立式循环泵结构动刚度对转子振动特性的影响

Effect of Dynamic Structure Stiffness on Rotor Characteristics of Vertical Pump

采用有限元法对AP1000核电厂立式循环泵转子部件的支承结构动刚度进行分析,结果显示其支承结构的动刚度值随着频率的增加而逐渐降低,其动刚度曲线在结构共振频率点发生急剧的下降。结合该分析结果,分别针对刚性支承、水润滑轴承支承以及考虑支承结构动刚度3种情况下的转子振动特性进行对比分析。分析结果显示,在上述3种情况下,转子1阶横向弯曲振动频率变化较小,其频率值分别为28.1、18.7、15.3 Hz,转子高阶振动频率及振型受支承动刚度影响较大。在考虑支承动刚度的影响情况时,转子高阶振动频率下降明显。

The support structure dynamic stiffness of rotor of vertical circulation pump used in AP1000 nuclear power plant was analyzed with finite element method, and the results demonstrated that the dynamic stiffness value decreased with frequencies and suddenly drop at resonant frequency. Based on this relation result, a contrast modal analysis about three situations which consider rigid bearing stiffness, sliding bearing stiffness and support structure dynamic stiffness respectively were done for the rotor model＇s dynamic characteristic. The result demonstrated that the difference between 1 st lateral vibration frequency of rotor are not obvious, the frequencies were 28.1,21.7 and 20.2Hz, nevertheless the higher vibration frequency difference between the three situations are obvious. The higher vibration frequencies decreased apparently with the support stiffness considered.