Ecology of consumption. Science and technology: Do-it-yourself home hydro generators are comparable in power to solar panels and wind turbines, but produce a much larger volume of electricity.

Since electricity tariffs in Lately began to grow, renewable sources of electricity are becoming increasingly important among the population, making it possible to obtain electricity almost free of charge. Among such sources known to mankind, it is worth highlighting solar panels, wind generators, as well as domestic hydroelectric power plants. But the latter are quite complex, because they have to work in very aggressive conditions. Although this does not mean that it is impossible to build a mini-hydroelectric power station with your own hands.

To do everything correctly and efficiently, the main thing is to choose the right materials. They must ensure maximum durability of the station. Do-it-yourself home hydro generators, whose power is comparable to that of solar panels and wind turbines, can produce a much larger amount of energy. But although a lot depends on the materials, everything does not end there.

VARIETIES OF MINI HYDRO POWER PLANTS

Exists a large number of various variations of mini-hydroelectric power stations, each of which has its own advantages, features and disadvantages. The following types of these devices are distinguished:

• garland;
• propeller;
• Daria rotor;
• water wheel with blades.

A garland hydroelectric power station consists of a cable on which rotors are attached. Such a cable is pulled across the river and immersed in water. The flow of water in the river begins to rotate the rotors, which in turn rotate the cable, at one end of which there is a bearing, and at the other - a generator.

The next type is a water wheel with blades. It is installed perpendicular to the water surface, submerging less than half. As the flow of water acts on the wheel, it rotates and causes the generator for the mini-hydroelectric power station on which this wheel is attached to rotate.

As for the propeller hydroelectric power station, it is a wind turbine located under water with vertical rotor. The width of the blades of such a windmill does not exceed 2 centimeters. This width is enough for water, because this is the nominal value that allows you to produce maximum amount electricity with minimal resistance. True, this width is optimal only for flow speeds up to 2 meters per second.

As for other conditions, the parameters of the rotor blades are calculated separately. And the Darrieus rotor is a vertically positioned rotor that operates on the principle of differential pressure. Everything happens similarly with an airplane wing, which is affected by lift.

ADVANTAGES AND DISADVANTAGES

If we consider a garland hydroelectric power station, then it has a number of obvious shortcomings. Firstly, the long cable used in the design poses a danger to others. Rotors hidden under water also pose a great danger. Well, in addition, it is worth noting low performance Efficiency and high material consumption.

As for the disadvantages of the Darrieus rotor, in order for the device to start generating electricity, it must first be spun up. True, in this case, power is taken directly above the water, so no matter how the water flow changes, the generator will generate electricity.

All of the above are factors that make hydraulic turbines for mini-hydroelectric power plants and water wheels more popular. If we consider the manual construction of such devices, they are not so complicated. And in addition, when minimum costs such mini-hydroelectric power plants are capable of producing maximum efficiency indicators. So the criteria for popularity are obvious.

WHERE TO START CONSTRUCTION

The construction of a mini-hydroelectric power station with your own hands should begin with measuring the speed indicators of river flows. This is done very simply: just mark a distance of 10 meters upstream, pick up a stopwatch, throw a chip into the water, and note the time it takes for it to cover the measured distance.

Ultimately, if you divide 10 meters by the number of seconds taken, you get the speed of the river in meters per second. It is worth considering that there is no point in building mini-hydroelectric power stations in places where the flow speed does not exceed 1 m/s.

If you need to figure out how mini-hydroelectric power stations are made in areas where the river speed is low, then you can try to increase the flow by organizing a height difference. This can be done by installing a drain pipe into the reservoir. In this case, the diameter of the pipe will directly affect the speed of water flow. The smaller the diameter, the faster the flow.

This approach makes it possible to organize a mini-hydroelectric power station even if there is a small stream passing near the house. That is, a collapsible dam is organized on it, below which a mini-hydroelectric power station is installed directly to power the house and household appliances. published

Recently, due to rising electricity tariffs, renewable sources of virtually free energy are becoming increasingly relevant.

Small hydroelectric power station or small hydroelectric power station (SHPP) - a hydroelectric power station that generates a relatively small amount of electricity and is based on hydropower plants with a capacity of 1 to 3000 kW. There is no concept of a small hydroelectric power station generally accepted for all countries; their installed capacity is taken as the main characteristic of such hydroelectric power stations.

Installations for small hydropower are classified by power into:

• equipment for mini hydroelectric power stations with a capacity of up to 100 kW;
• equipment for micro hydroelectric power plants with a power of up to 1000 kW.

From the well-known classical triad: solar panels, wind generators, hydroelectric generators (hydroelectric power plants), the latter the most complex. Firstly, they work in aggressive conditions, and secondly, they have the maximum operating time in an equal period of time.

It is easiest to make damless hydroelectric power stations, because The construction of a dam is quite complex and expensive and often requires coordination with local authorities or at least with neighbors. Damless mini hydroelectric power stations are called flow-through ones. There are four main options for such devices.

Types of mini hydroelectric power stations

Water wheel is a wheel with blades mounted perpendicular to the surface of the water. The wheel is less than half immersed in the flow. Water presses on the blades and rotates the wheel. There are also turbine wheels with special blades optimized for liquid flow. But that's enough complex designs more factory than homemade.

Garland mini-hydroelectric power station- is a cable with rotors rigidly attached to it. The cable is thrown from one bank of the river to the other. The rotors are strung like beads on a cable and are completely immersed in water. The flow of water rotates the rotors, the rotors rotate the cable. One end of the cable is connected to the bearing, the other to the generator shaft.

Rotor Daria is a vertical rotor that rotates due to the pressure difference on its blades. The pressure difference is created due to the flow of liquid around complex surfaces. The effect is similar to the lift of a hydrofoil or the lift of an airplane wing.

Propeller is an underwater “windmill” with a vertical rotor. Unlike an air propeller, an underwater propeller has blades of minimal width. For water, a blade width of only 2 cm is sufficient. With such a width there will be minimal resistance and maximum speed rotation. This width of the blades was chosen for a flow speed of 0.8-2 meters per second. At higher speeds, other sizes may be optimal.

Advantages and disadvantages of various mini-hydroelectric power plant systems

Flaws garland SHPP obvious: high material consumption, danger to others (long underwater cable, rotors hidden in the water, blocking the river), low efficiency. Garlyandnaya hydroelectric power station is a small dam. Rotor Daria Difficult to manufacture, it needs to be untwisted at the beginning of work. But it is attractive because the rotor axis is located vertically and power can be taken off over water, without additional gears. Such a rotor will rotate with any change in flow direction.

Thus, from the point of view of ease of manufacture and obtaining maximum efficiency with minimal cost, it is necessary to choose a design like water wheel or propeller.

Design of a small hydraulic power station

Design of a small hydroelectric power station is based on a hydraulic unit, which includes a power unit, a water intake device and control elements. Depending on what hydro resources are used by small hydropower plants, they are divided into several categories:

Channel or dam stations with small reservoirs;

Stationary mini hydroelectric power stations using the energy of the free flow of rivers;

SHPPs that use existing differences in water levels at various water management facilities;

Mobile mini hydroelectric power plants in containers, used as pressure diversion plastic pipes or flexible reinforced hoses.

Types of hydraulic units for small hydroelectric power plants

The basis for a small hydraulic station is a hydraulic unit, which, in turn, is based on a turbine of one type or another. There are hydraulic units with:

Axial turbines;

Radial-axial turbines;

Bucket turbines;

Rotary blade turbines.

SHPPs are classified depending on maximum use water pressure on:

High-pressure - more than 60 m;

Medium pressure - from 25 m;

Low pressure - from 3 to 25 m.

The types of turbines used in the equipment also differ depending on the water pressure used by the microhydroelectric power plant. Bucket and radial-axial turbines are designed for high-pressure hydroelectric power plants. Rotary-blade and radial-axial turbines are used at medium-pressure stations. At low-pressure small hydroelectric power stations (SHPPs), rotary-blade turbines are mainly installed in reinforced concrete chambers.

As for the operating principle of a mini hydroelectric power station turbine, it is almost identical in all designs: water under pressure flows onto the turbine blades, which begin to rotate. The rotational energy is transferred to a hydrogenerator, which is responsible for generating electricity. Turbines for objects are selected in accordance with certain technical characteristics, among which the main one is water pressure. In addition, turbines are selected depending on the type of chamber that comes with the kit - steel or reinforced concrete.

The power of mini-hydroelectric power plants depends on the pressure and flow of water, as well as on the efficiency of the turbines and generators used. Due to the fact that, according to natural laws, the water level is constantly changing, depending on the season, as well as for a number of other reasons, it is customary to take cyclic power as an expression of the power of a hydroelectric station. For example, there are annual, monthly, weekly or daily work cycles.

When choosing a mini hydroelectric power station, you should focus on this power equipment, which would be adapted to the specific needs of the facility and meet criteria such as:

Availability of reliable and easy-to-use control and monitoring equipment;

Equipment control in automatic mode with the ability to switch to manual control if necessary;

The generator and turbine of the hydraulic unit must have reliable protection from probable emergency situations;

Areas and volumes construction work for the installation of small hydroelectric power stations should be minimal.

Benefits of using mini hydroelectric power stations:

Hydroelectric power stations low power have a number of advantages that make this equipment increasingly popular. First of all, it is worth noting environmental safety mini hydro power plants are a criterion that is becoming increasingly important in light of protection issues environment. Small hydroelectric power plants do not have a harmful effect on either the properties or the quality of water. The water areas where a low-power hydroelectric power station is installed can be used both for fishing activities and as a source of water supply settlements. In addition, for the operation of small hydroelectric power stations there is no need for large reservoirs. They can function using the energy of the flow of small rivers and even streams.

Concerning economic efficiency, then here too micro and mini hydroelectric power plants have many advantages. Stations designed with modern technologies, are easy to operate and are fully automated. Thus, the equipment does not require human presence. Experts note that the quality of the current generated by small hydroelectric power plants meets GOST requirements for both voltage and frequency. At the same time, mini hydroelectric power stations can operate both autonomously and as part of the power grid.

Speaking about small hydroelectric power plants, it is worth noting their advantage, such as their full service life, which is at least 40 years. Well, and most importantly, small-scale energy facilities do not require the organization of large reservoirs with corresponding flooding of the territory and colossal material damage.

One of the most important economic factors is the eternal renewability of hydraulic resources. If we calculate the literal benefits from the use of small hydroelectric power plants, it turns out that the electricity generated by them is almost 4 times cheaper than the electricity that the consumer receives from thermal power plants. It is for this reason that today hydroelectric power plants are increasingly being used to supply power to electrically intensive industries.

Let's not forget that small hydroelectric power plants do not require the purchase of any fuel. In addition, they are distinguished by a relatively simple technology for generating electricity, as a result of which labor costs per unit of power at hydroelectric power plants are almost 10 times less than at thermal power plants.

If there is a river or even a small stream flowing near your home, then with the help of a homemade mini hydroelectric power station you can get free electricity. Perhaps this will not be a very large addition to the budget, but the realization that you have your own electricity costs much more. Well, if, for example, at a dacha, there is no central power supply, then even small amounts of electricity will be simply necessary. And so, to create a homemade hydroelectric power station, at least two conditions are necessary - the availability of a water resource and desire.

If both are present, then the first thing to do is measure the speed of the river flow. This is very simple to do - throw a twig into the river and measure the time during which it floats 10 meters. Dividing meters by seconds gives you the current speed in m/s. If the speed is less than 1 m/s, then a productive mini hydroelectric power station will not work. In this case, you can try to increase the flow speed by artificially narrowing the channel or making a small dam if you are dealing with a small stream.

As a guide, you can use the relationship between the flow speed in m/s and the power of electricity removed from the propeller shaft in kW (screw diameter 1 meter). The data is experimental; in reality, the resulting power depends on many factors, but it is suitable for evaluation. So:

• 0.5 m/s – 0.03 kW,
• 0.7 m/s – 0.07 kW,
• 1 m/s – 0.14 kW,
• 1.5 m/s – 0.31 kW,
• 2 m/s – 0.55 kW,
• 2.5 m/s – 0.86 kW,
• 3 m/s -1.24 kW,
• 4 m/s – 2.2 kW, etc.

The power of a homemade mini hydroelectric power station is proportional to the cube of the flow velocity. As already indicated, if the flow speed is insufficient, try to artificially increase it, if this is of course possible.

Types of mini-hydroelectric power plants

There are several main options for homemade mini hydroelectric power plants.


This is a wheel with blades mounted perpendicular to the surface of the water. The wheel is less than half immersed in the flow. Water presses on the blades and rotates the wheel. There are also turbine wheels with special blades optimized for liquid flow. But these are quite complex designs, more factory-made than home-made.

This is a vertical axis rotor used to generate electrical energy. A vertical rotor that rotates due to the pressure difference on its blades. The pressure difference is created due to the flow of liquid around complex surfaces. The effect is similar to the lift of a hydrofoil or the lift of an airplane wing. This design was patented by Georges Jean-Marie Darrieux, a French aeronautical engineer in 1931. Also often used in wind turbine designs.

Garland A hydroelectric power station consists of light turbines - hydraulic propellers, strung and rigidly fixed in the form of a garland on a cable thrown across the river. One end of the cable is fixed in the support bearing, the other rotates the generator rotor. In this case, the cable plays the role of a kind of shaft, the rotational motion of which is transmitted to the generator. The flow of water rotates the rotors, the rotors rotate the cable.

Also borrowed from the designs of wind power plants, a kind of “underwater wind turbine” with a vertical rotor. Unlike an air propeller, an underwater propeller has blades of minimal width. For water, a blade width of only 2 cm is sufficient. With such a width, there will be minimal resistance and maximum rotation speed. This width of the blades was chosen for a flow speed of 0.8-2 meters per second. At higher speeds, other sizes may be optimal. The propeller moves not due to water pressure, but due to the generation of lifting force. Just like an airplane wing. The propeller blades move across the flow rather than being dragged in the direction of the flow.

Advantages and disadvantages of various homemade mini hydroelectric power station systems

The disadvantages of a garland hydroelectric power station are obvious: high material consumption, danger to others (long underwater cable, rotors hidden in the water, blocking the river), low efficiency. The Garland hydroelectric power station is a kind of small dam. It is advisable to use in uninhabited, remote areas with appropriate warning signs. Permission from authorities and environmentalists may be required. The second option is a small stream in your garden.

The Daria rotor is difficult to calculate and manufacture. At the beginning of work you need to unwind it. But it is attractive because the rotor axis is located vertically and power can be taken off over water, without additional gears. Such a rotor will rotate with any change in flow direction - this is a plus.

Most common during construction homemade hydroelectric power plants received schematics of the propeller and water wheel. Since these options are relatively simple to manufacture, they require minimum payments and are implemented at minimal cost, have high efficiency, and are easy to set up and operate.

An example of a simple mini-hydroelectric power station

The simplest hydroelectric power station can be quickly built from an ordinary bicycle with a dynamic headlight. Several blades (2-3) must be prepared from galvanized iron or thin sheet aluminum. The blades should be the length from the wheel rim to the hub, and 2-4 cm wide. These blades are installed between the spokes using any available method or using pre-prepared fasteners.

If you are using two blades, place them opposite each other. If you want to add more blades, then divide the circumference of the wheel by the number of blades and install them at equal intervals. You can experiment with the depth of immersion of the wheel with blades in the water. It is usually one-third to one-half immersed.

The option of a traveling wind power plant was considered earlier.

Such a micro hydroelectric power station does not take up much space and will serve cyclists perfectly - the main thing is the presence of a stream or rivulet - which is usually the place where the camp is set up. A mini hydroelectric power station from a bicycle will be able to illuminate a tent and charge Cell Phones or other gadgets.

Due to the constant rise in price of carbohydrate energy resources, experts are paying increasing attention to the advantages provided by the use of electricity obtained more in an economical way. One of the most economical and environmentally friendly ways to generate electricity is a hydroelectric power station for the home, the costs of which are reduced to primary construction and maintenance equipment. But not every area has natural opportunities for the construction of such structures, which require a powerful water flow and a large difference in heights created by the dam; in this case, mini hydroelectric power stations come to the aid of power engineers.

Operating principle and mini hydroelectric power station

The operating principle of this equipment is quite simple, which adds to its reliability. The water flow, falling on the turbine blades, rotates a hydraulic drive connected to an electric generator, which ensures the generation of electricity under the control of a control system.
Modern mini hydroelectric power plants are equipped with a control system that makes it possible to operate in automatic mode with an immediate transition to manual control in the event of an emergency. emergency situation. Multi-level protection system allows you to avoid equipment overloads when changing external conditions. The design of the stations allows us to minimize construction work during the installation of the necessary equipment.

Types of mini hydroelectric power stations

A mini hydroelectric power plant is equipment with a capacity from 1 to 3000 kW, which includes a water intake device (turbine), a generating power unit and an equipment control system.
Depending on the used water resources mini hydroelectric power stations are divided into several categories:

• run-of-river stations using the energy of small rivers with organized reservoirs. Mainly used on flat terrain;
• stationary stations that use the energy of fast flows in the exploitation of mountain rivers;
• stations that use differences in water flow at industrial enterprises;
• mobile stations using reinforced hoses to organize flow.

According to the expected pressure of the water flow, the hydraulic unit and its turbine are designed to match the power of the electric generating unit to ensure the required rotation speed of the generator and facilitate the creation of the required current frequency.

For various conditions operation of mini hydroelectric power stations, appropriate turbine designs have been developed:

• with a high water flow pressure of more than 60 m, radial-axial and bucket turbines are used;
• with an average flow intensity of 25 - 60 m, turbines of rotary-blade and radial-axial designs have proven themselves well;
• on low-pressure flows it is more profitable to use rotary-blade and propeller structures placed in reinforced concrete chambers.

Video of a home made hydroelectric power station

Features of connecting mini hydroelectric power stations

The design of this equipment allows stations to be connected directly to the power supply network; in this case, a synchronous generator is used. For creating local network They use an asynchronous unit, which is equipped with a ballast load unit necessary to dissipate excess power in order to avoid failure of power supply systems and sudden changes in the main parameters of the network.

Advantages and disadvantages of mini hydroelectric power stations

The advantages of such systems include:

• environmental safety of the equipment and the absence of the need to flood large areas;
• low cost of generated electricity, which is several times cheaper than that generated at thermal power plants;
• simplicity and reliability of the equipment used and the possibility of its operation in autonomous mode;
• inexhaustibility of used natural resource

Disadvantages include:

• interruptions in the power supply to certain regions when equipment fails, in the case of using a mini hydroelectric power station as a local source. This is compensated by the presence of an emergency power supply that is connected automatically;
• weak production and repair base this energy supply sector in our country.

Next in line are designs, the prototype of which was the free-flow (model 1964) garland hydroelectric power station of V. Blinov.

The hydroelectric power plants that will be discussed are free-flow, with a rather original turbine made of so-called Savonius rotors, strung on a common (maybe flexible, composite) working shaft. They do not require dams or other large-scale hydraulic structures for their installation. They are able to work with full efficiency even in shallow water, which, combined with the simplicity, compactness and reliability of the design, make these hydroelectric power stations very promising for those farmers and gardeners whose plots of land are located near small watercourses (rivers, streams and ditches).

Unlike dams, free-flow hydropower plants are known to use only the kinetic energy of flowing water. To determine power there is a formula:

N=0.5*p*V3*F*n (1),

N - power on the working shaft (W),
- p - density of water (1000 kt/m3),
- V - river flow speed (m/s),
- F - cross-sectional area of ​​the active (submersible) part of the working body of the hydraulic machine (m2),
- n - energy conversion efficiency.

As can be seen from formula 1, at a river speed of 1 m/s per one square meter The cross section of the active part of the hydraulic machine ideally (when n=1) has a power equal to only 500 W. This value is clearly small for industrial use, but quite sufficient for a farmer’s or summer resident’s subsidiary plot. Moreover, it can be increased through the parallel operation of several “hydroenergy garlands”.

And one more subtlety. The speed of the river in its different sections is different. Therefore, before starting the construction of a mini-hydroelectric power station, it is necessary to determine the energy potential of your river using the simple method outlined. Let us only recall that the distance covered by the measuring float and divided by the time it passes will correspond to the average flow speed in this area. It should also be noted: this parameter will change depending on the time of year.

Therefore, design calculations should be made based on the average (over the planned period of operation of the mini-hydroelectric power station) river flow speed.

Fig.1. Savonius rotors for homemade garland mini-hydroelectric power plants:

a, b - blades; 1 - transverse, 2 - end.

Next, you need to determine the size of the active part of the hydraulic machine and its type. Since the entire mini-hydroelectric power station should be as simple and uncomplicated to manufacture as possible, the most suitable type The converter is a Savonius rotor of end-end design. When working with complete immersion in water, the value F can be taken equal to the product rotor diameter D by its length L, and n=0.5. The rotation frequency f is determined with an accuracy acceptable for practice using the formula:

f=48V/3.14D (rpm) (2).

To make the hydroelectric power plant as compact as possible, the power specified in the calculation should be correlated with the actual load, the power supply of which should be provided by the mini-hydroelectric power station (since, unlike a wind turbine, the current will be continuously supplied to the consumer network). As a rule, this electricity is used for lighting, powering the TV, radio, and refrigerator. Moreover, only the latter is constantly put into operation throughout the day. The rest of the electrical appliances work mainly in the evening. Based on this, it is advisable to focus on the maximum power from one “hydroenergy garland” of about 250-300 W, covering the peak load with a battery charged from a mini-hydroelectric power station.

The transmission of torque from the working shaft of a hydraulic power plant to the pulley of an electric generator is usually carried out using an intermediate transmission. However, this element, strictly speaking, can be excluded if the generator used in the design of a microhydroelectric power station has an operating rotation speed of less than 750 rpm. However, you often have to refuse direct communication. Indeed, for the vast majority of generators domestic production working speed rotation at the beginning of “distribution” of power lies in the range of 1500-3000 rpm. This means that additional coordination is needed between the shafts of the hydropower plant and the electric generator.

Well, now that the preliminary theoretical part is behind us, let’s look at specific designs. Each of them has its own advantages.

Here, for example, is a semi-stationary free-flow mini-hydroelectric power station with a horizontal arrangement of two coaxial, rotated 90° relative to each other (to facilitate self-starting) and rigidly connected transverse-type Savonius rotors. Moreover, the main parts and components of this homemade hydropower plant are made of wood as the most affordable and “obedient” building material.

The proposed mini-hydroelectric power station is submersible. That is, its supporting frame is located across the watercourse at the bottom and is strengthened with guy ropes or poles (if, for example, there are walkways, a boat dock, etc. nearby). This is done in order to avoid the structure being carried away by the watercourse itself.

Fig.2. Submersible mini hydroelectric power station with horizontal transverse rotors:
1 - base spar (beam 150x100, 2 pcs.), 2 - lower cross member (board 150x45, 2 pcs.), 3 - middle cross member (beam 150x120, 2 pcs.), 4 - riser (round timber with a diameter of 100, 4 pcs. .), 5 upper spar (board 150x45, 2 pcs.), 6 - upper cross member (board 100x40, 4 pcs.), 7 - intermediate shaft (stainless steel, rod with a diameter of 30), 8 - pulley block, 9 - generator direct current, 10 - “gander” with a porcelain roller and two-core insulated wire, 11 - base plate (board 200x40), 12 - drive pulley, 13 - wooden bearing assembly (2 pcs.), 14 - “hydroenergy garland” rotor (D600, L1000, 2 pcs.), 15 disk (from knocked into a shield boards 20-40 mm thick, 3 pcs.); metal elements fastenings (including braces, hubs of outer discs) are not shown.

Of course, the depth of the river at the installation site of the mini hydroelectric power station should be less than the height of the support frame. Otherwise, it is very difficult (if not impossible) to avoid water getting into the electric generator. Well, if the place where the mini hydroelectric power station is supposed to be located has a depth of more than 1.5 m or there is a large amount of water and flow speed that varies greatly throughout the year (which, by the way, is quite typical for snow-fed watercourses), then this design It is recommended to equip with floats. This will also allow it to be easily moved when installed on a river.

The supporting frame of a mini hydroelectric power station is a rectangular frame made of timber, boards and small logs, fastened with nails and wire (cables). Metal parts of the structure (nails, bolts, clamps, angles, etc.) should, if possible, be made of of stainless steel or other corrosion-resistant alloys.

Well, since the operation of such a mini hydroelectric power station is often possible in Russian conditions only seasonally (due to the freezing of most rivers), then after the expiration of the operation period, the entire structure pulled ashore is subject to thorough inspection. Rotten ones are replaced in a timely manner wooden elements, rusty, despite Taken measures precautions, metal parts.

One of the main components of our mini-hydroelectric power station is a “hydroenergy garland” of two rigidly fixed (and forming a single whole on the working shaft) rotors. Their disks can be easily made from boards 20-30 mm thick. To do this, making a shield out of them, use a compass to build a circle with a diameter of 600 mm. After which, each of the boards is cut according to the curve obtained on it. Having knocked the workpieces together on two strips (to give the required rigidity), they repeat everything three times - according to the number of required disks.

As for the blades, it is advisable to make them from roofing iron. Or better yet, from cylindrical stainless containers (barrels) of suitable size and cut in half (along the axis), in which agricultural fertilizers and other aggressive materials are usually stored and transported. In extreme cases, the blades can be made of wood. But their weight (especially after a long stay in water) will increase significantly. And this should be remembered when creating mini-hydroelectric power plants on floats.

Spiked supports are attached to the ends of the “hydroenergy garland”. Essentially, these are short cylinders with a wide flange and an end slot for a key. The flange is attached to the corresponding rotor disk with four bolts.

To reduce friction, there are bearings located on the middle crossbars. And since ordinary ball or roller bearings are unsuitable for working in water, they use... homemade wooden ones. The design of each of them consists of two clamps and insert boards with a hole for the passage of a tenon support. Moreover, the middle bearing shells are positioned so that the wood fibers run parallel to the shaft. In addition, special measures are taken to ensure that the insert boards are firmly fixed against lateral movement. This is done using tightening bolts.

Fig.3. Sliding bearing assembly:
1 - crimp bracket (St3, strip 50x8, 4 pcs.), 2 - middle frame cross member, 3 - crimp insert (made of hard wood, 2 pcs.), 4 replaceable insert (made of hard wood, 2 pcs.) , 5 - M10 bolt with Grover nut and washer (4 sets), 6 - M8 stud with two nuts and washers (2 pcs.).

Any automobile generator is used as an electric generator in the microhydroelectric power station under consideration. They produce 12-14 V DC and can be easily connected to both battery and electrical appliances. The power of these machines is about 300 W.

Quite acceptable for self-made and the design of a portable mini hydroelectric power station with a vertical arrangement of a “garland” and a generator. Such a hydroelectric station, according to the author of the development, is the least material-intensive. The supporting structure of the installation, which fixes its position in the river bed, is a hollow steel rod (for example, from pipe sections). Its length is chosen based on the nature of the bottom of the watercourse and the speed of the flow. Moreover, such that the sharp end of the rod, driven into the bottom, would guarantee the stability of the mini-hydroelectric power station and its non-disruption by the current. Possibly additional use stretch marks.
Having determined the active surface of the rotor using formula (1) and measuring the depth of the river at the installation site of the mini hydroelectric power station, it is easy to calculate the diameter of the Savonius rotors used here. To make the design simple and self-starting, it is advisable to make a “hydroenergy garland” of two rotors connected so that the blades of the first are offset by 90° relative to the second (along the axis of rotation). Moreover, to increase operating efficiency, the structure on the side of the oncoming flow is equipped with a shield that plays the role of a guide vane. Well, the working shaft is mounted in the sliding bearings of the upper and lower supports. In principle, for a short period of operation of a mini hydroelectric power station (for example, on a hiking trip), ball bearings can also be used large diameter. However, if there is sand or silt in the water, these units will have to be washed in clean water after each use.

Rice. 4. Mini hydroelectric power station with a vertical arrangement of end-type rotors:
1 - support rod, 2 - lower bearing assembly, 3 - "hydroenergy garland" disk (3 pcs.), 4 - rotor (D600, 2 pcs.), 5 - upper bearing assembly, 6 - working shaft, 7 - transmission, 8 - electric generator, 9 - “gander” with a porcelain roller and two-core insulated wire, 10 - generator mounting clamp, 11 - movable guide panel; a, b - blades: the braces at the upper end of the support rod are not shown.

The supports are bolted and welded to the rod, depending on the weight of the “hydroenergy garland” and the need to disassemble it into parts. The upper end of the working shaft of the hydraulic machine is also the input shaft of the multiplier, for which (as the simplest and most technologically advanced) a belt can be used.

The electric generator is again taken from a car. It is easy to attach it to the support rod with a clamp. And the wires themselves coming from the generator must have reliable waterproofing. In the illustrations, the exact geometric proportions of the intermediate transmission are not shown, as they depend on the parameters of the specific generator you have. Well, transmission belts can be made from an old car inner tube, cutting it into strips 20 mm wide and then twisting it into bundles.

For power supply to small villages, a garland mini-hydroelectric power station designed by V. Blinov is suitable, which is nothing more than a chain of barrel-shaped Savonius rotors with a diameter of 300-400 mm, attached to a flexible cable stretched across the river. One end of the cable is attached to the hinged support, and the other through a simple multiplier to the generator shaft. At a flow speed of 1.5-2.0 m/s, the chain of rotors makes up to 90 rpm. And the small size of the elements of the “hydroenergy garland” makes it possible to operate this micro-hydroelectric power station on rivers with a depth of less than one meter.

It must be said that before 1964, V. Blinov managed to create several portable and stationary mini hydroelectric power stations of his own design, the largest of which was a hydroelectric power station built near the village of Porozhki (Tver region). A pair of garlands here drove two standard automobile and tractor generators with a total power of 3.5 kW.

MK 10 1997 I. Dokunin