| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat pump water heater where there are ensured an improvement of durability and an improvement of operation efficiency. SOLUTION: The water heater is provided with a refrigerant circulation circuit which comprises connecting in order a compressor 1, a refrigerant versus water heat exchanger 2, a pressure reducer 3 for controlling a flow rate of a refrigerant and a vaporizer 4, and a hot water supply circuit consisting of a hot water storage tank 5, a circulation pump 6, and the foregoing refrigerant versus water heat exchanger 2, connected in order of mention; a discharge temperature detection means 13 for detecting discharge temperature of the compressor 1, and control means 11 for controlling valve opening of the pressure reducer 3 such that the discharge temperature of the compressor 1 becomes a previously set target discharge temperature. Accordingly, a proper refrigerant is circulated through the refrigerant circuit at all times, so that abnormal temperature rise and abnormal pressure rise are eliminated, and hence durability is improved together with an improvement of operation efficiency. |
