| Summary: | 碩士 === 元智大學 === 化學工程與材料科學學系 === 102 === This study establishes a one-dimensional, two-phase, dynamic proton exchange membrane fuel cell model, including the cathode diffusion layer, the anode diffusion layer, and the proton exchange membrane. The Stefan-Maxwell equations are used to describe the multi-component gas phase diffusion. Liquid water transport is driven by the capillary head that established in the gas diffusion layer. The dynamic behavior of PEMFC is determined by the hydration of water content in the membrane and the water saturation of liquid water in the gas diffusion layers.
In the study, we evaluate the effects of operating parameters, including sweeping rate, cell temperature, imposed pressure drop and feed relative humidity. It can be found that cell performance and membrane water content are highly correlated, cell is better performed if membrane is better hydrated at high potential. At low potential, cathode gas diffusion layer (GDL) is suffered from water flooding, and dry cathode feed is preferred. We study for the conductivity of the membrane, found that some differences about the resistance on experimental data and the calculation, so we change the electro-osmotic coefficient and diffusion coefficient for further testing finite.
We establish the agglomerate model of catalyst layer, we found that catalyst layer is important for simulation. The agglomerate in the catalyst layer consists of ionomer film and water film over Pt catalytic area. We test the operating parameters, including cell temperature, imposed pressure difference and feed relative humidity.
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