Abstract: A working fluid filled in a refrigerant circulation system comprising a compressor, a condenser, an expansion mechanism, an evaporator, and an accumulator, the working fluid comprising: a refrigerant; and a refrigerating machine oil, wherein the refrigerant comprises a hydrocarbon refrigerant having 2 to 4 carbon atoms, the refrigerating machine oil has a mixed aniline point of 20° C. or higher and 50° C. or lower and a viscosity index of 110 or more, an amount of the refrigerant dissolved in the working fluid is 40% by mass or less under conditions of a temperature of 80° C. and an absolute pressure of 2.8 MPa, and the refrigerating machine oil has a kinematic viscosity at ?10° C. of 200 mm2/s or more and 3000 mm2/s or less.

Abstract: An aspect of the present invention provides a refrigerating machine oil containing an ester-based base oil, at least one epoxy compound selected from an alkyl glycidyl ether and an aryl glycidyl ether, and a phenol-based antioxidant, wherein a content of the epoxy compound is 0.7% by mass or more based on a total amount of the refrigerating machine oil, and the refrigerating machine oil is used with a refrigerant containing trifluoroiodomethane.

Abstract: The present invention provides a refrigerating machine oil comprising a hydrocarbon-based base oil having a viscosity index of 120 or less, and the refrigerating machine oil being used with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant.

Abstract: The present invention provides a refrigerating machine oil comprising a lubricating base oil and at least one selected from the group consisting of an amine salt of phosphonic acid and an amine salt of phosphonic acid monoester, and a method for producing the same.

Abstract: A working fluid composition for a refrigerating machine, containing: a refrigerant containing trifluoroiodometbane; and a refrigerating machine oil containing a polyol ester and a hindered phenol compound, wherein a content of the hindered phenol compound is 0.6 to 10% by mass based on a total amount of the refrigerating machine oil.

Abstract: A working fluid composition for a refrigerating machine, containing: a refrigerant containing trifluoroiodomethane; and a refrigerating machine oil containing a complex ester synthesized from a polyhydric alcohol, a polybasic acid, and at least one selected from a monohydric alcohol and a monocarboxylic fatty acid.

Abstract: A method for operating a refrigerant circulation system comprising a compressor, a condenser, an expansion mechanism, and an evaporator connected in this order with piping, wherein a refrigerant comprising trifluoroiodomethane is used as a refrigerant; a refrigerating machine oil comprising, as a base oil, a polyolester synthesized from a polyhydric alcohol and fatty acids, with a proportion of a fatty acid having 9 carbon atoms in the fatty acids being 65 mol % or less is used as a refrigerating machine oil; and a temperature of an entire area of the refrigerant circulation system is kept at 160° C. or lower.

Abstract: One aspect of the present invention is a refrigerating machine including a refrigerant circulation system including a compressor, a condenser, an expansion mechanism, and an evaporator, and the refrigerant circulation system being filled with a refrigerant and a refrigerating machine oil, wherein the refrigerating machine oil contains: a first base oil having a compatible region with the refrigerant in a range of a temperature of 30° C. or lower and an oil ratio of 1 to 80% by mass; and a second base oil having a kinematic viscosity at 40° C. lower than the first base oil and having a narrower compatible region with the refrigerant than the first base oil.

Abstract: One aspect of the present invention is a refrigerating machine oil comprising a base oil, a dithiophosphoric acid ester, and a phosphonate ester.

Abstract: The present invention provides a refrigerating machine oil comprising a lubricating base oil and at least one selected from the group consisting of an amine salt of phosphonic acid and an amine salt of phosphonic acid monoester, and a method for producing the same.

Abstract: One aspect of the present invention is a refrigerating machine oil comprising a base oil, a dithiophosphoric acid ester, and an amine salt of an acidic phosphoric acid ester.

Abstract: The present invention, in one aspect, provides a refrigerating machine oil including a lubricating base oil and a compound represented by the following formula (A): wherein R1 and R2 each independently represent a monovalent hydrocarbon group, and R3 and R4 each independently represent a hydrogen atom or an alkyl group, the refrigerating machine oil being used with a refrigerant including an unsaturated hydrofluorocarbon.

Abstract: The present invention provides a refrigerating machine oil comprising a hydrocarbon-based base oil having a viscosity index of 120 or less, and the refrigerating machine oil being used with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant.

Abstract: One aspect of the present invention is a refrigerating machine including a refrigerant circulation system including a compressor, a condenser, an expansion mechanism, and an evaporator, and the refrigerant circulation system being filled with a refrigerant and a refrigerating machine oil, wherein the refrigerating machine oil contains: a first base oil having a compatible region with the refrigerant in a range of a temperature of 30° C. or lower and an oil ratio of 1 to 80% by mass; and a second base oil having a kinematic viscosity at 40° C. lower than the first base oil and having a narrower compatible region with the refrigerant than the first base oil.

Abstract: The present invention provides a refrigerating machine oil comprising, as a base oil, at least one oxygen-containing oil having a carbon/oxygen molar ratio of 2.5 or more and 7.5 or less, and the refrigerating machine oil being used with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant.

Abstract: The present invention provides a working fluid composition for a refrigerating machine containing: a refrigerating machine oil containing: a first ester that is a polyol ester of dipentaerythritol and at least one fatty acid selected from fatty acids having 4 to 10 carbon atoms, and has a kinematic viscosity at 100° C. of 7.0 mm2/s or more; and a second ester that is a complex ester of a polyhydric alcohol containing at least one selected from neopentyl glycol, trimethylolpropane and pentaerythritol, a polybasic acid having 6 to 12 carbon atoms, and a monohydric alcohol having 4 to 18 carbon atoms or a fatty acid having 4 to 18 carbon atoms; and a refrigerant containing difluoromethane.

Abstract: The present invention, in one aspect, provides a refrigerating machine oil including a lubricating base oil and a compound represented by the following formula (A): wherein R1 and R2 each independently represent a monovalent hydrocarbon group, and R3 and R4 each independently represent a hydrogen atom or an alkyl group, the refrigerating machine oil being used with a refrigerant including an unsaturated hydrofluorocarbon.

Abstract: The present invention provides a refrigerating machine oil including a lubricating base oil and a compound represented by the following formula (A): wherein Ra and Rb each independently represent a monovalent hydrocarbon group, Rc represents a divalent hydrocarbon group, X represents a polar group, and Za and Zb each independently represent oxygen atom or sulfur atom.

Abstract: The present invention provides a refrigerating machine oil comprising, as a base oil, at least one oxygen-containing oil having a carbon/oxygen molar ratio of 2.5 or more and 7.5 or less, and the refrigerating machine oil being used with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant.

Abstract: The present invention provides a working fluid composition for a refrigerating machine containing: a refrigerating machine oil containing: a first ester that is a polyol ester of dipentaerythritol and at least one fatty acid selected from fatty acids having 4 to 10 carbon atoms, and has a kinematic viscosity at 100° C. of 7.0 mm2/s or more; and a second ester that is a complex ester of a polyhydric alcohol containing at least one selected from neopentyl glycol, trimethylolpropane and pentaerythritol, a polybasic acid having 6 to 12 carbon atoms, and a monohydric alcohol having 4 to 18 carbon atoms or a fatty acid having 4 to 18 carbon atoms; and a refrigerant containing difluoromethane.