RU80901U1 - WIND POWER PLANT - Google Patents

Abstract

The utility model relates to the field of power plants - wind power plants, supplying enterprises and settlements with electricity.

The technical result of the utility model is the creation of small-sized wind turbines with a high coefficient of utilization of wind energy and suitable for operation in the absence of other energy sources

The essence of the utility model: a wind power installation includes a rotor with blades mounted on a shaft, and at least one more rotor, which are mounted in pairs on a horizontal shaft equipped with a two-armed pulley for transmitting torque when the shaft rotates simultaneously to two generators producing alternating and direct currents, respectively.

Description

The utility model relates to the field of power plants - wind power plants, supplying enterprises and settlements with electricity. Wind turbines have been known since antiquity.

Recently, there has again been a great interest in wind power plants (wind turbines) of various capacities, the number of which is growing from year to year. Moreover, special attention is paid to wind turbines of high power. So, there is a project to create wind turbines for 2500 kW. The impeller diameter is about 100 m with a tower height of 60 m.

However, this raises problems of the mechanical strength of the entire station, as well as a problem of an ecological nature - when the blades rotate, infrasound is generated that negatively affects living organisms, including humans. Therefore, the prevailing opinion is that at present it is most advisable to use wind turbines with a capacity of 5 to 100 kW. Almost all strength problems of such plants are satisfactorily solved, with the exception of the elimination of infrasound [1, 2].

Currently, two types of wind turbines are considered: propeller and rotor types.

Propeller-type wind turbines are faster. Their wind energy utilization coefficient reaches 52-58%. But they are more difficult to manufacture in comparison with the installation of the rotary type, they have significantly larger overall dimensions, they are peddling with a sharp increase in wind speed. To obtain the same power, the diameter of the propeller-type wind turbines is approximately 2.5 times larger than the rotor diameter.

A rotary wind turbine has a large torque, it is not afraid of overloads with a sharp increase in wind speed, that is, the stability of its operation is much higher. The power removed by a rotor-type wind turbine can be increased by installing another tier of blades.

As a prototype used rotary wind turbines.

The specified wind turbine has several disadvantages.

1. Very low wind energy utilization. This is because the rotor works due to aerodynamic asymmetry. The wind, blowing around the rotor, equally affects all the blades falling into its front. This means that one half uses the wind power completely, and the other, on the contrary, is braked. The incoming wind flow breaks down from the convex side of the blade and can hit

into the inside of the other blade. Moreover, the magnitude of the loss of wind energy is inconsistent and pulsates depending on the position of the external convexity of one blade and the adjacent pocket, thereby creating the possibility of resonance. When resonance occurs, the possibility of generating infrasound arises. The fourth blade remains without the influence of the wind flow.

2. The dependence of the rotor speed on the area of the blades. With an increase in area it feeds the number of revolutions. This means that the rotor speed is 200-500 rpm.

3. The location of the rotor on a vertical shaft makes it difficult to place the impeller on the second tier.

4. The removed power of a wind turbine is limited to 1-2 tiers. It is already difficult to establish a larger number of tiers due to difficulties associated with the mechanical strength of the shaft and the stability of the rack.

The objective of the utility model is the creation of small-sized wind turbines, the power of which would be 1.5-20.0 kW with a high coefficient of utilization of wind energy and suitable for operation in the absence of other energy sources.

The technical result of the utility model is the creation of small-sized wind turbines with a high coefficient of utilization of wind energy.

The essence of the utility model: a wind power installation includes a rotor with blades mounted on a shaft, and at least one more rotor, which are mounted in pairs on a horizontal shaft equipped with a two-armed pulley for transmitting torque when the shaft rotates simultaneously to two generators producing alternating and direct currents, respectively.

The installation is installed on a rotating platform with the ability to occupy a position corresponding to the optimal direction of flow and air pressure.

Each rotor is equipped with a diffuser, repeating the shape of the rotor in diameter, with a bell directed at an angle of at least 20 ° in the direction of the incoming wind flow.

Each rotor is equipped with a diffuser, which is a system of screens, from which one screen closes the self-braking half of the rotor, and the others direct the incoming wind flow to the blades, so that part of the wind flow captured by the diffuser constantly presses on them.

The rotor blades, made as a segment, have a surface that receives the pressure of the wind flow, in the form of folds irregularly located around the perimeter,

which under the pressure of the air flow change their shape, neutralizing the occurrence of resonance.

The ratio of the diameter of the rotor to its height is 1.618.

The diffuser of each rotor is equipped with valves or louvers regulating the volume of the incoming wind flow, mounted on the diffuser bell, which regulate the flow of wind to the rotor blades.

Sashes or louvers are equipped with a stopper that fixes the given position of the sash.

Wind energy is transformed into electrical energy by means of electric generators. At the same time, direct and alternating currents can be obtained.

To prevent the generation of infrasound, the blades are made of flexible material collected in folds located irregularly.

Figure 1 shows the location of the blades 1, their fastening on the crosspiece 2 and to the shaft 3 with bolts 4 and a system of screens 7, 9, 10, 11, of which the screen 7 in the form of a curtain prevents the flow of air, delaying the rotation of the rotor, screens 9 , 10, 11 determine the direction of air movement. The weather vane 5, 6 deploys the installation perpendicular to the air flow. The diffuser 8 is mounted on the frame 12, with wings 13, 14 and stopper 15.

Comparison of the movement of air flows in the prototype and in the proposed wind turbine allows us to draw the following conclusions. In the first case, the efficiency is 15-18%. This is explained by the fact that less than 50% of the power of the feed stream is used for useful work. The second half of the flow brakes the working wheel. In the second case, braking on the incoming flows is eliminated by the screen 7. The presence of the diffuser 8 allows you to increase the area of the incoming flow by 10-20 times, the energy of which is almost completely converted into mechanical energy of rotation of the shaft. Therefore, the efficiency approaches 80-90%. It can be more. This depends, in particular, on the dimensions of the diffuser.

To adjust the operation of the wind turbine and its stop, the diffuser is equipped with wings 13, 14. During operation, the wings are installed along the air stream. By turning the valves, the wind supply to the rotor is regulated. Each leaf is equipped with a stopper 15, fixing the predetermined position of the stopper.

Sashes can be replaced with blinds.

Figure 2 shows the diffuser 1 without screens and the impeller 2 on the shaft 3. The shaded area of the impeller 4 does not produce useful work.

Figure 3 and 4 shows the wind turbine assembly in two versions: wind turbine-2-a and wind turbine-4-a with two and four rotors (impellers) 1, respectively, diffusers 2, reinforced

on racks 3 and the frame. Each wind turbine is equipped with two alternating current and alternating current generators 4, 5 with transmission systems 14. Impellers 1, diffusers 2, racks 3, generators 4, 5 are mounted on a moving platform 6, which can rotate relative to a fixed platform 8 mounted on a tower (on the roof of the building or pillar) 9. The wind turbine is rotated using the turning unit 10 and the weather vane 11 on the stand 13. The number and size of the wind vane depends on the mass of the wind turbine. In addition, the impellers themselves stabilize their position.

The presence of two or three weathercocks improves the stability of the wind turbine system retention perpendicular to the air flow.

The number of rotors 1 on the common shaft 12 can be increased. When choosing the dimensions of the impeller, the ratio of diameter to height is d / H = 1.618 (golden ratio).

Where: d - impeller diameter;

H is the height of the impeller.

Wind turbine operation

The installation of this type begins to work efficiently, with wind at a speed of 4-5 m / s.

At any position of the wind turbine relative to the direction of the wind, the stopper is released (not shown in Figs. 7 and 8) and thanks to the weathercocks 11, the entire block is turned towards (perpendicularly) to the flow. The wind, giving its energy to the rotor blades, spins it, and with it the shaft 12 and pulleys 14, which transmit rotation to the current generators 4, 5. The received energy is either used directly or stored in batteries (not shown in the diagram).

Example.

For testing, a wind turbine with two impellers was manufactured. Moreover, the ratio of the diameter of the rotor and its height was 1.618.

The general parameters corresponded to the parameters of the VEU-2-A: the impeller (rotor) diameter was 1.6 m, the height was 1.0 m. An automobile generator of about 2 kW was used as a generator.

Wind speed ranged from 5 to 8 m / s. It was found that the speed of the impeller immediately reached 1000 rpm or more against the expected 600-650 rpm.

The installed pulleys were supposed to provide approximately 2000-2500 rpm./min, which were required to work according to the standard. An increase in the number of revolutions led to a change in the operating mode of the generator. Therefore, almost immediately, the relay turned off the generator. It was necessary to change the gear ratio between the pulley diameters on the shaft of the impellers of the wind turbine and the generator.

Based on the tests developed, wind turbines were developed, designed, manufactured, the schemes are presented in figures 3 and 4, technical and economic indicators are in the table below.

Technical and economic indicators of wind turbines №№ Name Units Types of apparatus VEU-2-A VEU-4-A one Impeller diameter mm 1600 1600 2 Impeller height mm 650-1000 650-1000 3 Number of wheels PC 2 four four Air speed m / s from 5 from 5 5 Developed Power kw 2.5-5.0 5-10,0 6 Type of electric current - constant, variable constant, variable 7 Infrasound Generation - absent absent 8 Tower height m not less than 10 not less than 10 Note: 1. Power can be increased by installing additional rotors or by changing their diameters and heights. 2. The cost of manufacturing a wind turbine-4-a is approximately 30% higher than a wind turbine-2-a.

Used Books:

1. Protsenko A.N. Energy today and tomorrow. - M .: "Young Guard", 1987.

2. “More than enough?” Sat. articles edited by R. Clark. - M .: Energoatomizdat, 1984.

3. Samoilov P. Wind - assistant. St. Petersburg: CAM, No. 3, 1995, pp. 9-11.

Claims (8)

1. Wind power installation, including a rotor mounted on the shaft with blades, characterized in that it contains at least one more rotor, which are mounted in pairs on a horizontal shaft equipped with a two-armed pulley for transmitting torque when the shaft rotates simultaneously to two generators producing alternating and constant currents respectively. 2. Installation according to claim 1, characterized in that it is installed on a rotating platform with the ability to occupy a position corresponding to the optimal direction of flow and air pressure. 3. Installation according to claim 1, characterized in that each rotor is equipped with a diffuser that repeats the shape of the rotor in diameter, with a bell directed at an angle of at least 20 ° in the direction of the incoming wind flow. 4. Installation according to claim 1, characterized in that each rotor is equipped with a diffuser, which is a system of screens, of which one screen closes the self-braking half of the rotor, and the others direct the incoming wind flow onto the blades so that part of the wind flow constantly presses on them captured by the diffuser. 5. Installation according to claim 4, characterized in that the rotor blades, made as a segment, have a surface that receives the pressure of the wind flow, in the form of folds irregularly located around the perimeter, which change their shape under the pressure of the air flow, neutralizing the occurrence of resonance. 6. Installation according to claim 5, characterized in that the ratio of the diameter of the rotor to its height is 1.618. 7. Installation according to claim 3, characterized in that the diffuser of each rotor is equipped with valves or louvers regulating the volume of the incoming wind flow, mounted on the diffuser bell, which regulate the flow of wind to the rotor blades. 8. Installation according to claim 7, characterized in that the flaps or shutters are equipped with a stopper that fixes their position.