Numerical study on thermal stress of solid oxide electrolyzer cell with various flow configurations

Abstract

Development of solid oxide electrolyzer cell (SOEC) is of great significance for hydrogen energy utilization. In order to have a better understanding of the multiphysics field processes in SOEC, numerical simulation is a necessary means to be adopted. In this study, a complete three-dimensional model of a planar SOEC short stack with three flow configurations (co-flow, cross-flow, counter-flow) was built. Multiple physical fields, including electron(ion), momentum, mass, and heat transfer, and thermal stress as well, were considered. The accuracy of the model was verified by comparing with the experimental results, with the maximum relative error less than 5%. The performances of SOEC with variant flow configurations were compared in detail. Due to the difference of flow configurations, the distribution of temperature, current density, hydrogen mole fraction, and stress present different characteristics. The effects of the operating voltage and the inlet gas temperature on hydrogen production and stress concentration in SOEC were also studied. The results show that compared with co-flow and counter-flow, the hydrogen production rate of cross-flow increases by about 15%, while the stress concentration decreasing by about 70%. All results show the better performance of cross-flow configuration, which provides guidance for design and application of SOEC.