Impact of Schroeder's paradox on cold start-up failure of proton exchange membrane fuel cells: Three-dimension simulation based on OpenFOAM

Abstract

In the cold environment, the increase in mass transfer resistance enhances non-equilibrium thermodynamic phenomena of the membrane water in proton exchange membrane fuel cells, such as Schroeder's paradox, but these phenomena were ignored in the classic model. In this study, the impacts of Schroeder's paradox on cold start-up failure, especially ice distributions at different temperatures, were discussed. The transfer procedure from the equilibrium to non-equilibrium between membrane water and vapor was described. A non-equilibrium boundedness model was developed and was run in OpenFOAM, and this model was compared to equilibrium unboundedness models previously and equilibrium boundedness models. Results show that non-equilibrium characteristics cannot be neglected at −20 °C. If the boundedness is considered, output voltages of the equilibrium assumption (frozen membrane water) decrease faster than the non-equilibrium assumption. Icing deteriorates the reabsorption capacity of the membrane and enhances the non-equilibrium between the membrane and the environment.