Steam Turbine Start-Up Failure

Rubbing of Blades

Sketch of casing bow

Bottom half insulation blanket thickness

LocationU.A.E
ApplicationFloating Storage & Regasification Unit (FSRU)
Machine TypeN. 2 Steam Turbines
ServicePower generation
Power10 MW

Challenge

Turbine trip during start-up on both units. Severe damage to the rotors due to rubbing against the stator

Solution

  • RCA indicated casing bow (non uniform expansion), resulting from an insufficient thermal insulation of the casing
  • Re-calculation of the thickness of the thermal insulation
  • Suggested new procedure for turbine warm-up
  • Revised seal radial clearance

Result

Turbine started up and is now working correctly