Original scientific paper
Numerical Investigation of Effects of Porous Layer Properties and Thickness on Performance of PEMFC
Utku GULAN
; ERH Zürich, Institute of Environmental Engineering, Chair of Groundwater and Hydromechanics,Zürich, Switzerland
Hasmet TURKOGLU
; Gazi University, Faculty of Engineering and Architecture, Department of Mechanical Engineering, Maltepe, Ankara, Turkey
Abstract
In this study, fluid flow and concentration distribution on the cathode side of a
Proton Exchange Membrane Fuel Cell were numerically analyzed. The problem
domain consists of a cathode gas flow channel, cathode gas diffusion layer and
cathode catalyst layer. The governing equations, continuity, momentum and
concentration equations were discritized by the control volume method and
solved using a computer program based on SIMPLE algorithm. Simulations were
made for different values of gas diffusion layer porosity, catalyst layer porosity
and the ratio of the cathode gas diffusion layer thickness to the gas flow channel
height. Using the results of these simulations, the effects of these parameters on
flow, oxygen concentration and current density distribution were analyzed. It is
observed that increasing the porosities of the gas diffusion layer and catalyst
layer increases the current and power densities. The increase in the porosity
of the gas diffusion layer also increases the oxygen concentration in both gas
diffusion and catalyst layers but decreases the oxygen concentration in gas flow
channel. Simulations also showed that increasing porosity of the catalyst layer
increases the oxygen concentration in a catalyst layer but decreases the oxygen
concentration in a gas flow channel and gas diffusion layer. It is also seen that the
effect of the gas diffusion layer porosity is more dominant on cell performance
compared to the catalyst layer porosity. The analysis of the effect of the ratio of
the cathode gas diffusion layer thickness to the gas flow channel height on the
cell performance showed that the increasing ratio of the cathode gas diffusion
layer thickness to the gas flow channel height decreases the current and power
densities. An analysis of the data obtained from simulations also shows that
increasing the ratio of the cathode gas diffusion layer thickness to the gas flow
channel height increases the oxygen concentration in the gas flow channel but
decreases the oxygen concentration in both gas diffusion and catalyst layers.
Keywords
Computational Fluid Dynamics; Porous Medium; Proton Exchange Membrane Fuel Cells
Hrčak ID:
66558
URI
Publication date:
29.10.2010.
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