WO2024009394A1 - Climatiseur et procédé de détection de fuite de fluide frigorigène - Google Patents

Climatiseur et procédé de détection de fuite de fluide frigorigène Download PDF

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Publication number
WO2024009394A1
WO2024009394A1 PCT/JP2022/026716 JP2022026716W WO2024009394A1 WO 2024009394 A1 WO2024009394 A1 WO 2024009394A1 JP 2022026716 W JP2022026716 W JP 2022026716W WO 2024009394 A1 WO2024009394 A1 WO 2024009394A1
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Prior art keywords
refrigerant
pressure
heat exchanger
air conditioner
control device
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PCT/JP2022/026716
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English (en)
Japanese (ja)
Inventor
雄誠 小野
宗希 石山
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三菱電機株式会社
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Priority to PCT/JP2022/026716 priority Critical patent/WO2024009394A1/fr
Publication of WO2024009394A1 publication Critical patent/WO2024009394A1/fr

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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

Definitions

  • the present disclosure relates to an air conditioner using a non-azeotropic refrigerant mixture and a refrigerant leak detection method in an air conditioner using a non-azeotropic refrigerant mixture.
  • Patent Document 1 JP-A-8-54161 discloses a method for detecting refrigerant leakage in a refrigeration system using a non-azeotropic mixed refrigerant.
  • a non-azeotropic refrigerant mixture is a mixture of multiple types of refrigerants having different boiling points, such as a high boiling point refrigerant and a low boiling point refrigerant.
  • a non-azeotropic refrigerant mixture is used in a refrigeration cycle, if a refrigerant leak occurs, the low-boiling point refrigerant will leak to the outside before the high-boiling point refrigerant, so the mixing ratio of the non-azeotropic refrigerant mixture existing in the refrigerant circuit will decrease. It may change from the original mixing ratio.
  • Patent Document 1 uses such a non-azeotropic mixed refrigerant in the refrigeration cycle, and the temperature and pressure of the refrigerant in the refrigerant circuit change when the refrigeration system is stopped.
  • the refrigerant leakage is detected by comparing the measured temperature and pressure of the refrigerant with data prepared in advance that defines the amount of refrigerant leakage with respect to the temperature and pressure of the refrigerant.
  • Patent Document 1 refrigerant leakage can be detected using data that defines the amount of refrigerant leakage with respect to the temperature and pressure of the refrigerant prepared in advance.
  • the refrigerant composition is likely to change during the initial stage of shutdown, as the refrigerant distribution differs in each element of the refrigerant circuit, making it difficult to accurately detect refrigerant leaks. is difficult.
  • the temperature and pressure of the non-azeotropic refrigerant mixture may change not only due to refrigerant leaks but also when the refrigerant composition changes depending on environmental conditions such as outside temperature. Therefore, if the refrigerant composition changes depending on the environmental conditions, it is not possible to accurately detect refrigerant leaks using the data prepared in advance, and even though no refrigerant leaks have occurred, the environmental conditions There is a possibility that it may be erroneously determined that a refrigerant leak has occurred due to a change in the temperature and pressure of the non-azeotropic mixed refrigerant.
  • the present disclosure has been made to solve the above problems, and an object of the present disclosure is to provide a technique for accurately detecting refrigerant leakage in an air conditioner using a non-azeotropic mixed refrigerant.
  • the air conditioner according to the present disclosure is an air conditioner that uses a non-azeotropic mixed refrigerant.
  • the air conditioner includes a compressor, a high-pressure side heat exchanger, an expansion device, and a low-pressure side heat exchanger, and includes a refrigerant circuit configured to circulate a non-azeotropic mixed refrigerant, and a control device that controls the refrigerant circuit. and at least one pressure sensor that measures the pressure of refrigerant flowing through the refrigerant circuit.
  • the control device obtains a single refrigerant in the refrigerant circuit by recovering the non-azeotropic mixed refrigerant flowing in the refrigerant circuit, and when the amount of decrease in the measured value of the at least one pressure sensor is equal to or more than a threshold value, It is determined that a refrigerant leak has occurred.
  • a refrigerant leak detection method is a refrigerant leak detection method in an air conditioner using a non-azeotropic mixed refrigerant.
  • the air conditioner includes a compressor, a high-pressure side heat exchanger, an expansion device, and a low-pressure side heat exchanger, and includes a refrigerant circuit configured to circulate a non-azeotropic mixed refrigerant, and a control device that controls the refrigerant circuit. and at least one pressure sensor that measures the pressure of refrigerant flowing through the refrigerant circuit.
  • a refrigerant leak detection method by a control device includes the steps of: obtaining a single refrigerant in a refrigerant circuit by recovering a non-azeotropic mixed refrigerant flowing through the refrigerant circuit; and the amount of decrease in the measured value of at least one pressure sensor is equal to or greater than a threshold value. and determining that a refrigerant leak has occurred in the refrigerant circuit.
  • a single refrigerant is obtained in a refrigerant circuit by recovering a non-azeotropic mixed refrigerant flowing through the refrigerant circuit, and the amount of decrease in the pressure of the single refrigerant measured by a pressure sensor is Since it is determined whether or not there is a refrigerant leak based on this, the refrigerant leak can be detected with high accuracy.
  • FIG. 1 is a diagram showing the configuration of an air conditioner according to Embodiment 1.
  • FIG. 3 is a flowchart for explaining a refrigerant leak detection process executed by the air conditioner control device according to the first embodiment. It is a graph showing pressure change with respect to refrigerant residual rate.
  • FIG. 3 is a diagram showing the configuration of an air conditioner according to a second embodiment. 7 is a flowchart for explaining refrigerant leak detection processing executed by the air conditioner control device according to the second embodiment.
  • FIG. 7 is a diagram showing the configuration of an air conditioner according to Embodiment 3.
  • 12 is a flowchart for explaining refrigerant leak detection processing executed by the air conditioner control device according to Embodiment 3.
  • FIG. 1 is a diagram showing the configuration of an air conditioner 1 according to the first embodiment. Note that FIG. 1 functionally shows the connection relationship and arrangement of each device in the air conditioner 1, and does not necessarily show the arrangement in a physical space.
  • FIG. 1 is a diagram showing the configuration of an air conditioner 1 according to the first embodiment.
  • the air conditioner 1 includes a refrigerant circuit 200 and a control device 100.
  • the refrigerant circuit 200 includes an outdoor unit 300 and an indoor unit 400.
  • Indoor unit 400 and outdoor unit 300 are connected by extension pipe 21 and extension pipe 24, and a non-azeotropic mixed refrigerant circulates between outdoor unit 300 and indoor unit 400.
  • a non-azeotropic refrigerant mixture is a mixture of multiple types of refrigerants having different boiling points, such as a high boiling point refrigerant and a low boiling point refrigerant.
  • R454C is used as a non-azeotropic mixed refrigerant
  • R1234yf is used as a high boiling point refrigerant
  • R32 is used as a low boiling point refrigerant.
  • the boiling point of R1234yf, which is a high boiling point refrigerant is about -29°C
  • the boiling point of R32 which is a low boiling point refrigerant
  • a single refrigerant is a refrigerant made of one type of refrigerant, such as only R454C or only R1234yf.
  • refrigerant is used to include non-azeotropic refrigerant mixtures and single refrigerants, unless a "non-azeotropic refrigerant mixture” and a “single refrigerant” are particularly distinguished.
  • the outdoor unit 300 includes a four-way valve 40, a compressor 30, an outdoor heat exchanger 51, and an expansion device 70.
  • the four-way valve 40 includes a connection port 41, a connection port 42, a connection port 43, and a connection port 44.
  • the connection port 41 of the four-way valve 40 is connected to the suction port 31 of the compressor 30 via piping 12 and piping 13.
  • a connection port 42 of the four-way valve 40 is connected to an outdoor heat exchanger 51 via a pipe 15.
  • a connection port 43 of the four-way valve 40 is connected to a discharge port 32 of the compressor 30 via a pipe 14.
  • the connection port 44 of the four-way valve 40 is connected to the indoor unit 400 via the pipe 11 and the extension pipe 24.
  • the four-way valve 40 is configured to switch its internal communication state under the control of the control device 100.
  • the compressor 30 is configured to operate and stop, and further to change the rotational speed during operation, under the control of the control device 100.
  • the control device 100 controls the compressor 30 and arbitrarily changes the drive frequency of the compressor 30.
  • the compressor 30 changes the number of rotations per unit time, that is, the rotational speed, in accordance with changes in the drive frequency, thereby changing the amount of refrigerant discharged.
  • Various types of compressors can be employed as the compressor 30. For example, a scroll type, a rotary type, a screw type, etc. can be employed as the compressor 30.
  • the outdoor heat exchanger 51 exchanges heat between air sucked in from outside by a blower (not shown), that is, outside air, and a refrigerant.
  • a blower not shown
  • One end of the outdoor heat exchanger 51 is connected to the connection port 42 of the four-way valve 40 via the pipe 15.
  • the other end of the outdoor heat exchanger 51 is connected to an expansion device 70 via a pipe 16.
  • the expansion device 70 is, for example, an electronic expansion valve whose opening degree is adjusted under the control of the control device 100.
  • the expansion device 70 lowers the pressure of the refrigerant that has flowed in, and allows the refrigerant obtained by the reduced pressure to flow out.
  • the control device 100 can adjust the amount of pressure reduction of the refrigerant by adjusting the opening degree of the expansion device 70.
  • the expansion device 70 may be a capillary tube that adjusts the flow rate of the refrigerant based on a pressure difference.
  • the indoor unit 400 includes an indoor heat exchanger 61.
  • the indoor heat exchanger 61 exchanges heat between air sucked in from the room by a blower (not shown) and a refrigerant.
  • One end side of the indoor heat exchanger 61 is connected to the outdoor unit 300 via the piping 23 and the extension piping 24.
  • the other end side of the indoor heat exchanger 61 is connected to the outdoor unit 300 via the piping 22 and the extension piping 21.
  • the control device 100 includes a control section 101 and a storage section 102.
  • the control device 100 is capable of communicating with each actuator of the refrigerant circuit 200, such as the compressor 30, the expansion device 70, and the four-way valve 40, in order to control each actuator of the refrigerant circuit 200.
  • the control device 100 may be mounted on either the outdoor unit 300 or the indoor unit 400, or may be separate from the outdoor unit 300 and the indoor unit 400.
  • the control unit 101 is the main body of calculation that controls each actuator of the refrigerant circuit 200 by executing various programs.
  • the control unit 101 is configured with a processor such as a CPU (central processing unit) or an MPU (micro-processing unit), for example.
  • a processor which is an example of the control unit 101, has a function of executing various processes by executing a program, but some or all of these functions may be implemented using an ASIC (Application Specific Integrated Circuit) or an FPGA (Field -It may be implemented using a dedicated hardware circuit such as a Programmable Gate Array.
  • a “processor” is not limited to a narrowly defined processor such as a CPU or MPU that executes processing using a stored program method, but may also include a hard-wired circuit such as an ASIC or an FPGA. Therefore, the "processor”, which is an example of the control unit 101, can also be read as a processing circuit whose processing is defined in advance by a computer-readable code and/or a hard-wired circuit.
  • the storage unit 102 includes volatile memory such as DRAM (dynamic random access memory) and SRAM (static random access memory), or nonvolatile memory such as ROM (read only memory) and flash memory. Furthermore, the storage unit 102 may be an SSD (solid state drive) or an HDD (hard disk drive), and in this case, the control unit 101 is a volatile memory such as DRAM and SRAM, or a ROM and flash memory. It may also include non-volatile memory.
  • volatile memory such as DRAM (dynamic random access memory) and SRAM (static random access memory)
  • nonvolatile memory such as ROM (read only memory) and flash memory
  • the storage unit 102 may be an SSD (solid state drive) or an HDD (hard disk drive)
  • the control unit 101 is a volatile memory such as DRAM and SRAM, or a ROM and flash memory. It may also include non-volatile memory.
  • the storage unit 102 stores, for example, various programs in which processing procedures of the control unit 101 are described.
  • the control unit 101 controls each actuator of the refrigerant circuit 200 by executing a program stored in the storage unit 102. Note that part or all of the processing procedure of the control unit 101 may be implemented using a dedicated hardware circuit.
  • the air conditioner 1 configured as described above is controlled to one of multiple types of operation modes, including a cooling operation mode in which the indoor space to be air-conditioned is cooled, and a heating operation mode in which the indoor space is heated. .
  • the internal communication state of the four-way valve 40 is as shown by the solid line in FIG. communicates with the connection port 43. That is, in the cooling operation mode, the suction port 31 of the compressor 30 is connected to the indoor heat exchanger 61, and the discharge port 32 of the compressor 30 is connected to the outdoor heat exchanger 51.
  • the compressor 30 sucks the low-temperature, low-pressure gas refrigerant from the indoor heat exchanger 61, and increases the pressure of the gas refrigerant by compressing the sucked gas refrigerant.
  • the compressor 30 discharges the high-temperature, high-pressure gas refrigerant obtained by compression to the outdoor heat exchanger 51.
  • the outdoor heat exchanger 51 becomes a "high pressure side heat exchanger" and works as a condenser.
  • the outdoor heat exchanger 51 exchanges heat between the high temperature and high pressure gas refrigerant from the compressor 30 and the air sucked in from outside.
  • the gas refrigerant that radiates heat to the air through this heat exchange is condensed inside the outdoor heat exchanger 51 and changes into a high-temperature, high-pressure liquid refrigerant.
  • the high temperature and high pressure liquid refrigerant obtained by the outdoor heat exchanger 51 flows out to the expansion device 70 .
  • the expansion device 70 lowers the pressure of the high temperature and high pressure liquid refrigerant from the outdoor heat exchanger 51.
  • the low-temperature, low-pressure gas-liquid two-phase refrigerant obtained by the pressure reduction in the expansion device 70 flows out to the indoor heat exchanger 61 .
  • the indoor heat exchanger 61 becomes a "low pressure side heat exchanger" and works as an evaporator.
  • the indoor heat exchanger 61 exchanges heat between the low-temperature, low-pressure, gas-liquid two-phase refrigerant from the expansion device 70 and the air sucked in from the room.
  • the gas-liquid two-phase refrigerant that absorbs heat from the air through this heat exchange evaporates inside the indoor heat exchanger 61 and changes into a low-temperature, low-pressure gas refrigerant.
  • the low temperature, low pressure gas refrigerant obtained by the indoor heat exchanger 61 flows out to the compressor 30.
  • the air whose heat has been absorbed by the gas refrigerant in the indoor heat exchanger 61 is sent into the indoor space again. This cools the indoor space.
  • the refrigerant is transferred to the compressor 30, the outdoor heat exchanger 51 (high temperature side heat exchanger, condenser), the expansion device 70, and the indoor heat exchanger 61 (low temperature side heat exchanger, evaporator). It is distributed in the order of
  • the internal communication state of the four-way valve 40 is as shown by the dotted line in FIG. do. That is, in the heating operation mode, the suction port 31 of the compressor 30 is connected to the outdoor heat exchanger 51, and the discharge port 32 of the compressor 30 is connected to the indoor heat exchanger 61.
  • the compressor 30 sucks the low-temperature, low-pressure gas refrigerant flowing in from the outdoor heat exchanger 51, and increases the pressure of the gas refrigerant by compressing the sucked gas refrigerant.
  • the compressor 30 discharges the high-temperature, high-pressure gas refrigerant obtained through compression to the indoor heat exchanger 61 .
  • the indoor heat exchanger 61 becomes a "high pressure side heat exchanger" and works as a condenser.
  • the indoor heat exchanger 61 exchanges heat between the high-temperature, high-pressure gas refrigerant from the compressor 30 and the air sucked in from the indoor space.
  • the gas refrigerant that radiates heat to the air through this heat exchange condenses inside the indoor heat exchanger 61 and changes into a high-temperature, high-pressure liquid refrigerant.
  • the high temperature and high pressure liquid refrigerant obtained by the indoor heat exchanger 61 flows out to the expansion device 70 .
  • the air that has absorbed heat from the gas refrigerant in the indoor heat exchanger 61 is sent into the indoor space again. This heats the indoor space.
  • the expansion device 70 lowers the pressure of the high temperature and high pressure liquid refrigerant from the indoor heat exchanger 61.
  • the low-temperature, low-pressure gas-liquid two-phase refrigerant obtained by the expansion device 70 flows out to the outdoor heat exchanger 51.
  • the outdoor heat exchanger 51 becomes a "low pressure side heat exchanger" and works as an evaporator.
  • the outdoor heat exchanger 51 exchanges heat between the low-temperature, low-pressure, gas-liquid two-phase refrigerant from the expansion device 70 and the air sucked in from outside.
  • the gas-liquid two-phase refrigerant that absorbs heat from the air through this heat exchange evaporates inside the outdoor heat exchanger 51 and changes into a low-temperature, low-pressure gas refrigerant.
  • the low temperature, low pressure gas refrigerant obtained by the outdoor heat exchanger 51 flows out to the compressor 30.
  • the refrigerant is transferred to the compressor 30, the indoor heat exchanger 61 (high temperature side heat exchanger, condenser), the expansion device 70, and the outdoor heat exchanger 51 (low temperature side heat exchanger, evaporator). It is distributed in the order of
  • the air conditioner 1 for example, if the non-azeotropic mixed refrigerant sealed in the refrigerant circuit 200 leaks from the piping or various actuators constituting the refrigerant circuit 200, the amount of refrigerant required for the operation of the air conditioner 1 may decrease. Insufficient air conditioning capacity may be caused. Therefore, in the air conditioner 1, it is important to detect refrigerant leakage from the refrigerant circuit 200. However, when a non-azeotropic refrigerant mixture is used, if a refrigerant leak occurs, the composition of the non-azeotropic refrigerant mixture changes from the initial mixing ratio, so it is difficult to detect refrigerant leakage for the non-azeotropic refrigerant mixture. is necessary.
  • the refrigerant flowing through the refrigerant circuit 200 is made into a single refrigerant by recovering the non-azeotropic mixed refrigerant flowing through the refrigerant circuit 200, and the refrigerant obtained in the refrigerant circuit 200 is
  • the system is configured to detect refrigerant leakage for a single refrigerant.
  • the air conditioner 1 includes a recovery container 75, an on-off valve 71, an on-off valve 72, a gas vent pipe 25, a temperature sensor 81, a temperature sensor 82, and a pressure sensor 91. and a pressure sensor 92.
  • the recovery container 75 is provided at a position where it can recover the gas-liquid two-phase non-azeotropic mixed refrigerant that has flowed out from the expansion device 70 out of the non-azeotropic mixed refrigerant circulating in the refrigerant circuit 200.
  • the recovery container 75 is provided between the expansion device 70 and the low-pressure side heat exchanger in the outdoor unit 300.
  • the recovery container 75 is provided between the expansion device 70 and the indoor heat exchanger 61 (low-pressure side heat exchanger) in the outdoor unit 300.
  • the recovery container 75 is, for example, a receiver, and stores the gas-liquid two-phase non-azeotropic mixed refrigerant that has flowed out from the expansion device 70 through the high-pressure side heat exchanger.
  • the recovery container 75 is provided between the expansion device 70 and the indoor heat exchanger 61 (low-pressure side heat exchanger).
  • the recovery container 75 may be provided not only at the position shown in FIG. 1 but also at any other position as long as it is at a position where the gas-liquid two-phase non-azeotropic mixed refrigerant circulating in the refrigerant circuit 200 can be recovered. good.
  • the recovery container 75 may be provided between the expansion device 70 and the outdoor heat exchanger 51 (low-pressure side heat exchanger) in the outdoor unit 300.
  • the on-off valve 71 is provided between the recovery container 75 and the low-pressure side heat exchanger in the outdoor unit 300.
  • the on-off valve 71 is provided between the recovery container 75 and the indoor heat exchanger 61 (low-pressure side heat exchanger), and is connected to the recovery container 75 by the pipe 19, while the on-off valve 71 is connected to the recovery container 75 by the pipe 20. It is connected to the extension pipe 21.
  • the on-off valve 71 is, for example, a solenoid valve, and when it is opened according to the control of the control device 100, the path between the recovery container 75 and the indoor heat exchanger 61 (low-pressure side heat exchanger) is set to non-azeotropic mixture. The path is connected so that the refrigerant flows, and when the path is closed according to the control of the control device 100, the path between the recovery container 75 and the indoor heat exchanger 61 (low pressure side heat exchanger) is connected to the non-azeotropic mixed refrigerant. The route is blocked to prevent the flow of water.
  • a solenoid valve when it is opened according to the control of the control device 100, the path between the recovery container 75 and the indoor heat exchanger 61 (low-pressure side heat exchanger) is set to non-azeotropic mixture. The path is connected so that the refrigerant flows, and when the path is closed according to the control of the control device 100, the path between the recovery container 75 and the indoor heat exchanger 61 (low pressure side heat
  • the on-off valve 72 is provided at a position opposite to the on-off valve 71 with respect to the collection container 75 in the path through which the non-azeotropic mixed refrigerant flows.
  • the on-off valve 72 is provided between the expansion device 70 and the recovery container 75 in the outdoor unit 300, and is connected to the expansion device 70 through the piping 17, while being connected to the recovery container 75 through the piping 18. It is connected.
  • the on-off valve 72 is, for example, a solenoid valve, and when it is opened under the control of the control device 100, the path is connected between the expansion device 70 and the recovery container 75 so that the non-azeotropic mixed refrigerant flows therethrough. However, when it is closed according to the control of the control device 100, the path between the expansion device 70 and the recovery container 75 is blocked so that the non-azeotropic mixed refrigerant does not flow through the path.
  • the gas vent pipe 25 is a pipe for returning the gas refrigerant contained in the gas-liquid two-phase non-azeotropic mixed refrigerant collected by the collection container 75 to the suction port 31 of the compressor 30 in the refrigerant circuit 200.
  • One end of the gas vent pipe 25 is connected to the pipe 13 connected to the suction port 31 of the compressor 30, and the other end of the gas vent pipe 25 is connected to the inside of the recovery container 75.
  • the temperature sensor 81 measures the temperature of the refrigerant flowing through the indoor heat exchanger 61.
  • the temperature sensor 81 is provided in the pipe 22 connected to the indoor heat exchanger 61 in the indoor unit 400, and measures the temperature of the refrigerant flowing through the pipe 22.
  • the temperature sensor 81 may be provided in the pipe 23 connected to the indoor heat exchanger 61 to measure the temperature of the refrigerant flowing through the pipe 23.
  • a signal T1 indicating the refrigerant temperature measured by the temperature sensor 81 is transmitted to the control device 100.
  • the temperature sensor 82 measures the temperature of the refrigerant flowing through the outdoor heat exchanger 51.
  • the temperature sensor 82 is provided in the pipe 16 connected to the outdoor heat exchanger 51 in the outdoor unit 300, and measures the temperature of the refrigerant flowing through the pipe 16.
  • the temperature sensor 82 may be provided in the pipe 15 connected to the outdoor heat exchanger 51 to measure the temperature of the refrigerant flowing through the pipe 15.
  • a signal T2 indicating the refrigerant temperature measured by the temperature sensor 82 is transmitted to the control device 100.
  • the air conditioner 1 may include both the temperature sensor 81 and the temperature sensor 82, or may include either one of the temperature sensor 81 and the temperature sensor 82.
  • the pressure sensor 91 measures the pressure of the refrigerant flowing through the indoor heat exchanger 61.
  • the pressure sensor 91 is provided in the pipe 23 connected to the indoor heat exchanger 61 in the indoor unit 400, and measures the pressure of the refrigerant flowing through the pipe 23.
  • the pressure sensor 91 may be provided in the pipe 22 connected to the indoor heat exchanger 61 to measure the pressure of the refrigerant flowing through the pipe 22.
  • a signal P1 indicating the refrigerant pressure measured by the pressure sensor 91 is transmitted to the control device 100.
  • the pressure sensor 92 measures the pressure of the refrigerant flowing through the outdoor heat exchanger 51.
  • the pressure sensor 92 is provided in the pipe 15 connected to the outdoor heat exchanger 51 in the outdoor unit 300, and measures the pressure of the refrigerant flowing through the pipe 15.
  • the pressure sensor 92 may be provided in the pipe 16 connected to the outdoor heat exchanger 51 to measure the pressure of the refrigerant flowing through the pipe 16.
  • a signal P2 indicating the refrigerant pressure measured by the pressure sensor 92 is transmitted to the control device 100.
  • the air conditioner 1 may include both the pressure sensor 91 and the pressure sensor 92, or may include either one of the pressure sensor 91 and the pressure sensor 92.
  • FIG. 2 is a flowchart for explaining the refrigerant leak detection process executed by the control device 100 of the air conditioner 1 according to the first embodiment.
  • the control device 100 executes the refrigerant leak detection process shown in the flowchart shown in FIG. 2 by executing a program stored in the storage unit 102.
  • the refrigerant leak detection process in this flowchart is called and executed from the main control routine of the control device 100 at regular intervals.
  • "S" is used as an abbreviation of "STEP".
  • the control device 100 determines whether a stop condition for stopping the operation of the air conditioner 1 is satisfied (S101). For example, the control device 100 determines whether a stop operation has been performed by the user using a remote controller (not shown). Alternatively, the control device 100 determines whether or not the operation stop timing has arrived based on a timer preset by the user. If the stop condition is not satisfied (NO in S101), the control device 100 ends this process.
  • the control device 100 closes the first on-off valve (S102).
  • the "first on-off valve” is an on-off valve that opens or closes the path between the recovery container 75 and the low-pressure side heat exchanger, and in the example of FIG. 1, the on-off valve 71 corresponds to the "first on-off valve". do.
  • the control device 100 closes the first on-off valve, the non-azeotropic mixed refrigerant that has flowed into the recovery container 75 through the expansion device 70 remains in the recovery container 75 .
  • the gaseous refrigerant contained in the non-azeotropic mixed refrigerant collected by the collection container 75 is returned to the suction port 31 of the compressor 30 in the refrigerant circuit 200 through the gas vent pipe 25.
  • the liquid refrigerant contained in the non-azeotropic mixed refrigerant collected by the collection container 75 remains in the collection container 75.
  • the ratio of the gaseous refrigerant to the high-boiling refrigerant for example, R1234yf
  • the ratio of the gaseous refrigerant to the high-boiling refrigerant for example, R1234yf
  • R32 is included in a higher proportion, and the proportion in which a high boiling point refrigerant (for example, R1234yf) is included in the liquid refrigerant is higher than the proportion in which a low boiling point refrigerant (for example, R32) is included. Therefore, among the non-azeotropic mixed refrigerants recovered by the recovery container 75, the gaseous low-boiling refrigerant (for example, R32) is returned to the refrigerant circuit 200 through the gas vent pipe 25, and the liquid-state high-boiling refrigerant (for example, R1234yf) remains in the collection container 75. Through such processing, only a gaseous low-boiling point refrigerant (for example, R32) is present in the refrigerant circuit 200.
  • a gaseous low-boiling point refrigerant for example, R32
  • the control device 100 measures the temperature of the refrigerant flowing through the refrigerant circuit 200, and converts the obtained refrigerant temperature into a saturation pressure (S103). For example, the control device 100 measures the temperature of the refrigerant flowing through the indoor heat exchanger 61 using the temperature sensor 81, and converts the obtained refrigerant temperature into a saturation pressure. Note that the control device 100 may measure the temperature of the refrigerant flowing through the outdoor heat exchanger 51 using the temperature sensor 82, and convert the obtained refrigerant temperature into a saturation pressure.
  • the control device 100 determines whether the converted saturation pressure is the same or approximately the same as the saturation pressure of a predetermined single refrigerant, a gaseous low-boiling refrigerant (for example, R32) (S104). That is, the control device 100 determines whether the only refrigerant flowing through the refrigerant circuit 200 other than the refrigerant present in the recovery container 75 is a single refrigerant in a gas state (for example, R32). For example, the control device 100 determines whether the difference between the converted saturation pressure and the saturation pressure of a predetermined single refrigerant (for example, R32) is less than a determination value, and determines whether the difference is less than the determination value. In this case, it is determined that the refrigerant flowing through the refrigerant circuit 200 other than the refrigerant present in the recovery container 75 has become a single refrigerant (for example, R32).
  • a gaseous low-boiling refrigerant for example, R32
  • the control device 100 If the converted saturation pressure is not the same or substantially the same as the saturation pressure of a predetermined single refrigerant (for example, R32) (NO in S104), the control device 100 returns to the process of S103 and causes the refrigerant to flow through the refrigerant circuit 200 again. The temperature of the refrigerant is converted into a saturation pressure, and the process of S104 is executed.
  • a predetermined single refrigerant for example, R32
  • the control device 100 determines that the refrigerant flowing through the refrigerant circuit 200 is It is determined that the refrigerant (for example, R32) has been used, and the second on-off valve is closed (S105).
  • the "second on-off valve” is an on-off valve that opens or closes the path between the expansion device 70 and the collection container 75, and in the example of FIG. 1, the on-off valve 72 corresponds to the "second on-off valve.”
  • the first on-off valve for example, the on-off valve 71
  • the low-pressure side heat exchanger for example, the indoor heat exchanger 61
  • the compressor 30, and the high-pressure side heat exchanger for example, the outdoor
  • the first route passes through the heat exchanger 51) and the expansion device 70 to the second on-off valve (for example, on-off valve 72), and from the second on-off valve (for example, on-off valve 72), passes through the recovery container 75.
  • the path in the refrigerant circuit is separated from the second path leading to the first on-off valve (for example, on-off valve 71).
  • the control device 100 stops the operation of the air conditioner 1 (S106). For example, the control device 100 stops the operation of the compressor 30.
  • the control device 100 starts measuring the pressure of the refrigerant flowing through the refrigerant circuit 200 (S107). For example, the control device 100 starts measuring the pressure of a single refrigerant (for example, R32) flowing through the indoor heat exchanger 61 using the pressure sensor 91. Note that the control device 100 may start measuring the pressure of a single refrigerant (for example, R32) flowing through the outdoor heat exchanger 51 using the pressure sensor 92.
  • the control device 100 calculates the time-series change in the acquired refrigerant pressure over a predetermined period of time, and determines whether the amount of decrease in the refrigerant pressure has exceeded the threshold (S108). That is, the control device 100 determines whether or not the refrigerant pressure has decreased due to a refrigerant leak, and if the amount of decrease in the refrigerant pressure exceeds a threshold value, the control device 100 determines whether a refrigerant leak has occurred somewhere in the first path. It is determined that the
  • the control device 100 determines that no refrigerant leak has occurred, and ends this process. On the other hand, if the amount of decrease in the refrigerant pressure is equal to or greater than the threshold (YES in S108), the control device 100 determines that a refrigerant leak has occurred, and executes abnormality processing corresponding to the refrigerant leak (S109). For example, as an abnormality process, the control device 100 may send an alert signal to a user-operable remote control (not shown) to notify the user that a refrigerant leak has occurred, or send an alert to a higher-level controller or a management server of the control device 100. It may send a signal to notify the administrator that a refrigerant leak has occurred. After that, the control device 100 ends this process.
  • a user-operable remote control not shown
  • the air conditioner 1 recovers the high boiling point refrigerant (for example, R1234yf) in the liquid state from among the non-azeotropic mixed refrigerants flowing through the refrigerant circuit 200 into the collection container 75, thereby recovering the gas state.
  • a refrigerant leak is detected by allowing only a low boiling point refrigerant (for example, R32) to exist in the refrigerant circuit 200, and observing a decrease in the pressure of the gaseous low boiling point refrigerant (for example, R32) existing in the refrigerant circuit 200. do.
  • FIG. 3 is a graph showing pressure changes with respect to refrigerant residual rate.
  • the refrigerant in the gas state has a larger pressure change with respect to the refrigerant residual rate than the refrigerant in the gas-liquid two-phase state.
  • the air conditioner 1 allows only the gaseous low boiling point refrigerant (for example, R32) to exist in the refrigerant circuit 200, and the gaseous low boiling point refrigerant (for example, R32) existing in the refrigerant circuit 200.
  • the gaseous low boiling point refrigerant for example, R32
  • the air conditioner 1 allows only a gaseous low boiling point refrigerant (for example, R32) to exist in the refrigerant circuit 200, when the operation is stopped, the refrigerant distribution differs in each element of the refrigerant circuit 200. It is possible to suppress variations in composition.
  • the air conditioner 1 does not erroneously determine that a refrigerant leak has occurred due to a change in the temperature and pressure of the non-azeotropic mixed refrigerant depending on the environmental conditions, and the Refrigerant leakage can be detected accurately based on the drop in pressure.
  • the air conditioner 1 returns a gaseous low boiling point refrigerant (for example, R32) among the non-azeotropic mixed refrigerant collected by the collection container 75 to the refrigerant circuit 200 using the gas vent pipe 25.
  • a gaseous low boiling point refrigerant for example, R32
  • only the liquid high boiling point refrigerant for example, R1234yf
  • the air conditioner 1 can easily separate a low boiling point refrigerant (for example, R32) and a high boiling point refrigerant (for example, R1234yf) from the non-azeotropic mixed refrigerant, and can detect refrigerant leaks with higher accuracy. Can be done.
  • the air conditioner 1 determines whether the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32) based on the temperature of the refrigerant flowing through the refrigerant circuit 200, and controls the refrigerant circuit 200.
  • the second on-off valve is closed to complete refrigerant recovery.
  • the air conditioner 1 can detect a refrigerant leak by observing the pressure drop of the single refrigerant after confirming that the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32). Therefore, refrigerant leakage can be detected more accurately than detecting refrigerant leakage by observing the pressure of the non-azeotropic mixed refrigerant.
  • Embodiment 2 An air conditioner 2 according to a second embodiment will be described with reference to FIGS. 4 and 5. Below, regarding the air conditioner 2 according to the second embodiment, the same configuration and processing steps as the air conditioner 1 according to the first embodiment are given the same reference numerals, and the air conditioner 2 according to the first embodiment Different configurations and processing steps will be given different symbols and their contents will be explained below.
  • FIG. 4 is a diagram showing the configuration of the air conditioner 2 according to the second embodiment.
  • the air conditioner 2 further includes a capacitance sensor 76 that measures the capacitance of the refrigerant flowing through the refrigerant circuit 200.
  • the air conditioner 2 includes a capacitance sensor 76 inside the collection container 75 that measures the capacitance of the refrigerant collected by the collection container 75.
  • a signal C1 indicating the capacitance of the refrigerant measured by the capacitance sensor 76 is transmitted to the control device 100.
  • FIG. 5 is a flowchart for explaining the refrigerant leak detection process executed by the control device 100 of the air conditioner 2 according to the second embodiment.
  • the control device 100 executes the refrigerant leak detection process shown in the flowchart shown in FIG. 5 by executing a program stored in the storage unit 102.
  • the refrigerant leak detection process in this flowchart is called and executed from the main control routine of the control device 100 at regular intervals.
  • "S" is used as an abbreviation of "STEP".
  • the control device 100 converts the temperature of the refrigerant measured by the temperature sensor into a saturation pressure, and based on the converted saturation pressure and the predetermined saturation pressure of a single refrigerant.
  • the control device 100 according to the second embodiment shown in FIG. It is configured to determine whether the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant based on the capacitance of the refrigerant measured by the sensor 76 and the predetermined capacitance of a single refrigerant. (S203, S204).
  • control device 100 closes the first on-off valve and recovers the non-azeotropic mixed refrigerant by the recovery container 75 (S102), and then controls the refrigerant recovered by the recovery container 75.
  • the capacitance is measured by the capacitance sensor 76 (S203).
  • the control device 100 determines whether the measured capacitance of the refrigerant is the same or substantially the same as the capacitance of a predetermined single refrigerant, a liquid high boiling point refrigerant (for example, R1234yf). S204). That is, the control device 100 determines whether the refrigerant present in the recovery container 75 is only a single refrigerant in a liquid state (for example, R1234yf). In other words, the control device 100 determines whether the only refrigerant flowing through the refrigerant circuit 200 other than the refrigerant present in the recovery container 75 is a single refrigerant in a gas state (for example, R32).
  • the control device 100 determines whether the difference between the measured capacitance of the refrigerant in the recovery container 75 and the capacitance of a predetermined single refrigerant (for example, R1234yf) is less than a determination value. However, if the difference is less than the determination value, it is determined that the refrigerant flowing through the refrigerant circuit 200 other than the refrigerant present in the recovery container 75 has become a single refrigerant (for example, R32).
  • a predetermined single refrigerant for example, R1234yf
  • the control device 100 If the measured capacitance of the refrigerant is not the same or substantially the same as the capacitance of a predetermined single refrigerant (for example, R1234yf) (NO in S204), the control device 100 returns to the process of S203 and returns to the collection container again.
  • the capacitance of the refrigerant recovered by step 75 is measured, and the process of step S204 is executed.
  • the control device 100 controls the refrigerant flowing through the refrigerant circuit 200. It is determined that the refrigerant has become a single refrigerant (for example, R32), and the processes from S105 onwards are executed.
  • a predetermined single refrigerant for example, R1234yf
  • the refrigerant present in the collection container 75 is a single refrigerant in a liquid state (for example, R1234yf).
  • the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32), and if the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32), The second on-off valve is closed to complete refrigerant recovery.
  • the air conditioner 2 can directly detect the composition of the refrigerant present in the collection container 75 using the capacitance sensor 76, so that the refrigerant present in the collection container 75 is in a liquid state. It is possible to accurately determine whether or not the refrigerant is a refrigerant (for example, R1234yf). As a result, the air conditioner 2 can detect refrigerant leaks with higher accuracy.
  • a refrigerant for example, R1234yf
  • Embodiment 3 The air conditioner 3 according to the third embodiment will be described with reference to FIGS. 6 and 7. Below, regarding the air conditioner 3 according to the third embodiment, the same configuration and processing steps as the air conditioner 1 according to the first embodiment will be denoted by the same reference numerals, and the air conditioner 3 according to the third embodiment will be described with the same reference numerals. Different configurations and processing steps will be given different symbols and their contents will be explained below.
  • FIG. 6 is a diagram showing the configuration of the air conditioner 3 according to the third embodiment.
  • the air conditioner 3 does not include a recovery container 75, and divides the path in the refrigerant circuit 200 between the indoor unit 400 side and the outdoor unit 300 side, and the refrigerant circuit on the indoor unit 400 side. 200 is configured to retain a single refrigerant (eg, R32) in a gaseous state in a path within the refrigerant 200 .
  • a single refrigerant eg, R32
  • the air conditioner 3 includes an on-off valve 73 and an on-off valve 74 in the refrigerant circuit 200.
  • the on-off valve 73 is provided between the expansion device 70 and the low-pressure side heat exchanger in the outdoor unit 300.
  • the on-off valve 73 is provided between the expansion device 70 and the indoor heat exchanger 61 (low-pressure side heat exchanger), and is connected to the expansion device 70 by piping 17, while being connected to the expansion device 70 by piping 20. It is connected to the extension pipe 21.
  • the on-off valve 74 is provided between the low-pressure side heat exchanger and the compressor 30 in the outdoor unit 300.
  • the on-off valve 74 is provided between the indoor heat exchanger 61 (low-pressure side heat exchanger) and the compressor 30, and is connected to the extension pipe 24 by the pipe 11, while the on-off valve 74 is connected to the extension pipe 24 by the pipe 26. It is connected to the connection port 44 of the four-way valve 40.
  • FIG. 7 is a flowchart for explaining the refrigerant leak detection process executed by the control device 100 of the air conditioner 3 according to the third embodiment.
  • FIG. 7 is a flowchart for explaining the refrigerant leak detection process executed by the control device 100 of the air conditioner 3 according to the third embodiment.
  • the control device 100 executes the refrigerant leak detection process shown in the flowchart shown in FIG. 7 by executing a program stored in the storage unit 102.
  • the refrigerant leak detection process in this flowchart is called and executed from the main control routine of the control device 100 at regular intervals.
  • "S" is used as an abbreviation of "STEP".
  • the control device 100 determines whether a stop condition for stopping the operation of the air conditioner 3 is satisfied (S301).
  • the contents of the stop condition are the same as the stop condition determined by the air conditioner 1 according to the first embodiment. If the stop condition is not satisfied (NO in S301), the control device 100 ends this process.
  • the control device 100 closes the first on-off valve (S302).
  • the "first on-off valve” is an on-off valve that opens or closes the path between the expansion device 70 and the low-pressure side heat exchanger, and in the example of FIG. 6, the on-off valve 73 corresponds to the "first on-off valve". do.
  • the control device 100 closes the first on-off valve the non-azeotropic refrigerant mixture that has passed through the expansion device 70 remains in front of the first on-off valve.
  • the control device 100 measures the temperature of the refrigerant flowing through the low-pressure side heat exchanger, and converts the obtained refrigerant temperature into a saturation pressure (S303). For example, the control device 100 measures the temperature of the refrigerant flowing through the indoor heat exchanger 61 using the first temperature sensor, and converts the obtained refrigerant temperature into a saturation pressure.
  • the "first temperature sensor” is a temperature sensor that measures the temperature of the refrigerant flowing through the low-pressure side heat exchanger, and in the example of FIG. 7, the temperature sensor 81 corresponds to the "first temperature sensor.”
  • the control device 100 determines whether the converted saturation pressure is the same or approximately the same as the saturation pressure of a predetermined single refrigerant, a gaseous low-boiling refrigerant (for example, R32) (S304). That is, the control device 100 determines whether the refrigerant flowing through the low-pressure side heat exchanger is only a single refrigerant in a gas state (for example, R32). For example, the control device 100 determines whether the difference between the converted saturation pressure and the saturation pressure of a predetermined single refrigerant (for example, R32) is less than a determination value, and determines whether the difference is less than the determination value. If this is the case, it is determined that the refrigerant flowing through the low-pressure side heat exchanger is a single refrigerant in a gas state (for example, R32).
  • the control device 100 If the converted saturation pressure is not the same or substantially the same as the saturation pressure of a predetermined single refrigerant (for example, R32) (NO in S304), the control device 100 returns to the process of S303 and controls the low-pressure side heat exchanger again. The temperature of the refrigerant flowing through is converted into a saturation pressure, and the process of S304 is executed.
  • a predetermined single refrigerant for example, R32
  • the control device 100 determines that the refrigerant flowing through the low-pressure side heat exchanger is It is determined that the single refrigerant in the gas state (for example, R32) is used, and the second on-off valve is closed (S305).
  • the "second on-off valve” is an on-off valve that opens or closes the path between the low-pressure side heat exchanger and the compressor 30, and in the example of FIG. 6, the on-off valve 74 corresponds to the "second on-off valve". do.
  • the first on-off valve for example, on-off valve 73
  • the low pressure side heat exchanger for example, indoor heat exchanger 61
  • the second on-off valve for example, on-off valve 74
  • the second on-off valve for example, the on-off valve 74
  • the path in the refrigerant circuit is separated from the second path on the high pressure side up to the first on-off valve (for example, on-off valve 73).
  • the control device 100 stops the operation of the air conditioner 2 (S306). For example, the control device 100 stops the operation of the compressor 30.
  • the control device 100 starts measuring the pressure of the refrigerant flowing through the low-pressure side heat exchanger (S307). For example, the control device 100 starts measuring the pressure of a single refrigerant (for example, R32) flowing through the indoor heat exchanger 61 using the pressure sensor 91.
  • the control device 100 calculates the time-series change in the acquired refrigerant pressure over a predetermined period of time, and determines whether the amount of decrease in the refrigerant pressure has exceeded the first threshold (S308). That is, the control device 100 determines whether or not the refrigerant pressure has decreased due to refrigerant leakage, and when the amount of decrease in the refrigerant pressure exceeds the first threshold value, the control device 100 determines whether or not the refrigerant pressure has decreased due to refrigerant leakage, and if the amount of decrease in the refrigerant pressure exceeds the first threshold value, the control device 100 determines whether or not the refrigerant pressure has decreased due to a refrigerant leak, and if the amount of decrease in the refrigerant pressure exceeds the first threshold value, the control device 100 determines whether or not the refrigerant pressure has decreased due to a refrigerant leak. It is determined that there is a refrigerant leak at some location.
  • the control device 100 determines that a refrigerant leak has occurred in the first path on the low pressure side, and performs abnormality processing corresponding to the refrigerant leak. Execute (S309).
  • the contents of the abnormality processing are the same as the abnormality processing executed by the air conditioner 1 according to the first embodiment.
  • the control device 100 determines that there is no refrigerant leak in the first path on the low-pressure side, and proceeds to the process of S310.
  • liquid refrigerant exists in the path on the outdoor unit 300 side
  • refrigerant leakage based on the amount of pressure drop is more difficult to detect with liquid refrigerant than with gaseous refrigerant that exists in the path on the indoor unit 400 side.
  • the liquid refrigerant present in the path on the outdoor unit 300 side includes refrigeration oil used in the compressor 30, if refrigerant leaks in the path on the outdoor unit 300 side, the amount of refrigerant in the path decreases. This reduces the degree of melting of the refrigerating machine oil in the refrigerant.
  • the air conditioner 3 uses this principle to detect refrigerant leakage in the path on the outdoor unit 300 side.
  • the control device 100 measures the temperature of the refrigerant flowing through the high-pressure side heat exchanger, and converts the obtained refrigerant temperature into a saturation pressure (S310).
  • the control device 100 measures the temperature of the refrigerant flowing through the outdoor heat exchanger 51 using the second temperature sensor, and converts the obtained refrigerant temperature into a saturation pressure.
  • the "second temperature sensor” is a temperature sensor that measures the temperature of the refrigerant flowing through the high-pressure side heat exchanger, and in the example of FIG. 7, the temperature sensor 82 corresponds to the "second temperature sensor.”
  • the control device 100 starts measuring the pressure of the refrigerant flowing through the high-pressure side heat exchanger (S311). For example, the control device 100 starts measuring the pressure of the refrigerant flowing through the outdoor heat exchanger 51 using the pressure sensor 92.
  • the control device 100 calculates the difference between the saturation pressure acquired in the process of S310 and the pressure of the refrigerant flowing through the outdoor heat exchanger 51 acquired in the process of S311, and determines whether the difference is greater than or equal to the second threshold value. is determined (S312).
  • the control device 100 controls the high-pressure side. It is determined that there is no refrigerant leakage in the second path, and the process ends.
  • the control device 100 It is determined that there is a refrigerant leak in the second path on the high pressure side, and abnormality processing corresponding to the refrigerant leak is executed (S313).
  • the contents of the abnormality processing are the same as the abnormality processing executed by the air conditioner 1 according to the first embodiment. After that, the control device 100 ends this process.
  • the air conditioner 3 allows only the low boiling point refrigerant (for example, R32) in the gas state out of the non-azeotropic mixed refrigerant flowing through the refrigerant circuit 200 into the refrigerant circuit 200 on the indoor unit 400 side.
  • a refrigerant leak is detected by observing a decrease in the pressure of a gaseous low boiling point refrigerant (for example, R32) existing in the refrigerant circuit 200 on the indoor unit 400 side.
  • the air conditioner 3 allows only the gaseous low boiling point refrigerant (for example, R32) to exist in the refrigerant circuit 200 on the indoor unit 400 side, the refrigerant distribution in each element of the refrigerant circuit is affected when the operation is stopped. By being different, it is possible to suppress variations in the refrigerant composition.
  • the air conditioner 3 does not erroneously determine that a refrigerant leak has occurred due to a change in the temperature and pressure of the non-azeotropic mixed refrigerant depending on the environmental conditions, and the Refrigerant leakage can be detected accurately based on the drop in pressure.
  • the air conditioner 3 divides the path in the refrigerant circuit 200 between the indoor unit 400 side and the outdoor unit 300 side using the on-off valve 73 and the on-off valve 74, thereby opening the recovery container 75. There is no need to use it, and refrigerant leakage can be detected not only in the refrigerant circuit 200 on the indoor unit 400 side but also in the refrigerant circuit 200 on the outdoor unit 300 side.
  • Embodiment 4 The air conditioner 4 according to the fourth embodiment will be described with reference to FIGS. 8 and 9. Below, regarding the air conditioner 4 according to Embodiment 4, the same configuration and processing steps as the air conditioner 1 according to Embodiment 1 will be denoted by the same reference numerals, and the air conditioner 4 according to Embodiment 1 will be described with the same reference numerals. Different configurations and processing steps will be given different symbols and their contents will be explained below.
  • FIG. 8 is a diagram showing the configuration of the air conditioner 4 according to the fourth embodiment.
  • the air conditioner 4 further includes a liquid level sensor 77 that detects the height of the liquid level of the non-azeotropic mixed refrigerant collected in the collection container 75.
  • a signal L1 indicating the height of the liquid level of the non-azeotropic mixed refrigerant detected by the liquid level sensor 77 is transmitted to the control device 100.
  • FIG. 9 is a flowchart for explaining the refrigerant leak detection process executed by the control device 100 of the air conditioner 4 according to the fourth embodiment.
  • the control device 100 executes the refrigerant leak detection process shown in the flowchart shown in FIG. 9 by executing a program stored in the storage unit 102.
  • the refrigerant leak detection process in this flowchart is called and executed from the main control routine of the control device 100 at regular intervals.
  • "S" is used as an abbreviation of "STEP".
  • the refrigerant flowing through the refrigerant circuit 200 is controlled to It is configured to determine whether or not the refrigerant is the same (S403, S404).
  • control device 100 closes the first on-off valve and collects the non-azeotropic mixed refrigerant in the recovery container 75 (S102), and then uses the liquid level sensor 77 to collect the non-azeotropic mixed refrigerant in the recovery container 75.
  • the height of the liquid level of the non-azeotropic mixed refrigerant is detected (S403).
  • the control device 100 determines whether the detected height of the liquid level has stabilized over a predetermined period of time (S404). That is, the control device 100 determines whether the recovery of the non-azeotropic mixed refrigerant by the recovery container 75 has been completed. As described in the first embodiment, among the non-azeotropic mixed refrigerants collected by the collection container 75, the gaseous low-boiling refrigerant (for example, R32) returns to the refrigerant circuit 200 using the gas vent pipe 25.
  • the gaseous low-boiling refrigerant for example, R32
  • the refrigerant present in the collection container 75 becomes a single refrigerant in a liquid state (for example, R1234yf), which is present in the collection container 75.
  • the refrigerant other than the refrigerant flowing through the refrigerant circuit 200 becomes a single refrigerant in a gas state (for example, R32).
  • control device 100 If the height of the liquid level detected by the liquid level sensor 77 is not stable for a predetermined period of time (NO in S404), the control device 100 returns to the process of S403 and collects the non-liquid recovered by the recovery container 75 again. The height of the liquid level of the azeotropic refrigerant mixture is detected, and the process of S404 is executed.
  • the control device 100 determines that the recovery of the non-azeotropic mixed refrigerant by the recovery container 75 has ended. That is, it is determined that the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32), and the processing from S105 onwards is executed.
  • the air conditioner 4 determines whether the collection of the non-azeotropic mixed refrigerant by the collection container 75 has been completed based on whether the liquid level of the refrigerant collected by the collection container 75 has stabilized. In other words, it is determined whether the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32), and when the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32), the second refrigerant is determined. Close the on-off valve to finish refrigerant recovery.
  • the air conditioner 4 can directly detect the end of recovery of the non-azeotropic mixed refrigerant by the recovery container 75 using the liquid level sensor 77, so that the refrigerant present in the recovery container 75 is in a liquid state. It is possible to accurately determine whether the refrigerant is a single refrigerant (for example, R1234yf). As a result, the air conditioner 2 can detect refrigerant leaks with higher accuracy.
  • the present disclosure relates to air conditioners 1 to 4 using non-azeotropic mixed refrigerants.
  • the air conditioners 1 to 4 include a compressor 30, an outdoor heat exchanger 51, an expansion device 70, and an indoor heat exchanger 61, and are configured to circulate a non-azeotropic mixed refrigerant.
  • the refrigerant circuit 200 includes a refrigerant circuit 200 configured, a control device 100 that controls the refrigerant circuit 200, and at least one pressure sensor 91, 92 that measures the pressure of refrigerant flowing through the refrigerant circuit 200.
  • the control device 100 obtains a single refrigerant (for example, R32) in the refrigerant circuit 200 by recovering the non-azeotropic mixed refrigerant flowing through the refrigerant circuit 200, and the amount of decrease in the measured value of the at least one pressure sensor 91, 92 is If it is equal to or greater than the threshold value, it is determined that there is a refrigerant leak in the refrigerant circuit 200.
  • a single refrigerant for example, R32
  • the air conditioners 1 to 4 collect a high boiling point refrigerant (for example, R1234yf) in a liquid state from among the non-azeotropic mixed refrigerants flowing through the refrigerant circuit 200 into the collection container 75. Only a gaseous low boiling point refrigerant (for example, R32) is present in the refrigerant circuit 200, and a decrease in the pressure of the gaseous low boiling point refrigerant (for example, R32) existing in the refrigerant circuit 200 is observed to detect refrigerant leakage. Detect.
  • a gaseous low boiling point refrigerant for example, R32
  • the air conditioners 1 to 4 only a gaseous low-boiling point refrigerant (for example, R32) is present in the refrigerant circuit 200, so when the operation is stopped, the refrigerant composition changes due to the difference in refrigerant distribution in each element of the refrigerant circuit 200. Variations can be suppressed.
  • the air conditioners 1 to 4 do not erroneously determine that a refrigerant leak has occurred due to a change in the temperature and pressure of the non-azeotropic mixed refrigerant depending on the environmental conditions. ) Refrigerant leakage can be detected with high accuracy based on the decrease in pressure.
  • the air conditioners 1, 2, and 4 include a recovery container 75 for recovering the non-azeotropic mixed refrigerant flowing through the refrigerant circuit 200, a recovery container 75, and an indoor heat exchanger.
  • the device further includes an on-off valve 71 that opens or closes a path between the device and the device 61.
  • the control device 100 closes the on-off valve 71 and collects the non-azeotropic mixed refrigerant flowing into the recovery container 75 using the recovery container 75 .
  • the air conditioners 1, 2, and 4 can recover the non-azeotropic mixed refrigerant flowing into the recovery container 75 using the recovery container 75.
  • the air conditioners 1, 2, and 4 degas the refrigerant in a gas state contained in the non-azeotropic mixed refrigerant collected by the collection container 75 and return it to the refrigerant circuit 200. Piping 25 is further provided.
  • the air conditioners 1, 2, and 4 can pass the gaseous low-boiling refrigerant (for example, R32) out of the non-azeotropic mixed refrigerant collected by the collection container 75 through the degassing pipe 25. While the refrigerant is used and returned to the refrigerant circuit 200, only the high boiling point refrigerant (for example, R1234yf) in the liquid state can be preferentially recovered in the recovery container 75.
  • the boiling point refrigerant for example, R1234yf
  • the air conditioner 1 further includes temperature sensors 81 and 82 that measure the temperature of the refrigerant flowing through the refrigerant circuit 200.
  • the control device 100 converts the refrigerant temperature measured by the temperature sensors 81 and 82 into a saturation pressure, and controls the refrigerant flowing through the refrigerant circuit 200 based on the converted saturation pressure and the predetermined saturation pressure of a single refrigerant. Determine whether or not is a single refrigerant.
  • the air conditioner 1 determines whether the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32) based on the temperature of the refrigerant flowing through the refrigerant circuit 200, and When the refrigerant flowing through the circuit 200 is a single refrigerant (for example, R32), the on-off valve 72 can be closed to end refrigerant recovery.
  • a single refrigerant for example, R32
  • the air conditioner 2 further includes a capacitance sensor 76 that measures the capacitance of the refrigerant flowing through the refrigerant circuit 200.
  • the control device 100 determines whether the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant based on the refrigerant capacitance measured by the capacitance sensor 76 and the predetermined capacitance of a single refrigerant. Determine.
  • the air conditioner 2 can detect whether the refrigerant present in the collection container 75 is a single liquid refrigerant (for example, R1234yf) based on the capacitance of the refrigerant collected by the collection container 75. In other words, it is determined whether the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32), and if the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32), Refrigerant recovery can be completed by closing the on-off valve 72.
  • a single liquid refrigerant for example, R1234yf
  • the air conditioner 4 further includes a liquid level sensor 77 that detects the height of the liquid level of the non-azeotropic mixed refrigerant collected in the recovery container 75. Based on the height of the liquid level detected by the liquid level sensor 77, the control device 100 determines whether the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant.
  • the air conditioner 4 can determine whether the collection of the non-azeotropic mixed refrigerant by the collection container 75 has been completed based on whether the liquid level of the refrigerant collected by the collection container 75 has stabilized. In other words, it is determined whether the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32), and when the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32), the on-off valve is 72 may be closed to terminate refrigerant recovery.
  • the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32)
  • the on-off valve is 72 may be closed to terminate refrigerant recovery.
  • the air conditioner 3 includes an on-off valve 73 that opens or closes a path between the expansion device 70 and the indoor heat exchanger 61, and an on-off valve 73 that opens or closes a path between the indoor heat exchanger 61 and the compressor 30. It further includes an on-off valve 74 that opens or closes the path between the two.
  • the control device 100 closes the on-off valve 73 and closes the on-off valve 74 when the refrigerant flowing through the indoor heat exchanger 61 is a single refrigerant. Fasten different single refrigerants.
  • the air conditioner 3 allows only the low boiling point refrigerant (for example, R32) in the gas state to enter the refrigerant circuit 200 on the indoor unit 400 side among the non-azeotropic mixed refrigerants flowing through the refrigerant circuit 200.
  • a refrigerant leak is detected by observing a decrease in the pressure of a gaseous low boiling point refrigerant (for example, R32) existing in the refrigerant circuit 200 on the indoor unit 400 side.
  • the air conditioner 3 allows only a gaseous low-boiling refrigerant (for example, R32) to exist in the refrigerant circuit 200 on the indoor unit 400 side, when the operation is stopped, the refrigerant distribution differs in each element of the refrigerant circuit. It is possible to suppress variations in composition.
  • the air conditioner 3 does not erroneously determine that a refrigerant leak has occurred due to a change in the temperature and pressure of the non-azeotropic mixed refrigerant depending on the environmental conditions, and the Refrigerant leakage can be detected accurately based on the drop in pressure.
  • the air conditioner 3 further includes a temperature sensor 81 that measures the temperature of the refrigerant flowing through the indoor heat exchanger 61. After closing the on-off valve 73, the control device 100 converts the refrigerant temperature measured by the temperature sensor 81 into a saturation pressure, and based on the converted saturation pressure and the predetermined saturation pressure of a single refrigerant, It is determined whether the refrigerant flowing through the indoor heat exchanger 61 is a single refrigerant.
  • the air conditioner 3 determines whether the refrigerant flowing through the refrigerant circuit 200 is a single refrigerant (for example, R32) based on the temperature of the refrigerant flowing through the indoor heat exchanger 61.
  • the on-off valve 74 can be closed to complete refrigerant recovery.
  • the air conditioner 3 further includes a temperature sensor 82 that measures the temperature of the refrigerant flowing through the outdoor heat exchanger 51.
  • At least one pressure sensor 91, 92 includes a pressure sensor 91 that measures the pressure of the refrigerant flowing through the indoor heat exchanger 61, and a pressure sensor 92 that measures the pressure of the refrigerant flowing through the outdoor heat exchanger 51.
  • the control device 100 controls the on-off valves 73 and 74 when the amount of decrease in the measured value of the pressure sensor 91 is equal to or greater than a first threshold value. It is determined that there is a refrigerant leak in the path between the indoor heat exchanger 61 and the refrigerant temperature measured by the temperature sensor 82 is converted to saturation pressure, and the converted saturation pressure and the pressure sensor If the difference between the measured value of .
  • the air conditioner 3 uses the on-off valve 73 and the on-off valve 74 to divide the path in the refrigerant circuit 200 between the indoor unit 400 side and the outdoor unit 300 side, thereby recovering the refrigerant. There is no need to use the container 75, and refrigerant leakage can be detected not only in the refrigerant circuit 200 on the indoor unit 400 side but also in the refrigerant circuit 200 on the outdoor unit 300 side.
  • the present disclosure is a refrigerant leak detection method in air conditioners 1 to 4 using a non-azeotropic mixed refrigerant.
  • the air conditioners 1 to 4 each include a refrigerant circuit 200 that includes a compressor 30, an outdoor heat exchanger 51, an expansion device 70, and an indoor heat exchanger 61, and is configured to circulate a non-azeotropic mixed refrigerant; It includes a control device 100 that controls the circuit 200 and at least one pressure sensor 91, 92 that measures the pressure of refrigerant flowing through the refrigerant circuit 200.
  • the refrigerant leak detection method by the control device 100 includes the steps of obtaining a single refrigerant in the refrigerant circuit 200 by collecting the non-azeotropic mixed refrigerant flowing through the refrigerant circuit 200, and a decrease in the measured value of at least one pressure sensor 91, 92. and a step of determining that refrigerant leakage has occurred in refrigerant circuit 200 when the amount is equal to or greater than a threshold value.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

Un climatiseur (1) comprend : un circuit de fluide frigorigène (200) comprenant un compresseur (30), un échangeur de chaleur côté haute pression, un dispositif d'expansion (70) et un échangeur de chaleur côté basse pression et conçu pour faire circuler un fluide frigorigène mélangé non azéotrope ; un dispositif de commande (100) qui commande le circuit de fluide frigorigène (200) ; et au moins un capteur de pression (91, 92) qui mesure la pression du fluide frigorigène s'écoulant à travers le circuit de fluide frigorigène (200). Lorsqu'un fluide frigorigène unique est obtenu dans le circuit de fluide frigorigène (200) par récupération du fluide frigorigène mixte non azéotrope s'écoulant à travers le circuit de fluide frigorigène (200), et la quantité de diminution de la valeur mesurée dudit au moins un capteur de pression (91, 92) est supérieure ou égale à la valeur de seuil, le dispositif de commande (100) détermine qu'une fuite de fluide frigorigène s'est produite dans le circuit de fluide frigorigène (200).
PCT/JP2022/026716 2022-07-05 2022-07-05 Climatiseur et procédé de détection de fuite de fluide frigorigène WO2024009394A1 (fr)

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Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07198235A (ja) * 1993-12-28 1995-08-01 Mitsubishi Heavy Ind Ltd 空気調和装置
JPH0854161A (ja) * 1994-08-11 1996-02-27 Sanyo Electric Co Ltd 冷凍装置の冷媒漏洩検出方法
JPH08261607A (ja) * 1995-03-24 1996-10-11 Mitsubishi Electric Corp 混合冷媒充填装置および混合冷媒充填方法
JP2001141322A (ja) * 1999-11-12 2001-05-25 Matsushita Refrig Co Ltd ヒートポンプ装置
JP2008256254A (ja) * 2007-04-04 2008-10-23 Daikin Ind Ltd 冷凍装置および冷媒組成の推定方法
WO2019021428A1 (fr) * 2017-07-27 2019-01-31 三菱電機株式会社 Dispositif de climatisation et de réfrigération, et dispositif de commande
WO2019021346A1 (fr) * 2017-07-24 2019-01-31 三菱電機株式会社 Dispositif frigorifique
WO2019053858A1 (fr) * 2017-09-14 2019-03-21 三菱電機株式会社 Appareil à cycle de réfrigération et appareil de réfrigération
JP2019052819A (ja) * 2017-09-19 2019-04-04 ダイキン工業株式会社 ガス漏れ量検知方法及び冷凍装置の運転方法
WO2021192275A1 (fr) * 2020-03-27 2021-09-30 三菱電機株式会社 Unité extérieure et dispositif à cycle de réfrigération équipé de cette dernière

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07198235A (ja) * 1993-12-28 1995-08-01 Mitsubishi Heavy Ind Ltd 空気調和装置
JPH0854161A (ja) * 1994-08-11 1996-02-27 Sanyo Electric Co Ltd 冷凍装置の冷媒漏洩検出方法
JPH08261607A (ja) * 1995-03-24 1996-10-11 Mitsubishi Electric Corp 混合冷媒充填装置および混合冷媒充填方法
JP2001141322A (ja) * 1999-11-12 2001-05-25 Matsushita Refrig Co Ltd ヒートポンプ装置
JP2008256254A (ja) * 2007-04-04 2008-10-23 Daikin Ind Ltd 冷凍装置および冷媒組成の推定方法
WO2019021346A1 (fr) * 2017-07-24 2019-01-31 三菱電機株式会社 Dispositif frigorifique
WO2019021428A1 (fr) * 2017-07-27 2019-01-31 三菱電機株式会社 Dispositif de climatisation et de réfrigération, et dispositif de commande
WO2019053858A1 (fr) * 2017-09-14 2019-03-21 三菱電機株式会社 Appareil à cycle de réfrigération et appareil de réfrigération
JP2019052819A (ja) * 2017-09-19 2019-04-04 ダイキン工業株式会社 ガス漏れ量検知方法及び冷凍装置の運転方法
WO2021192275A1 (fr) * 2020-03-27 2021-09-30 三菱電機株式会社 Unité extérieure et dispositif à cycle de réfrigération équipé de cette dernière

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