WINDTRACKER TWIN-TURBINE SYSTEM
The turbine system for wind and/or water power, wherein the radial turbines have a rotor which can rotate about an axis and comprises one or more turbine blades, wherein the turbine blades are aligned parallel to the rotor, wherein the turbine blades are arranged within a cylindrical shell, which is arranged concentrically around the axis and has an outer radius R1 and an inner radius R2, is characterized in that the turbine blades have a specific geometry and in that two radial turbines (1, 2) which are aligned alongside one another and parallel are arranged, which radial turbines (1, 2) are connected to one another and can pivot about a pivoting axis (15) parallel to the turbine axes (18), wherein the pivoting axis and the guide surfaces (3, 4) are not located on the connecting line between the turbine axes, and are both located on the same side of the connecting line. It is proposed that the abstract be published without any drawing.
The invention relates to a turbine system in accordance with the preamble of claim 1.
PRIOR ARTSavonius turbines are known (see also
A decisive unbalance as a result of the cyclically varying load strength from the flow during rotation is characteristic of the Savonius rotor, even when the weight distribution is perfectly balanced. This unbalance due to load alternation can be minimized by arranging a larger number of blades, generally three, instead of two. However, this greatly reduces the efficiency of the Savonius rotor, by approximately 30%.
By comparison with the known three-blade wind generators having a horizontal axis of rotation and aircraft-type blades, a radial turbine has the major advantage of operating independently of the direction of the incident wind. Thus, the radial turbine having a vertical axis of rotation does not have to be turned to the wind.
In a particularly economical embodiment, the radial turbine is provided with deflector plates that collect the wind energy and deflect it onto the blades of the radial turbine in a concentrated form. However, this has the drawback that, because of the deflector plate, independence from the wind direction is no longer achieved. The radial turbine comprising a deflector plate therefore has to be tracked to the wind.
If the Savonius turbine is equipped with deflector plates, it gains at low wind speeds, but loses all the more at higher wind speeds.
OBJECT AND SOLUTION ACCORDING TO THE INVENTIONObject of the invention: much better use is to be made of the wind energy, with a much higher efficiency than in conventional Savonius turbines. It should still be possible to use the wind turbine even when the wind would be too weak to drive conventional Savonius turbines.
The wind turbines should operate with no noise and very little vibration, in such a way that they can even be used on residential buildings in urban areas.
A radial turbine is also to be used which comprises a deflector plate and which automatically turns to an optimum angular position with respect to the incident wind, and is thus self-tracking, without a tracking arrangement being necessary for this purpose. The advantages of the deflector plate in the radial turbine are thus to be combined with the independence of the radial turbine from the incident wind direction.
A minimum unbalance with high performance is to be ensured by way of the special construction and geometry.
This object is achieved in accordance with the invention by the features of claim 1.
Advantageous embodiments of the invention are specified in the dependent claims.
It is known that the Savonius rotor and the Darrieus rotor do not gain in performance as a result of deflector plates. The Savonius rotor gains in weak wind, but this is conditional on speed, and leads to losses at higher wind speeds. Since the turbine is dependent on the wind direction, it decreases in overall efficiency.
This problem is solved by the invention.
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- a) As a result of the aerodynamic nose (wind splitter) together with the turbine of the novel construction, energy yield is demonstrably increased at all wind strengths.
- b) As a result of the optimum arrangement of the aerodynamic parts, including the rotary connection, the turbine system follows the wind in all directions without a motor drive.
As a result of the specific shape and arrangement of the turbine blades in connection with the wind splitter in accordance with the parameter ranges given in claim 1, rotational speeds up to three times higher than in known Savonius turbines are obtained, along with an efficiency of up to 66%, by contrast with the efficiency of 28% achieved by conventional turbines. The turbine according to the invention can be used even in very weak wind which would no longer be sufficient to drive conventional Savonius turbines.
By contrast with the Savonius rotor, the wind turbine according to the invention does not have an unbalance of the type described above, even in a particularly advantageous embodiment where three turbine blades are provided.
It is particularly expedient to combine the geometry according to the invention of the turbine blades with a deflector surface according to claim 2, also known as a wind splitter.
Another important consideration: suppose there are two turbines in a system enclosed by deflector plates and having additional beveled concentration plates and/or wind guide plates which are attached above and below the turbines. As a result of the closed system and the additional concentration plates and/or wind guide plates, optimum use is made of what is known as the Magnus effect, and as a result the system according to the invention, which is mounted on a mast, can rotate to the wind automatically and thus always receive an optimum wind flow. This “turning to the wind” has been demonstrated in a number of specific models in natural wind.
The Magnus effect, named after Heinrich Gustav Magnus (1802-1870), who discovered it, is a phenomenon in fluid mechanics, specifically the transverse force effect (force) experienced by a round rotating body (cylinder or ball) in a flow.
By way of frictional effects, a rotating roller induces rotation in the fluid surrounding it. If there is additionally a flow over the roller, the different speeds of fluid overlap. As a result, the fluid flows around the rotating roller faster on one side than on the other (in the rest system of the roller). On the side of the roller where the frictional effects are greater, it is as if the fluid were flowing more rapidly. This results in “deflection” of the roller, pushing the roller downwards (see
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- Football players kick the ball with spin in such a way that it flies into the goal in an arc. The more quickly it rotates, the greater the deviation of the path (curling cross, knuckleball).
- Table tennis players and tennis players use this effect, for example with topspin and slicing.
- Curve balls in baseball and riseballs in softball.
- Spin-bowling in cricket.
- Golf balls have a large number of small depressions on the surface, known as dimples. As turbulators, they improve the adhesion of the boundary layer which lies against the ball and is entrained by the rotation thereof. This increases the formation of turbulence and the associated deviation of the ball due to the Magnus effect. Since the golf ball rotates backwards as a result of the wedge shape of the golf club, it is lifted by the Magnus effect; it does not simply fly like a cannonball, but instead experiences a lift. Additional deviations to the left or right are possible, and are also used by players who have mastered this technique. Moreover, the supercritical turbulent circulation reduces the air resistance, and this in turn leads to greater flight distances.
According to the invention, high performance is achieved in combination with low installation costs, in such a way that the cost-effectiveness, in terms of power output, is much greater than in the known wind generators comprising a horizontal shaft and blades of the aircraft-wing type.
To increase the cost-effectiveness, a ring generator is provided for power generation. In addition, to increase the cost-effectiveness further, the mast and the wind splitter can be used as advertising space.
With the blade shape according to the invention of the individual turbines and the specific arrangement of the two turbines with respect to one another, it is particularly advantageous that the two turbines do not obstruct one another, but can instead boost one another, even at low wind speeds, assisted by the low-frequency pressure oscillation taking place in the rear cavity of the V-shaped wind splitter.
By contrast with the known wind generators comprising a horizontal shaft and three blades, the radial turbine according to the invention can be operated even at relatively low wind speeds. As a result of the Magnus effect, the radial turbine according to the invention “pulls” the wind in, as it were, and amplifies low wind speeds. For example, the radial turbine according to the invention can also be used in circulating winds, in which the wind speed is greater below at a low height than at the large height at which the three-blade wind generators have to be operated simply because of the blade size. A wind speed which is too low for the known three-blade turbines in any case is sufficient for energy production with the radial turbine according to the invention.
In the event of fluctuations in the wind direction, the radial turbine according to the invention adjusts itself automatically, partly as a result of the Magnus effect, and immediately rotates to the optimum direction, even at wind speeds of less than 1 m/s. Rapid adaptations of this type of the generator are not possible with the known three-blade turbines.
Since the radial turbine according to the invention only takes up a small amount of space, it can be used as an add-on to pre-existing parts of buildings or structural elements, for example as an attachment to a street light.
In the following, a plurality of embodiments of the invention are described in greater detail by way of drawings. Like reference numerals have the same significance in all of the drawings and are therefore only be explained once.
In the drawings:
Wind flows onto the wind turbine according to the invention of
A grid mast construction is provided above the rotary connection, and is used and can be used as a frame for the special accumulator mounting system and turbine system.
A safety space, which is protected and grounded by the outer shell of the mast, preferably a thick-walled steel tube, and may contain various sensitive technological components, is located below the rotary connection, without any additional costs. The use according to the invention of the turbine system makes it possible to create safety spaces, and to use wind generators in the pre-existing infrastructure (streets, rails etc.), in areas where construction would otherwise be impossible.
It can clearly be seen that in a wind speed range from approximately 0.7 to 1.8 m/s a conventional Savonius turbine is stationary, but the wind turbine according to the invention rotates at rotational speed of 50 to 150 revolutions per minute. In the wind speed range from approximately 1.7 to 2.7, the wind turbine according to the invention rotates at approximately 2 to 15 times the rotational speed of the conventional Savonius turbine.
A series of measurement results for the properties of the wind turbine according to the invention and for a conventional Savonius wind turbine, which were both exposed to the same wind conditions, is shown graphically in
As regards the prior art, it can additionally be established that 2 basic types of wind generators have achieved success:
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- a) Horizontal-axis wind turbines (HAWTs) with wind incident in the axial direction
- b) Vertical-axis wind turbines (VAWTs) with wind incident transverse to the axial direction
The inventive solution disclosed herein relates primarily to VAWTs, although horizontal mounting with an incident wind flow transverse to the axial direction is also possible in special cases.
There are also many variations/modifications among commercially available VAWT systems, starting from 2 basic types (see for example German Wikipedia “Windturbine”):
Savonius rotor
Giromill/Darrieus rotor
Unlike the turbine according to the invention, the Savonius rotor cannot run faster as a result of a deflector plate or deflector surface. However, this can be demonstrated with the invention.
The variations relate to the number and the special shape of the rotor blades, the attachment of wind guide elements, and in some cases a screw-shaped configuration for achieving a more constant speed during rotation. The solution according to the invention thus relates to particular, relatively precisely determined shapes and arrangements which have been found to be particularly efficient in the development process.
This description of the invention is therefore supplemented by a further embodiment, in connection with a further narrowly defined parameter space analogous to Table 1 for describing the shape, as follows.
The further embodiment of the wind turbine according to the invention also corresponds to
For completeness, it is noted that the height (or length) of the turbine may be in a wide range of ratios to the radius. That is to say, depending on the place of use, the height or length of the turbine is approximately 0.3 to 100 times the turbine radius, it also being possible, for reasons of construction or stability, to understand a long or high turbine as a positive coupling of a plurality of turbines to a shaft which may optionally be connected by means of positive couplings.
The purpose of the turbine system is to obtain energy from wind in an optimum manner, priority being given to obtaining electrical energy. For this purpose, a generator is mechanically connected to the turbine shaft positively or non-positively, directly or indirectly via a transmission, in a manner adapted to the turbine system, said turbine shaft being positively or non-positively connected to the turbines so as to ensure force transmission from the turbine to the generator. In this context, one generator may be used for both turbines, or each turbine may be connected individually to one respective generator.
The generator is controlled in a manner adapted to the wind speed, in such a way that by regulating the generated power an electromagnetic braking torque is transmitted to the turbine, so as to set an optimum tip speed ratio (TSR) for energy conversion that is between 45% and 65% of the tip speed ratio of the unbraked turbine. This ensures that the maximum possible energy can always be “harvested”.
In the embodiment, a height:radius ratio of approximately 20 is set, the turbines on a shaft being mounted individually approximately every 5 m, and being interconnected via a flexible positive coupling and connected to the end of a shaft directly or indirectly via a transmission comprising a current generator.
For increased efficiency, two turbine deflector plate systems may advantageously be brought together with reflective symmetry as a wind splitter system, in such a way that for example with a vertical axis of rotation, the left deflector plate deflects the wind to the left turbine and the right deflector plate deflects the wind to the right turbine as seen in the primary wind direction. In this context, the deflector plates may advantageously be in the form of a “nose” with a rounded “bridge” as a connection between the two deflector plates, so as to form a closed wind guide system, the wind splitter.
Preferably, the distance between the V-shaped wind splitter and the turbines is variable and adjustable, so as to achieve optimum operating conditions for all wind conditions.
As a function of the wind speed, the V-shaped wind splitter is brought into the optimum position, based on the distance and inclination with respect to the turbine blades and the turbine shaft.
For an overall height of 20 m, the height of the turbines is 10 m. The turbines have a diameter of 1 m. The expected capacity for a site on the coast, where the wind generator captures the circulating coastal wind, is approximately 21,700 kWh, with an efficiency averaged over the year of 38%.
The rotary bearings 10, 11 on the one hand and 13, 14 on the other hand are kept at a distance by a spacer collar 23, 24. The spacer collar is in the form of a hollow tube.
Finally,
What is known as a thread test was carried out on the system according to the invention (
The significance of the reference numerals in
A side effect is the ping-pong ball which is “suspended” in an oblique airstream. As a result of the Coanda effect, the flow of the airstream is not stripped away from the ball, but encircles it (almost) completely without being stripped away. Since the ball is suspended slightly below the center of the airstream, the air does not flow around it symmetrically. More air is deflected downwards, since the flow speed and flow cross-section are lower at the underside of the ball than at the upper side. As a result, the ball experiences an upward force. This is superposed on the Magnus effect (the ball rotating). The two effects each prevent the ball from falling downwards and only allow it to “slip” along the underside of the airstream. The resistance of the ball to the flow holds it at a distance from the nozzle, and gravity prevents it from simply being blown away. Thus, the ball can float in a more or less stable position.
Evaluation of static and dynamic torque measurements on the wind turbine according to the invention of diameter 1 m and length 1 m in
MoersThe following data are taken into account, directly or indirectly, in the evaluation:
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- Static torque measurements (stationary torque) from 24 to 26 Sep. 2010
- Dynamic torque measurements in the period from 4 to 8 Nov. 2010
An eddy current brake, with which various braking forces could be set by varying the coil current, was also used during the dynamic measurements in each case.
The measurement values were checked for plausibility and evaluated using various averaging and filtering methods.
The result data for wind speeds of between 2 and 8 m/s are compiled in the following table.
Torque [Nm] vs. rotational speed [rpm]; parameter wind speed [m/s]
Key to graph:
♦ 2 m/s measurement
▴ 3 m/s measurement
X 4 m/s measurement
+ 5 m/s measurement
− 6 m/s from measurement
▪ 7 m/s from measurement
x 8 m/s from measurement
------- max. torque
- - - - ave. torque
Mech. Power
Extrapolation in the maximum power range with average PC=35%
Mechanical power [W] vs. torque [rpm]; parameter wind speed [m/s]
Key to Graph:
▪ 2 m/s eddy current brake
x 3 m/s eddy current brake
4 m/s eddy current brake
− 5 m/s eddy current brake
♦ 6 m/s from eddy current brake
▴ 7 m/s from eddy current brake
X 8 m/s from eddy current brake
Since the dynamic measurements thus far have only been carried out with relatively weak braking forces, the interpolation outside the measurement range that has been established thus far is shown in dashed lines. In this context, it has been assumed that at the maximum power point a power coefficient of 35% is achieved. From the dispersion of the result data, sufficiently precise calibration verification for the measurement technique used can provisionally be placed at approximately 30-40%. Otherwise, the systematic errors in the measurement technique have to be additionally taken into account. The power coefficient can be determined more precisely if further measurements at higher braking forces are taken into account.
The turbine system according to the invention can also advantageously be used in water for obtaining energy from the flow of water, that is to say as a marine turbine system.
In a further embodiment, a grid mast construction, which is and/or can be used as a frame for the special accumulator and turbine mounting system, is provided above the rotary connection that is fixed to a stationary mast (cf.
Since the lower region of the tower below the rotary connection is made from steel tubing, it forms a cavity which can be used for safely installing highly sensitive technology, since ventilation and/or heating and/or suitable air conditioning, particularly in relation to air humidity, can be provided.
The base part may be used in a configuration as a further energy store or as a water reservoir or oil store, and may be designed accordingly. Heat pumps (with heat pipes) may be integrated into the base part.
In the present invention, the turbine blades (air foils) are mounted on a plurality of milled support arms that in turn are fastened to a rotary part on the shaft on both sides by two “support hearts” which are screwed together. This reduces the weight and makes it possible for the turbine to reach full speed more quickly (cf.
In addition, the support hearts make it possible to replace the turbine blades individually by screwing. The very heavy fixed circular disks, which are entrained in rotation and are conventional in the Savonius turbine, are replaced with stationary grille face panels that are additionally rounded for better wind introduction. As a result, the weight of the rotating parts and the losses from the Thom effect are greatly reduced. The wind energy can thus be harvested with a high level of efficiency.
The support hearts which are used according to the invention are much lighter. The grille face panels are held together by a mast that is a functional replacement for the heavy frame construction conventional in the Savonius turbine.
It is advantageous to bring together a plurality of windtrackers to form a decentralized network-communicating energy supply system and other applications. It is therefore proposed to provide an arrangement of the turbine systems according to the invention and/or of the windtrackers along the traffic infrastructure, such as streets, motorways, railway lines and canals, which arrangement is additionally provided for telecommunications or for buffering current from the grid in times of low current uptake and/or for use as an advertising medium and/or as street lighting and/or for providing safety spaces.
LIST OF REFERENCE NUMERALS
- 1 radial turbine
- 2 radial turbine
- 3 wind splitter
- 5 steel mast
- 6 base plate
- 7 support plate
- 8 support plate
- 9 support plate
- 10 (rotary) bearing
- 11 (rotary) bearing
- 12 (rotary) bearing
- 13 (rotary) bearing
- 14 (rotary) bearing
- 15 longitudinal axis
- 16 turbine bearing
- 17 turbine bearing
- 18 turbine shaft
- 19 turbine bearing
- 20 turbine bearing
- 21 turbine bearing
- 22 turbine bearing
- 23 spacer collar
- 24 spacer collar
- 25 turbine blades
- 26 upper collar flange
- 27 guide flange
- 28 wind
- 29 modified deflector surface
- 30 concentration plate or concentration surface
- 31 Magnus effect
- 32 Coanda effect
- 33 Magnus/Coanda superposition
- 34 high lift
- 35 negative pressure
- 36 overpressure
- 37 thread direction breaks away
- 110 upper curve
- 111 curve
- 112 curve
- 113 curve
- 201 milled support arms
- 202 support hearts
- 203 turbine blades
- 301 external radius of the turbines or turbine blades
- 302 rounding of the concentration plate and/or wind guide plate
- 303 concentration plate and/or wind guide plate
- 304 grid mast
- 305 V-shaped wind splitter
Claims
1. A turbine system for wind or water power, comprising two radial turbines, wherein where f1=0.19 to 0.32, where f2=1.2 to 2.4, and where f8=0.11 to 0.19, and
- the radial turbines comprise a rotor which can rotate about a shaft and which comprises one or more turbine blades, the turbine blades being orientated parallel to the rotor, the turbine blades being arranged within a cylindrical shell that is arranged concentrically about the shaft and has an external radius R1 and an internal radius R2,
- the internal radius is R2=f1×R1
- each turbine blade has a first region which extends from the internal radius R2 to the external radius R1, is curved towards the shaft, and has a radius of curvature R3=f2×R1
- a second region, which is externally adjacent to the first region, is positioned on the outside of the cylindrical shell, and has a curvature towards the shaft, the curvature pointing to the same side as the curvature of the first region, the radius of curvature R4 of the second region being R4=f3×R1 where f3>0.7,
- the second region is of a width B2=f8×R1
- two radial turbines, orientated parallel side by side, are arranged with a vertical rotation shaft, are interconnected, and are pivotable about a pivot shaft parallel to the turbine shafts, the pivot shaft and a V-shaped wind splitter being positioned outside the line connecting the turbine shafts and both being on the same side of the connecting line.
2. The turbine system according to claim 1, wherein a deflector surface orientated parallel to the rotor is arranged outside the cylindrical shell, and is of a width
- B3=f9×R1
- where f9=0.7 to 2.5, the edge of the deflector surface facing the turbine shaft being at a distance A2 A2=f6×R1
- where f6=0.25 to 0.55 from a first longitudinal section plane through the turbine shaft,
- and at a distance A1 A1=f5×R1
- where f5=1.00 to 1.10 from a second longitudinal section plane through the turbine shaft, the second longitudinal section plane being perpendicular to the first longitudinal section plane, and in that the deflector surface has an angle of incidence α=40° to 60°
- with respect to the first longitudinal section plane.
3. The turbine system according to claim 1, wherein the total width B1 of the turbine blade is
- B1=f7×R1
- where f7=0.9 to 1.1.
4. The turbine system according to claim 1, wherein the kinked edge between the first and the second region of the turbine blade has a radius of curvature
- R5=f4×R1
- where f4=0.01 to 0.08.
5. The turbine system according to claim 1, wherein the turbine shaft is in the form of an axle having a diameter
- D1=f10×R1
- where f10=0.03 to 0.13.
6. The turbine system according to claim 1, wherein three rotor blades are provided, and are arranged evenly distributed about the shaft and are balanced.
7. The turbine system according to claim 1, wherein the two turbines rotate in opposite directions.
8. The turbine system according to claim 1, wherein a ring generator is provided for generating current.
9. The turbine system according to claim 8, wherein the generator can be controlled so as to set the optimum tip speed ratio of the turbine.
10. The turbine system according to claim 1, wherein the turbine system is fastened to a mast, pontoon, base part, building roof or the like via the rotary connection.
11. The turbine system according to claim 1, wherein a plurality of these turbine systems are arranged above one another or side by side on a mast.
12. The turbine system according to claim 1, wherein the turbine system rotates to the optimum wind or water flow direction automatically, without a motor-driven tracking means, without a control system, and without additional deflector surfaces.
13. Wind or water generator according to claim 1, wherein the distance between the V-shaped wind splitter and the turbines is adjustable.
14. The turbine system according to claim 1, wherein the lower region of the mast or the deflector surface is formed as an advertising space or advertising medium.
15. The turbine system according to claim 1, wherein the pivot shaft comprises a rotary connection, and a grid mast, to which an accumulator system or a turbine support system can be fixed, is provided above the rotary connection.
16. The turbine system according to claim 1, further comprising:
- means for automatically moving the radial turbines closer together when a predetermined wind speed is reached.
17. The turbine system according to claim 1, wherein the radial turbines are divided into a plurality of individual turbines mounted individually along a shaft.
18. The turbine system according to claim 1, wherein a safety space, which is protected and grounded, is provided below the rotary connection for accommodating sensitive technological components, the safety space preferably comprising ventilation or heating or suitable air conditioning, particularly in relation to air humidity.
19. The turbine system according to claim 1, wherein the base part can be used as a further energy store or as a water reservoir or oil store.
20. The turbine system according to claim 1, wherein heat pumps are integrated into the base part.
21. The turbine system according to claim 1, wherein the deflector surfaces are mounted on a plurality of milled support arms that in turn are fastened to a rotary part on the shaft on both sides by two support hearts which are screwed together.
22. The turbine system according to claim 1, wherein stationary grille face panels are provided at the upper and lower end of the turbine, and the grille face panels are rounded in the front region.
23. The turbine system according to claim 1, wherein LED elements are attached to the turbine blades and can be actuated as a function of the rotation so as to achieve advertising effects.
24. The turbine system according to claim 1, wherein a grid mast, including the turbine mounting and the turbines, is fastened to the rotary connection of the mast.
25-26. (canceled)
Type: Application
Filed: Sep 14, 2011
Publication Date: Jul 4, 2013
Inventor: Dennis Patrick Steel (Moers)
Application Number: 13/822,318
International Classification: F01D 15/00 (20060101);