Refrigerator oil and working fluid composition for refrigerators
The present invention provides a refrigerating machine oil comprising: an ester of a polyhydric alcohol and a fatty acid as a base oil; and an ether compound of a polyhydric alcohol, the refrigerating machine oil being used with an unsaturated hydrofluorocarbon refrigerant.
1. A working fluid composition for a refrigerating machine comprising:
a refrigerating machine oil; and
an unsaturated hydrofluorocarbon refrigerant,
wherein the refrigerating machine oil comprises:
an ester of a polyhydric alcohol and a fatty acid as a base oil; and
an ether compound of a polyhydric alcohol having 3 to 6 hydroxy groups.
2. The working fluid composition for a refrigerating machine according to claim 1 , wherein the unsaturated hydrofluorocarbon is at least one selected from 1,3,3,3-tetrafluoropropene and 2,3,3,3-tetrafluoropropene.
3. The working fluid composition for a refrigerating machine according to claim 1 , wherein the ether compound is a compound represented by the following formula (1):
wherein R 1 , R 2 , and R 3 each independently represent a hydrogen atom, a C1 to C22 alkyl group, an alkenyl group, or an aryl group, and wherein at least one of R 1 , R 2 , and R 3 represents the group other than a hydrogen atom.
4. The working fluid composition for a refrigerating machine according to claim 1 , wherein a content of the ether compound is 0.4% by mass or less based on a total amount of the refrigerating machine oil.
5. The working fluid composition for a refrigerating machine according to claim 1 , wherein the ether compound is a monoether compound.