WHAT ARE THE TYPES OF GAS TURBINE POWER PLANTS?

Gas turbine engines derive their power from fuel which is burned in a combustion chamber. The gases which are produced as a result of the burning of the fuel are directed to the turbine which in turn uses it for the production of electricity. Similar to all other systems, gas turbine systems demand a fair amount of maintenance from time to time and this is why industrial setups require gas turbine maintenance training to ensure proper maintenance of the system for optimal functionality.

For proper maintenance culture, there is a need to better understand the components of the gas turbine power plants. The Gas turbine power plants comprise of three engine sections;

The compressor

The compressor part of the gas turbine power plant is responsible for drawing in air and pressurizing it. The pressurized air is then fed into the combustion chamber. The air, however, is continuously being fed into the chamber at high speed and this ensures the smooth functioning of the system.

The combustion system

The combustion system is made up of a ring of fuel injectors whose jobs, as reflective of their name is to incorporate fuel into the chambers in the system. The fuel which is injected from the injectors is mixed with pressurized air which is already present in the chamber thus causing a mixture which is burned at 2000oF. The burning of the mixture of fuel and pressurized air generates high temperatures and gas streams that are diverted into the turbine.

The turbine

The turbine is made up of several aerofoil section blades which have been designed to spread throughout it. As the turbine receives the hot stream of gases, the blades begin to spin. The spinning of the blades does two things essentially;

  • Makes the compressor draw in more pressurized air
  • Makes the generators spin, and in turn, provide electricity 

When choosing land-based gas turbines, there are two main options to choose from;

The heavy frame engines

The heavy frame engines have a low-pressure ratio (the ratio of the inlet pressure to that of the pressure generated by the compressor discharge) which is most often than not less than 20.

  1. Aero-derivative engines

These engines are derived from jet engines and have been designed such that they can work at a high compression ratio. With the aero-derivative engines, it is possible to reach compression ratios of as high as 30. The engines, in this case, have the advantage of size over the heavy frame engines as they are smaller and compact thus making them the better choice for smaller power output needs. 

It is important to note that turbines with larger frames produce more emission and contribute to environmental pollution through the production of NOx.

Gas Turbine Applications

Gas turbines are used primarily for the generation of large scale electricity. Based on the design, a gas turbine can generate as much as 600 MV to 400MW, especially when they are combined with a steam turbine capable of generating as much as 200 MW.

Gas turbines are mostly used to generate electricity to remote areas, for transportation containers, and for mobile electricity supplies. Ideally, gas turbines take between 10 to 20 minutes to startup thus making them a better choice for a backup power source for companies.

Gas turbines can also be erected and installed quickly, considering their small scale attributes compared to nuclear plants and coal.

To learn more about gas turbine and maintenance, visit https://ajss.com.au/training/