阻旋栅对梳齿密封动静特性影响研究  

Effects of Swirl Brakes on Static and Rotordynamic Performance of Labyrinth Seals

作　　者：吴可欣 张万福[1,3] 曹浩 陈璐琪 尹露 李春 WU Kexin;ZHANG Wanfu;CAO Hao;CHEN Luqi;YIN Lu;LI Chun(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;State Grid Hunan Electric Power Company Limited Research Institute,Hunan Changsha 410007,China;Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering,Shanghai 200093,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]国网湖南省电力有限公司电力科学研究院,湖南长沙410007 [3]上海市动力工程多相流动与传热重点实验室,上海200093

出　　处：《摩擦学学报》2020年第5期647-655,共9页Tribology

基　　金：国家自然科学基金项目(51875361)资助。

摘　　要：阻旋栅可改变密封进口流体周向流动与进口预旋,是提高系统稳定性的主要方法之一.本文作者应用计算流体力学方法研究了阻旋栅几何参数对梳齿密封动静特性的影响,计算分析了阻旋栅在不同长度、间隙、周向个数及不同进口预旋比下密封流场分布与动力特性系数,并与无阻旋栅梳齿密封进行对比.研究表明:阻旋栅能够有效抑制密封进口周向流动、降低密封腔室周向压力;随着阻旋栅周向个数与阻旋栅间隙的减小,其抑制效果增强,阻旋栅长度的增加对周向速度影响则越来越小;提高预旋比将使密封内流体周向速度增加.与传统梳齿密封相比,具有阻旋栅的梳齿密封直接阻尼增加,交叉刚度降低,进而有效阻尼提高.阻旋栅间隙s=0.20 mm、长度l=3.25 mm、数量n=90时密封有效阻尼较大,系统稳定性最好.Swirl brakes can dramatically change the circumferential swirl flow and the preswirl at the seal inlet.The swirl brake is generally used to improve the stability of seal system.In this paper,the geometric parameters of a swirl brake were studied to evaluate its effect on the static and rotor dynamic performance for the labyrinth seal by employing computational fluid dynamics(CFD)method.Influences of length,clearance and number of the swirl brake,and inlet preswirl ratio were analyzed and compared with the conventional labyrinth seal without swirl brakes.The result showed that the swirl brake significantly reduced the circumferential velocity and pressure at the seal inlet.With the increasing number and decreasing clearance,the efficiency of swirl brakes was improved.While the effect on the circumferential velocity degraded as the swirl brake length increased.Preswirl ratio enhanced the circumferential velocity.In addition,compared with the conventional labyrinth seal,the labyrinth seal with swirl brakes showed greater direct damping,lower cross-coupled stiffness,and resultant larger effective damping.Regarding to the optimization of swirl brake geometry,the effective damping and stability of the seal system showed best performances with the clearance of 0.20 mm,length of 3.25 mm and circumferential number of 90.

关 键 词：阻旋栅 梳齿密封 动力特性 计算流体力学 预旋 

分 类 号：TK263[动力工程及工程热物理—动力机械及工程]