| 摘要 |
PURPOSE:To stabilize the temperature of feed hot water by a method wherein the quantity of feed water is controled in proportion to the output of a temperature controler which is adopted to control the amount of heat supply on the base of the difference between the temperature of the feed hot water and a set temperature. CONSTITUTION:The signal from a detector 4 for detecting the temperature of hot water from a heat exchanger 2 is transmitted to the temperature controler 3 and a water controler 7 and the signal is compared to the set temperature signal from a temperature setting device 5 to thereby obtain the difference between the temperature of hot water and the set temperature. Then the output of the temperature controler 3 is transmitted to a heat controler 6 so as to control the amount of heat supplied to the boiler 1 and at the same time, it is transmitted to the water controler 7. When starting the water heater, the flow rate of feed water is made maximum and once the temperature of hot water has been controled constant and in that condition, when the amount of heat supply reaches a maximum and the above mentioned temperature difference becomes higher than a predetermined value, the water controler 7 operates a feed water controler 8 so that the quantity of feed water Fw is controled to make the temperature difference zero. In this case, the duration of the driving time (t) for the control device 8 corresponding to the quantity of feed water Fw is operated in accordance with the attached characteristic graph. |
