综放开采冒落顶煤体堆积状态与放出率定量化研究  

Quantitative study on piled state of collapsed top coal and drawing ratio in longwall with top coal caving

作　　者：闫少宏[1] 申宇鹏 YAN Shaohong;SHEN Yupeng(School of Energy and Mining Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)能源与矿业学院,北京100083

出　　处：《采矿与安全工程学报》2023年第4期656-667,共12页Journal of Mining & Safety Engineering

基　　金：国家重点研发计划项目(2018YFC0604501)。

摘　　要：影响顶煤体冒落后堆积状态与放出率的主要因素有顶煤体厚度、采煤机割煤高度、顶煤体破断角、顶煤体滞后垮落距离、直接顶垮落与堆积特性。通过对比分析得出,顶煤、直接顶不同组合条件下,顶煤体冒落堆积状态的差异性是造成厚硬顶煤放出率低的根本原因。基于中硬、硬煤的顶煤破断角<90°条件下顶煤体的冒落特性,将其运动轨迹简化为圆周运动和自由落体运动,建立顶煤体冒落堆积计算模型,得出冒落顶煤在支架后方形成“四边形堆积”或“三角形堆积”状态。通过理论推导得出两种堆积状态的具体参数公式,并提出顶煤放出率的量化计算公式。研究表明:顶煤体冒落堆积轮廓由影响顶煤体冒落堆积的5个因素决定,顶煤放出率由其冒落堆积轮廓决定。由此可得,影响顶煤冒落堆积的5个因素与顶煤放出率定量关系为顶煤放出率与顶煤体破断角呈对数增大规律、与顶煤体滞后垮落距离呈指数减小规律、与顶煤厚度呈指数减小规律、与采煤机割煤高度呈指数增大规律、与矸石的充填角度呈指数增大规律、与自然安息角呈指数减小规律。这些研究成果不仅可以定量计算出工作面顶煤的放出率,为不同开采条件下厚硬顶煤的放出率研究提供预测模型,也可为厚硬顶煤弱化方案选取及效果评价提供理论指导。The main factors affecting the piled state and drawing ratio of top coal caving are the thickness of top coal,the cutting height of shearer,the breaking angle of top coal,the lag caving distance of top coal,and the direct roof caving and piled characteristics.By comparing and analyzing,it is found that the reason for the low release rate of thick hard top coal is the variations in the collapse and pile states of top coal under various combinations of top coal and direct top coal.Based on the caving characteristics of the collapsed top coal under the condition of breaking angle of medium hard coal and hard coal<9o°,the motion trajectory is simplified as circular motion and free fall motion,and model of collapsed top coal is established.It is concluded that the caving coal forms a state of"quadrilateral piled state"or"triangle piled state"behind the support.Theoretically,two state-specific parameter formulas are provided,combined with a quantitative formula for top coal drawing ratio.The research shows the piled state of collapsed top coal is determined by the five elements of the piled state of collapsed top coal,and the top coal drawing rate is determined by its pile profile,so it can be obtained that there is a quantitative relationship between the top coal drawing rate and its five elements,which is as follows:The top coal drawing ratio increases logarithmically with the breaking angle of top coal,while decreasing exponentially with the lagging caving distance of top coal and the thickness of top coal;increases exponentially with the cutting height of shearer and the filling angle of waste;decreases exponentially with natural angle of top coal.They provide not only a prediction model for the study of the drawing ratio of thick hard top coal under different mining conditions,but also a theoretical guidance for the selection and effect evaluation of the weakening scheme of thick hard top coal.

关 键 词：综放开采 堆积状态 放出率 顶煤体破断角 滞后垮落 

分 类 号：TD823[矿业工程—煤矿开采]