升速过程中正交方向上振动相位差及截面最大振动分析  

Analysis of the Vibration Phase Difference in the Orthogonal Direction and the Maximum Vibration of Cross Section during the Runup Process

作　　者：孙栓柱[1] 孙彬[1] 周春蕾[1] 黄翔[1] SUN Shuan-zhu;SUN Bin;ZHOU Chun-lei;HUANG Xiang(Jiangsu Frontier Electric Technology Co.,Ltd.,Nanjing 211106,China)

机构地区：[1]江苏方天电力技术有限公司,南京211106

出　　处：《汽轮机技术》2020年第6期411-413,416,共4页Turbine Technology

基　　金：江苏方天电力技术有限公司“燃煤发电机组重要设备及重大危险源状态评估模型、事故诊断系统设计及应用”(KJ201911)资助。

摘　　要：大型旋转机械在轴承的垂直和水平方向上安装了振动传感器。通过简化的转子模型以及基于有限元的汽轮发电机组动力学模型分析了不平衡激励下升速过程中两个方向上振动相位差随转速变化情况。研究结果表明,升速过程中相位差会在较大范围内变化,与轴承各向异性、系统阻尼、固有频率、转速等因素有关。阻尼、固有频率等系统参数确定时,相位差则是转速的函数。在两个方向各自临界转速附近相位差变化幅度较大。根据两个方向振动幅值和相位差可以准确计算出截面最大振动,该值小于两个方向上振动幅值平方和后的平方根值,在临界转速附近两种计算方法的差值较大。根据截面最大振动值评估振动对轴承安全运行的危害比较合理。The transducersare installed in the vertical and the horizontal direction of the bearing of large rotating machinery.Based on the simplified rotor model and the finite element model of turbo generator,variation of phase difference in two directions in the run up process under unbalance force excitation is analyzed.The results show that the phase difference changes in a large range in the run upprocess.The phase difference is related to bearing anisotropy,system damping,natural frequency and speed.When the parameters such as damping and natural frequency are determined,the phase difference is a function of rotational speed.The change is more intense near the critical speed zone of each direction.The maximum vibration of the section can be calculated accurately from the amplitude and phase difference of two transducers.This value is less than the square root of the sum of the squares of the vibration in two directions.The difference between the two methods is large near the critical speed zone.It is reasonable to evaluate the damage of vibration to the safe operation of bearing according to the maximum vibration value of cross section.

关 键 词：振动 旋转机械 故障诊断 

分 类 号：TK05[动力工程及工程热物理]