| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hot water storage type water heater with improved COP by using medium temperature water in a hot water storage tank as much as possible at the start of hot water supply. <P>SOLUTION: When the temperature of the medium temperature water is at least a prescribed temperature higher than an optional hot water supply set temperature, a medium temperature water mixing valve is fully opened on the medium temperature water side, and when the temperature of the medium temperature water is less than the prescribed temperature higher than the arbitrary hot water supply set temperature, the medium temperature water mixing valve is feedback-controlled so that the temperature of mixed hot water becomes the prescribed temperature higher than the optional hot water supply set temperature without waiting for the hot water to be stabilized. Thereby, regardless of stabilization of the temperature of supplied hot water at the start of the hot water supply, the medium temperature water mixing valve fully opened on a medium temperature water return pipe side can be kept in the fully opened state by the temperature of the medium temperature water, or the medium temperature water mixing valve is immediately feedback-controlled to use as much medium temperature water as possible so that water is heated from low temperatures by a heat pump unit to improve the COP. <P>COPYRIGHT: (C)2009,JPO&INPIT |
