Book/Dissertation / PhD Thesis

FZJ-2020-02318

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Modeling and Simulation of Polymer Electrolyte Fuel Cells

Zhang, S. (Corresponding author)FZJ*

2020
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich
ISBN: 978-3-95806-472-0

Please use a persistent id in citations: http://hdl.handle.net/2128/25282  urn:nbn:de:0001-2020072229

Abstract: Polymer electrolyte fuel cells are efficient and clean devices that convert chemical energy directly into electricity. Great attention has been received during the past decade on experimental and numerical studies. Comprehensive experimental investigations of fuel cells are still very expensive and challenging considering various parameters in fuel cell operations, designs, and optimizations. The numerical procedure provides an alternative way for fuel cell analysis. With the development of computational power, e.g. high performance computing facility, the limitation of numerical applications on the analysis of PEFCs is decreasing. The numerical method may serve as an easy and fast tool nowadays. The major transport phenomena involved in PEFCs includes fluid flow, heat and mass transfer, species and charge transfer, electrochemical reaction. Numerical models need to take some or all of the major physical processes into account. Therefore, in the present study, two PEFC models are developed and implemented into an open-source library OpenFOAM$^{®}$, which allows large scale parallel calculations. These models, a detailed model and a homogeneous model, consider cell-level and stack-level applications. The detailed model is based on the conventional computational fluid dynamics, whereas the homogeneous model is derived from the detailed model and appliesa distributed resistance analogy. Both models enable simulations concerning three-dimensional, single-phase and two-phase, multi-region, multiphysics, and nonisothermal situations. An Eulerian-Eulerian approach is applied to describe two-phase flow. Both models are numerically verified and experimentally validated viafin-house designed HT-PEFCs and LT-PEFCs, including prototypes with nominal active area of (4.2 X 4.2) 16 cm$^{2}$ and (11.2 X 19) 200 cm$^{2}$. The detailed and homogeneous models are applied on both HT-PEFCs and LTPEFCs respectively: 1. The local variations of current density and gas mole fractions are large in fuel cells with serpentine ow paths. The serpentine flow path leads to higher pressure drop, however, contributes to better reactants redistribution and higher local current density. 2. The homogeneous model is compared with a previously developed detailed model with good agreement. Simulation results are presented; both models provide finer scale results than experimental measurements. 3. The catalyst layer cracks and MEA failure are numerically simulated via the detailed model. Cracks present slight effects on cell performance, however, significant on local values. The MEA failure is found resulted from the high local temperature and/or mechanical damage. 4. A LT-PEFC is simulated via the homogeneous model. The results are also presented. Therefore, the present models are ready to be applied in other PEFC designs.

Note: RWTH Aachen, Diss., 2019

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Contributing Institute(s):

1. Elektrochemische Verfahrenstechnik (IEK-14)

Research Program(s):

1. 135 - Fuel Cells (POF3-135) (POF3-135)

Appears in the scientific report 2020

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