Numerical analysis of afterburner chamber design for solid oxide fuel cell system

Abstract

This article applies computational fluid dynamics (CFD) to investigate the thermal and flow fields in the afterburner of solid oxide fuel cell (SOFC) systems. The objective is to estimate the performance of the burner to serve as a reference for performance improvement through structure design. The elliptical baffled burner, which enhances the effect of convective heat transfer and temperature uniformity effectively and suppresses the NOx formation as well, is proposed in this work. Additionally, low residual fuel exhaust and pressure drop are achieved. These advantages make it highly capable of being adopted in the industrial and commercial SOFC systems. The fuel of lower caloric value causes decreases in temperature and generation of NOx in the burner as the stack fuel utilization increases. For a 25 kW SOFC system, the stack fuel utilization of 80% reduces exhaust temperature by 65 K and NO emission by 38% than that of 70%.