Local thermal non-equilibrium effects in porous electrodes of the hydrogen-fueled SOFC

The assumption of local thermal equilibrium (LTE) between the gas and solid matrix within porous electrodes of solid oxide fuel cells (SOFCs) is commonly used in predictive state-of-the-art thermal-fluidic models, yet its validity has never been properly established. In this paper, a two-equation, thermal non-equilibrium model of heat transfer between the gas and solid phase and its simple scaling analysis are used to estimate the magnitude of the temperature difference that would be expected between the gas and solid phase, and thus the significance of local thermal non-equilibrium (LTNE) effects. A simple criterion is developed for determining under what conditions LTNE effects may safely be neglected, and when they are likely to become significant.