설비개선이 터빈-발전기 축계의 비틀림 고유주파수에 미치는 영향 평가

Excessive torsional vibrations can result in blade failures and retaining ring failures. The severity of torsional oscillations and stress depends upon the relationship between the excitation frequencies and torsional natural frequencies. The difference between theses frequencies is referred to as the separation margin. ISO and manufacturers regulate this separation margin to ensure the system’s reliability. Recently, Turbine-generators have been replaced for the integrity reinforcement and the efficiency improvement, also, the last stage blade’s failures of LP turbines due to torsional vibration have been reported. In this paper the measured torsional vibration of the turbine-generator is analyzed to ensure the system’s reliability.