Research into different types of wind generator blade

TABLE OF CONTENTS

 

SUMMARY 1-2

 

INTRODUCTION 3-4

 

CHAPTER 1. Wind power. 5-7

Work principles  of wind turbine. Types of wind turbines. 5-22

1.2 Vane wind power plant. 7-10

1.3 Wind power resources of Kazakhstan. 10-15

1.4 The influence on climate. Development prospects of wind power. 15-22

 

CHAPTER 2.

Research into different types of wind generator blades. 23-25

2.1 Research into local wind power. 26

2.2 Selection of an optimum type of wind generator blade. 24-25

 

CONCLUSION 26

 

BIBLIOGRAPHY 27-28

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SUMMARY

 

Aim of research: Research into some types of the wind generator blades.

Hypothesis:  Use of wind generators is necessary for receiving cheap electricity.  The construction of different types of the wind generator in the world, particularly in Kazakhstan.

Research stages and procedure: the current state of the wind power has been analyzed. Placement and mechanism conditions of wind turbines have been considered. Local winds capacity has been investigated, the optimum geometry of wind generator flank has been calculated.

Experiment technique: electric power is calculated by installation of wind generator with different types of blades.

Novelty and independence degree of research: Different types of wind generator blades and wind stream capacity have been investigated

Work results and conclusions: Wind power is available practically in any place of the planet. Somewhere it is stronger, somewhere it is weaker. Wind power is demanded especially in remote places where other electricity delivery ways are complicated. The work results are of valuable for wind power.

 

 

 

 

                                                           

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                                                                    Introduction

Wind power is the branch of power which is specialized on transformation of kinetic energy of air masses in the atmosphere in electric, mechanical, thermal or any other form of energy what is convenient to use in a national economy. Such a transformation can be made by the units as wind generator (for electric energy obtaining), a windmill (for transformation to mechanical energy), a sail (for use in transport) and others. [1]

Wind power belongs to the renewable type of energy, because it is a consequence of sun activity. In the end of 2010 the general rated capacity of all wind generators was 196,6 gigawatt, that’s why the wind power is the  roughly developing branch. The same year the quantity of the electric energy made by all wind generators of the world was 430 TVT (2,5% of all electric energy made by mankind). Some countries especially intensively develop wind power, in particular, in 2011 in Denmark 28% of all electricity was produced by wind generators, in Portugal — 19%, in Ireland — 14%, in Spain — 16% and in Germany — 8%. In May, 2009 80 countries of the world were using wind power on a commercial basis. [1,2] ]

Large wind power plants join in the general network, smaller ones are used for electricity to remote areas. Unlike to fossil fuel, wind power is almost inexhaustible, everywhere available and more ecologically pure. However the construction of wind power plants is interfaced to some technical and economic difficulties which are slowing down distribution of wind power. In particular, inconstancy of wind streams doesn't make problems at a small proportion of wind power in the general production the electric power, but the growth of this proportion makes to increase problems of reliability of electricity generation. Intellectual management of electric power distribution is used to solve such  problems.

Wind power plants build in places with a high average speed of wind — from 4,5 m/s and above.

Modern wind generators are more expensive than diesel or petrol units with similar capacity, but they have one big plus - it has no need to pay for "fuel" used for their charging so as nobody sells wind unlike to oil processing products. Stocks of natural gas is enough for 60 years at the same rate of consumption. Certainly, the report is based only on data of the confirmed stocks of gas. By 2030 the mankind will annually consume 4381 trillion cubic meter of natural gas what can lead to the world crisis. Such world situation of oil stocks forces more people to pay attention to alternative, renewable energy. The hybrid and electric mechanical engineering develops, scientists work for new ways of energy obtaining from various carriers, ecologists and nature fighters insist on reduction of harmful emissions in the atmosphere that conducts to global warming. [2]

Purpose: To investigate different types of wind generator blades .

Tasks: To consider local wind resource and to prove possibility of creation of the wind generator. Creation of working model of the wind generator. To compare various types of wings of the wind generator and to choose the most suitable one for the research.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CHAPTER 1. Wind power

1. Wind turbine work principles.

 

According to work principles there have three types of wind turbines - vane, rotary and drum. The rotation axis of the  first type wind turbine coincides with the wind direction, the second type axis of rotation makes vertical position and the third type is on horizontal position.

Vane type wind turbines perceive identical strengthening of a wind via all the wings and at the same time perform identical work that can't be told about work of rotary and drum type wind turbines. These last ones not all their wings are exposed to the simultaneous wind pressure as a result of a inequality of wind pressure on wings on both sides of the rotation axis. These type rotation axes are usually take place across the wind direction so that the parts of wings which go in the wind direction would work with full surface and other parts should be protected from the wind or should be turned by the edges to the wind. That is why wind power efficiency of rotary and drum type engines (fig. 2), less than  vane type (fig. 1). [2,3]

Vane type wind engines may be low-speed multi-blade and high-speed with two or three blades (fig. 3).

              

                                                      Рис.3

The main feature of low-speed engines is their big weight per capacity unit, which is approximately 2-2,5 times as much as similar weight of  high-speed type engines.

As we know the wind at the earth has the speed close to zero.  Wind speed quickly increases in process of removal from the earth.  Wind force and its distribution are strongly influenced by a land relief.  Significant wind speed increase is observed on hills and heights.  Therefore wind turbines, at first, are established relatively on highland district and secondly, on special towers or masts.  Theoretically the wind over the earth accrues under more difficult law, in connection with considerable change of air temperature on height, and big speeds increase with height more slowly than lower ones.

As it is known air has weight. Weight of one cubic meter of air at temperature  +15 *C and barometric pressure  700 mm is defined by size

 ɤ =1,22kg/m ³.

(1)

The mass per unit of air is defined division of weight of the unit to acceleration of gravity q, that is ρ = ɤ / q.

(2)

The rate ρ is called the mass density of air. The mass of one cubic meter of the air having the speed of v, at full use of losses can perform work:

R=ρv² / 2=v²/16 kg\m                                               

(3)

Or the mass of moving air M cubic meter at speed of v m/s, develops energy: R = M v ² / 2

(4)

The mass of the air M in relation to the wind, passing during 1 sec., through the area which is throwed by wings of the wind engine, will be: M =ρ F v unless the wind turbine has no braking impact on a stream of passable air. (5)

Therefore energy of air stream will be expressed by a formula:

      R = M v ² / 2=ρ F v v ²/2 = ρ F v ³/2 (6)

Therefore, wind power proportionally to a cube of its speed.

As it was shown above energy of 1 m ³ air at its speed of v is expressed like:

A=ρ/2 ²

(7)

The greatest number of energy which can be given by the wind wheel of the same diameter, depends on v speed for R. (tab. 1)

 

0,1	0,2	0,333	0,4	0,5	0,6	0,7	0,8	0,9
0,324	0,512	0,593	0,576	0,50	0,384	0,252	0,128	0,306

Table.1

 

It leads to the very important practical conclusion:

• a) the maximum efficiency of ideal wind wheel power is equal: ε = 0,593

(8)

• b) wind wheel speed loss on the plane is equal to one third of speed of the wind: v2=1/3v1

(9)

• c) total  speed loss of the wind behind the wind wheel is 2 times as much as speed loss on the wind wheel plane: v3 = (1-1/3v1) =2/3v1

(10)

And it means that wind speed behind the wind wheel is three times less than wind speed in front of the wheel. [3] ]

Durability of the wind engine mechanism is defined by the settlement rate of its wheel at the settlement power. For multi-blade low-speed wind engines the durability of mechanisms depends on that effort which touches the wind turbine from a place of beginning of its work. The torque is defined by formula below:

М=R/ω =ε ρ/2 by F v ³/ω =ε  ρ/2 F v ² r/z

(11)

 

• Where: R- capacity
• ω – angular speed of wheel rotation
• • ε – efficiency of wind power, v – wind speed 

 

 

 

 

 

 

 

 

 

 

1.2 Vane WPP

Vane WPP – the other name is wind turbines of the traditional scheme – is a blade mechanism with a horizontal axis of rotation. The wind unit rotates with the maximum speed when blades are located perpendicular to an air stream.

Therefore there are devices of automatic axis turn in a design of: in small WPP - a wing stabilizer, and in the powerful stations working for a chain, - an electronic control system of roving. Small vane WPP of constant current are connected to the electric generator directly, powerful stations are equipped with a reducer.

Types of vane wind turbines only differ in number of blades.  Rotation speed of vane wind turbines is inversely proportional to the number of wings therefore the units which have blades more than three practically aren't used.  Capacity of WPP depends on the speed of the wind and scope of wind wheel blades.

The wind power efficiency of vane WPP is much higher than other wind-driven generators, not without reason they occupy more than 90% of the market.

Rotary WPP with a vertical axis of rotation (fig. 4), unlike vane ones, can work at any direction of the wind, without changing its position. When the wind stream amplifies, the rotary WPP quickly increase the draft force, then wind wheel rotation speed gets stabilization. Wind turbines of this group are low-speed, therefore they don't create big noise. There are multi-polar electric generators in them which work with small turns and allow to apply simple electric circuits without risk of crash in a casual flaw. The low-speed demands the using of multi-polar generator which works at small turns. [3,4]

 

 

Fig. 4

There is a rotary WPP with the vertical rotation axis in this picture.

 

 

Such generators have no wide circulation and the use of animators which raise reducer is not effectively because of low efficiency of the last.

The design of blade WPP with the rotor scheme provides the maximum speed of rotation at the start and its automatic self-regulation during the work. Wind wheel speed decreases because of increasing loading and the rotating moment increases. [4,5]

One of advantages of the rotary design is its ability to control "from where the wind blows" without extra shifts that is very essential for ground ransacking streams.Wind turbines of this kind are been building in the USA, Japan, England, Germany, Canada. The rotary blade wind turbine is most easy-to-work. Its design provides the maximum moment at the start of wind turbine and automatic self-regulation of rotation speed during the work. The rotation speed decreases concerning the increase of loading  and rotary moment increases up to a full stop.

As experts believe, orthogonal wind aggregates are perspective for big power. Today the fans of orthogonal designs are faced certain difficulties. In particular, a start problem is among them. It used the same profile of a wing in orthogonal installations as well as in subsonic plane. The plane should run up before "rely" on the carrying power of the wing.

The matter is the same regarding orthogonal installation. At first it is necessary to bring energy to it – to untwist and finish to certain aerodynamic parameters, and after then she will pass from an engine mode to a generator mode. Selection of power begins at wind speed of about 5 m/s, and rated power is reached at speed of 14-16 m/s. Predesigns of wind turbines provide their use in the range from 50 to 20 000 kW. In the 2000 kW realistic installation the diameter of a ring on which wings move, is about 80 meters. Powerful wind turbine has big sizes. However it is possible to manage with the small one – to make it with the amount instead of the size.

Having supplied each electric generator with the separate converter it is possible to summarize output capacity developed by generators. In this case reliability and survivability of wind turbine increases. [5]

 

 

 

 

 

 

 

 

1.3 Energy resources of the wind of Kazakhstan

Proceeding from requirements of a national economy of Kazakhstan, usage of the wind power can be planned in following main directions:

a. wind power use for mechanization of work processes in livestock branch of the national economy and for creation of steady water supply and flood, advantage in livestock areas.

b. wind power usage for mechanical rising of water on irrigation of fields and subsidiary farms of the enterprises, foremost, insurance sites for receiving the guaranteed crop "About post-war lifting of agriculture".

c. wind power usage for electrification of work processes and an electric lighting in artels of producers' cooperation and in local industry enterprises which are far from large or average power supplying systems.

d. wind power usage for electrification of the rural, regional centers or the average scale enterprises during the work of powerful wind engine bushes which are located on heights and in different climatic conditions on an united power system in parallel either with hydrostations or with thermal stations depending on their existence in the power complex of this area.

e. usage of wind power should have special value on oil pumping via wind turbines which are on oil fields of Kazakhstan.

f. wind power usage for electrification of small and average railway stations of Kazakhstan. It is known that the railroads of the Republic of Kazakhstan last long distances and in majority take place in waterless steppe, in zones of favorable winds. Special thermal installations aren't profitable for electrification of these stations. [6]

g. . Wind power useage prospects are defined by the existence of the appropriate wind power resources. Kazakhstan is exclusively rich in wind resources. About 50% of the territory of Kazakhstan have the average annual wind speed of 4-5 m/s, and a number of areas has wind speed 6 m/s and more that predetermines very good prospects for wind power usage (fig. 5). According to the experts’ valuation, Kazakhstan is one of the most suitable countries for wind power development in the world. Windy places are located near the Caspian Sea, in central part and in the north of Kazakhstan, in the South and the southeast of Kazakhstan.

Рис.5

 По некоторым данным  теоретический ветропотенциал Казахстана  составляет около 1820 млрд. кВт. Ч в год. Для точной оценки ветропотенциала перспективных мест необходимы специальные метеоисследования с использованием метеомачт высотой 30-80м в течении как минимум одного года. Полученные метеоданные используются для расчета годовой выработки электроэнергии ветроустановками. Результаты расчетов используются для подготовки технико-экономического обоснования строительства ВЭС. Для двух площадок в Алматинской области - Джунгарские ворота(рис.6) и Шелекский коридор(рис.8), детальные метеоисследования и оценка ветрового потенциала были проведены при поддержке со стороны ПРООН в течении 1998-2000гг. Как показали эти исследования Джунгарские(рис.7) ворота имеют очень высокий ветропотенциал. Среднегодовая скорость ветра составляет здесь 9,7 м/с на высоте 50 метров, а плотность ветровой потока порядка 1050 Вт/м2. Это дает возможность вырабатывать примерно 4400 кВт. Ч электроэнергии на кВт установленной мощности ВЭС, что делает это место уникальным для целей ветроэнергетики. Наличие свободного пространства дает возможность установить здесь несколько сот МВт мощности ВЭС с годовой выработкой

электроэнергии порядка 1 млрд. кВт. Ч. В настоящее время предусматривается строительство пилотной ВЭС 5 МВт в этом районе. Предполагается, что ВЭС будет вырабатывать порядка 18 млн. кВт. Ч электроэнергии в год при стоимости электроэнергии порядка 4,5 центов США/кВт. Ч. В случае успешного опыта эксплуатации мощность ВЭС может быть увеличена до 50 МВт.

                                 На рис.6 изображены Джунгарские ворота

                                                            

 

 

 

 

 

Рис 7.

На рисунке изображен  ВЭС Джунгарские ворота 

Шелекский коридор, расположенный  между горными хребтами Заилийский Алатау и Жетысуйский на расстоянии 150 км от г. Алматы, также имеет хороший  ветровой потенциал со среднегодовой  скоростью ветра 7,8м/с на высоте 50 метров и плотностью ветрового потока порядка 510 Вт/м2, что дает возможность вырабатывать порядка 3200 кВт. Ч электроэнергии на каждый кВт. Установленного мощности ВЭС. Это сопоставимо с хорошими ветровыми местами в Европе. В Шелекском коридоре(рис.8) также возможна

установка сотен МВт  мощности ВЭС с годовой выработкой электроэнергии порядка 1 млрд. кВтч. Оба  места, Джунгарские ворота и Шелекский  коридор, расположены в районах  с большим дефицитом электроэнергии, что делает привлекательными строительство ВЭС в этих местах. [7]

                                                                                                                

Fig.8

 

Kazakhstan experts in association with the international experts from Germany defined perspective places for WPP construction on the basis of analysis of meteo data including following factors:

1 . Availability of power lines and substations for power delivery;

2 . Local topography and height above sea level;

3 . Availability of transport communications;

4 . Presence of energy consumers;

5 . Possibility of construction of WPP;

6 . Presence of preliminary studies on WPP construction.

Eight places in different regions of Kazakhstan were chosen for wind potential researches with the purpose of WPP construction. Further continuation of such researches is supposed.

Wind generators for Astana (fig. 9). Wind potential of the Astana WPP (tab. 2)

Wind potential	6,54 m/s
WPP capacity	41 MWt
Annual producing of electric energy	115 627 MWt/h

                                                                                                                         Tab.2