Electrochemical Analysis of an Anode-Supported Axially Symmetrical One Dimensional Tubular Solid Oxide Fuel Cell

Objectives: In this paper, modeling and simulation of an anode supported axially symmetric tubular SOFC was performed. The nodal and current density variation of properties of SOFC were analyzed. The tubular SOFC was fed with 89% H2-11% water as fuel and high temperature air as the oxidant. The molar flow rates were adjusted so as to obtain the specified 85% fuel utilization&25% O2 utilization of air. The SOFC was operated at a reference of 1 std. atm. pressure and 1000ºC temperature. Also, electrochemical analysis and computational fluid dynamics study of various components was done. Methods: The model developed was in congruence with experimental data available for commercial prototypic 2.2 cm diameter Siemens Westinghouse tubular SOFC 1.5 m axial length located at Pittsburgh. Findings: The nodal variation graphs depicted a decreasing concentration of reactants and increasing one for the products along the length of the Tubular SOFC. The losses encountered due to polarizations are found to decrease along the SOFC. The Nernst potential and polarization losses as expected increase with an increasing current density. The graph for variation of Voltage with a change in current density showed a decrease in voltage developed with increasing current density and was found to very closely approach the plot developed for Siemens Westinghouse tubular SOFC experimental data. The results although closely matches the experimental results are also helpful in designing of a practical Tubular SOFC. Applications: The modeled tubular SOFC can be further improved by variation of properties along the radial direction; any angular variation in properties for homogenous system can still be ignored.