Quasi-3D modeling of water transport in PEM fuel cell: numerical results and analytical treatment
Research Center "Juelich", DE
Keywords: PEM fuel cell
A model of water vapor transport in the polymer electrolyte fuel cell is presented. The mass balance equations of water in MEA take into account diffusion in voids, nonlinear diffusion in membrane and electroosmotic effect. The model accounts for water transport in the feed channels on both sides of the cell. The model is incorporated into our quasi-3D model of PEM fuel cell. Detailed maps of water distribution in a cell cross section are presented and along-the-channel profile of local current density is calculated. It is shown that this profile strongly depends on the level of humidification of the feed gases.
For low humidification a distinct peak of local current density arise. This peak reflects a competition of the two along-the-channel processes: accumulation of water, which increases membrane conductivity and exhaustion of feed gas (oxygen or hydrogen). A simple analytical model of the effect is built and comparison with numerical results is performed.
NSTI Nanotech 2003 Conference Technical Program Abstract