Thermal Investigation of Solid Oxide Fuel Cell Ni-YSZ Anode supported with Cooling System: A FEM Approach

Abstract

Solid oxide fuel cell (SOFC) is preferred for power generation owing to its high-temperature waste heat recovery and low pollutant emissions. Nevertheless, SOFC operation is highly dependent on an effective cooling system, and the temperature gradient (ΔT) causes the distribution of thermal stress. The trade-off between meeting the SOFC requirement to operate at elevated temperature and minimizing thermal stress by reducing ΔT in the SOFC stack is required. Therefore, a cooling system for the SOFC stack is required to control the temperature homogeneity in the stack. In this study, a 3D finite element method containing heat transfer and energy charge equations was developed and then applied to investigate the effects of the (i) cooling plate and (ii) cooling fin on temperature distribution. The conventional stack orientation (i) parallel flow and (ii) counter flow were considered and compared with the adiabatic model in Ansys thermal analysis. The analysis was carried out under steady-state conditions. Considering that the temperature distribution varies according to the operating temperature and environment, the ambient temperature was set at 800 °C, 750 °C, 700 °C, and 650 °C. The study showed that the steepness of ΔT for a fin with the parallel flow is 1.5% better than for counterflow in the same operating scenario. Notably, the contribution of the cooling plate can minimize ΔT by 10% more than the fin. In addition, cooling measures are required to ensure the long-term stability of the cell during prolonged operation.