【作者】 王超；

【导师】 邓广哲；

【作者基本信息】 西安科技大学 ， 采矿工程， 2017， 硕士

【摘要】 针对陕北侏罗纪煤田千万吨级大型现代化矿井,煤炭运输距离长、运量大,煤炭转载过程中块煤破碎问题,以及设备磨损、煤尘、噪音等问题突出,采用EDEM数值分析方法、破碎理论分析、现场试验等综合手段,对大流量、长距离、多转载煤炭运输转载块煤率损失机理和控制进行了以下研究。通过物理力学实验测定煤的物理力学参数,采用EDEM建立煤块颗粒结构模型和粘结接触模型,分析不同入射速度、入射角度、煤块形状、煤块强度,材质等情况下煤块的碰撞破碎过程,得出煤块入射速度和角度越大,破碎越严重及其之间的二元拟合关系;得出加橡胶内衬情况下,块煤破碎率降低了 21.5%;块煤强度增大,块煤破碎较难。仿真分析了球形、立方体、片状块煤的碰撞过程,得出其碰撞力键断裂率分别是:立方块13%,片状43%,球形3%,从而进一步得出碰撞接触面积越大,煤块碰撞破碎越难。建立了千万吨级块煤颗粒流模型,对块煤的堆积角、煤流轨迹、煤流质量流率、卸料速度等问题进行研究,并与现场情况进行对比,模拟结果与理论计算完全相符。对块煤破碎的转载损失及止损进行仿真分析,得出弧形型挡料板能有效减少冲击;得出煤流在冲击缓冲箱后,速度大大降低,且煤流冲击缓冲箱后煤流离散性较大,不利于防尘,冲击系数是弧形挡料板的50倍,不利于防破碎;对煤流高、低位的煤颗粒进行追踪监测,发现高位的煤流颗粒在缓冲堆内部缓慢运动,低位的煤颗粒沿缓冲斜面迅速离开缓冲箱,从而出现后来的低位煤流颗粒总是在不断的冲击之前的高位煤流颗粒;理论分析并仿真分析得出弧形溜槽能更好的避免跌落过程中引起的冲击过大问题;通过对溜槽末端有、无弧形导向段的情况进行仿真,得出有弧形导向段的溜槽能更好减少煤流对下部胶带运输机皮带面的冲击。将研究结果应用于转龙湾煤矿转载站改造中,根据存在的问题设计了新的转载站,通过仿真验证了新转载站在煤流速度控制和防破碎方面的优越性,将设计的转载站应用了生产现场,使块煤率提高了 12.1%。更多还原

【Abstract】 In allusion to the large-scale modern mine of Jurassiccoal field in northern shanxi province,long transportation distance、large freight volume、lump coal breaking problem in the process of coal transshipment and the serious problems of equipment wear、coal dust、noise and so on,which adopted the EDEM numerical analysis method、broken theoretical analysis、field experiment and other methods to study the large flow、long distance、the loss mechanism and control of multi-reshipped coal transport lump coal rate.The physical and mechanical parameters of coal were determined by physical mechanics experiment,and the particle structure model and bond contact model were established by Edem,and the different incidence velocity,incidence angle,coal shape,the collision and crushing process of coal under the condition of coal strength and material,the higher the incidence velocity and angle of coal,the more serious fragmentation and the two-element fitting relationship between the coals and the rubber liner,the lump coal crushing rate decreased 21.5%,the lump coal strength increased and the lump coal crushing was difficult.Simulation and analysis of the collision process of spherical,cubic,flake lump coal,the impact force bond fracture rate is:cubic block 13%,flaky 43%,spherical 3%,so that the larger the contact area,the more difficult the collision of coal.The particle flow model of tens of millions of tons of lump coal was established,and the problems such as stacking angle,coal flow trajectory,coal flow mass flow rate and unloading velocity were studied,and the simulation results were in full conformity with the theoretical calculation.The simulation analysis of the lost and loss of lump coal fragmentation shows that the arc type baffle plate can effectively reduce the impact.The coal flow is greatly reduced after the impact buffer box,and the coal flow dispersion is larger after the impact buffer box,it is not good for dustproof,the impact coefficient is 50 times times of the arc baffle plate,it is not conducive to prevent crushing;the coal-flow high,low coal particles tracking monitoring,found that the high level of coal particles in the buffer pile in the internal slow movement,low coal particles along the buffer ramp quickly left the buffer box Thus the later low coal flow particles are always in constant impact before the high coal flow particles;The theoretical analysis and simulation result shows that the curved chute can avoid the large impact problem caused by the falling process,and through the simulation of the Arc-Free guide section,it is concluded that the chute with curved guide section can reduce the impact of the coal flow on the belt of the lower belt conveyor.The results of the above analysis are applied to the reconstruction of the transfer station of the ZhuanLongWan coal mine.According to the existing problems and the previous research results designed a new transfer station,Through simulation proved that the superiority of new transfer station in terms of speed of coal flow control and shatterproof,applied the design of the transfer station to the production scene and increased the lump coal rate by 12.1%.更多还原