Abstract:
Hydrogen energy is a significant component of the energy system in the future, but at present, the production is still dominated by blue hydrogen/gray hydrogen made from fossil energy, and the gap to situation of low-carbon is large. Renewable energy hydrogen production is one of the important technologies to achieve the large-scale consumption of renewable energy and dynamic balance of power supply and demand of power system. However, renewable energy power has strong random and fluctuating characteristics, and the operating efficiency and life of the multi-stack hydrogen production system are difficult to guarantee. This paper analyzes the performance of proton exchange membrane electrolysis, summarizes the efficiency characteristics and the operation constraints such as overload, low load and start-stop. Secondly, based on the electrolytic hydrogen production model, a multi-stack hydrogen production operation optimization strategy considering efficiency and life is proposed, a four-stage electrolytic hydrogen production optimization operation model is designed, and an improved rotating strategy based on state of health (SoH) is proposed. Case analysis shows that under the strategy proposed in this paper, the multi-stack hydrogen production system can operate in stable conditions for 56% of the operation time, compared with other strategies, the degradation is reduced by 30.6%−39.8%, so through the four-stage step-by-step operation, it can effectively reduce the start-stop, overload, and fluctuation operation time, effectively reducing the degradation faced in the process of matching renewable energy operation. Through power distribution based on maximum efficiency points, the efficiency is increased by 2.9%−9.2%, and the overall economic benefits are enhanced by
500000 to
950000 yuan. At the same time, the operating difference between the electrolyzers is controlled within 0.1% of the rated voltage, the improved rotating strategy based on SoH effectively improves the uniformity of operation among electrolyzers. The proposed optimal operation strategy improves the efficiency and lifetime of the multi-stack hydrogen production system matching renewable energy, and has guiding significance for the actual operation of the multi-stack hydrogen production system.