综放顶煤放出规律与放煤步距的离散元仿真研究

综放开采的合理放煤步距是研制综放工作面成套技术装备的基础，是提高综放工作面采出率与煤质的关键之一。对颗粒状散体介质离散元软件进行再开发时，单元的接触关系采用弹性及阻尼元件，以适应煤矸放出过程的力学特性，基于Windows环境进行封装处理，通过添加虚拟壁功能实现分层散体介质的仿真处理。在低位综放支架、放煤口水平投影宽度为0.8m条件下，对不同采煤步距(0．6，0．8，1．0，1．2m)的项煤放出规律进行了离散元仿真研究，从顶煤损失与含矸率两个方面分析得到综放合理放煤步距为1．0m，较合理的放煤步距为0．8m，即分别稍大于或等于放煤口水平投影宽度。综放工作面采煤机截深、支架及运输机前移步距应按合理或较合理放煤步距设计。据此研制成功综放成套设备(步距为0．8m)，实现了适应项煤放出规律的一采一放、平行作业的采放工艺，大幅度提高顶煤综放开采的高产高效水平。

NUMERICAL SIMULATION BY DISTINCT ELEMENT CODE ON DRAWING LAW AND INTERVAL OF FULLY-MECHANIZED COAL MINING WITH CAVING METHOD

Feasible drawing interval is the basis to study mining equipment of fully-mechanize coal mining with caving method. It is also a key to increase recoverable ratio of coal face and to improve quality of coal. By redeveloping the distinct element software of loose grain media,the contact relation among elements is simulated by elastic and damping elements to keep consistence with top coal drawing process. Based on Windows environment,the virtual wall is made to simulate distinctive multi-layer media. Under the condition of 0.8 m width of falling opening with lower position falling method,the falling law of top coal is simulated by distinct element method in different drawing intervals of 0.6,0.8,1.0,and 1.2 m. In the light of loss ratio of top coal and refuse rate,the drawing law and the feasible interval are studied and it is found that the scientific drawing interval is 1.0 m and the lower limit is 0.8 m. The study results of this paper are applied to determine the cut depth of coal-winning machine and the moving interval of support and conveying equipment. By using this equipment with interval of 0.8 m,the mining technology of one cut by one drawing and parallel operation is successfully applied to raise the standard of high production and effect.