Three-Dimensional Computational Fluid Dynamics Modelling for a Planar Solid Oxide Fuel Cell of a New Design

The aim of the work is to investigate the electrochemical processes of a planar Solid Oxide Fuel Cell (SOFC) and to estimate the performance of a novel SOFC design. The design involves cross-flow bipolar plates. Flow channels were designed to connect pairs of four orifices at the corners of the SOFC plates. Each of the bipolar plates has an air channel system on one side and a fuel channel system on the other side. One pair of channels in adjacent plates is used for the air flow along the cathode electrode, the other for the fuel flow along the anode of each cell. A schematic of the design proposed by Bossel [1] is shown in Fig. 1.

            Figure 1. A schematic of the proposed planar SOFC design:

(a) cathode side view, (b) anode side view [1]

A three-dimensional Computational Fluid Dynamics (CFD) model for an anode-supported planar SOFC with complex bipolar plates has been developed using the ANSYS Fluent code with additional Fuel Cell Tools module. The conservation equations of mass, momentum, energy and species as well as electrochemical models were solved for the fuel cell. The distributions of temperature and gas flow through the gas channels and PEN (positive electrode/electrolyte/negative electrode) structure were studied. The results identified the most susceptible areas for significant increase of the temperature at high current density, which can lead to hot spots formation and destruction of the electrodes. Knowledge of such parameters as the flow fields, pressure losses or temperature variation over the fuel cell area allowed to validate the effectiveness of the new SOFC design and is useful in further design modification.

Acknowledgments

The research programme leading to these results received funding from the European Union’s Seventh Framework Programme (FP7/2007-2013) for the Fuel Cells and Hydrogen Joint Technology Initiative under grant agreement no [325323]. Acknowledgments are due to the partners of SAFARI project. The work was also financed from the Polish research funds awarded for the project No. 3043/7.PR/2014/2 of international cooperation within SAFARI in years 2014-2016.

[1] U. Bossel, Rapid startup SOFC modules, Energy Procedia, 28, 2012, 48-56. DOI: 10.1016/j.egypro.2012.08.039.