Experimental Study on Performance of Condensing Heat Pipe Heat Recovery Device in Gas Water Heater

摘要

A condensing gravity heat pipe heat recovery device, which can be installed at the rear of conventional gas water heater, was designed based on general heat pipe heat exchanger design calculations, and a series of experiments were conducted to study the effect of heat load of gas water heater and inlet flow of cooling water on the exhaust sensible and latent heat recovery as well as the thermal efficiency of gas water heater. The experimental results show that the recovered sensible and latent heat will remarkably increase by the rise of heat load. In addition, the increase of inlet flow rate can improve the thermal efficiency of gas water heater and the highest heat efficiency can reach over 100%. Moreover, it is also found that the existence of non condensable gas in exhaust gas will have a significant impact on the heat recovery.