Gas Turbines in Modern Industry

Common Applications

• Turbo Generators (GTG)
• Turbo Compressors

Overview of Gas Turbine Power Plants

• Generator: Electrical machine needing a prime mover (gas turbine).
• Gas Turbine Function: Transforms chemical energy in fuel (e.g., natural gas) into mechanical energy.
• Mechanical Energy Transfer: From turbine exit shaft to generator via gearbox.
• Electrical Energy Generation: Low/medium voltage output requires step-up transformers for transmission.

Gas Turbine Mechanism

• Basic Principle: Similar to rocket propulsion; high-pressure exhaust gas creates mechanical energy.
• Fixed Structure: When the rocket is fixed, exhaust gas forces act backward, driving turbine blades to create rotational movement.
• Energy Transformation: Chemical energy to rotational mechanical energy.

Components of Gas Turbines

• Combustion Triangle: Combustion requires Fuel, Air, and Heat.
• Combustion Chamber: Air intake mixes with natural gas, requiring proper air-gas ratio based on:
  • Heating value of gas
  • Quality of air (moisture, altitude, etc.)
• Ignition System: Provides initial sparks for combustion, later turned off once stable combustion is achieved.
• Exhaust Gas Management: High-pressure exhaust gas drives turbine blades.

Air Handling and Conditioning

• Air Intake: Must be filtered and monitored for contamination.
• Instrumentation: Monitors draft pressure and temperature.
• Preconditioning: Air may require preheating in harsh environments.
• Differential Pressure Monitoring: Alerts operator of filter clogging.

Air Compressor

• Type: Axial compressor with multiple stages of blades.
• Monitoring: Discharge pressure and temperature for combustion quality management.

Fuel Gas Characteristics

• Importance: Essential for design and operation; performance guarantees depend on fuel gas details.
• Monitoring: Pressure and temperature during normal operation are critical.
• Fuel Injection: Conducted in combustion chamber, with monitoring of temperatures via sensors (e.g., thermocouples).

Exhaust Gas and Turbine Operation

• Exhaust Gas Role: Drives turbine blades for rotation.
• Monitoring: High RPM, load-driven surge, vibrations, and speeds for performance and protection.

Conclusion

• Gas turbines are complex machines requiring detailed study and monitoring.
• Proprietary technologies may vary between manufacturers.

Additional Learning

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