低透气性煤层水射流瓦斯增透关键技术研究  

Key technologies of hydraulic flushing gas permeability-enhancement in low-permeability coal seams

作　　者：张小军 ZHANG Xiaojun(Shaanxi Coal Science Research Institute,Xi’an 710001,China)

机构地区：[1]陕西省煤炭科学研究所,陕西西安710001

出　　处：《西安科技大学学报》2021年第3期410-416,共7页Journal of Xi’an University of Science and Technology

基　　金：国家科技部科研院所技术开发研究专项资金项目(2011EG122206)。

摘　　要：低透气性煤层瓦斯抽采问题一直是中国煤炭企业在安全生产中的一个重要课题。基于流体连续介质理论,联立连续性方程、Euler方程、能量方程及张量总和表达式建立水射流冲击煤体的控制方程,给出射流压力与射流流速及流量的关系式,确定射流压力与射流流速及流量之间呈正相关趋势。通过ANSYS/LS-DYNA模拟研究水射流压力与切割半径间的关系,结果表明射流压力越大,切割深度越远,但切割压力越大,伴随而来的峰值应力不稳定现象越剧烈;冲击水压为60 MPa时,冲击深度趋于平缓峰值,冲击效率较高。采用实验室实验方法确定水射流喷口半径,初步检验水射流对低渗透煤体的切割效果良好。工业性试验结果表明水射流增加了煤体贯通裂隙,扩大了瓦斯的渗出范围,瓦斯抽采效率明显提升。The problem of gas extraction from low permeability coal seams has always been an important issue for coal enterprises in Chinese safe production.This paper establishes a control equation of water jet impact on coal body based on the theory of fluid continuum medium,the joint continuity equation,Euler equation,energy equation and tensor sum expression,builds the relationship between jet pressure and jet flow rate and traffic,and determines the positive correlation trend between jet pressure and jet flow rate and flow rate.The relationship between hydraulic flushing pressure and cutting radius was investigated by ANSYS/LS-DYNA simulations,indicating that the higher the pressure,the farther the cutting depth,but the higher the cutting pressure,the more dramatic the accompanying peak stress instability.When the impact water pressure is 60 MPa,the impact depth tends to level off the peak with the impact efficiency higher.The radius of the water jet nozzle was determined by laboratory experimental method,and the preliminary test shows that the water jet has good effects on cutting and breaking coal of low permeability coal body.The results of industrial experiments shows that hydraulic flushing increases the penetration fissures of coal body,expands the range of gas seepage,and significantly improves the gas extraction efficiency.

关 键 词：低透气性煤层 瓦斯开采 水射流增透 数值模拟 关键技术 

分 类 号：TD231[矿业工程—矿井建设]