THE SEA WATER HEAT SOURCE CASCADE HEAT PUMP SYSTEM

摘要

A cascade heat pump system using sea water is provided to prevent operation with an excessive compression rate for preventing efficiency decrease caused by a high compression rate when an atmospheric temperature is lowered or high temperature water is produced. A cascade heat pump system using sea water includes a sea water heat exchanger unit, a heat media circulating unit, a low stage refrigerant circulating unit and a high stage refrigerant circulating unit. The heat exchange is carried out by a sea water heat exchanger(14) between sea water heat exchanger unit and the heat media circulating unit, a low stage condenser(12) or a low stage evaporator(18) between the heat media circulating and the low stage refrigerant circulating unit and a cascade heat exchanger(16) serving as a receiver between the low and high stage refrigerant circulating units. If a temperature difference between fluids is low, a low stage compressor is driven alone. In the other case, high and low stage compressors(11,21) are driven together simultaneously for reducing irreversibility in compression procedure.