摘要
针对本煤层瓦斯抽采钻孔密封性差、封孔长度不够、钻孔形变较大、钻孔及周围煤体漏风严重等造成抽采瓦斯浓度偏低、衰减速度较快及稳定性差等技术难题,基于＂固封液-液封气＂,受限空间膨胀、渗流力学等理论,进行了钻孔及煤体密封技术的实验模拟与现场验证,研究并开发了固液耦合流体壁式密封新技术及设备。研究表明,采用固液耦合流体壁式密封技术可对抽采钻孔及周围煤体裂隙实施动态密封,最终形成粘液、裂隙及钻孔周围煤体相互耦合的立体封面,有效阻止了因抽采负压增大而导致的巷道空气通过钻孔及周围煤体裂隙向抽采钻孔的漏入,使得瓦斯抽采过程浓度稳定,单孔平均浓度提高4-5倍,显著地提高了本煤层瓦斯的抽采效率。
Considering the technical problems such as poor sealing effect, insufficient sealing length, large borehole deformation and the serious air leakage in borehole and surrounding coal body during gas drainage process in min-ing-coal bed, which have caused the lower gas concentration, the faster decay rate and poor stability, based on the theories of＆quot;sealing liquid by solid and sealing air by liquid＆quot;, limited space expansion and seepage mechanics, the experimental simulation and site validation for sealing technology of borehole and coal body were conducted, and the new technology and equipment of fluid wall sealing by solid-liquid coupling were studied and developed.The results showed that applying the fluid wall sealing technology can implement dynamic sealing for drainage borehole and coal body fractures around it, and eventually form the coupled stereoscopic covers by mucus, fractures and coal body around borehole.It effectively prevented the air leakage from roadway to drainage borehole through borehole and surrounding coal body fractures caused by increasing of drainage negative pressure, and kept the constant con-centration in process of gas drainage.The average concentration of single hole was improved by 4-5 times, and the gas drainage efficiency in mining-coal bed was evidently improved.
出处
《中国安全生产科学技术》
CAS
CSCD
北大核心
2015年第4期33-39,共7页
Journal of Safety Science and Technology
基金
国家自然科学基金资助项目(51304112)
关键词
本煤层
固液耦合
流体壁式密封
瓦斯浓度
mining-coal bed
solid-liquid coupling
fluid wall sealing
gas concentration
