为降低高海拔矿井开采过程中的粉尘污染，改善通风除尘效果，减少矿井粉尘对作业人员的危害，依据圆管湍流特征对井巷风流分布规律和粉尘受力情况进行分析，建立了最低排尘风速的理论模型;并根据海拔上升导致的环境参数改变，对排尘风速的变化进行定量分析。根据实测结果，以拉萨市甲玛矿4490分层6号探矿巷为研究背景，采用Soildworks和ANSYS建立掘进工作面通风除尘模型。在风流流场模拟的基础上，对不同海拔高度下各粒径的粉尘运动轨迹进行数值模拟研究。结果表明，粉尘在风流的携带作用下向前扩散，粒径越小，扩散距离越远;当海拔上升环境参数改变后，粉尘颗粒的受力情况发生变化，运动状态也随之改变。在相同风速条件下，当海拔升高后，颗粒沉降速度增大，扩散距离变短，风流中粉尘质量流率下降，特别是呼吸性粉尘;0.25 m/s的风速难以将呼尘全部携带排出工作面，存在二次飞扬的可能，所以高原环境下的排尘风速应随环境参数变化进行调整。因此，为了将作业过程中产生的呼尘排出工作面，对各个海拔高度不同风速下的工作面沿程呼尘质量浓度变化进行分析，得到了不同海拔高度的最低排尘风速。将模拟得到的风速值与理论模型进行比较分析，误差均在3%以下，所以该模型可用于确定不同海拔高度的最低排尘风速，以便于高原矿井需风量的准确计算。

In order to reduce the dust pollution during mining at high altitude mine,improve the effect of dust removal by ventilation and reduce the danger of mine dust to operators,a theoretical model of minimum dust exhausting wind speed has been established by the distribution law of wind flow in the roadway and the force applied on dust based on the turbulence characteristics of the circular tube.According to the change of environmental parameters caused by the altitude increase,the dust exhausting wind speed is quantitatively analyzed.According to the measured results,taking the No.6 exploration roadway of layer 4490 of Jiama Mine in Lasa as the research background,the ventilation and dust removal model for the heading face is established using Soildworks and ANSYS.On the basis of the simulation results of the wind flow,the dust trajectories of various particle sizes at different altitudes are simulated.The results show that the dust diffuses forward under the carrying effect of wind,and the smaller the particle size,the farther the diffusion distance.When the environmental parameters change after the altitude increases,the force applied to the dust particles changes and the movement state also changes.Under the same wind speed,especially for the respirable dust,when the altitude increases,the particle sedimentation rate increases,the diffusion distance becomes shorter,and the dust mass flow rate in the wind flow decreases.It is difficult for the wind speed of 0.25 m/s to carry all the dust out of the working face,resulting in the possibility of secondary dust contamination.Therefore,the dust exhausting wind speed in the plateau mine should be adjusted with the change of environmental parameters.Therefore,in order to exhaust dust from the heading face,the variation of the respirable dust concentration along the heading face under different wind speeds at various altitudes is analyzed,and the minimum dust exhausting wind speed at different altitudes are obtained.Comparing the simulation results with the theoretical model,the error is less than 3%,so the model can be used to determine the minimum dust exhausting wind speed at different altitudes,so as to calculate the wind demand of the plateau mine.

1 排尘风速理论模型

   1.1 粒子在紊流中的运动方程

   1.2 最低排尘风速的理论模型构建

2 几何模型的建立和求解

   2.1 几何模型和网格划分

   2.2 网格独立性验证

   2.3 计算模型的参数设定

3 数值模拟结果及分析

   3.1 风流流场分析

   3.2 不同粒径的粉尘运动情况分析

   3.3 不同海拔高度对粉尘扩散的影响

   3.4 不同风速呼尘扩散分析及模拟结果验证

   3.5 不同海拔最低排尘风速的确定

4 理论模型与模拟结果对比

5 结论