Beyond the Blades: The Turbine’s Vital Role in Gas Turbine Efficiency

The role of the turbine

The high-pressure and high-temperature combustion gas coming out of the combustion chamber expands and decelerates to impact the turbine to do work.

This drives the compressor to do work, and drives the accessories to work through the accessory casing transmission.

Turbine compresses gas? Who can compress high-temperature and high-pressure gas?

The number of compressor blades increases from few to many. The blade angle gradually decreases, and the material also changes. The turbine blades are more than the compressor blades. This is mainly because the gas needs to pass through to do work.

The compressor blades and the guide vanes in the compressor are both compression-diffusion.

The turbine blades are diffusion-compression.

The turbine is coaxially connected with the high and low pressure compressors.

The turbine is coaxially connected with the high and low pressure compressors. It is called a single rotor engine.

The turbine is coaxial with the high and low pressure compressors (the main shaft is high pressure, and the one passing through the middle of the main shaft is low pressure.)

No matter how it is connected, it is to provide power to the compressor.

A turbine is a kind of impeller machine used to extract work (transliterated as turbine, turbine). According to the working medium, there are: wind turbine - wind turbine, hydraulic turbine - water turbine, steam turbine - steam turbine, exhaust gas turbine - the one in the turbocharger, gas turbine - the one used in the gas turbine engine, gas turbine, the function is to extract the work in the gas to drive the coaxial compressor to compress the air.

When the aircraft engine is started, a starter is used to drive the core engine to rotate. Starters include electric motors, air turbine starters (using high-pressure compressed air), and gas turbine starters (a small, micro engine). When the speed rises to a state suitable for combustion chamber ignition, fuel injection and ignition begin. At this time, the starter and gas turbine jointly drive the compressor to work; the speed continues to rise, and when the power of the gas turbine is sufficient to maintain the operation of the engine, it reaches a self-sustaining state. The speed at this time is called the self-sustaining speed, and the starter can actually be disengaged. This speed corresponds to the disengagement speed, and sometimes it will be slightly greater than the self-sustaining speed for faster acceleration; then the turbine alone drives the compressor to increase the speed to the idle state, and above the idle state, the throttle can be pushed to switch between acceleration and deceleration states.