WO2025062532A1 - 冷凍サイクル装置 - Google Patents

冷凍サイクル装置 Download PDF

Info

Publication number
WO2025062532A1
WO2025062532A1 PCT/JP2023/034105 JP2023034105W WO2025062532A1 WO 2025062532 A1 WO2025062532 A1 WO 2025062532A1 JP 2023034105 W JP2023034105 W JP 2023034105W WO 2025062532 A1 WO2025062532 A1 WO 2025062532A1
Authority
WO
WIPO (PCT)
Prior art keywords
oil
compressor
gas
pipe
oil tank
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.)
Pending
Application number
PCT/JP2023/034105
Other languages
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
Original Assignee
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/JP2023/034105 priority Critical patent/WO2025062532A1/ja
Priority to JP2025547047A priority patent/JPWO2025062532A1/ja
Publication of WO2025062532A1 publication Critical patent/WO2025062532A1/ja
Anticipated expiration legal-status Critical
Pending legal-status Critical Current

Links

Images

Classifications

    • 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

Definitions

  • This disclosure relates to a refrigeration cycle device.
  • Some refrigeration cycle devices are equipped with an oil return mechanism that holds a surplus of refrigeration oil and returns the required amount to the compressor to prevent a shortage of lubricating oil (refrigeration oil) in the compressor.
  • the refrigeration cycle device described in JP 2010-71568 A (Patent Document 1) is equipped with an oil return mechanism, an accumulator for separating and holding the refrigeration oil discharged from the compressor together with the refrigerant, and an oil regulator for preventing an excessive amount of refrigeration oil from being returned from the accumulator to the compressor.
  • the oil regulator is connected to the compressor via a suction pipe and a pressure equalizing pipe, and the pressure and oil level in the oil regulator are set to be the same as those in the compressor.
  • a float valve provided in the oil regulator is opened, and the excess oil in the accumulator is supplied to the compressor via the oil regulator and the suction pipe.
  • the oil return mechanism described above cannot be applied to a refrigeration cycle apparatus that uses a refrigerant, such as carbon dioxide (CO 2 ), whose operating pressure is higher than the withstand pressure of a typical float valve.
  • a refrigerant such as carbon dioxide (CO 2 )
  • the main objective of this disclosure is to provide a refrigeration cycle device that can avoid a shortage of refrigeration oil in the compressor and prevent oversupply of refrigeration oil to the compressor, even when a refrigerant with a high operating pressure is used.
  • the refrigeration cycle device of the present disclosure includes a main circuit having a compressor, a condenser, an expansion valve, an evaporator, a gas-liquid separator, and a suction pipe, and an oil return passage connected between the gas-liquid separator and the compressor and having an oil return pipe, an on-off valve, an oil tank, and an oil equalizing pipe and a pressure equalizing pipe.
  • the compressor discharges a working medium containing a refrigerant and a refrigeration oil.
  • the gas-liquid separator is configured to separate the working medium flowing out from the evaporator into a gas phase portion and a liquid phase portion.
  • the gas-liquid separator has a first outlet through which the gas phase portion of the working medium flows out, and a second outlet through which the liquid phase portion of the working medium flows out.
  • the suction pipe connects between the first outlet and the suction port of the compressor.
  • the oil return pipe connects between the second outlet and the oil tank.
  • the on-off valve opens and closes the oil return pipe.
  • the volume of the oil tank is larger than the volume of the compressor.
  • the oil equalizing pipe and the pressure equalizing pipe are connected in parallel between the oil tank and the compressor.
  • the oil equalization pipe is disposed below the pressure equalization pipe.
  • the refrigeration cycle device further includes a sensor for detecting the degree of superheat of the refrigerant flowing through the suction pipe, and a control device for controlling the opening degree of the on-off valve according to the degree of superheat detected by the sensor.
  • the refrigeration cycle device disclosed herein can avoid a shortage of refrigeration oil in the compressor and prevent oversupply of refrigeration oil to the compressor, even when a refrigerant with a high operating pressure is used.
  • FIG. 11 is a diagram for explaining a first modified example of the refrigeration cycle device according to the embodiment.
  • FIG. 11 is a diagram for explaining a second modified example of the refrigeration cycle device according to the embodiment.
  • FIG. 1 is a refrigerant circuit diagram of the refrigeration cycle device 100 according to an embodiment.
  • the refrigeration cycle device 100 according to an embodiment is, for example, a refrigerator.
  • the refrigeration cycle device 100 includes a main circuit MC and an oil return line RC.
  • the oil return line RC branches off from the main circuit MC.
  • the refrigeration cycle device 100 according to the embodiment also includes a sensor 20 and a control device 30.
  • the main circuit MC has a compressor 1, a condenser 2, an expansion valve 3, an evaporator 4, a gas-liquid separator 5, and a suction pipe SP.
  • the main circuit MC is configured so that the refrigerant flows through the compressor 1, condenser 2, expansion valve 3, evaporator 4, gas-liquid separator 5, and suction pipe SP in that order.
  • the main circuit MC is configured by connecting the compressor 1, condenser 2, expansion valve 3, evaporator 4, and gas-liquid separator 5 via piping.
  • the suction pipe SP is a pipe that connects the gas-liquid separator 5 and the compressor 1 in the main circuit MC.
  • the oil return line RC branches off from the main circuit MC.
  • the oil return line RC connects the gas-liquid separator 5 and the compressor 1.
  • the oil return line RC has an oil return pipe RP, an on-off valve 6, an oil tank 7, an oil equalizing pipe OE, and a pressure equalizing pipe PE.
  • the oil return line RC is configured so that the refrigeration oil flows in the following order: gas-liquid separator 5, oil return pipe RP, on-off valve 6, oil tank 7, and oil equalizing pipe OE.
  • the compressor 1 compresses the refrigerant that is sucked in and discharges it.
  • the compressor 1 includes a compressor body (not shown) and a sealed container 11 that houses the compressor body.
  • the compressor body includes an electric unit and a compression unit that is driven by the electric unit to compress the refrigerant in the sealed container 11.
  • the sealed container 11 has an inner bottom surface 11A that extends along the horizontal direction and an inner side surface 11B that extends in a direction intersecting the inner bottom surface 11A.
  • the compressor body is disposed on the inner bottom surface 11A of the sealed container 11.
  • the inner bottom surface 11A of the sealed container 11 is referred to as the inner bottom surface 11A of the compressor 1.
  • the area of the inner bottom surface 11A of the compressor 1 is smaller than the area of the inner bottom surface 71A of the oil tank described later.
  • the suction volume of the compression unit is referred to as the volume of the compressor 1.
  • Refrigeration oil is stored in the compressor 1.
  • the refrigeration oil acts as a lubricant for the compression section of the compressor 1.
  • the compressor 1 discharges a working medium containing a refrigerant and refrigeration oil.
  • the compressor 1 has a discharge port 12 for discharging the working medium to the outside of the sealed container 11, a suction port 13 for drawing the refrigerant into the inside of the sealed container 11, an oil return port 14 for returning the refrigeration oil to the inside of the sealed container 11, and a communication port 15 for allowing gas refrigerant to flow between the sealed container 11 and the oil tank 7.
  • the discharge port 12 is connected to the condenser 2 via a discharge pipe.
  • the suction port 13 is connected to the gas-liquid separator 5 via a suction pipe SP.
  • the oil return port 14 is connected to the oil tank 7 via an oil equalizing pipe OE.
  • the communication port 15 is connected to the oil tank 7 via a pressure equalizing pipe PE.
  • the communication port 15 is located above the oil return port 14.
  • the communication port 15 is located, for example, below the suction port 13.
  • the refrigeration oil discharged from the discharge port 12 of the compressor 1 flows together with the refrigerant to the gas-liquid separator 5 in the main circuit MC, then passes through the oil return line RC and is returned to the inside of the sealed container 11 from the oil return port 14 of the compressor 1.
  • the refrigeration oil stored in the compressor 1 is set to an appropriate amount in order to operate the compressor 1 normally.
  • the refrigeration oil stored in the compressor 1 is set to a required minimum amount and a maximum allowable amount.
  • the amount of refrigeration oil stored in the compressor 1 is maintained at or above the required minimum amount and below the maximum allowable amount.
  • the oil return port 14 is configured to be located below the oil level OL of the refrigeration oil when this minimum amount of refrigeration oil is stored in the sealed container 11.
  • the communication port 15 is configured to be located above the oil level OL of the refrigeration oil when this maximum amount of refrigeration oil is stored in the sealed container 11.
  • Compressor 1 may be a so-called two-stage compressor that includes a low-stage compression section that compresses low-pressure refrigerant into intermediate-pressure refrigerant, and a high-stage compression section that compresses the intermediate-pressure refrigerant into high-pressure refrigerant.
  • the sum of the suction volumes of the compression sections is referred to as the volume of compressor 1.
  • the condenser 2 is configured to condense the refrigerant discharged from the discharge port 12 of the compressor 1.
  • the condenser 2 is, for example, a fin-and-tube type heat exchanger having a plurality of fins and a heat transfer tube passing through the plurality of fins.
  • the expansion valve 3 is configured to reduce the pressure of the refrigerant flowing out of the condenser 2.
  • the expansion valve 3 is, for example, a solenoid valve.
  • the expansion valve 3 can adjust the flow rate of the refrigerant based on instructions from, for example, the control device 30.
  • the evaporator 4 is configured to evaporate the refrigerant that flows out from the expansion valve 3.
  • the evaporator 4 is, for example, a fin-and-tube type heat exchanger having multiple fins and a heat transfer tube that passes through the multiple fins.
  • the gas-liquid separator 5 is configured to separate the working medium flowing out from the evaporator 4 into a gas phase portion and a liquid phase portion.
  • the gas-liquid separator 5 may have any configuration as long as it can separate the working medium flowing out from the evaporator 4 into gas and liquid portions.
  • the gas-liquid separator 5 shown in FIG. 2 is an accumulator.
  • the gas phase portion of the working medium separated by the gas-liquid separator 5 is composed of gas refrigerant.
  • the liquid phase portion of the working medium separated by the gas-liquid separator 5 contains refrigerating machine oil.
  • the liquid phase portion of the working medium separated by the gas-liquid separator 5 is composed of, for example, liquid refrigerant and refrigerating machine oil.
  • the gas-liquid separator 5 has a container 51 capable of storing both the gas phase and liquid phase of the working medium, an inlet 52 through which the working fluid flowing out of the evaporator 4 flows into the container 51, a first outlet 53 through which the gas phase of the working medium flows out from inside the container 51 to the outside, and a second outlet 54 through which the liquid phase of the working medium flows out from inside the container 51 to the outside.
  • the inlet 52 is positioned to face the inner circumferential surface of the container 51.
  • the first outlet 53 is positioned above the second outlet 54.
  • the suction pipe SP connects the first outlet 53 of the gas-liquid separator 5 and the suction port 13 of the compressor 1.
  • the suction pipe SP is configured to guide the gas phase portion of the working medium separated in the gas-liquid separator 5 to the compressor 1.
  • the oil return line RC is connected between the gas-liquid separator 5 and the compressor 1.
  • the oil return line RC connects the second outlet 54 of the gas-liquid separator 5 and the oil return port 14 of the compressor 1.
  • the oil return line RC has an oil return pipe RP, an on-off valve 6, an oil tank 7, an oil equalizing pipe OE, and a pressure equalizing pipe PE.
  • the oil return line RC is configured so that refrigeration oil flows through the oil return pipe RP, the oil tank 7, and the oil equalizing pipe OE in that order.
  • the oil return line RC is configured by connecting the gas-liquid separator 5, the on-off valve 6, the oil tank 7, and the compressor 1 via piping.
  • the oil return pipe RP is a pipe that connects the second outlet 54 of the gas-liquid separator 5 and the inlet 72 of the oil tank 7.
  • the oil return pipe RP is configured to guide the liquid phase portion of the working medium separated in the gas-liquid separator 5 to the oil tank 7.
  • the on-off valve 6 opens and closes the oil return pipe RP.
  • the on-off valve 6 is, for example, a solenoid valve.
  • the on-off valve 6 is configured to be able to open and close the oil return pipe RP based on instructions from the control device 30.
  • the oil tank 7 is capable of storing refrigeration oil and liquid refrigerant.
  • the volume of the oil tank 7 is larger than the volume of the compressor 1.
  • the volume of the oil tank 7 is larger than the volume of the container 51 of the gas-liquid separator 5.
  • the volume of the oil tank 7 is larger than the sum of the volume of the container 51 of the gas-liquid separator 5 and the volume of the portion of the oil return pipe RP that is located closer to the second outlet 52 of the gas-liquid separator 5 than the on-off valve 6.
  • the compressor 1 holds the amount of refrigeration oil required for lubrication, and the oil tank 7 holds an excess amount of refrigeration oil (surplus oil).
  • the amount of refrigeration oil stored in the oil tank 7 is greater than the amount of refrigeration oil stored in the compressor 1.
  • the oil tank 7 can store the entire amount of refrigeration oil contained in the main circuit MC and the oil return line RC.
  • the mass fraction of the refrigeration oil is higher than the mass fraction of the liquid refrigerant.
  • the oil tank 7 has a sufficiently large volume relative to the compressor 1 so that the refrigeration oil stored in the oil tank 7 is not diluted by the liquid refrigerant to an extent that it cannot function as a lubricant.
  • the volume of the oil tank 7 is, for example, at least twice the volume of the compressor 1, or it may be at least three times, or it may be at least five times.
  • the oil tank 7 has a container 71 capable of storing refrigeration oil and liquid refrigerant, an inlet 72 connected to the second outlet 54 of the gas-liquid separator 5 via an oil return pipe RP, a third outlet 73 connected to the oil return port 14 of the compressor 1 via an oil equalization pipe OE, and a communication port 74 connected to the communication port 15 of the compressor 1 via a pressure equalization pipe PE.
  • the communication port 74 is located above the third outlet 73.
  • the container 71 has an inner bottom surface 71A extending horizontally and an inner side surface 71B extending in a direction intersecting the inner bottom surface 71A.
  • the area of the inner bottom surface 71A of the oil tank 7 is larger than the area of the inner bottom surface 11A of the compressor 1.
  • the maximum dimension (width) of the inner bottom surface 71A of the oil tank 7 is larger than the maximum dimension (height) of the inner side surface 71B of the oil tank 7 in a direction perpendicular to the inner bottom surface 71A of the oil tank 7 (up-down direction).
  • the volume of the oil tank 7 is larger than the volume of a typical oil regulator.
  • the area of the inner bottom surface 71A of the oil tank 7 is larger than the area of the inner bottom surface of a typical oil regulator.
  • the oil equalization pipe OE and the pressure equalization pipe PE are pipes that connect the oil tank 7 and the compressor 1 in parallel.
  • the oil equalization pipe OE is located lower than the pressure equalization pipe PE.
  • the oil equalization pipe OE is configured to allow refrigeration oil containing liquid refrigerant to flow through it.
  • the pressure equalization pipe PE is configured to allow the gas phase portion (gas refrigerant) to flow through it.
  • the oil equalization pipe OE and the pressure equalization pipe PE connect the oil tank 7 and the compressor 1 in parallel so that the liquid level LL of the refrigeration oil containing liquid refrigerant stored in the oil tank 7 is aligned with the oil level OL of the refrigeration oil stored in the compressor 1.
  • the liquid level LL being aligned with the oil level OL means that the liquid level LL and the oil level OL are located on the same plane.
  • the inner bottom surface 71A of the oil tank 7 is arranged, for example, on the same plane as the inner bottom surface 11A of the compressor 1.
  • the height of the liquid level LL of the refrigeration oil and liquid refrigerant stored in the oil tank 7 is equal to the height of the oil level OL of the refrigeration oil stored in the compressor 1.
  • the volume and shape of the oil tank 7 are configured so that the oil level OL and the liquid level LL do not exceed the height of the oil level OL when the maximum amount of refrigeration oil is stored in the sealed container 11.
  • the oil equalization pipe OE is provided below the pressure equalization pipe PE.
  • the oil equalization pipe OE and the pressure equalization pipe PE are configured so as not to disturb the oil level in the compressor 1 and the liquid level in the oil tank 7 when the refrigeration oil flows in and out between the oil tank 7 and the compressor 1 via the oil equalization pipe OE and the gas-phase refrigerant flows in and out between the oil tank 7 and the compressor 1 via the pressure equalization pipe PE.
  • the oil equalization pipe OE is configured to be located below the oil level in the compressor 1 and the liquid level in the oil tank 7 when the minimum amount of refrigeration oil is stored in the compressor 1.
  • the pressure equalization pipe PE is configured to be located above the oil level in the compressor 1 and the liquid level in the oil tank 7 when the maximum amount of refrigeration oil is stored in the compressor 1.
  • Sensor 20 is configured to detect the degree of superheat (hereinafter referred to as suction superheat) of the refrigerant flowing through suction pipe SP.
  • Suction superheat means the temperature difference between the temperature of the refrigerant sucked into compressor 1 (hereinafter referred to as suction temperature) and the saturated gas temperature corresponding to the pressure of the refrigerant sucked into compressor 1 (hereinafter referred to as suction pressure).
  • Sensor 20 includes a temperature sensor that detects the suction temperature and a pressure sensor that detects the suction pressure. Sensor 20 outputs a measured signal to control device 30.
  • the control device 30 controls the opening degree of the on-off valve 6 according to the above-mentioned suction superheat degree detected by the sensor 20.
  • the control device 30 is configured to open the on-off valve 6 when the suction superheat degree detected by the sensor 20 decreases to a first judgment value.
  • the control device 30 is configured to maintain the on-off valve 6 in a closed state when the suction superheat degree detected by the sensor 20 is higher than the first judgment value.
  • the first judgment value of the suction superheat degree for switching the on-off valve 6 from a closed state to an open state is, for example, 0 (zero).
  • the first judgment value of the suction superheat degree may be any number greater than zero.
  • the above-mentioned first judgment value of the suction superheat degree may be set as any value capable of suppressing the occurrence of liquid backflow to the compressor 1 and preventing the occurrence of overcharging of the compressor 1.
  • the control device 30 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory).
  • the CPU deploys and executes the control program stored in the ROM.
  • the refrigerant mainly circulates through the main circuit MC, and the refrigeration oil circulates through an oil return circuit that is composed of a flow path that connects the discharge port 12 of the compressor 1 and the gas-liquid separator 5 in the main circuit MC, and an oil return line RC.
  • the refrigerant that flows into the compressor 1 from the intake port 13 is compressed by the compressor 1 to become a high-temperature, high-pressure gas refrigerant, which is discharged together with refrigeration oil from the discharge port 12 of the compressor 1.
  • the working medium which contains the gas refrigerant and refrigeration oil discharged from the discharge port 12 of the compressor 1, flows into the condenser 2.
  • the gas refrigerant is condensed in the condenser 2 to become a liquid refrigerant, which flows out of the condenser 2 together with the refrigeration oil.
  • the working medium containing the liquid refrigerant and refrigeration oil flowing out of the condenser 2 flows into the expansion valve 3.
  • the liquid refrigerant is reduced in pressure by the expansion valve 3 to become a low-pressure two-phase gas-liquid refrigerant, which flows out from the expansion valve 3 together with the refrigeration oil.
  • the working medium containing the two-phase gas-liquid refrigerant and refrigeration oil flowing out of the expansion valve 3 flows into the evaporator 4.
  • the two-phase gas-liquid refrigerant is evaporated in the evaporator 4 to become a gas refrigerant, which flows out from the evaporator 4 together with the refrigeration oil.
  • the working medium containing gas refrigerant and refrigeration oil flowing out of the evaporator 4 flows into the gas-liquid separator 5, where it is separated into a gas phase portion containing gas refrigerant and a liquid phase portion containing liquid refrigerant and refrigeration oil.
  • the gas phase portion of the working medium separated in the gas-liquid separator 5 flows out from the first outlet 53 of the gas-liquid separator 5 and is sucked into the suction port 13 of the compressor 1 via the suction pipe SP. In this way, the refrigerant circulates through the main circuit MC of the refrigeration cycle device 100.
  • the liquid phase portion of the working medium separated in the gas-liquid separator 5 is stored in the gas-liquid separator 5 when the on-off valve 6 is closed.
  • the liquid phase portion of the working medium separated in the gas-liquid separator 5 flows out from the second outlet 54 of the gas-liquid separator 5 and into the oil tank 7 via the oil return pipe RP.
  • the liquid level LL in the oil tank 7 is kept even with the oil level OL in the compressor 1. This ensures that a sufficient amount of refrigeration oil is always stored in the compressor 1, making it possible to avoid a shortage of refrigeration oil.
  • the on-off valve 6 is closed when the degree of intake superheat detected by the sensor 20 is higher than the first judgment value.
  • the on-off valve 6 is open when the degree of intake superheat detected by the sensor 20 is equal to or lower than the first judgment value.
  • the suction superheat degree decreases when the amount of refrigeration oil stored in the compressor 1 decreases, or when the amount of liquid refrigerant stored in the gas-liquid separator 5 increases and the dryness of the refrigerant flowing into the suction pipe SP from the first outlet 53 decreases.
  • the on-off valve 6 is opened.
  • the volume of the oil tank 7 is larger than the sum of the volume of the container 51 of the gas-liquid separator 5 and the volume of the portion of the oil return pipe RP located on the second outlet 52 side of the gas-liquid separator 5 from the on-off valve 6. Therefore, even if the entire amount of liquid refrigerant stored in the gas-liquid separator 5 and the portion of the oil return pipe RP located on the second outlet 52 side from the on-off valve 6 flows into the oil tank 7 while the on-off valve 6 is closed, it is possible to avoid dilution of the refrigeration oil in the oil tank 7 and the compressor 1 by the liquid refrigerant.
  • the degree of intake superheat becomes higher than the first judgment value. After it is detected that the degree of intake superheat is higher than the first judgment value, the on-off valve 6 is closed again.
  • the gas-liquid separator 5 may be configured as an oil separator.
  • the gas-liquid separator 5 shown in Fig. 2 has a container 51, an inlet 52, a first outlet 53, and a second outlet 54, similar to the gas-liquid separator 5 shown in Fig. 1.
  • the inlet 52 is disposed so as to face the inner circumferential surface of the container 51.
  • the first outlet 53 is disposed above the second outlet 54.
  • the container 51 and the inlet 52 may be configured to make the working fluid flowing out from the inlet 52 flow in a spiral shape on the inner circumferential surface of the container 51, and to separate the refrigerating machine oil and the refrigerant by centrifugal forces applied to each of them.
  • the gas-liquid separator 5 may be configured as a branch pipe.
  • the gas-liquid separator 5 may be configured as a T-pipe, for example.
  • the gas-liquid separator 5 may also be configured as a Y-pipe.
  • the gas-liquid separator 5 shown in FIG. 3 has an inlet 52, a first outlet 53, and a second outlet 54, similar to the gas-liquid separator 5 shown in FIG. 1.
  • the inlet 52 is arranged to face a portion of the inner circumferential surface of the T-shaped tube or Y-shaped tube that extends in the vertical direction between the first outlet 53 and the second outlet 54.
  • the first outlet 53 is arranged above the second outlet 54.
  • the first outlet 53 is arranged above the portion of the inner circumferential surface of the T-shaped tube or Y-shaped tube that faces the inlet 52.
  • the second outlet 54 is arranged below the portion of the inner circumferential surface of the T-shaped tube or Y-shaped tube that faces the inlet 52.
  • the oil return line RC of the refrigeration cycle device 100 has an oil tank 7 with a volume larger than that of the compressor 1, instead of an oil regulator. Furthermore, in the refrigeration cycle device 100, the oil equalizing pipe OE and the pressure equalizing pipe PE are connected in parallel between the oil tank 7 and the compressor 1 so that the liquid level LL of the refrigeration oil and liquid refrigerant stored in the oil tank 7 is equal to the oil level OL of the refrigeration oil stored in the compressor 1. Therefore, according to the refrigeration cycle device 100, it is possible to avoid a shortage of refrigeration oil in the compressor 1 without using an oil regulator having a float valve. In other words, according to the refrigeration cycle device 100, it is possible to avoid a shortage of refrigeration oil in the compressor 1 even when a refrigerant with a high operating pressure is used.
  • the refrigeration cycle device 100 can use a refrigerant with an operating pressure of 10 MPa or more.
  • the refrigeration cycle device 100 can use carbon dioxide as the refrigerant.
  • the refrigeration cycle device 100 further includes a gas-liquid separator 5, an on-off valve 6 that opens and closes an oil return pipe RP that connects between the second outlet 54 of the gas-liquid separator 5 and the inlet 72 of the oil tank 7, a sensor 20 for detecting the superheat (suction superheat) of the refrigerant flowing through the suction pipe SP, and a control device 30 that controls the opening degree of the on-off valve 6 according to the suction superheat detected by the sensor 20.
  • the refrigeration cycle device 100 can suppress over-fueling and liquid backflow to the compressor 1 during normal operation, and prevent breakdowns in the compressor 1.
  • the on-off valve 6 can be closed when the suction superheat is higher than the first judgment value. This can prevent overcharging of the compressor 1. Furthermore, the on-off valve 6 can be opened when the suction superheat falls below the first judgment value. This can prevent liquid backflow to the compressor 1.
  • the first judgment value of the suction superheat for switching the on-off valve 6 from a closed state to an open state may be zero. This can suppress the occurrence of liquid backflow into the compressor 1, compared to when the first judgment value is less than zero.
  • the oil tank 7 is capable of storing the entire amount of refrigeration oil contained in the main circuit MC and the oil return line RC.
  • the volume of such an oil tank 7 is sufficiently larger than the volume of the compressor 1, and the amount of refrigeration oil stored in the oil tank 7 is greater than the amount of refrigeration oil stored in the compressor 1. Therefore, even when the on-off valve 6 is closed, refrigeration oil can be supplied from the oil tank 7 to the compressor 1 via the oil equalization pipe OE, so that a shortage of refrigeration oil in the compressor 1 can be avoided.
  • a situation in which the refrigeration oil stored in the oil tank 7 is diluted by liquid refrigerant to such an extent that it is no longer able to function as a lubricant can be avoided.
  • the area of the inner bottom surface 71A of the oil tank 7 is larger than the area of the inner bottom surface 11A of the compressor 1.
  • the maximum dimension of the inner bottom surface 71A of the oil tank 7 is larger than the maximum dimension of the inner side surface 71B of the oil tank 7 in a direction perpendicular to the inner bottom surface 71A of the oil tank 7.
  • the volume of such an oil tank 7 is sufficiently larger than the volume of the compressor 1, and the amount of refrigeration oil stored in the oil tank 7 is greater than the amount of refrigeration oil stored in the compressor 1.
  • the gas-liquid separator 5 may be an accumulator, an oil separator, or a branch pipe. If the gas-liquid separator 5 is a branch pipe, the refrigeration cycle device 100 can be made smaller than when the gas-liquid separator 5 is an accumulator or an oil separator.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Compressor (AREA)
PCT/JP2023/034105 2023-09-20 2023-09-20 冷凍サイクル装置 Pending WO2025062532A1 (ja)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/JP2023/034105 WO2025062532A1 (ja) 2023-09-20 2023-09-20 冷凍サイクル装置
JP2025547047A JPWO2025062532A1 (https=) 2023-09-20 2023-09-20

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2023/034105 WO2025062532A1 (ja) 2023-09-20 2023-09-20 冷凍サイクル装置

Publications (1)

Publication Number Publication Date
WO2025062532A1 true WO2025062532A1 (ja) 2025-03-27

Family

ID=95072405

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/034105 Pending WO2025062532A1 (ja) 2023-09-20 2023-09-20 冷凍サイクル装置

Country Status (2)

Country Link
JP (1) JPWO2025062532A1 (https=)
WO (1) WO2025062532A1 (https=)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010071568A (ja) * 2008-09-19 2010-04-02 Mitsubishi Electric Corp 冷凍装置
WO2014045394A1 (ja) * 2012-09-21 2014-03-27 三菱電機株式会社 冷凍装置
JP2014214913A (ja) * 2013-04-23 2014-11-17 三菱電機株式会社 油戻し制御装置及び冷凍装置
JP2017032163A (ja) * 2015-07-29 2017-02-09 パナソニックＩｐマネジメント株式会社 空気調和装置
WO2018116407A1 (ja) * 2016-12-21 2018-06-28 三菱電機株式会社 冷凍サイクル装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010071568A (ja) * 2008-09-19 2010-04-02 Mitsubishi Electric Corp 冷凍装置
WO2014045394A1 (ja) * 2012-09-21 2014-03-27 三菱電機株式会社 冷凍装置
JP2014214913A (ja) * 2013-04-23 2014-11-17 三菱電機株式会社 油戻し制御装置及び冷凍装置
JP2017032163A (ja) * 2015-07-29 2017-02-09 パナソニックＩｐマネジメント株式会社 空気調和装置
WO2018116407A1 (ja) * 2016-12-21 2018-06-28 三菱電機株式会社 冷凍サイクル装置

Also Published As

Publication number Publication date
JPWO2025062532A1 (https=) 2025-03-27

Similar Documents

Publication Publication Date Title
JP5084950B2 (ja) 冷凍装置
JP5502459B2 (ja) 冷凍装置
JPH0232547B2 (https=)
JP2010127531A (ja) 冷凍空調装置
US6606867B1 (en) Suction line heat exchanger storage tank for transcritical cycles
WO2003036188A1 (en) Refrigerating equipment
JP7122507B2 (ja) 冷凍サイクル装置
JP5484890B2 (ja) 冷凍装置
KR100846567B1 (ko) 냉동장치
JP6080031B2 (ja) 冷凍装置
JP2013155972A (ja) 冷凍装置
JP6179842B2 (ja) 冷凍装置及び冷凍装置用増設冷媒量調整装置
US20190301778A1 (en) Refrigeration cycle apparatus
JP7005172B2 (ja) 空気調和機
JP7174299B2 (ja) 冷凍装置
JP5975706B2 (ja) アキュムレータ及び冷凍サイクル装置
JP5225895B2 (ja) 空気調和装置
JP2010127481A (ja) 空気調和機
WO2025062532A1 (ja) 冷凍サイクル装置
JP3435822B2 (ja) 空気調和装置
JP2015169347A (ja) ヒートポンプ装置
JP3492427B2 (ja) 冷凍空調装置
JP5934931B2 (ja) 冷凍サイクル装置用タンク及びそれを備えた冷凍サイクル装置
JP6065261B2 (ja) 冷凍装置
JP4130676B2 (ja) 圧縮機均油装置及び冷凍機

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23953020

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2025547047

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 2025547047

Country of ref document: JP