封闭材料对分岔管道中瓦斯爆炸特性的影响

Influence of sealing materials on gas explosion characteristics in bifurcated pipes

为探究管口封闭材料对分岔管道中爆炸压力和火焰速度的影响,在自主搭建的玻璃管道中进行瓦斯爆炸试验,分别在30、45、60和90°分岔管道管口采用聚氯乙烯(PVC)薄膜和亚克力板封口,通过数据采集系统收集瓦斯爆炸特性参数,分析压力和火焰的变化特性。结果表明:在双PVC薄膜管道中,爆炸压力逐渐降低,火焰速度先上升后下降,随后快速上升;随着分岔角度增大,管道中爆炸压力和火焰速度均增大;在直管和支管封闭管道中,PVC薄膜封闭端的爆炸压力减小,亚克力板封闭端的爆炸压力增大;而火焰速度在分岔角前先上升后下降,在分岔角后,PVC薄膜封闭端火焰速度剧增,亚克力板封闭端出现火焰振荡现象;随着分岔角度增大,直管封闭管道的爆炸压力和火焰速度均先减小后增大,而支管封闭管道中爆炸压力和火焰速度呈减小趋势。

In order to study influence of sealing material on explosion pressure and flame velocity in bifurcation pipes,gas explosion tests were carried out in a self-built glass pipe.Firstly,nostrils at 30,45,60 and 90°of bifurcation pipes were sealed with PVC film and acrylic plate.Then,parameters of gas explosion were collected by data acquisition system,and variation characteristics of pressure and flame were analyzed.The results show that the explosion pressure decreases gradually while flame velocity increases first and then decreases before it increases again rapidly in double PVC membrane pipe.And as bifurcation angle rises,both of the two factors show a trend of increase.In the straight and branch closed pipes,explosion pressure at the closed end of PVC film decreases while that at the closed end of acrylic plate increases.Flame velocity increases first and then decreases before the bifurcation angle,but it increases sharply after the angle at the closed end of PVC film,and flame oscillation at the closed end of acrylic plate appears.With the increase of the angle,explosion pressure and flame speed of straight closed pipes decrease first and then increase,while those of the branch closed pipe are decreasing.