Abstract:

The reliability and efficiency in the operating process of the high-pressure hydrogen refueling station (HRS) is the prerequisite for promoting the broad application of hydrogen fuel power. Temperature control during the refueling process is crucial to the safety of the vehicle tank. This paper displays a simulation of the complete thermodynamics process of the high-pressure hydrogen refueling process by developing a dynamic model, which is combined with the mass equation, energy equation, and heat transfer equation. The transient temperature, pressure, mass flow rate of hydrogen, and cooling demand during the refueling process are discussed. Aiming at higher efficiency and less energy consumption, the optimization strategies of operation in HRS are proposed. Under the target of 95% state of charge (SOC) and 80℃ final gas temperature in the vehicle tank, the effects of ambient temperature, the initial pressure of the vehicle tank, and refueling time on the pre-cooling temperature are analyzed. Moreover, the effects of nozzle diameter on the temperature rise of the vehicle tank, the cooling load, and the total cooling capacity of the heat exchanger are discussed. The results show that in most cases, the pre-cooling temperature can be increased by 5℃ with the ambient temperature decreasing by 5℃, the charging pressure increasing by 4 MPa, and the refueling time extending by one minute. The nozzle diameter has little influence on the final temperature of the vehicle tank and the refueling time but has a great influence on the cooling load of the heat exchanger. When the nozzle diameter is reduced from 8 mm to 5 mm, the final temperature in the tank is only increased by 6%, the refueling time is only extended by 5 s, but the peak cooling load and total cooling capacity of the heat exchanger are reduced by 25% and 7.3%, respectively.

Key words: hydrogen refueling, dynamic simulation, thermodynamics process, energy consumption, pre-cooling temperature, optimization

摘要：

高压氢气加注站可靠高效的运行是氢燃料动力大规模应用的技术前提，加注过程中对氢气进行温度控制是罐内温度安全性的重要保证。对氢燃料电池汽车的高压氢气加注过程建立完整的热力学模型，计算加注过程各个系统节点瞬态的热力学参数、氢气质量流量以及换热器冷负荷，分析影响预冷温度的因素，讨论喷嘴直径对车载储氢罐温升和换热器冷负荷的影响，并根据计算结果提出系统运行的优化策略。结果表明预冷温度可根据加注条件相应调整，对于大多数工况点，当环境温度每降低大约5℃、起充压力每增高大约4 MPa或者加注时间每延长1 min，预冷温度可提高大约5℃；加注枪的喷嘴直径对加注时间和车载储氢罐氢气终温的影响较小，但对换热器冷负荷影响较大，当喷嘴直径由8 mm减小为5 mm时，罐内终温仅升高6%，加注时间仅延长5 s，而换热器峰值冷负荷和总冷量分别降低了25%、7.3%。

关键词: 加氢, 动态仿真, 热力学过程, 能耗, 预冷温度, 优化