An accurate and efficient multiphysics 3D model for the design and operation analysis of production-scale solid oxide cell stacks

A rapid and reliable numerical model to predict solid oxide cell (SOC) stack behaviors is essential for technology advancement. This work reports the development of an accurate and efficient multiphysics model for production-scale SOC stacks. An analytical model is constructed to consider the ohmic resistance of current conduction in thin electrodes, simplifying modeling process. The model demonstrates good agreement with experimental I-V curves. A detailed mesh optimization is performed for all components of SOC stacks to ensure grid independence in flow, electrochemistry, and thermal fields. Moreover, a well-designed simulation strategy is presented, contributing equally to the computational efficiency as mesh optimization. A multiphysics simulation of a 5 kW SOEC stack takes only 50 min on a 2-CPU/24-core workstation, demonstrating the applicability of the model. The fuel uniformity of a H2O-SOEC (H2-SOFC) stack is found to increase (decrease) with increased fuel utilization, with underlying mechanism revealed through a representative 2D flow model.