摘要
伴随着掺氢天然气项目的落地使用,其安全性也备受关注。为预防掺氢天然气储运过程中的爆炸事故,通过气体爆炸极限测定装置和CHEMKIN软件,研究了掺氢甲烷混合气体的爆炸极限变化和化学动力学过程。通过分析不同掺氢比例下,掺氢甲烷混合气体的爆炸极限、绝热温度、压力和自由基的变化规律,明确氢气体积分数对混合气体爆燃特性的影响,并评估Le Chatelier定律在掺氢混合气爆炸极限估算方面的适用性。结果表明:爆炸极限范围会随掺氢比例的增大呈现指数上升的趋势,但掺氢比例20%以下气体的爆炸极限变化很小;Le Chatelier定律适用于估算低掺氢比例混合气体的爆炸极限;氢气的掺入会改变混合气的绝热温度和绝热压力,但影响很小;氢气通过提升自由基·H和·OH在反应中的体积分数促进掺氢甲烷混合气的爆炸。
This study employs an integrated experimental-computational approach to evaluate how hydrogen blending alters the explosion characteristics of methane-air mixtures.Experimentally,explosion-limit maps were established in a sealed vessel operated under carefully controlled initial temperature and pressure conditions.Homogeneous CH4 H2 air mixtures with various hydrogen volume fractions were prepared by partial-pressure filling followed by thorough mixing.For each composition,the lower and upper explosion limits were identified through synchronized observations of visible flame propagation and post-test pressure traces.Each test condition was repeated at least three times to ensure statistical reproducibility and consistent limit assignment.Computationally,detailedchemistry simulations within the CHEMKIN framework quantified the constant-volume adiabatic flame temperature,adiabatic pressure rise,and the time-resolved evolution of the radical pool(·H,·OH,·O).Complementary reaction-path and local sensitivity analyses were conducted to isolate rate-controlling steps near the flammability boundaries,thereby linking observed macroscopic limit shifts to the underlying chain-branching kinetics.To benchmark common engineering practice,predictions from Le Chatelier's mixing rule were compared with both experimental measurements and kinetics-based simulations,with special attention paid to the low-hydrogen regime of practical interest.Results show that the explosion-limit interval broadens systematically with increasing hydrogen fraction.The expansion is modest below approximately 20%H2,where Le Chatelier's rule remains in close agreement with experiments.However,at higher hydrogen contents,the broadening accelerates in an exponential-like fashion,and the empirical rule increasingly underestimates the expanded limits,underscoring the dominant role of kinetics beyond simple mixture averaging.Notably,simulations indicate only minor changes in adiabatic temperature and adiabatic pressure rise relative to methane-air baselines,yet they reveal substantially elevated concentrations of·H and·OH.These increases shorten induction times,intensify chain branching,and help sustain flame propagation—providing a mechanistic foundation for the observed broadening of explosion limits.Overall,the combined dataset delineates the applicability domain of Le Chatelier's rule and supports kinetics-informed assessments at higher hydrogen fractions,thereby defining safer operating guidelines for hydrogen-enriched natural gas systems.
作者
彭世垚
刘罗茜
刘振翼
张瀚文
柴冲
崔绍华
田灿
徐栋
PENG Shiyao;LIU Luoqian;LIU Zhenyi;ZHANG Hanwen;CHAI Chong;CUI Shaohua;TIAN Can;XU Dong(PipeChina Institute of Science and Technology,Tianjin 300450,China;State Key Laboratory of Explosion Science and Safety Protection,Beijing Institute of Technology,Beijing 100081,China;PipeChina,Beijing 100013,China)
出处
《安全与环境学报》
北大核心
2026年第2期595-602,共8页
Journal of Safety and Environment
基金
国家石油天然气管网集团有限公司定向课题(DTXNY202203)。
关键词
安全工程
爆炸极限
甲烷
氢气
动力学分析
safety engineering
explosion limits
CH4
H2
dynamic analysis
