时变油膜力下贯流式机组耦合故障动力学分析  

Dynamic analysis on misalignment and rub-impact faults of tubular turbines under time-varying nonlinear oil film forces

作　　者：党建[1] 贾嵘[1] 武桦[1] 董开松 

机构地区：[1]西安理工大学水利水电学院,西安710048 [2]甘肃省电力科学研究院,兰州730050

出　　处：《水力发电学报》2017年第11期23-31,共9页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金(51779206;51279161);陕西省水利科技计划项目(2015slkj-04);电网公司科技项目(522722150012)

摘　　要：多故障源耦合激励诱发的贯流式机组操作油管与受油器浮动瓦碰摩现象,会造成振动加剧及漏油、窜油故障,直接影响机组安全稳定运行。本文在考虑时变非线性油膜力的基础上,建立了贯流式机组不对中-碰摩耦合故障非线性动力模型,研究了不对中量、操作油杂质和受油器径向刚度对系统动力学特性的影响。结果表明:不对中量和油膜力耦合作用下系统响应存在复杂的拟周期运动,频谱出现了幅值较大的低频谐波成分;操作油中的杂质诱发了碰摩的发生,且碰摩力和不对中量及油膜力相互激发放大致使谐波成分更加复杂。受油器径向刚度的减小导致径向振动加剧,并诱发系统动力响应进入不稳定的混沌状态。研究结果为机组安全运行和耦合故障诊断提供了理论依据。Rub-impact between the oil pipe and floating tile of a tubular turbine under excitation by multi-fault source coupling could cause the aggravation of its vibrations and oil leakage that reduce its operating safety considerably. Considering the time-varying nonlinear oil film forces, this study develops a coupling dynamic model for a tubular turbine system with misalignment and rub-impact, and examines their effects on the dynamic behaviors of the system under interaction with the oil impurities and radial stiffness of the oil receiver. Results show that the system undergoes diverse nonlinear motions such as periodic motions and quasi-periods corresponding to different magnitudes of misalignment, featured with a vibration spectrum dominated by various low frequencies and large amplitudes. And working oil impurity induces the occurrence of rub-impact; the harmonic components become more complicated under the coupling effect and mutual excitation of misalignment, rub-impact and oil film forces. Moreover, reduction in the radial stiffness of oil supply may lead to an unstable chaotic state of the system. The results would lay a theoretical basis for safe operation and multi-fault diagnosis of hydropower units.

关 键 词：水轮发电机组 多故障源耦合 时变非线性油膜力 碰摩 非线性动力学 

分 类 号：TV734.2[水利工程—水利水电工程] TH113.1[机械工程—机械设计及理论]