LATTICE BOLTZMANN MODELING OF ADVECTION-DIFFUSION TRANSPORT WITH ELECTROCHEMICAL REACTIONS IN A POROUS SOFC ANODE STRUCTURE

摘要

Lattice Boltzmann method (LBM) is a method that can be used to capture the detailed activities of the transport processes at microscale. Here LBM is used to model the porous anode for an anode-supported Solid Oxide Fuel Cell (SOFC). The purpose of this study is to investigate the effects of electrochemical reactions on the transport processes by a 3D model at microscale. A porous 3D modeling domain is created with randomly placed spheres to resemble the part of the anode structure close to the electrolyte. The 3D model is simulated with parallel computing in Python using Palabos and also MATLAB to capture the active microscopic catalytic effects on the heat and mass transport. A multicomponent reaction-advection-diffusion transport for three components (H_2, H_2O and O~(2-)) is analyzed with electrochemical reactions and particle collisions. This combined with the heat, momentum and charge transport in the 3D model. It is here been shown that LBM can be used to evaluate the microscale effect of electrochemical reactions on the transport processes and some potential risk of hot spots to reduce harming interaction sites. The electrochemical potential is gradually increased along the flow direction as the species come in contact with each other. There is a potential risk for a hot spot when the active interacting species reach a catalytic layer and the smooth flow pattern is disturbed. Improving the flow structure by the catalytic interface can increase interaction of the reforming reactions and the electrochemical reactions, which in turn can improve the cell performance.