1. CACTUS MOON EDUCATION, LLC www.cactusmooneducation.com
ELECTRICITY GENERATION
COMBINED-CYCLE POWER PLANT TECHNOLOGY
EDUCATION MODULE
(CCP01PP)
CACTUS MOON
EDUCATION, LLC

2. INDEX Slide 1 Title Slide Slide 2 Index
Slide 3 Combined-Cycle Power Plant
Slide The Combustion Turbine Generator
Slide The Steam Turbine Generator
Slide The Combined-Cycle Generator

3. Combined-Cycle Technology
Combined-Cycle power plant technology is one of the most efficient methods of generating electricity.
A Combined-Cycle power plant “combines” two different thermodynamic cycles. These are:
The Brayton Cycle – as used in a combustion turbine
The Rankine Cycle – as used in a simple steam turbine

4. The Combustion Turbine Generator
The Combustion turbine (CT) is like a jet engine but instead of producing thrust to power an aircraft it is used to power an electric generator.
There are three stages in a CT
The compressor stage
The combustor stage
The power stage
Fuel is burned in the combustors to heat air which is used to spin the turbine blades.
The exhaust gas from the turbine is very hot (1,000 deg F) and is typically lost to the atmosphere from the exhaust stack.

5. The Combustion Turbine Generator3
The heated air is expanded into the power stage 4
The exhaust gasses are released into the stack 2
The compressed air is heated by burning fuel in the combustors
Fuel
Air is drawn into the compressor stage and is compressed 1 5
An electric generator connected to the turbine shaft generates electricity

6. The Steam Turbine Generator
A steam turbine is one of the simplest and oldest methods of generating electricity.
Water is boiled and turned into steam.
The steam is used to power a turbine/electric generator.
The exhaust steam is condensed back into water ready to boiled again.

7. The Steam Turbine Generator5
An electric generator connected to the turbine shaft generates electricity 4
The “spent” steam is condensed back into water to be reheated in the boiler again
Fuel 1
Fuel is burned in the boiler to heat water 3
The pressure of the steam forces the turbine blades to move and rotate the shaft 2
The water is turned into steam and fed to the inlet of the steam turbine

8. The Combined-Cycle Generator
In a Combined-Cycle generator, the hot exhaust from a Combustion Turbine generator is used as the heat source to boil water for a Steam Turbine generator.
A specailly designed heat exchanger, the Heat Recovery Steam Generator, transfers the heat from the exhaust gas to the water.
Making use of the hot exhaust gas in this way results in the Combined-Cycle generator having a very high efficiency of over 60%

9. The Combined-Cycle Generator1
The combustion turbine operates exactly as described earlier and turns a generator to make electricity
Fuel 5
An electric generator connected to the turbine shaft generates electricity 3
The combustion turbine stack has now become the Heat Recovery Steam Generator (HRSG) 2
The steam turbine boiler is replaced by a heat exchanger in the combustion turbine exhaust gasses 4
The “spent” steam is condensed back into water to be reheated in the boiler again