The history of using gas turbine is as early as in 50 A.D. but in today’s world, it has emerged as one of the major power producers which is one of the efficient and economical ways to produce the energy. The Gas turbine engines procure the power from the fuel burning in the combustion chamber and using this high-pressure gas to rotate the turbine.
The natural gas-fueled powered plants are installed with gas turbines which are usually very complex but have three major parts which are mentioned below:
- The Compressor
The role of the compressor is to pull the air inside the engine, pressurize it and then feed it to the combustion chamber at a very high speed of several hundreds of miles per hour.
- The Combustion System
It refers to the ring of fuel injectors that injects the steady natural gas in the combustion chambers where it gets mixed up with the air. This prepared mixture is then burned at a temperature which is more than 2000 degrees of Fahrenheit.
This combustion produces high pressure as well as high-temperature gas which enters the turbine section and expands itself in it.
- The Turbine
Turbine is a rotary mechanical device, which can also be called an array of stationery and rotating aero foil-section blades. These moving blades perform two functions-
- to spin the generator to produce the electricity
- to drive the compressor so that it can draw more amount of pressurized air into the combustion system.
This ultimately produces more energy for different markets of energy.
What are the types of Gas turbines?
The land-based gas turbines are major of two types, the details are given below:
- Aeroderivative engines
As can be derived from the name also, these engines are derived from jet engines and operates at a very high compression ratio which is usually more than 30 psi.
It is very compact in structure and can be used where a small power output or less energy is required.
It is one of the popular choices as it is lighter significantly and responds faster comparatively. Overall, the flexibility, reliability, and efficiency make it a better choice than the other one.
- Heavy Frame Engines
These are usually very large physically and possess a lower pressure ratio which is normally below 20 psi.
Also, they have a capacity for larger power generation which results in higher emissions. So, constantly the research is being done to achieve the grade of low emission of pollutants.
How to Boost Efficiency of the Gas turbine?
- Keeping the temperature higher.
Higher is the temperature, the higher is the efficiency. The gas turbines reach the temperature of around 2300 degrees F but the materials with which the turbines are made cannot withstand such high temperature and are sustainable only till 1500–1700-degree F. To solve this issue some air from the compressor is used to cool down the turbine which ultimately decrease the efficiency.
Also, the Department of Energy has made some breakthrough innovations by using the combination of advanced materials and innovative cooling techniques. This helped to raise the temperature further by 300 degrees F which increase the efficiency of the turbine by 60%.
- Install the Heat Recovery System Generator (HRSG) or Recuperator
It reuses the waste heat coming out of the exhaust outlet of the turbine to preheat the discharge air from the compressor before it finally enters the chamber of combustion. Additional electric power is generated by the high-pressure steam coming out of these boilers.
Gas Turbine Power Plant-Working Principle:
- The air is compressed in the Gas turbine power plant which then passes through the combustion chamber where its temperature rises.
- Now, this high pressure and high-temperature air pass through the gas turbine where the gas expands and produces kinetic energy.
- Due to the Kinetic energy produced, the air is now able to perform the mechanical work of rotating the turbine.
- The alternator, shaft, and air compressor are common in the gas turbine power plant. The energy produced is partially also used to compress the air.
- This kind of gas turbine plant is majorly used in hydroelectric power plants.
Advantages of Gas Turbine Power Plant:
- Gas turbine parts and services are much more compact and simpler in construction than the steam turbine power plant.
- The running cost and capital cost of the Gas turbine power plant are lesser than the steam turbine plant.
- As there is no steam required in Gas turbine power plant so there is no requirement for the condenser or the cooling tower.
- Gas turbine power plant can be started and operated more instantly than a steam power plant.
- They have comparatively fewer chances of operational failure and less downtime as well.
- The flexibility of using any fuel in the gas like petrol, diesel, Kerosene, etc. in the turbine power plant is another advantage.
Disadvantages of Gas Turbine Power Plant:
- A major part of the energy produced in the turbine is used to run the air compressor which comparatively reduces the efficiency of the Gas turbine rather than the steam turbine power plant.
- The auxiliary power supply is required to start the gas turbine power plant.
- The lifespan of the system gets smaller due to the very high temperature of the furnace of the gas turbine power plant and usually gas turbine parts for sale.
- Gas turbine power plant is not used to produce bulk commercial electricity due to its low efficiency and is only used to provide auxiliary power to other plants like hydroelectric power plants.
From the above points, it can be concluded that the gas turbine power plant is one of the effective media to produce energy. A simple turbine has an energy efficiency of around 20-35%. But after the Department of Energy’s innovation, efficiency increased to 60%. And by using the waste heat from the exhaust, the overall efficiency reaches 80%. Thus, by innovative techniques the Gas Turbine power plant can be used more efficiently.