Research on Cold Start Strategy of Vehicle Multi-Stack Fuel Cell System 2023-01-7036

To study the cold start of muti-stack fuel cell system (MFCS), a novel thermal management subsystem structure and corresponding cold start strategies are proposed. Firstly, leveraging the distinctive configuration of the MFCS that can be sequentially initiated, we augmented the existing thermal management subsystem with the incorporation of two additional collection valves and two bypass diverter valves, which affords an increased degree of flexibility in the formulation of cold-start strategies. Secondly, we innovatively propose a hierarchical auxiliary heating cold start strategy and an average auxiliary heating cold start tailored for MFCS consisting of power levels of 20 kW, 70 kW, and 120 kW. Furthermore, we have developed a controller to address temperature control challenges during the start-up process. The results demonstrate that the multi-stack hierarchical auxiliary heating cold start strategy yields a significant reduction in energy consumption and startup time during the cold-start process, in comparison to the average preheating strategy. Moreover, when prioritizing the preheating of the 20 kW stack, its energy consumption metric and start-up time are further improved by preemptively preheating other stacks, resulting in a 20% reduction in startup time and a concurrent 20.39% decrease in energy consumption.