粉体云幕对瓦斯煤尘爆炸隔爆效果的试验研究

为了探索瓦斯煤尘爆炸的防治技术措施,在大尺度断面巷道开展粉体云幕的隔爆性能测试。运用直径2 m大尺度管道及其附属敞开空间,研究粉体云幕的形成过程及其动态分布特征;在此基础上,以爆炸压力、火焰速度为特征参数,在断面7. 2 m^2大型地下巷道内进行瓦斯煤尘爆炸及隔爆试验。研究结果表明:隔爆粉体在60 ms时可覆盖7. 4 m^2断面,在1 200 ms绝大部分粉体喷出,形成有效隔爆屏障;在试验条件下,粉体云幕面密度8. 1 kg/m^2时,爆炸火焰在13 m范围内被完全熄灭,最大爆炸压力由云幕前的0. 293 MPa降低至0. 126 MPa,下降了57. 0%,140 m位置的爆炸压力上升时间延迟了137 ms;随粉体云浓度的增加,隔爆效果增强,粉体云幕能在短距离范围内扑灭爆炸火焰,并大幅衰减爆炸冲击波压力。

Experimental study on suppression of gas and coal dust explosion by powder clouds

In order to explore prevention and control measures for gas and coal dust explosion,explosionproof performance of powder clouds is tested in roadways with large-scale sections. Firstly,an 2 m large pipe and its open space were used to study formation process and dynamic distribution characteristics of powder clouds. On this basis,with explosion pressure and flame velocity as characteristic parameters,gas and coal dust explosion and suppression experiments were conducted in a large roadway with a section of 7.2 m^2. The results show that the powder can cover 7. 4 m^2 section at 60 ms,and most of the powder is ejected at 1 200 ms,forming an effective explosion-proof barrier. When surface density of powder cloud reaches 8. 1 kg/m^2,flame can be completely extinguished within 13 m,and maximum explosion pressure is reduced by 57. 0% from 0. 293 to 0. 126 MPa while pressure rising time at 140 m is delayed by 137 ms.As power concentration increases,suppression effect of cloud curtain is enhanced,and it can extinguish flame in a short distance and greatly attenuate explosion pressure.