不同泄放条件下高压氢气泄漏激波传播行为及诱导自燃特性

中国石油大学(华东)储运与建筑工程学院

高压氢气;泄漏;自燃;管道结构;激波;数值模拟

Study on shock wave propagation behavior and induced spontaneous combustion characteristics in high-pressure hydrogen leakage under varying discharge conditions
WU Di,LI Yixuan,CUI Gan

College of Pipeline and Civil Engineering, China University of Petroleum (East China)

high-pressure hydrogen, leakage, spontaneous combustion, tube structure, shock wave, numerical simulation

DOI: 10.6047/j.issn.1000-8241.2024.03.006

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【目的】氢气作为一种清洁高效的能源,有望缓解能源紧缺问题,然而其较高的火灾危险性是氢能应用的重要瓶颈之一。【方法】采用大涡模拟模型、涡耗散概念模型、瞬间破裂模式及21步氢-空气详细化学反应机理,建立激波管高压氢气泄漏模型。改变高压氢气泄放条件(泄放压力、管径、管道几何形状),探究激波在管道内的传播特性;提出前导激波平均强度概念,探究管内激波诱导自燃规律,分析前导激波强度对氢气、氧气混合程度的影响。【结果】管径越大,管道内激波强度越小,传播速度越慢;随着泄放压力增加,激波强度随之增加,激波传播速度增大,管道中网状激波结构更加清晰。下游管道几何形状对于激波的作用有显著影响,非锐角管道角度越大,第1次反射激波后压力越小。在未自燃工况下,氢气摩尔分数增加量、氧气摩尔分数减少量与激波强度呈正相关变化趋势;在自燃工况下,由于燃烧消耗作用与激波混合作用相互叠加,随着激波强度增加,氢气摩尔分数增加量降低,而氧气摩尔分数减少量升高。【结论】研究结果对于充分认识高压氢气泄漏自燃机理具有重要科学意义。建议开展耦合多特征参数的高压氢气泄漏自燃预测模型以及高压氢气泄漏自燃抑制技术研究工作,从而为氢气的安全储存及利用提供支撑。(图 16表1,参[42]
[Objective] Hydrogen, being a clean and efficient energy source, holds significant potential in addressing challenges like energy shortage. However, its inherent high risk of fire poses a major obstacle to its broader applications. [Methods] A high-pressure hydrogen leakage model based on shock tubes was developed for this study, by integrating a large eddy simulation model, eddy dissipation conceptual model, instantaneous rupture model, and a 21-step detailed hydrogen-air chemical reaction mechanism. With varying discharge conditions of high-pressure hydrogen, such as discharge pressure, tube diameter, and tube geometry, this study investigated the propagation characteristics of shock waves in shock tubes. It introduced the concept of the average intensity of leading shock waves and explored the law of spontaneous combustion induced by shock waves in shock tubes. Moreover, the influence of varying leading shock wave intensities on the extent of hydrogen and oxygen mixing was analyzed. [Results] This study revealed that a larger tube diameter resulted in a reduced intensity of shock waves and a slower propagation velocity inside the shock tubes. Furthermore, increasing the discharge pressure led to higher intensity and propagation velocity of shock waves, resulting in a more distinct reticulated structure of shock waves inside the tubes. The downstream tube geometry had a significant impact on the behavior of shock waves. Specifically, a larger non-acute tube angle caused a decrease in pressure following the first reflected shock wave. Moreover, under non-spontaneous combustion conditions, there was a positive correlation between shock wave intensity and the increase in hydrogen mole fraction, as well as the decrease in oxygen mole fraction. Under spontaneous combustion conditions, the increase in shock wave intensity corresponded to a narrower increase in hydrogen mole fraction and a more significant decrease in oxygen mole fraction, attributed to the combined effects of combustion consumption and shock wave mixing. [Conclusion] The findings of this study present significant scientific insights for a better understanding of the spontaneous combustion mechanism associated with high-pressure hydrogen leakage. Based on these results, further research is recommended to develop a prediction model for spontaneous combustion under high-pressure hydrogen leakage, considering multiple characteristic parameters. Additionally, it is advised to focus on the development of technologies aimed at suppressing spontaneous combustion. These research endeavors collectively aim to ensure the safe storage and application of hydrogen. (16 Figures, 1 Table, 42 References)
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