| 摘要 |
<p>PURPOSE:To reduce the heat loss generated within the duration from the time of heating-up to the time of service by a method wherein the required hour to energize to a heating element is calculated based upon the heat quantity of remaining hot water and the energizing is started at such a certain time as to heat up the water in a hot water storage tank simultaneously with the time of expiration of midnight power supply time. CONSTITUTION:A heater 3 and a temperature detector 12 are provided at the lower part of the hot water storage tank 11 and a communicating pipe 17 communicates the lower part of the hot water storage tank 11 to a hot water supply pipe 14 and provided with a circulating pump 16 in itself. Let Vl be the total volume of the hot water storage tank 11 filled full of hot water having the temperature of T1 deg.C. When V1l of the hot water is consumed, V2l of the hot water with the temperature of T1 deg.C is left behind and, after that, V1l of the water with the temperature of t deg.C is added to the hot water storage tank 11. At this moment, the water in the hot water storage tank 11 is agitated by operating the pump 16 to uniformize the temperatures of the water to turn to be T2 deg.C. Under the condition as described above, the heat quantity C kcal of remaining hot water, the heat quantity Cin kcal to be added to the water in the hot water storage tank 11 to rise to the required boiling-up temperature of T deg.C and the required energizing hour Hhr are obtained from the relationships as follows: C=V(T2-t), Cin= V(T-t)-C, H=Cin/(860.W) where W is the rated consumption electric energy of the heating element. Accordingly, the energizing is started Hhr before the time of the end of midnight power supply.</p> |
