Analysis of Heat and Mass Transfer for a Single-Planar-Anode-Supported Solid Oxide Fuel Cell Considering Internal Reforming

Abstract

The temperature uniformity and component concentration distributions in solid oxide fuel cells during operating processes can influence the cell electrochemical and thermal characteristics. A three-dimensional thermal-fluid numerical model including electrochemical reactions and water-gas-shift (WGS) reaction for a single channel solid oxide fuel cell was developed to study the steady-state characteristics, which include distributions of the temperature (T), temperature gradient (ΔT/Δx), and fuel utilization. It was shown that the maximum temperature (Tmax) changed with operating voltage and the maximum temperature gradient ((ΔT/Δx)max) occurred at the inlet of the channel of a solid oxide fuel cell by simulation. Moreover, the natural convection condition had a great influence on T and ΔT/Δx. The thermal stress generated by temperature differences was the key parameter and increasing the convection heat-transfer coefficient can greatly reduce the thermal stress. In addition, the results also showed that there were lower temperature gradients and lower current density at high working voltage; therefore, choosing the proper operating voltage can obtain better cell performance.