Abstract Safety is the primary concern during the processes of storage, transportation and application of liquid hydrogen. The flammable vapor cloud formed by liquid hydrogen spill poses serious threat to life and property, and it is vital to determine safe distance (the maximum downwind distance of flammable vapor cloud to the spill source) for risk assessment and safe protection. Three-dimensional CFD simulations predicting liquid hydrogen spill in open environment are performed, and variation characteristics of safe distance with different parameters are analyzed. The wind transporting, the atmospheric turbulence, and the shear force between cloud and air are all enhanced by increased wind speed, and consequently the safe distance increases in the first phase and then decreases with wind speed. Safe distance is positively related to liquid spill rate, while the increase rate slows down gradually. A correlation that relates safe distance with wind speed and spill rate is then established for the real-time guidance in a liquid hydrogen spill accident.

中文翻译：

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液氢泄漏事故安全距离评价与预测

摘要 安全是液氢储存、运输和应用过程中的首要问题。液氢泄漏形成的易燃蒸气云对生命财产构成严重威胁，确定安全距离（易燃蒸气云到泄漏源的最大顺风距离）对于风险评估和安全防护至关重要。进行了开放环境液氢溢出预测的三维CFD模拟，分析了不同参数下安全距离的变化特征。风的传输、大气湍流和云与空气之间的剪切力都随着风速的增加而增强，因此安全距离在第一阶段增加，然后随着风速的增加而减小。安全距离与液体泄漏率呈正相关，而增加率逐渐减慢。然后建立将安全距离与风速和泄漏率相关联的相关性，用于液氢泄漏事故的实时指导。