Simulation Methodology on Analyzing Clamping Mode for Single Proton Exchange Membrane Fuel Cell

ABSTRACT In proton exchange membrane fuel cells (PEMFCs), a low interfacial pressure between the bipolar plates and the membrane exchange assembly (MEA) results in a high contact resistance. Conversely, an excessive interfacial pressure reduces the porosity of the gas diffusion layer (GDLs) and may damage the proton exchange membrane (PEM). Consequently, the performance of a PEMFC is critically dependent upon the clamping method. Accordingly, this study emphasizes the development of a numerical methodology for analyzing clamping of a PEMFC and constructs a detailed three-dimensional (3D) full-scale finite element (FE) model of a PEMFC with the traditional and most popular point-load design as an example. The numerical method is first validated by experiments. A series of simulations are then performed on the example cases ( i.e. 2-bolt, 4-bolt or 6-bolt) to analyze their behaviors on the contact pressure between the bipolar plates and the MEA and the corresponding effects on the GDL porosity and the contact resistance, under the constraints that the membrane and gaskets remain within their respective elastic limits and the porosity of the GDL has a value higher than 0.5. Overall, to complete the analysis procedures proposed in this paper, the results show that the six-bolt clamping mode with a tightening torque of 16 N-m achieves a uniform pressure distribution and a high interfacial pressure, and therefore represents the optimal clamping mode for the performed example cases.