Structural Vibration Analysis of Large Turbogenerator
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摘要: 针对某大型汽轮发电机(简称“发电机”)发生结构振动超标问题,对发电机进行了三维建模仿真模拟及停机模态试验。结果表明,结构振动的原因可能是由于发电机固有频率接近转子工作频率(50 Hz)而引发的结构共振。针对结构共振问题,从理论与实际出发提出提升支撑刚度、增加阻尼吸振器和底载分配调频这3种解决共振的方案,最终采用了在发电机氢冷器管道上增加阻尼吸振器的减振方案,使得发电机汽、励两端的瓦振大幅降低,可保证发电机在长期安全运行范围内,解决了长期存在的发电机振动高重要缺陷。Abstract: Aiming at the problem that the structural vibration of a large turbogenerator (hereinafter referred to as “generator”) exceeds the standard, the three-dimensional modeling simulation and shutdown modal test of the generator are carried out. The results show that the reason of structural vibration may be the structural resonance caused by the natural frequency of the generator close to the rotor working frequency (50 Hz). Based on the theory and practice of structural resonance, three solutions are proposed to solve the resonance, including increasing the support stiffness, adding the damping vibration absorber and bottom load distribution frequency modulation. Finally, by adding the damping vibration absorber on the generator hydrogen cooler pipe, the bushing vibration at both ends of the generator steam and excitation is greatly reduced, which can ensure that the generator can safely operate for a long time, and solve the long-standing important defect of high generator vibration.
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Key words:
- Generator /
- Simulation /
- Modal test /
- Resonance /
- Damping vibration absorber
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表 1 发电机模态分析频率及参与质量
Table 1. Generator Modal Analysis Frequency and Effective Mass
序号 频率/Hz 参与质量(m1)/t X方向 Y方向 Z方向 1 42.22 265.562 0.011 0.021 2 48.01 0.003 0.012 0.160 3 54.24 0.007 230.863 0.048 序号 频率/Hz 参与质量(m2)/t X旋转方向 Y旋转方向 Z旋转方向 1 42.22 0.288 932.879 0.175 2 48.01 0.042 0.0713 2870.360 3 54.24 2855.230 0.0539 0.005 表 2 发电机固有频率试验结果与仿真数据对比
Table 2. Comparison of Natural Frequency Test Results and Simulation Data of Generator
序号 试验频率/Hz 计算频率/Hz 振型 误差/% 阻尼比/% 1 41.49 42.22 Y扭振 1.8 1.51 2 47.45 48.01 Z扭振 1.2 1.23 3 57.69 54.24 X扭振 5.9 3.16 表 3 发电机振动测量结果(改造前后)
Table 3. Vibration Measurement Results of Generator (Before And After Transformation)
阶段 位 置 汽端振动/μm 励端振动/μm 轴振X 轴振Y 瓦振W 轴振X 轴振Y 瓦振W 改造前 62.3 87.0 55.3 67.4 55.6 47.5 改造后 58.8 67.9 22.8 29.1 28.2 19.7 -
[1] 刘伟,史庆峰,黄少华,等. 660 MW水氢氢冷发电机定子振动的分析与处理[J]. 中国核电,2018, 11(4): 512-517. [2] 黄玉盈. 结构振动分析基础[M]. 武汉: 华中工学院出版社, 1988: 173-203. [3] 王林军,曹慧萍. 基于ANSYS-Workbench的转子模态分析[J]. 三峡大学学报:自然科学版,2014, 36(6): 89-93. [4] 吴东东,李娟. 大型汽轮发电机定子绕组三维模型建立及模态分析[J]. 电气技术,2018, 19(4): 5-9,27. doi: 10.3969/j.issn.1673-3800.2018.04.005 [5] VIDHYA B, SRINIVAS K N. Vibration analysis including stator, rotor, housing and dynamic response analysis of flux reversal generator[J]. Journal of Electrical Systems and Information Technology, 2018, 5(2): 144-157. doi: 10.1016/j.jesit.2018.02.004 [6] WANG Y X, WANG Y, LIN L. Virtual prototype and modal analysis of stator system of large turbo-generator[J]. Applied Mechanics and Materials, 2012, 190-191: 232-236. doi: 10.4028/www.scientific.net/AMM.190-191.232