Challenge
Major overhaul on a 300MW Siemens Steam Turbine and increasing the durability of the rotor
Solution
- Welding refurbishment of the last stage blades both flows (tips and trailing edges) and of the vanes from the first stage
- De-blading all of LP-rotor stages
- Rehabilitation of the grooves on the LP-rotor discs (unexpected indication of cracks) including shoot peening
- FEM calculation of the grooves in the LP-rotor after repair works main cause for cracks is weak design of blade root crack removal by grinding
Benefits
- LP rotor successfully overhauled and repaired
- All unforeseen obstacles overcome
- Repair method for cracks was developed and verified prior to application in consultation with AZT and VGB
- Main contributors for awarding:
- Technical skills
- Short realization time
- Attractive performance ratio
