惰性气体抑制瓦斯爆燃火焰传播特性实验研究*

为研究惰性气体抑制瓦斯爆燃火焰传播特性，在自行搭建的中尺度爆炸激波管道上，采用数据采集系统、压电式传感器、火焰传感器、同步控制系统和激光纹影测试系统，通过对比4种不同喷射压力（0.5,1.5,2.5,3.5 MPa）的实验工况，选用N2做为惰性介质时抑制火焰的传播特性与喷射压力密切相关，火焰传播速度随着喷射压力增加呈现先增加后减弱的趋势。研究结果表明:少量N2在管道中扩散，加剧了未反应预混气体的扰动状态，造成火焰阵面褶皱的卷吸能力增强，进而加速化学反应进程，促进预混气体燃烧；喷射压力为1.5 MPa时，火焰阵面拉升、变形最强，火焰传播速度提高，最高可达到250 m/s；喷射压力为3.5 MPa时，火焰阵面出现明显三维凹陷结构，运动发生明显滞后现象，火焰传播速度大幅度降低至5.4 m/s，惰性气体抑制火焰传播效果明显。

Experimental study on flame propagation characteristics of gas explosion suppression by inert gas

On the self-built meso-scale explosion shock wave pipeline,the data acquisition system,piezoelectric sensor,flame sensor,synchronous control system and laser schlieren test system were used,and through comparing four experimental conditions of different injection pressures (0.5,1.5,2.5 and 3.5 MPa),the flame suppression was closely related to the injection pressure when nitrogen was used as inert medium,and the flame propagation velocity increased first and then decreased with the increase of injection pressure.The results showed that the diffusion of a small amount of nitrogen in the pipeline aggravated the disturbance of the unreacted premixed gas,and increased the entrainment capacity of the fold on the flame front,thus accelerating the chemical reaction process and promoting the combustion of premixed gas.When the injection pressure was 1.5 MPa,the flame front was the most stretched and deformed,and the flame propagation velocity increased,which could reach the highest value of 250 m/s.When the injection pressure was 3.5 MPa,there was obvious three-dimensional concave structure on the flame front,and the movement lagged behind obviously.The flame propagation velocity reduced to 5.4 m/s greatly,and the suppression effect of inert gas on flame propagation was obvious.