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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

A THREE-DIMENSIONAL ANALYSIS OF LOCALIZED TRANSPORT PHENOMENA IN SOFC ANODE

Get access (open in a dialog) DOI: 10.1615/IHTC16.nmt.024211
pages 7091-7098

Resumo

In this research, a fully three-dimensional, micro-scale, multi-phase, heterogeneous numerical simulation of transport phenomena inside a solid oxide fuel cell anode was developed. A typical anode consists of three different phases: electron-conducting phase, ion conducting phase, and the pores. In a fuel cell, hydrogen penetrates an electrode through pores and reacts with oxygen that was transported from the cathode in the form of an ion. The electrons that are the product of this reaction are then transported to the external circuit via electron-conducting phase. Therefore, the electrochemical reaction occurs only at the border of those three phases, so-called Triple Phase Boundary. Having said that, an electrode of solid oxide fuel cell must have extremely complex microstructure to promote the electrochemical reaction in the biggest possible volume of the electrode. In this complex system, the intensity of the electrochemical reaction varies following the local microstructure morphology. Microstructure features, such as triple phase boundary, can be directly observed by the tomography techniques such as a combination of the focused ion beam and scanning electron micro-scope, coupled with three-dimensional reconstruction techniques. A program was developed for reading a set of two-dimensional images that comes from electron tomography and constructed a system of parallel three-dimensional numerical meshes that corresponds to three different phases in the anode. Furthermore, potential fields and reactant concentrations across the electrode have been computed. The presented simulation has great potential as a tool for microstructure-oriented design. It puts additional spotlight on the complex process of transport phenomena inside an electrode.