A Study of Temperature Distribution Across a Solid Oxide Fuel Cell Stack

In this work, a three-dimensional model of a solid oxide fuel cell (SOFC) stack is developed to predict the temperature distribution across the stack. The model simulates a particular SOFC stack comprising of five single cells. Isothermal and adiabatic walls are chosen as the different boundary conditions in order to simulate the real situation, which lies somewhere in between. In the situation where adiabatic walls are assumed, the result shows that heat convection dominates the heat transfer process. However, heat conduction plays a major role when the isothermal walls are assumed. It is found that the highest temperature found in the isothermal stack is 1135 K at an operating temperature of 1073 K. The temperature difference is significant with the hottest point located in the middle of the active area. In the adiabatic stack, the temperature is at its maximum of 1574 K near the outlets of fuel and air at the same operating temperature. It should be kept in mind that both situations will have effects on the temperature behavior of the stack in reality. The temperature and current distributions of stack models in this work are also plotted in three dimensions and the analyses of stack performances are given. By comparing the results of five-cell and ten-cell stack models, the temperature differences of the five-cell stack and the ten-cell stack are 62 and 109 K, respectively. This indicates that there is a drastic temperature change throughout the stack when the stack size is increased.