DE102012213213B4 - Swimming platform for wind turbines - Google Patents

Abstract

Floating platform (1) for vertical axis wind turbines (6), comprising: at least two elongated floating bodies (2), the longitudinal axis of which is perpendicular to the water surface; at least two vertical axis wind turbines (6), which are each arranged on the top of the at least two floating bodies (2), with a direction of rotation (9) of at least one of the vertical axis wind turbines (6) opposite to a direction of rotation (9) of a respective other vertical axis wind turbine (6) another floating body (2) of the floating platform (1); at least one first connecting element (3); and at least one second connecting element (4) which comprises a centrally arranged anchoring (5); The at least two floating bodies (2) are each pivotably connected to one another via a first connecting element (3), the at least two floating bodies (2) are each pivotably connected to one another via a second connecting element (4), and the first and second connecting elements ( 3, 4) are parallel to one another, so that a parallel swinging of the floating bodies to one another is possible in the plane which is defined by the vertical floating body axes of the two connected floating bodies.

Description

The present invention relates to the technical field of wind turbines. The present invention relates to a floating platform for vertical axis wind turbines.

In the course of the further development of wind power plants, in particular for power generation from wind energy, more and more extensive construction measures are being made in order to construct large so-called wind farms, consisting of many individual wind power plants. As a result, the search for undeveloped suitable locations for such wind turbines is becoming increasingly difficult. In order to develop sufficient expansion areas for wind farms, areas that are difficult to access or difficult to access come to the fore, such as B. Water surfaces (seas, lakes, rivers, etc.). Wind turbines on water surfaces offer particular advantages, since here usually uniform wind conditions prevail, which promise a consistently high current efficiency.

However, the safe construction of wind turbines on water surfaces is difficult and expensive. In addition, conventional wind turbines erected on water surfaces are rigidly and inflexibly fixed on their predetermined pedestals, so that subsequently no location changes can be made. Therefore, there are efforts to develop buoyant wind turbines.

The DE 197 27 330 A1 discloses a horizontal axis offshore wind turbine that operates one or more wind turbines in grouped arrangement on a floatable anchorage platform, and that platform is free to rotate about the anchor point for alignment with prevailing wind and flow directions.

The US 2011/0311360 A1 discloses a horizontal axis offshore wind turbine with at least one float, a horizontal axis wind turbine. The floating body is a buoy body connected to a steering arm, which in turn is connected to a rotatable connection structure anchored to the seabed.

The DE 10 2007 028 839 A1 discloses a tubular truss support tower for floating horizontal axis wind turbines.

The US 2011/0140426 A1 discloses a horizontal axis wind turbine with variable height.

The DE 103 37 997 B4 discloses an attachment device for an offshore wind turbine with a foundation having means for holding the wind turbine, wherein the foundation floats in the water and fixed by anchoring means to the seabed. The fastening device is characterized in that the foundation has a vertically oriented cylindrical portion along which a helical wing for vertically stabilizing the fastening device extends.

However, such individual floats are very susceptible to waves and can easily be knocked over by these or, over the vibration frequency of the float, overturned or submerged under water. A single float behaves in the water as a vertically suspended spring pendulum with a natural frequency, wherein the buoyancy of the floating body replaces the vertical spring restoring force of the spring pendulum. If the frequency or a multiple of the frequency of the waves on the body of water is very close to this natural frequency, an unwanted swinging of this pendulum may occur. These effects are known from architecture. In the case of a float, such effects could tilt or submerge the entire system, resulting in irreparable damage. The application has the object to provide a swimming platform for wind turbines, which is not susceptible to waves and prevents the platform from tipping over.

The object is achieved by a swimming platform with the features of claim 1.

The present invention provides a swimming platform with the features of claim 1, which is immune to waves and can prevent tipping over the swimming platform.

In particular, a swim platform for vertical axis wind turbines according to the present invention comprises at least two elongate floats substantially vertically floating and each comprising at least a first connecting element and at least a second connecting element having a centrally located anchoring. The at least two floating bodies are each pivotally connected to one another via the first connecting element and via the second connecting element, wherein the first and the second connecting element are substantially parallel to one another. The pivoting plane extends through the two vertical longitudinal axes of the floating body. The second connecting element is preferably the upper connecting element and thus closer to the water surface. Alternatively, the second Connecting element can also be arranged as a lower connecting element.

The swimming platform according to the invention may further comprise at least one vibration damper in the floats. At least one of the connecting elements may each be coupled within at least one floating body to a generator adapted to generate electric current from the wave-induced relative oscillations of the floating bodies. The at least two floating bodies may be hollow, have a substantially round cross-sectional area and each comprise a substantially cylindrical upper part with a first diameter and a substantially cylindrical lower part with a second diameter which is larger than the first diameter. In addition, the at least two floating bodies may each comprise a substantially frusto-conical middle part.

The upper part of the floating platform according to the invention may be formed in the region of the water surface as a truss girder to reduce a resistance of the at least two floats against impinging waves or water currents.

The at least two floats may be made of a metal such as a bent sheet or a concrete shell casting process using concrete or a concrete mix. The at least two floating bodies may each be divided by plates into at least three segments, wherein at least one of the lower segments comprises ballast. In the floating platform according to the invention, at least one segment may be designed as a ballast tank in order to set a floating height of the floating bodies. Within each of at least one segment of the at least two floating bodies, one or more modules may be arranged, the module or modules comprising at least one of a plant control device, a water pump, a current transformer, a current rectifier, a current transformer, a current storage device, a hydrogen production unit and a hydrogen storage device.

The swimming platform further comprises at least two wind turbines, which are each arranged on the upper side of one of the at least two floating bodies. These wind turbines are preferably of the same type. The anchoring of the floating platform according to the invention may comprise at least one pair of coils for inductively transmitting power from the floating platform to a power cable. Optionally, the anchoring may comprise an upper anchoring element and a lower anchoring element, each having a substantially annular projection which engage each other. The projections may have a substantially L-shaped cross-section, in order to allow the first anchoring element and the second anchoring element are rotatable by 360 ° to each other. The upper and lower anchoring members may further include internal bores which direct an attacking water pressure upon vertical movements of the anchorage to tensile or compressive loaded friction surfaces on the anchoring elements or their annular projections, such that a film of water reduces friction at the loaded locations ,

The wind turbines are vertical rotor wind turbines and vertical axis wind turbines (VAWT). A rotational direction of at least one of the vertical rotor wind turbines is opposite to a direction of rotation of a respective other vertical rotor wind turbine on another floating body of the floating platform.

The floating platform described above may be further characterized in that the torques generated by the wind turbines are transmitted to the first connecting element. In this case, the torques generated by the wind turbines and transmitted to the first connector may add up to zero.

Alternatively, the speeds of the vertical rotor wind turbines may be variable by selectively braking individual vertical rotor wind turbines to produce a torque of the platform through different rotational speeds of the vertical rotor wind turbines.

Another aspect of the present invention is a swimming platform system comprising at least two of the above-described floating platforms. Further, wind direction sensors provided on the floating platforms and transmitting wind direction data to platform controls of the floating platforms may be provided, the plant controllers being adapted to communicate with each other and, together with data from the wind direction sensors, automatically align with the vertical rotor wind turbines in terms of power efficiency calculate each individual swimming platform and implement it by selective braking of the vertical rotor wind turbines.

Brief description of the drawings

The drawings described below are schematic drawings. Here, in both the description and in the drawings, the same or similar parts are designated by the same reference numerals.

1a and 1b Figure 12 are schematic illustrations of the present invention using vertical axis wind turbines.

2a and 2 B are schematic representations of the present invention with water surface and anchoring.

3 is a schematic representation of the present invention, showing a first connecting element.

4 Figure 3 is a schematic representation of the present invention showing a second anchored fastener.

5 Figure 4 is a schematic illustration of the present invention showing the different rotational orientation of vertical axis wind turbines.

6a - 6c FIG. 12 are schematic illustrations of the present invention showing anchoring with attachment to the ground, cross-sectional view of the anchoring, and a schematic view of inductive current transfer. FIG.

7 is a schematic representation of the present invention, showing the holes in the anchorage.

8th Figure 3 is a schematic representation of the present invention showing a segmented float.

Detailed description of the invention

1a and 1b are schematic representations of the present invention when using wind turbines, in particular vertical axis wind turbines (VAWT). It should be noted that a floating platform of the present invention is preferably operated with wind turbines of the same type. 1a and 1b show a swimming platform 1 for wind turbines 6 , In this first embodiment, the invention is with two elongated floats 2 described. The at least two floats may be made of a metal such as a bent sheet or a concrete shell casting process using concrete or a concrete mix. It should be noted, however, that the number of floats 2 can go beyond two. The two floats 2 swim essentially vertically in the water. The swimming platform 1 further comprises at least a first connecting element 3 and a second connecting element 4 , which has a central anchoring 5 includes. If the platform 1 more than two floats 2 includes, is also the number of fasteners 3 . 4 to ensure a connection between the floats, which allows a parallel displacement of the elements to each other. The number of first fasteners 3 Depending on the weight of the platform, depending on the load of the system 1 , the maximum wind strength and the maximum swell. More first fasteners 3 increase the stability, but also the weight and the cost of the platform 1 , The second connecting element is preferably the upper connecting element and thus closer to the water surface. Alternatively, the second connecting element can also be arranged as a lower connecting element.

The at least two floats 2 are each about the first connecting element 3 and the second connecting element 4 pivotally connected to each other, wherein the first and the second connecting element 3 . 4 are arranged substantially parallel to each other and with a sufficient distance. This arrangement allows the floats of the platform wave-induced parallel to each other in a plane through the vertical float axes oscillate and this vibration energy is either damped, such as board-shaped fasteners 3 . 4 , or is converted into electricity by generators. Here are the fasteners 3 . 4 each within the float 2 coupled with a mechanism that converts the oscillating motion into a circular motion, thereby driving a generator to recover from the wave-induced relative oscillations of the floats 2 to generate electricity.

The floats 2 may also include a vibration damper (not shown) provided in the form of a weight comprising a metal, a metal mixture, concrete or other sufficiently dense material. This vibration damper is arranged with resilient elements in the floats, so that deflections of the float 2 be steamed. Preferably, the vibration damper is particularly for vaporizing frequencies in the range of the natural frequency of the float 2 and / or the platform 1 designed. This is done by deliberately adjusting the weight, position and suspension of the vibration damper.

2a and 2 B are schematic representations of the present invention with water surface 8th and anchoring 5 , The second connecting element described above 4 has a central anchorage 5 on. The second connection element 4 is preferably the upper connecting element and thus closer to the water surface. This is advantageous in the case of strong water currents in order to reduce a tilting moment of the system. Alternatively, the second connecting element 4 be arranged as a lower connecting element. The anchorage 5 serves the platform 1 at the bottom 7 anchoring the water. This can be done by a mooring, or by an anchoring system, anchor stones, anchor holes or other sufficiently stable anchoring options, as in 2a and 2 B will be shown. An anchoring of the platform is preferred 1 with fixed points applied, however, anchorages with two, three or more fixed points are also at the bottom 7 possible. Due to the stable position of the platform a highly vertically biased fixation of the platform is not necessary, whereby the load on the anchor points and anchoring is reduced. The anchor points can thus be created easier and cheaper, such as smaller anchor stones or holes with a smaller depth.

3 is a schematic representation of the present invention, showing a first connecting element. 4 Figure 3 is a schematic representation of the present invention showing a second anchored fastener. As in 3 shown, the fasteners 3 . 4 be designed as a simple connecting rods with joints at both ends. Alternatively, as in 4 Shown is also an education as a flat connecting boards to create a resistance to vertical displacement in the water conceivable. Another variant, not shown, is the training as truss with the lowest possible resistance. The second connection element 4 additionally has a central anchoring 5 on how to continue in 4 is shown.

5 Figure 4 is a schematic illustration of the present invention showing the different rotational orientation of the vertical axis wind turbines. In the embodiment of the 5 are the wind turbines 6 Vertical rotor wind turbines 6 , However, horizontal rotor wind turbines (not shown) are also suitable for mounting on a platform 1 of the present invention. A direction of rotation 9 at least one of the vertical rotor wind turbines 6 can be opposite to a direction of rotation 9 a respective other vertical rotor wind turbine 6 on another float 2 the swimming platform 1 be like in 5 is shown. This has the advantage that the torques of the wind turbines 6 cancel each other out and no net torque on the platform 1 affects what the platform 1 would turn.

6a - 6c show that power can be transmitted to a submarine cable through a direct cable connection ( 6a ). Alternatively, the anchoring 5 comprise at least one pair of coils, which are adapted, the generated power inductively from the floating platform 1 to be transmitted to a power cable ( 6b and 6c ). Due to the inductive transmission wear parts in the area of anchoring 5 saved and / or protected. In addition, the two anchoring elements can rotate 360 ° to each other, which avoids stressing the Storm cable by twisting, such as when the floating platform rotates through 360 °. In 6c an alternative embodiment of anchoring with two anchoring elements with spherical surface is shown. Also, this embodiment can be rotated by 360 °, without twisting a connected power take-off cable.

7 is a detail view of a section of the anchorage 5 that holes in an optional embodiment 10 can have. These holes are supplied with water through shallow hoppers that are open to the water surface. The funnel shape forces water between the two 360 ° rotatable anchoring elements when anchoring 5 is pressed horizontally through the water, such as when the entire swimming platform 1 or the second connecting element 4 swing vertically. The inflowing through the pressure gradient water ensures a continuous water storage at the loaded by the water pressure or water resistance anchoring element sections.

The holes 10 with the funnel-shaped openings located at the top and bottom of the anchorage 5 , Through the constant up and down movements of the swimming platform 1 will pressure water over the holes 10 pushed through the further course of the holes up to the storage areas to act as a water storage. The holes can be present on the top and bottom in varying numbers, but at least 2 per top and bottom. Optionally, the areas of anchoring 5 at the holes 10 and around the holes 10 be treated or equipped with an anti-fouling agent, such as a suitable coating or sheath.

8th is a schematic representation of the present invention, which is a float 2 with segmentation points. The two floats 2 of the present invention are hollow and have a substantially round cross-sectional area. Furthermore, the floats 2 each a substantially cylindrical upper part 10 with a first diameter a, a substantially frusto-conical middle part 11 and a substantially cylindrical base 12 with a second diameter b that is greater than the first diameter a. Through the thinner top 10 becomes the resistance to wave motion of the water surface 8th additionally mitigated what the swimming platform 1 allows a more stable position in the water.

In addition, the upper part 10 in the area of the water surface 8th be designed as a truss (not shown) to a resistance of the two floating bodies 2 to further reduce against impulsive waves.

As in further 8th shown, the two floating bodies 2 each divided by plates into at least three segments. At least one of the lower segments may comprise ballast. This ballast can be introduced in the form of ballast stones, sand or silt from the river bed or concrete. In principle, however, any material that is significantly denser than water and can be transported sufficiently easily to the installation site or obtained on site is suitable here.

In addition, at least one segment may be formed as a ballast tank to a floating height of the floating body 2 adjust. The pumps required for this can be either when installing the platform 1 on a ship or within an upper segment of the platform 1 be provided.

Within the segments of the swimming platform 1 The present invention may also include modules 13 be arranged as further in 8th will be shown. These modules 13 can contain a variety of elements and devices necessary for the function of the platform 1 or the installed wind turbines 6 are needed. Such devices may include, for example, a plant control device, a water pump, a power converter, a current rectifier, a current transformer, a power storage device such as a battery, a hydrogen production unit, and a hydrogen storage device. The hydrogen production and storage device may enable operation of the plant without direct mains connection. Such are platforms 1 as locally flexible "dispensers" for ships as conceivable, as the fuel supply of remote islands or temporary expeditions. However, it is also possible to use it in large quantities to generate hydrogen, which could relieve the already installed power grids on land and at sea and make large energy storage devices unnecessary to absorb surplus or fluctuating energy products from wind and solar energy.

The speeds of the vertical rotor wind turbines 6 In the present embodiment, by selectively braking individual vertical rotor wind turbines 6 be variable. The braking can be done by mechanical brakes or flaps on the vertical rotor wind turbines 6 flown. Another alternative to braking is simply one of the two vertical rotor wind turbines 6 be decoupled from the respective power generator, which minimizes the wind resistance of the respective vertical wind turbine. This can be a on the platform 1 acting torque by different rotational speeds of the vertical rotor wind turbines 6 be generated. The two mechanisms that enable this torque generation are the wind resistance change of a braked or decoupled vertical rotor wind turbine 6 as well as a net torque on the platform 1 acts when the two torques of the vertical rotor wind turbines 6 do not add to zero.

An additional embodiment of the present invention relates to a floating platform system comprising at least two of the above-described floating platforms 1 , In addition to what is described above, wind direction sensors are on the floating platforms 1 intended. Wind direction data of the sensors become plant controls of the floating platforms 1 whereby the plant controllers can communicate with each other and, together with data from the wind direction sensors, automatically optimizes the current efficiency optimized orientation of each individual swimming platform 1 can calculate. This can be done either via a central system or via a computer network from the individual plant controllers. In addition to the wind data, temperature data, such as weather forecasts, and flow data can also be included in the calculations.

The optimized alignment described above allows each individual wind turbine to achieve increased energy yield through improved wind conditions, as wind shade can be minimized by other wind turbines. The calculated optimized alignment of the platforms 1 can automatically by the above described selective braking or decoupling of the generators of the vertical rotor wind turbines 6 be implemented. In addition, such a system has the advantage that it always provides the highest possible energy yield without the need for people to make adjustments or calculations. Such an intelligent wind farm can operate completely autonomously and requires only human intervention for maintenance and repairs. The above embodiment describes a platform 1 from two floats 2 , However, there are platforms 1 also with three or more floats 2 possible. The number of fasteners 3 . 4 only needs to be increased accordingly to the floats 2 ring-shaped or reticulate to connect. Due to the increased number of floats, however, more complex joints, such as ball joints, for connecting with the fasteners needed.

One can use an inventive buoyant wind power system 1 Use wherever the foundation of pile foundations for conventional wind turbines is not feasible for reasons of water depth (eg too deep) or the condition of the substrate (eg silt) or for cost reasons. The present invention is also suitable for wind power use in wetlands or permafrost zones.

Claims (17)

Floating platform ( 1 ) for vertical axis wind turbines ( 6 ), comprising: at least two elongated floats ( 2 ) whose longitudinal axis is perpendicular to the water surface; at least two vertical axis wind turbines ( 6 ), each at the top of the at least two floats ( 2 ) are arranged, wherein a direction of rotation ( 9 ) at least one of the vertical axis wind turbines ( 6 ) opposite to a direction of rotation ( 9 ) of a respective other vertical axis wind turbines ( 6 ) on another floating body ( 2 ) of the swimming platform ( 1 ); at least one first connecting element ( 3 ); and at least one second connecting element ( 4 ), which has a central anchorage ( 5 ); the at least two floats ( 2 ) each via a first connecting element ( 3 ) are pivotally connected to each other, the at least two floats ( 2 ) in each case via a second connecting element ( 4 ) are pivotally connected to each other, and wherein the first and the second connecting element ( 3 . 4 ) are parallel to each other, so that a parallel swinging of the floating body to each other in the plane is possible, which is defined by the vertical floating body axes of the two associated floating body. Floating platform ( 1 ) according to claim 1, wherein at least one floating body comprises a vibration damper. Floating platform ( 1 ) according to one of the preceding claims, wherein at least one of the connecting elements ( 3 . 4 ) each within the float ( 2 ) are coupled to a generator adapted to recover from the wave-induced relative oscillations of the floats ( 2 ) to generate electricity. Floating platform ( 1 ) according to one of the preceding claims, wherein the at least two floating bodies ( 2 ) are hollow, have a round cross-sectional area and each comprise: a cylindrical top ( 10 ) having a first diameter (a); and a cylindrical lower part ( 12 ) having a second diameter (b) greater than the first diameter (a). Floating platform ( 1 ) according to claim 4, wherein the upper part ( 10 ) in the area of the water surface ( 8th ) is designed as a truss girder to a resistance of at least two floats ( 2 ) to reduce against incident waves. Floating platform ( 1 ) according to claim 4 or 5, wherein the at least two floats ( 2 ) each comprise: a truncated cone-shaped central part ( 11 ). Floating platform ( 1 ) according to one of the preceding claims, wherein the at least two floating bodies ( 2 ) are each divided by plates into at least three segments. Floating platform ( 1 ) according to claim 7, wherein at least one of the lower segments comprises ballast. Floating platform ( 1 ) according to claim 7 or 8, wherein at least one segment is formed as a ballast tank to a floating height of the floats ( 2 ). Floating platform ( 1 ) according to claim 1, wherein the anchoring ( 5 ) comprises at least one pair of coils for powering inductively from the swimming platform ( 1 ) to a power cable. Floating platform ( 1 ) according to claim 1 or 10, wherein the anchoring ( 5 ) comprise an upper anchoring element and a lower anchoring element, each having an annular projection which engage with each other, the projections thereby having an L-shaped cross-section to allow the first anchoring element and the second anchoring element are rotatable by 360 ° to each other , Floating platform ( 1 ) according to claim 1, 10 or 11, wherein the anchoring ( 5 ) internal holes ( 10 ), which has an attacking water pressure during vertical movements of the anchorage ( 5 ) at by tensile or compressive forces loaded friction surfaces on the anchoring elements or lead their annular projections, so that a water film reduces the friction at the loaded sites. Floating platform ( 1 ) according to one of claims 1 or 7 to 12, wherein within in each case at least one segment of the at least two floating bodies ( 2 ) Modules ( 13 ), the modules ( 13 ) comprise at least one of a plant control device, a water pump, a power converter, a current rectifier, a current transformer, a current storage device, a hydrogen production unit, and a hydrogen storage device. Floating platform ( 1 ) according to claim 1, wherein the torques generated by the vertical axis wind turbines ( 6 ) are generated via the floats ( 2 ) on the first connecting element ( 3 ) be transmitted. Floating platform ( 1 ) according to claim 14, wherein the speeds of the vertical axis wind turbines ( 6 ) by selective braking of individual vertical axis wind turbines ( 6 ) are variable to a total torque of the floating platform ( 1 ) by different rotational speeds of the vertical axis wind turbines ( 6 ) to create. Floating platform ( 1 ) according to one of claims 1 or 10 to 15, wherein the wind turbines are of the same type. Swimming platform system comprising: at least two floating platforms ( 1 ) according to any one of claims 1 to 16; and wind direction sensors attached to the floating platforms ( 1 ) and wind direction data for plant controls of the floating platforms ( 1 ), where the plant controllers are capable of communicating with each other and, together with data from the wind direction sensors, automatically determine a current efficiency of the vertical axis wind turbines ( 6 ) improved alignment of each individual swimming platform ( 1 ) and by selectively braking the vertical axis wind turbines ( 6 ) implement.

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