煤矿钻孔粉尘产运规律的现场实测及数值模拟

    Field measurement and numerical simulation of dust generation and movement regularities in coal mine drilling holes

    • 摘要: 为有效提升煤矿干式钻孔粉尘控制效果,进一步改善煤矿钻孔现场作业环境,采用现场实测与数值模拟相结合的研究手段,以钻孔尘源实测产尘强度、粒径分布为输入参数,对煤层干式钻孔粉尘产生、运动和沉降规律进行数值模拟和深入洞察分析,并探明钻场粉尘浓度空间分布特征,为煤层钻孔粉尘控制装置研发提供科学依据和技术指导。通过研究发现,粉尘颗粒自孔底产生后,在压风裹挟作用下自孔口螺旋式高速喷出,并在巷道壁面阻碍及巷道风流携带双重作用下随风流扩散,横向随机脉动;粉尘沉降过程中,粉尘颗粒越大,沉降至地面所需时间越短,随风流扩散距离越近;钻孔锥形分布区域内,粉尘浓度沿钻孔轴线方向逐步降低,覆盖范围逐渐增大;巷道沿程分布区域内,x轴方向粉尘浓度先急速增大、后逐步缓慢降低,y轴方向粉尘浓度机道整体大于人行道,z轴方向粉尘浓度由钻孔高度向上下两侧逐步降低。

       

      Abstract: In order to effectively improve the dust control effect of dry drilling hole in coal mines and further improve the working environment at the coal mine drilling site, a research method combining on-site measurement and numerical simulation is adopted. Taking the measured dust generation intensity and particle size distribution of the drilling hole dust source as input parameters, numerical simulation and in-depth insight analysis are carried out on the generation, movement and settlement regularities of the dust in dry drilling hole of coal seams. Moreover, the spatial distribution characteristics of the dust concentration in the drilling field are explored to provide a scientific basis and technical guidance for the research and development of the dust control device for coal seam drilling holes. Through the research, it is found that: after the dust particles are generated at the bottom of the hole, they are spirally and rapidly ejected from the hole mouth under the entrainment of the compressed air. Under the dual effects of the obstruction of the roadway wall surface and the carrying of the roadway air flow, the dust particles diffuse with the air flow and randomly pulsate transversely. During the dust settlement process, the larger the dust particles are, the shorter the time required for them to settle to the ground is, and the closer the diffusion distance with the air flow is. Within the conical distribution area of the drilling hole, the dust concentration gradually decreases along the direction of the drilling axis, and the coverage range gradually increases. Within the distribution area along the roadway, the dust concentration in the x-axis direction first increases rapidly and then gradually decreases slowly. The dust concentration in the machine lane in the y-axis direction is generally higher than that in the sidewalk. In the z-axis direction, the dust concentration gradually decreases from the height of the drilling hole to both the upper and lower sides.

       

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