| 摘要 |
PURPOSE:To supply hot water at a predetermined temperature with a high efficiency, by a method wherein a water flow rate conforming to the maximum capability of a heater is set in accordance with a feed water temperature and a preset temperature, and a water flow contron valve is controlled in accordance with the difference between the flow rate thus set and a detected flow rate, in a heater for a hot water supply device or the like. CONSTITUTION:In the operation, a temperature rise by heating is calculated by comparing an output from a temperature setter 23 and an output from an inlet temperature detector 19 with each other, and based on the temperature rise thus calculated and the maximum capability of the heater 11, a flow rate setting calculating circuit 25 calculates the maximum flow rate of water passed to a heat exchanger 10. When passing of water is started by the user, the flow rate of water thus passed is calculated by a flow rate calculating circuit 26 on the basis of on output from a pressure detector 8 which detects a pressure difference across an orifice intermediately fitted in a passage for water. The flow control valve 6 in a flow controller 1 is controlled on the basis of the difference between the flow rate thus detected and an output from the circuit 25. The difference between an output from an outlet temperature detector 20 and the output from the temperature setter 23 is corrected by an output from a differenciating circuit 29 for calculating the change rate of the flow rate, and a heating controller 12 is controlled. |
