立式主泵水膜涡动故障诊断及机理分析  

Fault Diagnosis and Mechanism Study of Water-film Whirl in Vertical Reactor Coolant Pumps

作　　者：王琇峰[1] 洪银聪 丘大谋[1] WANG Xiufeng;HONG Yincong;QIU Damou(School of Mechanical Engineering,Xi’an Jiaotong University,Xi’an 710049)

机构地区：[1]西安交通大学机械工程学院,西安710049

出　　处：《机械工程学报》2020年第11期89-95,共7页Journal of Mechanical Engineering

基　　金：国家自然科学基金研究群体资助项目(51421004)

摘　　要：针对国内某核电厂多台立式反应堆冷却剂泵(以下简称主泵)均存在的低频振动问题,采用时频分析、二维全息谱等信号处理方法对现场采集的泵轴振动数据开展分析,总结启机、正常运行阶段泵轴振动数据时域、频域特征,根据信号特征推测主泵出现低频振动问题的根本原因为水润滑轴承水膜涡动故障。进一步地,针对上述推测开展立式转子滑动轴承水膜涡动故障振动机理研究。结合流体连续性理论和牛顿流体特性,解释水膜半速涡动频率特征;根据主泵轴承供水压力略高于15.4MPa的运行工况,得到轴承内部润滑水压力分布特征,进一步分析润滑水压力合力,解释了水膜涡动导致自激振动的激励力。建立水膜涡动故障动力学数值模型,获得故障对应的振动特征。上述研究结果对立式转子水膜涡动故障诊断及其设计改进具有一定的参考价值。Aiming at the diagnosis of subsynchronous vibration problem which exists in multiple vertical reactor coolant pumps(RCPs for short)in a domestic nuclear power plant, the signal processing methods such as time-frequency analysis、2 D holospectrum are employed to analyze the vibration data of pump shaft. The time domain and frequency domain characteristics of vibration data during start-up and normal operation phase is summarized, according to which the basic reason of the subsynchronous vibration problem of RCPs is thought to be water film whirl failure occurring in the water-lubricated bearing. The mechanism of water-film whirl problem of vertical sliding bearing is further studied aiming at explaining the above phenomenon. Based on the fluid continuity theory and Newtonian fluid characteristics, the frequency characteristics of the water-film half-speed whirl is explained. According to the fact that the bearing water supply pressure is slightly higher than 15.4 MPa in the operating condition, the pressure distribution characteristics of the lubricating water inside the bearing are obtained, and the direction of the resultant force of the lubrication water pressure is further studied, which shows that the exciting force of self-excited vibration is provided by the water film whirl. A dynamic numerical model of water-film whirl failure is established to obtain the corresponding vibration characteristics. The above research has certain reference value for the fault diagnosis of water-film whirl and design improvement of vertical rotor.

关 键 词：水膜涡动 故障诊断 立式主泵 滑动轴承 

分 类 号：TH113[机械工程—机械设计及理论]