【作者】 李辉；

【导师】 景国勋；

【作者基本信息】 河南理工大学 ， 矿业工程， 2015， 博士

【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。更多还原

【Abstract】 Gas pre-drainage drilling was an effective measure of gasmanagement,but it was a difficult thing drilling in soft coal,the application of traditional hydraulic drilling was easy to collapse the borehole and suspend the drilling,designrequirement and gas extraction could not be achieved.The application of pressured wind drilling also has problem whether the pressure was high or low,when the pressure was high,there was more pulverized,gas ejection in serious area,gasoverrun,induction of outburst,environmental pollution and healthydamage of miner;when the pressure was low,the drill got stuck and borehole got blocked was common,theaccident broken and seized the drill occurred usually,also design requirement could not be realized.Drilling of soft coal was the key issue of gas prevention and the prerequisite of the realization of gas prevention.The paper focused on the characteristic of the soft mine,investigated the process that drilling in soft mine,the coal mine,thefacilities,the driving force and so on,put forward that using the indicated negative pressure system as the driving force and in a manner of blow-out pulverized from interior of drill to drilling,the fundamental purpose was to resolve the problem thatgas ejection,drill got stuck,gasoverrun and pulverized in engineering,theoreticalresearchedthe law and characteristics that the pulverizedmigrated in the interior of drill provided the theoretical foundation for blow-out pulverized.The paperused the negative pressure gas conveying theory,gas-solid two-phase flow theory,CFD numerical simulation and field test as the method to make the study of basic parameters about the process of drilling as wind velocity,pressure loss,aperture,transmission capacity,and conveying distance.The study found that the size of drill diameter had a significant impact on the delivery performanceof the particle;Found out the relationship between the transmission capacity and the flow parameters that included transport pressure,solid velocity,gas velocity,slip velocity,solidgasratio and porosity,and inferred the formula.Therelationshipbetween transmission capacity,conveyed distance andangle of drilling was investigated out.Found out the factors that influencedthe characteristics of dense phase pneumatic conveying resistance based on the analysis on the flow theory,probed the mechanism of dense phase pneumatic conveyingsimultaneously.Fitout high precision resistance characteristics formula ofhorizontal and vertical pipe andthe formula that considered the drill rotational resistance.The negative pressure drilling system,special drill and special drill pipe and pulverized collecting box has been developed.It could make pulverizedand gas migrated in closed system when used the new drilling system to drill,realized the drilling had no pulverized andno gas.The operation process and specification has been made according to the geological conditions of coalseam and drilling parameters of test coal mine.The equipment,developed by the application of research findings,achieved great consequent through fieldapplication,resolved the problem drilling in soft coal effectively,implemented the purpose of the research,and provided new method and apparatus for drilling in soft mine.更多还原