Energy efficient design of a domestic porous burner using alumina ball packing

Porous burners are emerging as efficient alternatives for domestic cooking applications. This study replaced the metal mesh preheating medium with alumina balls of 5, 6, and 8 mm diameters arranged in different packing configurations, aiming to enhance thermal efficiency, heat transfer, and CO emission. Differences in porosity and geometry between alumina balls and metal mesh lead to changes in flame temperature uniformity and burner surface characteristics. Experiments were conducted across various power inputs ranging from 1.83 to 9.83 kW and equivalence ratios between 0.5 and 1.2. A novel heat balance model was developed to quantify radiative and convective heat transfer contributions from the burner to the cooking pot. Replacing the metal mesh with alumina balls increases radiative heat transfer by up to 200 % and improves flame submergence and temperature uniformity, resulting in a 7 % increase in thermal efficiency and a 13 % reduction in cooking duration. CO emission levels remained stable and within the safety limits defined by the EN 30-1-1 standard, ranging from 2 to 33 ppm. The gradient packing achieved the optimal balance between heat transfer enhancement and emission control among the tested configurations. The findings establish a solid foundation for optimizing the geometry of the preheating zone in porous burners, thereby promoting greater combustion stability, improved thermal efficiency, and superior environmental performance in domestic cooking applications.