筛缝角度对三产品旋流分级筛内部流场影响的仿真研究.pdf

江苏高校优势学科建设工程项目资助 硕士学位论文 筛缝角度对三产品旋流分级筛内部流场影 响的仿真研究 Simulation of the Screen Angle on the Internal Flow Field of the Three-Product Hydro-Cyclone Screen 作 者李佳伟 导 师张文军 研究员 中国矿业大学 二〇二〇年七月 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 筛缝角度对三产品旋流分级筛内部流场影响的仿 真研究 Simulation of the Screen Angle on the Internal Flow Field of the Three-Product Hydro-Cyclone Screen 作 者 李佳伟 导 师 张文军 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 杨建国 评 阅 人 二〇二〇年七月 万方数据 致谢致谢 三年的时光白驹过隙，转瞬即逝，时间流逝的同时我得到更多的是收获。在 硕士学习期间所有的经历与成长都离不开给过我很多支持、帮助和鼓励我的人， 在学位论文即将完成之际我要向他们表示诚挚的谢意。 首先， 非常荣幸成为中国矿业大学的一员， 好学力行、 求是创新、 艰苦奋斗、 自强不息的矿大精神时刻激励着我不断前进。在矿大有幸认识了陈建中老师、沈 丽娟老师和张文军老师，在学习和生活中三位老师给了我最大的帮助。感谢三位 老师三年来对我在生活上的悉心关照，对科学研究和工程实践上的谆谆教导，本 文能够顺利完成离不开三位老师的指导及帮助。 三位老师不仅是我科研学习上的 导师，也是我人生的导师，三位老师在学术上认真严谨、在科研上精益求精、在 生活中朴实热情，这些良好的品质让我受益终身。在此谨向陈建中老师、沈丽娟 老师和张文军老师表示我最诚挚的敬意和感谢 其次，衷心地感谢各位同窗好友，与你们相处的每天都在收获知识，收获快 乐，收获成长，遇见你们是我的幸运也是今后人生的幸运。在此感谢七年的室友 优秀的郝亚男硕士，感谢课题组里的师姐李永改老师和师兄王传真、黄彦龙和聂 庆民博士对我的指导与帮助，感谢师兄马丁、张帅猛、马卫平、曹云剑、贾凯、 黎涛硕士及师姐刘璇、李杉杉硕士一直以来对我的指导与帮助，尤其是师兄王传 真博士、黎涛硕士和师姐李杉杉硕士在我模拟的过程中给予的很多指导，让我避 开很多的弯路，极大地提高了工作效率，谢谢你们一路陪伴一路相随一路互帮互 助。正是因为处在课题组这个温馨的大家庭中，我才能快乐的度过了在矿大的每 一天以及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，你们的包容和鼓励以及默默的付出，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 感谢矿大感谢所有人愿大家都越来越好 由于本人水平的有限，本论文中难免会出现错误和不当之处，敬请读者批评 指正。 万方数据 I 摘摘 要要 三产品旋流分级筛作为一种新型的煤泥分级设备在工业上取得了良好的应 用效果，具有很高的研究价值和广阔的应用前景。筛网是三产品旋流分级筛的重 要结构，对内部流场具有重要影响。研究筛网结构对内部流场的影响对进一步理 解和优化三产品旋流分级筛具有重要的应用价值。本文以 CFD 数值模拟方法为 基础，以 FLUENT 软件迭代求解获取设备流场信息，探讨了筛网的不同筛缝角 度条件对设备内部流场的影响。 通过对比筛缝分别为迎流布置与沿径向布置的筛网结构的三产品旋流分级 筛内部流场信息发现迎流的筛缝结构使筛网外侧总压力值增大，流体返流向筛 内， 呈现与最初切向速度方向相反的现象。在迎流的筛缝结构的基础上减小筛缝 尺寸，发现总压力有所减小，筛内切向速度有所降低，筛下切向速度升高。 筛缝背向旋流方向与沿径向布置的筛网结构对比发现 背流的筛缝结构有助 于筛网内侧和筛网外侧筛下腔体部分压力值和切向速度的增大， 有利于消除流体 筛网外侧返流至筛网内侧，筛下出料流量有所增加，底流流量和溢流流量减少。 在背流的筛缝结构的基础上减小筛缝的大小对三产品旋流分级筛内部流场的影 响主要表现为筛网内外压力差的差异更大，筛下出料口流量有所减少，底流流量 和溢流流量都是有略微增加。 在不同参数条件下研究筛缝角度对内部流场的影响发现 筛下腔体厚度增大 或增加筛下出料口个数后， 在筛网结构为筛缝沿着径向方向时筛网内外压差和筛 网内侧切向速度有所增大， 在筛缝为迎合旋流方向时筛网内外压力和切向速度有 所降低， 在筛缝为背向旋流方向时流场变化较小； 入料速度由8.5m/s增加为12m/s， 三种筛网结构中返流点的轴向位置都无改变，总压力和速度值都会有所增加， 各 出料口流量都分别以入料流速增加率相似的增长率增加。 本文通过对不同筛缝角度的三产品旋流分级筛进行研究， 发现背流的筛缝结 构、 增加筛下腔体厚度和筛下出料口个数有利于流体的透筛和增强筛内旋流强度， 为结构优化提供了一个的新思路， 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。 关键词关键词筛缝角度；内部流场；FLUENT；三产品旋流分级筛 万方数据 II Abstract The three-product hydro-cyclone screen is a new type of slime classification equipment, which has achieved good application results in industry and has high research value and broad application prospects. The screen is an important part of the three-product hydro-cyclone screen, which has an important impact on the internal flow field. Studying the influence of the screen angle on the internal flow field has a high use value for further understanding and optimization of the three-product hydro-cyclone screen. In this paper, based on the CFD numerical simulation , and the FLUENT software is used to iteratively obtain the flow field ination of the equipment, and influence of different screen angles on the internal flow field of the equipment is discussed. By comparing the internal flow field ination of the three-product hydro-cyclone screen with the along-flow screen and the radially arranged screen angle, it is found that the total pressure value outside the screen of the along-flow screen angle is greater, and the fluid flowed into the screen, showing a phenomenon opposite to the original tangential velocity direction. On the basis of the screen angle of the along-flow, the size of the screen gap was reduced, and it was found that the total pressure and the tangential velocity inside the screen was reduced, the tangential velocity outside the screen was increased. Comparing the structure of the back-flow screen with the screen angle arranged in the radial direction, it was found that the back-flow screen angle helps increase the pressure value and tangential velocity of the inside the screen and outside the screen, it is beneficial to eliminate the backflow of the fluid outside to the inside of the screen, the discharge flow outside the screen has increased, and the underflow and overflow flow have been reduced. On the basis of the back-flow screen angle, the effect of reducing the size of the screen gap on the internal flow field of the three-product hydro-cyclone screen is mainly manifested by the greater difference in pressure-difference between inside and outside of the screen, and the discharge flow outside the screen has been reduced, and the underflow and overflow flows have increased slightly. Studying the effect of the screen angle on the internal flow field with different parameter conditions found that increase the thickness of the cavity outside the screen or increase the number of outlets under the screen, when the screen angle is along the radial direction, the pressure difference between the inside and outside of the screen 万方数据 III and the tangential velocity inside the screen increase; when the screen angle is along-flow, the pressure and tangential velocity near the screen decrease; when the screen angle is back-flow, the flow field changes less. The feeding speed is increased from 8.5m/s to 12m/s, the axial position of the backflow point in the three screen angles has not changed, the total pressure and velocity values have increased, and the flow rate of each outlet is increased at a similar growth rate to the rate of increase of the feed flow rate. In this paper, through the study of three-product hydro-cyclone screen with different screen angles, it is found that the back-flow screen angle, increasing the thickness of the under-screen cavity and the number of under-screen outlets are beneficial to the fluid through the screen and enhance the strength of the swirl in the screen. The research in this paper provides new ideas for the structural optimization of the three-product hydro-cyclone screen, and also lays a good theoretical foundation for better application of the equipment to production practice. Keywords screen angle; internal flow field; FLUENT; three-product hydro-cyclone screen 万方数据 IV 目目 录录 摘摘 要要 ........................................................................................................................ I I 目目 录录 ...................................................................................................................... IVIV 图清单图清单 .................................................................................................................. VIIIVIII 表清单表清单 .................................................................................................................. XIIIXIII 变量注释表变量注释表 ............................................................................................................ XIVXIV 1 1 绪论绪论 ........................................................................................................................ 1 1 1.1 研究背景与意义.................................................. 1 1.2 课题的提出...................................................... 1 1.3 研究内容和目的.................................................. 2 1.4 技术路线........................................................ 3 2 2 文献综述文献综述 ................................................................................................................ 4 4 2.1 三产品旋流分级筛概述............................................ 4 2.2 三产品旋流分级筛筛网结构与物料的透筛分析........................ 8 2.3 三产品旋流分级筛的数值模拟研究.................................. 9 2.4 小结........................................................... 12 3 3 三产品旋流分级筛模型构建与数值模拟三产品旋流分级筛模型构建与数值模拟 .......................................................... 1313 3.1 计算域的确定................................................... 13 3.2 网格划分....................................................... 14 3.3 模型选择及参数设置............................................. 16 3.4 小结........................................................... 20 4 4 迎流的筛缝角度对流场的影响迎流的筛缝角度对流场的影响 .......................................................................... 2121 4.1 迎流的筛缝角度对压力的影响..................................... 22 4.2 迎流的筛缝角度对速度的影响..................................... 25 4.3 迎流的筛缝角度对各出料产品流量的影响........................... 30 4.4 迎流的筛缝角度下筛缝大小对流场的影响........................... 31 4.5 小结........................................................... 34 5 5 背流的筛缝角度对流场的影响背流的筛缝角度对流场的影响 .......................................................................... 3636 5.1 背流的筛缝角度对压力的影响..................................... 36 5.2 背流的筛缝角度对速度的影响..................................... 38 5.3 背流的筛缝角度对各出料口流量的影响............................. 44 5.4 背流的筛缝角度下筛缝大小对流场的影响........................... 44 万方数据 V 5.5 小结........................................................... 49 6 6 不同参数条件下筛缝角度对内部流场的影响不同参数条件下筛缝角度对内部流场的影响 .................................................. 5151 6.1 不同筛下腔体厚度时筛缝角度对流场的影响......................... 51 6.2 双筛下出料口时筛缝角度对流场的影响............................. 58 6.3 不同入料流速时筛缝角度对流场的影响............................. 62 6.4 小结........................................................... 67 7 7 结论及展望结论及展望 .......................................................................................................... 6868 7.1 主要研究工作和结论............................................. 68 7.2 创新点......................................................... 69 7.3 展望........................................................... 69 参考文献参考文献 .................................................................................................................. 7171 作者简历作者简历 .................................................................................................................. 7575 万方数据 VI Contents Abstract ........................................................................................................................ II Contents ..................................................................................................................... VI List of Figures ......................................................................................................... VIII List of Tables ........................................................................................................... XIII List of Variables...................................................................................................... XIV 1 Introduction ............................................................................................................... 1 1.1 Research Background and Significance ................................................................... 1 1.2 Proposal of the Subject ............................................................................................ 1 1.3 Research Content and Purpose................................................................................. 2 1.4 Technical Route ........................................................................................................ 3 2 Literature review ....................................................................................................... 4 2.1 Overview of the Three-product Hydro-cyclone Screen ........................................... 4 2.2 Screen Structure and Material Through-screen Analysis of the Three-product Hydro-cyclone Screen .................................................................................................... 8 2.3 Numerical Simulation Research on Three-product Hydro-cyclone Screen ............. 9 2.4 Summary ................................................................................................................ 12 3 Model Construction and Numerical Simulation of Three-product Hydro-cyclone Screen ................................................................................................ 13 3.1 Calculation Domain Determination ....................................................................... 13 3.2 Meshing.................................................................................................................. 14 3.3 Model Selection and Parameter Setting ................................................................. 16 3.4 Summary ................................................................................................................ 20 4 Influence of Along-flow Screen Angle on Flow Field ........................................... 21 4.1 Effect of Along-flow Screen Angle on Pressure .................................................... 22 4.2 Effect of Along-flow Screen Angle on Velocity .................................................... 25 4.3 Impact of Along-flow Screen Angle on the Flow Rate of Each Output Product ... 30 4.4 The Influence of Screen Size on the Flow Field under the Along-flow Screen Angle ............................................................................................................................ 31 4.5 Summary ................................................................................................................ 34 5 Influence of Back-flow Screen Angle on Flow Field ............................................ 36 5.1 Effect of Back-flow Screen Angle on Pressure ...................................................... 36 万方数据 VII 5.2 Effect of Back-flow Screen Angle on Velocity ...................................................... 38 5.3 Influence of Back-flow Screen Angle on the Flow Rate of Each Outlet ............... 44 5.4 Influence of Screen Size on Flow Field under Back-flow Screen Angle .............. 44 5.5 Summary ................................................................................................................ 49 6 Effect of Screen Angle With Different Parameters on Internal Flow Field ....... 51 6.1 Effect of Screen Angle on Flow Field under Different Thickness Cavities ........... 51 6.2 Influence of Screen Angle on Flow Field under the Condition of Double Outlet outside Screen .............................................................................................................. 58 6.3 Influence of Screen Angle on Flow Field under Different Feed Velocity ............. 62 6.4 Summary ................................................................................................................ 67 7 Conclusion and Prospects ....................................................................................... 68 7.1 Main Research Work and Conclusion ..........................