| 摘要 |
<p>PURPOSE:To reduce the expense of maintenance by reducing various kinds of radiation losses, by a method wherein a necessary electrification time is calculated by referring a detected value of a quantity and a temperature of residual hot water in a hot water reservoir, and electrification is started in the midway of a midnight electrification time so that the above necessary electrification time can be consumed at a completion of the midnight electrification time. CONSTITUTION:If hot water reserving capacity of a hot water reservoir 1 is V liter (hot water temperature: T1 deg.C), correcting temperature, such as a fixed supply water temperature immediately after an inrush into a midnight electrification time and the lowest annula temperature for various places is t deg.C, a detected value of a water is T2 deg.C, a calorific value K1[K1=(T1-t)X V]which is to be stored within the hot water reservoir 1 by a completion time of electrification for midnight electric power is calculated by an arithmetic unit A 12. Then, a calorific value K2[K2=(T2-t)XV]to be remained in the hot water reservoir 1 as residual hot water is calculated by an arithmetic unit B 13. Operation of an equation (K1-K2)divided by 860divided by W is done by an arithmetic unit C 14 based on the K1 and K2 calculated by the arithmetic units A 12 and B 13 respectively, and a necessary electrification time is calculated by a net calorific value (1kWH=860kcal) to be applied which is obtained by deducting a calorific value corresponding to residual hot water. Electrification to a heating unit 9 is started by a timer 15 from the midway of a midnight electrification time so that the necessary electrification time calculated by the arithmetic unit C 14 can be obtained by a completion time of midnight electrification.</p> |
