2005 Volume 84 Issue 1 Pages 62-67
The present study has been carried out to evaluate the performance of natural gas (13A) fired water heater with titanium heat exchanger for latent heat recovery. The latent heat recovery with condensation is very useful method to enhance the thermal efficiency of the water heater. However, it is usually accompa-nied with corrosion problem of heat exchanger caused by strong acid condensate that is formed due to the hazardous gases such as SOx or NOx. In this study, titanium heat exchanger was adopted as secondary heat exchanger because they have excellent corrosion resistance. The experiments were conducted for mass flow rate and inlet temperature of supplied water and setting temperature of hot water as parameters, respectively. Tube arrangements of heat exchanger including inline and staggered configurations were investigated. In the terms of thermal efficiency, the performance of the water heater was evaluated based on the net calorific value at maximum rated output. As a result, the thermal efficiency of gas fired water heater with latent heat recovery heat exchanger was approximately 10% higher than that of the conventional instantaneous water heater. In addition, it was found that the overall heat conductance of the heat ex-changer with staggered tube rows is more efficient than that of the inline tube rows.