Patent ID: 8276383

Claim:
A system comprising: a Rankine cycle closed circuit; a turbine within the closed circuit; and a refrigerant within the closed circuit configured for driving the turbine; wherein the refrigerant is one of a group of nine quaternary organic heat exchange fluid mixtures each having respective first, second, third and fourth components, the group consisting of: (a) by weight, 1 to 60% HFC245ca, 1 to 69% HFC236ea, 20 to 88% HFC125 and 10 to 78% HFC152a; (b) by weight, 1 to 85% HFC236ea, 1 to 85% HFC134a, 13 to 97% HFC125 and 1 to 85% HFC152a; (c) by weight, 1 to 85% HFC245ca, 1 to 85% HFC134a, 13 to 97% HFC125 and 1 to 85% HFC152a; (d) by weight, 1 to 20% HFC236ea, 1 to 10% HFC245ca, 1 to 10% HFC365mfc and 60 to 97% HFC152a; (e) by weight, 1 to 25% HFC236ea, 1 to 25% HFC245ca, 20 to 97% HFC125 and 1 to 30% HFC365mfc; (f) by weight, 1 to 15% HFC245ca, 1 to 15% HFC236ea, 55 to 97% HFC134a and 1 to 15% HFC365mfc; (g) by weight, 1 to 83% HFC245fa, 2 to 84% HFC236fa, 13 to 95% HFC125 and 2 to 84% HFC134a; (h) by weight, 1 to 76% HFC236fa, 13 to 88% HFC134a, 7 to 82% HFC125 and 4 to 79% HFC152a; and (i) by weight, 1 to 76% HFC245fa, 10 to 85% HFC134a, 10 to 85% HFC125 and 4 to 79% HFC152a.