DOI: 10.1615/ICHMT.2004.CHT-04
ISBN Print: 978-1-56700-174-7
ISSN: 2578-5486
A DISTRIBUTED RESISTANCE ANALOGY FOR SOLID OXIDE FUEL CELLS
ABSTRAKT
This paper describes the theory and application of the method of distributed resistances to calculations of fluid flow, heat/mass transfer and electrochemistry in solid oxide fuel cells. It is postulated that the transport equations may be simplified, by replacing diffusion fluxes with rate terms involving resistance (conductance) terms. Mass transfer effects are accounted-for by incorporating the solution to the one-dimensional convection-diffusion problem when computing inter-phase heat transfer coefficients and the Nernst potential, where wall mass fractions are required. Calculations are performed for a single fuel cell, and for a manifold-stack assembly of 10 such cells. The domain is discretised using a multiply shared space method. Both potentiostatic and galvanostatic conditions are considered. Calculations performed using the distributed resistance analogy, are compared to those obtained using a detailed numerical method whereby the full transport equations are solved on a fine mesh. Agreement is excellent. It is concluded that the distributed resistance analogy may be used to successfully predict transport phenomena in fuel stacks at a fraction of the computational cost required to perform calculations using conventional means.