Investigation of Combined Electric and Mass Transport Effects on Local Electrochemical Reaction in a PEMFC

摘要

The objective of this study is to explore the combined effect of electric and mass transport on the local reaction characteristics in the cathode electrode of a proton exchange membrane fuel cell. A three dimensional numerical model describing the underlying transport processes including electric currents and fluids is utilized to conduct the investigation with two different bipolar plate configurations by adjusting the transverse dimensions of shoulder and channel at inlet and outlet ports. Therefore, two flow field patterns, IEOC and ICOE are developed and employed. The simulation also considers various parameters such as cell voltage and shoulder-channel area ratio. Results show that the major transport species are highly non-uniform throughout the interested domain and their intensity distributions are influenced by the operation condition and flow field pattern. Furthermore, the local electrochemical reaction exhibits a characteristic resulting from a compromise of the relative strengths between potential field and reactant concentration. At different operation condition and electrode position, decisive factor that influents regional cell reaction is discussed. A further resolution is accomplished on segmental average current density for the new flow field configurations employed in this study.