Temperature Equalization Control Strategy for Multi-Stack Solid Oxide Fuel Cell System Based on Anode Ni Particles Coarsening Mechanism

In solid oxide fuel cell (SOFC) system, the multi-stack fuel cell system (MFCS) often has an uneven distribution of reactant fluxes, leading to temperature difference between stacks, as well as inconsistent degradation between stacks, while the degradation of the stacks further causes the temperature of the stacks to rise, which in turn accelerates the degradation of the system, thus greatly reducing the performance of the system, such as efficiency and lifetime. In this paper, a two-layer temperature control strategy is proposed. For the inconsistency of reactant flow between stacks, the temperature consistency control in the inner loop is performed by controlling the current. The outer loop adopts temperature stability control for the temperature rise due to stacks degradation in the multi-stack SOFC system. The multi-stack SOFC system built with an anode Ni particle coarsening mechanism, at an inter-stack reactant flow ratio of 55:45, increases the overall system lifetime from 4835h to 12,355h, the overall power generation from 46,392kWh to 114,220kWh, and the efficiency degradation rate is reduced from 0.87%/kh to 0.77%/kh. The proposed temperature control strategy proved to be effective in extending the system lifetime and improving the system efficiency.