斗轮挖掘机取料过程的离散元仿真分析

Discrete element simulation analysis on reclaiming process of bucket wheel excavator

采用离散元法对WUD 400/700型输煤斗轮挖掘机的取料过程进行数值模拟,分析了颗粒的运动形态与速度分布、不同进给速度对取料效率的影响、不同铲斗几何结构对工作载荷的影响。结果表明:离散元仿真切屑体积的变化趋势与理论切屑体积的变化过程相符,证实了仿真模型的正确性;当斗轮转速为5 r/min时,斗轮挖掘机分层分段取料作业的最优进给速度为0.35 m/s;椭圆曲面铲斗的工作载荷σP明显小于圆弧曲面铲斗的σP,铲斗前壁的σP小于后壁的σP。本研究显示离散元仿真是分析输煤斗轮挖掘机取料过程的一种有效数值手段,可为斗轮挖掘机进给速度的合理选择、铲斗几何结构的有效改进提供参考。

Discrete element method is used for numerical simulation of reclaiming process of WUD 400/700 coal conveying bucket wheel excavator,and the influence of particle motion,velocity distribution and different feeding speeds on reclaiming efficiency is analyzed,and so is the influence of different geometric structures of the bucket on working load.The results show that chip volume based on discrete element simulation changes in the same way as theoretical chip volume,thus proving that the simulation model is correct.When the bucket wheel rotates at the speed of 5 r/min,optimal feeding speed of the bucket wheel excavator for layered and segmented reclaiming is 0.35 m/s.Furthermore,working loadσP of elliptic curved bucket is obviously lower than that of circular curved bucket,andσP of the bucket’s front wall is smaller than that of rear wall.The research demonstrates that discrete element simulation is an effective numerical approach to analyzing the reclaiming process of coal conveying bucket wheel excavator,which can be useful reference for reasonable selection of feeding speed of bucket wheel excavator and effective improvement of geometric structures of the bucket.