综掘工作面粉尘运移规律与综合降尘技术研究

发布时间：2018-05-22 10:06

本文选题：综掘工作面 + 数值模拟　；参考：《安徽建筑大学》2017年硕士论文

【摘要】：随着掘进工艺技术的进步,综掘面粉尘产生量显著增大。部分煤矿在无防尘措施的情况下,综掘工作面的粉尘浓度达到500~1000 mg/m3,超过《煤矿安全规程》的最高允许浓度的几十倍。粉尘不仅破坏生产设备的工作环境、加速机械磨损、降低作业人员的视觉能见度、增加事故发生率外,而且对职工的身体健康构成很大威胁,特别是呼吸性粉尘浓度的大幅上升使得尘肺病发生的几率大增。所以,粉尘治理迫在眉睫。本文通过现场实测、理论分析以及数值模拟的方法研究综掘面粉尘的运移规律。首先,对兖矿东滩煤矿1307轨顺工作面粉尘浓度进行了现场实测,并实验室分析了该工作面粉尘的分散度等颗粒特性。再者,基于气固两相流理论,采用k-e模型对工作面粉尘运移规律进行了Fluent数值模拟,结合风流流场图及巷道内浓度分布图,对粉尘的运移规律进行了描述。最后,通过数值模拟技术得到该巷道模型在长压短抽除尘方式下的最优除尘工艺参数。本文设计的综合降尘系统由综掘机高压喷雾降尘系统与可控大风量长压短抽除尘系统组成:综掘机高压喷雾降尘系统采用G型喷嘴、喷雾压力采用12MPa,喷雾装置安装在掘进机头后方2.5m处;可控大风量长压短抽除尘系统工艺参数与数值模拟得出结果保持一致(Lc=4m,Ly=16m,抽压比=1.4)。并对该综合降尘系统进行了工程应用。本文研究得出的主要结论如下:(1)东滩煤矿1307轨顺工作面粉尘的粒径主要分布在0~50mm之间,其中小于50mm的粉尘达到总量的98.8%,表明工作面粉尘中小颗粒粉尘占到了大多数,人体吸入粉尘的可能性增加。(2)由粉尘运移规律的数值模拟可知:高浓度粉尘主要集中在距迎头10米的范围内,浓度最高可达到1500mg/m3以上,并随着距离的增加,粉尘浓度逐渐减低;距离巷道底板近的高浓度粉尘区域要比远处的要广,扩散的距离也越远;抽出风筒一侧的的粉尘浓度要高于压入风筒一侧的浓度,迎头处的粉尘浓度在X轴的反向较高;由底板处的粉尘浓度分布可以看出,压入风筒一侧的粉尘沉降距离比抽出风筒的沉降距离要长;粉尘浓度最高位置并不是在迎头部位,而是在距离迎头5m附近;从整个巷道内粉尘的分布情况看出,30m后的粉尘运移达到稳定,浓度保持在80mg/m3。(3)对该工作面的最适除尘工艺参数(抽、压风筒距离及抽压比)范围进行了数值模拟,模拟结果表明在压入风量为280m3/min时,压入风筒距离工作面16m、抽出风筒距离工作面4m、抽压比为1.4时,巷道内粉尘浓度处于一个很低的水平。(4)对该综合降尘系统进行工程应用后,生产时的总粉尘和呼吸性粉尘降尘效率均达96%以上,距迎头5m(司机位置)和距迎头15m处巷道内的总粉尘浓度分别为7.5 mg/m3和4.7 mg/m3,呼吸性粉尘浓度分别为2.2 mg/m3和2.0 mg/m3,掘进工作面的作业环境得到了极大的改善。
[Abstract]:With the progress of tunneling technology, the dust production of fully mechanized face increases significantly. In some coal mines without dustproof measures, the dust concentration of fully mechanized working face reaches 500mg / m3, which is more than tens of times of the maximum allowable concentration of coal mine safety regulations. Dust not only destroys the working environment of production equipment, accelerates the wear of machinery, reduces the visual visibility of workers and increases the incidence of accidents, but also poses a great threat to the health of workers. In particular, a large increase in respiratory dust concentration increases the probability of pneumoconiosis. Therefore, dust control is imminent. In this paper, the field measurement, theoretical analysis and numerical simulation are used to study the migration law of flour dust in fully-mechanized digging. Firstly, the dust concentration of the 1307 track working face in Dongtan Coal Mine of Yankuang Coal Mine was measured on the spot, and the particle characteristics such as the dispersion of the dust in the working face were analyzed in the laboratory. Furthermore, based on the gas-solid two-phase flow theory, the Fluent numerical simulation of dust migration law is carried out by using k-e model, and the dust migration law is described by combining the air-flow field diagram and the distribution chart of concentration in roadway. Finally, the optimal process parameters of the tunnel model under the condition of long pressure and short dust extraction are obtained by numerical simulation. The integrated dust control system designed in this paper consists of a high pressure spray dust control system of a fully mechanized excavator and a controlled large air volume long pressure and short extraction system. The high pressure spray dust control system of a fully mechanized excavator adopts a G type nozzle. The spray pressure is 12 MPA, the spray device is installed at 2.5 m behind the head of the roadheader, and the process parameters of the controlled large air volume, long pressure, short extraction and dust removal system are consistent with the results of numerical simulation. The results are consistent with those obtained by numerical simulation. The pump pressure ratio is 1.4 m and the pump pressure ratio is 1.4 m. The project application of the integrated dust control system is also carried out. The main conclusions of this paper are as follows: (1) the particle size of dust in 1307 track working face of Dongtan Coal Mine is mainly distributed in the range of 0~50mm, in which the dust less than 50mm reaches 98.8% of the total amount, indicating that the dust of small particles accounts for most of the dust in the working face. The possibility of inhaling dust is increased. 2) from the numerical simulation of dust migration law, it can be seen that the concentration of high concentration dust is mainly within the range of 10 meters from head to head, the highest concentration can reach above 1500mg/m3, and with the increase of distance, the dust concentration decreases gradually; The area of high concentration dust near the floor of roadway is wider than that in the distance, and the distance of diffusion is wider, the dust concentration on the side of the air duct is higher than that on the side of the pressure tube, and the concentration of dust at the head is higher in the opposite direction of the X axis. From the dust concentration distribution at the bottom plate, it can be seen that the distance of dust deposition on one side of the air duct is longer than that of the extraction tube, and the highest dust concentration is not in the head-on position, but in the vicinity of 5 m from the head of the air tube. From the distribution of dust in the whole roadway, it is found that the dust migration is stable after 30 m, and the concentration is kept at 80 mg / m ~ (3. 3) the optimum parameters of dust removal (extraction, pressure tube distance and suction ratio) are numerically simulated. The simulation results show that the dust concentration in the roadway is at a very low level when the air volume is 280m3/min, the distance between the air pipe and the working face is 16m, the distance between the air tube and the working face is 4m, the ratio of suction pressure is 1.4, and the dust concentration in the roadway is at a very low level. The dedusting efficiency of total dust and respiratory dust in production is over 96%. The total dust concentration in the roadway is 7.5 mg/m3 and 4.7 mg / m3, respectively, and the concentration of respiratory dust is 2.2 mg/m3 and 2.0 mg / m3, respectively. The working environment of the heading face has been greatly improved.
【学位授予单位】：安徽建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD714

【参考文献】