Effect of operating parameters on the hygro–thermal stresses in proton exchange membranes of fuel cells

A full three-dimensional, nonisothermal computational fluid dynamics model of a proton exchange membrane (PEM) fuel cell with straight flow field channels has been developed to simulate the hygro and thermal stresses in polymer membrane, which are occurring in the cell during operation. The behavior of the membrane during the operation of a unit cell has been studied and investigated. This comprehensive model accounts for the major transport phenomena in a PEM fuel cell: convective and diffusive heat and mass transfer, electrode kinetics, transport and phase change mechanism of water, and potential fields. The model is shown to be able to realize the many interacting, complex electrochemical, transport phenomena, and stresses distribution that cannot be studied experimentally. This model is used to study the effect of operating parameters on fuel cell performance and hygro–thermal stresses in polymer membrane. Detailed analyses of the fuel cell performance under various operating conditions have been conducted and examined. The analysis helped identifying critical parameters and shed insight into the physical mechanisms leading to a fuel cell performance under various operating conditions.