Patent ID: 7624586

Claim:
A freezing device comprising: a single refrigerant circuit in which a refrigerant discharged from a compressor is condensed and then evaporated to exert a cooling function and which allows heat exchange between the evaporated refrigerant and the condensed refrigerant, wherein there is introduced into the refrigerant circuit: a non-chlorine-containing and a non-azeotropic mixed refrigerant containing R245fa, R600, R23 and R14; a non-chlorine-containing and a non-azeotropic mixed refrigerant containing R245fa, R600, R116 and R14; a non-chlorine-containing and a non-azeotropic mixed refrigerant containing R245fa, R600, R508A and R14; or a non-chlorine-containing and a non-azeotropic mixed refrigerant containing R245fa, R600, R508B and R14; wherein with respect to a total weight of the non-azeotropic mixed refrigerant, a total weight ratio of the refrigerants R245fa and R600 is set to a range of 40 wt % to 80 wt %, a weight ratio of the refrigerant R23, R116, R508A or R508B is set to a range of 15 wt % to 47 wt %, and a weight ratio of the refrigerant R14 is set to a range of 3 wt % to 20 wt %; and wherein R245fa and R600 are mixed at a ratio so as to be incombustible.