甲烷爆炸初期关键自由基化学发光与爆炸压力的耦合关系分析

Analysis of Coupling Relationship Between Critical Free Radical and Explosion Pressure in the Initial Stage of Methane Explosion

为建立甲烷爆炸初期微观化学反应机理与宏观爆炸压力之间的联系,利用20L标准球型爆炸测试装置和光栅光谱仪采集了甲烷爆炸初期爆炸压力数据,采用光谱分析和数据同步分析方法研究了CO2、C2、CHO·、OH·、C3等关键激发态自由基及分子的光谱强度和爆炸压力的耦合变化关系。研究表明,CO2在爆炸升压阶段大量生成;C2、CHO·在爆炸感应期内大量产生,在爆炸升压阶段大量消耗;OH·含量在整个甲烷爆炸的过程中处于较高水平。微观角度CO2大量生成在宏观上部分表现为爆炸压力的迅速上升,其含量变化趋势与升压过程呈正相关关系;C2、CHO·迅速消耗在宏观上部分表现为爆炸压力的迅速上升,其含量变化趋势与升压过程呈负相关关系。在爆炸感应期减少C2、CHO·的生成,降低其含量;在整个甲烷爆炸的过程中抑制OH·产生,降低其含量;减少或抑制CO2的生成,可以减缓或抑制爆炸进程,有效减小甲烷爆炸的压力。

To establish the relationship between the microscopic chemical reaction mechanism and the macroscopic explosion pressure in the initial stage of methane explosion,the coupling relationship between content changes of key free radicals or molecules(such as CO2,C2,CHO·,OH·,C3)and explosion pressure was investigated experimentally.The flame emission spectrum explosion pressure were obtained by a 20-Litre standard spherical explosion container and a grating spectrometer.Studies show that large amounts of CO2are produced during the pressure rising period,while the formation of C2 and CHO·are primarily in the explosion induction period and they are consumed rapidly when explosion pressure rises.The content of OH·is at a high level throughout the methane explosion.The rapid increase of CO2accompanies with pressure rising,which reveals a positive correlation.On the contrary,the consumption of C2 and CHO·accelerates when explosion pressure rises,revealing that they are correlated negatively.Formation reduction of C2 and CHO·and their corresponding contents during the explosion induction period,suppression on OH·production during the whole methane explosion and decrease or inhibition in CO2formation can slow down or inhibit the explosion process and effectively reduce the methane explosion pressure.The result shows that it is possible to inhibit explosion and reduce the pressure efficiently through the manipulation of decreasing the production of C2 and CHO·in the induction period,reducing the content of OH·throughout methane explosion and suppressing the formation of CO2.Key words:methane explosion;explosion pressure;free radicals;spectrum analysis.