Power Division

Gas-fired combined-cycle power plant

A gas-fired combined-cycle power plant, also known as a combined-cycle gas turbine power plant (CCGT), combines the advantages of two thermal processes to optimum effect: electricity production via a gas turbine combined with a steam turbine.

The gas turbine produces around two-thirds of the power plant's entire electrical output.

Gas-fired combined-cycle power plants are technologically advanced and used throughout the world. Compared with other types of fossil fuel power plants, they are highly efficient

Gas-fired combined-cycle power plants are often built on a modular basis, being composed of several different units. Each unit is practically a self-contained power plant that can be operated independently of the others.

As in an aircraft engine, a mixture of compressed air and fuel is burned. The hot gases produced during this process drive the turbine and, with it, the generator coupled to it.

The steam turbine produces the remaining electrical power output (i.e. around a third) from the hot gases leaving the gas turbine. In the heat recovery steam generator, the exhaust gases transfer their heat to the circulating water: the pressurized water vaporises, which causes the temperature in the system to rise. The steam drives the steam turbine and, with it, the generator that is coupled to it.