Numerical modeling of manifold design and flow uniformity analysis of an external manifold solid oxide fuel cell stack

摘要

Computational fluid dynamics (CFD) technique and experimental measurement are combined to investigate the effects of several geometric parameters on flow uniformity and pressure distribution in an external manifold solid oxide fuel cell (SOFC) stack. The model of numerical simulation is composed of channels, tubes and manifolds based on a realistic 20-cell stack. Analysis results show that gas resistance in the channel can improve the flow uniformity. However, channel resistance only has a limited effect under high mass flow rate. With the increase of inlet tube diameter, the flow uniformity improves gradually but this has little impact on pressure drop. On contrary, the larger diameter of outlet tube reduces the pressure drop effectively with minor improvement on flow uniformity. The dimensions of the flared inlet tube and the round perforated sheet in the manifold are designed to optimize both flow uniformity and pressure drop. Practical experimental stack is established and the velocity in the outlet of the channel is measured. The trends of the experimental measurements are corresponding well with the numerical results. The investigation emphasizes the importance of geometric parameters to gas flow and provides optimized strategies for external manifold SOFC stack. (C) 2020 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.