• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2020, Vol. 56 ›› Issue (3): 144-151.doi: 10.3901/JME.2020.03.144

• 摩擦学 • 上一篇    下一篇

迷宫密封临界稳定性研究

顾乾磊1, 张万福1, 陈璐琪1, 马凯1, 李春1, 杨建刚2   

  1. 1. 上海理工大学能源与动力工程学院 上海 200093;
    2. 东南大学火电机组振动国家工程研究中心 南京 210096
  • 收稿日期:2019-06-06 修回日期:2019-09-25 出版日期:2020-02-05 发布日期:2020-04-09
  • 通讯作者: 张万福(通信作者),男,1986年出生,博士,副教授,主要研究方向为透平机械流体激振、转子动力学及旋转机械故障诊断。E-mail:zwf5202006@163.com
  • 作者简介:顾乾磊,男,1995年出生。主要研究方向为密封动力学。E-mail:18321257669@163.com
  • 基金资助:
    国家自然科学基金资助项目(51875361,51575105,51676131)。

Study on the Critical Stable State of the Labyrinth Seal

GU Qianlei1, ZHANG Wanfu1, CHEN Luqi1, MA Kai1, LI Chun1, YANG Jiangang2   

  1. 1. School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093;
    2. National Engineering Research Center of Turbogenerator Vibration, Southeast University, Nanjing 210096
  • Received:2019-06-06 Revised:2019-09-25 Online:2020-02-05 Published:2020-04-09

摘要: 建立迷宫密封试验装置与数值分析模型,开展静态与动态稳定性分析,研究进口压力、转速及密封齿数对系统稳定性的影响,并以密封腔为单元对密封段转子受力进行分解,分析各密封腔对密封段转子整体切向气流力影响,提出“穿越齿数”与“临界稳定性”概念。研究表明:各密封腔对应转子切向气流力方向沿泄漏方向逐渐变化,并存在一个使切向气流力为零的穿越齿数。当密封齿数小于穿越齿数时,密封静态交叉刚度均为负值,且稳定性随转速与进口压力的提升而增加;当密封齿数大于穿越齿数时,密封静态交叉刚度均为正值,且稳定性随转速与进口压力的增加而降低;当齿数等于穿越齿数时系统处于临界稳定状态,切向气流力接近于零;转子涡动频率的增加将增大穿越齿数。

关键词: 迷宫密封, 切向力, 穿越齿数, 稳定性, 计算流体力学

Abstract: The experimental device and numerical analysis model for the labyrinth seal are established. The effects of inlet pressure, rotational speed and teeth number on the system stability are studied. The flow-induced force acting on the rotor is decomposed with the sealing chamber as the unit, the contribution of each seal cavity to the overall tangential flow-induced force is analysed, and the concepts of the crossover teeth number and critical stability are put forward. The results show that the signs of tangential flow-induced force in each seal cavity change gradually along the leakage direction, and there is a crossover teeth number that makes a zero tangential flow-induced force. When the number of seal teeth is less than crossover teeth number, the static cross-coupled stiffness coefficient is negative and the stability increases with the increasing rotational speed and inlet pressure. When the number of seal teeth is larger than the number of crossover teeth number, the static cross-coupled stiffness coefficient is positive and the stability decreases with the increasing rotational speed and inlet pressure. When the number of seal teeth is equal to crossover teeth number, the system is in a critical stable state and the tangential flow-induced force is close to zero. The increase of whirling frequency will increase the crossover teeth number.

Key words: labyrinth seal, tangential flow-induced force, crossover teeth number, stability, computational fluid dynamics

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