Influence of clamping pressure on contact pressure uniformity and electrical output performance of proton exchange membrane fuel cell

Abstract

The contact pressure distributions are initially analyzed by conducting structural simulations on a single cell and a 40-cell stack of proton exchange membrane fuel cell (PEMFC) at various clamping pressures. The corresponding experimental pressure-sensitive film distributions are obtained that shows a good agreement with the simulation results. Then, the experimental and simulation data are compared by transforming images of pressure-sensitive film from experiments into detailed contact pressure data. The contact pressure uniformity of the simulation and experiment are compared by introducing mean pressure error and fluctuating intensity, and the optimal pressure range for best contact pressure uniformity is determined to be between 1.25 MPa and 1.67 MPa. Finally, CFD simulation approach is utilized to assess the electrical output performance. When comparing interface contact resistance (ICR) to porosity, the results indicate a reduction in power density of 5.1% and 1.2% at low clamping pressure compared to the case without taking ICR and porosity into account, while it decreases by 7.5% and 6.3% under high clamping pressure, respectively. It also deduced that there exists an optimal clamping pressure range for the best electrical output performance. The optimal clamping pressure is approximately 1.33 MPa, which is consistent with the previous structural results. In summary, experiments and numerical calculations of structure and fluid are carried out in this study to comprehensively evaluate the influence of clamping pressure on the structural and electrical performance of the PEMFC, the methods of experiments and simulations can offer guidance on the stack assembly process in practical applications.