特厚煤层综放开采顶煤遗失机理及放煤步距优化数值模拟研究  

Numerical simulation study of top-coal loss mechanism and reasonable cycle step length for extra-thick coal seam top-coal drawing

作　　者：李东印[1] 王耀闯 王伸[1,2] 朱时廷 王祖洸 LI Dongyin;WANG Yaochuang;WANG Shen;ZHU Shiting;WANG Zuguang(School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,Henan,China;Postdoctoral Station of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,Henan,China;Tongxin Coal Mine,Datong Coal Mine Group Co.,Ltd.,Datong 037003,Shanxi,China)

机构地区：[1]河南理工大学能源科学与工程学院,河南焦作454000 [2]河南理工大学安全科学与工程博士后科研流动站,河南焦作454000 [3]大同煤矿集团有限公司同忻煤矿,山西大同037003

出　　处：《河南理工大学学报（自然科学版）》2023年第2期1-10,共10页Journal of Henan Polytechnic University（Natural Science）

基　　金：国家重点研发计划项目(2018YFC0604502);中国博士后科学基金资助项目(2020M672227);河南省自然科学基金资助项目(202300410175)。

摘　　要：为确定特厚煤层综放开采的合理放煤步距,探究放煤步距对顶煤遗失和回收率的影响机理,以塔山煤矿8222综放工作面为工程背景,采用CDEM颗粒-块体单元耦合数值模拟方法,建立考虑液压支架支撑作用的二维走向开采数值模型,研究特厚煤层综放开采放煤步距对遗煤形态、放煤漏斗、煤岩分界线等的影响,揭示“见矸关门”条件下的顶煤遗失机制,探索顶煤在采空区内随综放工作面循环推进的遗失规律。结果表明:随着综放工作面不断推进,液压支架上方的矸石提前到达放煤口,采空区一侧部分顶煤未能放出而留在采空区内,造成顶煤遗失;放煤步距对煤岩界面形态和煤岩相互侵入有显著影响,进而影响顶煤回收率和混矸率;通过数值分析、顶煤回收率和总回收量指标确定了塔山煤矿8222综放工作面12 m顶煤厚度下最佳放煤步距,为0.8 m。In order to study the reasonable value of the parameters of the cycle step length(CLS)in fullymechanized top-coal drawing of extra-thick coal seam,and to explore the influence of CLS on top-coal loss mechanism and top-coal recovery rate,CDEM particle block element coupling numerical simulation method,taking the 8222 fully mechanized top-coal drawing face of Tashan Coal Mine as the engineering back⁃ground,the CDEM particle block element coupling numerical simulation method was adopted to establishe the mathematical model considering the support effect of hydraulic support.The two-dimensional strike mining numerical model was used to analyze the coal cycling step length,the shape of residual coal,the coal funnel,and the coal rock interface line.The mechanism of top-coal loss was revealed under the condition of“rock apear,close the opening”,and the strip loss law of top coal with the advance of circulation in the goaf was found.The results showed that:With the continuous advance of the working face,the rock above the hydraulic support reaches the coal drawing mouth in advance,and part of the top coal on one side of the goaf fails to be discharged and remained in the goaf,resulting in the loss of top coal.The distance of drawing coal had a significant effect on the interface shape of coal and rock and the mutual invasion of coal and rock,and then affected the top-coal recovery rate and mixed rock rate.In addition,the evolution law of coal-rock interface line and top-coal recovery rate under the conditions of different cycling lengths were analyzed.Through nu⁃merical analysis and according to the top-coal recovery rate and total recovery index,the best cycling length was 0.8 m under 12 m top coal back end thickness in 8222 fully mechanized top-coal drawing face of Tashan Coal Mine.

关 键 词：综放开采 放煤步距 特厚煤层 颗粒-块体单元耦合方法 顶煤回收率 

分 类 号：TD713[矿业工程—矿井通风与安全]