大采高综采技术在榆神矿区迅速普及，但是由于地质条件、通风方式等多种因素综合作用导致许多采煤工作面出现低氧现象，工作面大型采煤设备改变了巷道空间形状，使风流分布发生了改变，从而影响到工作面低氧分布及人员安全。

本文主要采用现场实测、理论数据分析及数值模拟等手段相结合，研究工作面呼吸带、液压支架人行道处及回风隅角附近的低氧气体分布规律及变化趋势，据此确定低氧防治重点区域及优化措施，为防治低氧危害提供理论基础。主要成果如下：

首先，通过对东胜某矿综采面现场布点观测，确定了空间各位置低氧气体成分及浓度，表明低氧气体主要来源于采空区，煤样微观结构分析和程序升温氧化实验表明，采空区遗煤氧化及煤层释放出的氮气是造成工作面低氧的主要原因；影响低氧气体分布的主要因素有地质条件、通风方式、地表裂隙、超大面积采空区及气压变化等。据此确定了低氧气体在综采工作面空间扩散分布规律，确定回风隅角、人行道及机尾三个低氧重点防治区域。

其次，以气相流动理论现场实测数据为基础，使用CFD软件建模，分析井下工作面低氧气体基本性质及其随风运移数学模型，提出了欧拉模型为适宜的数值求解方法；合理设置边界条件及连续相参数，对该综采面空间低氧运移规律开展数值模拟，研究了其在风速为0.95 m/s、漏风程度为0.1 m/s情况下空间各位置的风流分布及低氧运移扩散规律以及两者之间的联系，即低氧分布受湍流和风流的变化影响明显。

再次，调整参数，分别模拟5个不同风速、3个不同漏风程度对呼吸带、人行道及回风隅角处低氧分布的影响。确定了预防低氧气体扩散双因素及重点防治实验区域。通过优化双因素确定综合防治方案的具体参数即工作面最佳综合低氧防治方案为入口风速为1.5 m/s和漏风程度为0.01 m/s。

最后，依据模拟参数确定煤矿综合防治措施方案的提出及实施。并提出综采工作面低氧综合防治措施方案。小范围增大风速能加速低氧气体排泄有利于回升重点区域的氧浓度。针对重点防治区域以预防检测为主，设立地面大气压监测和工作面气体监测形成预警监测系统，并采取工作面和采空区分开防治。工作面通过局部增大风流和局部堵漏去防治综采面的低氧气体涌现；采空区通过地表填埋堵漏和阀门排泄气压去防治采空区气体涌出。当采空区和工作面压差过大，使用均压通风可以有效解决低氧问题。各措施之间相辅相成互相作用形成一套可行有效的综合低氧防治方案，经现场实践，低氧问题治理效果显著。

The large mining height fully mechanized mining technology is rapidly popularized in the Yushen mining area. However, due to the combined effects of geological conditions, ventilation methods and other factors, many coal face The airflow distribution has changed, which affects the low-oxygen distribution on the working face and the safety of personnel.

This paper mainly uses the combination of on-site measurement, theoretical data analysis and numerical simulation to study the distribution and change trend of hypoxic gas at the breathing belt of the working face, the sidewalk of the hydraulic support and the corner of the return air, and determine the key points of hypoxia prevention and treatment based on this. Regional and optimized measures provide a theoretical basis for the prevention and control of hypoxia hazards. The main results are as follows:

First of all, through field observation of a fully mechanized mining face of a mine in Dongsheng, the composition and concentration of low-oxygen gas at various locations in the space have been determined, indicating that low-oxygen gas mainly comes from the goaf. The microstructure analysis of coal samples and the temperature-programmed oxidation experiment show that, The oxidation of leftover coal in the goaf and the nitrogen released from the coal seam are the main causes of low oxygen in the working face; the main factors affecting the distribution of low oxygen gas include geological conditions, ventilation methods, surface fissures, large-scale goafs, and pressure changes. Based on this, the spatial diffusion and distribution law of low-oxygen gas in fully mechanized mining face was determined, and three key hypoxic prevention and control areas, namely, the return air corner, the sidewalk and the tail of the machine were determined.

Secondly, based on the field measured data of the gas phase flow theory, using CFD software to model, analyze the basic properties of low-oxygen gas in the downhole working face and the mathematical model of its movement with the wind, and propose the Euler model as a suitable numerical solution method; reasonable settings With boundary conditions and continuous phase parameters, numerical simulations were carried out on the spatial low-oxygen migration law of the fully mechanized coal mining face, and the airflow distribution and low-level airflow at various locations in the space were studied when the wind speed was 0.95 m/s and the air leakage degree was 0.1 m/s. The law of oxygen transport and diffusion and the relationship between the two, that is, the distribution of low oxygen is obviously affected by the changes of turbulence and wind current.

Again, adjust the parameters to simulate the effects of 5 different wind speeds and 3 different air leakage degrees on the hypoxic distribution of the breathing zone, sidewalk and return air corner. The dual factors of preventing the diffusion of low-oxygen gas and the key experimental areas for prevention and control have been determined. The specific parameters of the comprehensive prevention and control plan are determined by optimizing the two factors, that is, the best comprehensive hypoxia prevention and control plan for the working face is that the inlet wind speed is 1.5 m/s and the air leakage degree is 0.01 m/s.

Finally, according to the simulation parameters, the proposal and implementation of comprehensive prevention measures for coal mines are determined. And put forward the comprehensive prevention and control measures of hypoxia in fully mechanized mining face. Increasing the wind speed in a small range can accelerate the excretion of low-oxygen gas and is beneficial to recover the oxygen concentration in key areas. Focus on prevention and detection in key prevention and control areas, establish ground atmospheric pressure monitoring and working face gas monitoring to form an early warning monitoring system, and adopt separate prevention and control of working face and goaf area. The working face can prevent and control the emergence of low-oxygen gas in the fully mechanized mining face by locally increasing the air flow and partial leaking; the goaf is prevented and prevented from the gas gushing in the goaf through the surface landfilling and leakage plugging and the valve discharge air pressure. When the pressure difference between the goaf and the working face is too large, the use of equalized pressure ventilation can effectively solve the problem of hypoxia. The various measures complement each other to form a set of feasible and effective comprehensive hypoxic prevention and control programs. After field practice, the effect of hypoxic problem treatment is remarkable.

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