大型现代化煤矿块煤转载防破碎仿真研究

发布时间：2018-07-03 00:30

本文选题：转载站 + 块煤　；参考：《西安科技大学》2017年硕士论文

【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%。
[Abstract]:In view of the large modern coal mine of ten million tons in Jurassic coal field of northern Shaanxi, the coal transport distance is long, the volume of coal transportation is large, the coal is broken in the process of coal transfer, and the problems of equipment wear, coal dust and noise are prominent, the EDEM numerical analysis method is adopted. This paper studies the mechanism and control of coal rate loss in large flow, long distance and long distance coal transportation by comprehensive means such as crushing theory analysis and field test. The physical and mechanical parameters of coal were measured by physical and mechanical experiments. The particle structure model and bond contact model were established by EDEM, and the different incident velocity, incident angle, coal block shape, coal mass strength were analyzed. Under the condition of material and other conditions, the collision process of coal block is obtained. The bigger the incident velocity and angle of coal block is, the more serious the breakage is and the binary fitting relationship between them is obtained. When rubber lining is added, the crushing rate of block coal decreases by 21.5wt%, and the strength of block coal increases. Block coal is difficult to break. The collision process of spherical, cubic and flake block coal is simulated and analyzed, and the fracture rate of collision force bond is obtained as follows: vertical block 13, sheet 43 and spherical 3. The larger the impact contact area is, the more difficult it is to break the coal block. The particle flow model of ten million tonnage block coal is established. The accumulation angle, coal flow trajectory, coal flow mass flow rate and discharge speed of block coal are studied, and the simulation results are in good agreement with the theoretical calculation. Based on the simulation analysis of the transfer loss and stop loss of block coal crushing, it is concluded that the arc block plate can effectively reduce the impact, and the coal flow speed is greatly reduced after the impact of the buffer box, and the coal flow dispersion is larger after the coal flow impact the buffer box. It is not good for dust prevention, the impact coefficient is 50 times as high as the arc block, which is not good for the prevention of breakage, the high coal flow particles are tracked and monitored, and it is found that the high coal flow particles are moving slowly in the buffer reactor. The low coal particles leave the buffer box quickly along the buffering inclined plane, thus the later low coal flow particles always appear before the continuous impact of the high coal flow particles; Theoretical analysis and simulation analysis show that the arc chute can better avoid the excessive impact caused by the falling process. It is concluded that the chute with arc guide section can reduce the impact of coal flow on the belt surface of the lower belt conveyor. The research results are applied to the reconstruction of the coal transfer station in Xilongwan Coal Mine. According to the existing problems, a new reloading station is designed. The superiority of the new reprint station in coal flow speed control and anti-crushing is verified by simulation. The designed transfer station is applied to the production site and the block coal rate is increased by 12. 1%.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD528.1

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