| 摘要 |
<p>PURPOSE:To accelerate the rise time of hot water supply by a method wherein a circulating closed loop is formed by a first heat exchanger and a second heat exchanger and a lower outlet piping when the outlet temperature of the second heat exchanger exceeds the predetermined first temperature and at the same time the temperature at the upper part of a hot water storage tank exceeds the predetermined second temperature, which is lower than the first temperature. CONSTITUTION:When the temperature of the water circulating in a second circulating closed loop detected by a temperature detector 16 exceeds the predetermined first temperature t1 and at the same time the temperature of the hot water at the upper part of a hot water storage tank 5 detected by a temperature detector 14 in the hot water storage tank 5 exceeds the predetermined second temperature t2, which is lower than the first temperature, a solenoid valve 42 is open and solenoid valves 9 and 44 are closed, resulting in forming a first circulating closed loop by a lower outlet piping 41, a first heat exchanger 3 and a second heat exchanger. The temperature of hot water can be raised for a short time, because the heating of the whole hot water storage tank 5 is unnecessary by selectively forming the circulating closed loop under the control of the opening and closing actions of the solenoid valves 9 and 44.</p> |
