【作者】 冀前辉；

【导师】 殷新胜；

【作者基本信息】 煤炭科学研究总院 ， 矿产普查与勘探， 2009， 硕士

【摘要】 瓦斯事故是我国煤矿生产中最严重的灾害之一,钻孔抽采是瓦斯治理的有效方法。松软煤层成孔困难、渗透性差,在我国所采煤层中占有很大比例,在这样的煤层中钻进成为亟需解决的难题。利用矿井工作压风为风源的空气钻进在松软煤层钻进中取得一定的效果,但由于供风流量不稳定、压力低,经常造成卡钻事故,制约着钻孔深度的提高,因此供风流量和供风压力就成为空气钻进中的关键参数。本文利用气固两相流理论,结合地面模拟实验研究,对空气钻进过程中供风流量和供风压力的变化规律进行探讨,得出使用井下移动空压机形成独立供风系统,利用中风压空气钻进是解决松软煤层钻孔难题的有效途径。中风压空气钻进排渣量大,返出的含尘气体流速高,给除尘带来极大困难,现有简易除尘装置除尘效果差,残留的粉尘为矿井安全埋下隐患。本文采用计算流体动力学软件对旋风除尘器进行了数值模拟,深入研究了旋风除尘器的内部流场和颗粒运动轨迹。并结合中风压空气钻进的特点,利用惯性、水浴、文丘里三种除尘原理,研制出三级无动力孔口除尘装置。利用强力钻机、井下防爆移动空压机、大通孔中风压密封钻杆及三翼刮刀钻头,在淮北矿业集团祈南煤矿34下3采区进行了现场试验,在f系数为0.5～0.8的松软突出煤层中完成进尺2171m;现场检测,除尘装置的除尘效率达到93%。通过对中风压空气钻进供风参数的研究,得出了试验点供风参数选择的经验公式。合理的设备配套对松软煤层钻进具有指导作用。更多还原

【Abstract】 Gas accident is one of the most serious disasters in coalmine production. Gas drainage after hole drilling is an effective method to keep away this accident. Soft coalbed with defects of difficult porosity and low permeability occupies a great proportion of coalbed extracted in our country. Drilling in coalbed with these two defects has been a burning problem.Some effects have been obtained after compressed air entry by taking mining compressed air as the air supply. However, since the air flow supply is instable and low in pressure, this often leads to frequent jamming of the drilling tool and restrains the increase of drilling depth. Hence, the air supply flow and pressure become the key factors for air drilling. The paper explores change rule of the air suppy flow and pressure in the course of air drilling by using the gas-solid two-phase flow theory and combining the ground simulation experiment research, and we get an effective method to solve the difficult drilling problem of the soft coalbed by forming an independent air supply system with the movable underground air compressor and by using a moderate pressure compressed air drilling.The moderate pressure air drilling is accompanied by large slag-off drainage and high flow rate of returning dusty air, which brings great difficulty in dust collection. Bad effects of the current simple dust collector hide a danger for mine safety considering existing dust residue. This paper simulates digitally the cyclone dust collector via computional fluid dynamics software and further studys the internal flow field and particle movement traces. In addition, 3-stage powerless dust collector is developed by combing 3 principles of inertial, wet and venturi dust collection in combination with moderate air pressure drilling. The field test is executed in Qi’nan Coalmine of Huaibei Mining (Group) Co. Ltd., using consolidated rig, underground explosion-proof portable air compressor, moderate air pressure large hole sealing drill pipe and three-way bit. 2171m drilling footage is completed in weak outburst coalbed with drillability coefficient ranging from 0.5 to 0.8. According to the field test, efficiency of the dust collecor reaches 93%.An empirical formula for parameter selection is derived from studying air supply parameters of moderate pressure air drilling. Proper equipment matching can be taken for guidance in drilling in soft coalbed.更多还原