Gas Turbine is used in Power Plant for driving the Generator,by which we can produce Electricity with other arrangements.Compressed Air plays the vital role in every Gas Turbine Plant.This Compressed Air is obtained from Air Compressor.
Usually Rotary Air Compressor are used with a Gas Turbine.Mostly Centrifugal Compressors or Axial Compressors are used.
Now we will see the details of each Air Compressor.
01)Centrifugal Air Compressor:-
The Impeller which consist of large number of Blades,is mounted on the Compressor Shaft,inside the Stationary Casing.As the Impeller rotates,the Pressure in suction region falls and hence the Air enters through the Eye and flows Radially outwards through Impeller Blades.As a result Velocity and Pressure of Air increases.
Later this Air enters and flows through the Convergent Passages formed by the Diffuser Blades.At this stage the Velocity of Air is decreases but the Pressure increases still further.We may say that,during this stage the Velocity Energy is converted into Pressure Energy.
Finally this High Pressure Air escapes from the Compressor Delivery Portion.This is Single Stage Compression and is suitable for small pressure ratios.You can obtain High Pressure Ratios by arranging the number of Air Compressor in series.
02)Axial Air Compressor:-
This type of Compressors are more commonly used now a days.In Axial Compressor,the Air flows in an Axial Direction right from Intake to the Delivery.
The Working Principle is as illustrated below.
The Stator,which have Stator Blades encloses the Rotor,which are provided with Rotor Blades.As the Air enters from Suction Region,it flows through the alternately arranged Stator and Rotor Blade Rings.
In flowing through each pair of Blade Rings formed up of one Rotor Blade Ring and one Stator Blade Ring,the Air gets Compressed successively.The Air is finally Delivered from Delivery Region,which is smaller in size compare to Suction side.
I have tried to disclose as much as knowledge I have, but engineering is such a vast field that can not be covered in single post.You can still search from Internet for more details.
You may also interested in following...................
5 Main Advantages Of Gas Turbine Over Steam Turbine.
10 Major Parts of Reciprocating Air Compressor.
How to Start and Stop Air Compressor.