Influences of geometrical and operational factors on proton exchange membrane (PEM) fuel cell performance and design of a new flow field

In this study, a mathematical model was created for chemical reactions in the fuel cell as well as heat and fluid flow and this model was applied to a known serpentine type fuel cell for verification purposes. Three-dimensional, serpentine channel PEM fuel cell was analyzed in single phase using the Computational Fluid Dynamics (CFD) method. The study was carried out separately in transient regime and steady state. The model PEMFC is considered including membrane, catalyst layers, gas diffusion layers, gas flow channels, anode and cathode current collector plates. In the transient regime study, the response of the fuel cell to a step change in mass flow rates was sought. Step changes of 20% in mass flow rates were applied to the inlet boundary conditions and time dependent power and current density responses of the fuel cell were analyzed for various operating voltage values. Polarization curves were generated for the evaluation of the fuel cell performance, and their variations in time were presented. In the steady state study, the effects operating pressure, exchange coefficient and stoichiometric flow ratio on the fuel cell performance were investigated. It is of primary importance to establish parameters that affect performance in the fuel cell and optimize them for high performance. The results obtained are presented in terms of fuel cell characteristic curve. In addition, a new flow area has been designed and a new three-dimensional serpentine flow area with manifold and intermediate reservoirs has been created. Design-related works are carried out within the scope of TUBITAK project.