What is the correct sequence for starting operations of a gas turbine?

The correct sequence for starting operations of a gas turbine begins with cranking, followed by purging, acceleration, and finally firing.

Starting with cranking, this phase involves engaging the starter system, which turns the turbine shaft to a speed sufficient for ignition. It is essential to establish this rotation before introducing fuel and air into the combustion chamber.

Once the turbine is being cranked, purging is the next critical step. During purging, the combustion chamber is flushed to remove any accumulated fuel gases and ensure that there are no flammable mixtures remaining before introducing a spark. This is a safety measure that helps prevent potential explosions or uncontrolled combustion.

Acceleration follows purging; as the turbine begins to run, it must reach the appropriate speed for stable combustion. This phase involves monitoring the turbine’s RPM to ensure it accelerates properly to the ignition point.

Finally, firing is initiated once the turbine has reached the desired operational parameters. At this point, fuel is ignited to create combustion, starting the main operational cycle of the turbine.

This sequence is crucial for safe and effective operation, ensuring that all necessary precautions are taken to avoid hazards associated with gas turbine startups.