Condensation type gas heat exchanger and anti-overheating device

According to the condensation type gas heat exchanger and the overheating prevention device, when a water quantity detection element detects that condensate water in an evaporation cavity is too little, a control element controls a water supplementing assembly to work, and therefore water supplementing treatment is conducted on the evaporation cavity in time, and the overheating problem caused by the fact that the condensate water in the evaporation cavity is too little is avoided. Certainly, after water replenishing is completed, the water replenishing assembly can also be stopped in time, and the phenomenon that condensate water flows backwards from the smoke inlet due to excessive water replenishing is avoided. 本实用新型涉及一种冷凝式燃气换热器及防过热装置，当水量检测元件检测到蒸发腔内的冷凝水过少时，控制元件控制补水组件工作，从而对蒸发腔及时进行补水处理，避免因蒸发腔内的冷凝水过少而发生过热问题。当然，补水完成后，补水组件也能及时进行截止，避免补水过多而导致冷凝水从进烟口处发生倒灌。