Steam Turbine – Generator : Failure Modes, Troubleshooting and Industry Proven Repair Methods

This course provides each delegate with a detailed and applied review of the most common

turbine failure modes. Our instructor will focus on risk-informed repair and life extension

strategies which have a significant bottom line impact. The course will also offer best practices

and maintenance considerations for flexible operation, which typically includes more cycling,

lower minimum loads, and greater capacity ratings. All modules are supplemented with current

case studies demonstrating the applied techniques.

MODULE 1 – Steam Turbine Design, Failure Modes, and Advanced Troubleshooting

• Industry failure statistics-locating the areas of highest risk

• Steam turbine design features – key features for your unit and technology

advancements

• Common failure modes for steam turbines –explained, impacted components, how to

manage and impact of flexible operations on each failure mode

• High Cycle Fatigue

• Low Cycle Fatigue

• Stress Corrosion Cracking

• Solid Particle Erosion

• Water Droplet Erosion

• Creep and Embrittlement

• Foreign Object Damage

• Advanced Troubleshooting – detecting and mitigating before manifesting into a forced

outage

• Turbine vibration – unlocking the secrets of rotor lateral and torsional vibration

• Nondestructive testing – most effective nondestructive inspections to detect known

failure modes

• OEM Technical Advisories/Service Bulletins – management and integration into outage

scopes

MODULE 2 – Generator Reliability Improvements, Failure Modes, and Troubleshooting

• Key components and design features – overview and purpose of each components

• Winding Insulation Types

• Retaining Rings – 18-5 vs. 18-18

• Hydrogen vs. Air Cooled

• Auxiliary Equipment (exciter, grounding brushes, high voltage bushings,

coolers, heaters, etc.)

• Failure modes – stator vs. rotor/field: visual and electrical signs, root causes, and

mitigating actions

• Electrical testing – overview of standard electrical testing and information proved by

each and acceptance criteria

• NDE techniques – Recommended techniques for retaining rings, fan blades, etc.

• Outage type – robot vs. rotor out, pros and cons of each

• Generator capability curve – how to read and importance

• Economical repair options – looseness, girth cracking, oil ingress

• Operations – operational data trending, flux probes and partial discharge monitoring

MODULE 3 – Impact of Flexible Operations on Steam turbine and Economical Repair

Options

• Turbine operational audits – how to identify and avoid common operational pitfalls

• Impact of renewable energy and gas prices on steam turbine assets

• Ultra-Minimum Load

• Two-Shift Cycling

• Steam turbine rotor retrofits – key considerations, performance benefits, technology

enhancements

• “No-brainers” to regain lost capacity – upgraded sealing technologies, blade path repairs

and smoothing

• Emergent issues on combined-cycle steam turbines – unplanned findings early in unit

life on both rotor and casings

• Strategies to safely reduce cold start times – benefits of steam seal preheat and

modified hold speeds/times

• Material sampling and life extension assessments – fix only what is broken

• Targeted outage repairs – how to get back online with as little spend, time and risk as

possible

• Repair options and considerations – casing cracking, stress corrosion cracking, rotor

bow, solid particle erosion and water droplet erosion, foreign object damage

• Outage planning and risk assessments for key turbine hardware – how to optimize

outage intervals based on current hardware condition

Practical Case Studies

• Blade failures and repair strategies – high-cycle fatigue, low-cycle fatigue, aeroelastic

vibration, water droplet erosion and solid particle erosion

• Stress corrosion cracking and repair options

• Casing cracking

• Rotor shaft cracking

• Rotor bow repairs

• Generator boresonic inspection interval extensions

• Remaining life studies – creep, low-cycle fatigue, stress corrosion cracking