a device that converts wind energy into rotational energy. The main working part of a wind turbine is a rotating unit - a wheel driven by the wind and rigidly connected to a shaft, the rotation of which drives equipment that performs useful work. The shaft can be installed horizontally or vertically. Wind turbines are usually used to generate energy consumed periodically: when pumping water into a tank, grinding grain, in temporary, emergency and local power supply networks.
Historical reference. Although surface winds do not always blow, change their direction and their strength is not constant, the wind turbine is one of the oldest machines for obtaining energy from natural sources. Due to the questionable reliability of ancient written accounts of wind turbines, it is not entirely clear when and where such machines first appeared. But, judging by some records, they already existed before the 7th century. AD It is known that they were used in Persia in the 10th century, and in Western Europe the first devices of this type appeared at the end of the 12th century. During the 16th century. The tented type of Dutch windmill was finally formed. No significant changes in their design were observed until the beginning of the 20th century, when, as a result of research, the shapes and coatings of mill wings were significantly improved. Since low-speed machines are cumbersome, in the second half of the 20th century. began to build high-speed wind turbines, i.e. those whose wind wheels can make a large number of revolutions per minute with a high efficiency of wind energy utilization.
Modern types of wind turbines. Currently, three main types of wind turbines are used - drum, wing (screw type) and rotor (with an S-shaped repeller profile).
Drum and vane. Although the drum-type wind wheel has the lowest wind energy utilization rate compared to other modern repellers, it is the most widely used. Many farms use it to pump water if for some reason there is no mains electricity. A typical shape of such a wheel with sheet metal blades is shown in Fig. 1. Drum and vane type wind wheels rotate on a horizontal shaft, so they must be turned into the wind to get the best performance. To do this, they are given a rudder - a blade located in a vertical plane, which ensures that the wind wheel turns into the wind. The diameter of the wheel of the world's largest vane-type wind turbine is 53 m, the maximum width of its blade is 4.9 m. The wind wheel is directly connected to an electric generator with a power of 1000 kW, which develops at a wind speed of at least 48 km/h. Its blades are adjusted in such a way that the rotation speed of the wind wheel remains constant and equal to 30 rpm in the wind speed range from 24 to 112 km/h. Due to the fact that the winds blow quite often in the area where such wind turbines are located, the wind turbine typically produces 50% of the maximum power and powers the public electrical grid. Vane wind turbines are widely used in remote rural areas to provide electricity to farms, including charging the batteries of radio communication systems. They are also used in onboard propulsion systems of aircraft and guided missiles.
S-shaped rotor. An S-shaped rotor mounted on a vertical shaft (Fig. 2) is good because a wind turbine with such a repeller does not need to be brought into the wind. Although the torque on its shaft varies from minimum to one-third of maximum per half turn, it does not depend on the direction of the wind. When a smooth circular cylinder rotates under the influence of wind, a force perpendicular to the direction of the wind acts on the body of the cylinder. This phenomenon is called the Magnus effect, after the German physicist who studied it (1852). In 1920-1930, A. Flettner used rotating cylinders (Flettner rotors) and S-shaped rotors instead of bladed wind wheels, and also as propulsors of a ship that made the transition from Europe to America and back.
Wind energy utilization rate. The power obtained from the wind is usually small - less than 4 kW is developed by an obsolete type of Dutch windmill at a wind speed of 32 km/h. The power of the wind flow, which can be used, is formed from the kinetic energy of air masses sweeping per unit time perpendicular to an area of a given size. In a wind turbine, this area is determined by the windward surface of the repeller. Taking into account the altitude above sea level, the air pressure on it and its temperature, the available power N (in kW) per unit area is determined by the equation N = 0.0000446 V3 (m/s). The wind energy utilization coefficient is usually defined as the ratio of the power developed on the wind turbine shaft to the available power of the wind flow acting on the windward surface of the wind wheel. This coefficient becomes maximum at a certain ratio between the speed of the outer edge of the wind wheel blade w and the wind speed u; the value of this w/u ratio depends on the type of wind turbine. The wind energy utilization rate depends on the type of wind wheel and ranges from 5-10% (Dutch mill with flat wings, w/u = 2.5) to 35-40% (profiled wing repeller, 5 R€ w/u R€ 10) .
LITERATURE
Wind power. M., 1982 Yaras L. et al. Wind energy. M., 1982
a device that converts wind energy into rotational energy. The main working part of a wind turbine is a rotating unit - a wheel driven by the wind and rigidly connected to a shaft, the rotation of which drives equipment that performs useful work. The shaft can be installed horizontally or vertically. Wind turbines are usually used to generate energy consumed periodically: when pumping water into a tank, grinding grain, in temporary, emergency and local power supply networks. Historical reference. Although surface winds do not always blow, change their direction and their strength is not constant, the wind turbine is one of the oldest machines for obtaining energy from natural sources. Due to the questionable reliability of ancient written accounts of wind turbines, it is not entirely clear when and where such machines first appeared. But, judging by some records, they already existed before the 7th century. AD It is known that they were used in Persia in the 10th century, and in Western Europe the first devices of this type appeared at the end of the 12th century. During the 16th century. The tented type of Dutch windmill was finally formed. No significant changes in their design were observed until the beginning of the 20th century, when, as a result of research, the shapes and coatings of mill wings were significantly improved. Since low-speed machines are cumbersome, in the second half of the 20th century. began to build high-speed wind turbines, i.e. those whose wind wheels can make a large number of revolutions per minute with a high efficiency of wind energy utilization. Modern types of wind turbines. Currently, three main types of wind turbines are used - drum, wing (screw type) and rotor (with an S-shaped repeller profile). Drum and vane. Although the drum-type wind wheel has the lowest wind energy utilization rate compared to other modern repellers, it is the most widely used. Many farms use it to pump water if for some reason there is no mains electricity. A typical shape of such a wheel with sheet metal blades is shown in Fig. 1. Drum and vane type wind wheels rotate on a horizontal shaft, so they must be turned into the wind to get the best performance. To do this, they are given a rudder - a blade located in a vertical plane, which ensures that the wind wheel turns into the wind. The diameter of the wheel of the world's largest vane-type wind turbine is 53 m, the maximum width of its blade is 4.9 m. The wind wheel is directly connected to an electric generator with a power of 1000 kW, which develops at a wind speed of at least 48 km/h. Its blades are adjusted in such a way that the rotation speed of the wind wheel remains constant and equal to 30 rpm in the wind speed range from 24 to 112 km/h. Due to the fact that the winds blow quite often in the area where such wind turbines are located, the wind turbine typically produces 50% of its maximum power and feeds the public electricity grid. Vane wind turbines are widely used in remote rural areas to provide electricity to farms, including charging the batteries of radio communication systems. They are also used in onboard propulsion systems of aircraft and guided missiles. S-shaped rotor. An S-shaped rotor mounted on a vertical shaft (Fig. 2) is good because a wind turbine with such a repeller does not need to be brought into the wind. Although the torque on its shaft varies from minimum to one-third of maximum per half turn, it does not depend on the direction of the wind. When a smooth circular cylinder rotates under the influence of wind, a force perpendicular to the direction of the wind acts on the body of the cylinder. This phenomenon is called the Magnus effect, after the German physicist who studied it (1852). In 1920-1930, A. Flettner used rotating cylinders (Flettner rotors) and S-shaped rotors instead of bladed wind wheels, and also as propulsors of a ship that made the transition from Europe to America and back. Wind energy utilization rate. The power obtained from the wind is usually small - less than 4 kW is developed by an obsolete type of Dutch windmill at a wind speed of 32 km/h. The power of the wind flow, which can be used, is formed from the kinetic energy of air masses sweeping per unit time perpendicular to an area of a given size. In a wind turbine, this area is determined by the windward surface of the repeller. Taking into account the altitude above sea level, the air pressure on it and its temperature, the available power N (in kW) per unit area is determined by the equation N = 0.0000446 V3 (m/s). The wind energy utilization coefficient is usually defined as the ratio of the power developed on the wind turbine shaft to the available power of the wind flow acting on the windward surface of the wind wheel. This coefficient becomes maximum at a certain ratio between the speed of the outer edge of the wind wheel blade w and the wind speed u; the value of this w/u ratio depends on the type of wind turbine. The wind energy utilization coefficient depends on the type of wind wheel and ranges from 5-10% (Dutch mill with flat wings, w/u = 2.5) to 35-40% (profiled wing repeller, 5 × w/u × 10).
WIND ENGINE
a device that converts wind energy into rotational energy. The main working part of a wind turbine is a rotating unit - a wheel driven by the wind and rigidly connected to a shaft, the rotation of which drives equipment that performs useful work. The shaft can be installed horizontally or vertically. Wind turbines are usually used to generate energy consumed periodically: when pumping water into a tank, grinding grain, in temporary, emergency and local power supply networks.
Historical reference. Although surface winds do not always blow, change their direction and their strength is not constant, the wind turbine is one of the oldest machines for obtaining energy from natural sources. Due to the questionable reliability of ancient written accounts of wind turbines, it is not entirely clear when and where such machines first appeared. But, judging by some records, they already existed before the 7th century. AD It is known that they were used in Persia in the 10th century, and in Western Europe the first devices of this type appeared at the end of the 12th century. During the 16th century. The tented type of Dutch windmill was finally formed. No significant changes in their design were observed until the beginning of the 20th century, when, as a result of research, the shapes and coatings of mill wings were significantly improved. Since low-speed machines are cumbersome, in the second half of the 20th century. began to build high-speed wind turbines, i.e. those whose wind wheels can make a large number of revolutions per minute with a high efficiency of wind energy utilization.
Modern types of wind turbines. Currently, three main types of wind turbines are used - drum, wing (screw type) and rotor (with an S-shaped repeller profile).
Drum and vane. Although the drum-type wind wheel has the lowest wind energy utilization rate compared to other modern repellers, it is the most widely used. Many farms use it to pump water if for some reason there is no mains electricity. A typical shape of such a wheel with sheet metal blades is shown in Fig. 1. Drum and vane type wind wheels rotate on a horizontal shaft, so they must be turned into the wind to get the best performance. To do this, they are given a rudder - a blade located in a vertical plane, which ensures that the wind wheel turns into the wind. The diameter of the wheel of the world's largest vane-type wind turbine is 53 m, the maximum width of its blade is 4.9 m. The wind wheel is directly connected to an electric generator with a power of 1000 kW, which develops at a wind speed of at least 48 km/h. Its blades are adjusted in such a way that the rotation speed of the wind wheel remains constant and equal to 30 rpm in the wind speed range from 24 to 112 km/h. Due to the fact that the winds blow quite often in the area where such wind turbines are located, the wind turbine typically produces 50% of the maximum power and powers the public electrical grid. Vane wind turbines are widely used in remote rural areas to provide electricity to farms, including charging the batteries of radio communication systems. They are also used in onboard propulsion systems of aircraft and guided missiles.
S-shaped rotor. An S-shaped rotor mounted on a vertical shaft (Fig. 2) is good because a wind turbine with such a repeller does not need to be brought into the wind. Although the torque on its shaft varies from minimum to one-third of maximum per half turn, it does not depend on the direction of the wind. When a smooth circular cylinder rotates under the influence of wind, a force perpendicular to the direction of the wind acts on the body of the cylinder. This phenomenon is called the Magnus effect, after the German physicist who studied it (1852). In 1920-1930, A. Flettner used rotating cylinders (Flettner rotors) and S-shaped rotors instead of bladed wind wheels, and also as propulsors of a ship that made the transition from Europe to America and back.
Wind energy utilization rate. The power obtained from the wind is usually small - less than 4 kW is developed by an obsolete type of Dutch windmill at a wind speed of 32 km/h. The power of the wind flow, which can be used, is formed from the kinetic energy of air masses sweeping per unit time perpendicular to an area of a given size. In a wind turbine, this area is determined by the windward surface of the repeller. Taking into account the altitude above sea level, the air pressure on it and its temperature, the available power N (in kW) per unit area is determined by the equation N = 0.0000446 V3 (m/s). The wind energy utilization coefficient is usually defined as the ratio of the power developed on the wind turbine shaft to the available power of the wind flow acting on the windward surface of the wind wheel. This coefficient becomes maximum at a certain ratio between the speed of the outer edge of the wind wheel blade w and the wind speed u; the value of this w/u ratio depends on the type of wind turbine. The wind energy utilization coefficient depends on the type of wind wheel and ranges from 5-10% (Dutch mill with flat wings, w/u = 2.5) to 35-40% (profiled wing repeller, 5 Ј w/u Ј 10).
LITERATURE
Wind power. M., 1982 Yaras L. et al. Wind energy. M., 1982
Collier's Encyclopedia. - Open Society. 2000 .
Synonyms:See what “WIND MOTOR” is in other dictionaries:
Wind turbine... Spelling dictionary-reference book
Engine, pneumatic wind engine, windmill, windrotor Dictionary of Russian synonyms. wind turbine noun, number of synonyms: 4 wind turbine (8) ... Synonym dictionary
Uses wind energy to generate mechanical energy. Predominantly widespread are vane wind turbines, in which the axis of rotation of the wind wheel coincides with the direction of the air flow... Big Encyclopedic Dictionary
wind turbine- VD A device for converting wind energy into mechanical energy of rotation of a wind wheel. [GOST R 51237 98] Topics wind power Synonyms VD EN wind motor ... Technical Translator's Guide
wind turbine- wind engine... Dictionary of abbreviations and abbreviations
WIND ENGINE- (wind turbine) a motor that uses the kinetic energy of the wind to generate mechanical energy. Primitive view of V. windmill. There are: vane, carousel, or rotary, and drum... Big Polytechnic Encyclopedia
An engine that uses the kinetic energy of the wind to generate mechanical energy. As a working organ of the wind, which perceives the energy (pressure) of the wind flow and converts it into mechanical energy of rotation of the shaft, it is used... ... Great Soviet Encyclopedia
A machine that converts the kinetic energy of the wind into mechanical energy. The working part of a wind turbine is a wind wheel, which receives the pressure of the air flow and converts it into mechanical energy of rotation of the shaft. Distinguish... ... Encyclopedia of technology
I; m. Engine driven by wind power. * * * A wind turbine uses wind energy to generate mechanical energy. Most common are vane wind turbines, in which the axis of rotation of the wind wheel coincides with... ... encyclopedic Dictionary
An engine using kinetic wind energy for mechanical generation. energy. There are wing-shaped V. (see Fig.), usually with a horizontal axis of rotation, with a coefficient. use of wind energy up to 0.48 (most common); carousel,... ... Big Encyclopedic Polytechnic Dictionary
Most types of wind turbines have been known for so long that history is silent about the names of their inventors.
Types of wind generators:
The main types of wind turbines are shown in the figure. They are divided into two groups:
wind turbines with a horizontal axis of rotation (vane) (2...5);
wind turbines with a vertical axis of rotation (rotary: bladed (1) and orthogonal (6)).
The types of vane wind turbines differ only in the number of blades.
Winged
For vane wind turbines, the greatest efficiency of which is achieved when the air flow is perpendicular to the plane of rotation of the wing blades, a device for automatic rotation of the rotation axis is required.
For this purpose, a stabilizer wing is used.
Carousel wind turbines have the advantage that they can operate in any wind direction without changing their position.
The coefficient of wind energy utilization (see figure) for vane wind turbines is much higher than for rotary wind turbines.
At the same time, carousels have a much higher torque.
It is maximum for rotary blade units, at zero relative wind speed.
The spread of impeller wind turbines is explained by the magnitude of their rotation speed.
They can be directly connected to an electric current generator without a multiplier.
The rotation speed of vane wind turbines is inversely proportional to the number of wings, therefore, units with more than three blades are practically not used.
Carousel
The difference in aerodynamics gives rotary wind turbines an advantage over traditional wind turbines.
As the wind speed increases, they quickly increase their traction force, after which the rotation speed stabilizes.
Carousel wind turbines are low-speed and this allows the use of simple electrical circuits, for example, with an asynchronous generator, without the risk of an accident in the event of an accidental gust of wind.
Slowness puts forward one limiting requirement - the use of a multi-pole generator operating at low speeds.
Such generators are not widespread, and the use of multipliers (multiplier [lat. Multiplicator - multiplying] - increasing gear) is not effective due to the low efficiency of the latter.
An even more important advantage of the carousel design was its ability, without additional tricks, to monitor “where the wind is blowing from,” which is very important for surface yaw flows.
Wind turbines of this type are being built in the USA, Japan, England, Germany, and Canada.
The rotary blade wind turbine is the easiest to operate. Its design ensures maximum torque when starting the wind turbine and automatic self-regulation of the maximum rotation speed during operation.
As the load increases, the rotation speed decreases and the torque increases until a complete stop.
Orthogonal
Orthogonal wind turbines, as experts believe, are promising for large-scale energy.
Today, wind worshipers of orthogonal structures face certain difficulties. Among them, in particular, is the launch problem.
Orthogonal installations use the same wing profile as a subsonic aircraft (see Fig. 6).
The plane, before “leaning” on the lifting force of the wing, must take off. The same is the case with the orthogonal installation.
First, you need to supply energy to it - spin it up and bring it to certain aerodynamic parameters, and only then, it itself will switch from engine mode to generator mode.
Power take-off begins at a wind speed of about 5 m/s, and the rated power is achieved at a speed of 14...16 m/s.
Preliminary calculations of wind turbines provide for their use in the range from 50 to 20,000 kW.
In a realistic installation with a power of 2000 kW, the diameter of the ring along which the wings move would be about 80 meters.
The powerful wind turbine is large in size. However, you can get by with small ones - take the number, not the size.
By equipping each electric generator with a separate converter, it is possible to sum up the output power generated by the generators.
In this case, the reliability and survivability of the wind turbine increases.
Many people are interested in wind energy. The reasons for this interest are different: for some, this is one of the few opportunities to provide their home with electricity; someone considers a windmill as a backup power source; others want to gain complete independence from central power grids. Today there is such an opportunity - it is necessary to install a wind generator and not very complex auxiliary equipment on the site. However, there are still some nuances that you should know about in advance.
The kinetic energy of the wind can be converted into either electrical, mechanical or thermal energy. Thus, with the help of wind, it is possible not only to provide a house with electricity, but also, for example, to lift water from a well, without intermediate transformation of the kinetic energy of the wind flow into electrical energy.
In one case or another, you will need a wind power plant, which includes a wind turbine equipped with an energy converter and a battery. The energy converter can be electric generators, hydraulic pumps, compressors. For example, if a wind power plant will only serve for irrigation, then there is no point in first receiving electricity and then using it to power electric pumps. An extra link in energy transformation reduces the efficiency of a wind power plant. In economic practice, only two types of converters are mainly used - electrical and mechanical (for pumping water). In the first case, we are talking about the accumulation of electrical energy, which is used by consumers; in the second about wind pumps that provide the necessary pressure in drip irrigation systems, sprinkler systems, and domestic water supply systems.
Types of wind turbines
Any wind turbine has blades, which, having windage, absorb part of the kinetic energy of the wind flow. The shape of these blades and the design of the wind wheel can be different. There are three main types of wind turbines: vane (similar to a propeller), rotor (carousel) and drum. The most common are winged working parts of a wind wheel, the axis of rotation of which is located horizontally. Their share is at least 90% of the total number of wind turbines.
It is these “windmills” that can be found in large numbers in Europe, and especially in the Netherlands. Wind energy projects in this country, which started in the middle of the last century, have already paid for themselves many times over. Contrary to popular belief that a wind power plant is not capable of generating enough electricity to match the costs of its installation and maintenance, in Holland entire villages are powered exclusively by wind turbines. One powerful wind power plant can provide full electricity to several hundred(!) cottages. The wind turbine of such an installation is installed on a very strong and stable structure, which is based on a massive reinforced concrete slab buried 15-20 meters deep. It, like a tree root, holds up a high tower, inside of which there is a ladder that allows servicing the wind turbine. No stretch marks are used.
Vane wind turbines consist of a wind wheel, a head, an orientation mechanism (tail) and a tower (or mast, depending on the size).
A wind wheel can be equipped with from one to eight or more blades. Depending on their number, wind turbines are divided into high-speed (up to 4 blades), medium-speed (4...8 blades) and low-speed (from 8 blades).
The head is designed in such a way that it can rotate around the vertical axis of the tower. Its shape depends on the power and purpose of the wind turbine - in turn, factors that determine the transmission mechanism system, its design and the number of stages.
The tail works like a weather vane and turns its head in the wind. Its surface area depends on the aerodynamic parameters of the wind wheel blades.
The tower raises the wind turbine above all obstacles that reduce the pressure flow of the wind, and also ensures the safety of the rotation of the blades. When the wind speed exceeds 35-45 m/s, the braking system is activated, completely stopping the wind turbine.
The number of blades of a propeller wind wheel depends on the average wind speed in the area where the wind power plant is installed. In open spaces, sea and ocean coasts, small-bladed vane wind engines are used, which require a minimum wind speed of 5-8 m/s to start. These are the simplest wind turbines in design, having high efficiency, but creating a lot of noise.
In areas where wind speeds rarely exceed 5 m/s, it is generally recommended to install multi-bladed wind turbines. They operate almost silently, but also have lower efficiency than small-bladed ones; In addition, the production of multi-bladed wind turbines requires more materials, because During operation, a wind turbine of this type experiences increased gyroscopic loads.
Rotary wind turbines(aka carousel) also have a simple design, but have much lower efficiency - a maximum of 18%. The problem with their use is also that they use rather rare multi-pole electric generators. Rotary wind turbines have a vertical axis of rotation and blades that operate like a sail. One of the advantages of this type of wind turbine is the absence of an orientation mechanism. The vertical axis of rotation allows the safe use of a rotor wind wheel at a low tower height. Such wind turbines start at low wind speeds and do not make noise. The main disadvantage of rotary wind turbines is the low wind utilization factor, since only a part of the blades are constantly involved in operation; the rest either overcome wind resistance or are isolated from it by an umbrella (casing).
Over the past decade, the market for wind power plants (WPPs) has expanded significantly, primarily with compact models that could be used in homesteads and farms. They are designed for a low initial wind speed of 2.5...3 m/s and installation of a wind turbine at a height of 6...17 m. The nominal amount of electricity is generated already at 6...8 m/s (wind turbine rotation speed 250...300 rpm).
Wind generators at work
The wind speed is not constant and therefore it is not possible to obtain “clean” electricity with stable parameters from the converter. The generator, as a rule, produces a voltage of 0...56 V. The generated “dirty” energy is accumulated by the batteries that are equipped with the wind turbine, which ensures uninterrupted operation of the system. During periods of strong winds, the installation operates at maximum power and stores energy for future use in order to release it in calm or low wind conditions. Solar panels are often used together with a wind turbine to charge the batteries in the summer, when the winds are especially weak.
To convert the direct current of the batteries into alternating current with parameters of 220V/50 Hz, wind turbines are equipped with inverters.
In order to overcome peak loads, wind turbines are combined with auxiliary sources of electricity, such as diesel and gasoline generators, as well as (as an auxiliary) centralized power grid.
Individual low-power wind power plants are gradually becoming cheaper and more efficient. At the same time, the prospects for their use for private homes and farms are increasing. For example, for cottages in remote areas, it is important to have an autonomous wind power plant with a capacity of 20-50 kW, which guarantees the operation of the main electrical equipment in the absence of all other sources.
Wind pumps
People learned to raise water from the depths with the help of the wind a long time ago, but this method is not forgotten today, especially where sources of electricity are not available. The idea of the invention is simple - to use wind energy to drive a water pump.
Wind pumps are most widespread in the USA. Once they decided the fate of the country's economy, and today they have also become a kind of religious building in the traditional setting of an American ranch.
In the post-Soviet space, wind pumps are a rarity, although during the gardening boom of the mid-80s their popularity increased. Circumstances forced it. Nowadays, prerequisites are also emerging for turning to the already forgotten “Daisies” and “Aquarius”, since the share of electricity in the cost of vegetable products is growing from year to year.
The wind-mechanical unit “Romashka” was developed by NPO Vetroen. His drawings were first published in the magazine “Modelist-Konstruktor” in 1988, which outlined guidelines for making a wind pump yourself.
Both units have the most simplified design. They are designed to suck water from a depth of up to 8 m and operate even at a wind speed of 3 m/s. The “Romashka” wind wheel has 12 blades and drives the pump diaphragm through a cam-lever mechanism with a vertical rod passing inside the wind turbine support.
At a wind speed of 5 m/s, the Romashka wind pump raises 8-meter depth up to 300 liters of water per hour, and is capable of delivering it to a height of up to 10 meters. Paired with a drip irrigation system, this unit provides a real opportunity to cultivate garden crops in remote areas, if there is a reservoir or well up to 8 meters deep.
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