Damage was detected on the nose cone structures of 7 Gamesa G90/2000 wind turbines in a French wind farm. Instead of just repairing, Maintenance Partners used its vision of Engineered Services to improve the lifetime and reliability of the equipment.
Cause of nose cone structure damage
Wind turbines are subject to continuous vibrations. Due to poor design and quality, this type of wind turbine is prone to nose cone structure cracks due to vibrations. These cracks can form a hazard for the structural integrity of the wind turbines. Moreover, the damage could lead to potentially very large repair costs and turbine downtime in case of a complete nose cone replacement.
Inspection
To determine the extent of the damage, Maintenance Partners was asked to inspect the nose cones of all turbines in the wind farm.
MP’s field teams carried out visual inspections and used non-destructive testing techniques to check the welds for cracks. The inspections showed cracks developing in the connecting welds between the tubes that form the nose cone structure.
After the inspections, a detailed report with repair proposal was drawn up. The repair proposal offered the most cost effective solution to the client in which production losses were reduced to a minimum.
To correct the nose cone structure problems, MP’s Engineering department has developed an upgrade method with improved solution to safely extend the lifetime in the long run (until decommissioning of the wind turbine).
Repairs: Temporary Safety Kit
Due to the winter windy season coming up, to reduce the outage time to a minimum and to avoid further damage, MP proposed the customer to repair the nose cone structure in the shortest possible timeframe and on the shortest notice. First, Temporary safety kits were installed to immediately reduce the hazards caused by this damage.
Structural Upgrade
After installation of the safety kits, MP implemented the upgrades to each turbine. The upgrade included:
- Safety kit
- Dismantling
- Cleaning
- Replacing 6 damaged structural tubes for each nose cone structure
- Welding of structure using special purpose procedures
- Application of Strengthening plates
- Installation of additional calipers
- Passivation for corrosion resistance
- NDT including Cofrend 2 welding certification
- Conformity certificate
- Material certificate
Because all works had to be performed onsite and inside the nacelle, elaborate safety measures were taken to ensure the safety of all workers onsite and the turbine itself.
Afterwards, the turbines were recommissioned and started up by MP’s field team.
Results for Customer
After applying the upgrades, the customer is now sure that the nose cone structures are solid and that they will last until decommissioning.
Contact us
Are you looking for an inspection of the nose structures in your Gamesa G90 turbines or do you want to know how we can optimize your wind turbine efficiency? Call us at +32(0)81 40 08 21 or send us a message using the form below: