SUPERCRITICAL REFRIGERATION CYCLE

摘要

A supercritical refrigeration cycle using CO2 for a refrigerant and having a pressure exceeding the critical point of the refrigerant on a high-pressure side, wherein: the supercritical refrigeration cycle allows the refrigerant and a part of a lubricating oil to circulate, and the lubricating oil used does not contain an epoxy-based oxygen scavenger or an additive which is thermally decomposed on the high-pressure side and its decomposed components make a chemical reaction to produce a compound having low solubility to the refrigerant so as to prevent a deposit from being produced at a portion where the refrigerant is decompressed.