JP2008180426A - Refrigeration system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigeration system capable of sufficiently suppressing a copper plating phenomenon. <P>SOLUTION: The refrigeration system 1 is provided with a coolant circuit 2. The coolant circuit is filled with a coolant and a copper deactivator. The coolant includes 50wt.ppm or more of water. A 1/2 mole equivalent number or more of a water mole equivalent number of the copper deactivator is added. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a refrigeration apparatus that can suppress a copper plating phenomenon.

  In a refrigerant circuit of a refrigeration apparatus, a compression mechanism, an evaporator, an expansion mechanism, a condenser, and the like are often connected by a copper tube from the viewpoint of workability on site. When such a refrigerant circuit is filled with a refrigerant having a relatively large amount of water, particularly carbon dioxide, the reactions shown in the following chemical reaction formulas (1) to (3) occur, and copper ions are generated in the refrigerant. To do. When this copper ion comes into contact with an iron component such as a compression mechanism or an expansion mechanism, a reaction shown in the following chemical reaction formula (4) occurs and the component is plated with copper (hereinafter copper plating). (Refer to Non-Patent Document 1, Patent Documents 1 and 2, etc.). For example, when such a copper plating phenomenon occurs in the capillary (expansion mechanism), there arises a problem that the capillary is clogged. Further, for example, when such a copper plating phenomenon occurs on a sliding part of a compressor, the surface of the sliding part becomes rough, which causes a problem of adversely affecting the reliability of the compressor.

このような銅メッキ現象を抑制する方法として、例えば、エポキシ化合物により水分を捕捉させる方法（例えば、特許文献１等参照）や、基油粘度及びその基油中の水分含有量を規定する方法（例えば、特許文献２等参照）が提案されている。
特開平６−２４０２７９号公報 特開２００１−１９９８９号公報 特開２００１−２５５０３０号公報 中尾英人、外３名，「冷媒圧縮機における銅の析出現象に及ぼす冷凍機油としゅう動材料の影響」，トライポロジスト，第５０巻，第２号（２００５），ｐ１８７−１９２

As a method for suppressing such a copper plating phenomenon, for example, a method of capturing moisture with an epoxy compound (see, for example, Patent Document 1), a method of defining the base oil viscosity and the moisture content in the base oil ( For example, see Patent Document 2).
JP-A-6-240279 JP 2001-19989 A JP 2001-255030 A Hideo Nakao, 3 others, “Effects of refrigeration oil and sliding material on copper precipitation phenomenon in refrigerant compressors”, Tripodist, Vol. 50, No. 2 (2005), p187-192

  However, even if the inventor actually tried the above method, the copper plating phenomenon could not be sufficiently suppressed.

  The subject of this invention is providing the freezing apparatus which can fully suppress a copper plating phenomenon.

  The refrigeration apparatus according to the first invention includes a refrigerant circuit. The refrigerant circuit is filled with a refrigerant and a copper deactivator. For the refrigerant, 50 wt. Contains more than ppm ppm of water. The copper deactivator is added in an amount equal to or greater than ½ molar equivalent of water. The “copper deactivator” here is, for example, a benzotriazole-based compound, and the compound represented by the following chemical formula 1 is particularly preferable. In Formula 1, the substituent (R) bonded to the aromatic nucleus and the substituent (R) bonded to the nitrogen atom may be the same or different from each other. Further, the two substituents (R) bonded to the nitrogen atom may be the same or different from each other. The copper deactivator according to the present invention is preferably one in which the substituent bonded to the aromatic nucleus is a methyl group and the two substituents bonded to the nitrogen atom are 2-ethylhexyl groups.

  According to the above chemical reaction formula, 1 mol of copper ion is generated per 2 mol of water. For this reason, if the copper deactivator more than the 1/2 molar equivalent number of the molar equivalent number of water is added to a refrigerant circuit, all the copper ions generated in a refrigerant circuit can be inactivated. For this reason, in this refrigeration apparatus, the copper plating phenomenon is sufficiently suppressed.

  A refrigeration apparatus according to a second aspect of the present invention is the refrigeration apparatus according to the first aspect of the present invention, wherein the refrigerant circuit is further filled with lubricating oil. The copper deactivator is mixed in the lubricating oil. The “lubricating oil” referred to here is, for example, polyalkylene glycol (PAG), polyvinyl ether (PVE), polyalphaolefin (PAO), poly (oxyethylene) alkyl ether (POE), naphthene oil, paraffin oil, Carbonate oil, alkylbenzene oil, and the like.

  For this reason, in this refrigeration apparatus, the copper deactivator is dissolved in the lubricating oil, and easily comes into contact with the copper ions in the refrigerant. Therefore, in this refrigeration apparatus, the copper deactivator easily exhibits its function.

  The refrigeration apparatus according to the third invention is the refrigeration apparatus according to the second invention, wherein the lubricating oil is polyalkylene glycol (PAG), polyvinyl ether (PVE), polyalphaolefin (PAO), poly (oxyethylene) alkyl. At least one lubricating oil selected from the group consisting of ether (POE), naphthenic oil, paraffin oil, carbonate oil, and alkylbenzene oil.

  For this reason, the conventional lubricating oil can be used in this refrigeration apparatus.

  A refrigeration apparatus according to a fourth invention is the refrigeration apparatus according to any one of the first to third inventions, wherein the refrigerant is at least selected from the group consisting of a fluorocarbon refrigerant, a hydrocarbon refrigerant, and carbon dioxide. One refrigerant.

  For this reason, a conventional refrigerant can be used in this refrigeration apparatus.

  A refrigeration apparatus according to a fifth aspect is the refrigeration apparatus according to any one of the first to fourth aspects, wherein the refrigerant circuit is further filled with an acid scavenger.

  For this reason, in this refrigeration apparatus, generation of copper ions can be suppressed. Therefore, in this refrigeration apparatus, the copper plating phenomenon can be further sufficiently suppressed.

  A refrigeration apparatus according to a sixth aspect of the invention includes a refrigerant circuit. The refrigerant circuit is filled with carbon dioxide, a benzotriazole compound, polyalkylene glycol (PAG), and an epoxy compound. For carbon dioxide, 50 wt. Contains more than ppm ppm of water. The benzotriazole-based compound is added in an amount equal to or greater than ½ molar equivalent of water.

  According to the above chemical reaction formula, 1 mol of copper ion is generated per 2 mol of water. For this reason, if a benzotriazole-based compound (copper deactivator) having a molar equivalent number equal to or greater than 1/2 molar equivalent of water is added to the refrigerant circuit, all copper ions generated in the refrigerant circuit are inactivated. be able to. The refrigerant circuit is also filled with an epoxy compound. For this reason, in this refrigeration apparatus, generation of copper ions can be suppressed. Therefore, in this refrigeration apparatus, the copper plating phenomenon is sufficiently suppressed.

  A refrigeration apparatus according to a seventh aspect includes a refrigerant circuit. The refrigerant circuit is filled with a fluorocarbon refrigerant, a benzotriazole compound, polyvinyl ether (PVE), and an epoxy compound. For chlorofluorocarbon refrigerants, 50 wt. Contains more than ppm ppm of water. The benzotriazole-based compound is added in an amount equal to or greater than ½ molar equivalent of water.

  According to the above chemical reaction formula, 1 mol of copper ion is generated per 2 mol of water. For this reason, if a benzotriazole-based compound (copper deactivator) having a molar equivalent number equal to or greater than 1/2 molar equivalent of water is added to the refrigerant circuit, all copper ions generated in the refrigerant circuit are inactivated. be able to. The refrigerant circuit is also filled with an epoxy compound. For this reason, in this refrigeration apparatus, generation of copper ions can be suppressed. Therefore, in this refrigeration apparatus, the copper plating phenomenon is sufficiently suppressed.

  In the refrigeration apparatus according to the first invention, the copper plating phenomenon is sufficiently suppressed.

  In the refrigeration apparatus according to the second aspect of the invention, the copper deactivator is dissolved in the lubricating oil and easily comes into contact with the copper ions in the refrigerant. Therefore, in this refrigeration apparatus, the copper deactivator easily exhibits its function.

  In the refrigeration apparatus according to the third aspect of the invention, conventional lubricating oil can be used.

  In the refrigeration apparatus according to the fourth invention, a conventional refrigerant can be used.

  In the refrigeration apparatus according to the fifth aspect of the invention, the generation of copper ions can be suppressed. Therefore, in this refrigeration apparatus, the copper plating phenomenon can be further sufficiently suppressed.

  In the refrigeration apparatus according to the sixth aspect of the invention, the copper plating phenomenon is sufficiently suppressed.

  In the refrigeration apparatus according to the seventh aspect, the copper plating phenomenon is sufficiently suppressed.

<Configuration of air conditioner>
A schematic refrigerant circuit 2 of an air-conditioning apparatus 1 according to an embodiment of the present invention is shown in FIG.

  This air conditioner 1 is an air conditioner capable of cooling operation and heating operation, and mainly includes a refrigerant circuit 2 and blower fans 26 and 32. The refrigerant circuit 2 is filled with at least one refrigerant selected from the group consisting of a fluorocarbon refrigerant, a hydrocarbon refrigerant, and carbon dioxide. Further, this refrigerant contains 50 wt. Contains more than ppm ppm of water.

  The refrigerant circuit 2 mainly includes a compressor 11, a four-way switching valve 12, an outdoor heat exchanger 13, an internal heat exchanger 14, a first electric expansion valve 15, a liquid receiver 16, a second electric expansion valve 17, and an indoor room. A heat exchanger 31 is provided, and each device is connected via a refrigerant pipe as shown in FIG.

  And in this Embodiment, the air conditioning apparatus 1 is a separation-type air conditioning apparatus, Comprising: The indoor unit 30 which mainly has the indoor heat exchanger 31 and the indoor fan 32, the compressor 11, and a four-way switching valve 12, the outdoor heat exchanger 13, the internal heat exchanger 14, the first electric expansion valve 15, the liquid receiver 16 and the second electric expansion valve 17, and the refrigerant liquid piping of the indoor unit 30. The first connecting pipe 41 connects the refrigerant liquid piping of the outdoor unit 10, and the second connecting pipe 42 connects the refrigerant gas piping of the indoor unit 30 and the refrigerant gas piping of the outdoor unit 10. It can be said that there is. The refrigerant liquid piping of the outdoor unit 10 and the first communication pipe 41 are connected via the first shut-off valve 18 of the outdoor unit 10, and the refrigerant gas piping and the second communication pipe 42 of the outdoor unit 10 are connected to the outdoor unit 10. The second closing valves 19 are connected to each other.

(1) Indoor unit The indoor unit 30 mainly includes an indoor heat exchanger 31 and an indoor fan 32.

  The indoor heat exchanger 31 is a heat exchanger for exchanging heat between indoor air, which is air in an air-conditioned room, and a refrigerant.

  The indoor fan 32 is a fan for taking in the air in the air-conditioned room into the unit 30 and sending out conditioned air, which is air after heat exchange with the refrigerant via the indoor heat exchanger 31, to the air-conditioned room again.

  By adopting such a configuration, the indoor unit 30 exchanges heat between the indoor air taken in by the indoor fan 32 and the liquid refrigerant flowing through the indoor heat exchanger 31 during the cooling operation, thereby conditioned air ( It is possible to generate conditioned air (warm air) by exchanging heat between the indoor air taken in by the indoor fan 32 and the supercritical refrigerant flowing through the indoor heat exchanger 31 during heating operation. Yes.

(2) Outdoor unit The outdoor unit 10 mainly includes a compressor 11, a four-way switching valve 12, an outdoor heat exchanger 13, an internal heat exchanger 14, a first electric expansion valve 15, a liquid receiver 16, and a second electric motor. An expansion valve 17 and an outdoor fan 26 are included.

  The compressor 11 is a device for sucking low-pressure gas refrigerant flowing through the suction pipe, compressing it into a supercritical state, and then discharging it to the discharge pipe. The compressor 11 includes polyalkylene glycol (PAG), polyvinyl ether (PVE), polyalphaolefin (PAO), poly (oxyethylene) alkyl ether (POE), naphthene oil, paraffin oil, carbonate oil, and At least one lubricating oil selected from the group consisting of alkylbenzene oils is injected. In addition, a benzotriazole-based compound is added to the lubricating oil as a copper deactivator, and an epoxy-based compound is added as an acid scavenger. Examples of the epoxy compound used as the acid scavenger include phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α-olefin oxide, and epoxidized soybean oil. Among these epoxy compounds, phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, and α-olefin oxide are preferable from the viewpoint of compatibility with a lubricating oil. The alkyl group of the alkyl glycidyl ether and the alkylene group of the alkylene glycol glycidyl ether may have a branched chain, usually have 3 to 30 carbon atoms, and preferably have 4 to 24 carbon atoms. Preferably it has 6 to 16 carbon atoms. The α-olefin oxide generally has 4 to 30 carbon atoms, preferably 4 to 24 carbon atoms, and more preferably 6 to 16 carbon atoms. . In the embodiment of the present invention, as the acid scavenger, only one kind may be used, or two or more kinds may be used in combination. Moreover, it is preferable that the compounding quantity of the acid scavenger with respect to lubricating oil exists in the range of 0.005 wt%-5 wt%. This is because if the blending amount is less than 0.005 wt%, a sufficient effect may not be obtained, and if the blending amount exceeds 5 wt%, sludge may be generated.

  When the refrigerant is carbon dioxide, polyalkylene glycol (PAG) is preferably used as the lubricating oil, and when the refrigerant is a fluorocarbon refrigerant, polyvinyl ether (PVE) is preferably used as the lubricating oil. preferable. The benzotriazole-based compound is added in an amount equal to or greater than ½ molar equivalent relative to 1 molar equivalent of moisture in the refrigerant.

  The four-way switching valve 12 is a valve for switching the flow direction of the refrigerant corresponding to each operation. During the cooling operation, the four-way switching valve 12 connects the discharge side of the compressor 11 and the high temperature side of the outdoor heat exchanger 13 and compresses them. The suction side of the machine 11 and the gas side of the indoor heat exchanger 31 are connected via the internal heat exchanger 14, and the discharge side of the compressor 11 and the second closing valve 19 are connected to the internal heat exchanger 14 during heating operation. And the suction side of the compressor 11 and the gas side of the outdoor heat exchanger 13 can be connected.

  The outdoor heat exchanger 13 can cool the high-pressure supercritical refrigerant discharged from the compressor 11 during the cooling operation using air outside the air conditioning room as a heat source, and the liquid returned from the indoor heat exchanger 31 during the heating operation. It is possible to evaporate the refrigerant.

  The internal heat exchanger 14 includes a refrigerant pipe (hereinafter referred to as a tenth refrigerant pipe) connecting the low temperature side (or liquid side) of the outdoor heat exchanger 13 and the first electric expansion valve 15, a four-way switching valve 12, It is a heat exchanger configured by arranging a refrigerant pipe (hereinafter referred to as an eleventh refrigerant pipe) connected to the compressor 11 in the vicinity. In the internal heat exchanger 14, heat exchange is performed between the high-temperature and high-pressure supercritical refrigerant flowing through the tenth refrigerant pipe and the low-temperature and low-pressure gas refrigerant flowing through the eleventh refrigerant pipe during the cooling operation.

  The first electric expansion valve 15 is for reducing the pressure of supercritical refrigerant (at the time of cooling operation) flowing out from the low temperature side of the outdoor heat exchanger 13 or liquid refrigerant (at the time of heating operation) flowing in through the receiver 16. It is.

  The liquid receiver 16 is for storing a surplus refrigerant according to the operation mode and the air conditioning load.

  The second electric expansion valve 17 depressurizes the liquid refrigerant flowing through the liquid receiver 16 (during cooling operation) or supercritical refrigerant flowing out from the low temperature side of the indoor heat exchanger 31 (during heating operation). belongs to.

  The outdoor fan 26 is a fan for taking in outdoor air into the unit 10 and exhausting the air after exchanging heat with the refrigerant via the outdoor heat exchanger 13.

<Operation of air conditioner>
The operation of the air conditioner 1 will be described with reference to FIG. As described above, the air conditioner 1 can perform a cooling operation and a heating operation.

(1) Cooling operation During the cooling operation, the four-way switching valve 12 is in the state indicated by the solid line in FIG. 1, that is, the discharge side of the compressor 11 is connected to the high temperature side of the outdoor heat exchanger 13, and the compressor 11 Is connected to the second closing valve 19 via the internal heat exchanger 14. At this time, the first closing valve 18 and the second closing valve 19 are opened.

  When the compressor 11 is started in the state of the refrigerant circuit 2, the gas refrigerant is sucked into the compressor 11 and compressed to be in a supercritical state, and then the outdoor heat is passed through the four-way switching valve 12. It is sent to the exchanger 13 and cooled in the outdoor heat exchanger 13.

  The cooled supercritical refrigerant is sent to the first electric expansion valve 15 via the internal heat exchanger 14. At this time, the supercritical refrigerant is cooled by the low-temperature gas refrigerant flowing through the eleventh refrigerant pipe of the internal heat exchanger 14. The supercritical refrigerant sent to the first electric expansion valve 15 is reduced in pressure and saturated, and then sent to the second electric expansion valve 17 via the liquid receiver 16. The saturated refrigerant sent to the second electric expansion valve 17 is reduced in pressure to become liquid refrigerant, and then supplied to the indoor heat exchanger 31 via the first closing valve 18 to cool and evaporate the indoor air. It becomes a gas refrigerant.

  Then, the gas refrigerant is sucked into the compressor 11 again via the second closing valve 19, the internal heat exchanger 14, and the four-way switching valve 12. At this time, the gas refrigerant is heated by the high-temperature supercritical refrigerant flowing through the tenth refrigerant pipe of the internal heat exchanger 14. In this way, the cooling operation is performed.

(2) Heating operation During the heating operation, the four-way switching valve 12 is in the state indicated by the broken line in FIG. 1, that is, the discharge side of the compressor 11 is connected to the second closing valve 19 and the suction side of the compressor 11 is It is in a state of being connected to the gas side of the outdoor heat exchanger 13 via the internal heat exchanger 14. At this time, the first closing valve 18 and the second closing valve 19 are opened.

  When the compressor 11 is started in the state of the refrigerant circuit 2, the gas refrigerant is sucked into the compressor 11 and compressed to be in a supercritical state, and then the four-way switching valve 12 and the second closing valve 19. To be supplied to the indoor heat exchanger 31.

  Then, the supercritical refrigerant is cooled while heating the indoor air in the indoor heat exchanger 31. The cooled supercritical refrigerant is sent to the second electric expansion valve 17 through the first closing valve. The supercritical refrigerant sent to the second electric expansion valve 17 is decompressed and saturated, and then sent to the first electric expansion valve 15 via the liquid receiver 16. The saturated refrigerant sent to the first electric expansion valve 15 is reduced in pressure to become a liquid refrigerant, and then sent to the outdoor heat exchanger 13 via the internal heat exchanger 14, and in the outdoor heat exchanger 13. It is evaporated to become a gas refrigerant. At this time, the gas refrigerant is heated by the high-temperature supercritical refrigerant flowing through the eleventh refrigerant pipe of the internal heat exchanger 14. Then, this gas refrigerant is sucked into the compressor 11 again via the four-way switching valve 12. In this way, the heating operation is performed.

<Suppression of copper plating phenomenon>
Hereinafter, a copper plating test and the result are shown as an Example and a comparative example.

  In an autoclave with an internal volume of 120 mL, 40 g of polyalkylene glycol (PAG) oil, 40 g of carbon dioxide refrigerant, 4.0 g of N, N-bis (2-ethylhexyl) -4-methyl-1H-benzotriazole-1-methyl Amine (or N, N-bis (2-ethylhexyl) -5-methyl-1H-benzotriazole-1-methylamine) (Irgamet 39 manufactured by Ciba Specialty Chemicals) (see Formula 2 below), 2.4 g of water, After adding iron pieces, copper pieces and aluminum pieces, the autoclave was sealed and left at 175 degrees Celsius for 10 days. Here, N, N-bis (2-ethylhexyl) -4-methyl-1H-benzotriazole-1-methylamine functioning as a copper deactivator is capable of capturing 2 moles of copper ions per mole. Have Therefore, in this example, the copper deactivator is added in an amount of 1.55 molar equivalents relative to 1 molar equivalent of water (the molecular weight of water is 18.01, N, N-bis (The molecular weight of (2-ethylhexyl) -4-methyl-1H-benzotriazole-1-methylamine was calculated as 386.62).

  And after that, when it was confirmed whether the copper plating was formed in the iron piece, the copper plating was not formed (refer Table 1).

  A copper plating test was conducted in the same manner as in Example 1 except that the polyalkylene glycol (PAG) oil was replaced with polyvinyl ether (PVE) oil and the amount of water added was changed to 1.6 g. As a result, copper plating was not formed on the iron piece (see Table 1). In this example, the copper deactivator is added in 2.33 molar equivalents per 1 molar equivalent of water.

  Polyalkylene glycol (PAG) oil is replaced with polyvinyl ether (PVE) oil, carbon dioxide refrigerant is replaced with HFC refrigerant, N, N-bis (2-ethylhexyl) -4-methyl-1H-benzotriazole-1-methyl A copper plating test was conducted in the same manner as in Example 1 except that the amount of amine added was changed to 2.4 g and the amount of water added was changed to 0.8 g. As a result, copper plating was not formed on the iron piece (see Table 1). In this example, the copper deactivator is added in an amount of 2.80 molar equivalents relative to 1 molar equivalent of water.

  The polyalkylene glycol (PAG) oil is replaced with polyalphaolefin (PAO) oil, the carbon dioxide refrigerant is replaced with a hydrocarbon refrigerant, and N, N-bis (2-ethylhexyl) -4-methyl-1H-benzotriazole-1 -The copper plating test was conducted in the same manner as in Example 1 except that the addition amount of methylamine was changed to 0.8 g and the addition amount of water was changed to 0.4 g. As a result, copper plating was not formed on the iron piece (see Table 1). In this example, the copper deactivator is added in an amount of 1.86 molar equivalents relative to 1 molar equivalent of water.

(Comparative Example 1)
A copper plating test was conducted in the same manner as in Example 1 except that N, N-bis (2-ethylhexyl) -4-methyl-1H-benzotriazole-1-methylamine was not added. As a result, copper plating was formed on the iron piece (see Table 1).

(Comparative Example 2)
A copper plating test was conducted in the same manner as in Example 2 except that N, N-bis (2-ethylhexyl) -4-methyl-1H-benzotriazole-1-methylamine was not added. As a result, copper plating was formed on the iron piece (see Table 1).

(Comparative Example 3)
A copper plating test was conducted in the same manner as in Example 3 except that N, N-bis (2-ethylhexyl) -4-methyl-1H-benzotriazole-1-methylamine was not added. As a result, copper plating was formed on the iron piece (see Table 1).

(Comparative Example 4)
A copper plating test was conducted in the same manner as in Example 4 except that N, N-bis (2-ethylhexyl) -4-methyl-1H-benzotriazole-1-methylamine was not added. As a result, copper plating was formed on the iron piece (see Table 1).

<Characteristics of air conditioner>
In the air conditioner 1 according to the present embodiment, a copper deactivator having a ½ molar equivalent number relative to 1 molar equivalent number of water is added to the refrigerant. For this reason, in this air conditioning apparatus 1, all the copper ions generated in the refrigerant circuit 2 can be inactivated. Moreover, in this air conditioning apparatus 1, an epoxy compound is added to the refrigerant as an acid scavenger. For this reason, in this air conditioning apparatus 1, generation | occurrence | production of a copper ion can be suppressed. Therefore, in this air conditioner 1, the copper plating phenomenon is sufficiently suppressed.

  The refrigeration apparatus according to the present invention has a feature that the copper plating phenomenon is sufficiently suppressed, and is useful as a refrigeration apparatus for renewal demand.

It is a refrigerant circuit figure of the air harmony device concerning an embodiment of the invention.

Explanation of symbols

1 Air conditioning equipment (refrigeration equipment)
2 Refrigerant circuit

Claims (7)

50 wt. a refrigerant containing more than ppm water,
A refrigeration apparatus (1) comprising a refrigerant circuit (2) filled with a copper deactivator having a molar equivalent number equal to or greater than ½ molar equivalent number of the water. The refrigerant circuit is further filled with lubricating oil,
The refrigeration apparatus according to claim 1, wherein the copper deactivator is mixed in the lubricating oil. The lubricating oil comprises polyalkylene glycol (PAG), polyvinyl ether (PVE), polyalphaolefin (PAO), poly (oxyethylene) alkyl ether (POE), naphthene oil, paraffin oil, carbonate oil, and alkylbenzene oil. The refrigeration apparatus according to claim 2, wherein the refrigeration apparatus is at least one lubricating oil selected from the group. The refrigeration apparatus according to any one of claims 1 to 3, wherein the refrigerant is at least one refrigerant selected from the group consisting of a fluorocarbon refrigerant, a hydrocarbon refrigerant, and carbon dioxide. The refrigeration apparatus according to claim 1, wherein the refrigerant circuit is further filled with an acid scavenger. 50 wt. carbon dioxide containing more than ppm water,
A benzotriazole-based compound having a molar equivalent number of 1/2 or more of the molar equivalent number of water;
Polyalkylene glycol (PAG);
A refrigeration apparatus (1) comprising a refrigerant circuit (2) filled with an epoxy compound. 50 wt. a fluorocarbon refrigerant containing more than ppm water,
A benzotriazole-based compound having a molar equivalent number of 1/2 or more of the molar equivalent number of water;
Polyvinyl ether (PVE),
A refrigeration apparatus (1) comprising a refrigerant circuit (2) filled with an epoxy compound.

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