煤与瓦斯突出冲击波穿越门墙孔洞能量耗散规律及安全尺寸

Energy dissipation laws and hole safety dimensions of coal and gas outburst shock wave passing through door wall

为揭示煤与瓦斯突出冲击波穿越防突风门孔洞时的能量耗散规律,以通车防突风门底坎为研究对象,基于不同突出压力、防突风门底坎尺寸条件下的煤与瓦斯突出物理试验和数值模拟结果,分析了突出冲击波在巷道中及穿越防突风门底坎时的传播规律,并根据突出冲击波超压与巷道通风阻力的关系,以及冲击波超压对人体的伤害准则,确定防突风门底坎安全尺寸。结果表明:(1)通过巷道交叉口的冲击波主要在直巷道中传播;冲击波传播速度、超压与突出压力成正相关关系。(2)导致距防突风门前较近位置处冲击波超压增大的主要原因是入射冲击波与撞击防突风门后的反射冲击波叠加作用;叠加后的冲击波超压、反射冲击波超压随防突风门底坎尺寸减小而增大。(3)防突风门底坎尺寸越小,冲击波受防突风门底坎阻滞作用越强,入射冲击波越难以绕过防突风门底坎继续向前传播。(4)分支巷道与防突风门较近时,应在分支巷道安装相应的防逆流装置。(5)防突风门底坎尺寸为15 mm以下时,穿越2道防突风门底坎后的冲击波不会造成瓦斯逆流,且穿越2道风门底坎后的冲击波超压不会对人体产生伤害,因此,矿井防突风门底坎的安全尺寸设定为15 mm以下较为合理。(6)理论分析、物理试验和数值模拟所得结果基本一致,说明分析结果是可靠的。

In order to reveal the law of energy dissipation when the outburst shock wave passes through the hole in the anti-surge door, the sill of the anti-surge door was taken as the research object. The propagation law of the outburst shock wave in the roadway and when it crosses the bottom sill of the outburst prevention door was analyzed based on the physical test and numerical simulation of coal and gas outburst under the conditions of different outburst pressures and bottom sill sizes of the outburst prevention door. According to the relationship between the overpressure of the outburst shock wave and the ventilation resistance of the roadway, as well as the damage criterion of the overpressure of the outburst shock wave to the human body, the size of the bottom sill of the outburst prevention door was determined. The research results show that(1) the outburst shock wave passing through the intersection of the roadway mainly propagates in the straight roadway. The shock wave propagation velocity and overpressure are positively correlated with the outburst pressure.(2) The main reason for the increase in shock wave overpressure near the front of the outburst prevention door is the superposition of the incident shock wave and the reflected shock wave after hitting the outburst prevention door. The superimposed shock wave overpressure and reflected shock wave overpressure increase with the decrease of the bottom sill size of outburst prevention door.(3) The smaller the size of the bottom sill of the outburst prevention door is, the stronger the shock wave is blocked by the outburst prevention door’s bottom sill, and the more difficult it continues to propagate forward for the incident shock wave to bypass the bottom sill of outburst prevention door.(4) When the branch roadway is close to the outburst prevention door, the corresponding backflow prevention device should be installed in the branch roadway.(5) When the bottom sill size of the outburst prevention door is less than 15 mm, the shock wave after passing through the bottom sills of two wind door will not cause gas backflow, and the overpressure of the shock wave after passing through the bottom sill of two wind door will not cause harm to the human body. Therefore, it is reasonable to set the safety size of the bottom sill of mine outburst prevention door to 15 mm or less.(6) The results of theoretical analysis, physical test and numerical simulation are basically the same, indicating that the analysis results in this paper are reliable.