煤矿负压钻进管内颗粒运移特性研究及钻进设备研发

发布时间：2018-03-13 21:36

本文选题：负压钻进　切入点：气力输送　出处：《河南理工大学》2015年博士论文　论文类型：学位论文

【摘要】：瓦斯预抽钻孔是瓦斯治理的有效措施,但是在松软煤层钻孔施工困难,采用传统的水力排渣,容易造成钻孔垮塌,中断钻进过程,无法实现钻孔的设计要求,达不到瓦斯抽采的需要。采用压风排渣,若风压大,排出粉尘大,特别是瓦斯严重的区域常发生喷孔,造成瓦斯超限,甚至会诱导突出,同时出现粉尘过大,污染环境,影响工人的健康;若风压小,卡钻、堵孔现象时有发生,并且容易造成卡钻杆、折断等事故,也会造成无法实现钻孔的设计要求。松软煤层钻进问题成为瓦斯防治的关键问题,也是实现瓦斯防治的前提条件。针对松软煤层的特点,以松软煤层钻进过程为研究对象,研究煤层、钻具、排渣动力等要素,提出采用独立负压系统为动力,钻杆内排渣的方式进行打钻,主要目的是在工程上解决松软煤层钻进过程中的喷孔、卡钻、瓦斯超限和煤尘问题,在理论上研究钻屑在钻杆内的运移规律、特性,为负压排渣提供理论基础。运用负压气体输送理论、气固两相流理论、CFD数值模拟、现场试验等手段对负压钻进过程中的风速、压力损失、孔径、输送能力、输送距离等基础参数进行研究。研究发现,钻杆管径的大小对颗粒的输送性能有很大的影响;找到了输送能力与输送压力、固体速度、气体速度、滑移速度、固气比、空隙率等流动参数之间的关系,回归出关系式。考察了输送能力与是输送距离、钻杆倾角之间的关系。在对流动特性理论分析的基础上,得出了影响浓相气力输送阻力特性的各因素,同时探讨了浓相气力输送的机理。得出了精度较高的水平、垂直管道的阻力特性公式,得出了考虑钻杆旋转情况的阻力公式。研制了负压钻进系统、专用钻头和专用钻杆、集尘箱。利用研制的新型钻进系统,钻进时能够实现煤尘、瓦斯在封闭的系统内运移,实现无尘无瓦斯钻进。针对试验矿井施工地点煤层地质条件和钻孔施工工艺参数,制定了操作工艺和规范。应用研究结论为指导而研发的设备,经过现场应用,取得较好的效果,有效的解决了松软煤层钻进过程中出现的问题,实现了研究的目的,为松软煤层钻进提供了一项新的方法和设备。
[Abstract]:Gas pre-drainage drilling is an effective measure for gas control, but it is difficult to drill holes in soft coal seams, and the traditional hydraulic slag drainage can easily cause borehole collapse, interrupt the drilling process, and can not meet the design requirements of boreholes. If the pressure air drains slag, if the wind pressure is high, the dust will be large, especially in the serious area of gas, the gas will exceed the limit, even induce outburst, at the same time, the dust will be too big and the environment will be polluted. If the wind pressure is small, the phenomenon of drilling and blocking holes occur frequently, and it is easy to cause accidents such as drill pipe jam and breakage, which will lead to the failure to meet the design requirements of drilling holes. The key problem of gas prevention and control is drilling in soft coal seams, and the problem of drilling in soft coal seams becomes a key problem in gas prevention and control. According to the characteristics of soft coal seam, the drilling process of soft coal seam is taken as the research object, and the factors such as coal seam, drilling tool and slag discharging power are studied, and the independent negative pressure system is put forward as the power. The main purpose of drilling is to solve the problems of jetting hole, sticking, gas exceeding limit and coal dust in the drilling process of soft coal seam in engineering. In theory, the migration law and characteristics of drilling debris in drill pipe are studied. Using the theory of negative pressure gas transportation, gas-solid two-phase flow theory, CFD numerical simulation, field test and other means to negative pressure drilling process of wind speed, pressure loss, pore size, transport capacity, The basic parameters such as transportation distance were studied. It was found that the diameter of drill pipe had a great influence on the conveying performance of particles, and the transportation capacity and conveying pressure, solid velocity, gas velocity, slip velocity, solid-gas ratio were found. The relationship between flow parameters, such as porosity, and so on, is regressed. The relationship between conveying capacity, conveying distance and drill pipe inclination is investigated. On the basis of theoretical analysis of flow characteristics, The factors affecting the resistance characteristics of dense phase pneumatic conveying are obtained, and the mechanism of dense phase pneumatic conveying is discussed. The formulas of resistance characteristics of horizontal and vertical pipelines with high accuracy are obtained. The resistance formula considering the rotary condition of drill pipe is obtained. A negative pressure drilling system, a special drill bit and a special drill pipe, a dust collecting box are developed. By using the developed new drilling system, coal dust and gas can be transported in a closed system. According to the geological conditions of coal seam in the construction site of test mine and the technological parameters of borehole construction, the operation technology and standard are established. The equipment developed under the guidance of the research conclusion is applied in the field. It has achieved better results, effectively solved the problems in the process of soft coal seam drilling, realized the purpose of research, and provided a new method and equipment for soft coal seam drilling.
【学位授予单位】：河南理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD712.6

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