Parametric study of kW-class solid oxide fuel cell stacks fueled by hydrogen and methane with fully multiphysical coupling model

Abstract Multiphysics models are important tools for the design and optimization of solid oxide fuel cells (SOFCs). The computational efficiency of a sophisticated multiphysics model is improved by a factor of 4 by symmetry utilization and grid optimization, allowing its routine use for the analysis and diagnosis of industrial-sized SOFC stacks. The predictive power of the model is tested by the experimental data. Parametric numerical studies, together with indepth theoretical analyses, on the performance characteristics of kW-class stacks fueled by H2 and CH4 are carried out with this accurate model. It is concluded: (1) CH4 is advantageous for providing lower maximum temperature and temperature gradient, and higher energy efficiency. (2) H2 is advantageous for generating more electricity and being more resistant to fuel starvation. (3) Insufficient air supply can cause high thermal gradient. (4) Fuel uniformity is critically dependent on the stack design and affects all aspects of stack performance.