大型分级破碎机破碎机理及冲击动力学特性研究.pdf

煤炭科学研究总院 博士学位论文 大型分级破碎机破碎机理及冲击大型分级破碎机破碎机理及冲击 动力学特性研究动力学特性研究 作者姓名王保强 学科专业采矿工程 导师姓名王国法 研究员 完成时间二○一九年五月二十七日 万方数据 China Coal Research Institute A dissertation for doctors degree Study on crushing mechanism and impact dynamic characteristics of large-scale sieving crusher Author’s NameBaoqiang Wang specialityMining Engineering SupervisorProf. Guofa Wang Finished timeMay 27th, 2019 万方数据 煤炭科学研究总院学位论文原创声明煤炭科学研究总院学位论文原创声明 本人郑重声明此处所提交的学位论文 大型分级破碎机破碎机理及冲击动 力学特性研究 ， 是本人在导师指导下， 在煤炭科学研究总院攻读博士学位期间 独立进行研究工作所取得的成果。据本人所知，论文中除已注明部分外不包含 他人已发表或撰写过的研究成果。对本文的研究工作做出重要贡献的个人和集 体，均已在文中以明确方式注明。本声明的法律结果将完全由本人承担。 作者签名日期年月日 煤炭科学研究总院学位论文使用授权书煤炭科学研究总院学位论文使用授权书 大型分级破碎机破碎机理及冲击动力学特性研究系本人在煤炭科学研 究总院攻读学位期间在导师指导下完成的学位论文。本论文的研究成果归煤炭 科学研究总院所有，本论文的研究内容不得以其他单位的名义发表。本人完全 了解煤炭科学研究总院关于保存、使用学位论文的规定，同意学校保留并向有 关部门送交论文的复印件和电子版本，允许论文被查阅和借阅，同意学校将论 文加入中国优秀博硕士学位论文全文数据库和编入中国知识资源总库 。 本人授权煤炭科学研究总院，可以采用影印、缩印或其他复制手段保存论文， 可以公布论文的全部或部分内容。 本学位论文属于（请在以下相应方框内打“√“; 保密□,在年解密后适用本授权书 不保密□ 作者签名日期年月日 导师签名日期年月日 万方数据 摘要 I 摘摘 要要 随着大型露天煤矿的持续开发， 半连续开采工艺因其较强的适应性逐渐成为 绝大多数露天矿煤炭生产的主流工艺， 而大型半移动或全移动破碎站是该生产工 艺中不可或缺的关键装备，发展最为迅速，其核心设备都是处理量 1000t/h 以上 的大型分级破碎机。分级破碎机原煤直接入料，混粒度物料破碎过程复杂，影响 破碎性能因素繁多，由于缺乏有效研究手段，对破碎机理和破碎效果影响规律不 清楚，且在大尺度入料的高能频繁冲击下，齿辊结构动态特性及损伤机理不明， 导致齿辊优化设计缺乏理论依据，传统大型分级破碎机多依赖经验设计，影响其 高效作业和可靠运行。 论文以神华宝日希勒千万吨级露天矿破碎系统为背景开展研究，引入 DEM 方法模拟破碎过程数值解析分级破碎机理， 利用冲击动力学方法揭示大型分级破 碎设备动态特性，借助试验样机验证理论和数值模型，为大型分级破碎机设计和 应用提供基础理论依据。开展的主要工作及取得的研究结论如下 （1）研究了分级破碎过程的颗粒承载特性，建立了中、大颗粒齿顶咬入过 程的破碎齿-光辊刺破力学模型和小颗粒齿背研磨过程的双光辊碾磨力学模型， 推导了颗粒承载计算公式，发现颗粒分级破碎主要受颗粒粒度和咬合位置影响， 并从颗粒承载的角度分析确定了分级破碎过程的工作参数和结构参数影响因素， 对实际破碎试验的煤样进行了模拟工作环境的基本力学特性测试， 明确试验模型 机的破碎需求。 （2）建立分级破碎机 DEM 唯像模型，采用虚拟破碎试验的方法，分析了 分级破碎机工作参数对破碎性能的影响特性，研究了两齿辊等速下的齿辊转速、 齿辊转动形式及非等速下的齿辊转速差对单位时间处理量及完全破碎时间的影 响规律，发现了破碎机最优齿辊转速，且齿辊反转时单位时间处理量约为正转时 的 1.37 倍。 （3）研究了破碎齿辊结构参数（如齿辊是否等高齿、齿辊等高齿密度和齿 盘布置方式等）对破碎过程的单位时间处理量和破碎能耗的影响，发现分级破碎 过程齿辊输出力矩的波动特性， 通过响应面法进行了齿辊结构参数与工作参数的 协同优化设计， 获取了处理量和完全破碎时间与各因素的定量关系及影响的显著 性顺序，进而提出分级破碎机性能提升方法。 （4）研究了冲击作用下分级破碎过程中齿辊承载特性，进行了四种工况条 件下齿辊结构的强度分析， 建立了齿辊集中参数扭转振动模型和分布质量横向振 动模型，并提出了分析冲击作用下的动态响应方法，破碎齿辊横向振动固有频率 和振型比值与有限元分析结果相近。采用离散元法-有限元法耦合方法，进行了 万方数据 摘要 II 工况下破碎齿辊的承载特性分析， 发现随着入料位置处布料长度和入料高度的增 加，齿辊最大变形增大。应用断裂力学原理，推导了破碎齿的局部柔度，发现随 着破碎齿裂纹深度增大，局部刚度大幅降低。 （5）依据虚拟破碎试验中最优破碎效果的参数配置，设计了分级破碎机实 验模型的破碎试验系统，进行了破碎效果如处理量、破碎时间、累积产率、过粉 碎率的影响特性，以及能耗特性和不同煤种的破碎效果的测试分析，测试值与理 论值或数值模拟值接近，电源频率为 40Hz 和 50Hz 的情况下的破碎过程平均功 率分别为 3.0kW 和 2.8kW，齿辊输出力矩波动随着破碎粒度减小而增大，在 74r/min 时，破碎机的粒度过粉碎率最小，对多种煤样的破碎规律具有鲁棒性。 关键词分级破碎机破碎机理冲击动力学离散元颗粒 万方数据 Abstract III Abstract With the continuous development of large-scale open-pit coal mines, the semi-continuous mining process has gradually become the mainstream process for most open-pit mine coal production due to its strong adaptability, and large semi-mobile or full-mobile crushing stations are indispensable in this production process. The core equipment is a large-scale sieving crusher with a capacity of more than 1000t/h. The raw coal of the sieving crusher is directly fed, the crushing process of the mixed granular material is complicated, and the factors affecting the crushing granularity are various. Due to the lack of effective research means, the influence law of the crushing mechanism and the crushing effect is unclear, and under the high energy frequent impact of large-scale feeding, The dynamic characteristics and damage mechanism of the toothed roller structure are not clear, which leads to the lack of theoretical basis for the optimium design of the toothed roller. The traditional large-scale sieving crusher relies on the experience design, which affects its efficient operation and reliable operation. The research is carried out in the background of the 10 million-ton open-pit mine crushing system in Shenhua Baori Hiller area. The DEM is used to simulate the numerical analysis of the crushing process, and the impact dynamics is utilized. The reveals the dynamic characteristics of large-scale grading crushing equipment, and provides theoretical basis for the design and application of large-scale grading crusher by means of test prototype verification theory and numerical model. The main work and conclusions of the research obtained are as follows 1 The bearing characteristics of the particels in the crushing process was studised by establishing the crushing tooth-light roll piercing mechanical model for the the medium and large particle, as well as the tooth-back-indeced milling mechanical model for the small particle. Then, the calculation ula of the particle load were obtained and from which it was found that the crushing process is mainly affected by the particle size and position. In order to carry out the design of the similar model of the crushing model machine, the basic mechanical properties of the coal samples from the actual crushing working environment were tested. And from the perspective of particle bearing property, the working parameters and structural parameters of the sieving crushing process are determined. The basic mechanical properties of the simulated working environment were tested on the coal samples of 万方数据 Abstract IV the actual crushing test, and the crushing requirements of the test model machine were clarified. 2 The DEM phenomenological model of the sieving crusher was established. The effect of the working parameters of the sieving crusher on the crushing perance was studied by the of virtual crushing test. The effect of the rotational speed of the two toothed roller at the constant speed, the rotating of the toothed roller and the rotating speed error on the the unit time and the complete crushing time was analyzed. The optimum tooth roller speed of the crusher was found, and the processing time per unit time when the tooth roll was reversed was about 1.37 times of the forward rotation. 3 The influence of the structural parameters of the crushing roller such as the high tooth of the toothed roller, the high tooth density of the toothed roller and the arrangement of the toothed disc on the unit time capacity and crushing energy consumption of the crushing process was studied. The fluctuation characteristics of the output torque of the toothed roller in the staged crushing process were found. The synergistic optimization design of the structural parameters and working parameters of the toothed roll was carried out by the response surface . The quantitative relationship between the treatment volume and the complete crushing time and various factors and the significance of the influence were obtained. In order, a for improving the perance of the sieving crusher was proposed. 4 The bearing characteristics of the crushing teeth in the sieving crushing process under impact were studied, and the strength analysis under the four working conditions of the toothed roller structure was carried out. The torsional vibration model of the toothed roller concentration and the lateral vibration model of the toothed roller were established. According to the dynamic response , the natural frequency and mode shape of the transverse vibration of the crushing roller are similar to those of the finite element analysis. The discrete element -finite element coupling DEM-FEM was used to analyze the bearing characteristics of the crushing roller under working conditions. It is found that the maximum deation of the toothed roller increases with the increase of the length of the feeding position and the height of the feeding. Based on the principle of fracture mechanics, the local flexibility of the crush tooth was derived. It is found that the local stiffness is greatly reduced as the crack depth of the crush tooth increases. 5 According to the parameter configuration based on optimal crushing effect of 万方数据 Abstract V virtual crushing test, the crushing test system of the experimental model of the sieving crusher was designed. The test results of crushing effects such as treatment volume and crushing time, cumulative yield, over-grinding rate influence characteristics, energy consumption characteristics and crushing effects of different coal types were carried out. The test values were close to theoretical values or numerical simulation values, and the average power of the crushing process at 40 Hz and 50 Hz is 3.0 kW and 2.8 kW, respectively. The fluctuation of the output torque of the toothed roller increases with the reduction of the crushing size. At 74 r/min, the crusher has the smallest particle size and pulverization rate. The breaking rules of various coal samples are robust. Key Words Sieving crusher, Breaking mechanism, Impact dynamic, Discrete Element ,Particle 万方数据 目录 VI 目目 录录 摘 要.............................................................................................................................I 第 1 章 绪论.................................................................................................................1 1.1 研究背景及意义............................................................................................1 1.1.1 选题背景.............................................................................................1 1.1.2 选题意义.............................................................................................2 1.2 国内外研究现状及文献综述........................................................................3 1.2.1 大型分级破碎机发展现状.................................................................3 1.2.2 分级破碎机理研究现状.....................................................................7 1.2.3 破碎机动力学问题研究现状...........................................................13 1.2.4 尚需进一步研究的科学问题...........................................................15 1.3 研究内容及方法..........................................................................................15 1.4 技术路线......................................................................................................16 第 2 章 分级破碎过程的颗粒承载特性研究...........................................................18 2.1 分级破碎机基本原理..................................................................................18 2.2 分级破碎过程的颗粒力学模型..................................................................20 2.2.1 齿顶咬入过程的破碎齿-光辊刺破力学特性.................................20 2.2.2 齿背研磨过程的双光辊碾磨力学特性...........................................22 2.3 物料破碎过程表征......................................................................................23 2.3.1 固有缺陷对动态破碎的影响...........................................................23 2.3.2 破碎块度的预测...............................................................................24 2.3.3 物料破碎的影响特性分析...............................................................25 2.4 物料的基本力学参数测试..........................................................................26 2.5 本章小结......................................................................................................29 第 3 章 分级破碎机工作参数对破碎性能的影响特性分析...................................30 3.1 分级破碎机 DEM 唯像模型建立...............................................................31 3.1.1 DEM 基本原理..................................................................................31 3.1.2 DEM 唯像模型..................................................................................34 3.1.3 模型样机的破碎试验.......................................................................36 3.2 等速下齿辊转速对破碎性能的影响..........................................................38 3.2.1 对单位时间处理量的影响特性.......................................................38 3.2.2 对完全破碎时间的影响特性...........................................................40 3.3 齿辊转动形式对破碎性能的影响..............................................................41 3.3.1 对单位时间处理量的影响特性.......................................................42 万方数据 目录 VII 3.3.2 对完全破碎时间的影响特性...........................................................43 3.4 不等转速差对破碎性能的影响..................................................................44 3.4.1 对单位时间处理量的影响特性.......................................................45 3.4.2 对完全破碎时间的影响特性...........................................................46 3.5 本章小结......................................................................................................47 第 4 章 破碎齿辊结构参数对破碎过程的影响及协同优化...................................48 4.1 齿型对破碎过程的影响..............................................................................48 4.1.1 对单位时间处理量的影响特性.......................................................49 4.1.2 对破碎物料受力的影响特性...........................................................50 4.1.3 对破碎能耗的影响特性...................................................................51 4.2 齿辊破碎齿密度对破碎过程的影响..........................................................54 4.2.1 对单位时间处理量的影响特性.......................................................54 4.2.2 对破碎物料受力的影响特性...........................................................55 4.2.3 对破碎能耗的影响特性...................................................................56 4.3 齿盘布置方式对破碎过程的影响..............................................................58 4.3.1 对单位时间处理量的影响特性.......................................................59 4.3.2 对破碎物料受力的影响特性...........................................................60 4.3.3 对破碎能耗的影响特性...................................................................60 4.4 基于响应曲面设计方法的破碎性能的协同优化......................................63 4.4.1 RSM 的基本原理..............................................................................63 4.4.2 模型拟合...........................................................................................64 4.4.3 模型分析...........................................................................................71 4.5 本章小结......................................................................................................72 第 5 章 分级破碎机的冲击动力学特性研究...........................................................74 5.1 破碎齿冲击作用下的强度分析..................................................................74 5.1.1 破碎过程中齿辊承载分析...............................................................74 5.1.2 静强度校核.......................................................................................76 5.2 破碎齿辊动力学特性..................................................................................78 5.2.1 齿辊集中参数扭转振动模型...........................................................79 5.2.2 齿辊分布质量横向振动模型...........................................................81 5.2.3 冲击作用下的动态响应分析...........................................................88 5.3 破碎齿冲击动力学特性的 DEM-FEM 耦合分析.....................................91 5.3.1 破碎齿磨损特性...............................................................................91 5.3.2 入料高度的影响规律.......................................................................92 5.3.3 布料长度的影响规律.......................................................................93 5.4 破碎齿冲击作用下的损伤机理..................................................................94 万方数据 目录 VIII 5.5 本章小结......................................................................................................97 第 6 章 分级破碎机实验模型机的试验研究...........................................................98 6.1 试验系统设计......................