| 摘要 |
<p>PURPOSE:To prevent overheating by disposing a dam having a drain hole on the burning chamber bottom plate to form a holding space between the system body and wall, and, at the time of abnormal temperature rise due to the hot water flow rate reduction from the upstream, shutting off the fuel supply to the burner by detecting the temperature in the space. CONSTITUTION:The hot water well 3 in the lowermost part of the heater body 2 and the burning chamber 4 above it are separated by the bottom plate 25 of the burning chamber. Water sprinkled from a feed water nozzle 15 is heated by a burner 5 and flows down along the wall of the heater body 2 to be collected in the hot water well 3. A dam 35 is disposed on the bottom plate 25. The dam 35 has a drain hole which is smaller than the lower limit of the water sprinkling rate. Therefore, a holding space is formed between the dam and the wall where there is always hot water, and its temperature is detected by a temperature detecting element 38. When there is a malfunction and the water sprinkling is stopped, the amount of hot water in the holding space is reduced, and, at the same time, its temperature rises. When the temperature rise is detected, a fuel supply valve 18 for the burner 5 is controlled to stop the burning at the burner 5. Therefore, the overheating of the burning chamber 4 can be prevented.</p> |
