Geometry and flow field optimization design of solid oxide fuel cell stack for temperature and flow rate uniformity improvement

Abstract

Solid Oxide Fuel Cells (SOFCs) represent an advanced energy conversion device capable of directly transforming the chemical energy derived from hydrogen or hydrocarbon fuels into electrical energy under high-temperature operating conditions. One of the primary factors contributing to cell failure and performance degradation in high temperature operation condition is the thermal stress induced by the mismatch in thermal expansion coefficients among the constituent materials. Therefore, the effect of geometric parameters and flow fields of SOFC stack on flow rate, temperature was analyzed using numerical simulation methods for uniformity improvement. The results show that the manifold width significantly affects the temperature distribution of the stack. When the manifold width is increased from 6 mm to 10 mm, a maximum improvement of 25.8 % in flow uniformity can be reached. Furthermore, the flow field structure has a considerable impact on both the temperature and flow distribution within the SOFC stack. In the L-type flow field SOFC stack, flow rate and temperature uniformity are significantly improved, with the maximum reduction in temperature standard deviation reaching 29.7 %, and flow uniformity achieves an optimal improvement of up to 72 %.