Successful major overhaul of 64 MW BBC (GE) turbo generator completed, June 2021

Turbo Generator (63 MW, BBC) Major Overhaul


Scope of Works:

– Dismantling of steam turbine, generator and exciter
– Cleaning, sandblasting, inspection, NDT of steam turbine parts
Life Time Assessment (LTA)
– Reblading of LP rotor section (7 rows, reverse engineering, blades manufacturing, installation)
– Rotor LP, IP and HP stages, balancing piston, inner and outer glands seal strips replacement
– Turbine rotor High Speed Balancing (HSB)
– Generator inspection and testing
– Main Stop Valves (MSV), HP, IP and LP Control Valves repair (blue print checks), including replacement and fitting of worn seats/diffusers, stems, plugs, bushings etc.
– MSV, HP, IP and LP control valves actuators overhaul, testing and calibration
– Repairs of cracks in stationaries found during inspection
– Repair of bearings (hand scraping)
– Jacking oil system repair and adjustment
– Turning gear system repair
– Inspection and calibration of all instruments (pressure, vibrations and temperature transmitters)
– Shaft alignment (turbine, generator, exciter), including generator stator re-alignment
– Lubrication and control oil pipeline cleaning (flushing and chemical cleaning)
– Oil reservoir cleaning, sandblasting and coating
– Lube oil and jacking oil pumps overhauling (including electric motors)
– Lube oil heat exchangers cleaning and flushing
– Oil mist separator overhauling
– Gland Steam condenser with vapors extraction fan cleaning, repair and testing
– Desuperheater dismantling, inspection, repair and testing
– Extraction lines gate and check valves dismantling, inspection, in-situ repairs and assembly
– Commissioning of all systems and TG start-up

After overhaul, vibrations are found to be within class A limits (as new). Rated power (63 MW) reached during test run.


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