| 摘要 |
<P>PROBLEM TO BE SOLVED: To further improve thermal efficiency of a water heating appliance such as a water heater provided with a heat exchanger for heating flowing water by combustion heat of a burner. <P>SOLUTION: A temperature becomes uneven in the main heat exchanger 8 of the water heater 1 because of a temperature rise in the flowing water flowing in a main heat transfer pipe 15. Therefore, by utilizing this temperature distribution, a drain is heated and evaporated at a drain evaporating part 24 of a drain evaporator 9 by using low temperature combustion exhaust gas passing through a low temperature side part, or an water inflow side. Therefore, a high temperature side part of the main heat exchanger 8, or high temperature combustion exhaust gas passing through a water outflow side can be used for heat recovery at an auxiliary heat exchanger 10 and recovery quantity of sensible heat can be increased. As a result, heat can be recovered from the combustion exhaust gas of the burner with extremely high efficiency, and thus the water heater with extremely high thermal efficiency and requiring no drain treatment can be provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
