基于射流理论的瓦斯压力与突出参数关系研究

Research on the relationship between gas pressure and outburst parameters based on jet flow theory

随着深部开采,煤与瓦斯突出作为我国煤矿最严重的自然灾害,其发生频度和强度越来越大。瓦斯压力是煤与瓦斯突出的关键动力源之一,针对其作用机制还不太清楚的实际情况,基于现场观察到的突出射流特征,引入射流理论,建立了煤与瓦斯突出的射流力学模型,推导了瓦斯压力与突出速度和突出流量间的关系表达式,分析了煤体密度对突出的影响。利用自主研制的可实时改变轴压的围压和孔隙压的主动突出式煤与瓦斯突出模拟仪,试验模拟了不同煤层开采深度下,当轴压和围压一定时,随着瓦斯压力的增加,最终发生煤与瓦斯突出的过程,得到了瓦斯压力与煤层深度和突出强度间的关系。研究结果表明:瓦斯压力与含瓦斯煤体突出速度及流量间均呈幂指数增长规律,与煤层开采深度具有线性关系,与突出强度间具有幂指数关系。瓦斯压力随深度增大的幅度为0.01 MPa/m,与前人研究结果一致。所得结论可供对煤与瓦斯突出机理的认识预测和防治参考。

With deep mining,coal and gas outburst have become the most serious natural disaster of mines in China,and the occurrence frequency and intensity would become more and more serious,in which gas pressure is one of the key dynamic sources. Because the practical situation is that the mechanism and rule is still not clear and definite,this study established a mechanical model of jet flow according to the characteristics of jet flow observed on site,deduced the relationship expressions of gas pressure,outburst velocity and flow with the introduction of the jet flow theory,and analyzed the influence of coal density on gas outburst. Then,using autonomously developed active simulator of coal and gas outburst which can change axial pressure,confining pressure and pore pressure in real-time,experiments of outburst process were conducted to simulate the condition of gradually increasing gas pressure with given axial pressure and confining pressure. Then,the relationship among gas pressure,coal depth and outburst intensity were presented. Results show that,gas pressure is in power exponent increasing relationship with both outburst velocity and flow,and in linear relationship with coal depth. The gas pressure and outburst intensity are also in power exponential relationship. The increment of gas pressure is 0. 01 MPa / m with coal depth,which is consistent with predecessor's research results. The results could give a reference to understanding,forecast and prevention of gas ourburst.