Over View of Hydro Projects

7/31/2019 Over View of Hydro Projects

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OVER VIEW OF HYDROPROJECTS

By : P S RAWATCDE (PE-Hydro)


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Why Hydro Power?

Renewable and environmentally benign source of Power.

Ability for instantaneous starting, stopping and load variation.

Provides valuable peaking power. No fuel cost and hence inflation free.

Development of multipurpose projects with optimal watermanagement drinking water, flood control, irrigation andtourism.

Low cost of energy in long run.


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Meeting Peak Demands

Hydroelectric plants:

Start easily and quickly and change power outputrapidly

Suplement large thermal plants (coal andnuclear), which serve base loads.

Save oil/natural gas


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STAGES OF PLANNING

SITE SELECTION/PRE-FEASIBILITYSTUDIES

PROJECTFEASIBLITY

EVALUATION &APPRAISAL

CONSTRUCTION STAGE

COST ESTIMATE

OTHER INPUTS

CIVIL, MECH, ELECT & C&I INPUTS

BASIC ENGGSITE SPECIFIC STUDIES/INVESTIGATIONS

FEASIBILITYREPORT/DETAILED PROJ

REPORT

Statutory clearances

MOEF CLEARANCE

TECHNO ECONOMIC CLEARANCE

INVESTMENT DECISION


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STUDIES FOR HYDRO POWER

PROJECTS

Topographical Study

Geological & Geotech Study

Hydrological Study

Meteorological Study

Seismic Study

Socio-Economic Study

EIA Study Construction Material Survey

Transportation Study

Disaster Management Studies


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FR STUDIES AND INVESTIGATIONS

FR PREPARATION

GEO-TECHNICAL

INVESTIGATION

METEROLOGICAL

STUDY

CONSTRUCTIONMATERIAL SURVEY

EIA

STUDIES

SEISIMIC

STUDIES

TRANSPORTATION

STUDY

TOPOGRAPHICAL

SURVEY

DISASTER

MANAGEMENT

STUDIES

SOCIO-ECONOMICSTUDIES

HYDROLOGICALSTUDY


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DPR PREPARATION

DPRPREPARATION

GEOLOGY

GEO-TECHNICAL

ASPECTS

COST ESTIMATE

CONSTRUCTIONMATERIAL SURVEY

FINANCIAL &

ECONOMIC

EVALUATION

POWER POTENTIAL

&

INSTALLED CAPACITY

CONSTRUCTIONAL

METHODOLOGY&

EQUIPMENT PLANNING

SITE LAYOUT

ENVIRONMENTAL &

ECOLOGICAL ASPECTS

SURVEYS &MAPPING

HYDROLOGICALSTUDY


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INITIAL STEPS

POWER POTENTIAL STUDY

CALCULATION OF DISCHARGE Q CALCULATION OF HEAD

DETERMINATION OF INSTALLEDCAPACITY


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POWER POTENTIAL STUDY

DATAS ARE TAKEN ON 10 DAYS

AVERAGE POWER POTENTIAL IS ARRIVED AT 90%

DEPENDABLE YEAR I.E. POWER ISAVAIBALE FOR THE 90% TIME OF THE

TOTAL YEARS CONSIDERED


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Table - 5.3

Mean Ten Daily Runoff at Rupsiyabagar-Khasiyabara ( Site no 22) on Goriganga

Catchment Area =1235 Sq.Km Unit : Cumecs

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Annualaverage

21.77 17.28 27.21 26.56 42.03 85.24 146.40 271.47 248.91 73.02 32.52 21.84

1962 20.01 18.45 29.76 34.15 48.56 93.30 146.84 278.90 188.64 61.42 27.88 19.20 80.63

18.99 22.60 34.08 42.45 50.84 129.19 155.27 233.50 141.54 41.82 23.77 16.84

15.79 11.06 18.04 20.39 41.02 78.98 171.65 266.95 220.24 55.24 29.66 21.12

1963 14.52 11.81 19.73 26.22 47.39 86.44 172.16 274.26 166.91 46.46 25.43 18.56 75.92

13.78 14.47 22.60 32.59 49.61 119.70 182.05 229.61 125.23 31.63 21.68 16.28

15.69 10.90 12.22 16.99 24.64 60.42 167.50 198.69 220.72 60.97 29.35 21.33

1964 14.43 11.64 13.37 21.85 28.47 66.13 168.00 204.12 167.28 51.29 25.16 18.75 65.89

13.69 12.67 15.31 27.16 29.80 91.57 177.65 170.90 125.51 34.92 21.45 16.44

16.18 12.61 17.75 22.15 31.02 64.34 111.75 138.77 128.99 36.57 22.59 16.98

1965 14.88 13.47 19.42 28.49 35.83 70.42 112.08 142.57 97.76 30.76 19.37 14.93 50.30

14.12 16.50 22.24 35.40 37.51 97.51 118.52 119.36 73.35 20.94 16.51 13.09

12.56 10.52 11.35 11.70 28.41 63.32 126.68 217.15 144.67 37.71 22.06 16.46

1966 11.55 11.24 12.41 15.05 32.82 69.30 127.06 223.10 109.64 31.72 18.91 14.47 56.45

10.96 13.77 14.21 18.71 34.36 95.97 134.36 186.78 82.26 21.60 16.13 12.69

12.46 8.94 9.60 11.33 19.56 55.02 137.46 223.34 177.11 48.59 25.97 19.46

1967 11.46 9.54 10.50 14.56 22.60 60.22 137.87 229.45 134.22 40.87 22.26 17.11 59.18

10.88 11.69 12.03 18.10 23.66 83.39 145.79 192.10 100.71 27.83 18.98 15.00

16.38 12.37 18.34 17.75 36.67 80.78 168.98 214.01 152.44 53.18 27.45 19.46

1968 15.06 13.21 20.05 22.82 42.37 88.41 169.48 219.87 115.53 44.73 23.53 17.11 66.12

14.29 14.38 22.96 28.36 44.35 122.43 179.22 184.08 86.68 30.45 20.06 15.00

Hydro Power Generation - PLANNING


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Hydro Power Generation - PLANNING


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DEVELOPMENT OF HYDRO ELECTRICPOWER PLANTS

A. Based on Head(i) High Head plants (>300m)

(ii) Medium Head plants (30m-600m)(iii) Low Head plants (


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DEVELOPMENT OF HYDRO ELECTRIC

POWER PLANTS

C. Based on Hydraulic Characteristics

(i) Run-of-River plant(ii) Pondage scheme

(iii) Plant with Storage reservoir

(iv) Pumped Storage plants


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d) Based on Capacity

i) Micro Hydel plants (Power 0.1-1 MW,Head


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ELEMENTS OF H. E. PLANT

CATCHMENT AREA RESERVOIR DIVERSION STRUCTURE: DAM/ BARRAGE INTAKE/ HEAD REGULATOR DESILTING CHAMBER/ BASIN HRT (HEADRACE TUNNEL.) SURGE TANKS ( IN CASE OF LONG WATER CONDUIT PRESSURE SHAFT/PENSTOCK POWERHOUSE (FOR HOUSING TURBINE, GENERATOR,

TRANSFORMER AND OTHER ELECTRICAL AND MECHANICALAUX.)

TAIL RACE TUNNEL/ CHANNEL SWITCHYARD FOR TRANSMISSION OF POWER


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3D Pictorial View of HEP Layout (partial)


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Inside a Typical Hydro Power Plant

Koldam Hydro Power Project


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PROJECT

VIEW POINT

DiversionTunnels

PowerHousePenstocks

Switchyard

Koldam Hydro Power Project

Layout

(Single Dam)


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Loharinag Pala Hydro Power Project Layout


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Tapovan Hydro PowerProject Layout


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Layout of Barrage

FLOW

TWO LANEROAD BRIDGE

ROAD BRIDGETWO LANE

60m 9m 46.30m

56.5m

LAUNCHINGAPRON

APRON

LAUNCHING

55.5m45.0m22.5m

2139

2139

2139

2151

2151

21372136

2136

2136

2136

2139

2139

2152

2152

2139

PIERS

L

73.40m

REGULATOR

C OF BARRAGE AXIS

AXIS OF INLET


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EL.2133.0

General Layout- Barrage, Power Intake,DesiltingChamber, HRT


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Layout of Power House

ADIT TO TRT(6.0m D-SHAPE)

L S ti Th h P Sh ft


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L-Section Through Pressure Shaft

HRT 6m

HORSE SHOE

EL. 2092m

PRESSURE SHAFT

B/F VALVE CHAMBER

SLAB FOR ORIFICE, 2.5m

SURGE SHAFT 14m

INTERMEDIATE ADITTO PRESSURE SHAFTINV.EL.1970m

(DOWNSURGE LEVEL)

ELEVATIONINMETRE

2078.02

ADIT TO PRESSURESHAFT BOTTOM

C/L EL 1671m

TAIL RACE TUNNEL 7.5mEL 1684m

TRANSFORMER CAVERN

POWER HOUSE CAVERN

EL 1710m

[18WX26HX144L (M)]

[22WX47HX155L (M)]

EL 1708m

TWL 1665m

BUS BARGALLERY

(UPSURGE LEVEL)EL. 2204m

424.659

m

407

.02m

121.119m

4m , STEEL LINED

N.S.L.

EL.1940.00

T.R.T. OUT FALL POINTINVERT LEVEL 1660m

HORSE SHOE

ADIT TOSURGE SHAFT


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Section Through Pelton Turbine

FALSE CEILING(CRANE SPAN)

E.O.T CRANE 2 NOS.(CAPACITY 2x250T/30T)SPAN 20100mm

11500

C OF PENSTOCKL

EL.1677.00


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DIVERSION STRUCTURE


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BARRAGE

A barrier provided with a series of gatesacross the river to regulate the water surfacelevel and pattern of flow upstream.


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Spillways

Safeguarding structure provided to relievethe reservoir of the excess water which canotherwise endanger the stability of the damStructure.


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SPILLWAY OF THE THREE GORGES PROJECT


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Site Selection

Availability of in-situ rock in foundation.

Probable seepage aspect. Existence of snow avalanche.

Availability of space for accommodatingBarrage intake and other facilities.


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Plan of Barrage & Desilting Area

BHAGIRATHIRIVER

START OF HRT

SFT- SIZE 3200x2925

CONST ADIT TO

POWERLINE

(250 X 14 X 16 m)

TO CHAMBERS

ACCESS TUNNEL TO

GATE OPER. CHAMBERS

LENGTH 478 M

BARRAGE

BASIN

HEAD REGULATOR

3 NOS. DESILTING CHAMBERS

AXIS OF

TRASH RACK

END OF DESILTING

START OF INLET TRANSITION

INSP. GALLERY


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DESILTING CHAMBER


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NECESSITY

Most of the rivers carry heavy sediment load either insuspension or as bed load. The suspended load,

especially the sharp edged fine sand (quartz)transported by rivers in hilly terrain causes rapidwear of turbine runner blades / buckets due toabrasion. This abrasion tendency increases with thehead. In course of time, this may result in shut down

of units for considerable duration thereby, causingenormous loss of power and revenue. Therefore, it isnecessary to provide necessary arrangements forexclusion of sediments from the water.


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Length of Chamber

The length of the basin is calculated from thetime taken by the particles to reach bottom ofthe chamber in still water neglecting theeffect of turbulence.


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Silt Flushing Conduits

The silt settled at the bottom of hoppers is flushed by flushingconduits running at the bottom of each chamber.

The flushing discharge is 15-20% of the design discharge ofHRT, which shall be controlled on the downstream of chamberby installation of silt flushing gates.

The size of silt flushing conduit depends on the flow velocity inthe conduit. The velocity should be greater than 3.0m/s. Avelocity less than this give rise to silt sedimentation in thetunnel. The higher velocity results in erosion of lining.


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HEAD RACE TUNNEL


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Layout of HRT

Length should be minimum

Least number of bends

Length of Construction Adits should be min.

Sufficient vertical rock cover is available(>H)

Sufficient horizontal rock cover is available(>2H)

back


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Geometric Design..

Circular

D shaped

Horse shoe

Modified horse shoe

Fixing up the cross section

Various shapes of cross section


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CIRCULAR SECTION

Circular section is most

suitable from hydraulicand structuralconsiderations.

However, it is difficult to

excavate, particularlywhere the cross-sectionalarea is small.


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D SHAPE SECTION

Advantage is,

added width ofthe invert whichgives moreworking spaceduringconstruction

S S


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Tunnels

These sections are a compromise between circular andD-shaped sections

These sections also afford easy change over to circularsections with minimum additional cost in reaches whererock quality is poor or rock cover is inadequate

Horse Shoe & Modified Horse Shoe

Section

back


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Hydraulic design


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Design considerations.

No air lock

Area of X-section provided should be sufficient to

carry max required flow.

No Negative pressures

Minimum losses


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Tunnel Support


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Tunnel rock support system

Primary support- provided immediately after excavation, most ofthe times is an active support

Final support- final support, it is a passive support


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Primary support

Includes one or a combination of

Shotcrete, wire mesh Rock bolts

Steel ribs

Depending upon class of rock i.e

Very Good ,good, fair, poor , very poor


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TYPICAL DETAILS FOR HORSE SHOE TUNNEL THROUGHSOUND ROCK

back


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TYPICAL DETAILS FOR HORSE SHOE TUNNELS

THROUGH FAIR ROCK

back


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Shotcrete

back

Shotcrete


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Rock bolts

Steel ribs


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Steel ribs


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Final support

Cast in situ tunnel lining

Pre cast segmental lining


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Construction

Drill and blast

Mechanical excavation

back


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Drill and blast

Full face- entire tunnel face is excavated in one go

Heading and benching

back


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Mechanical excavation

TBM

Road header


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BACK


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SURGE TANK


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Surge Tank

What is a Surge Tank/ Shaft?

Purpose of providing a Surge Shaft?

Location?

Types of Surge tanks

Hydraulic Design

Structural Design Construction Methodology


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Schematic diagram of a hydroelectric plant.

Purpose of providing Surge shaft

1. To radically reduce thepressure surges due to

water hammer and toexempt thereby thepressure tunnel fromexcessive internal loads


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Purpose of providing Surge shaft

2. To improve regulation

3. Supply of water to the turbines in case of suddenopening of valves/ down surge


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Design Loads

Internal Water Pressure

External water Pressure

External Grout Pressure

External Rock Pressure

Seismic Stress

Dead Loads Live Loads


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Rock support

Rock bolts

Shotcrete

Lining

Grouting

Contact Grouting

Consolidation Grouting


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PENSTOCK / PRESSURE SHAFT


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How does a pressure shaft look like?


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i) a) Surface penstocksconduit is laid exposed and is supported above ground by

saddle supports or ring girder supports

ii) b) Embedded penstocksconduit is embedded in large mass of dam concrete serving as

water tight membrane

iii c) Buried penstocksconduit is laid in open trenches and backfilled with earth.

d) In tunnelconduit is placed in open tunnel and is either supported in

similar manner as surface penstocks or backfilled with concrete.

Penstock Classification


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It should stand against maximum internal pressureincluding dynamic pressure.

It should stand against frequent dynamic changes.

It should have required impact strength to be able todeform plastically in the presence of stressconcentrations at notches and bends.

It should have good weldability without preheating,and

It should not require any stress relieving after

welding

Steel for Penstock - Requirements


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Bifurcation of HRT intoPressure shafts under

construction.

Fabrication procedure of penstock ferrule


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Fabrication procedure of penstock ferrule


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Power House EQUIPMENT PROVIDED IN THE POWERHOUSE INCLUDES:

HYDRAULIC TURBINES (PELTON, FRANCIS, KAPLAN, BULB,DERIAZ ETC.)

GENERATORS & ELCTRICAL AUXILIARIES EOT CRANE

TRANSFORMERS

GOVERNORS

MAIN INLET VALVE (MIV)

HVAC SYSTEM

DRAINAGE AND DEWATERING SYSTEM FIRE PROTECTION SYSTEM

SWITCHYARD

SELECTION CRITERIA FOR TYPE OF HYDRO


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SELECTION CRITERIA FOR TYPE OF HYDROTURBINE

Depends mainly on:Head availableSpecific Speed

Impulse Turbine :- Pelton Wheel turbine for Head>300m

Reaction Turbine:- Francis Turbine for Head 30m to 400mKaplan Turbine for Head 10m to 60mBulb/Tubular Turbine Head 3 to 30m

In the overlapping zone of head more detailed analysis is required fromtechno-economic considerations.


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Hydraulic TurbinesHydraulic Turbines

Impulse Turbine Reaction Turbine

Pelton Turbine Francis Turbine

Propeller Turbine

Kaplan Turbine

Bulb Turbine

Deriaz Turbine


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Types of Hydraulic Turbines

Reaction Turbines

Derive power from pressure drop across turbine

Totally immersed in water Angular & linear motion converted to shaft power

Propeller, Francis, and Kaplan turbines

Impulse Turbines

Convert kinetic energy of water jet hitting buckets No pressure drop across turbines

Pelton, Turgo, and crossflow turbines


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Turbines of NTPC Projects

PROJECT TYPE OF TURBINE

Koldam(4X200 MW) Francis

Loharinag Pala(4X150 MW) Pelton

Tapovan Vishnugad(4X130 MW) Pelton

Lata-Tapovan(3X57 MW) Francis

Rammam( 3X40MW) Pelton

P lt T bi


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Pelton Turbine It may be horizontal or vertical type.

It is impulsive turbine used for low discharge and high head installations(300m-1800m) and power upto 400MW. Its specific speed lies in the range of 6-60. It is highly suitable for flow variations but not suitable for high head

variations. It has flatter efficiency-load curve so highly suitable for part load

operation (upto 30%). Runner consists of a large circular disc on the periphery of which a

number of two-lobe symmetric ellipsoidal buckets are evenly mounted. Splitter in the middle of the bucket divides the jet into two equal streams. The nozzle governs the quantity of flow with the help of a spear valve

controlled by the Governor action and directs the flow on the wheel.


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Pelton Turbine


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FrancisTurbine It is a reaction turbine, i.e. during energy transfer from water to the runner

there is a drop in static pressure as well as a drop in velocity head. These are very versatile and used for medium discharge and medium head

(30m-750m) and power upto 900MW. Its specific speed lies in the range of 50-400. Water from the penstock enters a spiral or scroll casing which surrounds the

runner then enters the guide vanes which are pivoted and can be turnedsuitably to regulate the flow and output.

Pressure at the inlet is more than at the outlet and the runner is always fullof water.

Not suitable for partial load operation due to low efficiency. Should not operate below 50% load due to cavitation and vibration. These have average suitability for head and discharge variations.


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Francis Turbine

Runner

Spiral CasingSectional View


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MECHANICAL AUXILIARIES

EOT CRANE( ELECTRIC OVERHEAD CRANE)

COOLING WATER SYSTEM

DRAINAGE AND DEWATERING SYSTEM

HP/LP COMPRESSOR SYSYEM

FIRE PROTECTION SYSTEM

HVAC SYSTEM

Three Gorges Dam (China)


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g ( )


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Itaip Dam (Brazil & Paraguay)

Itaipu, Wikipedia.org


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Itaipu Dam, Brazil

Hoover Dam, USAOldman River Dam

Guri Dam, Venezuela

THANK


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THANK YOU

Documents

Over View of Hydro Projects