2. HYDRO POWER
•A hydroelectric power station converts the kinetic, or movement, energy in flowing or falling water into electrical energy.
•Turbines and generators are helpful for extract energy from moving water.
5. PARTS OF A HYDROELECTRIC PLANT
•DAM:
Raisesthewaterleveloftherivertocreatefallingwater.Alsocontrolstheflowofwater.
•TURBINE:
Theforceoffallingwaterpushingagainsttheturbine'sbladescausestheturbinetospin.
Awaterturbineismuchlikeawindmill.
Theturbineconvertsthekineticenergyoffallingwaterintomechanicalenergy.
9. HYDRAULIC TURBINE MAY BE CLASSIFIED ACCORDING TO SEVERAL CONSIDERATIONS AS FOLLOWS:
•Actionofthewaterflowing.
•Directionofflowofwater.
•Theheadandquantityofwaterrequired.
•Thespecificspeed.
10. ACCORDING TO THE ACTION OF THE WATER FLOWING
•Impulse turbine
•Reaction turbine
15. ACCORDING TO THE HEAD AND QUANTITY OF WATER REQUIRED.
•Highheadturbine(above200m)
Example:Peltonwheel
•Mediumheadturbine(60mto200m)
Example:ModernFrancisturbine
•Lowheadturbine(lessthan60m)
Example:Kaplanturbine
16. ACCORDING TO THE SPECIFIC SPEED
•Low specific speed (10 to 35rpm)
Example : Peltonwheel
•Medium specific speed (60 to 400rpm)
Example : Francis turbine
•High specific speed (300 to 1000rpm)
Example : Kaplan turbine
23. COMPARISION OF PELTON WHEEL WITH OTHER TURBINE
Thenumberofnozzlescanbeincreasedordecreasedaccordingtothequantityofwateravailable.
PresenceofdrafttubeinKaplanandFrancisturbines,wherethevacuumiscreatedtoformtheeffectivehead.
PeltonwheeloperatesinatmosphericpressuresothereisnodrafttubeinPeltonwheel.
28. •GUIDE VANESThe function of the guide or stay vanes is to convert the pressure energy of the fluid into the momentum energy. The guide vanes are operated either by means of a wheel (or) automatically by a governor.
RUNNER BLADESWater enter radiallyand leaves axially. The runner is connected to generator so electricity is produced.
30. COMPARISION OF PELTON WHEEL AND FRANCIS TURBINE
•ThepartsofaPeltonwheelaremoreeasilyaccessibleandiseasiertorepairthem.
•ForthesameheadtherunningspeedofFrancisturbineismorethanPeltonwheel.Thisreducescostofgeneratorsanddimensionsofunit.
31. DIFFERENCE BETWEEN KAPLAN AND FRANCIS TURBINE
Francis turbine is medium specific speed but Kaplan turbine is high specific speed.
Francis turbine is mixed flow reaction turbine but Kaplan is only axial flow reaction turbine.
Kaplan turbines have adjustable blades but Francis turbine is not adjustable.
37. OPERATION OF KAPLAN TURBINE
•Thewaterfromthepenstocksentersthescrollcasingandthenmovestotheguidevanes.
•Fromtheguidevanes,thewaterturnsthrough90°andflowsaxiallythroughtherunner.
•Theshaftoftheturbineisvertical.ThelowerendoftheshaftismadelargerandiscalledHub.
•ThevanesarefixedonthehubandhenceHubactsasrunnerforaxialflowturbine.
38. COMPARISON WITH OTHER TURBINES
•AnotherdifferenceisthatinPeltonturbinenodrafttubeisusedwhereasinFrancisandKaplanturbinedrafttubeisused.
•InPeltonturbinethepressureenergyisconvertedintokineticenergycompletelyandisfullyutilizedhencethereisnoneedofdrafttube.
•Inreactionturbine,unutilizedkineticenergyisavailableattheoutletofturbinehencetoutilizethatkineticenergyinthewateradrafttubeisused.