【作者】 王飞；

【导师】 秦波涛；

【作者基本信息】 中国矿业大学 ， 安全工程（专业学位）， 2020， 硕士

【摘要】 煤炭是我国的基础能源,近年来随着煤矿机械化程度的提高,井下粉尘的危害日益严重。综掘面作为井下主要产尘源之一,在生产过程中产生大量粉尘,严重威胁井下工人身心健康。针对综掘面粉尘难以治理这一现状,本文通过现场测试、数值模拟、理论分析相结合的方法,对平煤十矿一综掘面风流场和粉尘空间分布进行研究,并根据井下条件制定了粉尘综合防治措施。通过在掘进巷道内布置测点,对各位置粉尘浓度进行测定,研究综掘面粉尘空间分布。并进一步对综掘面前端4m位置处所采粉尘进行分散度研究,拟合得出该综掘面粉尘R-R分布函数:(4_（9）=0⁽（-（（9/46））1.59）,为后文研究提供必要参数。为对综掘面提出合理降尘措施,本文基于交界面混合网格通过CFD仿真模拟,系统研究了综掘面风流场和粉尘运移规律。通过对风流场分析可知,在5m位置处回风侧部分风流往上流动,流动过程中受顶板影响最终流向进风一侧,巷道内风流在20m处整体处于相对稳定状态。利用后处理软件对粉尘颗粒进行瞬态分析,在10s后粉尘便可运移至掘进机后方,同时在掘进机后方进风侧粉尘跟随风流往回风侧扩散。在巷道前端由于涡流的存在使得粉尘在涡流区域聚集,30s后出现高浓度粉尘聚集现象。同时为研究粉尘运移的影响因素,本文通过对风流、粉尘粒径、尘源位置三个方面进行系统分析。并针对综掘面研究过程中现有模拟多以面尘源来喷射粉尘这一现状,本文通过UDF构建了移动产尘源,研究了移动尘源对巷道内粉尘分布的影响。根据综掘面粉尘现状及井下条件,对该工作面粉尘提出综合防治措施。首先,根据综掘面现状制定了三种压风方案,通过对比不同压风条件下巷道行人侧及司机位置处的粉尘浓度,得出压风量在470 m³/min时最有利于该巷道内粉尘的排出。其次,通过安装水幕对巷道内粉尘进一步进行捕捉,为提高水幕降尘能力,通过实验对比了不同孔径喷嘴在5Mpa条件下的雾化及降尘效果,得出1.5mm喷嘴为水幕最优喷嘴孔径。同时通过模拟得出在巷道25m位置处水幕产生的雾滴能有效覆盖巷道断面,对粉尘进行全断面捕捉。最后,为提高水基介质对粉尘的捕捉能力,通过在井下制备活性磁化水来提高雾滴降尘效率。通过优化通风、安装水幕和改善水基介质等措施,对综掘面粉尘进行综合防治,全尘和呼尘的降尘效率达到81.3%和78.4%,有效降低了巷道内粉尘浓度,改善井下作业环境。该论文有图54幅,表16个,参考文献86篇。更多还原

【Abstract】 Coal is China’s basic energy source.In recent years,with the improvement of coal mine mechanization,the danger of underground dust has become increasingly serious.As one of the main sources of underground dust production,fully digging face produces a lot of dust during the production process,which seriously threatens the physical and mental health of underground workers.Aiming at the problem of dust control in comprehensive mining,this paper studies the wind flow field and dust spatial distribution of the first comprehensive mining face of Pingmei No.10 Mine through a combination of on-site testing,numerical simulation and theoretical analysis,and formulates the dust according to the underground conditions Comprehensive prevention measures.By arranging measuring points in the driving roadway,the dust concentration at each location is measured to study the spatial distribution of the dust in the comprehensive tunneling.And further study the dispersion degree of the dust collected at the position of 4m in front of the fully digging face,and fit the R-R distribution function of the fully digging dust:(4_（9）=0⁽（-（（9/46））1.59）,as The following research provides the necessary parameters.In order to propose reasonable dust-reduction measures for fully digging face,this paper systematically studies the wind flow field and dust movement law of fully digging face through CFD simulation based on interface mixed grid.According to the analysis of the wind flow field,it can be seen that at the 5m position,part of the wind flow on the return side flows upwards.During the flow process,the wind flows to the inlet side due to the influence of the roof.When the wind flow moves to the 20m position,the wind flow is in a relatively stable state.And the post-processing software is used to analyze the dust particles transiently.After 10s,the dust can be transported to the back of the roadheader.At the same time,the dust on the air inlet side of the roadheader diffuses along the wind flow to the return air side.At the front end of the roadway,due to the presence of eddy currents,dust accumulates in the vortex area,and high concentration dust accumulation occurs after 30s.At the same time,in order to study the influencing factors of dust movement,this paper systematically analyzes the dust through three aspects:wind current,dust source location and dust particle size.Aiming at the current situation of the existing simulation of spraying dust with surface dust sources in the research process of tunneling face,this paper builds a mobile dust source through UDF and studies the influence of mobile dust source on the dust distribution in the roadway.According to the status of comprehensive excavation dust and underground conditions,comprehensive prevention measures for the working dust are proposed.First of all,according to the current situation of the comprehensive excavation surface,three pressure-pressing schemes were developed.By comparing the dust concentration at the pedestrian side and the driver’s position of the roadway under different pressure conditions,it was concluded that the air pressure at 470 m³/min is most beneficial to the dust in the roadway of discharge.Secondly,by installing a water curtain to further capture the dust in the roadway,in order to improve the water curtain’s dust-reducing ability,the atomization and dust-reducing effects of different aperture nozzles under5Mpa conditions were compared through experiments,and the 1.5mm nozzle was the best nozzle Aperture.At the same time,through simulation,it is concluded that the fog droplets generated by the water curtain at the position of 25m of the roadway can effectively cover the cross section of the roadway and capture the full cross section of the dust.Finally,in order to improve the ability of water-based media to capture dust,the efficiency of mist drop dust reduction is improved by preparing active magnetized water underground.Through measures such as optimization of ventilation,installation of water curtains and improvement of water-based media,comprehensive prevention and control of dust from comprehensive excavation was carried out.The dust reduction efficiency of all dust and exhalation reached 81.3%and 78.4%,effectively reducing the dust concentration in the roadway and improving underground operations surroundings.The paper has 54 pictures,16 tables,and 86 references.更多还原