| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a bath water heater with a single tank and double water pipes which is capable of preventing a reheating operation after filling hot water from taking long time because a hot water temperature in case of filling the hot water by calculating a heating amount for FF (Feedforward Feedback) control from an estimated feed water temperature obtained by back calculation becomes extremely lower than a predetermined temperature, when a small amount of water is fed. <P>SOLUTION: When the detected temperature of a bath supply temperature sensor 42 is lower than the predetermined temperature at a hot water feeding of a small water amount, the FF control is carried out by calculating the feed water temperature by using a heat absorption distribution ratio corresponding to a case where there is no pass of water in a bath supply pipe 16. When the detected temperature is the predetermined temperature or higher, the feed water temperature is calculated by using the heat absorption distribution ratio when there is pass of water in the bath supply pipe 16 and a bath return pipe 17 with the ratio of, for instance, 1:1. If the feed water temperature is normal, the FF control is carried out by using the feed water temperature, and if it is abnormally high, the FF control is carried out by calculating the feed water temperature by changing to the heat absorption distribution ratio in case of a small amount of the flow rate of bath supply pipe 16. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
