Gas turbine engines are powered through fuel that is burned in a combustion chamber. The gases that result from this are directed to a turbine which runs on them. These engines are common in Gas Turbine Power Plants that produce electricity, and are made of three  sections:
The Compressor is a part of the engine which draws in air and pressurizes it so that it can feed the combustion chamber. The air being fed goes through the chamber at high speeds.
The Combustion System involves a ring of fuel injectors that incorporate fuel into the chambers in the system. The fuel mixes with the air already present in the chambers, and the resulting mixture is burned at 2000°F. The process generates high temperatures along with a gas stream that gets into and expands via the turbine.
The Turbine comprises of an array of aerofoil section blades which are spread throughout it. As the hot combustion gases enter, they start to spin the blades. This does two things: 1) it makes the compressor draw more pressurized air, and 2) it makes the generator spin, and produce electricity.
There are 2 types of land based gas turbines namely:
Heavy Frame Engines
These have a low pressure ratio which is usually below 20, and are quite large. By pressure ratio we mean the inlet pressure and the ratio of the pressure generated by the compressor discharge.
As the name implies, these are derived from jet engines and work at quite high compression ratios which can go up to 30. The engines are quite small and compact which makes them ideal for smaller power outputs in smaller plants. Turbines that have larger frames produce more emissions but they need to be designed to reduce the pollutants that are emitted, such as NOx.
Application of Gas Turbines
Gas turbines are typically used for generating electricity on a large scale. They can be designed to generate up to 600 MV or 400 MW if they are combined with a steam turbine that generates 200 MW.
Gas turbines are typically used for generating electricity on a large scale. They can be designed to generate up to 600 MV or 400 MW if they are combined with a steam turbine that generates 200 MW. Click To Tweet
Rather than being used to generate base load electricity, these setups are typically used to provide electricity to remote areas, such as oil and gas fields. On the other hand, they are also quite useful in main electricity grids for emergency power supply.
Gas turbines that are not as powerful or generate just 5 MW are often used in transportation containers and as mobile electricity supplies that can be delivered via trucks.
Gas power plants that generate electricity take 10 to 20 minutes at most to start up which makes them the ideal choice as backup plants for utility companies. Since they are smaller in scale compared to coal and nuclear plants, they can be erected fast and at a lower cost. Since these don’t need as much water when compared to steam power plants, they can be converted easily into combined cycle power plants which may prove to be more efficient.
In addition, gas turbine power plants are more flexible when it comes to fuel economy. They can be altered to accommodate almost any type of natural gas or light petroleum products, such as paraffin and gasoline. Besides natural gas, heavy oils can also be used to fuel these turbines if their viscosity is reduced to less dangerous levels. This can be done in the turbine combustion chambers.
Generation Training by 360Training.com
360Training.com is the largest NERC approved online training provider for all workers who are involved in or work with transmission, generation, and distribution utilities. The courses on power generation are designed to provide in-depth understanding of the technologies that are involved in a power plant, such as gas turbines and hydroelectric turbines.
The course can be taken online at any time, from any location. Sign up or allow your employees to sign up so that they can remain safe while they work in the plant. The course can be taken on any mobile device that has a good internet connection, so students can plan their attendance as per their own schedule.
Once the course is completed, students will receive a certification of completion. However, please keep in mind that this does not include any content that can be taken as approval by NCEES or RCEP.