Gas Turbine Start-Up Failure

Bearing Vibration Spectrum

Old Bearing

New Bearing

LocationEgypt
ApplicationNatural gas extraction plant
Machine TypeN.2 Two-shaft Heavy-duty Gas Turbines
ServicePower generation
Power5 MW

Challenge

After a maintenance stop, Turbine could not start due to high vibrations (both low and high frequency)

Solution

  • RCA results: not appropriate bearing clearances and oil inlet design
  • Bearings replaced with 4-lobe types (low-frequency vibration)
  • Trim balancing (for synchronous vibration)

Result

Gas Turbine started up and is now running correctly