高压氢气射流事故后果演变机制研究

Accidental jets from high-pressure hydrogen are always critical concerns to the implementation of hydrogen as an energy carrier. However, prediction and prevention of the hydrogen jets and the subsequent consequences are still with great uncertainty due to the unclearness of the evolving mechanism of the process. This project will focus on the devleopment process of accidental jets from high-pressure hydrogen and the subsequent typical consequences including jet fires and flash fires. First of all, the developments of hydrogen jets and the subsequcent typical flammable events will be studied both experimentally and theoretically. The achivmeved data such as hydrogen concentrations and thermal radiation will be used to anaylze the evolving mechanism of the process including the evolving approaches, events sequences, transformation conditions and key impact factors. A series of numerical models with experimental validation will be developed to quantitatively describe the hydrogen jets and potential jet fires and flash fires. Secondly, the influences of both system factors and environment variables on the development of the jet fires and flash fires will be numerically investigated to quantitatively determine the variations of evolving process. Finally, the safety control approaches will be discussed and some new risk mitigation methods will be suggested based on the evolving mechanism of hydrogen jets. The outcomes of this project will be a clear description that reveals the evolving mechanism of the high pressure hydrogen jets, two numerical models that quantitatively predict the hydrogen jet fires and flash fires, and a group of safety control approaches that reduce the risks of hydrogen jets. These achievements is expected to deepen our understanding of the relationship of "Discharge-Dispersion-Combustion" for hydrogen jets, lay a foundation for the quantified risk analysis of high pressure hydrogen systems, and guide the improvement of safety control measures.

以高压氢气射流为研究对象，通过理论建模和实验测试定量分析射流事件发展演变过程，研究射流事故后果演变机制及其中的科学问题。重点研究闪火和射流火焰两种典型事故后果发展的演变路径、演变时序、演变条件和关键影响因素，为深入理解高压氢气行为、定量预测射流事故后果危害提供理论支持；考察系统因素和环境因素对射流事故后果演变进程的影响规律，分条件定量描述事故后果发展过程，为量化评价高压氢气射流事故后果危害提供分析方法。探讨干预射流事故后果演变进程、阻断事故后果发生条件的可能方式，提出若干高压氢气风险控制方法，为提高氢气安全水平提供理论指导。本研究不仅可揭示高压氢气射流事故后果演变机制，深化对高压氢气"释压-扩散-燃烧"事故链演变关系的认识，丰富现有氢安全理论体系，同时可初步建立射流事故后果预测模型，定量把握高压氢气射流行为和后果，为氢气量化风险评价体系的建立提供科学依据。

以氢燃料电池为代表的氢能应用近年来发展迅速，氢气泄漏安全问题日益成为各界关注的热点问题之一，开展氢气泄漏事故后果演变机制研究，对丰富现有氢安全理论、完善氢安全标准、提高氢气设备安全水平及推动氢能相关产业发展等方面均具有重要意义。. 项目以高压氢气射流为研究对象，通过建模和实验定量分析射流事故发生发展演变过程，为深入理解和把握高压氢气射流行为、定量预测射流事故后果危害提供科学依据。主要研究工作包括高压氢气射流理论分析、高压氢气射流泄漏数值建模、高压氢气泄漏实验验证三个部分。首先，开展了高压氢气释放泄漏理论分析工作，建立了有限容积下射流等效孔径流动状态模型，为后续高效求解非稳态射流近场流场状态变化奠定了基础。其次，在等效孔径流动状态模型的基础上，建立了高压氢气射流体积源模型，通过控制质量、动量和能量在体积源内的输入，间接反映等效孔径随时间变化而变化所带来的影响，从而解决了非稳态泄漏源的动态模拟计算问题。最后，在上述数值建模和计算研究的基础上，设计并开展了小型高压射流泄漏实验，将实验数据与模型计算结果对比，验证了模型的适用性。模型的计算结果与实验数据对比表明：等效孔径模型在氢气压降和泄漏时长的预测与实验值吻合良好，模型使用过程中可以用绝热假设获得压力衰减和泄漏时长的近似估计。体积源模型计算预测值与实验测试值吻合较好，计算值略高于实验值，适用于自由射流以及体积源尺寸远小于障碍物距离的高压氢气射流泄漏计算。. 项目提出的高压氢气射流模型和实验数据，揭示描述了氢气射流事故后果发展进程，为深入理解高压氢气泄漏行为和后果提供了科学依据，可深化对高压氢气泄漏事故链演变关系的认识。项目所建立的高压氢气射流事故模型，计算结果与实验值吻合较好，为定量把握高压氢气泄漏事故危害、预测高压氢气风险水平提供了方法工具。项目中的模型计算结果和相关实验数据也可为氢气相关安全标准和规范的制定及完善提供科学参照。