Effects of water vapor proportion in generated water on performance of polymer electrolyte fuel cells under dry operating conditions

摘要

A one-dimensional, non-isothermal, single-phase, steady-state model is developed for dry operating conditions to investigate the effects of different types of generated water as liquid or vapor in electrochemical reaction on the proton exchange membrane fuel cell (PEMFC) performance, A parameter (\u393) denoting vapor phase fraction in generated water is employed in the model. The agglomerate model with thin film was employed in catalyst layers. Water transport and its effects on cell performance were discussed under different operating conditions such as reactants relative humidity, vapor phase fraction and micro-porous layer thickness. The results indicated that the net water transport coefficients were positive under equal feeding gas humidity in both anode and cathode. At high current density, the more the proportion of water vapor in generated water is, the better cell performance is. However, at low current density, the effect of vapor phase proportion on cell performance is not very obvious.