Numerical predictions of porous burners with integrated heat exchanger for household applications

A numerical method for the calculation of premixed methane combustion and heat transfer in porous burners with built-in heat exchangers is presented. The flow, temperature, and major species concentration fields were calculated by solving the mass, momentum, gas, and solid energy and species conservation equations. Nonequilibrium between the gas and solid phases was considered by using separate energy equations for the gas and the solid and by coupling them through a convective heat transfer coefficient. The porous medium was assumed to emit, absorb, and isotropically scatter radiation. Centerline gas and solid temperatures were compared with available experimental data obtained for two different burner configurations. The results show reasonable accuracy, indicating that the present algorithm is a valid tool for future engineering design.