Patent ID: 6418737
Filing Date: 2002-07-16
Classification: F24H,F25B,Y02B

Abstract:
A heat pump type hot-water supply system comprising:a heat pump cycle including refrigerant, a compressor, a first heat exchanger, a pressure-reducing device, and a second heat exchanger which are annularly connected to each other, said pressure reducing device including a variable sized orifice; a defrosting control unit for defrosting the second heat exchanger during a defrosting operation by controlling an opening degree of the pressure-reducing device, all refrigerant flowing to said second heat exchanger flowing through said variable sized orifice during the defrosting operation; a reservoir for storing liquid that is to be heated during an ordinary operation; a circulation pipe passing through the first heat exchanger so that the liquid in the reservoir circulates in the circulation pipe while passing through the first heat exchanger; a pump for circulating the liquid in the circulation pipe, wherein: the opening degree of the variable orifice of the pressure-reducing device during the defrosting operation is controlled by the defrosting control unit to be larger than that during the ordinary operation; and the defrosting control unit stops an operation of the pump a the defrosting operation.