DE102007028839A1 - Pipe framework supporting tower for floating wind turbine i.e. offshore wind turbine, has diagonal bar running rightwards from corners of base and provided by tower outer side and opening out in area of corners of interconnection ring - Google Patents

Abstract

The tower (18) has a polygonal interconnection ring with multiple corners, formed by a number of cross-beams. A number of diagonal bars running diagonally upwards extend to the corners of the ring based on corners of a base (38). The two diagonal bars are assumed in different directions, and the corners of the ring are arranged such that each diagonal bar running rightwards from the corners of the base and provided by a tower outer side together with the cross-beams running leftwards from the corner of the base opens out in an area of the corners of the ring.

Description

FIELD OF THE INVENTION

The The invention relates to a tubular truss supporting tower for support high loads, especially for floating wind turbines as well as a construction such. B. a wind turbine, a crane, a bridge pier, an antenna mast, an observation deck, a power pole, a cable car support u. Like. With a tube truss tower. Here, the term support tower is used as a generic term for uses all types of tower, pier or mast constructions, the whatsoever loads, z. As power lines, Platforms, wind power rotors, ropes of cable cars, etc. wear.

BACKGROUND OF THE INVENTION

On the field of the invention are different truss towers known, the z. B. used in cranes and electricity pylons become. For example, truss towers with a triangular Ground plan used as antenna masts. Lattice towers, which have a square plan are called high voltage pylons and today partly as towers for wind turbines used on land up to 160 m height. For the construction will be the commercial steel profiles used, and the masts have continuous corner stems, from the foundation to the support turret pass.

at The known truss towers are the continuous corner stems with diagonal and horizontal profile struts to one stable truss connected. In the truss nodes become the profile struts usually only connected with a screw. This construction is because of too low security for statically and dynamically highly loaded Towers, as they are z. For example, for offshore wind turbines be needed, unsuitable.

Because of the more favorable wind conditions over Wind turbines in the offshore area can be used by the sea Significantly increase energy yield. The design principles of let large wind turbines installed on land but only partially transferred to the offshore sector. The harsh environmental conditions call for new techniques or specifically adapted solutions.

environmental influences are generally much more difficult to control at sea as on land. Offshore wind turbines are located i. d. R. outside the visibility about 20 km from the coast. They become exclusive optimized for energy production. Come to the wind loads the sea forces from waves, currents, tides as well as massive corrosion and vibration problems. Other design criteria such as B. Noise development of the rotor blades, shadows, Infrasound, acceptance and aesthetics of the construction project lose importance on the other hand.

Lattice towers on floating platforms are already out of the oil industry known. These offshore facilities are used for oil exploration and oil production. The towers (so-called Derricks) are on very large semi-divers, have one square plan and become the exchange or the Extension of the drill pipe needed. From The tower structure is predominantly vertical Take loads with a few tons of weight. The support tower height is 20 to 30 m. It has been shown, however, that too such towers for large offshore wind turbines are unsuitable.

Stationary Offshore wind turbines are deep or shallow on the seabed founded and economical up to approx. 50 m water depth. So far, all offshore wind turbines have independent of the kind of foundation, a massive support tower from a steel tube with a large diameter. At the head of the Steel support tower concentrate very high weights. Here is the rotatably mounted nacelle with the wind rotor. Inside the nacelle are rotor bearings and shaft, gearbox and generator housed, also adjusting the rotor blades, drive for wind direction tracking and measuring, control and safety technology. All together results in big ones Wind turbines a total weight of 200 tons and more. Come in addition the weight of the tower in the order of magnitude from 150 to 200 tons.

Next The high weight of the entire system has a large external effect static and dynamic forces from wind, sea, ocean currents and if necessary, ice drift on wind turbines in the offshore area. Today have These systems range from 1.0 to approx. 5 MW (el). Are planned Units up to 10 MW.

Size floating offshore wind turbines resting on anchored platforms be erected and used in larger Water depths are only just beginning a new development.

Offshore wind turbines are z. B. known from the publications US2007001464 . US2004103655 . EP1348867 . WO03076800 . WO02073032 . GB2378679 . WO0210589 . WO03004869 . EP0767876 . DE3224976 ). Of these documents relates to GB2378679 a floating platform, which is anchored to the ground by means of tension ropes (so-called "tension legs").

Floating anchored units have the advantage of being independent of varying water depth and soil conditions of the Seabed are. Standardized platform systems are possible the almost over the lengths of the traction cables adapt to every water depth and location.

at anchored floating units it comes to a combination from self-weight and external environmental pollution horizontal and vertical loads. The common focus Internal and external loads are offshore wind turbines inevitably very high above the water surface, so that normally no swimming stability given is. Only through the large buoyancy surplus of Underwater construction of the platform and with the bracing on the large heavyweight anchor blocks located on the seabed manages the floating offshore wind turbine in a stable stable Position. At a very high center of gravity they grow disproportionate anchoring forces acting on the structure at. Despite security measures can already be during the construction, assembly and transport phase critical and stable security Situations arise.

DISCLOSURE OF THE INVENTION

Of the Invention is based on the object, a tubular truss supporting tower to specify, in relation to known constructions low weight to support high loads even under difficult operating conditions, in particular in offshore wind turbines, be able to.

A Another object of the invention is the very top-heavy floating Wind turbines constructively improve so that the Mass and load center of gravity as far down as possible is brought to the water surface.

The above objects are achieved by a tubular truss supporting tower for supporting large loads, in particular for floating wind turbines, in which the tower is a base with a polygonal outline with a number of n (n ≥ 3, n ε N ₊ , N ₊ = set of natural numbers greater Zero) has vertices, the support tower has a first formed by a number of n cross struts polygonal cross connecting ring with n vertices, the height is in the proper installation state of the Rohrfachwerkturms above the base, starting from the corner points of the base to the vertices of the first cross connecting ring out Number of obliquely upwardly extending diagonal braces extends, each extending from each corner point of the base two diagonal struts in different directions and the vertices of the first cross-connecting ring are arranged such that seen from the outside of the tower any of any vertices of Ba sis running diagonal strut to the right above together with the transverse strut extending from the right to the corner point of the base to the top left extending cross-section in the region of the same corner point of the first cross-connecting ring.

Prefers The tubular truss supporting tower has a plurality of polygonal ones Cross connection rings, each by a number of n cross struts are formed and each possess n vertices, starting out from the vertices of a cross connection ring to the vertices of the adjacent cross connecting ring, a number of 2n obliquely extending diagonal struts extends and wherein the diagonal struts arranged between two adjacent cross-connecting rings are that seen from the tower outside each from any corner of a cross connection ring to the right top diagonal strut together with the one on the right to the vertex adjacent vertex running to the left above Cross strut in the region of the same corner point of the adjacent cross connecting ring empties. In this case, n is preferably in the range from 4 to 12 and is in particular equal to 6, 7 or 8.

Of the Pipe framework tower can over the height cylindrical upwards, d. H. a constant horizontal Possess cross-section. He can also think about the height conically tapering upwards or, seen from the diameter, a z. B. hyperbolic course.

Prefers the tubular truss tower stands on a structurally reinforced Base.

The Diagonal and / or transverse struts can be made of steel, CFRP (carbon fiber reinforced Plastic) or other composite materials and in the field the vertices via special fasteners together connected or directly bolted together, glued or welded. Especially for tubular truss towers for offshore wind turbines can the ratio greatest width of the Tower to the tower height advantageously between 1: 7 and 1:12 are.

has the tubular truss support tower has at least two cross connection rings, so can the areas between two levels as sections prefabricated, so that the tower easily on the ground by stacking can be mounted by sections. The distance between vary the cross connection rings.

The object is further solved by a A structure such as, in particular, a crane, a bridge pier, an antenna mast, a viewing platform, a power pole, a cable car support or a wind turbine having a tube truss supporting tower according to any one of claims 1 to 16.

at an offshore wind turbine, the support tower can be advantageous be on a constructively reinforced basis that the forces acting on the tower and bending moments in a lower one Structure of a Tension Leg platform transmits.

The inventive solution for construction the Rohrfachwerkturmes offers an effective measure for improved swimming stability. The innovative design of the tower reduces the dead weight, reduces the Wind load on the construction, improves the position of the center of gravity and limits the vibration excitation of the system. The transport the components, prefabrication and assembly are much easier and more economical.

Of the Support tower is designed and dimensioned as a tubular framework for large horizontal forces and vertical forces at the head of the support tower. Such forces result in a wind turbine from its own weight of tower, Gondola, rotor blades, storage, generator and further in a horizontal direction from the wind forces on the support tower and the rotor blades. Wind and peak gusts work out each direction on the structure, while the support tower get a high rigidity, so that even under load the horizontal displacements of the tower tower low are. The supporting body weight should be at a floating Wind turbine as possible because of the floating stability be small. The diameter at the Stützturmfuß can in such a system can not be arbitrarily large because the stand area for the erection of the wind power tower is very limited on a floating platform. Another Reason for a slim support turret shape arises in that the superimposed under load rotor blade, superimposed with the horizontal displacement of the tower, in never touch the support tower. The leaf tip must have a sufficient safety distance from the tower comply. So as not to overhang the nacelle with the rotor bearing to let, is in addition the rotation plane of the wind rotor inclined by 2 to 6 ° to the vertical.

Around Floating stability, the metacenter, that is, the point at which the line of action turns when the body is turned the buoyancy with the symmetry axis intersects, above the center of gravity lie. For this reason, must in a floating wind turbine the common focus of the floating platform and the rest Components of the system as far down as possible become. A constructive measure is therefore the high Support tower with high stability as possible easy to build. Comparing a 50 m high one-piece steel tube tower with a tubular truss construction according to the invention, so weighs z. B. the truss tower with the same load capacity only about 50 to 60%.

One Another advantage arises for the horizontal load out of wind. The tube truss tower has a substantial lower wind resistance than a massive pipe support tower.

It is known that when passing a rotor blade on a conventional massive pipe support the air between Rotor blade and support tower is compressed. This pulsating Air congestion leads to vibrations and is considered in the professional world as so-called infrasound phenomenon described. The continuous one Load changes during operation (about 30 million / year) can to premature fatigue on the rotor blade and lead the support tower construction. In a tubular truss tower according to the invention Infrasonic can not occur, resulting in life and operational safety the system significantly improved.

With the inventive solution for construction the tower can have the required construction mass without sacrificing stability and technical life be reduced. Increased by the lower material usage at the same time the economic efficiency of the plant.

The Application width of the pipe truss tower is large. He can z. B. both wind turbines on land, in heavy accessible areas (easy transport of items and easy installation on site) as well as for stationary or floating wind turbines are used in the sea. Of the Pipe truss tower can for other tasks be used advantageously, for. B. for all types of highly loaded Supporting tower structures, bridge piers, antenna masts, Observation platforms, masts for cable cars, electricity pylons. Basically, the construction principle of the tubular truss supporting tower also applicable to truss braces made of sectional steel or other materials, depending on function and loads.

Further Details and advantages of the invention will become apparent from the following purely exemplary and non-limiting description of a Embodiment in conjunction with the drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

1 schematically shows a erfindungsge Permitted wind turbine in the anchored to the seabed state.

2 shows the pipe truss supporting tower of the plant according to 1 on an enlarged scale.

3 shows a construction detail, wherein the cross struts in the region of the truss nodes on specially welded connecting plates 36 are bolted.

DESCRIPTION OF PREFERRED EMBODIMENTS

In the 1 is schematically the basic structure of an offshore wind turbine 2 shown the tension-leg platform 4 with anchoring ropes or chains 8th anchoring elements anchored to the ground 10 and the tubular truss supporting tower according to the invention together with wind power rotor 20 , three rotor blades 22 and the gondola 24 the wind turbine and a central body 16 includes.

The pipe truss tower 18 stands on a constructively reinforced basis 38 at the top of the central body 16 at the same time as access to the interior of the submerged buoyancy body 6 serves. The base 38 is constructively sized to take the big moments and vertical forces out of the turret 18 pick up and into the central body 16 or the entire underwater unit 4 can initiate. The base 38 At the same time serves as access to a z. B. Material and personnel on the floating platform 4 bring to.

As in 2 good to see, is the support tower 18 the wind turbine 2 multi-limbed designed as tubular framework. At the tower tower is the rotatably mounted nacelle 24 in which the wind power rotor 20 , Generator and auxiliary equipment and measuring technology are housed. The structure of the truss tower 18 results from the arrangement of diagonal struts 30 with cross struts 32 in truss nodes 34 connected to each other.

This construction of the innovative truss tower 18 differs from the traditional truss constructions. The support tower is composed of tubular elements. In the case of an octagonal cross section, there are eight diagonal struts 30 around the tower in a clockwise direction from the base to the support turret and another eight diagonal braces 30 counterclockwise.

At each intersection of the diagonal struts 30 there is a so-called half-timbered knot 34 in which the intersecting tubes are welded together. In the horizontal direction are the nodes with cross struts 32 connected, so that there is a uniform stable triangular structure over the entire support turret surface. Two diagonal struts 30 make up together with a cross strut 32 each a statically determined triangle.

The triangular structure of the innovative tower tower construction 18 is designed so that all diagonal struts 30 in the same way absorb and forward the forces. This gives it in this truss system 26 no preference for special "corner handles" as support elements 1 , Order and stiffening truss profiles 2 , Order as with high voltage pylons. Instead of four main girders (corner posts) per supporting tower cross-section of a high voltage mast, the tubular truss supporting tower has 18 in each cross section each about 16 supporting tubular steel elements (diagonal struts) 30 , The support tower construction 18 This makes it more stable, less deformable and much safer.

The construction principle of the innovative tubular framework 26 has the great advantage that the footprint of the support tower 18 can be kept relatively small. The slim support tower 18 is particularly suitable for installation on a floating platform 4 in the sea.

The geometric structure of the tubular truss construction also makes it possible to extend the tower upwards over the height, ie to erect it with a constant horizontal cross section. A conical or hyperbolic profile of the cross section over the height of the support tower is possible. These shapes can be achieved by the gradual lengthening or shortening of the transverse struts 32 be reached in each section. Through this triangle arrangement receives the tower 18 a high load capacity and a special rigidity. This construction can accommodate large horizontal and vertical forces. The horizontal deformation of the support tower due to the horizontal force is very small and amounts to only about 1% of the construction height of the support tower 18 ,

The support tower 18 stands on a constructively reinforced basis 38 To ensure that all acting forces and bending moments are safely in the lower structure of the Tension Leg platform 4 transferred to. Due to the eightfold storage of the support tower 18 becomes a point-like load concentration on the base 38 avoided, regardless of any wind direction.

In the 3 is shown a special case. Instead of steel tubes are used for the cross struts 34 Struts made of CFRP (carbon fiber reinforced plastic) selected at the truss nodes 40 must be screwed high strength. For this purpose, specially welded connection plates are at the nodes 36 intended.

Also the combination of CFK diagonal struts 44 and CFK cross braces 46 is possible in principle. For this purpose, however, the node connections must be completely screwed. Because of the static and dynamic loads of the tower 18 Only high-strength screw can be used, preferably with at least two screws per strut connection.

The In particular, the invention has the advantage that the support tower due to the special structural design over a high strength and material-saving construction and is in constructive and economic terms for the extreme loads particularly advantageous in the offshore sector. His wind resistance is is much smaller than a massive steel tube tower or Concrete tower and is (depending on the version) only around 60% of the wind load on a massive tower.

The Weight of the tower is only about 50 to 70% of the weight of a massive steel tube tower.

By the open construction can pass when passing a rotor blade Wind turbine at the tower no infrasound phenomenon pulsating air jam occur. Because of the lack of vibration amplification this advantageously increases the technical life and operational safety of the plant.

The Lightweight construction saves building material, transport and assembly costs. This construction is more economical overall than the conventional tower solutions.

in the Compared to a lattice framework made of section steel has the inventive Pipe framework construction lower free surfaces and is thus better protected against corrosion.

It is possible to place the tower in sections 28 which can be transported, assembled and assembled on site without heavy lifting equipment.

Of the The tower is over due to its geometry a high stability, so that even at large Horizontal load the horizontal deformation paths very small (the largest deflection is approx. 1% of the construction height).

The truss nodes 34 (that is, the vertices) of each cross connect ring, but need not be in a horizontal plane. The individual truss nodes 34 a cross connecting ring z. B. alternately higher or lower, in which case the diagonal struts of a triangle receive different lengths and the cross braces do not extend horizontally, but at an angle to the horizontal.

A truss node 34 Steel can not only be used as a welded pipe element in the crossing point of the cross struts 32 formed with the diagonal struts, but also designed as a cast steel in the form of a finished part, in which case the connection to the diagonal struts 30 or the cross struts 32 each over a welded mounting earpunch 48 will be produced.

Be used for the struts other materials than steel, z. As CFK or GRP, a knot design over conventional welds is usually not possible. Then other connection and connection techniques are used. In the truss node 40 For example, the struts can be screwed together or joined together in a form-locking, tension-resistant and pressure-resistant manner, but also joined together by innovative chemical or physical processes. In particular, adhesive bonds are suitable here to take over this function. The complete truss node 40 can also be manufactured as a preformed carbon fiber or fiberglass and then with the CFK struts 44 and 46 screwed or glued. As an example, a truss node 40 with adaptation to the special material properties of the horizontal bars made of CFRP in 3 shown.

The Design principle of the tower can be for each in practice desired size can be adjusted. A so-called upscaling or downscaling is possible without difficulty. Typical orders of magnitude for offshore wind turbines are z. B .: support tower height: 50 m, rotor diameter: 92 m, load to be carried by the tower (rotor, nacelle etc.): 100 t, wall thickness of the tubes of the supporting tower: 10 mm, diameter of these tubes: 30 cm, diameter of the tower: approx. 5 m (octagonal cross section).

2

floating Offshore wind turbine (complete system)

4

"Tension-Leg" platform (anchored underwater unit)

6

submerged buoyancy

8th

anchoring ropes or chains

10

Heavyweight anchor block

12

Seabed

14

power cable

16

central body

18

Tube truss support tower

20

Wind rotor

22

rotor blade

24

gondola the wind turbine

26

spatial Truss consisting of tubular struts

28

Supporting tower section, Support tower section between two layers ("cross connection rings") the cross struts

30

diagonal strut

32

crossmember

34

Truss nodes, welded

36

Node connecting plate for high-strength screwing

38

Base for the tubular truss tower

40

Truss nodes for connecting the CFK cross braces

42

Truss nodes for connection of CRP diagonal strut and CRP cross strut

44

CFRP crossmember

46

CFRP diagonal strut

48

Mounting tube shock, welded

S. W.L

Static water level

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 2007001464 [0010]
• US 2004103655 [0010]
• - EP 1348867 [0010]
• WO 03076800 [0010]
• WO 02073032 [0010]
• GB 2378679 [0010, 0010]
• WO 0210589 [0010]
• WO 03004869 [0010]
• - EP 0767876 [0010]
• - DE 3224976 [0010]

Claims (19)

Pipe truss supporting tower for supporting large loads, in particular for floating wind turbines, characterized in that - the support tower has a base with a polygonal outline with a number of n (n ≥ 3, n ε N ₊ , N ₊ = set of natural numbers greater than zero) vertices In that the support tower has a first polygonal cross connection ring with n corner points formed by a number of n transverse struts which is higher in height than the base in the intended setting up position of the tubular truss tower, that starting from the corner points of the base towards the corner points of the first transverse connecting ring Number of obliquely upwardly extending diagonal braces extends, - from each corner point of the base two diagonal struts in different directions emanating in such a way and the vertices of the first cross connecting ring are arranged such that seen from the outside of the tower any of any corner points of Basi s diagonal strut extending to the top right opens together with the transverse strut extending from the right to the corner point of the base to the top left in the region of the same corner point of the first cross-connecting ring. Pipe framework support tower according to claim 1, characterized in - that a plurality of polygonal Cross connecting rings is provided, each by a number of n transverse struts are formed and have each n vertices and - That starting from the vertices a cross connecting ring to the vertices of the adjacent cross connecting ring a number of 2n oblique diagonal struts extends - Where the diagonal braces between so two adjacent cross connection rings are arranged, that of the tower outside seen any from any corner a cross connecting ring to the top right diagonal strut together with the corner point adjacent from the right to the vertex on the left above the transverse strut in the area of the same corner of the adjacent cross connecting ring opens. Pipe truss tower according to claim 1 or 2, characterized in that n is in the range of 4 to 12 and preferably equal to 6, 7 or 8. Pipe framework support tower according to one of the claims 1 to 3, characterized in that two in the same area Corner point opening diagonal braces connected there, in particular welded, screwed or glued. Pipe framework support tower according to one of the claims 1 to 4, characterized in that the ends of the transverse struts in the area of the corner points with the diagonal braces opening there connected, in particular welded, screwed or glued. Pipe framework support tower according to one of the claims 1 to 5, characterized in that in the region of the vertices separate connecting elements for connecting the in the respective Area diagonal and transverse struts are provided. Pipe framework support tower according to one of the claims 1 to 6, characterized in that the support tower over the height is cylindrically upwards, d. H. has a constant horizontal cross-section. Pipe framework support tower according to one of the claims 1 to 6, characterized in that the support tower over the height tapers conically upwards, or, from Diameter seen, a hyperbolic course Has. Pipe framework support tower according to one of the claims 1 to 8, characterized in that the support tower stands on a constructively reinforced basis. Pipe framework support tower according to one of the claims 1 to 9, characterized in that the diagonal and / or Cross struts made of steel tubes with round or square, in particular square or pentagonal cross section. Pipe framework support tower according to one of the claims 1 to 9, characterized in that the diagonal and / or Cross struts made of CFRP pipes (carbon fiber reinforced Plastic) or other composite materials with round or angular, in particular square or pentagonal cross section. Pipe framework support tower according to one of the claims 1 to 11, characterized in that certain diagonal and / or cross struts made of steel, others made of CFRP or other composite materials exist and in the field of vertices on special fasteners connected to each other. Pipe framework support tower according to one of the claims 1 to 12, characterized in that the ratio largest width of the tower to the tower height between 1: 7 and 1:12 lies. Pipe truss supporting tower according to one of claims 1 to 13, having at least two transverse connecting rings, characterized in that the regions between two transverse connecting rings are designed as sections ( 28 ) can be prefabricated so that the tower can be mounted on site by putting sections together. Pipe framework support tower according to one of the claims 1 to 14 with a plurality of cross connection rings, characterized that the distance between the cross connection rings varies. Pipe framework support tower according to one of the claims 1 to 15, characterized in that the vertices of a Cross connection ring lie in one plane Pipe framework support tower according to one of the claims 1 to 15, characterized in that the vertices of a Cross connecting ring at different heights. Construction such as in particular crane, bridge pier, Antenna mast, viewing platform, power pole, cable car support, Wind turbine, characterized by a pipe truss tower after one of claims 1 to 17. Construction according to claim 18 in the form of an offshore wind turbine, characterized in that the support tower ( 18 ) on a constructively reinforced basis ( 38 ), the forces acting on the tower and bending moments in a lower structure of a Tension-Leg platform ( 4 ) transmits.