矿井火区典型可燃气体对甲烷化学动力学的影响分析

Analysis of influence of typical combustible gas on methane chemical kinetics in mine fire area

为研究多元混合气体对CH_(4)爆炸过程的影响,选取矿井火区典型可燃气体CH_(4)、C_(2)H_(6)、C_(2)H_(4)、CO、H_(2),利用CHEMKIN软件模拟分析了不同组分C_(2)H_(6)/C_(2)H_(4)/CO/H_(2)瓦斯混合气体爆炸反应过程。研究结果表明:随着混合气体组分中各可燃气体体积分数的增大,CH_(4)的爆炸压力和温度不断增高,CH_(4)体积分数和O_(2)体积分数迅速下降,点火延迟时间明显缩短;在爆炸产生的有毒有害气体中,CO的体积分数最高;H*、OH*自由基的体积分数持续增大,O*自由基呈现先增大后减小的趋势。敏感性分析发现促进自由基生成的反应步主要是R38(H+O_(2)■O+OH)和R119(HO_(2)+CH_(3)■OH+CH_(3)O),抑制其生成的主要反应步为R98(OH+CH_(4)■CH_(3)+H_(2)O)和R53(H+CH_(4)■CH_(3)+H_(2))。

In order to study the influence of multi-component gas on methane explosion,the representative combustible gases CH_(4),C_(2)H_(6),C_(2)H_(4),CO and H_(2)were selected,and the CHEMKIN software was used to simulate and analyze the reaction process of C_(2)H_(6)/C_(2)H_(4)/CO/H_(2)gas explosion.The results show that:with the increase of the volume fraction of each combustible gas in the mixture,the explosion pressure and temperature of methane continue to increase,the volume fraction of methane and oxygen decrease rapidly,and the ignition extension time shortens obviously;among the toxic and harmful gases produced by explosion,the volume fraction of CO is the highest;the volume fraction of H*and OH*radicals continues to increase,while the volume fraction of O*radicals first increases and then decreases.Sensitivity analysis finds that the main reaction steps that promote free radical formation are R38:H+O_(2)■O+OH and R119:HO_(2)+CH_(3)■OH+CH_(3)O,while R98:OH+CH_(4)■CH_(3)+H_(2)O and R53:H+CH_(4)■CH_(3)+H_(2)are the main reaction steps that inhibit free radical formation.