采煤机滚筒装煤过程仿真及装煤效率研究

发布时间：2018-05-30 10:49

本文选题：滚筒采煤机 + 装煤效率　；参考：《太原理工大学》2017年硕士论文

【摘要】：滚筒式采煤机是以螺旋滚筒作为工作机构的采煤装备,除了完成截煤之外,其另一个主要功能是把截落的煤炭装入采煤工作面的刮板输送机。数十年来,滚筒式采煤机螺旋滚筒的装煤效率一直是业内关注的重点,而薄煤层滚筒采煤机的装煤效率低的问题则更加突出。本文结合理论分析,采用离散元软件仿真的方法,对影响采煤机滚筒装煤效率的主要结构参数、运动参数、煤体性质参数、滚筒结构形式等因素进行了研究。基于采煤机滚筒装煤机理,对叶片上某一煤颗粒进行了力学分析、运动学分析,推导出计算装煤效率的理论模型,由此模型分析得出影响滚筒装煤效率的主要因素包括滚筒直径、叶片直径、筒毂直径、叶片厚度、叶片头数、螺旋升角、滚筒宽度等滚筒结构参数,滚筒转速、牵引速度等运动参数,以及采高、充满系数、摩擦角、煤流的松散系数等。结合采煤机滚筒的结构特点和工作特点,对上述各因素对滚筒装煤效率的影响规律进一步做了较为深入的分析,为提高螺旋滚筒的装煤效率提供了理论依据。基于离散元基本原理,利用PFC3D软件建立了煤壁模型及刮板输送机中部槽简易模型。利用UG软件建立了滚筒三维模型并导入PFC软件中,与煤壁模型及刮板输送机中部槽简易模型共同组成了采煤机滚筒装煤仿真模型。以某型号薄煤层采煤机为研究对象,以叶片螺旋升角、滚筒转速、牵引速度为主要设计变量,分别对采煤机滚筒的顺转、逆转装煤过程进行仿真,统计滚筒装煤效率以及装煤过程中滚筒叶片包络范围内颗粒速度、颗粒数,得到了三个因素对滚筒装煤效率的影响程度、影响规律以及它们最佳匹配组合。以滚筒转速为研究重点,得到了转速对煤流X、Y、Z三个方向分速度的影响规律,为采煤机滚筒的结构设计和实际工作中运动参数选择提供了一定的参考价值。根据滚筒装煤机理及采煤机工作特点,分析了煤的湿度、摩擦系数、煤岩密度、煤块大小等煤岩性质参数对装煤效率的影响。利用颗粒流离散元软件仿真,重点研究了煤的摩擦系数、煤与叶片之间的摩擦系数、煤颗粒大小对滚筒装煤效率的影响规律,为进一步完善滚筒装煤理论内容提供了实验依据。采用离散元仿真方法,以尺寸规格相同的普通螺旋滚筒、锥形螺旋滚筒、变升角螺旋滚筒、叶片轴向倾斜螺旋滚筒为研究对象,从煤流的轴向速度和抛出距离两个角度研究滚筒的装煤能力,通过分析煤流运动轨迹及煤流与叶片的微观作用机理,得出:滚筒逆转时,变升角螺旋滚筒和叶片轴向倾斜螺旋滚筒可提高装煤效率;而滚筒顺转时,叶片轴向倾斜螺旋滚筒可提高装煤效率,通过对这两种滚筒结构形式进行了力学分析,提出今后应从减小煤流与叶片之间的摩擦力,缩短煤流在滚筒内部运动时间,增大煤流在滚筒内部加速度这几个方面对滚筒结构形式进行改进。
[Abstract]:The drum shearer is a kind of coal mining equipment which takes the spiral drum as the working mechanism. In addition to the coal cutting, its other main function is to load the cut coal into the scraper conveyor of the coal mining face. In recent decades, the coal loading efficiency of drum shearer has been the focus of the industry, while the low efficiency of thin coal seam drum shearer is more prominent. Based on the theoretical analysis and discrete element simulation method, the main structural parameters, motion parameters, coal body property parameters and drum structure form which affect the coal filling efficiency of the shearer are studied in this paper. Based on the coal loading mechanism of the shearer drum, the mechanical analysis and kinematics analysis of a coal particle on the blade are carried out, and the theoretical model for calculating the coal loading efficiency is derived. Based on the model analysis, the main factors affecting the efficiency of coal loading are obtained, such as drum diameter, blade diameter, hub diameter, blade thickness, blade head number, spiral lift angle, drum width and other drum structural parameters, drum rotational speed, etc. Traction speed and other motion parameters, as well as mining height, full coefficient, friction angle, coal flow loose coefficient. Combined with the structural and working characteristics of the shearer drum, the influence of the above factors on the coal filling efficiency of the drum is further analyzed, which provides a theoretical basis for improving the charging efficiency of the spiral drum. Based on the basic principle of discrete element, the coal wall model and the simple model of the middle slot of scraper conveyor are established by using PFC3D software. The three-dimensional model of drum is established by UG software and imported into PFC software. The simulation model of coal drum loading of shearer is made up of coal wall model and simple model of middle slot of scraper conveyor. Taking a certain type of thin coal seam shearer as the research object, taking the blade spiral rising angle, drum speed and traction speed as the main design variables, respectively, the paper simulates the coal loading process of the shearer. According to the statistics of coal filling efficiency, particle velocity and particle number in the envelop range of drum blade during coal loading, the influence of three factors on the coal loading efficiency, the influence law and the best matching combination are obtained. Taking the rotational speed of the drum as the research emphasis, the influence of the rotational speed on the speed of the coal flow in three directions is obtained, which provides a certain reference value for the structural design of the drum of the shearer and the selection of the motion parameters in the actual work. According to the coal loading mechanism of drum and the working characteristics of shearer, the influence of coal moisture, friction coefficient, density of coal and rock, size of coal block on coal loading efficiency is analyzed. The influence of coal friction coefficient, friction coefficient between coal and blade and the size of coal particle on the coal filling efficiency of roller is studied by using discrete element software of particle flow, which provides an experimental basis for further improving the theoretical content of drum charging. Using discrete element simulation method, the common spiral drum, conical spiral drum, variable lift angle spiral drum and axial inclined helical drum with the same size are studied. From the angle of axial velocity and throwing distance of coal flow, the coal loading capacity of roller is studied. By analyzing the movement track of coal flow and the microscopic action mechanism between coal flow and blade, it is concluded that when the drum reverses, The efficiency of coal loading can be improved by variable angle spiral drum and blade axial inclined helical drum, and when the roller is rotating, the blade axial inclined helical drum can improve the coal loading efficiency. The mechanical analysis of these two types of drum structure is carried out. It is suggested that the structure of the drum should be improved from the aspects of reducing the friction between the coal flow and the blade, shortening the movement time of the coal flow inside the drum and increasing the acceleration of the coal flow inside the drum.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD421.6

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