惰性气体影响乙烯爆炸极限参数及动力学特性

为研究惰性气体对乙烯爆炸极限参数及动力学特性的影响，使用标准可燃气体爆炸极限装置和CHEMKIN软件，对比分析了N₂和CO₂对乙烯的爆炸极限、临界氧浓度和爆炸三角形的影响，通过模拟得到乙烯爆炸过程中温度、压力、·H、·O、·OH浓度变化，并进行了敏感性分析。结果表明，N₂和CO₂都使乙烯爆炸极限缩小，爆炸危险度减小，达到爆炸临界点时，N₂添加量为60.1%,CO₂添加量为43.3%，此时CO₂惰化的临界氧浓度为11.1%,N₂惰化的临界氧体积分数为7.7%。通过分析爆炸三角形，CO₂惰化下的乙烯爆炸区和窒息比相比N₂惰化下的明显减小。此外，N₂和CO₂均使乙烯的点火延迟时间增加，且爆炸后的温度和压力及自由基浓度均有所减小，通过对两种惰化条件下的乙烯爆炸过程中关键自由基变化的敏感性分析，发现R38、R46、R112、R119、R...

Effect of inert gas on ethylene explosion limit parameters and kinetic characteristics

To study the effect of inert gases on the explosion limits and chemical kinetics of ethylene, a standard test device was employed to analyze effects of N₂ and CO₂ on the explosion limit, critical oxygen concentration, and explosion triangle of ethylene. The sensitivity was analyzed after the simulation on the gas explosion include the temperature, pressure, concentration of ·H, ·O, ·OH by CHEMKIN software.The results showed that both N₂ and CO₂ narrowed the ethylene explosion limit and reduced the explosion hazard, reaching the explosion critical point with 60.1% N₂ addition and 43.3% CO₂ addition, when the critical oxygen concentration for CO₂ inerting was 11.1% and for N₂ inerting was 7.7%. By analyzing the explosion triangle, the explosion zone and asphyxiation ratio of ethylene under CO₂ inerting were significantly reduced compared with those under N₂ inerting. In addition, both N₂ and CO₂ increased the ignition delay time of ethylene and decreased the temperature and pressure and radical concentration after the explosion, the sensitivity analysis of key radical changes during ethylene explosion under two inert conditions revealed that R38, R46, R112, R119, R285, and R294 promoted the generation of ·H, ·O, ·OH, and R25 and R173 inhibited the generation of ·H, ·O, ·OH. In terms of sensitivity reduction coefficient, the inhibition effect of CO₂ was larger than that of N₂, which also indicated that the inerting effect of CO₂ was better than that of N₂ to a certain extent. This can provide some theoretical basis for the safe use of ethylene in petrochemical industry and the prevention and control of explosion accidents.