定容燃烧弹中瓦斯爆炸的反应动力学模拟

Kinetic Simulation of Gas Explosion in Constant Volume Bomb

通过修改化学动力学计算软件CHEMKIN.Ⅲ中的SENKIN程序包,采用详细化学反应机理建立定容燃烧弹中瓦斯爆炸的计算模型.利用此模型对瓦斯爆炸过程中反应物浓度、活化中心浓度和爆炸后部分致灾性气体浓度的变化趋势进行分析.同时,分析瓦斯中甲烷体积分数对瓦斯爆炸动力学特性的影响,通过对瓦斯爆炸详细反应机理的敏感性分析,找出影响瓦斯爆炸及爆炸后部分致灾性气体生成的关键反应.结果表明,当瓦斯中甲烷体积分数为7%时,瓦斯爆炸后温度、压力分别为2 700.K和0.22.MPa,同时随着瓦斯中甲烷体积分数增加,瓦斯爆炸后温度、压力及CO体积分数升高.通过分析,得到促进瓦斯爆炸的主要反应,促进CO、CO2和NO2生成的关键反应.

Through amending the SENKIN code of CHEMKIN 1I chemical kinetics package, the computational model of gas explosion in constant volume bomb was built, and the detailed reaction mechanisms were adopted. Variational cur- rents of volume fractions of reactants, active centers in the explosion process and volume fractions of catastrophic gases after explosion were analyzed by this model. At the same time, the effects of volume fraction of CH4 in the gas on kinetic characteristics of gas explosion were simulated. Furthermore, through sensitivity analysis of reaction mechanisms of gas explosion, the key reactions that affect gas explosion and formation of catastrophic gases were found out. The results show that temperature and pressure are 2 700 K and 0.22 MPa respectively after gas explosion when the volume fraction of CH4 in the gas is 7%. At the same time, with the increase of volume fraction of CH4 in the gas, temperature, pressure and volume fraction of CO increase too. The key reactions that activate gas explosion formation of CO, CO2 and NO2 are found.