HYDRO POWER PLANT

General Plant Details

• In 1878, the world's first house to be powered with hydroelectricity was Cragside in Northumberland, England.

• French engineer Bernard Forest de Bélidor published Architecture Hydraulique which described vertical- and horizontal-axis hydraulic machines

• Hydropower plants produce about 24 percent of the world's electricity

• The world's hydropower plants output a combined total of 675,000 megawatts

• The oldest Hydropower power plant in India is in Darjeeling District in West Bengal.  It’s installed capacity is 130KW and was commissioned in the year 1897 .

•

World's Hydroelectric Capacity

CountryAnnual hydroelectric

production (TWh)

Installedcapacity (GW)

Capacityfactor

% of totalcapacity

China 585.2 196.79 0.37 22.25

Canada 369.5 88.974 0.59 61.12

Brasil 363.8 69.080 0.56 85.56

United States 250.6 79.511 0.42 5.74

Russia 167.0 45.000 0.42 17.64

Norway 140.5 27.528 0.49 98.25

India 115.6 33.600 0.43 15.80

Venezuela 86.8 67.17

Japan 69.2 27.229 0.37 7.21

Sweden 65.5 16.209 0.46 44.34

Plant Layout

Dam Intake Turbine

Francis Turbine,

Pelton Turbine,

Kaplan Turbine Generators Transformer Power lines Outflow

Generators

• Hoover Dam has a total of 17 generators, each of which can generate up to 133 megawatts

• Current of 16,500 volts moves from the generator to the transformer, where the current ramps up to 230,000 volts before being transmitted

• Usually 3 phase synchronous motor is used

• P = 3 VI cos O

• Pth = (wQH) KW

• 1000

• Pactual = Pth X overall efficiency

Types of turbine

• Impulse Turbines • These are used where a high head of water, combined with a low flow

rate is available. The water is injected onto the turbine buckets or blades through nozzles arranged around the impeller.

• Types of Impulse Turbines• Turbo Turbine, Pelton Wheel, Cross flow Turbine • Reaction Turbines• Types of Reaction Turbines• Propeller Turbine, Francis Turbine, Kaplan Turbine • Propeller Turbine• form of a ships propeller, having between three to six blades. The

blades and hub are completely submerged in the water which rotates the propeller.

Dam Types

• Poor rock and earth foundation – Earth dam• Narrow dam – Arch dam• Valley is wide, weak foundation – Buttress dam• Any valley width, good foundations – Steel dam• Any valley width, any foundations – Timber dam• Wide valley with gentle slopes – Earth dam• Rocky bed – Solid gravity dam

Spillways

• Excess accumualtion of water endangers the stability of dam structures

• Solid gravity• Trough spillway• Side channel spillway• Saddle spillway• Emergency spillway• Shaft spillway• Siphon spillway

Water flows over the body

Water flows through the body

Conduits

• Channels which leads water to turbine and a tailrace which conducts water

• Canal• Flume• Tunnel• Pipeline• Penstock• Open conduits – least expensive but cost increases as

height increases• Closed conduits – Slope is too great for a canal

Open Conduits

Closed Conduits

Penstocks

• Thickness of penstock = pd \ 2fn• p = pressure (water hammer)• d = internal diameter of penstock• f = hoop stress• n = joint efficiency

• Penstock materials – RCC (18m head), wood, steel (any head)

• Buried penstocks (need cathodic protection)• Exposed penstock (easy maintenance)

Surge Tanks

Used to prevent water hammer Serve as supply tank during high loads condition

Types – Simple Inclined (to save space) Expansion chamber Restricted orifice Differential

Classification of Hydro Power Plant

• According to head• High (100m)• Medium (80 – 100m)• Low (25 – 80mm)

• According to nature of load• Base load• Peak load

• According to quantity of water• Run of river (without pond)• Run of river (with pond)• Storage • Pump storage• Mini – macro plants

Impulse (Pelton) turbine

Tangential flow turbine For high heads and low

discharge Bucket shape used to guide

the flow of water Uses potential energy Specific speed

Ns = 10 – 35 Can produce up to 200

megawatts

Reaction turbine (Francis)

• Uses both potential and kinetic energies

• Inward flow turbine• Used for medium head and

discharge• Water flows in closed conduit

unlike pelton wheel• Runner is always full of water• Can produce up to 800

megawatts

Kaplan turbine

• Used for low head and high discharge

• Blades are adjustable and can be rotated about pivot

• Can be used up to 400 megawatts

Life of Hydro Plant Components

COMPONENTS AVERAGE LIFE (YEARS)

Reservoirs 70 -80

Dams 100

Penstocks 50

Building 40

Generators 25

Turbines 5

Pumps 20 -25

Plants in India

Station Place Generator units Capacity (MW)

Srisaila Dam Andhra Pradesh 6 × 150, 7 × 110 1,670

Sardar Sarovar Gujrat 6X200, 5X140 1,450

Bhakra Dam Himachal Pradesh

5 X 108, 5 X 157

1,325

Kalinadi Karnataka 2X50, 2x135, 4X150, 3X50, 3X40

1,225

Sharavathi Karnataka 10 X 103.5, 2X27.5, 4X60

1,469

Nagarjunasagar Andhra Pradesh 1 X 110, 7 X 100.8, 5 X 30

965

• Advantages• clean fuel source • domestic source of

energy • renewable power

source

• Disadvantages

REFERENCES

• Books• Powerplant Engineering – Rajput

• Website• www.Ishan-international.com• www.Brighthub.com