01 / AIR & COMBUSTIONAir becomes a high-energy gas stream.
The compressor raises the pressure of incoming air. Fuel is introduced to the combustion section, where chemical energy becomes heat. The resulting hot gas expands through the turbine stages.
The gas fuel train includes filtration, regulation, shutoff and control functions. The liquid train includes a pump, filtration, shutoff and control functions. Real packages contain additional systems.
02 / TWO SHAFTSThe gas generator sustains itself.
The compressor turbine drives the compressor on shaft A. The free power turbine extracts more energy from the hot gas on an independent shaft B. Shaft B drives the gearbox and alternator.
The visible gap between the shafts is intentional. Energy reaches the free power turbine through the gas stream, not a mechanical coupling to the compressor shaft.
03 / FUEL TRANSFEROne fuel takes over from the other.
Move the slider or start the animation to see the diesel control valve closing while the gas control valve opens. The energy bars show a normalized conceptual handover from liquid fuel to gas.
The two valve motions are stylized and nonlinear. No real valve characteristic, fuel flow, calorific-value correction, load response, purge logic, protection logic, or transition duration is represented. The unchanged flame is an idealized continuity cue.
04 / HEAT RECOVERYUseful energy remains in the exhaust.
The turbine exhaust travels upward into the waste heat recovery unit. Heat crosses the exchanger surface into a separate process-fluid circuit, shown in violet. Exhaust and process fluid do not mix.
This diagram leaves the heat-transfer fluid unspecified. A particular installation could have a different heat-recovery duty, fluid, layout and control scheme.
05 / STARTINGThe starter accelerates shaft A.
An induction motor drives a hydraulic pump; fluid power feeds a hydraulic starter motor through its disengaging clutch to accessory gearing on shaft A. A turbine-control cabinet interfaces with starting equipment and shaft-speed sensing.
Select Start drive to see the starter and shaft A rotate. Select Running to disengage the starter and show independent shaft-B rotation. The optional story adds assumed-permitted diesel firing, acceleration, running and transfer. No actual start procedure, timing or exact OEM starter installation is claimed.
06 / BRUSHLESS EXCITATIONThe exciter field stays still; its armature rotates.
The AVR controls current in a stationary exciter field. The shaft-mounted exciter armature produces AC, which a rotating rectifier converts to DC for the main rotor field. The main alternator then induces voltage in its stationary output windings.
This is an illustrative brushless option, pending confirmation of the installed excitation system. No PMG is asserted.
07 / GRID INTERFACESpeed control becomes power control.
Before grid connection, the governor controls turbine speed and generator frequency while the AVR controls voltage. Phase angle, frequency and voltage are compared for synchronization, and phase sequence must be correct.
Once coupled to a stiff grid, frequency constrains synchronous speed. Governor action changes torque and active power; excitation affects reactive power and voltage according to the control mode and network conditions. The illustrated breaker remains open.
08 / BLADE HEIGHTCompression and expansion change flow volume.
Compressor blades generally become shorter downstream as air is compressed and its density rises. Turbine blade height can increase downstream as the gas expands and its specific volume rises.
These are general trends. Real annulus area, blade height, hub diameter, cooling, mass flow and stage loading are design-dependent. The model is not dimensionally exact and the turbine train is not reversed.
09 / COMPRESSOR BLEEDRelease compressor air during starting.
The interstage bleed branch vents air to atmosphere to help avoid compressor surge during starting. The reference manual describes it closing as compressor speed and its actuating air pressure increase.
Open during cranking, closing during acceleration and closed in Running are simplified teaching states. No actual stroke law, closure speed or power threshold is represented. This branch is distinct from the separate P2 blow-off system.
