Combined Cycle Power Plant: How It Works
Inner Workings of a Combined-Cycle Power Plant
A combined-cycle power plant uses both a gas and a steam turbine together to produce up to 50 percent more electricity from the same fuel than a traditional simple-cycle plant. The waste heat from the gas turbine is routed to the nearby steam turbine, which generates extra power.
How a Combined-Cycle Power Plant Produces Electricity
This is how a combined-cycle plant works to produce electricity and captures waste heat from the gas turbine to increase efficiency and electrical output.
Gas turbine burns fuel.
- The gas turbine compresses air and mixes it with fuel that is heated to a very high temperature. The hot air-fuel mixture moves through the gas turbine blades, making them spin.
- The fast-spinning turbine drives a generator that converts a portion of the spinning energy into electricity.
Heat recovery system captures exhaust.
- A Heat Recovery Steam Generator (HRSG) captures exhaust heat from the gas turbine that would otherwise escape through the exhaust stack.
- The HRSG creates steam from the gas turbine exhaust heat and delivers it to the steam turbine.
Steam turbine delivers additional electricity.
- The steam turbine sends its energy to the generator drive shaft, where it is converted into additional electricity.