NUMERICAL STUDY AND OPTIMISATION OF CHANNEL GEOMETRY AND GAS DIFFUSION LAYER OF A PEM FUEL CELL

Fuel cell technology offers a promising alternative to conventional fossil fuel energy sources. Proton exchange membrane fuel cells (PEMFC) in particular have become sustainable choice for the automotive industries because of its low pollution, low noise and quick start-up at low temperatures. Researches are on-going to improve its performance and reduce cost of this class of energy systems. In this work, a novel approach to optimise proton exchange membrane (PEM) fuel cell gas channels in the systems bipolar plates with the aim of globally optimising the overall system net power performance at minimised pressure drop and subsequently low pumping power requirement for the reactant species gas was carried out. In addition, the effect of various gas diffusion layer (GDL) properties on the fuel cell performance was examined. Simulations were done ranging from 0.6 to 1.6 mm for channel width, 0.5 to 3.0 mm for channel depth and 0.1 to 0.7 for the GDL porosity. A gradient based optimisation algorithm is implemented which effectively handles an objective function obtained from a computational fluid dynamics simulation to further enhance the obtained optimum values of the examined multiple parameters for the fuel cell system. The results indicate that effective match of reactant gas channel and GDL properties enhance the performance of the fuel cell system. The numerical results computed agree well with experimental data in the literature. Consequently, the results obtained provide useful information for improving the design of fuel cells.