Performance Tests on Medium-Scale Porous Radiant Burners for LPG Cooking Applications

The principle of operation of the porous radiant burner (PRB) is based on porous medium combustion (PMC) in which the combustion of fuel and air mixture takes place inside a matrix of open cavities in the presence of an inert solid surface. Since the porous matrix has high thermal conductivity and high emissivity, the contributions of conduction and radiation in the PMC are significant. In the present paper, performance tests on PRB used for medium scale cooking applications of capacity 5-10 kW are presented. The PRB chosen for the study is SiC-based porous burner of diameter 120 mm and 90% porosity. Liquefied petroleum gas (LPG) is used as a fuel. Effects of different heat inputs in the range of 5 10 kW on the thermal efficiency and emission levels of PRB are investigated. For the conventional LPG burner of 5-10 kW capacity, the measured value of thermal efficiencies is in the range of 30-40%, and the CO and NOx are in the range of 350-1145 ppm and 40 109 ppm, respectively. These emissions levels are well above the world health organization standards. Within range of parameters tested, the SiCbased PRB yields the maximum thermal efficiency of about 50%, which is about 25 % higher than the conventional stoves. The measured emission levels are also much lower than the conventional stoves.