Gas & Steam Turbine Maintenance

• Gas turbines and steam turbines are critical components in power generation and mechanical drive applications.
• Effective maintenance practices are essential for ensuring their reliable and efficient operation.
• Maintenance strategies encompass preventive, predictive, and corrective measures.

Gas Turbine Maintenance

• Gas turbines operate at high temperatures and speeds, requiring specialized maintenance.
• Maintenance intervals are typically based on operating hours or starts/stops.

Inspection

• Regular visual inspections are crucial for identifying potential problems.
• Check for leaks, corrosion, erosion, and any signs of damage.
• Borescope inspections of internal components like blades and combustors are essential.

Filtration System Maintenance

• Air intake filters prevent dust and debris from entering the turbine.
• Clean or replace filters regularly to maintain airflow and prevent fouling.
• Inspect filter housings for leaks and damage.

Combustion System Maintenance

• Combustion chambers are subject to high temperatures and thermal stress.
• Inspect combustor liners, fuel nozzles, and igniters for damage or wear.
• Perform fuel nozzle testing and calibration.

Turbine Blade Maintenance

• Turbine blades are critical components susceptible to erosion, corrosion, and creep.
• Non-destructive testing (NDT) methods like dye penetrant, eddy current, and ultrasonic testing are used to detect cracks and defects.
• Blade repair or replacement is necessary when damage exceeds acceptable limits.

Bearing Maintenance

• Turbine bearings support the rotor and ensure smooth operation.
• Monitor bearing vibration, temperature, and oil condition.
• Perform oil analysis to detect wear particles and contamination.
• Replace bearings based on condition monitoring or scheduled intervals.

Alignment

• Proper alignment between the turbine and driven equipment is crucial.
• Misalignment can cause excessive vibration, bearing wear, and coupling failure.
• Perform alignment checks regularly and correct as needed.

Steam Turbine Maintenance

• Steam turbines utilize high-temperature, high-pressure steam to generate power.
• Maintenance focuses on preventing erosion, corrosion, and scaling.

Inspection

• Visual inspections are essential for identifying leaks, corrosion, and erosion.
• Check for insulation damage and steam impingement.

Valve Maintenance

• Steam turbine valves control steam flow and pressure.
• Inspect valve stems, discs, and seats for wear and leakage.
• Overhaul valves periodically to ensure proper operation.

Nozzle and Blade Maintenance

• Steam nozzles and blades are subject to erosion from water droplets in the steam.
• Inspect for erosion, corrosion, and foreign object damage (FOD).
• Use NDT methods to detect cracks and defects.
• Repair or replace damaged nozzles and blades.

Rotor Maintenance

• Steam turbine rotors are large, heavy components.
• Inspect for cracks, erosion, and bowing.
• Perform NDT on critical areas like blade attachments and couplings.
• Balance the rotor if necessary to reduce vibration.

Condenser Maintenance

• The condenser cools and condenses exhaust steam.
• Maintain condenser vacuum to maximize turbine efficiency.
• Clean condenser tubes regularly to remove scale and fouling.
• Inspect for air leaks and corrosion.

Lubrication System Maintenance

• Proper lubrication is crucial for steam turbine bearings and gears.
• Monitor oil levels, temperature, and condition.
• Perform oil analysis to detect wear particles and contamination.
• Replace oil filters regularly.

Governing System Maintenance

• The governing system controls turbine speed and load.
• Calibrate and test the governing system regularly.
• Inspect and maintain control valves and actuators.

Common Maintenance Practices

Vibration Analysis

• Vibration analysis is a powerful tool for detecting mechanical problems.
• Regular vibration monitoring can identify imbalance, misalignment, bearing defects, and other issues.
• Analyze vibration spectra to pinpoint the source of the problem.

Oil Analysis

• Oil analysis provides valuable information about the condition of lubricants and the machinery they protect.
• Monitor viscosity, acidity, water content, and wear particles.
• Identify potential problems early and prevent catastrophic failures.

Thermography

• Infrared thermography detects temperature anomalies.
• Identify hot spots in electrical connections, bearings, and other components.

Non-Destructive Testing (NDT)

• NDT methods are used to detect surface and subsurface defects without damaging the component.
• Common NDT methods include:
  • Dye Penetrant Testing
  • Magnetic Particle Testing
  • Ultrasonic Testing
  • Radiographic Testing
  • Eddy Current Testing

Balancing

• Balancing reduces vibration caused by mass imbalance in rotating components.
• Static balancing corrects for imbalance in a single plane.
• Dynamic balancing corrects for imbalance in multiple planes.

Alignment

• Proper alignment between rotating components minimizes stress and vibration.
• Use laser alignment tools for accurate alignment.

Cleaning

• Regular cleaning removes dirt, dust, and debris that can cause overheating, corrosion, and erosion.
• Clean air filters, coolers, and other components regularly.

Documentation

• Maintain accurate records of all maintenance activities.
• Track operating hours, maintenance intervals, and repair history.
• Use a computerized maintenance management system (CMMS) to manage data.

Safety

• Follow all safety procedures when performing maintenance.
• Wear appropriate personal protective equipment (PPE).
• Lockout/tagout equipment before starting work.
• Use calibrated tools and equipment.

Training

• Provide adequate training for maintenance personnel.
• Train on specific equipment and maintenance procedures.
• Keep training up-to-date with new technologies and best practices.

Condition Monitoring

• Implement condition monitoring programs to track equipment health.
• Use sensors and data analytics to detect anomalies and predict failures.
• Predictive maintenance strategies reduce downtime and maintenance costs.