CO2 REFRIGERATION SYSTEM HAVING HEAT PUMP AND MULTIPLE MODES OF OPERATION

摘要

PROBLEM TO BE SOLVED: To provide a CO₂ heat pump system and its manufacturing method without causing the practical problem such as requiring a valve capable of coping with high pressure CO₂, an accumulator of a proper size and a system inside heat exchanger endurable against high system pressure in a whole reversible system.;SOLUTION: While a refrigeration system 10 is operated in an air-conditioning or cooling (A/C) mode, CO₂ of a refrigerant enters a first evaporator 14 from a compressor 12, and then, enters a second evaporator 18. A liquid coolant flows through a second coolant loop 19, and further lowers the refrigerant temperature, but a heat load of the second evaporator 18 can be reduced more than that of the air-cooled first evaporator 14. The refrigerant coming out of the second evaporator flows in the high pressure side of a suction line inside heat exchanger 20 before turning to an expansion device or an expansion valve 22, and flows in an air to refrigerant type evaporator 24 after coming out of the expansion valve 22.;COPYRIGHT: (C)2009,JPO&INPIT