WO2009041819A2

WO2009041819A2 - Device for generating power from wind flow or water flow

Info

Publication number: WO2009041819A2
Application number: PCT/NL2008/050624
Authority: WO
Inventors: Eric Ten Cate
Original assignee: Tenca; Eneco B.V
Priority date: 2007-09-28
Filing date: 2008-09-29
Publication date: 2009-04-02
Also published as: WO2009041819A3; NL2000889C2

Abstract

The invention relates to a device (1) for generating power from wind flow or water flow. Device (1) comprises a frame (10) on which at least one mast (20) is movably mounted at a first outer end. At least one blade (30) is mounted on a second outer end of the mast. The blade and the mast are movable under the influence of wind flow or water flow. Device (1) is further provided with means for generating power which are coupled to the first outer end of the mast. According to the invention the mast (20) is adapted to perform a reciprocating movement.

Description

DEVICE FOR GENERATING POWER FROM WIND FLOW OR WATER FLOW

The invention relates to a device for generating power from wind flow or water flow.

Diverse embodiments of such a device are known in the relevant field. A known example is the wind turbine, which is usually used to generate (green) electricity, sometimes in large farms' with many wind turbines on land or at sea (offshore). There are two basic designs of the known wind turbine: with a horizontal axis or with a vertical axis. The Horizontal Axis Wind Turbine is provided with a rotor with (three) rotor blades which rotate on a horizontal axis. The Vertical Axis Wind Turbine is provided with a rotor with (helical) rotor blades which rotate on a vertical axis. The best known types of VAWTs are Darrieus and Savonius.

The invention has for its object to provide a device for generating power from wind flow or water flow having an alternative design.

The device according to the invention comprises a frame; at least one mast which is mounted at a first outer end for movement on the frame; and at least one blade which is mounted on a second outer end of the mast; wherein the blade and the mast are movable under the influence of wind flow or water flow; and wherein the device is further provided with means for generating power which are coupled to the first outer end of the mast, wherein the mast is adapted to perform a reciprocating movement. In the device according to the invention only the blade is situated at the top of the mast, while the means for generating power are situated at the bottom of the mast, whereby the device has a low centre of gravity. A small foundation and a lighter mast will hereby suffice. The high position of the blade results in less noise nuisance. The low position of the means for generating power makes them easily accessible, which results in lower maintenance costs. Owing to the reciprocating movement the forces exerted on the blade are moreover more constant than in the case of a rotating movement, and this has a positive effect on the lifespan of the blade.

In a first preferred embodiment of the device according to the invention the reciprocating movement can be performed between two extreme positions located on either side of a central position, in which central position the mast extends substantially perpendicularly of the frame in the position of use of the device.

According to a further preferred embodiment, the device according to the invention comprises a counterweight fixed to the first outer end of the mast. The counterweight provides for balance and is necessary for an optimum energy management. The counterweight can preferably be coupled releasably to the means for generating power in order to raise the mast to the position of use or lower it into the rest position. The installation of the device can hereby take place in simple manner without large cranes, and so at lower cost. Maintenance can be carried out in the rest position. In addition, the rest position can also serve as storm locking position.

In a practical preferred embodiment the device according to the invention further comprises means for rotating the frame. The position of the mast and the blade can hereby be adjusted optimally to the wind direction. In another preferred embodiment the blade is mounted tiltably on the mast such that during the movement of the mast the blade extends substantially perpendicularly of the direction of movement. The speed of the blade during the reciprocating movement is thereby substantially the same over the whole area thereof. It is not therefore necessary to give the blade a twisted form, and a simpler and therefore cheaper construction of the blade will suffice.

The device according to the invention preferably comprises means for automatically adjusting the wind angle of the blade in the extreme positions of the mast.

In yet another preferred embodiment the device according to the invention comprises a housing in which the frame and the means for generating power are accommodated. In an elegant preferred embodiment the housing is situated at least partially underground.

According to an energetically advantageous embodiment, the device according to the invention comprises a flywheel which can be coupled to the means for generating power.

The means for generating power preferably comprise a mechanical transmission and a power generator, so that the device according to the invention is suitable as wind turbine for generating (green) electricity.

The invention will now be discussed in more detail with reference to the drawings, in which

Figures 1 A.B.C show schematic side views of a preferred embodiment of a device according to the invention in three positions of the mast;

Figure 2A is a cut-away schematic side view of a part of the device of figure 1 in the position of use;

Figure 2B shows the device of figure 2A in rest position; Figure 3A shows a cut-away schematic front view of an upper part of the device of figure 1 in the right-hand position of the mast;

Figure 3B shows a rear view of the device of figure 3A;

Figure 3C is a cut-away schematic front view of a lower part of the device of figure 1 in the right-hand position of the mast;

Figures 4A₁ B, C show schematic top views of the device of figure 1 in the three positions of the mast; and

Figure 5 is a schematic side view of the device of figure 1 with an additional housing.

Figures 1 A, B and C show a preferred embodiment of a device 1 according to the invention which is suitable for generating power from wind. In figure 1A device 1 occupies the extreme left-hand position. In figure 1B device 1 occupies the central position. In figure 1C device 1 occupies the extreme right-hand position. Device 1 comprises a frame 10. A mast 20 is mounted at a first outer end for movement on frame 10. Device 1 further comprises at least one blade 30 which is mounted on a second outer end of mast 20. Mast 20 is adapted together with blade 30 to perform a reciprocating movement under the influence of wind. In the context of the present invention a reciprocating movement is understood to mean a movement back and forth from a central point. The reciprocating movement can be performed between the two extreme positions shown in figures 1 A and 1C. This movement here always passes through the central position as shown in figure 1B, in which the mast extends substantially perpendicularly of the frame. In the extreme left-hand position mast 20 has a swing through a reciprocating angle U₁ relative to the central position (shown as a (broken) line). In the extreme right-hand position mast 20 has a swing through a reciprocating angle U₂ relative to the central position. It is generally the case that:

I U₁I = I U₂

Figure 2A shows a cut-away schematic side view of a part of device 1 in the position of use. The rest position of device 1 is shown in figure 2B.

Mast 20 is mounted with the first outer end on frame 10 for rotation about a shaft 21. A counterweight 22 is fixed to the first outer end of mast 20. Device 1 is further provided with means 40 for generating power which are coupled to the first outer end of mast 20. The movement of mast 20 is transmitted to a (power) generator 44 via a drive rod 41 , a crankshaft 42 and a transmission 43. A flywheel 45 is preferably placed between transmission 43 and generator 44.

Frame 10 has a number of legs 11 supporting on a rotation ring 12. The rotation ring is accommodated in a foundation 13 with a concrete edge 14 provided on the inner side with support rollers 15 for securing rotation ring 12. A motor, for instance a yaw motor 16, is provided for the purpose of rotating the rotation ring. Through rotation of the frame the position of mast 20 with blade 30 can thus be optimally adjusted to the prevailing wind direction. The foundation 13 is preferably arranged wholly or partially buried in the ground. At the position of counterweight 22 the mast 20 is coupled releasabty to means 40 for generating power. In the shown preferred embodiment this is realized by means of a releasable mounting of drive rod 41 on pin 24 at the bottom of mast 20. In addition, it is possible to envisage many other possibilities for realizing the releasable coupling. An example hereof is an alternative drive rod of adjustable length. When drive rod 41 is coupled to crankshaft 42 during installation, mast 20 will move automatically to the central position as shown in figure 1 B owing to counterweight 22. The mast can be lowered (see figure 2B) by uncoupling drive rod 41 and crankshaft 42. If necessary, the mast can be secured in the lowered position in simple manner, for instance when the maximum allowed wind force is exceeded. Figures 3A and 3B show respectively a partly cut-away schematic front view and rear view of an upper part of the device of figure 1 in the right-hand position of the mast. Figure 3C shows a partly cut-away schematic front view of a lower part of the device of figure 1 in the right-hand position of the mast. Blade 30 is mounted tirtably on mast 20. Device 1 is provided with means for tilting blade 30 relative to mast 20. Blade 30 is mounted on a shaft 31 at the second outer end of mast 20. The means for tilting blade 30 comprise a yoke 32 arranged on a shaft 39 transversely of blade shaft 31. Two tensioning cables 33, 34 are attached to yoke

32. An example of suitable tensioning cables are steel cables. Tensioning cables

33, 34 have an equal length and extend substantially parallel to each other in mast 20. Tensioning cables 33 and 34 are fixed at the bottom of the mast to a yoke 23 arranged on shaft 21. As a result the blade will extend, during movement of the mast, substantially perpendicularly of the direction of movement.

If yoke 23 is fixed in an orientation parallel to the ground surface M (i.e. in horizontal position in the shown horizontal placing of frame 10 on a flat ground surface), yoke 32 will also continue to have an orientation parallel to the ground surface M (in this example also a horizontal position) during the reciprocating movement of mast 20. Blade shaft 31 and blade 30 extend substantially transversely of yoke 32, i.e. blade 30 has an orientation transversely of ground surface M (in this example a vertical position) in a horizontal position of yoke 32.

Device 1 is further provided with means for adjusting the wind angle, i.e. the angle of the blade relative to the wind direction. These adjusting means are also adapted to allow automatic turning of blade 30 in the extreme positions of mast 20. Blade 30 is arranged rotatably about blade shaft 31 for this purpose. The means for adjusting the wind angle comprise a flange 35 arranged under blade 30 on blade shaft 31. A motor 36 and a (gear) transmission 37 provide for rotation of the blade.

Arranged round blade shaft 31 is a discus-shaped housing 38 in which are accommodated the means for tilting the blade, i.e. yoke 32 and the top side of tensioning cables 33, 34, and the means for adjusting the wind angle, i.e. flange 35, motor 36 and transmission 37. The discus-shaped housing 38 is shown partially in figures 3A and 3B.

The movements of mast 20 and blade 30 of device 1 are illustrated in figures 4A, 4B and 4C. In all the figures the wind direction is designated with W and the direction of movement of mast 20 with B.

In figure 4A mast 20 occupies the extreme left-hand position. Frame 10 is rotated to the optimal position of mast 20, taking the wind direction W into account. Blade 30 is rotated relative to mast 20 to the shown optimal orientation with wind angle α i, taking the wind direction W into account. Device 1 is now ready for forward movement in the direction of movement Bfomαr_d-

In figure 4B mast 20 occupies the central position. In this position the mast extends substantially perpendicularly of frame 10. With a horizontal placing of frame 10 on a flat ground surface the mast 20 occupies a vertical position. The orientation of blade 30 is unchanged.

In figure 4C mast 20 occupies the extreme right-hand position. Just before mast 20 takes up the extreme right-hand position, the adjusting means have caused the blade to turn to the shown orientation with associated wind angle α₂. The two wind angles for forward and return movement are related via the relation

Device 1 is now ready for return movement in the direction of movement

BtBtum- Frame 10 and means 40 for generating power are optionally accommodated in a housing 50 as shown in figure 5. Housing 50 can be arranged partially buried in the ground. The invention is of course not limited to the described and shown preferred embodiments, but extends to any embodiment falling within the scope of protection as defined in the claims as seen in the light of the foregoing description and accompanying drawings.

Claims

1. Device (1 ) for generating power from wind flow or water flow, comprising: - a frame (10); - at least one mast (20) which is mounted at a first outer end for movement on the frame; and

- at least one blade (30) which is mounted on a second outer end of the mast; wherein the blade and the mast are movable under the influence of wind flow or water flow; and wherein the device is further provided with means (40) for generating power which are coupled to the first outer end of the mast, wherein the mast (20) is adapted to perform a reciprocating movement.

2. Device as claimed in claim 1 , wherein the reciprocating movement can be performed between two extreme positions located on either side of a central position, in which central position the mast (20) extends substantially perpendicularly of the frame (10) in the position of use of the device.

3. Device as claimed in claim 2, further comprising a counterweight (22) fixed to the first outer end of the mast (20).

4. Device as claimed in claim 1 , 2 or 3, further comprising means (12, 13, 14, 15, 16) for rotating the frame.

5. Device as claimed in any of the foregoing claims, wherein the blade (30) is mounted tiltably on the mast (20) such that during the movement of the mast the blade extends substantially perpendicularly of the direction of movement.

6. Device as claimed in any of the foregoing claims, further comprising means (35, 36, 37) for automatically adjusting the wind angle of the blade (30) in the extreme positions of the mast (20).

7. Device as claimed in any of the foregoing claims, further comprising a housing in which the frame (10) and the means (40) for generating power are accommodated.

8. Device as claimed in claim 7, wherein the housing is situated at least partially underground. θ. Device as claimed in any of the foregoing claims, further comprising a flywheel (45) which can be coupled to the means (40) for generating power.

10. Device as claimed in any of the foregoing claims, wherein the means (40) for generating power comprise a mechanical transmission (43) and a power generator (44).