WO2013104935A1

WO2013104935A1 - Wind-generator with horizontal parallelogram of bars for translational movements of wings

Info

Publication number: WO2013104935A1
Application number: PCT/HR2012/000007
Authority: WO
Inventors: Ivan Ivkovic; Marinko Jukic
Original assignee: Ivan Ivkovic; Marinko Jukic
Priority date: 2012-01-12
Filing date: 2012-03-14
Publication date: 2013-07-18
Also published as: HRP20120045A2; EP2802771A1

Abstract

Wind generator with horizontal parallelogram of bars for translation- al movements of one or more symmetric aerodynamic wings that are placed vertically. Changing the wing motion from rotational to trans- lational eliminates the vortex resistance, remaining only the signifi¬ cantly lesser wing resistance. The translational movement is enabled by the horizontal parallelogram of bars comprising: the lower work¬ ing bar (6) and the control bar (8) with the console (10) and the actu¬ ator (11). The parallelogram of bars changes the angle of attack (a) of air stream to the wing (1), thus utilising the aerodynamic force (F) to move the wings to one and the other sides. The aerodynamic force is transmitted by the working bars (4) and (6) to the working shaft (12) on which is fitted an off-centre (13) with tang (17). The tang turns the fly-wheel (18) and the shaft (19) with the generator (21) that pro¬ duces electricity.

Description

WIND-GENERATOR WITH HORIZONTAL PARALLELOGRAM OF BARS FOR TRANSLATIONAL MOVEMENTS OF WINGS

INVENTION DESCRIPTION

1. FIELD OF APPLICATION

The invention relates to devices aimed to utilisation of kinetic energy of wind, turning it firstly into mechanical energy, and then by electric generators into electric energy.

In the International Patent Classification, it is classified as Section F - Mechanical engineering, Class F 03 D - Wind motors, Group F 03 D 3/06 - Rotors, 5/06 - Wind- engaging parts swinging to-and-fro and not rotating, 7/06 - Wind motors having rotation axis substantially at right angle of attack to wind direction, and 1 1/00 - related to Details and component parts.

2. TECHNICAL PROBLEM

In spite of the relatively high usability factor of present wind turbines with horizontal axis and wings, reaching up to 60% of the wind kinetic energy, there are two conceptual technical problems:

First: the entire area of rotation of wings participates in decreasing the wind kinetic energy, that is, slows the air flow through the same area, in doing this creating a resistance force of long arm and large moment of breakup of the carrying tower.

It is well known that at wind speeds above 80 km/h wind generators with wings are stopped, just when the wind energy is abundant.

Besides the rigorous safety measures, installed are also parallel protection systems, usually self-breaking systems, activated automatically to prevent damages to wings or the entire wind generator. Fracture of wings is particularly dangerous if occurred at maximum revolutions and when at 45° angle of attack to the carrying tower. Calculations indicate that wing of a wind generator of 40 m in diameter could fall as far as 165 m from the wind- generator tower in that case. Second: When rotating, wings have different circumferential velocities along their lengths, and in order to achieve the best wind streamline angle of attack, the wing is to be geometrically twisted, this resulting in decreasing the wind turbine effect.

Besides the above mentioned conceptual issues, there is also the issue of assembling and servicing of wings, generator and turbine as well as of the rest of the equipment mounted on a high tower. This is performed with special cranes, which makes the obtained energy more expensive.

Ecological issues should not to be neglected either. With a 20 m long wing rotating at 30 rpm, the wing tip moves at the circumferential velocity of 220 km/h. This circumferential velocity is very much dangerous for birds, and cavitations around the wing and when passing by the tower produces noises - the intermittent noise.

The technical problem that is solved by this invention relates to constructing a wind generator that will efficiently eliminate the above mentioned technical problems and enable better transformation of the wind's kinetic energy into electricity.

3. STATE OF THE ART

Presently, there are two types of wind generators in use:

- wind generators with horizontal rotation axis, where wings, normally three of them, rotate; and

- wind generators with vertical rotation axis, with various numbers and shapes of wings that turn around vertical column.

The technical solution produced by the same authors in the Patent Application No. HR P20100151A, with one wing swinging around a vertical axis and with a vertical bar parallelogram, requires a counterweight to balance the mass of the wing. The wing is positioned into the wind by means of a stabiliser, and everything is mounted on a platform. This technical solution has not obtained the required precision in positioning the wing and utilisation of the wind, and sudden wind eddying shocks could damage the transmission. Wind generators are divided into three groups by their sizes, that is, installed powers: small, up to 100 kW, medium, from 100 kW to 1.5 MW, and large, over 1.5 MW. Wind generators are to be used only at locations where the average wind speed is over 4.5 m/sec, and an ideal location should have constant wind flow, free of turbulences. These can be divided into inland, coastal and off-shore ones.

4. DISCLOSURE OF THE INVENTION

The essence of the invention is wind generator with a horizontal parallelogram of bars for translational movements of wings. The translational wing movement is transmitted by the horizontal bar parallelogram that turns a working shaft with off-centre that, in turn, rotates a fly-wheel positioned on a common shaft with the electric generator. The control bar of the horizontal bar parallelogram is fitted an actuator that enables positioning of the wing always at the best angle of attack.

The wind generator with horizontal parallelogram of bars for translational movements of wings has at least one symmetrical airfoil shaped wing. The wings are positioned vertical and firmly fitted to consoles.

This invention describes in further details embodiment and functioning of wind generator with horizontal parallelogram of bars for translational movements of two wings.

5. ILLUSTRATION DESCRIPTIONS

Figure 1 shows wind generator with horizontal parallelogram of bars for translational movements of two wings - perspective view.

Figure 2 shows wind generator with horizontal parallelogram of bars for translational movements of two wings - front view.

Figure 3 shows the wind generator shown in the Figure 2 - side view.

Figure 4 shows the wind generator shown in the Figure 2 - top view.

Figure 5 shows the wind generator shown in the Figure 4 in its left-side intermediate position - top view.

Figure 6 shows the wind generator shown in the Figure 4 in its right-side intermediate position - top view.

Figure 7 shows wind generator with horizontal parallelogram of bars for translational movements of one wing - top view.

Figure 8 shows wind generator with horizontal parallelogram of bars for translational movements of three wings - top view.

Figure 9 shows ideal air flow around a horizontal shaft wind generator. Figure 10 shows vectorial presentation of forces acting at aerodynamic profile of wing of a horizontal shaft wind generator.

6. DETAILED DESCRIPTION OF AN INVENTION EMBODIMENT AND ITS FUNCTIONING

In solving the first two technical conceptual problems applied is horizontal parallelogram of bars for translational wing movement, instead of rotating the wings.

The wind generator with horizontal parallelogram of bars for translational wing movements is designed in several variants, with regard to the number of its wings. Figure 1 shows a two-wing wind generator of the variant B, Figure 7 shows a one-wing wind generator of the variant C, and Figure 8 shows a three-wing wind generator of the variant D. Similarly, wind generators may have more than three wings.

This invention description presents in more details wind generator with horizontal parallelogram of bars for translational movements of two wings.

Hereinafter, instead of its full name "wind generator with horizontal parallelogram of bars for translational movements of two wings", the invention is referred to as a "two-wing wind generator".

Two-wing wind generator - variant B

Figures 2, 3 and 4 show embodiment of a two-wing wind generator, in its front and side views, as well as the upper view with wings in the central position, whereas Figures 5 and 6 show its upper views with wings in the left-side and right-side intermediate positions. Wings 1 are shaped as symmetric airfoils. The wings are firmly, vertically and mutually parallel fitted to the lower console 2 and the upper console 3. The consoles ate connected to a wing at about 1/4 of its length from its bottom end and 1/4 from its upper end, respectively.

To the upper console 3 is connected, by joint 5, upper working bar 4. To the lower console 2 is connected, by joint 7, lower working bar 6. The upper and the lower working bars are firmly fitted to working shaft 12 that, when wings are in motion, swings left and right.

To the lower consol 2 is also connected, by joint 9, control bar 8. The control bar 8 is fitted with actuator 1 1. The control bar turns in console 10 that is firmly fitted to tubular extension 16 of platform 14. The platform 14 is connected to electro motor 15 that swings the platform 14.

At the top of the working shaft 12 are fitted wind indicator 22 and anemometer 23. The wind indicator shows wind direction, and the anemometer wind force. The wind indicator and the anemometer are connected with the actuator 11 and the electro motor 15, this making the wings 1 to move translational, swing and change the movement direction, relative to the wind direction and force. Translational movement is enabled by the horizontal bar parallelogram comprising the lower working bar 6 and the control bar 8. The horizontal bar parallelogram, comprising the lower working bar 6 and the control bar 8 with the console 10 and the actuator 11 , maintains the parallel position of the wings when swinging left and right, where the best angle of attack a of air streamlines to the wing 1 remains unchanged. Centreline of the wing left-to-right swing is downwind, that is, the centreline of the angle 2β is always to be downwind, Fig. 4.

At its bottom end, the working shaft 12 has off-centre 13. The off-centre 13 has, at its arm, tang 17 that is positioned from the working shaft 12 at the distance "L". The tang 17 turns fly-wheel 18. The size "L" of the arm is conditioned by the deflection angle β and the fly-wheel size, aimed to smoother passing the dead point in its rotation. The fly-wheel constantly rotates in the same direction, thus turning the swinging moment of the working shaft into mechanical work. At the common generator shaft 19 with the fly-wheel are fitted revolution multiplier 20 and electricity generator 21 that turns wind energy into electricity. The fly-wheel 18 is necessary because the wings 1 at their swing end-positions change the angle of attack a into opposite direction, and the wing passes through a zero drive. In order to create aerodynamic force F at the wings 1 , Figures 6, 8 and 9, the wings are to be at the angle of attack a of wind direction to the wing chord. Constancy of the angle of attack a throughout the oscillation is provided by the horizontal bar parallelogram.

Making the wing move to the opposite side, that is, obtaining a force of the opposite sign, requires retracting, that is, shortening, the control bar 8, by 10-25°, this depending on the actuator speed, before the swing end points, in order to obtain the opposite angle of attack a. Consecutive synchronous changing the angle of attack a at the wing oscillation ends results also in changing the direction of the aerodynamic force F.

In order to limit the aerodynamic force F, and thereby also torque at the working shaft 12, to its maximum load value, the force F at the wings 1 is to be proportionate to the angle of attack a and the wind speed. This is one of the ways of protecting from extreme wind forces. The actuator receives information on the value of extracting or retracting the control bar 8 into or from the actuator 11 , changing thereby the angle of attack a, from the anemometer 23. The stronger the wind, the lesser the control bar 8 is extracted or retracted into or from the actuator 11 , and vice versa.

The aerodynamic force F at wings of the wind generator with horizontal parallelogram of bars for translational movements having three or more wings is multiplied, where mutual distance between the wings is to be at least about 20% larger than the length of the wing chord.

The described embodiment of wind generator with one or more wings makes high towers unnecessary, and other essential wind generator parts are placed on the ground. This reduces costs of constructing, assembling and servicing. There are no rotating wings that endanger the surrounding area when broken, because here a wing may, in the worst option, fall next to the tower. Small speed of wing translational movement eliminates dangers for birds.

Wind generators with one or more wings, according to this invention, eliminate setbacks about circumferential forces that appear at rotating wings in wind generators with horizontal shafts.

In order to demonstrate the difference between technical solutions of wind generators with one or more wings, according to this invention, Figure 9 shows air flow around the wind generator with horizontal shaft and rotating wings, whereas Figure 10 shows vectorial presentation of forces acting at aerodynamic profile of wing of a horizontal shaft wind generator.

Functioning of the invention

Wind generator with horizontal parallelogram of bars for translational movements of two wings is started as follows:

When wind started, the wind indicator 22 automatically positions itself into the wind direction. At the same time, the wind indicator instructs, by wire or wirelessly, the electro motor 15 to turn the platform 14 with the tubular extension 16 to which is fitted the console 10 of the control bar 8. The control bar 8 and the lower working bar 6 make parts of the horizontal bar parallelogram, to which, via the lower console 2, fitted are the wings , that are also positioned into the wind direction, regardless of the position they had been in before the wind started.

Wing movements, between the two end positions, are transmitted by the upper working bar 4 and the lower working bar 6 to the working shaft 2. The working shaft turns the off- centre 13 that, by the tang 17 at the tip of the arm "L", moves fly-wheel 18. The fly-wheel is fitted at the common generator shaft 19 with the revolution multiplier 20 and the electricity generator 21 , the latter producing electricity.

In order to create the aerodynamic force F at the wings 1 , the wind direction and the wing chord are to be at the angle of attack a between each other. Constancy of the angle of attack a throughout the oscillation is provided by the horizontal bar parallelogram and the actuator 1 .

In order to make the wing 1 move to the opposite side, that is, to obtain a force of the opposite sign, the actuator 11 retracts, that is, shortens, the control bar 8 by 10-25° before the oscillation end points, in order to obtain the opposite angle of attack a. Consecutive synchronous changing the angle of attack a at the wing oscillation ends results also in changing the direction of the aerodynamic force F.

The aerodynamic force F at the wings is proportionate to the angle of attack a and the wind speed. In order to limit the aerodynamic force F, and thereby also torque at the working shaft 12, to its maximum load value, the amount of "shortening" or "extending" the control bar 8, and thereby also the angle of attack a, the actuator 11 receives information from the anemometer 23. The stronger the wind, the lesser are changes at the actuator, and vice versa. This is one of the ways in which the wind generator is protected from extreme wind forces. The actuator may be electrical, mechanical, pneumatic or hydraulic.

In wind generators with larger numbers of wings the aerodynamic force is multiplied. Here, mutual distance between the wings is to be at least about 20% larger than the length of the wing chord.

LETTER AND NUMERAL REFERENCES IN DESCRIPTION AND FIGURES

B - wind generator with two wings / two-wing wind generator

C - wind generator with one wing / one-wing wind generator

D - wind generator with three wings / three-wing wind generator

1 - wings

2 - lower wing console

3 - upper wing console

4 - upper working bar

5 - upper working bar to upper wing console joint

6 - lower working bar, parallelogram element 7 - lower working bar to lower wing console joint

8 - control bar, parallelogram element

9 - control bar to lower wing console joint

10 - control bar console

11 - actuator

12 - working shaft

13 - working shaft off-centre

14 - platform with gears

5 - electro motor with platform yaw transmission

16 - tubular extension of platform

17 - off-centre tang

18 - fly-wheel

19 - generator shaft

20 - revolution multiplier

21 - electricity generator

22 - wind indicator

23 - anemometer

24 - housing

„L" - off-centre arm size

F - aerodynamic force at wings

Fo - resistance force

a - wind streamlines to wings angle of attack - optimum angle of attack

β - angle of maximum deflection of wings to the right and the left sides

A - wing rotation area

V_! - wind vectorial value through the rotation area

V₂ - wind vectorial value through the A2 area

h - tower height to the rotation point

T - tangential force

S - axial force

R - F and F₀ forces resultant

v - wind speed vectorial value

u - circumferential speed

w - v and u speeds resultant defining the angle of attack a along classical wind turbine wings 7. INVENTION APPLICATION

Application of the invention is obvious from its very description.

Wind generator with horizontal parallelogram of bars for translational movements of wings contributes to obtaining clean energy since it may work at much greater wind speeds. Experts will find obvious possibilities of certain modifications in the described embodiment of wind generator with horizontal parallelogram of bars for translational movements of wings, yet without leaving the scope and spirit of the invention.

Claims

PATENT CLAIMS

1. Wind generator with horizontal parallelogram of bars for translational movements of wings, wherein the wind generator as per a variant (B) has two symmetric aerodynamic wings (1), vertically positioned, firmly fitted to lower wing console (2) and upper wing console (3); the said wind generator has lower working bar (6) that is by one end firmly connected by joint (7) to working shaft (12); the said wind generator has upper working bar (4) that is by one end firmly connected by joint (5) to working shaft (12); the upper and the lower working bars, while the wings move, turn the working shaft (12); the said wind generator has control bar (8) that is by one end firmly connected by joint (9) to the lower console (2) and by the other end to console (10) in which it turns, the console (10) is firmly connected to tubular extension (16) of a platform (14); the said wind generator has actuator (11) through which is passed the control bar (8); the actuator enables positioning the wings (1) always at the optimum angle of attack (a); the said wind generator has the platform (14) turned by electro motor (15) when so instructed by wind indicator (22) in order to direct wings into the wind; to the working shaft (12) is connected off-centre (13) that at its arm has tang (17) that is positioned by value ("L") far from the working shaft (12), the tang (17) drives fly-wheel (18) that rotates constantly; the said wind generator has generator shaft (19) to which are connected the fly-wheel (18), revolution multiplier (20) and electricity generator (21); the said wind generator has anemometer (23) that measures wind speed and wind indicator (22) that indicates wind direction.

2. Wind generator as claimed in Claim 1 and variant (C), wherein it has one symmetric aerodynamic wing (1).

3. Wind generator as claimed in Claim 1 and variant (D), wherein it has three symmetric aerodynamic wings (1 ).

4. Wind generator as claimed in Claims 1 , 2 and 3, wherein the said actuator (11) can be electrical, mechanical, pneumatic or hydraulic.

5. Wind generator as claimed in Claims 1 , 2 and 3, wherein the platform (14), the electro motor (15), the off-centre ( 3), the fly-wheel (18), the generator shaft (19), the revolutions multiplier (20) and the electricity generator (21) are housed in common housing (24) situated on the ground.

6. Wind generator as claimed in Claims 1 , 2, 3 and 4, wherein the said horizontal parallelogram of bars comprises the lower working bar (6) and the control bar (8) with the console (10) and the actuator (11).