半封闭空间明火引燃油气特性实验

摘要

A semi-confined vessel was built to study the explosion of the gasoline/air mixture ignited by a pilot flame.The flame propagation at different gasoline/air volume fractions were characterized through the flame images from a high-speed camera.The pressures development at different gasoline/air volume fractions were characterized according to the pressure data acquired by a high-frequency pressure sensor.The results showed that the gasoline/air volume fraction had a significant influence on the flame's species,propagation velocity,pressure and pressure rise rate.The flame exhibited an obvious zoning phenomenon,was observed to divide into a flame kernel and a flame front.The speed of the vertical flame front was faster than that of the horizontal flame front.The pressure development process went through four stages,and produced a phenomenon of two pressure peaks.A strong coupling effect was formed between the flame and the pressure wave in the process of the gasoline/air explosion%为研究明火引燃油气着火爆炸特性,建立了半封闭着火爆炸实验平台.通过高速摄影仪拍摄的火焰图像,研究不同油气体积分数下的火焰传播特性.根据高频压力传感器采集的容器内压力变化情况,分析不同油气体积分数下的压力发展特性.结果表明,油气体积分数对火焰组分、火焰传播速度、压力和压力变化速率有显著影响;火焰具有明显的分区现象,可分为燃烧核和火焰阵面,并且纵向火焰阵面速度大于横向火焰阵面速度;容器内压力发展历程可分为4个阶段,而且会形成压力双峰现象;油气爆炸过程中,火焰结构与压力波形成了强烈的耦合作用.