煤矿运输巷扬尘输运规律及雾化降尘技术研究

发布时间：2018-02-20 03:10

本文关键词： 风力扬尘风力输运车辆运行皮带振动雾滴存活时间　出处：《辽宁工程技术大学》2015年博士论文　论文类型：学位论文

【摘要】：矿井粉尘污染对井下作业工人的危害很大,是导致煤矿开采行业职业病的主要原因。运输巷道主要是输煤皮带巷和运料及行人的辅运巷,运输巷粉尘的产生和输运不同于采掘工作面,有必要对其进行有针对性的研究。在现场实测和实验研究的基础上,利用COMSOL Multiphysics 5.0开展三维数值模拟,对风流因素、车辆行驶及皮带运行等过程对粉尘的影响进行研究；采用Matlab14.0根据雾滴蒸发过程中的传热传质控制方程自编程序对其蒸发过程进行仿真试验,探索推导雾滴存活时间的综合函数,为提高喷雾降尘效率提供支撑；结合理论分析、现场实测、数值模拟和仿真试验对雾化降尘系统工艺进行优化并在现场考察其应用效果。(1)开展了巷道风流温、湿度和压力等对风流密度、动力粘度等影响的理论计算和粉尘自身含水率对其密度及粒径影响的研究。温度降低、湿度和压力增大导致风流的动力粘度降低；含水率增加会增加颗粒的密度和粒径；风流动力粘度降低,粉尘的运移范围更大,污染范围更广。(2)采用数值模拟的方法对巷道中风流速度、车辆和皮带运行参数以及粉尘自身粒径变化对巷道中风力扬尘和粉尘风力输运的影响进行研究。风速增大,巷道的扬尘强度增大,粉尘在一定范围内浓度降低,但污染范围更广,远距离处风速增加粉尘浓度增加；车辆顺风行驶时,距车头尾25-30 m处出现粉尘浓度的“双峰”分布,逆风时行驶时,距车尾25-35 m处出现粉尘浓度“单峰”分布且逆风峰值远大于顺风峰值；车速越大扬尘强度和粉尘浓度都越大；皮带振幅和运行速度越大、振动频率越高扬尘强度和粉尘浓度越大。(3)进行了喷嘴雾化效果实验研究和降尘效率计算。实验表明型号为PZF(ψ1.2 mm)的喷嘴在气压为0.11-0.65 MPa,水压为0.45-2.55 MPa, ALR为0.02-0.11,水流量为500-700kg/h时其雾滴速度70-220 m/s,粒径为20-80μm,其理论降尘效率达90%。(4)采用Matlab14.0,基于雾滴蒸发过程的传热传质控制方程对其蒸发过程进行了仿真试验研究。雾滴蒸发过程主要受6个因素的影响,雾滴初始半径、环境湿度、风流压力增加雾滴的存活时间延长；雾滴与风流的相对速度、环境初始温度以及雾滴的初始温度增加其存活时间降低,但雾滴初始温度对其影响较小。通过均匀试验并结合因子分析进行降维处理,推导出含有5个关键参数的雾滴存活时间计算公式,对比显示其具有较高的精度。(5)开展了雾化降尘系统现场应用效果考察。根据数值模拟与仿真试验研究结果设计了运输巷粉尘自动监测和自动雾化降尘系统方案,搭建了自动雾化降尘系统,进行了现场应用和降尘效率考察,结果显示自动雾化降尘系统的降尘效率可以达到86%以上。
[Abstract]:Mine dust pollution is a major cause of occupational disease in coal mining industry, and it is the main cause of occupational disease in coal mining industry. The main transportation roadway is coal conveyance belt roadway and auxiliary roadway for transporting materials and pedestrians. The generation and transport of dust in transport roadway is different from that in mining face, so it is necessary to study it pertinently. On the basis of field measurement and experimental study, using COMSOL Multiphysics 5.0 to carry out three-dimensional numerical simulation, the factors of air flow are analyzed. The influence of vehicle driving and belt running on dust was studied, and the simulation test was carried out by Matlab14.0 according to the heat and mass transfer control equation of droplet evaporation, and the comprehensive function of droplet survival time was deduced. In order to provide support for improving the efficiency of spray dust control, combined with theoretical analysis, field measurement, numerical simulation and simulation test, the process of atomization dust control system was optimized and its application effect was investigated in the field. The theoretical calculation of the influence of humidity and pressure on air flow density and dynamic viscosity, and the study of the influence of dust moisture content on its density and particle size. The decrease of temperature, the increase of humidity and pressure leads to the decrease of dynamic viscosity of air flow. The increase of water content will increase the density and particle size of particles, decrease the dynamic viscosity of air flow, increase the range of dust migration, and increase the range of pollution. (2) numerical simulation method is used to simulate the velocity of air flow in roadway. The effects of vehicle and belt operation parameters and dust particle size on wind dust and dust transport in roadway are studied. The wind speed increases, the dust intensity increases, and the dust concentration decreases within a certain range. However, the range of pollution is wider, the wind speed increases at a long distance and the dust concentration increases. When the vehicle is driving in the wind, the "double peak" distribution of dust concentration appears at 25-30 m from the front and the tail of the vehicle, and when driving against the wind, There is a "single peak" distribution of dust concentration at 25-35 m from the rear of the vehicle, and the peak value of the headwind is much larger than that of the downwind peak; the greater the speed of driving, the greater the dust intensity and dust concentration, the greater the belt amplitude and the running speed. The higher the vibration frequency, the greater the dust intensity and dust concentration.) the atomization effect of the nozzle and the dust reduction efficiency are studied. The experimental results show that the nozzle with PZF (蠄 1.2mm) has a pressure of 0.11-0.65 MPA, a water pressure of 0.45-2.55 MPA, a ALR of 0.02-0.11, and a water flow rate of 500-700kg / h. The droplet velocity is 70-220 m / s, the particle size is 20-80 渭 m, and the theoretical dust reduction efficiency is 90 渭 m. Matlab14.0 is used to simulate the evaporation process based on the heat and mass transfer control equation of droplet evaporation. The droplet evaporation process is mainly affected by six factors. The relative velocity of droplet to air flow, the initial temperature of the environment and the initial temperature of the droplet were increased, and the survival time of droplet was decreased with the increase of the initial radius of the droplet, the humidity of the environment, the pressure of the air flow, the relative velocity of the droplet and the wind flow. However, the initial temperature of droplet has little effect on it. Through uniform test and factor analysis, the formula for calculating the droplet survival time with five key parameters is derived. The comparison shows that it has high precision. (5) the field application effect of atomization dust control system is investigated. According to the results of numerical simulation and simulation test, the scheme of automatic dust monitoring and automatic atomization dust control system in transportation roadway is designed. The automatic atomization dust control system was built, and the field application and dust removal efficiency were investigated. The results show that the dust control efficiency of the automatic atomization dust control system can reach more than 86%.
【学位授予单位】：辽宁工程技术大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD714.4

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