hydro power plants-1

8/10/2019 Hydro Power Plants-1

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Hydro power plants


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Hydro power plants

Tail water

Draft tube gate

Draft tube

Turbine

Main valve

Penstock

Air inlet

Inlet gate

Surge shaft

TunnelSand trap

Trash rack

Self closing valve


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The principle the water conduits of

a traditional high head power plant


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Ulla- Frre

Original figur ved Statkraft Vestlandsverkene


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Intake gate

Intake trashrack

Headrace tunnel

Anchor block

Surge tank

Penstock inlet

Valve

Tunnel Inlettrashrack

Tunnel Inlet

Anchor block

Exp. joint

Shaddle

Power house

TailraceIV G

SC

DTR

DT end gate

Desilting basin

gate hoist

IV -inlet valveR -turbine runnerSC -spiral caseG -generator

Typical Power House with Francis Turbine


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Arrangement of a small

hydropower plant


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H = 39 mQ = 513 m3/sP = 182 MW

Drunner=7,5 m

Ligga Power Plant, Norrbotten, Sweden


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Borcha Power Plant, Turkey

H = 87,5 mP = 150 MW

Drunner=5,5 m


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Water in take

Dam

Coarse trash rack

Intake gate

Sediment settling basement


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Dams

Rockfill dams

Pilar og platedammer

Hvelvdammer


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Rock-fill dams

1. Core Moraine, crushed soft rock, concrete, asphalt

2. Filter zone Sandy gravel

3. Transition zone Fine blasted rock

4. Supporting shell Blasted rock


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Slab concrete dam


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Arc dam


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Gates in Hydro Power Plants


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Types of Gates

Radial Gates

Wheel Gates

Slide Gates

Flap Gates

Rubber Gates


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Radial Gates at lvkarleby, Sweden


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Radial Gate

The forces actingon the arc will betransferred to thebearing


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Slide Gate

Jhimruk Power Plant, Nepal


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Flap Gate


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Rubber gate

Reinforced rubberOpen position

Flow disturbance

Reinforced rubberClosed positionBracket

Air inlet


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Circular gate

ManholeHinge

Ladder

RibsPipe

End cover

Bolt

Fastening element

FrameSeal


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Circular gate

Jhimruk Power Plant, Nepal


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Trash Racks

Panauti Power Plant, Nepal


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Theun Hinboun Power PlantLaos


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GravfossPower Plant

Norway

Trash Rack size:

Width: 12 meter

Height: 13 meter

Stainless Steel


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CompRackTrash Rack delivered

by VA-Tech


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Cleaning the trash rack


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Pipes

Materials Calculation of the change of length due to the

change of the temperature

Calculation of the head loss

Calculation of maximum pressure

Static pressure

Water hammer

Calculation of the pipe thickness

Calculation of the economical correct diameter

Calculation of the forces acting on the anchors


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Materials

Steel

Polyethylene, PE

Glass-fibre reinforced UnsaturatedPolyesterplastic , GUP

Wood

Concrete


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MaterialsMaterial Max.

Diameter

Max.

Pressure

Max.

Stresses[m] [m] [MPa]

Steel, St.37 150

Steel, St.42 190

Steel, St.52 206

PE ~ 1,0 160 5

GUP 2,4Max. p = 160 m.

320Max. D: 1,4 m.

Wood ~5 80

Concrete ~5 ~ 400

St l i i t k


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Steel pipes in penstockNore Power Plant, Norway


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GUP-PipeRaubergfossen Power Plant, Norway


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Wood Pipes

Breivikbotn Power Plant, Norway vre Porsa Power Plant, Norway


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Calculation of the change of length

due to the change of the temperature

LTL Where:

L = Change of length [m]

L = Length [m]

= Coefficient of thermal expansion [m/oC m]T = Change of temperature [oC]


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Calculation of the head loss

g2c

DLfh

2

f

Where:hf = Head loss [m]

f = Friction factor [ - ]

L = Length of pipe [m]

D = Diameter of the pipe [m]

c = Water velocity [m/s]

g = Gravity [m/s2]


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ExampleCalculation of the head loss

DcRe

Power Plant data:H = 100 m Head

Q = 10 m3/s Flow Rate

L = 1000 m Length of pipe

D = 2,0 m Diameter of the pipe

The pipe material is steel

Where:

c = 3,2 m/s Water velocity

n = 1,30810-6 m2/s Kinetic viscosity

Re = 4,9 106 Reynolds number

g2

c

D

Lfh

2

f


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0,013

Where:

Re = 4,9 106 Reynolds number

e = 0,045 mm Roughness


e/D = 2,25 10-5 Relative roughness

f = 0,013 Friction factor



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ExampleCalculation of the head loss

Power Plant data:H = 100 m Head





Where:

f = 0,013 Friction factor

c = 3,2 m/s Water velocity

g = 9,82 m/s2 Gravity

m4,382,92

2,3

2

1000013,0

g2

c

D

Lfh

22

f


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Calculation of maximum pressure

Static head, Hgr (Gross Head)

Water hammer, hwh Deflection between pipe supports

Friction in the axial direction

Hgr


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Maximum pressure rise due to the

Water Hammer

g

cah maxwh

hwh = Pressure rise due to water hammer [mWC]

a = Speed of sound in the penstock [m/s]cmax = maximum velocity [m/s]

g = gravity [m/s2]

Jowkowsky

a

L2TIF C

E ample


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Example

Jowkowsky

m1020gcah maxwh

a = 1000 [m/s]cmax = 10 [m/s]

g = 9,81 [m/s2]

a

L2TC


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Maximum pressure rise due to the

Water Hammer

C

max

C

maxwh

Tg

L2c

T

aL2

g

cah

Where:hwh = Pressure rise due to water hammer [mWC]

a = Speed of sound in the penstock [m/s]cmax = maximum velocity [m/s]

g = gravity [m/s2]

L = Length [m]

TC = Time to close the main valve or guide vanes [s]

a

L2TIF C


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Example

m61

Tg

L2ch

C

maxwh

L = 300 [m]

TC = 10 [s]cmax = 10 [m/s]

g = 9,81 [m/s2]


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Calculation of the pipe thickness

t

Crp

tL2CpDL

sit

tsi

whgr hHgp

Where:

L = Length of the pipe [m]

Di = Inner diameter of the pipe [m]p = Pressure inside the pipe [Pa]

t = Stresses in the pipe material [Pa]

t = Thickness of the pipe [m]

Cs = Coefficient of safety [ - ]

= Density of the water [kg/m3]

Hgr = Gross Head [m]

hwh = Pressure rise due to water hammer [m]

p

t t

Based on: Material properties

Pressure from:

Water hammer

Static head

Example


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ExampleCalculation of the pipe thickness

m009,0Crp

t

tL2CpDL

t

si

tsi

MPa57,1hHgp whgr

Where:

L = 0,001 m Length of the pipeDi = 2,0 m Inner diameter of the pipe

t = 206 MPa Stresses in the pipe material

= 1000 kg/m3 Density of the water

Cs = 1,2 Coefficient of safetyHgr = 100 m Gross Head

hwh = 61 m Pressure rise due to water hammer

p

t t

Based on: Material properties

Pressure from:

Water hammer

Static head

C l l ti f th i l


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Calculation of the economical

correct diameter of the pipe

Diameter [m]

Cost[$]

0

dD

KKd

dD

dK tftot

Example


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ExampleCalculation of the economical correct diameter of the pipe

Hydraulic Losses

Where:

PLoss= Loss of power due to the head loss [W]

= Density of the water [kg/m3]

g = gravity [m/s2]

Q = Flow rate [m3/s]

hf = Head loss [m]

f = Friction factor [ - ]


r = Radius of the pipe [m]C2 = Calculation coefficient

5

2

42

2

fLossrC

rg2Q

r2LfQghQgP

Power Plant data:

H = 100 m Head


hplant = 85 % Plant efficiency


Example


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Cost of the Hydraulic Losses per year

Where:

Kf = Cost for the hydraulic losses []

PLoss = Loss of power due to the head loss [W]

T = Energy production time [h/year]

kWhprice= Energy price [/kWh]

r = Radius of the pipe [m]C2 = Calculation coefficient

price5

2priceLossf kWhT

r

CkWhTPK

Example


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Present value of the Hydraulic Losses per year

price5

2f kWhT

r

CK

Where:


T = Energy production time [h/year]kWhprice= Energy price [/kWh]

r = Radius of the pipe [m]

C2 = Calculation coefficient

Present value for 20 year of operation:

n

1ii

fpvf

I1

KK

Where:

Kf pv = Present value of the hydraulic losses []

n = Lifetime, (Number of year ) [-]I = Interest rate -

Example


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Cost for the Pipe Material

2

1mmm rCLrp

r2Ltr2Vm

Where:

m = Mass of the pipe [kg]

m = Density of the material [kg/m3]

V = Volume of material [m3]

r = Radius of pipe [m]


p = Pressure in the pipe [MPa]

= Maximum stress [MPa]


Kt = Installation costs []

M = Cost for the material [

/kg]

2

1t rCMmMK

NB:

This is a simplification

because no other

component then the pipeis calculated


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Installation Costs:

Pipes

Maintenance

Interests

Etc.


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2

1t rCMK

Where:


Kt = Installation costs []

T = Energy production time [h/year]

kWhprice= Energy price [/kWh]

r = Radius of the pipe [m]



M = Cost for the material [/kg]

n = Lifetime, (Number of year ) [-]I = Interest rate [-]

n

1ii

price5

2

pvfI1

kWhTrC

K

0I1

kWhTC

r5rCM2

drKKd

n

1ii

price26

ft


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7

n

1i

i

price2

n

1ii

price2

6

ft

I1CM

kWhTC

2

5r

0I1

kWhTC

r

5rCM2

dr

KKd

C l l ti f th f ti


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Calculation of the forces acting on

the anchors

C l l ti f th f ti


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the anchorsF5

F4F3

F1

F2

F

F1= Force due to the water pressure [N]

F2= Force due to the water pressure [N]

F3= Friction force due to the pillars upstream the anchor [N]

F4= Friction force due to the expansion joint upstream the anchor [N]

F5= Friction force due to the expansion joint downstream the anchor [N]



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the anchors

G

F

R


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Valves


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Principle drawings of valves

Open positionClosed position

Spherical valve Gate valve

Hollow-jet valve Butterfly valve

Spherical valve


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Spherical valve

B


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Bypass system


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Butterfly valve

B tt fl


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Butterfly

valve

Butterfly valve


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Butterfly valve

disk types

Hollow jet Valve


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Hollow-jet Valve


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Pelton turbines

Large heads (from

100 meter to 1800

meter)

Relatively small flowrate

Maximum of 6

nozzles

Good efficiency over

a vide range

Jostedal,Norway


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Kvrner

, y

F i t bi


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Francis turbines

Heads between 15and 700 meter

Medium Flow Rates

Good efficiencyh=0.96 for modern

machines


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SVARTISEN


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Kaplan turbines

Low head (from 70

meter and down to 5

meter) Large flow rates

The runner vanes can

be governed

Good efficiency over

a vide range


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hydro power plants-1

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