Planar Solid-Oxide Fuel Cell System Demonstration at UT SimCenter.

摘要

A three-dimensional, unstructured, multi-species reacting flow solver is developed to model solid oxide fuel cells (SOFCs) as well as catalytic reactors. The finite volume based solver utilizes density-based method to solve the coupled system of governing equations. Numerical results for both SOFC and reactor obtained using the in-house code are compared with the experimental results from the literature for validation purposes. Effects of mass flow rates of incoming species on performance of SOFC as well as catalytic reactor are investigated. Two different methods namely direct differentiation and discrete adjoint method are implemented in the code to compute sensitivity derivatives for computational design. The catalytic partial oxidation of methane over both platinum and rhodium catalysts is studied using the in-house solver. Eight gas-phase species (CH4, CO2, H2O, N2, O2, CO, OH and H2) are considered for the simulation. The surface chemistry is modeled using detailed reaction mechanisms including 24 heterogeneous reactions with 11 surface-adsorbed species for Pt catalyst and 38 heterogeneous reactions with 20 surface-adsorbed species for Rh catalyst. The numerical results are compared with the experimental data and good agreement is observed. The effects of the design variables of inlet velocity, methane/oxygen ratio, catalytic wall temperature and catalyst loading on the cost functions representing methane conversion and hydrogen production are numerically investigated. The design cycle is performed using two gradient-based optimization algorithms to improve the value of the implemented cost function and optimize the reactor performance. A capability to perform thermo-mechanical analysis is developed by coupling the multispecies solver with the structures code.