| abstract |
PROBLEM TO BE SOLVED: To achieve good viscosity of a refrigerating machine oil which has good compatibility with HFC, sufficiently secures the reliability of a compressor and achieves high efficiency, and generates organic acids by hydrolysis and thermal decomposition. It is an object of the present invention to suppress the generated CO 2 to a level that does not affect the cooling performance. SOLUTION: In a refrigeration cycle including a compressor, a condenser 2, an expansion mechanism 3, a dryer 5 and an evaporator 4, and using a hydrofluorocarbon as a refrigerant, the refrigeration cycle has a viscosity of 4%. 2-70 cSt at 0 ° C, 1-9 cS at 100 ° C t and a carbonate bond (—O—CO—O By using the refrigerating machine oil 6 having at least one carbonate oil as a base oil, the reliability of the compressor can be sufficiently ensured, the viscosity of the refrigerating machine oil with high efficiency can be realized, and hydrolysis and thermal decomposition can be realized. less generation of organic acids by, CO 2 generated can be obtained excellent refrigerating device compatibility with suppressed to a level that does not affect the cooling performance insulating material. |