JP2017150753A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator that can suppress an increase in viscosity resistance in a sliding portion of a compressor and can improve performance.SOLUTION: A refrigerator includes a refrigeration cycle in which a compressor, a condenser, an expansion mechanism and an evaporator are connected annularly. In the refrigerator, a condensation temperature may reach 46°C or higher. The condensation temperature is a temperature that causes a refrigerant circulating in the refrigeration cycle to be condensed. Refrigerating machine oil for lubricating the compressor is filled in the refrigeration cycle. The refrigerating machine oil is oil of which separation temperature is higher than the condensation temperature. The separation temperature is a temperature that causes a mixture of the refrigerating machine oil and the refrigerant to be separated into the refrigerating machine oil and the refrigerant. Since the separation temperature is higher than the condensation temperature, separation of the refrigerant circulating in the refrigeration cycle from the refrigerating machine oil is suppressed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a refrigeration apparatus having a relatively high temperature at which refrigerant is condensed.

In recent years, in a refrigeration apparatus such as an air conditioner, a refrigerant containing hydrofluorocarbon (HFC) is mainly used as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2001-226690). HFC is, for example, R134a represented by the molecular formula C ₂ H ₂ F ₄ , R32 represented by the molecular formula CH ₂ F ₂ , and R410A and R407c that are mixed refrigerants. Since HFC does not contain chlorine, the effect of destroying the ozone layer is small compared to chlorofluorocarbon and hydrochlorofluorocarbon.

  However, among refrigerants containing HFC, there are refrigerants that are poorly compatible with refrigerating machine oil and are easily separated from refrigerating machine oil. When the refrigerant and the refrigerating machine oil are separated, the refrigerating machine oil having a high viscosity is supplied to the sliding part of the compressor, and the viscous resistance in the sliding part of the compressor is increased. Thereby, the power loss of a compressor increases and there exists a possibility that the performance of a compressor may fall.

  An object of the present invention is to provide a refrigeration apparatus that can suppress an increase in viscous resistance at a sliding portion of a compressor and improve performance.

  A refrigeration apparatus according to a first aspect of the present invention includes a refrigeration cycle in which a compressor, a condenser, an expansion mechanism, and an evaporator are connected in an annular shape. In this refrigeration apparatus, the condensation temperature may be 46 ° C. or higher. The condensation temperature is a temperature at which the refrigerant circulating in the refrigeration cycle condenses in the condenser. The refrigeration cycle contains refrigeration oil for lubricating the compressor. Refrigerator oil is an oil whose separation temperature is higher than the condensation temperature. The separation temperature is a temperature at which the mixture of the refrigerating machine oil and the refrigerant is separated into the refrigerating machine oil and the refrigerant.

  The refrigeration apparatus according to the first aspect is used in an environment where the outside air temperature is relatively high. Specifically, in this refrigeration apparatus, the condensation temperature, which is the temperature at which the refrigerant compressed by the compressor is condensed by the condenser, may be 46 ° C. or higher. However, the separation temperature, which is the temperature at which the mixture of refrigerating machine oil and refrigerant used in this refrigeration apparatus separates, is higher than the condensation temperature. Therefore, during operation of the refrigeration apparatus, the refrigerant circulating in the refrigeration cycle is suppressed from being separated from the refrigeration oil, so that the low-viscosity refrigeration oil containing the refrigerant is supplied to the sliding portion of the compressor. Therefore, the refrigerating apparatus according to the first aspect can suppress the supply of refrigerating machine oil having a high viscosity to the sliding portion of the compressor and improve the performance.

  The refrigerating apparatus according to the second aspect of the present invention is the refrigerating apparatus according to the first aspect, wherein the refrigerating machine oil is an oil whose separation temperature is higher than the condensation temperature when the oil concentration is 35 ± 10 wt%. . The oil concentration is the concentration of refrigerating machine oil contained in the mixture of refrigerating machine oil and refrigerant.

  In the refrigeration apparatus according to the second aspect, since the separation temperature is higher than the condensation temperature even when the oil concentration is relatively low at 35 ± 10 wt%, the refrigerant is prevented from separating from the refrigeration oil. Therefore, the refrigeration apparatus according to the second aspect can suppress an increase in viscous resistance at the sliding portion of the compressor and improve the performance.

  The refrigeration apparatus according to the third aspect of the present invention is the refrigeration apparatus according to the first aspect or the second aspect, and the refrigeration oil is an oil whose separation temperature is higher than the condensation temperature when the compressor is started.

  The refrigeration apparatus according to the third aspect is used in an environment where the outside air temperature is relatively high, the oil concentration at the time of startup is the lowest, and the oil concentration tends to gradually increase after startup. At the start-up time when the oil concentration is the lowest, the separation temperature remains higher than the condensation temperature even if the separation temperature is higher than the condensation temperature and the oil concentration gradually increases after the start-up. Therefore, the refrigerant is prevented from separating from the refrigeration oil after the refrigeration apparatus is started. Therefore, the refrigeration apparatus according to the third aspect can suppress an increase in the viscous resistance at the sliding portion of the compressor and improve the performance.

  A refrigeration apparatus according to a fourth aspect of the present invention is the refrigeration apparatus according to any one of the first to third aspects, wherein the refrigerant includes HFC.

The refrigeration apparatus according to the fourth aspect uses a refrigerant containing HFC. HFC is, for example, R134a represented by the molecular formula C ₂ H ₂ F ₄ , R32 represented by the molecular formula CH ₂ F ₂ , and R410A and R407c that are mixed refrigerants. Since HFC does not contain chlorine, the effect of destroying the ozone layer is small compared to chlorofluorocarbon and hydrochlorofluorocarbon. However, among refrigerants containing HFC, there are refrigerants that are poorly compatible with refrigerating machine oil and whose viscosity resistance tends to increase when separated from refrigerating machine oil. However, since the separation temperature is higher than the condensation temperature and the refrigerant is prevented from separating from the refrigerating machine oil, an increase in the viscosity of the refrigerating machine oil is suppressed. Therefore, the refrigeration apparatus according to the fourth aspect can suppress an increase in viscous resistance at the sliding portion of the compressor and improve the performance.

  A refrigeration apparatus according to a fifth aspect of the present invention is the refrigeration apparatus according to any one of the first to fourth aspects, wherein the condenser is installed outdoors and the evaporator is installed indoors.

  The refrigeration apparatus according to the fifth aspect is a dedicated cooling device. Since the condenser of this refrigeration apparatus is installed in an external environment having a relatively high temperature, the condensation temperature may be 46 ° C. or higher. However, since the separation temperature is higher than the condensation temperature, the refrigerant is prevented from separating from the refrigerating machine oil. Therefore, the refrigeration apparatus according to the fifth aspect can suppress an increase in the viscous resistance at the sliding portion of the compressor and improve the performance.

  The refrigeration apparatus according to the sixth aspect of the present invention is the refrigeration apparatus according to any one of the first to fifth aspects, and the condensation temperature may be 52 ° C. or higher.

  The refrigeration apparatus according to the sixth aspect can be used in an environment where the outside air temperature is high such that the condensation temperature is 52 ° C. or higher.

  The refrigeration apparatus according to the first to fifth aspects of the present invention can improve the performance by suppressing an increase in viscous resistance at the sliding portion of the compressor.

It is a refrigerant circuit figure of the air harmony device concerning the embodiment of the present invention. It is a graph showing the bilayer separation temperature curve of the mixture of R32 and polyvinyl ether oil, and the driving | running locus | trajectory of the said mixture. It is a graph showing the bilayer separation temperature curve of the mixture of R32 and a polyol ester oil, and the driving | running locus | trajectory of the said mixture. It is a refrigerant circuit figure of the air harmony device concerning modification A.

(1) Configuration of Air Conditioner An air conditioner 1 as a refrigeration apparatus according to an embodiment of the present invention will be described. FIG. 1 is a refrigerant circuit diagram of the air conditioner 1. The air conditioner 1 includes a refrigeration cycle in which a compressor 2, an outdoor heat exchanger 4, an expansion mechanism 5, and an indoor heat exchanger 6 are connected in a ring shape. The air conditioner 1 is a cooling-only device that can perform only a cooling operation. In FIG. 1, the solid line arrow represents the flow direction of the refrigerant circulating in the refrigeration cycle when the air conditioner 1 is in operation. The air conditioner 1 can be used in an environment where the outside air temperature is high. Specifically, the air conditioner 1 can be used in an environment where the outside air temperature is 46 ° C. or higher. Preferably, the air conditioner 1 can be used in an environment where the outside air temperature is 52 ° C. or higher.

  The refrigeration cycle of the air conditioner 1 that performs the cooling operation will be described. First, the compressor 2 compresses the low-pressure gas refrigerant and discharges the high-pressure gas refrigerant. The compressed refrigerant discharged from the compressor 2 is supplied to the outdoor heat exchanger 4. The outdoor heat exchanger 4 condenses the high-pressure gas refrigerant and discharges the high-pressure liquid refrigerant. The refrigerant discharged from the outdoor heat exchanger 4 passes through the expansion valve of the expansion mechanism 5, becomes a low-pressure gas-liquid mixed refrigerant, and is supplied to the indoor heat exchanger 6. The indoor heat exchanger 6 evaporates the low-pressure gas-liquid mixed refrigerant and discharges the low-pressure gas refrigerant. The refrigerant discharged from the indoor heat exchanger 6 is supplied to the compressor 2.

  The air conditioner 1 is a cooling-only device, the outdoor heat exchanger 4 functions as a condenser, and the indoor heat exchanger 6 functions as an evaporator. Therefore, the room is cooled by the latent heat of vaporization of the refrigerant generated in the indoor heat exchanger 6. The condensation temperature, which is the temperature at which the refrigerant is condensed in the outdoor heat exchanger 4, is 46 ° C. or higher, and preferably 52 ° C. or higher.

  Refrigerating machine oil is enclosed in the refrigeration cycle of the air conditioner 1. The refrigerating machine oil is a lubricating oil mainly used for preventing wear and seizure in the sliding portion of the compressor 2. For example, when the compressor 2 is a scroll compressor, the sliding portion of the compressor 2 is a thrust sliding surface between two scrolls, a sliding surface between a crankshaft and a bearing, and the like.

As the refrigerant circulating in the refrigerant circuit of the air conditioner 1, an HFC-based refrigerant containing hydrofluorocarbon (HFC) is used. HFC is, for example, R134a represented by the molecular formula C ₂ H ₂ F ₄ , R32 represented by the molecular formula CH ₂ F ₂ , and R410A and R407c that are mixed refrigerants. The global warming potential of the HFC-based refrigerant is preferably 1000 or less, more preferably 500 or less, still more preferably 300 or less, and particularly preferably 100 or less. From the viewpoint of the global warming potential, the HFC-based refrigerant is preferably an R32-based refrigerant containing more than 50% by weight of R32. Specific examples of the R32 refrigerant include R32 alone, a mixture of R32 and HFO-1234yf, a mixture of R32 and HFO-1123, and the like.

  Since the HFC-based refrigerant does not contain chlorine, it has less influence on global warming and less effective in destroying the ozone layer than other fluorine-based refrigerants such as chlorofluorocarbon and hydrochlorofluorocarbon. However, HFC-based refrigerants include R32-based refrigerants that are less compatible with refrigerating machine oils than other fluorine-based refrigerants and are easily separated from refrigerating machine oils when the condensation temperature is 46 ° C. or higher. When the refrigerant and the refrigerating machine oil are separated, the viscous resistance at the sliding portion of the compressor 2 increases, and the performance of the compressor 2 may be deteriorated.

(2) Composition of refrigeration oil Next, the composition of the refrigeration oil enclosed in the refrigeration cycle will be described. Refrigerating machine oil mainly consists of a base oil, an acid scavenger, an extreme pressure agent, and an antioxidant.

  As the base oil, mineral oil or synthetic oil is used. As the base oil, one having good compatibility with the HFC refrigerant used in the air conditioner 1 is appropriately selected. The mineral oil is, for example, a naphthenic mineral oil or a paraffinic mineral oil. Synthetic oils are, for example, ester compounds, ether compounds, poly α-olefins, and alkylbenzenes. Specific examples of the synthetic oil include polyvinyl ether, polyol ester, polyalkylene glycol and the like. In addition, as a base oil, the mixture which combined 2 or more types of said mineral oil or synthetic oil may be used.

  The acid scavenger is an additive used for suppressing deterioration of the refrigerating machine oil due to the acid by reacting with an acid such as hydrofluoric acid generated by the decomposition of the HFC refrigerant. The acid scavenger is, for example, an epoxy compound, a carbodiimide compound, or a tempen compound. Specific examples of the acid scavenger include 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, epoxidized cyclohexyl carbinol, di (alkylphenyl) carbodiimide, β-pinene and the like. Acids such as hydrofluoric acid generated by the decomposition of the HFC refrigerant are captured by the acid scavenger contained in the refrigeration oil. Thereby, deterioration of the refrigerating machine oil resulting from the acid generated by the decomposition of the HFC-based refrigerant and corrosion of metal parts such as the expansion valve of the expansion mechanism 5 are suppressed.

  The extreme pressure agent is an additive used for preventing wear and seizure in the sliding portion of the compressor 2. Refrigerating machine oil prevents contact between the sliding members by forming an oil film between the surfaces of the members that slide on each other at the sliding portion. However, when a low-viscosity refrigerating machine oil such as polyvinyl ether is used and when the pressure applied to the sliding member is high, the sliding members easily come into contact with each other. The extreme pressure agent suppresses the occurrence of wear and seizure by forming a film by reacting with the surfaces of members that slide on each other at the sliding portion. Examples of the extreme pressure agent include phosphate ester, phosphite ester, thiophosphate, sulfide ester, sulfide, thiobisphenol, and the like. Specific examples of extreme pressure agents include tricresyl phosphate (TCP), triphenyl phosphate (TPP), triphenyl phosphorothioate (TPPT), amine, C11-14 side chain alkyl, monohexyl and dihexyl phosphate. TCP is adsorbed on the surface of the sliding member and decomposes to form a phosphate coating.

  Antioxidants are additives used to prevent the refrigeration machine oil from being oxidized. Specific examples of the antioxidant include zinc dithiophosphate, organic sulfur compound, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,2 Phenols such as' -methylenebis (4-methyl-6-tert-butylphenol), amine-based antioxidants such as phenyl-α-naphthylamine, N, N'-di-phenyl-p-phenylenediamine, N, N Examples include '-disalicylidene-1,2-diaminopropane.

(3) Characteristics of Refrigerating Machine Oil Next, characteristics of the refrigerating machine oil used in the air conditioner 1 will be described. First, an example of a two-layer separation temperature curve of a mixture of an HFC-based refrigerant and refrigeration oil (hereinafter simply referred to as “mixture”) and an operation locus of the mixture will be described with reference to FIGS. explain. Here, the HFC-based refrigerant is R32 alone.

  In FIG. 2, the horizontal axis represents the oil concentration which is the concentration (wt%) of the refrigerating machine oil contained in the mixture, and the vertical axis represents the temperature of the mixture. The refrigerating machine oil is polyvinyl ether oil. Curves L1 and L2 are two-layer separation temperature curves. A region R1 above the upper curve L1 and a region R2 below the lower curve L2 are regions where R32 and polyvinyl ether oil are separated into two layers. A region R3 between the curves L1 and L2 is a region where R32 and polyvinyl ether oil are not separated into two layers. That is, the region R3 is a region where R32 and polyvinyl ether oil are dissolved in each other.

  In FIG. 3, the horizontal axis represents the oil concentration that is the concentration (wt%) of the refrigerating machine oil contained in the mixture, and the vertical axis represents the temperature of the mixture. The refrigerating machine oil is a polyol ester oil. Curves L4 and L5 are two-layer separation temperature curves. A region R4 above the upper curve L4 and a region R5 below the lower curve L5 are regions where R32 and polyol ester oil are separated into two layers. A region R6 between the curve L4 and the curve L5 is a region where R32 and polyol ester oil are not separated into two layers. That is, the region R6 is a region where R32 and polyol ester oil are dissolved.

  Although depending on the composition of the refrigerating machine oil, when R32 is used as the refrigerant, the minimum value of the oil concentration of the mixture of the refrigerant and the refrigerating machine oil is 35 ± 10 wt%.

  2 and 3, a straight line LM represents an operation locus of the mixture when the air conditioner 1 is used in an environment where the outside air temperature is high. The operation trajectories of the mixture indicated by the straight line LM in FIGS. 2 and 3 are common. The straight line LM represents the transition of the state of the mixture existing inside the compressor 2 when the air conditioner 1 is started. Prior to activation of the air conditioner 1, the mixture is in the state of the point P1 of the straight line LM. Since the compressor 2 is installed outdoors, the temperature of the mixture existing inside the compressor 2 is close to the outside air temperature before the air conditioner 1 is started. When the air conditioner 1 is activated, the temperature of the compressor 2 increases as the operating time of the air conditioner 1 elapses, so that the temperature of the mixture also rises, and the liquid refrigerant contained in the mixture gradually evaporates. As a result, the oil concentration of the mixture increases gradually. 2 and 3, the oil concentration of the mixture gradually increases from about 35 wt% at the point P1 when the air conditioner 1 is started. That is, the point P1 shows a state when the oil concentration is the minimum value.

  The operating locus LM of the mixture at the start of the air conditioner 1 exists in a region R3 where R32 and polyvinyl ether oil are not separated into two layers in FIG. 2, and in FIG. Present in the region R6 where the layers are not separated. Therefore, at the time of starting the air conditioning apparatus 1, the mixture does not separate into two layers of R32 and refrigerating machine oil. When the mixture is separated into two layers, the viscosity of the refrigerating machine oil increases. The refrigerating machine oil used in the air conditioner 1 is an oil having a characteristic that the separation temperature, which is the temperature at which the mixture separates into R32 and refrigerating machine oil, is higher than the condensation temperature. Here, the separation temperature is a high-temperature side separation temperature indicated by the upper two-layer separation temperature curve L1 in FIG. 2 and the upper two-layer separation temperature curve L4 in FIG. In the refrigeration cycle, the maximum temperature of the mixture is the condensation temperature. Therefore, when the separation temperature on the high temperature side is higher than the condensation temperature, the mixture does not separate into R32 and refrigerating machine oil. On the other hand, when the condensation temperature is higher than the separation temperature on the high temperature side, the mixture may be separated into R32 and refrigerating machine oil.

(4) Features The air conditioner 1 is used in an environment where the outside air temperature is relatively high, and the condensation temperature that is the temperature at which the refrigerant compressed by the compressor 2 is condensed by the outdoor heat exchanger 4 is 46 ° C. or higher. There is a case. However, the separation temperature, which is the temperature at which the mixture of the refrigerating machine oil and the refrigerant used in the air conditioner 1 is separated into two layers, is higher than the condensation temperature. Therefore, during the operation of the air conditioner 1, the mixture enclosed in the refrigeration cycle is suppressed from being separated into the refrigerant and the refrigeration oil. As a result, it is possible to suppress the supply of a low-lubricant refrigerant that does not sufficiently contain refrigeration oil to the sliding portion of the compressor 2. Therefore, the air conditioner 1 can suppress an increase in the viscous resistance at the sliding portion of the compressor 2 and improve the performance.

  The air conditioner 1 is used in an environment where the outside air temperature is relatively high, and the oil concentration of the mixture (oil concentration at the point P1 in FIGS. 2 and 3) before activation of the air conditioner 1 is 35 ± 10 wt%. The lowest is the tendency that the oil concentration of the mixture gradually increases after the air conditioner 1 is started. However, as shown in FIGS. 2 and 3, even if the oil concentration of the mixture gradually increases after the air conditioner 1 is started, the temperature of the mixture remains lower than the separation temperature. Therefore, during the operation of the air conditioner 1, the mixture enclosed in the refrigeration cycle is suppressed from being separated into the refrigerant and the refrigeration oil. Therefore, the air conditioner 1 can suppress an increase in the viscous resistance at the sliding portion of the compressor 2 and improve the performance.

  The air conditioner 1 uses an HFC refrigerant. R32, which is a kind of HFC-based refrigerant, has poor compatibility with refrigerating machine oil as compared with other fluorine-based refrigerants, and viscosity resistance tends to increase when separated from refrigerating machine oil. However, since the air conditioning apparatus 1 uses oil having a separation temperature higher than the condensation temperature as the refrigeration oil, the separation of the mixture of the refrigeration oil and the refrigerant into the refrigerant and the refrigeration oil is suppressed. As a result, an increase in the viscosity of the refrigerating machine oil is suppressed. Therefore, the air conditioner 1 can suppress an increase in the viscous resistance at the sliding portion of the compressor 2 and improve the performance.

  On the high temperature side, the temperature at which the mixture of R32 and the refrigerating machine oil is separated into two layers is lower than the temperature at which the mixture of R410A or R407C and the refrigerating machine oil is separated into two layers. Therefore, in an environment where the outside air temperature is high, the mixture of R32 and refrigerating machine oil tends to be separated into two layers when the air conditioner 1 is started, as compared with the mixture of R410A or R407C and refrigerating machine oil. Therefore, by using the refrigerating machine oil having a characteristic that the separation temperature is higher than the condensation temperature, the two-layer separation of the mixture at the start-up of the air conditioner 1 is suppressed, and as a result, the increase in the viscosity of the refrigerating machine oil is suppressed. . Therefore, the air conditioner 1 can suppress an increase in the viscous resistance at the sliding portion of the compressor 2 and improve the performance.

(5) Modifications Although the embodiment of the present invention has been described above, the specific configuration of the present invention can be changed without departing from the gist of the present invention. Hereinafter, modified examples applicable to the embodiment of the present invention will be described.

(5-1) Modification A
In this embodiment, the air conditioning apparatus 1 is a cooling-only device. However, the air conditioning apparatus 1 may be a device having both a cooling function and a heating function. FIG. 4 is a refrigerant circuit diagram of the air-conditioning apparatus 1 in the present modification. The air conditioner 1 mainly includes a compressor 2, a four-way switching valve 3, an outdoor heat exchanger 4, an expansion mechanism 5, and an indoor heat exchanger 6. In FIG. 4, the solid line arrows represent the refrigerant flow during the cooling operation, and the dotted line arrows represent the refrigerant flow during the heating operation.

  During the cooling operation, the outdoor heat exchanger 4 functions as a condenser, and the indoor heat exchanger 6 functions as an evaporator. That is, the room is cooled by the latent heat of vaporization of the refrigerant generated in the indoor heat exchanger 6. On the other hand, during the heating operation, by switching the four-way switching valve 3, the outdoor heat exchanger 4 functions as an evaporator, and the indoor heat exchanger 6 functions as a condenser. That is, the room is heated by the condensation latent heat of the refrigerant generated in the outdoor heat exchanger 4.

  Also in this modification, by using the refrigerating machine oil having a characteristic that the separation temperature is higher than the condensation temperature, the two-layer separation of the mixture at the start-up of the air conditioner 1 is suppressed, and as a result, the viscosity of the refrigerating machine oil increases. Is suppressed. Therefore, the air conditioner 1 can suppress an increase in the viscous resistance at the sliding portion of the compressor 2 and improve the performance.

(5-2) Modification B
In this embodiment, the refrigerating machine oil contains an extreme pressure agent and an antioxidant. However, the refrigerating machine oil may contain only one of the extreme pressure agent and the antioxidant, and may not contain the extreme pressure agent and the antioxidant.

  The refrigeration apparatus according to the present invention can suppress an increase in viscous resistance at the sliding portion of the compressor and improve performance.

1 Air conditioning equipment (refrigeration equipment)
2 Compressor 4 Outdoor heat exchanger (condenser, evaporator)
5 Expansion mechanism 6 Indoor heat exchanger (evaporator, condenser)

JP 2001-226690 A

Claims (6)

A refrigeration system comprising a refrigeration cycle in which a compressor, a condenser, an expansion mechanism, and an evaporator are connected in an annular shape, and the condensation temperature at which the refrigerant circulating in the refrigeration cycle condenses in the condenser may be 46 ° C. or higher. Because
The refrigeration cycle contains refrigeration oil for lubricating the compressor,
The refrigerating machine oil is an oil in which a separation temperature at which a mixture of the refrigerating machine oil and the refrigerant is separated into the refrigerating machine oil and the refrigerant becomes higher than the condensation temperature.
Refrigeration equipment. The refrigerating machine oil is an oil whose separation temperature is higher than the condensation temperature when the oil concentration, which is the concentration of the refrigerating machine oil contained in the mixture, is 35 ± 10 wt%.
The refrigeration apparatus according to claim 1. The refrigerating machine oil is an oil in which the separation temperature becomes higher than the condensation temperature when the compressor is started.
The refrigeration apparatus according to claim 1 or 2. The refrigerant includes HFC,
The refrigeration apparatus according to any one of claims 1 to 3. The condenser is installed outdoors,
The evaporator is installed indoors,
The refrigeration apparatus according to any one of claims 1 to 4. In the refrigeration apparatus, the condensation temperature may be 52 ° C. or higher.
The refrigeration apparatus according to any one of claims 1 to 4.

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