WO2019106764A1 - 冷凍装置および室外機 - Google Patents
冷凍装置および室外機 Download PDFInfo
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- WO2019106764A1 WO2019106764A1 PCT/JP2017/042868 JP2017042868W WO2019106764A1 WO 2019106764 A1 WO2019106764 A1 WO 2019106764A1 JP 2017042868 W JP2017042868 W JP 2017042868W WO 2019106764 A1 WO2019106764 A1 WO 2019106764A1
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- refrigerant
- compressor
- expansion valve
- bypass
- valve
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- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
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- 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
- F25B41/00—Fluid-circulation arrangements
- F25B41/30—Expansion means; Dispositions thereof
- F25B41/39—Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator
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- 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
- F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
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- 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
- F25B2600/00—Control issues
- F25B2600/02—Compressor control
- F25B2600/027—Compressor control by controlling pressure
- F25B2600/0271—Compressor control by controlling pressure the discharge pressure
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- 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
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2509—Economiser valves
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- 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
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2513—Expansion valves
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- 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
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/19—Pressures
- F25B2700/193—Pressures of the compressor
- F25B2700/1931—Discharge pressures
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- 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
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/19—Pressures
- F25B2700/193—Pressures of the compressor
- F25B2700/1933—Suction pressures
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/005—Arrangement or mounting of control or safety devices of safety devices
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- 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
- F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
- F25B9/002—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant
- F25B9/008—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant the refrigerant being carbon dioxide
Definitions
- the present invention relates to a refrigeration apparatus having a refrigerant circuit in which a refrigerant circulates, and an outdoor unit included in the refrigeration apparatus.
- R744 (CO 2 ) refrigerant has a GWP of 1 and is a nontoxic refrigerant.
- the R744 (CO 2 ) refrigerant is considered to be one of the refrigerants that can contribute to global warming countermeasures by replacing the R404A refrigerant having a GWP of about 4000 and the HFC refrigerant such as an R410A refrigerant having a GWP of about 2000.
- Patent Document 1 As a refrigeration cycle using R744 (CO 2 ) refrigerant, there is known a refrigeration system provided with a pressure reducing device on the downstream side of a gas cooler (see, for example, Patent Document 1).
- the refrigeration system of Patent Document 1 has a refrigerant circuit in which a compressor, a gas cooler, a cascade heat exchanger, a second pressure reducing device, a liquid receiver, a first pressure reducing device and an evaporator are sequentially connected via a refrigerant pipe. .
- the refrigeration system is provided with a circuit that connects the liquid receiver and the compressor via an on-off valve.
- the refrigerant is depressurized on the outdoor unit side, and then flows into the indoor unit through an extension pipe.
- the length of the extension pipe may change depending on the installation environment, and the amount of refrigerant required may change depending on the length of the extension pipe and the use environment (outside temperature, internal temperature, etc.).
- a receiver is provided to adjust the amount of refrigerant.
- the refrigeration system disclosed in Patent Document 1 may operate in a supercritical cycle in which the refrigerant does not become liquid no matter how compressed it is.
- the refrigerant may not be sufficiently stored in the receiver depending on the use conditions such as the ambient temperature.
- the operation as the refrigeration cycle may become unstable. For example, it is because it may be in a refrigerant excess state in places other than a liquid receiver.
- R744 CO 2
- the present invention has been made to solve the problems as described above, and provides a refrigeration apparatus and an outdoor unit that operate stably under various usage conditions such as a change in ambient temperature.
- a compressor, a gas cooler, a receiver, a low pressure expansion valve, and an evaporator are connected to a refrigerant pipe, and provided between the gas cooler and the receiver.
- a control device that performs control to increase the opening degree of the bypass adjustment valve.
- a compressor, a gas cooler, a receiver, a low pressure expansion valve and an evaporator are connected to a refrigerant pipe, and the compressor, the gas cooler and the receiver of a refrigerant circuit in which the refrigerant circulates
- An outdoor unit comprising: a high pressure expansion valve provided between the gas cooler and the liquid receiver; an accumulator provided between the evaporator and the compressor and storing a refrigerant; And a bypass circuit connecting between the low pressure expansion valve and the refrigerant inlet side of the accumulator, a bypass adjusting valve provided in the bypass circuit to adjust the flow rate of the refrigerant, and the discharge side of the compressor from the discharge side
- the control device performs control to increase the opening degree of the bypass adjusting valve when the amount of refrigerant stored up to the liquid receiver exceeds a determined threshold value.
- the outdoor unit can be stably operated even under various operating conditions such as a change in ambient temperature, with the operation of the surplus refrigerant in the receiver becoming unstable.
- FIG. 7 is a Ph diagram showing the state of the refrigerant when the outside air temperature is low in the refrigerant circuit shown in FIG. 1.
- FIG. 7 is a Ph diagram showing the state of the refrigerant when the outside air temperature is high in the refrigerant circuit shown in FIG. 1.
- this Embodiment 1 it is a flowchart which shows the control procedure which a control apparatus performs with respect to a bypass regulating valve.
- Embodiment 2 it is a flowchart which shows the control procedure which a control apparatus performs with respect to a bypass regulating valve. It is a schematic diagram for demonstrating the structure of the accumulator shown in FIG. It is a refrigerant circuit figure which shows another structural example of the freezing apparatus shown in FIG. It is a refrigerant circuit figure which shows another structural example of the freezing apparatus shown in FIG.
- FIG. 1 is a refrigerant circuit diagram of a refrigeration apparatus according to Embodiment 1 of the present invention.
- the refrigeration system 1 includes an outdoor unit 100 and an indoor unit 200 connected by a refrigerant circuit 5 and a control device 300 that controls each device of the refrigerant circuit 5.
- the indoor unit 200 is, for example, used to cool food and the like.
- the indoor unit 200 may be a showcase such as a supermarket, or may be a unit cooler installed in a cold storage warehouse and a freezer storage.
- the outdoor unit 100 includes a compressor 101 that compresses and discharges a refrigerant, a gas cooler 102 that exchanges heat with the outdoor air, a high pressure expansion valve 103 that reduces the pressure of a high pressure refrigerant to a medium pressure, and a liquid receiver 104. And a fan 102a.
- the high pressure expansion valve 103 is provided between the gas cooler 102 and the receiver 104.
- An accumulator 108 is provided on the refrigerant suction side of the compressor 101.
- the compressor 101 is, for example, an inverter type compressor whose capacity can be changed by changing the operating rotational speed.
- the gas cooler 102 is a heat exchanger that functions as a condenser.
- the gas cooler 102 is not limited to the air-cooling type, and may be of a type that exchanges heat with the refrigerant. Below, the case where the gas cooler 102 is air-cooling type is demonstrated.
- the receiver 104 is a container for storing high-pressure liquid refrigerant.
- the accumulator 108 stores the refrigerant returned from the indoor unit 200, and separates the gas refrigerant from the stored refrigerant.
- the fan 102 a supplies the outdoor air to the gas cooler 102.
- a first heat exchanger 105 is provided between the high pressure expansion valve 103 and the liquid receiver 104.
- a second heat exchanger 106 is provided in the refrigerant pipe on the refrigerant outlet side of the liquid receiver 104.
- the first heat exchanger 105 is a heat exchanger that exchanges heat between the refrigerant and the refrigerant to make the medium pressure liquid refrigerant.
- the second heat exchanger 106 is a heat exchanger that exchanges heat between the refrigerant and the refrigerant to make it into a supercooled liquid state.
- the first heat exchanger 105 and the second heat exchanger 106 are formed of, for example, a plate heat exchanger or a double pipe, but any heat exchangers may be used as long as they exchange heat with each other.
- the outdoor unit 100 has a bypass circuit 7 that connects the refrigerant outlet side of the second heat exchanger 106 and the refrigerant inlet side of the accumulator 108.
- the bypass circuit 7 is connected to the refrigerant inlet side of the accumulator 108 from the refrigerant outlet side of the second heat exchanger 106 via the secondary side of the first heat exchanger 105 and the second heat exchanger 106.
- a bypass adjusting valve 107 is provided upstream of the refrigerant inlet on the secondary side of the second heat exchanger 106.
- bypass adjustment valve 107 is provided between the refrigerant outlet on the primary side of the second heat exchanger 106 and the refrigerant inlet on the secondary side of the second heat exchanger 106.
- the bypass adjusting valve 107 adjusts the flow rate of the refrigerant branched from the refrigerant circuit 5 to reduce the pressure of the medium pressure refrigerant to a low pressure.
- the refrigerant pipe connected to the refrigerant outlet on the primary side of the second heat exchanger 106 is connected to the indoor unit 200 via the extension pipe 301.
- the refrigerant pipe connected to the refrigerant inlet of the accumulator 108 is connected to the indoor unit 200 via the extension pipe 302.
- the indoor unit 200 has a low pressure expansion valve 201 and an evaporator 202.
- the low pressure expansion valve 201 expands and vaporizes the medium pressure liquid refrigerant.
- the evaporator 202 is a heat exchanger that exchanges heat with the air of the air conditioning target space.
- the extension pipe 301 is connected to the refrigerant inlet side of the low pressure expansion valve 201 of the indoor unit 200.
- the refrigerant outlet of the low pressure expansion valve 201 is connected to the refrigerant inlet of the evaporator 202 by a refrigerant pipe.
- the refrigerant outlet side of the evaporator 202 is connected to the extension pipe 302.
- the pipe coming out of the indoor unit 200 is connected to the extension pipe 302, and returns to the outdoor unit 100.
- the extension pipe 301 is connected to the outdoor unit 100 via the refrigerant pipe and the refrigerant inlet side of the accumulator 108.
- the compressor 101, the gas cooler 102, the liquid receiver 104, the low pressure expansion valve 201, and the evaporator 202 are connected by a refrigerant pipe, and a refrigerant circuit 5 in which the refrigerant circulates is configured.
- the refrigerant circuit 5 is provided with pressure sensors 112 to 114 for measuring the pressure of the refrigerant.
- the pressure sensor 112 is provided on the refrigerant pipe on the refrigerant discharge side of the compressor 101.
- the pressure sensor 112 measures the discharge pressure of the refrigerant discharged from the compressor 101.
- the pressure sensor 114 is provided on a refrigerant pipe on the refrigerant inlet side of the accumulator 108.
- the pressure sensor 114 measures the suction pressure of the gas refrigerant sucked into the compressor 101.
- the pressure sensor 113 is provided between the high pressure expansion valve 103 and the first heat exchanger 105.
- the pressure sensor 113 measures the pressure of the refrigerant flowing out of the high pressure expansion valve 103.
- FIG. 2 is a functional block diagram showing one configuration example of the control device shown in FIG.
- the control device 300 is, for example, a microcomputer.
- Control device 300 has a CPU (Central Processing Unit) and a memory (not shown).
- the control device 300 includes refrigeration cycle means 311, retention determination means 312, and opening degree control means 313.
- the refrigeration cycle unit 311, the retention determination unit 312, and the opening degree control unit 313 are configured in the refrigeration apparatus 1 by the CPU executing a program stored in the memory.
- Control device 300 may be provided in outdoor unit 100.
- the control device 300 is connected by wire or wirelessly to the pressure sensors 112 to 114, the high pressure expansion valve 103, the low pressure expansion valve 201, the bypass adjustment valve 107, the compressor 101 and the fan 102a.
- sensors for measuring the temperature and pressure of the refrigerant may be provided in the refrigeration system 1, and these sensors are connected to the control device 300 in a wired or wireless manner.
- a temperature sensor that measures the temperature of the refrigerant of the evaporator 202 or a pressure sensor that measures the pressure of the refrigerant of the evaporator 202 may be provided.
- the refrigeration cycle means 311 operates the number of rotations of the compressor 101, the number of rotations of the fan 102a, and the degree of opening of the high pressure expansion valve 103 and the low pressure expansion valve 201 based on information of various sensors and setting information inputted by the user. And control.
- the retention determination means 312 compares the amount of refrigerant stored between the discharge side of the compressor and the receiver with a predetermined threshold, and determines whether the amount of stored refrigerant exceeds the threshold. In the first embodiment, the retention determination means 312 makes the determination using the measurement value of the pressure sensor 112.
- the opening degree control means 313 controls the opening degree of the bypass adjustment valve 107 in accordance with the determination result of the retention determination means 312.
- the opening degree control means 313 increases the opening degree of the bypass adjusting valve 107 when the measured value of the pressure sensor 112 exceeds the threshold value, and the opening degree of the bypass adjusting valve 107 when the measured value of the pressure sensor 112 is equal to or less than the threshold value.
- Make The refrigeration cycle means 311 may instruct the opening degree control means 313 the opening degree of the bypass adjustment valve 107 via the retention judgment means 312.
- FIG. 2 shows the case where the control device 300 controls the low pressure expansion valve 201
- the outdoor unit 100 is connected with an indoor unit 200 manufactured by a manufacturer different from the manufacturer of the outdoor unit 100. There is something to be done. Therefore, it is also assumed that control of the refrigerant apparatus provided in the indoor unit 200 may not be performed from the outdoor unit 100 side.
- the refrigerant to be used is a natural refrigerant such as R744 (CO 2 ) refrigerant
- the refrigerant used is a natural refrigerant such as R744 (CO 2 ) refrigerant
- the pressure in the pipe increases while the compressor 101 is stopped, depending on the refrigerant pressure after being reduced by the high-pressure expansion valve 103.
- the first safety valve 109, the second safety valve 110, and the third safety valve 111 may be provided in the refrigerant circuit 5.
- the valves when the pressure inside the refrigerant circuit 5 exceeds the set value, the valves are switched from the closed state to the open state.
- the first safety valve 109, the second safety valve 110 and the third safety valve 111 release the pressure to the atmosphere when the pressure inside the refrigerant circuit 5 rises above the set value, and prevents the refrigerant piping and the pressure vessel from bursting. Play. Since the refrigerant is a natural refrigerant, there is no problem if the refrigerant is released into the atmosphere.
- the first safety valve 109 is provided on the refrigerant outlet side of the high pressure expansion valve 103.
- the first safety valve 109 is provided, for example, between the liquid receiver 104 and the low pressure expansion valve 201, and the pressure can be reduced promptly by releasing the liquid refrigerant.
- the second safety valve 110 is provided on the suction side of the compressor 101.
- the third safety valve 111 is provided on the discharge side of the compressor 101.
- FIG. 1 shows the configuration in which the first safety valve 109, the second safety valve 110 and the third safety valve 111 are provided in the refrigerant circuit 5, but at least one safety valve is provided in the refrigerant circuit 5 It should be done.
- the bypass adjustment valve 107 shown in FIG. 1 is configured to be connected to the refrigerant inlet side of the accumulator 108 via the second heat exchanger 106 and the first heat exchanger 105 in this order.
- the heat exchanger 105 and the second heat exchanger 106 may be connected in this order.
- FIG. 3 is a refrigerant circuit diagram showing another configuration example of the refrigeration apparatus shown in FIG.
- the refrigeration system 1a shown in FIG. 3 has two bypass circuits 7a and 7b instead of the bypass circuit 7.
- the bypass circuit 7 a is connected to the refrigerant inlet side of the accumulator 108 from the refrigerant outlet side of the second heat exchanger 106 via the secondary side of the second heat exchanger 106.
- the bypass circuit 7 b is connected to the bypass circuit 7 a from the refrigerant outlet side of the second heat exchanger 106 via the secondary side of the first heat exchanger 105.
- a bypass adjustment valve 107a is provided between the refrigerant outlet side of the second heat exchanger 106 and the refrigerant inlet on the secondary side of the second heat exchanger 106.
- a bypass adjusting valve 107b is provided between the refrigerant outlet side of the second heat exchanger 106 and the refrigerant inlet on the secondary side of the first heat exchanger 105.
- the refrigeration system 1a shown in FIG. 3 further improves the control accuracy with respect to the refrigerant flowing out to the bypass circuits 7a and 7b.
- the refrigeration apparatus 1 shown in FIG. 1 has a smaller number of expansion valves than the refrigeration apparatus 1a shown in FIG. 3, so that the manufacturing cost of the apparatus is suppressed from increasing and expansion valve control becomes complicated. Is suppressed.
- the compressor 101 compresses and discharges the refrigerant.
- the high temperature and high pressure gas refrigerant discharged from the compressor 101 flows into the gas cooler 102.
- the gas cooler 102 the refrigerant exchanges heat with the outdoor air so that heat is taken away and it becomes a high pressure liquid refrigerant or a supercritical state.
- the refrigerant flowing out of the gas cooler 102 is decompressed in the high-pressure expansion valve 103, and becomes a gas-liquid two-phase state of the medium-temperature and medium-pressure liquid refrigerant and the gas refrigerant.
- the pressure of the refrigerant is reduced by the high pressure expansion valve 103, and the refrigerant pressure on the refrigerant outlet side of the high pressure expansion valve 103 is made constant, so that the receiver 104, the first heat exchanger 105, and the second heat exchanger 106
- the design pressure resistance of the piping and equipment such as the extension pipes 301 and 302 can be reduced.
- the thickness of the refrigerant pipe used in the refrigeration system 1 can be reduced, and the cost of the refrigeration system 1 can be reduced.
- the high pressure expansion valve 103 temporarily reduces the pressure of the refrigerant.
- the high-pressure expansion valve 103 reduces the pressure of the refrigerant to a refrigerant pressure (for example, 4.15 MPa) equivalent to that of a conventional refrigeration apparatus using a refrigerant such as HFC, piping such as the extension piping 301 and 302 and As an apparatus, what is used by the conventional refrigerating apparatus can be used. Since the piping and equipment used in the HFC are inexpensive due to the mass production effect, it is possible to suppress an increase in the manufacturing cost of the refrigeration system 1.
- the refrigerant flowing out of the high pressure expansion valve 103 exchanges heat with the refrigerant on the secondary side in the first heat exchanger 105, becomes an intermediate pressure liquid refrigerant, and flows into the liquid receiver 104.
- the refrigerant is separated into gas and liquid, and only the saturated liquid refrigerant flows into the second heat exchanger 106.
- the liquid refrigerant exchanges heat with the refrigerant on the secondary side to become a medium pressure supercooled liquid, and then flows out of the second heat exchanger 106.
- the refrigerant flowing out of the second heat exchanger 106 is branched into two.
- One of the branched refrigerant flows into the bypass circuit 7, and the other of the branched refrigerant flows out of the outdoor unit 100.
- the refrigerant flowing into the bypass circuit 7 is depressurized by the bypass adjustment valve 107, and is brought into a gas-liquid two-phase state of low-temperature low-pressure liquid refrigerant and gas refrigerant.
- the gas-liquid two-phase refrigerant flows on the secondary side of the second heat exchanger 106 and the first heat exchanger 105, and exchanges heat with the refrigerant on the primary side.
- the refrigerant flowing out of the first heat exchanger 105 flows into the refrigerant inlet of the accumulator 108.
- the refrigerant flowing out of the outdoor unit 100 flows into the indoor unit 200 via the extension pipe 301.
- the refrigerant flowing into the indoor unit 200 is decompressed in the low pressure expansion valve 201, and is brought into a gas-liquid two-phase state of the low-temperature low-pressure liquid refrigerant and the gas refrigerant.
- the gas-liquid two-phase refrigerant evaporates in the evaporator 202 to be a low-pressure gas refrigerant.
- the gas refrigerant flowing out of the evaporator 202 returns to the outdoor unit 100 via the extension pipe 302.
- the refrigerant returned to the outdoor unit 100 is separated into a gas and a liquid in the accumulator 108, and then the gas refrigerant returns to the compressor 101.
- control performed by the control device 300 on the devices provided in the refrigerant circuit 5 will be described.
- the control described here is an example, and may differ from the control performed when an abnormality or the like occurs in the refrigeration system 1.
- the refrigeration cycle means 311 controls the rotational speed of the compressor 101 so that the low pressure measured by the pressure sensor 114 becomes constant.
- the refrigeration cycle unit 311 increases the rotational speed of the compressor 101.
- the refrigeration cycle unit 311 reduces the rotational speed of the compressor 101.
- This control makes the low pressure constant.
- the low pressure depends on the load of the object to be cooled, such as a showcase, a cold storage warehouse and a freezer storage. For example, when the load to be cooled is high because the number of items to be cooled is high, the low pressure tends to be high. On the other hand, when the load to be cooled is low, the low pressure tends to be low.
- the target monitored by the refrigeration cycle means 311 may be the evaporation temperature instead of the low pressure.
- the refrigeration cycle unit 311 controls the number of rotations of the fan 102 a based on the condensation temperature. When the outside air temperature is high, the condensation temperature tends to be high. In this case, the refrigeration cycle means 311 increases the rotational speed of the fan 102a. When the outside air temperature is low, the condensation temperature tends to be low. In this case, the refrigeration cycle means 311 reduces the rotational speed of the fan 102a.
- the refrigeration cycle means 311 controls the degree of opening of the high pressure expansion valve 103 so that the pressure measured by the pressure sensor 113 becomes constant. If the pressure measured by the pressure sensor 113 is higher than a predetermined threshold, the refrigeration cycle means 311 reduces the degree of opening of the high pressure expansion valve 103, and if the pressure measured by the pressure sensor 113 is lower than the threshold, the refrigeration cycle 311 measures The opening degree of the high pressure expansion valve 103 is increased.
- the degree of opening of the high pressure expansion valve 103 is made too small, the circulation of the refrigerant is restricted, so that the refrigerant is clogged at the refrigerant inlet side of the high pressure expansion valve 103. In this case, the discharge pressure of the compressor 101 is excessively increased. Therefore, it is necessary not to make the opening degree of the high pressure expansion valve 103 too small.
- the discharge pressure of the compressor 101 is measured by a pressure sensor 112, as shown in FIG.
- the control to keep the pressure measured by the pressure sensor 113 is not limited to the case of controlling the opening degree of the high pressure expansion valve 103, and the opening degree of the bypass adjusting valve 107 may be controlled.
- the refrigeration cycle means 311 releases the increased pressure to the suction side of the compressor 101 by increasing the opening degree of the bypass adjustment valve 107. Even in this control, the pressure measured by the pressure sensor 113 can be reduced. Therefore, the control of the high pressure expansion valve 103 and the bypass adjusting valve 107 may be combined to adjust the pressure measured by the pressure sensor 113.
- the optimum number of rotations of each device may be determined by combining the control meeting the respective conditions. .
- FIG. 4 is a Ph diagram showing the state of the refrigerant when the outside air temperature is low in the refrigerant circuit shown in FIG.
- FIG. 5 is a Ph diagram showing the state of the refrigerant when the outside air temperature is high in the refrigerant circuit shown in FIG.
- the horizontal axis is enthalpy h [KJ / Kg]
- the vertical axis is pressure P [MPa].
- the states of the refrigerant in the Ph diagram are assigned numbers 1 to 7 for the sake of explanation.
- the process of state 1 ⁇ state 2 represents the compression process by the compressor 101.
- the refrigerant is compressed, the pressure is increased, and the enthalpy is increased by obtaining the power of the compressor 101.
- a process of state 2 ⁇ state 3 represents a condensation process by the gas cooler 102.
- the high-temperature and high-pressure gas refrigerant releases heat at the gas cooler 102, and the enthalpy decreases.
- the ambient temperature of the gas cooler 102 is low, as shown in FIG. 4, the refrigerant condenses and becomes liquid refrigerant.
- the pressure of the gas cooler 102 hardly decreases.
- the process of state 3 ⁇ state 4 represents a pressure reducing process by the high pressure expansion valve 103. Since the refrigerant is depressurized in the depressurizing process of the high pressure expansion valve 103, the pressure is lowered. However, enthalpy does not change because the refrigerant does not work to the outside. Further, the refrigerant after the pressure reduction is in a gas-liquid two-phase state of the liquid refrigerant and the gas refrigerant. In the process of state 4 ⁇ state 5, in the first heat exchanger 105, the refrigerant and the refrigerant exchange heat with each other to be in a saturated liquid state and flow into the liquid receiver 104.
- state 5 ⁇ state 6 represents heat exchange in the second heat exchanger 106.
- the saturated liquid refrigerant that has flowed out of the liquid receiver 104 exchanges heat with the refrigerant in the second heat exchanger 106 and becomes a supercooled liquid state.
- the extension piping may be long or the height difference between the indoor unit and the outdoor unit may be large due to the difference in the installation environment.
- a pressure loss causes a gas-liquid two-phase state of the liquid refrigerant and the gas refrigerant.
- a process of state 6 ⁇ state 7 represents a pressure reducing process by the low pressure expansion valve 201 of the indoor unit 200.
- the pressure of the refrigerant is reduced because the pressure is reduced.
- enthalpy does not change because the refrigerant does not work to the outside.
- state 7 ⁇ state 1 represents the evaporation process by the evaporator 202 of the indoor unit 200.
- the refrigerant receives heat from the outside and evaporates. At that time, although the pressure of the refrigerant does not change, the enthalpy increases because the refrigerant receives heat.
- the Ph diagram differs depending on the ambient temperature of the gas cooler 102 as shown in FIGS. 4 and 5.
- the length of the process from state 2 to state 3 is shorter than in the case where the outside air temperature is low (in the case shown in FIG. 4) . That is, the decrease in enthalpy decreases.
- the enthalpy difference in the gas cooler 102 is large in terms of the physical properties of the refrigerant even if the refrigerant temperature drops to about the same as the ambient temperature of the gas cooler 102. It can not be taken.
- the bypass adjustment valve 107 may be controlled so that the temperature of the refrigerant flowing out of the bypass adjustment valve 107 is lowered.
- enlarging the first heat exchanger 105 leads to an increase in the manufacturing cost of the device.
- the temperature of the refrigerant flowing through the bypass control valve 107 is equal to the saturation temperature (evaporation temperature) of the low pressure, the evaporation temperature becomes high when used in a refrigeration application or the like. Therefore, it is difficult to lower the temperature of the refrigerant flowing out of the bypass adjustment valve 107.
- the refrigerant flowing into the receiver 104 may not be in a saturated liquid state.
- the liquid refrigerant can not be sufficiently stored in the liquid receiver 104. If the liquid refrigerant can not be stored in the liquid receiver 104, there is no place to store the excess refrigerant, so the refrigeration cycle becomes unstable, and there may be an abnormality in each part such as a rise in the refrigerant pressure. In particular, when the discharge pressure measured by the pressure sensor 112 is increased, the refrigerant circuit 5 may be abnormal.
- the refrigeration cycle may become unstable based on changes in the refrigerant circuit 5, the refrigerant pressure in the refrigerant circuit 5, and the enthalpy.
- the heat exchange in the first heat exchanger 105 is insufficient, so the liquid refrigerant can not be stored sufficiently in the receiver 104, and excess refrigerant is stored. There is no place to keep it.
- the refrigeration cycle becomes unstable by controlling the bypass control valve 107 to transfer the storage location of the surplus refrigerant from the receiver 104 to the accumulator 108 based on the cause. To eliminate things.
- FIG. 6 is a flowchart showing a control procedure performed by the control device on the bypass adjustment valve in the first embodiment.
- step ST1 the retention determination means 312 determines whether the pressure measured by the pressure sensor 112 exceeds a set threshold.
- the threshold is, for example, 10 MPa. That is, in step ST1, the retention determination means 312 determines whether the discharge pressure of the refrigerant of the compressor 101 exceeds the threshold.
- the saturation temperature of the pressure measured by the pressure sensor 112 is a temperature equal to or slightly higher than the ambient temperature of the gas cooler 102.
- the temperature difference between the saturation temperature and the ambient temperature is, for example, 5 ° C. to 10 ° C.
- the controller 300 does not store the refrigerant in the receiver 104, and the excess refrigerant is accumulated between the discharge port of the compressor 101 and the gas cooler 102. It is determined that the pressure measured by the pressure sensor 112 has increased.
- step ST2 the opening degree control means 313 performs control in step ST2.
- the opening control means 313 increases the opening of the bypass adjusting valve 107.
- the controller 300 may prevent the opening degree of the bypass adjusting valve 107 from becoming equal to or more than the threshold value of the maximum opening degree.
- a memory not shown in the diagram of the control device 300 stores a threshold of the maximum opening smaller than the full opening.
- step ST1 when the pressure measured by the pressure sensor 112 is equal to or less than the threshold as a result of the determination in step ST1, the opening control means 313 performs sufficient heat exchange between the refrigerant and the outdoor air in the first heat exchanger 105. It is determined that the refrigerant is stored in the liquid receiver 104. Then, the opening degree control means 313 performs control of step ST3. In step ST3, the opening degree control means 313 reduces the opening degree of the bypass adjusting valve 107. As a result, the amount of refrigerant flowing to the accumulator 108 is reduced. After steps ST2 and ST3, the control device 300 returns to step ST1 shown in FIG. 6 again (step ST4).
- the indoor unit 200 is sent via the extension pipe 301.
- the amount of refrigerant flowing in will be reduced.
- the amount of heat exchange in the evaporator 202 decreases, leading to a decrease in cooling capacity. Therefore, when the surplus refrigerant is sufficiently stored in the liquid receiver 104 and the refrigeration system 1 can be operated stably, reducing the opening degree of the bypass adjusting valve 107 leads to improvement of the cooling capacity.
- the opening degree of the bypass adjusting valve 107 is reduced to completely close the valve, heat exchange can not be performed in the first heat exchanger 105 and the second heat exchanger 106. Therefore, when the opening degree control means 313 reduces the opening degree of the bypass adjusting valve 107 in step ST3 shown in FIG. 6, the opening degree is controlled to be equal to or more than the threshold of the minimum opening degree. Let's not do it.
- a memory not shown in the diagram of the control device 300 stores the minimum opening threshold.
- the controller 300 increases the opening degree of the bypass adjustment valve 107 to store the surplus refrigerant that can not be stored on the accumulator 108 side. it can.
- the discharge pressure of the compressor 101 rises unexpectedly, the discharge pressure can be reduced.
- the operation of the refrigeration system 1 can be stabilized.
- the volume of the accumulator 108 is preferably equal to or greater than the volume of the receiver 104.
- the bypass adjusting valve 107 of the bypass circuit 7 connecting the refrigerant outlet side of the receiver 104 and the refrigerant inlet side of the accumulator 108 Control to increase the opening degree of
- the refrigeration apparatus 1 can be prevented from becoming unstable due to the surplus refrigerant in the liquid receiver 104, and can be operated stably. As a result, the reliability of the refrigeration system 1 is improved.
- the refrigeration system 1 Since R744 (CO 2 ) refrigerant has a high operating pressure, it is necessary to increase the pressure resistance of piping and equipment in the refrigeration cycle.
- the refrigeration system 1 according to the first embodiment is configured to once depressurize the refrigerant flowing out of the gas cooler 102 and then flow out to the indoor unit 200. Therefore, the apparatus of the conventional refrigeration apparatus can be used for the apparatus through which the decompressed refrigerant flows, and the design pressure resistance of the extension piping and the indoor unit can be reduced. Therefore, it is suppressed that a manufacturing cost becomes high, and a high-level installation construction technique is not required. Furthermore, in the first embodiment, complicated control is not required in order to operate the refrigeration system 1 stably by suppressing the excess refrigerant in the liquid receiver 104. Therefore, the refrigeration system 1 can be stably operated with less cost and simple control.
- the control device 300 controls the bypass adjusting valve 107 to move the surplus refrigerant of the liquid receiver 104 to the accumulator 108, thereby suppressing an increase in the discharge pressure of the compressor 101, thereby reducing the refrigeration system 1
- the control device 300 controls the bypass adjusting valve 107 to improve the return of the refrigeration oil discharged from the compressor 101 to the compressor 101, and to improve the reliability of the refrigeration system 1 as well. It is a thing.
- the refrigeration apparatus 1 of the second embodiment has the same configuration as the refrigeration apparatus 1 described in the first embodiment, the detailed description of the same configuration is omitted, and different points such as operation are detailed. explain.
- refrigeration oil for improving the lubricity of the compressor may be in two phases without melting of the oil and the refrigerant depending on the temperature and pressure used. May separate.
- the refrigerant discharged from the compressor includes not only the refrigerant but also refrigeration oil. Therefore, after the oil discharged from the compressor 101 flows through the gas cooler 102 and the like, it accumulates in the receiver 104. Since the receiver 104 has a role of gas-liquid separation, the refrigerant often flows in from the upper side of the container and the refrigerant flows out from the lower side of the container.
- the refrigerant and the refrigerator oil are separated into two phases, the oil is accumulated in the upper layer, and the refrigerant is accumulated in the lower layer. Therefore, the oil that has entered the liquid receiver 104 is accumulated in the liquid receiver 104 without returning to the compressor 101.
- FIG. 7 is a flowchart showing a control procedure performed by the control device on the bypass adjusting valve in the second embodiment.
- the retention determination means 312 determines whether the operating time of the compressor 101 exceeds the set time.
- the set time is, for example, 2 hours.
- the residence judging means 312 discharges a certain amount of refrigerating machine oil from the compressor 101, and the storage amount of the refrigerating machine oil in the compressor 101 is determined. It is judged that it has fallen to the following.
- a memory not shown in the diagram of the control device 300 stores the set time and the threshold value of the storage amount of the refrigerator oil.
- determination of whether the storage amount of refrigeration oil in the compressor 101 is below a threshold value is not restricted to determination of step ST11 shown in FIG.
- An oil level sensor may be provided in the compressor 101, and the retention determination means 312 may determine the storage amount of refrigeration oil in the compressor 101 from the measurement value of the oil level sensor.
- the operating time may be a continuous operating time or an integral value of intermittent operating time.
- step ST12 the opening degree control means 313 performs control in step ST12.
- step ST12 the opening degree control means 313 increases the opening degree of the bypass adjusting valve 107 as in step ST2 shown in FIG.
- the amount of refrigerant flowing through the bypass adjustment valve 107 increases, and the amount of refrigerant returned to the refrigerant inlet of the accumulator 108 increases.
- the refrigerant accumulated in the receiver 104 is moved to the accumulator 108 side, and the refrigeration oil accumulated in the receiver 104 is also moved to the accumulator 108 together with the refrigerant.
- step ST13 the retention determination means 312 determines whether or not a predetermined time has elapsed since the control of step ST12.
- the fixed time is, for example, 5 minutes. If it is determined in step ST13 that the predetermined time has not elapsed, the opening degree control means 313 maintains the opening degree of the bypass adjusting valve 107.
- the retention determination means 312 determines that the refrigerant and the refrigerator oil stored in the receiver 104 have sufficiently moved to the accumulator 108. As a result of the determination, the opening degree control means 313 controls step ST14.
- step ST14 the opening degree control means 313 reduces the opening degree of the bypass adjusting valve 107. As the opening degree of the bypass adjusting valve 107 becomes smaller, the refrigerant stored in the accumulator 108 is sent out to the liquid receiver 104 again.
- FIG. 8 is a schematic diagram for illustrating the configuration of the accumulator shown in FIG.
- the accumulator 108 has an inflow pipe 21 into which a mixture of refrigerant and refrigerator oil flows, and an outflow pipe 22 from which the gas refrigerant flows out to the compressor 101.
- the accumulator 108 separates the refrigerant into a gas-liquid two phase, and the refrigerant suction port of the outflow pipe 22 is above the oil level of the two-phase separated refrigerator oil in order to take out only the gas refrigerant from the upper side of the container.
- the accumulator 108 is generally provided with small holes 23 for returning refrigeration oil accumulated at the bottom to the compressor 101 via a pipe not shown.
- step ST12 to ST13 the refrigerant and refrigerator oil accumulated in the receiver 104 move to the accumulator 108.
- the opening degree control means 313 reduces the opening degree of the bypass adjusting valve 107 in step ST14.
- the refrigerant stored in the accumulator 108 is sent out to the liquid receiver 104 side, and the liquid level of the refrigerant and the refrigeration oil accumulated in the accumulator 108 decreases. If the position of the lower surface of the refrigeration oil falls to the vicinity of the small hole 23 at the bottom of the accumulator 108, the refrigeration oil will return to the compressor 101 again.
- step ST13 although the case where the parameter for determining whether the refrigerant of the liquid receiver 104 has been stored in the accumulator 108 is time has been described, the parameter is not limited to time.
- sensors for measuring the temperature and pressure of the refrigerant in each part and the height of the liquid level may be provided, and at least one of the temperature, the pressure and the height of the liquid level of the refrigerant may be used.
- step ST15 the opening degree control means 313 controls step ST15.
- step ST15 the opening degree control means 313 reduces the opening degree of the bypass adjustment valve 107.
- step ST15 shown in FIG. 7 the opening degree control means 313 opens the bypass opening valve at a minimum when the opening degree of the bypass adjusting valve 107 is reduced, as in step ST3 of FIG. 6 described in the first embodiment. Control so as to be equal to or higher than the power threshold so that the valve is not fully closed.
- control device 300 returns again to step ST11 shown in FIG. 7 (step ST16).
- control device 300 increases the opening degree of the bypass adjustment valve 107 to move the refrigerant and the refrigerator oil stored in the liquid receiver 104 to the accumulator 108 side. Therefore, oil exhaustion in the compressor 101 can be prevented, and the reliability of the refrigeration system 1 can also be improved.
- the first safety valve 109, the second safety valve 110 and the third safety valve 111 are provided in the refrigerant circuit 5 in the configuration examples shown in FIGS. 1 and 3.
- the safety valve is relatively expensive. Therefore, some of these safety valves may be replaced with other configurations.
- FIG. 9 is a refrigerant circuit diagram showing another configuration example of the refrigeration system shown in FIG.
- a capillary tube 116 is provided in a circuit that bypasses the high pressure expansion valve 103.
- a check valve 115 is provided in a pipe that connects the refrigerant inlet side of the accumulator 108 and the refrigerant outlet side of the second heat exchanger 106. The check valve 115 allows the flow of the refrigerant from the suction side of the compressor to the refrigerant outlet side of the high pressure expansion valve, and prevents the flow of the refrigerant in the opposite direction.
- the circuit bypassing the high pressure expansion valve 103 serves as the third safety valve 111, and the check valve 115 serves as the second safety valve 110.
- the refrigeration system 1b is not provided with the second safety valve 110 and the third safety valve 111 shown in FIG. In the refrigeration system 1b, inexpensive parts such as the capillary tube 116 and the check valve 115 are used instead of the second safety valve 110 and the third safety valve 111.
- the high pressure expansion valve 103 is formed of, for example, an electronic expansion valve capable of adjusting the opening degree, and is fully closed when power is not supplied, such as at the time of a power failure.
- the capillary tube 116 is provided in parallel to the high pressure expansion valve 103. Therefore, even when the high pressure expansion valve 103 is fully closed when the power is not supplied, such as at the time of a power failure, the refrigerant The gas cooler 102 and the first heat exchanger 105 of the circuit 5 can be bypassed. Therefore, the refrigerant accumulated in the flow path from the compressor 101 to the high pressure expansion valve 103 flows to the refrigerant outlet side of the high pressure expansion valve 103. Further, as shown in FIG.
- the check valve 115 by providing the check valve 115, the refrigerant pressure from the low pressure expansion valve 201 to the suction side of the compressor 101 becomes larger than the refrigerant pressure from the high pressure expansion valve 103 to the low pressure expansion valve 201. In this case, the refrigerant flows to the first safety valve 109. Therefore, by using the capillary tube 116 and the check valve 115, when a pressure rise occurs in the refrigerant circuit 5, the refrigerant flows into the first safety valve 109 side, and the safety when the pressure rises is secured. Note that, instead of the capillary tube 116, a solenoid valve that is closed when energized and opened when power fails may be used.
- the compressor 101, the gas cooler 102, the low pressure expansion valve 201, and the evaporator 202 are connected to a refrigerant pipe, and a refrigerant circuit 5 in which the refrigerant circulates. And a first safety valve 109 provided therebetween.
- the check valve 115 By providing the check valve 115 in the pipe connected in parallel with the low pressure expansion valve 201 and the evaporator 202, the safety when the pressure of the refrigerant rises is secured.
- the high pressure expansion valve 103 is provided between the gas cooler 102 and the low pressure expansion valve 201, the pressure of the refrigerant is increased by providing the capillary tube 116 provided in parallel with the high pressure expansion valve 103. The security of when is secured.
- the first safety valve 109 is provided downstream of the flow of the refrigerant than the liquid receiver 104, so that the pressure is rapidly reduced. It can be done.
- FIG. 10 is a refrigerant circuit diagram showing another configuration example of the refrigeration apparatus shown in FIG.
- the refrigeration system 1c has two bypass circuits 7a and 7c instead of the bypass circuit 7 shown in FIG.
- the bypass circuit 7a is the same as the configuration shown in FIG. 3, and thus the detailed description thereof is omitted.
- the bypass circuit 7c is provided with a pipe for removing the gas refrigerant from the upper part of the liquid receiver 104, and the pipe is connected to the refrigerant inlet side of the accumulator 108 after joining the bypass circuit 7a.
- the bypass circuit 7c has a bypass adjusting valve 107c.
- the first heat exchanger 105 shown in FIG. 1 is not provided in the refrigeration system 1c.
- the bypass circuit 7c shown in FIG. 10 serves to extract the refrigerant gas from the upper portion of the liquid receiver 104, and can obtain the same effect as the first heat exchanger 105. That is, the control device 300 can move the refrigerant and the refrigerating machine oil in the liquid receiver 104 to the accumulator 108 side by adjusting the opening degree of the bypass adjusting valve 107c.
- the refrigeration apparatus 1c shown in FIG. 10 further improves the control accuracy with respect to the refrigerant flowing out to the bypass circuits 7a and 7c as compared with the refrigeration apparatus 1 shown in FIG.
- the refrigeration system 1 shown in FIG. 1 has a smaller number of expansion valves than the refrigeration system 1 c shown in FIG. 10, so the increase in the manufacturing cost of the system is suppressed and the expansion valve control becomes complicated. Is suppressed.
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Abstract
Description
本実施の形態1の室外機を含む冷凍装置の構成を説明する。図1は、本発明の実施の形態1における冷凍装置の冷媒回路図である。冷凍装置1は、冷媒回路5で接続される室外機100および室内機200と、冷媒回路5の各機器を制御する制御装置300とを有する。室内機200は、例えば、食品などを冷やすために用いられるものである。室内機200は、スーパーマーケットなどのショーケースであってもよく、冷蔵倉庫および冷凍倉庫に設置されるユニットクーラであってもよい。
制御装置300は、例えば、マイクロコンピュータである。制御装置300は、図に示さない、CPU(Central Processing Unit)およびメモリを有する。制御装置300は、冷凍サイクル手段311と、滞留判定手段312と、開度制御手段313とを有する。メモリが記憶するプログラムをCPUが実行することで、冷凍サイクル手段311、滞留判定手段312および開度制御手段313が冷凍装置1に構成される。制御装置300は、室外機100に設けられていてもよい。
実施の形態1では、制御装置300がバイパス調整弁107を制御して受液器104の余剰冷媒をアキュムレータ108に移動させることで、圧縮機101の吐出圧力の上昇を抑制し、冷凍装置1を安定に運転する場合を説明した。本実施の形態2は、制御装置300がバイパス調整弁107を制御して、圧縮機101から吐出された冷凍機油の圧縮機101への戻りを改善し、冷凍装置1の信頼性の向上も図るものである。なお、本実施の形態2の冷凍装置1は、実施の形態1で説明した冷凍装置1と同様な構成であるため、同様な構成についての詳細な説明を省略し、動作など異なる点について詳細に説明する。
Claims (14)
- 圧縮機、ガスクーラ、受液器、低圧膨張弁および蒸発器が冷媒配管に接続され、冷媒が循環する冷媒回路と、
前記ガスクーラと前記受液器との間に設けられた高圧膨張弁と、
前記蒸発器と前記圧縮機との間に設けられ、冷媒を貯留するアキュムレータと、
前記受液器および前記低圧膨張弁の間と前記アキュムレータの冷媒入口側とを接続するバイパス回路と、
前記バイパス回路に設けられ、前記冷媒の流量を調整するバイパス調整弁と、
前記圧縮機の吐出側から前記受液器までの間に貯留する冷媒量が決められた閾値を超える場合、前記バイパス調整弁の開度を大きくする制御を行う制御装置と、
を有する冷凍装置。 - 前記圧縮機の吐出側の冷媒の吐出圧力を測定する圧力センサをさらに有し、
前記制御装置は、
前記吐出圧力が決められた閾値を超えた場合、前記バイパス調整弁の開度を大きくする、請求項1に記載の冷凍装置。 - 前記制御装置は、
前記圧縮機の冷凍機油の貯留量が決められた閾値以下である場合、前記バイパス調整弁の開度を大きくする、請求項1に記載の冷凍装置。 - 前記制御装置は、
前記圧縮機の運転時間が決められた設定時間を超えると、前記バイパス調整弁の開度を大きくする、請求項1に記載の冷凍装置。 - 前記アキュムレータの容積は前記受液器の容積以上である、請求項1~4のいずれか1項に記載の冷凍装置。
- 前記高圧膨張弁の冷媒出口側に設けられた第1の安全弁をさらに有する、請求項1~5のいずれか1項に記載の冷凍装置。
- 圧縮機、ガスクーラ、受液器、低圧膨張弁および蒸発器が冷媒配管に接続され、冷媒が循環する冷媒回路と、
前記ガスクーラと前記受液器との間に設けられた高圧膨張弁と、
前記蒸発器と前記圧縮機との間に設けられ、冷媒を貯留するアキュムレータと、
前記受液器および前記低圧膨張弁の間と前記アキュムレータの冷媒入口側とを接続するバイパス回路と、
前記バイパス回路に設けられ、前記冷媒の流量を調整するバイパス調整弁と、
前記高圧膨張弁の冷媒出口側に設けられた第1の安全弁と、
を有する冷凍装置。 - 前記第1の安全弁が、前記受液器と前記低圧膨張弁との間に設けられた、請求項6または請求項7に記載の冷凍装置。
- 前記高圧膨張弁と並列に設けられたキャピラリチューブをさらに有する、請求項6~8のいずれか1項に記載の冷凍装置。
- 前記アキュムレータの冷媒入口側と前記高圧膨張弁の冷媒出口側とを接続する配管に設けられ、該アキュムレータの冷媒入口側から該高圧膨張弁の冷媒出口側への冷媒の流れを許容する逆止弁をさらに有する、請求項6~9のいずれか1項に記載の冷凍装置。
- 前記圧縮機の吸入側に設けられた第2の安全弁をさらに有する、請求項1~9のいずれか1項に記載の冷凍装置。
- 前記圧縮機の吐出側に設けられた第3の安全弁をさらに有する、請求項1~10のいずれか1項に記載の冷凍装置。
- 前記制御装置は、
前記高圧膨張弁の冷媒出口側の圧力が4.15MPa以下になるように、該高圧膨張弁および前記バイパス調整弁のうち、少なくともいずれかの弁の開度を制御する、請求項1~6のいずれか1項に記載の冷凍装置。 - 圧縮機、ガスクーラ、受液器、低圧膨張弁および蒸発器が冷媒配管に接続され、冷媒が循環する冷媒回路の、前記圧縮機、前記ガスクーラおよび前記受液器を有する室外機であって、
前記ガスクーラと前記受液器との間に設けられた高圧膨張弁と、
前記蒸発器と前記圧縮機との間に設けられ、冷媒を貯留するアキュムレータと、
前記受液器および前記低圧膨張弁の間と前記アキュムレータの冷媒入口側とを接続するバイパス回路と、
前記バイパス回路に設けられ、前記冷媒の流量を調整するバイパス調整弁と、
前記圧縮機の吐出側から前記受液器までの間に貯留する冷媒量が決められた閾値を超える場合、前記バイパス調整弁の開度を大きくする制御を行う制御装置と、
を有する室外機。
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JP2010112582A (ja) * | 2008-11-04 | 2010-05-20 | Daikin Ind Ltd | 冷凍装置 |
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2017
- 2017-11-29 JP JP2019556465A patent/JP6833065B2/ja active Active
- 2017-11-29 WO PCT/JP2017/042868 patent/WO2019106764A1/ja active Application Filing
- 2017-11-29 GB GB2006902.7A patent/GB2581720C/en active Active
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JPH0311388B2 (ja) * | 1984-08-24 | 1991-02-15 | Daikin Ind Ltd | |
JP2004226025A (ja) * | 2003-01-24 | 2004-08-12 | Fujitsu General Ltd | 空気調和機 |
JP2006275440A (ja) * | 2005-03-30 | 2006-10-12 | Mitsubishi Electric Corp | 冷凍装置 |
JP2006329540A (ja) * | 2005-05-27 | 2006-12-07 | Valeo Thermal Systems Japan Corp | 冷凍サイクルの制御装置 |
JP2008096093A (ja) * | 2006-09-11 | 2008-04-24 | Daikin Ind Ltd | 冷凍装置 |
JP2012047375A (ja) * | 2010-08-25 | 2012-03-08 | Hitachi Appliances Inc | 空気調和システム |
JP2013002737A (ja) * | 2011-06-16 | 2013-01-07 | Mitsubishi Electric Corp | 冷凍サイクル装置 |
JP5819000B2 (ja) * | 2012-09-21 | 2015-11-18 | 三菱電機株式会社 | 冷凍装置 |
WO2015063838A1 (ja) * | 2013-10-28 | 2015-05-07 | 三菱電機株式会社 | 冷凍サイクル装置 |
WO2015174054A1 (ja) * | 2014-05-12 | 2015-11-19 | パナソニックIpマネジメント株式会社 | 冷凍サイクル装置 |
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GB2581720A (en) | 2020-08-26 |
GB2581720C (en) | 2021-10-20 |
GB2581720B (en) | 2021-10-06 |
JPWO2019106764A1 (ja) | 2020-06-18 |
JP6833065B2 (ja) | 2021-02-24 |
GB202006902D0 (en) | 2020-06-24 |
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