Tribology at Vattenfall R&D Past, Present and Future Challenges 2017-11-28, Gregory Simmons, Jan Ukonsaari

Inlet gate: Hydraulic system Gearbox, wire Boundary lubricated bushings Sliding seals Transformer: Oil for cooling and isolation Short circuit breaker Dam Waste gate (missing): Hydraulic system Gearbox, wire Boundary lubricated bushings Sliding seals Turbine and Generator: 2-3 st guide bearings 1 thrust bearing Hydrodynamic lubrication Oil Seal, static and dynamic Air seal, dynamic Sliding generator feet Shaft joints Wicket gate system: Hydraulic system, links, joints Boundary lubricated bushings Runner wheel system: Hydraulic system (Kaplan) Oil, water, air environment Seals, oil, water, air Inlet tube Machine Station Draft tube Draft tube gate

Water hydraulics Water based hydraulic fluid 8 years of testing Initial testing and material selection Discovery: Water evaporates Ongoing investigation

Vertical shafts and bearings Rotordynamics Bearing characteristics

Oil filtration How to specify off-line filtration Build internal competence Don’t trust ’salesmen’

Kaplan blade bearings Oil free kaplan hubs Water lubricated bearings

Vattenfall and wind 1000 + wind turbines in operation 6+ TWh annual power production ~3000 MW installed capacity ~1500 MW offshore 650+ MW / year growth Industry is still immature

Gearbox problems Bearing failures Various mechanisms Failure by design Forms of fatigue

Gearbox problems Bearing failures Various mechanisms Failure by design Forms of fatigue Repair in place not possible

Gearbox problems Lubricate for life (easy?) How long do lubricants function? What is the limiting factor? First limit – wear particles Second limit – copper corrosion Third limit – ????

Offshore wind Built at shipyard Direct load to ship Several machines per trip ’Unlimited’ transportability Packaged for fastest installation Installed 70 km offshore

Monopiles

Blade bearings

Standardisation Active in standardisation committees In 100 years people will say ’wow, those are beautiful machines’

Standardisation Introducing ’sliding technology’ Active in standardisation committees Introducing ’sliding technology’ In 100 years people will say ’wow, those are beautiful machines’

Standardisation Introducing ’sliding technology’ Active in standardisation committees Introducing ’sliding technology’ In 100 years people will say ’wow, those are beautiful machines’

Future opportunities Rolling contacts  hydrodynamic sliding contacts Gear contacts  direct drive or ‘happy combination’ Fragile ‘High tech’  Robust ‘Low tech’ Complicated systems  Simplified systems Design for maintenance When is a machine series manufactured or an individual? When are statistical models no longer applicable?