The effect of wall thermal conductivity on the thermal performance of a partially filled micro porous combustor

Abstract

As the key component of the micro power system, the thermal performance of the micro combustor is crucial to the system efficiency. In this paper, the numerical simulation of a micro combustor partially filled with porous medium was conducted. The thermal non-equilibrium model was employed in to investigate the heat transfer between the gas and porous medium. The effect of wall thermal conductivity on thermal performance, chemical reactions in porous medium, and the heat recirculation through porous medium and wall was deeply analyzed. The results show that, in stable operation range, higher wall thermal conductivity or inlet velocity enhances the heat recirculation and reduces the heat loss ratio. The enhancement effect of wall thermal conductivity on reaction rate of R179 “i-C3H7+O2=C3H6+HO2” in porous medium zone is stronger for high inlet velocity and negligible for low inlet velocity. Increasing the wall thermal conductivity can promote the heat recirculation of the micro combustion mainly through gas-to-porous heat convection, while the gas-to-wall heat convection exchange can promote the flame moving upstream, extending the stable operation range of the micro porous combustor.