| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance a boiling-up capacity with increased COP to prevent shortage of hot water by changing a boiling-up state in simultaneous operation of hot water storing operation and hot water supplying operation, for example, controlling the boiling-up temperature to the boiling-up temperature in only hot water storing operation or lower. <P>SOLUTION: This water heater comprises a heat pump cycle 10 having a compressor 11, a hot water supplying heat exchanger 12, an expansion valve 13 and an evaporator 14 mutually connected through piping, and a hot water storage tank 21 storing a liquid heated by use of the heat pump cycle 10. This water heater further comprises a boiling-up state variable means 73 varying the boiling-up state to the tank 21 in a case of simultaneous operation of hot water storing operation and hot water supplying operation to adjust the boiling-up temperature to the maximum boiling-up capacity of the heat pump cycle. Therefore, the boiling-up capacity can be enhanced with increased COP, and shortage of hot water can be prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
