1. Group : 06

2.  Rotary engine that exact energy from a fluid flow and convert in to useful work.  Consists of rotor assembly with blades attached.  Moving fluid acts on the blades.  Water, Steam, Gas turbines….

3. Water turbine.  Developed in the 19 th century.  Two types of water turbines. o Reaction turbine. o Impulse turbine.  Turbine selection mostly based on available water head, less on water flow rate.

4. Reaction turbine.  Water pressure drops when passing through the turbine wheels.  i.e. increase the kinetic energy.  That energy transfer to the turbine wheels.  Have a housing to contain the water pressure.  Used in low and medium head applications.

5. Reaction turbine runner.

6. Impulse turbine  Water is injected to the turbine by nozzles.  That high velocity water jet impact with curved turbine blades which change the direction of water flow.  That change in momentum(impulse) creates a force on the blades, which causes to spin the turbine runner.  No pressure change occurs at the turbine blades. So turbine needn’t a housing.  Used in very high head applications.

7. Impulse turbine runner

8. Francis turbine  Developed by James B. Francis.  Type of inward flow reaction turbine.  Most common water turbine type.  Water inlet is spiral shaped.

9. Francis Inlet Scroll, Grand Coulee Dam

10. Francis turbine cont….  Wicket gates direct water tangentially to the turbine wheels.  Water flow is controlled by adjusting wicket gates.

11. Francis turbine cont…  Efficiency is typically over 90%.  Efficiency is reduced with flow rate.  Can be used with 20m-700m water heads.  Output power may vary from just a few kWs to 1 GW.  During law power demand this can be used as a pump to fill the reservoir. Graph

12. Francis turbine cont…  Francis turbine employed PS in Sri Lanka. PS Rated Power(MW) Water Head(m) Kothmale3*67227-189 Victoria3*70208-140 Randenigala2*6184-51 Rantambe2*24.533.73-22 Ukuwela2*2089.39-70.1 Bowatenna1*4052.73-44.8 Wimalasurendra2*25227.4-245 Canyon2*30198.2-222 Polpitiya2*37.5259-265 Samanala Wewa2*60300-341 Kukule Ganga2*40140

13. Kaplan turbine  Developed by Viktor kaplan in 1913.  Evolution of Francis turbine, but revolutionized ability to develop the low head hydro sites.  Propeller type inward flow reaction turbine that has adjustable blades.  Used in high flow, low head power production.

14. Operation of Kaplan turbine

15. Kaplan turbine cont…  Efficiency can be improved by varying the geometry of wicket gates and turbine blades for a range of flow conditions.  Efficiency is typically over 90%.  Lower in very low head Applications. Graph

16. Efficiency Vs Water Head

17. Kaplan turbine cont…  Udawalawe PS employs Three kaplan turbine units.(water head is 13m and rated power is 2MW per unit).  Because propeller blades are rotated by high pressure hydraulic oil, positive seal must provided to prevent emission oil to the waterway.

18. Pelton wheel turbine…  Invented by Lester Allen Pelton in 1870.  Impulse type water terbine.  Most efficient type of water turbine.

19. Plan view of a Pelton turbine

20. Pelton wheel turbine cont…  Used in relatively high water heads with low flow rate.  To get maximum power and efficiency, the velocity of water jet should twice as the turbine runner periphery.  used mostly in mini and micro hydro power plants.  Can be run even in light loads efficiently, which does not occur in Fracis or Kaplan turbines. Graph

21. Pelton wheel turbine cont…  Pelton wheel turbine employed PS in Sri Lanka PS Rated power(MW) Water head(m) Old Laxapana2*12.5472.5-476.7 New Lakxapana2*50518-527 Nilambe2*1.6113.3-107.7 Erathne mini hydro 2*5.15450

22. Turgo turbine  Developed in 1919 by Gilkes as a modification of the Pelton wheel.  Impulse type water turbine.  Operates in head ranges where francis and Pelton wheel overlap(i.e. medium head).  Populer for small hydro projects.  Runner is less expensive than Pelton wheel.  Runner is one half times larger than a same power pelton wheel runner.

23. Turgo turbine cont…

24. Efficiency Vs Flow Rate Francis Kaplan Pelton

25. Selection of Turbine.

26. THANK YOU…..!