CLASSIFICATION OF TURBINE
Turbine
Impulse Turbine Reaction Turbine
Pelton
Wheel
Girard
Turbine
Francis
Turbine
Kaplan
Turbine
Propeller
Turbine
Turgo
Turbine
GENERAL LAYOUT OF A HYDRO ELECTRIC POWER PLANT
GENERAL LAYOUT OF A HYDRO ELECTRIC POWER PLANT
GENERAL LAYOUT OF A HYDRO ELECTRIC POWER PLANT
❖Adamwhichisconstructedacrossarivertostorewater.
❖Itprovidesnecessarypotentialenergytonozzlesofa
turbine.
❖Itactsaswaterreservoir.Topsurfaceofwaterindamis
calledheadrace.
❖Thepenstockisalargediameterpipeusuallymadeof
reinforcedconcreteorsteel.
❖Itcarrieswaterunderpressurefromthewaterstoredina
damorreservoirtotheturbines.
GENERAL LAYOUT OF A HYDRO ELECTRIC POWER PLANT
❖AWaterturbinewhichconvertshydraulicenergyinto
mechanicalenergy.
❖Awaterturbinecanbesethorizontalorvertical.The
choiceisgovernedbycost,typeofturbine,buildingspace
andplantlayoutetc.
❖Atailraceisadischargecanalintowhichwateris
dischargedfromtheturbine.
❖Differenceofheadraceandtailraceleveliscalledgross
head,H
g.
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖ThemaincomponentsofaPeltonwheelare
❖Nozzleandspearassembly
❖Runnerandbuckets
❖Casing
❖Brakingjet
❖Deflector
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖NOZZLE AND SPEAR ASSEMBLY
❖Theneedlespearisprovidedinthe
nozzletoregulatethewaterflow
throughthenozzle.
❖Itprovidesthesmoothflowofwaterwithnegligibleloss
ofenergy.
❖Aspearisaconicalneedlewhichcanbemovedinaxial
directionbyoperatingthewheeleithermanuallyor
automatically.
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖NOZZLE AND SPEAR ASSEMBLY
❖Whenthespearismovedinforward
directionintothenozzle,itreducedthe
nozzleexitarea,hence,thequantityof
waterflowstrikingthebucketsis
reduced.
❖Ifthespearismovedbackwards,itincreasestheflowrateofwater.
❖Thenozzleconvertsthepotentialenergyofwaterintokinetic
energybeforejetstrikesthebuckets.
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖RUNNER AND BUCKETS
❖Theturbinerotorcalledrunnerisa
circulardiscfixedwithbuckets.
❖Itisprovidedwithcylindricalbossand
keyedtothesupportingshaftinsmall
thrustbearings.
❖Therunnercarriescup-shapedbucketsmorethat15innumber
whicharemountedatequidistancearounditsperiphery.
❖Thebucketsareeithercastintegrallywiththecirculardiscor
theseareboltedindividuallytotherunner,ithelpsineasy
replacementofbucketswhenwornout.
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖RUNNER AND BUCKETS
❖Theturbinerotorcalled
runnerisacirculardiscfixed
withbuckets.
❖Itisprovidedwithcylindricalboss
andkeyedtothesupportingshaftin
smallthrustbearings.
❖Therunnercarriescup-shapedbucketsmorethat15innumber
whicharemountedatequidistancearounditsperiphery.
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖RUNNER AND BUCKETS
❖Thebucketsareeithercast
integrallywiththecircular
discorthesearebolted
individuallytotherunner,it
helpsineasyreplacementof
bucketswhenwornout.
❖Bucketsaremadeofcastironcaststeel,specialsteelsorstainless
steelwithinnersurfacepolishedtoreducefrictionlossesofwater
jet.
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖RUNNER AND BUCKETS
❖Theshapeofthebucketsisof
doublehemisphericalcupor
bowl.
❖Eachbowlofthebucketis
separatedbyawallcalled
splitteroraridge.
❖Thewaterstrikesthebucketatthesplitterwhichsplitsthewater
intotwoequalstreamsofthehemisphericalbowl.
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖RUNNER AND BUCKETS
❖Themaximumforcewillbe
obtainedwhenthejetis
deflectedthrough180°into
exacthemisphericalbowl.
❖Inpracticethejetisdeflectedthrough160°to170°
❖Itavoidsstrikingtheexitjetwiththebackofthesucceeding
bucket,thusexertingaretardingforceonit.
❖Thisalsoavoidsthesplashingofwaterwithasplitter.
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖RUNNER AND BUCKETS
❖Peltonwheelisprovidedwith
twohemisphericalcupssince
thesplittersplitsthejetinto
twoequalstreams,theaxial
componentofeachstream
velocityisequalandopposite
duetowhichtheaxialthrust
bntheshaftisnegligible
❖Peltonwheelneedsverysmallthrustbearings.
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖RUNNER AND BUCKETS
❖Anundercutisprovidedand
surfaceofspoonsisraisedso
thatwatercanbedeflected
backthroughtheangleof160°
to170°withthevertical
without disturbingthe
incomingbucket.
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖BRAKING JET
❖Theturbineisbroughttorest,thenozzle
iscompletelyclosedbypushingforward
thespear.
❖Therunnercontinuestorotateduetoits
inertiaforaconsiderableperiodoftime
tillitcomestorest.
❖Inordertobringtherunnertostopinashortesttime,asmall
nozzleisprovidedwhichissuesthewaterjetandfallsontheback
ofbuckets.
❖Itactsasahydraulicbrakeforreducingthespeedofrunner.
CONSTRUCTION AND WORKING OF PELTON WHEEL
❖DEFLECTOR
❖Adeflectorisprovided
whichishingedtothe
casingtodeflectthejetof
waterawayfromstriking
thebucketsincasethe
loadonturbinesuddenly
reduces.
❖Itpreventstherunnerofturbineattainingunsafespeedscalled
runawayspeed.
FORMULA USED
❖WORK DONE BY JET PER SECOND
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FORMULA USED
❖OVERALL EFFICIENCY
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❖DISCHARGE OF SINGLE JET
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❖NUMBER OF JET
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❖NUMBER OF BUCKET
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❖DIMENSIONS OF BUCKET
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FORMULA USED
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FORMULA USED
❖POWER LOST IN NOZZLE
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FORMULA USED
❖RESULTANT FORCE ON BUCKET
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SOLUTION:
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