How it works
Combined-cycle power plant - Functioning, operation, example

The main actuators used to control the operation of the combustion turbine affect :

• fuel flow ;

• the air flow admitted to the compressor.

These are the fuel inlet valve (regulating and shut-off valve for gas, reverse flow valve for liquid fuels), and the variable-incidence vanes of the compressor's first diaphragm row. These devices are usually referred to as IGVs (inlet gate valves). Compressor stage blow-off valves and secondary air inlet valves for the combustion chamber complete the system.

To increase the power delivered by a combustion turbine, it is possible to open the IGVs. However, this use is limited by the risk of compressor surging. Increasing the gas inlet temperature to the turbine raises...