基于等-变环量的轴流风机设计及性能优化研究.pdf

硕士学位论文 基于等-变环量的轴流风机设计及性能优化 研究 Research on Design and Perance Optimization of Axial Fan Based on Equal- Variable Circulation 作 者王思杰 导 师李意民教授 中国矿业大学 2021 年 5 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 TH443 学校代码 10290 UDC 密 级 公开 中国矿业大学 硕士学位论文 基于等-变环量的轴流风机设计及性能优化研究 Research on Design and Perance Optimization of Axial Fan Based on Equal-Variable Circulation 作 者 王思杰 导 师 李意民 申请学位 工学硕士学位 培养单位 电力学院 学科专业 动力工程及工程热物理 研究方向 轴流风机优化 答辩委员会主席 周怀春 评 阅 人 二○二一年五月 万方数据 致谢致谢 时光荏苒，自二十三年前呱呱坠地起，转眼间求学已近十九载。自踏入校园 求学以来便是大家中的平凡一员，懵懵懂懂度过了十二年一心求学求知的生活， 终于跨入一片从未想象过的土地并在这里成长为一个自强自立的中国青年。 如今， 求学的路程已接近终点，终以此篇论文作为对自己十九载求学路的答卷。于此， 对在人生这个重要阶段内任何帮助和伤害过我的所有人表示感谢 首先，对我的父亲和母亲表示最诚挚的感谢，在矿大七年求学时光，我做的 任何一个重要的决定都离不开他们的全力支持， 也是他们自小的言传身教让我养 成慎独自尊的性格，拥有这样的父母是我人生中最幸福的一件事。 其次，感谢恩师李意民老师和周忠宁老师，正是李老师严谨的治学风格和严 格的求学态度，让我在一周一周的汇报中不断成长，能度过这段枯燥而艰难的研 究生活同样离不开周老师像兄长一般在生活和科研过程中的时刻激励， 若不是周 老师多次的指导和鼓励，研究生涯可能早已夭折。 同样要感谢三年来在实验室陪伴我的梁迪师兄、张欣蕾师姐、陈铭师兄、闫 乐师兄、冯非凡和张国杰师兄，初接触课题时的无数个难熬的夜晚都是与他们在 实验室一同度过，克服困难的喜悦也是与他们一同分享，无数喜怒哀乐都一同飘 散在这三年的青春。 最后， 感谢多年来陪伴我的所有朋友， 有十余年友谊的李航、 陈宇飞、 姚昆、 张达， 有以刘志涵、 李丰翼、 张咏欣为代表的轮滑社的小伙伴们， 有安逸、 储奇、 李啸天、秦岩、马晓华、陈委这样幽默风趣且性格坚韧的同窗，还有于今年相熟 的各位辅导员老师们， 在受到鼓励的同时也从他们的身上学习到了很多为人处事 的道理。 毕业在即，在中国矿业大学求学的日子将是我一生中最宝贵的财富，我将带 着这段时光踏上未来的道路，遇上更多有趣的人，承担更多沉重的责任，完成更 多有意义的事，成为一个更优秀的人。 “言念君子， 温其如玉” ， 希望自己在认识更大的世界时仍然可以不忘初心， 始终对世界充满希望。 万方数据 I 摘摘 要要 轴流风机广泛应用于电力、采矿、石油、纺织等领域，随着轴流风机的应用 愈发广泛， 针对轴流风机翼型以及叶片气动外形改造成为改善轴流风机性能的一 大重要手段。本文基于已有的低压轴流风机设计方法，通过分析原叶片的做功情 况提出了等-变环量设计方法，同时采用前掠改型与叶顶选型的方式对所得叶片 做进一步优化， 并通过数值模拟与实验的方法对设计所得叶片进行性能及流场分 析。 首先对传统扭叶片进行分析， 通过横向对比等-变环量设计、 等环量设计、 变 环量设计所得叶片的性能及流场信息，在压力速度场、轴向速度、叶片载荷方面 对等-变环量设计的优势进行了分析，结果表明等-变环量设计可以稳定提高叶 片的全压，全压提升范围为 20-40Pa，其效率与其他设计方法基本相同且叶片吸 力面高负压区域面积大，吸力面气流速度大，吸入性能好，出口轴向速度大于其 它两种叶片，平均提升可达 4，高负荷区面积较大，具备更强的做功能力。 其次对设计所得叶片前掠改型， 通过改变叶片的前掠高度及前掠角度分析叶 片的气动性能，对比其外特性参数发现自 60相对叶高开始前掠 20可以得到 气动性能最佳的前掠叶片。通过分析流道内压力速度场、轴向速度分布、叶片顶 部流线及负荷表明同样进行前掠改型的基础上，等-变环量设计所得前掠叶片具 有更优秀的气动性能，计算流量范围内等-变环量设计叶片全压平均提升 2.6， 在设计工况下采用等-变环量设计可使流量提升 3.34，全压提升 6.35。在小流 量工况下，前掠改型效果明显，前掠叶片叶顶部分无分离流动且具有更均匀的载 荷分布，叶顶做功能力强。 最后针对等-变环量前掠叶片探讨叶顶间隙对其的影响，主要分析了间隙流 场、泄漏情况、分离状态及间隙附近二次流，研究了叶顶间隙对性能影响的内在 机理。 研究表明 随着叶顶间隙的增加， 泄漏面积增加会导致叶轮机械效率降低。 在相同泄漏面积工况下，变叶顶间隙工作效率优于等叶顶间隙，其中渐缩型叶顶 间隙效率最高，渐扩型叶顶间隙效率与等叶顶间隙效率相近。 关键词关键词轴流风机；数值模拟；内部流场；等-变环量 万方数据 II Abstract Axial fans are widely used in electric power, mining, petroleum, textile and other fields. With the increasing application of axial fans, the transation of axial fan airfoil and blade aerodynamic shape has become an important for improving the perance of axial fans. Based on the existing low-pressure axial fan design , this paper proposes an equal-variable circulation design by analyzing the work of the original blades. At the same time, the obtained blades are further optimized by means of forward sweep modification and blade tip selection. Numerical simulation and experimental s are used to analyze the perance and flow of the designed blade. First, for traditional twisted blades, the perance and flow field ination of the blades obtained by equal-variable circulation design, equal circulation design, and variable circulation design are compared horizontally. The advantages of equal-variable circulation design are analyzed in terms of pressure velocity field, axial velocity and blade load. The results show that the equal-variable circulation design can stably increase the total pressure of the blade, and the range of the total pressure is 20-40Pa. Its efficiency is basically the same as other design s, and the area of the high negative pressure area of the blade suction surface is large. The suction surface has a large airflow velocity and good suction perance. The outlet axial velocity is higher than that of the other two blades, and the average increase can reach 4. The area of the high-load area is larger and it has stronger perance. Secondly, a forward-swept modification was made to the designed blade. In this paper, the aerodynamic perance of the blade is obtained by changing the forward sweep height and forward sweep angle of the blade. By comparing their perance parameters, it is found that the forward swept blade with the best aerodynamic perance can be obtained by sweeping forward 20 from 60 relative blade height. The analysis of the pressure and velocity field in the flow channel, the axial velocity distribution, the streamline on the top of the blade and the load show that the forward- swept blade obtained by the equal-variable circulation design has better aerodynamic perance based on the same forward-swept modification. In the calculated flow range, the total pressure of the equal-variable circulation design blades is increased by an average of 2.6. In the design conditions, the equal-variable circulation design can increase the flow rate by 3.34 and the total pressure by 6.35. In small flow conditions, the forward-swept modification effect is obvious, the tip of the forward- 万方数据 III swept blade has no separation flow and has a more uni load distribution, and the tip of the blade is powerful. Finally, the effect of tip clearance on the blade is discussed for the forward-swept blade with equal-variable circulation. This paper mainly analyzes the flow field in the tip clearance, the leakage, the separation state and the secondary flow near the clearance. The internal mechanism of the effect of blade tip clearance on perance is studied. As the tip clearance increases, the leakage area increases, which will cause the mechanical efficiency of the impeller to decrease. When the leakage area is the same, the working efficiency of the variable tip clearance is better than the equal tip clearance, and the tapered tip clearance has the highest efficiency, and the efficiency of the tapered tip clearance is similar to the efficiency of the equal tip clearance. Keywords axial fan; numerical simulation; internal flow field; equal-variable circulation 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........................................................................................................................... X 变量注释表变量注释表 ................................................................................................................ XI 1 绪论绪论............................................................................................................................ 1 1.1 研究背景及意义 ..................................................................................................... 1 1.2 轴流风机设计方法及优化研究现状 ..................................................................... 2 1.3 轴流前掠叶片研究现状 ......................................................................................... 3 1.4 叶顶间隙对流动影响的研究现状 ......................................................................... 5 1.5 本文主要研究内容 ................................................................................................. 6 2 等等-变环量设计方法及数值方法变环量设计方法及数值方法 .............................................................................. 8 2.1 引言 ......................................................................................................................... 8 2.2 等-变环量设计方法 ............................................................................................... 8 2.3 数值计算方法 ......................................................................................................... 9 2.4 控制方程的离散 ................................................................................................... 10 2.5 湍流模型 ............................................................................................................... 11 2.6 本章小结 ............................................................................................................... 13 3 等等-变环量叶片模型建立及数值模拟变环量叶片模型建立及数值模拟 .................................................................... 14 3.1 引言 ....................................................................................................................... 14 3.2 模型建立及网格划分 ........................................................................................... 14 3.3 网格无关性验证及模拟结果验证 ....................................................................... 15 3.4 等/变环量、等-变环量叶片内流特征分析 ........................................................ 17 3.5 安装角对等-变环量叶片的影响 ......................................................................... 25 3.6 本章小结 ............................................................................................................... 28 4 弦向前掠对等弦向前掠对等-变环量设计的影响变环量设计的影响 ........................................................................ 29 4.1 引言 ....................................................................................................................... 29 4.2 前掠起始高度及角度对叶片流动特性的影响 ................................................... 29 4.3 等/变环量、等-变环量前掠叶片内流特征分析 ................................................ 31 4.4 前掠改型对等-变环量设计影响 ......................................................................... 38 4.5 本章小结 ............................................................................................................... 41 万方数据 V 5 叶顶间隙对等叶顶间隙对等-变变环量叶片内部流动影响环量叶片内部流动影响 ............................................................ 43 5.1 引言 ....................................................................................................................... 43 5.2 基于等-变环量前掠叶片的不同叶顶间隙形式流动特性 ................................. 43 5.3 等-变环量前掠叶片叶顶泄漏涡结构分析 ......................................................... 46 5.4 等-变环量前掠叶片叶顶泄漏涡对二次流的影响 ............................................. 48 5.5 实验风机验证 ....................................................................................................... 48 5.6 本章小结 ............................................................................................................... 49 6 结论与展望结论与展望 ............................................................................................................. 51 6.1 结论 ....................................................................................................................... 51 6.2 展望 ....................................................................................................................... 52 参考文献参考文献 ..................................................................................................................... 53 作者简历作者简历 ..................................................................................................................... 58 论文原创性声明论文原创性声明 ......................................................................................................... 59 学位论文数据集学位论文数据集 ......................................................................................................... 60 万方数据 VI Contents Abstract ........................................................................................................................ II Contents ..................................................................................................................... VI List of Figures ......................................................................................................... VIII List of Tables ................................................................................................................ X List of Variables......................................................................................................... XI 1 Introduction ............................................................................................................... 1 1.1 The background and significance of the research .................................................... 1 1.2 Research status of design and optimization of axial fan ............................. 2 1.3 Research Status of Forward-swept Blade Axial Fan................................................ 3 1.4 Research Status of the Effect of Tip Clearance on Flow ......................................... 5 1.5 Main Research Content of this Paper ....................................................................... 6 2 Equal-Variable Circulation Design and Numerical .................. 8 2.1 Introduction .............................................................................................................. 8 2.2 Equal-variable Circulation Design ............................................................. 8 2.3 Numerical Calculation ................................................................................ 9 2.4 Discrete of Governing Equation ............................................................... 10 2.5 Turbulence Model .................................................................................................. 11 2.6 Chapter Summary .................................................................................................. 13 3 Model Establishment and Numerical Simulation of Equal-variable Circulation Blade ............................................................................................................................ 14 3.1 Introduction ............................................................................................................ 14 3.2 Model Building and Meshing ................................................................................ 14 3.3 Grid Independence Verification and Simulation Result Verification ..................... 15 3.4 Analysis of Internal Flow Characteristics of Equal/Variable Circulation and Equal- variable Circulation Blades .......................................................................................... 17 3.5 Influence of Installation Angle on Equal-variable Circulation Blades .................. 25 3.6 Chapter Summary .................................................................................................. 28 4 The Effect of Forward-sweep in Chord Direction on Equal-variable Circulation design ........................................................................................................................... 29 4.1 Introduction ................