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WO2023210457A1 - Dispositif de réfrigération - Google Patents

Dispositif de réfrigération Download PDF

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Publication number
WO2023210457A1
WO2023210457A1 PCT/JP2023/015550 JP2023015550W WO2023210457A1 WO 2023210457 A1 WO2023210457 A1 WO 2023210457A1 JP 2023015550 W JP2023015550 W JP 2023015550W WO 2023210457 A1 WO2023210457 A1 WO 2023210457A1
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WO
WIPO (PCT)
Prior art keywords
refrigerant
compressor
pressure
control device
air conditioner
Prior art date
Application number
PCT/JP2023/015550
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English (en)
Japanese (ja)
Inventor
一彦 三原
雅也 本間
晃 鶸田
Original Assignee
パナソニックＩｐマネジメント株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by パナソニックＩｐマネジメント株式会社 filed Critical パナソニックＩｐマネジメント株式会社
Publication of WO2023210457A1 publication Critical patent/WO2023210457A1/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
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems

Definitions

  • the present invention relates to a refrigeration device.
  • Patent Document 1 discloses a refrigerator using low GWP (Global Warming Potential).
  • the refrigerator of Patent Document 1 uses trans-1,2-difluoroethylene (HFO-1132(E)), 2,3,3,3-tetrafluoro-1-propene (R1234yf), and trifluoroethylene (HFO-1123). ) etc.
  • the present disclosure provides a refrigeration system that can suppress the influence of the disproportionation reaction in a refrigeration cycle when the disproportionation reaction of the refrigerant occurs.
  • the refrigeration system includes a compressor, a heat source side heat exchanger, a user side heat exchanger, an expansion mechanism, a heating operation state in which the user side heat exchanger operates as a condenser, and a heating operation state in which the user side heat exchanger operates as a condenser.
  • a switching valve that switches between a cooling operating state in which the exchanger operates as a condenser; and a control device; the control device uses a working medium containing ethylene-based fluoroolefin as a refrigerant; If it is detected that the pressure of the working medium in the high pressure section including the compressor and the condenser has increased to a threshold value or more, the switching valve is controlled to switch from the heating operation state to the cooling operation state. Make the switch.
  • the refrigeration device achieves low GWP by using a working medium containing ethylene-based fluoroolefins as a refrigerant, and can suppress the effects when a refrigerant disproportionation reaction occurs.
  • FIG. 1 is a diagram showing the configuration of an air conditioner according to Embodiment 1 of the present invention.
  • Figure 2 is a diagram showing the configuration of the compressor.
  • FIG. 3 is a diagram showing the configuration of an air conditioner according to Embodiment 1 of the present invention.
  • FIG. 4 is a flowchart showing the operation of the air conditioner according to the first embodiment.
  • FIG. 5 is a diagram showing the configuration of an air conditioner according to Embodiment 2 of the present invention.
  • FIG. 6 is a diagram showing the configuration of an air conditioner according to Embodiment 3 of the present invention.
  • FIG. 7 is a diagram showing the configuration of an air conditioner according to Embodiment 4 of the present invention.
  • FIG. 8 is a diagram showing the configuration of an air conditioner according to Embodiment 5 of the present invention.
  • the present disclosure provides a refrigeration system that can suppress the influence of the disproportionation reaction in a refrigeration cycle when the disproportionation reaction of the refrigerant occurs.
  • a refrigeration system that can suppress the influence of the disproportionation reaction in a refrigeration cycle when the disproportionation reaction of the refrigerant occurs.
  • FIGS. 1 to 4 Embodiment 1 will be described below using FIGS. 1 to 4.
  • FIGS. 1 to 4. [1-1. Configuration of air conditioner] 1 and 3 are diagrams showing the configuration of air conditioner 1 in Embodiment 1, and FIG. 2 is a diagram showing the configuration of compressor 100 included in air conditioner 1.
  • the air conditioner 1 shown in FIGS. 1 and 3 is an example to which the refrigeration circuit of the present invention is applied.
  • FIG. 1 shows a cooling operation state of the air conditioner 1
  • FIG. 3 shows a heating operation state of the air conditioner 1.
  • the air conditioner 1 includes a compressor 100, heat exchangers 11a and 11b, expansion valves 12a and 12b, a heat exchanger 13, an expansion valve 14, a gas-liquid separator 15, a valve 16, four-way valves 21 and 22, and Equipped with refrigerant piping to connect.
  • the air conditioner 1 also includes a control device 10 that controls the expansion valves 12a, 12b, the expansion valve 14, the valve 16, and the four-way valves 21, 22.
  • the four-way valves 21 and 22 correspond to an example of a switching valve.
  • the compressor 100 includes a suction port 104, a discharge pipe 105, and an injection section 125, as will be described later with reference to FIG.
  • the compressor 100 sucks and compresses refrigerant through a suction port 104, and discharges high-pressure refrigerant through a discharge pipe 105.
  • the heat exchangers 11a and 11b are user-side heat exchangers that are installed in the indoor unit and perform cooling and heating of the conditioned space. Heat exchanger 11a and heat exchanger 11b are connected in parallel.
  • the heat exchanger 13 is a heat source side heat exchanger installed in the outdoor unit. Each of heat exchanger 11a, heat exchanger 11b, and heat exchanger 13 is provided with a fan.
  • a pipe 41 connected to the suction port 104 of the compressor 100, a pipe 42 connected to the discharge pipe 105, a pipe 44 connected to the heat exchangers 11a and 11b, and a pipe 46 connected to the heat exchanger 13 are connected to the four-way valve 21.
  • Piping 41 corresponds to an example of suction piping.
  • the pipe 42 corresponds to an example of a discharge pipe.
  • the four-way valve 21 switches connections between the pipes 41 , 42 , 44 , and 46 under the control of the control device 10 .
  • a pipe 45 connected to the heat exchangers 11a and 11b, a pipe 47 connected to the heat exchanger 13, and a pipe 48 and a pipe 49 connected to the gas-liquid separator 15 are connected to the four-way valve 22.
  • Piping 49 is a piping that allows the refrigerant to flow into the gas-liquid separator 15
  • piping 48 is a piping that allows the refrigerant to flow out from the gas-liquid separator 15.
  • the gas-liquid separator 15 is a tank that stores the refrigerant flowing in from the pipe 48 and can separate and take out the liquid refrigerant and the gas refrigerant.
  • the gas-liquid separator 15 corresponds to an example of a refrigerant storage section.
  • the four-way valve 22 switches connections between the pipes 45 , 47 , 48 , and 49 under the control of the control device 10 .
  • FIG. 1 the flow of refrigerant in the cooling operation state is shown by arrows labeled RC.
  • FIG. 2 the flow of the refrigerant in the heating operation state is shown by arrows labeled RH.
  • FIGS. 1 to 3 and FIGS. 5 to 7, which will be described later the flow of the refrigerant that is common between the cooling operation state and the heating operation state is shown by an arrow with a symbol R.
  • the four-way valve 21 connects the pipe 42 and the pipe 46, and connects the pipe 44 and the pipe 41.
  • the four-way valve 22 connects the piping 47 and the piping 49, and connects the piping 48 and the piping 45.
  • the refrigerant discharged from the compressor 100 into the discharge pipe 105 flows into the heat exchanger 13 via the pipe 42 and the four-way valve 21, and is condensed in the heat exchanger 13. . That is, the heat exchanger 13 functions as a condenser in the cooling operation state.
  • the refrigerant condensed in the heat exchanger 13 flows into the gas-liquid separator 15 through the pipe 47, the four-way valve 22, and the pipe 49.
  • liquid refrigerant is supplied from the gas-liquid separator 15 to the expansion valves 12a and 12b through the pipe 48 and the four-way valve 22.
  • the expansion valve 12a reduces the pressure of the refrigerant and supplies it to the heat exchanger 11a
  • the expansion valve 12b reduces the pressure of the refrigerant and supplies it to the heat exchanger 11b.
  • the heat exchangers 11a and 11b function as evaporators during cooling operation, and vaporize the refrigerant whose pressure has been reduced by the expansion valves 12a and 12b.
  • the refrigerant vaporized in the heat exchangers 11a and 11b is sent to the compressor 100 through the pipe 44, the four-way valve 21, and the pipe 41.
  • the four-way valve 21 connects the piping 42 and the piping 44, and connects the piping 46 and the piping 41.
  • the four-way valve 22 connects the piping 47 and the piping 48 and connects the piping 49 and the piping 45.
  • the refrigerant discharged from the discharge pipe 105 flows into the heat exchangers 11a and 11b through the pipe 42 and the four-way valve 21, and is condensed in the heat exchangers 11a and 11b. That is, in the heating operation state, the heat exchangers 11a and 11b function as condensers.
  • the refrigerant condensed in the heat exchangers 11a and 11b flows into the gas-liquid separator 15 through the pipe 45, the four-way valve 22, and the pipe 49.
  • liquid refrigerant is supplied from the gas-liquid separator 15 to the expansion valve 14 through the pipe 48 and the four-way valve 22.
  • the expansion valve 14 reduces the pressure of the refrigerant and supplies it to the heat exchanger 13 .
  • the heat exchanger 13 functions as an evaporator in the heating operation state, and vaporizes the refrigerant whose pressure has been reduced by the expansion valve 14.
  • the refrigerant vaporized in the heat exchanger 13 is sucked into the suction port 104 through the pipe 46, the four-way valve 21, and the pipe 41.
  • the control device 10 includes a processor such as a microcontroller.
  • the control device 10 controls the air conditioner 1 by executing a program using a processor or by using programmed hardware functions.
  • the control device 10 controls the four-way valve 21 and the four-way valve 22 to switch between the cooling operation state and the heating operation state. Further, the control device 10 adjusts the opening degrees of the expansion valves 12a and 12b in the cooling operation state. The control device 10 adjusts the opening degree of the expansion valve 14 in the heating operation state.
  • the control device 10 executes control to open and close the valve 16 provided in the pipe 43.
  • the valve 16 is composed of an electric valve, a solenoid valve, or an expansion valve.
  • the control device 10 controls opening and closing of the valve 16 and adjusts the opening degree of the valve 16.
  • the air conditioner 1 may include one or more of a temperature sensor (not shown) that detects the temperature of the electric motor 110 and a temperature sensor (not shown) that detects the temperature of the refrigerant discharged by the compression mechanism 120. These temperature sensors are connected to the control device 10.
  • the control device 10 detects either or both of the temperature of the electric motor 110 and the temperature of the refrigerant discharged by the compression mechanism 120 by acquiring the detection value of the temperature sensor. Further, the control device 10 may calculate the pressure of the refrigerant discharged by the compression mechanism 120 based on the temperature of the refrigerant discharged by the compression mechanism 120.
  • the air conditioner 1 may include a pressure sensor that detects the pressure of the refrigerant discharged by the compression mechanism 120. Furthermore, the air conditioner 1 may include a heat exchanger temperature sensor (not shown) that detects the temperatures of the heat exchangers 11a, 11b, and the heat exchanger 13. In this case, the control device 10 may calculate the pressure and temperature of the refrigerant discharged by the compression mechanism 120 based on the detected value of the heat exchanger temperature sensor, or may be configured without the above-mentioned temperature sensor. .
  • the pipe 43 supplies gaseous refrigerant from the gas-liquid separator 15 to the compressor 100. Since the pipe 43 supplies the refrigerant stored in the gas-liquid separator 15 to the compressor 100 through a route different from the pipe 48 connected to the suction port 104, it can be called a bypass pipe. Piping 43 is connected to injection section 125 of compressor 100. The compressor 100 is cooled by supplying refrigerant to the injection section 125 through the pipe 43.
  • the injection unit 125 corresponds to an example of a refrigerant supply unit.
  • the pipe 43 corresponds to an example of a refrigerant pipe.
  • a relief valve 60 is provided in the pipe 42 connected to the discharge pipe 105.
  • a relief valve 60 is provided in the piping 42.
  • the relief valve 60 is a valve that automatically opens when the pressure of the refrigerant exceeds a preset pressure, and reduces the pressure in the compression chamber of the compression mechanism 120 and the discharge pipe 105.
  • the relief valve 60 corresponds to an example of pressure release means.
  • the relief valve 60 may be provided in the discharge pipe 105.
  • compressor 100 has a container 102. As shown in FIG. The container 102 houses a compression mechanism 120 that compresses refrigerant and an electric motor 110 that drives the compression mechanism 120. Electric motor 110 has a stator 111 and a rotor 112. A crankshaft 103 is connected to the rotor 112, and the crankshaft 103 is rotatably supported by bearings 107 and 108. Thereby, the rotor 112 is rotatably held together with the crankshaft 103.
  • the electric motor 110 is located, for example, in the lower part of the internal space of the container 102, and the compression mechanism 120 is located above the electric motor 110.
  • Refrigerating machine oil (not shown) is stored at the bottom of the container 102 .
  • the electric motor 110 is a so-called concentrated winding motor.
  • the stator 111 has teeth having three-phase stator windings and a yoke that connects the teeth, and the stator windings of the stator 111 are connected to an inverter-type drive circuit 116 by lead wires (not shown). be done.
  • the rotor 112 has a permanent magnet and rotates together with the crankshaft 103 by a rotating magnetic field generated by a current flowing through the stator 111.
  • Drive circuit 116 outputs a drive current to stator 111 under control of electric motor 110.
  • the compression mechanism 120 is, for example, a scroll type compression mechanism.
  • the compression mechanism 120 includes a fixed scroll 121 and an oscillating scroll 122 combined with the fixed scroll 121, and a space between the fixed scroll 121 and the oscillating scroll 122 functions as a compression chamber.
  • the compression mechanism 120 compresses the refrigerant by rotating the swinging scroll 122 together with the crankshaft 103.
  • the refrigerant compressed by the compression mechanism 120 is discharged through the discharge pipe 105.
  • the compressor 100 is a so-called internal low pressure type compressor in which a compression mechanism 120 sucks and compresses the refrigerant flowing into the container 102 through the suction port 104.
  • the refrigerant flowing into the container 102 from the suction port 104 is sucked into the compression mechanism 120 through an air gap, which is a space between the stator 111 and the rotor 112 of the electric motor 110, as shown by arrow RI.
  • the electric motor 110 is cooled by the refrigerant flowing through the air gap.
  • the injection part 125 is a tube that communicates between the inside and outside of the container 102, and the tip of the injection part 125 opens into the compression chamber of the compression mechanism 120.
  • the piping 43 is connected to the injection section 125 as described above, and gaseous refrigerant is supplied through the piping 43.
  • the refrigerant in the gas-liquid separator 15 is sucked into the compression mechanism 120.
  • the gaseous refrigerant is extracted from the gas-liquid separator 15, thereby reducing the pressure of the refrigerant in the gas-liquid separator 15 and causing the refrigerant to expand in the gas-liquid separator 15.
  • the injection part 125 may be opened inside the container 102 at or near a suction port through which the compression mechanism 120 sucks the refrigerant inside the container 102 . In this case as well, the effect of extracting the gaseous refrigerant from the gas-liquid separator 15 can be produced.
  • the refrigerant used in the air conditioner 1 is a working medium containing ethylene-based fluoroolefin.
  • ethylene-based fluoroolefins include 1,1,2-trifluoroethylene (HFO-1123), trans-1,2-difluoroethylene (HFO-1132(E)), and cis-1,2-difluoroethylene (HFO-1123).
  • the working medium may include two or more refrigerant components. That is, it may contain an ethylene-based fluoroolefin (for example, 1,1,2-trifluoroethylene) selected from the above examples and a second refrigerant component.
  • the second refrigerant component may include one or more refrigerants selected from hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), saturated hydrocarbons, carbon dioxide, or other refrigerants.
  • hydrofluorocarbon examples include difluoromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, pentafluoropropane, hexafluoropropane, heptafluoropropane, pentafluorobutane, and heptafluorocyclopentane.
  • hydrofluoroolefins include monofluoropropene, trifluoropropene, tetrafluoropropene, pentafluoropropene, and hexafluorobutene.
  • Saturated hydrocarbons include, for example, ethane, n-propane, cyclopropane, n-butane, cyclobutane, isobutane (2-methylpropane), methylcyclopropane, n-pentane, isopentane (2-methylbutane), neopentane (2,2 -dimethylpropane) and methylcyclobutane, but other hydrocarbons may also be used.
  • the second refrigerant component may include multiple components. That is, the second refrigerant component may include two or more refrigerant components selected from hydrofluorocarbons, hydrofluoroolefins, saturated hydrocarbons, carbon dioxide, and other refrigerants.
  • the working medium used as a refrigerant in the air conditioner 1 may contain a disproportionation inhibitor in addition to the refrigerant components.
  • Disproportionation inhibitors are, for example, saturated hydrocarbons.
  • the working medium may include a disproportionation inhibitor consisting of one or more components.
  • Saturated hydrocarbons utilized as disproportionation inhibitors include ethane, n-propane, cyclopropane, n-butane, cyclobutane, isobutane (2-methylpropane), methylcyclopropane, n-pentane, isopentane (2-methylbutane). ), neopentane (2,2-dimethylpropane), and methylcyclobutane, but other saturated hydrocarbons may also be used.
  • a particularly preferred disproportionation inhibitor is n-propane.
  • the disproportionation inhibitor may be, for example, a haloalkane having 1 to 2 carbon atoms.
  • haloalkanes having one carbon number, ie, halomethanes used as disproportionation inhibitors include (mono)iodomethane (CH 3 I), diiodomethane (CH 2 I 2 ), dibromomethane (CH 2 Br 2 ), and bromomethane.
  • haloalkane having 2 carbon atoms that is, haloethane, used as a disproportionation inhibitor
  • CF 3 CH 2 I 1,1,1-trifluoro-2-iodoethane
  • CH 3 CH 2 I monoiodoethane
  • CH 3 CH 2 Br monobromoethane
  • CH 3 CI 3 1,1,1-triiodoethane
  • the working medium may include a plurality of disproportionation inhibitors selected from the above-mentioned saturated hydrocarbons and the above-mentioned haloalkanes. Further, the working medium may contain one type of saturated hydrocarbon or may contain two or more types of saturated hydrocarbons. Further, the working medium may contain one type of haloalkane, or may contain two or more types of haloalkanes.
  • a preferred example of the working medium is a mixture containing 1,1,2-trifluoroethylene and n-propane.
  • This working medium may contain the second refrigerant component described above, or may contain other components.
  • Each of the above working media may contain unavoidable impurities.
  • Unavoidable impurities include various additives including stabilizers added for the purpose of stabilization during transportation and storage, residues or by-products of synthetic raw materials for refrigerant components, and substances mixed in for other reasons. Can be mentioned.
  • the mass ratio of 1,1,2-trifluoroethylene and n-propane contained in the working medium can be changed as appropriate.
  • the capacity of a refrigeration cycle is correlated to the mass ratio of refrigerant components contained in the working medium. Therefore, in order to maintain the performance of the refrigeration cycle, it is desirable that the working medium contains n-propane, which is a disproportionation inhibitor, in an amount of 40% by mass or less.
  • Ethylene-based fluoroolefins include, for example, ethylene-based fluoroolefins in which a disproportionation reaction occurs.
  • ethylene-based fluoroolefins as refrigerants, there are advantages of low GWP and high refrigerating capacity.
  • disproportionation reactions may occur under certain conditions.
  • the disproportionation reaction is known as a reaction in which radicals are generated from molecules contained in a refrigerant, and self-decomposition of the refrigerant progresses due to a chain reaction. When a disproportionation reaction occurs, it causes a sudden pressure increase in the refrigeration cycle.
  • the specific conditions under which the disproportionation reaction can occur include the refrigerant being at a high temperature, the refrigerant being under high pressure, and the refrigerant being exposed to an electrical discharge phenomenon.
  • the disproportionation reaction of the refrigerant can be prevented or suppressed by eliminating or preventing any of high temperature, high pressure, and discharge phenomena.
  • a typical example of a discharge phenomenon that induces a disproportionation reaction is a short circuit that occurs between stator windings of stator 111 in electric motor 110. This type of short circuit is called a layer short or a layer short.
  • the air conditioner 1 of this embodiment includes a configuration that suppresses the disproportionation reaction of the refrigerant.
  • Compressor 100 is of internal low pressure type. Therefore, since the refrigerant pressure inside the container 102 is equal to the pressure on the suction side of the compression mechanism 120, the refrigerant is unlikely to reach a high temperature and high pressure state in and around the electric motor 110. Therefore, even if a layer short occurs in the electric motor 110, a disproportionation reaction of the refrigerant is unlikely to be induced.
  • the refrigerant sucked in from the suction port 104 passes through the air gap between the stator 111 and the rotor 112 and reaches the compression mechanism 120, so the temperature of the electric motor 110 increases due to the refrigerant passing through the air gap. is suppressed. Therefore, the electric motor 110 and the refrigerant around it are unlikely to reach a high temperature and high pressure state, so even if a layer short occurs in the electric motor 110, a disproportionation reaction of the refrigerant is unlikely to be induced.
  • the air conditioner 1 includes a pipe 43 and an injection section 125 that supply liquid refrigerant to the compression chamber of the compressor 100.
  • the control device 10 opens the valve 16 when the temperature of the compressor 100 satisfies a preset condition, and causes the injection section 125 to supply refrigerant.
  • the preset condition is, for example, that the temperature of the compressor 100 is equal to or higher than a threshold value.
  • the temperature of the compressor 100 is the temperature of the electric motor 110 or the temperature of the refrigerant discharged from the compression mechanism 120.
  • the control device 10 opens the valve 16 when detecting that the temperature of the electric motor 110 or the temperature of the refrigerant discharged from the compression mechanism 120 exceeds a threshold value. Thereby, the compression mechanism 120 can be cooled, and the disproportionation reaction can be suppressed.
  • the valve 16 when the valve 16 is opened, the pressure of the refrigerant in the gas-liquid separator 15 is reduced as the refrigerant flows out from the gas-liquid separator 15 to the pipe 43, and the refrigerant is expanded in the gas-liquid separator 15. can be done.
  • the gas-liquid separator 15 functions as a type of heat exchanger, and therefore, the gas-liquid separator 15 can be called an intercooler, for example. Due to this action, the refrigerant discharged from the compressor 100 is depressurized in two stages in the expansion valve 14 and the gas-liquid separator 15 when the air conditioner 1 is in a cooling operation state. That is, the expansion valve 14 and the gas-liquid separator 15 constitute a two-stage expansion mechanism.
  • the region where the refrigerant becomes high temperature and high pressure in the cooling operation state is the region indicated by the symbol HP in FIG. 1 . Since the expansion valve 14 and the gas-liquid separator 15 constitute a two-stage expansion mechanism, the region HP can be limited to a narrow range. Therefore, even if a refrigerant disproportionation reaction occurs, the range in which the refrigerant chain reaction propagates can be narrowed. Furthermore, by configuring a two-stage expansion process, the temperature of the compression mechanism 120 can be lowered, and the disproportionation reaction can be suppressed more effectively.
  • the air conditioner 1 can control the opening and closing of the valve 16 by the control device 10, and for example, closes the valve 16 in a state where the possibility of a disproportionation reaction occurring is low. Therefore, the operating efficiency of the air conditioner 1 can be improved.
  • the air conditioner 1 includes a relief valve 60. Therefore, even if a disproportionation reaction occurs, the relief valve 60 opens in response to the increase in refrigerant pressure accompanying the disproportionation reaction, thereby preventing an excessive increase in pressure in the refrigeration cycle.
  • the disproportionation reaction of the refrigerant is suppressed.
  • a refrigerant containing an inert disproportionation inhibitor suppresses the disproportionation reaction of ethylene-based fluoroolefins due to its thermodilution effect.
  • certain disproportionation inhibitors scavenge radicals, which are active intermediates produced in disproportionation reactions. Thereby, it is possible to prevent a chain reaction by trapping radicals generated in the initial stage of the reaction, and to suppress the propagation of the chain reaction. These effects can suppress the disproportionation reaction of the refrigerant.
  • control by control device Here, a description will be given of control by which the control device 10 suppresses the disproportionation reaction of the refrigerant. As described above, the control device 10 controls the opening of the valve 16 when the temperature of the compressor 100 satisfies a preset condition. Further, the control device 10 suppresses the disproportionation reaction by operating the four-way valves 21, 22 and other valves.
  • FIG. 4 is a flowchart showing the operation of the control device 10.
  • the control device 10 monitors whether the refrigerant pressure in the high pressure section of the air conditioner 1 has increased to a threshold value or more (step S11).
  • the high-pressure section is a range in which high-pressure refrigerant flows in the air conditioner 1, and includes, for example, any one of the compression mechanism 120, the discharge pipe 105, and the region HP shown in FIG.
  • the control device 10 determines the pressure of the refrigerant discharged from the compression mechanism 120.
  • step S11 If the pressure is lower than the threshold (step S11; NO), the control device 10 continues monitoring in step S11 at predetermined time intervals.
  • the threshold value is set in advance in the control device 10.
  • the threshold value is the pressure at which the refrigerant disproportionation reaction in the compressor 100 is estimated to have occurred, or the value of the pressure at which the disproportionation reaction is likely to occur. If the control device 10 determines that the pressure of the refrigerant discharged from the compressor 100 has increased above the threshold value (step S11; YES), there is a possibility that a refrigerant disproportionation reaction has occurred in the high pressure section of the air conditioner 1. is high. In this case, although not shown in FIG. 4, the control device 10 does not perform control to open the valve 16 and cause the refrigerant to flow from the injection section 125 into the compression mechanism 120. Furthermore, the control device 10 may perform control to close the valve 16.
  • control device 10 determines whether the air conditioner 1 is in heating operation (step S12). When the air conditioner 1 is in heating operation (step S12; YES), the control device 10 operates the four-way valve 21 and the four-way valve 22 to switch the air conditioner 1 to cooling operation (step S13).
  • control device 10 controls the valve to be controlled. Control is performed to close the opening to the first opening degree (step S14). In step S14, the control device 10 closes at least the expansion valve 14 to the first opening degree. The control device 10 may perform control to close the expansion valves 12a and 12b to the first opening degree in step S14.
  • the first opening degree is a predetermined opening degree at which the valve is in an open state rather than a fully closed state.
  • the first opening degree may be a value set corresponding to each valve, or may be a set value common to all valves. For example, when fully opening is 100%, the first opening degree can be 10%.
  • the control device 10 closes the valve, propagation of the disproportionation reaction beyond the valve can be suppressed. Further, if the valve is fully closed, the pressure increase due to the disproportionation reaction may change more rapidly, so it is effective to set the valve to the first opening degree instead of fully closing the valve.
  • the control device 10 monitors whether the increase in pressure in the high pressure section has stopped (step S15). If the increase in pressure has not stopped (step S15; NO), monitoring in step S15 is continued at predetermined time intervals. If it is determined that the increase in pressure has stopped (step S15; YES), the control device 10 performs control to close the valve, which was closed to the first opening degree in step S14, to a fully closed state (step S16). After that, the control device 10 executes notification (step S17).
  • the notification in step S17 is not limited as long as it can notify the administrator of the air conditioner 1 of the occurrence of the disproportionation reaction.
  • the control device 10 may notify the device that manages the air conditioner 1 of the occurrence of the disproportionation reaction, or cause the display of the remote control device that operates the air conditioner 1 to display the occurrence of the disproportionation reaction.
  • the display may be displayed on a display included in the indoor unit of the air conditioner 1.
  • sounds and images may be output under the control of the control device 10.
  • the control device 10 may stop the compressor 100 at any of steps S12 to S16.
  • step S11 and step S15 described above the control device 10 estimates the pressure of the refrigerant discharged from the compressor 100 based on the temperature of the refrigerant discharged from the compressor 100 and the temperatures of the heat exchangers 11a, 11b and the heat exchanger 13. , the estimated pressure may be determined.
  • control device 10 determines the pressure of the refrigerant discharged from the compressor 100 in step S11 and step S15, but this is just an example.
  • the control device 10 may make the determination based on the temperature of the refrigerant discharged from the compressor 100, for example.
  • the control device 10 may directly detect the temperature of the refrigerant discharged from the compressor 100 using a temperature sensor, or may detect the temperature of the refrigerant discharged from the compressor 100 based on the pressure of the discharged refrigerant or the temperature of the heat exchangers 11a, 11b, and the heat exchanger 13.
  • the determination may be made based on the estimated temperature of the refrigerant discharged from the compressor 100.
  • the four-way valves 21 and 22 of the air conditioner 1 are constituted by low differential pressure operating type four-way valves or electromagnetic on-off valves.
  • pilot-type four-way switching valves are used as the four-way valves 21 and 22
  • the heating operation state can be quickly switched to the cooling operation state in step S13. It has the advantage of being carried out.
  • the air conditioner 1 of the first embodiment includes the compressor 100, the heat exchanger 13 which is the heat source side heat exchanger, and the heat exchangers 11a and 11b which are the usage side heat exchangers.
  • the air conditioner 1 includes four-way valves 21 and 22 that switch between a heating operation state in which the heat exchangers 11a and 11b operate as condensers and a cooling operation state in which the heat exchanger 13 operates as a condenser, and a control device 10. and.
  • the air conditioner 1 uses a working medium containing ethylene-based fluoroolefin as a refrigerant.
  • the control device 10 When the control device 10 detects that the pressure of the working medium in the high-pressure section including the compressor 100 and the condenser has increased to a threshold value or more in the heating operation state, the control device 10 controls the four-way valves 21 and 22 to return to the heating operation state. Switch from to cooling operation state. Thereby, the air conditioner 1 can realize a low GWP by using a working medium containing ethylene-based fluoroolefin. Further, the air conditioner 1 switches the air conditioner 1 from the heating operation state to the cooling operation when there is a possibility that a refrigerant disproportionation reaction has occurred, or when it is estimated that a disproportionation reaction has occurred. state to narrow the region HP through which high-pressure refrigerant flows.
  • the region HP where the pressure of the refrigerant rapidly increases due to the disproportionation reaction can be limited, and the influence of the disproportionation reaction on the refrigeration cycle can be suppressed.
  • the control of the control device 10 prevents or suppresses the influence of the disproportionation reaction from reaching the conditioned space. can.
  • the expansion mechanism includes an expansion valve 14 or expansion valves 12a, 12b located at the outlet of the condenser.
  • the air conditioner 1 includes a control device 10 that controls expansion valves 12a, 12b, and 14.
  • the control device 10 operates one of the expansion valves 12a, 12b, and 14 in the closing direction to a first opening degree when it is detected that the pressure of the working medium in the high-pressure part of the air conditioner 1 has increased to a threshold value or more. Then, when the pressure of the working medium in the high pressure section stops increasing, the expansion valve is operated in the closing direction to the second opening degree.
  • the second opening degree is, for example, a fully closed state.
  • the high pressure section includes, for example, a compressor 100 and a condenser.
  • the air conditioner 1 includes a relief valve 60 in a pipe 42 through which the compressor 100 discharges compressed refrigerant, which releases the pressure when the pressure in the pipe 42 is equal to or higher than a set pressure.
  • the compressor 100 includes a suction port 104 that sucks in a working medium, a compression mechanism 120 that compresses the working medium sucked from the suction port 104, and a compression mechanism that is connected to a different path from the suction port 104. and an injection section 125 that supplies a working medium to 120 .
  • the compressor 100 is an internal low-pressure type compressor in which a compression mechanism 120 is housed in a container 102 together with an electric motor 110, and the compression mechanism 120 sucks and compresses the working medium inside the container 102.
  • the condenser is the heat exchanger 13
  • the evaporator is the heat exchangers 11a and 11b.
  • the condenser is the heat exchanger 11a, 11b, and the evaporator is the heat exchanger 13.
  • the air conditioner 1 can realize a low GWP by using a working medium containing ethylene-based fluoroolefin.
  • a configuration in which the disproportionation reaction of the ethylene-based fluoroolefin is less likely to occur is realized. Therefore, disproportionation reactions can be suppressed when using a refrigerant with a low GWP.
  • the air conditioner 1 also includes a gas-liquid separator 15 disposed between the condenser and the evaporator, and a pipe 43 that sends a gaseous working medium from the gas-liquid separator 15 to the injection section 125.
  • the expansion mechanism constitutes a two-stage expansion process including an expansion valve 14 or expansion valves 12a, 12b disposed at the outlet of the condenser and operating as a first-stage pressure reduction mechanism, and a gas-liquid separator 15.
  • the region through which the high-pressure refrigerant flows in the air conditioner 1 can be limited to a narrow range, so it is possible to realize a configuration in which the disproportionation reaction of the refrigerant is difficult to propagate.
  • a temperature rise in the compression mechanism 120 can be suppressed and a configuration in which disproportionation reactions are less likely to occur can be realized.
  • the air conditioner 1 includes a pipe 41 that connects to the suction port 104 of the compressor 100 or a pipe 43 that allows a working medium to flow into a container 102 that accommodates the electric motor 110.
  • the air conditioner 1 includes a valve 16 that opens and closes the pipe 43 and a control device 10 that controls the valve 16.
  • the control device 10 controls the valve 16 to be opened when the temperature of the compression mechanism 120 satisfies preset conditions.
  • the temperature of the compression mechanism 120 satisfies preset conditions
  • the refrigerant is extracted from the gas-liquid separator 15 through the pipe 43, thereby reducing the pressure of the refrigerant in the gas-liquid separator 15, and separating the gas and liquid.
  • the refrigerant can be expanded in the vessel 15. Therefore, the gas-liquid separator 15 can act as an intercooler, and a two-stage expansion process can be configured in the expansion valve 14 and the gas-liquid separator 15.
  • the air conditioner 1 includes a heat exchanger 13 that is a heat source side heat exchanger, and heat exchangers 11a and 11b that are usage side heat exchangers.
  • the air conditioner 1 includes four-way valves 21 and 22 that switch between a heating operating state in which the heat exchangers 11a and 11b operate as condensers and a cooling operating state in which the heat exchanger 13 operates as a condenser.
  • the control device 10 detects that the pressure of the working medium in the high-pressure section including the compressor 100 and the condenser has increased to a threshold value or more in the heating operation state, the control device 10 controls the four-way valves 21 and 22 to return to the heating operation state. Switch from to cooling operation state.
  • the four-way valves 21 and 22 may be configured with a low differential pressure operated four-way valve or an electromagnetic on-off valve. In this case, when it is estimated that a disproportionation reaction has occurred in the high pressure section of the air conditioner 1 in the heating operating state, it is possible to quickly switch to the cooling operating state.
  • FIG. 5 is a diagram showing the configuration of the air conditioner 2 in the second embodiment.
  • the air conditioner 2 shown in FIG. 5 is an example to which the refrigeration circuit of the present invention is applied.
  • the air conditioner 2 has a compressor 200.
  • the compressor 200 is a two-stage compressor that includes a first compressor 100A and a second compressor 100B.
  • the first compressor 100A and the second compressor 100B do not include the injection section 125, but have the same configuration as the compressor 100 except for this point.
  • the first compressor 100A and the second compressor 100B have the same suction port 104 as the compressor 100, and the suction port 104 of the first compressor 100A corresponds to an example of the suction part of the entire compressor 200. do.
  • description of the configurations of the first compressor 100A and the second compressor 100B will be omitted.
  • the first compressor 100A is connected to the pipe 41, compresses the gaseous refrigerant supplied from the pipe 41, and discharges the compressed refrigerant to the connecting pipe 201.
  • the connecting pipe 201 is a pipe that connects the discharge side of the first compressor 100A and the suction side of the second compressor 100B.
  • the second compressor 100B sucks refrigerant from the connecting pipe 201, compresses it, and discharges the compressed high-pressure refrigerant to the pipe 42.
  • the first compressor 100A is a first-stage compressor and corresponds to an example of a first compression mechanism.
  • the second compressor 100B is a second stage compressor and corresponds to an example of a second compression mechanism.
  • a pipe 43 is connected to the connecting pipe 201 at the injection section 202.
  • the valve 16 is open, the refrigerant flows out from the gas-liquid separator 15 to the pipe 43, reducing the pressure of the refrigerant in the gas-liquid separator 15, and causing the refrigerant to flow into the gas-liquid separator 15.
  • the gas-liquid separator 15 functions as a type of heat exchanger. Due to this action, the pressure of the refrigerant is reduced in two stages in the expansion valve 14 and the gas-liquid separator 15 when the air conditioner 2 is in the cooling operation state. That is, the expansion valve 14 and the gas-liquid separator 15 constitute a two-stage expansion mechanism.
  • the region where the refrigerant becomes high temperature and high pressure in the cooling operation state is a high pressure section of the air conditioner 2 and includes any one of the compressor 200, the pipes 42 and 46, and the four-way valve 21. Since the expansion valve 14 and the gas-liquid separator 15 constitute a two-stage expansion mechanism, the region HP can be limited to a narrow range. Therefore, even if a refrigerant disproportionation reaction occurs, the range in which the refrigerant chain reaction propagates can be narrowed. Furthermore, by configuring a two-stage expansion process, the temperature of the compression mechanism 120 can be lowered, and the disproportionation reaction can be suppressed more effectively.
  • the injection unit 202 corresponds to an example of a refrigerant supply unit.
  • the four-way valve 21 and the four-way valve 22 are connected to the control device 20.
  • the four-way valve 21 and the four-way valve 22 operate under the control of the control device 20 to switch the air conditioner 2 between a cooling operation state and a heating operation state.
  • the compressor 200 may be a compound type compressor that accommodates a first compression mechanism in the first stage and a second compression mechanism in the second stage in one container. In this case, if the pipe 43 is connected to the suction side of the second compression mechanism, the same effect as the air conditioner 2 shown in FIG. 4 can be expected.
  • the refrigerant used in the air conditioner 2 is the working medium described as the refrigerant of the air conditioner 1 in the first embodiment. That is, the air conditioner 2 uses a working medium containing ethylene-based fluoroolefin as a refrigerant.
  • This working medium may include two or more refrigerant components.
  • the working medium used as a refrigerant in the air conditioner 2 may include a disproportionation inhibitor in addition to the refrigerant component.
  • the working medium may include a plurality of disproportionation inhibitors selected from saturated hydrocarbons and haloalkanes. Further, the working medium may contain one type of saturated hydrocarbon or may contain two or more types of saturated hydrocarbons. Further, the working medium may contain one type of haloalkane, or may contain two or more types of haloalkanes.
  • a preferred example of the working medium is a mixture containing 1,1,2-trifluoroethylene and n-propane, and containing unavoidable impurities.
  • This working medium may contain the second refrigerant component described above, or may contain other components.
  • the air conditioner 2 includes a control device 20.
  • the control device 20 includes a processor such as a microcontroller.
  • the control device 10 controls the air conditioner 2 by executing a program using a processor or by using programmed hardware functions.
  • the control device 20 is connected to a four-way valve 21 and a four-way valve 22.
  • the four-way valve 21 switches connections between the pipes 41 , 42 , 44 , and 46 under the control of the control device 20 .
  • the four-way valve 22 switches connections between the pipes 45 , 47 , 48 , and 49 under the control of the control device 20 .
  • the control device 20 operates the four-way valve 21 and the four-way valve 22 to switch between the cooling operation state and the heating operation state. That is, when the air conditioner 2 performs cooling operation, the control device 20 connects the piping 41 and the piping 44 and connects the piping 42 and the piping 46 using the four-way valve 21. Further, the control device 20 connects the piping 48 and the piping 45 and connects the piping 47 and the piping 49 using the four-way valve 22. When the air conditioner 2 performs heating operation, the control device 20 connects the piping 41 and the piping 46 and connects the piping 42 and the piping 44 using the four-way valve 21. Further, the control device 20 connects the piping 49 and the piping 45 and connects the piping 47 and the piping 48 using the four-way valve 22.
  • the expansion valves 12a, 12b, the expansion valve 14, and the valve 16 are connected to the control device 20.
  • the control device 20 fully opens the expansion valve 14 in the cooling operation state and adjusts the opening degrees of the expansion valves 12a and 12b.
  • the control device 20 fully opens the expansion valves 12a and 12b in the heating operation state, and adjusts the opening degree of the expansion valve 14.
  • the air conditioner 2 includes a temperature sensor (not shown) that detects the temperature of the electric motor of the first compressor 100A and/or the electric motor of the second compressor 100B, and a temperature sensor (not shown) that detects the temperature of the refrigerant discharged by the second compressor 100B. It may also include one or more of the following: a temperature sensor (not shown); These temperature sensors are connected to the control device 20.
  • the control device 20 detects either or both of the temperature of the electric motor and the temperature of the refrigerant discharged by the second compressor 100B by acquiring the detected value of the temperature sensor. Further, the control device 20 may calculate the pressure of the refrigerant discharged by the second compressor 100B based on the temperature of the refrigerant discharged by the second compressor 100B.
  • the air conditioner 2 may include a pressure sensor that detects the pressure of the refrigerant discharged by the second compressor 100B. Additionally, the air conditioner 2 may include a heat exchanger temperature sensor (not shown) that detects the temperatures of the heat exchangers 11a, 11b, and the heat exchanger 13. In this case, the control device 20 may calculate the pressure and temperature of the refrigerant discharged by the second compressor 100B based on the detected value of the heat exchanger temperature sensor. Good too.
  • the control device 20 executes control to open and close the valve 16.
  • the valve 16 is composed of an electric valve, a solenoid valve, or an expansion valve.
  • the control device 20 controls opening and closing of the valve 16 and adjusts the degree of opening of the valve 16.
  • the air conditioner 2 suppresses the disproportionation reaction of the refrigerant under the control of the control device 20 .
  • the control device 20 performs control to open the valve 16 when the temperature of the electric motor or the temperature of the refrigerant discharged from the second compressor 100B exceeds a threshold value. Further, the control device 20 suppresses the disproportionation reaction by operating the four-way valves 21, 22 and other valves.
  • the control device 20 executes the operation described with reference to FIG. 4, for example.
  • the control device 20 executes control to switch the air conditioner 2 from the heating operation state to the cooling operation state when the refrigerant pressure in the high pressure section of the air conditioner 2 increases to a threshold value or more.
  • the high pressure parts of the air conditioner 2 are, for example, the second compressor 100B, the piping 42, and the like.
  • control device 20 when the air conditioner 2 is in the cooling operation and when the air conditioner 2 is switched from the heating operation state to the cooling operation state, the control device 20 performs control to close the valve to be controlled to the first opening degree. I do. Then, when the pressure in the high pressure section stops increasing, the control device 20 performs control to close the valve that has been closed to the first opening degree to a fully closed state. After that, the control device 20 executes the notification. While performing these controls, the control device 20 may stop the compressor 200.
  • the air conditioner 2 of the second embodiment responds to the disproportionation reaction in the refrigeration cycle when the refrigerant disproportionation reaction occurs. The impact of this can be suppressed. That is, the air conditioner 2 includes a compressor 200, a heat exchanger 13 that is a heat source side heat exchanger, heat exchangers 11a and 11b that are usage side heat exchangers, and an expansion mechanism.
  • the air conditioner 2 includes four-way valves 21 and 22 that switch between a heating operating state in which the heat exchangers 11a and 11b operate as condensers and a cooling operating state in which the heat exchanger 13 operates as a condenser, and a control device 20.
  • the air conditioner 2 uses a working medium containing ethylene-based fluoroolefin as a refrigerant.
  • the control device 20 detects that the pressure of the working medium in the high-pressure section including the compressor 200 and the condenser has increased to a threshold value or more in the heating operation state, the control device 20 controls the four-way valves 21 and 22 to return to the heating operation state. Switch from to cooling operation state.
  • the air conditioner 2 achieves low GWP by using a working medium containing ethylene-based fluoroolefins.
  • the air conditioner 2 switches the air conditioner 2 from the heating operation state to the cooling operation when there is a possibility that a refrigerant disproportionation reaction has occurred, or when it is estimated that a disproportionation reaction has occurred. state to narrow the region HP through which high-pressure refrigerant flows. Thereby, the region where the pressure of the refrigerant rapidly increases due to the disproportionation reaction can be limited, and the influence of the disproportionation reaction can be suppressed.
  • the expansion mechanism of the air conditioner 2 includes an expansion valve 14 or expansion valves 12a, 12b arranged at the outlet of the condenser.
  • the control device 20 controls the expansion valves 12a, 12b, and 14.
  • the control device 20 operates one of the expansion valves 12a, 12b, and 14 in the closing direction to a first opening degree when it is detected that the pressure of the working medium in the high-pressure part of the air conditioner 2 has increased to a threshold value or more. Then, when the pressure of the working medium in the high pressure section stops increasing, the expansion valve is operated in the closing direction to the second opening degree.
  • the second opening degree is, for example, a fully closed state.
  • the high pressure section includes, for example, a compressor 100 and a condenser.
  • the air conditioner 2 includes a relief valve 60 in a pipe 42 through which the compressor 200 discharges compressed refrigerant, which releases the pressure when the pressure in the pipe 42 is equal to or higher than a set pressure.
  • the compressor 200 includes a suction port 104 that sucks a working medium, a first compressor 100A that compresses the working medium sucked from the suction port 104, and a first compressor 100A that compresses the working medium.
  • This is a two-stage compressor including a second compressor 100B that compresses the working medium.
  • the air conditioner 2 includes an injection section 202 that supplies a working medium between the first compressor 100A and the second compressor 100B. As a result, the air conditioner 2 can achieve low GWP by using a working medium containing ethylene-based fluoroolefins.
  • the injection unit 202 supplies refrigerant to the connecting pipe 201 between the first compressor 100A and the second compressor 100B, thereby lowering the temperature of the refrigerant discharged from the compressor 200. Achieve a configuration in which disproportionation reactions are less likely to occur. Therefore, disproportionation reactions can be suppressed when using a refrigerant with a low GWP. Furthermore, by using the two-stage compressor 200, the air conditioner 2 can suppress the compression ratio of each of the first compressor 100A and the second compressor 100B. Therefore, it is possible to reduce compression loss and the load on the electric motor of the compressor 200, and it can be expected to suppress a rise in the temperature of the electric motor.
  • control device 20 detects that the pressure of the working medium in the high pressure section has increased to a threshold value or more in the heating operation state of the air conditioner 2, the control device 20 controls the four-way valves 21 and 22 to change the heating operation state to the cooling state. Switch to operating state.
  • the control device 20 controls the four-way valves 21 and 22 to change the heating operation state to the cooling state. Switch to operating state.
  • the region through which the high-pressure refrigerant flows can be restricted by switching to the cooling operation state.
  • propagation of the disproportionation reaction can be suppressed.
  • high-pressure refrigerant does not flow to the heat exchangers 11a and 11b, which are the utilization side heat exchangers, so that the influence of the disproportionation reaction can be avoided from reaching the conditioned space.
  • the air conditioner 2 includes a pipe 43 that allows the working medium to flow into the injection section 202 from the gas-liquid separator 15 .
  • the air conditioner 2 includes a valve 16 that opens and closes the pipe 43 and a control device 20 that controls the valve 16.
  • the control device 20 controls the valve 16 to be opened when the temperature of the compressor 200 satisfies preset conditions.
  • the refrigerant is extracted from the gas-liquid separator 15 through the pipe 43, thereby reducing the pressure of the refrigerant in the gas-liquid separator 15, and separating the gas and liquid.
  • the refrigerant can be expanded in the vessel 15.
  • the gas-liquid separator 15 can act as an intercooler, and a two-stage expansion process can be configured in the expansion valve 14 and the gas-liquid separator 15. This makes it possible to eliminate a situation in which a disproportionation reaction is likely to occur in the compressor 200. Furthermore, when it is estimated that a disproportionation reaction has occurred in the compressor 200, the disproportionation reaction can be suppressed or stopped.
  • FIG. 6 is a diagram showing the configuration of an air conditioner 1A in the third embodiment.
  • An air conditioner 1A shown in FIG. 6 is an example to which the refrigeration circuit of the present invention is applied.
  • the air conditioner 1A has a configuration in which a pipe 55 and a valve 56 are added to the air conditioner 1 described with reference to FIGS. 1 to 4.
  • the configuration of each part except for the piping 55 and the valve 56 is the same as the configuration described in Embodiment 1, so the same reference numerals are given and the explanation will be omitted.
  • the pipe 55 is a refrigerant pipe that connects the pipe 48 and the pipe 41.
  • a valve 56 is provided in the pipe 55.
  • the valve 56 is composed of, for example, a solenoid valve, and opens and closes under the control of the control device 10.
  • the valve 56 may be a solenoid valve.
  • the control device 10 can adjust the opening degree of the valve 56 in addition to opening and closing the valve 56.
  • Piping 55 corresponds to an example of a motor cooling circuit
  • valve 56 corresponds to an example of a motor cooling valve.
  • refrigerant flows through the pipe 55 from the pipe 48 to the pipe 41.
  • the refrigerant flowing through the pipe 55 is a liquid refrigerant flowing from the gas-liquid separator 15 to the pipe 48 .
  • This refrigerant passes through the pipe 41 and reaches the suction port 104, and is supplied into the container 102.
  • liquid refrigerant is supplied to the electric motor 110 from the suction port 104.
  • This refrigerant cools the electric motor 110 in the process of being sucked into the compression mechanism 120 through the suction port 104.
  • Piping 55 may be directly connected to container 102 containing electric motor 110.
  • the temperature of the electric motor 110 can be lowered by supplying liquid refrigerant from the pipe 55 to the container 102.
  • the electric motor 110 can be cooled more effectively.
  • control device 10 executes the opening/closing control of the valve 16 described above and the control shown in FIG. 4.
  • control device 10 controls the valve 56 to be opened when the temperature of the compressor 100 satisfies a preset condition.
  • the preset condition is, for example, a temperature threshold of the compressor 100. Specifically, it is the temperature of the compressor 100 or the temperature of the refrigerant discharged from the compression mechanism 120.
  • the control device 10 opens the valve 56 when the temperature of the electric motor 110 or the temperature of the refrigerant discharged from the compression mechanism 120 exceeds a threshold value. By opening the valve 56, the control device 10 can supply liquid refrigerant to the electric motor 110 and lower the temperature of the electric motor 110. Thereby, the electric motor 110 can be cooled and the disproportionation reaction can be suppressed.
  • the air conditioner 1A controls the pipe 55 that allows liquid working medium to flow into the container 102 of the compressor 100 through the pipe 41, the valve 56 that opens and closes the pipe 55, and the valve 56.
  • a control device 10 is provided.
  • the control device 10 controls the valve 56 to be opened when the temperature of the compressor 100 satisfies preset conditions.
  • the electric motor 110 can be cooled by the liquid refrigerant.
  • the electric motor 110 reaches a high temperature and is in a state where a refrigerant disproportionation reaction is likely to occur, or when a refrigerant disproportionation reaction is estimated to occur, the electric motor 110 is cooled. can. Therefore, the disproportionation reaction of the refrigerant can be suppressed or stopped.
  • FIG. 7 is a diagram showing the configuration of an air conditioner 2A in Embodiment 4.
  • An air conditioner 2A shown in FIG. 7 is an example to which the refrigeration circuit of the present invention is applied.
  • the air conditioner 2A has a configuration in which the air conditioner 2 described with reference to FIG. 5 is provided with a pipe 57, a valve 58, and a valve 59.
  • the configuration of each part other than the piping 57, valve 58, and valve 59 is the same as the configuration described in the second embodiment, so the same reference numerals are given and the explanation will be omitted.
  • One end of the pipe 57 is connected to the pipe 48, and liquid refrigerant flows from the gas-liquid separator 15 to the pipe 57.
  • the pipe 57 branches into two branches at a branching portion 205 .
  • the pipe 57 is connected to the connecting pipe 201 at the connecting part 203 and to the pipe 41 at the connecting part 204.
  • a valve 58 is provided between the branch section 205 and the connection section 203, and a valve 59 is provided between the branch section 205 and the connection section 204.
  • the valves 58 and 59 are each formed of, for example, a solenoid valve, and are opened and closed under the control of the control device 20.
  • the valves 58 and 59 may be constituted by electromagnetic valves.
  • the control device 20 can adjust the opening degree of each of the valves 58 and 59 in addition to opening and closing the valves 58 and 59.
  • the pipe 57 corresponds to an example of a motor cooling circuit
  • the valves 58 and 59 correspond to an example of a motor cooling valve.
  • control device 20 executes the opening/closing control of the valve 16 described above and the control shown in FIG. 4, as described in the second embodiment.
  • control device 20 controls the valves 58 and 59 to be opened when the temperature of the compressor 200 satisfies preset conditions.
  • the preset condition is, for example, a temperature threshold of the compressor 200. Specifically, it is the temperature of the electric motor included in the first compressor 100A and/or the electric motor included in the second compressor 100B, or the temperature of the refrigerant discharged from the first compressor 100A and/or the second compressor 100B. .
  • the control device 20 opens the valve 58 when the temperature of the electric motor of the second compressor 100B or the temperature of the refrigerant discharged from the second compressor 100B exceeds a threshold value.
  • the control device 20 can cause the second compressor 100B to suck liquid refrigerant, thereby lowering the temperature of the electric motor of the second compressor 100B and the refrigerant discharged from the second compressor 100B.
  • the control device 20 opens the valve 59 when the temperature of the electric motor of the first compressor 100A or the temperature of the refrigerant discharged from the first compressor 100A exceeds a threshold value.
  • the control device 20 can cause the first compressor 100A to suck liquid refrigerant, thereby lowering the temperature of the electric motor of the first compressor 100A and the refrigerant discharged from the first compressor 100A.
  • the compressor 200 can be cooled to suppress or prevent the disproportionation reaction.
  • the air conditioner 2A of the fourth embodiment includes the pipe 57 that allows liquid working medium to flow into the compressor 200 through the pipe 43, the valves 58 and 59 that open and close the pipe 57, and the valves 58 and 59. and a control device 20 for controlling.
  • the control device 20 controls the valves 58 and 59 to be opened when the temperature of the compressor 200 satisfies preset conditions. Thereby, the compressor 200 can be cooled by allowing the refrigerant to flow into the compressor 200 through the pipe 43.
  • the electric motor of the first compressor 100A or the second compressor 100B reaches a high temperature and is in a state where a refrigerant disproportionation reaction is likely to occur, or it is estimated that a refrigerant disproportionation reaction is likely to occur. If this occurs, the motor can be cooled down. Therefore, the disproportionation reaction of the refrigerant can be suppressed or stopped.
  • FIG. 8 is a diagram showing the configuration of the air conditioner 3 in the fifth embodiment.
  • the air conditioner 3 shown in FIG. 8 is an example to which the refrigeration circuit of the present invention is applied.
  • the air conditioner 3 has a configuration common to a part of the air conditioner 1 described with reference to FIGS. 1 to 4. These common configurations are given the same reference numerals as those in Embodiment 1, and a description thereof will be omitted.
  • the present disclosure is applicable not only to the air conditioners 1, 1A, 2, and 2A of Embodiments 1 to 4 described above, but also to a refrigeration system that can switch between cooling operation and heating operation.
  • the air conditioner 3 corresponds to an example of this type of refrigeration device.
  • the air conditioner 3 includes heat exchangers 11a and 11b as usage side heat exchangers, expansion valves 12a and 12b provided in piping connected to the heat exchangers 11a and 11b, and a heat exchanger as a heat source side heat exchanger. 13 and an expansion valve 14 provided in a pipe 47 connected to the heat exchanger 13.
  • the air conditioner 3 also includes a compressor 100 and a four-way valve 21 that switches between the heat exchangers 11a, 11b or the heat exchanger 13 and connects to the piping 42 on the discharge side of the compressor 100.
  • the air conditioner 3 includes a control device 10A that controls the four-way valve 21.
  • the control device 10A like the control device 10, includes a processor such as a microcontroller.
  • the control device 10A controls the air conditioner 3 by executing a program using a processor or by using programmed hardware functions.
  • the control device 10A controls the four-way valve 21 to switch between a cooling operation state and a heating operation state.
  • control device 10A uses the four-way valve 21 to connect a pipe 42 through which the compressor 100 discharges high-pressure refrigerant to a pipe 46 connected to the heat exchanger 13, and a pipe 44 connected to the heat exchangers 11a and 11b. It is connected to the suction side piping 41 of the compressor 100. Thereby, the air conditioner 3 executes the cooling operation. During cooling operation, high-pressure refrigerant discharged from the compressor 100 is condensed in the heat exchanger 13 and sent to the heat exchangers 11a and 11b via the expansion valves 12a and 12b.
  • FIG. 8 shows the cooling operation state of the air conditioner 3.
  • the high pressure section HP includes, for example, a compressor 100, a pipe 42 through which a high pressure refrigerant flows, a four-way valve 21, and a heat exchanger 13.
  • the air conditioner 3 When the air conditioner 3 performs heating operation under the control of the control device 10A, the high-pressure refrigerant discharged by the compressor 100 is condensed in the heat exchangers 11a and 11b, and is transferred to the heat exchanger 13 via the expansion valve 14. Sent. This refrigerant is depressurized by the expansion valve 14, evaporated in the heat exchanger 13, and sucked into the compressor 100 through the pipe 41.
  • the region HP includes the compressor 100, the piping 42, the four-way valve 21, and the heat exchangers 11a and 11b.
  • the air conditioner 3 performs a cooling operation in which the heat exchanger 13 is operated as a condenser, and a cooling operation in which the heat exchanger 11a and 11b are operated as a condenser and the heat exchanger 13 is operated as an evaporator.
  • This is a refrigeration system that can switch between heating operation and heating operation using a four-way valve 21.
  • the air conditioner 3 may include one or more of a temperature sensor (not shown) that detects the temperature of the electric motor 110 and a temperature sensor (not shown) that detects the temperature of the refrigerant discharged by the compression mechanism 120. These temperature sensors are connected to the control device 10A.
  • the control device 10A detects either or both of the temperature of the electric motor 110 and the temperature of the refrigerant discharged by the compression mechanism 120 by acquiring the detected value of the temperature sensor. Further, the control device 10A may calculate the pressure of the refrigerant discharged by the compression mechanism 120 based on the temperature of the refrigerant discharged by the compression mechanism 120.
  • the air conditioner 3 may include a pressure sensor that detects the pressure of the refrigerant discharged by the compression mechanism 120.
  • the air conditioner 3 may include a heat exchanger temperature sensor (not shown) that detects the temperatures of the heat exchangers 11a, 11b and the heat exchanger 13.
  • the control device 10A may calculate the pressure and temperature of the refrigerant discharged by the compression mechanism 120 based on the detected value of the heat exchanger temperature sensor, or may be configured without the temperature sensor described above. .
  • the control device 10A executes the control shown in FIG. 4 similarly to the control device 10. That is, when the control device 10A detects that the pressure of the refrigerant in the high pressure portion HP has increased to a threshold value or more during the heating operation of the air conditioner 3, the control device 10A switches the air conditioner 3 to the cooling operation.
  • the air conditioner 3 includes the compressor 100, the heat exchanger 13 which is a heat source side heat exchanger, the heat exchangers 11a and 11b which are usage side heat exchangers, and an expansion mechanism.
  • the air conditioner 3 includes a four-way valve 21 that switches between a heating operation state in which the heat exchangers 11a and 11b operate as a condenser and a cooling operation state in which the heat exchanger 13 operates as a condenser, and a control device 10A. Equipped with The air conditioner 3 uses a working medium containing ethylene-based fluoroolefin as a refrigerant.
  • the control device 10A When the control device 10A detects that the pressure of the working medium in the high-pressure section including the compressor 100 and the condenser has increased to a threshold value or more in the heating operation state, the control device 10A controls the four-way valve 21 to switch from the heating operation state to the cooling state. Switch to operating state.
  • the air conditioner 3 can realize a low GWP by using a working medium containing ethylene-based fluoroolefin. Further, the air conditioner 3 switches the air conditioner 3 from the heating operation state to the cooling operation when there is a possibility that a refrigerant disproportionation reaction has occurred, or when it is estimated that a disproportionation reaction has occurred. state to narrow the region HP through which high-pressure refrigerant flows.
  • the region HP where the pressure of the refrigerant rapidly increases due to the disproportionation reaction can be limited, and the influence of the disproportionation reaction on the refrigeration cycle can be suppressed.
  • the control of the control device 10A prevents or suppresses the influence of the disproportionation reaction from reaching the conditioned space. can.
  • the expansion mechanism includes an expansion valve 14 or expansion valves 12a, 12b located at the outlet of the condenser.
  • the air conditioner 3 includes a control device 10A that controls the expansion valves 12a, 12b, and 14.
  • the control device 10A operates one of the expansion valves 12a, 12b, and 14 in the closing direction to a first opening degree when it is detected that the pressure of the working medium in the high-pressure part of the air conditioner 3 has increased to a threshold value or more. Then, when the pressure of the working medium in the high pressure section stops increasing, the expansion valve is operated in the closing direction to the second opening degree.
  • the second opening degree is, for example, a fully closed state.
  • the high pressure section includes, for example, a compressor 100 and a condenser.
  • the pipe 42 through which the compressor 100 discharges the compressed refrigerant is provided with a relief valve 60 that releases the pressure when the pressure in the pipe 42 is equal to or higher than the set pressure. You can. In this case, when the pressure in the pipe 42 suddenly increases due to the occurrence of the disproportionation reaction, the pressure in the pipe 42 can be released, and the influence of the disproportionation reaction can be reduced.
  • the relief valve 60 also called an overflow valve
  • the pressure release means may be a rupture disk that ruptures to release the pressure when the pressure in the pipe 42 exceeds a set pressure.
  • the compressor 100, the first compressor 100A, and the second compressor 100B in the embodiments described above are not limited to scroll compressors, but may be rotary compressors, or reciprocating compressors. It may be.
  • the air conditioner 1 may include a temperature sensor that detects the temperature of the heat exchangers 11a, 11b, and 13, and the same applies to the air conditioners 1A, 2, and 2A.
  • the air conditioners 1 and 1A may include a refrigerant temperature sensor that detects the temperature of the refrigerant discharged by the compressor 100.
  • the air conditioners 2 and 2A may include a refrigerant temperature sensor that detects the temperature of the refrigerant discharged by the compressor 200. These sensors may be connected to the control devices 10, 20 as appropriate so that the control devices 10, 20 can acquire the detected values of the sensors.
  • a compressor A heat source side heat exchanger, a user side heat exchanger, an expansion mechanism, a heating operation state in which the user side heat exchanger operates as a condenser, and a heating operation state in which the heat source side heat exchanger is operated as a condenser.
  • a switching valve that switches between a cooling operation state in which the condenser is operated and a control device; the control device uses a working medium containing ethylene-based fluoroolefin as a refrigerant;
  • the switching valve is controlled to switch from the heating operation state to the cooling operation state.
  • a refrigeration device characterized by the following.
  • the expansion mechanism includes an expansion valve disposed at the outlet of the condenser, and the control device causes the pressure of the working medium in a high-pressure section including the compressor and the condenser to rise to a threshold value or more.
  • the expansion valve is operated in the closing direction to a first opening degree, and then, when the pressure of the working medium in the high pressure section stops increasing, the expansion valve is operated to a second opening degree.
  • the refrigeration device according to technique 1 characterized in that the refrigeration device is operated in a closing direction.
  • the refrigeration system includes an air conditioner that cools and heats a space to be conditioned, a refrigeration system that includes a refrigerator or a freezer that has the function of switching between cooling and heating, and a refrigeration system that combines these. It can also be used for other purposes.
  • Air conditioning equipment (refrigeration equipment) 10, 10A, 20 Control device 11a, 11b Heat exchanger (user side heat exchanger) 12a, 12b expansion valve 13 heat exchanger (heat source side heat exchanger) 14 Expansion valve 15 Gas-liquid separator (refrigerant storage section) 16 Valve 20 Control device 21, 22 Four-way valve (switching valve) 41 Piping (suction piping) 42 Piping (discharge piping) 43 Piping (refrigerant piping) 44, 45, 46, 47, 48, 49 Piping 55, 57 Piping (motor cooling circuit) 56, 58, 59 valves (motor cooling valve) 60 Relief valve (pressure release means) 100, 200 compressor 102 container 103 crankshaft 104 suction port (suction part) 105 discharge pipe 107, 108 bearing 110 electric motor 111 stator 112 rotor 116 drive circuit 120 compression mechanism 125 injection section (refrigerant supply section) 100A 1st compressor (1st compression mechanism)

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)

Abstract

La présente invention supprime les effets provoqués dans un cycle de réfrigération lorsqu'une réaction de dismutation d'un fluide frigorigène se produit.　Un dispositif de réfrigération selon la présente divulgation comprend : un compresseur ; un échangeur de chaleur côté source de chaleur ; un échangeur de chaleur côté utilisation ; un mécanisme d'expansion ; une soupape de commutation qui commute entre un état de fonctionnement de chauffage pour faire fonctionner l'échangeur de chaleur côté utilisation en tant que condenseur et un état de fonctionnement de refroidissement pour faire fonctionner l'échangeur de chaleur côté source de chaleur en tant que condenseur ; et un dispositif de commande, un milieu de travail contenant une fluoro-oléfine à base d'éthylène étant utilisé en tant que fluide frigorigène et, lorsqu'il est détecté que, dans l'état de fonctionnement de chauffage, la pression du milieu de travail dans une partie haute pression qui comprend le compresseur et le condenseur a augmenté jusqu'à une valeur seuil ou plus, le dispositif de commande commande la soupape de commutation pour commuter de l'état de fonctionnement de chauffage à l'état de fonctionnement de refroidissement.
PCT/JP2023/015550 2022-04-28 2023-04-19 Dispositif de réfrigération WO2023210457A1 (fr)

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JP2022-074973 2022-04-28

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4846771A (fr) * 1971-10-13 1973-07-03
JPS6317362A (ja) * 1986-07-10 1988-01-25 三菱電機株式会社 冷暖房装置
JPH08159621A (ja) * 1994-12-08 1996-06-21 Hitachi Ltd 空気調和機
JP2009058146A (ja) * 2007-08-30 2009-03-19 Sanden Corp 冷凍空調装置
JP2009092353A (ja) * 2007-10-12 2009-04-30 Hitachi Appliances Inc 空気調和機
JP2019194310A (ja) * 2018-04-25 2019-11-07 ダイキン工業株式会社 冷媒を含有する組成物、熱移動媒体及び熱サイクルシステム
JP2021055983A (ja) * 2019-09-30 2021-04-08 ダイキン工業株式会社 熱源ユニット及び冷凍装置

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4846771A (fr) * 1971-10-13 1973-07-03
JPS6317362A (ja) * 1986-07-10 1988-01-25 三菱電機株式会社 冷暖房装置
JPH08159621A (ja) * 1994-12-08 1996-06-21 Hitachi Ltd 空気調和機
JP2009058146A (ja) * 2007-08-30 2009-03-19 Sanden Corp 冷凍空調装置
JP2009092353A (ja) * 2007-10-12 2009-04-30 Hitachi Appliances Inc 空気調和機
JP2019194310A (ja) * 2018-04-25 2019-11-07 ダイキン工業株式会社 冷媒を含有する組成物、熱移動媒体及び熱サイクルシステム
JP2021055983A (ja) * 2019-09-30 2021-04-08 ダイキン工業株式会社 熱源ユニット及び冷凍装置

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