There were many abnormal vibration problems occurred in steam turbine during the entire system startup of gas-steam combined cycle power plant

seriously affecting the safe and stable operation of the unit.On the basis of vibration analysis and testing

many problems were found with steam turbines

such as the critical speed and warm-up speed setting

vibration sensor bracket resonance and No.5 bearing installation fault.After treatment the unit runs normally with good vibration performance.That provide reference for same type units.