Hydro Power Plant

Prepared by: Nimesh Gajjar

Introduction

hydrology cycle.swf

What is hydro power?

• Water which is high up has gravitational potential energy• Energy is released when water falls• Hydro power takes this energy and converts it into something more useful

• Power: P = Q x m x g x H

• P: power, Watts• Q: flow rate, cubic metres per second• m: mass of falling water (1,000 kg per cubic metre for water)• g: acceleration due to gravity, 9.81 m/s/s• H: head, metres, height through which water falls

Micro hydro_ how it works.mp4

How Hydropower Works! (ctd…)

• Water from the reservoir flows due to gravity to drive the turbine.

• Turbine is connected to a generator.

• Power generated is transmitted over power lines.

071_hydroelec_plnts.swf

HydroelectricDam.swf

genAnimation.swf

Dam• A dam is a barrier which stores water and creates water head.

Function : Provide water head

Penstock:

• Open or closed conduits which carry water to turbines.• Made of reinforced concrete(low head < 30m) or steel (high head).

Function : To carry water from reservoir to turbine

Surge tank:It is small reservoir or tank (open at top) in which water raise or falls to reduce the pressure swings in the conduits. Location : Near the beginning of the conduit (penstock). Working :

Function : To limit abnormal pressure in the conduit

Spill ways:

Function : Discharge surplus water from the storage reservoir into river on the down stream side of dam.

Forebay :

Function : Regulating reservoir storing water temporarily when load on the plant is reduced and provide water for initial increases on account of increasing load

Reservoir :

Function : Stores water during the rainy season and supplies the same during the dry season.

Tail race :

Function : Give free exit to water after doing its work in turbine.

Power House:

Located at the foot of the dam and near the storage reservoir.Function : Generation of electricity.

Generator – Turbine assembly

Impulse Turbine (Pelton)

Pelton wheel installation(source: http://www.acre.murdoch.edu.au/ago/hydro/hydro.html)

Pelton Wheels

• Nozzles direct forceful streams of water against a series of spoon-shaped buckets mounted around the edge of a wheel.

• Each bucket reverses the flow of water and this impulse spins the turbine.

Pelton Wheels (continued…)

• Suited for high head, low flow sites.

• The largest units can be up to 200 MW.

• Can operate with heads as small as 15 meters and as high as 1,800 meters.

B2.2.4 Hydropower system design Turbines: Pelton wheel

Design of Pelton turbines

Reaction Turbines

• Combined action of pressure and moving water.

• Runner placed directly in the water stream flowing over the blades rather than striking each individually.

• lower head and higher flows than compared with the impulse turbines.

Reaction Turbine (Francis)

Francis turbine installation(source: http://www.acre.murdoch.edu.au/ago/hydro/hydro.html)

Francis Turbines

• The inlet is spiral shaped.• Guide vanes direct the water

tangentially to the runner.• This radial flow acts on the

runner vanes, causing the runner to spin.

• The guide vanes (or wicket gate) may be adjustable to allow efficient turbine operation for a range of water flow conditions.

Francis Turbines (continued…)

• Best suited for sites with high flows and low to medium head.

• Efficiency of 90%.• expensive to design,

manufacture and install, but operate for decades.

The Francis Turbine

B2.2.4 Hydropower system design Turbines: Francis

Guide vanesGuide vanesGuide vanesGuide vanesGuide vanesGuide vanes

Runner inlet (Φ 0.870m)

Guide vane outlet for designα) (Φ 0.913m)

ClosedPosition

Max. Opening Position

R a d i a l v i e wrunner guide vanes and stay vanes

R a d i a l v i e wrunner guide vanes and stay vanes

R a d i a l v i e wrunner guide vanes and stay vanes

R a d i a l v i e wrunner guide vanes and stay vanes

R a d i a l v i e wrunner guide vanes and stay vanes

R a d i a l v i e wrunner guide vanes and stay vanes

R a d i a l v i e wrunner guide vanes and stay vanes

R a d i a l v i e wrunner guide vanes and stay vanes

R a d i a l v i e wrunner guide vanes and stay vanes

R a d i a l v i e wrunner guide vanes and stay vanes

R a d i a l v i e wrunner guide vanes and stay vanesR a d i a l v i e wrunner guide vanes and stay vanes

Water from spiral casing

Water particle

Reaction Turbine (Kaplan)

Kaplan or propeller turbine installation(source: http://www.acre.murdoch.edu.au/ago/hydro/hydro.html)

B2.2.4 Hydropower system design Turbines: Kaplan (1913)

Kaplan Turbine

B2.2.4 Hydropower system design Turbines: Kaplan

TURBINE HEAD IN METRES Kalpan 2<H<40 Francis 10<H<350 Pelton 50<H<1300

Turbine vs head/flow

• Graphic showing turbine vs head and flo

The Indian Scenario

• The potential is about 84000 MW in the country.• Pumped storage sites have been found recently which leads to

a further addition of a maximum of 94000 MW.

• Annual yield is assessed to be about 420 billion units per year though with seasonal energy the value crosses600 billion mark.

• The possible installed capacity is around 150000 MW (Based on the report submitted by CEA to the Ministry of Power)

Continued …

• The proportion of hydro power increased from 35% from the first five year plan to 46% in the third five year plan but has since then decreased continuously to 25% in 2001.

• The theoretical potential of small hydro power is 10071 MW.

• Currently about 17% of the potential is being harnessed • About 6.3% is still under construction.

• fullhydroelectric.swf

• Hydro.flv

• wmmed100.wmv