CFD analysis of cooling effects in H2-fed solid oxide fuel cells

A model is presented that describes the main physical phenomena affecting in the performance of a Solid-Oxide Fuel Cell (SOFC). The implementation of the model uses an in-house algorithm in a computational fluid-dynamics (CFD) framework that may be used to optimize the SOFC operational parameters. The physical phenomena considered in the model are: (i) mass conservation: multicomponent and multimodal mass transfer in gas channels and electrodes (convection, ordinary diffusion, Knudsen diffusion); (ii) momentum conservation in the gas channels and electrodes; (iii) energy conservation: coupled heat transfer across the whole cell (gas channels, electrodes and electrolyte); (iv) electrochemistry: half-reactions are considered to take place at the electrode-electrolyte interfaces, and activation losses are computed using the general version of the Butler-Volmer equation. The main features of this CFD tool are: (i) it allows the prediction of the characteristic (I-V) curve of an H₂-fed cell; (ii) it is suitable for both tubular and planar cells; (iii) it has been implemented using OpenFOAM-1.5-dev, an open-source CFD-platform based on the Finite Volume Method.The numerical results are validated with published experimental I-V curves for a hydrogen-fed anode-supported micro-tubular SOFC, and a numerical analysis of the influence of different operation conditions on the temperature distribution is performed to procure a better understanding of the heat management of the cell.