Operational Optimization and Connection Structure Assessment of Multi-stack Solid Oxide Fuel Cell System

Solid oxide fuel cells have great potential as a clean and efficient energy conversion method, especially for multi-stack systems in high-power scenarios. However, for a multi-stack system, the gas path connection structure has a significant impact on the system performance, which is an important factor to be considered in the system integration. In order to address this issue, this paper proposes a methodology for evaluating multi-stack connection structures that takes into account the thermal and electrical characteristics. The methodology starts with the modeling of multi-stack solid oxide fuel cell systems with three different gas path connection structures. Secondly, the systems with each connection structure are separately optimized for operating conditions to obtain their optimal operating points taking into account the thermoelectric safety constraints. Finally, the data under the optimal operating conditions are utilized to construct a comprehensive assessment model of the connection structures. The results show that the series-parallel gas path connection structure will be superior to the series or parallel one.