Numerical simulation of cell-to-cell performance variation within a syngas-fuelled planar solid oxide fuel cell stack

The cell-to-cell voltage variation in a planar solid oxide fuel cell (SOFC) stack is numerically investigated, considering the coupling effect of the heat transfer. and uniform mass flow rate distribution between cells. The model integrates validated three-dimensional electro-chemical button cell sub-models with the structure of a real counter-flow planar SOFC stack. A uniform characteristic diagram is defined to analyse the variation of the cell voltage distribution in a planar SOFC stack. A quantitative index of uniformity is proposed to compare and explain the difference in the cell voltage distribution uniformity in planar SOFC stacks. The simulation results indicate that the distribution characteristics of the cell voltage within a planar SOFC stack are primarily determined by the combined effects of the mass flow rate distribution and temperature distribution. The mass flow rate distribution dominates the overall cell voltage distribution trend, and the temperature distribution mainly dominates the cell voltage distribution of the cell near the top and bottom of the stack due to the thermal effects. The simulation results also indicate the relative uniform cell voltage distribution in planar SOFC stacks in the case of using syngas as a fuel instead of hydrogen. (C) 2016 Elsevier Ltd. All rights reserved.