HEAT PUMP CIRCUIT AND HEAT PUMP TYPE WATER HEATER

PROBLEM TO BE SOLVED: To provide a heat pump circuit preventing noise due to flowing sound of a heating medium and failure of a compressor due to inflow of the liquefied heating medium, etc. even when the liquefied heating medium (refrigerant) is sealed in a predetermined range in a heat pump circuit and then, control for releasing the heating medium is executed again, and a heat pump type water heater. SOLUTION: The heat pump type water heater 1 includes the heat pump circuit 2 comprising the compressor 5, a condenser 6, an expansion valve 7, an evaporator 8 and piping interconnecting these apparatuses to form an annular circuit. Shut-off valves 15, 16 are arranged in the circuit so as to sandwich the condenser 6, and the liquefied heating medium can be sealed and stored between the shut-off valves 15, 16. When the sealed heating medium is released again, control is performed to increase an opening of the expansion valve 7 over time, so as to increase a flow rate of the heating medium made to pass through the expansion valve 7 over time. COPYRIGHT: (C)2011,JPO&INPIT