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http://dx.doi.org/10.5050/KSNVE.2013.23.3.267

Effects of Generator Retrofit on Torsional Natural Frequency of Turbine-generator Train and Study on Measurement Results  

Lee, Hyuk-Soon (Dept. of Mechanical Design Engineering, Chungnam National University)
Yoo, Seong-Yeon (Chungnam National University)
Publication Information
Transactions of the Korean Society for Noise and Vibration Engineering / v.23, no.3, 2013 , pp. 267-273 More about this Journal
Abstract
Recently, turbine-generators have been replaced for the integrity reinforcement and the efficiency improvement, also, the blade's failures of LP turbines due to torsional vibration have been reported. Excessive torsional vibrations can result in failures of components. The severity of torsional oscillations and stress depends upon the separation margin between the excitation frequencies and torsional natural frequencies. Therefore it is needed to measure the torsional natural frequencies after replacement of the components to conform the separation margin of torsional natural frequencies. In this study torsional vibration measurements were performed after LP turbine and generator replacement and the torsional natural frequencies for the turbine-generator train were calculated to evaluate the effects of generator replacement on torsional natural frequencies of turbine-generator train. It is expected that these evaluation results will be used effectively to identify the root causes of torsional vibration problems.
Keywords
Torsional Vibration; Turbine-generator; Separation Margin; Blade-rotor Coupled Mode;
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