HYDRAULIC TURBINES :• Designed to work under a condition that head ofwater should be above a certain minimum level.• Without a certain minimum level of water in thedam a turbine cannot be run.
ADVANTAGES :• Simple construction• Easily controllable• Efficient• Ability to work at peak load or stand by plant
CLASSIFICATION :a. Based on action of water on moving blades:1. Impulse turbines2. Reaction turbinesb. Direction of flow of water:1. Tangential flow turbine2. Radial flow turbine3. Axial flow turbine4. Mixed flow turbine
c. Position of shaft:1. Vertical shaft turbines2. Horizontal shaft turbinesd. Head of water:1. High head turbines2. Medium head turbines3. Low head turbinese. Based on speed:f. Based on specific speed:
IMPULSE TURBINES:• Wheel passages are not completely filled with water.• Water acts on buckets at atmospheric pressure.• Water is supplied on few points at the periphery ofwheel.• How does it works?
REACTION TURBINES:• Water passages are completely filled with water.• Water acting on vanes is under pressure greaterthan atmospheric.• Water enters all round the periphery of wheel.• How does it works?