The document discusses different types of turbines. It describes the Francis turbine in detail. The Francis turbine is a mixed-flow reaction turbine used for medium heads and speeds. It has components like a penstock, scroll casing, speed ring, stay vanes, guide vanes, runner blades, and draft tube. Water enters the scroll casing and is directed by the guide vanes towards the radially inward curved runner blades to extract energy before exiting through the draft tube. The document also briefly describes the Kaplan turbine, an axial-flow reaction turbine suitable for low heads. Both the guide vanes and runner blades of the Kaplan turbine can be adjusted for high efficiency.
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.
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
21.
22.
23.
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.