Gas turbine power plants use gas turbines as their prime mover to generate electricity. These units come in various sizes ranging up to 300 MW plants. However, the working principle of a gas turbine power plant is similar to that of a steam turbine plant. These are different in many aspects, such as the power output and efficiency level, etc. 

This article will discuss the working principle of a gas turbine power plant in detail. Before discussing its working principle, let us know what a gas turbine is and how it works?

What Is a Gas Turbine Power Plant?

Gas Power Plant

A gas turbine is a Power Plant Engine that can use natural gas or other liquids as fuel to turn mechanical energy into electricity. The gas turbine power plant is a thermal power station that creates electricity by using a turbine to drive an electrical generator or motor. 

It consists of a gas-fired combustion turbine, heat recovery steam generator, and one or more electric generators driven by a gearbox mounted on its shaft. 

The entire unit sits in its building or enclosure called a nacelle, which can open or close depending on its use and configuration. It produces electrical energy by burning fuel at all times. However, there are other types with varying degrees of efficiency and complexity.

Principle of Gas Turbine:

Principle of gas turbine

A gas turbine engine draws power by burning fuel in a combustor and driving the turbine with rapidly flowing combustion gas. It is much like high-pressure steam drives a steam turbine. A simple gas turbine consists of three main sections: compressor, combustor, and power turbine. Gas turbines operate on the principle of the Brayton cycle, which mixes compressed air with fuel and burns it under constant pressure conditions. The resulting hot gas expands through the turbine to do its job.

  • Air is drawn into an air inlet and compressed by a compressor. 
  • Fuel is then added to the compressed air in the combustor, mixing with fuel and igniting. 
  • The burning gases expand through a power turbine which drives one or more generators to produce electricity. 
  • The exhaust gases exit the turbine through an exhaust system.

Flow Processes inside the Gas Turbine:

In a gas turbine, air enters at ambient temperature and pressure from a source such as an outside air inlet. 

The flow is compressed by a compressor and mixed with fuel (natural gas or liquid petroleum gas) to create an explosive mixture of gases called fuel-air mixture. 

  • The fuel-air mixture then flows through a combustion chamber where it’s ignited by an igniter and burns rapidly. 
  • The burning of fuel increases its temperature adiabatically to above 1150°C. 
  • This hot gas drives one or more turbine stages. 
  • From turbines, exhaust gases enter the smoke chamber, which is cooled down to around 350°C using fresh air from the air inlet. 
  • These cooled-down gases, called flue gases, leave through the chimney.

Working Methods of Gas Turbine:

Gas turbines heat a mixture of fuel and air to a very high temperature, rotating turbine blades to generate electricity. A rotating turbine drives a generator that converts energy into electricity. 

The gas turbine can efficiently generate electricity in combined cycle power plants with steam turbines.

1.The air-fuel mixture ignites: 

The gas turbine compresses the air and mixes it with the fuel, burning it at very high temperatures to produce hot gas.

2.Hot gas spins turbine blades: 

The hot air-fuel mixture moves through the turbine’s blades, causing the blades to spin rapidly.

3.Rotating blades rotate the drive shaft: 

High-speed rotating turbine blades rotate the turbine drive shaft. 

 4 .The rotation of the turbine drives the generator. 

The rotating turbine is connected to the generator rod and rotates a large magnet surrounded by a copper coil. 

5.Generator magnets move electrons to generate electricity.

The rapidly rotating generator magnets generate a strong magnetic field that aligns and moves electrons around a copper coil. The movement of these electrons through the wire is electricity.

Get Industrial Power Generation Solutions With Prismecs:

Our team offers a complete package regardless of operating environment or energy needs, from design and engineering to supply chain, test run, and even MRO. We help you secure the parts and develop a solution. Then we install, operate, and maintain it. 

As the power generation sector evolves, our experts continue to operate your customers with the most efficient and affordable solutions. If you need further assistance, contact us at 18887747632

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