Patent ID: 7152426

Claim:
A refrigeration system employing a low boiling point oil-containing refrigerant that is a gas at ambient temperature, for cooling a thermal transfer fluid to be used in cooling process equipment comprising: a compressor having a suction input and providing a pressurized refrigerant output; an oil separator receiving the refrigerant output and returning a substantial part of the oil therein to the compressor input; a condenser system receiving the pressurized refrigerant output from the oil separator and providing a pressurized liquid refrigerant output; a counterflow subcooler receiving the pressurized liquid refrigerant as one input and returning suction input refrigerant as a second input; an excess volume cylinder coupled to receive a restricted flow of gaseous refrigerant from the suction input refrigerant to limit pressure buildup; a heat exchanger/evaporator coupled to receive pressurized refrigerant and the thermal transfer fluid separately, but in heat exchange relation, and an expansion valve device coupled to receive the pressurized liquid refrigerant from the subcooler and providing a selected mixture of expanded liquid/vapor to the heat exchanger/evaporator.