TURBINE
*The Hydraulic energy machines, which convert the hydraulic energy into mechanical energy, are called "turbines" . While the hydraulic machines which convert the mechanical energy into hydraulic energy are called "Pump".
*Turbines consist of mainly Pelton turbine, Francis Turbine and Kaplan turbine.
1. PELTON WHEEL (or) PELTON TURBINE
*The pelton wheel (or) pelton turbine is a tangential flow impulse turbine. The water strikes the bucket along the tangent of the runner.
*The energy available at the inlet of the turbine is only kinetic energy. The pressure at the inlet and outlet of the turbine is atmospheric.
*The main parts are Nozzle, Runner and buckets, Casing, Breaking jet.
2. KAPLAN TURBINE
*Kaplan Turbine is an Axial Flow Reaction Turbine. For Axial Flow Turbines, the water flows through the runner along the direction parallel to the axis of rotation of the runner.
*Reaction Turbine means that the water at the inlet of the Turbine possesses Kinetic Energy as well as Pressure Energy. For Axial Flow Reaction Turbine, the shaft of the turbine is vertical.
*The lower end of the shaft is made larger and is called ‘Hub’ or ‘Boss’. The vanes are fixed on the hub and hence Hub acts as runner for axial flow turbine.
*The main parts are Casing, Guide Vanes, Hub with vanes, Draft Tube.
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Draft Tube : The water at exit cannot be directly discharged to the tail race. A tube (or) pipe of gradually increasing area is used for discharging water from the exit of turbine to the tail race. This tube of increasing area is called "Draft Tube".
3. FRANCIS TURBINE
*The Francis turbine is a type of water turbine that was developed by James B. Francis in Lowell, Massachusetts. It is an inward-flow reaction turbine that combines radial and axial flow concepts.
*In the modern Francis Turbine, the water enters the runner of the turbine in the radial direction at outlet and leaves in the axial direction at the inlet of the runner. Thus the modern Francis turbine is a mixed flow type turbine.
Comparison of Pelton, Francis & Kaplan Turbine
4. STEAM TURBINE
*A steam turbine is a type of electric power generator in which a shaft is made to rotate by the movement of steam past sets of blades arranged in circles.
*Modern steam-powered systems burn coal or gas to generate steam in boilers, which is then run through a steam turbine.
