CFD Modeling: Different Kinetic Approaches for Internal Reforming Reactions in an Anode-Supported SOFC
Författare
Summary, in English
Fuel cells are electrochemical devices that convert chemical energy into electricity. Solid oxide fuel cells (SOFCs) are a particularly interesting type because they can reform hydrocarbon fuels directly within the cell, which are possible thanks to their high operating temperature. The purpose of this study is to develop an anode-supported SOFC theoretical model, to enhance the understanding of the internal reforming reactions and their effects on the transport processes.
A CFD approach, based on the finite element method, is implemented to unravel the interaction between internal reforming reactions, momentum, heat and mass transport. The three different steam reforming reaction rates applied were developed and correlated to experimental studies found in the literature. An equilibrium rate equation is implemented for the water-gas shift reaction. The result showed that the reaction rates are very fast and differ quite a lot in the size. The pre-exponential values, in relation to the partial pressures, and the activation energy was affected the reaction rate. It was shown that the anode structure and catalytic composition have a major impact on the reforming reaction rate and on the cell performance. The large difference between the different activation energies and pre-exponential values found in the literature reveals that several parameters probably have significant influence on the reaction rate. As the experiments with the same chemical compositions can be conducted on a cell or only a reformer, it is important to reflect over the effect this has on the kinetic model. To fully understand the effect of the parameters connected to the internal reforming reaction, micro scale modeling is needed.
A CFD approach, based on the finite element method, is implemented to unravel the interaction between internal reforming reactions, momentum, heat and mass transport. The three different steam reforming reaction rates applied were developed and correlated to experimental studies found in the literature. An equilibrium rate equation is implemented for the water-gas shift reaction. The result showed that the reaction rates are very fast and differ quite a lot in the size. The pre-exponential values, in relation to the partial pressures, and the activation energy was affected the reaction rate. It was shown that the anode structure and catalytic composition have a major impact on the reforming reaction rate and on the cell performance. The large difference between the different activation energies and pre-exponential values found in the literature reveals that several parameters probably have significant influence on the reaction rate. As the experiments with the same chemical compositions can be conducted on a cell or only a reformer, it is important to reflect over the effect this has on the kinetic model. To fully understand the effect of the parameters connected to the internal reforming reaction, micro scale modeling is needed.
Avdelning/ar
Publiceringsår
2011
Språk
Engelska
Publikation/Tidskrift/Serie
Journal of Fuel Cell Science and Technology
Volym
8
Issue
031014
Fulltext
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
American Society Of Mechanical Engineers (ASME)
Ämne
- Energy Engineering
Nyckelord
- SOFC
- modeling
- internal reforming reactions
- anode-supported
- transport processes.
Status
Published
Forskningsgrupp
- heat transfer
ISBN/ISSN/Övrigt
- ISSN: 1551-6989