梳齿密封静态稳定性理论与实验研究  

Theoretical and experimental study on the static stability of labyrinth seals

作　　者：马凯 张万福[1] 张尧 顾乾磊 陈璐琪 李春[1] 杨建刚[2] MA Kai;ZHANG Wanfu;ZHANG Yao;GU Qianlei;CHEN Luqi;LI Chun;YANG Jiangang(Institute of Fluid Machinery and Engineering,School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;National Engineering Research Center of Turbogenerator Vibration,Southeast University,Nanjing 210096,China)

机构地区：[1]上海理工大学能源与动力工程学院流体机械及工程研究所,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

出　　处：《振动与冲击》2019年第20期140-147,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(51875361;51575105;51676131)

摘　　要：梳齿密封静态稳定性直接影响转子系统安全与稳定运行。以梳齿密封为对象,提出了密封气流力与静态刚度系数实验识别方法,建立了密封三维流体力学分析模型,研究了不同偏心率、不同进口压力下梳齿密封静特性变化。研究表明:理论和实验结果相吻合,不同偏心状态下梳齿密封会产生一个使转子偏离静子几何中心的气流力和负的直接刚度,且两者都随偏心率和进口压力的增大而不断增加。实验密封出现的静态不稳定现象主要是由于密封小间隙速度沿密封泄漏方向增加较快,质量惯性力显著增大,压力能降低,从而导致大间隙压力大于小间隙,产生使转子偏离中心的气流力及负刚度,最终导致了静态不稳定。The static stability of labyrinth seals directly affects the safe and stable operation of a rotor system.This paper proposed an experimental method to identify the fluid-induced force and static stiffness coefficients.A three-dimensional fluid model of the labyrinth seals was established.And the static characteristics under different eccentricities and inlet pressure were studied.Theoretical results show a good agreement with the experiment results.The labyrinth seal with different eccentricities produces a fluid-induced force and a negative direct stiffness,which causes the rotor deviating from the geometric center of the stator.Both the fluid-induced force and negative direct stiffness increase with eccentricity and inlet pressure.The static instability is mainly due to the fact that the fluid velocity in the small clearance increases more rapidly along the seal leakage path.The mass inertial force is increased significantly and the pressure decreases.This results in greater pressure distribution in the larger clearance.The fluid-induced force and negative stiffness that tend to push the rotor away from the stator center are produced,and eventually lead to the static instability of labyrinth seals.

关 键 词：梳齿密封 气流力 直接刚度系数 静态稳定性 

分 类 号：TK263.2[动力工程及工程热物理—动力机械及工程]