受限空间瓦斯爆炸与氢气促进机理研究

为探索受限空间中瓦斯爆炸及氢气对爆炸过程的影响,采用GRI-Mech 3.0甲烷燃烧机理,建立受限空间中瓦斯爆炸的数学模型,应用CHEMKIN软件,对受限空间内瓦斯爆炸过程及氢气对反应物浓度、活化中心浓度、主要致灾性气体浓度的影响进行模拟分析。通过对反应机理的敏感性分析,找出影响瓦斯爆炸及爆炸后主要致灾性气体生成的关键反应步。结果表明:混合气中分别充入0.5%,2%,3.5%氢气时,爆炸时间分别提前0.005 7,0.010 5,0.011 1 s;爆炸后压力分别提高2.53,4.05,7.60 kPa;爆炸后温度分别提高20,60,100 K。由此可见,随着混合气中氢气含量的增加,瓦斯引爆时间越来越短,其爆炸强度也随之增大,且氢气在一定程度上对有害气体CO,CO2,NO,NO2的生成有很大影响。

Study on the Methane Explosion in an Enclosed Space and Hydrogen Promoting Mechanism

In order to explore the methane explosion process and the effect of hydrogen on the process in an enclosed space,the reaction mechanism of GRI-Mech 3.0 was used in this paper.The mathematical model was established for methane explosion in enclosed space.The process of methane explosion and the effects of hydrogen on the concentration of reactants,active centers and main catastrophic gases were numerically analyzed by applying the software CHEMKIN.Furthermore,through the sensitivity analysis of the reaction mechanisms of methane explosion,the key reactions affecting the methane explosion and the formation of main catastrophic gases after explosion were found.The results show that the explosion time respectively advances 0.005 7 s、0.010 5 s、0.011 1 s.when the hydrogen of 0.5%,2% and 3.5% is filled into the mixture gas correspondingly.At the same time,the explosion pressure increases by 2.53×103 Pa,4.05×103 Pa,7.60×103 Pa and the explosion temperature rises by 20 K,60 K,100 K,respectively.Therefore,the detonation time of methane explosion becomes shorter and the intensity of methane explosion is higher and higher with increase in the hydrogen content.Furthermore,hydrogen will influence the formation of poisonous and harmful gas(such as CO,CO2,NO and NO2) to some extent.