摘要
突出流体的动力冲击效应是煤与瓦斯突出灾害的主要致灾因素之一。为进一步认识该过程中煤-瓦斯两相流的冲击动力致灾机制,开展不同巷道布置形式下的突出物理模拟试验,分析突出过程中冲击力时空演化特征、冲击力特征参数及其致灾毁伤等级分布。研究结果表明:在直巷中,气流及稀疏两相流阶段冲击力的演化趋势随距突出源区距离的增加而愈发复杂;冲击力随着固-气比的增大而增大,峰值冲击力在稠密两相流阶段;冲击力衰减过程中存在起伏现象,表明突出能量的释放是阶段完成的;尾部结构对直线段的冲击力有巨大的影响,表现为直角L型>T型>圆弧L型;随时间的推移,直巷道中部逐渐发展成为严重灾害区,巷道致灾范围逐渐扩大,且主要向突出源区方向扩展;在拐弯巷道中,冲击力演化受气相的影响远大于固相;拐弯巷道内有灾害集中区的存在;冲击力在巷道内呈现出齿状的分布,尤其在拐弯巷道中呈现强-弱相间的分布特征;直角L型的动力致灾力度和致灾面积都大于圆弧L和T型;重灾区主要分布在直巷道中前部和拐弯巷道,同时,在直巷道尾部和拐弯巷道部分地域有安全区的存在;直角拐弯结构和平角分岔结构都存在能量集中释放从而导致冲击动力致灾增强的机制;弧形结构可有效降低冲击动力致灾力度,减少拐弯巷道灾害集中区的数量,避免或减弱能量的集中释放;正压作用时间呈周期性V字型分布;比冲量沿巷道呈现多峰波动分布;与峰值冲击力对比,加入正压作用时间因素后其差异性主要体现在直巷道中前端;直巷道末端和拐弯巷道的冲击力时程演化规律受尾部结构的影响较大。
The dynamic impact effect of outburst fluid is one of the main disaster-causing factors of coal and gas outburst disasters.To further understand the disaster-causing mechanism of coal-gas two-phase flow in this process,some physical simulation tests of outbursts under different roadway layouts were carried out to analyze the spatial and temporal evolution characteristics of impact force,impact force characteristic parameters,and the distribution of disaster-causing damage level in the outburst process.The results show that in the straight roadway,the evolution trend of impact force in the airflow and thin two-phase flow stages becomes more and more complicated with the increaseof distance from the coal seam.The impact force increases with the increase of the solid-gas ratio,and the peak impact force is in the dense two-phase flow stage.There is an undulation phenomenon in the decay of impact force,which indicates that the release of outburst energy is completed in stages.The tail structure has a great influence on the impact force in the straight section,which is L-shaped>T-shaped>L(arc)shaped.Over time,the middle of the straight roadway gradually develops into a serious disaster area,and the disaster-causing range of the roadway gradually expands,mainly in the direction of the coal seam.In the turning roadway,the impact force evolution is much more influenced by the gas phase than the solid phase.There are disaster concentration areas in the turning roadway.The impact force shows a tooth-like distribution in the roadway,especially in the turning roadway,which shows a strong-weak phase distribution.The dynamic disaster intensity and disaster area of the L-shape are greater than those of the L(arc)and T-shape.The hardest-hit areas are mainly located in the middle and front of the straight roadway,while there are safety areas at the end of the straight roadway and in some areas of the turning roadway.The right-angle turning structure and the flat-angle bifurcated structure both have the mechanism of concentrated energy release which leads to enhanced impact force.Arc structure can effectively reduce the disaster intensity caused by impact power,reduce the number of disaster concentration areas of turning roadway,and avoid or weaken the centralized release of energy.The time of positive pressure is distributed in a periodic V-shape.The specific impulse volume shows multi-peak fluctuation distribution along the roadway.Compared with the peak impact force,the difference is mainly reflected in the front end of the straight roadway after adding the positive pressure action time factor.The time evolution of impact force at the end of the straight roadway and the turning roadway is influenced by the tail structure.
作者
许江
程亮
彭守建
周斌
焦峰
杨海林
魏仁忠
XU Jiang;CHENG Liang;PENG Shoujian;ZHOU Bin;JIAO Feng;YANG Hailin;WEI Renzhong(l.State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;College of Safety Science and Engineering,Xi'an Unwersity of Science and Technology,Xi'an 710054,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2023年第1期238-250,共13页
Journal of China Coal Society
基金
国家自然科学基金面上资助项目(51874055,52074047)
中央高校基本科研业务费资助项目(2022CDJQY-011)。
关键词
煤与瓦斯突出
两相流
冲击力
巷道结构
动力致灾
毁伤等级
coal and gas outburst
two-phase flow
impact force
roadway structure
dynamic disaster
damage level
