Finite element methodologies are widely used in the attempt to minimize the expense for testing and mock-ups. The same approach could be extensively used in predicting PEMFC (Proton Exchange Membrane Fuel Cell) performance, considering all of the aspects related to this modern and complex technology, from electric to thermal and structural, to fluid-dynamics behavior. The present work focuses on the clamping pressure of the stack and its influence on the electro-chemical performance of the fuel cell. The main objective is to evaluate PEMFC performance related to several clamping configurations defined by the user when assembling the entire stack. The concept is to simulate the behavior of more deformable components and predict their influence on the overall performance. In particular, a structural analysis of a small representative portion of fuel cell has been carried out, based on a well defined clamping pressure, in order to define a curve of deformation of the gas diffusion layer: the deformation itself has been consequently correlated to the PEMFC electrical properties with the assistance of analytical and empirical studies present in literature.
Structural analysis has been followed by a Computational Fluid-dynamics (CFD) fuel cell simulation (based on a proprietary model developed by the team) in order to assess its performance after the deformation. The results have exhibited that an increment in the cell electrical performance could be achieved by compressing the stack, especially at high current densities and low voltages.
This technique could be cyclically performed within the “iSight” environment, integrated together with CFD, electro-chemical and structural simulation in a unique framework.
The final concept would be to define a suitable clamping device able to reproduce the load distribution applied by the user during the structural analysis, through a reverse engineering approach. Therefore, this approach would start from the clamping pressure and then define the suitable the torque of the bolts (or other clamping device) to get that precise pressure that has been simulated.