| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve thermal efficiency by averaging surface temperatures of a main heat exchanger and suppressing generation of a local drain. <P>SOLUTION: A temperature of the main heat exchanger 8 of a water heater 1 becomes low as on a water inflow side when a flow rate distribution of combustion exhaust gas is even, and surface temperatures of respective parts of the main heat exchanger 8 become even by controlling the flow rate distribution by a drain evaporator 9 so that the combustion exhaust gas flows in more as on the water inflow side. As a result, heat exchange quantity on the water inflow side can be increased without generating the drain in the main heat exchanger 8. Therefore, heat can be exchanged at a maximum by the main heat exchanger 8, tiny sensible heat which can not be recovered by the main heat exchanger 8 is recovered by an auxiliary heat exchanger 10, and the thermal efficiency of the water heater 1 as a whole can be improved. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
