突出灾变后瓦斯风压诱致风流振荡机理研究

Study on the mechanism of gas wind pressure induced wind flow oscillation after outburst disaster

  • 摘要: 风流振荡效应是灾变后矿井通风网络的重要特征,但目前对风流振荡现象研究较少,且缺乏对风流振荡特征的深入探讨。针对上述问题,以并联下行通风网络为研究对象,对灾变风流和瓦斯气团呈现的振荡效应进行了研究。基于阻尼振动理论构建了开环气流振荡模型,在Matlab软件中采用龙格-库塔法进行数值求解,分析得出瓦斯气团在并联巷道中的振荡特征:随着初始风速增大,瓦斯气团的振幅增大,瓦斯在并联管路中的影响范围将扩大。建立实际巷道的相似模型,模拟并联巷道内风速随时间变化的情况,实验结果表明:由于瓦斯风压和通风机风压的作用,并联巷道中出现了风速反复增大、减小现象,即风流振荡现象;初始风速由0.35 m/s增大至0.62 m/s时,风流振荡时间由50 s缩短至35 s,并且最大反向风速由-0.4 m/s左右变为-0.12 m/s左右,说明增大初始风速有利于瓦斯气团扩散和排出。提出了并联倾斜瓦斯积聚井巷风流振荡的预防与控制措施:对空气支路施加挡风措施;对瓦斯支路加强局部通风,增大风速。

     

    Abstract: The wind flow oscillation effect is an important characteristic of the post-disaster mine ventilation network, but there are few studies on the wind flow oscillation phenomenon and there is a lack of in-depth discussion on the wind flow oscillation characteristics. In order to solve the above problems, taking the parallel downward ventilation network as the research object, the oscillation effects of disaster wind flow and gas mass are studied.Based on the damped vibration theory, an open-loop airflow oscillation model is constructed and the Runge-Kuttamethod is used to solve the numerical problem in Matlab software so as to analyze the oscillation characteristics of the gas mass in the parallel roadway. As the initial wind speed increases, the amplitude of the gas mass increases and the impact range of gas in the parallel pipeline is expanded.A similar model of the actual roadway is established to simulate the change of wind speed in parallel roadways with time. The experimental results show that due to the effect of gas wind pressure and ventilator wind pressure, the wind speed repeatedly increases and decreases in the parallel roadways, i.e. wind flow oscillation phenomenon. When the initial wind speed increases from 0.35 m/s to 0.62 m/s, the wind flow oscillation time is shortened from 50 s to 35 s, and the maximum reverse wind speed is changed from -0.4 m/s to -0.12 m/s. This shows that the increase of the initial wind speed is more conducive to the diffusion and discharge of gas mass.The prevention and control measures of wind flow oscillation in parallel inclined gas accumulation shaft are proposed, including imposing wind-blocking measures on the air branch; strengthening local ventilation and increasing wind speed on the gas branch.

     

/

返回文章
返回