Explain the construction and working of Kaplan turbine.

In this content, you can learn about introduction of Kaplan turbine and it's working principle.

 Q 1. Explain the construction and working of a Kaplan turbine? 

        Or, what is the construction and working of Kaplan turbine? 

       KAPLAN TURBINE

This is one of the lowest head turbine. Kaplan Turbine is invented by Dr. Victor Kaplan. It works under very high discharge. It is an axial flow turbine. 

It has only vertical shaft. Runner blades of Kaplan turbine are adjustable. It is propeller type. The number of runner blades (3 to 8) usually 4. The specific speed of Kaplan turbine is above 200 to 900 m.

Construction of Kaplan turbine

• The components of Kaplan turbine is similar  to that of Francis turbine. 

• The runner vanes of Kaplan turbine are  adjustable just like the guides vanes of Francis turbine. 

• The turbine gives good efficiency even at  different load conditions and water flows over the blades without shock. 

• The construction of Kaplan turbine is as shown below in the figure. 

Fig.1:-Kaplan turbine runner

   

     Working of Kaplan turbine

• In Kaplan turbine water enters the runner in an axial direction and during the process of energy transfer, it travels across the blade passage in the axial direction and leaves axially. 

         

  Figure:- Part-(a)

• The pressure, at inlet of blades is larger than the pressure at the exit of the blades. 

• The energy transfer is due to the change in magnitude of relative velocity across the blades. 

      

   Figure:- Part-(b)

• In Kaplan turbine, the runner blades are adjustable and it can be rotated about pivots fixed to the boss of runner.

 The blades are adjustable automatically by servomechanism so that at all loads, the flow enters without shock. Thus a high efficiency is maintained even at part load. 

                                 Figure:- Part- (c)

Conclusion:-

you have learnt about the construction of Kaplan turbine and working  principle of Kaplan turbine.