Suscripción a Biblioteca: Guest
Proceedings of CHT-12. ICHMT International Symposium on Advances in Computational Heat Transfer.
July, 1-6, 2012, Bath, England

DOI: 10.1615/ICHMT.2012.CHT-12


ISBN: 978-1-56700-303-1

ISSN: 2578-5486

MALDISTRIBUTION OF FUEL/AIR FLOWS IN A STACK OF PLANAR SOFC CAUSED BY TEMPERATURE NON-UNIFORMITY

pages 317-333
DOI: 10.1615/ICHMT.2012.CHT-12.190
Get accessGet access

SINOPSIS

A numerical model for an anode-supported direct-internal-reforming planar solid oxide fuel cell (SOFC) short stack was developed. In this model, the volume-averaging method is applied to the flow passages by assuming that a porous metal is inserted in the passages as current collectors. This treatment reduces the computational time and cost by avoiding a full three-dimensional simulation while maintaining the ability to solve the flow and pressure fields in the streamwise and spanwise directions. Quasi-three-dimensional multicomponent gas flow fields, the temperature field, and the electric potential/current fields were solved. The steam-reforming reaction of methane, the water-gas shift reaction, and the electrochemical reactions of hydrogen were taken into account. The model was applied to a short stack consisting of 10 cells. A heat-loss model based on radiative heat transfer was applied to the top wall surface of the stack. The temperature gradient was found to have eased owing to the heat-loss effect; however, the decrease in the average cell temperature increased the internal loss of the cell and lowered the cell efficiency. The difference in the average cell temperature affected the gas viscosity and led to the maldistribution of both the fuel and air flows in the stack. The fuel utilization of one cell in the stack was shown to be very different from the overall fuel utilization of the entire stack. The cooling air tends to flow to the colder side of the stack, worsening the temperature non-uniformity. The results show the importance of careful thermal management of SOFCs, particularly in a small system.

Portal Digitalde Biblioteca Digital eLibros Revistas Referencias y Libros de Ponencias Colecciones Precios y Políticas de Suscripcione Begell House Contáctenos Language English 中文 Русский Português German French Spain