局部通风条件下CO扩散数值流场规律研究

发布时间：2018-05-30 09:05

本文选题：局部通风 + 数值模拟实验　；参考：《昆明理工大学》2013年硕士论文

【摘要】：在金属非金属地下矿山较大以上事故中,因火灾和炮烟引起的中毒窒息事故所占比例超过40%,事故起数和死亡人数均位于地下矿山各类事故之首。在这类事故中,有相当一部分是因局部通风不良所致。局部通风效果不良的原因,主要是抽出式局部通风的有效吸程较短,出于保护风筒不被爆破飞石破坏的需要,一般在掘进中风筒口到工作面的距离都会大于有效吸程。因此,需要研究在不满足有效吸程条件下提高局部通风效果的方法。结合实际情况及前人的研究成果,本文采用了现场实测试验与模拟试验相结合的研究方法。即用CFD软件建立局部通风数值模拟模型,现场实测与模型模拟结果进行对比验证,然后利用模型进行多个方案、多次重复的试验,获得了丰富的试验数据,为改善抽出式局部通风效果的可能方案提供了依据。为此,在本课题研究中自行设计并制作了基于STC12C5608AD单片机的CO监测系统,并编写了单片机程序及上位机软件程序。制定并实施了局部通风现场实验方案。在云锡老厂1800运输巷新掘甩车场的独头掘进工作面,对爆破后CO浓度变化进行了实时监测。根据现场测量的巷道参数,在CFD前处理软件中对巷道进行建模并划分网格。将划分好的网格导入CFD软件中设置参数及边界条件,建立了“局部通风条件下CO扩散的三维湍流模型”。将CFD模型模拟的结果与现场监测的结果进行对比,验证了所建模型的可靠性和有效性。利用所建模型,通过改变模拟试验的通风方式、巷道断面积、风速、风筒直径和风筒到工作面距离等参数,进行了多方案模拟试验,得到不同模拟参数对局部通风效果的影响以及参数改变对“有效吸程”的影响。研究结果表明,理论研究得出的“循环涡流区’和“有效通风距离”在现实中存在；同时验证了计算“有效射程”和“有效吸程”的经验公式,提出了类似条件下对经验公式使用和修正的建议；在“有效射程”和“有效吸程”无法满足的情况下,可以通过增大风筒口风速、增加风筒直径和延长通风时间等方式加速“循环涡流区”内的有毒气体和炮烟的排除。本课题研制的、基于单片机的CO监测系统,通过更换其他种类的传感器,可用于其他矿井通风参数的监测,对地下矿山通风监测实现智能化有实际意义。本文经过现场和模拟试验获得的研究结果及建议,对改善局部通风效果,减少井下通风不良导致的事故,具有一定指导意义。
[Abstract]:The proportion of poisoning and asphyxiation accidents caused by fire and gunfire is more than 40 in the accidents of metal nonmetallic underground mines. The number of accidents and the number of deaths are both the first among all kinds of accidents in underground mines. A considerable part of these accidents are due to poor local ventilation. The main reason for the bad effect of local ventilation is that the effective suction distance of the extraction type local ventilation is short, and the distance from the heading stroke tube to the working face is generally larger than the effective suction distance in order to protect the tube-tube from being destroyed by blasting flying stones. Therefore, it is necessary to study the methods to improve the local ventilation effect without satisfying the effective suction conditions. Combined with the actual situation and the previous research results, this paper adopts the method of combining the field test with the simulation test. The numerical simulation model of local ventilation is established by using CFD software, and the results of field measurement and model simulation are compared and verified. Then, the model is used to carry out multiple projects and repeated experiments, and abundant test data are obtained. It provides a basis for improving the effect of local ventilation. Therefore, a CO monitoring system based on STC12C5608AD single chip microcomputer is designed and manufactured in this research. The program of MCU and the software program of upper computer are also written. The local ventilation field experiment scheme was established and implemented. Real time monitoring of CO concentration change after blasting was carried out in the single head driving face of new driving yard of 1800 transport lane in Yunxi Laoshan Plant. According to the parameters of roadway measured in the field, the roadway is modeled and meshed in CFD pre-processing software. A three-dimensional turbulent model of CO diffusion under local ventilation was established by introducing the divided mesh into CFD software to set up parameters and boundary conditions. The simulation results of CFD model are compared with the results of field monitoring, and the reliability and validity of the model are verified. By changing the ventilation mode, roadway sectional area, wind speed, tuyere diameter and the distance from the tube to the working face, the multi-scheme simulation test was carried out by using the established model. The influence of different simulation parameters on local ventilation and the effect of parameter change on effective suction are obtained. The results show that the "circulating vortex zone" and "effective ventilation distance" obtained by theoretical research exist in reality, and the empirical formulas for calculating "effective range" and "effective suction distance" are also verified. Suggestions for the use and modification of the empirical formula under similar conditions are proposed. In cases where "effective range" and "effective suction range" cannot be satisfied, the wind speed can be increased by increasing the wind speed of the nozzle. Increasing the diameter of the tuyere and prolonging the ventilation time to speed up the elimination of toxic gas and smoke in the swirl zone. The CO monitoring system based on single chip microcomputer developed in this paper can be used to monitor the ventilation parameters of other mines by replacing other kinds of sensors. It is of practical significance to realize intelligent ventilation monitoring in underground mines. The research results and suggestions obtained from the field and simulation tests in this paper have certain guiding significance for improving the effect of local ventilation and reducing the accidents caused by poor underground ventilation.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TD721

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