Classification of turbines – heads and efficiencies – velocity triangles. Axial, radial and mixed flow turbines. Pelton wheel, Francis turbine and Kaplan turbines- working principles - work done by water on the runner – draft tube. Specific speed - unit quantities – performance curves for turbines – governing of turbines.

1. UNIT-V
TURBINES

2. Unit-5
TURBINE

4. Classification of turbines

6. Nozzle

7. Velocity diagram

8. SPLITTER
BUCKETSORVANES
RUNNER
15

9. PELTON WHEEL
..(5)
•At

11. FRANCIS TURBINE

12. • Named after American Engineer
J.B.Francis
• It is a mixed flow reaction turbine with
medium head and medium specific speed
• Penstock
• Scroll/Spiral casing
• Speed ring/Stay ring
• Stay vanes
• Guide vanes/Wicket vane
• Runner blades
• Draft tube

13. • Water from the penstock enters the scroll casing which
completely surrounds the runner.
• Involute casing provides an even distribution of
water(constant velocity) around the circumference of the
runner.
• Stay rings directs water from scroll casing to guide vanes.
• The guide vanes
• -regulate the quantity of water supplied tothe
runner(to take care of the load variations)
• -direct water to the runner at an appropriate angle.
• The runner consists of a series of curved vanes evenly
arranged around the circumference.

14. • The difference in pressure between the inlet and
• outlet of the runner is called reaction pressure.
• Water enters the runner from the guide vanes towards the centre
radially and discharges out axially- Mixed flow turbine.
• After doing work water is discharged to the tail race through a
closed tube of gradually enlarging section called draft tube.
• As water flows through the runner the change from pressure to
kinetic energy takes place gradually.
• At the entrance to the runner only a part of energy of water is
converted into kinetic energy and substantial part remains in the
form of pressure energy.

15. FRANCIS TURBINE …3

20. KAPLAN TURBINE
• Developed by Austrian Engineer
• V. Kaplan.
• Suitable for relatively low heads and requires
large volume of water to develop large power.
• Kaplan turbine is a reaction turbine in which
water enters and leaves the runner blades
axially-Axial flow turbine

24. • The shaft of an axial flow reaction turbine is
vertical.
• The lower end of the shaft is made bigger and is
known as hub or boss.
• The runner vanes are fixed on the hub or boss.
• Kaplan turbine works on the reaction principle as
Francis turbine.
• Only difference is that water enters and leaves
the turbine axially – Axial flow turbine.
• Both the guide vane(wicket gate) angle and
runner vane angle can be adjusted which gives
rise to high efficiency.

25. KAPLAN TURBINE …1

28. GOVERNING OF PELTON WHEEL