Gas Turbine

Overview

A gas turbine generates electricity by burning fuel in a continuous flow of compressed air and extracting work from the hot expanding gas. This heavy-duty industrial machine produces around 180 MW in simple cycle and approaches 60% efficiency in combined-cycle configuration, where exhaust heat raises steam for a bottoming steam turbine. It serves baseload, mid-merit, and peaking duty on the grid, running at 3000 RPM to synchronise with a 50 Hz system.

How it works

Air enters through the Air Inlet System, which filters, silences, and conditions the intake flow. The Axial Compressor, a 17-stage axial machine, raises the air to roughly 18 times atmospheric pressure. This compressed air feeds the Combustion System system, a can-annular array of combustors where fuel is injected and burned; dry low-NOx staging keeps emissions low while raising gas temperature to about 1400 °C.

The hot, high-pressure gas expands through the Turbine Section, a four-stage turbine whose air-cooled blades convert thermal energy into shaft torque. The same shaft drives the compressor and, through the Load Gearbox & Coupling, the Generator, a synchronous machine producing electricity at 15.75 kV. Spent gas leaves via the Exhaust System diffuser and stack, or passes to a heat-recovery boiler in combined cycle.

The rotor is carried by the Shaft & Bearing Assembly assembly, journal and thrust bearings fed by the Lube Oil Skid. Fuel is metered and pressurised by the Fuel Skid, while the Starting & Cooling Package package provides starting torque and component cooling air. The Control System system governs speed, load, temperature limits, and protection, and the entire machine sits within a ventilated Acoustic Enclosure for noise and fire containment.