倾斜筛网三产品旋流分级筛流场研究.pdf

江苏高校优势学科建设工程项目资助 硕士学位论文 倾斜筛网三产品旋流分级筛流场研究 Study on Flow Field of Three-product Cyclone Classification Screen with Inclined Screen 作 者李杉杉 导 师陈建中 教授 中国矿业大学 二〇一九年五月 万方数据 学位论文使用授权声明学位论文使用授权声明 本人完全了解中国矿业大学有关保留、使用学位论文的规定，同意本人 所撰写的学位论文的使用授权按照学校的管理规定处理 作为申请学位的条件之一，学位论文著作权拥有者须授权所在学校拥有 学位论文的部分使用权，即①学校档案馆和图书馆有权保留学位论文的纸 质版和电子版， 可以使用影印、 缩印或扫描等复制手段保存和汇编学位论文； ②为教学和科研目的，学校档案馆和图书馆可以将公开的学位论文作为资料 在档案馆、图书馆等场所或在校园网上供校内师生阅读、浏览。另外，根据 有关法规，同意中国国家图书馆保存研究生学位论文。 （保密的学位论文在解密后适用本授权书）。 作者签名 导师签名 年 月 日 年 月 日 万方数据 中图分类号 TD94 学校代码 10290 UDC 622.7 密 级 公开 中国矿业大学 硕士学位论文 倾斜筛网三产品旋流分级筛流场研究 Study on Flow Field of Three-product Cyclone Classification Screen with Inclined Screen 作 者 李杉杉 导 师 陈建中 申请学位 工学硕士 培养单位 化工学院 学科专业 矿物加工工程 研究方向 细粒分级 答辩委员会主席 陶秀祥 评 阅 人 陶秀祥 任瑞晨 二〇一九年五月 万方数据 II 致谢致谢 逝者如斯，不舍昼夜。硕士研究生三年的求学历程即将画上句号。此刻 回首过往，经历过的挫折、磨砺与最终的收获与成长，万种滋味涌向心间， 久久难以平静。对于那些曾经引导、激励、帮助我的人，我心中充满了感激 之情，谢谢你们的鼓励、帮助和支持让我这三年收获满满。 首先，我很荣幸能够来到中国矿业大学，成为一粒“小煤球”，这三年 我切切实实的感受到了浓厚的学术氛围以及矿大学子严谨治学的求学精神， 这些时刻激励着我不断前进。当然更要感谢矿大让我能够有机会成为陈建中 教授和沈丽娟教授的学生。感谢两位导师三年来对我生活上的悉心关照，对 科学研究和工程设计上的谆谆教导，本文能够顺利完成离不开两位老师的指 导及帮助。您们不仅是我科研上的导师，也是我人生的导师，我很庆幸能够 进入本课题组，师从沈老师和陈老师，在此谨向沈老师以及陈老师表示我最 诚挚的敬意和感谢 同时，衷心的感谢课题组师兄师姐师弟们，与你们相处的每天都在收获 知识，收获快乐，收获成长，遇见你们让我感到十分的幸运。在此感谢王传 真、黄彦龙和李永改三位博士对我的指导与帮助，尤其是师兄王传真在我模 拟过程中给予的巨大帮助，让我避开很多弯路，极大地提高了工作效率。感 谢师兄李阿庆、程远志、王猛、华成杰、马丁、张帅猛、张明腾、师姐刘璇 对我的指导与帮助。感谢同窗贾凯、曹云剑、黎涛一直以来的陪伴和帮助， 谢谢你们一路陪伴一路相随一路互帮互助，感谢师弟李佳伟给予的莫大鼓励。 正是因为处在课题组这个温馨的大家庭中，我才能顺利及时的完成毕业实验， 在此祝他（她）们在今后的人生中顺顺利利。 最后， 我要衷心感谢我的家人， 你们的支持鼓励、 宽容理解、 教育培养， 是我不断前进的动力，你们是我坚强的后盾。 感谢一直以来给予教育及指导的所有老师，感谢为评阅本论文而付出宝 贵时间和精力的专家和教授们 感谢母校感谢所有人愿我们都越来越好 由于本人水平的限制，本论文中难免会出现错误和不当之处，敬请批评 指正，谢谢。 作者于中国矿业大学 2019 年 5 月 万方数据 I 摘摘 要要 三产品旋流分级筛是一种新型高效的细粒煤分级设备， 在工业中已取得较好 的应用成果，具有较高的研究价值及广阔的应用前景。本课题采用 CFD 数值模 拟方法，以倾斜筛网三产品旋流分级筛为研究对象，探究倾斜筛网对设备内部流 场的影响。首先根据设备的结构特点及工作原理，对研究对象进行理论分析，为 FLUENT 模拟过程中计算模型的选择及边界条件的设置提供依据。其次使用 Solidworks 软件建立设备三维模型，用 ICEM-CFD 软件进行网格处理，通过 FLUENT 软件迭代求解得出设备流场信息。 通过对比筛网存在 10゜倾角及筛网不存在倾角的三产品旋流分级筛内部流 场差异发现，当筛网存在倾角时，三产品旋流分级筛最大切向速度轨迹面半径减 小，相同位置处切向速度降低，离心强度相应变小，最大切向速度随轴向高度降 低而减小的幅度变大。外螺旋的轴向速度增加，零速包络面面积减小，设备离心 分级粒度降低。从压力的角度来看，筛网存在倾角时，总压值和静压值随半径增 大而增加的幅度减小，筛网下端出现零压差值点，产生“返流”现象，筛网有效 筛分面积降低。 通过改变倾斜筛网的高度、筛下出料口位置及入口流量的大小，探究主要参 数改变对设备流场的影响分析结果发现， 降低筛网高度能够有效控制筛下 “返流” ， 筛网高度为 109mm 是“返流”出现的临界筛网高度，从“返流”对设备影响的 角度来看，其筛网高度的最佳值应在 109mm 左右，切向速度随筛网高度降低而 增加。筛下出料口位于筛网下端时，设备内部具有更大的切向速度，“返流”越 晚出现。入口流量增加，零压差值点的压力变大，但位置基本不变，通过改变入 口流量不能改善 “返流” 带来的不利影响， 各出口流量随入口流量的增加而增大， 且均符合一次函数关系。 本文通过对倾斜筛网三产品旋流分级筛的研究， 提供了一个结构优化的新思 路，同时为该设备更好的在生产实践中应用打下良好理论基础。 本论文有图 44 幅，表 5 个，参考文献 77 篇。 关键词关键词FLUENT；倾斜筛网；筛网高度；入口流量；三产品旋流分级筛 万方数据 II Abstract As a new type of high-efficiency fine-grain coal grading equipment, it has achieved good application results in industry, so three-product cyclone classification screen has high research value and broad application prospects.This article takes this device as the research object, with the of CFD numerical simulation, exploring the influence of inclined screen on the internal flow field of the equipment. In this paper, firstly based on the structural characteristics and working principle of the equipment, theoretical analysis of the research object, to provides a basis for the setting of conditions and the selection of models in FLUENT simulation. The equipment flow field model was established by the software of Solidworks, the grid processing was pered by ICEM- CFD software, and the internal flow field ination of the equipment was obtained by FLUENT software. By comparing the internal flow field difference of two equipments which screen has 10゜ inclination and screen has 0゜inclination. We can find out that when the screen has a inclination the path radius of maximum tangential velocity of this equipment will decrease, the tangential velocity and centrifugal strength will decrease at the same position, the amplitude of tangential velocity decreases as the axial height decreases will increase. The axial velocity of the outer spiral will increases, and the area of the zero-speed envelope surface and the separation particle size will decreases. From the point of view of pressure, when the screen has inclination, the amplitude of total pressure and static pressure increase with increasing radius will decreases, there will be a zero pressure point ,thus creating a “Backflow” phenomenon at the bottom of the screen, the effective screen area of screen will decreases. By changing the height of the inclined screen the position of screen- below outlet and the size of the inlet flow, exploring the influence of main parameters on the flow field of equipment, We can find out that reducing the height of the screen can effectively control the emergence of “Backflow”, the screen height of 109mm is the critical screen height that “Backflow” appears, from the perspective of the influence of “Backflow” on the equipment, the optimum value of the screen height should be about 109mm, the smaller the height of the screen, the greater the tangential velocity in this equipment. When the screen- below outlet is located at the end of the screen, the equipment has a greater tangential speed，and “Backflow“ will appear later. With the increase of inlet flow, the pressure of the zero-pressure point will increase, but the position of the the 万方数据 III zero-pressure point will not change. By changing the inlet flow, the “Backflow” phenomenon can not be improved，each outlet flow increases with the increase of the inlet flow rate, and all meet the linear relationship. In this paper, through the simulation study on the Three-product cyclone classification screen with inclined screen provides a new idea of structural optimization and lays a good theoretical foundation for the application of this equipment in production practice. This paper has 44 figures, 5 tables, 77 references. Keywords FLUENT；inclined screen; screen height; inlet flow; three-product cyclone classification screen 万方数据 IV 目目 录录 摘摘 要要............................................................................................................................ I 目目 录录......................................................................................................................... IV 图清单图清单...................................................................................................................... VIII 表清单表清单......................................................................................................................... XI 变量注释表变量注释表 ............................................................................................................... XII 1 绪论绪论 ........................................................................................................................... 1 1.1 研究背景及意义 .................................................................................................... 1 1.2 课题提出 ................................................................................................................. 1 1.3 主要研究内容 ........................................................................................................ 2 1.4 技术路线 ................................................................................................................ 3 2 文献综述文献综述 ................................................................................................................... 4 2.1 三产品旋流分级筛研究进展 ................................................................................. 4 2.2 三产品旋流分级筛工业应用 ................................................................................. 7 2.3 三产品旋流分级筛内部流动理论分析 ................................................................. 8 2.4 计算流体力学 ....................................................................................................... 13 2.5 小结 ....................................................................................................................... 15 3 倾斜筛网倾斜筛网三产品旋流分级筛三产品旋流分级筛 CFD 模型构建模型构建 ......................................................... 16 3.1 计算域的确定 ....................................................................................................... 16 3.2 网格划分 ............................................................................................................... 17 3.3 模型选择及参数设置 ........................................................................................... 18 3.4 小结 ....................................................................................................................... 23 4 倾斜筛网对倾斜筛网对三产品旋流分级筛三产品旋流分级筛流场影响流场影响 ............................................................. 24 4.1 速度场对比 ........................................................................................................... 25 4.2 压力场对比 ........................................................................................................... 35 4.3 各出口流量分布对比 ........................................................................................... 42 4.4 小结 ...................................................................................................................... 42 5 主要参数对主要参数对倾斜筛网倾斜筛网三产品旋流分级筛流场影响三产品旋流分级筛流场影响 ............................................. 43 5.1 筛网高度对内部流场影响 ................................................................................... 43 5.2 筛下出料口位置对内部流场影响 ....................................................................... 48 万方数据 V 5.3 入口流量对内部流场影响 ................................................................................... 52 5.4 小结 ....................................................................................................................... 55 6 结论及展望结论及展望 ............................................................................................................. 57 6.1 结论 ....................................................................................................................... 57 6.2 创新点 ................................................................................................................... 58 6.3 展望 ....................................................................................................................... 58 参考文献参考文献 ..................................................................................................................... 59 作作者简历者简历 ..................................................................................................................... 63 学位论文原创性声明学位论文原创性声明 ................................................................................................. 64 学位论文数据集学位论文数据集 ......................................................................................................... 65 万方数据 VI Contents Abstract ........................................................................................................................ II Contents ..................................................................................................................... VI List of Figures ......................................................................................................... VIII List of Tables ............................................................................................................. XI List of Variables ....................................................................................................... XII 1 Introduction ............................................................................................................... 1 1.1 Research Background and Significance ................................................................... 1 1.2 Subject Support ........................................................................................................ 1 1.3 Main Research Content ............................................................................................ 2 1.4 Technical Route ........................................................................................................ 3 2 Literature Review ..................................................................................................... 4 2.1 The Progress of Study on Three-product Cyclone Classification Screen ................ 4 2.2 The Industrial Application of Three-product Cyclone Classification Screen .......... 7 2.3 Theoretical Analysis Inernial Flow of Three-product Cyclone Classification Screen ........................................................................................................................................ 8 2.4 Computational Fluid Dynamics Classificatio ........................................................ 13 2.5 Brief Summary ....................................................................................................... 15 3 The CFD Model of Three-product Cyclone Classification Screen with Inclined Screen .......................................................................................................................... 16 3.1 Determining the Calculation Domain .................................................................... 16 3.2 Dividing Grid ......................................................................................................... 17 3.3 Selecting Model and Setting of Parameter ............................................................. 18 3.4 Brief Summary ....................................................................................................... 23 4 Effect of Inclined Screen on Internal Flow Field in Three-Product Cyclone Classification Screen .................................................................................................. 24 4.1 Velocity Contrast .................................................................................................... 25 4.2 Pressure Contrast ................................................................................................... 35 4.3 Comparison of The Distribution of Export Flows ................................................. 42 4.4 Brief Summary ....................................................................................................... 42 万方数据 VII 5 Effect of the Main Parameters on Internal Flow Field in Three-Product Cyclone Classification Screen with Inclined Screen ............................................... 43 5.1 Influence of the Screen Heigh on Internal Flow Field ........................................... 43 5.2 Influence of the Screen- below Outlet Position on Internal Flow Field ................ 48 5.3 Influence of Inlet Flow on Internal Flow Field ...................................................... 52 5.4 Brief Summary ....................................................................................................... 55 6 Conclusions and Prospects ....................................................