| 摘要 |
<p>PURPOSE:To provide a uniform load of electrical power by a method wherein a required electrical energization time is calculated in response to a remaining amount of hot water, a temperature of the remaining hot water and a heat calorie of hot water calculated in reference to a water feeding temperature and then an electrical energization starting time is set in reference to a result of comparison between the required electrical energization time and a reference electrical energization time. CONSTITUTION:A heat calorie K2 of remained hot water is calculated at a calculation device 4 in reference to outputs from a sensor device 1 for sensing a remaining amount of hot water, a sensor device 2 for sensing a temperature of remaining hot water and a water feeding temperature sensor 3, and then a heat calorie K1 of hot water to be stored in a tank is calculated by a calculation device 6 in reference to a boiling-up hot water temperature set by the boiling-up hot water temperature setting or calculation means 5. A required electrical energization time HA for a heater 14 is calculated by a calculation device 7 in reference to both heat calories K1 and K2 and then an electrical energization starting time for starting an electrical energization for the heater 14 is determined in accordance with an electrical energization shift mode for boiling-up the hot water within a specified electrical power time range such as a mid-night electrical power time range in consideration of the electrical energization time HA. In this case, when the required electrical energization time is less than the reference electrical energization time, the specified time set during the electrical power load reducing time is set to the electrical energization starting time.</p> |
