突出冲击动力诱致防突设施破坏机制及瓦斯逆流规律研究

The failure of ventilation system caused by coal and gas outburst is an important cause of heavy casualties in coal mine. In view of the failure of coal and gas outburst on ventilation system, the damage mechanism of anti-outburst facilities and the law of gas backward flow caused by coal and gas outburst impact energy will be studied in this project, in order to reveal the mechanism and regularity of failure to ventilation facilities and airflow stability. By using the methods of theoretical analysis, numerical simulation and physical experiment, the time-space dynamic change characteristics and laws of outburst energy parameters such as shock wave and gas are analyzed during outburst period, and the failure modes and conditions of failure to ventilation system caused by coal and gas outburst. The failure mechanism of outburst impact energy on the outburst prevention ventilation door and device is revealed, and the dissipation loss rule of outburst gas-pulverized coal flow through the hole of door wall is revealed, and the criterion of gas backward flow in new air roadway after outburst occurs is constructed. The gas-coal flow through the hole in the ventilation facility will lead to the gas backward flow and the disaster will be enlarged. The anti-outburst door and the anti- backward-flow device are the key ventilation and safety facilities to prevent the expansion of the coal and gas outburst disaster accident. Therefore, it is very important to study the damage mechanism and gas backward flow law of outburst prevention facilities. The results of the project will provide theoretical support of the scientific formulation for the technical standards of ventilation facilities, independent ventilation technical requirements and emergency rescue plans.

煤与瓦斯突出对通风系统破坏失效是突出灾害事故造成煤矿重大人员伤亡的重要原因。针对煤与瓦斯突出对通风系统破坏失效问题，本项目拟开展突出冲击动力诱致防突设施破坏机制及瓦斯逆流规律研究，以揭示突出能量对通风设施、风流稳定破坏失效的机制与规律。采用理论分析、数值模拟和物理实验的方法，分析突出时期冲击波、瓦斯等突出能量多参数的时空动态变化特征规律，分析突出对通风系统破坏失效模式与条件，揭示突出冲击动力对防突风门和防逆流装置破坏失效机制、突出瓦斯-煤粉流穿越门墙孔洞时的耗散损失规律，构建突出发生后新风巷道内瓦斯逆流判据。瓦斯-煤粉流穿越通风设施孔洞将导致瓦斯逆流、灾害扩大，防突风门和防逆流装置是防止煤与瓦斯突出灾害事故扩大的关键通风安全设施，因此研究防突设施的破坏机制和瓦斯逆流规律至关重要。项目成果将为防突风门与防逆流装置等通风设施技术标准、独立通风技术要求及应急救援预案的科学制定提供理论支撑。

煤与瓦斯突出对通风系统破坏失效是突出灾害事故造成煤矿重大人员伤亡的重要原因。针对煤与瓦斯突出对通风系统破坏失效问题，采用理论分析、数值模拟和物理实验的方法，分析突出时期冲击波、瓦斯等突出能量多参数的时空动态变化特征规律，分析突出对通风系统破坏失效模式与条件，揭示突出冲击动力对防突风门和防逆流装置破坏失效机制、突出瓦斯-煤粉流穿越门墙孔洞时的耗散损失规律，构建突出发生后新风巷道内瓦斯逆流判据。研究结果表明，木质风门和风筒防逆流装置难以在0.74MPa突出压力的突出冲击波下保持结构完好；2MPa突出压力下，25mm厚度的Q460钢制防逆流风门和25mm厚度的结构加强风筒防逆流装置可以满足安全需求；突出瓦斯压力相同时，风门底部和中心区域更易遭到损伤破坏；同一工况条件下，风门的位移量等梯度从中央向四周逐渐递减；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、不会对人体造成伤害，防突风门底坎的安全尺寸设定为15 mm以下较为合理；撞击风门产生的反射冲击波与入射冲击波叠加后使得距防突风门较近位置处的冲击波峰值抬升；大量煤粉及冲击波被阻挡在风门外，煤粉穿越第一道风门的损失率大于70%，穿越两道风门的煤粉仅为总突出煤量的7%。突出冲击波穿越第一道反向风门后超压衰减70%以上，穿越第二道风门超压峰值小于1.5kPa，说明两道反向风门阻挡效果显著。0.5 MPa、0.74 MPa、1 MPa下煤体运移至两道风门间的移动功占试验煤体总移动功的7.1%、9.0%及9.6%；突出射流经过T型巷道分流，部分气流流向出风口，与正常通风新风运移方向相同，属于顺流段，突出超压在通风机的机械风压作用下平均衰减率为0.528；另一部分气流向进风口逆流运移，并于因惯性运移的新风产生冲击产生局部超压，突出超压平均衰减率为0.347。研究结果对制定防突设施技术标准提供理论支撑。