PNNL

Abstract

A simulation tool for modeling planar solid oxide fuel cells is demonstrated. The tool combines the versatility of a commercial thermo-fluids simulation code with a validated electrochemistry calculation method. Its function is to predict the flow and distribution of anode and cathode gases, temperature and current distributions, and fuel utilization. The finite volume calculations are performed on complex three-dimensional meshes. A generic single-cell stack model, including internal manifolds, was created to simulate three-dimensional cases of cross-flow, co-flow, and counterflow stack designs. Cyclic boundary conditions were imposed at the top and bottom of the model domain, while the lateral walls were assumed adiabatic. The three cases show that, for a given average cell temperature, similar fuel utilizations can result irrespective of the flow configuration. Temperature distributions, which largely determine thermal stresses during operation, are dependent on the chosen geometry/flow configuration. The co-flow case exhibited advantages for control of thermal and stress distributions.