Investigation on Flow Distribution in an External Manifold SOFC Stack by Computational Fluid Dynamics Technique

摘要

In this study, the flow distribution in a planar solid oxide fuel cell (SOFC) stack with external manifolds is investigated by computational fluid dynamics (CFD) technique. Three dimensional external manifold models are constructed for a SOFC stack composed of 24 cells. CFD simulations with air as operating gas are implemented for two types of stacks with different inlet manifolds, including the manifold with three tube inlets (T-manifold) and the manifold with a gas chamber on top (C-manifold). The influences of different parameters such as channel resistance and gas feeding rate on flow distribution are studied. Modeling results indicate that the increase of channel resistance and a lower gas feeding rate can respectively improve the uniformity factor of T-manifold and C-manifold from 0.963 to 0.995 and 0.989 to 0.998. For a given channel resistance, the pressure distribution in the inlet manifold plays a dominant role in the flow distribution. In addition, flow distribution in the stack with C-manifold is generally more uniform than the stack with T-manifold. Furthermore, flow characteristics of the two type inlet manifolds are investigated by measuring velocity distribution of the gas at manifold outlets using a hot-wire anemometer.