大型核电汽轮机推力轴承油膜失稳振动研究  

Oil Whirl Vibration Analysis for Thrust Bearings of Large Nuclear Steam Turbines

作　　者：史庆峰 SHI Qingfeng(CNNP Nuclear Power Operations Management Co.,Ltd.,Haiyan 314300,Zhejiang Province,China)

机构地区：[1]中核核电运行管理有限公司

出　　处：《动力工程学报》2019年第6期512-516,共5页Journal of Chinese Society of Power Engineering

摘　　要：针对某些机型核电汽轮机出现轴向振动与径向振动耦合的现象,采用大型核电汽轮发电机组推力轴承可倾瓦块模型,对运行中油膜失稳引起的自激振动进行了机理分析。通过建立转子轴向运动方程,对某650 MW核电机组启机过程中推力轴承载荷进行了测量,计算得出不同轴向载荷和推力轴承间隙比条件下的油膜刚度和阻尼,并分析了推力轴承油膜失稳引起的转子轴向自激振动的频率特点。结果表明:轴向载荷、转速和油膜阻尼是引起推力轴承可倾瓦块轴向自激振动的主要因素;减小推力轴承间隙和增大润滑油压可以抑制转子轴向自激振动。Aiming at the coupling phenomenon of axial vibration with radial vibration existing in some nuclear steam turbines,a mechanism analysis was conducted on the self-excited vibration caused by oil whirl based on the model of thrust bearing tilting pad for large nuclear power turbo-generator sets.By establishing a dynamic equation for rotor axial shifting,and through the measurement of thrust bearing load in start-up process of a 650 MW nuclear power unit,the stiffness and damping of the oil film were calculated under different conditions of axial load and thrust bearing clearance ratio.Meanwhile,the characteristic frequency of rotor axial vibration caused by the oil film instability was analyzed.Results show that the axial load,rotary speed and oil film damping are the main factors leading to the self-excited vibration of the thrust bearing tilting pad.The axial low-frequency vibration of the turbine rotor could be inhibited by reducing the thrust bearing clearance and increasing the lubricating oil pressure.

关 键 词：推力轴承 可倾瓦块 油膜失稳 轴向自激振动 

分 类 号：TK263.6[动力工程及工程热物理—动力机械及工程]