JP2014240702A - Refrigeration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration device that uses a refrigerant consisting principally of hydrofluoroolefin and that secures reliability and high efficiency by suppressing production of a polymer during a refrigeration cycle.SOLUTION: A refrigeration device includes a refrigerant circulation path in which a working refrigerant obtained by mixing hydrofluoroolefin having double bonds between carbon and carbon with a single refrigerant or with hydrofluoroolefin at least containing it without fail and not having double bonds is charged, which reaches a compressor 120 from the compressor via a condenser 121, an expansion mechanism 122, and an evaporator 123 so that the refrigerant is circulated. Refrigerator oil of the compressor 120 has a dynamic viscosity of 0.1 to 100 mm/s in operation. Consequently, polymer production is suppressed by avoiding a high-pressure, high-temperature state as a generation condition of a refrigerant polymer, and equipment in the refrigeration device can be prevented from deteriorating or breaking owing to the polymer.

Description

  The present invention relates to a refrigeration apparatus using a hydrofluoroolefin having a double bond between carbon as a refrigerant.

  Currently, efforts are being made to prevent global warming on a global scale. In contrast, refrigerant manufacturers, refrigeration oil manufacturers, and air conditioning equipment manufacturers are researching and developing new refrigerants and refrigeration oils for new refrigerants with the aim of further reducing and improving the global warming potential (GWP), etc. Has been done. As a new refrigerant aiming at such an improvement, unsaturated fluorinated hydrocarbon refrigerants such as HFO1234yf and HFO1234ze are currently expected to be used (see, for example, Patent Document 1).

A conventional compressor and refrigeration cycle apparatus using an HFC refrigerant will be described with reference to FIGS. 4 to 6 (see, for example, Patent Documents 2 and 3).
FIG. 4 is a longitudinal sectional view of a rotary compressor used under the conventional HFC-based refrigerant described in Patent Document 2.

  A stator 2 a of the motor 2 is fixed to the upper part of the sealed container 1, and a compression mechanism unit 5 having a shaft 4 driven by the rotor 2 b is fixed to the lower part of the sealed container 1. A main bearing 7 is fixed to the upper end of the cylinder 6 of the compression mechanism section 5 and a secondary bearing 8 is fixed to the lower end with bolts or the like. In the cylinder 6, a piston 9 is inserted into the eccentric portion 4 a of the shaft 4 to perform eccentric rotation.

  In addition, R410A (mixture of HFC32 and HFC125) is sealed as a refrigerant in the sealed container 1, and from the viewpoint of compatibility with the refrigerant, for example, polyol ester (POE) or polyvinyl ether ( A refrigerating machine oil 3 having a polarity such as PVE) is stored.

  FIG. 5 is a cross-sectional view of a rotary compressor used under the conventional HFC-based refrigerant described in Patent Document 2. A piston 9 is inserted into the inner surface of the cylinder 6 and rotates with the rotation of the shaft 4. The refrigerant is sucked and compressed in the suction chamber 13 and the compression chamber 14 partitioned by the vane 10.

  About the rotary compressor comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, the refrigerant is sucked into the suction chamber 13 from the suction port 12 provided in the cylinder 6. Further, the refrigerant in the compression chamber 14 is compressed with the leftward rotation (in the direction of the arrow) of the piston 9, passes through the discharge notch 15, and is discharged into the sealed container 1 from the discharge port (not shown). The compressed refrigerant discharged into the hermetic container 1 passes through the gap of the motor 2 and is discharged from the discharge pipe 16 at the upper part of the hermetic container 1, and the mist of the refrigerating machine oil 3 around at that time is also discharged together.

  Next, a basic refrigeration cycle apparatus provided with a rotary compressor 20 that sucks and compresses the HFC refrigerant described in Patent Document 3 and discharges the refrigerant will be described with reference to FIG.

As shown in FIG. 6, the rotary compressor 20 compresses the low-temperature and low-pressure refrigerant gas, discharges the high-temperature and high-pressure refrigerant gas, and sends it to the condenser 21. The HFC-based refrigerant gas sent to the condenser 21 becomes a high-temperature and high-pressure refrigerant liquid while releasing its heat into the air, and is sent to an expansion mechanism (for example, an expansion valve or a capillary tube) 22. The high-temperature and high-pressure refrigerant liquid passing through the expansion mechanism 22 is sent to the evaporator 23 as low-temperature and low-pressure wet steam due to the throttling effect. The refrigerant that has entered the evaporator 23 absorbs heat from the surroundings and evaporates, and the low-temperature and low-pressure refrigerant gas that has exited the evaporator 23 is sucked into the rotary compressor 20, and the same cycle is repeated thereafter.

JP 2010-2074 A JP 11-236890 A JP-A-8-240362

  However, the unsaturated fluorinated hydrocarbon refrigerants that have been studied in recent years have one of the features of a low GWP value. However, since they have unsaturated bonds in the molecule, conventional saturated fluorinated hydrocarbon refrigerants such as HFC410A are used. Reactivity is high, and thermal and chemical stability is poor. Therefore, there is a possibility of reacting with radicals generated in a portion where the temperature is high, such as a sliding portion of the compressor. Hydrofluoroolefins that have reacted with radicals decompose to release hydrogen fluoride, or a plurality of hydrofluoroolefins are polymerized into oligomers to form viscous liquids or solids as polymerization proceeds further. As a result of the confirmation experiment, a solid product estimated to be a polymer of refrigerant was generated in the air conditioner reliability test. When such a product is generated, there is a high possibility of adverse effects such as biting into a minute gap in the apparatus.

  The present invention solves the above-mentioned conventional problems, and by optimizing the viscosity of the refrigeration oil in the refrigeration cycle to the viscosity suitable for the working refrigerant in the actual operation state during the compressor operation, the generation of the refrigerant polymer It is an object of the present invention to provide a refrigeration apparatus that can stably operate over a long period of time, preventing damage in the apparatus and deterioration of the performance of the refrigeration cycle.

In order to solve the above-mentioned conventional problems, the present invention mixes a hydrofluoroolefin having a double bond between carbon and a single refrigerant, or a hydrofluorocarbon which always contains at least a double bond and does not have a double bond. the working refrigerant is sealed, includes a refrigerant circulation path in which the refrigerant is circulated by the compressor, the kinematic viscosity of the refrigerating machine oil at the time of operation to the compressor is equal to or less than 0.1 mm ² / s or more 100 mm ² / s refrigeration The machine oil is used. Thereby, generation | occurrence | production of a polymer can be suppressed and damage to an apparatus and a performance fall can be prevented.

  The refrigerating apparatus of the present invention can maintain the refrigerating machine oil in a state of excellent wear resistance even when using a low GWP refrigerant having a property that a refrigerant polymer is easily generated. By preventing the occurrence of high pressure and high temperature, which are the conditions for generating the polymer, it is possible to suppress the production of the polymer, and to prevent damage to the apparatus and performance degradation. This makes it possible to provide a refrigeration apparatus that achieves high efficiency and high reliability.

Cycle diagram of the refrigeration apparatus in Embodiment 1 of the present invention Longitudinal sectional view of a rotary compressor in the refrigeration apparatus of Embodiment 1 Cross section of rotary compressor in refrigerating apparatus of embodiment 1 A longitudinal sectional view of a rotary compressor in a conventional refrigeration layer Cross-sectional view of the conventional rotary compressor Cycle diagram of the conventional refrigeration cycle device

According to a first aspect of the present invention, a hydrofluoric olefin having a double bond between carbon and a single refrigerant, or a working refrigerant mixed with a hydrofluorocarbon which always contains at least the double fluorocarbon is contained, includes a refrigerant circulation circuit which the refrigerant is circulated by a compressor, the said compressor is a configuration in which the kinematic viscosity of the refrigerating machine oil at the time of operation using the refrigerating machine oil is not more than 0.1 mm ² / s or more 100 mm ² / s .

  According to this configuration, the refrigerating machine oil can be maintained in a state with excellent wear resistance, and the occurrence of high temperature and high pressure conditions at the extreme sliding locations that are the generation factors of the polymer can be suppressed. By preventing clogging of the circulation path due to the polymer and realizing operational stability, it is possible to prevent damage to each device in the refrigeration cycle and performance degradation.

  The second invention is that the refrigerating machine oil of the first invention contains an acid scavenger in the refrigerating machine oil. According to this configuration, deterioration of the refrigerating machine oil can be prevented, decomposition of the refrigerant can be suppressed, generation of a polymer can be suppressed, and the reliability of the refrigeration apparatus can be further improved.

  The third invention is to contain an antiwear agent in the refrigerating machine oil, particularly in the refrigeration apparatus of the first or second invention. According to this structure, generation | occurrence | production of a polymer can be suppressed by suppressing generation | occurrence | production of the high temperature and high pressure state in a sliding location, and an abrasion-resistant characteristic can be improved.

  According to a fourth aspect of the present invention, in the refrigeration apparatus of the first aspect of the invention, the compression mechanism portion of the compressor has a piston and a vane in the cylinder, and the raw material of the vane is subjected to nitriding treatment using high-speed tool steel Alternatively, the sintered alloy steel is sintered and quenched. According to this configuration, while maintaining the wear resistance of the compression mechanism, the decomposition of the refrigerant and the refrigerating machine oil is suppressed, and the local temperature rise at the sliding portion of the vane and the piston is alleviated, and the polymer By preventing the occurrence, the long-term reliability of the compressor and the refrigeration cycle apparatus using the compressor can be ensured. In addition, a hard structure in which W, Mo, Cr, and V-based carbides are dispersed in a fine martensite dough can be obtained by sintering and quenching the vanes. Since cast iron is inexpensive, it can be a compressor with excellent mass productivity.

  In the fifth invention, particularly, the sintered alloy steel of the refrigeration apparatus of the fourth invention is a high-speed tool steel. According to this configuration, it is possible to make the wear resistance more excellent among the sintered alloy steels.

  In a sixth aspect of the invention, in the refrigeration apparatus of any one of the first to fifth aspects of the invention, the compression mechanism portion of the compressor has a piston and a vane in the cylinder. Is made of iron-based ceramic surface treated. According to this configuration, it is possible to suppress the temperature rise due to sliding friction at the tip of the vane that is severely slid and the outer periphery of the piston, and to reduce the decomposition of the refrigerant, in addition, it is possible to maintain the polarity of the surface of the sliding portion, Since the uniform extreme pressure layer is formed on the sliding surface, the reliability of the sliding surface can be ensured.

  According to a seventh aspect of the present invention, in particular, the working refrigerant in the refrigeration apparatus according to any one of the first to sixth aspects, the hydrofluoroolefin is tetrafluoropropene or trifluoropropene, a single refrigerant, or a main component thereof, and global warming A mixed refrigerant that is a mixture of two or three components so that the coefficient is 5 or more and 750 or less is used as a working refrigerant, and a rotary compressor that has low environmental impact, is highly reliable, and is highly efficient. Can be provided.

The eighth invention is the working refrigerant in the refrigeration apparatus of any one of the first to eighth inventions, the hydrofluoroolefin is mainly composed of tetrafluoropropene or trifluoropropene, difluoromethane and pentafluoroethane, and global warming. A refrigerant mixture obtained by mixing two or three components so that the coefficient is 5 or more and 750 or less is used as a working refrigerant, and a highly reliable and highly efficient rotary compressor can be provided effectively. .

  According to a ninth aspect of the present invention, there are provided polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycols or monoethers thereof and polyvinyl ethers as refrigeration oils used as working refrigerants in the refrigeration apparatus according to any one of the first to sixth aspects of the invention. Synthetic oils based on oxygenated compounds such as copolymers, polyol esters and polycarbonates, or synthetic oils based on alkylbenzenes and α-olefins as the main component. An efficient rotary compressor can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a cycle diagram of the refrigeration apparatus in Embodiment 1 of the present invention. In FIG. 1, the same components as those in the conventional refrigeration apparatus of FIG.

  In FIG. 1, the refrigeration apparatus forms a refrigeration cycle by connecting a compressor 120, a condenser 121, an expansion mechanism (for example, an expansion valve or capillary tube) 122, and an evaporator 123 through a circulation path.

  The compressor 120 compresses the low-temperature and low-pressure refrigerant gas, discharges the high-temperature and high-pressure refrigerant gas, and sends it to the condenser 121. The refrigerant gas sent to the condenser 121 becomes a high-temperature and high-pressure refrigerant liquid and is sent to the expansion mechanism 122 while releasing the heat into the air. The high-temperature and high-pressure refrigerant liquid that passes through the expansion mechanism 122 becomes low-temperature and low-pressure wet steam due to the throttling effect, and is sent to the evaporator 123. The refrigerant entering the evaporator 123 absorbs heat from the surroundings and evaporates, and the low-temperature and low-pressure refrigerant gas exiting the evaporator 123 is sucked into the rotary compressor 120, and the same cycle is repeated thereafter.

  The hydrofluoroolefin refrigerant used in the refrigeration apparatus may be decomposed by oxidation in a high-temperature environment to generate hydrogen fluoride, and at the same time undergo a polymerization reaction to form a polymer.

  In the refrigeration apparatus, a motor part 102 and a discharge part 115 (to be described later) in the compressor 120 are the highest temperature parts, and the sliding part is further heated. As described above, the hydrofluoroolefin refrigerant may cause a polymerization reaction to form an oligomer or an organic solid polymer at such a high temperature portion.

In the present embodiment, the refrigerating machine oil 103 (described later) during operation of the compressor 120 has a kinematic viscosity of 0.1 mm ² / s to 100 mm ² / s. The refrigerating machine oil 103 is compatible with the working refrigerant, and the solubility in the refrigerating machine oil 103 varies depending on the pressure and temperature when the compressor 120 is operated. Since the kinematic viscosity of the refrigerating machine oil 103 changes depending on the solubility of the working refrigerant, by ensuring the actual kinematic viscosity at the time of operation of the compressor 120, the pressure in the actual operation range does not depend on the viscosity in the air atmosphere, Accurate oil film strength corresponding to temperature conditions can be maintained. For this reason, generation | occurrence | production of the high temperature in a sliding part can be suppressed, and high reliability can be maintained.

Generally, in the refrigeration apparatus, the kinematic viscosity of the refrigerating machine oil 103 is the lowest when starting. This is because a large amount of working refrigerant dissolves in the refrigerating machine oil 103 when the ambient temperature becomes low during the stop. In the confirmation experiment of the present invention, it was confirmed that no refrigerant polymer was generated if the actual oil viscosity at the start-up was 0.1 mm ² / s or more. Increasing the kinematic viscosity of the refrigerating machine oil 103 improves the reliability of the sliding part, but as the kinematic viscosity rises, the high-viscosity refrigerating machine oil 103 is agitated at the rotation and sliding part of the compressor 120. Loss due to When a general refrigeration device performance measurement is performed in the confirmation experiment and the refrigeration oil 103 with a kinematic viscosity of the refrigeration oil 103 of 100 mm ² / s or more is used, the required input power to the compressor 120 is less than the conventional refrigeration oil 103. It was confirmed that it increased by more than 10%. For this reason, it is impractical to use a refrigerating machine oil 103 that has a great influence on performance and has a kinematic viscosity of 100 mm ² / s or more.

  FIG. 2 shows a longitudinal sectional view of the rotary compressor according to Embodiment 1 of the present invention. In FIG. 2 and FIG. 3 to be described later, the same components as those of the conventional refrigeration apparatus shown in FIGS.

  The stator 102a of the motor 102 is fixed to the upper part of the hermetic container 101, and the compression mechanism part 105 having the shaft 104 driven by the rotor 102b is fixed to the lower part of the hermetic container 101. A main bearing 107 is fixed to the upper end of the cylinder 106 of the compression mechanism 105, and a secondary bearing 108 is fixed to the lower end with bolts or the like. In the cylinder 106, the piston 109 is inserted into the eccentric portion 104a of the shaft 104 and rotates eccentrically. A vane 110 is inserted into the vane groove 106 a of the cylinder 106, and a vane spring 111 is installed on the back surface portion 110 b of the vane 110, and urges the tip portion 110 a of the vane 110 to abut the outer periphery of the piston 109. .

  Further, in the sealed container 101, tetrafluoropropene (hereinafter referred to as HFO1234yf refrigerant), which is a kind of hydrofluoroolefin having a double bond between carbons, is enclosed. Refrigerating machine oil 103 containing a base oil compatible with the HFO1234yf refrigerant is stored at the bottom of the sealed container 101. In the present embodiment, it is possible to use a refrigerating machine oil 103 mainly composed of at least one base oil of polyol ester, polyvinyl ether, or polyalkylene glycol. The refrigerating machine oil 103 according to the present embodiment uses the refrigerating machine oil 103 mainly composed of only the polyol ester among these three types.

  Here, the polyol ester refrigerating machine oil 103 is synthesized by a dehydration reaction between a polyhydric alcohol and a saturated or unsaturated fatty acid. As the polyhydric alcohol, neopentyl glycol, pentaerythritol, dipentaerythritol and the like are used according to the viscosity of the refrigerating machine oil 103. One saturated fatty acid includes straight-chain fatty acids such as hexanoic acid, heptanoic acid, nonanoic acid, and decanoic acid, and branched such as 2-methylhexanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid. Chain fatty acids are used. Note that polyol ester oils containing linear fatty acids have good sliding properties but poor hydrolyzability, and ester oils containing branched chain fatty acids have the advantage of being difficult to hydrolyze, although they have slightly poor sliding properties. Should.

The refrigerating machine oil 103 of the present embodiment includes various additives such as a sulfur-based extreme pressure additive, an antioxidant such as dibutyl-p-cresol, an acid scavenger such as an epoxy-containing compound, and an antifoaming agent. Selectively added. Examples of sulfur-based extreme pressure additives include sulfurized fats and oils, sulfurized fatty acids, sulfurized esters, sulfurized olefins, dialkyl polysulfides, dibenzyl disulfides, oligomer polysulfides, and the like. These sulfur-based extreme pressure additives preferably have 3 or less sulfur bridges. If the sulfur cross-linking length is 4 or more, sulfur is likely to be released into the refrigerating machine oil 103, which may undesirably corrode copper used in piping or the like in the refrigeration cycle. It is also preferable to use a metal deactivator for the purpose of preventing sulfur copper pipe corrosion. In the present embodiment, benzotriazoles are used as a metal deactivator. In order to improve the extreme pressure effect, a phosphorus-based extreme pressure additive may be used. Phosphorus extreme pressure additives include phosphate esters such as tricresyl phosphate and triphenyl phosphate, phosphite esters, amine salts of acidic phosphate esters, etc., but excellent compatibility with refrigerating machine oil 103 Acid phosphates such as tricresyl phosphate and triphenyl phosphate are optimal. Phosphorus extreme pressure additives are effective at lower loads than sulfur extreme pressure additives, so using sulfur extreme pressure additives and phosphorus extreme pressure additives in a wide frequency range with inverter control Ideal for use in compressors of refrigeration cycles.

  The compressor used in the present embodiment is a general rotary compressor, in which a piston 109 is eccentrically rotated in a cylinder 106 and sucks, compresses, and discharges refrigerant while pushing the vane 110 tip. For this reason, a surface treatment film is formed at the tip of the vane 110 that becomes the sliding portion. Specifically, CrN, DLC, TiN, etc. are mentioned. The surface treatment film at the tip of the vane 110 has a polarity maintaining effect, and is formed by dispersing, for example, graphite having connected benzene rings. When the refrigerating machine oil 103 approaches, the polarity is induced in the surface treatment film by being induced by the polarity, and shows the polarity. As a result, the extreme pressure additive in the refrigerating machine oil 103 is adsorbed to further form an extreme pressure layer. When the extreme pressure layer formed causes severe sliding conditions, for example, when left for half a day at a low outside temperature of −10 ° C. or less and then starts up with heating and starts operating at maximum capacity, the lubricating oil in the sliding part is insufficient. However, since the extreme pressure layer is sufficiently formed in the sliding portion as in the present embodiment, abnormal wear of the sliding portion does not occur.

   The operation and action of the rotary compressor configured as described above will be described below with reference to FIG.

  First, the HFO 1234yf refrigerant is sucked into the suction chamber 113 from the suction port 112 provided in the cylinder 106. In addition, the refrigerant in the compression chamber 114 composed of the vane 110, the piston 109, the cylinder 106, and the like is compressed with the rotation of the piston 109 in the left direction (arrow direction), passes through the discharge notch 115, and discharge port (not shown). ) Is discharged into the sealed container 101. The refrigerant gas discharged into the hermetic container 101 passes through the gap of the motor 102 and is discharged from the discharge pipe 116 at the upper part of the hermetic container 101, and the mist of the refrigerating machine oil 103 around at that time is also discharged together.

  In the configuration of the rotary compression mechanism, the place where the sliding state is most severe is a contact sliding portion between the tip 110a of the vane 110 and the outer periphery of the piston 109. Since a high discharge pressure is applied to the back portion 110b of the vane 110 in addition to the vane spring 111 and a large force due to a differential pressure with respect to the pressure in the cylinder 106 is acting, the contact state between the tip portion 110a of the vane 110 and the outer periphery of the piston 109 Becomes mixed lubrication or boundary lubrication and is in a harsh environment.

  Here, the base material of the vane 110 is subjected to nitriding treatment using steel such as SKH (high speed tool steel), SKD, SUS, or SCM, and chromium nitride (hereinafter referred to as CrN) is applied to the surface of the tip 110a of the vane 110. A surface treatment film made of ceramics such as diamond-like carbon (hereinafter referred to as DLC) is applied by a PVD treatment method. The surface hardness is about HV 1500 to 2000, and the surface roughness of the tip 110a of the vane 110 that is the sliding surface is about Ra 0.2 μm.

  On the other hand, the base material of the piston 109 contains 0.7 to 1.0 wt% of chromium (Cr), 0.2 to 0.4 wt% of molybdenum (Mo), and 0.2 to 0.4 wt% of nickel (Ni). Cast iron (hereinafter, cast iron containing Mo, Cr, and Ni is referred to as monichro cast iron), and the surface hardness is set to about HRC 50 to 51 by quenching, sub-zero, tempering, standing to cool, and the like. Further, since there are fine concave portions made of graphite on the outer periphery of the piston 109 which is a sliding surface, the surface roughness of the flat portion excluding the fine concave portions is finished to about Ra 0.2 μm.

  Note that the tetrafluoropropene (HFO1234yf) used in the present embodiment has a small temperature difference in spite of non-azeotropic refrigerant mixture by mixing hydrofluorocarbons (HFC32, HFC125) having no double bond. Since the behavior approaches that of the pseudo azeotropic refrigerant mixture, the cooling performance and the cooling performance coefficient (COP) of the cooling device can be improved. In this embodiment, the HFO1234yf refrigerant is used alone, but the same effect can be obtained even if a mixed refrigerant is used.

  Here, the GWP of the mixed refrigerant needs to be two-component mixed or three-component mixed so as to be 5 or more and 750 or less, preferably 350 or less. In order to mix HFO1234yf and HFC32 to make GWP 350 or less, it is desirable that HFO1234yf be 48.5 wt% or more. Further, in order to mix HFO1234yf and HFC125 to make GWP750 or less, it is desirable that HFO1234yf be 78.7 wt% or more, and in order to make GWP350 or less, HFO1234yf is 91.6 wt% or more. As a result, even if a refrigerant that cannot be recovered is released into the atmosphere, the effect on global warming can be kept to a minimum.

  In the present embodiment, polyol ester oil compatible with HFO1234yf is used as the refrigerator oil 103, but similarly, the refrigerator oil 103 made of polyvinyl ether or polyalkylene glycol having compatibility is used. The refrigerating machine oil 103 that has gone out to the refrigerating cycle can be recovered in the compressor 120, and similarly, the highly reliable compressor 120 can be obtained. Moreover, since the above refrigerating machine oil is compatible as a mixed refrigerant with the HFC refrigerant, the same effect can be obtained.

  In this embodiment, a rotary compressor is described as an example of the compressor. However, this may be any other known type of compressor such as a scroll compressor. It is.

  As described above, the refrigeration apparatus according to the present invention uses a refrigerator oil suitable for the refrigeration cycle even when using a low GWP refrigerant having a property that a refrigerant polymer is easily generated. It is possible to suppress deterioration and performance degradation, and it can be applied to many uses such as air conditioners, car air conditioners, refrigerators, dehumidifiers, heat pump dryers, heat pump water heaters, and beverage vending machines.

DESCRIPTION OF SYMBOLS 103 Refrigerating machine oil 105 Compression mechanism part 106 Cylinder 109 Piston 110 Vane 120 Compressor 121 Condenser 122 Expansion mechanism 123 Evaporator

Claims (9)

A single refrigerant containing hydrofluoroolefin having a double bond between carbon and carbon or at least a working refrigerant mixed with hydrofluorocarbon having no double bond is enclosed, and the refrigerant is circulated by a compressor. includes a refrigerant circulation pathway, refrigeration system, characterized in that the said compressor being used is refrigerating machine oil refrigerating machine oil kinematic viscosity of 0.1 mm ² / s or more 100 mm ² / s or less of the time of operation . The refrigerating apparatus according to claim 1, wherein an acid scavenger is contained in the refrigerating machine oil. The refrigeration apparatus according to claim 1 or 2, wherein an antiwear agent is contained in the refrigerating machine oil. The compression mechanism of the compressor has a piston and a vane in the cylinder, and the raw material of the vane is subjected to nitriding treatment using high-speed tool steel or sintering and quenching treatment using sintered alloy steel. The refrigeration apparatus according to any one of claims 1 to 3, wherein the refrigeration apparatus is performed. 5. The refrigeration apparatus according to claim 4, wherein the sintered alloy steel of the vane is a high speed tool steel. The compression mechanism portion of the compressor has a piston and a vane in a cylinder, and the vane is formed of a ceramic as a base material or a ceramic surface-treated surface of a base material made of iron. The refrigeration apparatus according to any one of claims 1 to 3. Hydrofluoroolefin is tetrafluoropropene or trifluoropropene, and is a single refrigerant or a mixed refrigerant in which two or three components are mixed so that their main component is a global warming potential of 5 or more and 750 or less. The refrigeration apparatus according to any one of claims 1 to 6, wherein the refrigeration apparatus is a working refrigerant. Hydrofluoroolefin is a mixed refrigerant in which tetrafluoropropene or trifluoropropene is the main component and difluoromethane and pentafluoroethane are mixed in two or three components so that the global warming potential is 5 or more and 750 or less. The refrigeration apparatus according to claim 1, wherein the refrigeration apparatus is a working refrigerant. Is it a synthetic oil mainly composed of polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycols or their monoether and polyvinyl ether copolymers, polyol esters, and oxygenates of polycarbonates as refrigeration oils? The refrigeration apparatus according to any one of claims 1 to 8, wherein the refrigeration apparatus is a synthetic oil mainly composed of alkylbenzenes or α-olefins.