WO2005052363A1

WO2005052363A1 - Wind turbine

Info

Publication number: WO2005052363A1
Application number: PCT/EP2003/013088
Authority: WO
Inventors: Georg Reitz
Original assignee: Kott, Klaus-Manfred
Priority date: 2003-11-21
Filing date: 2003-11-21
Publication date: 2005-06-09
Also published as: EP1702159A1; AU2003293712A1

Abstract

The invention relates to a wind farm (1) comprising a device (10), which is used to convert wind kinetic energy into mechanical energy, and a device which is used to convert the produced mechanical energy into electric energy. Said wind farm is characterised in that it comprises a wind channel (9) provided with a first cross-sectional area, wherein the device (10) which is used to convert wind energy into mechanical energy is arranged, and a wind stream bundle device (8) which comprises an inlet (5) provided with a second larger cross-sectional area compared to the first, and which can guide a wind stream which enters into the inlet (5), without turbulence as a laminar flow in the wind channel (9).

Description

COAT WIND TURBINE

description

The invention relates to a wind turbine for converting wind energy into electrical energy and a method for generating electrical energy from wind energy in a wind turbine.

By promoting renewable energy concepts, such wind turbines have been the subject of technical research and development for several years. The wind turbines used so far work predominantly on the principle of buoyancy, whereby aerodynamically shaped rotor blades are used. Taking into account this principle, today's wind turbines are usually equipped with horizontal axis rotors, which must be tracked to the wind direction. For wind turbines, there is a requirement for minimum distances of obstacles, which can lead to turbulence of the air flow, since only laminar flows can be processed. Basically, with increasing altitude, both the wind speed and the uniformity of the wind increase. In today's wind turbines, the optimal use is given when the air flowed through the rotor surface has just enough energy to flow away, in order to develop no braking effect. For this purpose, the point was determined at which the speed of the wind is reduced to a good third when passing through the surface described by the rotor. The number of rotor blades is insignificant for the energy efficiency. Subsequently, the mechanical energy generated by the rotor blades is guided via gear and rotor shaft to a generator, which converts them into electrical energy. Partly there are light transmissions that transmit the forces directly from the hub to the gearbox and thus can do without the heavy rotor shaft. The masts usually have a height of 10 to 100 m, with increasing height not only the energy yield, but also the construction costs due to the complex statics.

However, there are still some disadvantages that the wind turbines of the prior art have. First and foremost, it is disadvantageous that by the constant change of the natural wind speed, the force that can be transmitted to the generator fluctuates, while at wind speeds of less than 4 m / s (about 3 wind force) in fact, no conversion of the kinetic energy of the wind is possible anymore. If, on the other hand, the wind speed rises above 10 wind speed (about 26 m / s), the rotors must be placed in feathered position, otherwise they can no longer withstand the mechanical load. This is primarily due to the considerable static loads due to the large dimensions of the rotor blades.

The present invention is therefore an object of the invention to provide a wind turbine that ensures a reliable conversion of the kinetic energy of the wind into electrical energy even at strongly fluctuating or extreme wind speeds.

This is achieved in that the wind turbine has a wind tunnel with a first cross-sectional area, in the area of which the device for converting wind energy into mechanical energy is arranged, and that a wind power bundling device is provided which has an inlet opening with a second, compared to the first cross-sectional area having a larger cross-sectional area and which is adapted to direct a entering into the inlet port wind stream without substantial turbulence as a laminar flow in the wind tunnel. Due to this structural design, the total kinetic energy of the wind contained in the large cross-sectional area can be directed into the narrower wind tunnel, where due to the smaller dimensions, easier processing is possible. In addition, due to the higher wind speed in the wind tunnel, it is possible to use wind energy even at low wind speeds. Finally, it is possible at particularly high wind speeds to limit the kinetic energy of the wind by changing the diameter of the wind tunnel or dissipation of parts of the wind so that the system can produce electricity even at extremely high wind speeds.

Advantageously, the wind turbine has a Windstromverbreiterungsvorrichtung, which is arranged behind the wind tunnel and having an outlet opening with a third, compared to the first cross-sectional area larger cross-sectional area. As a result of this measure, the static pressure conditions behind the wind tunnel are improved, and the wind passing the wind power plant can extract the air which has been decelerated by the conversion device in the wind tunnel from the outlet opening due to the resulting suction effect. The use of suitable guide elements that produce air flow channels with a small cross-sectional area, this suction effect can be enhanced.

Preferably, the wind turbine on a suitable rotatable support device, so that the inlet opening can always be aligned in the direction of wind flow.

In order to ensure the most frictionless and safe rotation of the wind turbine, the rotatable support device preferably has a float, which is guided immersed in a container with liquid.

The forces acting on the support device are advantageously compensated particularly well that between the side walls of the container and the float a narrow space is arranged, which is at least partially filled in the immersed state of the float by liquid columns.

For an automatic alignment of the system in the wind direction, it is advantageous if an alignment sail is arranged in the outer area of the wind turbine.

In addition to the use of conventional turbines in the wind tunnel, it is particularly advantageous if the device for converting wind energy into mechanical energy has a plurality of rotor blades, which are connected at their outer ends by means of an annular connecting element, and the connecting element runs in a circular guide rail.

For better control of the kinetic energy of the wind to be processed, at least one further wind tunnel is preferably provided, which surrounds the first wind tunnel and can be opened and closed.

To optimize the power obtained, it is advantageous if rotor blades are also arranged in the further wind tunnel, are connected to one another at their inner ends by means of a second annular connecting element, wherein the connecting element runs in a second circular guide rail, and the rotor blades at their outer ends are connected by means of a third annular connecting element, wherein the connecting element has outwardly pointed teeth, which serve for engagement with a gear. Further details, features and advantages of the present invention will become apparent from the following description with reference to the drawings. It shows

Fig. 1 is a sketched cross-sectional view of an embodiment of the upper part of the wind turbine according to the invention;

Fig. 2 is a sketched cross-sectional view of a second embodiment of the upper part of the wind turbine according to the invention with several wind channels;

FIG. 3 is an end view of the wind tunnels of the wind turbine of FIG. 2; FIG.

4 shows a preferred embodiment of a wind power broadening device of a wind power plant according to the invention; and

Fig. 5 is a sketched cross-sectional view of a wind turbine according to the invention.

In Fig. 1, a first embodiment of the upper part of a wind turbine 1 according to the invention is shown. The wind turbine 1 has an elongate building element 3, which at one end face an inlet opening 5 and at the other end side an outlet opening 7 shows. The cross-sectional area of the inlet opening 5 is preferably circular and has a diameter of between 5 and 70 m, and depending on the arrangement of the other elements, a different diameter is conceivable. The cross-sectional area of the outlet opening 7 in the present example is identical to that of the inlet opening 5, but other geometrical shapes or other size ratios are also conceivable. Directly behind the inlet opening 5, a wind power bundling device 8 is arranged, which is designed funnel-shaped in the present case and directs the wind flow in narrowing flow lines to a wind tunnel 9. The wind tunnel 9 preferably also has a circular cross-section and has a significantly smaller diameter than the inlet opening 5. In the region of the wind tunnel 9, in the present example at its end, a device for converting the kinetic energy of the wind into mechanical energy 10 is arranged.

The devices for converting the kinetic wind energy into mechanical energy and then into electrical energy on the one hand may be a commercial turbine with a connected generator or any other known from the prior art device. A preferred embodiment of such a device 10 will be described in detail later with reference to FIG.

Behind the wind tunnel 9, a wind power broadening device 12 is arranged, which is formed in the present example case as a reverse funnel and derives the braked by the device 10 wind flow back into the environment.

The operating principle of the wind turbine 1 will be explained below. The wind flow enters the inlet opening 5 and is compressed by the funnel-shaped wind power bundling device 8 laminar in the direction of the wind tunnel 9, whereby the speed of the wind flow increases and at the same time the static pressure decreases. In the wind tunnel 9, kinetic energy is withdrawn from the wind by the device 10, and this is thereby decelerated. The wind passing past the wind turbine 1 develops at the end of the outlet opening 7 a suction which accelerates the slow wind currents contained in the wind power broadening device 12 outwards again. This creates a kind of double Venturi nozzle in which the kinetic energy of the wind in the wind tunnel 9 is converted.

2, a second embodiment of the upper part of a wind turbine 1 according to the invention is shown. Around the inner wind tunnel 9 are further wind channels 14 concentrically arranged, which show a ring shape. Each of the wind channels 14 can be opened and closed, which is done in the illustrated example case by moving suitable wall sections 15 of the wind power bundling device 8. The wall sections 15 are moved by means of circumferential hinges 16 which are located in the area of the funnel, and the mechanical design of the opening and closing construction is such that the wall sections 15 mutually overlap when moved inwardly. Thus, either the central wind tunnel 9 or an arbitrary number of other wind tunnels 14 are additionally opened by the movement of the wall sections 15 so that the speed achieved in each wind tunnel is relatively constant and changes in the speed of the wind flow are open Close additional wind channels 14 can be compensated, so that the generator can always run in the optimum range of rotation. The additional opening and closing of the further wind passages 14 can either be person-controlled or the wind speed can be reduced. automatically adjust the use of wind sensors and suitable control circuits. In order to also utilize the wind currents in the outer wind tunnels 14, there are advantageously in the wind tunnels 14 further devices 18 for converting the kinetic energy of the wind into mechanical energy, which are detailed below with reference to FIG. In turn, movable wall sections 19 of the wind power widening device 12, which move around further joints 20, can be arranged at the rear end of the wind passages 14. However, it is also possible to leave all wind channels 14 open to the rear.

In Fig. 3, an inventive arrangement of three wind channels 9, 14 is shown. In the inner wind tunnel 9, a first device 10 for converting the kinetic energy of the wind into mechanical energy is included. In the illustrated embodiment, the device has four rotor blades 22, which are connected at their inner end to a shaft 24 and withdraw kinetic energy from the wind flowing through the wind tunnel 9 in a manner known per se, because due to the aerodynamic configuration of the rotor blades 22, these are themselves in the wind power and thus drive the shaft 24, which in turn is connected to a generator (not shown) for generating electrical energy. For better stabilization of the rotor blades 22, these are connected to each other at their outer end by means of an annular connecting element 26 which runs as smoothly as possible in a circular guide rail (not shown). Thus, even very high wind speeds can be implemented without the mechanical stresses of the device 10 require a shutdown of the wind turbine 1.

The second and third wind tunnel 14 also each have rotor blades 28, which are connected to one another at their inner ends by means of a further annular connecting element 30. In the illustrated example case eight of these rotor blades 28 are arranged in the second wind tunnel 14, in the third wind tunnel 12 are. The annular connecting element 30 is guided in each case in a further circular guide rail (not shown), in which it runs relatively smoothly. For the utilization of the generated mechanical energy in the outer wind tunnels 14, the rotor blades are connected at their outer ends to each other by means of a further annular connecting element 32, which has, for example, spikes towards the outside (not shown). These prongs may intervene in the rotational movement of the rotor blades 28, for example, in suitable gears (not shown), which transfer the kinetic energy to a generator. FIG. 4 shows a particularly preferred embodiment of the wind power broadening device 12. In this case, 7 guide elements 34 are arranged in the region of the outlet opening, which produce air flow channels with a small cross-sectional area. The flowing past the wind turbine 1 air generated in these channels a particularly high suction effect, so that the decelerated by the device 10 air flow due to the channel effect undergoes a special acceleration to the outlet port 7 out. It is also conceivable to insert further guide elements behind the outlet opening 7, which guide the wind flowing past the wind turbine 1 in the direction of the outlet openings of the air flow channels and thus further enhance the suction effect.

Fig. 5 shows a sketched cross-sectional view of a complete wind turbine 1. The previously described upper part of the wind turbine 1 rests on a support plate 38 which is fixedly connected to a rotatable support device 40. The support device comprises a carrier 42 and a floating body 44 connected thereto, which is immersed in about two thirds in a liquid bath 46, which is located in a container 48. Between float 44 and the side walls of the container 48 only a narrow area is provided, in which the liquid columns can rise and fall, depending on the loads acting on the support 40 over the upper part of the wind turbine 1. Due to the size ratios ensures that the float 44 only relatively small height differences, preferably in the millimeter range covers. Laterally, the float 44 is guided on the side walls of the container 48 via suitable guide means (not shown). Thus, an alignment of the inlet opening 5 can be achieved in the wind flow. When using an arranged on the upper part of the wind turbine 1 alignment sail 50, the system is automatically rotated in the wind direction, including the virtually frictionless rotation of the support device in the liquid bath 40 makes a significant contribution.

Of course, the geometrical conditions or the mechanical solutions for implementing the idea according to the invention are not limited to the forms shown, but all the same mechanical configurations are also applicable.

The wind turbine according to the invention can be used both on land and on water, and it is also conceivable in terms of a balanced energy concept to use the electricity obtained at least partially for the production of hydrogen, which can then be stored.

Claims

Expectations

1. Wind power plant (1) with a device (10) for converting the kinetic energy of the wind into mechanical energy and with a device for converting the generated mechanical energy into electrical energy, characterized in that it has a wind tunnel (9) with a first cross-sectional area has, in the area of which the device (10) for converting wind energy into mechanical energy is arranged, and that a wind power bundle device (8) is provided which has an inlet opening (5) with a second cross-sectional area which is larger in comparison to the first cross-sectional area and which is suitable for directing a wind stream entering the inlet opening (5) into the wind tunnel (9) as a laminar flow without substantial turbulence.

2. Wind power plant (1) according to claim 1, characterized in that the wind power bundle device (8) is substantially funnel-shaped.

3. Wind power plant (1) according to claim 1 or 2, characterized in that it has a wind power broadening device (12) which is arranged behind the wind tunnel (9) and an outlet opening (7) with a third, also larger in comparison to the first cross-sectional area Has cross-sectional area.

4. Wind power plant (1) according to claim 3, characterized in that the wind power broadening device (12) is substantially funnel-shaped.

5. Wind power plant (1) according to claim 3 or 4, characterized in that the wind power broadening device (12) has guide elements (36) which produce air flow channels with a small cross-sectional area.

6. Wind power plant (1) according to one of the preceding claims, characterized in that it has a suitable rotatable support device (40) so that egg ne orientation of the inlet opening (5) in the wind stream can be adjusted.

7. Wind power plant (1) according to claim 6, characterized in that the rotatable support device (40) has a floating body (44) which is guided in a container (48) immersed in liquid and can be rotated there almost without friction.

8. Wind turbine (1) according to claim 7, characterized in that between the side walls of the container (48) and the floating body (44) a narrow space is arranged, which is at least partially filled by liquid columns in the immersed state of the floating body (44).

9. Wind turbine (1) according to one of claims 6 to 8, characterized in that an alignment sail (50) is arranged in the outer region of the wind turbine (1), which ensures automatic alignment of the inlet opening (5) in the wind stream.

10. Wind power plant (1) according to one of the preceding claims, characterized in that the device (10) for converting wind energy into mechanical energy has a plurality of rotor blades (22) which are arranged in the wind tunnel (9).

11. Wind turbine (1) according to claim 10, characterized in that the rotor blades (22) are connected to one another at their outer ends by means of an annular connecting element (26), and the connecting element (26) runs in a circular guide rail.

12. Wind power plant (1) according to one of the preceding claims, characterized in that at least one further wind tunnel (14) is provided which surrounds the first wind tunnel (9) and which can be opened and closed.

13. Wind power plant (1) according to claim 12, characterized in that rotor blades (28) are arranged in the further wind tunnel (14), which are connected at their inner ends by means of a second annular connecting element (30), and the connecting element (30) runs in a second circular guide rail.

14. Wind power plant (1) according to claim 13, characterized in that the rotor blades (28) are connected at their outer ends by means of a third annular connecting element (32), the connecting element (32) having outwardly tines which engage with serve a gear.

15. A method for generating electrical energy from wind energy in a wind power plant (1), characterized in that the wind current is received in an input opening (5) with a predetermined cross-sectional area and is passed as a laminar flow into a wind tunnel (9) without substantial turbulence , which has a smaller cross-sectional area than the inlet opening (5), the wind energy of the bundled wind current in the region of the wind tunnel (9) being converted into mechanical energy and then into electrical energy by means of a suitable device (10).

16. The method according to claim 15, characterized in that the air flowing past the wind turbine (1) exerts a suction effect on the braked air behind the conversion device (10).