WO2023234316A1 - Dispositif à cycle frigorifique - Google Patents

Dispositif à cycle frigorifique Download PDF

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Publication number
WO2023234316A1
WO2023234316A1 PCT/JP2023/020155 JP2023020155W WO2023234316A1 WO 2023234316 A1 WO2023234316 A1 WO 2023234316A1 JP 2023020155 W JP2023020155 W JP 2023020155W WO 2023234316 A1 WO2023234316 A1 WO 2023234316A1
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Prior art keywords
indoor
refrigeration cycle
expansion valve
unit
cycle device
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PCT/JP2023/020155
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English (en)
Japanese (ja)
Inventor
明広 重田
晃 鶸田
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パナソニックＩｐマネジメント株式会社
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Publication of WO2023234316A1 publication Critical patent/WO2023234316A1/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
    • F25B5/00—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity
    • F25B5/02—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity arranged in parallel

Definitions

  • the present disclosure relates to a refrigeration cycle device.
  • Patent Document 1 discloses a refrigeration cycle device that uses a thermochemically unstable refrigerant. This refrigeration cycle device reduces the driving speed of the compressor when the temperature of the working medium discharged from the compressor transiently transitions to a region where it exceeds a predetermined value. lower the temperature.
  • the present disclosure provides a refrigeration cycle device that can suppress the disproportionation reaction of a working medium without impairing user comfort.
  • a refrigeration cycle device includes an outdoor unit equipped with a compressor and a plurality of indoor units equipped with an expansion valve. , when some of the indoor units are in operation and the discharge temperature of the compressor is equal to or higher than a predetermined temperature, the control unit controls at least one of the indoor units that are out of operation. The expansion valve of one of the indoor units is opened.
  • the refrigeration cycle device can suppress the disproportionation reaction of the working medium without impairing user comfort.
  • FIG. 1 is a diagram showing the overall configuration of a refrigeration cycle device in Embodiment 1.
  • Figure 2 is a refrigeration cycle diagram of the refrigeration cycle device.
  • Figure 3 is a block diagram of the refrigeration cycle device.
  • FIG. 4 is a flowchart showing the operation of the refrigeration cycle device.
  • FIG. 1 is a diagram schematically showing the overall configuration of a refrigeration cycle device 1 according to the first embodiment.
  • the refrigeration cycle device 1 includes an indoor unit 10 and an outdoor unit 30.
  • the indoor unit 10 is a device placed inside a building such as an office building or a residence, or a mobile object such as a ship, and performs air conditioning for the indoor space.
  • the outdoor unit 30 is a device mainly installed outdoors, and supplies a working medium to the indoor unit 10 via the gas pipe 20 and the liquid pipe 40.
  • the refrigeration cycle device 1 is configured by connecting four indoor units 10 to one outdoor unit 30. Furthermore, the refrigeration cycle device 1 is provided indoors with an operation section (not shown) corresponding to each indoor unit 10, and the user sets the temperature setting etc. of the air conditioning operation of the corresponding indoor unit 10 via the operation section.
  • the air conditioning operation including the cooling operation and heating operation of the indoor unit 10 will be simply referred to as operation.
  • the number of indoor units 10 that constitute one refrigeration cycle device 1 is not limited to four.
  • three refrigeration cycle devices 1 each independently perform air conditioning on the first floor F1, second floor F2, and third floor F3 of building B. For convenience of explanation, only one refrigeration cycle device 1 will be explained.
  • the refrigeration cycle device 1 uses a working medium containing ethylene-based fluoroolefin in the refrigeration cycle circuit.
  • Ethylene-based fluoroolefins are characterized by many having low GWP.
  • ethylene-based fluoroolefins cause a disproportionation reaction when exposed to a discharge phenomenon at high temperature and pressure. The occurrence of a disproportionation reaction may cause a sudden pressure increase within the refrigeration cycle. Details regarding the working medium will be described later.
  • FIG. 2 is a refrigeration cycle diagram of the refrigeration cycle device 1.
  • the four indoor units 10 are connected in parallel to the outdoor unit 30 via gas pipes 20 and liquid pipes 40.
  • Each indoor unit 10 has an indoor heat exchanger 11, an indoor fan 13, and an indoor expansion valve 15.
  • the indoor heat exchanger 11 is, for example, a fin-tube type heat exchanger, and exchanges heat between the working medium flowing inside and the outside air.
  • the indoor fan 13 is, for example, a centrifugal fan, and is connected to the output shaft of an indoor fan motor 13a, which is an electronically controllable motor, and rotates when the indoor fan motor 13a is driven. The indoor fan 13 rotates to draw indoor air into the indoor unit 10 and blow it out into the room through the indoor heat exchanger 11.
  • the indoor expansion valve (expansion valve) 15 is a valve whose opening/closing and opening degree can be changed by electronic control.
  • the indoor expansion valve 15 allows the working medium to flow when it is opened, and blocks the flow of the working medium when it is closed. Further, by changing the opening degree of the indoor expansion valve 15, the flow rate of the working medium flowing through each indoor heat exchanger 11 and the magnitude of the pressure reduction of the working medium in the indoor expansion valve 15 are changed.
  • the outdoor unit 30 includes a compressor 31, a four-way valve 33, an outdoor heat exchanger 35, an outdoor fan 37, and an outdoor expansion valve 39.
  • the compressor 31 is, for example, a scroll type compressor, and sucks in a gaseous working medium, compresses it, and discharges it.
  • a working medium temperature sensor 32 is attached near the discharge port of the compressor 31.
  • the working medium temperature sensor 32 measures the discharge temperature T, which is the temperature of the working medium discharged by the compressor 31.
  • the four-way valve 33 is a device that communicates with the discharge side of the compressor 31, the suction side of the compressor 31, the outdoor heat exchanger 35, and the gas pipe 20, and can switch the flow path of the working medium by electronic control. . By switching the flow path of the working medium using the four-way valve 33, whether the indoor heat exchanger 11 functions as an evaporator or a condenser is switched. Thereby, whether the indoor unit 10 performs the cooling operation or the heating operation is switched.
  • the outdoor heat exchanger 35 is, for example, a fin-tube type heat exchanger, and exchanges heat between the working medium flowing inside and the outside air.
  • the outdoor fan 37 is, for example, an axial fan, is connected to an output shaft of an outdoor fan motor 37a, which is an electronically controllable motor, and rotates when the outdoor fan motor 37a is driven.
  • the outdoor fan 37 sucks outside air into the outdoor unit 30 by rotating, and blows out the sucked outside air to the outside of the outdoor unit 30 through the outdoor heat exchanger 35.
  • the outdoor expansion valve 39 is a valve whose opening degree can be changed, for example, by electronic control, and reduces the pressure of the working medium passing therethrough.
  • the gas pipe 20 is a refrigerant pipe that communicates the four-way valve 33 with the indoor expansion valve 15 of each indoor unit 10.
  • the working medium flowing inside the gas pipe 20 is mainly in a gaseous state.
  • the liquid pipe 40 is a refrigerant pipe that communicates the outdoor expansion valve 39 with the indoor heat exchanger 11 included in each indoor unit 10 .
  • the working medium flowing inside the liquid pipe 40 is mainly in a liquid state.
  • FIG. 3 is a block diagram showing the configuration of the control system of the refrigeration cycle device 1. As shown in FIG. Note that since the four indoor units 10 have the same configuration, the detailed configuration of only one indoor unit 10 is described in FIG. 3, and the detailed configuration of the three indoor units 10 is omitted.
  • the indoor unit 10 includes a room temperature sensor 12, an indoor communication section 14, and a human sensor 16.
  • the room temperature sensor 12 is a sensor that measures room temperature at a predetermined sampling rate.
  • the indoor communication unit 14 is constituted by communication hardware such as a connector and a communication circuit according to a predetermined communication standard, and communicates with the outdoor unit 30 via control wiring.
  • the human sensor 16 is, for example, an infrared type sensor, and detects a person in the space where the indoor unit 10 is installed.
  • the outdoor unit 30 includes an outdoor communication section 34 and a control section 70.
  • the outdoor communication section 34 is constituted by communication hardware such as a connector and a communication circuit according to a predetermined communication standard, and communicates with the indoor communication section 14 via control wiring.
  • the control unit 70 controls the operation of each part of the refrigeration cycle device 1.
  • the control unit 70 includes an outdoor unit memory 71, an outdoor unit processor 73, and an outdoor unit interface 75.
  • the outdoor unit memory 71 is a memory that stores programs and data.
  • the outdoor unit memory 71 stores various control programs and data processed by the outdoor unit processor 73.
  • the outdoor unit memory 71 has a nonvolatile storage area.
  • the outdoor unit memory 71 may include a volatile storage area and constitute a work area for the outdoor unit processor 73.
  • the outdoor unit processor 73 is a processor such as a CPU or MPU.
  • the outdoor unit processor 73 functions as a device control section 73a and a determination section 73b by reading and executing a control program stored in the outdoor unit memory 71.
  • the outdoor unit interface 75 is an interface equipped with communication hardware such as a connector and a communication circuit that conforms to a predetermined communication standard.
  • the outdoor unit interface 75 communicates with the outdoor communication unit 34, the compressor 31, the four-way valve 33, the outdoor fan motor 37a, the outdoor expansion valve 39, and the working medium temperature sensor 32.
  • the device control unit 73a receives as a signal an operation performed by a user on an operation unit (not shown) provided indoors, and executes operation by controlling each device of the refrigeration cycle device 1 according to the received signal.
  • the device control unit 73a controls each part of the outdoor unit 30, such as the outdoor communication unit 34, the compressor 31, the four-way valve 33, the outdoor fan motor 37a, and the outdoor expansion valve 39, via the outdoor unit interface 75.
  • the device control unit 73a also controls each part of the indoor unit 10, such as the indoor fan motor 13a and the indoor expansion valve 15, through the outdoor communication unit 34 and the indoor communication unit 14, and operates the four indoor units 10 individually. or stop operation. Note that the state in which the indoor unit 10 is not operating includes the state in which the indoor unit 10 is in thermo-off operation.
  • thermo-off operation is an operation performed when the determination unit 73b (described later) determines that the room temperature data measured by the room temperature sensor 12 matches the set temperature set by the user.
  • the indoor expansion valve 15 of the indoor unit 10 is closed to prevent the room temperature from changing more than necessary.
  • the determination unit 73b receives measurement data of the discharge temperature T from the working medium temperature sensor 32. Further, the determination unit 73b receives room temperature data measured by the room temperature sensor 12 and data from the human sensor 16 via the outdoor communication unit 34 and the indoor communication unit 14. As will be described later, the determination unit 73b performs various determinations based on the received various data, and changes the control of each device by the device control unit 73a based on the results of the determination.
  • the refrigerant used in the refrigeration cycle device 1 is a working medium containing ethylene-based fluoroolefin.
  • 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 refrigeration cycle device 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 (CH3I), diiodomethane (CH2I2), dibromomethane (CH2Br2), bromomethane (CH3Br), and dichloromethane (CH2Cl2).
  • chloroiodomethane (CH2ClI), dibromochloromethane (CHBr2Cl), tetraiodidemethane (CI4), carbon tetrabromide (CBr4), bromotrichloromethane (CBrCl3), dibromodichloromethane (CBr2Cl2), tribromofluoromethane (CBr3F ), fluorodiiodomethane (CHFI2), difluoroiodomethane (CHF2I), difluorodiiodomethane (CF2I2), dibromodifluoromethane (CBr2F2), trifluoroiodomethane (CF3I), but other halomethanes Good too.
  • haloalkanes having 2 carbon atoms that is, haloethane, used as disproportionation inhibitors
  • CF3CH2I 1,1,1-trifluoro-2-iodoethane
  • CH3CH2I monoiodoethane
  • CH3CH2Br monobromoethane
  • 1,1,1-triiodoethane CH3CI3
  • 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.
  • the predetermined temperature T1 used in the following explanation depends, for example, on the heat resistance of the insulating paper inserted between the magnetic steel plate and the magnet wire that generates a magnetic field when energized in the stator of the motor that constitutes the compressor 31. Determined accordingly.
  • the heat resistance class of the insulating paper specified in JIS C 4003 is heat resistance class B
  • the heat resistance temperature is 130°C. If the insulating paper is placed under a temperature condition higher than this heat-resistant temperature, the insulation between the magnet wire and the electromagnetic steel sheet will be broken, increasing the possibility that a discharge phenomenon that causes a disproportionation reaction will occur. Since the insulating paper is under substantially the same temperature condition as the discharge temperature T, the refrigeration cycle device 1 changes its operation depending on whether the measured value of the discharge temperature T is equal to or higher than the predetermined temperature T1.
  • insulating paper of heat resistance class E specified in JIS C 4003 is used, and its heat resistance temperature is 120°C.
  • the predetermined temperature T1 is 115° C., which is the heat-resistant temperature plus a margin of about 5K for safety. Note that when the temperature of the working medium is 150° C. or higher, the risk of occurrence of a disproportionation reaction increases regardless of the heat resistance temperature of the insulating paper. Therefore, even if insulating paper with a heat resistance temperature of 150° C. or higher is used, the predetermined temperature T1 is set to 150° C. with a margin for safety. That is, the predetermined temperature T1 is set based on the lower of the temperature at which the risk of occurrence of a discharge phenomenon increases and the temperature at which the risk of occurrence of a disproportionation reaction due to high temperature itself increases.
  • FIG. 4 is a flowchart of the refrigeration cycle device 1 and shows the operation of the refrigeration cycle device 1.
  • a plurality of indoor units 10 among the four indoor units 10 of the refrigeration cycle device 1 are in operation at the start of the flowchart in FIG. 4 .
  • the device control unit 73a operates the compressor 31 to circulate the working medium through the refrigeration cycle circuit. Further, the device control unit 73a closes the indoor expansion valve 15 provided in the indoor unit 10 that is not in operation, and opens the indoor expansion valve 15 provided in the indoor unit 10 that is in operation. As a result, the working medium that is circulated by the drive of the compressor 31 does not flow to the indoor unit 10 that is not in operation, but flows only to the indoor unit 10 that is in operation.
  • the device control unit 73a also controls the opening degree of the indoor expansion valve 15 provided in the indoor unit 10 during operation to increase in general proportion to the condensing capacity or evaporation capacity required of each indoor unit 10. , controls the indoor expansion valve 15.
  • the condensing capacity and evaporation capacity required of each indoor unit 10 mainly increase as the difference between the set temperature and the room temperature and the rotation speed of the indoor fan 13 increase.
  • the device control unit 73a selects the indoor units 10 in order of the pressure loss dP occurring in the working medium from the compressor 31 to the indoor unit 10 in descending order of the operating indoor units 10.
  • the opening degree of the expansion valve 15 is further increased.
  • the opening degree of the indoor expansion valve 15 per condensing capacity or evaporation capacity of the indoor unit 10 increases in order from the indoor unit 10 with the largest pressure loss dP.
  • the pressure loss dP is determined by factors such as the length of the refrigerant pipe from the compressor 31 to the indoor unit 10, the thickness of the refrigerant pipe, the number and curvature of curved parts of the refrigerant pipe, and the height of the indoor unit 10 with respect to the compressor 31. It mainly depends on the installation situation of the cycle device 1.
  • the device control unit 73a selects the indoor expansion valves 15 in order from the indoor units 10 with the longest refrigerant piping between the outdoor unit 30 and each indoor unit 10, assuming that the indoor units 10 have the largest pressure loss dP. Control may also be performed.
  • the order of the lengths of the refrigerant pipes between the outdoor unit 30 and each indoor unit 10 is determined by an operator when installing the refrigeration cycle device 1, for example, and the order based on the judgment is stored in the outdoor unit memory 71.
  • the device control unit 73a determines that the indoor units 10 with the largest pressure loss dP are the indoor units 10 with the largest pressure loss dP, and expands the indoor units 10 in order from the smallest measured value of the pressure of the working medium in the refrigerant piping in the vicinity of each indoor unit 10 in operation. Valve 15 may also be controlled.
  • the pressure of the working medium in the refrigerant pipes in the vicinity of each indoor unit 10 is measured, for example, by a pressure sensor (not shown) connected to the indoor unit 10, and is transmitted to the device control unit 73a via the indoor communication unit 14 and the outdoor communication unit 34. It may also be configured to be sent.
  • the device control unit 73a can control the indoor expansion valve 15 in consideration of pressure loss dP, including not only factors determined at the time of installation of the refrigeration cycle device 1, but also factors such as air conditioning load, for example.
  • the working medium temperature sensor 32 continues to measure the discharge temperature T of the working medium discharged from the compressor 31 at a predetermined sampling rate.
  • the value data is transmitted to the determination unit 73b.
  • the determination unit 73b determines whether the received measured value of the discharge temperature T is equal to or higher than a predetermined temperature T1 (step S1). When it is determined that the measured value of the discharge temperature T is less than the predetermined temperature T1 (step S1: NO), the refrigeration cycle device 1 continues normal operation. On the other hand, if it is determined that the measured value of the discharge temperature T is equal to or higher than the predetermined temperature T1 (step S1: YES), the process moves to step S2.
  • step S2 the device control unit 73a increases the opening degree of the indoor expansion valve 15 in order of the indoor units 10 in operation, starting with the one with the smallest pressure loss dP from the compressor 31.
  • the working medium quickly moves from the high pressure side to the low pressure side within the refrigeration cycle circuit. Therefore, within the refrigeration cycle, the pressure on the high pressure side drops rapidly.
  • step S3 the determination unit 73b determines whether all the indoor units 10 of the four indoor units 10 of the refrigeration cycle device 1 are operating.
  • step S3: YES the process moves to step S4. If the determination unit 73b determines that all the indoor units 10 of the refrigeration cycle device 1 are not in operation (step S3: NO), that is, some of the indoor units 10 are in operation and other If some of the indoor units 10 are not operating, the process moves to step S5.
  • step S4 the determination unit 73b determines whether the indoor unit 10 that was in operation has been newly stopped.
  • the indoor unit 10 is newly stopped, for example, when the operating indoor unit 10 is stopped by a user's operation, or when the operating indoor unit 10 is shifted to thermo-off operation, etc. can be mentioned.
  • the determining unit 73b determines that the indoor unit 10 in operation has been newly stopped (step S4: YES)
  • the process moves to step S5.
  • the determination unit 73b repeats the determination in step S4 until the indoor unit 10 is newly stopped.
  • step S5 the device control unit 73a opens the indoor expansion valve 15 provided in at least one indoor unit 10 among the indoor units 10 whose operation is stopped. Thereby, the pressure on the high pressure side in the refrigeration cycle circuit can easily escape to the low pressure side via the indoor expansion valve 15 which is opened.
  • the opening degree of the indoor expansion valve 15 that is opened in step S5 may be smaller than the minimum opening degree that is the minimum value of the opening degree of the indoor unit 10 during operation. This degree of opening is hereinafter referred to as slight opening.
  • the range of opening degrees used during operation of the indoor unit 10 is determined, for example, by the relationship between the opening degree of the indoor expansion valve 15 and the Cv value defined in JIS B 0100. Specifically, in the range of the opening degree of the indoor expansion valve 15 used during operation of the indoor unit 10, the Cv curve plotted with the opening degree of the indoor expansion valve 15 and the Cv value as axes is approximately a straight line. In this embodiment, the opening degree is a region of about 5% or more.
  • the minimum opening degree is the smallest opening degree in this area, the minimum opening degree is approximately 5%.
  • the Cv value indicating the ease of fluid flow changes rapidly with respect to a change in the opening degree of the indoor expansion valve 15. Therefore, a region where the degree of opening is less than about 5% is not suitable for controlling the flow rate of the working medium. Therefore, in this embodiment, when the indoor unit 10 is operating, the device control section 73a controls the opening degree of the corresponding indoor expansion valve 15 so as not to become less than about 5%.
  • step S5 the number and degree of opening of the indoor expansion valves 15 that are opened among the indoor expansion valves 15 of the indoor unit 10 that is not operating may be set according to the discharge temperature T, respectively.
  • the total opening degree of the indoor expansion valves 15 that are opened in step S5 may be controlled so as to be correlated to the temperature range in which the discharge temperature T exceeds the predetermined temperature T1. According to this, when the discharge temperature T is high, the pressure on the high pressure side in the refrigeration cycle circuit escapes more easily, so that the occurrence of the disproportionation reaction can be effectively suppressed.
  • the total opening degree of the indoor expansion valves 15 of the indoor units 10 that have stopped operating is controlled to be equal to or less than the total opening degree of the indoor expansion valves 15 of the indoor units 10 that are in operation. It is preferable.
  • step S5 the equipment control unit 73a closes the indoor expansion valve 15 of the indoor unit 10 that has the human sensor 16 that is sensing a person among the indoor units 10 that are not operating, and closes the indoor expansion valve 15 of the indoor unit 10 that is not sensing a person.
  • the opening degree of the indoor expansion valve 15 of the indoor unit 10 having the human sensor 16 may be slightly opened. According to this, in step S6, which will be described later, it is possible to suppress the rotation of the indoor fan 13 of the indoor unit 10 that is not in operation, which may cause a person near the indoor unit 10 to feel uncomfortable.
  • step S6 the indoor fan motor 13a of the indoor unit 10, which has the indoor expansion valve 15 opened in step S5 and is currently stopped, starts driving under the control of the device control unit 73a.
  • the indoor fan 13 rotates, and the working medium in the indoor heat exchanger 11 and the air exchange heat. Therefore, the temperature of the working medium of the refrigeration cycle device 1 decreases.
  • the device control unit 73a controls the rotation speed of the indoor fan motor 13a of the indoor unit 10 in which the human sensor 16 does not detect a person, and the rotation speed of the indoor fan motor 13a of the indoor unit 10 in which the human sensor 16 detects a person.
  • the rotation speed may be lower than the rotation speed of the motor 13a. According to this, it is possible to prevent the indoor fan 13 of the indoor unit 10 that is not operating from rotating at high speed from causing a feeling of discomfort to people who are near the indoor unit 10.
  • step S7 NO
  • the equipment control unit 73a slightly opens the indoor expansion valve 15 for the newly stopped indoor unit 10, and The indoor fan 13 is rotated by driving the fan motor 13a.
  • the device control unit 73a changes the rotation speed of the indoor fan motor 13a of the indoor unit 10 whose operation has been stopped by shifting to thermo-off operation, for example, by the user's operation. It may be configured to be lower than the number.
  • step S7 the determination unit 73b determines whether the discharge temperature T is equal to or higher than the second temperature T2.
  • the second temperature T2 is about 0K to 20K lower than the predetermined temperature T1, and is 105° C. in this embodiment.
  • step S7: YES the determination unit 73b determines that the discharge temperature T is equal to or higher than the second temperature T2
  • step S7: NO the determination unit 73b determines that the discharge temperature T is less than the second temperature T2.
  • step S8 if the indoor expansion valve 15 of the indoor unit 10 whose operation is stopped is open, the indoor expansion valve 15 is closed.
  • step S9 if the indoor fan motor 13a of the indoor unit 10 that is not operating is being driven, the driving of the indoor fan motor 13a is stopped, and the rotation of the indoor fan 13 is stopped. Thereby, the refrigeration cycle device 1 returns to normal operation.
  • the refrigeration cycle device 1 includes an outdoor unit 30 including a compressor 31 and a plurality of indoor units 10 including an indoor expansion valve 15.
  • a working medium containing fluoroolefin is used, and the control unit 70 is configured such that some of the indoor units 10 are in operation and the discharge temperature T of the compressor 31 is a predetermined temperature T1.
  • the indoor expansion valve 15 of at least one indoor unit 10 among the indoor units 10 whose operation is stopped is opened. According to this configuration, when the indoor expansion valve 15 of the indoor unit 10 that is not operating is opened, the pressure within the refrigeration cycle circuit is reduced. Therefore, the occurrence of disproportionation reactions can be suppressed without impairing the comfort of the air conditioner user.
  • the control unit 70 opens the indoor expansion valve 15 of the indoor unit 10 that has been stopped.
  • the indoor expansion valve 15 of the indoor unit 10 that has stopped operating is opened without being closed, thereby suppressing a sudden pressure rise in the refrigeration cycle circuit due to a decrease in the number of operating indoor units 10. can do. Therefore, the occurrence of disproportionation reactions can be suppressed without impairing the comfort of air conditioning users.
  • the control unit 70 rotates the indoor fan 13 of the indoor unit 10 that has the indoor expansion valve 15 that is open among the indoor units 10 that are not operating. According to this configuration, the temperature of the working medium in the refrigeration cycle circuit can be lowered. Thereby, the occurrence of disproportionation reactions can be suppressed without impairing the convenience of air conditioning users.
  • the control unit 70 slightly opens the indoor expansion valve 15 of at least one indoor unit 10 among the indoor units 10 whose operation is stopped. According to this configuration, the pressure within the refrigeration cycle circuit can be reduced while suppressing the flow rate of the working medium that passes through the indoor unit 10 while the operation is stopped. Therefore, the occurrence of disproportionation reactions can be suppressed while suppressing energy loss due to the working medium flowing through the indoor unit 10 while the operation is stopped.
  • the slight opening is an opening smaller than the minimum opening of the indoor expansion valve 15 of the indoor unit 10 during operation. According to this configuration, the pressure within the refrigeration cycle circuit can be reduced while suppressing the flow rate of the working medium that passes through the indoor unit 10 while the operation is stopped. Therefore, the occurrence of disproportionation reactions can be suppressed while suppressing energy loss due to the working medium flowing through the indoor unit 10 while the operation is stopped.
  • the control unit 70 increases the opening degree of the indoor expansion valve 15 per condensing capacity or evaporating capacity of the indoor unit 10 in order of the indoor units 10 in operation, starting with the one with the largest pressure loss dP from the compressor 31. According to this configuration, even if the total required condensing capacity or evaporating capacity of all the indoor units 10 changes and the discharge amount of the compressor 31 changes, the pressure in the refrigeration cycle circuit will not rise excessively. can be suppressed. Further, when the indoor unit 10 is in cooling operation, an increase in the degree of cooling heating of the working medium flowing out from the indoor unit 10 can be suppressed, and an increase in the discharge temperature T of the compressor 31 can be suppressed. Therefore, the occurrence of disproportionation reactions can be suppressed.
  • the control unit 70 controls the air flow from the compressor 31 among the indoor units 10 in operation.
  • the opening degrees of the indoor expansion valves 15 are increased in descending order of pressure loss dP. According to this configuration, the refrigerant on the high pressure side in the refrigeration cycle circuit can be quickly moved to the low pressure side. As a result, excessive pressure rise within the refrigeration cycle circuit can be suppressed, especially when the refrigeration cycle device 1 is operating under conditions where the air conditioning load is large, or when the number of indoor units 10 in operation is reduced. . Therefore, the occurrence of disproportionation reactions can be suppressed.
  • Embodiment 1 has been described as an example of the technology disclosed in this application.
  • the technology in the present disclosure is not limited to this, and can also be applied to embodiments in which changes, replacements, additions, omissions, etc. are made.
  • the control unit 70 determines that the discharge temperature T is equal to or higher than the predetermined temperature T1 (step S1: YES), and some of the indoor units 10 are in operation (step S3: NO). ), the indoor expansion valve 15 of the indoor unit 10 that is not operating is opened, but this is just an example. For example, regardless of the discharge temperature T, if there is an indoor unit 10 that is out of operation, the indoor expansion valve 15 provided in at least one indoor unit 10 that is out of operation is always open, and The opening degree may be slightly opened.
  • the refrigeration cycle device 1 is a refrigeration cycle device that includes an outdoor unit 30 that includes a compressor 31 and a plurality of indoor units 10 that includes an indoor expansion valve 15.
  • an outdoor unit 30 that includes a compressor 31
  • a plurality of indoor units 10 that includes an indoor expansion valve 15.
  • the indoor expansion valve 15 is always slightly opened. According to this configuration, when the indoor expansion valve 15 of the indoor unit 10 that is not operating is opened, the pressure within the refrigeration cycle circuit is reduced. Therefore, the occurrence of disproportionation reactions can be suppressed without impairing the comfort of the air conditioner user.
  • the working medium temperature sensor 32 measures the discharge temperature T of the working medium discharged from the compressor 31, but this is just an example.
  • a pressure sensor (not shown) is attached to the discharge side of the compressor 31, and the estimated value of the discharge temperature T is calculated from the pressure value measured by the pressure sensor by utilizing the high correlation between the temperature and pressure of the working medium. It may also be a configuration.
  • step S7 NO
  • the control unit 70 closes the indoor expansion valve 15 of the indoor unit 10 that is not operating.
  • this is an example.
  • the control unit 70 may be configured to close the indoor expansion valve 15 after a predetermined period of time has elapsed since the opening of the indoor expansion valve 15. Good too. This prevents the working medium from continuing to flow into the indoor unit 10 while the operation is stopped for a long time while suppressing a sudden pressure increase in the refrigeration cycle circuit. Therefore, the energy efficiency of the refrigeration cycle device 1 can be improved while suppressing the occurrence of disproportionation reactions.
  • the human sensor 16 is an infrared type sensor, but this is just an example.
  • the human sensor 16 may be a camera, and the refrigeration cycle apparatus 1 may be configured to determine whether a person is near the indoor unit 10 based on video data.
  • the human sensor 16 may be of an ultrasonic type, and the refrigeration cycle device 1 may be configured to determine whether a person is near the indoor unit 10 based on the reflected intensity of the generated ultrasonic waves.
  • the outdoor unit processor 73 may be composed of a plurality of processors, or may be composed of a single processor.
  • the outdoor unit processor 73 may be hardware programmed to implement corresponding functional units. That is, the outdoor unit processor 73 is configured with, for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).
  • ASIC Application Specific Integrated Circuit
  • FPGA Field Programmable Gate Array
  • each part shown in FIG. 3 is an example, and the specific implementation form is not particularly limited. That is, it is not necessarily necessary to implement hardware corresponding to each part individually, and it is of course possible to have a configuration in which the functions of each part are realized by one processor executing a program. Furthermore, in the embodiments described above, some of the functions implemented by software may be implemented by hardware, or some functions implemented by hardware may be implemented by software. In addition, the specific detailed configurations of each part of the indoor unit 10 and the outdoor unit 30 can be arbitrarily changed without departing from the spirit of the present disclosure.
  • the operation step units shown in FIG. 4 are divided according to the main processing contents in order to facilitate understanding of the operation of each part of the refrigeration cycle device 1. There are no restrictions on operation. Depending on the processing content, the process may be divided into more steps. Furthermore, the process may be divided so that one step unit includes more processes. Further, the order of the steps may be changed as appropriate without interfering with the spirit of the present disclosure.
  • a refrigeration cycle device comprising an outdoor unit equipped with a compressor and a plurality of indoor units equipped with expansion valves, using a working medium containing an ethylene-based fluoroolefin as a refrigerant, and comprising a control section, the control section
  • the expansion valve of the indoor unit is opened.
  • the expansion valve of the indoor unit whose operation is stopped is opened, and the pressure within the refrigeration cycle circuit is reduced. Therefore, the occurrence of disproportionation reactions can be suppressed without impairing the comfort of the air conditioner user.
  • the control unit increases the opening degree of the expansion valve per condensing capacity or evaporation capacity of the indoor unit in order of the pressure loss from the compressor among the indoor units in operation.
  • the refrigeration cycle device according to any one of Techniques 1 to 5, characterized in that: Thereby, even if the total required condensing capacity or evaporating capacity of all the indoor units changes and the discharge amount of the compressor changes, it is possible to suppress the pressure in the refrigeration cycle circuit from increasing excessively. Further, when the indoor unit is in cooling operation, it is possible to suppress an increase in the cooling heating degree of the working medium flowing out from the indoor unit, and it is possible to suppress an increase in the discharge temperature of the compressor. Therefore, the occurrence of disproportionation reactions can be suppressed.
  • the control unit may control one of the indoor units in operation to 7.
  • the refrigeration cycle device according to any one of techniques 1 to 6, wherein the opening degree of the expansion valve is increased in order of decreasing pressure loss from the compressor. Thereby, the refrigerant on the high pressure side in the refrigeration cycle circuit can be quickly moved to the low pressure side. This makes it possible to suppress excessive pressure rise within the refrigeration cycle circuit, especially when the refrigeration cycle device is operating under conditions where the air conditioning load is large, or when the number of indoor units in operation is reduced. Therefore, the occurrence of disproportionation reactions can be suppressed.
  • a working medium containing an ethylene-based fluoroolefin is used as a refrigerant, and a part of the plurality of indoor units is 2.
  • a refrigeration cycle device characterized in that when the indoor unit is in operation, the expansion valve of at least one of the indoor units that is not in operation is always kept slightly open. As a result, the expansion valve of the indoor unit whose operation is stopped is opened, and the pressure within the refrigeration cycle circuit is reduced. Therefore, the occurrence of disproportionation reactions can be suppressed without impairing the comfort of the air conditioner user.
  • the present disclosure is applicable to a refrigeration cycle device that uses a working medium containing an ethylene-based fluoroolefin. Specifically, the present disclosure is applicable to air conditioners and the like that use a working medium containing ethylene-based fluoroolefins.
  • Refrigeration cycle device 10 Indoor unit 11 Indoor heat exchanger 12 Room temperature sensor 13 Indoor fan 13a Indoor fan motor 14 Indoor communication unit 15 Indoor expansion valve (expansion valve) 16 Human sensor 20 Gas pipe 30 Outdoor unit 31 Compressor 32 Working medium temperature sensor 33 Four-way valve 34 Outdoor communication unit 35 Outdoor heat exchanger 37 Outdoor fan 37a Outdoor fan motor 39 Outdoor expansion valve 40 Liquid pipe 70 Control unit 71 Outdoor unit Memory 73 Outdoor unit processor 73a Equipment control section 73b Judgment section 75 Outdoor unit interface B Building

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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

L'invention concerne un dispositif à cycle de réfrigération qui peut atténuer une réaction de dismutation d'un milieu de travail sans perte de confort pour un utilisateur.　Un dispositif à cycle de réfrigération (1) selon la présente divulgation comprend : une unité extérieure (30) pourvue d'un compresseur (31) ; et une pluralité d'unités intérieures (10) pourvues chacune d'un détendeur (15). Le dispositif à cycle de réfrigération comprend en outre une unité de commande (70) qui utilise un milieu de travail comprenant une fluorooléfine à base d'éthylène en tant que fluide frigorigène. L'unité de commande (70) ouvre le détendeur (15) d'au moins une unité intérieure (10) parmi des unités intérieures (10) qui se sont arrêtées de fonctionner si certaines de la pluralité d'unités intérieures (10) sont en fonctionnement et une température de décharge (T) du compresseur (31) est supérieure ou égale à une température prescrite (T1).
PCT/JP2023/020155 2022-06-01 2023-05-30 Dispositif à cycle frigorifique WO2023234316A1 (fr)

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JP2022-089807 2022-06-01

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0835710A (ja) * 1994-07-22 1996-02-06 Mitsubishi Heavy Ind Ltd マルチタイプ空気調和機の制御装置
WO2015174054A1 (fr) * 2014-05-12 2015-11-19 パナソニックＩｐマネジメント株式会社 Dispositif à cycle de réfrigération
JP2020091080A (ja) * 2018-12-06 2020-06-11 三菱電機株式会社 冷凍サイクル装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0835710A (ja) * 1994-07-22 1996-02-06 Mitsubishi Heavy Ind Ltd マルチタイプ空気調和機の制御装置
WO2015174054A1 (fr) * 2014-05-12 2015-11-19 パナソニックＩｐマネジメント株式会社 Dispositif à cycle de réfrigération
JP2020091080A (ja) * 2018-12-06 2020-06-11 三菱電機株式会社 冷凍サイクル装置

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