Lubricant for refrigerating machine employing ammonia refrigerant

Abstract

The present invention provides a lubricant for a compression type refrigeration system using ammonia as a refrigerant, which comprises polyether compounds and aromatic amine compounds or phenothiazine compounds, and preferably further comprises alcohol compounds such as polyhydric alcohol partial ether and/or benzotriazole compounds. Further, the present invention provides a working fluid composition comprising the lubricant and an ammonia refrigerant, and a refrigeration system which is filled with the working fluid composition. The lubricant has not only good compatibility with ammonia, but excellent stability and lubricating property, and therefore can suitably used in a compression type refrigeration system using an ammonia refrigerant that does not have the possibility of ozone layer depletion and global warming phenomenon.

Dependencies are inferred from the claim text.