量の前記第1計算値と前記第2計算値との差分を、予め記憶された差分値と比較することにより前記熱交換器のスケールの堆積状態を判定する。
Furthermore, a fourth refrigeration cycle system according to the present disclosure includes a refrigerant circuit having a compressor and in which a refrigerant is circulated by the compressor, a heat medium circuit having a heat source side pump and a load side pump and in which a heat medium is circulated by the heat source side pump and the load side pump, a heat exchanger that exchanges heat between the refrigerant and the heat medium, and a system control device that controls the heat source side pump, wherein the heat medium circuit has a load device provided downstream of the heat exchanger and a free bypass piping that bypasses the load device, the heat source side pump pressure-feeds the heat medium to the heat exchanger, and the load side pump pressure-feeds the heat medium to the load device. In this refrigeration cycle system, a pressure difference between the front and rear of the heat exchanger is detected by a pressure sensor provided in the heat medium circuit. The system control device includes a first detection unit that detects the pump pressure difference between before and after the heat source pump, and a second detection unit that is provided in the heat medium circuit and detects the pump pressure difference between before and after the heat source pump. The system control device determines the head of the heat source pump from the pressure difference detected by the first detection unit and the rotation speed of the heat source pump, calculates the load side flow rate of the heat medium flowing to the load side of the heat medium circuit based on the pressure difference and the head to obtain a first calculated value, calculates the load side flow rate of the heat medium flowing to the load side of the heat medium circuit based on the pressure difference detected by the first detection unit and the pump pressure difference detected by the second detection unit to obtain a second calculated value, and compares the difference between the first and second calculated values of the load side flow rate with a difference value stored in advance to determine the scale deposition state of the heat exchanger.
本開示に係る第1の冷凍サイクルシステム、第2の冷凍サイクルシステム、第3の冷凍サイクルシステム及び第4の冷凍サイクルシステムでは、熱媒体回路に設けられた第1検出部及び第2検出部を用いて異なる方法で得たバイパス差圧(又は負荷側流量)の計算値と実測値との差分、あるいはバイパス差圧(又は負荷側流量)の第1計算値と第2計算値との差分を、予め記憶された差分値と比較することにより熱交換器のスケールの堆積状態が判定される。本開示では第1検出部及び第2検出部はいずれもスケールの堆積する熱媒体回路に設けられるので、それらの検出値に基づき熱交換器のスケールの堆積状態を判定することにより、従来のように冷媒の飽和温度と熱交換器から流出する熱媒体の温度との温度差に基づき熱交換器のスケールの堆積状態を判定する構成と比べて、負荷変動及び運転条件の変動による影響を少なくして、より正確に熱交換器のスケールの堆積状態を判定することができる。
In the first, second, third and fourth refrigeration cycle systems according to the present disclosure, the scale buildup state of the heat exchanger is determined by comparing the difference between the calculated and actual values of the bypass differential pressure (or load side flow rate) obtained by different methods using the first and second detection units provided in the heat medium circuit, or the difference between the first and second calculated values of the bypass differential pressure (or load side flow rate), with a pre-stored difference value. In the present disclosure, the first and second detection units are both provided in the heat medium circuit where scale buildup occurs, and therefore, by determining the scale buildup state of the heat exchanger based on these detection values, the scale buildup state of the heat exchanger can be determined more accurately with less influence from load fluctuations and fluctuations in operating conditions, compared to a conventional configuration in which the scale buildup state of the heat exchanger is determined based on the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the heat exchanger.
以下、本開示に係る冷凍サイクルシステムの実施の形態を、図面を参照して説明する。本開示は、以下の実施の形態に限定されるものではなく、本開示の主旨を逸脱しない範囲で種々に変形することが可能である。また、図面に示す冷凍サイクルシステムは、本開示の冷凍サイクルシステムの一例を示すものであり、図面に示された冷凍サイクルシステムによって本開示の冷凍サイクルシステムが限定されるものではない。また、各図において、同一の符号を付したものは、同一の又はこれに相当するものであり、これは明細書の全文において共通している。
Below, an embodiment of the refrigeration cycle system according to the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiment, and various modifications are possible without departing from the spirit of the present disclosure. Furthermore, the refrigeration cycle system shown in the drawings is an example of the refrigeration cycle system of the present disclosure, and the refrigeration cycle system of the present disclosure is not limited to the refrigeration cycle system shown in the drawings. Furthermore, in each drawing, items with the same reference numerals are the same or equivalent, and this is common throughout the entire specification.
実施の形態1.
(冷凍サイクルシステム10の構成)
図1は、本開示の実施の形態1に係る冷凍サイクルシステム10の概略構成を示す回路図である。図2は、図1の冷凍サイクル装置20の構成の一例を示す回路図である。図2中、実線の白抜き矢印は、冷媒の流れる方向を示しており、また、図1及び図2中、破線の白抜き矢印は、熱媒体の流れる方を示している。図1及び図2に基づき、冷凍サイクルシステム10の概略構成について説明する。Embodiment 1.
(Configuration of refrigeration cycle system 10)
Fig. 1 is a circuit diagram showing a schematic configuration of arefrigeration cycle system 10 according to a first embodiment of the present disclosure. Fig. 2 is a circuit diagram showing an example of the configuration of a refrigeration cycle device 20 of Fig. 1. In Fig. 2, solid white arrows indicate the direction in which a refrigerant flows, and in Figs. 1 and 2, dashed white arrows indicate the direction in which a heat medium flows. The schematic configuration of the refrigeration cycle system 10 will be described with reference to Figs. 1 and 2.
(冷凍サイクルシステム10の構成)
図1は、本開示の実施の形態1に係る冷凍サイクルシステム10の概略構成を示す回路図である。図2は、図1の冷凍サイクル装置20の構成の一例を示す回路図である。図2中、実線の白抜き矢印は、冷媒の流れる方向を示しており、また、図1及び図2中、破線の白抜き矢印は、熱媒体の流れる方を示している。図1及び図2に基づき、冷凍サイクルシステム10の概略構成について説明する。
(Configuration of refrigeration cycle system 10)
Fig. 1 is a circuit diagram showing a schematic configuration of a
図1に示されるように、冷凍サイクルシステム10は、冷媒が循環する冷媒回路27と、例えば水等の熱媒体が循環する熱媒体回路40と、冷媒と熱媒体とを熱交換させる水熱交換器(以下、熱交換器26ともいう)とを備える。なお、熱媒体回路40を流れる熱媒体を水としたが、その他の不凍液等の流体でもよい。熱媒体回路40は、熱交換器26に熱媒体を圧送する熱源側ポンプ30を有し、熱交換器26において冷媒と熱交換した熱媒体を、負荷装置70に供給するものである。負荷装置70は、例えば空調機である。
As shown in FIG. 1, the refrigeration cycle system 10 includes a refrigerant circuit 27 through which a refrigerant circulates, a heat medium circuit 40 through which a heat medium such as water circulates, and a water heat exchanger (hereinafter also referred to as heat exchanger 26) that exchanges heat between the refrigerant and the heat medium. Note that the heat medium flowing through the heat medium circuit 40 is water, but other fluids such as antifreeze may also be used. The heat medium circuit 40 has a heat source side pump 30 that pressurizes the heat medium to the heat exchanger 26, and supplies the heat medium that has exchanged heat with the refrigerant in the heat exchanger 26 to a load device 70. The load device 70 is, for example, an air conditioner.
図1の冷凍サイクルシステム10は、冷媒回路27を搭載した冷凍サイクル装置20を複数台備えている。なお、冷凍サイクルシステム10が備える冷凍サイクル装置20の台数は何台でもよく、例えば1台でもよい。冷凍サイクル装置20は熱源機として機能するものであり、例えば空冷式ヒートポンプチラーである。冷凍サイクル装置20は、熱媒体回路40の一部を含む構成とされる。複数の冷凍サイクル装置20はそれぞれ、水熱交換器(熱交換器26)及び熱源側ポンプ30が設けられた後述する熱源側枝管40aを有する。熱媒体回路40において、これら複数の熱源側枝管40aは互いに並列接続されて、負荷側の回路部分に対して接続されている。すなわち、冷凍サイクルシステム10は、1つの熱媒体回路40を循環する熱媒体と、複数の冷凍サイクル装置20の各冷媒回路27に循環する冷媒とが熱交換する構成とされ、複数の冷凍サイクル装置20で生じた熱を、熱媒体を介して一以上の負荷装置70に供給する。なお、熱媒体回路40の構成については、後述する。
The refrigeration cycle system 10 in FIG. 1 includes a plurality of refrigeration cycle devices 20 each equipped with a refrigerant circuit 27. The number of refrigeration cycle devices 20 included in the refrigeration cycle system 10 may be any number, for example, it may be one. The refrigeration cycle device 20 functions as a heat source device, for example, an air-cooled heat pump chiller. The refrigeration cycle device 20 is configured to include a part of the heat medium circuit 40. Each of the plurality of refrigeration cycle devices 20 has a heat source side branch pipe 40a described later in which a water heat exchanger (heat exchanger 26) and a heat source side pump 30 are provided. In the heat medium circuit 40, these plurality of heat source side branch pipes 40a are connected in parallel to each other and connected to the load side circuit portion. That is, the refrigeration cycle system 10 is configured to exchange heat between the heat medium circulating in one heat medium circuit 40 and the refrigerant circulating in each refrigerant circuit 27 of the plurality of refrigeration cycle devices 20, and the heat generated in the plurality of refrigeration cycle devices 20 is supplied to one or more load devices 70 via the heat medium. The configuration of the heat medium circuit 40 will be described later.
図2に示されるように、冷媒回路27は、圧縮機22、空気熱交換器(熱交換器24)、減圧装置25、及び水熱交換器(熱交換器26)が冷媒配管を介して環状に接続され、形成されている。圧縮機22は、冷媒を圧縮して冷媒回路27に循環させるものである。圧縮機22は、例えば、運転周波数を変化させることにより単位時間あたりの冷媒の送出量である容量が制御されるインバータ圧縮機等からなる。熱交換器24は、例えばフィンアンドチューブ型熱交換器からなり、空気と冷媒とを熱交換させるものである。ファン28は、熱交換器24に対して室外空気を供給し、熱交換器24による熱交換を促進するものである。ファン28の回転数が制御されることにより熱交換器24に対する送風量が制御される。減圧装置25は、例えば電子膨張弁からなり、開度を変化させることにより、水熱交換器(熱交換器26)に流入する冷媒の圧力を制御する。減圧装置25は、熱交換器24から流出した高圧の冷媒を減圧する。熱交換器26は、熱媒体回路40を循環する熱媒体と冷媒回路27を流れる冷媒とを熱交換させるものである。
As shown in FIG. 2, the refrigerant circuit 27 is formed by connecting the compressor 22, the air heat exchanger (heat exchanger 24), the pressure reducing device 25, and the water heat exchanger (heat exchanger 26) in a ring shape via refrigerant piping. The compressor 22 compresses the refrigerant and circulates it in the refrigerant circuit 27. The compressor 22 is, for example, an inverter compressor whose capacity, which is the amount of refrigerant sent out per unit time, is controlled by changing the operating frequency. The heat exchanger 24 is, for example, a fin-and-tube type heat exchanger, and exchanges heat between the air and the refrigerant. The fan 28 supplies outdoor air to the heat exchanger 24 to promote heat exchange by the heat exchanger 24. The amount of air sent to the heat exchanger 24 is controlled by controlling the rotation speed of the fan 28. The pressure reducing device 25 is, for example, an electronic expansion valve, and controls the pressure of the refrigerant flowing into the water heat exchanger (heat exchanger 26) by changing the opening degree. The pressure reducing device 25 reduces the pressure of the high-pressure refrigerant that flows out of the heat exchanger 24. The heat exchanger 26 exchanges heat between the heat medium circulating in the heat medium circuit 40 and the refrigerant flowing in the refrigerant circuit 27.
図2の冷媒回路27では、圧縮機22の吐出側が空気熱交換器(熱交換器24)に接続され、熱交換器24と減圧装置25とが接続され、減圧装置25と水熱交換器(熱交換器26)とが接続され、熱交換器26は、圧縮機22の吸入側に接続されている。この場合において、熱交換器24は凝縮器として機能し、水熱交換器(熱交換器26)は蒸発器として機能する。熱交換器26では、熱源側ポンプ30により圧送された熱媒体が、冷媒回路27の減圧装置25により減圧された冷媒によって冷却される。図2の例では、熱交換器26において熱媒体と冷媒とは並行するように流れる。
In the refrigerant circuit 27 of FIG. 2, the discharge side of the compressor 22 is connected to an air heat exchanger (heat exchanger 24), the heat exchanger 24 is connected to a pressure reducing device 25, the pressure reducing device 25 is connected to a water heat exchanger (heat exchanger 26), and the heat exchanger 26 is connected to the suction side of the compressor 22. In this case, the heat exchanger 24 functions as a condenser, and the water heat exchanger (heat exchanger 26) functions as an evaporator. In the heat exchanger 26, the heat medium pumped by the heat source side pump 30 is cooled by the refrigerant decompressed by the pressure reducing device 25 of the refrigerant circuit 27. In the example of FIG. 2, the heat medium and the refrigerant flow in parallel in the heat exchanger 26.
なお、冷媒回路27の構成はこの構成に限定されない。例えば、圧縮機22の冷媒の吐出側に四方弁等の流路切替装置を設けることで、冷媒が圧縮機22、熱交換器24、減圧装置25及び熱交換器26の順に流れる冷房運転と、冷媒が圧縮機22、熱交換器26、減圧装置25及び熱交換器24の順に流れる暖房運転とを切り替えて実施する構成でもよい。また、図2の例では、凝縮器である熱交換器24を空気熱交換器で構成し、冷凍サイクル装置20を空冷式としたが、熱交換器24を水熱交換器で構成し、冷凍サイクル装置20を水冷式としてもよい。
The configuration of the refrigerant circuit 27 is not limited to this configuration. For example, a flow switching device such as a four-way valve may be provided on the refrigerant discharge side of the compressor 22 to switch between a cooling operation in which the refrigerant flows through the compressor 22, heat exchanger 24, pressure reducing device 25, and heat exchanger 26 in that order, and a heating operation in which the refrigerant flows through the compressor 22, heat exchanger 26, pressure reducing device 25, and heat exchanger 24 in that order. In the example of FIG. 2, the heat exchanger 24, which is the condenser, is configured as an air heat exchanger, and the refrigeration cycle device 20 is air-cooled, but the heat exchanger 24 may be configured as a water heat exchanger, and the refrigeration cycle device 20 may be water-cooled.
また、冷凍サイクル装置20は、その冷媒回路27及び熱源側ポンプ30を制御する制御装置21を備える。具体的には、制御装置21は、圧縮機22の周波数、減圧装置25の開度、ファン28の回転数、及び熱源側ポンプ30の周波数(すなわち回転数)を制御する。
The refrigeration cycle device 20 also includes a control device 21 that controls the refrigerant circuit 27 and the heat source side pump 30. Specifically, the control device 21 controls the frequency of the compressor 22, the opening degree of the pressure reducing device 25, the rotation speed of the fan 28, and the frequency (i.e., the rotation speed) of the heat source side pump 30.
制御装置21は、その機能を実現する回路デバイスのようなハードウェアで構成される。あるいは、制御装置21は、プログラムを格納するメモリと、CPU(Central Processing Unit)とを有し、CPUがプログラムを実行することにより制御装置21の機能が実現される。
The control device 21 is configured with hardware such as a circuit device that realizes its functions. Alternatively, the control device 21 has a memory that stores programs and a CPU (Central Processing Unit), and the functions of the control device 21 are realized by the CPU executing the programs.
また、冷凍サイクル装置20は、その水熱交換器における熱媒体の入口側と出口側との差圧、すなわち熱源側枝管40aにおける熱交換器26の前後の差圧(以下、熱交換器差圧ともいう)を検出する熱交換器差圧検出部31を備える。熱交換器差圧検出部31は、例えば差圧計で構成される。冷凍サイクル装置20の制御装置21は、熱交換器差圧検出部31と接続され、制御装置21には、熱交換器差圧検出部31により検出された熱交換器差圧ΔPhex(i)が入力される。以下、熱交換器差圧検出部31を、第1検出部と称する場合がある。
The refrigeration cycle device 20 also includes a heat exchanger differential pressure detection unit 31 that detects the differential pressure between the inlet and outlet sides of the heat medium in the water heat exchanger, i.e., the differential pressure before and after the heat exchanger 26 in the heat source side branch pipe 40a (hereinafter also referred to as the heat exchanger differential pressure). The heat exchanger differential pressure detection unit 31 is composed of, for example, a differential pressure gauge. The control device 21 of the refrigeration cycle device 20 is connected to the heat exchanger differential pressure detection unit 31, and the heat exchanger differential pressure ΔPhex(i) detected by the heat exchanger differential pressure detection unit 31 is input to the control device 21. Hereinafter, the heat exchanger differential pressure detection unit 31 may be referred to as the first detection unit.
なお、熱交換器差圧検出部31を差圧計で構成する代わりに、2つの圧力センサで構成し、各圧力センサを熱交換器26の前後にそれぞれ取り付けて制御装置21において熱交換器差圧ΔPhex(i)を求める構成としてもよい。
In addition, instead of configuring the heat exchanger differential pressure detection unit 31 as a differential pressure gauge, it may be configured as two pressure sensors, each of which is attached before and after the heat exchanger 26, and the heat exchanger differential pressure ΔPhex(i) may be calculated in the control device 21.
以下、図1に基づき、熱媒体回路40の構成について説明する。図1の例では、熱媒体回路40の負荷側の回路部分には2台の負荷装置70が設けられている。なお、冷凍サイクルシステム10において負荷側の回路部分に設けられる負荷装置70の台数は何台でもよく、例えば1台でも、あるいは3台以上でもよい。負荷装置70は、例えば、エアハンドリングユニット又はファンコイルユニット等の空調機である。負荷装置70は、室内の空気と熱媒体回路40を循環する熱媒体との間で熱交換する負荷側熱交換器(不図示)を有する。
The configuration of the heat medium circuit 40 will be described below with reference to FIG. 1. In the example of FIG. 1, two load devices 70 are provided in the load side circuit portion of the heat medium circuit 40. Any number of load devices 70 may be provided in the load side circuit portion in the refrigeration cycle system 10, for example, one, or three or more. The load device 70 is, for example, an air conditioner such as an air handling unit or a fan coil unit. The load device 70 has a load side heat exchanger (not shown) that exchanges heat between the air in the room and the heat medium circulating through the heat medium circuit 40.
図1に示されるように、熱媒体回路40の負荷側の回路部分は、それぞれに負荷装置70が設けられる互いに並列接続された複数の負荷側枝管40bと、複数の負荷側枝管40bの各下流側端部が接続される第2還水側ヘッダ管42bとを有する。また、熱媒体回路40の負荷側の回路部分は、この第2還水側ヘッダ管42bと、後述する第1還水側ヘッダ管42aとを接続する合流管40cを有する。各負荷側枝管40bには、例えば比例二方弁である負荷側膨張弁71が設けられている。負荷側膨張弁71は、負荷側枝管40bにおいて負荷装置70から熱媒体が流出する側、すなわち負荷装置70と第2還水側ヘッダ管42bとの間に設けられている。また、合流管40cには、熱媒体回路40の負荷側の回路部分を流れる熱媒体の流量(以下、負荷側流量ともいう)を検出する負荷側流量計73が設けられている。なお、実施の形態1の冷凍サイクルシステム10では、負荷側流量計73は省略してもよい。
As shown in FIG. 1, the load side circuit portion of the heat medium circuit 40 has a plurality of load side branch pipes 40b connected in parallel to each other, each of which is provided with a load device 70, and a second return side header pipe 42b to which each downstream end of the plurality of load side branch pipes 40b is connected. The load side circuit portion of the heat medium circuit 40 also has a junction pipe 40c that connects the second return side header pipe 42b and a first return side header pipe 42a described below. Each load side branch pipe 40b is provided with a load side expansion valve 71, which is, for example, a proportional two-way valve. The load side expansion valve 71 is provided on the side of the load side branch pipe 40b where the heat medium flows out from the load device 70, that is, between the load device 70 and the second return side header pipe 42b. The junction pipe 40c is also provided with a load side flow meter 73 that detects the flow rate of the heat medium flowing through the load side circuit portion of the heat medium circuit 40 (hereinafter also referred to as the load side flow rate). In addition, in the refrigeration cycle system 10 of embodiment 1, the load side flow meter 73 may be omitted.
図1に示されるように、熱媒体回路40の熱源側の回路部分は、合流管40cを介して第2還水側ヘッダ管42bと接続される第1還水側ヘッダ管42aと、複数の負荷側枝管40bの各上流側端部が接続される往水側ヘッダ管41と、それぞれに熱交換器26及び熱源側ポンプ30が設けられた複数の熱源側枝管40aと、を有する。複数の熱源側枝管40aの下流側端部は往水側ヘッダ管41に接続され、複数の熱源側枝管40aの上流側端部は第1還水側ヘッダ管42aに接続されている。
As shown in FIG. 1, the heat source side circuit portion of the heat medium circuit 40 has a first return water side header pipe 42a connected to a second return water side header pipe 42b via a junction pipe 40c, a supply water side header pipe 41 to which the upstream ends of the multiple load side branch pipes 40b are connected, and multiple heat source side branch pipes 40a each equipped with a heat exchanger 26 and a heat source side pump 30. The downstream ends of the multiple heat source side branch pipes 40a are connected to the supply water side header pipe 41, and the upstream ends of the multiple heat source side branch pipes 40a are connected to the first return water side header pipe 42a.
第1還水側ヘッダ管42aは、負荷側の回路部分から戻った熱媒体を複数の熱源側枝管40aに分配する。各熱源側ポンプ30は、第1還水側ヘッダ管42aで分配された熱媒体を水熱交換器(熱交換器26)に圧送する。熱源側ポンプ30により熱交換器26に圧送された熱媒体は、熱交換器26において冷媒回路27の冷媒と熱交換することで冷却される。複数の熱交換器26のそれぞれで冷却された熱媒体は、往水側ヘッダ管41に流入する。往水側ヘッダ管41は、複数の冷凍サイクル装置20のそれぞれで冷却されて往水側ヘッダ管41に流入した熱媒体を合流させ、下流側に設けられた複数の負荷装置70に分配し、供給する。
The first return water side header pipe 42a distributes the heat medium returning from the load side circuit portion to the multiple heat source side branch pipes 40a. Each heat source side pump 30 pressurizes the heat medium distributed by the first return water side header pipe 42a to the water heat exchanger (heat exchanger 26). The heat medium pressurized by the heat source side pump 30 to the heat exchanger 26 is cooled by heat exchange with the refrigerant of the refrigerant circuit 27 in the heat exchanger 26. The heat medium cooled in each of the multiple heat exchangers 26 flows into the supply water side header pipe 41. The supply water side header pipe 41 merges the heat medium cooled in each of the multiple refrigeration cycle devices 20 and flowing into the supply water side header pipe 41, and distributes and supplies it to the multiple load devices 70 provided downstream.
また、熱媒体回路40は、負荷側の回路部分をバイパスする(すなわち複数の負荷装置70をバイパスする)バイパス配管80を有している。バイパス配管80は、熱媒体回路40において複数の冷凍サイクル装置20の前後にそれぞれ設けられた往水側ヘッダ管41と第1還水側ヘッダ管42aとを接続する。
The heat medium circuit 40 also has a bypass pipe 80 that bypasses the load side circuit portion (i.e., bypasses the multiple load devices 70). The bypass pipe 80 connects the supply water side header pipe 41 and the first return water side header pipe 42a that are provided before and after the multiple refrigeration cycle devices 20 in the heat medium circuit 40.
図1に示される実施の形態1の冷凍サイクルシステム10は、熱媒体回路40において熱源側の回路部分のみに熱源側ポンプ30が設けられる単式ポンプシステムを採用したものであり、負荷側の回路部分にはポンプが設けられていない。そして、バイパス配管80には、バイパス配管80に流れる熱媒体の流量を調整するバイパス弁81が設けられている。単式ポンプシステムでは、バイパス配管80の前後の差圧(以下、バイパス差圧ともいう)すなわちバイパス配管80の上流側にある往水側ヘッダ管41と下流側にある第1還水側ヘッダ管42aとの差圧を、バイパス弁81の開度により調整する構成となっている。また、実施の形態1の冷凍サイクルシステム10は、バイパス配管80の前後のバイパス差圧を検出するバイパス差圧検出部90を備える。バイパス差圧検出部90は、例えば差圧計で構成される。以下、バイパス差圧検出部90を、第2検出部と称する場合がある。
The refrigeration cycle system 10 of the first embodiment shown in FIG. 1 employs a single pump system in which the heat source pump 30 is provided only in the heat source side circuit portion of the heat medium circuit 40, and no pump is provided in the load side circuit portion. The bypass piping 80 is provided with a bypass valve 81 that adjusts the flow rate of the heat medium flowing through the bypass piping 80. In the single pump system, the differential pressure before and after the bypass piping 80 (hereinafter also referred to as the bypass differential pressure), that is, the differential pressure between the forward water header pipe 41 on the upstream side of the bypass piping 80 and the first return water header pipe 42a on the downstream side, is adjusted by the opening degree of the bypass valve 81. The refrigeration cycle system 10 of the first embodiment also includes a bypass differential pressure detection unit 90 that detects the bypass differential pressure before and after the bypass piping 80. The bypass differential pressure detection unit 90 is composed of, for example, a differential pressure gauge. Hereinafter, the bypass differential pressure detection unit 90 may be referred to as the second detection unit.
冷凍サイクルシステム10は、熱媒体回路40を制御するシステム制御装置21aを備える。システム制御装置21aは、その機能を実現する回路デバイスのようなハードウェアで構成される。あるいは、システム制御装置21aは、プログラムを格納するメモリと、CPU(Central Processing Unit)とを有し、CPUがプログラムを実行することによりシステム制御装置21aの機能が実現される。
The refrigeration cycle system 10 includes a system control device 21a that controls the heat medium circuit 40. The system control device 21a is configured with hardware such as a circuit device that realizes its functions. Alternatively, the system control device 21a has a memory that stores programs and a CPU (Central Processing Unit), and the functions of the system control device 21a are realized by the CPU executing the programs.
システム制御装置21aは、負荷側流量計73、バイパス差圧検出部90及びバイパス弁81とそれぞれ接続されている。システム制御装置21aには、負荷側流量計73により検出された負荷側流量、及びバイパス差圧検出部90により検出されたバイパス差圧(バイパス差圧の実測値B)がそれぞれ入力される。また、システム制御装置21aは、バイパス弁81に、指示開度を出力する。
The system control device 21a is connected to the load side flow meter 73, the bypass differential pressure detection unit 90, and the bypass valve 81. The load side flow rate detected by the load side flow meter 73 and the bypass differential pressure detected by the bypass differential pressure detection unit 90 (actual measured value B of the bypass differential pressure) are input to the system control device 21a. The system control device 21a also outputs an instruction opening to the bypass valve 81.
上記のようなシステム制御装置21aへの入力及びシステム制御装置21aからの出力は、例えば、DC4~20[mA]の電流信号として入力又は出力される。この場合において、各電流信号の電流は、負荷側流量、バイパス差圧、又はバイパス弁81への指示開度に応じた電流とされる。
The inputs to and outputs from the system control device 21a as described above are input or output as current signals of, for example, DC 4 to 20 mA. In this case, the current of each current signal is a current corresponding to the load side flow rate, the bypass differential pressure, or the command opening of the bypass valve 81.
なお、バイパス差圧検出部90を差圧計とする代わりに2つの圧力センサで構成し、各圧力センサをバイパス配管80の前後すなわち往水側ヘッダ管41と第1還水側ヘッダ管42aとに取り付けて、システム制御装置21aによりバイパス差圧を求める構成としてもよい。
In addition, instead of using a differential pressure gauge, the bypass differential pressure detection unit 90 may be configured with two pressure sensors, with each pressure sensor attached before and after the bypass piping 80, i.e., to the forward water header pipe 41 and the first return water header pipe 42a, and the bypass differential pressure may be determined by the system control device 21a.
冷凍サイクルシステム10において、冷凍サイクル装置20の制御装置21は、他の冷凍サイクル装置20の制御装置21と連携して、対応する冷媒回路27及び熱源側ポンプ30の動作を制御するように構成されている。連携のために、複数の冷凍サイクル装置20の一台が代表機として設定され、この代表機の制御装置21が、代表機以外の冷凍サイクル装置20の制御装置21とそれぞれ通信を行うようにしてもよい。図1の例では、代表機(図示下側の冷凍サイクル装置20)の制御装置21が、システム制御装置21aとして機能する。
In the refrigeration cycle system 10, the control device 21 of the refrigeration cycle device 20 is configured to cooperate with the control devices 21 of the other refrigeration cycle devices 20 to control the operation of the corresponding refrigerant circuit 27 and heat source side pump 30. For the cooperation, one of the multiple refrigeration cycle devices 20 may be set as a representative device, and the control device 21 of this representative device may communicate with each of the control devices 21 of the refrigeration cycle devices 20 other than the representative device. In the example of FIG. 1, the control device 21 of the representative device (the refrigeration cycle device 20 on the lower side in the figure) functions as the system control device 21a.
システム制御装置21aは、各冷凍サイクル装置20から熱源側ポンプ30の運転周波数Fp(i)及び熱交換器26の前後の差圧(熱交換器差圧ΔPhex(i))を取得する。また、上述したように、システム制御装置21aには、負荷側流量計73から負荷側流量が入力され、また、バイパス差圧検出部90からバイパス差圧(バイパス差圧の実測値B)が入力される。システム制御装置21aは、取得した複数の冷凍サイクル装置20の運転周波数Fp(i)、及びバイパス差圧の実測値Bに応じて開度指令をバイパス弁81に出力する。バイパス弁81はシステム制御装置21aからの開度指令により開度を調整する。これにより、バイパス配管80を介して、往水側ヘッダ管41から第1還水側ヘッダ管42aへ流れる熱媒体の流量が調整され、熱源機である各冷凍サイクル装置20に流れる熱媒体の流量と、各負荷装置70に流れる熱媒体の流量との差分が調整される。このような調整を行うことで、往水側ヘッダ管41と第1還水側ヘッダ管42aとの差圧すなわちバイパス差圧が調整されるが、調整後においても、バイパス差圧はバイパス差圧検出部90により検出される。
The system control device 21a acquires the operating frequency Fp(i) of the heat source pump 30 and the differential pressure (heat exchanger differential pressure ΔPhex(i)) before and after the heat exchanger 26 from each refrigeration cycle device 20. As described above, the load side flow rate is input from the load side flow meter 73 to the system control device 21a, and the bypass differential pressure (actual measurement value B of the bypass differential pressure) is input from the bypass differential pressure detection unit 90. The system control device 21a outputs an opening command to the bypass valve 81 according to the operating frequency Fp(i) of the multiple refrigeration cycle devices 20 acquired and the actual measurement value B of the bypass differential pressure. The bypass valve 81 adjusts the opening according to the opening command from the system control device 21a. As a result, the flow rate of the heat medium flowing from the supply water side header pipe 41 to the first return water side header pipe 42a via the bypass piping 80 is adjusted, and the difference between the flow rate of the heat medium flowing to each refrigeration cycle device 20, which is a heat source device, and the flow rate of the heat medium flowing to each load device 70 is adjusted. By making such adjustments, the pressure difference between the forward water header pipe 41 and the first return water header pipe 42a, i.e., the bypass pressure difference, is adjusted, but even after the adjustments, the bypass pressure difference is detected by the bypass pressure difference detection unit 90.
本開示の冷凍サイクルシステム10において、システム制御装置21aは、熱媒体回路40の状態をもとに水熱交換器(熱交換器26)のスケールの堆積状態を判定する。冷凍サイクルシステム10は、システム制御装置21aによるスケール堆積判定の結果を報知する報知部99を備える。報知部99は、例えば液晶ディスプレイ又はスピーカ等で構成され、スケール堆積判定の結果を表示する。例えば定期点検の作業者は、報知部99に表示された結果を確認することで、熱交換器26のスケール堆積判定の結果を知ることができる。システム制御装置21aは、例えば、熱交換器26のスケールの堆積量が一定以上であると判断した場合に、報知部99によりその旨、あるいは洗浄が必要である旨を報知する構成でもよい。
In the refrigeration cycle system 10 of the present disclosure, the system control device 21a judges the scale buildup state of the water heat exchanger (heat exchanger 26) based on the state of the heat medium circuit 40. The refrigeration cycle system 10 includes an alarm unit 99 that notifies the result of the scale buildup judgment by the system control device 21a. The alarm unit 99 is configured, for example, as an LCD display or a speaker, and displays the result of the scale buildup judgment. For example, an operator performing regular inspection can know the result of the scale buildup judgment of the heat exchanger 26 by checking the result displayed on the alarm unit 99. For example, when the system control device 21a judges that the amount of scale buildup in the heat exchanger 26 is equal to or greater than a certain amount, the alarm unit 99 may be configured to notify that fact, or that cleaning is required.
図3は、図1の水熱交換器(熱交換器26)の水頭損失と流量との関係を示す図である。図4は、図1のポンプ(熱源側ポンプ30)の揚程特性を示す図である。図5は、図1のシステム制御装置21aが行うスケール堆積判定のフローチャートである。以下、図3~図5に基づき、単式ポンプシステムを採用した冷凍サイクルシステム10においてシステム制御装置21aが行うスケール堆積判定の一例について説明する。
FIG. 3 is a diagram showing the relationship between head loss and flow rate of the water heat exchanger (heat exchanger 26) in FIG. 1. FIG. 4 is a diagram showing the head characteristics of the pump (heat source side pump 30) in FIG. 1. FIG. 5 is a flowchart showing the scale buildup determination performed by the system control device 21a in FIG. 1. Below, with reference to FIGS. 3 to 5, an example of scale buildup determination performed by the system control device 21a in the refrigeration cycle system 10 employing a single pump system will be described.
実施の形態1の冷凍サイクルシステム10では、システム制御装置21aは、熱媒体回路40の状態として熱交換器差圧検出部31の検出値(熱交換器差圧ΔPhex(i))及びバイパス差圧検出部90の検出値(バイパス差圧の実測値B)を用いて、熱交換器26のスケールの堆積状態を判定する。
In the refrigeration cycle system 10 of the first embodiment, the system control device 21a determines the state of scale buildup in the heat exchanger 26 as the state of the heat medium circuit 40 using the detection value (heat exchanger differential pressure ΔPhex(i)) of the heat exchanger differential pressure detection unit 31 and the detection value (actual measured value B of the bypass differential pressure) of the bypass differential pressure detection unit 90.
図3において、横軸は水熱交換器(熱交換器26)を流れる熱媒体の流量[m3/h]を示し、縦軸は水熱交換器(熱交換器26)における熱媒体の水頭損失[kPa]を示す。図4において、横軸は熱源側ポンプ30が送り出すことのできる熱媒体の流量Vwを示し、縦軸は揚程圧力Pを示す。揚程圧力Pは、熱源側ポンプ30による熱媒体の昇圧量であり、熱源側ポンプ30のポンプ揚程に相当する。図4には、熱源側ポンプ30の運転周波数FpがFp1、Fp2及びFp3(Fp1<Fp2<Fp3)であるときの熱媒体の流量Vwと揚程圧力Pとの関係を表すポンプ揚程曲線C1、C2及びC3を示す。
In Fig. 3, the horizontal axis indicates the flow rate [ m3 /h] of the heat medium flowing through the water heat exchanger (heat exchanger 26), and the vertical axis indicates the head loss [kPa] of the heat medium in the water heat exchanger (heat exchanger 26). In Fig. 4, the horizontal axis indicates the flow rate Vw of the heat medium that can be delivered by the heat source side pump 30, and the vertical axis indicates the head pressure P. The head pressure P is the amount of pressure increase of the heat medium by the heat source side pump 30, and corresponds to the pump head of the heat source side pump 30. Fig. 4 shows pump head curves C1, C2, and C3 that represent the relationship between the flow rate Vw of the heat medium and the head pressure P when the operating frequency Fp of the heat source side pump 30 is Fp1, Fp2, and Fp3 (Fp1<Fp2<Fp3).
図3に示されるように、熱交換器26を流れる熱媒体の流量が大きくなると、水頭損失すなわち熱交換器26の前後の差圧が大きくなる。また、図4に示されるように、熱源側ポンプ30が送り出す熱媒体の流量Vwが多いほど、揚程圧力Pは小さい。同じ流量Vwに対しては、熱源側ポンプ30の運転周波数Fpが大きい程、揚程圧力Pは大きい。また、同じ揚程圧力Pに対しては、熱源側ポンプ30の運転周波数Fpが大きい程、流量Vwが多くなる。
As shown in FIG. 3, as the flow rate of the heat medium flowing through the heat exchanger 26 increases, the head loss, i.e., the pressure difference before and after the heat exchanger 26, increases. Also, as shown in FIG. 4, the greater the flow rate Vw of the heat medium pumped out by the heat source side pump 30, the smaller the head pressure P. For the same flow rate Vw, the higher the operating frequency Fp of the heat source side pump 30, the greater the head pressure P. Also, for the same head pressure P, the higher the operating frequency Fp of the heat source side pump 30, the greater the flow rate Vw.
システム制御装置21aは、冷凍サイクルシステム10の運用開始後の稼働時に、熱交換器差圧検出部31により検出された熱交換器差圧ΔPhex(i)を用いてバイパス差圧を算出し、算出されたバイパス差圧の計算値Aと、バイパス差圧検出部90により検出したバイパス差圧の実測値Bとの差分Dabを、予め記憶された差分値(例えば、試運転時等の初期状態に得た計算値Aと実測値Bとの差分Dab_0)と比較することにより、熱交換器26のスケールの堆積状態を判定する。詳しくは、システム制御装置21aは、稼働時の差分が、予め記憶された差分値から一定量以上乖離した場合に、熱交換器26に一定量以上のスケールが堆積しているものと判定し、その旨を報知部99により報知する。
During operation after the start of operation of the refrigeration cycle system 10, the system control device 21a calculates the bypass differential pressure using the heat exchanger differential pressure ΔPhex(i) detected by the heat exchanger differential pressure detection unit 31, and compares the difference Dab between the calculated bypass differential pressure value A and the actual measured bypass differential pressure value B detected by the bypass differential pressure detection unit 90 with a pre-stored difference value (for example, the difference Dab_0 between the calculated value A and the actual measured bypass differential pressure B obtained in an initial state such as during a test run). In more detail, when the difference during operation deviates by a certain amount or more from the pre-stored difference value, the system control device 21a determines that a certain amount or more of scale has accumulated in the heat exchanger 26, and notifies this fact via the notification unit 99.
熱交換器差圧検出部31により検出された熱交換器差圧ΔPhex(i)からバイパス差圧の計算値Aを算出できるように、図3に示される熱交換器26の特性、及び図4に示される熱源側ポンプ30の揚程特性が、表又は式の形式でシステム制御装置21aに予め記憶されている。
The characteristics of the heat exchanger 26 shown in FIG. 3 and the head characteristics of the heat source side pump 30 shown in FIG. 4 are stored in advance in the system control device 21a in the form of a table or formula so that the bypass differential pressure calculation value A can be calculated from the heat exchanger differential pressure ΔPhex(i) detected by the heat exchanger differential pressure detection unit 31.
例えば、熱交換器26における水頭損失(すなわち熱交換器差圧ΔPhex(i))と熱媒体の流量Vwとの関係は、以下の式(1)の形式で記憶されている。ここで、式(1)のf1(ΔPhex(i))は、熱交換器差圧ΔPhex(i)の関数である。各パラメータの(i)は、冷凍サイクル装置20の台数を意味している。熱交換器26を流れる熱媒体の流量は、熱源側ポンプ30を流れる熱媒体の流量であり、また、熱源機である冷凍サイクル装置20を流れる熱媒体の流量でもある。
For example, the relationship between the head loss in the heat exchanger 26 (i.e., the heat exchanger differential pressure ΔPhex(i)) and the heat medium flow rate Vw is stored in the form of the following formula (1). Here, f1(ΔPhex(i)) in formula (1) is a function of the heat exchanger differential pressure ΔPhex(i). The (i) in each parameter indicates the number of refrigeration cycle devices 20. The flow rate of the heat medium flowing through the heat exchanger 26 is the flow rate of the heat medium flowing through the heat source side pump 30, and is also the flow rate of the heat medium flowing through the refrigeration cycle device 20, which is the heat source machine.
Vw(i)=f1(ΔPhex(i))・・・(1)
Vw(i) = f1(ΔPhex(i)) ... (1)
また例えば、熱源側ポンプ30の運転周波数Fp(すなわち回転数)と流量Vw(i)と揚程圧力P(すなわちポンプ揚程ΔPp(i))との関係が、以下の式(2)の形式で記憶されている。ここで、式(2)のf2(Fp,Vw(i))は、熱源側ポンプ30の運転周波数Fp及び流量Vw(i)の関数である。
Also, for example, the relationship between the operating frequency Fp (i.e., rotation speed), flow rate Vw(i), and head pressure P (i.e., pump head ΔPp(i)) of the heat source side pump 30 is stored in the form of the following formula (2). Here, f2(Fp, Vw(i)) in formula (2) is a function of the operating frequency Fp and flow rate Vw(i) of the heat source side pump 30.
ΔPp(i)=f2(Fp,Vw(i))・・・(2)
ΔPp(i)=f2(Fp, Vw(i))・・・(2)
図1に示されるように冷凍サイクルシステム10が複数の冷凍サイクル装置20を含む構成では、冷凍サイクルシステム10は、冷凍サイクル装置20の台数と同数の熱交換器差圧検出部31(図2参照)を有する。この場合、システム制御装置21aは、スケール堆積判定に、複数の熱交換器差圧検出部31で検出された熱交換器差圧ΔPhex(i)と、1つのバイパス差圧検出部90で検出されたバイパス差圧の実測値Bとを用いる。
In a configuration in which the refrigeration cycle system 10 includes multiple refrigeration cycle devices 20 as shown in FIG. 1, the refrigeration cycle system 10 has the same number of heat exchanger differential pressure detection units 31 (see FIG. 2) as the number of refrigeration cycle devices 20. In this case, the system control device 21a uses the heat exchanger differential pressure ΔPhex(i) detected by the multiple heat exchanger differential pressure detection units 31 and the actual bypass differential pressure value B detected by one bypass differential pressure detection unit 90 to determine scale accumulation.
(冷凍サイクルシステム10の試運転時)
冷凍サイクルシステム10を構築した直後の試運転時には、水熱交換器(熱交換器26)にスケールが無い。この初期状態において、システム制御装置21aは、複数の冷凍サイクル装置20の制御装置21から、それらの熱交換器差圧検出部31で検出された熱交換器差圧ΔPhex(i)及び熱源側ポンプ30の運転周波数Fpを取得する。また、システム制御装置21aには、バイパス差圧検出部90からバイパス差圧の実測値Bが入力される。システム制御装置21aは、式(1)を用いて、取得した熱交換器差圧ΔPhex(i)から熱交換器26内を流れる熱媒体の流量、即ち冷凍サイクル装置20を流れる熱媒体の流量Vw(i)を算出する。さらに、システム制御装置21aは、式(2)を用いて、算出された流量Vw(i)及び取得した熱源側ポンプ30の運転周波数Fp(すなわち回転数)からポンプ揚程ΔPp(i)を算出する。システム制御装置21aは、複数の冷凍サイクル装置20のそれぞれについて、式(1)及び式(2)を用いて上記のポンプ揚程ΔPp(i)を算出する。そして、システム制御装置21aは、以下の式(3)を用いて、各冷凍サイクル装置20におけるポンプ揚程ΔPp(i)と熱交換器差圧ΔPhex(i)との差の平均値を求め、求めた平均値をバイパス差圧の計算値Aとする。 (During test run of the refrigeration cycle system 10)
During a trial run immediately after constructing therefrigeration cycle system 10, there is no scale in the water heat exchanger (heat exchanger 26). In this initial state, the system control device 21a acquires the heat exchanger differential pressure ΔPhex(i) detected by the heat exchanger differential pressure detection unit 31 and the operation frequency Fp of the heat source side pump 30 from the control devices 21 of the multiple refrigeration cycle devices 20. In addition, the actual measurement value B of the bypass differential pressure is input from the bypass differential pressure detection unit 90 to the system control device 21a. The system control device 21a calculates the flow rate of the heat medium flowing in the heat exchanger 26, i.e., the flow rate Vw(i) of the heat medium flowing through the refrigeration cycle device 20, from the acquired heat exchanger differential pressure ΔPhex(i) using equation (1). Furthermore, the system control device 21a calculates the pump head ΔPp(i) from the calculated flow rate Vw(i) and the acquired operation frequency Fp (i.e., the rotation speed) of the heat source side pump 30 using equation (2). The system control device 21a calculates the pump head ΔPp(i) using equations (1) and (2) for each of the multiple refrigeration cycle devices 20. Then, the system control device 21a calculates an average value of the differences between the pump head ΔPp(i) and the heat exchanger differential pressure ΔPhex(i) in each refrigeration cycle device 20 using the following equation (3), and sets the calculated average value as the bypass differential pressure calculation value A.
冷凍サイクルシステム10を構築した直後の試運転時には、水熱交換器(熱交換器26)にスケールが無い。この初期状態において、システム制御装置21aは、複数の冷凍サイクル装置20の制御装置21から、それらの熱交換器差圧検出部31で検出された熱交換器差圧ΔPhex(i)及び熱源側ポンプ30の運転周波数Fpを取得する。また、システム制御装置21aには、バイパス差圧検出部90からバイパス差圧の実測値Bが入力される。システム制御装置21aは、式(1)を用いて、取得した熱交換器差圧ΔPhex(i)から熱交換器26内を流れる熱媒体の流量、即ち冷凍サイクル装置20を流れる熱媒体の流量Vw(i)を算出する。さらに、システム制御装置21aは、式(2)を用いて、算出された流量Vw(i)及び取得した熱源側ポンプ30の運転周波数Fp(すなわち回転数)からポンプ揚程ΔPp(i)を算出する。システム制御装置21aは、複数の冷凍サイクル装置20のそれぞれについて、式(1)及び式(2)を用いて上記のポンプ揚程ΔPp(i)を算出する。そして、システム制御装置21aは、以下の式(3)を用いて、各冷凍サイクル装置20におけるポンプ揚程ΔPp(i)と熱交換器差圧ΔPhex(i)との差の平均値を求め、求めた平均値をバイパス差圧の計算値Aとする。 (During test run of the refrigeration cycle system 10)
During a trial run immediately after constructing the
A=Ave(ΔPp(i)-ΔPhex(i))・・・(3)
A = Ave (ΔPp(i) - ΔPhex(i)) ... (3)
換言すると、バイパス差圧の計算値Aは、熱源側枝管40aにおける冷凍サイクル装置20の前後の差圧(ΔPp(i)-ΔPhex(i))を、全ての熱源側枝管40aについて平均したものである。そして、システム制御装置21aは、式(3)を用いて得たバイパス差圧の計算値A、すなわち熱媒体回路40の熱源側の回路部分の状態をもとに算出されたバイパス差圧と、バイパス差圧検出部90で直接検出されたバイパス差圧の実測値Bとの差分を算出し、初期状態の差分Dab_0として記憶する。
In other words, the calculated value A of the bypass differential pressure is the average of the pressure differences (ΔPp(i) - ΔPhex(i)) before and after the refrigeration cycle device 20 in the heat source side branch pipe 40a for all heat source side branch pipes 40a. The system control device 21a then calculates the difference between the calculated value A of the bypass differential pressure obtained using formula (3), i.e., the bypass differential pressure calculated based on the state of the heat source side circuit part of the heat medium circuit 40, and the actual measured value B of the bypass differential pressure detected directly by the bypass differential pressure detection unit 90, and stores this as the initial state difference Dab_0.
(冷凍サイクルシステム10の稼働時)
冷凍サイクルシステム10の運用開始後の稼働時、熱交換器26のスケールの堆積量は次第に増加する。冷凍サイクルシステム10の運用開始後の稼働時、システム制御装置21aは、試運転時と同様に、各熱交換器差圧ΔPhex(i)とバイパス差圧の実測値Bとを取得し、バイパス差圧の計算値Aを算出し、計算値Aと実測値Bとの差分を求める。そして、冷凍サイクルシステム10の運用開始後の稼働時には、システム制御装置21aは、稼働時に得た差分と初期状態で得た差分と比較することにより、複数の熱交換器26に対するスケールの堆積状態を判定する。 (When therefrigeration cycle system 10 is in operation)
During operation of therefrigeration cycle system 10 after the start of operation, the amount of scale buildup in the heat exchangers 26 gradually increases. During operation of the refrigeration cycle system 10 after the start of operation, the system control device 21a acquires each heat exchanger differential pressure ΔPhex(i) and an actual measurement value B of the bypass differential pressure, calculates a calculated value A of the bypass differential pressure, and obtains a difference between the calculated value A and the actual measurement value B, as in the case of a test run. Then, during operation of the refrigeration cycle system 10 after the start of operation, the system control device 21a compares the difference obtained during operation with the difference obtained in the initial state to determine the scale buildup state for the multiple heat exchangers 26.
冷凍サイクルシステム10の運用開始後の稼働時、熱交換器26のスケールの堆積量は次第に増加する。冷凍サイクルシステム10の運用開始後の稼働時、システム制御装置21aは、試運転時と同様に、各熱交換器差圧ΔPhex(i)とバイパス差圧の実測値Bとを取得し、バイパス差圧の計算値Aを算出し、計算値Aと実測値Bとの差分を求める。そして、冷凍サイクルシステム10の運用開始後の稼働時には、システム制御装置21aは、稼働時に得た差分と初期状態で得た差分と比較することにより、複数の熱交換器26に対するスケールの堆積状態を判定する。 (When the
During operation of the
図5に基づき、冷凍サイクルシステム10の運用開始後の稼働時においてシステム制御装置21aが行うスケール堆積判定のフローについて説明する。冷凍サイクルシステム10の稼働時に、システム制御装置21aは、複数の冷凍サイクル装置20の各制御装置21から、熱交換器差圧検出部31で検出された熱交換器差圧ΔPhex(i)を取得する(ステップS10)。また、システム制御装置21aは、複数の冷凍サイクル装置20の各制御装置21から、熱源側ポンプ30の運転周波数Fpを取得する。また、システム制御装置21aには、バイパス差圧検出部90からバイパス差圧の実測値Bが入力される。
With reference to FIG. 5, the flow of scale accumulation determination performed by the system control device 21a during operation after the start of operation of the refrigeration cycle system 10 will be described. During operation of the refrigeration cycle system 10, the system control device 21a acquires the heat exchanger differential pressure ΔPhex(i) detected by the heat exchanger differential pressure detection unit 31 from each control device 21 of the multiple refrigeration cycle devices 20 (step S10). The system control device 21a also acquires the operating frequency Fp of the heat source side pump 30 from each control device 21 of the multiple refrigeration cycle devices 20. The system control device 21a also receives an actual measured value B of the bypass differential pressure from the bypass differential pressure detection unit 90.
システム制御装置21aは、各冷凍サイクル装置20について、取得した熱交換器差圧ΔPhex(i)から熱交換器26を流れる熱媒体の流量Vw(i)、即ち冷凍サイクル装置20を流れる熱媒体の流量を、式(1)を用いて算出する(ステップS11)。さらに、システム制御装置21aは、ステップS11で算出された流量Vw(i)、及び取得した熱源側ポンプ30の運転周波数Fpから、式(2)を用いてポンプ揚程ΔPp(i)を算出する(ステップS12)。システム制御装置21aは、各冷凍サイクル装置20についてステップS11及びS12の演算を行い、ステップS12で算出されたポンプ揚程ΔPp(i)及びステップS10で取得した熱交換器差圧ΔPhex(i)から、式(3)を用いてバイパス差圧の計算値Aを得る(ステップS13)。
The system control device 21a calculates the flow rate Vw(i) of the heat medium flowing through the heat exchanger 26, i.e., the flow rate of the heat medium flowing through the refrigeration cycle device 20, for each refrigeration cycle device 20 from the acquired heat exchanger differential pressure ΔPhex(i) using formula (1) (step S11). Furthermore, the system control device 21a calculates the pump head ΔPp(i) using formula (2) from the flow rate Vw(i) calculated in step S11 and the acquired operating frequency Fp of the heat source side pump 30 (step S12). The system control device 21a performs the calculations of steps S11 and S12 for each refrigeration cycle device 20, and obtains a bypass differential pressure calculation value A using formula (3) from the pump head ΔPp(i) calculated in step S12 and the heat exchanger differential pressure ΔPhex(i) acquired in step S10 (step S13).
ここで得られるバイパス差圧の計算値Aは、このときの複数の冷凍サイクル装置20の熱交換器26における熱媒体の流路の状態を反映したものとなる。複数の冷凍サイクル装置20において熱交換器26のスケールの堆積量が増えると、摩擦等によりそれら熱交換器26内での熱媒体の水頭損失(すなわち、熱交換器差圧ΔPhex(i))が大きくなるので流量[m3/h]が増加し、熱源側ポンプ30の揚程圧力P(すなわち、ポンプ揚程ΔPp(i))が小さくなる。したがって、スケールの堆積量が増えると、ポンプ揚程ΔPp(i)が小さくなり、且つ熱交換器差圧ΔPhex(i)が大きくなるので、バイパス差圧の計算値Aは小さくなる。
The calculated value A of the bypass differential pressure obtained here reflects the state of the flow path of the heat medium in the heat exchangers 26 of the multiple refrigeration cycle devices 20 at this time. When the amount of scale deposition in the heat exchangers 26 of the multiple refrigeration cycle devices 20 increases, the head loss of the heat medium in the heat exchangers 26 (i.e., the heat exchanger differential pressure ΔPhex(i)) increases due to friction, etc., so the flow rate [ m3 /h] increases and the head pressure P of the heat source side pump 30 (i.e., the pump head ΔPp(i)) decreases. Therefore, when the amount of scale deposition increases, the pump head ΔPp(i) decreases and the heat exchanger differential pressure ΔPhex(i) increases, so the calculated value A of the bypass differential pressure decreases.
システム制御装置21aは、ステップS13において算出して得たバイパス差圧の計算値Aと、バイパス差圧検出部90から入力されたバイパス差圧の実測値Bとの差分Dabを算出する(ステップS14)。そして、システム制御装置21aは、稼働時に得たこの差分Dabが、予め記憶された差分値(すなわち初期状態で取得しておいた差分Dab_0)から一定量以上乖離しているか否かを判定する(ステップS15)。稼働時の差分Dabが初期状態の差分Dab_0から一定量以上乖離する場合(ステップS15;YES)、システム制御装置21aは、冷凍サイクルシステム10の複数の熱交換器26に一定量以上のスケールが堆積しているものと判断して報知部99等によりその旨を報知する(ステップS16)。
The system control device 21a calculates the difference Dab between the calculated value A of the bypass differential pressure calculated in step S13 and the actual measured value B of the bypass differential pressure input from the bypass differential pressure detection unit 90 (step S14). The system control device 21a then determines whether this difference Dab obtained during operation deviates from the pre-stored difference value (i.e., the difference Dab_0 obtained in the initial state) by a certain amount or more (step S15). If the difference Dab during operation deviates from the difference Dab_0 in the initial state by a certain amount or more (step S15; YES), the system control device 21a determines that a certain amount or more of scale has accumulated in the multiple heat exchangers 26 of the refrigeration cycle system 10 and notifies the fact by the notification unit 99 or the like (step S16).
ここで、稼働時の差分Dabが初期状態の差分Dab_0から一定量以上乖離する場合とは、稼働時の差分から初期状態の差分Dab_0を減算した値の正負は問わず、その値の絶対値で判断してよい。
Here, when the difference Dab during operation deviates by a certain amount or more from the difference Dab_0 in the initial state, the difference may be determined by the absolute value of the difference Dab_0 in the initial state subtracted from the difference during operation, regardless of whether the difference is positive or negative.
このように、単式ポンプシステムである実施の形態1の冷凍サイクルシステム10では、運用開始後の稼働時に、システム制御装置21aは、バイパス差圧の計算値Aと実測値Bとの差分Dabを算出し、算出された稼働時の差分Dabと、試運転時に予め算出し記憶しておいた初期状態の差分Dab_0とを比較することで、その比較結果により、経年的な熱交換器26へのスケールの堆積状態が判定できる。
In this way, in the refrigeration cycle system 10 of embodiment 1, which is a single pump system, during operation after the start of operation, the system control device 21a calculates the difference Dab between the calculated bypass differential pressure A and the measured value B, and compares the calculated difference Dab during operation with the initial state difference Dab_0 calculated and stored in advance during trial operation, and the state of scale buildup on the heat exchanger 26 over time can be determined based on the comparison result.
また、冷凍サイクルシステム10の複数の熱交換器26に一定量以上のスケールが堆積したと判断する判断基準は、例えば差分Dabを学習し、学習済みの差分Dabを基に決定すればよい。この場合において、システム制御装置21aは、計算値Aと、実測値Bと、それらの差分Dabとを記憶し学習する機能を備える。システム制御装置21aは、冷凍サイクルシステム10を稼働していく過程において差分Dabを学習し、学習した差分Dabに基づきスケールの堆積状態の判定を行う。
The criteria for determining that a certain amount of scale has accumulated in the multiple heat exchangers 26 of the refrigeration cycle system 10 may be determined, for example, by learning the difference Dab and determining the difference Dab based on the learned difference Dab. In this case, the system control device 21a has a function for storing and learning the calculated value A, the measured value B, and the difference Dab between them. The system control device 21a learns the difference Dab in the process of operating the refrigeration cycle system 10 and determines the scale accumulation state based on the learned difference Dab.
なお、熱交換器26のスケール堆積状態の判定方法は、図5の例に限定されない。図5の例では、熱交換器差圧検出部31により検出された熱交換器差圧ΔPhex(i)から熱源側ポンプ30のポンプ揚程ΔPp(i)が算出され、熱交換器差圧ΔPhex(i)及び算出されたポンプ揚程ΔPp(i)に基づきバイパス差圧が算出され、算出されたバイパス差圧の計算値Aと、バイパス差圧検出部90により検出されたバイパス差圧の実測値Bとの差分Dabに基づきスケールの堆積状態が判定された。以下では、実測値Bの代わりに、計算値Aとは異なる方法で求めた計算値Cを、計算値Aと比較してスケールの堆積状態を判定する方法について説明する。
The method of determining the scale accumulation state of the heat exchanger 26 is not limited to the example shown in FIG. 5. In the example shown in FIG. 5, the pump head ΔPp(i) of the heat source pump 30 is calculated from the heat exchanger differential pressure ΔPhex(i) detected by the heat exchanger differential pressure detection unit 31, the bypass differential pressure is calculated based on the heat exchanger differential pressure ΔPhex(i) and the calculated pump head ΔPp(i), and the scale accumulation state is determined based on the difference Dab between the calculated value A of the calculated bypass differential pressure and the actual measured value B of the bypass differential pressure detected by the bypass differential pressure detection unit 90. Below, a method of determining the scale accumulation state by comparing a calculated value C obtained by a method different from the calculated value A instead of the actual measured value B with the calculated value A will be described.
図6は、図2の冷凍サイクル装置20の変形例を示す回路図である。図6中、実線の白抜き矢印は、冷媒の流れる方向を示しており、また、破線の白抜き矢印は、熱媒体の流れる方を示している。
FIG. 6 is a circuit diagram showing a modified example of the refrigeration cycle device 20 in FIG. 2. In FIG. 6, the solid white arrows indicate the direction in which the refrigerant flows, and the dashed white arrows indicate the direction in which the heat transfer medium flows.
図6の冷凍サイクル装置20において、熱源側枝管40aには、熱交換器26の前後の差圧を検出する熱交換器差圧検出部31、及び、熱源側ポンプ30の前後のポンプ差圧(すなわちポンプ揚程)を検出するポンプ差圧検出部32が設けられている。ポンプ差圧検出部32は、例えば差圧計である。図6の例では、熱交換器差圧検出部31を第1検出部と称し、ポンプ差圧検出部32を第2検出部と称する場合がある。なお、ポンプ差圧検出部32として差圧計を用いる代わりに、熱源側ポンプ30の前後に設けた2つの圧力センサを用いてもよい。
In the refrigeration cycle device 20 of FIG. 6, the heat source side branch pipe 40a is provided with a heat exchanger differential pressure detection unit 31 that detects the differential pressure before and after the heat exchanger 26, and a pump differential pressure detection unit 32 that detects the pump differential pressure before and after the heat source side pump 30 (i.e., the pump head). The pump differential pressure detection unit 32 is, for example, a differential pressure gauge. In the example of FIG. 6, the heat exchanger differential pressure detection unit 31 may be referred to as the first detection unit, and the pump differential pressure detection unit 32 may be referred to as the second detection unit. Note that instead of using a differential pressure gauge as the pump differential pressure detection unit 32, two pressure sensors provided before and after the heat source side pump 30 may be used.
システム制御装置21aは、以下の式(4)を用いてバイパス差圧を求め、計算値Cを得る。計算値Aのパラメータであるポンプ揚程ΔPp(i)は、熱交換器差圧検出部31により検出された熱交換器差圧ΔPhex(i)から式(1)及び式(2)を用いて算出したものであったが、計算値Cを求める式(4)中のΔPp_a(i)は、ポンプ差圧検出部32により直接検出されるポンプ揚程の実測値である。
The system control device 21a calculates the bypass differential pressure using the following formula (4) to obtain the calculated value C. The pump head ΔPp(i), which is a parameter of the calculated value A, is calculated from the heat exchanger differential pressure ΔPhex(i) detected by the heat exchanger differential pressure detection unit 31 using formulas (1) and (2), but ΔPp_a(i) in formula (4) for calculating the calculated value C is the actual pump head value detected directly by the pump differential pressure detection unit 32.
C=Ave(ΔPp_a(i)-ΔPhex(i))・・・(4)
C = Ave (ΔPp_a(i) - ΔPhex(i)) ... (4)
冷凍サイクルシステム10の試運転時に、システム制御装置21aは、バイパス差圧の計算値A及び計算値Cをそれぞれ算出し、それらの差分を算出して初期状態の差分Dac_0として記憶する。冷凍サイクルシステム10の運用開始後の稼働時には、システム制御装置21aは、バイパス差圧の計算値A及び計算値Cをそれぞれ算出し、それらの差分Dacを算出して、稼働時の差分Dacと初期状態の差分Dac_0と比較することにより熱交換器26のスケールの堆積状態を判定する。
During a trial run of the refrigeration cycle system 10, the system control device 21a calculates the bypass differential pressures A and C, respectively, and calculates the difference between them and stores it as the initial state difference Dac_0. During operation after the start of operation of the refrigeration cycle system 10, the system control device 21a calculates the bypass differential pressures A and C, respectively, and calculates the difference Dac between them, and determines the scale accumulation state of the heat exchanger 26 by comparing the difference Dac during operation with the initial state difference Dac_0.
このように、熱交換器差圧検出部31とポンプ差圧検出部32とをスケール堆積判定に用いる構成では、冷凍サイクル装置20の台数分の第2検出部(ポンプ差圧検出部32)が必要となる。一方、図1~図5のように、熱交換器差圧検出部31とバイパス差圧検出部90とをスケール堆積判定に用いる構成では、冷凍サイクル装置20の台数とは無関係に1つの第2検出部(図1のバイパス差圧検出部90)を設ければよいので、冷凍サイクルシステム10の構造を簡易化できる。
In this way, in a configuration in which the heat exchanger differential pressure detection unit 31 and the pump differential pressure detection unit 32 are used to determine scale buildup, a second detection unit (pump differential pressure detection unit 32) is required for each refrigeration cycle device 20. On the other hand, in a configuration in which the heat exchanger differential pressure detection unit 31 and the bypass differential pressure detection unit 90 are used to determine scale buildup as shown in Figures 1 to 5, only one second detection unit (bypass differential pressure detection unit 90 in Figure 1) is required regardless of the number of refrigeration cycle devices 20, which simplifies the structure of the refrigeration cycle system 10.
以上のように、実施の形態1に係る冷凍サイクルシステム10は、圧縮機22を有し、圧縮機22により冷媒が循環する冷媒回路27と、熱源側ポンプ30を有し、熱源側ポンプ30により熱媒体が循環する熱媒体回路40と、冷媒と熱媒体との間で熱交換を行う熱交換器26と、熱源側ポンプ30を制御するシステム制御装置21aと、を備え、熱媒体回路40は、熱交換器26の下流側に設けられる負荷装置70と、負荷装置70をバイパスするバイパス配管80とを有したものである。また、冷凍サイクルシステム10は、熱媒体回路40に設けられ、熱交換器26の前後の差圧を検出する第1検出部(熱交換器差圧検出部31)と、熱媒体回路40に設けられ、バイパス配管80の前後のバイパス差圧を検出する第2検出部(バイパス差圧検出部90)と、を備える。システム制御装置21aは、第1検出部により検出された差圧(熱交換器差圧ΔPhex(i))と、熱源側ポンプ30の回転数(例えば、運転周波数Fp)から熱源側ポンプ30の揚程(ΔPp(i))を求め、差圧(熱交換器差圧ΔPhex(i))及び揚程(ΔPp(i))に基づきバイパス配管80の前後のバイパス差圧を算出する。システム制御装置21aは、算出されたバイパス差圧の計算値Aと、第2検出部により検出されたバイパス差圧の実測値Bとの差分Dabを、予め記憶された差分値(例えば、初期状態の差分Dab_0)と比較することにより熱交換器26のスケールの堆積状態を判定する。
As described above, the refrigeration cycle system 10 according to the first embodiment includes a refrigerant circuit 27 having a compressor 22 and a refrigerant circulating by the compressor 22, a heat medium circuit 40 having a heat source side pump 30 and a heat medium circulating by the heat source side pump 30, a heat exchanger 26 for exchanging heat between the refrigerant and the heat medium, and a system control device 21a for controlling the heat source side pump 30. The heat medium circuit 40 includes a load device 70 provided downstream of the heat exchanger 26 and a bypass piping 80 bypassing the load device 70. The refrigeration cycle system 10 also includes a first detection unit (heat exchanger differential pressure detection unit 31) provided in the heat medium circuit 40 for detecting a differential pressure before and after the heat exchanger 26, and a second detection unit (bypass differential pressure detection unit 90) provided in the heat medium circuit 40 for detecting a bypass differential pressure before and after the bypass piping 80. The system control device 21a obtains the head (ΔPp(i)) of the heat source side pump 30 from the differential pressure (heat exchanger differential pressure ΔPhex(i)) detected by the first detection unit and the rotation speed (e.g., operating frequency Fp) of the heat source side pump 30, and calculates the bypass differential pressure before and after the bypass piping 80 based on the differential pressure (heat exchanger differential pressure ΔPhex(i)) and the head (ΔPp(i)). The system control device 21a compares the difference Dab between the calculated value A of the calculated bypass differential pressure and the actual measured value B of the bypass differential pressure detected by the second detection unit with a previously stored difference value (e.g., the difference Dab_0 in the initial state) to determine the scale deposition state of the heat exchanger 26.
このように、実施の形態1に係る冷凍サイクルシステム10では、熱媒体回路40に設けられた第1検出部及び第2検出部を用いて異なる方法で得たバイパス差圧の計算値Aと実測値Bとの差分Dabを、予め記憶された差分値と比較することにより熱交換器26のスケールの堆積状態が判定される。そして、第1検出部及び第2検出部はいずれもスケールの堆積する熱媒体回路40に設けられるので、それらの検出値(熱交換器差圧ΔPhex(i)及びバイパス差圧の実測値B)を用いて得られる、バイパス差圧の計算値Aと実測値Bとの差分Dabに基づき熱交換器26のスケールの堆積状態を判定する本開示の構成では、従来のように冷媒の飽和温度と熱交換器から流出する熱媒体の温度との温度差に基づき熱交換器のスケールの堆積状態を判定する構成と比べて、負荷変動及び運転条件の変動による影響が少ない、より正確な判定を行うことができる。
In this way, in the refrigeration cycle system 10 according to the first embodiment, the scale buildup state of the heat exchanger 26 is determined by comparing the difference Dab between the calculated value A and the measured value B of the bypass differential pressure obtained by different methods using the first and second detection units provided in the heat medium circuit 40 with the difference value stored in advance. Since both the first and second detection units are provided in the heat medium circuit 40 where scale buildup occurs, the configuration of the present disclosure, which determines the scale buildup state of the heat exchanger 26 based on the difference Dab between the calculated value A and the measured value B of the bypass differential pressure obtained using these detection values (heat exchanger differential pressure ΔPhex(i) and the measured value B of the bypass differential pressure), can perform a more accurate determination that is less affected by load fluctuations and fluctuations in operating conditions than a conventional configuration in which the scale buildup state of the heat exchanger is determined based on the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the heat exchanger.
また、図6の変形例では、冷凍サイクルシステム10は、圧縮機22を有し、圧縮機22により冷媒が循環する冷媒回路27と、熱源側ポンプ30を有し、熱源側ポンプ30により熱媒体が循環する熱媒体回路40と、冷媒と熱媒体との間で熱交換を行う熱交換器26と、熱源側ポンプ30を制御するシステム制御装置21aと、を備え、熱媒体回路40は、熱交換器26の下流側に設けられる負荷装置70と、負荷装置70をバイパスするバイパス配管80とを有したものである。また、冷凍サイクルシステム10は、熱媒体回路40に設けられ、熱交換器26の前後の差圧を検出する第1検出部(熱交換器差圧検出部31)と、熱媒体回路40に設けられ、熱源側ポンプ30の前後のポンプ差圧を検出する第2検出部(ポンプ差圧検出部32)と、を備える。システム制御装置21aは、第1検出部により検出された差圧(熱交換器差圧ΔPhex(i))と、熱源側ポンプ30の回転数(例えば、運転周波数Fp)から熱源側ポンプ30の揚程(ΔPp(i))を求め、差圧(熱交換器差圧ΔPhex(i))及び揚程(ΔPp(i))に基づきバイパス配管の前後のバイパス差圧を算出して第1計算値(計算値A)を得るとともに、第1検出部により検出された差圧(熱交換器差圧ΔPhex(i))及び第2検出部により検出されたポンプ差圧(揚程の実測値ΔPp_a(i))に基づきバイパス配管80の前後のバイパス差圧を算出して第2計算値(計算値C)を得る。そして、システム制御装置21aは、バイパス差圧の第1計算値(計算値A)と第2計算値(計算値C)との差分Dacを、予め記憶された差分値(初期状態のDac_0)と比較することにより熱交換器26のスケールの堆積状態を判定する。
6, the refrigeration cycle system 10 includes a refrigerant circuit 27 having a compressor 22 and circulating a refrigerant by the compressor 22, a heat medium circuit 40 having a heat source side pump 30 and circulating a heat medium by the heat source side pump 30, a heat exchanger 26 exchanging heat between the refrigerant and the heat medium, and a system control device 21a controlling the heat source side pump 30, and the heat medium circuit 40 includes a load device 70 provided downstream of the heat exchanger 26 and a bypass piping 80 bypassing the load device 70. The refrigeration cycle system 10 also includes a first detection unit (heat exchanger differential pressure detection unit 31) provided in the heat medium circuit 40 for detecting a differential pressure before and after the heat exchanger 26, and a second detection unit (pump differential pressure detection unit 32) provided in the heat medium circuit 40 for detecting a pump differential pressure before and after the heat source side pump 30. The system control device 21a determines the head (ΔPp(i)) of the heat source side pump 30 from the differential pressure (heat exchanger differential pressure ΔPhex(i)) detected by the first detection unit and the rotation speed (e.g., operating frequency Fp) of the heat source side pump 30, calculates the bypass differential pressure before and after the bypass piping based on the differential pressure (heat exchanger differential pressure ΔPhex(i)) and the head (ΔPp(i)) to obtain a first calculated value (calculated value A), and calculates the bypass differential pressure before and after the bypass piping 80 based on the differential pressure (heat exchanger differential pressure ΔPhex(i)) detected by the first detection unit and the pump differential pressure (actual measured head value ΔPp_a(i)) detected by the second detection unit to obtain a second calculated value (calculated value C). The system control device 21a then compares the difference Dac between the first calculated value (calculated value A) and the second calculated value (calculated value C) of the bypass differential pressure with a previously stored difference value (Dac_0 in the initial state) to determine the scale buildup state of the heat exchanger 26.
このように、図6の変形例では、熱媒体回路40に設けられた第1検出部及び第2検出部を用いて異なる方法で得たバイパス差圧の第1計算値(計算値A)と第2計算値(計算値C)との差分Dacを、予め記憶された差分値(初期状態の差分Dac_0)と比較することにより熱交換器26のスケールの堆積状態が判定される。そして、第1検出部及び第2検出部はいずれもスケールの堆積する熱媒体回路40に設けられるので、それらの検出値(熱交換器差圧ΔPhex(i)及び揚程の実測値ΔPp_a(i))を用いて得られる、バイパス差圧の第1計算値と第2計算値との差分Dacに基づき熱交換器26のスケールの堆積状態を判定する本開示の構成では、従来のように冷媒の飽和温度と熱交換器から流出する熱媒体の温度との温度差に基づき熱交換器のスケールの堆積状態を判定する構成と比べて、負荷変動及び運転条件の変動による影響が少なく、より正確な判定を行うことができる。
6, the scale buildup state of the heat exchanger 26 is determined by comparing the difference Dac between the first calculated value (calculated value A) and the second calculated value (calculated value C) of the bypass differential pressure obtained by different methods using the first and second detection units provided in the heat medium circuit 40 with a pre-stored difference value (initial state difference Dac_0). Since both the first and second detection units are provided in the heat medium circuit 40 where scale buildup occurs, the configuration of the present disclosure, which determines the scale buildup state of the heat exchanger 26 based on the difference Dac between the first and second calculated values of the bypass differential pressure obtained using the detection values (heat exchanger differential pressure ΔPhex(i) and actual head value ΔPp_a(i)), is less affected by load fluctuations and operating condition fluctuations and can perform more accurate determinations than the conventional configuration in which the scale buildup state of the heat exchanger is determined based on the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the heat exchanger.
また、システム制御装置21aは、熱交換器26にスケールが無い初期状態に算出された差分Dac_0を、予め記憶された差分値として記憶する。したがって、その冷凍サイクルシステムの構成で得た初期状態を用いて稼働時のスケール堆積判定を行うことができるので、判定の正確性が向上する。
The system control device 21a also stores the difference Dac_0 calculated for the initial state when there is no scale in the heat exchanger 26 as a pre-stored difference value. Therefore, the scale accumulation judgment during operation can be performed using the initial state obtained by the configuration of the refrigeration cycle system, improving the accuracy of the judgment.
また、冷凍サイクルシステム10は、冷媒回路27、熱源側ポンプ30及び熱交換器26を有する冷凍サイクル装置20を複数台備え、熱媒体回路40は、各冷凍サイクル装置20の熱源側ポンプ30及び熱交換器26が設けられる熱源側枝管40aを複数有し、複数の熱源側枝管40aが互いに並列接続されて負荷側と接続されたものである。
The refrigeration cycle system 10 also includes a plurality of refrigeration cycle devices 20 each having a refrigerant circuit 27, a heat source side pump 30, and a heat exchanger 26, and the heat medium circuit 40 includes a plurality of heat source side branch pipes 40a in which the heat source side pumps 30 and heat exchangers 26 of each refrigeration cycle device 20 are provided, and the plurality of heat source side branch pipes 40a are connected in parallel to each other and connected to the load side.
このように冷凍サイクルシステム10が複数台の冷凍サイクル装置20を備える場合であっても、冷凍サイクルシステム10が一台の冷凍サイクル装置20のみを備える場合と同様、熱媒体回路40の状態から複数の熱交換器26のスケールの堆積状態を判定することができる。
Even if the refrigeration cycle system 10 includes multiple refrigeration cycle devices 20 in this way, the scale accumulation state of the multiple heat exchangers 26 can be determined from the state of the heat medium circuit 40, just as in the case where the refrigeration cycle system 10 includes only one refrigeration cycle device 20.
また、冷凍サイクルシステム10は、ディスプレイ又はスピーカを有する報知部99を備える。システム制御装置21aは、差分Dab(又は差分Dac)が予め記憶された差分値から一定量以上乖離した場合に、スケールが堆積している旨を報知部99により報知するように構成されている。
The refrigeration cycle system 10 also includes an alarm unit 99 having a display or a speaker. The system control device 21a is configured to notify the user by the alarm unit 99 that scale has accumulated when the difference Dab (or the difference Dac) deviates from a pre-stored difference value by a certain amount or more.
これにより、例えば定期点検の作業者は、熱交換器26のスケールが一定量以上となったことを知ることができ、報知された場合には熱交換器26の洗浄等の対処ができるので、スケールによる熱交換器26の詰まり又は熱交換効率の極端な低下といった異常の発生を回避できる。
As a result, for example, an operator performing regular inspections can know when the amount of scale on the heat exchanger 26 exceeds a certain amount, and when notified, can take measures such as cleaning the heat exchanger 26, thereby preventing abnormalities such as clogging of the heat exchanger 26 due to scale or an extreme drop in heat exchange efficiency.
実施の形態2.
図7は、本開示の実施の形態2に係る冷凍サイクルシステム110の概略構成を示す回路図である。実施の形態1の冷凍サイクルシステム10は単式ポンプシステムを採用したものであったが、実施の形態2の冷凍サイクルシステム110は複式ポンプシステムを採用したものである。また、実施の形態2の冷凍サイクルシステム110では、スケール堆積状態の判定に用いる第2検出部が、実施の形態1の場合とは異なる。図7に基づき、実施の形態2の冷凍サイクルシステム110の回路構成について説明する。本実施の形態2では、実施の形態1と同一の部分は同一の符合を付して説明を省略し、実施の形態1との相違点を中心に説明する。 Embodiment 2.
Fig. 7 is a circuit diagram showing a schematic configuration of arefrigeration cycle system 110 according to a second embodiment of the present disclosure. The refrigeration cycle system 10 of the first embodiment employs a single pump system, whereas the refrigeration cycle system 110 of the second embodiment employs a dual pump system. In addition, in the refrigeration cycle system 110 of the second embodiment, the second detection unit used to determine the scale accumulation state is different from that in the first embodiment. The circuit configuration of the refrigeration cycle system 110 of the second embodiment will be described with reference to Fig. 7. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals and description thereof will be omitted, and differences from the first embodiment will be mainly described.
図7は、本開示の実施の形態2に係る冷凍サイクルシステム110の概略構成を示す回路図である。実施の形態1の冷凍サイクルシステム10は単式ポンプシステムを採用したものであったが、実施の形態2の冷凍サイクルシステム110は複式ポンプシステムを採用したものである。また、実施の形態2の冷凍サイクルシステム110では、スケール堆積状態の判定に用いる第2検出部が、実施の形態1の場合とは異なる。図7に基づき、実施の形態2の冷凍サイクルシステム110の回路構成について説明する。本実施の形態2では、実施の形態1と同一の部分は同一の符合を付して説明を省略し、実施の形態1との相違点を中心に説明する。 Embodiment 2.
Fig. 7 is a circuit diagram showing a schematic configuration of a
図7に示されるように、複式ポンプシステムを採用した冷凍サイクルシステム110では、熱媒体回路140の熱源側の回路部分及び負荷側の回路部分のそれぞれに、ポンプが設けられる。以下、熱源側の回路部分に設けられたポンプを熱源側ポンプ30と称し、負荷側の回路部分に設けられたポンプを負荷側ポンプ144と称する。実施の形態2では、熱媒体回路140において負荷側の回路部分をバイパスするすなわち複数の負荷装置70をバイパスする配管は、バイパス弁81(図1参照)が無いフリーバイパス配管180である。
As shown in FIG. 7, in a refrigeration cycle system 110 employing a dual pump system, a pump is provided in each of the heat source side circuit portion and the load side circuit portion of the heat medium circuit 140. Hereinafter, the pump provided in the heat source side circuit portion is referred to as the heat source side pump 30, and the pump provided in the load side circuit portion is referred to as the load side pump 144. In the second embodiment, the piping that bypasses the load side circuit portion in the heat medium circuit 140, i.e., that bypasses the multiple load devices 70, is a free bypass piping 180 that does not have a bypass valve 81 (see FIG. 1).
熱媒体回路140における熱源側の回路部分の構成は、図1に示した実施の形態1の場合と同様である。熱源側の回路部分は、それぞれに熱交換器26及び熱源側ポンプ30が設けられた複数の熱源側枝管140aと、複数の熱源側枝管140aの各上流側端部が接続される第1還水側ヘッダ管142aと、複数の熱源側枝管140aの各下流側端部が接続される第1往水側ヘッダ管141aとを有する。
The configuration of the heat source side circuit portion of the heat medium circuit 140 is the same as in the first embodiment shown in FIG. 1. The heat source side circuit portion has a plurality of heat source side branch pipes 140a, each of which is provided with a heat exchanger 26 and a heat source side pump 30, a first return water side header pipe 142a to which the upstream ends of the plurality of heat source side branch pipes 140a are connected, and a first supply water side header pipe 141a to which the downstream ends of the plurality of heat source side branch pipes 140a are connected.
熱媒体回路140における負荷側の回路部分は、図1に示した実施の形態1の場合と同様、それぞれに負荷装置70及び負荷側膨張弁71が設けられる複数の負荷側枝管140bと、複数の負荷側枝管140bの各下流側端部が接続される第2還水側ヘッダ管142bと、この第2還水側ヘッダ管142bと熱源機の側の第1還水側ヘッダ管142aとを接続する合流管140cと、合流管140cに設けられた負荷側流量計73とを有する。ただし、実施の形態2の熱媒体回路140では、往水側ヘッダ管141は、熱源機(冷凍サイクル装置20)の側の第1往水側ヘッダ管141aと、負荷装置70の側の第2往水側ヘッダ管141bとを有し、第1往水側ヘッダ管141aと第2往水側ヘッダ管141bとは、負荷側ポンプ144が設けられる接続配管140dにより接続されている。
The load side circuit portion of the heat medium circuit 140, as in the first embodiment shown in FIG. 1, has a plurality of load side branch pipes 140b each provided with a load device 70 and a load side expansion valve 71, a second return water side header pipe 142b to which the downstream ends of the plurality of load side branch pipes 140b are connected, a junction pipe 140c connecting the second return water side header pipe 142b and the first return water side header pipe 142a on the heat source side, and a load side flow meter 73 provided on the junction pipe 140c. However, in the heat medium circuit 140 of the second embodiment, the forward water side header pipe 141 has a first forward water side header pipe 141a on the heat source side (refrigeration cycle device 20) side and a second forward water side header pipe 141b on the load device 70 side, and the first forward water side header pipe 141a and the second forward water side header pipe 141b are connected by a connection pipe 140d on which a load side pump 144 is provided.
図7の例では、冷凍サイクルシステム10は、4台の冷凍サイクル装置20により冷却された熱媒体を2台の負荷装置70に分配して循環させる構成とされる。詳しくは、熱媒体回路40は、4つの熱源側枝管40aと、第1往水側ヘッダ管141aと、3つの接続配管140dと、第2往水側ヘッダ管141bと、2つの負荷側枝管140bと、第2還水側ヘッダ管142bと、合流管140cと、第1還水側ヘッダ管142aとが順次接続された構成とされる。3つの接続配管140dのうち2つの接続配管140dには、熱源側の第1往水側ヘッダ管141aから負荷側の第2往水側ヘッダ管141bへ熱媒体を圧送する負荷側ポンプ144がそれぞれ設けられている。また、3つの接続配管140dのうち残りの1つの接続配管140dには、例えば比例二方弁である往水側膨張弁145が設けられている。
In the example of FIG. 7, the refrigeration cycle system 10 is configured to distribute and circulate the heat medium cooled by four refrigeration cycle devices 20 to two load devices 70. In detail, the heat medium circuit 40 is configured to sequentially connect four heat source side branch pipes 40a, a first water supply side header pipe 141a, three connection pipes 140d, a second water supply side header pipe 141b, two load side branch pipes 140b, a second return water side header pipe 142b, a junction pipe 140c, and a first return water side header pipe 142a. Two of the three connection pipes 140d are provided with load side pumps 144 that pump the heat medium from the first water supply side header pipe 141a on the heat source side to the second water supply side header pipe 141b on the load side. In addition, the remaining one of the three connection pipes 140d is provided with a forward water expansion valve 145, which is, for example, a proportional two-way valve.
システム制御装置21aは、負荷側流量計73と接続され、負荷側流量計73で検出された負荷側流量はシステム制御装置21aに入力される。また、システム制御装置21aには、負荷側ポンプ144及び往水側膨張弁145がそれぞれ接続され、システム制御装置21aは、負荷側ポンプ144の周波数及び往水側膨張弁145の開度を制御する構成となっている。
The system control device 21a is connected to a load side flow meter 73, and the load side flow rate detected by the load side flow meter 73 is input to the system control device 21a. In addition, the load side pump 144 and the forward water expansion valve 145 are each connected to the system control device 21a, and the system control device 21a is configured to control the frequency of the load side pump 144 and the opening of the forward water expansion valve 145.
熱媒体回路140において、フリーバイパス配管180は、熱源側の回路部分の両端部である第1往水側ヘッダ管141aと第1還水側ヘッダ管142aとを接続する。フリーバイパス配管180は、各負荷装置70に流れる熱媒体の流量よりも、各水熱交換器(熱交換器26)に流れる熱媒体の流量が多い場合に、各流量の差分に相当する熱媒体を、2つの負荷装置70をバイパスして第1往水側ヘッダ管141aから第1還水側ヘッダ管142aへ流通させる。
In the heat medium circuit 140, the free bypass piping 180 connects the first forward water header pipe 141a and the first return water header pipe 142a, which are both ends of the circuit portion on the heat source side. When the flow rate of the heat medium flowing through each water heat exchanger (heat exchanger 26) is greater than the flow rate of the heat medium flowing through each load device 70, the free bypass piping 180 allows the heat medium equivalent to the difference between the flow rates to bypass the two load devices 70 and circulate from the first forward water header pipe 141a to the first return water header pipe 142a.
また、実施の形態2の冷凍サイクルシステム110においても、実施の形態1の場合と同様、システム制御装置121aは、熱媒体回路140の状態を基に水熱交換器(熱交換器26)のスケール堆積状態を判定する。実施の形態1では、熱媒体回路40の状態として、熱交換器差圧検出部31により検出される熱交換器26の前後の差圧及びバイパス差圧検出部90により検出されるバイパス配管80の前後のバイパス差圧が用いられたが、実施の形態2では、熱媒体回路40の状態として、熱交換器差圧検出部31により検出される熱交換器26の前後の差圧及び負荷側流量計73により検出される負荷側を流れる熱媒体の流量(以下、負荷側流量ともいう)が用いられる。すなわち、実施の形態2では、第1検出部は熱交換器差圧検出部31であり、第2検出部は負荷側流量計73である。
In the refrigeration cycle system 110 of the second embodiment, as in the first embodiment, the system control device 121a determines the scale deposition state of the water heat exchanger (heat exchanger 26) based on the state of the heat medium circuit 140. In the first embodiment, the differential pressure before and after the heat exchanger 26 detected by the heat exchanger differential pressure detection unit 31 and the bypass differential pressure before and after the bypass piping 80 detected by the bypass differential pressure detection unit 90 are used as the state of the heat medium circuit 40, but in the second embodiment, the differential pressure before and after the heat exchanger 26 detected by the heat exchanger differential pressure detection unit 31 and the flow rate of the heat medium flowing on the load side detected by the load side flow meter 73 (hereinafter also referred to as the load side flow rate) are used as the state of the heat medium circuit 40. That is, in the second embodiment, the first detection unit is the heat exchanger differential pressure detection unit 31, and the second detection unit is the load side flow meter 73.
(冷凍サイクルシステム110の試運転時)
冷凍サイクルシステム110を構築した直後の試運転時には、水熱交換器(熱交換器26)にスケールが堆積していない。この初期状態において、システム制御装置121aは、複数の冷凍サイクル装置20の制御装置21から、それらの熱交換器差圧検出部31で検出された熱交換器26の前後の差圧(熱交換器差圧ΔPhex(i))を取得する。また、システム制御装置121aには、負荷側流量計73で検出された負荷側流量の実測値FBが入力される。 (During test run of the refrigeration cycle system 110)
During a trial run immediately after constructing therefrigeration cycle system 110, no scale has accumulated in the water heat exchanger (heat exchanger 26). In this initial state, the system control device 121a acquires the differential pressures (heat exchanger differential pressure ΔPhex(i)) across the heat exchanger 26 detected by the heat exchanger differential pressure detection units 31 from the control devices 21 of the multiple refrigeration cycle devices 20. In addition, the actual measured value FB of the load side flow rate detected by the load side flow meter 73 is input to the system control device 121a.
冷凍サイクルシステム110を構築した直後の試運転時には、水熱交換器(熱交換器26)にスケールが堆積していない。この初期状態において、システム制御装置121aは、複数の冷凍サイクル装置20の制御装置21から、それらの熱交換器差圧検出部31で検出された熱交換器26の前後の差圧(熱交換器差圧ΔPhex(i))を取得する。また、システム制御装置121aには、負荷側流量計73で検出された負荷側流量の実測値FBが入力される。 (During test run of the refrigeration cycle system 110)
During a trial run immediately after constructing the
システム制御装置121aは、まず、取得した複数の熱交換器差圧ΔPhex(i)から、式(1)~式(3)を用いて、バイパス差圧の計算値Aを算出する。すなわち、システム制御装置21aは、式(1)を用いて、取得した熱交換器差圧ΔPhex(i)から熱交換器26内を流れる流量、すなわち冷凍サイクル装置20を流れる流量Vw(i)を算出し、式(2)を用いて流量Vw(i)からポンプ揚程ΔPp(i)を算出し、ポンプ揚程ΔPp(i)及び熱交換器差圧ΔPhex(i)から、式(3)を用いてバイパス差圧の計算値Aを得る。
The system control device 121a first calculates the bypass differential pressure calculation value A from the acquired multiple heat exchanger differential pressures ΔPhex(i) using equations (1) to (3). That is, the system control device 21a calculates the flow rate through the heat exchanger 26, i.e., the flow rate Vw(i) through the refrigeration cycle device 20, from the acquired heat exchanger differential pressures ΔPhex(i) using equation (1), calculates the pump head ΔPp(i) from the flow rate Vw(i) using equation (2), and obtains the bypass differential pressure calculation value A from the pump head ΔPp(i) and the heat exchanger differential pressure ΔPhex(i) using equation (3).
そして、システム制御装置121aは、バイパス差圧の計算値Aと、予め学習しておいたフリーバイパス配管180のCv値(以下、Cvとする)とを用いて以下の式(5)から、フリーバイパス配管180を流れるバイパス流量を求め、計算値BFaを得る。
Then, the system control device 121a uses the calculated bypass differential pressure A and the previously learned Cv value (hereafter referred to as Cv) of the free bypass piping 180 to calculate the bypass flow rate through the free bypass piping 180 from the following formula (5), thereby obtaining the calculated value BFa.
BFa=Cv×(A[kPa]^0.5)・・・(5)
BFa = Cv x (A [kPa]^0.5) ... (5)
ここで、フリーバイパス配管180のCv値については、試運転時にCv値を学習して学習済みのCv値を取得しておく。フリーバイパス配管180のCv値は、故障時などの特別な場合を除いて基本的に変わることが無いので、試運転時に学習したものを運用開始後にも使うことができる。
Here, the Cv value of the free bypass piping 180 is learned during the trial run and the learned Cv value is obtained. The Cv value of the free bypass piping 180 basically does not change except in special cases such as when a failure occurs, so the value learned during the trial run can be used after the start of operation.
さらに、システム制御装置121aは、算出したバイパス流量の計算値BFaと、各冷凍サイクル装置20を流れる熱媒体の流量Vw(i)とを用いて、以下の式(6)から、負荷側を流れる負荷側流量を求め、計算値FAを得る。具体的には、各冷凍サイクル装置20に流れる熱媒体の流量Vw(i)を、冷凍サイクルシステム10の全ての冷凍サイクル装置20について合計した流量から、式(5)で得たバイパス流量の計算値BFaを減算することで、負荷側を流れる熱媒体の流量の計算値FAが得られる。
Furthermore, the system control device 121a uses the calculated bypass flow rate BFa and the flow rate Vw(i) of the heat medium flowing through each refrigeration cycle device 20 to determine the load side flow rate flowing through the load side from the following equation (6), obtaining a calculated value FA. Specifically, the flow rate Vw(i) of the heat medium flowing through each refrigeration cycle device 20 is calculated by subtracting the calculated bypass flow rate BFa obtained from equation (5) from the total flow rate for all refrigeration cycle devices 20 in the refrigeration cycle system 10, thereby obtaining the calculated flow rate FA of the heat medium flowing through the load side.
FA=Total(Vw(i))-BFa・・・(6)
FA = Total (Vw(i)) - BFa ... (6)
システム制御装置21aは、式(6)で得た負荷側流量の計算値FA、すなわち熱媒体回路40の熱源側の回路部分の状態から求めた負荷側流量と、負荷側流量計73で検出された負荷側流量の実測値FBとの差分を算出し、算出した差分を初期状態の差分Dfab_0として記憶する。
The system control device 21a calculates the difference between the calculated value FA of the load side flow rate obtained by equation (6), i.e., the load side flow rate obtained from the state of the circuit portion on the heat source side of the heat medium circuit 40, and the actual measured value FB of the load side flow rate detected by the load side flow meter 73, and stores the calculated difference as the initial state difference Dfab_0.
(冷凍サイクルシステム110の稼働時)
冷凍サイクルシステム110の運用開始後の稼働時、熱交換器26のスケールの堆積量は次第に増加する。冷凍サイクルシステム110の運用開始後の稼働時、システム制御装置121aは、試運転時と同様に、各熱交換器差圧ΔPhex(i)と負荷側流量の実測値FBとを取得し、負荷側流量の計算値FAを算出し、計算値FAと実測値FBとの差分Dfabを求める。そして、冷凍サイクルシステム110の運用開始後の稼働時には、システム制御装置121aは、稼働時に得た差分Dfabと試運転時に得た差分Dfab_0と比較することにより、複数の熱交換器26に対するスケールの堆積状態を判定する。 (When therefrigeration cycle system 110 is in operation)
During operation of therefrigeration cycle system 110 after the start of operation, the amount of scale buildup in the heat exchanger 26 gradually increases. During operation of the refrigeration cycle system 110 after the start of operation, the system control device 121a acquires each heat exchanger differential pressure ΔPhex(i) and the actual measured value FB of the load side flow rate, calculates a calculated value FA of the load side flow rate, and obtains a difference Dfab between the calculated value FA and the actual measured value FB, as in the case of the test run. During operation of the refrigeration cycle system 110 after the start of operation, the system control device 121a compares the difference Dfab obtained during operation with the difference Dfab_0 obtained during the test run to determine the scale buildup state for the multiple heat exchangers 26.
冷凍サイクルシステム110の運用開始後の稼働時、熱交換器26のスケールの堆積量は次第に増加する。冷凍サイクルシステム110の運用開始後の稼働時、システム制御装置121aは、試運転時と同様に、各熱交換器差圧ΔPhex(i)と負荷側流量の実測値FBとを取得し、負荷側流量の計算値FAを算出し、計算値FAと実測値FBとの差分Dfabを求める。そして、冷凍サイクルシステム110の運用開始後の稼働時には、システム制御装置121aは、稼働時に得た差分Dfabと試運転時に得た差分Dfab_0と比較することにより、複数の熱交換器26に対するスケールの堆積状態を判定する。 (When the
During operation of the
図8は、図7のシステム制御装置121aが行うスケール堆積判定のフローチャートである。図8に基づき、冷凍サイクルシステム110の運用開始後の稼働時においてシステム制御装置121aが行うスケール堆積判定のフローについて説明する。冷凍サイクルシステム110の稼働時に、システム制御装置121aは、複数の冷凍サイクル装置20の制御装置21から、熱交換器差圧検出部31(図2参照)で検出された熱交換器差圧ΔPhex(i)を取得する(ステップS20)。また、システム制御装置121aは、複数の冷凍サイクル装置20の制御装置21から、それらの熱源側ポンプ30の運転周波数Fp(すなわち回転数)を取得する。また、システム制御装置121aには、負荷側流量計73から、負荷側の合流管40cを流れる熱媒体の流量すなわち負荷側流量の実測値FBが入力される。
FIG. 8 is a flow chart of the scale deposition determination performed by the system control device 121a of FIG. 7. Based on FIG. 8, the flow of the scale deposition determination performed by the system control device 121a during operation after the start of operation of the refrigeration cycle system 110 will be described. During operation of the refrigeration cycle system 110, the system control device 121a acquires the heat exchanger differential pressure ΔPhex(i) detected by the heat exchanger differential pressure detection unit 31 (see FIG. 2) from the control devices 21 of the multiple refrigeration cycle devices 20 (step S20). In addition, the system control device 121a acquires the operating frequency Fp (i.e., the rotation speed) of the heat source side pump 30 from the control devices 21 of the multiple refrigeration cycle devices 20. In addition, the system control device 121a receives the flow rate of the heat medium flowing through the load side junction pipe 40c, i.e., the actual measured value FB of the load side flow rate, from the load side flow meter 73.
システム制御装置121aは、各冷凍サイクル装置20について、熱交換器差圧ΔPhex(i)から熱交換器26を流れる熱媒体の流量、即ち冷凍サイクル装置20を流れる熱媒体の流量Vw(i)を、式(1)を用いて算出する(ステップS21)。さらに、システム制御装置121aは、ステップS21で算出された流量Vw(i)、及び取得した熱源側ポンプ30の運転周波数Fp(すなわち回転数)から、式(2)を用いてポンプ揚程ΔPp(i)を算出する(ステップS22)。システム制御装置121aは、各冷凍サイクル装置20についてステップS11及びS22の演算を行い、ステップS22で算出されたポンプ揚程ΔPp(i)及びステップS20で取得した熱交換器差圧ΔPhex(i)から、式(3)を用いてバイパス差圧の計算値Aを得る(ステップS23)。さらに、システム制御装置121aは、バイパス差圧の計算値A、及び予め学習しておいたフリーバイパス配管180のCv値から、式(5)を用いてバイパス流量を求め、計算値BFaを得る(ステップS23)。システム制御装置121aは、各冷凍サイクル装置20についてステップS21で算出された流量Vw(i)、及びステップS23で算出されたバイパス流量の計算値BFaから、式(6)を用いて負荷側流量を求め、計算値FAを得る(ステップS24)。
The system control device 121a calculates the flow rate of the heat medium flowing through the heat exchanger 26 from the heat exchanger differential pressure ΔPhex(i) for each refrigeration cycle device 20, i.e., the flow rate Vw(i) of the heat medium flowing through the refrigeration cycle device 20, using formula (1) (step S21). Furthermore, the system control device 121a calculates the pump head ΔPp(i) using formula (2) from the flow rate Vw(i) calculated in step S21 and the operating frequency Fp (i.e., the rotation speed) of the heat source side pump 30 obtained (step S22). The system control device 121a performs the calculations of steps S11 and S22 for each refrigeration cycle device 20, and obtains the bypass differential pressure calculation value A using formula (3) from the pump head ΔPp(i) calculated in step S22 and the heat exchanger differential pressure ΔPhex(i) obtained in step S20 (step S23). Furthermore, the system control device 121a calculates the bypass flow rate using equation (5) from the calculated bypass differential pressure A and the previously learned Cv value of the free bypass piping 180, and obtains the calculated value BFa (step S23). The system control device 121a calculates the load side flow rate using equation (6) from the flow rate Vw(i) calculated in step S21 for each refrigeration cycle device 20 and the calculated bypass flow rate BFa calculated in step S23, and obtains the calculated value FA (step S24).
ここで得られる負荷側流量の計算値FAは、このときの複数の冷凍サイクル装置20の熱交換器26における熱媒体の流路の状態を反映したものとなる。複数の冷凍サイクル装置20の熱交換器26においてスケールの堆積量が増加すると、摩擦等によりそれら熱交換器26内での熱媒体の水頭損失(すなわち、熱交換器差圧ΔPhex(i))が大きくなるので流量[m3/h]が増加し、熱源側ポンプ30の揚程圧力P(すなわち、ポンプ揚程ΔPp(i))が小さくなる。したがって、スケールの堆積量が増えると、ポンプ揚程ΔPp(i)が小さくなり、且つ熱交換器差圧ΔPhex(i)が大きくなるので、バイパス差圧の計算値Aは小さくなり、負荷側流量の計算値FAは大きくなる。
The calculated load side flow rate FA obtained here reflects the state of the flow path of the heat medium in the heat exchangers 26 of the multiple refrigeration cycle devices 20 at this time. When the amount of scale deposition increases in the heat exchangers 26 of the multiple refrigeration cycle devices 20, the head loss of the heat medium in the heat exchangers 26 (i.e., the heat exchanger differential pressure ΔPhex(i)) increases due to friction, etc., so the flow rate [ m3 /h] increases and the head pressure P of the heat source side pump 30 (i.e., the pump head ΔPp(i)) decreases. Therefore, when the amount of scale deposition increases, the pump head ΔPp(i) decreases and the heat exchanger differential pressure ΔPhex(i) increases, so the calculated bypass differential pressure A decreases and the calculated load side flow rate FA increases.
システム制御装置121aは、ステップS24で算出して得た負荷側流量の計算値FAと、負荷側流量計73で検出された負荷側流量の実測値FBとの差分Dfabを算出する(ステップS25)。そして、システム制御装置121aは、稼働時に得たこの差分Dfabが、予め記憶された差分Dfab_0(すなわち初期状態で取得しておいた差分Dfab_0)から一定量以上乖離しているか否かを判定する(ステップS26)。稼働時の差分Dfabが初期状態の差分Dfab_0から一定量以上乖離する場合には(ステップS26;YES)、システム制御装置121aは、冷凍サイクルシステム110の複数の熱交換器26に一定量以上のスケールが堆積しているものと判断して報知部99等によりその旨を報知する(ステップS27)。
The system controller 121a calculates the difference Dfab between the calculated load side flow rate FA calculated in step S24 and the actual load side flow rate FB detected by the load side flow meter 73 (step S25). The system controller 121a then determines whether this difference Dfab obtained during operation deviates by a certain amount or more from the previously stored difference Dfab_0 (i.e., the difference Dfab_0 obtained in the initial state) (step S26). If the difference Dfab during operation deviates by a certain amount or more from the difference Dfab_0 in the initial state (step S26; YES), the system controller 121a determines that a certain amount or more of scale has accumulated in the multiple heat exchangers 26 of the refrigeration cycle system 110 and notifies the same via the notification unit 99 or the like (step S27).
ここで、稼働時の差分Dfabが初期状態の差分Dfab_0から一定量以上乖離する場合とは、稼働時の差分Dfabから初期状態の差分Dfab_0を減算した値の正負は問わず、その値の絶対値で判断してよい。
Here, when the difference Dfab during operation deviates from the difference Dfab_0 in the initial state by a certain amount or more, this can be determined by the absolute value of the difference Dfab during operation minus the difference Dfab_0 in the initial state, regardless of whether the difference is positive or negative.
このように、複式ポンプシステムである実施の形態2の冷凍サイクルシステム110では、運用開始後の稼働時に、システム制御装置21aは、負荷側流量の計算値FAと実測値FBとの差分Dfabを算出し、算出された稼働時の差分Dfabと、試運転時に予め算出し記憶しておいた初期状態の差分Dfab_0とを比較することで、その比較結果により、経年的な熱交換器26へのスケールの堆積状態が判定できる。
In this way, in the refrigeration cycle system 110 of embodiment 2, which is a dual pump system, during operation after the start of operation, the system control device 21a calculates the difference Dfab between the calculated load side flow rate FA and the measured value FB, and compares the calculated difference Dfab during operation with the initial state difference Dfab_0 calculated and stored in advance during trial operation, and the state of scale buildup on the heat exchanger 26 over time can be determined based on the comparison result.
なお、負荷側流量の実測値FBの代わりに、計算値FAとは別の方法で求めた負荷側流量の計算値FCを用いて、スケール堆積判定を行うこともできる。例えば、図6に示したように、各冷凍サイクル装置20の熱源側枝管40aに熱交換器差圧検出部31及びポンプ差圧検出部32を設け、これらの検出値を用いて式(4)~(6)から、負荷側流量の計算値FCが得られる。システム制御装置121aは、式(1)~(3)、(5)及び(6)から得た負荷側流量の計算値FAと、負荷側流量の計算値FCとの差分Dfacを算出し、この差分Dfacが、試運転時に算出しておいた差分Dfac_0から一定量以上乖離している場合に、冷凍サイクルシステム110の複数の熱交換器26に一定量以上のスケールが堆積しているものと判断し、報知部99等によりその旨を報知する。
In addition, instead of the measured value FB of the load side flow rate, the calculated value FC of the load side flow rate obtained by a method other than the calculated value FA can be used to determine the accumulation of scale. For example, as shown in FIG. 6, a heat exchanger differential pressure detection unit 31 and a pump differential pressure detection unit 32 are provided in the heat source side branch pipe 40a of each refrigeration cycle device 20, and the calculated value FC of the load side flow rate is obtained from equations (4) to (6) using these detection values. The system control device 121a calculates the difference Dfac between the calculated value FA of the load side flow rate obtained from equations (1) to (3), (5), and (6) and the calculated value FC of the load side flow rate. If this difference Dfac deviates by a certain amount or more from the difference Dfac_0 calculated during the trial operation, it is determined that a certain amount or more of scale has accumulated in the multiple heat exchangers 26 of the refrigeration cycle system 110, and the notification unit 99 or the like notifies the fact.
以上のように、実施の形態2に係る冷凍サイクルシステム110は、圧縮機22を有し、圧縮機22により冷媒が循環する冷媒回路27と、熱源側ポンプ30及び負荷側ポンプ144を有し、熱源側ポンプ30及び負荷側ポンプ144により熱媒体が循環する熱媒体回路40と、冷媒と熱媒体との間で熱交換を行う熱交換器26と、熱源側ポンプ30を制御するシステム制御装置121aと、を備える。熱媒体回路40は、熱交換器26の下流側に設けられる負荷装置と70、負荷装置70をバイパスするフリーバイパス配管180とを有したものである。熱源側ポンプ30は、熱交換器26に熱媒体を圧送するものであり、負荷側ポンプ144は、負荷装置70に熱媒体を圧送するものである。また、冷凍サイクルシステム110は、熱媒体回路40に設けられ、熱交換器26の前後の差圧を検出する第1検出部(熱交換器差圧検出部31)と、熱媒体回路40の負荷側に設けられ、熱媒体の負荷側流量を検出する第2検出部(負荷側流量計73)と、備える。システム制御装置121aは、第1検出部により検出された差圧(熱交換器差圧ΔPhex(i))と、熱源側ポンプ30の回転数(例えば、運転周波数Fp)から熱源側ポンプ30の揚程(ΔPp(i))を求め、差圧(熱交換器差圧ΔPhex(i))及び揚程(ΔPp(i))に基づき熱媒体回路40の負荷側に流れる熱媒体の負荷側流量を算出する。システム制御装置121aは、算出された負荷側流量の計算値FAと、第2検出部により検出された負荷側流量の実測値FBとの差分Dfabを、予め記憶された差分値(例えば、初期状態の差分Dfab_0)と比較することにより熱交換器26のスケールの堆積状態を判定する。
As described above, the refrigeration cycle system 110 according to the second embodiment includes a refrigerant circuit 27 having a compressor 22 and in which a refrigerant is circulated by the compressor 22, a heat medium circuit 40 having a heat source side pump 30 and a load side pump 144 and in which a heat medium is circulated by the heat source side pump 30 and the load side pump 144, a heat exchanger 26 that exchanges heat between the refrigerant and the heat medium, and a system control device 121a that controls the heat source side pump 30. The heat medium circuit 40 includes a load device 70 provided downstream of the heat exchanger 26, and a free bypass piping 180 that bypasses the load device 70. The heat source side pump 30 pumps the heat medium to the heat exchanger 26, and the load side pump 144 pumps the heat medium to the load device 70. The refrigeration cycle system 110 further includes a first detector (heat exchanger differential pressure detector 31) provided in the heat medium circuit 40 for detecting a pressure difference between before and after the heat exchanger 26, and a second detector (load side flow meter 73) provided on the load side of the heat medium circuit 40 for detecting a load side flow rate of the heat medium. The system control device 121a obtains the head (ΔPp(i)) of the heat source side pump 30 from the pressure difference (heat exchanger differential pressure ΔPhex(i)) detected by the first detector and the rotation speed (e.g., operating frequency Fp) of the heat source side pump 30, and calculates the load side flow rate of the heat medium flowing on the load side of the heat medium circuit 40 based on the pressure difference (heat exchanger differential pressure ΔPhex(i)) and the head (ΔPp(i)). The system control device 121a determines the scale buildup state of the heat exchanger 26 by comparing the difference Dfab between the calculated load side flow rate FA and the actual load side flow rate FB detected by the second detection unit with a pre-stored difference value (e.g., the difference Dfab_0 in the initial state).
このように、実施の形態2に係る冷凍サイクルシステム110では、熱媒体回路40に設けられた第1検出部及び第2検出部を用いて異なる方法で得た負荷側流量の計算値Aと実測値Bとの差分Dfabを、予め記憶された差分値と比較することにより熱交換器26のスケールの堆積状態が判定される。そして、第1検出部及び第2検出部はいずれもスケールの堆積する熱媒体回路40に設けられるので、それらの検出値(熱交換器差圧ΔPhex(i)及び負荷側流量の実測値FB)を用いて得られる、負荷側流量の計算値FAと実測値FBとの差分Dfabに基づき熱交換器26のスケールの堆積状態を判定する本開示の構成では、従来のように冷媒の飽和温度と熱交換器から流出する熱媒体の温度との温度差に基づき熱交換器のスケールの堆積状態を判定する構成と比べて、負荷変動及び運転条件の変動による影響が少ない、より正確な判定を行うことができる。
In this way, in the refrigeration cycle system 110 according to the second embodiment, the difference Dfab between the calculated value A and the measured value B of the load side flow rate obtained by different methods using the first and second detection units provided in the heat medium circuit 40 is compared with the difference value stored in advance to determine the scale accumulation state of the heat exchanger 26. Since both the first and second detection units are provided in the heat medium circuit 40 where scale accumulates, the configuration of the present disclosure, which determines the scale accumulation state of the heat exchanger 26 based on the difference Dfab between the calculated value FA and the measured value FB of the load side flow rate obtained using these detection values (heat exchanger differential pressure ΔPhex(i) and the measured value FB of the load side flow rate), can perform a more accurate determination that is less affected by fluctuations in load and operating conditions than a conventional configuration in which the scale accumulation state of the heat exchanger is determined based on the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the heat exchanger.
また、実施の形態2の冷凍サイクルシステム110の変形例(図6参照)は、圧縮機22を有し、圧縮機22により冷媒が循環する冷媒回路27と、熱源側ポンプ30及び負荷側ポンプ144を有し、熱源側ポンプ30及び負荷側ポンプ144により熱媒体が循環する熱媒体回路40と、冷媒と熱媒体との間で熱交換を行う熱交換器26と、熱源側ポンプ30を制御するシステム制御装置121aと、を備える。熱媒体回路40は、熱交換器26の下流側に設けられる負荷装置と70、負荷装置70をバイパスするフリーバイパス配管180とを有したものである。熱源側ポンプ30は、熱交換器26に熱媒体を圧送するものであり、負荷側ポンプ144は、負荷装置70に熱媒体を圧送するものである。また、冷凍サイクルシステム110は、熱媒体回路40に設けられ、熱交換器26の前後の差圧を検出する第1検出部(熱交換器差圧検出部31)と、熱媒体回路40に設けられ、熱源側ポンプ30の前後のポンプ差圧を検出する第2検出部(ポンプ差圧検出部32)と、を備える。システム制御装置121aは、第1検出部により検出された差圧(熱交換器差圧ΔPhex(i))と、熱源側ポンプ30の回転数(例えば、運転周波数Fp)から熱源側ポンプ30の揚程(ΔPp(i))を求め、差圧(熱交換器差圧ΔPhex(i))及び揚程(ΔPp(i))に基づき熱媒体回路40の負荷側に流れる熱媒体の負荷側流量を算出して第1計算値(計算値FA)を得るとともに、第1検出部により検出された差圧及び第2検出部により検出されたポンプ差圧(揚程の実測値ΔPp_a(i))に基づき熱媒体回路40の負荷側に流れる熱媒体の負荷側流量を算出して第2計算値(計算値FC)を得る。そして、システム制御装置121aは、負荷側流量の第1計算値と第2計算値との差分Dfacを、予め記憶された差分値(初期状態の差分Dfac_0)と比較することにより熱交換器26のスケールの堆積状態を判定する。
Also, a modified example of the refrigeration cycle system 110 of the second embodiment (see FIG. 6) includes a refrigerant circuit 27 having a compressor 22 and circulating a refrigerant by the compressor 22, a heat medium circuit 40 having a heat source side pump 30 and a load side pump 144 and circulating a heat medium by the heat source side pump 30 and the load side pump 144, a heat exchanger 26 that exchanges heat between the refrigerant and the heat medium, and a system control device 121a that controls the heat source side pump 30. The heat medium circuit 40 includes a load device 70 provided downstream of the heat exchanger 26, and a free bypass piping 180 that bypasses the load device 70. The heat source side pump 30 pumps the heat medium to the heat exchanger 26, and the load side pump 144 pumps the heat medium to the load device 70. The refrigeration cycle system 110 also includes a first detection unit (heat exchanger differential pressure detection unit 31) provided in the heat medium circuit 40 for detecting the differential pressure before and after the heat exchanger 26, and a second detection unit (pump differential pressure detection unit 32) provided in the heat medium circuit 40 for detecting the pump differential pressure before and after the heat source side pump 30. The system control device 121a determines the head (ΔPp(i)) of the heat source side pump 30 from the differential pressure (heat exchanger differential pressure ΔPhex(i)) detected by the first detection unit and the rotation speed (e.g., operating frequency Fp) of the heat source side pump 30, calculates the load side flow rate of the heat medium flowing on the load side of the heat medium circuit 40 based on the differential pressure (heat exchanger differential pressure ΔPhex(i)) and the head (ΔPp(i)) to obtain a first calculated value (calculated value FA), and calculates the load side flow rate of the heat medium flowing on the load side of the heat medium circuit 40 based on the differential pressure detected by the first detection unit and the pump differential pressure (actual measured head value ΔPp_a(i)) detected by the second detection unit to obtain a second calculated value (calculated value FC). Then, the system control device 121a determines the scale buildup state of the heat exchanger 26 by comparing the difference Dfac between the first and second calculated values of the load side flow rate with a previously stored difference value (the initial state difference Dfac_0).
このように、冷凍サイクルシステム110の変形例(図6参照)では、熱媒体回路40に設けられた第1検出部及び第2検出部を用いて異なる方法で得た負荷側流量の第1計算値(計算値FA)と第2計算値(計算値FC)との差分Dfacを、予め記憶された差分値(初期状態の差分Dfac_0)と比較することにより熱交換器26のスケールの堆積状態が判定される。そして、第1検出部及び第2検出部はいずれもスケールの堆積する熱媒体回路40に設けられるので、それらの検出値(熱交換器差圧ΔPhex(i)及び揚程の実測値ΔPp_a(i))を用いて得られる、負荷側流量の第1計算値と第2計算値との差分Dfacに基づき熱交換器26のスケールの堆積状態を判定する本開示の構成では、従来のように冷媒の飽和温度と熱交換器から流出する熱媒体の温度との温度差に基づき熱交換器のスケールの堆積状態を判定する構成と比べて、負荷変動及び運転条件の変動による影響が少なく、より正確な判定を行うことができる。
In this way, in the modified example of the refrigeration cycle system 110 (see FIG. 6), the difference Dfac between the first calculated value (calculated value FA) and the second calculated value (calculated value FC) of the load side flow rate obtained by different methods using the first and second detection units provided in the heat medium circuit 40 is compared with a pre-stored difference value (initial state difference Dfac_0) to determine the scale accumulation state of the heat exchanger 26. Since both the first and second detection units are provided in the heat medium circuit 40 where scale accumulates, the configuration of the present disclosure, which determines the scale accumulation state of the heat exchanger 26 based on the difference Dfac between the first and second calculated values of the load side flow rate obtained using the detection values (heat exchanger differential pressure ΔPhex(i) and actual head value ΔPp_a(i)), is less affected by load fluctuations and fluctuations in operating conditions and can perform more accurate determinations than the conventional configuration in which the scale accumulation state of the heat exchanger is determined based on the temperature difference between the saturation temperature of the refrigerant and the temperature of the heat medium flowing out of the heat exchanger.
10、110 冷凍サイクルシステム、20 冷凍サイクル装置、21 制御装置、21a、121a システム制御装置、22 圧縮機、24 熱交換器、25 減圧装置、26 熱交換器、27 冷媒回路、28 ファン、30 熱源側ポンプ、31 熱交換器差圧検出部、32 ポンプ差圧検出部、40、140 熱媒体回路、40a、140a 熱源側枝管、40b、140b 負荷側枝管、40c、140c 合流管、41、141 往水側ヘッダ管、42a、142a 第1還水側ヘッダ管、42b、142b 第2還水側ヘッダ管、70 負荷装置、71 負荷側膨張弁、73 負荷側流量計、80 バイパス配管、81 バイパス弁、90 バイパス差圧検出部、99 報知部、140d 接続配管、141a 第1往水側ヘッダ管、141b 第2往水側ヘッダ管、144 負荷側ポンプ、145 往水側膨張弁、180 フリーバイパス配管。
10, 110 refrigeration cycle system, 20 refrigeration cycle device, 21 control device, 21a, 121a system control device, 22 compressor, 24 heat exchanger, 25 pressure reducing device, 26 heat exchanger, 27 refrigerant circuit, 28 fan, 30 heat source side pump, 31 heat exchanger differential pressure detection unit, 32 pump differential pressure detection unit, 40, 140 heat medium circuit, 40a, 140a heat source side branch pipe, 40b, 140b load side branch pipe, 40c, 140c junction pipe, 4 1, 141 forward water header pipe, 42a, 142a first return water header pipe, 42b, 142b second return water header pipe, 70 load device, 71 load expansion valve, 73 load flow meter, 80 bypass piping, 81 bypass valve, 90 bypass differential pressure detector, 99 alarm, 140d connection piping, 141a first forward water header pipe, 141b second forward water header pipe, 144 load pump, 145 forward water expansion valve, 180 free bypass piping.
Claims (7)
- 圧縮機を有し、前記圧縮機により冷媒が循環する冷媒回路と、熱源側ポンプを有し、前記熱源側ポンプにより熱媒体が循環する熱媒体回路と、前記冷媒と前記熱媒体との間で熱交換を行う熱交換器と、前記熱源側ポンプを制御するシステム制御装置と、を備え、前記熱媒体回路は、前記熱交換器の下流側に設けられる負荷装置と、前記負荷装置をバイパスするバイパス配管とを有したものである冷凍サイクルシステムにおいて、
前記熱媒体回路に設けられ、前記熱交換器の前後の差圧を検出する第1検出部と、
前記熱媒体回路に設けられ、前記バイパス配管の前後のバイパス差圧を検出する第2検出部と、を備え、
前記システム制御装置は、
前記第1検出部により検出された前記差圧と、前記熱源側ポンプの回転数から前記熱源側ポンプの揚程を求め、前記差圧及び前記揚程に基づき前記バイパス配管の前後の前記バイパス差圧を算出し、
算出された前記バイパス差圧の計算値と、前記第2検出部により検出された前記バイパス差圧の実測値との差分を、予め記憶された差分値と比較することにより前記熱交換器のスケールの堆積状態を判定する
冷凍サイクルシステム。 A refrigeration cycle system comprising: a refrigerant circuit having a compressor and in which a refrigerant is circulated by the compressor; a heat medium circuit having a heat source side pump and in which a heat medium is circulated by the heat source side pump; a heat exchanger performing heat exchange between the refrigerant and the heat medium; and a system control device controlling the heat source side pump, wherein the heat medium circuit has a load device provided downstream of the heat exchanger and a bypass piping that bypasses the load device,
A first detection unit provided in the heat medium circuit and configured to detect a pressure difference before and after the heat exchanger;
a second detection unit provided in the heat medium circuit and configured to detect a bypass differential pressure before and after the bypass piping;
The system control device includes:
determining a head of the heat source side pump from the differential pressure detected by the first detection unit and a rotation speed of the heat source side pump, and calculating the bypass differential pressure before and after the bypass piping based on the differential pressure and the head;
a difference between the calculated value of the bypass differential pressure and the actual measured value of the bypass differential pressure detected by the second detection unit, with a pre-stored difference value, thereby determining a scale deposition state of the heat exchanger. - 圧縮機を有し、前記圧縮機により冷媒が循環する冷媒回路と、熱源側ポンプを有し、前記熱源側ポンプにより熱媒体が循環する熱媒体回路と、前記冷媒と前記熱媒体との間で熱交換を行う熱交換器と、前記熱源側ポンプを制御するシステム制御装置と、を備え、前記熱媒体回路は、前記熱交換器の下流側に設けられる負荷装置と、前記負荷装置をバイパスするバイパス配管とを有したものである冷凍サイクルシステムにおいて、
前記熱媒体回路に設けられ、前記熱交換器の前後の差圧を検出する第1検出部と、
前記熱媒体回路に設けられ、前記熱源側ポンプの前後のポンプ差圧を検出する第2検出部と、を備え、
前記システム制御装置は、
前記第1検出部により検出された前記差圧と、前記熱源側ポンプの回転数から前記熱源側ポンプの揚程を求め、前記差圧及び前記揚程に基づき前記バイパス配管の前後のバイパス差圧を算出して第1計算値を得るとともに、前記第1検出部により検出された前記差圧及び前記第2検出部により検出された前記ポンプ差圧に基づき前記バイパス配管の前後の前記バイパス差圧を算出して第2計算値を得、
前記バイパス差圧の前記第1計算値と前記第2計算値との差分を、予め記憶された差分値と比較することにより前記熱交換器のスケールの堆積状態を判定する
冷凍サイクルシステム。 A refrigeration cycle system comprising: a refrigerant circuit having a compressor and in which a refrigerant is circulated by the compressor; a heat medium circuit having a heat source side pump and in which a heat medium is circulated by the heat source side pump; a heat exchanger performing heat exchange between the refrigerant and the heat medium; and a system control device controlling the heat source side pump, wherein the heat medium circuit has a load device provided downstream of the heat exchanger and a bypass piping that bypasses the load device,
A first detection unit provided in the heat medium circuit and configured to detect a pressure difference before and after the heat exchanger;
a second detection unit provided in the heat medium circuit and detecting a pump pressure difference between before and after the heat source pump;
The system control device includes:
determining a head of the heat source side pump from the differential pressure detected by the first detection unit and a rotation speed of the heat source side pump, calculating a bypass differential pressure before and after the bypass piping based on the differential pressure and the head to obtain a first calculated value, and calculating the bypass differential pressure before and after the bypass piping based on the differential pressure detected by the first detection unit and the pump differential pressure detected by the second detection unit to obtain a second calculated value;
a difference between the first calculated value and the second calculated value of the bypass differential pressure is compared with a pre-stored difference value to determine a scale build-up state of the heat exchanger. - 圧縮機を有し、前記圧縮機により冷媒が循環する冷媒回路と、熱源側ポンプ及び負荷側ポンプを有し、前記熱源側ポンプ及び前記負荷側ポンプにより熱媒体が循環する熱媒体回路と、前記冷媒と前記熱媒体との間で熱交換を行う熱交換器と、前記熱源側ポンプを制御するシステム制御装置と、を備え、前記熱媒体回路は、前記熱交換器の下流側に設けられる負荷装置と、前記負荷装置をバイパスするフリーバイパス配管とを有したものであり、前記熱源側ポンプは、前記熱交換器に前記熱媒体を圧送するものであり、前記負荷側ポンプは、前記負荷装置に前記熱媒体を圧送するものである冷凍サイクルシステムにおいて、
前記熱媒体回路に設けられ、前記熱交換器の前後の差圧を検出する第1検出部と、
前記熱媒体回路の負荷側に設けられ、前記熱媒体の負荷側流量を検出する第2検出部と、備え、
前記システム制御装置は、
前記第1検出部により検出された前記差圧と、前記熱源側ポンプの回転数から前記熱源側ポンプの揚程を求め、前記差圧及び前記揚程に基づき前記熱媒体回路の負荷側に流れる前記熱媒体の前記負荷側流量を算出し、
算出された前記負荷側流量の計算値と、前記第2検出部により検出された前記負荷側流量の実測値との差分を、予め記憶された差分値と比較することにより前記熱交換器のスケールの堆積状態を判定する
冷凍サイクルシステム。 A refrigeration cycle system comprising: a refrigerant circuit having a compressor, in which a refrigerant is circulated by the compressor; a heat medium circuit having a heat source side pump and a load side pump, in which a heat medium is circulated by the heat source side pump and the load side pump; a heat exchanger that exchanges heat between the refrigerant and the heat medium; and a system control device that controls the heat source side pump, wherein the heat medium circuit has a load device provided downstream of the heat exchanger and a free bypass piping that bypasses the load device, the heat source side pump pressure-feeds the heat medium to the heat exchanger, and the load side pump pressure-feeds the heat medium to the load device,
A first detection unit provided in the heat medium circuit and configured to detect a pressure difference before and after the heat exchanger;
A second detection unit is provided on a load side of the heat medium circuit and detects a load side flow rate of the heat medium,
The system control device includes:
determining a head of the heat source side pump from the differential pressure detected by the first detection unit and a rotation speed of the heat source side pump, and calculating the load side flow rate of the heat medium flowing on the load side of the heat medium circuit based on the differential pressure and the head;
a difference between the calculated value of the load side flow rate and the actual value of the load side flow rate detected by the second detection unit, and a pre-stored difference value is compared to determine the scale deposition state of the heat exchanger. - 圧縮機を有し、前記圧縮機により冷媒が循環する冷媒回路と、熱源側ポンプ及び負荷側ポンプを有し、前記熱源側ポンプ及び前記負荷側ポンプにより熱媒体が循環する熱媒体回路と、前記冷媒と前記熱媒体との間で熱交換を行う熱交換器と、前記熱源側ポンプを制御するシステム制御装置と、を備え、前記熱媒体回路は、前記熱交換器の下流側に設けられる負荷装置と、前記負荷装置をバイパスするフリーバイパス配管とを有したものであり、前記熱源側ポンプは、前記熱交換器に前記熱媒体を圧送するものであり、前記負荷側ポンプは、前記負荷装置に前記熱媒体を圧送するものである冷凍サイクルシステムにおいて、
前記熱媒体回路に設けられ、前記熱交換器の前後の差圧を検出する第1検出部と、
前記熱媒体回路に設けられ、前記熱源側ポンプの前後のポンプ差圧を検出する第2検出部と、を備え、
前記システム制御装置は、
前記第1検出部により検出された前記差圧と、前記熱源側ポンプの回転数から前記熱源側ポンプの揚程を求め、前記差圧及び前記揚程に基づき前記熱媒体回路の負荷側に流れる前記熱媒体の負荷側流量を算出して第1計算値を得るとともに、前記第1検出部により検出された前記差圧及び前記第2検出部により検出された前記ポンプ差圧に基づき前記熱媒体回路の負荷側に流れる前記熱媒体の前記負荷側流量を算出して第2計算値を得、
前記負荷側流量の前記第1計算値と前記第2計算値との差分を、予め記憶された差分値と比較することにより前記熱交換器のスケールの堆積状態を判定する
冷凍サイクルシステム。 A refrigeration cycle system comprising: a refrigerant circuit having a compressor, in which a refrigerant is circulated by the compressor; a heat medium circuit having a heat source side pump and a load side pump, in which a heat medium is circulated by the heat source side pump and the load side pump; a heat exchanger that exchanges heat between the refrigerant and the heat medium; and a system control device that controls the heat source side pump, wherein the heat medium circuit has a load device provided downstream of the heat exchanger and a free bypass piping that bypasses the load device, the heat source side pump pressure-feeds the heat medium to the heat exchanger, and the load side pump pressure-feeds the heat medium to the load device,
A first detection unit provided in the heat medium circuit and configured to detect a pressure difference before and after the heat exchanger;
a second detection unit provided in the heat medium circuit and detecting a pump pressure difference between before and after the heat source pump;
The system control device includes:
a head of the heat source side pump is obtained from the differential pressure detected by the first detection unit and a rotation speed of the heat source side pump, a load side flow rate of the heat medium flowing on the load side of the heat medium circuit is calculated based on the differential pressure and the head to obtain a first calculated value, and a load side flow rate of the heat medium flowing on the load side of the heat medium circuit is calculated based on the differential pressure detected by the first detection unit and the pump differential pressure detected by the second detection unit to obtain a second calculated value;
a difference between the first calculated value and the second calculated value of the load side flow rate is compared with a pre-stored difference value to determine a scale buildup state of the heat exchanger. - 前記システム制御装置は、前記熱交換器に前記スケールが無い初期状態に算出された前記差分を、前記予め記憶された差分値として記憶する
請求項1~4のいずれか一項に記載の冷凍サイクルシステム。 The refrigeration cycle system according to any one of claims 1 to 4, wherein the system control device stores the difference calculated in an initial state in which the heat exchanger has no scale, as the pre-stored difference value. - 前記冷媒回路、前記熱源側ポンプ及び前記熱交換器を有する冷凍サイクル装置を複数台備え、
前記熱媒体回路は、各冷凍サイクル装置の前記熱源側ポンプ及び前記熱交換器が設けられる熱源側枝管を複数有し、複数の前記熱源側枝管が互いに並列接続されて負荷側と接続されたものである
請求項1~5のいずれか一項に記載の冷凍サイクルシステム。 a plurality of refrigeration cycle devices each having the refrigerant circuit, the heat source side pump, and the heat exchanger;
The heat medium circuit has a plurality of heat source side branch pipes in which the heat source side pumps and the heat exchangers of each refrigeration cycle device are provided, and the plurality of heat source side branch pipes are connected in parallel to each other and connected to a load side. The refrigeration cycle system according to any one of claims 1 to 5. - ディスプレイ又はスピーカを有する報知部を備え、
前記システム制御装置は、前記差分が前記予め記憶された差分値から一定量以上乖離した場合に、前記スケールが堆積している旨を前記報知部により報知するように構成されている
請求項1~6のいずれか一項に記載の冷凍サイクルシステム。 A notification unit having a display or a speaker is provided,
The refrigeration cycle system according to any one of claims 1 to 6, wherein the system control device is configured to notify the fact that the scale is accumulating by the notification unit when the difference deviates from the pre-stored difference value by a certain amount or more.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2022/038500 WO2024084536A1 (en) | 2022-10-17 | 2022-10-17 | Refrigeration cycle system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2022/038500 WO2024084536A1 (en) | 2022-10-17 | 2022-10-17 | Refrigeration cycle system |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2024084536A1 true WO2024084536A1 (en) | 2024-04-25 |
Family
ID=90737308
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2022/038500 WO2024084536A1 (en) | 2022-10-17 | 2022-10-17 | Refrigeration cycle system |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2024084536A1 (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2019052811A (en) * | 2017-09-15 | 2019-04-04 | 高砂熱学工業株式会社 | Liquid spray device and control method thereof |
WO2020148887A1 (en) * | 2019-01-18 | 2020-07-23 | 三菱電機株式会社 | Chilling unit and cold/warm water system |
JP2021076259A (en) * | 2019-11-05 | 2021-05-20 | ダイキン工業株式会社 | Hot water supply device |
-
2022
- 2022-10-17 WO PCT/JP2022/038500 patent/WO2024084536A1/en unknown
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2019052811A (en) * | 2017-09-15 | 2019-04-04 | 高砂熱学工業株式会社 | Liquid spray device and control method thereof |
WO2020148887A1 (en) * | 2019-01-18 | 2020-07-23 | 三菱電機株式会社 | Chilling unit and cold/warm water system |
JP2021076259A (en) * | 2019-11-05 | 2021-05-20 | ダイキン工業株式会社 | Hot water supply device |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US11131490B2 (en) | Refrigeration device having condenser unit connected to compressor unit with on-site pipe interposed therebetween and remote from the compressor unit | |
CN107407514B (en) | Indoor unit of air conditioner | |
JP6723450B2 (en) | Heat source system | |
WO2014064792A1 (en) | Monitoring system | |
US11060779B2 (en) | Air-conditioning system and air-conditioning control method | |
JP5761960B2 (en) | Heat source equipment | |
CN107208953B (en) | refrigerating device | |
JP6444577B1 (en) | Air conditioner | |
JP2007255818A (en) | Diagnosing device for refrigerating cycle device, heat source-side unit and use-side unit having diagnosing device, and refrigerating cycle device | |
JP2007033002A (en) | Showcase cooler | |
WO2024084536A1 (en) | Refrigeration cycle system | |
WO2020012750A1 (en) | Heat source system, heat source machine, and control device | |
JP7072398B2 (en) | Integrated air conditioner management equipment and management program | |
WO2020070793A1 (en) | Refrigeration cycle apparatus | |
JP2020026928A (en) | Control device, refrigeration machine, control method and failure detection method | |
JP2011149622A (en) | Air conditioner | |
JP2011094915A (en) | Air conditioner | |
WO2018179333A1 (en) | Machine using refrigerant compression heat pump, diagnostic device for refrigerant compression heat pump, and diagnotic method for refrigerant compression heat pump | |
JP2020091080A (en) | Refrigeration cycle device | |
EP4163574A1 (en) | Refrigeration cycle device | |
JP6111692B2 (en) | Refrigeration equipment | |
JP2012137276A (en) | Air conditioning apparatus | |
WO2018011935A1 (en) | Refrigerating device | |
JPWO2021250789A5 (en) | ||
WO2015128899A1 (en) | Air conditioner device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 22962648 Country of ref document: EP Kind code of ref document: A1 |