WO2021048901A1 - 室外ユニットおよび冷凍サイクル装置 - Google Patents

室外ユニットおよび冷凍サイクル装置 Download PDF

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Publication number
WO2021048901A1
WO2021048901A1 PCT/JP2019/035373 JP2019035373W WO2021048901A1 WO 2021048901 A1 WO2021048901 A1 WO 2021048901A1 JP 2019035373 W JP2019035373 W JP 2019035373W WO 2021048901 A1 WO2021048901 A1 WO 2021048901A1
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WIPO (PCT)
Prior art keywords
refrigerant
compressor
passage
flow rate
state
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/JP2019/035373
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English (en)
French (fr)
Japanese (ja)
Inventor
智隆 石川
悠介 有井
素 早坂
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to PCT/JP2019/035373 priority Critical patent/WO2021048901A1/ja
Priority to ES19944704T priority patent/ES2964488T3/es
Priority to JP2021544990A priority patent/JP7224480B2/ja
Priority to CN201980099962.8A priority patent/CN114341567B/zh
Priority to FIEP19944704.6T priority patent/FI4030116T3/fi
Priority to EP19944704.6A priority patent/EP4030116B1/en
Priority to DK19944704.6T priority patent/DK4030116T3/da
Publication of WO2021048901A1 publication Critical patent/WO2021048901A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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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
    • F25B40/00—Subcoolers, desuperheaters or superheaters
    • 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
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/13—Economisers
    • 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
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/19—Pumping down refrigerant from one part of the cycle to another part of the cycle, e.g. when the cycle is changed from cooling to heating, or before a defrost cycle is started
    • 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
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/23—Separators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/23—Time delays
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/19—Pressures
    • F25B2700/193—Pressures of the compressor
    • F25B2700/1931—Discharge pressures
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/19—Pressures
    • F25B2700/193—Pressures of the compressor
    • F25B2700/1933—Suction pressures

Definitions

  • the present invention relates to an outdoor unit and a refrigeration cycle device.
  • Patent Document 1 discloses a refrigerating apparatus having an intermediate injection flow path and a suction injection flow path.
  • a part of the refrigerant flowing from the condenser to the evaporator can be merged with the intermediate pressure refrigerant of the compressor using the intermediate injection flow path, or the suction flow path can be used by using the suction injection flow path. It is also possible to join the low-pressure refrigerant sucked into the compressor in. Therefore, when the operation efficiency is deteriorated by using the intermediate injection flow path, the discharge temperature of the compressor can be lowered by using the suction injection flow path.
  • Pump-down operation is the process of moving the refrigerant from the load device to the outdoor unit and storing it by installing an on-off valve or the like in the piping through which the liquid refrigerant flows in the main refrigerant circuit and operating the compressor with the piping shut off. ..
  • Patent Document 1 the flow of the refrigerant is cut off on the indoor unit side and the pump down operation is executed on the load apparatus side due to the operation of the load apparatus being stopped.
  • the refrigerant of the load device is recovered in the outdoor unit.
  • the condensation temperature becomes close to the outside air temperature, and it becomes difficult for the condenser to liquefy the refrigerant, which takes time to recover the refrigerant and prolongs the pump down operation time. There is a problem that it will be stored.
  • An object of the present invention is to provide an outdoor unit and a refrigeration cycle device in which the refrigerant recovery time during pump-down operation is shortened.
  • the present disclosure relates to an outdoor unit of a refrigeration cycle device configured to be connected to a load device including a first inflator and an evaporator.
  • the outdoor unit is connected to a load device to form a circulation flow path through which the refrigerant circulates, a compressor and a condenser arranged in the first flow path, and a direction in which the refrigerant circulates.
  • the second flow path configured to branch from the branch point of the first flow path downstream of the condenser and return the refrigerant that has passed through the condenser to the compressor, and to the second flow path in order from the branch point.
  • It has a second expansion device, a receiver and a flow control valve to be arranged, and has a first passage and a second passage, and heat exchange is performed between the refrigerant flowing through the first passage and the refrigerant flowing through the second passage. It is equipped with a heat exchanger configured in.
  • the first passage of the heat exchanger is arranged between the condenser and the branch point of the first passage.
  • the second passage of the heat exchanger is arranged between the flow rate adjusting valve of the second passage and the compressor.
  • the flow rate adjusting valve is configured to adjust the flow rate of the liquid refrigerant discharged from the receiver.
  • the control state of the compressor and the flow rate adjusting valve becomes the first state in which the flow rate adjusting valve is closed while operating the compressor at the first time point. ..
  • the control state changes from the first state to the second state in which the flow rate adjusting valve is opened while operating the compressor.
  • the outdoor unit of the present disclosure even when the refrigerant recovery progresses during the pump down operation and the condensation temperature approaches the outside air temperature, the efficiency of the heat exchanger is maintained and the refrigerant is condensed. Therefore, the time required for recovering the refrigerant can be shortened.
  • FIG. 1 is an overall configuration diagram of a refrigeration cycle device according to the present embodiment. Note that FIG. 1 functionally shows the connection relationship and the arrangement configuration of each device in the refrigeration cycle apparatus, and does not necessarily show the arrangement in the physical space.
  • the refrigeration cycle device 1 includes an outdoor unit 2, a load device 3, and pipes 84 and 88.
  • the outdoor unit 2 has a refrigerant outlet port PO2 and a refrigerant inlet port PI2 for connecting to the load device 3.
  • the load device 3 has a refrigerant outlet port PO3 and a refrigerant inlet port PI3 for connecting to the outdoor unit 2.
  • the pipe 84 connects the refrigerant outlet port PO2 of the outdoor unit 2 and the refrigerant inlet port PI3 of the load device 3.
  • the pipe 88 connects the refrigerant outlet port PO3 of the load device 3 and the refrigerant inlet port PI2 of the outdoor unit 2.
  • the outdoor unit 2 of the refrigeration cycle device 1 is configured to be connected to the load device 3.
  • the outdoor unit 2 includes a compressor 10 having a suction port G1, a discharge port G2, and an intermediate pressure port G3, a condenser 20, a fan 22, a heat exchanger 30, and pipes 80 to 82, 89.
  • the heat exchanger 30 has a first passage H1 and a second passage H2, and is configured to exchange heat between the refrigerant flowing through the first passage H1 and the refrigerant flowing through the second passage H2.
  • the load device 3 includes a first expansion valve 50, an evaporator 60, pipes 85, 86, 87, and an on-off valve 28.
  • the evaporator 60 is configured to exchange heat between air and a refrigerant. In the refrigeration cycle device 1, the evaporator 60 evaporates the refrigerant by endothermic heat from the air in the cooling target space.
  • the first expansion valve 50 is, for example, a temperature expansion valve that is controlled independently of the outdoor unit 2.
  • the first expansion valve 50 may be an electronic expansion valve capable of reducing the pressure of the refrigerant.
  • the on-off valve 28 is closed when the load device 3 is stopped to shut off the refrigerant.
  • the compressor 10 compresses the refrigerant sucked from the pipe 89 and discharges it to the pipe 80.
  • the drive frequency of the compressor 10 can be arbitrarily changed by inverter control.
  • the compressor 10 is provided with an intermediate pressure port G3, so that the refrigerant from the intermediate pressure port G3 can flow into a portion in the middle of the compression process.
  • the compressor 10 is configured to adjust the rotation speed according to a control signal from the control device 100. By adjusting the rotation speed of the compressor 10, the circulation amount of the refrigerant is adjusted, and the capacity of the refrigeration cycle device 1 can be adjusted.
  • Various types of compressors 10 can be adopted, and for example, scroll type, rotary type, screw type and the like can be adopted.
  • the condenser 20 is configured such that a high-temperature and high-pressure gas refrigerant discharged from the compressor 10 exchanges heat (heat dissipation) with the outside air. By this heat exchange, the refrigerant is condensed and changed to a liquid phase.
  • the refrigerant discharged from the compressor 10 to the pipe 80 is condensed and liquefied in the condenser 20 and flows out to the pipe 81.
  • a fan 22 for sending outside air is attached to the condenser 20 in order to improve the efficiency of heat exchange.
  • the fan 22 supplies the condenser 20 with outside air through which the refrigerant exchanges heat in the condenser 20. By adjusting the rotation speed of the fan 22, the refrigerant pressure (high pressure side pressure) on the discharge side of the compressor 10 can be adjusted.
  • the refrigerant used in the refrigerant circuit of the refrigeration cycle device 1 is CO 2 , but if a state in which it is difficult to secure the degree of supercooling occurs, another refrigerant may be used.
  • the case of cooling a refrigerant such as CO 2 in a supercritical state is also referred to as a condenser 20.
  • the amount of decrease of the refrigerant in the supercritical state from the reference temperature is also referred to as the degree of supercooling.
  • the first flow path F1 from the refrigerant inlet port PI2 to the refrigerant outlet port PO2 via the first passage H1 of the compressor 10, the condenser 20, and the heat exchanger 30 is the first expansion valve 50 of the load device 3 and evaporation. Together with the first flow path F1 in which the vessel 60 is arranged, a circulation flow path through which the refrigerant circulates is formed. Hereinafter, this circulation flow path is also referred to as a "main refrigerant circuit" of the refrigeration cycle.
  • the outdoor unit 2 includes pipes 91, 92, 94 for flowing the refrigerant from the portion between the outlet of the first passage H1 of the circulation flow path and the refrigerant outlet port PO2 to the inlet of the second passage H2, and the second passage H2. Further, a pipe 96 for flowing a refrigerant from the outlet to the suction port G1 or the intermediate pressure port G3 of the compressor 10 is provided.
  • the second flow path F2 that branches from the main refrigerant circuit and sends the refrigerant to the compressor 10 via the second passage H2 is also referred to as an “injection flow path”.
  • the outdoor unit 2 is further arranged in the second flow path F2 and includes a receiver (receiver) 73 for storing the refrigerant.
  • the second expansion valve 71 is arranged between the pipe 91 branched from the portion between the outlet of the first passage H1 of the circulation flow path and the refrigerant outlet port PO2 and the pipe 92 connected to the inlet of the receiver 73. Will be done.
  • the outdoor unit 2 further includes a gas vent pipe 93 that connects the gas discharge port of the receiver 73 and the second passage H2 and discharges the refrigerant gas in the receiver 73, and the gas vent pipe 93 and the second passage H2.
  • a throttle device 70 arranged between the pipe 94 and the pipe 94 leading to the above, and a flow rate adjusting valve 72 for adjusting the refrigerant flow rate of the pipe 94 connected to the liquid refrigerant discharge port of the receiver 73 are provided.
  • the pipe 91 is a pipe that branches from the main refrigerant circuit and allows the refrigerant to flow into the liquid receiver 73.
  • the second expansion valve 71 is an electronic expansion valve capable of reducing the refrigerant in the high pressure portion of the main refrigerant circuit to an intermediate pressure.
  • the liquid receiver 73 is a container capable of separating the gas phase and the liquid phase of the refrigerant which has been decompressed into two phases in the container, storing the refrigerant, and adjusting the circulation amount of the refrigerant in the main refrigerant circuit.
  • the degassing pipe 93 connected to the upper part of the receiver 73 and the pipe 94 connected to the lower part of the receiver 73 are in a state where the refrigerant separated into the gas refrigerant and the liquid refrigerant is separated in the receiver 73. It is a pipe for taking out.
  • the flow rate adjusting valve 72 can adjust the amount of refrigerant in the liquid receiver 73 by adjusting the amount of liquid refrigerant discharged from the pipe 94.
  • the liquid receiver 73 By providing the liquid receiver 73 in the injection flow path in this way, it becomes easy to secure the degree of supercooling in the pipes 82 and 83 which are the liquid pipes. This is because, in general, since the gas refrigerant is present in the receiver 73, the refrigerant temperature becomes the saturation temperature, and therefore, if the receiver 73 is arranged in the pipe 82, the degree of supercooling cannot be ensured.
  • the intermediate pressure liquid refrigerant can be stored inside the receiver 73 even when the pressure in the high pressure portion of the main refrigerant circuit is high and the refrigerant is in a supercritical state. It will be possible. Therefore, the design pressure of the container of the receiver 73 can be made lower than that of the high-pressure portion, and the cost can be reduced by thinning the container.
  • the outdoor unit 2 further includes pressure sensors 110 and 111, temperature sensors 120 to 123, and a control device 100 that controls a compressor 10, a second expansion valve 71, and a flow rate adjusting valve 72.
  • the pressure sensor 110 detects the pressure PL of the suction port portion of the compressor 10 and outputs the detected value to the control device 100.
  • the pressure sensor 111 detects the discharge pressure PH of the compressor 10 and outputs the detected value to the control device 100.
  • the temperature sensor 120 detects the discharge temperature TH of the compressor 10 and outputs the detected value to the control device 100.
  • the temperature sensor 121 detects the refrigerant temperature T1 of the pipe 81 at the outlet of the condenser 20, and outputs the detected value to the control device 100.
  • the temperature sensor 122 detects the refrigerant temperature T2 at the outlet of the first passage H1 on the cooled side of the heat exchanger 30 and outputs the detected value to the control device 100.
  • the temperature sensor 123 detects the outside air temperature TA, which is the ambient temperature of the outdoor unit 2, and outputs the detected value to the control device 100.
  • the second flow path F2 controls the discharge temperature TH of the compressor 10 by inflowing the refrigerant which has become two phases by depressurizing into the compressor 10.
  • the amount of refrigerant in the main refrigerant circuit can be adjusted by the receiver 73 installed on the second flow path F2.
  • the second flow path F2 is also responsible for ensuring supercooling of the refrigerant in the main refrigerant circuit by heat exchange by the heat exchanger 30.
  • the control device 100 includes a CPU (Central Processing Unit) 102, a memory 104 (ROM (Read Only Memory) and RAM (Random Access Memory)), an input / output buffer (not shown) for inputting / outputting various signals, and the like. Consists of including.
  • the CPU 102 expands the program stored in the ROM into a RAM or the like and executes the program.
  • the program stored in the ROM is a program in which the processing procedure of the control device 100 is described.
  • the control device 100 executes control of each device in the outdoor unit 2 according to these programs. This control is not limited to software processing, but can also be processed by dedicated hardware (electronic circuit).
  • the control device 100 feedback-controls the second expansion valve 71 so that the discharge temperature TH of the compressor 10 matches the target temperature.
  • FIG. 2 is a flowchart for explaining the control of the second expansion valve 71.
  • the control device 100 increases the opening degree of the second expansion valve 71 (S22). As a result, the amount of refrigerant flowing into the intermediate pressure port G3 via the liquid receiver 73 increases, so that the discharge temperature TH decreases.
  • the control device 100 reduces the opening degree of the second expansion valve 71 (S24). As a result, the amount of refrigerant flowing into the intermediate pressure port G3 via the liquid receiver 73 is reduced, so that the discharge temperature TH rises.
  • the control device 100 maintains the opening degree of the second expansion valve 71 in the current state.
  • control device 100 controls the opening degree of the second expansion valve 71 so that the discharge temperature TH of the compressor 10 approaches the target temperature.
  • control device 100 feeds back the flow rate adjusting valve 72 so that the refrigerant temperature T1 at the outlet of the condenser 20 matches the target temperature in order to secure the supercooling degree SC of the refrigerant at the outlet of the condenser 20. Control.
  • FIG. 3 is a flowchart for explaining the control of the flow rate adjusting valve 72.
  • the control device 100 determines the flow rate adjusting valve 72. (S32).
  • the amount of liquid refrigerant discharged from the receiver 73 decreases and the amount of liquid refrigerant in the receiver 73 increases, so that the amount of refrigerant circulating in the main refrigerant circuit decreases and the refrigerant temperature T1 rises. Therefore, the degree of supercooling SC is reduced.
  • the control device 100 when the supercooling degree SC determined by the refrigerant temperature T1 at the outlet of the condenser 20 and the pressure of the condenser 20 (approximate by PH) is smaller than the target value (NO in S31 and YES in S33), the control device 100 , The opening degree of the flow rate adjusting valve 72 is increased (S34). As a result, the amount of liquid refrigerant discharged from the receiver 73 increases and the amount of liquid refrigerant stored in the receiver 73 decreases, so that the amount of refrigerant circulating in the main refrigerant circuit increases and the refrigerant temperature T1 rises. As it decreases, the degree of supercooling SC increases.
  • control device 100 maintains the opening degree of the flow rate adjusting valve 72 in the current state.
  • control device 100 controls the opening degree of the flow rate adjusting valve 72 so that the refrigerant temperature T1 at the outlet of the condenser 20 approaches the target temperature.
  • control device 100 feeds back the flow rate adjusting valve 72 so that the refrigerant temperature T1 at the outlet of the condenser 20 matches the target temperature in order to secure the supercooling degree SC of the refrigerant at the outlet of the condenser 20. While controlling, in the pump down operation, the flow rate adjusting valve 72 is closed and the liquid refrigerant is collected in the liquid receiver 73.
  • An on-off valve 28 or the like is installed in the pipe 85 through which the liquid refrigerant flows in the main refrigerant circuit, and the compressor 10 is operated with the pipe 85 shut off to move the refrigerant from the load device 3 to the outdoor unit 2 and store the refrigerant. This is called pump-down operation.
  • the pump-down operation is performed, for example, by closing the first expansion valve 50 before stopping the operation, closing the on-off valve 28, and then operating the compressor 10.
  • the signal instructing the start of the pump down operation is not transmitted from the load device 3 side to the outdoor unit 2, and in the outdoor unit 2, the pressure PL of the low pressure portion detected by the pressure sensor 110 is a threshold value.
  • the pump-down operation is executed by continuing the normal operation when the PA drops to PA.
  • the control device 100 stops the compressor 10 to stop the pump down. It has become. Since the compressor 10 is configured so that the refrigerant does not pass through in the stopped state, the refrigerant does not flow back to the load device 3.
  • FIG. 4 is a flowchart for explaining control during pump down operation.
  • the control device 100 determines whether or not the pressure PL of the low pressure portion detected by the pressure sensor 110 is lower than the threshold PA.
  • PL ⁇ threshold PA is satisfied (YES in S41)
  • the pump down operation after step S42 is executed.
  • PL ⁇ threshold PA is not established (NO in S41)
  • the pump down operation is not executed, and the control is returned to the normal operation process in step S47.
  • step S42 the control device 100 determines whether or not the refrigerant temperature T1 in the condenser 20 is lower than TA + ⁇ .
  • ⁇ indicates a temperature difference in which the efficiency of condensation of the refrigerant in the condenser 20 is significantly reduced when the temperature difference between the refrigerant and the outside air becomes smaller than this, and is a value appropriately determined.
  • the control device 100 closes the flow rate adjusting valve 72 in step S43. As a result, the gas refrigerant is discharged from the liquid receiver 73 from the degassing pipe 93, and the liquid refrigerant is recovered in the liquid receiver 73.
  • the control device 100 slightly increases the opening degree of the flow rate adjusting valve 72 in step S44.
  • the liquid refrigerant stored in the liquid receiver 73 flows into the second passage H2 of the heat exchanger 30.
  • the flow rate adjusting valve 72 is closed, the gas refrigerant flows from the gas vent pipe 93 in the second passage H2 of the heat exchanger 30.
  • the heat transfer coefficient between the refrigerant and the heat exchanger in the second passage H2 is low.
  • the heat transfer coefficient between the refrigerant and the heat exchanger in the second passage H2 is improved by 10 times or more.
  • the recovery of the liquid refrigerant can be promoted by condensing the refrigerant, which is difficult to be condensed in the condenser 20 when the recovery of the liquid refrigerant has progressed to some extent, in the heat exchanger 30.
  • the opening degree of the flow rate adjusting valve 72 is made too large, the amount of liquid refrigerant recovered will not increase. Therefore, the opening degree of the flow rate adjusting valve 72 in step S44 increases the amount of liquid refrigerant recovered in the receiver 73. Within the range to be used.
  • control device 100 further increases the rotation speed of the compressor 10 in step S37. As a result, it is possible to shorten the time for recovering the remaining refrigerant, which has been recovered and is difficult to condense.
  • step S46 the control device 100 determines whether or not the pressure PL of the low pressure portion detected by the pressure sensor 110 has dropped to the threshold value PB.
  • the threshold value PB is a value lower than the threshold value PA, and is a determination value for determining that the recovery of the refrigerant of the load device 3 is completed. As long as the pressure PL does not drop to the threshold value PB (NO in S46), the control device 100 continues the operation of the compressor 10 and continues the pump-down operation.
  • the control device 100 stops the compressor 10 and ends the pump down in step S47.
  • the control device 100 closes the flow rate adjusting valve 72 to store the liquid refrigerant in the receiver 73. Then, at the second time point in which the amount of the liquid refrigerant in the liquid receiver 73 increases and the efficiency of the condenser 20 decreases, the control device 100 slightly opens the flow rate adjusting valve 72 to improve the efficiency of the heat exchanger 30. Then, the condensation of the refrigerant in the first passage H1 is promoted. As a result, the time required to complete the pump-down operation can be shortened.
  • the present disclosure is an outdoor unit of a refrigeration cycle device 1 configured to be connected to a load device 3 including a first expansion valve 50 and an evaporator 60 corresponding to a "first expansion device".
  • the outdoor unit 2 includes a first flow path F1 that forms a circulation flow path through which the refrigerant circulates by being connected to the load device 3, and a compressor 10 and a condenser 20 that are arranged in the first flow path F1.
  • the second flow path F2 is configured to branch from the branch point of the first flow path F1 downstream of the condenser 20 and return the refrigerant that has passed through the condenser 20 to the compressor 10.
  • the second expansion valve 71, the receiver 73, and the flow rate adjusting valve 72, which correspond to the "second expansion device" are arranged in the second flow path F2 in order from the branch point, and the first passage H1 and the second passage. It includes a heat exchanger 30 having H2 and configured to exchange heat between the refrigerant flowing through the first passage H1 and the refrigerant flowing through the second passage H2, and the control device 100.
  • the first passage H1 of the heat exchanger 30 is arranged between the condenser 20 of the first flow path F1 and the branch point.
  • the second passage H2 of the heat exchanger 30 is arranged between the flow rate adjusting valve 72 of the second flow path F2 and the compressor 10.
  • the flow rate adjusting valve 72 is configured to adjust the discharge flow rate of the liquid refrigerant from the receiving receiver 73.
  • the control device 100 is configured to control the compressor 10 and the flow rate adjusting valve 72.
  • the control device 100 adjusts the control state of the compressor 10 and the flow rate adjusting valve 72 while operating the compressor 10 at the first time point.
  • the valve 72 is controlled to the first closed state.
  • the control device 100 is configured to transition from the first state to the second state in which the flow rate adjusting valve 72 is opened while operating the compressor 10 at the second time point after the first time point during the pump down operation. To.
  • the amount of the liquid refrigerant in the receiver 73 at the second time point is larger than the amount of the liquid refrigerant in the liquid receiver 73 at the first time point.
  • the control device 100 sets the control state of the compressor 10 and the flow rate adjusting valve 72 to the second state when the difference between the condensation temperature of the refrigerant in the condenser 20 and the outside air temperature becomes smaller than the threshold value. Control.
  • the control device 100 sets the control state of the compressor 10 and the flow rate adjusting valve 72 to the second state when the difference between the condensation temperature of the refrigerant in the condenser 20 and the outside air temperature becomes smaller than the threshold value. Control.
  • the control device 100 sets the control state of the compressor 10 and the flow rate adjusting valve 72 to the second state when the difference between the condensation temperature of the refrigerant in the condenser 20 and the outside air temperature becomes smaller than the threshold value. Control.
  • the opening degree of the flow rate adjusting valve 72 in the second state is fully opened for a long time, the amount of the liquid refrigerant in the receiver 73 will decrease. Therefore, in the second state, it is sufficient to open the flow rate adjusting valve 72 with a slight opening degree such that a circular flow of the liquid refrigerant is generated in the second passage H2 of the heat exchanger 30, or to repeatedly open and close for a short time. .. As a result, the efficiency of heat exchange in the heat exchanger 30 is improved, and the refrigerant passing through the first passage H1 is condensed in the heat exchanger 30, so that the recovery of the liquid refrigerant is promoted.
  • control device 100 is configured so that the rotation speed of the compressor 10 in the second state is higher than the rotation speed of the compressor 10 in the first state. As a result, it is possible to shorten the time for recovering the remaining refrigerant, which has been recovered and is difficult to condense.
  • the refrigeration cycle device 1 may be used as an air conditioner or the like.
  • 1 refrigeration cycle device 1 outdoor unit, 3 load device, 10 compressor, 20 condenser, 22 fan, 28 on-off valve, 30 heat exchanger, 71 second expansion valve, 50 first expansion valve, 60 evaporator, 70 Equipment, 72 flow control valve, 73 receiver, 74 flow path switching unit, 80, 81, 82, 83, 84, 85, 88, 89, 91, 92, 94, 96 piping, 93 degassing piping, 100 control Equipment, 104 memory, 110, 111 pressure sensor, 120, 121, 122, 123 temperature sensor, F1 first flow path, F2 second flow path, G1 suction port, G2 discharge port, G3 intermediate pressure port, H1 first passage , H2 2nd passage.

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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)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)
PCT/JP2019/035373 2019-09-09 2019-09-09 室外ユニットおよび冷凍サイクル装置 Ceased WO2021048901A1 (ja)

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PCT/JP2019/035373 WO2021048901A1 (ja) 2019-09-09 2019-09-09 室外ユニットおよび冷凍サイクル装置
ES19944704T ES2964488T3 (es) 2019-09-09 2019-09-09 Unidad exterior y dispositivo de ciclo de refrigeración
JP2021544990A JP7224480B2 (ja) 2019-09-09 2019-09-09 室外ユニットおよび冷凍サイクル装置
CN201980099962.8A CN114341567B (zh) 2019-09-09 2019-09-09 室外单元以及冷冻循环装置
FIEP19944704.6T FI4030116T3 (fi) 2019-09-09 2019-09-09 Ulkoyksikkö ja jäähdytyssyklilaite
EP19944704.6A EP4030116B1 (en) 2019-09-09 2019-09-09 Outdoor unit and refrigeration cycle device
DK19944704.6T DK4030116T3 (da) 2019-09-09 2019-09-09 Udendørsenhed og kølekredsløbsindretning

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CN113294925A (zh) * 2021-05-21 2021-08-24 浙江国祥股份有限公司 一种带复合式经济器的蒸发冷凝式冷水机组
WO2023199511A1 (ja) * 2022-04-15 2023-10-19 三菱電機株式会社 冷凍サイクル装置
WO2024023993A1 (ja) * 2022-07-27 2024-02-01 三菱電機株式会社 冷凍サイクル装置
EP4411278A4 (en) * 2021-10-18 2025-01-15 Mitsubishi Heavy Industries Thermal Systems, Ltd. Freezing apparatus

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JP2014001917A (ja) 2012-05-23 2014-01-09 Daikin Ind Ltd 冷凍装置
JP2014102008A (ja) * 2012-11-16 2014-06-05 Panasonic Corp 冷凍装置
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CN113294925A (zh) * 2021-05-21 2021-08-24 浙江国祥股份有限公司 一种带复合式经济器的蒸发冷凝式冷水机组
EP4411278A4 (en) * 2021-10-18 2025-01-15 Mitsubishi Heavy Industries Thermal Systems, Ltd. Freezing apparatus
WO2023199511A1 (ja) * 2022-04-15 2023-10-19 三菱電機株式会社 冷凍サイクル装置
WO2024023993A1 (ja) * 2022-07-27 2024-02-01 三菱電機株式会社 冷凍サイクル装置

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EP4030116A1 (en) 2022-07-20
ES2964488T3 (es) 2024-04-08
CN114341567A (zh) 2022-04-12
JPWO2021048901A1 (https=) 2021-03-18
EP4030116A4 (en) 2022-09-07
EP4030116B1 (en) 2023-10-11

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