| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform a heat pump hot water supply operation of high energy efficiency by preventing a rise of a water temperature at a lower portion of a hot water storage tank. <P>SOLUTION: This heat pump water heater comprises a refrigerant circuit constituted by successively connecting a heat exchanger 32 for hot water supply, a pressure reducing means 33 and an evaporator 34, a hot water supply circuit for circulating the water from the lower portion of the hot water storage tank 31 to an upper portion of the hot water storage tank 41 while passing through the heat exchanger 32 for hot water supply and a three-way valve 44 through a circulation pump 43, and a bypass circuit 47 connecting the three-way valve 44 and the lower portion of the hot water storage tank 41, and the three-way valve 44 is controlled to make the heat exchanger 32 for hot water supply communicate with the lower portion of the hot water storage tank 41 at the stop of the circulation pump 43 or a low flow-rate operation by the circulation pump 43, and thus the back-flow of the hot water of high-temperature at the upper portion of the hot water storage tank 41 and the rise of the water temperature at the lower portion of the hot water storage tank 41 are prevented, and the hot water supply operation of high energy efficiency can be performed. <P>COPYRIGHT: (C)2009,JPO&INPIT |
