Francis Turbine Working Principle and Operation, Advantage, Disadvantage

In this article we will learn about Francis Turbine Working Principle and Operation, Advantage, Disadvantage

The Francis turbine is a response turbine and It was created by James B Francis. It is an internal stream response turbine that consolidates spiral and hub stream ideas. The Francis turbine is the most well-known water turbine utilized today. 

The Francis turbine works a head scope of 10 meters to a few hundred meters and is fundamentally utilized for electrical force creation. 

The Main Parts of a Francis Turbine: 

A Francis Turbine comprises of the 5 primary parts those are: 

• Winding Casing 
• Stay Vanes 
• Guide Vanes 
• Sprinter Blades 
• Draft Tube 

Winding Casing: 

It gives an encased water way to contain the water pressure. The water moving from the supply or dam is made to go through this line with high pressing factor.

The cutting edges of the turbines are circularly positioned, which implies the water striking the sharp edges of the turbine should stream in the roundabout hub for proficient striking. 

Thus, the twisting packaging is utilized, yet because of the roundabout development of the water, it loses its pressing factor. 

To keep up a similar pressing factor, the distance across of the packaging is bit by bit decreased, to keep up the pressing factor consistently, along these lines uniform energy or speed striking the sprinter sharp edges. 

Also Read : Reversible and Irreversible Processes in Thermodynamics

Stay Vanes: 

This aides the water to the sprinter sharp edges. Stay vanes stay fixed at their position and diminishes the twirling of water because of spiral stream and as it enters the sprinter sharp edges. Subsequently, makes the turbine more productive. 

Guide Vanes: 

Guide vanes are otherwise called wicket doors. The primary capacity or utilizations of the guide vanes are to manage the water towards the sprinter. The water stream should be a point and that is suitable for the plan. 

Sprinter Blades: 

Assimilates the energy from the water and converts it to rotational movement of the primary shaft. 

The sprinter cutting edges configuration chooses how viably a turbine will perform. 

The sprinter sharp edges are isolated into two sections. The lower half is made looking like a little can so it utilizes the drive activity of water to turn the turbine. 

The upper piece of the sharp edges utilizes the response power of water moving through it. These two powers together make the sprinter turn. 

Draft Tube: 

The draft tube is an extending tube which is utilized to release the water through the sprinter and close to the tailrace. 

The principle capacity of the draft tube is to decrease the water speed at the hour of release. 

Its cross-segment region increments along its length, as the water emerging from sprinter cutting edges, is at extensively low pressing factor, so its extending cross-segment territory assists it with recuperating the pressing factor as it streams towards the tailrace. 

Also Read : Types of Manometer - Working Principle and Operation

We should See How a Francis Turbine Work? 

In the first place, the water is permitted to go into the winding packaging of the turbine, which manages the water through the stay vanes and guide vanes. The winding case is kept here in diminishing distance across so that to keep up the stream pressure. 

The stay vanes being fixed at their place eliminates the whirls from the water, which are created because of move through the winding packaging and attempts it to make the progression of water more direct to be diverted by flexible guide vanes. 

The point of guide vanes decides the point of strikes of water at the sprinter sharp edges in this way ensure the yield of the turbine. The sprinter sharp edges are fixed and can-not pitch or change their point. To put it plainly, the guide vane controls the force yield of a turbine. 

The exhibition and effectiveness of the Francis turbine are reliant upon the plan of the sprinter sharp edges. 

In a Francis turbine, the sprinter sharp edges are isolated into two sections. The lower half is made looking like a little pail with the goal that it utilizes the motivation activity of water to turn the turbine. 

The other or you can say the upper piece of the edges utilizes the response power of water moving through it. Hence, sprinter sharp edges utilize both pressing factor energy and active energy of water and turn the sprinter most proficiently. 

The water which is emerging from sprinter cutting edges would need both the motor energy and pressing factor energy. 

so we utilize the draft cylinder to recuperate the pressing factor as it propels towards tailrace, yet at the same time, we can't recuperate the strain to that degree that we can stop air to go into the sprinter lodging hence causing cavitation. 

Cavitation: 

The distinction in the pressing factor of water when the passageway to the turbine and exists to the turbine in the wake of striking the sprinter cutting edges is excessively high.

Because of more measure of pressing factor contrast, the air atoms which are generally at high pressing factor then the water comes out, enters the turbine packaging as air pockets. 

These air pocket continues detonating close to the outside of the sprinter edges consistently causing a stun wave, which delivers a sort of deformity at sprinters' surface called cavitation. 

The Francis turbine is a response turbine and It was created by James B Francis. It is an internal stream response turbine that joins outspread and pivotal stream ideas. The Francis turbine is the most well-known water turbine utilized today. 

The Francis turbine works a head scope of 10 meters to a few hundred meters and is principally utilized for electrical force creation.