综掘巷道径向涡旋运移对截割产尘污染的影响

Influence of radial vortex migration in fully-mechanized mining roadway on dust pollutioncaused by coal cutting

为了掌握综掘巷道风幕运移动态过程对截割产尘污染的影响规律,以进一步提高风幕阻尘效率。采用数值模拟与现场实测相结合,研究分析不同径向涡旋强度和运移距离条件下综掘巷道流场结构演变和粉尘污染。研究结果表明:径向涡旋以贴壁旋流形式运移,随径向涡旋强度和运移距离增大,运移过程中分别形成偏向压风侧和轴向的支流,随后径向涡旋转变为均匀轴向流场,粉尘污染随之分别呈不断减小和先增大后减小的规律。掘进司机处粉尘质量浓度与径向涡旋强度和运移距离间分别满足玻尔兹曼分布Boltzmann模型和对数正态分布LogNormal模型。当径向涡旋强度为0.9,运移距离为30 m时,能够实现高效控尘,现场实测结果显示,掘进司机处总尘和呼吸性粉尘降尘率分别达到82.7%和78.3%,能够有效改善人员作业环境。研究结果可为煤矿综掘巷道粉尘污染高效控制与治理提供参考。

In order to grasp the influence laws of the dynamic migration process of air curtain on the dust pollution caused by coal cutting in the fully-mechanized mining roadway,and further improve the dust blocking efficiency of air curtain,the flow field structure evolution and dust pollution of fully-mechanized mining roadway under different radial vortex intensities and migration distances were studied and analyzed by the combined methods of numerical simulation and on-site measurement.The results show that the radial vortices move in the form of wall-attached swirling flow.As the intensity and migration distance of radial vortex increase,the tributaries biased towards the pressure side and axial direction are formed respectively during the migration process.Subsequently,the radial vortices gradually transform into a uniform axial flow field,and the dust pollution present the law of continuous decrease,and the law of increase first and then decrease,respectively.The relationships between the dust concentration at the excavation driver’s location and the radial vortex intensity and migration distance satisfy the Boltzmann model and LogNormal model,respectively.When the radial vortex intensity is 0.9 and the migration distance is 30 m,the efficient dust control can be achieved.On-site measurement show that the total dust and respiratory dust reduction rates at the excavation driver’s location reach to 82.7%and 78.3%,respectively,effectively improving the working environment for personnel.The research results can provide reference for efficient control and treatment of dust pollution in the fully-mechanized mining roadway of coal mines.