凉水井矿综采工作面粉尘运移规律数值仿真

Numerical simulation of dust movement rules at fully-mechanized mining faces in Liangshuijing coal mine

为研究凉水井矿42112综采工作面粉尘运移规律,基于Fluent数值仿真软件,选用标准k-epsilon湍流模型以及DPM计算模型建立了气-固两相流的粉尘运移数学和物理模型。用数值仿真及现场实测的方法研究了凉水井矿综采工作面风流运动情况,以及在移架和割煤时粉尘的运移规律和悬浮时间。研究表明:风流沿工作面在速度上表现出“小-大-小”的规律,速率和湍流强度在采煤机附近达到最大,在人行道空间有一定的低值区域。移架产生的粉尘一部分随风流运动,另一部分因粒径不同沉降到巷道底板不同位置。采煤机割煤产生的大粒径粉尘在重力作用下逐渐沉降,小粒径粉尘随气流继续运动,粉尘浓度最大处为前后滚筒附近及后滚筒下风向10 m左右靠近煤壁一侧区域,但扩散性不大,随着粉尘团向后移动,影响范围不断扩大,直至向整个工作面弥散。综采工作面粉尘在距底板1 m处粉尘浓度最高且分布范围最广,在巷道上部空间,直径大于100μm的粉尘粒子迅速沉降,而随着粒径减小,粉尘悬浮时间也逐渐延长。本研究可为综采工作面除尘、抑尘提供参考。

In order to explore the movement pattern of dust generated by support advancing and shearer cutting at 42112 fully-mechanized mining face in Liangshuijing Coal Mine,based on Fluent numerical simulation software,the standard k-epsilon turbulence model and DPM on model were used to establish the mathernatical and physical models of the gas-solid two-phase flow dust transportation.The numerical simulation and on-site measurement method were used to study the air movement of the working faces,the dust migration law in moving and cutting the coal,and the suspension time at different heights and with different particle sizes.The results reveal that the airflow velocity shows the“small-large-small”pattern when the airflow enters the mining face,and the flow rate and turbulence intensity reach the maximum in the vicinity of the shearer and a low value area in the sidewalk space.Part of the dust generated by the moving frame is moving with the wind flow,and the other part is sliding to different positions of the roadway bottom plate due to different particle sizes.Among the dust generated by the coal cutting machine,the large-size dust gradually settles under the action of gravity,and the small-sized continues to move with the airflow.The maximum concentration is near the front and the rear drums and the wind direction of the rear drum is about 10 m near the coal wall side,where the diffusivity is not large.As the dust group moves backwards,the scope of influence continues to expand until it spreads to the entire working surface.In the fully mechanized mining working face,the dust has the highest concentration and the widest distribution range at 1 m from the bottom plate.In the upper space of the roadway,the dust particles with a diameter larger than 100μm settle rapidly,and as the particle size decreases,the dust suspension time also gradually increases.The conclusion here is helpful for dust removal and suppression in the fully mechanized mining face.