| Summary: | 碩士 === 南榮科技大學 === 工程科技研究所碩士班 === 105 === A three-dimensional numerical model of multi-component mixture transport is presented and implemented in COMSOL Multiphysics to study the affections of the operation parameters and the physical properties on the performance and the electric fields in the high temperature proton exchange membrane fuel cell (PEMFC) with 0.7847mm×1.0mm×20mm. The modeled section of the high temperature PEMFC consist of the gas channels, the anode, the cathode, and the electrodes. The model contains the conservation of mass, momentum, species, and charge with electrochemical reactions.
According to the numerical results, both the hydrogen mass fraction in the anode and the oxygen mass fraction in the cathode decrease along the flow direction, but the water mass fraction will increase. The maximum normal current density occurs at the inlet of the cathode. All the parameters, such as the physical properties of the porous electrodes and the operation conditions of the fuel cells, have unapparent effects upon the fuel cell performance and the electric fields at low current density. For high current density, increasing the fuel cell operation temperature, inlet pressure and outlet pressure, the porous material permeability, the porous material conductivity, the bipolar plate conductivity, the cathode stoichiometry, and reducing the fuel cell tortuosity of the porous media can improve the PEMFC performance and the electric fields.
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