Learn the concepts of Thermodynamics on Magic Marks
Fluid machines turbines
1.
2. Pelton turbine
It was invented by Lester Allan Pelton in the 1870s.
The Pelton wheel extracts energy from the impulse of
moving water,as
opposed to water's
dead weight
4. Kaplan turbine
The Kaplan turbine is a propeller-type water
turbine which has adjustable blades. It was developed
in 1913 by the Austrian professor Viktor Kaplan
5. Difference between Pelton ,Francis
and Kaplan Turbine
Type of turbine
Disposition of shafts
Number of vanes
Head
Flow rate
Specific speed
Efficiency
Power output
6. Type of turbine
Pelton wheel is an impulse type turbine while Francis
and Kaplan are inward flow reaction turbine
In Kaplan turbine, the water flow is axial and in
Francis turbine it is radial.
8. Number of vanes
The runner blades in the Kaplan turbine is less in
number.
Kaplan turbine has 3-8 vanes while Francis turbine has
16-24 vanes while the vanes for Pelton turbine are
generally greater than 15.
9. Head
Pelton wheel > Francis Turbine > Kaplan turbine
Pelton wheel requires a very high head as it is an
impulse turbine .kaplan turbine can operate at very
low heads of 2m
Typical operating speeds
Kaplan turbine 20 < H < 40
• Francis turbine 40 < H < 600
[6
• Pelton wheel 50 < H < 1300
11. Specific speed
The specific speed is the speed with which the turbine
turns for a particular discharge Q, with unit head and
thereby is able to produce unit power.
Specific speed of Kaplan turbine is 2 to 3 times that of
Fancis turbine.
13. Power output
Maximum Power is obtained by Francis turbine
followed by pelton wheel followed by Kaplan turbine.
14. Pelton wheel Francis turbine Kaplan turbine
Type of turbine Impulse turbine Inward Flow
reaction turbine
Partial Axial Flow
Disposition of
shafts
horizontal Vertical or
horizontal
Only vertical
Number of vanes >15 16-24 3-8
Head High(20-2000 m) Medium(10-700
m)
Low(0-30)
Flow rate Low(4-15 m³/s) Medium(4-55
m³/s)
very large(1-350
m³/s)
Specific speed 10-40 50-250 250-850
Maximum
Efficiency
90% 92% in laboratory 95%
Power output 200 MW 750 MW 120 MW
Type of runner
vanes
Fixed double
cupped
Non adjustible adjustible