| 摘要 |
PURPOSE:To obtain a hot-water temperature in which overshooting or the like is small under any conditions in the rate of influent water and a target set temperature, by calculating and determining the gas rate for slow ignition, and by slowly igniting gas, based on the rate of water being fed into a heat exchanger and a target set temperature. CONSTITUTION:An input signal (f), that is a result (j), being calculated in a slow ignition rate calculation circuit 26a, based on a set temperature signal (b) and a flow rate detecting signal (i), is introduced into an input selection circuit 25, passing through a slow ignition circuit 26, by the intermediary of a controlling circuit 26b. When the result (j) to be added to the controlling circuit 26b is within the predetermined variable range of the rate of gas fow slow ignition, and in addition, when the result (j) in larger or smaller exceeding the variable range of the rate of gas for slow ignition, the upper limit or the lower limit of variable range of the rate of gas for slow ignition is put out and inputted into the controlling circuit 26b as a signal (f), respectively. With such an arrangement, a hot-water temperature in which overshooting or the like is made small, having good response properties, can be obtained under any conditions in the rate of influent water and the target set temperature (a) of the hot water. |
