Refrigeration cycle device

Abstract

This refrigeration cycle device is provided with a refrigerant circuit including a compressor, wherein: the compressor is filled with refrigerating machine oil; a refrigerant is sealed within the refrigerant circuit; the refrigerant contains i (i is an integer equal to or greater than 1) types of compounds represented by CnH2n-mFm (n is 2 or 3, and m is an integer equal to or greater than 1 and less than 2n); at least one of the members constituting the refrigerant circuit is a rubber component; the rubber component is in contact with the refrigerating machine oil and the refrigerant; and expression (1): B×Σ\{Ai / (ni-1)\}≤0.24 is satisfied. Ai is the molar ratio of the i-th compound in the refrigerant, ni is the value of n for the i-th compound, Σ\{Ai / (ni-1)\} is the sum of Ai / (ni-1) for the i types of compounds, and B is the mass ratio of acrylonitrile units contained in the rubber constituting the rubber component.

Description

Refrigeration Cycle Equipment

[0001] The present disclosure relates to a refrigeration cycle device.

[0002] Currently, refrigerants used in refrigeration cycle devices are regulated by, for example, the Fluorocarbons Emission Control Act (enforced in April 2015). Specifically, an upper limit is set on the global warming potential (GWP) value of the refrigerants used. For this reason, the use of refrigerants with lower GWP is required.

[0003] In recent years, HFOs (hydrofluoroolefins) such as trans-1,2-difluoroethylene (HFO-1132(E)), trifluoroethylene (HFO-1123), and 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf) have been studied as refrigerants with low GWP values.

[0004] Rubber parts can be used as components of the refrigerant circuit of a refrigeration cycle device. The rubber that constitutes the rubber parts can be rubber containing acrylonitrile units, such as nitrile rubber. In general, the greater the amount of acrylonitrile units, the better the physical properties of the rubber tend to be.

[0005] For example, Patent Document 1 (JP 2018-128022 A) discloses a method for suppressing deterioration of rubber parts used in the refrigerant circuit of a refrigeration cycle device by increasing the amount of acrylonitrile units in the rubber that makes up the rubber parts.

[0006] Furthermore, Patent Document 2 (JP 2019-203138 A) discloses a method for appropriately suppressing rubber swelling caused by refrigerating machine oil or a mixed composition for a refrigerator in a refrigeration cycle device containing an unsaturated fluorohydrocarbon refrigerant, by using a refrigerating machine oil without impairing the compatibility between the unsaturated fluorohydrocarbon refrigerant and the refrigerating machine oil.

[0007] JP 2018-128022 A JP 2019-203138 A

[0008] However, when a refrigeration cycle is performed using a refrigerant with a sufficiently small GWP, such as the above-mentioned HFO refrigerant, deterioration of refrigeration oil due to the influence of the refrigerant and rubber parts within the refrigeration cycle device has not been studied to date.

[0009] An object of the present disclosure is to suppress deterioration in the quality of refrigeration oil and provide good reliability in a refrigeration cycle device that uses an HFO refrigerant.

[0010] The compressor is filled with refrigerant oil, and a refrigerant is sealed in the refrigerant circuit. The refrigerant is C ｎ H ２ｎ－ｍ F ｍ (n represents 2 or 3, and m represents an integer of 1 or more and less than 2n), at least one of the members constituting the refrigerant circuit is a rubber part, the rubber part is in contact with the refrigerating machine oil and the refrigerant, and the following formula (1) is satisfied: B×Σ{A ｉ / (n ｉ -1)}≦0.24...(1) [In formula (1), A ｉ represents the molar ratio of the i-th compound in the refrigerant, and n ｉ represents the value of n of the i-th compound, and Σ{A ｉ / (n ｉ -1)) is A for i kinds of the compounds. ｉ / (n ｉ -1), and B represents the mass ratio of acrylonitrile units contained in the rubber that constitutes the rubber part.]

[0011] According to the present disclosure, in a refrigeration cycle device that uses an HFO refrigerant, it is possible to suppress deterioration in the quality of refrigerating machine oil and provide good reliability.

[0012] Fig. 1 is a schematic diagram showing an example of a refrigeration cycle device according to embodiment 1. Fig. 2 is a cross-sectional schematic diagram showing an example of a compressor of the refrigeration cycle device according to embodiment 1. Fig. 3 is a graph showing the relationship between the mass ratio (value of B) of acrylonitrile units contained in rubber constituting a rubber part and the total acid number of refrigeration oil (Evaluation Test 1). Fig. 4 is a graph showing the relationship between Σ{Aｉ / (n ｉ 5 is a graph showing the relationship between the value of Σ{A −1)} and the total acid number of the refrigerating machine oil (Evaluation Test 2). ｉ / (n ｉ 1 is a graph showing the relationship between the value of (-1)) and the mass ratio (value of B) of acrylonitrile units contained in the rubber constituting the rubber part (Evaluation Test 3). In the drawing, "TAN" represents the total acid number.

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, dimensional relationships such as length, width, thickness, and depth have been appropriately changed for clarity and simplification of the drawings, and do not represent actual dimensional relationships.

[0014] Embodiment 1 A refrigeration cycle device according to one aspect of the present disclosure includes a refrigerant circuit including a compressor, the compressor is filled with refrigerating machine oil, and a refrigerant is sealed in the refrigerant circuit, and the refrigerant is C ｎ H ２ｎ－ｍ F ｍ (n represents 2 or 3, and m represents an integer of 1 or more and less than 2n), at least one of the components constituting the refrigerant circuit is a rubber part, the rubber part is in contact with the refrigerant oil and the refrigerant, and the refrigeration cycle device satisfies the following formula (1). In this specification, the above compound is also referred to as "compound X". B × Σ{A ｉ / (n ｉ -1)}≦0.24...(1) [In formula (1), A ｉ represents the molar ratio of the i-th compound X in the refrigerant, and n ｉ represents the value of n of the i-th compound X, and Σ{A ｉ / (n ｉ -1)) is the A ｉ / (n ｉ -1), and B represents the mass ratio of acrylonitrile units contained in the rubber that constitutes the rubber part.]

[0015] An outline of the refrigeration cycle apparatus of this embodiment will be briefly described. Fig. 1 is a schematic diagram showing an example of a refrigeration cycle apparatus according to embodiment 1. An outdoor unit 1 includes a compressor 3, a condenser 4, an outdoor blower 5, etc., and the compressor 3 and the condenser 4 are connected by piping. An indoor unit 2 includes an expansion valve 6, an evaporator 7, an indoor blower 8, etc., and the expansion valve 6 and the evaporator 7 are connected by piping.

[0016] The compressor 3 of the outdoor unit 1 and the evaporator 7 of the indoor unit 2 are connected by a gas pipe 10. The condenser 4 of the outdoor unit 1 and the expansion valve 6 of the indoor unit 2 are connected by a liquid pipe 9.

[0017] The refrigerant circuit 100 is formed by the above-described configuration of the refrigeration cycle device, and the refrigerant circulates within the refrigerant circuit 100 via the liquid pipe 9 and the gas pipe 10 .

[0018] The compressor 3 compresses the gaseous refrigerant in the gas pipe 10. The condenser 4 cools the gaseous refrigerant compressed by the compressor 3 to form a high-pressure liquid refrigerant or a two-phase gas-liquid refrigerant. The expansion valve 6 reduces the pressure of the high-pressure liquid refrigerant or the two-phase gas-liquid refrigerant. The evaporator 7 heats the reduced-pressure refrigerant to form a low-pressure gaseous refrigerant. The compressor 3 draws in the low-pressure gaseous refrigerant that has been converted by the evaporator 7 and compresses it again.

[0019] The outdoor fan 5 is a component that sends air to the condenser 4 and is provided to promote heat exchange between the refrigerant flowing through the condenser 4 and the air, thereby absorbing or releasing heat. The indoor fan 8 is a component that sends air to the evaporator 7 and is provided to promote heat exchange between the refrigerant flowing through the evaporator 7 and the air, thereby absorbing or releasing heat.

[0020] In this embodiment, a configuration for performing heat exchange between the condenser 4 and the evaporator 7 and air is described, but this is not limited to this, and for example, the configuration may be such that heat exchange is performed with a liquid such as water instead of air.

[0021] Furthermore, in this embodiment, a configuration in which the evaporator 7 is provided inside the indoor unit 2 is described, but this is not limited to this, and for example, the condenser 4 may be arranged indoors and the evaporator 7 may be arranged outdoors.

[0022] The outdoor unit 1 as described above may be provided with, for example, a four-way valve or a combination of multiple valves, and a switching mechanism for switching between the suction pipe and the discharge pipe of the compressor 3. By providing the switching mechanism, the heat exchanger in the outdoor unit 1 functions as the evaporator 7, and the heat exchanger in the indoor unit 2 functions as the condenser 4, making it possible to use heat from outside the room to heat the room.

[0023] The refrigeration cycle device may be, for example, a device capable of both cooling and heating, a device capable of only cooling, or a device capable of only heating. The use of the refrigeration cycle device according to this embodiment is not limited to air conditioning, but may also be for freezing, refrigeration, hot water supply, etc.

[0024] In the present embodiment, a configuration in which the expansion valve 6 is provided in the indoor unit 2 has been described, but the present invention is not limited to this, and for example, the expansion valve 6 may be provided in the outdoor unit 1. Also, for example, the expansion valve 6 may be provided in both the outdoor unit 1 and the indoor unit 2. Furthermore, for example, a plurality of indoor units 2 may be provided in the refrigerant circuit 100, and a plurality of outdoor units 1 may be provided.

[0025] <Refrigerant> Next, the refrigerant sealed in the refrigerant circuit in this embodiment will be described. ｎ H ２ｎ－ｍ F ｍ (n represents 2 or 3, and m represents an integer of 1 or more and less than 2n). ｉ / (n ｉ -1)) is the A ｉ / (n ｉ A in the above formula (1) represents the total value of ｉ represents the molar ratio of the i-th compound X in the refrigerant. ｉ represents the value of n of the i-th compound X. ｉ −1) means the ratio of the number of carbon-carbon double bonds to the total number of carbon-carbon bonds in the i-th compound X. Hereinafter, this ratio will also be referred to as the “double bond ratio” in the i-th compound X.

[0026] Compound X, which is at least a part of the refrigerant, is selected so that the value of the left side of formula (1) is 0.24 or less. The refrigerant may contain only one type of compound X, or may contain two or more types. When the value of the left side of formula (1) is 0.24 or less, deterioration of the refrigerating machine oil can be suppressed and the reliability of the compressor can be improved.

[0027] Compound X is a compound belonging to the HFO (hydrofluoroolefin) family and has a carbon-carbon double bond, which is a relatively unstable molecular structure, and therefore may oxidize the refrigerating machine oil described below. ｉ / (n ｉ As the value of {A -1)} increases, the refrigerating machine oil may deteriorate. Specifically, in the presence of air, compound X deteriorates due to oxidation, producing fluoride ions. The fluoride ions may oxidize and deteriorate the refrigerating machine oil. Therefore, by at least one of reducing the molar ratio of compound X in the refrigerant and reducing the double bond ratio in compound X so that the value of the left side of formula (1) becomes 0.24 or less, Σ{A ｉ / (n ｉ By reducing the value of (-1), deterioration of the refrigerating machine oil can be suppressed and the reliability of the compressor can be improved.

[0028] From the viewpoint of suppressing deterioration of the refrigerating machine oil and improving the reliability of the compressor, the value of the left side of formula (1) may be 0.23 or less, or may be 0.22 or less.

[0029] Examples of compound X include monofluoroethylene (HFO-1141), 1,1-difluoroethylene (HFO-1132a), (E)-1,2-difluoroethylene (HFO-1132(E)), (Z)-1,2-difluoroethylene (HFO-1132(Z)), trifluoroethylene (HFO-1123), (E)-1,2,3,3,3-pentafluoropropene (HFO-1225ye(E)), (Z)-1,2,3,3,3-pentafluoropropene (HFO-1225ye(Z)), 1,1,3,3,3-pentafluoropropene (HFO-1225zc), 2,3,3,3- Examples include tetrafluoropropene (HFO-1234yf), (E)-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)), (Z)-1,3,3,3-tetrafluoropropene (HFO-1234ze(Z)), (E)-1,2,3,3-tetrafluoropropene (HFO-1234ye(E)), (Z)-1,2,3,3-tetrafluoropropene (HFO-1234ye(Z)), 3,3,3-trifluoropropene (HFO-1243zf), 3,3-difluoropropene (HFO-1252zf), and 2-fluoropropene (HFO-1261yf).

[0030] From the viewpoint of reducing the GWP of the refrigerant, compound X preferably contains hydrofluoroethylene, and more preferably contains trifluoroethylene.

[0031] The content of compound X in the refrigerant (i.e., ΣA ｉ From the viewpoint of reducing the GWP of the refrigerant, the content of compound X in the refrigerant is preferably 10 mol % or more, and more preferably 20 mol % or more. From the viewpoint of suppressing deterioration of the refrigerating machine oil due to oxidation, the content of compound X in the refrigerant is preferably 90 mol % or less, and more preferably 80 mol % or less.

[0032] The refrigerant may be a mixture of compound X and one or more compounds selected from hydrocarbons having from 1 to 4 carbon atoms and halogenated hydrocarbons having from 1 to 4 carbon atoms (but other than compound X). Halogenated hydrocarbons include chlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, hydrofluoroolefins, hydrochlorofluoroolefins, and fluoroiodocarbons. Halogenated hydrocarbons have lower flammability than hydrocarbons due to the substitution of hydrogen atoms with halogen atoms, and mixing can reduce the flammability of the refrigerant. One method of mixing is to charge a refrigerant circuit with a refrigerant in a mixed state of all compounds. When using hydrocarbons having from 1 to 4 carbon atoms, additional hydrocarbons having from 1 to 4 carbon atoms may be charged into a refrigerant circuit that is already charged with compound X (and halogenated hydrocarbons) or in which a small amount of compound X remains.

[0033] Preferably, the halogenated hydrocarbon other than Compound X has an operating pressure similar to that of hydrocarbons having 1 to 4 carbon atoms. This increases the azeotropic property of the main component of the refrigerant, resulting in high cooling performance. Halogenated hydrocarbons having an operating pressure similar to that of hydrocarbons having 1 to 4 carbon atoms are halogenated hydrocarbons having 1 to 4 carbon atoms, and more preferably halogenated hydrocarbons having 1 to 3 carbon atoms. The reason why halogenated hydrocarbons having 1 to 3 carbon atoms are preferred is that when hydrocarbons are halogenated, their molecules become larger and tend to have a lower operating pressure compared to hydrocarbons with the same carbon number, and therefore the difference in operating pressure is greater when the carbon number is 4.

[0034] Examples of halogenated hydrocarbons having 1 to 3 carbon atoms include fluoroform (HFC-23), difluoromethane (HFC-32), pentafluoroethane (HFC-125), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,2-trifluoroethane (HFC-143), 1,1,1-trifluoroethane (HFC-143a), 1,2-difluoroethane (HFC-152), 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), trifluoroiodomethane (FIC-13I3), chlorodifluoromethane (HCFC-22), and dichlorodifluoromethane (CFC-12).

[0035] Among these, from the viewpoint of providing a good refrigeration cycle device, it is preferable that the refrigerant contains compound X and a saturated hydrocarbon having a carbon number of 2 or more and 4 or less. Examples of saturated hydrocarbons having a carbon number of 2 or more and 4 or less include ethane (R-170), propane (R-290), butane (R600), HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152, HFC-152a, HFC-161, and HCFC-22.

[0036] The refrigerant may contain carbon dioxide (R-744). Carbon dioxide has a low GWP of 1, which can contribute to reducing the environmental impact during the manufacture of refrigeration cycle devices. In addition, carbon dioxide is non-flammable, so mixing it can reduce the flammability of the refrigerant.

[0037] If air is contained in the refrigerant, it may accelerate the deterioration of the refrigerant, refrigeration oil, and materials inside the compressor, so it is preferable to remove the air from the refrigerant circuit before charging the refrigerant into the refrigerant circuit to prevent air from being mixed into the refrigerant.

[0038] <Rubber Parts> In this embodiment, rubber parts used in a refrigerant circuit will be described. In this embodiment, at least one of the members constituting the refrigerant circuit is a rubber part. The rubber part is made of rubber, and comes into contact with a refrigerant containing compound X and a refrigerating machine oil, which will be described later, in a refrigeration cycle device.

[0039] The rubber constituting the rubber part is selected so that the value of the left side of formula (1) is 0.24 or less. Specifically, rubber with a small value of B is used so that the value of the left side of formula (1) is 0.24 or less.

[0040] Compound X contained in a refrigerant in contact with a rubber part has a higher polarity than the corresponding hydrofluorocarbon (HFC). Therefore, compound X has a high permeability to the rubber part. Therefore, compound X tends to easily deteriorate refrigeration oil in contact with the rubber part. The permeability to the rubber part increases as the environment in which the rubber part is used becomes higher in temperature or pressure, and as the compatibility between the rubber part and the refrigeration oil increases. Therefore, by reducing the polarity of the rubber constituting the rubber part, i.e., by reducing the mass ratio (value B) of acrylonitrile units contained in the rubber constituting the rubber part, the permeability to the rubber part can be reduced. Reducing the permeability to the rubber part suppresses deterioration of the refrigeration oil, thereby improving the reliability of the compressor.

[0041] The value of B may be 0 or may be a value greater than 0. The value of the left side of formula (1) may be 0 or greater. The acrylonitrile unit refers to a constituent unit derived from an acrylonitrile monomer among the constituent units constituting the polymer main chain of the rubber.

[0042] In the present embodiment, examples of rubber that constitutes the rubber component include ethylene propylene diene rubber, chloroprene rubber, silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), and fluorinated rubber.

[0043] Nitrile rubber is a synthetic rubber obtained by copolymerizing acrylonitrile and butadiene. Hydrogenated nitrile rubber is a synthetic rubber obtained by chemically hydrogenating the double bonds of the butadiene units among the acrylonitrile units and butadiene units that constitute the polymer main chain of nitrile rubber. In this embodiment, when the rubber constituting the rubber component contains nitrile rubber or hydrogenated nitrile rubber, it is preferable to use one with a low mass ratio of acrylonitrile units (value B). Specifically, from the viewpoint of suppressing deterioration of refrigerating machine oil, the value B is preferably 0.50 or less, and preferably 0.45 or less. The value B may be, for example, 0.05 or more, 0.10 or more, or 0.20 or more.

[0044] <Compressor> In the present embodiment, the refrigeration cycle device includes a compressor. A refrigerant passes through the compressor. The compressor contains refrigeration oil containing, as a composition, at least one selected from polyalkylene glycol, polyol ester, polyvinyl ether, hydrocarbon-based synthetic oil, and mineral oil.

[0045] Fig. 2 is a cross-sectional schematic diagram showing an example of a compressor of a refrigeration cycle apparatus according to this embodiment. As shown in Fig. 2, the compressor 3 includes a shell 11. The shell 11 includes a compression mechanism 12 therein and an electric motor 13 that drives the compression mechanism 12. The shell 11 is also connected to a suction pipe 14 for allowing the refrigerant to flow into the interior and a discharge pipe 15 for allowing the refrigerant to flow out. An accumulator 16 is connected upstream of the suction pipe 14 to separate the refrigerant into gas and liquid and send the vapor to the suction pipe 14.

[0046] The refrigerant that has passed through the accumulator 16 flows from the suction pipe 14 into the compression mechanism 12 in the shell 11. The refrigerant that has flowed into the compression mechanism 12 is compressed to a high temperature and high pressure, and is then discharged from the discharge pipe 15. In other words, the compression mechanism 12 is configured to compress the refrigerant that has flowed into the shell 11 from the suction pipe 14 and discharge it from the discharge pipe 15.

[0047] The compression mechanism 12 is a rotary type compression mechanism that is made up of a combination of a rolling piston 17, a vane (not shown), etc. The crankshaft 10a, which is surrounded by the inner circumferential surface of a cylinder chamber 19 of a cylinder 18, the outer circumferential surface of the rolling piston 17, and the vane (not shown), changes in volume due to the eccentric rotational motion of the rolling piston 17, thereby compressing the refrigerant.

[0048] The compressed refrigerant is discharged from discharge hole 21 of upper bearing 20 into muffler space 22, and then from discharge hole 24 of discharge muffler 23 into shell 11. The discharged refrigerant passes through gaps in motor 13 (gaps between motor rotor 25 and motor stator 26, grooves on the outer peripheral surface of motor stator 26, etc.), and then is discharged from discharge pipe 15 to the downstream side of refrigerant circuit 100.

[0049] The compressor 3 has sliding parts inside the compression mechanism 12. To lubricate the sliding parts, refrigerating machine oil is stored in an oil reservoir 27 located below the compressor 3. The refrigerating machine oil stored in the oil reservoir 27 is supplied to the sliding parts inside the compression mechanism 12 by pump action through an oil supply hole (not shown) provided in the drive shaft 28. Because the refrigerating machine oil comes into contact with the refrigerant inside the compressor 3, some of the refrigerant dissolves in the refrigerating machine oil. The drive shaft 28 is supported by being located between an auxiliary bearing 29 and the upper shaft portion 20. The auxiliary bearing 29 compresses the refrigerant by closing the end face of the cylinder 18.

[0050] <Refrigerating Machine Oil> In this embodiment, the refrigerating machine oil filled in the compressor will be described. At least a portion of the refrigerating machine oil filled in the compressor circulates through the refrigerant circuit together with the refrigerant during operation. Examples of the refrigerating machine oil composition include ether-based synthetic oils such as polyalkylene glycol (PAG) and polyvinyl ether (PVE), ester-based synthetic oils such as polyol ester (POE), hydrocarbon-based synthetic oils such as polyalphaolefin (PAO), alkylbenzene (AB), and alkylnaphthalene (AN), and mineral oils such as paraffin and naphthene. The refrigerating machine oil may be composed of a single composition or a mixture.

[0051] Here, the composition of the refrigerating machine oil is a component that lubricates the inside of the compressor due to its kinematic viscosity, and is preferably a substance having a kinematic viscosity higher than that of the refrigerant. Specifically, the kinematic viscosity of the composition at 40°C is 5 mm or less from the viewpoint of lubricating the sliding parts of the compressor and not significantly reducing the cooling efficiency of the refrigeration cycle device. ２ / s or more 250mm ２ / s or less is preferred.

[0052] The PAG, which is the above-mentioned ether-based synthetic oil, is at least one polymer selected from the group consisting of an ethylene oxide group (EO group) and a propylene oxide group (PO group) represented by the following chemical formula (I).

[0053]

[0054] In the above chemical formula (I), l and p represent the average number of EO groups and PO groups, respectively. １ and R ２ is either a hydrogen atom or a hydrocarbon group having at least 1 carbon atom. The arrangement of the EO groups and PO groups may be any of a random copolymer, an alternating copolymer, and a block copolymer.

[0055] In the above chemical formula (I), l and p preferably satisfy the relationships of the following formulas (2) and (3). If the relationships of the following formulas (2) and (3) are not satisfied, the PAG may solidify at low temperatures: l + p ≦ 100 (2) p / (l + p) ≧ 0.20 (3)

[0056] R １ and R ２ is preferably a hydrocarbon group having one or more carbon atoms. １ and R ２ If is a hydrogen atom, the PAG becomes highly hygroscopic, and there is a risk of moisture being mixed in.

[0057] The PAG may be a PAG having a single structure or a mixture of PAGs having different structures, and by including a mixture of PAGs having different structures in the refrigerating machine oil, the properties of the refrigerating machine oil can be adjusted.

[0058] The synthetic ether oil PVE is a compound obtained by polymerization of a vinyl ether compound, and has a polyvinyl ether structure represented by chemical formula (II).

[0059]

[0060] In the above chemical formula (II), R ３ , R ４ , and R ５ R represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. ３ , R ４ , and R ５ may be the same or different. ６ represents a hydrocarbon group having 2 to 10 carbon atoms. ７ represents a hydrocarbon group having 1 to 10 carbon atoms. k represents the R ６ The average number of constituent units of O is 0 or more and 10 or less. ３ From R ７ may be the same or different for each structural unit. ６ If there are multiple Os, multiple Rs ６ O may be the same or different. s represents the number of polyvinyl ether structures contained in the PVE, and the average value is 2 or more.

[0061] R ３ , R ４ , and R ５ Specific examples of R include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, various pentyl groups, various hexyl groups, various heptyl groups, and various octyl groups, cycloalkyl groups such as cyclopentyl, cyclohexyl, various methylcyclohexyl groups, various ethylcyclohexyl groups, and various dimethylcyclohexyl groups, aryl groups such as phenyl, various methylphenyl groups, various ethylphenyl groups, and various dimethylphenyl groups, benzyl, various phenylethyl groups, and arylalkyl groups such as various methylbenzyl groups. ３ , R ４ , R ５is preferably a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms.

[0062] R ６ Specific examples of include hydrocarbon groups such as ethylene, phenylethylene, 1,2-propylene, 2-phenyl-1,2-propylene, 1,3-propylene, various butylene groups, various pentylene groups, various hexylene groups, various heptylene groups, various octylene groups, various nonylene groups, and various decylene groups; alicyclic groups having two bonding sites to an alicyclic hydrocarbon such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, and propylcyclohexane; aromatic hydrocarbon groups such as various phenylene groups, various methylphenylene groups, various ethylphenylene groups, various dimethylphenylene groups, and various naphthylenes; alkylaromatic groups having monovalent bonding sites on the alkyl moiety and aromatic moiety of alkylaromatic hydrocarbons such as toluene, xylene, and ethylbenzene; and alkylaromatic groups having a bonding site on the alkyl moiety of polyalkylaromatic hydrocarbons such as xylene and diethylbenzene. ６ is more preferably an aliphatic group having a carbon number of 2 or more and 4 or less. In chemical formula (II), k represents the number of repetitions, and its average value is preferably 0 or more and 10 or less, more preferably 0 or more and 5 or less.

[0063] R ７Specific examples of include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, and various decyl groups; cycloalkyl groups such as cyclopentyl, cyclohexyl, various methylcyclohexyl groups, various ethylcyclohexyl groups, various propylcyclohexyl groups, and various dimethylcyclohexyl groups; aryl groups such as phenyl, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butylphenyl groups, and various naphthyl groups; and arylalkyl groups such as benzyl, various phenylethyl groups, various methylbenzyl groups, various phenylpropyl groups, and various phenylbutyl groups. ７ is preferably a hydrocarbon group having 8 or less carbon atoms. When k is 0, R ７ is more preferably an alkyl group having 1 to 6 carbon atoms. When k is 1 or more, R ７ is more preferably an alkyl group having 1 to 4 carbon atoms.

[0064] Furthermore, the PVE may be a PVE of a single structure or a mixture of PVEs having different structures, and by including a mixture of PVEs having different structures in the refrigerating machine oil, the properties of the refrigerating machine oil can be adjusted.

[0065] The ester-based synthetic oil POE is an ester synthesized from a polyhydric alcohol and a fatty acid, and the synthesis method is not limited to dehydration condensation of the polyhydric alcohol and the fatty acid.

[0066] The fatty acid may be a mono- or di-basic fatty acid. The fatty acid may be either an unsaturated fatty acid or a saturated fatty acid, and may be either a straight-chain fatty acid or a branched-chain fatty acid.

[0067] The fatty acid is preferably a saturated fatty acid, because saturated fatty acids have high oxidation stability and therefore are less susceptible to thermal degradation of POE. The fatty acid preferably has a carbon number of 4 to 20, because this ensures that the kinematic viscosity of the POE is sufficient to lubricate the sliding parts of the compressor and does not significantly reduce the cooling efficiency of the refrigeration cycle device.

[0068] In this embodiment, specific examples of monovalent fatty acids having 4 to 20 carbon atoms include butanoic acid (including all isomers), pentanoic acid (including all isomers), hexanoic acid (including all isomers), heptanoic acid (including all isomers), octanoic acid (including all isomers), nonanoic acid (including all isomers), decanoic acid (including all isomers), undecanoic acid (including all isomers), dodecanoic acid (including all isomers), tridecanoic acid (including all isomers), tetradecanoic acid (including all isomers), pentadecanoic acid (including all isomers), hexadecanoic acid (including all isomers), heptadecanoic acid (including all isomers), octadecanoic acid (including all isomers), nonadecanoic acid (including all isomers), and icosanoic acid (including all isomers). These monovalent fatty acids having 4 to 20 carbon atoms may be linear or branched. More specifically, the fatty acid may be branched at the α-position and / or β-position, and 2-methylpropanoic acid, 2-methylbutanoic acid, 2-methylpentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-methylheptanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, and 2-ethylhexadecanoic acid are preferred, with 2-ethylhexanoic acid and 3,5,5-trimethylhexanoic acid being more preferred. This is because the steric hindrance of the branched chain gives the ester excellent resistance to hydrolysis.

[0069] In the present embodiment, specific examples of the divalent fatty acid having 4 or more and 20 or less carbon atoms include glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid.

[0070] The fatty acid may contain a fatty acid other than fatty acids having 4 to 20 carbon atoms. Examples of fatty acids other than fatty acids having 4 to 20 carbon atoms include fatty acids having 21 to 24 carbon atoms, specifically linear or branched heneicoic acid, linear or branched docosanoic acid, linear or branched tricosanoic acid, and linear or branched tetracosanoic acid. The fatty acid constituting the ester may be one of the above types, or may contain two or more types.

[0071] The polyhydric alcohol is preferably a polyhydric alcohol having 2 to 6 hydroxyl groups in order to lubricate the sliding parts of the compressor and not significantly reduce the cooling efficiency of the refrigeration cycle device. The number of carbon atoms in the polyhydric alcohol is preferably 4 to 12, and more preferably 5 to 10. Specifically, hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di-(trimethylolpropane), tri-(trimethylolpropane), pentaerythritol, and dipentaerythritol are preferred. The polyhydric alcohol constituting the ester may be one of the above types, or two or more types may be included.

[0072] The POE may be a partial ester in which some of the hydroxyl groups of the polyhydric alcohol remain unesterified, a complete ester in which all of the hydroxyl groups are esterified, or a mixture of a partial ester and a complete ester.

[0073] When the fatty acid is a divalent fatty acid, both carboxyl groups may be esterified, or only one carboxyl group may be esterified. When both carboxyl groups of a divalent fatty acid are esterified, one carboxyl group may be esterified with a monohydric alcohol instead of with a polyhydric alcohol. The monohydric alcohol preferably has 1 to 20 carbon atoms.

[0074] The POE may be a POE having a single structure or a mixture of POEs having different structures. By including a mixture of POEs having different structures in a refrigerating machine oil, the properties of the refrigerating machine oil can be adjusted.

[0075] Examples of PAOs, which are the above-mentioned hydrocarbon-based synthetic oils, include those obtained by polymerizing hydrocarbon monomers having an olefinic double bond. Examples of hydrocarbon monomers having an olefinic double bond include ethylene, propylene, various butenes, various pentenes, various hexenes, various heptenes, various octenes, diisobutylene, triisobutylene, styrene, α-methylstyrene, and various alkyl-substituted styrenes. The hydrocarbon monomers having an olefinic double bond may be used alone or in combination of two or more. Furthermore, the PAO may be a PAO having a single structure or a mixture of PAOs having different structures. By including a mixture of PAOs having different structures in a refrigerating machine oil, the properties of the refrigerating machine oil can be adjusted.

[0076] The hydrocarbon synthetic oil AB is a compound in which at least one hydrogen atom of benzene is substituted with a hydrocarbon group. The hydrocarbon synthetic oil AB is preferably one in which one to four hydrogen atoms of benzene are substituted with hydrocarbon groups, and more preferably one to two hydrogen atoms are substituted with hydrocarbon groups. This is because it is highly stable and available. The number of carbon atoms in the hydrocarbon group is preferably one to 19. This is because the kinematic viscosity of AB is sufficient to lubricate the sliding parts of the compressor and does not significantly reduce the cooling efficiency of the refrigeration cycle device.

[0077] In this embodiment, specific examples of hydrocarbon groups having 1 to 19 carbon atoms include methyl, ethyl, propyl (including all isomers), butyl (including all isomers), pentyl (including all isomers), hexyl (including all isomers), heptyl (including all isomers), octyl (including all isomers), nonyl (including all isomers), decyl (including all isomers), undecyl (including all isomers), dodecyl (including all isomers), tridecyl (including all isomers), tetradecyl (including all isomers), pentadecyl (including all isomers), hexadecyl (including all isomers), heptadecyl (including all isomers), octadecyl (including all isomers), nonadecyl (including all isomers), and eicosyl (including all isomers). The hydrocarbon group may be linear or branched.

[0078] Furthermore, AB may be AB having a single structure or a mixture of ABs having different structures. By including a mixture of ABs having different structures in a refrigerating machine oil, the properties of the refrigerating machine oil can be adjusted.

[0079] The AN hydrocarbon synthetic oil is a compound in which at least one hydrogen atom of naphthalene is substituted with a hydrocarbon group. The AN hydrocarbon synthetic oil is preferably one in which one to four hydrogen atoms of naphthalene are substituted with a hydrocarbon group, and more preferably one to three hydrogen atoms of naphthalene are substituted with a hydrocarbon group. This is because it is highly stable and available. The number of carbon atoms in the hydrocarbon group is preferably one to 19. This is because the kinematic viscosity of AN is sufficient to lubricate the sliding parts of the compressor and does not significantly reduce the cooling efficiency of the refrigeration cycle device.

[0080] In this embodiment, specific examples of hydrocarbon groups having 1 to 19 carbon atoms include methyl, ethyl, propyl (including all isomers), butyl (including all isomers), pentyl (including all isomers), hexyl (including all isomers), heptyl (including all isomers), octyl (including all isomers), nonyl (including all isomers), decyl (including all isomers), undecyl (including all isomers), dodecyl (including all isomers), tridecyl (including all isomers), tetradecyl (including all isomers), pentadecyl (including all isomers), hexadecyl (including all isomers), heptadecyl (including all isomers), octadecyl (including all isomers), nonadecyl (including all isomers), and eicosyl (including all isomers). The hydrocarbon group may be linear or branched.

[0081] Furthermore, the AN may be an AN having a single structure, or a mixture of ANs having different structures. By including a mixture of ANs having different structures in the refrigerating machine oil, the properties of the refrigerating machine oil can be adjusted.

[0082] Mineral oil is a lubricating oil obtained by separating and refining crude oil. Mineral oils are classified into paraffinic mineral oil and naphthenic mineral oil, but either of these or a mixture thereof may be used.

[0083] The refrigerating machine oil may contain, as additives, an antioxidant, an acid scavenger, and an extreme pressure agent (antiwear agent).

[0084] Examples of antioxidants include phenolic antioxidants such as 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, and 2,2′-methylenebis(4-methyl-6-tert-butylphenol), and amine antioxidants such as phenyl-α-naphthylamine and N,N′-di-phenyl-p-phenylenediamine.

[0085] The antioxidant has the effect of suppressing deterioration of the refrigerating machine oil. The content of the antioxidant relative to the refrigerating machine oil is preferably 0.05% by mass to 2% by mass, more preferably 0.2% by mass to 1% by mass. Although the inclusion of an antioxidant can suppress oxidative deterioration of the refrigerating machine oil, an excessive content of the antioxidant may decrease the kinematic viscosity of the refrigerating machine oil or may cause clogging of the refrigerant circuit as impurities due to deterioration.

[0086] Examples of the acid scavenger include epoxy compounds such as phenyl glycidyl ether, alkyl glycidyl ester, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α-olefin oxide, and epoxidized soybean oil. In particular, alkyl glycidyl ester, alkyl glycidyl ether, and α-olefin oxide are preferred.

[0087] The acid scavenger has the effect of capturing acid generated by deterioration of the refrigerating machine oil or organic materials (insulating films, sealing materials, etc.) present in the refrigerating machine circuit. Therefore, it has the effect of suppressing acid-induced deterioration of the refrigerating machine oil. The content of the acid scavenger relative to the refrigerating machine oil is preferably 0.05% by mass to 10% by mass, more preferably 0.1% by mass to 10% by mass. While the inclusion of an acid scavenger can suppress acid generation, an excessive content of the acid scavenger may decrease the kinematic viscosity of the refrigerating machine oil or may cause the refrigerating machine oil to clog as impurities due to deterioration.

[0088] Examples of extreme pressure agents (antiwear agents) include phosphorus-based extreme pressure agents such as phosphate esters, thiophosphate esters, acid phosphate esters, phosphites, and acid phosphites, as well as amine salts thereof. Preferred extreme pressure agents (antiwear agents) are phosphate esters, thiophosphate esters, or mixtures thereof. Specifically, tricresyl phosphate (O=P-(OC ７ H ７ ) ３ ), triphenyl phosphorothioate (S=P-(OC ６ H ５ ) ３ ), and triphenyl phosphate (O═P—(OC ６ H ５ ) ３), derivatives thereof or mixtures thereof are preferred.

[0089] Extreme pressure agents can reduce friction in the sliding parts of the compressor. As a result, deterioration of the refrigerating machine oil due to frictional heat can be suppressed. The content of the extreme pressure agent in the refrigerating machine oil is preferably 0.05% by mass or more and 5% by mass or less, and more preferably 0.1% by mass or more and 4% by mass or less. Although the inclusion of an extreme pressure agent can reduce friction in the sliding parts, an excessive content of the extreme pressure agent may corrode metals, reduce the kinematic viscosity of the refrigerating machine oil, or cause deterioration and block the refrigerant circuit as impurities.

[0090] The refrigerating machine oil may also contain an oxygen scavenger. Examples of the oxygen scavenger include sulfur-containing aromatic compounds such as 4,4'-thiobis(3-methyl-6-tert-butylphenol), diphenyl sulfide, dioctyldiphenyl sulfide, dialkyldiphenylene sulfide, benzothiophene, dibenzothiophene, phenothiazine, benzothiapyran, thiapyran, thianthrene, dibenzothiapyran, and diphenylene disulfide; aliphatic unsaturated compounds such as various olefins, dienes, and trienes; and cyclic terpenes having an unsaturated bond such as α-pinene, β-pinene, limonene, and phellandrene. Preferred acid scavengers include aliphatic unsaturated compounds and cyclic terpenes having an unsaturated bond.

[0091] The oxygen scavenger has the effect of suppressing oxidation degradation of the refrigerating machine oil. The content of the oxygen scavenger relative to the refrigerating machine oil is preferably 0.05% by mass to 5% by mass, more preferably 0.1% by mass to 3% by mass. Although the inclusion of an oxygen scavenger can suppress oxidation degradation of the refrigerating machine oil, an excessive content of the oxygen scavenger may decrease the kinematic viscosity of the refrigerating machine oil or may cause clogging of the refrigerant circuit as a contaminant due to degradation.

[0092] In addition, the refrigerating machine oil may contain a fluorescent agent, a coloring agent, etc., so that the refrigerant and the refrigerating machine oil can be visually detected. The fluorescent agent and the coloring agent are preferably added in an amount equal to or less than the saturated solubility of the refrigerating machine oil, so as to prevent precipitation at low temperatures.

[0093] If the refrigerating machine oil contains moisture, it may accelerate deterioration of the refrigerant, the refrigerating machine oil, metals in the refrigerant circuit, organic materials (polyester, etc.) in the refrigerant circuit, etc., and therefore the moisture content of the refrigerating machine oil to be filled is preferably 300 ppm by mass or less, and more preferably 100 ppm by mass or less.

[0094] In the above-described refrigeration cycle device, a rotary compressor is used as the compressor 3, but this is not limited to this. For example, a low-pressure shell type or high-pressure shell type scroll compressor or screw compressor may be used as the compressor 3.

[0095] The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to these examples.

[0096] <Evaluation Test 1> In order to evaluate the degree of deterioration of refrigerating machine oil when a refrigerant and a refrigerating machine oil are mixed in a test container made up of members including rubber parts, the test container, refrigerant, refrigerating machine oil, and rubber parts were prepared under the conditions shown in Table 1. In addition, the value of B, which is the mass ratio of acrylonitrile units contained in hydrogenated nitrile rubber, Σ{A ｉ / (n ｉ −1)} and the value of the left side of equation (1) are shown in Table 2.

[0097]

[0098]

[0099] The refrigerant was prepared by mixing HFO-1123 (manufactured by AGC) and R-290 (manufactured by Iwatani Industrial Gases Corporation) at 56 mol % and 44 mol %, respectively. 15 g of the refrigerant was sealed in a test vessel.

[0100] The refrigerating machine oil was prepared by adding 95.5% by mass of a polyol ester reagent (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product code 320-65295) as a composition, 0.5% by mass of 2,6-di-tert-butyl-4-methylphenol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product code 023-07395) as an antioxidant, 2.0% by mass of 2-ethylhexyl glycidyl ether (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product code 329-7425) as an acid scavenger, and 2.0% by mass of tricresyl phosphate (manufactured by Tokyo Chemical Industry Co., Ltd., product code P0273) as an extreme pressure agent (antiwear agent). Molecular sieves (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 133-0865) were added to the refrigerating machine oil so that the water content was less than 50 ppm, and moisture was removed. 60 g of refrigerating machine oil was sealed in a test container.

[0101] Except for Test No. 1-1, rubber parts containing hydrogenated nitrile rubber (commercially available) with different B values ​​were placed in the test container. In Test No. 1-1, a rubber part with a B value of 0 was placed. In Test No. 1-2, a rubber part with a B value of 0.25 was placed. In Test No. 1-3, a rubber part with a B value of 0.34 was placed. In Test No. 1-4, a rubber part with a B value of 0.44 was placed.

[0102] The deterioration test of the refrigeration oil was an autoclave test, which was conducted in accordance with JIS K2211:2009 (Appendix C). The autoclave test is a type of test method for chemical stability with refrigerants. The test vessel had a capacity of 200 cm ３ A portable reactor (TVS-N2-200, manufactured by Taiatsu Glass Industry Co., Ltd.) was used. Refrigerating machine oil was placed in the test vessel, which was then sealed. After the pressure was reduced, the refrigerant was injected. By injecting the refrigerant after the pressure was reduced, it is possible to simulate the state in which the refrigerating machine oil and refrigerant are mixed inside the compressor of a refrigeration cycle device. Next, the sealed test vessel was heated at 125°C to 200°C for a certain period of time, and the chemical stability was evaluated based on changes in the color, etc., of the refrigerating machine oil.

[0103] To evaluate the degree of deterioration of the refrigerating machine oil, the total acid number of the refrigerating machine oil was measured in accordance with JIS K2501:2003. The weight was measured using an electronic balance (AP125WD, manufactured by Shimadzu Corporation). To measure the total acid number of the refrigerating machine oil, a test vessel containing the refrigerating machine oil and the refrigerant was heated at 150°C for 336 hours using an oven (SPH-201S, manufactured by Espec Corporation).

[0104] The relationship between the value of B and the total acid number of the refrigerating machine oil after the test is shown in Figure 3. Test Nos. 1-1 to 1-3 correspond to Examples. Test No. 1-4 corresponds to Comparative Example. The total acid number of the refrigerating machine oil after the test increased in a linear relationship with an increase in the value of B. If the total acid number of the refrigerating machine oil after the test exceeds 0.15 mgKOH / g, problems such as clogging of the refrigerant circuit piping due to impurities generated by oxidation degradation of the refrigerating machine oil and corrosion of metal piping may occur. This may result in a decrease in the reliability of the refrigeration cycle device. As described above, Σ{A ｉ / (n ｉ It was confirmed that when the value of {−1)} is 0.56, if the value of B is 0.42 or less, the reliability of the refrigeration cycle device is high.

[0105] <Evaluation Test 2> In order to evaluate the degree of deterioration of refrigerating machine oil when a refrigerant and refrigerating machine oil were mixed in a test container composed of members including rubber parts, a test container, refrigerant, refrigerating machine oil, and rubber parts were prepared under the conditions shown in Table 3. In Evaluation Test 2, the test was carried out under the same conditions as Evaluation Test 1, except that the value of B of the hydrogenated nitrile rubber and the composition of the refrigerant were prepared under the conditions shown in Table 4. Therefore, the same conditions as in Evaluation Test 1 will not be described again here.

[0106]

[0107]

[0108] The refrigerant was prepared by mixing HFO-1123 and R-290. ｎ H ２ｎ－ｍ F ｍ(n represents 2 or 3, and m represents an integer of 1 or greater and less than 2n). In Test No. 2-1, the refrigerant was prepared so that the molar ratio of HFO-1123 in the refrigerant was 38 mol%. In Test No. 2-2, the refrigerant was prepared so that the molar ratio of HFO-1123 in the refrigerant was 51 mol%. In Test No. 2-3, the refrigerant was prepared so that the molar ratio of HFO-1123 in the refrigerant was 74 mol%.

[0109] The test vessel contained a rubber part containing hydrogenated nitrile rubber (commercially available) with a B value of 0.34.

[0110] The deterioration test of the refrigerating machine oil and the measurement of the total acid number of the refrigerating machine oil after the test were carried out in the same manner as in Evaluation Test 1.

[0111] Σ{A ｉ / (n ｉ The relationship between the value of Σ{A −1)} and the total acid number of the refrigerating machine oil after the test is shown in Figure 4. Test Nos. 2-1 and 2-2 correspond to Examples. Test No. 2-3 corresponds to a Comparative Example. The total acid number of the refrigerating machine oil after the test is calculated by Σ{A ｉ / (n ｉ -1)} increased in a linear relationship. If the total acid number of the refrigerating machine oil after the test exceeds 0.15 mgKOH / g, problems such as clogging of the refrigerant circuit piping due to impurities generated by oxidation degradation of the refrigerating machine oil and corrosion of metal piping may occur. Therefore, the reliability of the refrigeration cycle device may decrease. As described above, when the value of B is 0.34, Σ{A ｉ / (n ｉ It was confirmed that the reliability of the refrigeration cycle device is high when the value of {−1)} is 0.65 or less.

[0112] <Evaluation Test 3> In order to evaluate the degree of deterioration of refrigerating machine oil when a refrigerant and refrigerating machine oil were mixed in a test container composed of members including rubber parts, a test container, refrigerant, refrigerating machine oil, and rubber parts were prepared under the conditions shown in Table 5. Evaluation Test 3 was carried out under the same conditions as Evaluation Test 1, except that the value of B of the hydrogenated nitrile rubber and the composition of the refrigerant were adjusted. Therefore, the same conditions as Evaluation Test 1 will not be described again here.

[0113]

[0114] The refrigerant was prepared by mixing HFO-1123 and R-290 to an arbitrary value. ｎ H ２ｎ－ｍ F ｍ (n represents 2 or 3, and m represents an integer of 1 or more and less than 2n.) A rubber part in which the value of B was changed to an arbitrary value was enclosed in the test container.

[0115] The deterioration test of the refrigerating machine oil and the measurement of the total acid number of the refrigerating machine oil after the test were carried out in the same manner as in Evaluation Test 1.

[0116] Σ{A ｉ / (n ｉ The relationship between the value of Σ{A -1)} and the value of B is shown in Figure 5. Tested refrigerating machine oils with a total acid number of 0.15 or less and those with a total acid number exceeding 0.15 were plotted, respectively, to create a boundary curve. Tested refrigerating machine oils with a total acid number of 0.15 or less correspond to Examples. Tested refrigerating machine oils with a total acid number exceeding 0.15 correspond to Comparative Examples. The total acid number of the tested refrigerating machine oils is calculated by the function Σ{A ｉ / (n ｉ -1)} or an increase in the value of B. If the total acid number of the refrigerating machine oil after the test exceeds 0.15 mgKOH / g, problems such as clogging of the refrigerant circuit piping due to impurities generated by oxidation degradation of the refrigerating machine oil and corrosion of metal piping may occur. Therefore, the reliability of the refrigeration cycle device may decrease. As described above, the Σ{A ｉ / (n ｉ -1)) and the value of B, the reliability of the refrigeration cycle device was confirmed to be high.

[0117] The embodiments and examples disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0118] REFRIGERATED SYMBOLS 1 Outdoor unit, 2 Indoor unit, 3 Compressor, 4 Condenser, 5 Outdoor blower, 6 Expansion valve, 7 Evaporator, 8 Indoor blower, 9 Liquid pipe, 10 Gas pipe, 10a Crankshaft, 11 Shell, 12 Compression mechanism, 13 Electric motor, 14 Suction pipe, 15 Discharge pipe, 16 Accumulator, 17 Rolling piston, 18 Cylinder, 19 Cylinder chamber, 20 Upper bearing, 21 Upper bearing discharge hole, 22 Muffler space, 23 Discharge muffler, 24 Discharge muffler discharge hole, 25 Electric motor rotor, 26 Electric motor stator, 27 Oil reservoir, 28 Drive shaft, 29 Auxiliary bearing, 100 Refrigerant circuit.

Claims

1. A refrigerant circuit including a compressor is provided, the compressor is filled with refrigerating machine oil, a refrigerant is sealed in the refrigerant circuit, and the refrigerant is C ｎ H ２ｎ－ｍ F ｍ (n represents 2 or 3, and m represents an integer of 1 or more and less than 2n), at least one of the members constituting the refrigerant circuit is a rubber part, the rubber part is in contact with the refrigerating machine oil and the refrigerant, and the following formula (1) is satisfied: B×Σ{A ｉ / (n ｉ -1)}≦0.24...(1) [In formula (1), A ｉ represents the molar ratio of the i-th compound in the refrigerant, and n ｉ represents the value of n of the i-th compound, and Σ{A ｉ / (n ｉ -1)) is A for i kinds of the compounds. ｉ / (n ｉ -1), and B represents the mass ratio of acrylonitrile units contained in the rubber that constitutes the rubber part.] 2. The refrigeration cycle device according to claim 1, wherein the compound includes hydrofluoroethylene.

3. A refrigeration cycle device according to claim 1 or 2, wherein the refrigerant further contains saturated hydrocarbons having a carbon number of 2 or more and 4 or less.

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