CFD analysis of a symmetrical planar SOFC with heterogeneous electrode properties

Abstract A comprehensive 2-D CFD model is developed to investigate bi-electrode supported cell (BSC) performance. The model takes into account the coupled complex transport phenomena of mass/heat transfer, charge (electron/ion) transport, and electrochemical reactions. The uniqueness of this modeling work is that heterogeneous electrode properties are taken into account, which includes not only linear functionally graded porosity distribution but also various nonlinear distributions in a general sense according to porous electrode features in BSC design. Extensive numerical analysis is performed to elucidate various heterogeneous porous electrode property effects on cell performance. Results indicate that cell performance is strongly dependent on porous microstructure distributions of electrodes. Among the various porosity distributions, inverse parabolic porosity distribution shows promising effects on cell performance. For a given porosity distribution of electrodes, cell performance is also dependent on operating conditions, typically fuel/gas pressure losses across the electrodes. The mathematical model developed in this paper can be utilized for high performance BSC SOFC design and optimization.

[1]  Prabhakar Singh,et al.  Engineered cathodes for high performance SOFCs , 2003 .

[2]  S. Chan,et al.  A complete polarization model of a solid oxide fuel cell and its sensitivity to the change of cell component thickness , 2001 .

[3]  Jin Hyun Nam,et al.  Microstructural Optimization of Anode-Supported Solid Oxide Fuel Cells by a Comprehensive Microscale Model , 2006 .

[4]  Khiam Aik Khor,et al.  Simulation of a composite cathode in solid oxide fuel cells , 2004 .

[5]  Nigel Sammes,et al.  Mechanical properties of micro-tubular solid oxide fuel cell anodes , 2009 .

[6]  I. Dincer,et al.  Mathematical modeling of planar solid oxide fuel cells , 2006 .

[7]  Wilson K. S. Chiu,et al.  Nondestructive Reconstruction and Analysis of SOFC Anodes Using X-ray Computed Tomography at Sub-50 nm Resolution , 2008 .

[8]  J. Chung,et al.  Monte-Carlo simulation and performance optimization for the cathode microstructure in a solid oxide fuel cell , 2007 .

[9]  Yann Bultel,et al.  Theoretical optimisation of a SOFC composite cathode , 2005 .

[10]  Rupak Das,et al.  Microstructure and electrochemical properties of cathode materials for SOFCs prepared via pulsed laser deposition , 2006 .

[11]  L. A. Chick,et al.  Diffusion Limitations in the Porous Anodes of SOFCs , 2003 .

[12]  Dennis Y.C. Leung,et al.  Micro-scale modelling of solid oxide fuel cells with micro-structurally graded electrodes , 2007 .

[13]  W. Chiu,et al.  Mass transfer in graded microstructure solid oxide fuel cell electrodes , 2006 .

[14]  D. Jeon,et al.  A comprehensive micro-scale model for transport and reaction in intermediate temperature solid oxide fuel cells , 2006 .

[15]  S. Sofie,et al.  A symmetrical, planar SOFC design for NASA's high specific power density requirements , 2007 .

[16]  Ibrahim Dincer,et al.  A general electrolyte–electrode-assembly model for the performance characteristics of planar anode-supported solid oxide fuel cells , 2009 .

[17]  D. Jeon A comprehensive CFD model of anode-supported solid oxide fuel cells , 2009 .

[18]  V. Antonucci,et al.  Micro-modelling of solid oxide fuel cell electrodes , 1998 .

[19]  S. Sunde Simulations of Composite Electrodes in Fuel Cells , 2000 .

[20]  Michael R. von Spakovsky,et al.  Direct numerical calculation of the kinematic tortuosity of reactive mixture flow in the anode layer of solid oxide fuel cells by the lattice Boltzmann method , 2007 .

[21]  Svein Sunde,et al.  Monte Carlo Simulations of Conductivity of Composite Electrodes for Solid Oxide Fuel Cells , 1996 .

[22]  A. Virkar,et al.  Dependence of polarization in anode-supported solid oxide fuel cells on various cell parameters , 2005 .

[23]  Kuan-Zong Fung,et al.  The Effect of Porous Composite Electrode Structure on Solid Oxide Fuel Cell Performance I. Theoretical Analysis , 1997 .

[24]  Yixiang Shi,et al.  Numerical modeling of an anode-supported SOFC button cell considering anodic surface diffusion , 2007 .

[25]  W. Chiu,et al.  Modeling of gas transport through a tubular solid oxide fuel cell and the porous anode layer , 2008 .

[26]  Jon M. Hiller,et al.  Three-dimensional reconstruction of a solid-oxide fuel-cell anode , 2006, Nature materials.

[27]  Toshio Oshima,et al.  Estimation of the Co-ordination number in a Multi-Component Mixture of Spheres , 1983 .

[28]  Robert J. Kee,et al.  Anode barrier layers for tubular solid-oxide fuel cells with methane fuel streams , 2006 .

[29]  Nigel P. Brandon,et al.  Microstructural Modeling of Solid Oxide Fuel Cell Anodes , 2008 .