Abstract:

The liquid hydrogen has attracted significant attention in the field of hydrogen vehicles due to the advantages of high hydrogen storage density and good safety performance, especially in the application of long-distance and large-scale transportation for vehicles. As one of the core components of liquid hydrogen fuel vehicles, the vehicle-mounted liquid hydrogen bottle will directly affect the driving range of the vehicle. In the pipeline structure design of liquid hydrogen tank for vehicles, there is a localized large heat flow at the connection between the pipeline and the inner container, which has a significant impact on the non-destructive storage time of liquid hydrogen tank. In this paper, a three-dimensional numerical model is established. Under the premise of the same total heat leakage, the influence of three localized large heat flow positions at the top, middle and bottom and the uniform heat leakage conditions on the thermophysical field variation during the self-pressurization process of liquid hydrogen tank are numerically studied. The results show that the average pressurization rates within the 1000 s are 4.51, 3.01, 15.08 and 6.08 kPa·h^-1, respectively for the uniform heat leakage and the three localized large heat flow conditions at the top, middle, and bottom. Since the pressurization rate is the slowest under the top large heat flow condition, and the fastest under the middle large heat flow condition, it is recommended to set the connection position at the top of the inner container when designing the connection position between the pipeline and the inner container, so as to extend the non-destructive storage time of liquid hydrogen tank.

Key words: liquid hydrogen tank for vehicles, localized large heat flow, temperature field, pressure variation, phase change

摘要：

液氢因储氢密度高、安全性能好等优势，在氢能汽车领域受到了人们的重点关注，尤其在长距离、大规模运输过程应用。车载液氢瓶作为液氢燃料车的核心部件之一，其无损储存时间将直接影响整车的续驶里程。在车载液氢瓶管路结构设计中，管路与内容器连接处会存在较大的局部热流，其会对液氢瓶无损储存时间产生显著影响。通过建立三维数值模型，在总漏热量相同的前提下，研究了顶部、中间、底部三种局部大热流位置和均匀漏热条件对液氢瓶自增压过程中热物理场变化规律的影响。研究结果表明：均匀漏热和顶部、中间、底部三种局部大热流工况在1000 s内的平均增压速率分别为4.51、3.01、15.08和6.08 kPa·h^-1。由于顶部大热流工况下的增压速率最慢，中间大热流工况下的增压速率最快，因此在设计管路与内容器连接口位置时建议将连接位置设置于内容器顶部，以延长液氢瓶的无损储存时间。

关键词: 车载液氢瓶, 局部大热流, 温度场, 压力变化, 相变