| abstract |
Use of a double bond-containing hydrofluoroolefin refrigerant causes a problem that it generates hydrogen fluoride by cleavage and decomposition under influence of oxygen, leading to degradation of the materials and the refrigeration oil used in the refrigeration apparatus and causing troubles in the refrigeration apparatus. It is possible to provide a high-reliability longer-lasting refrigeration apparatus by inexpensive method, by using a double bond-containing hydrofluoroolefin refrigerant in a refrigerating cycle having a refrigerant circulation route extending from a compressor 1, via a condenser 2, an expansion mechanism 3, and an evaporator 4, back to the compressor 1 that contains an ester-based refrigeration oil containing an unsaturated fatty acid as a constituent fatty acid. |