Multiphysical field simulation of exchange current density effection on solid oxide fuel cell (SOFC) with methane mixture fuel

In order to understand the performance and internal parameter distribution of SOFC fueled by methane mixture in detail, the paper uses numerical simulation method to conduct three-dimensional multiphysics coupling simulation on a single-channel anode-supported planar SOFC. The uniqueness of the three-dimensional model is that it employs the anode exchange current density from the methane gas mixture and considers the electrochemical oxidation of carbon monoxide. The numerical model proposed in this work provides more accurate simulation results. The results show that compared with the model that uses the exchange current density equation from humidified hydrogen for simulation, the model that uses the exchange current density equation from methane mixture to simulate the performance curve is closer to the experimental value. When using methane gas mixture as fuel, the maximum temperature difference along the flow direction is 10 K and the maximum power density can reach 0.482 W/cm2. In the thickness direction of the SOFC, the current density is not much different at the inlet and outlet. Along the direction of flow, the current density decreases near the inlet and outlet. Reducing the rate of fuel flow or increasing gas inflow temperature can improve SOFC performance.