The impact of flow distributors on the performance of planar solid oxide fuel cell

This paper presents a newly established testing rig for planar solid oxide fuel cell. Two sets of nearly identical single-cell stacks except using different designs of flow distributors are measured to show how exactly the cell performance of such single-cell stacks would vary with a change in the degree of flow uniformity. It is found that by using small guide vanes around the feed header of commonly used rib-channel flow distributors to improve effectively the degree of flow uniformity, the power density of the single-cell stack can be increased by 10% as compared to that without using guide vanes under exactly the same experimental conditions. Also discussed are the start-up procedure and effects of hydrogen and air flow rates varying from 0.4 slpm to 1 slpm on cell performance of these two single-cell stacks which are measured over a range of the operating temperature varying from 650 °C to 850 °C. After 100 h of continuous cell operation, the examination of the reduction and oxidation stability of the anodic surface reveals that the improvement of flow uniformity in flow distributors is useful to achieve a more balanced use of the anodic catalyst.