【作者】 刘荣华；

【导师】 李夕兵； 施式亮；

【作者基本信息】 中南大学 ， 安全技术及工程， 2010， 博士

【摘要】 粉尘是煤矿五大灾害之一。随着当代采矿技术的不断发展,采掘机械化水平越来越高,实现了工作面的高产高效,为煤矿带来了巨大的经济效益,但同时也带来了十分严重的粉尘职业危害问题。一方面,粉尘对人体的健康危害极大,尤其是呼吸性粉尘。煤矿工人长期处于高浓度粉尘作业环境场所,极易患上尘肺病。据统计,目前煤炭系统尘肺病人数已超过30万人,约占我国总尘肺病人数的一半,对此国家每年要化费大量的医疗费用,同时也给患者及其家属带来极大痛苦。另一方面,煤矿井下粉尘浓度高,易引起爆炸。一旦井下发生煤尘爆炸,往往造成重大伤亡事故,甚至严重摧毁矿井,带来巨大的经济损失。此外,工作地点的粉尘会恶化劳动环境、降低能见度、影响劳动生产率、增加工伤事故率,并引起皮肤病和眼科疾病,加速机械设备的磨损。采掘工作面是煤矿井下产尘量最大、粉尘浓度最高的地点,尤其是综合机械化采煤工作面(简称综采工作面)。当采煤机割煤时,工作面原始粉尘浓度高达8000-10000mg/m3。尽管目前工作面采取了煤层注水、喷雾降尘等多种防尘措施,起到了一定效果,但是工作面粉尘浓度,特别是采煤机司机处的呼吸性粉尘浓度,仍难以控制到行业标准以下。为此,本论文从理论分析、实验研究、数值模拟及现场试验四个方面开展了利用空气幕隔断技术阻止采煤机割煤滚筒产生的粉尘向司机工作区扩散、降低司机处粉尘浓度的防尘新方法研究,主要研究内容如下：(1)以流体力学、气溶胶力学及空气动力学为基础,分析了综采工作面尘源扩散运动规律及其影响因素。(2)通过井下实测得到综采工作面粉尘和风流分布的基本规律,分析了综采工作面采煤机附近风流运动特性和粉尘分布特点。(3)根据平面射流理论,利用空气幕屏蔽作用,提出了综采工作面空气幕隔尘方法及理论,建立了空气幕隔尘的理论模型。(4)对综采工作面流场及粉尘分布现场实测数据进行综合分析,采用FLUENT软件数值模拟了采煤机割煤时呼吸性粉尘扩散及综采工作面空气幕的隔尘效果,并对空气幕设计参数及安装位置、安装角度对隔尘效果的影响进行了分析,得出了隔尘空气幕最佳设计及安装参数。(5)在实验室进行了多工况的相似模拟实验,实验结果与综采工作面现场实测及理论分析结果基本一致,并验证了空气幕设计、安装参数对其隔尘效果的影响。(6)在河北金牛能源有限责任公司(原邢台矿务局)葛泉煤矿1326和1528工作面进行了工业性试验。研究结果表明,在综采工作面采煤机上安装空气幕,其作用相当于一个“透明的无形屏障”,能有效地阻止采煤机截煤过程中粉尘向司机处扩散,尤其是阻止呼吸性粉尘的扩散,大大地降低综采工作面司机处的粉尘浓度。该装置成本低、操作简单实用、不影响司机的视线和操作,深受综采工作面司机的好评,在现场实际应用中获得了良好的安全环境经济效益及社会效应,具有广阔的推广应用前景。论文研究的主要创新点有：(1)首次提出了在综采工作面利用空气幕隔断技术来抑制采煤机截煤过程中粉尘向司机处扩散,降低采煤机司机工作区的粉尘浓度,同时提高采煤机的喷雾降尘效果,进一步改善整个工作面的作业环境,提高矿井安全生产可靠性的思想。(2)针对综采工作面作业空间特点,研究综采工作面空气幕隔尘机理,建立了综采工作面空气幕隔尘的理论模型。并引入旋风分离理论,提出了旋转风幕控尘新概念,分析了空气幕隔尘效率与粉尘粒径的关系,论证了空气幕能有效抑制煤壁侧呼吸性粉尘向司机处扩散。(3)通过理论计算分析和现场实测发现了采煤机割煤过程中所产生的粉尘由煤壁侧向司机处扩散,是滚筒割煤和煤炭垮落所产生的侧向扰动气流,以及粉尘在风流中弥散和扩散综合作用的结果。(4)通过相似模拟实验、数值模拟和现场工业性试验研究,得出了试验工作面条件下的空气幕最佳设计和安装参数,并有效解决了司机处呼吸性粉尘浓度超标的技术难题。更多还原

【Abstract】 Dust is one of the five disasters in coal mine. With the development of modern mining technology, the mining mechanization level becomes higher and higher, so the high yield and efficiency of the working face was achieved and the great economic benefits for the coal mine was obtained, but the serious dust disaster problem also was brought. On the one hand, Coal mine dust is seriously harmful to human health, especially the respirable dust. Coal miners are vulnerably suffered from occupational pneumoconiosis, when they are perpetually exposed in the operating places with high dust concentration. According to the statistical results, the pneumoconiosis patients in coal industry are beyond 300000, which is accounting for about half of total number of china, the pneumoconiosis not only costs the government a lot of medical expenses each year, but also brings serious disasters to patients and their families. On the other hand, the coal mine dust with high concentration is always easy to trigger dust explosion. Once the underground coal dust explosion occurred, the heavy casualties and enormous economic loss would be brought, even the serious mine destruction would be caused by the explosion accidents. In addition, the work-place dusts can cause the deterioration of working environment, reduce visibility, debase labor productivity, increase the rate of occupational accidents, cause diseases of skin and eye and accelerate the abrasion of machinery and equipment.The coal-mining face is the place where the largest amount of coal mine dust production and the highest dust concentration, especially, in a fully-mechanized coal mining face (abbreviation:fully-mechanized coal face). When the shearer cuts coal, the dust concentration in the work-face is 8000-10000mg/m3. Though many dust control measures, such as the coal seam water injection, dust suppression by spraying are adopted in current working face, the dust concentration, especially the concentration of respirable dust in the work-space of shearer drivers, is difficult to reach the industry standards. So the research on using the partition characteristics of air curtain to prevent the coal dust generated by cutting drum shearer from diffusion to the work-space of shearer drivers, reducing the dust concentration by a new method is carried out in this dissertation from theoretical analysis, experimental study, numerical simulation and field test. The main research contents are as follows:(1) Basing on fluid mechanics, aerosol mechanics and aerodynamics, the diffusion motion law and affected factors of dust in mechanized mining face is studied.(2) By measuring basic distribution law of dust and airflow in mechanized mining face, the dust distribution law and airflow motion characteristic in fully-mechanized coal face shearer are analyzed.(3) According to the plane jet theory and the shielding action of air curtain, the dust separation theory and method of air curtain in fully-mechanized coal face is put forward and the dust separation theory model of air curtain is established.(4) Through the comprehensive analysis on flow field of fully-mechanized coal face and measurement data of dust distribution, the prevention effect of air curtain and diffusion of respirable dust during shearer cutting coal are simulated by software FLUENT, and the design parameters and the installation location, installation angle of air curtain are also analyzed. Finally, the best air curtain parameters of design and installation are obtained.(5) The similar simulation experiment of the changeable conditions at experimental lab is carried out, the results obtained in lab are concordant with the results obtained from theoretical analysis and field test. Finally, the prevention effect and design parameters and installation parameters are validated.(6) Industrial test was carried out in 1326 and 1528 work-face of GeQuan coal mine, HeBei JinNiu Energy Co., Ltd(formerly Xingtai Mining Bureau).The results show that the air curtain installed in fully-mechanized coal face shearer acts as a "transparent invisible barrier", which can effectively prevent the dust from diffusion to work-space of shearer drivers during coal shearer cutting coal, especially the diffusion of respiratory dust, and greatly reduce dust concentration of the work-space of driver in the fully-mechanized coal face. The device is simple and practical to use in low cost, does not disturb the driver’s attention and operation, which obtains highly praise. So a good economic safety benefits and social effects of practical application are obtained, it has a broad prospects for the promotion and application.The principal innovations in this dissertation are as follows:(1) The ideas that using an air curtain to prevent dust diffusion to the driver in the fully-mechanized coal face during coal shearer cutting coal, debasing the dust concentration in the work-space of shearer drivers, improving the operating environment of the shearer drivers and increasing the safety production reliability, are first proposed.(2) Aim to the characteristics of work-space in fully-mechanized coal face, the dust separation mechanism of air curtain in work-face is studied, and the theoretical model of dust separation theory is established. Base on the rotating air separation theory, the dust control theory of rotating air curtain is put forward; relations between the efficiency of the dust separation and dust particle size are analyzed. The effectiveness of dust diffusion suppressed by air curtain is demonstrated.(3) By theoretical analysis and field testing study, the conclusions that the dust diffusion from coal wall to the driver is the comprehensive effect results of perturbation airflow, dispersion and diffusion of dust, are obtained.(4) By theoretical analysis, numerical simulation and field testing study, the best air curtain design and installation parameters on testing condition are obtained, and the technology problem of respirable dust beyond standard in work-place of driver is effectively solve.更多还原