采煤机滚筒截割破煤理论及截割动力学研究

发布时间：2018-11-26 15:37

【摘要】：滚筒式采煤机是机械化采煤作业的主要机械设备,在煤矿开采中占有重要地位。研究截齿与煤壁的相互作用规律,有助于进一步研究滚筒的截割性能,继而改善采煤机的工作效率、稳定性与寿命。有鉴于此,研究不同参数下截齿对煤壁的破坏作用与截割性能,对于螺旋滚筒的优化设计具有重要的意义。本课题对截齿与滚筒截割过程进行研究,主要包括以下内容。首先,基于对煤壁物理力学性质的了解,借助PFC3D软件建立了离散元煤壁模型,进行单轴抗压与巴西劈裂模拟试验,测出了模拟煤壁的力学性质,使之与真实煤壁相匹配;随后,利用UG软件建立镐型截齿模型并导入PFC3D,在不同切削厚度下对该模拟煤壁进行直线截割仿真,并利用回归分析的方法验证了煤壁模型的可靠性。其次,在切削厚度为5 mm、10 mm、15 mm的条件下,分别分析了截割角为40°、45°、50°和55°以及截割线速度为2 m/s、3 m/s、4 m/s和5 m/s十六种情况下煤壁微破坏、截齿载荷以及截割比能耗。再次,建立了双齿截割模型,研究了相关截割模式与非相关截割模式下镐型截齿截割机理与截割性能。此外,探讨了切削厚度为5 mm、10 mm、15 mm和20 mm的条件下及截线距为10 mm、20 mm、30 mm、40mm、50 mm、60 mm、70 mm和80 mm三十二种情况下镐型截齿对煤壁的微破坏、载荷以及截割比能耗。最后,建立了单齿旋转截割模型与滚筒截割模型,分别分析了截齿(滚筒)转速为40 r/min、50 r/min、60 r/min和70 r/min以及牵引速度为2 m/min、3 m/min、4 m/min和5 m/min十六种情况下截齿与滚筒的截割性能。通过上述研究内容,得出以下结论:利用回归分析法验证了仿真结果的正确性与模拟煤壁的可靠性;截割线速度越大,截齿对煤体的剪切错动作用越强,随着截割线速度与截割角的增大,截齿载荷与截割比能耗均呈先增大后减小的趋势,综合考虑,截割线速度应取3~4 m/s,截割角取45~50°为宜;截线距越大,截齿间的相互程度作用越弱,截齿对煤壁的剪切错动作用越强,截齿载荷越大,截线距与切削厚度之比为3.5~4之间时,截割比能耗最小;滚筒载荷随牵引速度的增大而增大,而随着滚筒转速的增大,滚筒载荷为先减小后增大,当截齿转速为60 r/min,牵引速度为2m/min时,滚筒载荷达到最小值,与单齿旋转截割仿真结果一致;滚筒截割比能耗随牵引速度的增大而减小,而当牵引速度恒定时,随着滚筒转速的增大,截割比能耗则为先减小后增大,当滚筒转速为50 r/min,牵引速度为5 m/min时,截割比能耗达到最小值,截割效率最高。
[Abstract]:Drum shearer is the main mechanical equipment of mechanized coal mining and plays an important role in coal mining. The study of the interaction between the cutter and the coal wall is helpful to further study the cutting performance of the drum and then to improve the working efficiency, stability and life of the shearer. In view of this, it is of great significance for the optimization design of spiral drum to study the failure and cutting performance of coal wall caused by cutting teeth under different parameters. In this paper, the cutting process of tooth cutting and drum cutting is studied, including the following contents. Firstly, based on the understanding of the physical and mechanical properties of coal wall, a discrete coal wall model is established by using PFC3D software. The uniaxial compression and Brazilian splitting simulation tests are carried out, and the mechanical properties of the simulated coal wall are measured to match the real coal wall. Then, the pick cutting model was established by UG software and PFC3D, was introduced to simulate the simulated coal wall with different cutting thickness. The reliability of the coal wall model was verified by regression analysis. Secondly, under the condition of cutting thickness of 5 mm,10 mm,15 mm, the coal wall microdamage under the cutting angle of 40 掳, 45 掳, 50 掳and 55 掳and the cutting speed of 2 m / s ~ 3 m / s ~ 4 m / s and 5 m / s is analyzed, respectively. Cutting load and cutting specific energy consumption. Thirdly, the double-tooth cutting model is established, and the mechanism and performance of pick cutting under the correlation cutting mode and the non-related cutting mode are studied. In addition, under the conditions of cutting thickness of 5 mm,10 mm,15 mm and 20 mm and intercept distance of 10 mm,20 mm,30 mm,40mm,50 mm,60 mm,70 mm and 80 mm 32, the micro-damage of coal wall caused by pick tooth is discussed. Load and cutting ratio energy consumption. Finally, the rotary cutting model of single tooth and the cutting model of drum are established. The rotational speed of cutter (drum) is 40 r / min 50 / min 60 r/min and 70 r/min, and the traction speed is 2 m / min ~ 3 m / min, respectively. Cutting performance of cutter and drum in 16 cases of 4 m/min and 5 m/min. The conclusions are as follows: the correctness of simulation results and the reliability of simulated coal wall are verified by regression analysis. With the increase of cutting speed and angle, the load and energy consumption of cutting increase first and then decrease. Considering synthetically, the cutting speed should be taken at 34 m / s. The cutting angle is 45 掳and 50 掳; The larger the intercept distance is, the weaker the interaction between the cutting teeth is, the stronger the cutting fault action of the cutting tooth is to the coal wall, the larger the cutting load is, and when the ratio of the cutting line distance to the cutting thickness is 3.5 ~ 4, the energy consumption of the cutting ratio is the least. The cylinder load increases with the increase of the traction speed, and decreases first and then increases with the increase of the rotational speed of the drum. When the gear cutting speed is 60 r / min and the traction speed is 2m/min, the drum load reaches the minimum value. The results are consistent with the simulation results of single-tooth rotary cutting. The specific cutting energy consumption of the cylinder decreases with the increase of the traction speed. When the traction speed is constant, the specific energy consumption decreases first and then increases with the increase of the drum speed. When the drum speed is 50 rmin and the traction speed is 5 m/min, the cutting specific energy consumption decreases first and then increases with the increase of the drum speed. The cutting ratio energy consumption reaches the minimum value and the cutting efficiency is the highest.
【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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