Experimental investigation and heat transfer analysis of a natural gas fueled porous burner in domestic application

Natural gas fired porous burners are increasingly utilized in heating appliances. In this study, a pot containing water is heated by a porous burner to analyze its heat transfers behavior. Dimensions of the aluminum pot are chosen according to a reference standard. A test rig for silicon carbide burner is designed and fabricated, including air and natural gas lines. The cooking pot is heated in working firing rates and for the test selected pot-burner gap D = 1.5 cm, resulted in maximum thermal efficiency of 29% coincided with minimum CO and NOx emission of 4 and 2.2 ppm, respectively. The main contribution of the study is to evaluate the side and bottom convection heat transfers to assess total thermal performance of a porous media burner. The side and bottom convection fractions are 28% and 58%, while surface and flame radiation are 2% and 12% measured in peak efficient case. In another test, the system was undergone the same heating power in which different equivalence ratios were applied to the burner. The best φ to result in ηmax = 23.9% was found to be φ = 0.998. Considering the pot-water system, the majority of heat absorbed is devoted to convection. The modular system can apply to different low power burners with the adjustable gap between burner surface and pot bottom gaining attention of researchers and also the industrial section. Measuring, differentiating and evaluating the balance between convective and radiative portions of the heat received by pot, is the main idea of this research to obtain a thorough insight of role of each mode on thermal efficiency and pollutants emission. Besides, proper equivalence ratio and distance gap are also presented to get an appropriate design of burner-pot system. As the masses, materials and dimensions are chosen according to standard, the results could be used by researchers in this area.