Working fluid composition for refrigerator
View Patent ↗The working fluid composition for a refrigerating machine of the present invention comprises a refrigerant comprising a first refrigerant component and a second refrigerant component, and having a global warming potential (GWP) of 500 or less, wherein the first refrigerant component is at least one selected from difluoromethane and tetrafluoropropene, and the second refrigerant component is at least one selected from carbon dioxide and a hydrocarbon having 3 to 4 carbon atoms; and a refrigerating machine oil comprising at least one selected from a polyol ester, a polyvinyl ether and a polyalkylene glycol compound as a base oil, wherein a carbon/oxygen molar ratio of the base oil is 2.5 or more and 5.8 or less.
1. A working fluid composition for a refrigerating machine, comprising:
a refrigerant, comprising
a first refrigerant component and
a second refrigerant component,
the refrigerant having a global warming potential (GWP) of 500 or less,
wherein
the first refrigerant component is at least one selected from
difluoromethane and
tetrafluoropropene, and
the second refrigerant component is a hydrocarbon having 3 to 4 carbon atoms, and
the sum of difluoromethane, tetrafluoropropene and the hydrocarbon is 80% by mass or more based on the total amount of the refrigerant; and
a refrigerating machine oil comprising at least one selected from a polyol ester and a polyvinyl ether as a base oil, wherein
a carbon/oxygen molar ratio of the polyol ester is from 3.2 to 5.0, and
a carbon/oxygen molar ratio of the polyvinyl ether is from 3.2 to 5.8; and
wherein a mass ratio of the refrigerant to the refrigerating machine oil is 90:10 to 30:70.
2. The working fluid composition for a refrigerating machine according to claim 1 , wherein the refrigerant comprises
hydrocarbon having 3 to 4 carbon atoms,
difluoromethane and
tetrafluoropropene, and
has a global warming potential of 400 or less.
3. The working fluid composition for a refrigerating machine according to claim 2 , wherein the refrigerant comprises
3 to 40 parts by mass of the hydrocarbon having 3 to 4 carbon atoms,
20 to 60 parts by mass of difluoromethane and
20 to 70 parts by mass of tetrafluoropropene
based on 100 parts by mass of the refrigerant.
4. The working fluid composition for a refrigerating machine according to claim 1 , wherein the hydrocarbon having 3 to 4 carbon atoms is propane or isobutane, and a global warming potential of the refrigerant is 300 or less.
5. The working fluid composition for a refrigerating machine according to claim 1 , wherein the polyol ester has a carbon/oxygen molar ratio of from 4.0 to 5.0, and the polyol ester is obtainable by synthesis from a fatty acid having 4 to 9 carbon atoms and a polyhydric alcohol having 4 to 12 carbon atoms.
6. The working fluid composition for a refrigerating machine according to claim 1 , wherein
the polyvinyl ether has a carbon/oxygen molar ratio of from 4.0 to 5.0, and
the polyvinyl ether has a structural unit represented by the following formula (1):
wherein
R 1 , R 2 and R 3 may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms,
R 4 represents a divalent hydrocarbon group having 1 to 10 carbon atoms or an ether bond oxygen-containing divalent hydrocarbon group having 2 to 20 carbon atoms,
R 5 represents a hydrocarbon group having 1 to 20 carbon atoms, m represents a number such that an average value of m in the polyvinyl ether is 0 to 10,
R 1 to R 5 may be the same or different in each occurrence of the structural units, and
when m represents 2 or more in one structural unit, a plurality of R 4 O may be the same or different.