Patent ID: 7704404
Filing Date: 2010-04-27
Classification: C09K

Abstract:
1. A process for producing low temperature refrigeration in a low temperature refrigeration system suitable for use with chlorodifluoromethane (R-22) refrigerant that achieves and maintains an evaporator temperature of below 32° F. (0° C.), the process comprising condensing a refrigerant and thereafter evaporating the refrigerant in the vicinity of a body to be cooled, wherein the refrigerant composition comprises from about 25 to about 30 mass % difluoromethane (R-32), from about 30 to about 35 mass % pentafluoroethane (R-125), and 40 mass % tetrafluoroethane (R-134a) whereby these three components are present in the refrigerant composition such that the operating characteristic of positive superheat provided during refrigeration is in the range of from about 8° to about 16° F. for an evaporation temperature range of about 15° to 30° F., in the range of from about 8° to about 12° F. for an evaporation temperature of about −15° F., and in the range of from about 4° to about 8° F. for an evaporation temperature of about −30° F., and wherein the operating characteristics of the refrigerant composition in regard to cooling capacity, efficiency (COP), and mass flow, when employed as the refrigerant in the refrigeration system, are each at least about 95% of those operating characteristics if chlorodifluoromethane (R-22) were to be employed as the refrigerant in said refrigeration system at identical refrigeration conditions.