Thermal field in SOFC fed by CH4: Molar fractions effect

Abstract

In the present work, the anode supported solid oxide fuel cell (AS_SOFC) is fed by air and fuel at cathode and at anode channels respectively. The fuel is a mixture of five components: methane (CH4), hydrogen (H2), carbon dioxide (CO2), carbon monoxide (CO) and steam (H2O), where a reforming phenomenon; an external or an internal one appears. At the SOFC anode side, an indirect or direct reforming phenomenon happens. The principal aim of this study is the visualization of the temperature fields under heat sources’ effect caused by the direct internal reforming reactions; the steam reforming reaction, the water gas shift reaction and the overall reforming reaction. The temperature gradient is discussed for several inlet fuel molar fractions. A program in FORTRAN language using the finite difference method is developed. The thermal fields’, in the plane perpendicular to the gas flow, is visualized by ‘‘Tec plot’’ program. This study requires a coupling conservation equations (mass, energy and species). The flows are governed by Darcy’s law. The results show that the fuel molar fractions cannot be ignored in the presence of direct internal reforming phenomenon.