In this article we will know about the difference between impulse and reaction turbine. We will know about the constructional difference between them.
1. Impulse Turbine
In impulse turbine steam is expanded in turbine nozzle and attains a high velocity. The steam jet impinges on the blades fixed on the rotor periphery. The rotor may be a built up rotor or integral rotor. A built up rotor consists of a forged steel shaft on which separate forged steel discs are shrunk and keyed. In an integral rotor the wheels and shaft are formed from one solid forging. The built up rotor is cheaper and easier to manufacture. However in integral rotor the discs cannot become loose. The high pressure and intermediate pressure rotor are, always, of integral type.
In this turbine complete expansion of steam takes place in the nozzle and steam pressure, during the flow of steam over the turbine blades, remains constant. Thus the pressure on the two sides of the blades is the same. The blades have symmetrical profile.
2. Reaction Turbine
In a reaction turbine only partial expansion takes place in the nozzle and further expansion takes place as the steam flows over the rotor blades. The relative velocity of steam increases as it expands while passing over the blades. There is difference in pressure on two sides of the moving blade. The blades have aero foil section.
It is seen from above that in a reaction turbine also partial expansion takes place in the nozzle which is an impulse action. As such all modern reaction turbines are basically impulse reaction but are designated as reaction turbines.
The modern reaction turbine has both stationary and moving blades. The blades are similar; each is so arranged that the area through which the steam leaves is less than that through which it enters. Pressure drop takes place in both stationary and moving blades. The restricted area at the out let of the blades causes the steam velocity to increase as steam leaves the blades.
Difference between Impulse turbine and Reaction Turbine
1. In this turbine only kinetic energy used to rotate the turbine.
In this turbine pressure energy and kinetic energy both are used to rotate the turbine. it is main difference between impulse and reaction turbine.
2. In impulse turbine water flow through the nozzle and strike the blade of turbine.
In Reaction turbine water is flow through guide blades.
3. In this turbine pressure energy converted into kinetic energy
In this turbine pressure energy does not converted into kinetic energy.
4 It is suitable for large head and lower flow rate. For example peloton wheel turbines
It is mostly used for high flow rate and lower head
5. The pressure of water always remains unchanged. These are main difference between impulse and reaction turbine.
In case of Reaction turbine the pressure of water changed
Advantage of Impulse and Reaction Turbine
Advantage of Impulse Turbine
1) It is in easy to construct because it has simple design.
2) It is a cheap turbine.
3) It has less maintenance.
4) It can be use in reverse direction.
Advantage of Reaction Turbine
1) It is a highly efficient as compared to impulse turbine.
2) Output power is more.
Working of Impulse and Reaction Turbine
For knowing detail about difference between impulse and reaction turbine we must need to know about working of impulse and reaction turbine.
Working of Impulse turbine
impulse turbine is simple turbine. In impulse turbine a high speed fluid is comes through a narrow nozzle to the turbine blades for rotation of turbine. The blade of impulse turbine is bucket shaped so that it gives a gives a perfect angle and rotates the turbine. So this is a simple construction turbine and easy to understand. This is a high efficient turbine also. Water turbine is a example of impulse turbine, this is used in hydro power plants.
Working of Reaction turbine
Reaction turbine reacts when it has pressure of fluid, and developed torque.The working of reaction turbine is based on Newtown's third law i.e. action and reaction is equal and opposite. In reaction turbine a nozzle is attached to the rotating blades. When pressured fluid leaves the nozzle it produce reaction force on the pipe and rotor is starts rotation in opposite direction to that fluid. When fluid is passes through the blades its pressure got low.
Hence these are difference between impulse and Reaction turbine if you will find any incorrect above article you must comment below in comment box.