Wind turbines for the home: types, approximate prices, do-it-yourself manufacturing. Coil connection process

Since ancient times, mankind has been using the power of the wind. Windmills, sailing ships are familiar to many, they were written about in books and historical films are made with their participation. Nowadays, the wind power generator has not lost its relevance, because. with it you can do free electricity in the country, which can also come in handy if the lights are turned off at the site. Let's talk about homemade windmills, which can be assembled from improvised materials and available parts. For you, we have provided one detailed instruction with pictures, as well as video ideas for several more assembly options. So, let's look at how to make a wind generator with your own hands at home.

Assembly instructions

There are several types of wind turbines: horizontal and vertical, turbine. They have fundamental differences, pluses and minuses. The principle of operation of all wind generators is the same - wind energy is converted into electrical energy and accumulated in batteries, and from them it goes to human needs. The most common type is horizontal.

Familiar and recognizable. The advantage of a horizontal wind turbine is more high efficiency compared to others, since the blades of a windmill are always under the influence of air flow. The disadvantages include the requirement for wind above 5 meters per second. This type of windmill is the easiest to make, so home craftsmen often take it as a basis.

If you decide to try your hand at assembling a wind turbine with your own hands, here are a few recommendations. You need to start with the generator, this is the heart of the system, the design of the screw assembly depends on its parameter. For this, automobile, imported ones are suitable, there is information about the use of stepper motors, from printers or other office equipment. You can also use a bicycle wheel motor to make your own windmill to generate electricity.

Having decided on the unit for converting the wind flow into electric current, it is necessary to assemble the gear unit for increasing the speed from the screw to the generator shaft. One revolution of the propeller transfers 4-5 revolutions to the shaft of the generator unit.

When the gearbox-generator assembly is assembled, they begin to find out its resistance to torque (grams per millimeter). To do this, you need to make a shoulder with a counterweight on the shaft of the future installation, and with the help of a load, find out at what weight the shoulder will go down. Less than 200 grams per meter is considered acceptable. Knowing the size of the shoulder, this is our blade length.

Many people think that the more blades the better. This is not entirely true, since we make the wind generator ourselves, and the details of the future power plant of the budget range. We need high speed, and many propellers create more resistance to the wind, as a result of which at some point the oncoming flow slows down the propeller and the efficiency of the installation drops. This can be avoided by a two-bladed propeller. Such a propeller in a normal wind can spin up to and more than 1000 revolutions. You can make the blades of a homemade wind generator from improvised means - from plywood and galvanizing to plastic from water pipes (as in the photo below) and other things. The main thing condition easy and durable.

A light screw will increase the efficiency of the windmill and sensitivity to air flow. Don't forget to balance the air wheel and remove bumps, otherwise you will hear howling and howling while the generator is running.

Next important element, this is the tail. It will keep the wheel in the wind flow, and turn the structure in case of a change in its direction.

To make a current collector or not, it's up to you, you may get by with a connector on the cable and periodically, manually unwind the twisted wire. During the test run of the wind generator, do not forget about safety precautions, the blades spun in the wind can chop cabbage like a samurai.

A tuned, balanced windmill is installed on a mast, at least 7 meters high from the ground, fixed with spacer cables. Further, an equally important node, a storage battery, it can be an old car that has lost its capacity or battery. It is impossible to connect the output of a homemade wind generator directly to the battery, this must be done through a charging relay, you can assemble it yourself or purchase it ready-made.

The principle of operation of the relay is to control the charge, and in the event of a charge, it switches the generator and battery to load ballast, the system strives to always be charged, preventing overcharging, and does not leave the generator without load. A windmill without load can spin up quite strongly to high speeds, damage the insulation in the windings by the generated potential. In addition, high speeds can cause mechanical destruction of elements. wind generator. Next is a voltage converter from 12 to 220 volts 50 Hz to connect household appliances.

Now the Internet is full of diagrams and drawings, where craftsmen show how to make a wind generator with powerful magnets on their own. Repeat or not, your business, whether it will justify itself, no one knows. But it’s worth trying to assemble a wind power plant for your home, and then decide what to buy and what to leave or make changes. Gain experience and possibly aim at a more serious device. Freedom and Diversity homemade windmills the element base is so extensive and diverse that it makes no sense to describe them all, the basic meaning remains the same - the wind flow spins the propeller, it transmits torque to the gearbox, increasing the shaft speed, the generator outputs voltage, then the relay keeps the charge level on the battery, and from it energy is already being extracted for various needs. Here, according to this principle, you can make a wind generator with your own hands at home. We hope our detailed instructions with photo examples, she explained to you how to make a suitable model of a windmill for a house or a summer residence. We also recommend that you familiarize yourself with the master classes on assembling a homemade device, which we provided in the video below.

Visual video tutorials

To easily make a wind generator to generate electricity at home, we recommend that you familiarize yourself with ready-made ideas in video examples:

One of the most available options renewable energy is the use of wind energy. For information on how to independently calculate, assemble and install a windmill, read this article.

Classification of wind generators

Installations are classified based on the following wind turbine criteria:

• location of the axis of rotation;
• number of blades;
• element material;
• screw pitch.

Wind turbines usually have design with horizontal and vertical axis of rotation.

Execution with a horizontal axis - a propeller design with one, two, three or more blades. This is the most common version of air power plants due to its high efficiency.

Vertical axis design - orthogonal and carousel designs on the example of Darrieus and Savonius rotors. The last two concepts should be clarified, since both have a certain significance in the design of wind generators.

The Darrieus rotor is an orthogonal design of a wind turbine, where the aerodynamic blades (two or more) are located symmetrically to each other at a certain distance and are mounted on radial beams. Enough difficult option wind turbine, requiring careful aerodynamic design of the blades.

The Savonius rotor is a carousel-type wind turbine design, where two semi-cylindrical blades are located one against the other, forming a sinusoidal shape as a whole. The efficiency of the structures is low (about 15%), but can be almost doubled if the blades are placed in the direction of the wave not horizontally, but vertically and a multi-tiered version is used with an angular displacement of each pair of blades relative to other pairs.

Advantages and disadvantages of "windmills"

The advantages of these devices are obvious, especially in relation to domestic operating conditions. Users of "windmills" actually get the opportunity to reproduce free electrical energy, except for small costs for construction and maintenance. However, the disadvantages of wind turbines are also obvious.

So in order to achieve effective work installation, the conditions for the stability of wind flows are required. Man cannot create such conditions. This is purely the prerogative of nature. Another one, but already technical disadvantage, noted low quality generated electricity, as a result of which it is necessary to supplement the system with expensive electrical modules (multipliers, chargers, batteries, converters, stabilizers).

Advantages and disadvantages in terms of the features of each of the modifications of wind turbines, perhaps, balance at zero. If the horizontal-axis modifications differ high value Efficiency, then for stable operation they require the use of wind flow direction controllers and hurricane wind protection devices. Vertical-axis modifications have low efficiency, but work stably without a wind direction tracking mechanism. At the same time, such wind turbines are characterized by a low level of noise, eliminate the effect of "spacing" in conditions strong winds are quite compact.

Homemade wind generators

Making a "windmill" with my own hands- the task is quite solvable. Moreover, a constructive and rational approach to business will help to minimize the inevitable financial costs. First of all, it is worth sketching a project, carrying out necessary calculations balancing and power. These actions will not only be the key to a successful construction wind farm, but also a guarantee of maintaining the integrity of all purchased equipment.

It is recommended to start with the construction of a micro-windmill with a power of several tens of watts. In the future, the experience gained will help create a more powerful design. When creating a home wind generator, you should not focus on obtaining high-quality electricity (220 V, 50 Hz), since this option will require significant financial investments. It is wiser to limit ourselves to using the initially received electricity, which can be successfully used without conversion for other purposes, for example, to support heating and hot water systems built on electric heaters (heaters) - such devices do not require a stable voltage and frequency. This makes it possible to create a simple circuit running directly from the generator.

Most likely, no one will argue that heating and hot water supply in the house are inferior in importance to household appliances and lighting fixtures, for the power of which they often seek to install home windmills. The device of a wind turbine is precisely for the purpose of providing the house with heat and hot water- This minimum costs and simplicity of design.

Generalized project of a home wind turbine

Structurally, a home project largely repeats an industrial installation. True, household solutions are often based on vertical-axis wind turbines and are equipped with low-voltage DC generators. The composition of household wind turbine modules, subject to the receipt of high-quality electricity (220 V, 50 Hz):

• wind turbine;
• wind orientation device;
• multiplier;
• DC generator (12 V, 24 V);
• battery charge module;
• rechargeable batteries (lithium-ion, lithium-polymer, lead-acid);
• DC voltage converter 12 V (24 V) to AC voltage 220 V.

Wind turbine PIC 8-6/2.5

How it works? Just. The wind turns the windmill. The torque is transmitted through the multiplier to the shaft of the DC generator. The energy received at the output of the generator through the charging module is accumulated in the batteries. From the battery terminals, a constant voltage of 12 V (24 V, 48 V) is supplied to the converter, where it is transformed into a voltage suitable for powering household electrical networks.

About generators for home "windmills"

Most residential wind turbine designs are typically constructed using low-speed DC motors. This is the simplest version of the generator that does not require modernization. Optimally - electric motors with permanent magnets, designed for a supply voltage of the order of 60-100 volts. There is a practice of using car generators, but for such a case, the introduction of a multiplier is required, since autogenerators produce the required voltage only at high (1800-2500) revolutions. One option is to rebuild induction motor alternating current, but also quite complex, requiring precise calculations, turning, installation of neodymium magnets in the rotor area. There is an option for a three-phase asynchronous motor with the connection of capacitors of the same capacity between the phases. Finally, there is the possibility of making a generator from scratch with your own hands. There are a lot of instructions for this.

Vertical-axis homemade "windmill"

A fairly efficient and, most importantly, inexpensive wind generator can be built on the basis of the Savonius rotor. Here, as an example, a micro-power plant is considered, the power of which does not exceed 20 W. However, this device is quite sufficient, for example, to provide electrical energy some household appliances powered by 12 volts.

Parts set:

1. Aluminum sheet 1.5-2 mm thick.
2. Plastic pipe: diameter 125 mm, length 3000 mm.
3. Aluminum pipe: diameter 32 mm, length 500 mm.
4. DC motor (potential generator), 30-60V, 360-450 rpm, for example, PIK8-6/2.5 electric motor.
5. Voltage controller.
6. Battery.

Making a Savonius rotor

Three "pancakes" with a diameter of 285 mm are cut out of an aluminum sheet. Holes are drilled in the center of each aluminum pipe 32 mm. It turns out something similar to CDs. From plastic pipe two pieces 150 mm long are cut off and cut in half lengthwise. The result is four semicircular blades 125x150 mm. All three aluminum "CDs" are put on a 32 mm pipe and fixed at a distance of 320, 170, 20 mm from top point strictly horizontal, forming two tiers. Blades are inserted between the discs, two per tier and fixed strictly one against the other, forming a sinusoid. In this case, the blades of the upper tier are displaced relative to the blades of the lower tier by an angle of 90 degrees. The result is a four-bladed Savonius rotor. For fastening elements, you can use rivets, self-tapping screws, corners, or use other methods.

Connecting to the engine and mounting on the mast

The shaft of DC motors with the above parameters usually has a diameter of no more than 10-12 mm. In order to connect the motor shaft to the wind turbine pipe, a brass bushing is pressed into the lower part of the pipe, having the required inner diameter. A hole is drilled through the wall of the pipe and the sleeve, a thread is cut to screw in the locking screw. Next, the wind turbine pipe is put on the generator shaft, after which the connection is rigidly fixed with a locking screw.

The rest of the plastic pipe (2800 mm) is the mast of the wind turbine. The generator assembly with the Savonius wheel is mounted at the top of the mast - it is simply inserted into the pipe until it stops. As a stop, a metal disk cover is used, fixed on the front end of the motor, having a diameter slightly larger than the diameter of the mast. Holes are drilled on the periphery of the lid for attaching braces. Since the diameter of the motor housing is smaller than the inner diameter of the pipe, gaskets or stops are used to align the generator in the center. The cable from the generator is passed inside the pipe and out through the window at the bottom. During installation, it is necessary to take into account the design of the generator protection against moisture, using sealing gaskets for this. Again, in order to protect against precipitation, an umbrella cap can be installed above the connection of the wind turbine pipe with the generator shaft.

Installation of the entire structure is carried out in an open, well-ventilated area. A hole 0.5 meters deep is dug under the mast, Bottom part the pipes are lowered into the pit, the structure is leveled with stretch marks, after which the pit is poured with concrete.

Voltage controller (simple charger)

A manufactured wind generator, as a rule, is not capable of delivering a voltage of 12 volts due to the low speed. The maximum frequency of rotation of the wind turbine at a wind speed of 6-8 m / s. reaches a value of 200-250 rpm. At the output, it is possible to obtain a voltage of the order of 5-7 volts. To charge the battery, a voltage of 13.5-15 volts is required. The way out is to use a simple switching voltage converter, assembled, for example, based on the LM2577ADJ voltage regulator. By applying 5 volts DC to the input of the converter, 12-15 volts are obtained at the output, which is quite enough to charge a car battery.

Ready voltage converter on LM2577

This micro-wind generator can certainly be improved. Increase the power of the turbine, change the material and height of the mast, add a DC-to-AC mains voltage converter, etc.

Horizontal-axial wind power plant

Parts set:

1. A plastic pipe with a diameter of 150 mm, an aluminum sheet 1.5-2.5 mm thick, a wooden block 80x40 1 m long, plumbing: flange - 3, corner - 2, tee - 1.
2. DC motor (generator) 30-60 V, 300-470 rpm.
3. Wheel-pulley for an engine with a diameter of 130-150 mm (aluminum, brass, textolite, etc.).
4. Steel pipes with a diameter of 25 mm and 32 mm and a length of 35 mm and 3000 mm, respectively.
5. Charging module for batteries.
6. Batteries.
7. Voltage converter 12 V - 120 V (220 V).

Production of a horizontal-axial "windmill"

Plastic pipe is necessary for the manufacture of wind turbine blades. A segment of such a pipe, 600 mm long, is cut lengthwise into four identical segments. The windmill requires three blades, which are made from the resulting segments by cutting off a piece of material diagonally to the full length, but not exactly from corner to corner, but from bottom corner to top corner, with a slight indent from the latter. The processing of the lower part of the segments is reduced to the formation of a fastening petal on each of the three segments. To do this, a square about 50x50 mm in size is cut along one edge, and the remaining part serves as a mounting petal.

The blades of the wind turbine are fixed on the wheel-pulley with the help of bolted connections. The pulley is mounted directly on the shaft of the DC motor - generator. A simple wooden block with a section of 80x40 mm and a length of 1 m is used as the chassis of the wind turbine. The generator is installed at one end wooden block. At the other end of the bar, a "tail" is mounted, made of aluminum sheet. At the bottom of the bar, fastened metal pipe 25 mm, designed to play the role of the shaft of the rotary mechanism. A three-meter metal pipe 32 mm is used as a mast. Top part mast is a sleeve of the rotary mechanism, where the wind turbine pipe is inserted. The mast support is made from a sheet of thick plywood. On this support, in the form of a disk with a diameter of 600 mm, a construction of sanitary parts is assembled, thanks to which the mast can be easily raised or lowered, or mounted or dismantled. Stretch marks are used to fasten the mast.

All electronics wind turbine mounted as a separate module, the interface of which provides for the connection of batteries and a consumer load. The module includes a battery charge controller and a voltage converter. Such devices can be assembled independently with the appropriate experience, or purchased on the market. There are many for sale different solutions, allowing to obtain the desired output values ​​of voltages and currents.

Combined wind turbines

Combined wind turbines are a serious option for a home energy module. Actually, the combination involves combining in a single system a wind generator, a solar battery, a diesel or gasoline power plant. You can combine in every possible way, based on the possibilities and needs. Naturally, when there is a three-in-one option, this is the most effective and reliable solution.

Also, under the combination of wind turbines, it is supposed to create wind power plants that have two various modifications. For example, when a Savonius rotor and a traditional three-blade machine work in the same bundle. The first turbine operates at low wind flow speeds, and the second only at nominal ones. Thus, the efficiency of the installation is maintained, unjustified energy losses are excluded, and in the case of asynchronous generators, reactive currents are compensated.

Combined systems are technically complex and costly options for home practice.

Calculation of the power of a wind farm

To calculate the power of a horizontal-axis wind generator, you can use the standard formula:

• N = p S V3 / 2
• N— installation power, W
• p- air density (1.2 kg / m 3)
• S- blown area, m 2
• V— wind flow speed, m/s

For example, the power of an installation with a maximum blade span of 1 meter, with a wind speed of 7 m / s, will be:

• N\u003d 1.2 1 343 / 2 \u003d 205.8 W

An approximate calculation of the power of a wind turbine created on the basis of the Savonius rotor can be calculated using the formula:

• N = p R H V3
• N— installation power, W
• R— impeller radius, m
• V— wind speed, m/s

For example, for the design of a wind power plant with a Savonius rotor mentioned in the text, the power value at a wind speed of 7 m / s. will be:

• N= 1.2 0.142 0.3 343 = 17.5 W

With the rise in electricity prices, there is a search and development of it everywhere alternative sources. In most regions of the country, it is advisable to use wind turbines. To fully provide electricity private house, requires a sufficiently powerful and expensive installation.

Wind generator for home

If you make a small wind generator, you can use electric current to heat water or use it for part of the lighting, for example, outbuildings, garden paths and porches. Heating water for household needs or heating is the simplest option use of wind energy without its accumulation and conversion. Here the question is more about whether there will be enough power for heating.

Before you make a generator, you first need to find out the features of the winds in the region.

Large wind generator, for many places Russian climate, not very suitable due to frequent changes in intensity and direction air currents. Above 1 kW, it will be inertial and will not be able to fully spin up when the wind changes. Inertia in the plane of rotation leads to overloads from the side wind, leading to its failure.

With the advent of low-power energy consumers, it makes sense to use small home-made wind generators of no more than 12 volts to illuminate the cottage LED lamps or charge phone batteries when there is no electricity in the house. When this is not necessary, the generator can be used to heat water.

Type of wind generator

For a windless area, only a sail wind generator is suitable. In order for the power supply to be constant, you will need a battery of at least 12V, a charger, an inverter, a stabilizer and a rectifier.

For low-wind areas, you can independently make a vertical wind generator with a power of no more than 2-3 kW. There are many options and they are almost as good as industrial designs. It is advisable to buy windmills with a sailing rotor. Reliable models with power from 1 to 100 kilowatts are produced in Taganrog.

In windy regions, you can make a vertical generator for your home with your own hands, if the required power is 0.5-1.5 kilowatts. The blades can be made from improvised means, for example, from a barrel. It is advisable to buy more productive devices. The cheapest are "sailboats". A vertical windmill is more expensive, but it works more reliably in strong winds.

DIY low-power windmill

At home, a small homemade wind generator is easy to make. To start working in the field of creating alternative energy sources and gaining valuable experience in this how to assemble a generator, you can make a simple device yourself by adapting a motor from a computer or printer.

12V wind generator with horizontal axis

To make a low-power windmill with your own hands, you must first prepare drawings or sketches.

At a rotation speed of 200-300 rpm. the voltage can be raised to 12 volts, and the generated power will be about 3 watts. It can be used to charge a small battery. For other generators, the power must be increased to 1000 rpm. Only then will they be effective. But here you need a gearbox that creates significant resistance and also has a high cost.

Electrical part

To assemble the generator, you need the following components:

1. a small motor from an old printer, drive or scanner;
2. 8 diodes type 1N4007 for two rectifier bridges;
3. capacitor with a capacity of 1000 microfarads;
4. PVC pipe and plastic parts;
5. aluminum plates.

The figure below shows the generator circuit.

Stepper motor: connection diagram to the rectifier and stabilizer

Diode bridges are connected to each motor winding, of which there are two. After the bridges, the LM7805 stabilizer is connected. As a result, the output is a voltage that is usually supplied to a 12-volt battery.

Power generators on neodymium magnets with extremely high strength clutch. They should be used carefully. At strong blow or heating to a temperature of 80-250 0 C (depending on the type), neodymium magnets demagnetize.

You can take the hub of a car as the basis for a do-it-yourself generator.

Rotor with neodymium magnets

About 20 neodymium magnets with a diameter of about 25 mm are glued onto the hub with superglue. Single-phase power generators are made with an equal number of poles and magnets.

Magnets located opposite each other must be attracted, i.e. turned by opposite poles. After gluing neodymium magnets, they are filled with epoxy resin.

Coils are wound round, and the total number of turns is 1000-1200. The power of the generator on neodymium magnets is selected so that it can be used as a source of direct current, about 6A to charge the battery at 12 V.

Mechanical

The blades are made from plastic pipe. Workpieces 10 cm wide and 50 cm long are drawn on it, and then cut out. A bushing is made on the motor shaft with a flange to which the blades are attached with screws. Their number can be from two to four. Plastic will not last long, but for the first time it will be enough. Now enough wear-resistant materials have appeared, for example, carbon fiber and polypropylene. Stronger aluminum alloy blades can then be made.

The blades are balanced by cutting extra parts at the ends, and the angle of inclination is created by heating them with a bend.

The generator is bolted to a piece of plastic pipe with a vertical axis welded to it. An aluminum alloy weather vane is also installed coaxially on the pipe. The axis is inserted into vertical pipe masts. A thrust bearing is installed between them. The whole structure can freely rotate in a horizontal plane.

The electrical board can be placed on a rotating part, and the voltage can be transmitted to the consumer through two slip rings with brushes. If the board with a rectifier is installed separately, then the number of rings will be six, how many pins a stepper motor has.

The windmill is mounted at a height of 5-8 m.

If the device will efficiently generate energy, it can be improved by making it vertically axial, for example, from a barrel. The design is less subject to lateral overloads than the horizontal one. The figure below shows a rotor with blades made from barrel fragments, mounted on an axis inside the frame and not subject to overturning force.

Wind turbine with a vertical axis and a barrel rotor

The profiled surface of the barrel creates additional rigidity, due to which thinner sheet metal can be used.

Wind generator with a capacity of more than 1 kilowatt

The device should bring tangible benefits and provide a voltage of 220 V so that you can turn on some electrical appliances. To do this, it must independently start and generate electricity in a wide range.

To make a wind generator with your own hands, you must first determine the design. It depends on how strong the wind is. If it is weak, then the sail version of the rotor may be the only option. More than 2-3 kilowatts of energy cannot be obtained here. In addition, it will need a gearbox and a powerful battery with a charger.

The price of all equipment is high, so you should find out if it will be beneficial for the house.

In areas with strong winds, homemade wind generator you can get 1.5-5 kilowatts of power. Then it can be connected to home network for 220V. It is difficult to make a device with more power on your own.

Electric generator from a DC motor

As a generator, you can use a low-speed motor that generates electricity at 400-500 rpm: PIK8-6/2.5 36V 0.3Nm 1600min-1. Body length 143 mm, diameter 80 mm, shaft diameter 12 mm.

What does a DC motor look like?

It needs a multiplier with a gear ratio of 1:12. With one revolution of the windmill blades, the generator will make 12 revolutions. The figure below shows a diagram of the device.

Windmill device diagram

The gearbox creates an additional load, but still less than for a car alternator or starter, where a gear ratio of at least 1:25 is required.

It is advisable to make the blades from an aluminum sheet measuring 60x12x2. If you install 6 of them on the motor, the device will not be so fast and will not go haywire with large gusts of wind. It should be possible to balance. To do this, the blades are soldered to the bushings with the possibility of winding onto the rotor so that they can be moved further or closer to its center.

Generator power on permanent magnets from ferrite or steel does not exceed 0.5-0.7 kilowatts. It can be increased only on special neodymium magnets.

A generator with a non-magnetized stator is not suitable for operation. With a small wind, it stops, and after that it will not be able to start on its own.

For constant heating in the cold season, a lot of energy is required, and heating big house- This is problem. For giving in this regard, it can come in handy when you have to go there no more than 1 time per week. If everything is weighed correctly, the heating system in the country works for only a few hours. The rest of the time the owners are in nature. Using a windmill as a source of direct current for charging the battery, in 1-2 weeks you can accumulate electricity for space heating for such a period of time, and thus create sufficient comfort for yourself.

To make a generator from an AC motor or a car starter, they need to be reworked. The motor can be upgraded to a generator if the rotor is made on neodymium magnets, machined to their thickness. It is made with the number of poles, like the stator, alternating with each other. The rotor on neodymium magnets glued to its surface should not stick during rotation.

Types of rotors

Rotor designs vary. Common options are shown in the figure below, where the values ​​​​of the wind energy utilization factor (KIEV) are indicated.

Types and designs of wind turbine rotors

For rotation, windmills are made with a vertical or horizontal axis. The vertical version has the advantage of ease of maintenance when the main nodes are located at the bottom. The thrust bearing is self-aligning and has a long service life.

The two blades of the Savonius rotor create jerks, which is not very convenient. For this reason, it is made of two pairs of blades spaced 2 levels apart with one rotated relative to the other by 90 0 . Barrels, buckets, pots can be used as blanks.

The Darrieus rotor, whose blades are made of elastic tape, is easy to manufacture. To facilitate promotion, their number should be odd. The movement is jerky, because of which the mechanical part quickly breaks. In addition, the tape vibrates as it rotates, making a roar. For permanent use similar design not very suitable, although the blades are sometimes made of sound-absorbing materials.
In an orthogonal rotor, the wings are profiled. The optimal number of blades is three. The device is high-speed, but it must be untwisted at start-up.

The helicoid rotor has a high efficiency due to the complex curvature of the blades, which reduces losses. It is used less frequently than other windmills due to its high cost.

Horizontal bladed rotor design is the most efficient. But it requires a stable average wind, and it also needs hurricane protection. Blades can be made from propylene when their diameter is less than 1 m.

If you cut the blades from a thick-walled plastic pipe or barrel, you will not be able to achieve power above 200 watts. The segment profile is not suitable for compressible gaseous media. A complex profile is needed here.

The diameter of the rotor depends on how much power is required, as well as on the number of blades. A two-blade 10 W requires a rotor with a diameter of 1.16 m, and a 100 W - 6.34 m. For a four-blade and a six-blade, the diameter will be 4.5 m and 3.68 m, respectively.

If you put the rotor directly on the generator shaft, its bearing will not last long, since the load on all the blades is uneven. The support bearing for the windmill shaft must be self-aligning, with two or three tiers. Then the rotor shaft will not be afraid of bends and displacements during rotation.

An important role in the operation of the windmill is played by the current collector, which must be regularly maintained: lubricated, cleaned, adjusted. The possibility of its prevention should be provided, although this is difficult to do.

Security

Wind turbines with a power exceeding 100 W are noisy devices. In the courtyard of a private house, you can install an industrial wind turbine if it is certified. Its height should be higher than the nearest houses. Even a low-power windmill cannot be installed on the roof. Mechanical vibrations from its work can create resonance and lead to the destruction of the structure.

High wind turbine rotation speeds require quality workmanship. Otherwise, if the device is destroyed, there is a danger that its parts may fly off long distances and cause injury to humans or pets. This should be especially taken into account when making a windmill with your own hands from improvised materials.

Video. Wind generator with your own hands.

The use of wind turbines is not advisable in all regions, since it depends on climatic features. In addition, making them with your own hands does not make sense without some experience and knowledge. To get started, you can take on the creation of a simple design with a power of several watts and a voltage of up to 12 volts with which you can charge your phone or light an energy-saving lamp. The use of neodymium magnets in the generator can significantly increase its power.

Powerful wind turbines, which take over a significant part of the power supply at home, are best purchased industrial, to create a voltage of 220V, while carefully weighing the pros and cons. If you combine them with other types of alternative energy sources, electricity can be enough for everything. household needs including the home heating system.

Russia has a dual position regarding wind energy resources. On the one hand, thanks to the huge total area and to the abundance of the plains the wind as a whole is plentiful, and for the most part even. On the other hand, our winds are predominantly low-potential, slow, see fig. On the third, in sparsely populated areas, the winds are violent. Based on this, the task of starting a wind generator on the farm is quite relevant. But, in order to decide whether to buy a fairly expensive device, or make it yourself, you need to think carefully about which type (and there are a lot of them) for what purpose to choose.

Basic concepts

1. KIEV - wind energy utilization factor. If a mechanistic flat wind model is used for calculation (see below), it is equal to the efficiency of the rotor of a wind power plant (APU).
2. Efficiency - end-to-end efficiency of the APU, from the oncoming wind to the terminals of the electric generator, or to the amount of water pumped into the tank.
3. The minimum operating wind speed (MPS) is its speed at which the windmill begins to give current to the load.
4. The maximum allowable wind speed (MPS) is its speed at which energy generation stops: the automation either turns off the generator, or puts the rotor in a weather vane, or folds it and hides it, or the rotor stops itself, or the APU simply collapses.
5. Starting wind speed (SV) - at this speed, the rotor is able to turn without load, spin up and enter the operating mode, after which the generator can be turned on.
6. Negative starting speed (OSS) - this means that the APU (or wind turbine - wind turbine, or WEA, wind power unit) to start at any wind speed requires mandatory spin-up from an external energy source.
7. Starting (initial) moment - the ability of the rotor, forcibly slowed down in the air flow, to create a torque on the shaft.
8. Wind turbine (VD) - part of the APU from the rotor to the shaft of the generator or pump, or other energy consumer.
9. Rotary wind generator - APU, in which wind energy is converted into torque on the power take-off shaft by rotating the rotor in the air flow.
10. The operating speed range of the rotor is the difference between MDS and MRS when operating at rated load.
11. Slow-speed windmill - in it the linear speed of the parts of the rotor in the flow does not significantly exceed the wind speed or below it. The dynamic head of the flow is directly converted into blade thrust.
12. High-speed windmill - the linear speed of the blades is significantly (up to 20 or more times) higher than the wind speed, and the rotor forms its own air circulation. The cycle of converting flow energy into thrust is complex.

Notes:

1. Low-speed APUs, as a rule, have KIEV lower than high-speed ones, but have a starting torque sufficient to spin up the generator without disconnecting the load and zero TCO, i.e. absolutely self-starting and applicable in the lightest winds.
2. Slowness and speed are relative concepts. A household windmill at 300 rpm can be low-speed, and powerful APUs of the EuroWind type, from which the fields of wind farms, wind farms (see Fig.) are recruited and whose rotors make about 10 rpm, are high-speed, because. with such a diameter, the linear speed of the blades and their aerodynamics over most of the span are quite “airplane”, see below.

What generator is needed?

An electric generator for a domestic windmill must generate electricity in a wide range of rotational speeds and have the ability to self-start without automation and external sources nutrition. In the case of using an APU with OSS (windmills with spin-up), which, as a rule, have high KIEV and efficiency, it must also be reversible, i.e. be able to work as an engine. At powers up to 5 kW, this condition is satisfied electric cars with permanent magnets based on niobium (supermagnets); on steel or ferrite magnets, you can count on no more than 0.5-0.7 kW.

Note: asynchronous alternators or collector alternators with a non-magnetized stator are not suitable at all. With a decrease in wind strength, they will “go out” long before its speed drops to MRS, and then they will not start themselves.

An excellent "heart" of the APU with a power of 0.3 to 1-2 kW is obtained from an alternator with a built-in rectifier; most of them are now. Firstly, they keep the output voltage of 11.6-14.7 V in a fairly wide range of speeds without external electronic stabilizers. Secondly, the silicon gates open when the voltage on the winding reaches about 1.4 V, and before that the generator "does not see" the load. To do this, the generator must already be quite well untwisted.

In most cases, the oscillator can be connected directly, without gear or belt drive, to the high-speed HP shaft by selecting the speed by choosing the number of blades, see below. "Fast-walkers" have a small or zero starting torque, but the rotor will have enough time to spin up without disconnecting the load before the valves open and the generator gives current.

Choice in the wind

Before deciding which wind generator to make, let's decide on the local aerology. in grey-greenish(windless) areas of the wind map, at least some sense will be only from a sailing wind turbine(and we'll talk about them later). If you need a constant power supply, you will have to add a booster (rectifier with voltage stabilizer), charger, powerful battery, inverter 12/24/36/48 VDC to 220/380 VAC 50 Hz. Such an economy will cost no less than $20,000, and it is unlikely that it will be possible to remove a long-term power of more than 3-4 kW. In general, with an inexorable desire for alternative energy, it is better to look for another source of it.

In yellow-green, slightly windy places, if you need electricity up to 2-3 kW, you can take on a low-speed vertical wind generator yourself. They have been developed innumerable, and there are designs that, in terms of KIEV and efficiency, are almost not inferior to industrial-made “blades”.

If you are going to buy a wind turbine for your home, then it is better to focus on a windmill with a sailing rotor. There are many disputes, and in theory not everything is clear yet, but they work. In the Russian Federation, "sailboats" are produced in Taganrog with a capacity of 1-100 kW.

In red, windy, regions, the choice depends on the required power. In the range of 0.5-1.5 kW, self-made "verticals" are justified; 1.5-5 kW - purchased "sailboats". "Vertical" can also be purchased, but it will cost more than the APU horizontal layout. And, finally, if you need a windmill with a power of 5 kW or more, then you need to choose between horizontal purchased “blades” or “sailboats”.

Note: many manufacturers, especially the second tier, offer kits of parts from which you can assemble a wind generator with a power of up to 10 kW on your own. Such a set will cost 20-50% cheaper than a ready-made one with installation. But before buying, you need to carefully study the aerology of the intended installation site, and then select the appropriate type and model according to the specifications.

About security

Parts of a domestic wind turbine in operation can have a linear speed exceeding 120 and even 150 m/s, and a piece of any solid material weighing 20 g, flying at a speed of 100 m / s, with a “successful” hit, it kills a healthy man on the spot. A steel or hard plastic plate 2 mm thick, moving at a speed of 20 m/s, cuts it in half.

In addition, most windmills over 100 watts are quite noisy. Many generate ultra-low (less than 16 Hz) frequency air pressure fluctuations - infrasounds. Infrasounds are inaudible, but detrimental to health, and spread very far.

Note: in the late 80s, there was a scandal in the United States - the largest wind farm in the country at that time had to be closed. The Indians from the reservation, 200 km from the field of her APU, proved in court that the health disorders that sharply increased in them after the commissioning of the wind farm were due to its infrasounds.

For the above reasons, the installation of the APU is allowed at a distance of at least 5 of their heights from the nearest residential buildings. In the yards of private households, it is possible to install windmills of industrial production, appropriately certified. It is generally impossible to install APUs on roofs - during their operation, even for low-power ones, there are alternating mechanical loads that can cause resonance building structure and its destruction.

Note: the height of the APU is the highest point of the swept disk (for bladed rotors) or geometric figure (for vertical APUs with a rotor on the pole). If the APU mast or the rotor axis protrude even higher, the height is calculated according to their top - the top.

Wind, aerodynamics, KIEV

A home-made wind generator obeys the same laws of nature as a factory-made one calculated on a computer. And the do-it-yourselfer needs to understand the basics of his work very well - most often he does not have at his disposal expensive ultra-modern materials and technological equipment. The aerodynamics of the APU is oh so difficult ...

Wind and KIEV

To calculate serial factory APUs, the so-called. flat mechanistic wind model. It is based on the following assumptions:

• Wind speed and direction are constant within the effective rotor surface.
• Air is a continuous medium.
• The effective surface of the rotor is equal to the swept area.
• The energy of the air flow is purely kinetic.

Under such conditions, the maximum energy of a unit volume of air is calculated according to the school formula, assuming the air density under normal conditions is 1.29 kg * cu. m. At a wind speed of 10 m / s, one cube of air carries 65 J, and from one square of the effective surface of the rotor it is possible, at 100% efficiency of the entire APU, to remove 650 W. This is a very simplistic approach - everyone knows that the wind is not perfectly even. But this has to be done in order to ensure the repeatability of products - a common thing in technology.

The flat model should not be ignored, it gives a clear minimum of available wind energy. But air, firstly, is compressible, and secondly, it is very fluid (dynamic viscosity is only 17.2 μPa * s). This means that the flow can flow around the swept area, reducing the effective surface and KIEV, which is most often observed. But in principle, the reverse situation is also possible: the wind flocks to the rotor and the area of ​​the effective surface then turns out to be greater than the swept one, and KIEV is greater than 1 relative to that for a flat wind.

Let's give two examples. The first is a pleasure yacht, rather heavy, the yacht can go not only against the wind, but also faster than it. The wind is meant external; the apparent wind must still be faster, otherwise how will it pull the ship?

The second is a classic of aviation history. On tests of the MIG-19, it turned out that the interceptor, which was a ton heavier than a front-line fighter, accelerates faster in speed. With the same engines in the same airframe.

Theorists did not know what to think, and seriously doubted the law of conservation of energy. In the end, it turned out that the point was the cone of the radar fairing protruding from the air intake. From its toe to the shell, an air seal appeared, as if raking it from the sides to the engine compressors. Since then, shock waves have become firmly established in theory as useful, and the fantastic flight performance of modern aircraft is due in no small measure to their skillful use.

Aerodynamics

The development of aerodynamics is usually divided into two eras - before N. G. Zhukovsky and after. His report "On attached vortices" dated November 15, 1905 was the beginning new era in aviation.

Before Zhukovsky, they flew on flat sails: it was believed that the particles of the oncoming flow give all their momentum to the leading edge of the wing. This made it possible to immediately get rid of the vector quantity - the angular momentum - which generated furious and most often non-analytical mathematics, go to much more convenient scalar purely energy relations, and eventually get the calculated pressure field on the carrier plane, more or less similar to the present one.

Such a mechanistic approach made it possible to create devices that could, at the very least, take to the air and fly from one place to another, without necessarily crashing to the ground somewhere along the way. But the desire to increase speed, carrying capacity and other flight qualities more and more revealed the imperfection of the original aerodynamic theory.

Zhukovsky's idea was this: along the top and bottom surfaces Wing air travels a different path. From the condition of medium continuity (vacuum bubbles do not form in the air by themselves), it follows that the velocities of the upper and lower flows descending from the trailing edge must differ. Due to the albeit small, but finite viscosity of the air, a vortex should form there due to the difference in speeds.

The vortex rotates, and the law of conservation of momentum, as immutable as the law of conservation of energy, is also valid for vector quantities, i.e. must take into account the direction of movement. Therefore, immediately, on the trailing edge, an oppositely rotating vortex with the same torque should form. For what? Due to the energy generated by the engine.

For the practice of aviation, this meant a revolution: by choosing the appropriate wing profile, it was possible to launch an attached vortex around the wing in the form of a circulation Г, increasing its lift. That is, by spending a part, and for high speeds and wing loads - a large part, of the engine power, you can create an air flow around the device, which allows you to achieve better flight qualities.

This made aviation an aviation, and not a part of aeronautics: now the aircraft could create the environment necessary for its flight and no longer be a toy of air currents. All you need is a more powerful engine, and more and more powerful ...

Again KIEV

But the windmill does not have a motor. He, on the contrary, must take energy from the wind and give it to consumers. And here it comes out - he pulled out his legs, his tail got stuck. They let too little wind energy into the rotor's own circulation - it will be weak, the blade thrust will be small, and KIEV and power will be low. Let's give a lot for circulation - the rotor will spin like crazy at idle in a light wind, but consumers again get little: they gave a little load, the rotor slowed down, the wind blew off the circulation, and the rotor stopped.

The law of conservation of energy gives the "golden mean" just in the middle: we give 50% of the energy to the load, and for the remaining 50% we twist the flow to the optimum. Practice confirms the assumptions: if the efficiency of a good pulling propeller is 75-80%, then the KIEV of a bladed rotor that is also carefully calculated and blown in a wind tunnel reaches 38-40%, i.e. up to half of what can be achieved with an excess of energy.

Modernity

Today, aerodynamics, armed with modern mathematics and computers, is increasingly moving away from inevitably simplifying models to accurate description behavior of a real body in a real flow. And here, in addition to the general line - power, power, and once again power! – side ways are discovered, but promising just with a limited amount of energy entering the system.

The famous alternative aviator Paul McCready created an airplane back in the 80s, with two motors from a 16 hp chainsaw. showing 360 km / h. Moreover, its chassis was a tricycle non-retractable, and the wheels were without fairings. None of McCready's vehicles went on line and went on combat duty, but two - one with piston engines and propellers, and the other jet - flew around for the first time in history. the globe without landing at one gas station.

The sails that gave rise to the original wing were also significantly affected by the development of the theory. "Live" aerodynamics allowed the yachts with a wind of 8 knots. stand on hydrofoils (see fig.); to disperse such a hulk to the desired speed with a propeller, an engine of at least 100 hp is required. Racing catamarans with the same wind go at a speed of about 30 knots. (55 km/h).

There are also finds that are completely non-trivial. Fans of the rarest and most extreme sport - base jumping - wearing an apecial wing suit, wingsuit, fly without a motor, maneuvering at a speed of more than 200 km / h (fig. on the right), and then land smoothly in a pre-selected place. In which fairy tale do people fly by themselves?

Many mysteries of nature have also been solved; in particular, the flight of a beetle. According to classical aerodynamics, it is not capable of flying. Just like the ancestor of the "stealth" F-117 with its diamond-shaped wing, it is also not able to take to the air. And the MIG-29 and Su-27, which can fly tail first for some time, do not fit into any ideas at all.

And why, then, when dealing with wind turbines, not a fun and not a tool for the destruction of their own kind, but a source of a vital resource, it is imperative to dance from the theory of weak flows with its model of a flat wind? Is there really no way to go further?

What to expect from a classic?

However, the classics should not be abandoned in any case. It provides a foundation without leaning on which one cannot rise higher. Just as set theory does not cancel the multiplication table, and quantum chromodynamics does not make apples fly up from trees.

So, what can you expect from the classical approach? Let's look at the picture. Left - types of rotors; they are depicted conditionally. 1 - vertical carousel, 2 - vertical orthogonal (wind turbine); 2-5 - bladed rotors with different number of blades with optimized profiles.

To the right of the horizontal axis is the relative speed of the rotor, i.e., the ratio of the linear speed of the blade to the wind speed. Vertically up - KIEV. And down - again, the relative torque. A single (100%) torque is considered to be one that creates a rotor forcibly decelerated in the flow with 100% KIEV, i.e. when all the energy of the flow is converted into rotational force.

This approach allows us to draw far-reaching conclusions. For example, the number of blades must be chosen not only and not so much according to the desired rotation speed: 3- and 4-blades immediately lose a lot in terms of KIEV and torque compared to 2- and 6-blades that work well in approximately the same speed range. And outwardly similar carousel and orthogonal have fundamentally different properties.

In general, preference should be given to bladed rotors, except in cases where extreme cheapness, simplicity, maintenance-free self-starting without automation are required, and it is impossible to climb the mast.

Note: we’ll talk about sailing rotors in particular - they don’t seem to fit into the classics.

Vertical lines

APUs with a vertical axis of rotation have an undeniable advantage for everyday life: their components that require maintenance are concentrated at the bottom and there is no need to lift them up. There remains, and even then not always, a self-aligning thrust bearing, but it is strong and durable. Therefore, when designing a simple wind generator, the selection of options must begin with verticals. Their main types are shown in fig.

sun

In the first position - the simplest, most often called the Savonius rotor. In fact, it was invented in 1924 in the USSR by Ya. A. and A. A. Voronin, and the Finnish industrialist Sigurd Savonius shamelessly appropriated the invention, ignoring the Soviet copyright certificate, and began mass production. But the introduction of the invention in the fate means a lot, so we, in order not to stir up the past and not to disturb the ashes of the dead, we will call this windmill the Voronin-Savonius rotor, or for short, the Sun.

VS for a do-it-yourselfer is good for everyone, except for the "locomotive" KIEV in 10-18%. However, in the USSR a lot of work was done on it, and there are developments. Below we will consider an improved design, not much more complicated, but according to KIEV, it gives odds to the blades.

Note: a two-blade BC does not spin, but jerks; The 4-blade is only slightly smoother, but loses a lot in KIEV. To improve 4-"trough" most often spread over two floors - a pair of blades below, and another pair, rotated 90 degrees horizontally, above them. KIEV is preserved, and the lateral loads on the mechanics weaken, but the bending ones increase somewhat, and with a wind of more than 25 m/s, such an APU has a shaft, i.e. without a bearing stretched by the guys above the rotor, “breaks the tower”.

Daria

The next one is the Daria rotor; KIEV - up to 20%. It is even simpler: the blades are made of a simple elastic band without any profile. The theory of the Darrieus rotor is not well developed yet. It is only clear that it begins to unwind due to the difference in the aerodynamic resistance of the hump and the belt pocket, and then it becomes like a high-speed one, forming its own circulation.

The rotational moment is small, and in the starting positions of the rotor parallel and perpendicular to the wind, it is absent at all, therefore self-promotion is possible only with an odd number of blades (wings?). In any case, the load from the generator must be disconnected for the duration of the promotion.

The Darrieus rotor has two more bad qualities. First, during rotation, the thrust vector of the blade describes a complete revolution relative to its aerodynamic focus, and not smoothly, but jerkily. Therefore, the Darrieus rotor quickly breaks its mechanics even with a flat wind.

Secondly, Daria not only makes noise, but yells and squeals, to the point that the tape is torn. This is due to its vibration. And the more blades, the stronger the roar. So, if Darya is made, then it is two-bladed, made of expensive high-strength sound-absorbing materials (carbon, mylar), and a small aircraft is used for spinning in the middle of the mast-pole.

orthogonal

At pos. 3 - orthogonal vertical rotor with profiled blades. Orthogonal because the wings stick out vertically. The transition from the BC to the orthogonal is illustrated in Fig. left.

The angle of installation of the blades relative to the tangent to the circle, touching the aerodynamic foci of the wings, can be either positive (in the figure) or negative, according to the strength of the wind. Sometimes the blades are made swivel and windcocks are placed on them, automatically holding the alpha, but such structures often break.

The central body (blue in the figure) makes it possible to increase the KIEV to almost 50%. more blades, a simple cylinder is sufficient. But the theory for the orthogonal optimal amount blades gives unambiguously: there should be exactly 3 of them.

Orthogonal refers to high-speed windmills with OSS, i.e. necessarily requires promotion during commissioning and after calm. According to the orthogonal scheme, serial maintenance-free APUs with a power of up to 20 kW are produced.

Helicoid

Helicoid rotor, or Gorlov rotor (pos. 4) - a kind of orthogonal that provides uniform rotation; an orthogonal with straight wings "tears" only slightly weaker than a two-bladed aircraft. The bending of the blades along the helicoid avoids the loss of KIEV due to their curvature. Although the curved blade rejects part of the flow without using it, it also rakes a part into the zone of the highest linear speed, compensating for losses. Helicoids are used less often than other windmills, because. due to the complexity of manufacturing, they turn out to be more expensive than counterparts of equal quality.

Barrel-barrel

For 5 pos. – BC type rotor surrounded by a guide vane; its scheme is shown in fig. on right. Rarely found in industrial design, tk. expensive land acquisition does not compensate for the increase in capacity, and the material consumption and complexity of production are high. But a do-it-yourselfer who is afraid of work is no longer a master, but a consumer, and if no more than 0.5-1.5 kW is needed, then for him a “barrel-barrel” is a tidbit:

• This type of rotor is absolutely safe, silent, does not create vibrations and can be installed anywhere, even on a playground.
• Bend the "trough" of galvanized and weld the frame of the pipes - the work is nonsense.
• Rotation is absolutely uniform, mechanical parts can be taken from the cheapest or from the trash.
• Not afraid of hurricanes - too strong wind cannot push into the "barrel"; a streamlined vortex cocoon appears around it (we will still encounter this effect).
• And most importantly, since the surface of the "grab" is several times larger than that of the rotor inside, KIEV can also be superunit, and the torque at 3 m / s at a "barrel" of three meters in diameter is such that a 1 kW generator with a maximum load, as It is said that it is better not to twitch.

Video: Lenz wind generator

In the 60s in the USSR, E. S. Biryukov patented a carousel APU with KIEV 46%. A little later, V. Blinov achieved 58% from the design on the same principle of KIEV, but there is no data on its tests. And full-scale tests of Biryukov’s Armed Forces were carried out by the staff of the Inventor and Rationalizer magazine. A two-story rotor with a diameter of 0.75 m and a height of 2 m with a fresh wind spun at full power asynchronous generator 1.2 kW and withstood 30 m / s without breakage. Drawings of the APU Biryukov are shown in fig.

1. roof galvanized rotor;
2. self-aligning double row ball bearing;
3. shrouds - 5 mm steel cable;
4. axle shaft - steel pipe with a wall thickness of 1.5-2.5 mm;
5. aerodynamic speed control levers;
6. speed control blades - 3-4 mm plywood or sheet plastic;
7. speed control rods;
8. speed controller load, its weight determines the speed;
9. drive pulley - a bicycle wheel without a tire with a chamber;
10. thrust bearing - thrust bearing;
11. driven pulley - regular generator pulley;
12. generator.

Biryukov received several copyright certificates for his APU. First, pay attention to the section of the rotor. When accelerating, it works like a sun, creating a large starting torque. As it spins, a vortex cushion is created in the outer pockets of the blades. From the wind's point of view, the blades become profiled and the rotor turns into a high-speed orthogonal, with the virtual profile changing according to the strength of the wind.

Secondly, the profiled channel between the blades in the operating speed range works as a central body. If the wind increases, then a vortex cushion is also created in it, which goes beyond the rotor. There is the same vortex cocoon as around the APU with a guide vane. The energy for its creation is taken from the wind, and it is no longer enough to break the windmill.

Thirdly, the speed controller is designed primarily for the turbine. He keeps her speed optimal from the point of view of KIEV. And the optimum frequency of rotation of the generator is provided by the choice of the gear ratio of the mechanics.

Note: after publications in the IR for 1965, Biryukov's Armed Forces disappeared into oblivion. The author did not wait for a response from authorities. The fate of many Soviet inventions. They say that some Japanese became a billionaire by regularly reading Soviet popular technical magazines and patenting everything worthy of attention.

Lopatniki

As u said, according to the classics, a horizontal wind turbine with a bladed rotor is the best. But, firstly, he needs a stable, at least medium-strength wind. Secondly, the design for the do-it-yourselfer is fraught with many pitfalls, which is why the fruit of long hard work often illuminates the toilet, hallway or porch at best, or even turns out to be only able to unwind itself.

According to the diagrams in Fig. consider in more detail; positions:

• Fig. BUT:

1. rotor blades;
2. generator;
3. generator frame;
4. protective weather vane (hurricane shovel);
5. current collector;
6. chassis;
7. rotary node;
8. working weather vane;
9. mast;
10. clamp for shrouds.

• Fig. B, top view:

1. protective weather vane;
2. working weather vane;
3. protective wind vane spring tension regulator.

• Fig. G, current collector:

1. collector with copper continuous ring tires;
2. spring-loaded copper-graphite brushes.

Note: hurricane protection for a horizontal blade with a diameter of more than 1 m is absolutely necessary, because. he is not capable of creating a vortex cocoon around himself. With smaller sizes it is possible to achieve a rotor endurance of up to 30 m/s with propylene blades.

So, where are we waiting for "stumbling"?

blades

To expect to achieve power on the generator shaft of more than 150-200 W on blades of any span, cut out of a thick-walled plastic pipe, as is often advised, is the hope of a hopeless amateur. A blade from a pipe (unless it is so thick that it is used simply as a blank) will have a segmental profile, i.e. its top, or both surfaces will be arcs of a circle.

Segment profiles are suitable for incompressible media, such as hydrofoils or propeller blades. For gases, a blade of variable profile and pitch is needed, for an example, see Fig .; span - 2 m. This will be a complex and time-consuming product that requires painstaking calculations in full theory, blowing in the pipe and field tests.

Generator

When the rotor is mounted directly on its shaft, the standard bearing will soon break - there is no equal load on all the blades in windmills. We need an intermediate shaft with a special support bearing and a mechanical transmission from it to the generator. For large windmills, a self-aligning double-row bearing is taken; in best models- three-tier, Fig. D in fig. higher. This allows the rotor shaft to not only bend slightly, but also move slightly from side to side or up and down.

Note: It took about 30 years to develop a thrust bearing for the EuroWind type APU.

emergency weather vane

The principle of its operation is shown in Fig. B. The wind, intensifying, presses on the shovel, the spring stretches, the rotor warps, its speed drops and in the end it becomes parallel to the flow. Everything seems to be fine, but - it was smooth on paper ...

On a windy day, try to hold the lid of boiled water or a large pot by the handle parallel to the wind. Just be careful - the fidgety piece of iron can hit the physiognomy so that it breaks the nose, cuts the lip, and even knocks out the eye.

Flat wind occurs only in theoretical calculations and, with sufficient accuracy for practice, in wind tunnels. In reality, a hurricane windmills with a hurricane shovel distorts more than completely defenseless ones. Still, it's better to change warped blades than to do everything all over again. In industrial settings, it's a different matter. There, the pitch of the blades, for each individually, monitors and regulates automation under the control of the on-board computer. And they are made from heavy-duty composites, not from water pipes.

current collector

This is a regularly serviced node. Any power engineer knows that the collector with brushes needs to be cleaned, lubricated, adjusted. And the mast is from water pipe. You won’t climb in, once a month or two you will have to throw the whole windmill to the ground and then raise it again. How long will he last from such "prevention"?

Video: bladed wind generator + solar panel for power supply to the dacha

Mini and micro

But as the size of the blade decreases, the difficulty decreases with the square of the wheel diameter. It is already possible to manufacture a horizontal bladed APU on its own for a power of up to 100 W. 6-blade will be optimal. With more blades, the diameter of the rotor, designed for the same power, will be smaller, but it will be difficult to firmly fix them on the hub. Rotors with less than 6 blades can be ignored: a 2-blade 100 W needs a rotor with a diameter of 6.34 m, and a 4-blade of the same power - 4.5 m. For a 6-blade power-diameter relationship is expressed as follows :

• 10 W - 1.16 m.
• 20 W - 1.64 m.
• 30 W - 2 m.
• 40 W - 2.32 m.
• 50 W - 2.6 m.
• 60 W - 2.84 m.
• 70 W - 3.08 m.
• 80 W - 3.28 m.
• 90 W - 3.48 m.
• 100 W - 3.68 m.
• 300 W - 6.34 m.

It will be optimal to count on a power of 10-20 watts. Firstly, a plastic blade with a span of more than 0.8 m without additional measures protection will not withstand winds of more than 20 m / s. Secondly, with a blade span of up to the same 0.8 m, the linear speed of its ends will not exceed the wind speed by more than three times, and the requirements for profiling with twist are reduced by orders of magnitude; here the “trough” with a segmented profile from a pipe will already work quite satisfactorily, pos. B in fig. And 10-20 W will provide power to the tablet, recharge the smartphone or light up the housekeeper light bulb.

Next, choose a generator. A Chinese motor is perfect - a wheel hub for electric bicycles, pos. 1 in fig. Its power as a motor is 200-300 watts, but in generator mode it will give up to about 100 watts. But will it fit us in terms of turnover?

The speed factor z for 6 blades is 3. The formula for calculating the speed of rotation under load is N = v / l * z * 60, where N is the speed of rotation, 1 / min, v is the wind speed, and l is the circumference of the rotor. With a blade span of 0.8 m and a wind of 5 m/s, we get 72 rpm; at 20 m/s - 288 rpm. A bicycle wheel also rotates at about the same speed, so we will remove our 10-20 watts from a generator that can give 100. You can put the rotor directly on its shaft.

But here the following problem arises: having spent a lot of work and money, at least for a motor, we got ... a toy! What is 10-20, well, 50 watts? And a bladed windmill that can power at least a TV set cannot be made at home. Is it possible to buy a ready-made mini-wind generator, and will it not cost less? Still as possible, and even as cheaper, see pos. 4 and 5. In addition, it will also be mobile. Put it on a stump - and use it.

The second option is if somewhere a stepper motor is lying around from an old 5- or 8-inch drive, or from a paper drive or carriage of an unusable inkjet or dot matrix printer. It can work as a generator, and attach a carousel rotor to it from cans(pos. 6) is easier than assembling a structure like that shown in pos. 3.

In general, according to the “blades”, the conclusion is unambiguous: home-made - rather in order to make one's heart's content, but not for real long-term energy efficiency.

Video: the simplest wind generator for dacha lighting

sailboats

The sailing wind generator has been known for a long time, but the soft panels of its blades (see Fig.) began to be made with the advent of high-strength wear-resistant synthetic fabrics and films. Multi-blade windmills with rigid sails are widely distributed around the world as a drive for low-power automatic pumps, but their technical data is even lower than that of carousels.

However, a soft sail like the wing of a windmill, it seems, was not so simple. It's not a matter of wind resistance (manufacturers do not limit the maximum allowable wind speed): yachtsmen-sailboats already know that it is almost impossible for the wind to break the panel of a Bermuda sail. Rather, the sheet will rip out, or the mast will break, or the whole vessel will make an “overkill turn”. It's about energy.

Unfortunately, exact test data cannot be found. Based on user feedback, it was possible to compile "synthetic" dependencies for the Taganrog-made wind turbine VEU-4.380/220.50 with a wind wheel diameter of 5 m, a wind head weight of 160 kg and a rotation speed of up to 40 1/min; they are shown in Fig.

Of course, there can be no guarantees for 100% reliability, but even so it is clear that there is no smell of a flat-mechanistic model here. In no way can a 5-meter wheel in a flat wind of 3 m / s give about 1 kW, at 7 m / s reach a plateau in power and then keep it until a severe storm. Manufacturers, by the way, declare that the nominal 4 kW can be obtained at 3 m / s, but when installed by them according to the results of local aerology studies.

Quantitative theory is also not found; The developers' explanations are unintelligible. However, since people buy Taganrog wind turbines and they work, it remains to be assumed that the declared conical circulation and propulsion effect are not fiction. In any case, they are possible.

Then, it turns out, BEFORE the rotor, according to the law of conservation of momentum, a conical vortex should also arise, but expanding and slow. And such a funnel will drive the wind to the rotor, its effective surface it will turn out to be more swept, and KIEV - over unity.

Field measurements of the pressure field in front of the rotor, at least with a household aneroid, could shed light on this question. If it turns out to be higher than from the sides to the side, then, indeed, sailing APUs work like a beetle flies.

Homemade generator

From the foregoing, it is clear that it is better for do-it-yourselfers to take on either verticals or sailboats. But both are very slow, and transferring to a high-speed generator is extra work, extra costs and loss. Is it possible to make an efficient low-speed electric generator yourself?

Yes, you can, on niobium alloy magnets, the so-called. supermagnets. The manufacturing process of the main parts is shown in Fig. Coils - each of 55 turns of 1 mm copper wire in heat-resistant high-strength enamel insulation, PEMM, PETV, etc. The height of the windings is 9 mm.

Notice the keyways in the rotor halves. They must be arranged so that the magnets (they are glued to the magnetic circuit with epoxy or acrylic) after assembly converge with opposite poles. "Pancakes" (magnetic circuits) must be made of a magnetically soft ferromagnet; normal structural steel will do. The thickness of the “pancakes” is at least 6 mm.

It's actually better to buy magnets with an axle hole and tighten them with screws; supermagnets are attracted to terrible force. For the same reason, a cylindrical spacer 12 mm high is put on the shaft between the "pancakes".

The windings that make up the stator sections are connected according to the schemes also shown in fig. The soldered ends should not be stretched, but should form loops, otherwise the epoxy, which will be filled with the stator, while solidifying, may break the wires.

The stator is cast in the mold to a thickness of 10 mm. It is not necessary to center and balance, the stator does not rotate. The gap between the rotor and the stator is 1 mm on each side. The stator in the generator housing must be securely fixed not only from displacement along the axis, but also from turning; a strong magnetic field with a current in the load will pull it along.

Video: do-it-yourself windmill generator

Conclusion

And what do we have in the end? Interest in "blades" is due rather to their spectacular appearance than valid operational qualities homemade and at low power. A self-made carousel APU will provide “standby” power for charging a car battery or powering a small house.

But with sailing APUs, masters with a creative vein should experiment, especially in a mini version, with a wheel of 1-2 m in diameter. If the assumptions of the developers are correct, then it will be possible to remove from this, using the Chinese generator engine described above, all of its 200-300 watts.

Andrey said:

Thank you for your free consultation ... And the prices “from firms” are not really expensive, and I think that craftsmen from the outback will be able to make generators like yours. And Li-po batteries can be ordered from China, inverters in Chelyabinsk are very good (with a smooth sine). And sails, blades or rotors are another reason for the flight of thoughts of our handy Russian men.

Ivan said:

question:
For windmills with a vertical axis (position 1) and the Lenz option, it is possible to add an additional detail - an impeller that is exposed to the wind and covers the useless side from it (going towards the wind). That is, the wind will not slow down the blade, but this “screen”. Setting downwind with a “tail” located behind the windmill itself below and above the blades (ridges). I read the article and an idea was born.

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Often, owners of private houses have an idea about the implementation backup power systems. The most simple and affordable way- this, of course, is either a generator, but many people turn their eyes to more difficult ways transformation of the so-called free energy (radiation, energy flowing water or wind) in .

Each of these methods has its own advantages and disadvantages. If everything is clear with the use of water flow (mini-hydroelectric power station) - this is available only in the immediate vicinity of a fairly fast-flowing river, then sunlight or wind can be used almost everywhere. Both of these methods will have a common disadvantage - if a water turbine can work around the clock, then either a wind generator is only effective for a while, which makes it necessary to include batteries in the structure of the home electrical network.

Since the conditions in Russia (short daylight hours most of the year, frequent precipitation) make the use of solar panels inefficient at their current cost and efficiency, design becomes the most profitable wind generator . Consider its principle of operation and possible options designs.