Windmill inside. Windmill - history. The evolution of modern windmills. From windmills to wind turbines

Technological processes production using windmills extremely varied. In accordance with this, the mills were divided into various types.

So, in the flour milling industry there were mills operating on one (see Fig. 4.3) or two (Fig. 4.11) millstones.

According to the constructive forms of turning into the wind, there were two main types of windmills - gantry and tent(Fig. 4.12). The gantry windmill (Fig. 4.12, a) completely turned around the oak pillar. The column was installed in the center of gravity, and not in the center of symmetry, on the foundation. Turning into the wind required a lot of effort. A single-stage transmission was used, rotating a short millstone shaft. The Bock mill also belongs to the gantry type (see Fig. 4.3). On fig. 4.13 shows a section of a later design of a gantry windmill.

On fig. 4.12, b shows the hipped (Dutch) type. The stationary building of the mill was supplied from above with a swivel frame carrying a wind wheel and covered with a roof in the form of a tent. Turning into the wind due to the lower weight of the turning parts required much less effort. The wind wheel could have an increased diameter due to the possibility of lifting it to great height. Most often, a two-stage transmission was used (see Fig. 4.11). On fig. 4.14 shows a more advanced design of the tent mill.

The quiver type occupied an intermediate position between the tent and gantry types. The turning circle was located at half the height of the mill.

Drainage mills, the rotary frame of which was at ground level, were referred to the quiver type.

The speed of windmills was limited by the strength of the transmission with wooden teeth of the wheels and pinions of the gears. Therefore, the increase in the coefficient of wind energy utilization due to the increase in the speed of the wind wheel was also limited. The teeth and pins (Fig. 4.15) were made according to a dry wood pattern (hornbeam, acacia, elm, maple or birch).

The wheel rim on the main shaft was made of birch or elm boards, laid in two layers, processed around the circumference from the outside and attracted to the spokes with bolts. The upper and lower disks of the pinion gear of the vertical shaft were connected from boards 40 mm thick in two layers. The discs were also bolted together. The wheel and gear were fastened with wedges. Since the wings were the main part of windmills, the development of the latter from the moment of their inception until sunset followed the path of improving, first of all, the design of the wings.

In older designs, the wing grille was covered with canvas. Gradually the tyos replaced the sail. The wings began to be sheathed with a weave (the best was spruce) 6 mm thick, constant in length (Fig. 4.16). Scraps of fabric on the sailing wing, cracks, and a rough-fitting plank on a plank wing reduced the lift of the wings by several times, and, consequently, the performance of the windmill by the same amount.

In the simplest mills, the wings were made with a constant blade wedging angle (from 14 to 15 °). Such wings were much simpler to manufacture, but their wind energy utilization coefficient was about 1.5 times less than that of wings with a helical blade. In some tent mills, the wings were made with a variable wedging angle: at the end from 0 to 10 ° and at the base from 16 to 30 °. One of the latest wing designs with semi-streamlined profiles is shown in fig. 4.17.

In Europe, the buildings of hipped windmills were built of stone by the time of the sunset of their era. General form such a mill is shown in Fig. 4.18 (in the background - a modern wind power plant).

At a windmill driven by a water pump for irrigating land (Fig. 4.19), the oldest type, like grain mills, in the event of a strong wind, the area of ​​\u200b\u200bthe wings was reduced manually to avoid damage by partially removing the sail (or opening the blinds). Through the use of the Hercules wind wheel with a diameter of 15 m (Fig. 4.20), built by the Associated Wind Turbine Society in Dresden, another step was taken to improve the efficiency of such installations.

But all these are low-speed wind turbines, which are characterized by a large number of blades or wide wings (see Fig. 4.3–4.5, 4.7–4.11, 4.13, 4.14, 4.18–4.20). They have a big creeping moment.

It was possible to increase the speed of wind pump installations using the Adler wind turbine from the Kester company in Holstein (Fig. 4.21, a) with a small number of blades and a large distance between them.

Installation with this wheel had an average speed. The high-speed wind wheel of the Aerodynamo company (Berlin) on the suction side of the wings already had valves (Fig. 4.21, b) for automatic control. In working condition, the valves were held by a spring and a stop in a horizontal position so that when the wing moved, they did not create significant resistance.

When a certain speed was exceeded, under the influence of centrifugal forces, the valves turned and created a lot of resistance, and also very significantly disrupted the smoothness of the flow on the wing, so that the lifting force of the wings was made less, as a result of which the wind was used to a lesser extent.

High-speed wind turbines made it possible to obtain high values ​​of the wind energy utilization factor and high power with the same dimensions, and had a small breaking moment.

On fig. 4.22 shows a wind turbine that pumped water with a lifting screw. Her wind wheel is of the same type as in Fig. 4.21, a, of the same company. The shape of the wing profiles is noteworthy.

In the XVIII-XIX centuries, windmills were built almost all over the world. The development of mechanical engineering made it possible to move from the handicraft production of wooden mills to the manufacture of wood-metal workshops and to the mass production of multi-blade wind turbines in the factory. metal structure. By the end of the 19th century, they were already equipped with systems for automatically controlling the speed of rotation and power, with mechanisms for fixing the wind wheel in the direction of the flow. The total annual output in the major industrialized countries amounted to hundreds of thousands of engines. A number of countries began to produce in significant quantities at factories also more advanced in design and economical high-speed wind turbines, designed primarily to obtain electrical energy. These engines of low power (0.75–1 kW) were usually carried out with two (Fig. 4.23, a) or three-blade (Fig. 4.23, b) vane-type wind wheel connected through a gearbox to a DC generator. They were supplied with an energy storage system, most often a battery. They were used in everyday life to illuminate small and remote objects and charge batteries.

It is typical to install the Berkut-3 wind turbine in the wind (see Fig. 4.23, a) using two windroses, unlike most similar wind turbines, where this function is performed by the tail (see Fig. 4.23, b, as well as Fig. 4.8– 4.10, 4.20–4.22). The windrose mechanism consists of two small wind wheels, the plane of rotation of which is perpendicular to the plane of rotation of the main wheel, working to drive a worm that turns the platform of the head of the wind turbine until the wheels lie in a plane parallel to the direction of the wind.

The number of revolutions in the Roralight wind turbine is limited by turning the blade using a centrifugal regulator mounted on the wind wheel shaft.

The significance of windmills and other wind turbines in people's lives and the development of human civilization is so great that they deserve not only a strict - technical - dry description, but also poetry.

Great master of lyrical prose K.G. Paustovsky (1892-1968) in his essay “Ilyinsky pool” left us an “ode” to a windmill as a legacy.

“Once in the summer I lived in the steppes beyond Voronezh. I spent all my days either in the wild linden park, or at the windmill, which stood on a dry mound.

Around the windmill grew a lot of rough purple immortelle. The plank roof of the windmill was half torn off by an air wave in those days when the Germans approached Voronezh.

The sky was visible through the hole in the roof. I lay down on the heated clay floor of the mill and read Ertel's novels or simply looked at the sky through the hole above my head.

A b

Rice. 4.21. Wind wheels manufactured by Adler (a) and Aerodynamo (b)

New, very white and bulging clouds constantly arose in it, and in a slow succession floated away to the north.

The quiet glow of these clouds reached the ground, passed over my face, and I closed my eyes to protect them from the harsh light. I rubbed a whisk of thyme on my palm and inhaled its scent with pleasure - dry, healing and southern. And it seemed to me that nearby, behind the windmill, the sea had already opened up, and that it was not the steppe that smelled of thyme, but its sands smoothed by the surf.

Sometimes I dozed off near the millstones. The millstones hewn from pink sandstone carried my thought back to the times of Hellas.

A few years later, I saw a statue of the Egyptian Queen Nefertiti, carved from the same stone as the millstones. I was struck by the femininity and tenderness that this rough sandstone contained. The ingenious sculptor extracted from the core of the stone the wondrous head of a quivering and affectionate young woman and presented it to the centuries, gave it to us, his distant descendants, who, like him, who seek imperishable beauty.

And two years later I saw in France, in Provence, the famous mill of the writer Alphonse Daudet. Once he made his dwelling in it.

Obviously, life at the windmill, which smelled of flour and old herbs, was surprisingly good. Especially at our Voronezh mill, and not at the mill of Alphonse Daudet. Because Dode lived in a stone mill, and ours was wooden, full of sweet smells of tar, bread and dodder, full of steppe fads, the light of clouds, the overflow of larks and the chirping of some small birds - either oatmeal or kings.

For many centuries, thanks to the wind, man moved across the seas and oceans, using sails to "catch" air currents. Approximately II-I centuries BC. dated the first known windmills found in Egypt near the city of Alexandria. These were drum-type stone mills. They had a wheel with wide blades mounted in a special drum in such a way that half of the wheel was outside, and the wind, pressing on the blades, rotated the wheel, which, in turn, set the millstones in motion. More advanced windmills of vane design in the 7th century AD. began to be used by the Persians, who lived on the territory of modern Iran. From the VIII-IX centuries, windmills spread throughout Europe and Rus'. At first, these mills ground grain, but gradually people began to use them also for pumping water and actuating various mechanisms. In particular, the Dutch thus drained polders - plots of land surrounded by dams. Until the middle of the 16th century, the so-called goat mills (in other words, German mills) were common in Europe. Their disadvantages were unreliability (tipped over by a storm) and limited productivity due to the fact that gantry mills were turned manually into the direction of the wind with the help of goats (hence the name), which means that they were not built too large. But in the middle of the 16th century, a mill was invented in Holland, in which only the roof with wings moved. Improved mills began to be called tent (or Dutch). Such mills were built very high, which made it possible to attach longer wings to them, thereby increasing power. Today, the highest windmills in the world are Dutch windmills called "North" and "Freedom", whose height exceeds 33 meters. At one time, Holland was the "leader" in the number of windmills, which were used not only for grinding grains and pumping water. Dyeing, oil, saw mills have become widespread. It was for the sawmill that a windmill was built in St. Petersburg, the design of which Peter I personally studied from the Dutch masters. Even paper was made using windmills, and today in the Dutch town of Zaanse Schans you can see the last mill (called "Teacher") for the production of paper. It is no coincidence that for a very long time paper from Holland was considered the best, and the American "Declaration of Independence" was printed on such paper.

New life for windmills

The advent of better technology seemed to send windmills into the realm of tourist curiosities. However, people quickly figured out that in such a "grandfather" way, i.e. Wind turbines can generate electricity. In July 1887, Scottish academic and professor James Blyth attempted to create a wind turbine to generate electricity. In 1891, he received a patent for his invention. A 10-meter wind turbine with fabric-covered wings was installed in the Scottish city of Marykirk and produced electricity for lighting. True, Blyth did not achieve commercial success. In the winter of 1887-1888, already in the United States, Charles F. Brush created a wind turbine that powered his house and laboratory until 1900. In 1890, Danish scientist and inventor Poul la Cour designed a wind turbine to produce hydrogen. This installation is considered the first electric windmill modern type. In the first half of the last century, wind turbines began to be installed in places where it was impossible to deliver electricity in the usual way. Since the 20s of the last century, wind turbines began to appear in the USA and Australia. In Russia in 1918, Professor V. Zalevsky became interested in obtaining electricity using wind. He created the theory of the windmill and formulated a number of principles that a wind turbine must meet. In 1925, Professor N. Zhukovsky organized a wind turbine department at the Central Aerohydrodynamic Institute. In the 1930s, the leadership Soviet Union seriously preoccupied with the use of wind energy. The production of wind turbines with a capacity of 3-4 kW was launched, and they were produced in series. The very first wind power station in the USSR was installed in 1930 in the city of Kursk. The power of the station was 8 kW. In 1931, the world's largest Yalta wind farm with a capacity of 100 kW was put into operation in the USSR. The construction and installation of wind turbines proceeded at a high pace until the early 60s. Suffice it to say that from 1950 to 1955 the Union produced up to 9 thousand wind turbines annually. When the virgin lands were being developed in Kazakhstan, the Soviet people built the first multi-unit wind farm, which worked in conjunction with a diesel engine; the total power of this installation was 400 kW. This wind farm has become an example for modern wind-diesel systems. However, by the end of the 60s, the wind power industry of the Soviet Union gave way to large thermal power plants, hydroelectric power plants and nuclear power plants, and the mass production of "windmills" was curtailed. They returned to WPP in the 90s of the XX century, unlike the USA and Europe. The beginning of modern wind energy is usually counted from 1979.

The current state of wind energy

It is curious that until about the mid-90s of the last century, the United States held the lead in terms of the total capacity of wind turbines. However, in 1996 Western Europe had 55% of the world's wind farm capacity. The windmills themselves have also changed. Until the mid-90s of the twentieth century, the world produced the most wind turbines with a capacity of 100 to 500 kW. Then there was a trend towards the production of units with a capacity of up to 2000 kW. These are truly gigantic windmills, the height of which exceeds 100 meters. Despite the ever-increasing growth in the number of wind farms, the share of electricity generated by wind power is just over 1% of the total electricity generation in the world. However, in some countries this share is significantly higher, for example, in Denmark it is more than 20%, in Germany - 14.3% (according to 2007 data), in India - about 3% (according to 2005 data). Wind Energy Potential Russian Federation is over 50,000 billion kWh/year. Translated into the language of economics, this is approximately 260 billion kWh / year, which equals approximately 30% of the electricity produced by all domestic power plants. In 2006, the installed capacity of wind farms in Russia was about 15 MW.

"Kulikovskaya" wind farm.

One of the most powerful Russian wind farms is located near the village of Kulikovo, Zelenogradsky district, Kaliningrad region. Its capacity is 5.1 MW (the wind park consists of 21 wind turbines, occupies about 20 hectares and is able to provide electricity to 145 apartments), and the average annual output is about 6 million kWh / year. It is also worth mentioning the Anadyr wind farm with a capacity of 2.5 MW in Chukotka. In the coming years, in the most different countries around the world, it is planned to significantly increase the amount of electricity received from windmills. However, the spread of WES can be difficult for a number of reasons, which will be discussed below.

Cons of wind energy

So, what are the main disadvantages of wind energy? First, the force of the wind is not constant. Therefore, there is a danger of disrupting the operation of the general power system (which itself "suffers" from peaks and drops in load) if it contains a significant share of electricity received from wind farms (according to some calculations, this share is 20-25%) . In addition, the "instability" of the wind forces a person to think about backup sources of electricity that could compensate for the missing part of the electricity at the right time. An example of such a reserve is gas turbine power plants or batteries. All this leads to an increase in the cost of wind energy. Secondly, wind power plants make a decent noise, which forced a number of European countries to pass a law limiting the noise level of windmills to 45 dB during the day and up to 35 dB at night. Added to the noise is low-frequency vibration transmitted through the soil. That is why residential buildings are usually located at a distance of 300 meters or more from wind power plants. Thirdly, the metal components of windmills produce radio interference, which is why in some places it is even necessary to build additional repeaters nearby. Of course, the instability of wind farms in terms of electricity supply is their main problem, and it is quite possible to put up with the rest of the shortcomings of windmills. Moreover, although significant areas around wind turbines are forcedly deserted, they are not empty, but are almost completely leased to farms (or other) farms. In this regard, the idea of ​​transferring wind farms to the issuance of not industrial-quality electrical energy (~ 220V, 50 Hz), but direct or alternating current, which would then be converted with the help of heating elements into heat, for example, to obtain hot water, heating and other needs. In this case, the problem of uninterrupted current supply fades into the background. In addition, wind turbines operate in the world, with the help of which they do not produce electricity, but raise water from wells. Similar installations are located in Kazakhstan, Uzbekistan and a number of other countries. As we see, and modern world wind turbines are widely used.

Wind generators as they are

The main components of a wind generator are: a propeller rotated by the force of the wind, a housing, a generator and a battery. In addition to stationary, there are mobile wind farms, the power of which is enough to power electrical appliances. The power of the wind generator is directly related to the area swept by the generator blades. The largest wind turbines in the world are produced by the German company Repower: the rotor diameter of such turbines is 126 meters, the weight of the nacelle is 200 tons, the height of the tower is 120 meters, and the power can reach up to 6 MW. The most common wind turbine design is with three blades and a horizontal axis of rotation, although two-bladed installations can still be seen today. At the moment, two types of wind turbines are common in the world: carousel and vane. There are also drum and other designs. In carousel (rotary) wind turbines, a wheel with blades is "planted" on the vertical axis. Unlike vaned ones, such windmills are able to operate in any direction of the wind without changing their position. These are low-speed installations that do not create much noise. They use multi-pole electric generators operating at low speeds - this allows the use of simple electrical circuits without the danger of an accident with a gust of wind. Vane windmills are bladed mechanisms with a horizontal axis of rotation. The stabilizer wing allows you to install the system in the most favorable position relative to the wind flow. Small winged DC wind farms are connected directly to the electric generator (without a multiplier), more powerful ones are equipped with a gearbox. In the world market, the share of vane wind farms exceeds 90%, which is the reason for the high utilization rate of wind energy. Among alternative designs, it is worth mentioning wind systems in which there are no moving parts. The rushing wind in them is cooled and, thanks to the thermoelectric Thomson effect, contributes to the generation of electrical energy.

Are there any prospects?

Of course, there are prospects. For more than a hundred years, wind turbines have been helping people get electricity literally from nothing, using only the kinetic energy of the air masses of the atmosphere. Thus, traditional types of fuel (firewood, coal, oil, natural gas) are saved, environmental pollution is reduced. The global economic crisis, which we are seeing developing and, we hope, successfully ending today, provides a lot of food for thought, and in particular, suggests the transition to alternative sources energy. High oil prices, interruptions in natural gas supplies (to Europe in particular) give wind energy an excellent chance for further development. It is no coincidence that alternative energy began to grow seriously abroad after the oil crisis in the mid-70s of the last century. At first, wind energy was subsidized by the state, but today this type of energy is a profitable business, although it is regulated by government agencies. In Russia, by the way, there is no necessary legislative framework for the development of wind energy, for this reason (and also due to the lack of serious investments; the wind farm of the Kulikovo wind farm is a gift from the Danish authorities !!!) in our country there are no more than four dozen modest wind farms that provide a total less than 0.1% of energy generated in the Russian Federation. Wind power is present in more than 50 countries around the world. Leading countries in terms of total installed capacity: Germany (18428 MW), Spain (10027 MW), USA (9149 MW), India (4430 MW), Denmark (3122 MW), the Netherlands (1290 MW), China (1260 MW) and Portugal (1000 MW). If, until recently, wind energy was actively developing in the EU and the USA, today wind farms are being built in large quantities in Canada, Asia, South America, Australia, Africa (in the ancestral home of A.S. Pushkin, Egypt succeeds in this matter). The trend is that wind energy will soon be powered not by individual houses, but by entire villages and cities, at first, of course, very small ones. One of these "swallows" was in 2008 the town of Rock Port (Missouri) - the first city in the United States that receives 100% of its energy from a wind farm (Wind Capital Group project). The so-called "small wind energy" can also be counted among the promising areas of energy (see our article "IT-tales: Small wind energy - for the home, for the family"). Wind power today is a rapidly growing industry. This is also evidenced by the numbers - in 2008, the total capacity of wind energy worldwide amounted to 120 GW. We hope that Russia will not remain aloof from the trends in the development of alternative energy, which uses the power of the wind to generate electricity or heat (as well as tides, geothermal sources, etc.), since there is plenty of territory and wind potential in Russia.