Abstract:

With the widespread application of hydrogen as a clean energy source, its safety issues are increasingly valued. Due to the dangerous characteristics of hydrogen such as low density, high dispersibility and wide combustible range, it is easy to form a large flammable cloud after leakage, which may cause fire or explosion in case of ignition source, posing a serious threat to public safety. Conducting safety research on the diffusion pattern of liquid hydrogen leakage can prevent and reduce hydrogen leakage accidents, protecting people's lives and property. This study employs computational fluid dynamics (CFD) software Fluent, combined with the Lee model and the volume of fluid (VOF) model, to simulate the leakage and vaporization process of liquid hydrogen. The study finds that an increase in wind speed extends the downwind diffusion distance while reducing the vertical height. Based on the diffusion pattern of combustible hydrogen clouds and considering the limitations of hydrogen gas sensors, a new method is proposed to predict hydrogen concentration by monitoring environmental temperature changes using temperature sensors. By analyzing the mathematical relationship between temperature and hydrogen concentration during the initial leakage phase, a mathematical model is established to verify that the temperature sensors arranged on the 0.8 m height plane can quickly respond to leaks and improve the safety management level of hydrogen refueling stations.

Key words: hydrogen, numerical simulation, gas-liquid flow, combustible hydrogen cloud diffusion, hydrogen refueling station safety, hydrogen concentration prediction

摘要：

随着氢能作为清洁能源广泛应用，其安全性问题日益受到重视。氢气由于具有低密度、高扩散性及宽可燃范围等危险特性，泄漏后易形成大范围可燃云团，遇点火源可能引发火灾或爆炸，对公共安全构成严重威胁。针对这一安全问题，对液氢泄漏扩散规律进行安全研究，可以预防和减少氢泄漏事故，保护人民生命财产安全。本研究采用计算流体动力学（computational fluid dynamics，CFD）软件Fluent，结合Lee模型和流体体积多相流（volume of fluid，VOF）模型，模拟液氢泄漏及气化过程。研究发现，风速增加会延长下风向扩散距离，降低垂直高度。并基于可燃气云扩散规律，针对氢气传感器的局限性，提出利用温度传感器监测环境温度变化来预测氢气浓度的新方法。通过分析泄漏初期温度与氢气浓度间的数学关系，建立数学模型，验证模型在0.8 m高度平面上布置的温度传感器能够快速响应泄漏事件，从而提高加氢站的安全管理水平。

关键词: 氢, 数值模拟, 气液两相流, 可燃氢气云团扩散, 加氢站安全, 氢浓度预测