WO2024075235A1 - Air conditioning device - Google Patents
Air conditioning device Download PDFInfo
- Publication number
- WO2024075235A1 WO2024075235A1 PCT/JP2022/037402 JP2022037402W WO2024075235A1 WO 2024075235 A1 WO2024075235 A1 WO 2024075235A1 JP 2022037402 W JP2022037402 W JP 2022037402W WO 2024075235 A1 WO2024075235 A1 WO 2024075235A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- flow rate
- refrigerant
- heat exchange
- fan
- control device
- Prior art date
Links
- 238000004378 air conditioning Methods 0.000 title claims abstract description 56
- 239000003507 refrigerant Substances 0.000 claims abstract description 180
- 230000007246 mechanism Effects 0.000 claims abstract description 76
- 230000008859 change Effects 0.000 claims description 15
- 230000009467 reduction Effects 0.000 claims description 7
- 238000011144 upstream manufacturing Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 39
- 230000007423 decrease Effects 0.000 description 26
- 238000001816 cooling Methods 0.000 description 19
- 238000000034 method Methods 0.000 description 16
- 230000003247 decreasing effect Effects 0.000 description 11
- 230000008569 process Effects 0.000 description 11
- 238000010438 heat treatment Methods 0.000 description 10
- 239000007788 liquid Substances 0.000 description 8
- 238000012545 processing Methods 0.000 description 5
- 238000004891 communication Methods 0.000 description 4
- 238000007906 compression Methods 0.000 description 4
- 230000006835 compression Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000005057 refrigeration Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 239000007787 solid Substances 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
Definitions
- This disclosure relates to air conditioning devices.
- a method widely used in air conditioning systems is to control the operating frequency of the compressor according to the load inside the room to adjust the indoor temperature.
- Compressors have a set frequency range within which they can operate.
- on-off operation is implemented to stabilize the room temperature by repeatedly operating (thermo on) and stopping (thermo off) the compressor.
- on-off operation has issues such as room temperature fluctuating up and down, reducing comfort, and the air conditioning system's coefficient of performance (COP) being lower than with continuous operation.
- COP coefficient of performance
- Patent Document 1 discloses a technique for forcibly reducing the opening of the expansion valve when operating near the lower limit frequency, thereby reducing the amount of refrigerant circulating and thereby lowering capacity and reducing the frequency of on-off operation.
- Patent Document 1 the opening of the expansion valve is made smaller than the optimal state, so the proportion of gas refrigerant in the evaporator increases. This causes the evaporator performance to decrease, and the evaporation temperature to decrease, resulting in a problem of a decrease in COP.
- the present disclosure aims to solve the above problem by providing an air conditioner that both reduces the frequency of on-off operation and prevents a decrease in COP.
- the present disclosure relates to an air conditioner.
- the air conditioner includes a refrigerant circuit including at least a compressor, a condenser, an expansion valve, and an evaporator, and configured to circulate a refrigerant, and a control device that controls the refrigerant circuit.
- the condenser includes a first heat exchange unit and a second heat exchange unit configured to allow the refrigerant to flow in parallel, and a flow rate adjustment mechanism configured to adjust the flow rate of the refrigerant passing through the second heat exchange unit.
- the control device is configured to be able to reduce the flow rate of the refrigerant passing through the second heat exchange unit by the flow rate adjustment mechanism to be lower than the flow rate of the refrigerant passing through the first heat exchange unit when the operating frequency of the compressor is a preset lower limit frequency.
- the control device is configured to increase the opening of the expansion valve after reducing the flow rate of the refrigerant passing through the second heat exchange unit by the flow rate adjustment mechanism when the air conditioning capacity of the refrigerant circuit is greater than the indoor load.
- the air conditioning device disclosed herein is capable of further reducing the air conditioning capacity even when the compressor is operating at the lower limit frequency. This makes it possible to suppress the frequency of on-off operation while also suppressing the decrease in COP.
- FIG. 1 is a diagram showing the configuration of an air conditioning device 1000 according to a first embodiment.
- 2 is a diagram showing a configuration example of an outdoor heat exchanger 211 in FIG. 1 .
- 4 is a flowchart for explaining control of the expansion valve 230.
- 13 is a diagram showing changes in the capacity of the air conditioner when the opening degree of the flow rate adjustment mechanism 272 is changed when the operating frequency of the compressor is at the lower limit frequency Fmin during cooling operation.
- FIG. This is a ph diagram of an air conditioning device when the circulation flow ratio is 100%.
- This is a ph diagram of an air conditioning device when the circulation flow rate ratio is 19%.
- 13 is a flowchart for explaining control of a flow rate adjustment mechanism 272.
- FIG. 13 is a diagram showing a change in the Cv value of the expansion valve 230 when the opening degree of the flow rate adjustment mechanism 272 is changed in a case where the operating frequency of the compressor 200 is the lower limit frequency Fmin during cooling operation.
- FIG. 13 is a diagram showing an approximation formula for a region where the circulation flow rate ratio is large.
- FIG. 13 is a diagram showing an approximation formula for a region where the circulation flow rate ratio is small.
- FIG. 13 is a diagram showing the results during heating operation.
- FIG. 11 is a diagram showing a first modified example in which the configuration of the outdoor heat exchanger 211 is changed.
- FIG. 13 is a diagram showing a second modified example in which the configuration of the outdoor heat exchanger 211 is changed.
- FIG. 13A and 13B are diagrams illustrating a third modified example in which the configuration of the flow rate adjusting mechanism is changed.
- FIG. 12 is a diagram showing the configuration of an air conditioning device 1200 according to a second embodiment.
- 16 is a diagram showing a configuration example of an outdoor heat exchanger 211 in FIG. 15 .
- 10 is a flowchart for explaining control of a flow rate adjustment mechanism 272 and fans 221 and 222.
- 18 is an example of a map referred to in steps S44 and S47 of FIG. 17.
- 13 is a diagram showing changes in the capacity of the air conditioner when the opening degree of the flow rate adjustment mechanism 272 and the rotation speed of the fan 221 are changed when the operating frequency F of the compressor 200 is at the lower limit frequency Fmin during cooling operation.
- FIG. 11 is a diagram showing a Cv value ratio of an expansion valve 230 relative to a circulation flow rate ratio in the second embodiment.
- FIG. 13 is a diagram showing fitting results and approximate equation results in a region where the circulation flow rate ratio is 28% to 100%.
- FIG. 13 is a diagram showing fitting results and approximate equation results in a region where the circulation flow rate ratio is 0 to 28%.
- 11 is a diagram showing changes in the capacity of the air conditioner relative to the Cv value ratio of the expansion valve 230.
- FIG. 20 corresponds to FIG. 19 when the rotation speed of the fan 221 is set to 0.
- FIG. 20 when the rotation speed of the fan 221 is set to 0.
- FIG. 21 when the rotation speed of the fan 221 is set to 0.
- FIG. 22 when the rotation speed of the fan 221 is set to 0.
- FIG. 23 when the rotation speed of the fan 221 is set to 0.
- FIG. FIG. 1 is a diagram illustrating an example of the configuration of a rotary vane type compressor.
- FIG. 1 is a diagram showing the configuration of an air-conditioning apparatus 1000 according to embodiment 1.
- the air-conditioning apparatus 1000 shown in Fig. 1 includes a refrigerant circuit 500 and a control device 100.
- the refrigerant circuit 500 of the air conditioning device 1000 includes a compressor 200, an outdoor heat exchanger 211, an outdoor blower (fan) 220, an expansion valve 230, a four-way valve 240, a flow rate adjustment mechanism 272, an indoor heat exchanger 110, and an indoor blower (fan) 120.
- the four-way valve 240 has ports P1 to P4.
- an electronic expansion valve LEV: Linear Expansion Valve
- LEV Linear Expansion Valve
- the refrigerant circuit 500 is arranged separately for an outdoor unit 1001 and an indoor unit 1002.
- the outdoor unit 1001 includes a compressor 200, a four-way valve 240, an outdoor heat exchanger 211, an outdoor fan 220, an expansion valve 230, and a control device 100.
- the indoor unit 1002 includes an indoor heat exchanger 110 and an indoor fan 120.
- the outdoor unit 1001 and the indoor unit 1002 are connected by pipes 310 and 320.
- Compressor 200 is configured to change its operating frequency according to a control signal received from control device 100.
- compressor 200 has a built-in drive motor with a variable rotation speed that is inverter-controlled, and when the operating frequency is changed, the rotation speed of the drive motor changes.
- the output of compressor 200 is adjusted by changing the operating frequency of compressor 200.
- the four-way valve 240 is controlled to be in either a cooling operation state or a heating operation state by a control signal received from the control device 100.
- the cooling operation state is a state in which port P1 and port P4 are in communication, and port P2 and port P3 are in communication, as shown by solid lines in FIG. 1.
- the heating operation state is a state in which port P1 and port P3 are in communication, and port P2 and port P4 are in communication, as shown by dashed lines in FIG. 1.
- the air conditioning device 1000 further includes temperature sensors 261-265.
- the temperature sensor 261 is disposed in the indoor unit 1002 and detects the room temperature T261 of the room to be air-conditioned.
- the temperature sensor 262 is disposed on the side connected to the pipe 320 (liquid pipe) of the indoor heat exchanger 110 and measures the refrigerant temperature T262.
- the temperature sensor 263 is disposed on the side connected to the pipe 310 (gas pipe) of the indoor heat exchanger 110 and measures the refrigerant temperature T263.
- the temperature sensor 264 is disposed on the side connected to the expansion valve 230 of the outdoor heat exchanger 211 and measures the refrigerant temperature T264.
- the temperature sensor 265 is disposed on the side connected to the port P4 of the four-way valve 240 of the outdoor heat exchanger 210 and measures the refrigerant temperature T265.
- the control device 100 controls the opening of the expansion valve 230 to adjust the SH (superheat) of the refrigerant at the evaporator outlet according to the outputs of the temperature sensors 261-265, and also controls the rotation of the fans 221 and 222.
- the control device 100 is composed of a CPU (Central Processing Unit) 101, memory 102 (ROM (Read Only Memory) and RAM (Random Access Memory)), an input/output buffer (not shown), etc.
- the CPU 101 deploys programs stored in the ROM into the RAM etc. and executes them.
- the programs stored in the ROM are programs in which the processing procedures of the control device 100 are written.
- the control device 100 controls each device in the air conditioning device 1000 in accordance with these programs. This control is not limited to processing by software, but can also be processed by dedicated hardware (electronic circuits).
- FIG. 1 the flow of refrigerant during cooling operation is shown by a solid line, and the flow of refrigerant during heating operation is shown by a dashed line.
- the control device 100 changes the frequency of the compressor 200 so that the indoor temperature becomes the target (set) temperature.
- FIG. 1 illustrates an air conditioner equipped with a four-way valve 240
- the air conditioner may be a cooling-only air conditioner that does not have a four-way valve 240.
- the outdoor heat exchanger 211 includes two heat exchange sections connected in parallel and a flow rate adjustment mechanism 272.
- the flow rate adjustment mechanism 272 is disposed at the refrigerant outlet of one of the heat exchange sections.
- FIG. 2 is a diagram showing an example of the configuration of the outdoor heat exchanger 211 in FIG. 1.
- the outdoor heat exchanger 211 includes a first heat exchange section 211A and a second heat exchange section 211B that are configured to allow a refrigerant to flow in parallel.
- FIG. 2 shows a side view of the outdoor heat exchanger 211 as seen from a lateral direction perpendicular to the wind direction.
- the flow rate adjustment mechanism 272 in FIG. 1 is installed between the refrigerant outlet POB of the second heat exchange section 211B and the junction of the refrigerant flow paths.
- the flow rate adjustment mechanism 272 is fully open unless otherwise specified.
- the outdoor heat exchanger 211 further includes a plurality of fins 211F that are provided in common to the first heat exchange section 211A and the second heat exchange section 211B.
- the plurality of fins 211F are arranged in layers from the front to the back of the page with intervals provided to allow air to pass through.
- the first heat exchange section 211A includes multiple pipes that pass through multiple fins 211F and connections that connect these multiple pipes on both sides.
- a circle indicates one pipe
- a solid line indicates a connection that connects the pipes on the side facing the page
- a dashed line indicates a connection that connects the pipes on the side facing the page.
- the second heat exchange section 211B like the first heat exchange section 211A, includes multiple pipes penetrating multiple fins 211F and connections connecting these multiple pipes on both sides.
- a circle indicates one pipe
- a solid line indicates a connection connecting the pipes on the side facing the page
- a dashed line indicates a connection connecting the pipes on the side facing the page.
- the flow rate adjustment mechanism 272 in FIG. 1 is installed on the refrigerant outlet POB side of the second heat exchange section 211B, but it may be installed on the refrigerant inlet PIB side. Also, the flow rate adjustment mechanism 272 may be installed upstream or downstream of the first heat exchange section 211A.
- Compressor 200 changes the frequency of compressor 200 so that the indoor temperature becomes the target (set) temperature.
- Figure 3 is a flowchart for explaining the control of the expansion valve 230.
- step S21 the control device 100 sets the opening of the expansion valve 230 to a default value. This default value will be described later with reference to Figures 8 to 10.
- step S22 the control device 100 initializes the variable Count to 0. If the variable Count is 1 or greater, this indicates that the expansion valve opening has been decreased multiple times, and if the variable Count is 0, this indicates that the expansion valve opening has not been decreased multiple times.
- step S23 the control device 100 reduces the opening of the expansion valve 230 by a fixed value.
- step S24 the control device 100 determines whether the degree of refrigerant superheat SH at the evaporator outlet has changed.
- the degree of refrigerant superheat SH at the evaporator outlet is calculated by subtracting the evaporation temperature T262 obtained by the temperature sensor 262 from the evaporator outlet temperature T263 obtained by the temperature sensor 263.
- the degree of refrigerant superheat SH at the evaporator outlet is calculated by subtracting the evaporation temperature T264 obtained by the temperature sensor 264 from the evaporator outlet temperature T265 obtained by the temperature sensor 265.
- step S24 If the answer in step S24 is NO, that is, if there is no change in the degree of refrigerant superheat SH at the evaporator outlet, it is considered that the state of the refrigerant at the evaporator outlet has not changed from the two-phase gas-liquid state. Therefore, in step S25, the control device 100 adds 1 to the variable Count, and then returns to the process in step S23, decreasing the opening degree of the expansion valve 230 by a fixed value.
- step S24 determines whether the variable Count is 0.
- step S26 returns NO, i.e., if the variable Count is not 0, the refrigerant superheat degree SH at the evaporator outlet has been appropriately controlled in steps S23 to S25, and the control device 100 ends the process of determining the opening degree of the expansion valve 230.
- step S26 if the answer is YES in step S26, the variable Count is 0, so step S24 is passed through in one go without going through step S25.
- the evaporator outlet is in a superheated gas state, and the degree of superheat (SH) is further increased in step S23, so this cannot be said to be an appropriate state. Therefore, in step S27, the opening of the expansion valve 230 is increased by a fixed value. Then, after a fixed time has elapsed, in step S28, it is determined whether there has been a change in the value of the refrigerant superheat SH at the evaporator outlet.
- step S28 returns YES, that is, if there has been a change in the refrigerant superheat degree SH at the evaporator outlet
- the process returns to step S27 and increases the opening degree of the expansion valve 230 by a fixed value since there has been a change in the value of the refrigerant superheat degree SH at the evaporator outlet.
- step S28 returns NO, that is, if there has been no change in the refrigerant superheat degree SH at the evaporator outlet, the evaporator outlet refrigerant can be determined to be in two phases (superheat degree 0) and the heat exchange efficiency in the evaporator is good, so the process of determining the opening degree of the expansion valve 230 is terminated.
- control is performed based on the value of the refrigerant superheat degree SH at the evaporator outlet, but it is also possible to predetermine a target value for the superheat degree or discharge refrigerant temperature of the discharge refrigerant of the compressor 200 corresponding to the value of the refrigerant superheat degree SH at the evaporator outlet, and control the expansion valve 230 based on the superheat degree or discharge refrigerant temperature of the discharge refrigerant.
- the refrigerant superheat degree SH at the evaporator outlet used in the flowchart of Figure 3 changes if there is a pressure loss between the temperature sensors or if there is a temperature gradient in the refrigerant.
- refrigerants low pressure refrigerants, e.g. 1234yf, propane, etc.
- the value of the refrigerant superheat degree SH at the evaporator outlet calculated using this method will be smaller, and for refrigerants with a large temperature gradient (non-azeotropic refrigerant mixtures), the value of the refrigerant superheat degree SH at the evaporator outlet calculated using this method will be larger.
- control device 100 may control the degree of superheat (SH) to 5 degrees or less.
- Fig. 4 is a diagram showing the change in capacity of the air conditioner when the opening degree of the flow rate adjustment mechanism 272 is changed when the operating frequency of the compressor is at the lower limit frequency Fmin during cooling operation.
- the vertical axis of Fig. 4 shows the capacity of the air conditioner, with 100% being when the flow rate adjustment mechanism 272 is fully open.
- the horizontal axis shows the circulation flow rate ratio (%) that changes according to the opening degree of the flow rate adjustment mechanism 272.
- the capacity ratio (%) shown on the vertical axis is a numerical value obtained by dividing (capacity of air conditioning device 1000) by (capacity of air conditioning device 1000 at a circulation flow rate ratio of 100%), expressed as a percentage.
- the circulation flow rate ratio (%) shown on the horizontal axis is a numerical value obtained by dividing (refrigerant flow rate flowing through second heat exchange section 211B) by (refrigerant flow rate flowing through first heat exchange section 211A), expressed as a percentage. If the circulation flow rate ratio is reduced to 50%, it is possible to reduce the capacity of air conditioning device 1000 by approximately 20%. If the flow rate adjustment mechanism 272 is fully closed and the refrigerant flow rate flowing through second heat exchange section 211B is set to 0, it is possible to reduce the capacity of air conditioning device 1000 to almost 0.
- Fig. 5 is a ph diagram of an air conditioner when the circulation flow rate ratio is 100%.
- Fig. 6 is a ph diagram of an air conditioner when the circulation flow rate ratio is 19%.
- Figs. 5 and 6 show the case where the air volume is fixed at the same 24 m 3 /min.
- the reason why the capacity decreases when the opening degree of the flow rate adjustment mechanism 272 is reduced is explained below.
- the opening degree of the flow rate adjustment mechanism 272 is reduced, the refrigerant flow rate flowing through the second heat exchange section 211B is reduced, and the amount of heat exchange in the second heat exchange section 211B is reduced.
- the refrigerant passing through the second heat exchange section 211B is more likely to complete heat exchange on the way from the refrigerant inlet PIB to the refrigerant outlet POB (or completes heat exchange completely), and the refrigerant temperature at the refrigerant outlet POB approaches the air temperature (or becomes completely the same as the air temperature).
- the amount of liquid refrigerant increases, and the amount of refrigerant in the second heat exchange section 211B increases. Therefore, the amount of refrigerant in the first heat exchange section 211A decreases, that is, the enthalpy of the refrigerant outlet POA also increases. As a result, the outlet enthalpy at the junction where the temperature sensor 264 is installed increases, and the evaporator inlet enthalpy also increases. As a result, as shown in FIG. 6, the enthalpy difference between the evaporator outlet and inlet decreases, and the air conditioning capacity decreases.
- the refrigeration cycle (C11-C12-C13-C14) shown in Figure 6 (circulation flow ratio 19%) is shorter in length in the horizontal direction (specific enthalpy direction).
- points C1 and C11 indicate the state of the evaporator outlet.
- Points C2 and C12 indicate the state of the compressor outlet.
- Points C3 and C13 indicate the state of the refrigerant confluence point where temperature sensor 264 is installed.
- Points C4 and C14 indicate the state of the evaporator inlet.
- Heat exchange capacity and heat exchange amount Q [kW] are expressed as the refrigerant circulation flow rate Gr [kg/s] x enthalpy difference ⁇ h [kJ/kg]. Therefore, the capacity decreases as the enthalpy difference, which is the length in the horizontal direction, decreases.
- FIG. 7 is a flowchart for explaining the control of the flow rate adjustment mechanism 272.
- the control device 100 determines whether the operating frequency F of the compressor 200 is the lower limit frequency Fmin.
- step S31 returns NO, that is, if the operating frequency F is greater than the lower limit frequency Fmin, the compressor 200 can perform normal control, increasing or decreasing the operating frequency F of the compressor 200 so that the indoor temperature becomes the set temperature. For this reason, the control device 100 ends the process by fully opening the flow rate adjustment mechanism 272 in step S37.
- the control device 100 controls the opening rate of the flow rate adjustment mechanism 272 to be fully open when the operating frequency F of the compressor 200 is other than the lower limit frequency Fmin. In this case, the control device 100 sets the rotation speed of the outdoor fan 220 to the rotation speed N corresponding to the operating frequency F of the compressor 200.
- step S31 the control device 100 determines whether the indoor heat exchange capacity of the air conditioner is greater than the indoor load.
- Ts indicates the indoor set temperature of the air conditioner
- Ta(start) indicates the temperature detected by the temperature sensor 261 at the start of step S32
- Ta(end) indicates the temperature detected by the temperature sensor 261 when a certain time has elapsed since the start of step S32.
- the certain time is, for example, about several minutes.
- step S32 returns YES, the capacity of the air conditioning device is greater than the indoor load even at the lower limit frequency Fmin, so the process proceeds to step S33, where the control device 100 determines whether the flow rate adjustment mechanism 272 is fully closed. If step S33 returns NO, the control device 100 reduces the opening of the flow rate adjustment mechanism 272 by a fixed value in step S34. This reduces the amount of heat exchanged in the second heat exchange section 211B, and reduces the air conditioning capacity. Then, in step S35, the control device 100 controls the opening of the expansion valve 230. The reason for performing step S35 after step S34 will be explained below.
- step S34 If the opening of the flow rate adjustment mechanism 272 is reduced by a certain value in step S34 without controlling the opening of the expansion valve 230, that is, with the opening fixed at the time of the initial transition to step S32, the circulation flow rate will decrease, resulting in operation with the refrigerant superheat SH at the evaporator outlet becoming too high, and the COP of the air conditioner will deteriorate. Therefore, by implementing the control of the expansion valve 230 shown in Figure 3 in step S35, it is possible to maintain the refrigerant superheat SH at the evaporator outlet at an appropriate value.
- the opening value of the expansion valve 230 in step S21 should be set to an opening corresponding to the Cv value ratio calculated using the approximation formula when first moving to step S32.
- the control of the expansion valve 230 shown in FIG. 3 may not be performed, and the opening may be directly changed to an opening corresponding to the Cv value ratio calculated using the approximation formula. In this case, if the accuracy of the approximation formula is high, the same results will be obtained as when the control in FIG. 3 is performed.
- Fig. 8 shows the change in the Cv value of the expansion valve 230 when the opening degree of the flow rate adjustment mechanism 272 is changed when the operating frequency of the compressor 200 is at the lower limit frequency Fmin during cooling operation.
- Fig. 9 shows the approximation formula for the region where the circulation flow rate ratio is large.
- Fig. 10 shows the approximation formula for the region where the circulation flow rate ratio is small.
- FIG. 8 shows that the smaller the opening of the flow rate adjustment mechanism 272 (the smaller the circulation flow rate ratio), the larger the opening of the expansion valve 230 must be. This is because the expansion valve 230 is controlled to keep the refrigerant superheat degree SH at the evaporator outlet constant by the control shown in FIG. 3.
- the opening of the flow rate adjustment mechanism 272 is changed when the operating frequency of the compressor 200 is at the lower limit frequency, it is desirable to make the refrigerant superheat degree SH at the evaporator outlet reach an appropriate value quickly in order not to lower the COP of the air conditioner. For example, if the circulation flow rate ratio is 19%, the setting value of the opening of the expansion valve 230 in step S21 of FIG.
- the slope of the graph is significantly different between the range where the circulation flow ratio is 19% to 100% and the range where the circulation flow ratio is 0 to 19%.
- this range is converted in Figure 4, it becomes the range where the capacity ratio is 41% to 100% and the range where the capacity ratio is 0% to 41%.
- An approximation formula was created by dividing the region into these two regions.
- the coefficient of determination R2 of the fitting results shown in FIG. 9 and FIG. 10 is 0.97 or more, which indicates that good approximation is achieved by linear approximation.
- step S35 after controlling the opening degree of the expansion valve 230 in step S35, the process proceeds to step S32, where the balance between the air conditioning capacity and the indoor load is determined again.
- step S32 the capacity of the air conditioner is equal to or less than the indoor load, so the compressor 200 can perform normal control, accelerating the operating frequency F of the compressor 200 (or maintaining it at Fmin) so that the indoor temperature becomes the set temperature, and the control device 100 ends the processing in FIG. 7.
- step S33 determines whether the flow rate adjustment mechanism 272 is fully closed, and the air conditioning capacity cannot be reduced any further. Therefore, the control device 100 turns off the thermostat of the compressor 200 in step S36, and ends the processing in FIG. 7.
- 11 is a diagram showing the results during heating operation. Unlike during cooling operation, it is shown that the capacity does not decrease as much as during cooling operation even if the opening degree of the flow rate adjustment mechanism 272 is reduced. The reason for this will be explained below.
- the refrigerant flow rate flowing through the second heat exchange section 211B decreases, and the amount of heat exchanged in the second heat exchange section 211B decreases.
- the refrigerant passing through the second heat exchange section 211B is more likely to complete heat exchange on the way from the refrigerant inlet PIB to the refrigerant outlet POB (or completes heat exchange completely), and the refrigerant temperature at the refrigerant outlet POB approaches the air temperature (or becomes completely the same as the air temperature).
- the amount of gas refrigerant increases, and the amount of refrigerant in the second heat exchange section 211B decreases.
- the amount of refrigerant in the first heat exchange section 211A increases, and the enthalpy difference between the evaporator inlet and outlet (the place where the temperature sensor 264 is installed and the place where the temperature sensor 265 is installed) decreases, resulting in a decrease in the air conditioning capacity.
- the amount of reduction in capacity is smaller than during cooling operation. This is because the first heat exchanger 211A and the second heat exchanger 211B are used as evaporators during heating operation, so the density of the refrigerant is small and the amount of change in the refrigerant is small.
- the indoor heat exchanger is configured to allow refrigerant to flow in parallel and a flow rate control mechanism is provided in at least one of the flow paths, it is also possible to reduce the capacity during heating operation.
- ⁇ Modification> 2 shows an example in which the first heat exchange section 211A and the second heat exchange section 211B are configured in one outdoor heat exchanger 211. Several modified examples of the heat exchanger will be described.
- FIG. 12 is a diagram showing a first modified example in which the configuration of the outdoor heat exchanger 211 is changed.
- a first heat exchange section 211A and a second heat exchange section 211B may be configured as a divided heat exchanger.
- a divided configuration refers to one in which the fins are provided separately as fins 211FA and fins 211FB. With such a configuration, when a large heat exchanger is required, it is possible to realize heat exchangers of various capacities by increasing or decreasing the number of small heat exchangers without having to design a new one.
- FIG. 13 is a diagram showing a second modified example in which the configuration of the outdoor heat exchanger 211 is changed.
- the outdoor heat exchanger 211 has one refrigerant inlet, and the refrigerant flow path is divided into two midway.
- the outdoor heat exchanger 211 may also be configured as shown in FIG. 13.
- FIG. 14 is a diagram showing a third modified example in which the configuration of the flow rate adjustment mechanism has been changed.
- the modified air conditioner 1010 shown in FIG. 14 includes a flow rate adjustment mechanism 270 that controls the flow rate of refrigerant flowing through the first heat exchange section 211A and the second heat exchange section 211B, instead of the flow rate adjustment mechanism 272 in the configuration of the air conditioner 1000. Even with this configuration, it is possible to reduce capacity by decreasing the circulation flow rate of the refrigerant flowing on one side.
- the air conditioner according to embodiment 1 can reduce the capacity when the operating frequency of the compressor is at the lower limit frequency, and can improve comfort by reducing the frequency of on-off operation.
- the heat exchanger in which the flow rate adjustment mechanism 272 is installed acts as a condenser, as shown in FIG. 4, it is possible to reduce the capacity ratio of the second heat exchange section 211B to almost 0, that is, to reduce the capacity (air conditioning capacity) of the air conditioner to almost 0.
- FIG. 15 is a diagram showing the configuration of an air conditioning apparatus 1200 according to embodiment 2. Regarding air conditioning apparatus 1200, only the differences from air conditioning apparatus 1000 shown in Figure 1 will be explained. Whereas air conditioning apparatus 1000 shown in Figure 1 has one outdoor blower (fan) 220, configuration 2 has two outdoor blowers (fans) 221 and 222.
- air conditioning apparatus 1000 shown in Figure 1 has one outdoor blower (fan) 220
- configuration 2 has two outdoor blowers (fans) 221 and 222.
- FIG. 16 is a diagram showing an example of the configuration of the outdoor heat exchanger 211 in FIG. 15.
- Fan 221 is provided corresponding to the first heat exchange section 211A
- fan 222 is provided corresponding to the second heat exchange section 211B.
- the rotation speeds of fans 221 and 222 can be controlled independently of each other by the control device 100. Therefore, in addition to adjusting the refrigerant flow rate with the flow rate adjustment mechanism 272, the air conditioning capacity of the air conditioner can be further changed by setting the rotation speeds of fans 221 and 222 to different speeds, or by rotating one of fans 221 and 222 and stopping the other.
- FIG. 17 is a flowchart for explaining the control of the flow rate adjustment mechanism 272 and the fans 221, 222.
- step S34 in the flowchart shown in FIG. 7 is changed to step S44, step S35 to step S45, and step S37 to step S47.
- Other processes are similar, so the description will not be repeated.
- step S44 the control device 100 reduces the opening degree of the flow rate adjustment mechanism 272 by a fixed value, and also reduces the rotation speed N of the fan 221 corresponding to the first heat exchange section 211A by a fixed value. This not only reduces the amount of heat exchanged in the second heat exchange section 211B, but also reduces the amount of heat exchanged in the first heat exchange section 211A by reducing the airflow rate of the fan 221. This makes it possible to further reduce the air conditioning capacity compared to step S34 in FIG. 7.
- control device 100 reduces rotation speed N of fan 221 while maintaining the rotation speed of fan 222.
- step S45 the control device 100 controls the opening of the expansion valve 230 according to the flowchart shown in FIG. 3.
- the value of the opening of the expansion valve 230 in step S21 may be set to the opening at the time of the initial transition to step S32, which corresponds to the Cv value ratio calculated using the approximation formula (shown later in FIGS. 20 to 22).
- step S45 the control of the expansion valve 230 shown in FIG. 3 may not be performed, and the opening may be directly changed to the opening corresponding to the Cv value ratio calculated using the approximation formula. In this case, if the accuracy of the approximation formula is high, the same result as when the control of FIG. 3 is performed will be obtained.
- step S47 the control device 100 fully opens the flow rate adjustment mechanism 272 and sets the rotation speed of the fans 221, 222 to the rotation speed N that corresponds to the operating frequency F of the compressor 200.
- FIG. 18 is an example of a map referenced in steps S44 and S47 of FIG. 17.
- the horizontal axis shows the operating frequency F of the compressor 200
- the vertical axis shows the fan rotation speed N.
- the control device 100 sets the fans 221 and 222 to the same rotation speed according to the map shown in FIG. 18. That is, when the operating frequency F is higher than Fmin and equal to or lower than F1, the control device 100 sets the rotation speeds of the fans 221 and 222 to the rotation speed N4 (low rotation). When the operating frequency F is higher than F1 and equal to or lower than F2, the control device 100 sets the rotation speeds of the fans 221 and 222 to the rotation speed N5 (medium rotation). When the operating frequency F is higher than F2, the control device 100 sets the rotation speeds of the fans 221 and 222 to the rotation speed N6 (high rotation).
- the control device 100 reduces the rotation speed of the fan 221 in stages from N4 to N3, N2, N1, and 0, while maintaining the rotation speed of the fan 222 at N4.
- the rotation speed of the fan 221 may be reduced all at once from N4 to 0.
- the reduction rate of the rotation speed of the fan 221 may be determined based on the ratio between the flow rate of the refrigerant passing through the first heat exchanger 211A and the flow rate of the refrigerant passing through the second heat exchanger 211B.
- Figure 19 shows the change in capacity of the air conditioner when the opening of the flow rate adjustment mechanism 272 and the rotation speed of the fan 221 are changed when the operating frequency F of the compressor 200 is at the lower limit frequency Fmin during cooling operation.
- the results indicated by the triangles in Figure 19 are the same as those in Figure 4, and show the results when only the flow rate is adjusted and the fan is controlled in the same way as in embodiment 1.
- the results indicated by the squares in Figure 19 show the results when the rotation speed of the fan 221 is controlled as in Figure 18 in addition to the flow rate adjustment. Note that the reduction in the rotation speed of the fan 221 is set to the same as the circulation flow rate ratio. In other words, the rotation speed of the fan 221 when the circulation flow rate ratio is 50% is set to 50% of the rotation speed of the fan 222.
- Figure 20 is a diagram showing the Cv value ratio of the expansion valve 230 versus the circulation flow rate ratio in embodiment 2. It shows that the smaller the opening of the flow rate adjustment mechanism 272 (the smaller the circulation flow rate ratio), the larger the opening of the expansion valve 230 needs to be. This is because the expansion valve 230 keeps the refrigerant superheat degree SH at the evaporator outlet constant by the control flow shown in Figure 3. If the opening of the flow rate adjustment mechanism 272 is changed when the operating frequency of the compressor 200 is at the lower limit frequency, it is desirable to allow the refrigerant superheat degree SH at the evaporator outlet to reach an appropriate value as soon as possible in order not to lower the COP of the air conditioning device.
- the default opening value of the expansion valve 230 in step S21 of FIG. 3 may be set to 304% of the Cv value of the expansion valve 230 when the circulation flow ratio is 100%, as shown in FIG. 20, if the circulation flow ratio is 28%.
- an approximation formula of the graph in FIG. 20 may be created.
- the slope of the graph is significantly different between the region where the circulation flow ratio is 28% to 100% and the region where the circulation flow ratio is 0 to 28%. For this reason, an approximation formula was created by dividing the range into two. Note that the region where the circulation flow ratio is 28% to 100% is the region where the capacity ratio is 41% to 100% when converted in Figure 19. Furthermore, the region where the circulation flow ratio is 0% to 28% is the region where the capacity ratio is 0% to 41% when converted in Figure 19.
- 21 is a diagram showing the fitting results and the approximation results for the region where the circulation flow rate ratio is 28% to 100%.
- FIG. 22 is a diagram showing the fitting results and the approximation results for the region where the circulation flow rate ratio is 0 to 28%.
- the coefficient of determination R2 is 0.94 or more, which indicates that good approximation is achieved by linear approximation.
- Figure 23 is a diagram showing the change in the capacity of the air conditioner with respect to the Cv value ratio of the expansion valve 230. It can be seen that the capacity of the air conditioner can be reduced by adding the change in the rotation speed of the fan 221, as shown by the square marks, compared to the case of only flow rate adjustment, as shown by the triangle marks, for the same Cv value ratio of the expansion valve 230. Since the operating frequency F of the compressor 200 is the lower limit frequency Fmin, the refrigerant flow rate is small, and the opening degree of the expansion valve 230 at a capacity ratio of 100% is small.
- the opening degree of the flow rate adjustment mechanism 272 when the opening degree of the flow rate adjustment mechanism 272 is reduced, the opening degree of the expansion valve 230 can be increased and the capacity can be reduced, but only up to the capacity corresponding to the maximum opening degree of the expansion valve 230.
- the capacity ratio can be reduced to 30% by reducing the opening degree of the flow rate adjustment mechanism 272, but it is possible to further reduce the capacity ratio to 20% by adding a reduction in the rotation speed of the fan 221.
- the capacity ratio is to be reduced to 30%, the same as when the opening degree of the flow rate adjustment mechanism 272 is reduced, the Cv value ratio of the expansion valve 230 should be 410%.
- a small expansion valve with a small diameter can be used, which has the advantages of reducing costs and making it easier to handle the refrigerant piping around the expansion valve 230.
- the rotation speed of the fan 221 is gradually reduced as shown in FIG. 18.
- the rotation speed of the fan 221 may be set to 0 while maintaining the rotation of the fan 222.
- FIG. 24 corresponds to FIG. 19 when the rotation speed of the fan 221 is set to 0.
- FIG. 25 corresponds to FIG. 20 when the rotation speed of the fan 221 is set to 0.
- FIG. 28 is a diagram corresponding to FIG. 23 in the case where the rotation speed of the fan 221 is set to 0.
- FIG. 24 to 28 with FIG. 19 to FIG. 23 it can be seen that, in FIG. 24 to 28, by setting the rotation speed of the fan 221 to 0, the capacity is further reduced at the same circulation flow rate ratio.
- the air conditioning apparatus of embodiment 2 has the same effect as embodiment 1, and in addition, when using the same expansion valve 230 as embodiment 1, it is possible to further reduce the air conditioning capacity by reducing the fan air volume.
- Various types of compressors 200 can be adopted, such as a rotary type, a reciprocating type, a scroll type, a screw type, and the like.
- the compressor 200 is particularly effective when it is a rotary vane type.
- Fig. 29 is a diagram showing an example of the configuration of a rotary vane type compressor.
- the compression mechanism in the rotary compressor includes a cylinder 201, a piston 202, a vane 203, a spring 204, a suction port 206, a discharge port 207, and a rotating shaft 208.
- the cylinder 201 is provided with a vane groove 201c that extends radially and is connected to the cylinder chamber, which is a circular space in FIG. 29, and that penetrates the cylinder in the axial direction.
- a vane 203 is slidably fitted into the vane groove 201c.
- a back pressure chamber 205 that introduces discharge pressure to the base of the vane groove 201c is provided, and the back pressure chamber 205 has a circular space in a plan view.
- the inside of the cylinder 201 is divided into a high pressure region 201a and a low pressure region 201b by the vane 203.
- the high pressure region 201a is filled with refrigerant at discharge pressure (Pd)
- the low pressure region 201b is filled with refrigerant at suction pressure (Ps).
- the vane 203 is in constant contact with the piston 202, enabling the refrigerant gas to be compressed.
- a check valve is provided at the discharge port 207, and when the pressure in the high pressure region 201a increases, the pressurized gas refrigerant is discharged from the discharge port 207.
- the resultant force of the forces acting toward the center of the cylinder 201 is called the pressing force, and the resultant force of the forces acting in the opposite direction of the cylinder 201 is called the separating force.
- the pressing force As the operating frequency of the compressor decreases, the pressing force also decreases, so the lower limit frequency of the compressor is determined within the range where pressing force > separating force holds.
- the minimum frequency of a rotary vane compressor is determined by the above conditions, and it tends to be higher than that of other types of compressors. For this reason, the range in which the operating frequency of a rotary vane compressor can be lowered to reduce the air conditioning capacity is narrow.
- the present disclosure relates to an air conditioning device 1000.
- the air conditioning device 1000 includes a refrigerant circuit 500 including at least a compressor 200, a condenser (211), an expansion valve 230, and an evaporator (110) configured to circulate a refrigerant, and a control device 100 that controls the refrigerant circuit 500.
- the condenser (211) includes a first heat exchanger 211A and a second heat exchanger 211B configured to allow the refrigerant to flow in parallel, and a flow rate adjustment mechanism 272 configured to adjust the flow rate of the refrigerant passing through the second heat exchanger 211B.
- the control device 100 is configured to be able to reduce the flow rate of the refrigerant passing through the second heat exchanger 211B by the flow rate adjustment mechanism 272 to be lower than the flow rate of the refrigerant passing through the first heat exchanger 211A when the operating frequency of the compressor 200 is a preset lower limit frequency Fmin. As shown in steps S34 and S35 of FIG. 7, when the air conditioning capacity of the refrigerant circuit 500 is greater than the indoor load, the control device 100 is configured to reduce the flow rate of the refrigerant passing through the second heat exchange section 211B using the flow rate adjustment mechanism 272, and then increase the opening of the expansion valve 230.
- the increase in the opening degree of the expansion valve 230 is determined based on the ratio between the flow rate of the refrigerant passing through the first heat exchange section 211A and the flow rate of the refrigerant passing through the second heat exchange section 211B.
- the increase in the opening degree of the expansion valve 230 may be determined using the map shown in FIG. 8.
- the increase in the opening degree of the expansion valve 230 may be determined using the approximation formulas shown in FIG. 9 and FIG. 10.
- the flow rate adjustment mechanism 272 is installed downstream of the second heat exchange section 211B in the example of FIG. 1.
- the flow rate adjustment mechanism 272 may also be installed upstream of the second heat exchange section 211B.
- the air conditioning device 1000 further includes a temperature sensor 261 that detects the room temperature.
- the control device 100 is configured to determine whether the air conditioning capacity is greater than the indoor load based on the change in the difference between the temperature detected by the temperature sensor 261 and a set temperature that is a target temperature for the room temperature.
- control device 100 is configured to control the expansion valve 230 so that the degree of superheat of the refrigerant at the outlet of the evaporator (110) or the refrigerant sucked into the compressor 200 is 5 degrees or less.
- the condenser (211) preferably further includes a first fan (221) and a second fan (222) whose rotation speeds can be controlled independently of each other by the control device.
- the first fan (221) is provided corresponding to the first heat exchange section 211A
- the second fan (222) is provided corresponding to the second heat exchange section 211B.
- the control device 100 uses the flow rate adjustment mechanism 272 to reduce the flow rate of the refrigerant passing through the second heat exchange section 211B to be lower than the flow rate of the refrigerant passing through the first heat exchange section 211A.
- control device 100 When the flow rate of the refrigerant passing through the second heat exchange section 211B is reduced to less than the flow rate of the refrigerant passing through the first heat exchange section 211A by the flow rate adjustment mechanism 272, the control device 100 is configured to reduce the rotation speed of the first fan (221) to less than the rotation speed of the second fan (222), as described in FIG. 18.
- the rate of reduction in the rotation speed of the first fan (221) is determined based on the ratio between the flow rate of the refrigerant passing through the first heat exchange section 211A and the flow rate of the refrigerant passing through the second heat exchange section 211B.
- control device 100 is configured to stop the rotation of the first fan (221) while maintaining the rotation of the second fan (222), as shown in FIG. 24.
- the compressor 200 is of the rotary vane type as shown in FIG.
- the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects.
- the scope of the present disclosure is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims.
- 100 control device 101 CPU, 102 memory, 110, 210, 211, 212 heat exchanger, 120 indoor fan, 200 compressor, 201 cylinder, 201a high pressure area, 201b low pressure area, 201c vane groove, 202 piston, 203 vane, 204 spring, 205 back pressure chamber, 206 intake port, 207 discharge port, 208 rotating shaft, 211A first heat exchange section, 211B second heat exchange section, 211F, 21 1FA, 211FB fins, 220 outdoor fan, 221, 222 fan, 230 expansion valve, 240 four-way valve, 261, 262, 263, 264, 265 temperature sensor, 270, 272 flow rate adjustment mechanism, 310, 320 piping, 500 refrigerant circuit, 1000, 1010, 1200 air conditioning unit, 1001 outdoor unit, 1002 indoor unit, P1, P2, P3, P4 ports, PIA, PIB refrigerant inlet, POA, POB refrigerant outlet.
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
An air conditioning device (1000) comprises a refrigerant circuit (500), and a control device (100) for controlling the refrigerant circuit (500). A condenser (211) includes a first heat exchanging unit and a second heat exchanging unit configured to be capable of allowing a refrigerant to flow in parallel, and a flow rate adjusting mechanism (272) configured to adjust a flow rate of the refrigerant passing through the second heat exchanging unit. The control device (100) is configured to be capable of causing the flow rate adjusting mechanism (272) to reduce the flow rate of the refrigerant passing through the second heat exchanging unit to below the flow rate of the refrigerant passing through the first heat exchanging unit if an operating frequency of a compressor (200) is a predetermined lower limit frequency. The control device (100) is configured to cause the flow rate adjusting mechanism (272) to reduce the flow rate of the refrigerant passing through the second heat exchanging unit if an air conditioning capability of the refrigerant circuit (500) is greater than an indoor load, and then to increase an opening degree of an expansion valve (230).
Description
本開示は、空気調和装置に関する。
This disclosure relates to air conditioning devices.
空気調和装置では、室内の負荷に応じて圧縮機の運転周波数を制御し、室内温度を調整する手法が広く採用されている。圧縮機には、運転可能な周波数範囲が決められている。春秋など室内負荷が小さく、圧縮機が下限周波数で運転しても室内温度を維持できない場合には、室温を安定させるために、圧縮機の運転(サーモオン)と停止(サーモオフ)を繰り返すオン-オフ運転が実施される。
A method widely used in air conditioning systems is to control the operating frequency of the compressor according to the load inside the room to adjust the indoor temperature. Compressors have a set frequency range within which they can operate. When the indoor load is small, such as in spring and autumn, and the indoor temperature cannot be maintained even when the compressor is operating at the minimum frequency, on-off operation is implemented to stabilize the room temperature by repeatedly operating (thermo on) and stopping (thermo off) the compressor.
しかしながら、オン-オフ運転には、室温の上下変動があり快適性を損なうといった課題、および、空気調和装置の成績係数(以下、COP)が連続運転より低下するといった課題がある。
However, on-off operation has issues such as room temperature fluctuating up and down, reducing comfort, and the air conditioning system's coefficient of performance (COP) being lower than with continuous operation.
そのため、特開平10-141740号公報(特許文献1)では、下限周波数の近傍で運転しているときに、膨張弁の開度を強制的に小さくし、冷媒循環量を減少させることで能力を低下させ、オン-オフ運転の発生頻度を低下させる技術が開示されている。
To this end, Japanese Patent Laid-Open Publication No. 10-141740 (Patent Document 1) discloses a technique for forcibly reducing the opening of the expansion valve when operating near the lower limit frequency, thereby reducing the amount of refrigerant circulating and thereby lowering capacity and reducing the frequency of on-off operation.
しかしながら、特開平10-141740号公報(特許文献1)に開示された技術では、膨張弁の開度を最適状態より小さくするため、蒸発器内のガス冷媒の割合が多くなる。このため蒸発器性能が低下し、蒸発温度が低下するので、COPが低下してしまうという課題がある。
However, in the technology disclosed in JP 10-141740 A (Patent Document 1), the opening of the expansion valve is made smaller than the optimal state, so the proportion of gas refrigerant in the evaporator increases. This causes the evaporator performance to decrease, and the evaporation temperature to decrease, resulting in a problem of a decrease in COP.
本開示は、上記課題を解決するものであって、オン-オフ運転の発生頻度の抑制と、COPの低下の抑制を両立する空気調和装置を提供することを目的とする。
The present disclosure aims to solve the above problem by providing an air conditioner that both reduces the frequency of on-off operation and prevents a decrease in COP.
本開示は、空気調和装置に関する。空気調和装置は、少なくとも圧縮機、凝縮器、膨張弁、および蒸発器を含み、冷媒が循環するように構成される冷媒回路と、冷媒回路を制御する制御装置とを備える。凝縮器は、冷媒を並行して流すことが可能に構成された第1熱交換部および第2熱交換部と、第2熱交換部を通過する冷媒の流量を調整するように構成された流量調整機構とを含む。制御装置は、圧縮機の運転周波数が予め設定された下限周波数である場合に、流量調整機構によって第2熱交換部を通過する冷媒の流量を第1熱交換部を通過する冷媒の流量よりも低下させることが可能に構成される。制御装置は、室内負荷よりも冷媒回路の空調能力が大きい場合には、流量調整機構によって第2熱交換部を通過する冷媒の流量を低下させた後に、膨張弁の開度を増加させるように構成される。
The present disclosure relates to an air conditioner. The air conditioner includes a refrigerant circuit including at least a compressor, a condenser, an expansion valve, and an evaporator, and configured to circulate a refrigerant, and a control device that controls the refrigerant circuit. The condenser includes a first heat exchange unit and a second heat exchange unit configured to allow the refrigerant to flow in parallel, and a flow rate adjustment mechanism configured to adjust the flow rate of the refrigerant passing through the second heat exchange unit. The control device is configured to be able to reduce the flow rate of the refrigerant passing through the second heat exchange unit by the flow rate adjustment mechanism to be lower than the flow rate of the refrigerant passing through the first heat exchange unit when the operating frequency of the compressor is a preset lower limit frequency. The control device is configured to increase the opening of the expansion valve after reducing the flow rate of the refrigerant passing through the second heat exchange unit by the flow rate adjustment mechanism when the air conditioning capacity of the refrigerant circuit is greater than the indoor load.
本開示の空気調和装置は、圧縮機が下限周波数で運転している場合でも、さらに空調能力を低減させることが可能である。このため、オン-オフ運転の発生頻度を抑制しつつ、COPの低下も抑制することができる。
The air conditioning device disclosed herein is capable of further reducing the air conditioning capacity even when the compressor is operating at the lower limit frequency. This makes it possible to suppress the frequency of on-off operation while also suppressing the decrease in COP.
以下、本開示の実施の形態について、図面を参照しながら詳細に説明する。以下では、複数の実施の形態について説明するが、各実施の形態で説明された構成を適宜組み合わせることは出願当初から予定されている。なお、図中同一または相当部分には同一符号を付してその説明は繰り返さない。なお、以下の図は各構成部材の大きさの関係が実際のものとは異なる場合がある。
Below, the embodiments of the present disclosure will be described in detail with reference to the drawings. Several embodiments will be described below, but it is planned from the beginning of the application that the configurations described in each embodiment will be appropriately combined. Note that the same or equivalent parts in the drawings will be given the same reference numerals and their description will not be repeated. Note that the size relationships between the components in the following drawings may differ from the actual ones.
実施の形態1.
図1は、実施の形態1の空気調和装置1000の構成を示す図である。図1に示す空気調和装置1000は、冷媒回路500と、制御装置100とを備える。Embodiment 1.
Fig. 1 is a diagram showing the configuration of an air-conditioning apparatus 1000 according to embodiment 1. The air-conditioning apparatus 1000 shown in Fig. 1 includes a refrigerant circuit 500 and a control device 100.
図1は、実施の形態1の空気調和装置1000の構成を示す図である。図1に示す空気調和装置1000は、冷媒回路500と、制御装置100とを備える。
Fig. 1 is a diagram showing the configuration of an air-
図1に示すように、空気調和装置1000の冷媒回路500は、圧縮機200、室外熱交換器211、室外送風機(ファン)220、膨張弁230、四方弁240、流量調整機構272、室内熱交換器110、室内送風機(ファン)120を含んで構成される。四方弁240はポートP1~P4を有する。膨張弁230としては、例えば電子膨張弁(LEV:Linear Expansion Valve)を用いることができる。
As shown in FIG. 1, the refrigerant circuit 500 of the air conditioning device 1000 includes a compressor 200, an outdoor heat exchanger 211, an outdoor blower (fan) 220, an expansion valve 230, a four-way valve 240, a flow rate adjustment mechanism 272, an indoor heat exchanger 110, and an indoor blower (fan) 120. The four-way valve 240 has ports P1 to P4. As the expansion valve 230, for example, an electronic expansion valve (LEV: Linear Expansion Valve) can be used.
冷媒回路500は、室外機1001と室内機1002に分かれて配置される。室外機1001は、圧縮機200と、四方弁240と、室外熱交換器211と、室外ファン220と、膨張弁230と、制御装置100とを含む。室内機1002は、室内熱交換器110と室内ファン120とを含む。室外機1001と室内機1002とは、配管310および320によって接続される。
The refrigerant circuit 500 is arranged separately for an outdoor unit 1001 and an indoor unit 1002. The outdoor unit 1001 includes a compressor 200, a four-way valve 240, an outdoor heat exchanger 211, an outdoor fan 220, an expansion valve 230, and a control device 100. The indoor unit 1002 includes an indoor heat exchanger 110 and an indoor fan 120. The outdoor unit 1001 and the indoor unit 1002 are connected by pipes 310 and 320.
圧縮機200は、制御装置100から受ける制御信号によって運転周波数を変更するように構成される。具体的には、圧縮機200は、インバータ制御された回転速度が可変の駆動モータを内蔵しており、運転周波数が変更されると駆動モータの回転速度が変化する。圧縮機200の運転周波数を変更することにより圧縮機200の出力が調整される。
Compressor 200 is configured to change its operating frequency according to a control signal received from control device 100. Specifically, compressor 200 has a built-in drive motor with a variable rotation speed that is inverter-controlled, and when the operating frequency is changed, the rotation speed of the drive motor changes. The output of compressor 200 is adjusted by changing the operating frequency of compressor 200.
四方弁240は、制御装置100から受ける制御信号によって冷房運転状態および暖房運転状態のいずれかになるように制御される。冷房運転状態は、図1に実線で示すように、ポートP1とポートP4とが連通し、ポートP2とポートP3とが連通する状態である。暖房運転状態は、図1に破線で示すように、ポートP1とポートP3とが連通し、ポートP2とポートP4とが連通する状態である。冷房運転状態で圧縮機200を運転することによって、実線矢印に示す向きに冷媒が冷媒回路中を循環する。また、暖房運転状態で圧縮機200を運転することによって、破線矢印に示す向きに冷媒が冷媒回路中を循環する。
The four-way valve 240 is controlled to be in either a cooling operation state or a heating operation state by a control signal received from the control device 100. The cooling operation state is a state in which port P1 and port P4 are in communication, and port P2 and port P3 are in communication, as shown by solid lines in FIG. 1. The heating operation state is a state in which port P1 and port P3 are in communication, and port P2 and port P4 are in communication, as shown by dashed lines in FIG. 1. By operating the compressor 200 in the cooling operation state, the refrigerant circulates through the refrigerant circuit in the direction shown by the solid arrow. Also, by operating the compressor 200 in the heating operation state, the refrigerant circulates through the refrigerant circuit in the direction shown by the dashed arrow.
空気調和装置1000は、温度センサ261~265をさらに含む。温度センサ261は、室内機1002に配置され空調の対象となる部屋の室温T261を検出する。温度センサ262は、室内熱交換器110の配管320(液管)に接続される側に配置され冷媒温度T262を計測する。温度センサ263は、室内熱交換器110の配管310(ガス管)に接続される側に配置され冷媒温度T263を計測する。温度センサ264は、室外熱交換器211の膨張弁230に接続される側に配置され、冷媒温度T264を計測する。温度センサ265は、室外熱交換器210の四方弁240のポートP4に接続される側に配置され、冷媒温度T265を計測する。
The air conditioning device 1000 further includes temperature sensors 261-265. The temperature sensor 261 is disposed in the indoor unit 1002 and detects the room temperature T261 of the room to be air-conditioned. The temperature sensor 262 is disposed on the side connected to the pipe 320 (liquid pipe) of the indoor heat exchanger 110 and measures the refrigerant temperature T262. The temperature sensor 263 is disposed on the side connected to the pipe 310 (gas pipe) of the indoor heat exchanger 110 and measures the refrigerant temperature T263. The temperature sensor 264 is disposed on the side connected to the expansion valve 230 of the outdoor heat exchanger 211 and measures the refrigerant temperature T264. The temperature sensor 265 is disposed on the side connected to the port P4 of the four-way valve 240 of the outdoor heat exchanger 210 and measures the refrigerant temperature T265.
制御装置100は、温度センサ261~265の出力に応じて、蒸発器出口部の冷媒のSH(スーパーヒート:過熱度)を調整するように膨張弁230の開度を制御するとともに、ファン221,222の回転を制御する。
The control device 100 controls the opening of the expansion valve 230 to adjust the SH (superheat) of the refrigerant at the evaporator outlet according to the outputs of the temperature sensors 261-265, and also controls the rotation of the fans 221 and 222.
制御装置100は、CPU(Central Processing Unit)101と、メモリ102(ROM(Read Only Memory)およびRAM(Random Access Memory))と、入出力バッファ(図示せず)等を含んで構成される。CPU101は、ROMに格納されているプログラムをRAM等に展開して実行する。ROMに格納されるプログラムは、制御装置100の処理手順が記されたプログラムである。制御装置100は、これらのプログラムに従って、空気調和装置1000における各機器の制御を実行する。この制御については、ソフトウェアによる処理に限られず、専用のハードウェア(電子回路)で処理することも可能である。
The control device 100 is composed of a CPU (Central Processing Unit) 101, memory 102 (ROM (Read Only Memory) and RAM (Random Access Memory)), an input/output buffer (not shown), etc. The CPU 101 deploys programs stored in the ROM into the RAM etc. and executes them. The programs stored in the ROM are programs in which the processing procedures of the control device 100 are written. The control device 100 controls each device in the air conditioning device 1000 in accordance with these programs. This control is not limited to processing by software, but can also be processed by dedicated hardware (electronic circuits).
図1中に、冷房運転中の冷媒の流れを実線で、暖房運転中の冷媒の流れを破線で示す。制御装置100は、室内温度が目標(設定)温度になるように圧縮機200の周波数を変更する。
In FIG. 1, the flow of refrigerant during cooling operation is shown by a solid line, and the flow of refrigerant during heating operation is shown by a dashed line. The control device 100 changes the frequency of the compressor 200 so that the indoor temperature becomes the target (set) temperature.
なお、図1には、四方弁240を備えた空気調和装置を例示したが、四方弁240がない冷房専用の空気調和装置としてもよい。
Note that while FIG. 1 illustrates an air conditioner equipped with a four-way valve 240, the air conditioner may be a cooling-only air conditioner that does not have a four-way valve 240.
室外熱交換器211は、並列接続された2つの熱交換部と、流量調整機構272とを含む。一方の熱交換部の冷媒出口には流量調整機構272が配置される。
The outdoor heat exchanger 211 includes two heat exchange sections connected in parallel and a flow rate adjustment mechanism 272. The flow rate adjustment mechanism 272 is disposed at the refrigerant outlet of one of the heat exchange sections.
図2は、図1における室外熱交換器211の構成例を示す図である。室外熱交換器211は、並列に冷媒を流すことが可能に構成された、第1熱交換部211Aと第2熱交換部211Bとを含む。図2には、風向に直交する側面方向から室外熱交換器211を見た側面図が示されている。
FIG. 2 is a diagram showing an example of the configuration of the outdoor heat exchanger 211 in FIG. 1. The outdoor heat exchanger 211 includes a first heat exchange section 211A and a second heat exchange section 211B that are configured to allow a refrigerant to flow in parallel. FIG. 2 shows a side view of the outdoor heat exchanger 211 as seen from a lateral direction perpendicular to the wind direction.
図1の流量調整機構272は、第2熱交換部211Bの冷媒出口POBと冷媒流路の合流部の間に設置されている。なお、流量調整機構272は特に断りのない限り開度は全開とされる。
The flow rate adjustment mechanism 272 in FIG. 1 is installed between the refrigerant outlet POB of the second heat exchange section 211B and the junction of the refrigerant flow paths. The flow rate adjustment mechanism 272 is fully open unless otherwise specified.
室外熱交換器211は、第1熱交換部211Aと第2熱交換部211Bに共通に設けられる複数のフィン211Fをさらに含む。複数のフィン211Fは、風が通過できるように間隔を設けて紙面手前から奥に向けて積層して配置されている。
The outdoor heat exchanger 211 further includes a plurality of fins 211F that are provided in common to the first heat exchange section 211A and the second heat exchange section 211B. The plurality of fins 211F are arranged in layers from the front to the back of the page with intervals provided to allow air to pass through.
第1熱交換部211Aは、複数のフィン211Fを貫通する複数の配管と、これらの複数の配管を両側面において接続する接続部とを含む。図2において、丸印は1本の配管を示し、実線は紙面手前側側面で配管を接続する接続部を示し、破線は紙面奥側側面で配管を接続する接続部を示す。これにより、冷媒入口PIAから流入した冷媒が、冷媒出口POAから流出する1本の冷媒流路が形成されている。
The first heat exchange section 211A includes multiple pipes that pass through multiple fins 211F and connections that connect these multiple pipes on both sides. In FIG. 2, a circle indicates one pipe, a solid line indicates a connection that connects the pipes on the side facing the page, and a dashed line indicates a connection that connects the pipes on the side facing the page. This forms a single refrigerant flow path in which the refrigerant that flows in from the refrigerant inlet PIA flows out from the refrigerant outlet POA.
第2熱交換部211Bについても、第1熱交換部211Aと同様に、複数のフィン211Fを貫通する複数の配管と、これらの複数の配管を両側面において接続する接続部とを含む。図2において丸印は1本の配管を示し、実線は紙面手前側側面で配管を接続する接続部を示し、破線は紙面奥側側面で配管を接続する接続部を示す。これにより、冷媒入口PIBから流入した冷媒が、冷媒出口POBから流出する1本の冷媒流路が形成されている。
The second heat exchange section 211B, like the first heat exchange section 211A, includes multiple pipes penetrating multiple fins 211F and connections connecting these multiple pipes on both sides. In FIG. 2, a circle indicates one pipe, a solid line indicates a connection connecting the pipes on the side facing the page, and a dashed line indicates a connection connecting the pipes on the side facing the page. This forms a single refrigerant flow path in which the refrigerant flowing in from the refrigerant inlet PIB flows out from the refrigerant outlet POB.
ここで、図1の流量調整機構272は、第2熱交換部211Bの冷媒出口POB側に設置されているが、冷媒入口PIB側でもよい。また、流量調整機構272は第1熱交換部211Aの上流または下流に設置されても良い。
Here, the flow rate adjustment mechanism 272 in FIG. 1 is installed on the refrigerant outlet POB side of the second heat exchange section 211B, but it may be installed on the refrigerant inlet PIB side. Also, the flow rate adjustment mechanism 272 may be installed upstream or downstream of the first heat exchange section 211A.
図1中に、冷房運転モード時の冷媒の流れが実線で示され、暖房運転モード時の冷媒の流れが破線で示される。圧縮機200は、室内温度が目標(設定)温度になるように圧縮機200の周波数を変更する。
In FIG. 1, the flow of refrigerant in cooling operation mode is shown by a solid line, and the flow of refrigerant in heating operation mode is shown by a dashed line. Compressor 200 changes the frequency of compressor 200 so that the indoor temperature becomes the target (set) temperature.
次に、膨張弁230の制御について説明する。図3は、膨張弁230の制御を説明するためのフローチャートである。
Next, the control of the expansion valve 230 will be described. Figure 3 is a flowchart for explaining the control of the expansion valve 230.
まず、ステップS21において、制御装置100は、膨張弁230の開度を既定値に設定する。なお、この規定値については、後に図8~図10で説明する。一定時間経過後、ステップS22において、制御装置100は、変数Countを0に初期化する。変数Countが1以上の場合は、膨張弁の開度を複数回減少させた履歴があることを示し、変数Countが0の場合は、膨張弁の開度を複数回減少させていなかったことを示す。
First, in step S21, the control device 100 sets the opening of the expansion valve 230 to a default value. This default value will be described later with reference to Figures 8 to 10. After a certain period of time has elapsed, in step S22, the control device 100 initializes the variable Count to 0. If the variable Count is 1 or greater, this indicates that the expansion valve opening has been decreased multiple times, and if the variable Count is 0, this indicates that the expansion valve opening has not been decreased multiple times.
その後、ステップS23において、制御装置100は、膨張弁230の開度を一定値減少させる。一定時間経過後、ステップS24において、制御装置100は、蒸発器出口の冷媒過熱度SHが変化したかを判断する。
Then, in step S23, the control device 100 reduces the opening of the expansion valve 230 by a fixed value. After a fixed time has elapsed, in step S24, the control device 100 determines whether the degree of refrigerant superheat SH at the evaporator outlet has changed.
冷房運転時には、蒸発器出口の冷媒過熱度SHは、温度センサ263で取得された蒸発器出口温度T263から温度センサ262で取得された蒸発温度T262を引くことによって計算される。一方、暖房運転時には、蒸発器出口の冷媒過熱度SHは、温度センサ265で取得された蒸発器出口温度T265から温度センサ264で取得された蒸発温度T264を引くことによって計算される。
During cooling operation, the degree of refrigerant superheat SH at the evaporator outlet is calculated by subtracting the evaporation temperature T262 obtained by the temperature sensor 262 from the evaporator outlet temperature T263 obtained by the temperature sensor 263. On the other hand, during heating operation, the degree of refrigerant superheat SH at the evaporator outlet is calculated by subtracting the evaporation temperature T264 obtained by the temperature sensor 264 from the evaporator outlet temperature T265 obtained by the temperature sensor 265.
ステップS24でNOと判定された場合、つまり蒸発器出口の冷媒過熱度SHに変化がなかった場合には、蒸発器出口の冷媒の状態が気液2相状態から変化がなかったと考えられる。このため、ステップS25で、制御装置100は、変数Countに1を加算した後、ステップS23に処理を戻し、膨張弁230の開度を一定値減少させる。
If the answer in step S24 is NO, that is, if there is no change in the degree of refrigerant superheat SH at the evaporator outlet, it is considered that the state of the refrigerant at the evaporator outlet has not changed from the two-phase gas-liquid state. Therefore, in step S25, the control device 100 adds 1 to the variable Count, and then returns to the process in step S23, decreasing the opening degree of the expansion valve 230 by a fixed value.
ステップS23~S25の処理を繰り返すことによって、ステップS21の既定開度で蒸発器出口部まで液冷媒が存在していた場合には、冷媒過熱度SHが蒸発器出口の冷媒過熱度SHが概ね0である最適な状態にすることができる。一方、ステップS24でYESと判定された場合(蒸発器出口の冷媒状態が過熱ガス状態の場合)、制御装置100は、ステップS26に移行し変数Countが0かどうかを判断する。
By repeating the processes of steps S23 to S25, if liquid refrigerant is present up to the evaporator outlet at the default opening in step S21, the refrigerant superheat degree SH at the evaporator outlet can be brought to an optimal state where the refrigerant superheat degree SH at the evaporator outlet is approximately 0. On the other hand, if the determination in step S24 is YES (if the refrigerant state at the evaporator outlet is a superheated gas state), the control device 100 proceeds to step S26 and determines whether the variable Count is 0.
ステップS26でNOと判定された場合、つまり変数Countが0でない場合には、ステップS23~S25で蒸発器出口の冷媒過熱度SHが適切に制御されているため、制御装置100は、膨張弁230の開度を決定する処理を終了する。
If step S26 returns NO, i.e., if the variable Count is not 0, the refrigerant superheat degree SH at the evaporator outlet has been appropriately controlled in steps S23 to S25, and the control device 100 ends the process of determining the opening degree of the expansion valve 230.
一方、ステップS26でYESと判定された場合、変数Countが0のため、ステップS25を経由せずにステップS24を一度で通過している。ステップS21の既定開度では蒸発器出口が過熱ガス状態で、そこからステップS23でさらに過熱度(SH)が増加しているため、適正な状態とは言えない。したがって、ステップS27において、膨張弁230の開度を一定値増加させる。そして、一定時間経過後、ステップS28において、蒸発器出口の冷媒過熱度SHの値に変化があるかを判断する。
On the other hand, if the answer is YES in step S26, the variable Count is 0, so step S24 is passed through in one go without going through step S25. At the default opening in step S21, the evaporator outlet is in a superheated gas state, and the degree of superheat (SH) is further increased in step S23, so this cannot be said to be an appropriate state. Therefore, in step S27, the opening of the expansion valve 230 is increased by a fixed value. Then, after a fixed time has elapsed, in step S28, it is determined whether there has been a change in the value of the refrigerant superheat SH at the evaporator outlet.
ステップS28でYESと判定された場合、つまり蒸発器出口の冷媒過熱度SHに変化があった場合は、蒸発器出口の冷媒過熱度SHの値に変化があるため、ステップS27に戻り、膨張弁230の開度を一定値増加させる。これを繰り返すことで、蒸発器出口の冷媒過熱度SHが概ね0である最適な状態にすることができる。一方、ステップS28でNOと判定された場合、つまり蒸発器出口の冷媒過熱度SHに変化がない場合には、蒸発器出口冷媒が気液2相(過熱度0)と判断でき、蒸発器での熱交換効率がよいため、膨張弁230の開度を決定する処理を終了する。
If step S28 returns YES, that is, if there has been a change in the refrigerant superheat degree SH at the evaporator outlet, the process returns to step S27 and increases the opening degree of the expansion valve 230 by a fixed value since there has been a change in the value of the refrigerant superheat degree SH at the evaporator outlet. By repeating this process, an optimal state in which the refrigerant superheat degree SH at the evaporator outlet is approximately 0 can be achieved. On the other hand, if step S28 returns NO, that is, if there has been no change in the refrigerant superheat degree SH at the evaporator outlet, the evaporator outlet refrigerant can be determined to be in two phases (superheat degree 0) and the heat exchange efficiency in the evaporator is good, so the process of determining the opening degree of the expansion valve 230 is terminated.
なお、過熱度=0において蒸発器での熱交換効率がよい理由は、ガス相では、顕熱のみだが、二相では顕熱+潜熱で熱交換できるためである。過熱度=0であれば、蒸発器は入口から出口まで二相状態であり熱交換能力がよく、かつ圧縮機に送られる冷媒はガス状態であるので液圧縮が防止できる。
The reason that the heat exchange efficiency in the evaporator is good when the degree of superheat = 0 is that in the gas phase, only sensible heat is exchanged, but in the two-phase, sensible heat + latent heat can be exchanged. When the degree of superheat = 0, the evaporator is in a two-phase state from the inlet to the outlet, so it has good heat exchange capacity, and the refrigerant sent to the compressor is in a gas state, so liquid compression can be prevented.
以上、膨張弁230の制御の流れについて説明した。図3のフローチャートでは、蒸発器出口の冷媒過熱度SHの値で制御したが、蒸発器出口の冷媒過熱度SHの値に対応する圧縮機200の吐出冷媒の過熱度または吐出冷媒温度の目標値を予め定めておき、吐出冷媒の過熱度または吐出冷媒温度に基づいて膨張弁230を制御してもよい。
The above describes the flow of control of the expansion valve 230. In the flowchart of FIG. 3, control is performed based on the value of the refrigerant superheat degree SH at the evaporator outlet, but it is also possible to predetermine a target value for the superheat degree or discharge refrigerant temperature of the discharge refrigerant of the compressor 200 corresponding to the value of the refrigerant superheat degree SH at the evaporator outlet, and control the expansion valve 230 based on the superheat degree or discharge refrigerant temperature of the discharge refrigerant.
図3のフローチャートで用いられた蒸発器出口の冷媒過熱度SHは、温度センサ間に圧力損失があったり、冷媒に温度勾配があったりすると変化する。R32などの現在主流の冷媒よりも圧力損失が大きくなる冷媒(低圧冷媒、例えば1234yf、プロパンなど)では、この手法で求まる蒸発器出口の冷媒過熱度SHの値は小さくなり、温度勾配が大きい冷媒(非共沸混合冷媒)では、この手法で求まる蒸発器出口の冷媒過熱度SHの値は大きくなる。
The refrigerant superheat degree SH at the evaporator outlet used in the flowchart of Figure 3 changes if there is a pressure loss between the temperature sensors or if there is a temperature gradient in the refrigerant. For refrigerants (low pressure refrigerants, e.g. 1234yf, propane, etc.) that have a larger pressure loss than currently mainstream refrigerants such as R32, the value of the refrigerant superheat degree SH at the evaporator outlet calculated using this method will be smaller, and for refrigerants with a large temperature gradient (non-azeotropic refrigerant mixtures), the value of the refrigerant superheat degree SH at the evaporator outlet calculated using this method will be larger.
また、現実的には過熱度(SH)が5deg程度であれば、蒸発器の性能はそれほど落ちないことから多少の誤差は許容される。したがって、ステップS24,S28において、制御装置100は、過熱度(SH)を5deg以下に制御しても良い。
In addition, in reality, if the degree of superheat (SH) is about 5 degrees, the performance of the evaporator does not decrease significantly, so some error is acceptable. Therefore, in steps S24 and S28, the control device 100 may control the degree of superheat (SH) to 5 degrees or less.
次に、流量調整機構272の制御について説明する。
図4は、冷房運転時に圧縮機の運転周波数が下限周波数Fminであるときに、流量調整機構272の開度を変化させた場合の空気調和装置の能力の変化を示す図である。図4の縦軸には流量調整機構272を全開としたときを100%とした空気調和装置の能力を示す。横軸には、流量調整機構272の開度に応じて変化する循環流量比(%)を示す。 Next, the control of the flowrate adjusting mechanism 272 will be described.
Fig. 4 is a diagram showing the change in capacity of the air conditioner when the opening degree of the flowrate adjustment mechanism 272 is changed when the operating frequency of the compressor is at the lower limit frequency Fmin during cooling operation. The vertical axis of Fig. 4 shows the capacity of the air conditioner, with 100% being when the flow rate adjustment mechanism 272 is fully open. The horizontal axis shows the circulation flow rate ratio (%) that changes according to the opening degree of the flow rate adjustment mechanism 272.
図4は、冷房運転時に圧縮機の運転周波数が下限周波数Fminであるときに、流量調整機構272の開度を変化させた場合の空気調和装置の能力の変化を示す図である。図4の縦軸には流量調整機構272を全開としたときを100%とした空気調和装置の能力を示す。横軸には、流量調整機構272の開度に応じて変化する循環流量比(%)を示す。 Next, the control of the flow
Fig. 4 is a diagram showing the change in capacity of the air conditioner when the opening degree of the flow
縦軸に示した能力比(%)は、(空気調和装置1000の能力)/(循環流量比100%での空気調和装置1000の能力)を%で表わした数値である。横軸に示した循環流量比(%)は、(第2熱交換部211Bに流れる冷媒流量)/(第1熱交換部211Aに流れる冷媒流量)を%で表わした数値である。循環流量比を50%まで低下させれば、空気調和装置1000の能力を約20%低下させることが可能である。流量調整機構272の開度を全閉し、第2熱交換部211Bに流れる冷媒流量を0とすれば、空気調和装置1000の能力をほぼ0とすることが可能である。
The capacity ratio (%) shown on the vertical axis is a numerical value obtained by dividing (capacity of air conditioning device 1000) by (capacity of air conditioning device 1000 at a circulation flow rate ratio of 100%), expressed as a percentage. The circulation flow rate ratio (%) shown on the horizontal axis is a numerical value obtained by dividing (refrigerant flow rate flowing through second heat exchange section 211B) by (refrigerant flow rate flowing through first heat exchange section 211A), expressed as a percentage. If the circulation flow rate ratio is reduced to 50%, it is possible to reduce the capacity of air conditioning device 1000 by approximately 20%. If the flow rate adjustment mechanism 272 is fully closed and the refrigerant flow rate flowing through second heat exchange section 211B is set to 0, it is possible to reduce the capacity of air conditioning device 1000 to almost 0.
図5は、循環流量比が100%である場合の空気調和装置のp-h線図である。図6は、循環流量比が19%である場合の空気調和装置のp-h線図である。図5、図6には、風量を同じ24m3/minに固定した場合を示した。
Fig. 5 is a ph diagram of an air conditioner when the circulation flow rate ratio is 100%. Fig. 6 is a ph diagram of an air conditioner when the circulation flow rate ratio is 19%. Figs. 5 and 6 show the case where the air volume is fixed at the same 24 m 3 /min.
流量調整機構272の開度が減少すると能力が低下する理由を以下に説明する。流量調整機構272の開度が減少すると、第2熱交換部211Bに流れる冷媒流量が減少するため、第2熱交換部211Bでの熱交換量が少なくなる。すると、第2熱交換部211Bを通過する冷媒は、冷媒入口PIBから冷媒出口POBに向かう途中で熱交換を完了しやすくなり(もしくは完全に熱交換を完了し)、冷媒出口POBでの冷媒温度は空気温度に近づく(もしくは完全に空気温度と同じなる)。つまり、液冷媒が多くなり、第2熱交換部211B内の冷媒量が増加する。そのため、第1熱交換部211A内の冷媒量が減少する、つまり、冷媒出口POAのエンタルピーも増加する。これにより、温度センサ264が設置されている合流地点での出口エンタルピーが増加し、蒸発器入口エンタルピーも増加する。その結果、図6に示すように蒸発器出口と入口のエンタルピー差が小さくなり空調能力が低下する。
The reason why the capacity decreases when the opening degree of the flow rate adjustment mechanism 272 is reduced is explained below. When the opening degree of the flow rate adjustment mechanism 272 is reduced, the refrigerant flow rate flowing through the second heat exchange section 211B is reduced, and the amount of heat exchange in the second heat exchange section 211B is reduced. Then, the refrigerant passing through the second heat exchange section 211B is more likely to complete heat exchange on the way from the refrigerant inlet PIB to the refrigerant outlet POB (or completes heat exchange completely), and the refrigerant temperature at the refrigerant outlet POB approaches the air temperature (or becomes completely the same as the air temperature). In other words, the amount of liquid refrigerant increases, and the amount of refrigerant in the second heat exchange section 211B increases. Therefore, the amount of refrigerant in the first heat exchange section 211A decreases, that is, the enthalpy of the refrigerant outlet POA also increases. As a result, the outlet enthalpy at the junction where the temperature sensor 264 is installed increases, and the evaporator inlet enthalpy also increases. As a result, as shown in FIG. 6, the enthalpy difference between the evaporator outlet and inlet decreases, and the air conditioning capacity decreases.
つまり、図5(循環流量比100%)で示した冷凍サイクル(C1-C2-C3-C4)と比較すると、図6(循環流量比19%)で示した冷凍サイクル(C11-C12-C13-C14)は、横軸方向(比エンタルピー方向)の長さが短くなっていることが分かる。なお、点C1および点C11は、蒸発器出口の状態を示す点である。点C2および点C12は、圧縮機出口の状態を示す点である。点C3および点C13は、温度センサ264が設置されている冷媒の合流地点の状態を示す点である。点C4および点C14は、蒸発器入口の状態を示す点である。
In other words, compared to the refrigeration cycle (C1-C2-C3-C4) shown in Figure 5 (circulation flow ratio 100%), the refrigeration cycle (C11-C12-C13-C14) shown in Figure 6 (circulation flow ratio 19%) is shorter in length in the horizontal direction (specific enthalpy direction). Note that points C1 and C11 indicate the state of the evaporator outlet. Points C2 and C12 indicate the state of the compressor outlet. Points C3 and C13 indicate the state of the refrigerant confluence point where temperature sensor 264 is installed. Points C4 and C14 indicate the state of the evaporator inlet.
熱交換能力および熱交換量Q[kW]は、冷媒の循環流量Gr[kg/s]×エンタルピー差Δh[kJ/kg]で示される。このため横軸方向の長さであるエンタルピー差が小さくなれば能力が小さくなる。
Heat exchange capacity and heat exchange amount Q [kW] are expressed as the refrigerant circulation flow rate Gr [kg/s] x enthalpy difference Δh [kJ/kg]. Therefore, the capacity decreases as the enthalpy difference, which is the length in the horizontal direction, decreases.
これは、同じ風量および圧縮機周波数でも、循環流量比を変化させると空調能力を半分程度に抑制した熱交換器が実現できることを意味している。
This means that even with the same air volume and compressor frequency, by changing the circulation flow ratio, it is possible to create a heat exchanger that reduces the air conditioning capacity by about half.
このように、下限周波数Fminで圧縮機200を運転している場合に、流量調整機構272の開度を低下させ、循環流量比を下げることにより、空気調和装置の能力を下げることが可能となる。
In this way, when the compressor 200 is operating at the lower limit frequency Fmin, it is possible to reduce the capacity of the air conditioning device by decreasing the opening of the flow rate adjustment mechanism 272 and lowering the circulation flow rate ratio.
図7は、流量調整機構272の制御について説明するためのフローチャートである。まず、図7のステップS31において、制御装置100は、圧縮機200の運転周波数Fが下限周波数Fminであるかどうかを判断する。
FIG. 7 is a flowchart for explaining the control of the flow rate adjustment mechanism 272. First, in step S31 of FIG. 7, the control device 100 determines whether the operating frequency F of the compressor 200 is the lower limit frequency Fmin.
ステップS31でNOと判定された場合、つまり運転周波数Fが下限周波数Fminより大きい場合には、圧縮機200は、室内温度が設定温度になるように圧縮機200の運転周波数Fを増加または減少させるという通常の制御が可能である。このため、制御装置100は、ステップS37で流量調整機構272の開度を全開にして終了する。上述したように、制御装置100は、流量調整機構272の開度を、圧縮機200の運転周波数Fが下限周波数Fmin以外では全開に制御する。この場合、制御装置100は、圧縮機200の運転周波数Fに対応する回転速度Nに室外ファン220の回転速度を設定する。
If step S31 returns NO, that is, if the operating frequency F is greater than the lower limit frequency Fmin, the compressor 200 can perform normal control, increasing or decreasing the operating frequency F of the compressor 200 so that the indoor temperature becomes the set temperature. For this reason, the control device 100 ends the process by fully opening the flow rate adjustment mechanism 272 in step S37. As described above, the control device 100 controls the opening rate of the flow rate adjustment mechanism 272 to be fully open when the operating frequency F of the compressor 200 is other than the lower limit frequency Fmin. In this case, the control device 100 sets the rotation speed of the outdoor fan 220 to the rotation speed N corresponding to the operating frequency F of the compressor 200.
一方、ステップS31でYesと判断された場合、制御装置100は、空気調和装置の室内熱交換能力が室内負荷より大きいかどうかを判断する。
On the other hand, if the answer is Yes in step S31, the control device 100 determines whether the indoor heat exchange capacity of the air conditioner is greater than the indoor load.
空気調和装置の室内熱交換能力が室内負荷より大きいかどうかは具体的には以下の式(1)で判断する。
|Ta(end)-Ts|>|(Ta(start)-Ts)| …(1)
ここで、Tsは空気調和装置の室内の設定温度を示し、Ta(start)は、ステップS32開始時に温度センサ261で検出された温度を示し、Ta(end)は、ステップS32開始時から一定時間経過時に温度センサ261で検出された温度を示す。一定時間は、例えば、数分程度とする。 Specifically, whether or not the indoor heat exchange capacity of the air conditioner is greater than the indoor load is determined by the following formula (1).
|Ta(end)-Ts|>|(Ta(start)-Ts)| ... (1)
Here, Ts indicates the indoor set temperature of the air conditioner, Ta(start) indicates the temperature detected by thetemperature sensor 261 at the start of step S32, and Ta(end) indicates the temperature detected by the temperature sensor 261 when a certain time has elapsed since the start of step S32. The certain time is, for example, about several minutes.
|Ta(end)-Ts|>|(Ta(start)-Ts)| …(1)
ここで、Tsは空気調和装置の室内の設定温度を示し、Ta(start)は、ステップS32開始時に温度センサ261で検出された温度を示し、Ta(end)は、ステップS32開始時から一定時間経過時に温度センサ261で検出された温度を示す。一定時間は、例えば、数分程度とする。 Specifically, whether or not the indoor heat exchange capacity of the air conditioner is greater than the indoor load is determined by the following formula (1).
|Ta(end)-Ts|>|(Ta(start)-Ts)| ... (1)
Here, Ts indicates the indoor set temperature of the air conditioner, Ta(start) indicates the temperature detected by the
上記式(1)が成り立つということは、一定時間経過時の室内温度と設定温度との差(|Ta(end)-Ts|)が、開始時の室内温度と設定温度との差(|(Ta(start)-Ts)|)より大きいときである。つまり、一定時間経過時に室内温度が設定温度から離れてしまった場合であり、この場合には室内熱交換能力が室内負荷より大きいということになる。
The above formula (1) holds true when the difference between the indoor temperature after a certain time has passed and the set temperature (|Ta(end) - Ts|) is greater than the difference between the indoor temperature at the start and the set temperature (|(Ta(start) - Ts)|). In other words, this is the case when the indoor temperature has deviated from the set temperature after a certain time has passed, in which case the indoor heat exchange capacity is greater than the indoor load.
ステップS32でYESと判定された場合は、下限周波数Fminでも空気調和装置の能力が室内負荷より大きいため、ステップS33に移行し、制御装置100は、流量調整機構272が全閉かどうかを判断する。ステップS33でNOと判定された場合、制御装置100は、ステップS34において流量調整機構272の開度を一定値減少させる。これにより、第2熱交換部211Bでの熱交換量を低下させ、空調能力を低下させる。その後、ステップS35で膨張弁230の開度の制御を実施する。ステップS35をステップS34の後に実施する理由を以下で説明する。
If step S32 returns YES, the capacity of the air conditioning device is greater than the indoor load even at the lower limit frequency Fmin, so the process proceeds to step S33, where the control device 100 determines whether the flow rate adjustment mechanism 272 is fully closed. If step S33 returns NO, the control device 100 reduces the opening of the flow rate adjustment mechanism 272 by a fixed value in step S34. This reduces the amount of heat exchanged in the second heat exchange section 211B, and reduces the air conditioning capacity. Then, in step S35, the control device 100 controls the opening of the expansion valve 230. The reason for performing step S35 after step S34 will be explained below.
膨張弁230の開度を制御せずに、つまりステップS32に最初に移行時の開度で固定した状態で、ステップS34にて流量調整機構272の開度を一定値減少すると、循環流量が低下するため、蒸発器出口部の冷媒過熱度SHが大きくなりすぎる運転となり、空気調和装置のCOPが悪化する。そのため、ステップS35にて、図3に示した膨張弁230の制御を実施することによって、蒸発器出口部の冷媒過熱度SHを適切な値に維持することが可能となる。
If the opening of the flow rate adjustment mechanism 272 is reduced by a certain value in step S34 without controlling the opening of the expansion valve 230, that is, with the opening fixed at the time of the initial transition to step S32, the circulation flow rate will decrease, resulting in operation with the refrigerant superheat SH at the evaporator outlet becoming too high, and the COP of the air conditioner will deteriorate. Therefore, by implementing the control of the expansion valve 230 shown in Figure 3 in step S35, it is possible to maintain the refrigerant superheat SH at the evaporator outlet at an appropriate value.
このとき、ステップS21での膨張弁230の開度の値は、蒸発器出口の冷媒過熱度SHを適切な値に早く到達させるために、ステップS32に最初に移行するときの開度に、近似式を用いて求めたCv値比に対応する開度に設定すると良い。または、ステップS35では、図3に示した膨張弁230の制御を実施せず、近似式を用いて求めたCv値比に対応する開度に直接変更してもよい。この場合、近似式の精度が高ければ図3の制御を実施した場合と同じ結果になる。
At this time, in order to quickly bring the refrigerant superheat SH at the evaporator outlet to an appropriate value, the opening value of the expansion valve 230 in step S21 should be set to an opening corresponding to the Cv value ratio calculated using the approximation formula when first moving to step S32. Alternatively, in step S35, the control of the expansion valve 230 shown in FIG. 3 may not be performed, and the opening may be directly changed to an opening corresponding to the Cv value ratio calculated using the approximation formula. In this case, if the accuracy of the approximation formula is high, the same results will be obtained as when the control in FIG. 3 is performed.
近似式について、図8~図10を用いて説明する。図8は、冷房運転時に、圧縮機200の運転周波数が下限周波数Fminである場合に流量調整機構272の開度を変化させたときに、対応する膨張弁230のCv値の変化を示す図である。図9は、循環流量比が大きい領域の近似式を示す図である。図10は、循環流量比が小さい領域の近似式を示す図である。
The approximation formula will be explained using Figs. 8 to 10. Fig. 8 shows the change in the Cv value of the expansion valve 230 when the opening degree of the flow rate adjustment mechanism 272 is changed when the operating frequency of the compressor 200 is at the lower limit frequency Fmin during cooling operation. Fig. 9 shows the approximation formula for the region where the circulation flow rate ratio is large. Fig. 10 shows the approximation formula for the region where the circulation flow rate ratio is small.
図8には、流量調整機構272の開度を小さくすればするほど(循環流量比を小さくすればするほど)、膨張弁230の開度を大きくする必要があることが示されている。これは、図3で示した制御によって蒸発器出口の冷媒過熱度SHを一定に保つように膨張弁230が制御されているためである。圧縮機200の運転周波数が下限周波数の時に流量調整機構272の開度を変化させた場合、空気調和装置のCOPを低下させないためにも蒸発器出口の冷媒過熱度SHを適切な値に早く到達させることが望ましい。図3のステップS21での膨張弁230の開度の設定値は、例えば循環流量比が19%であれば、循環流量比が100%のときのCv値の338%に対応する膨張弁230の開度にすれば良い。あらゆる循環流量比で膨張弁230のCv値の設定値を求めるためには、図8のグラフの近似式を作成すれば良い。
FIG. 8 shows that the smaller the opening of the flow rate adjustment mechanism 272 (the smaller the circulation flow rate ratio), the larger the opening of the expansion valve 230 must be. This is because the expansion valve 230 is controlled to keep the refrigerant superheat degree SH at the evaporator outlet constant by the control shown in FIG. 3. When the opening of the flow rate adjustment mechanism 272 is changed when the operating frequency of the compressor 200 is at the lower limit frequency, it is desirable to make the refrigerant superheat degree SH at the evaporator outlet reach an appropriate value quickly in order not to lower the COP of the air conditioner. For example, if the circulation flow rate ratio is 19%, the setting value of the opening of the expansion valve 230 in step S21 of FIG. 3 may be set to the opening of the expansion valve 230 corresponding to 338% of the Cv value when the circulation flow rate ratio is 100%. To find the setting value of the Cv value of the expansion valve 230 at any circulation flow rate ratio, an approximation formula of the graph in FIG. 8 may be created.
図8で循環流量比が19%~100%となる範囲と、循環流量比が0~19%となる範囲とでは、グラフの傾きが大きく異なる。図4でこの範囲を変換すると能力比が41%~100%となる範囲と、能力比が0%~41%となる範囲となる。領域をこれらの2つの領域に分けて近似式を作成した。
In Figure 8, the slope of the graph is significantly different between the range where the circulation flow ratio is 19% to 100% and the range where the circulation flow ratio is 0 to 19%. When this range is converted in Figure 4, it becomes the range where the capacity ratio is 41% to 100% and the range where the capacity ratio is 0% to 41%. An approximation formula was created by dividing the region into these two regions.
図9では、循環流量比をxで示し、膨張弁230のCv値比をyで示した場合に、x>19%の領域において、近似式y=-2.8009x+3.7344で示されている。この場合、R2は0.9763である。
9, when the circulation flow rate ratio is indicated by x and the Cv value ratio of the expansion valve 230 is indicated by y, in the region of x>19%, the approximation is expressed as y=-2.8009x+3.7344. In this case, R2 is 0.9763.
図10では、循環流量比をxで示し、膨張弁230のCv値比をyで示した場合に、x<19%の領域において、近似式y=-34.246x+9.5616で示されている。この場合、R2は0.9782である。
10, when the circulation flow rate ratio is indicated by x and the Cv value ratio of the expansion valve 230 is indicated by y, in the region where x<19%, the approximation is expressed as y=-34.246x+9.5616. In this case, R2 is 0.9782.
図9、図10に示されるフィッティングの結果の決定係数R2はいずれも0.97以上と線形近似で良く近似できていることが示されている。
The coefficient of determination R2 of the fitting results shown in FIG. 9 and FIG. 10 is 0.97 or more, which indicates that good approximation is achieved by linear approximation.
図7に戻って、ステップS35で膨張弁230の開度の制御を実施した後、ステップS32に移行し、空調能力と室内負荷のバランスを再度判定する。
Returning to FIG. 7, after controlling the opening degree of the expansion valve 230 in step S35, the process proceeds to step S32, where the balance between the air conditioning capacity and the indoor load is determined again.
このとき、ステップS34とステップS35の順序を逆にする、つまり、膨張弁230の開度を増加させてから、流量調整機構272の開度を減少することは、圧縮機200の故障の要因となるため望ましくない。その理由は、蒸発器出口の冷媒過熱度SHが低下するため、圧縮機200の吸入部に液冷媒が戻るリスクが高くなり、液圧縮のおそれがあるからである。
In this case, reversing the order of steps S34 and S35, i.e. increasing the opening of the expansion valve 230 and then decreasing the opening of the flow rate control mechanism 272, is not desirable because it can cause a breakdown in the compressor 200. The reason for this is that the refrigerant superheat SH at the evaporator outlet decreases, increasing the risk of liquid refrigerant returning to the suction section of the compressor 200, which could result in liquid compression.
一方、ステップS32でNoと判断された場合、空調機の能力が室内負荷以下であるため、圧縮機200は、室内温度が設定温度になるように圧縮機200の運転周波数Fを増速する(もしくはFminで維持する)という通常の制御が可能であるため、制御装置100は図7の処理を終了する。
On the other hand, if the answer is No in step S32, the capacity of the air conditioner is equal to or less than the indoor load, so the compressor 200 can perform normal control, accelerating the operating frequency F of the compressor 200 (or maintaining it at Fmin) so that the indoor temperature becomes the set temperature, and the control device 100 ends the processing in FIG. 7.
また、ステップS33でYESと判定された場合、流量調整機構272が全閉であるため、これ以上空調能力を低下させることができない。そのため、制御装置100は、ステップS36で圧縮機200をサーモオフし、図7の処理を終了する。
Also, if the determination in step S33 is YES, the flow rate adjustment mechanism 272 is fully closed, and the air conditioning capacity cannot be reduced any further. Therefore, the control device 100 turns off the thermostat of the compressor 200 in step S36, and ends the processing in FIG. 7.
以上、流量調整機構272の制御フローについて説明した。
図11は、暖房運転時の結果を示す図である。冷房運転時とは異なり、流量調整機構272の開度を減少させても冷房運転時ほど能力が低下しないことが示されている。この理由を以下で説明する。 The control flow of the flowrate adjusting mechanism 272 has been described above.
11 is a diagram showing the results during heating operation. Unlike during cooling operation, it is shown that the capacity does not decrease as much as during cooling operation even if the opening degree of the flowrate adjustment mechanism 272 is reduced. The reason for this will be explained below.
図11は、暖房運転時の結果を示す図である。冷房運転時とは異なり、流量調整機構272の開度を減少させても冷房運転時ほど能力が低下しないことが示されている。この理由を以下で説明する。 The control flow of the flow
11 is a diagram showing the results during heating operation. Unlike during cooling operation, it is shown that the capacity does not decrease as much as during cooling operation even if the opening degree of the flow
流量調整機構272の開度を減少させると、第2熱交換部211Bに流れる冷媒流量が減少するため、第2熱交換部211Bでの熱交換量が少なくなる。このため、第2熱交換部211Bを通過する冷媒は、冷媒入口PIBから冷媒出口POBに向かう途中で熱交換を完了しやすくなり(もしくは完全に熱交換を完了し)、冷媒出口POBでの冷媒温度は空気温度に近づく(もしくは完全に空気温度と同じなる)。つまり、ガス冷媒が多くなり、第2熱交換部211B内の冷媒量が減少する。そのため、第1熱交換部211A内の冷媒量が増加し、蒸発器入口と出口(温度センサ264が設置されている場所と温度センサ265が設置されている場所)のエンタルピー差が小さくなり空調能力が減少する。
When the opening degree of the flow rate adjustment mechanism 272 is reduced, the refrigerant flow rate flowing through the second heat exchange section 211B decreases, and the amount of heat exchanged in the second heat exchange section 211B decreases. As a result, the refrigerant passing through the second heat exchange section 211B is more likely to complete heat exchange on the way from the refrigerant inlet PIB to the refrigerant outlet POB (or completes heat exchange completely), and the refrigerant temperature at the refrigerant outlet POB approaches the air temperature (or becomes completely the same as the air temperature). In other words, the amount of gas refrigerant increases, and the amount of refrigerant in the second heat exchange section 211B decreases. As a result, the amount of refrigerant in the first heat exchange section 211A increases, and the enthalpy difference between the evaporator inlet and outlet (the place where the temperature sensor 264 is installed and the place where the temperature sensor 265 is installed) decreases, resulting in a decrease in the air conditioning capacity.
以上は、冷房運転時と同様である。しかし、冷房運転時と比べて、能力の減少量は小さい。それは、第1熱交換部211Aと第2熱交換部211Bが暖房運転時には蒸発器として使用されるため、冷媒の密度が小さく冷媒の変化量が小さいためである。
The above is the same as during cooling operation. However, the amount of reduction in capacity is smaller than during cooling operation. This is because the first heat exchanger 211A and the second heat exchanger 211B are used as evaporators during heating operation, so the density of the refrigerant is small and the amount of change in the refrigerant is small.
上記で説明したように、冷房運転時に流量調整機構272の開度を減少させることで、能力を低下させることが可能となる。同様に、室内熱交換器は並列に冷媒を流すことが可能に構成され、少なくとも片方の流路に流量調整機構を設けておれば、暖房運転時にも能力を低下させることは可能である。
As explained above, by decreasing the opening of the flow rate control mechanism 272 during cooling operation, it is possible to reduce the capacity. Similarly, if the indoor heat exchanger is configured to allow refrigerant to flow in parallel and a flow rate control mechanism is provided in at least one of the flow paths, it is also possible to reduce the capacity during heating operation.
<変形例>
図2では、1つの室外熱交換器211で第1熱交換部211Aと第2熱交換部211Bを構成した例を示した。いくつかの熱交換器の変形例について説明する。 <Modification>
2 shows an example in which the firstheat exchange section 211A and the second heat exchange section 211B are configured in one outdoor heat exchanger 211. Several modified examples of the heat exchanger will be described.
図2では、1つの室外熱交換器211で第1熱交換部211Aと第2熱交換部211Bを構成した例を示した。いくつかの熱交換器の変形例について説明する。 <Modification>
2 shows an example in which the first
図12は、室外熱交換器211の構成を変更した第1変形例を示す図である。図12に示すように分割された熱交換器として第1熱交換部211Aと第2熱交換部211Bを構成してもよい。分割されている構成とは、フィンがフィン211FAとフィン211FBに分かれて設けられているものを示す。このような構成とすれば、大型の熱交換器が必要になった場合に、新規に設計をしなくても小型の熱交換器の数を増減することにより種々の能力の熱交換器を実現することができる。
FIG. 12 is a diagram showing a first modified example in which the configuration of the outdoor heat exchanger 211 is changed. As shown in FIG. 12, a first heat exchange section 211A and a second heat exchange section 211B may be configured as a divided heat exchanger. A divided configuration refers to one in which the fins are provided separately as fins 211FA and fins 211FB. With such a configuration, when a large heat exchanger is required, it is possible to realize heat exchangers of various capacities by increasing or decreasing the number of small heat exchangers without having to design a new one.
図13は、室外熱交換器211の構成を変更した第2変形例を示す図である。図13に示す構成では、室外熱交換器211の冷媒入口が1つとなっており、途中で冷媒流路が2つに分割されている。室外熱交換器211を図13のような構成としてもよい。
FIG. 13 is a diagram showing a second modified example in which the configuration of the outdoor heat exchanger 211 is changed. In the configuration shown in FIG. 13, the outdoor heat exchanger 211 has one refrigerant inlet, and the refrigerant flow path is divided into two midway. The outdoor heat exchanger 211 may also be configured as shown in FIG. 13.
図14は、流量調整機構の構成を変更した第3変形例を示す図である。図14に示す変形例の空気調和装置1010は、空気調和装置1000の構成において、流量調整機構272に代えて、第1熱交換部211Aと第2熱交換部211Bに流れる冷媒流量を制御する流量調整機構270を含む。このような構成でも片側に流れる冷媒の循環流量を減少させることで能力を低下させることが可能である。
FIG. 14 is a diagram showing a third modified example in which the configuration of the flow rate adjustment mechanism has been changed. The modified air conditioner 1010 shown in FIG. 14 includes a flow rate adjustment mechanism 270 that controls the flow rate of refrigerant flowing through the first heat exchange section 211A and the second heat exchange section 211B, instead of the flow rate adjustment mechanism 272 in the configuration of the air conditioner 1000. Even with this configuration, it is possible to reduce capacity by decreasing the circulation flow rate of the refrigerant flowing on one side.
以上説明したように、実施の形態1に係る空気調和装置は、圧縮機の運転周波数が下限周波数のときの能力を低下することができ、オン-オフ運転の頻度を低下させることで快適性を向上できる。流量調整機構272が設置されている熱交換器が凝縮器として作用する場合に、図4に示すように、第2熱交換部211Bの能力比をほぼ0まで低下させること、すなわち空気調和装置の能力(空調能力)をほぼ0まで下げることが可能である。
As explained above, the air conditioner according to embodiment 1 can reduce the capacity when the operating frequency of the compressor is at the lower limit frequency, and can improve comfort by reducing the frequency of on-off operation. When the heat exchanger in which the flow rate adjustment mechanism 272 is installed acts as a condenser, as shown in FIG. 4, it is possible to reduce the capacity ratio of the second heat exchange section 211B to almost 0, that is, to reduce the capacity (air conditioning capacity) of the air conditioner to almost 0.
実施の形態2.
図15は、実施の形態2の空気調和装置1200の構成を示す図である。空気調和装置1200について、図1に示した空気調和装置1000との差異のみ説明する。図1に示した空気調和装置1000では室外送風機(ファン)220が1つであったのに対し、構成2では室外送風機(ファン)は221と222と2つ設けられている。 Embodiment 2.
Figure 15 is a diagram showing the configuration of anair conditioning apparatus 1200 according to embodiment 2. Regarding air conditioning apparatus 1200, only the differences from air conditioning apparatus 1000 shown in Figure 1 will be explained. Whereas air conditioning apparatus 1000 shown in Figure 1 has one outdoor blower (fan) 220, configuration 2 has two outdoor blowers (fans) 221 and 222.
図15は、実施の形態2の空気調和装置1200の構成を示す図である。空気調和装置1200について、図1に示した空気調和装置1000との差異のみ説明する。図1に示した空気調和装置1000では室外送風機(ファン)220が1つであったのに対し、構成2では室外送風機(ファン)は221と222と2つ設けられている。 Embodiment 2.
Figure 15 is a diagram showing the configuration of an
図16は、図15における室外熱交換器211の構成例を示す図である。ファン221は、第1熱交換部211Aに対応して設けられ、ファン222は第2熱交換部211Bに対応して設けられる。ファン221、222は制御装置100によって互いに独立して回転速度が制御可能である。したがって、流量調整機構272での冷媒流量調整に加えて、ファン221、222の回転速度を異なる速度とするか、またはファン221、222の一方を回転させ他方を停止させることにより、空気調和装置の空調能力をさらに変化させることができる。
FIG. 16 is a diagram showing an example of the configuration of the outdoor heat exchanger 211 in FIG. 15. Fan 221 is provided corresponding to the first heat exchange section 211A, and fan 222 is provided corresponding to the second heat exchange section 211B. The rotation speeds of fans 221 and 222 can be controlled independently of each other by the control device 100. Therefore, in addition to adjusting the refrigerant flow rate with the flow rate adjustment mechanism 272, the air conditioning capacity of the air conditioner can be further changed by setting the rotation speeds of fans 221 and 222 to different speeds, or by rotating one of fans 221 and 222 and stopping the other.
図17は、流量調整機構272とファン221、222の制御について説明するためのフローチャートである。図17に示したフローチャートは、図7に示したフローチャートのステップS34がステップS44に変更され、ステップS35がステップS45に変更され、ステップS37がステップS47に変更されている。他の処理については、同様であるので、説明は繰り返さない。
FIG. 17 is a flowchart for explaining the control of the flow rate adjustment mechanism 272 and the fans 221, 222. In the flowchart shown in FIG. 17, step S34 in the flowchart shown in FIG. 7 is changed to step S44, step S35 to step S45, and step S37 to step S47. Other processes are similar, so the description will not be repeated.
ステップS44では、制御装置100は、流量調整機構272の開度を一定値減少することに加えて、第1熱交換部211Aに対応するファン221の回転速度Nを一定値低下させる。これにより、第2熱交換部211Bでの熱交換量を低下に加え、ファン221の風量を低下することで第1熱交換部211Aの熱交換量も低下する。このため、図7のステップS34よりも空調能力をさらに低下させることができる。
In step S44, the control device 100 reduces the opening degree of the flow rate adjustment mechanism 272 by a fixed value, and also reduces the rotation speed N of the fan 221 corresponding to the first heat exchange section 211A by a fixed value. This not only reduces the amount of heat exchanged in the second heat exchange section 211B, but also reduces the amount of heat exchanged in the first heat exchange section 211A by reducing the airflow rate of the fan 221. This makes it possible to further reduce the air conditioning capacity compared to step S34 in FIG. 7.
圧縮機が下限周波数Fminであるときのファン221の回転速度Nの低下は、後に図18で説明する。
The decrease in the rotation speed N of the fan 221 when the compressor is at the lower limit frequency Fmin will be explained later in Figure 18.
ファン222ではなくファン221の回転速度Nを低下させる理由について説明する。流量調整機構272の開度を低下させることで、ファン222に対応する第2熱交換部211Bの冷媒流量が低下するため、第2熱交換部211Bの熱交換量は低下する。そのため、ファン222の回転速度を低下させても既に熱交換量は低下しているため、効果が小さくなる。その一方で、風量は、ユーザからの設定をある程度反映させるため、一定量を維持する必要がある。したがって、ステップS44では、制御装置100は、ファン222の回転速度を維持しつつファン221の回転速度Nを低下させる。
The reason for reducing the rotation speed N of fan 221 instead of fan 222 will be explained. By reducing the opening of flow rate adjustment mechanism 272, the refrigerant flow rate of second heat exchange section 211B corresponding to fan 222 decreases, and the heat exchange amount of second heat exchange section 211B decreases. Therefore, even if the rotation speed of fan 222 is reduced, the effect is small because the heat exchange amount has already decreased. On the other hand, the air volume needs to be maintained at a constant amount in order to reflect the user's settings to some extent. Therefore, in step S44, control device 100 reduces rotation speed N of fan 221 while maintaining the rotation speed of fan 222.
図17のステップS44の処理を実施後、ステップS45で制御装置100は、膨張弁230の開度を図3に示したフローチャートに従って制御する。ステップS21での膨張弁230の開度の値は、ステップS32に最初に移行時の開度に、近似式(後に図20~図22で示す)を用いて求めたCv値比に対応する開度に設定すると良い。もしくは、ステップS45では、図3に示した膨張弁230の制御を実施せず、近似式を用いて求めたCv値比に対応する開度に直接変更してもよい。この場合、近似式の精度が高ければ図3の制御を実施したのと同じ結果になる。
After performing the process of step S44 in FIG. 17, in step S45 the control device 100 controls the opening of the expansion valve 230 according to the flowchart shown in FIG. 3. The value of the opening of the expansion valve 230 in step S21 may be set to the opening at the time of the initial transition to step S32, which corresponds to the Cv value ratio calculated using the approximation formula (shown later in FIGS. 20 to 22). Alternatively, in step S45, the control of the expansion valve 230 shown in FIG. 3 may not be performed, and the opening may be directly changed to the opening corresponding to the Cv value ratio calculated using the approximation formula. In this case, if the accuracy of the approximation formula is high, the same result as when the control of FIG. 3 is performed will be obtained.
このとき、ステップS44とステップS45の順序を逆にする、つまり、膨張弁230の開度を増加させてから、流量調整機構272の開度を減少させると、蒸発器出口の冷媒過熱度SHが低下して、圧縮機200の吸入に液冷媒が戻るリスクが高くなり、圧縮機200の故障の要因となるため望ましくない。
In this case, if the order of steps S44 and S45 is reversed, that is, the opening of the expansion valve 230 is increased and then the opening of the flow rate control mechanism 272 is decreased, the refrigerant superheat SH at the evaporator outlet will decrease, increasing the risk of liquid refrigerant returning to the intake of the compressor 200, which is undesirable as it could cause a breakdown in the compressor 200.
ステップS47では、制御装置100は、流量調整機構272の開度を全開にし、かつ圧縮機200の運転周波数Fに対応する回転速度Nにファン221,222の回転速度を設定する。
In step S47, the control device 100 fully opens the flow rate adjustment mechanism 272 and sets the rotation speed of the fans 221, 222 to the rotation speed N that corresponds to the operating frequency F of the compressor 200.
図18は、図17のステップS44およびS47で参照されるマップの一例である。図18には、圧縮機200の運転周波数Fが横軸に示され、ファンの回転速度Nが縦軸に示されている。
FIG. 18 is an example of a map referenced in steps S44 and S47 of FIG. 17. In FIG. 18, the horizontal axis shows the operating frequency F of the compressor 200, and the vertical axis shows the fan rotation speed N.
圧縮機200の運転周波数Fが下限周波数であるFminよりも高い場合は、制御装置100は、図18に示したマップに従って、ファン221,222を同じ回転速度に設定する。すなわち運転周波数FがFminより高くF1以下である場合には、制御装置100は、ファン221、222の回転速度をともに回転速度N4(低回転)に設定する。また、運転周波数FがF1より高くF2以下である場合には、制御装置100は、ファン221,222の回転速度をともに回転速度N5(中回転)に設定する。また、運転周波数FがF2より高い場合には、制御装置100は、ファン221,222の回転速度をともに回転速度N6(高回転)に設定する。
When the operating frequency F of the compressor 200 is higher than the lower limit frequency Fmin, the control device 100 sets the fans 221 and 222 to the same rotation speed according to the map shown in FIG. 18. That is, when the operating frequency F is higher than Fmin and equal to or lower than F1, the control device 100 sets the rotation speeds of the fans 221 and 222 to the rotation speed N4 (low rotation). When the operating frequency F is higher than F1 and equal to or lower than F2, the control device 100 sets the rotation speeds of the fans 221 and 222 to the rotation speed N5 (medium rotation). When the operating frequency F is higher than F2, the control device 100 sets the rotation speeds of the fans 221 and 222 to the rotation speed N6 (high rotation).
一方、運転周波数FがFminである場合には、制御装置100は、ファン222の回転速度をN4に維持したまま、ファン221の回転速度をN4からN3、N2、N1、0の順に段階的に低下させる。または、ファン221の回転速度を、N4から0に一気に低下させても良い。このときに、ファン221の回転速度の低下率は、第1熱交換部211Aを通過する冷媒の流量と第2熱交換部211Bを通過する冷媒の流量との比率に基づいて決定してもよい。
On the other hand, when the operating frequency F is Fmin, the control device 100 reduces the rotation speed of the fan 221 in stages from N4 to N3, N2, N1, and 0, while maintaining the rotation speed of the fan 222 at N4. Alternatively, the rotation speed of the fan 221 may be reduced all at once from N4 to 0. At this time, the reduction rate of the rotation speed of the fan 221 may be determined based on the ratio between the flow rate of the refrigerant passing through the first heat exchanger 211A and the flow rate of the refrigerant passing through the second heat exchanger 211B.
図19は、冷房運転時に、圧縮機200の運転周波数Fが下限周波数Fminのときに流量調整機構272の開度とファン221の回転速度を変化させた場合の空調機の能力の変化を示す図である。図19の三角印の結果は、図4と同じ結果であり、流量調整のみ行ないファンは実施の形態1と同じように制御した結果を示す。図19の四角印の結果は、流量調整に加えてファン221の回転速度を図18のように制御した結果を示す。なお、ファン221の回転速度の低下は循環流量比と同じとした。つまり、循環流量比50%のときのファン221の回転速度は、ファン222の回転速度に対し50%と設定した。
Figure 19 shows the change in capacity of the air conditioner when the opening of the flow rate adjustment mechanism 272 and the rotation speed of the fan 221 are changed when the operating frequency F of the compressor 200 is at the lower limit frequency Fmin during cooling operation. The results indicated by the triangles in Figure 19 are the same as those in Figure 4, and show the results when only the flow rate is adjusted and the fan is controlled in the same way as in embodiment 1. The results indicated by the squares in Figure 19 show the results when the rotation speed of the fan 221 is controlled as in Figure 18 in addition to the flow rate adjustment. Note that the reduction in the rotation speed of the fan 221 is set to the same as the circulation flow rate ratio. In other words, the rotation speed of the fan 221 when the circulation flow rate ratio is 50% is set to 50% of the rotation speed of the fan 222.
ファン221の回転速度を変化させる制御を加えたことで、同じ循環流量比でも空調能力がさらに低下していることが分かる。
It can be seen that by adding control that changes the rotation speed of fan 221, the air conditioning capacity is further reduced even with the same circulation flow rate ratio.
図20は、実施の形態2における循環流量比に対する膨張弁230のCv値比を示す図である。流量調整機構272の開度を小さくすればするほど(循環流量比を小さくすればするほど)、膨張弁230の開度を大きくする必要があることが示されている。これは、膨張弁230が図3で示した制御フローによって蒸発器出口の冷媒過熱度SHを一定に保つようにしているためである。圧縮機200の運転周波数が下限周波数のときに流量調整機構272の開度を変化させた場合、空気調和装置のCOPを低下させないためにも蒸発器出口の冷媒過熱度SHを適切な値に早く到達させることが望ましい。
Figure 20 is a diagram showing the Cv value ratio of the expansion valve 230 versus the circulation flow rate ratio in embodiment 2. It shows that the smaller the opening of the flow rate adjustment mechanism 272 (the smaller the circulation flow rate ratio), the larger the opening of the expansion valve 230 needs to be. This is because the expansion valve 230 keeps the refrigerant superheat degree SH at the evaporator outlet constant by the control flow shown in Figure 3. If the opening of the flow rate adjustment mechanism 272 is changed when the operating frequency of the compressor 200 is at the lower limit frequency, it is desirable to allow the refrigerant superheat degree SH at the evaporator outlet to reach an appropriate value as soon as possible in order not to lower the COP of the air conditioning device.
実施の形態2における図3のステップS21での膨張弁230の開度の既定値は、例えば循環流量比が28%であれば、図20に示すように、循環流量比が100%のときの膨張弁230のCv値の304%に設定すれば良い。あらゆる循環流量比で膨張弁230のCv値の設定値を求めるためには、図20のグラフの近似式を作成すれば良い。
In the second embodiment, the default opening value of the expansion valve 230 in step S21 of FIG. 3 may be set to 304% of the Cv value of the expansion valve 230 when the circulation flow ratio is 100%, as shown in FIG. 20, if the circulation flow ratio is 28%. To find the set value of the Cv value of the expansion valve 230 for all circulation flow ratios, an approximation formula of the graph in FIG. 20 may be created.
図20では、循環流量比が28%~100%となる領域と、循環流量比が0~28%となる領域とでは、グラフの傾きが大きく異なる。このため、範囲を2つに分けて近似式を作成した。なお、循環流量比が28%~100%となる領域は、図19で変換すると能力比が41%~100%となる領域である。また循環流量比が0~28%となる領域は、図19で変換すると能力比が0%~41%となる領域である。
In Figure 20, the slope of the graph is significantly different between the region where the circulation flow ratio is 28% to 100% and the region where the circulation flow ratio is 0 to 28%. For this reason, an approximation formula was created by dividing the range into two. Note that the region where the circulation flow ratio is 28% to 100% is the region where the capacity ratio is 41% to 100% when converted in Figure 19. Furthermore, the region where the circulation flow ratio is 0% to 28% is the region where the capacity ratio is 0% to 41% when converted in Figure 19.
図21は、循環流量比が28%~100%の領域のフィッティングの結果と近似式の結果を示す図である。この領域では、近似式は、y=-2.7807x+3.8615となり、決定係数R2=0.988である。
21 is a diagram showing the fitting results and the approximation results for the region where the circulation flow rate ratio is 28% to 100%. In this region, the approximation formula is y = -2.7807x + 3.8615, and the coefficient of determination R 2 = 0.988.
図22は、循環流量比が0~28%の領域のフィッティングの結果と近似式の結果を示す図である。この領域では、近似式は、y=-19.514x+8.0881となり、決定係数R2=0.9456である。
22 is a diagram showing the fitting results and the approximation results for the region where the circulation flow rate ratio is 0 to 28%. In this region, the approximation formula is y = -19.514x + 8.0881, and the coefficient of determination R 2 = 0.9456.
図21、図22のいずれの場合も、決定係数R2は0.94以上と線形近似で良く近似できていることが示されている。
In both cases of FIG. 21 and FIG. 22, the coefficient of determination R2 is 0.94 or more, which indicates that good approximation is achieved by linear approximation.
図23は、膨張弁230のCv値比に対する空調機の能力の変化を示す図である。四角印に示すファン221の回転速度の変化を加えた場合の方が、同じ膨張弁230のCv値比に対し三角印に示す流量調整のみの場合よりも空調機の能力を低下させることが可能と分かる。圧縮機200の運転周波数Fが下限周波数Fminであるので、冷媒流量が少ないため、能力比100%での膨張弁230の開度は小さくなる。そのため、流量調整機構272の開度を低下させた際に、膨張弁230の開度を大きくし、能力低下させることが可能なのだが、膨張弁230の最大開度に対応する能力までとなる。例えば、最大開度がCv値比で500%の場合、流量調整機構272の開度の低下では、能力比30%まで低下させることが可能だが、ファン221の回転速度の低下も加えることで能力比20%までさらに低下させることが可能となる。また、流量調整機構272の開度の低下のみと同じ能力比30%まで低下させる場合、膨張弁230のCv値比で410%とすれば良い。つまり実施の形態2では、口径が小さい小型の膨張弁を使用することができ、コスト削減や、膨張弁230周りの冷媒配管の取り回しがしやすくなる等のメリットがある。
Figure 23 is a diagram showing the change in the capacity of the air conditioner with respect to the Cv value ratio of the expansion valve 230. It can be seen that the capacity of the air conditioner can be reduced by adding the change in the rotation speed of the fan 221, as shown by the square marks, compared to the case of only flow rate adjustment, as shown by the triangle marks, for the same Cv value ratio of the expansion valve 230. Since the operating frequency F of the compressor 200 is the lower limit frequency Fmin, the refrigerant flow rate is small, and the opening degree of the expansion valve 230 at a capacity ratio of 100% is small. Therefore, when the opening degree of the flow rate adjustment mechanism 272 is reduced, the opening degree of the expansion valve 230 can be increased and the capacity can be reduced, but only up to the capacity corresponding to the maximum opening degree of the expansion valve 230. For example, when the maximum opening degree is 500% in the Cv value ratio, the capacity ratio can be reduced to 30% by reducing the opening degree of the flow rate adjustment mechanism 272, but it is possible to further reduce the capacity ratio to 20% by adding a reduction in the rotation speed of the fan 221. Also, if the capacity ratio is to be reduced to 30%, the same as when the opening degree of the flow rate adjustment mechanism 272 is reduced, the Cv value ratio of the expansion valve 230 should be 410%. In other words, in the second embodiment, a small expansion valve with a small diameter can be used, which has the advantages of reducing costs and making it easier to handle the refrigerant piping around the expansion valve 230.
以上では、図18に示したように、ファン221の回転速度を段階的に低下させた場合を説明したが、流量調整機構272によって第2熱交換部211Bを通過する冷媒の流量を第1熱交換部211Aを通過する冷媒の流量よりも低下させた場合には、ファン222の回転を維持しつつファン221の回転速度を0としても良い。
The above describes the case where the rotation speed of the fan 221 is gradually reduced as shown in FIG. 18. However, if the flow rate of the refrigerant passing through the second heat exchange section 211B is reduced to be lower than the flow rate of the refrigerant passing through the first heat exchange section 211A by the flow rate adjustment mechanism 272, the rotation speed of the fan 221 may be set to 0 while maintaining the rotation of the fan 222.
図24は、ファン221の回転速度を0とした場合の図19に対応する図である。図25は、ファン221の回転速度を0とした場合の図20に対応する図である。
FIG. 24 corresponds to FIG. 19 when the rotation speed of the fan 221 is set to 0. FIG. 25 corresponds to FIG. 20 when the rotation speed of the fan 221 is set to 0.
図26は、ファン221の回転速度を0とした場合の図21に対応する図である。図26に示すように、循環流量比が28%~100%の領域では、近似式は、y=-2.4127x+4.0329となり、決定係数R2=0.7603である。
Fig. 26 is a diagram corresponding to Fig. 21 when the rotation speed of the fan 221 is set to 0. As shown in Fig. 26, in the region where the circulation flow rate ratio is 28% to 100%, the approximation formula is y = -2.4127x + 4.0329, and the coefficient of determination R 2 = 0.7603.
図27は、ファン221の回転速度を0とした場合の図22に対応する図である。図27に示すように、循環流量比が0~28%の領域では、近似式は、y=-18.992x+7.7526となり、決定係数R2=0.9664である。
Fig. 27 is a diagram corresponding to Fig. 22 when the rotation speed of the fan 221 is set to 0. As shown in Fig. 27, in the region where the circulation flow rate ratio is 0 to 28%, the approximation formula is y = -18.992x + 7.7526, and the coefficient of determination R 2 = 0.9664.
図28は、ファン221の回転速度を0とした場合の図23に対応する図である。
図24~図28を図19~図23と比較すると、図24~図28では、ファン221の回転速度を0としたことにより、同じ循環流量比でより能力が低下していることが示されている。 FIG. 28 is a diagram corresponding to FIG. 23 in the case where the rotation speed of thefan 221 is set to 0. In FIG.
24 to 28 with FIG. 19 to FIG. 23, it can be seen that, in FIG. 24 to 28, by setting the rotation speed of thefan 221 to 0, the capacity is further reduced at the same circulation flow rate ratio.
図24~図28を図19~図23と比較すると、図24~図28では、ファン221の回転速度を0としたことにより、同じ循環流量比でより能力が低下していることが示されている。 FIG. 28 is a diagram corresponding to FIG. 23 in the case where the rotation speed of the
24 to 28 with FIG. 19 to FIG. 23, it can be seen that, in FIG. 24 to 28, by setting the rotation speed of the
以上説明したように、実施の形態2の空気調和装置は、実施の形態1と同様な効果に加えて、実施の形態1と同じ膨張弁230を用いた場合、ファンの風量を低下することで、より空調能力を低下することが可能になる。
As explained above, the air conditioning apparatus of embodiment 2 has the same effect as embodiment 1, and in addition, when using the same expansion valve 230 as embodiment 1, it is possible to further reduce the air conditioning capacity by reducing the fan air volume.
また、空調能力の低下量を実施の形態1と同じ低下量とする場合、膨張弁230の小型化や膨張弁230周りの冷媒配管の取り回しがしやすくなる等のメリットがある。
In addition, if the reduction in air conditioning capacity is the same as in embodiment 1, there are advantages such as the expansion valve 230 being smaller and the refrigerant piping around the expansion valve 230 being easier to handle.
(実施の形態1~2に用いられる圧縮機について)
圧縮機200には種々のタイプ、例えば、ロータリータイプ、往復タイプ、スクロールタイプ、スクリュータイプ等のものを採用することができる。特に、圧縮機200は、ロータリーベーン式である場合に、特に効果が得られる。図29は、ロータリーベーン式の圧縮機の構成の一例を示す図である。ロータリー圧縮機における圧縮機構部はシリンダ201と、ピストン202と、ベーン203と、スプリング204と、吸入口206と、吐出口207と、回転軸208とを備える。 (Regarding the compressor used in the first and second embodiments)
Various types ofcompressors 200 can be adopted, such as a rotary type, a reciprocating type, a scroll type, a screw type, and the like. In particular, the compressor 200 is particularly effective when it is a rotary vane type. Fig. 29 is a diagram showing an example of the configuration of a rotary vane type compressor. The compression mechanism in the rotary compressor includes a cylinder 201, a piston 202, a vane 203, a spring 204, a suction port 206, a discharge port 207, and a rotating shaft 208.
圧縮機200には種々のタイプ、例えば、ロータリータイプ、往復タイプ、スクロールタイプ、スクリュータイプ等のものを採用することができる。特に、圧縮機200は、ロータリーベーン式である場合に、特に効果が得られる。図29は、ロータリーベーン式の圧縮機の構成の一例を示す図である。ロータリー圧縮機における圧縮機構部はシリンダ201と、ピストン202と、ベーン203と、スプリング204と、吸入口206と、吐出口207と、回転軸208とを備える。 (Regarding the compressor used in the first and second embodiments)
Various types of
シリンダ201には図29の円形の空間であるシリンダ室に連通し半径方向に延びるベーン溝201cが軸方向に貫通して設けられている。ベーン溝201cには、ベーン203が摺動自在に嵌入している。また、ベーン溝201cには、その基部に吐出圧を導く背圧室205が設けられており、背圧室205は、平面視で円形の空間を有する。
The cylinder 201 is provided with a vane groove 201c that extends radially and is connected to the cylinder chamber, which is a circular space in FIG. 29, and that penetrates the cylinder in the axial direction. A vane 203 is slidably fitted into the vane groove 201c. A back pressure chamber 205 that introduces discharge pressure to the base of the vane groove 201c is provided, and the back pressure chamber 205 has a circular space in a plan view.
ロータリー圧縮機の圧縮工程において、シリンダ201内はベーン203により高圧領域201aと低圧領域201bに仕切られており、高圧領域201aは吐出圧(Pd)、低圧領域201bは吸入圧(Ps)の冷媒で満たされている。ベーン203がピストン202と常に接触することで冷媒ガスの圧縮が可能になる。吐出口207には逆止弁が設けられており、高圧領域201aの圧力が高まると、加圧ガス冷媒は吐出口207から吐出される。シリンダ201の中心方向にかかる力の合力を押し付け力と呼び、シリンダ201の反対方向にかかる力の合力を離間力と呼ぶとする。圧縮機の運転周波数が小さくなると、押し付け力が小さくなるため、押し付け力>離間力が成り立つ範囲で圧縮機の下限周波数が決められている。
In the compression process of the rotary compressor, the inside of the cylinder 201 is divided into a high pressure region 201a and a low pressure region 201b by the vane 203. The high pressure region 201a is filled with refrigerant at discharge pressure (Pd), and the low pressure region 201b is filled with refrigerant at suction pressure (Ps). The vane 203 is in constant contact with the piston 202, enabling the refrigerant gas to be compressed. A check valve is provided at the discharge port 207, and when the pressure in the high pressure region 201a increases, the pressurized gas refrigerant is discharged from the discharge port 207. The resultant force of the forces acting toward the center of the cylinder 201 is called the pressing force, and the resultant force of the forces acting in the opposite direction of the cylinder 201 is called the separating force. As the operating frequency of the compressor decreases, the pressing force also decreases, so the lower limit frequency of the compressor is determined within the range where pressing force > separating force holds.
ロータリーベーン式の圧縮機は、上記のような条件により下限周波数が決められており、他の方式の圧縮機よりも下限周波数が高い傾向にある。このため、ロータリーベーン式の圧縮機は、運転周波数を低下させて空調能力を下げられる範囲が狭い。
The minimum frequency of a rotary vane compressor is determined by the above conditions, and it tends to be higher than that of other types of compressors. For this reason, the range in which the operating frequency of a rotary vane compressor can be lowered to reduce the air conditioning capacity is narrow.
実施の形態1~2に示した空気調和装置を用いれば、下限周波数が高いロータリーベーン式の圧縮機を使用する場合に、オン-オフ運転の発生頻度を少なくする効果が大きい。
The use of the air conditioning system shown in embodiments 1 and 2 has a significant effect in reducing the frequency of on-off operation when using a rotary vane compressor with a high lower limit frequency.
(まとめ)
以下に、本実施の形態について再び図面を参照しながら総括する。なお、括弧内については、冷房時に該当するユニットを記載している。 (summary)
The present embodiment will be summarized below with reference to the drawings again. Note that the units in parentheses are those applicable during cooling.
以下に、本実施の形態について再び図面を参照しながら総括する。なお、括弧内については、冷房時に該当するユニットを記載している。 (summary)
The present embodiment will be summarized below with reference to the drawings again. Note that the units in parentheses are those applicable during cooling.
本開示は、空気調和装置1000に関する。空気調和装置1000は、少なくとも圧縮機200、凝縮器(211)、膨張弁230、および蒸発器(110)を含み、冷媒が循環するように構成される冷媒回路500と、冷媒回路500を制御する制御装置100とを備える。図2に示すように、凝縮器(211)は、冷媒を並行して流すことが可能に構成された第1熱交換部211Aおよび第2熱交換部211Bと、第2熱交換部211Bを通過する冷媒の流量を調整するように構成された流量調整機構272とを含む。制御装置100は、圧縮機200の運転周波数が予め設定された下限周波数Fminである場合に、流量調整機構272によって第2熱交換部211Bを通過する冷媒の流量を第1熱交換部211Aを通過する冷媒の流量よりも低下させることが可能に構成される。図7のステップS34,S35に示すように、制御装置100は、室内負荷よりも冷媒回路500の空調能力が大きい場合には、流量調整機構272によって第2熱交換部211Bを通過する冷媒の流量を低下させた後に、膨張弁230の開度を増加させるように構成される。
The present disclosure relates to an air conditioning device 1000. The air conditioning device 1000 includes a refrigerant circuit 500 including at least a compressor 200, a condenser (211), an expansion valve 230, and an evaporator (110) configured to circulate a refrigerant, and a control device 100 that controls the refrigerant circuit 500. As shown in FIG. 2, the condenser (211) includes a first heat exchanger 211A and a second heat exchanger 211B configured to allow the refrigerant to flow in parallel, and a flow rate adjustment mechanism 272 configured to adjust the flow rate of the refrigerant passing through the second heat exchanger 211B. The control device 100 is configured to be able to reduce the flow rate of the refrigerant passing through the second heat exchanger 211B by the flow rate adjustment mechanism 272 to be lower than the flow rate of the refrigerant passing through the first heat exchanger 211A when the operating frequency of the compressor 200 is a preset lower limit frequency Fmin. As shown in steps S34 and S35 of FIG. 7, when the air conditioning capacity of the refrigerant circuit 500 is greater than the indoor load, the control device 100 is configured to reduce the flow rate of the refrigerant passing through the second heat exchange section 211B using the flow rate adjustment mechanism 272, and then increase the opening of the expansion valve 230.
好ましくは、膨張弁230の開度の増加量は、第1熱交換部211Aを通過する冷媒の流量と第2熱交換部211Bを通過する冷媒の流量との比率に基づいて決定される。例えば、図8に示すマップによって膨張弁230の開度の増加量を決定しても良い。また例えば、図9,図10に示した近似式によって膨張弁230の開度の増加量を決定しても良い。
Preferably, the increase in the opening degree of the expansion valve 230 is determined based on the ratio between the flow rate of the refrigerant passing through the first heat exchange section 211A and the flow rate of the refrigerant passing through the second heat exchange section 211B. For example, the increase in the opening degree of the expansion valve 230 may be determined using the map shown in FIG. 8. Also, for example, the increase in the opening degree of the expansion valve 230 may be determined using the approximation formulas shown in FIG. 9 and FIG. 10.
好ましくは、流量調整機構272は、例えば、図1の例では第2熱交換部211Bの下流に設置される。なお、流量調整機構272は、第2熱交換部211Bの上流に設置されても良い。
Preferably, the flow rate adjustment mechanism 272 is installed downstream of the second heat exchange section 211B in the example of FIG. 1. The flow rate adjustment mechanism 272 may also be installed upstream of the second heat exchange section 211B.
好ましくは、空気調和装置1000は、室温を検出する温度センサ261をさらに備える。制御装置100は、温度センサ261によって検出された温度と室温の目標温度である設定温度との差の変化に基づいて室内負荷よりも空調能力が大きいか否かを判断するように構成される。
Preferably, the air conditioning device 1000 further includes a temperature sensor 261 that detects the room temperature. The control device 100 is configured to determine whether the air conditioning capacity is greater than the indoor load based on the change in the difference between the temperature detected by the temperature sensor 261 and a set temperature that is a target temperature for the room temperature.
好ましくは、制御装置100は、蒸発器(110)の出口部の冷媒または圧縮機200の吸入冷媒の過熱度が5度以下になるように膨張弁230を制御するように構成される。
Preferably, the control device 100 is configured to control the expansion valve 230 so that the degree of superheat of the refrigerant at the outlet of the evaporator (110) or the refrigerant sucked into the compressor 200 is 5 degrees or less.
好ましくは、図15、図16に示すように、凝縮器(211)は、制御装置によって互いに独立して回転速度が制御可能な第1ファン(221)および第2ファン(222)をさらに含む。第1ファン(221)は、第1熱交換部211Aに対応して設けられ、第2ファン(222)は、第2熱交換部211Bに対応して設けられる。制御装置100は、圧縮機200の運転周波数が予め設定された下限周波数Fminであり、かつ室内負荷よりも冷媒回路500の空調能力が大きい場合には、流量調整機構272によって第2熱交換部211Bを通過する冷媒の流量を第1熱交換部211Aを通過する冷媒の流量よりも低下させる。制御装置100は、流量調整機構272によって第2熱交換部211Bを通過する冷媒の流量を第1熱交換部211Aを通過する冷媒の流量よりも低下させた場合には、図18で説明したように、第1ファン(221)の回転速度を第2ファン(222)の回転速度よりも低下させるように構成される。
15 and 16, the condenser (211) preferably further includes a first fan (221) and a second fan (222) whose rotation speeds can be controlled independently of each other by the control device. The first fan (221) is provided corresponding to the first heat exchange section 211A, and the second fan (222) is provided corresponding to the second heat exchange section 211B. When the operating frequency of the compressor 200 is a preset lower limit frequency Fmin and the air conditioning capacity of the refrigerant circuit 500 is greater than the indoor load, the control device 100 uses the flow rate adjustment mechanism 272 to reduce the flow rate of the refrigerant passing through the second heat exchange section 211B to be lower than the flow rate of the refrigerant passing through the first heat exchange section 211A. When the flow rate of the refrigerant passing through the second heat exchange section 211B is reduced to less than the flow rate of the refrigerant passing through the first heat exchange section 211A by the flow rate adjustment mechanism 272, the control device 100 is configured to reduce the rotation speed of the first fan (221) to less than the rotation speed of the second fan (222), as described in FIG. 18.
より好ましくは、第1ファン(221)の回転速度の低下率は、第1熱交換部211Aを通過する冷媒の流量と第2熱交換部211Bを通過する冷媒の流量との比率に基づいて決定される。
More preferably, the rate of reduction in the rotation speed of the first fan (221) is determined based on the ratio between the flow rate of the refrigerant passing through the first heat exchange section 211A and the flow rate of the refrigerant passing through the second heat exchange section 211B.
より好ましくは、制御装置100は、流量調整機構272によって第2熱交換部211Bを通過する冷媒の流量を第1熱交換部211Aを通過する冷媒の流量よりも低下させた場合には、図24に示すように、第2ファン(222)の回転を維持しつつ第1ファン(221)の回転を停止させるように構成される。
More preferably, when the flow rate of the refrigerant passing through the second heat exchange section 211B is reduced to be lower than the flow rate of the refrigerant passing through the first heat exchange section 211A by the flow rate adjustment mechanism 272, the control device 100 is configured to stop the rotation of the first fan (221) while maintaining the rotation of the second fan (222), as shown in FIG. 24.
好ましくは、圧縮機200は、図29に示すようなロータリーベーン式である。
今回開示された実施の形態は、すべての点で例示であって制限的なものではないと考えられるべきである。本開示の範囲は、上記した実施の形態の説明ではなくて請求の範囲によって示され、請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 Preferably, thecompressor 200 is of the rotary vane type as shown in FIG.
The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims.
今回開示された実施の形態は、すべての点で例示であって制限的なものではないと考えられるべきである。本開示の範囲は、上記した実施の形態の説明ではなくて請求の範囲によって示され、請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 Preferably, the
The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims.
100 制御装置、101 CPU、102 メモリ、110,210,211,212 熱交換器、120 室内ファン、200 圧縮機、201 シリンダ、201a 高圧領域、201b 低圧領域、201c ベーン溝、202 ピストン、203 ベーン、204 スプリング、205 背圧室、206 吸入口、207 吐出口、208 回転軸、211A 第1熱交換部、211B 第2熱交換部、211F,211FA,211FB フィン、220 室外ファン、221,222 ファン、230 膨張弁、240 四方弁、261,262,263,264,265 温度センサ、270,272 流量調整機構、310,320 配管、500 冷媒回路、1000,1010,1200 空気調和装置、1001 室外機、1002 室内機、P1,P2,P3,P4 ポート、PIA,PIB 冷媒入口、POA,POB 冷媒出口。
100 control device, 101 CPU, 102 memory, 110, 210, 211, 212 heat exchanger, 120 indoor fan, 200 compressor, 201 cylinder, 201a high pressure area, 201b low pressure area, 201c vane groove, 202 piston, 203 vane, 204 spring, 205 back pressure chamber, 206 intake port, 207 discharge port, 208 rotating shaft, 211A first heat exchange section, 211B second heat exchange section, 211F, 21 1FA, 211FB fins, 220 outdoor fan, 221, 222 fan, 230 expansion valve, 240 four-way valve, 261, 262, 263, 264, 265 temperature sensor, 270, 272 flow rate adjustment mechanism, 310, 320 piping, 500 refrigerant circuit, 1000, 1010, 1200 air conditioning unit, 1001 outdoor unit, 1002 indoor unit, P1, P2, P3, P4 ports, PIA, PIB refrigerant inlet, POA, POB refrigerant outlet.
Claims (9)
- 少なくとも圧縮機、凝縮器、膨張弁、および蒸発器を含み、冷媒が循環するように構成される冷媒回路と、
前記冷媒回路を制御する制御装置とを備え、
前記凝縮器は、
冷媒を並行して流すことが可能に構成された第1熱交換部および第2熱交換部と、
前記第2熱交換部を通過する冷媒の流量を調整するように構成された流量調整機構とを含み、
前記制御装置は、前記圧縮機の運転周波数が予め設定された下限周波数である場合に、前記流量調整機構によって前記第2熱交換部を通過する冷媒の流量を前記第1熱交換部を通過する冷媒の流量よりも低下させることが可能に構成され、
前記制御装置は、室内負荷よりも前記冷媒回路の空調能力が大きい場合には、前記流量調整機構によって前記第2熱交換部を通過する冷媒の流量を低下させた後に、前記膨張弁の開度を増加させるように構成される、空気調和装置。 A refrigerant circuit including at least a compressor, a condenser, an expansion valve, and an evaporator, configured to circulate a refrigerant;
A control device for controlling the refrigerant circuit,
The condenser is
a first heat exchange unit and a second heat exchange unit configured to allow a refrigerant to flow in parallel;
a flow rate adjusting mechanism configured to adjust a flow rate of the refrigerant passing through the second heat exchange portion,
the control device is configured to be able to reduce a flow rate of the refrigerant passing through the second heat exchange unit to be lower than a flow rate of the refrigerant passing through the first heat exchange unit by the flow rate adjustment mechanism when an operation frequency of the compressor is a preset lower limit frequency,
The control device is configured to, when the air conditioning capacity of the refrigerant circuit is greater than the indoor load, reduce the flow rate of the refrigerant passing through the second heat exchange section using the flow control mechanism, and then increase the opening degree of the expansion valve. - 前記膨張弁の開度の増加量は、前記第1熱交換部を通過する冷媒の流量と前記第2熱交換部を通過する冷媒の流量との比率に基づいて決定される、請求項1に記載の空気調和装置。 The air conditioner of claim 1, wherein the increase in the opening degree of the expansion valve is determined based on the ratio of the flow rate of the refrigerant passing through the first heat exchange section to the flow rate of the refrigerant passing through the second heat exchange section.
- 前記流量調整機構は、前記第2熱交換部の上流または下流に設置される、請求項1または2に記載の空気調和装置。 The air conditioner according to claim 1 or 2, wherein the flow rate adjustment mechanism is installed upstream or downstream of the second heat exchanger.
- 室温を検出する温度センサをさらに備え、
前記制御装置は、前記温度センサによって検出された温度と前記室温の目標温度である設定温度との差の変化に基づいて前記室内負荷よりも前記空調能力が大きいか否かを判断するように構成される、請求項1~3のいずれか1項に記載の空気調和装置。 Further comprising a temperature sensor for detecting a room temperature;
The air conditioning apparatus according to any one of claims 1 to 3, wherein the control device is configured to determine whether the air conditioning capacity is greater than the indoor load based on a change in the difference between the temperature detected by the temperature sensor and a set temperature which is a target temperature for the room temperature. - 前記制御装置は、前記蒸発器の出口部の冷媒または前記圧縮機の吸入冷媒の過熱度が5度以下になるように前記膨張弁を制御するように構成される、請求項1~4のいずれか1項に記載の空気調和装置。 The air conditioner according to any one of claims 1 to 4, wherein the control device is configured to control the expansion valve so that the degree of superheat of the refrigerant at the outlet of the evaporator or the refrigerant sucked into the compressor is 5 degrees or less.
- 前記凝縮器は、前記制御装置によって互いに独立して回転速度が制御可能な第1ファンおよび第2ファンをさらに含み、
前記第1ファンは、前記第1熱交換部に対応して設けられ、前記第2ファンは、前記第2熱交換部に対応して設けられ、
前記制御装置は、前記流量調整機構によって前記第2熱交換部を通過する冷媒の流量を前記第1熱交換部を通過する冷媒の流量よりも低下させた場合には、前記第1ファンの回転速度を前記第2ファンの回転速度よりも低下させるように構成される、請求項1~5のいずれか1項に記載の空気調和装置。 the condenser further includes a first fan and a second fan whose rotation speeds are independently controllable by the control device;
the first fan is provided corresponding to the first heat exchange unit, and the second fan is provided corresponding to the second heat exchange unit,
The air conditioning apparatus of any one of claims 1 to 5, wherein the control device is configured to reduce the rotation speed of the first fan to be lower than the rotation speed of the second fan when the flow rate of the refrigerant passing through the second heat exchange section is reduced by the flow control mechanism to be lower than the flow rate of the refrigerant passing through the first heat exchange section. - 前記第1ファンの回転速度の低下率は、前記第1熱交換部を通過する冷媒の流量と前記第2熱交換部を通過する冷媒の流量との比率に基づいて決定される、請求項6に記載の空気調和装置。 The air conditioner of claim 6, wherein the rate of reduction in the rotational speed of the first fan is determined based on the ratio of the flow rate of the refrigerant passing through the first heat exchange section to the flow rate of the refrigerant passing through the second heat exchange section.
- 前記制御装置は、前記流量調整機構によって前記第2熱交換部を通過する冷媒の流量を前記第1熱交換部を通過する冷媒の流量よりも低下させた場合には、前記第2ファンの回転を維持しつつ前記第1ファンの回転を停止させるように構成される、請求項6に記載の空気調和装置。 The air-conditioning device according to claim 6, wherein the control device is configured to stop the rotation of the first fan while maintaining the rotation of the second fan when the flow rate of the refrigerant passing through the second heat exchange unit is reduced by the flow rate adjustment mechanism to be lower than the flow rate of the refrigerant passing through the first heat exchange unit.
- 前記圧縮機は、ロータリーベーン式である、請求項1~8のいずれか1項に記載の空気調和装置。 An air conditioner according to any one of claims 1 to 8, wherein the compressor is of a rotary vane type.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2022/037402 WO2024075235A1 (en) | 2022-10-06 | 2022-10-06 | Air conditioning device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2022/037402 WO2024075235A1 (en) | 2022-10-06 | 2022-10-06 | Air conditioning device |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2024075235A1 true WO2024075235A1 (en) | 2024-04-11 |
Family
ID=90607856
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2022/037402 WO2024075235A1 (en) | 2022-10-06 | 2022-10-06 | Air conditioning device |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2024075235A1 (en) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2016205732A (en) * | 2015-04-24 | 2016-12-08 | 株式会社日立製作所 | Refrigeration cycle device |
WO2020157788A1 (en) * | 2019-01-28 | 2020-08-06 | 三菱電機株式会社 | Air conditioner |
-
2022
- 2022-10-06 WO PCT/JP2022/037402 patent/WO2024075235A1/en unknown
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2016205732A (en) * | 2015-04-24 | 2016-12-08 | 株式会社日立製作所 | Refrigeration cycle device |
WO2020157788A1 (en) * | 2019-01-28 | 2020-08-06 | 三菱電機株式会社 | Air conditioner |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP4457928B2 (en) | Refrigeration equipment | |
JP5182358B2 (en) | Refrigeration equipment | |
US20040134206A1 (en) | Apparatus and method for controlling operation of air conditioner | |
WO2013145006A1 (en) | Air conditioning device | |
WO2004063642A1 (en) | Refrigeration apparatus | |
KR101387478B1 (en) | Compression system and Air-conditioning system using the same | |
CN111051793B (en) | Air conditioning apparatus | |
JP2003121018A (en) | Refrigerating apparatus | |
JP4096544B2 (en) | Refrigeration equipment | |
JP2008039233A (en) | Refrigerating device | |
JP6758506B2 (en) | Air conditioner | |
CN113454408A (en) | Air conditioning apparatus | |
WO2020203708A1 (en) | Refrigeration cycle device | |
WO2024075235A1 (en) | Air conditioning device | |
JPWO2021019687A5 (en) | ||
WO2023243089A1 (en) | Air conditioning device | |
CN115342476A (en) | Electronic expansion valve control method and control device and multi-split air conditioning system | |
WO2020250986A1 (en) | Refrigerant cycle system | |
CN113272598B (en) | Air conditioner | |
JP7467827B2 (en) | Air conditioners | |
WO2023139758A1 (en) | Air conditioner | |
JP7216258B1 (en) | air conditioner | |
JP2019190760A (en) | Air conditioner | |
JP4692002B2 (en) | Air conditioner | |
WO2022230034A1 (en) | Air conditioning 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: 22961422 Country of ref document: EP Kind code of ref document: A1 |