| 摘要 |
<p>PURPOSE:To improve the thermal efficiency by performing the operation control easily and well corresponding to a needed amount of hot water by forming an intermediate zone between the upper and lower convection zones where water is sequentially heated from upper to lower level while the boundary layer between hot water and cold water is maintained and descends, and disposing a temperature sensor for controlling in said intermediate zone. CONSTITUTION:Since water in a second convection zone L flows out through a convection water flow outlet passage 5 into a first convection zone L which is separated from an intermediate zone M, and, at the same time, water in the lower part of the intermediate zone M flows into the convection zone L through a connecting part 6, the water in the intermediate zone is heated from upper to lower level as the boundary layer between hot water and cold water is maintained and descends. Therefore, based upon the temperature distribution of water in the intermediate zone M, the amount of hot water which has completed being heated can be determined, and, by disposing temperature sensors 11a, 11b, 11c for controlling in suitable locations in the intermediate zone, the operation control can be well performed corresponding to a needed amount of hot water.</p> |
