| abstract |
A binary refrigerating apparatus employs a refrigerant composition that has a small global-warming potential (GWP) to be earth friendly, can be used as a refrigerant capable of achieving a low temperature of −80° C., and is excellent in refrigerating capacity and other performance. A refrigerant composition used as a low-temperature-side refrigerant is a refrigerant mixture including a non-azeotropic mixture in which 20% by mass or less of carbon dioxide (R744) is mixed to difluoroethylene (R1132a). A refrigerant composition used as a high-temperature-side refrigerant is a combination of: a non-azeotropic mixture comprising the refrigerant group of difluoromethane (R32), pentafluoroethane (R125), 1,1,1,2-tetrafluoroethane (R134a) and 1,1,3-trifluoro ethane (R143a); and 1,1,1,2,3-pentafluoropentene (HFO-1234ze), having a global-warming potential (GWP) of 1500 or less. |