分岔管道阻塞条件下对瓦斯爆炸压力影响的试验研究

Experimental study on the impact of the gas explosion pressure under the blocked bifurcated piping condition

为了进一步探究瓦斯爆炸压力的传播特性,搭建拱形60°单分岔管道瓦斯爆炸试验平台。在支管道内分别增加阻塞率为20%、40%、60%的拱形环状阻塞板,阻塞率为40%的矩形和圆形通道阻塞板。监测不同位置处测点的压力变化,研究瓦斯爆炸时拱形单分叉管道内测点的压力峰值变化特性,定性分析阻塞板对分叉前管道内不同测点最大压力的影响。结果表明:随距离增加,管道内的测点最大压力呈先增大后减小的变化趋势;在没有阻塞板的条件下,传播管道内瓦斯爆炸的最大压力出现在8250 mm处,且大于增加拱形环状阻塞板条件下8250 mm处的压力峰值;随拱形环状阻塞板阻塞率增加,8250 mm处的最大压力呈现先增加后减小的变化趋势,阻塞率为20%~40%时,8250 mm处测得的压力峰值变化较小;对比阻塞率60%时与没有阻塞板条件下最大压力,4号测点压力减小40%以上;在支管增加阻塞板,阻碍了管道泄压,在管道11250 mm、12200 mm处的压力峰值均大于没有阻塞板条件下压力峰值;圆形通道阻塞板和矩形阻塞板条件下管道内最大压力出现在6750 mm处;阻塞率为40%时,矩形阻塞板对瓦斯爆炸管道内最大压力的减小最明显。

The present paper intends to explore the propagation feature of the gas explosion pressure further by building an experimental platform of the gas explosion in 60° arched single bifurcation pipeline.To reach the said research purpose,it is necessary for the branch pipe to add arch ring-shaped clogged plates with the clogged rates of 20%,40% and 60%,whereas the rectangular clogged plate and the circular channel clogged plate should be added with a clogged rate of 40%.And,then,the pressure changes should be made under the monitoring and control at the different measuring points,though it is also necessary to study and test the peak pressure variation features of the gas explosion in the arch single bifurcation pipeline through the qualitative analysis of the influence of the blocking plate on the maximum pressure of different measuring points in the pipeline.The results of our explosion and the qualitative analysis show that the maximum pressure tends to increase first and then decrease with the increase of the distance.And,then,the maximum pressure of the gas explosion in the propagation pipeline may turn to appear at 8.25 m without the clogged plate,for it should be greater than that at 8.25 m under the condition of adding the arch annular clogged plate.And,then,with the increase of the clogged rate of the arch ring-shaped clogged plate,it would be necessary to increase first and then decrease the maximum pressure of the measuring point of No.4.And,then,the blockage ratio may change from 20% to 40%,though the pressure change at No.4 measuring point may remain little.And,then,under the condition of 0.6 blockage ratio,the pressure of No.4 measuring point can be reduced by over 40% as compared with that without the clogged plate.And,consequently,another clogged plate can be added to the branch pipe so as to hinder the pressure relief of the pipeline.And,so,the value of the pressure peaks at 11.25 m and 12.2 m of the pipeline may turn to be greater than that without the clogged plate.Thus,the maximum pressure of gas explosion in the pipeline appears at No.3 measuring point under the conditions of circular channel blocking plate and rectangular blocking plate.Hence,when the clogged rate reaches 40%,it would be possible for the maximum pressure in the gas explosion pipeline to fall most obviously by the rectangular clogged plate.