综掘面粉尘运移规律模拟研究

发布时间：2018-09-18 10:24

【摘要】：综掘工作面粉尘的运移规律是事关综掘工作面粉尘防治原理与技术的关键科学问题。但在目前研究中,因粉尘运移规律及其变化过程复杂,致使粉尘运移、扩散及分布的变化规律及其相互关系等基本问题尚不清楚。本文在前期对气固两相流模拟研究的基础上,提出开展综掘工作面粉尘颗粒运移规律的系统研究:首先建立矩形巷道几何模型,采用了欧拉方法把颗粒相当拟流体来处理,研究了颗粒相在综掘巷道的运移分布特征,得到了送风速度、产尘量和通风方式对粉尘颗粒的分布的影响规律。同时获取了巷道内三维风场的详细信息。其次基于CFD-DEM模拟平台,对通过欧拉法获得风场进行离散化,采用离散单元法追踪网格内颗粒。对于颗粒间的碰撞问题,基于硬球模型通过DSMC和修正的南布方法来解决。研究不同粒径颗粒的分布规律,获得了送风速度、通风方式对粉尘颗粒的分布的影响规律,发现在一些工况下会出现颗粒漩涡。最后建立了拱形巷道模型,考虑了综掘机对通风的影响,基于Euler-Lagrange方法采用离散相模型,模拟了综掘面粉尘颗粒运移的全过程以及风幕对粉尘分布的影响,发现掘进机后方粉尘易发生沉降,浓度会升高。研究成果将有助于深刻认识综掘面粉尘颗粒的运移行为本质,可为综掘工作面粉尘防治原理与技术及制定有效的防尘、降尘措施提供更加科学合理的指导。
[Abstract]:The law of dust movement in fully mechanized working face is a key scientific problem related to the principle and technology of dust prevention and control in fully mechanized working face. However, in the present study, the basic problems of dust migration, diffusion and distribution and their relationship are still unclear due to the complexity of dust migration and its changing process. Based on the previous study of gas-solid two-phase flow simulation, this paper presents a systematic study on the law of dust particle migration in fully mechanized working face. Firstly, the geometric model of rectangular roadway is established, and Euler method is adopted to treat the particle equivalent to pseudo-fluid. The migration and distribution characteristics of particle phase in fully-mechanized roadway are studied, and the influence of air velocity, dust production amount and ventilation mode on the distribution of dust particles are obtained. At the same time, the detailed information of the three-dimensional wind field in the tunnel is obtained. Secondly, based on the CFD-DEM simulation platform, the wind field obtained by Euler method is discretized and the particles in the grid are tracked by the discrete element method. The collision problem between particles is solved by DSMC and modified Nambu method based on hard sphere model. The distribution law of different particle size is studied and the influence of air velocity and ventilation mode on the distribution of dust particles is obtained. It is found that particle swirls will appear under some working conditions. Finally, the arch roadway model is established, and the influence of fully mechanized excavator on ventilation is considered. Based on the discrete phase model based on Euler-Lagrange method, the whole process of dust particle movement and the influence of air curtain on dust distribution are simulated. It is found that the dust in the rear of the roadheader is prone to deposition and the concentration will increase. The research results will be helpful to deeply understand the nature of dust movement behavior in fully mechanized excavation face, and provide more scientific and reasonable guidance for dust prevention and control principle and technology of fully mechanized working face and the formulation of effective dust prevention and dedusting measures.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD714

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