Computational Fluid Dynamics study of the influence of number of channels on the performance of full-scale PEM fuel cell

Proton exchange membrane fuel cells are gaining momentum in the automotive sector due to their favorable characteristics such as quick refueling times, silent operation, high efficiency, and clean energy production with only byproducts being heat and water. In this study, numerical models are developed using state-of-the-art Computational Fluid Dynamics modeling software for full-scale single PEM (Proton Exchange Membrane) fuel cells with different flow fields. Commonly, for small-scale fuel cells, such as 25 cm2, single serpentine is used for operation. The objective of this work was to see if the performance can be enhanced by increasing the number of channels, while it was also important to keep the dimensions of the channels feasible for manufacturing using CNC (Computer Numerical Control) milling and the available drill bit sizes. The number of channels was increased from one to three and the relative humidity of the reactants was set to partially and fully humidified. The results of the simulations indicate a considerable difference in the performance of the cells on elevated current densities, especially for the cases with lower relative humidity. The results of this study outline the requirement for the development of a standardized flow field for testing small active area single cells in the future.