Course 1.pdf

7/28/2019 Course 1.pdf

1/28


2/28

The resource -72 TW. World need 15 TW/2000

Wind potential map at 80 m (source Standford University)


3/28

Resursele de vnt ale Romniei la 50 m inaltime

pentru diferite condiii topografice


4/28

1. A brief history of the development of wind energy from

antiquity until today

Since antiquity, mankind has been using wind energy; itis thus not a new idea. For centuries, windmills and

watermills were the only source of motive power for anumber of mechanical applications, some of which areeven still used today.

Humans have been using wind energy in their daily work

for some 4,000 years. Sails revolutionized seafaring,which no longer had to make it with muscle power.

In 1700 B.C., King Hammurabi of Babylon used windpowered scoops to irrigate Mesopotamia.

First details about horizontal axis windmills are found inhistorical documents from Persia, Tibet and China(horizontal shaft and blades revolving in the verticalplane).


5/28

The first horizontal axis windmill appeared in Englandaround 1150, in France in 1180, in Flanders in 1190, in

Germany in 1222 and in Danmark in 1259.

By the end of the nineteenth century, the typicalEuropean windmill used a rotor of 25 meters in diameter,

and the stocks reached up to 30 meters.

Windmills were used for grindring

grain and also for

pumping water to drain lakes and marshes.

By 1800 in Netherlands 90% of the power used inindustry was based on wind energy.

Industrialization led to a gradual decline in windmills, but

in 1940 wind energy still provide 11% of the Dutchindustrial energy.

When the European windmills slowly started to

disappear, they were introduced by settlers in NorthAmerica (reached it peak between 1920 and 1930).


6/28

2. The development of modern wind turbines since around1900

But the wind turbines that generate electricity today are new

and innovative.

Their success story began with a few technical innovations:

-

the use of synthetics to make rotor blades,

- developments in the field of aerodynamics,-

mechanical/electrical engineering,

-

control technology,

- power electronics .They all provide the technical basis for wind turbinescommonly used today!


7/28

In 1891, Poul

la Cour

of Denmark developed the first wind

turbine that generated direct current.

Danish engineers improved the technology during World Wars1 and 2, the wind turbines by the Danish company F.L. Smidthbuilt in 1941-42 can be considered forerunners of modern

wind turbine generators. The Danish philosophy was based onan upwind rotor with stall regulation, operating at slow speed.

In 1958, Johannes Juul

(pupil of Poul

la Cour) developed the

"Danish Concept," which allowed alternating current to be fedto the grid for the first time. This concept very quickly wonover. Today, almost half of all wind turbines operate accordingto this principle.

At the same time, the German Hutter

developed a new

approach: two slender fibreglass

blades mounted downwind of

the tower on a teetering hub (high efficiency).


8/28

With the oil crises at the beginning

of the 1970s, the

interest in wind power generation returned.

In the 1980s, the Danes developed small turbines with anominal output of 20 kW to 100 kW. Thanks to statesubsidies, these turbines were set up on farms and on

the coast to provide distributed power, with the excesspower not consumed locally being fed to the power grid.


9/28

3. Current status of wind power-

27.1 GW of wind power capacity installed globally in 2008, reaching at a total of 121

GW by the end of 2008.


10/28

The global annual market for wind turbines increased by 37% in 2008, following grouth

of 31%

both in 2006 and 2007, and 40% in 2005.

Over the past four years, the global annual market has more than

tripled from 8.3 GW in 2004

to 27.1GW in 2008.


11/28

All around the world wind energy is developing rapidly, and following the samedevelopment as conventional power sources in the past.


12/28

Despite much hype about a global nuclear energy revival, there is little marketevidence to support it.


13/28

Wind energy and the EUmember states

Germany

(24 GW) and

Spain (17 GW) continue tobe Europes undisputed

leaders, in terms of totalinstalled wind energycapacity.

In 2008, three largecountries: Italy (3.7 GW),France (3.4 GW) and UK

(3.2 GW) overtookDenmark (the third windenergy pioneer country).


14/28

Wind energy and the EU member states


15/28

Germany, Spain and Denmark-the three pioneering countries, arehome to 67.5% of the installed wind power in the EU.


16/28

The growth of off-shore wind

With 1.5 GW by the end of 2008, offshore accountedfor 2.3% of installed EU wind energy capacity (up from 1.9% in 2007)

Wind energy capacity compared to country size


17/28

Wind energy capacity compared to country size

and population

The total windpower capacity

installed at theend of 2008 willproduce 4.1% ofthe EU-27selectricitydemand in a

normal wind year.

Wind power inDenmark coversmore than 20% ofits total electricityconsumption,by

far the largestshare of anycountry in theworld.

Five EU countries-

Denmark,

Spain, Portugal,Ireland,and

Germany have

more than 5% oftheir electricitydemand

produced by windenergy.


18/28


19/28

Wind turbine development


20/28

Wind turbine development

Bigger and moreefficient 3.6-6 MW prototypesrunning

(Vestas,GE,SiemensWind, Enercon) 2 MW WT are stillthe best seller onthe market


21/28

Enercon

GmbH Germany

General data

Wind turbine name : Enercon

E-126/6000Nominal power : 6000 kW

Rotor diameter : 126 m

Hub height: 136 m

Turbine concept: Gearless,

variable speed, variable pitchcontrol.


22/28

Analizarea randamentului global al unui sistem de producere a

energiei electrice bazat pe turbin eoliani microhidrocentral

Schema lanului

de conversie

energetic

pentru

modelul

considerat

v

n modelul analizat turbina eolian este utilizat exclusiv pentru

pomparea apei n bazinul superior al centralei hidroelectrice.


23/28

Sistemul analizat este alctuit din treisubsisteme:

turbina eolian cu generatorul sincron, motorul asincron cu pompa centrifug,sistemul de conducte al apei pompate ibazinul superior de acumulare,

sistemul de evi, turbina hidraulici

generatorul electric.

C


24/28

Considerm ca i putere de intrare cea avolumului de aerVa, care se deplaseazcu viteza i care antreneaz turbinaeolian avnd aria efectivAR

:

(1.1) Puterea generat de turbin difer deputerea prin coeficientul de performan

30

2wRAP

=

( ) 03

,2

PcAcP pWRpW == (1.2)


25/28

valoarea maxim a lui Cp este 0,593 dar

din cauza pierderilor aerodinamice caredifer n funcie de construcia rotorului,valoarea obtinut n practic pentru Cpeste mai mic, fiind cuprins ntre 0.4 i0.5 pentru turbinele eoliene cu trei pale.

Arborele rotoric al generatorului sincroneste cuplat la turbina eolian prinintermediul cutiei de viteze, pentru seconsider un randament de 0,98.


26/28

Se adopt pentru randamentul

generatorului sincron (cu putere mai micde 10 kV) valoarea de =0,85, dac putereaeste mai mare, randamentul poate ajungela 0.95.

Puterea generat la bornele generatorului

sincron, innd cont de randamenteleelementelor lanului de conversie

energetic, va fi:0PcP GSCVpet = (1.3)


27/28

00 33,085,098,04,0 PPPet == (1.4)

La turaia nominal, randamentul pompei centrifugeeste de 80 % .

ST

Randamentul sistemului de transmisie al apei princonducteeste de 80 %, atunci puterea necesarpomprii apei n bazin este dat de relaia:

etSTPCMASBH PP = (1.5)

0PcP STPCMASGSCVpBH = (1.6)

R d t l l l i i i


28/28

Randamentul lanului conversieienergetice necesar pomprii apei nbazinul superior este dat de relaia:

1000

=PPBHBH (1.7)

1710017,01008,08,082,085,098,04,0 ===BH %

%

Documents

Course 1.pdf