煤层干式钻孔粉尘运动及粒径分布的数值模拟
Numerical simulation of the dust movement and particle size distribution during dry drilling in a coal seam

为有效地减轻煤层干式钻孔粉尘污染，改善现有粉尘防治效果，运用SolidWorks联合DesignModeler建模，采用Fluent对煤层干式钻孔粉尘运动进行数值模拟。研究发现：粉尘颗粒自孔底产生后，在环状狭缝射流及钻杆持续转动的双重作用下，向孔口方向高速喷出。随着粉尘颗粒在钻场内不断运动，粉尘扩散速度逐渐降低，粉尘质量流率不断减小，R-R分布指数缓慢增大，粉尘中位径及R-R特征粒径先增大后减小。粉尘质量浓度随时间推移先逐渐增大至最大值，而后围绕该最大值小幅波动；沿程先迅速上升至最大值，而后急剧降低至较小值，再逐步缓慢降低。该研究可为煤层干式钻孔粉尘控制装置结构参数的设定提供指导。
Abstract：This paper describes a numerical simulation of the dust movement during dry drilling in a coal seam to reduce dust pollution and improve dust control in a mine. SolidWorks and DesignModeler are used to build the models with Fluent then used to calculate the flow field. The results show that the jet flow from the cyclic slits and the continuous rotation of the drill pipe spew dust particles out from the bottom hole at high speed in the direction of the orifices. As the dust particles move away from the drill, the dust diffusion and mass flow rate gradually decrease. The R-R distribution index increases slowly with the median dust particle diameter and the R-R characteristic size first increasing and then decreasing. The dust concentration gradually increases to a maximum and then fluctuates a small amount around the maximum over time. The dust mass concentration along the seam quickly rose to a maximum, then dropped sharply and then more slowly. The results are then used to determine the structural parameters of dust control equipment during dry drilling in coal seams.