Dynamic analysis of a combined methane tri-reformer and Solid Oxide Fuel Cell system

In the operation of reformer-SOFC (Solid Oxide Fuel Cell) system, sudden changes of operating parameters may induce drastic impact on the materials, structure, and thermal stability of the fuel cells. The integration of a tri-reformer in the system offers the advantages of low energy consumption, reduced CO₂ emission and fuel flexibility. This paper establishes a 2D dynamic model of a methane tri-reformer-SOFC system, and for the first time reports the dynamic behavior of the system. The dynamic responses of the reformer and the SOFC to step changes in operation parameters (reformer inlet fuel composition, SOFC voltage, anode fuel flow rate, cathode air flow rate) are explored. By analyzing the spatial distributions, the changes in O₂/CH₄ ratio, operating voltage and anode flow rate pose significant impacts on the maximum fuel utilization, and the change in SOFC voltage induces a distinct overshoot in current density, accompanied by drastic change in the maximum temperature gradient. The electrode porosity can enhance mass and heat transfer and reduce the overshoot during the dynamic response, and should be chosen properly by weighing the transfer effect and the electrode efficiency. This work will provide guidelines for system optimization and control strategy development regarding safety, stability and efficiency.