The operation strategy of solar-hydrogen coupled integrated energy system considering power distribution of MFCS

High-temperature proton exchange membrane fuel cells have high efficiency, a simple water management system, high tolerance to impurities, and generate high-temperature heat, making them suitable for integrated energy systems (IES). Currently, research on the power allocation strategy of a multi-stack fuel cell system (MFCS) is mostly focused on transportation applications, emphasizing electrical efficiency and hydrogen consumption. However, MFCS often provides heating in IES, necessitating the consideration of thermal efficiency. Additionally, the lifespan of the stack is a major factor affecting the economic cost of the system and must also be incorporated into power allocation strategies. This paper aims to further promote the efficient application of MFCS within IES by proposing a solar-hydrogen coupled IES for office buildings. Considering the overall efficiency and stack lifespan, a segmented-optimal point operation allocation strategy is proposed. Furthermore, a coordinated operation strategy for the system's equipment is designed. MATLAB modeling is employed to configure the installed capacity of each equipment and calculate the operational results. The results show that the optimal number of stacks for this system is 5. Compared to an IES using a single-stack fuel cell system, MFCS-IES reduces the specific exergy cost by 9.15%, with a notable 56.0% decrease in stack replacement costs. During the operation of the stack, the thermal efficiency increased by an average of 13.27%, and the overall efficiency improved by 7.73%. This strategy avoids operation of the stack in low-power regions and reduces load fluctuations. As a result, the average degradation rate of the stack decreases by 50.44% in the MFCS, demonstrating significant performance enhancement.