Effects of bluff-body on the thermal performance of micro thermophotovoltaic system based on porous media combustion

Abstract

To improve thermophotovoltaic system efficiency, a porous media combustor with a bluff-body as the flame holder was proposed. A two-dimensional numerical simulation of premixed hydrogen/air combustion inside a planar porous media channel with the local thermal non-equilibrium model was conducted. Effects of the bluff-body flame holder on mean wall temperature and system efficiency were examined. By inserting the bluff-body, the blowout limits of the planar porous media combustor for ϕ = 0.6, 0.8, 1.0, 1.2 are increased by 33%, 19%, 12%, 20%, respectively. Numerical results show that the flame stabilization is dominated by flow and heat recirculation. Further analysis reveals the mechanism of heat transfer on flame stabilization due to three heat recirculation paths. Considering the view factor and the external quantum efficiency, the system efficiency with the bluff-body is increased by 14.72% as compared to the one without the bluff-body at ϕ = 0.8, vin = 4 m/s.