Claims:We Claim:

1. An adapter arrangement (14, 14a, 14b, 14c) for a hybrid tower (2) of a wind turbine (1),
- wherein a lower section of the hybrid tower (2) is designed as lat-tice section (13) and an upper tower section of the hybrid tower (2) is designed as tubular section (12),
- the lattice section (13) comprises at least three corner bars (15) connected with each other by cross girders (16) and cross braces (17), and the corner bars (15) are arranged in an angle (a) to a longitudinal axis (18) of the hybrid tower (2),
- the tubular section (12) comprises at least one tubular segment (19), and
- the lattice section (13) and the tubular section (12) are connected by means of the adapter arrangement (14, 14a, 14b, 14c), charac-terized in that
- the adapter arrangement (14, 14a, 14b, 14c) comprises a plurality of adapter plates (21, 21a, 21b, 21c) for connecting a transition piece (20) arranged at the lower end of the tubular section(12) and a connection bar arranged at the upper end of the lattice sec-tion (13) and wherein the adapter plates (21, 21a, 21b, 21c) are casted or welded parts.

2. The adapter arrangement (14, 14a, 14b, 14c) according to claim 1, characterized in that at least one of the plurality of adapter plates (21, 21a, 21b, 21c) are casted in one piece and/or that at least one of the plurality of adapter plates are welded in such a way that two plate segments are welded together, wherein each of the plate seg-ments is a casted part.

3. The adapter arrangement (14, 14a, 14b, 14c) according to claim 1 or 2, characterized in that the transition piece (20) having a cylindrical cross section.

4. The adapter arrangement (14, 14a, 14b, 14c) according to one of the preceding claims, characterized in that at least one adapter plate (21, 21a, 21b, 21c) is executed in two parts (21c1, 21c-2).

5. The adapter arrangement (14, 14a, 14b, 14c) according to one of the preceding claims, characterized in that in assembled state of the adapter arrangement (14, 14a, 14b, 14c) the transition piece (20) and the connection bars defining an angle (ß), wherein one of the plu-rality of the adapter plates (21, 21a, 21b, 21c) are at least partly ar-ranged at this angle (ß).

6. The adapter arrangement (14, 14a, 14b, 14c) according to one of the preceding claims, characterized in that the adapter plates (21, 21a, 21b, 21c) at least partially overlap the transition piece (20) in longi-tudinal direction of the hybrid tower (2) and the adapter plates (21, 21a, 21b, 21c), in assembled state of the adapter arrangement (14, 14a, 14b, 14c), are connected with the connection bars of the lattice section (13), and wherein the transition piece (20), in assembled state of the adapter arrangement (14, 14a, 14b, 14c), is connected with the tubular section (12).

7. The adapter arrangement (14, 14a, 14b, 14c) according to one of the preceding claims, characterized in that the adapter plate (21) hav-ing a first area (22, 22c-1, 22c-c) for fastening of the connection bars and a second area (23, 23c-1, 23c-2) for fastening the transition piece (20).

8. The adapter arrangement (14, 14a, 14b, 14c) according to claim 7, characterized in that the second area (23, 23c-1, 23c-2) of the adapter plate (21, 21b, 21c), from an orthogonal view to a longitudi-nal axis of the adapter plate (21, 21b, 21c), so that the adapter plate (21, 21a, 21b, 21c) basically forms a double Y-form.

9. A hybrid tower (2) for a wind turbine (1), characterized by an adapt-er arrangement (14, 14a, 14b, 14c) according to one of the claims 1 to 8.

10. A wind turbine (1), characterized by a hybrid tower (2) according to claim 9.

Dated this 20th day of January 2022
, Description:TITLE OF INVENTION

ADAPTER ARRANGEMENT FOR A HYBRID TOWER OF A WIND TURBINE

FIELD OF INVENTION

The present invention is directed to an adapter arrangement for a hybrid tower of a wind turbine, wherein the adapter arrangement comprises a plurality of adapter plates, which are casted or welded parts.

BACKGROUND

Very high steel tubular towers need certain stiffness due to arising vibra-tion and the natural frequency. That is why a large tower diameter or a large wall thickness is required. The anchorage of steel tubular towers is often realized by means of a flange, particularly by means of a T-flange, which is mostly braced with a foundation by two ring-circularly arranged rows of anchor screws.

A maximum travelling height of 4.5 meters results due to the height of bridges as the transport of steel tubular towers from the manufacturing sites of the manufacturers to the installation sites has to be mostly real-ized by heavy goods transports onshore. The tower segments are mostly horizontally transported during transport which is why the maximum di-ameter of the tower segments in the area of the flange should not exceed the travelling height. The distance between the road and the transported tower segments corresponds at most of the heavy goods vehicles to ap-proximately 0.1 to 0.2 meters. For this reason the maximum diameter of the tower segments including the flange should not exceed approximate-ly 4.3 or rather 4.4 meters. In order to provide a sufficient platform and enough space for the positioning of the anchor screws, the outer width of the flange – that is the part of the T-flange which exceeds the diameter of the lateral area – should be greater than 0.25, mostly greater than 0.3 me-ters. This applies especially for towers with a height of more than 80 me-ters. For this reason the maximum tower diameter in the panel of the lat-eral area without the flange at the usage of conventional anchorage sys-tems should not exceed a certain size, approximately 4.0 meters.

Because of the limitation in cross section of the tower segments due to the transport, different measures have to be taken for wind turbines with higher towers in order to guarantee a sufficient stiffness of the tower. One possibility is the development of the tower as lattice-tubular-hybrid tower. This hybrid tower combines a lattice section with a tubular section. Thus the advantage arises that the upper tower segment formed as tubular sec-tion is very torsional stiff and the lower tower segment formed as lattice section can be transported in individual parts to the installation site. Therefore a very large platform can be achieved which leads to a high bending stiffness without exceeding the maximum travelling height of the tower segments.

The lattice section comprises at least three corner bars which are con-nected by means of several stabilizers and horizontal cross girders. The corner bars are designed for dissipating the bending moments which op-erate perpendicularly to the tower axis as well as for dissipating forces which operate in the tower axis. The stabilizers and the cross girders of the lattice section are designed for dissipating torsional moments which operate around the section axis as well as for dissipating forces which operate perpendicularly to the section axis. At the tubular section all forc-es and moments are dissipated via the cylindrical shell of the tube. Hence a problem occurs to combine the round tubular section with the square lattice section.

For solving this problem it is common knowledge to use adapter plates, which are connected with a conical transition piece of the tubular section. These adapter plates are bended, which has several disadvantages. For example, a disadvantage is that due to the bending process no contour-accurate production is possible. As a result, shims are required during assembly, which negatively influence the transmission of force.

OBJECT OF THE INVENTION

One object of the invention is to provide an adapter plate which over-comes the disadvantages of the prior art.

SUMMARY OF THE INVENTION

This object is solved by an adapter arrangement with the following fea-tures.

The adapter arrangement for a hybrid tower of a wind turbine, wherein a lower section of the hybrid tower is designed as lattice section and an up-per tower section of the hybrid tower is designed as tubular section, the lattice section comprises at least three corner bars connected with each other by cross girders and cross braces, and the corner bars are arranged in an angle (a) to a longitudinal axis of the hybrid tower, the tubular sec-tion comprises at least one tubular segment, and the lattice section and the tubular section are connected by means of the adapter arrangement, wherein the adapter arrangement comprises a plurality of adapter plates for connecting a transition piece arranged at the lower end of the tubular section and connection bars arranged at the upper end of the lattice sec-tion and wherein the adapter plates are casted or welded parts. In this context plurality means more than one, especially more than three. In par-ticular, the connection bar is one of the corner bars of the lattice section, so that one adapter plate is assigned to one corner bar. More in particular the connection bar is lateral bar, wherein one adapter plate is assigned to one lateral bar. Advantageously, the lateral bar is arranged on a side of the upper end of the lattice section. More advantageous, at one side of the upper end of the lattice section more than one lateral bars are ar-ranged.

These adapter plates have several advantages, namely possibility of a contour-accurate design, which results in an optimal transmission of force and the use of shims can be dispensed as well as no limitation in designing and manufacturing of the adapter plates. Further the adapter arrangement can be pre-assembled. Because of an easier and standard-ized manufacturing the costs are reduced.

In particular the adapter plates can be connected to the transition piece and or connecting bars by welding and/or by fastening means, such as bolts, rivets, latches or screws or a combination thereof.

In a preferred embodiment of the adapter arrangement, at least one of the plurality of adapter plates are casted in one piece and/or that at least one of the plurality of adapter plates are welded in such a way that two plate segments are welded together, wherein each of the plate segments is a casted part.

In a further preferred embodiment of the adapter arrangement, the ar-rangement comprises a transition piece having a cylindrical cross section.

In a further preferred embodiment of the adapter arrangement, at least one adapter plate is executed in two parts. In particular, these two parts are symmetrical along the longitudinal axis. More in particular, the two parts are casted parts. Advantageously the two parts can be mounted to the transition piece with fastening means, such as bolts, rivets, latches or screws or a combination thereof or can be welded with the transition piece. This two part form has several advantages. Once, the casting mold is much easier in construction, so the manufacturing costs are more re-duced. Twice, the two parts of the adapter plate is easier to handle by the service personnel than one part adapter plate, so it is faster to mount the two parts of the adapter plate. Consequently the safety for the service personnel is increased and the costs are more reduced.

In a further preferred embodiment of the adapter arrangement, in assem-bled state of the adapter arrangement the transition piece and the corner bars defining an angle, wherein one of the plurality of the adapter plates are at least partly arranged at this angle (ß).

In a further preferred embodiment of the adapter arrangement, the adapter plates at least partially overlap the transition piece in longitudinal direc-tion of the hybrid tower and the adapter plates, in assembled state of the adapter arrangement, are connected with the corner bars of the lattice section, and wherein the transition piece, in assembled state of the adapter arrangement, is connected with the tubular section.

In a further preferred embodiment of the adapter arrangement, the adapter plate having a first area for fastening of the connection bars and a sec-ond area for fastening the transition piece.

In a further preferred embodiment of the adapter arrangement, the second area of the adapter plate, from an orthogonal view to a longitudinal axis of the adapter plate, so that the adapter plate basically forms a double Y-form.

A further aspect of the invention is directed to a hybrid tower for a wind turbine, wherein the hybrid tower comprises the said adapter arrange-ment.

A further aspect of the invention is directed to a wind turbine having said hybrid tower, which comprises said adapter arrangement.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be explained in more detail with respect to exem-plary embodiments with reference to the enclosed drawings, wherein:

Figure 1 shows a wind turbine (PRIOR ART),

Figure 2 shows a hybrid tower for a wind turbine according to Fig. 1;

Figure 3 shows a detailed view of adapter arrangement according to a first embodiment of the hybrid tower according to Fig. 2;

Figure 4 shows a front view of adapter plate for the adapter arrange-ment according to a first embodiment of Fig. 3;

Figure 5 shows a detailed view of adapter arrangement according to a second embodiment of the hybrid tower according to Fig. 2;

Figure 6 shows a rear view of adapter plate for the adapter arrange-ment according to the second embodiment of Fig. 5;

Figure 7 shows a rear view of adapter plate with support bars;

Figure 8 shows a detailed view of adapter arrangement according to a third embodiment of the hybrid tower according to Fig. 2;

Figure 9 shows a front view of adapter plate for the adapter arrange-ment according to the third embodiment of Fig. 8;

Figure 10 shows a detailed view of adapter arrangement according to a fourth embodiment of the hybrid tower according to Fig. 2 and

Figure 11 shows a rear view of adapter plate for the adapter arrange-ment according to the fourth embodiment of Fig. 10;

The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 depicts a schematic view of a wind turbine 1 with a hybrid tower 2 and a nacelle 3. Depending on given requirements the wind turbine 1 can be used for offshore or onshore applications. The nacelle 3 is rotata-ble mounted on the hybrid tower 2. The nacelle 3 incorporates a number of components of a drive train chain 4 comprising a rotor shaft (not shown) for example. The nacelle 3 also incorporates a generator (not shown) connected with a plurality of electrical components (not shown). Further the nacelle 3 comprises a yaw system (not shown) for rotating the nacelle 3. Said rotor shaft is connected to a rotor 5. The rotor 5 comprises three rotor blades 6 which are mounted to a hub 7. The hub 7 is connect-ed to the rotor shaft of the drive train chain 4. The rotor blades 6 are ad-justably mounted on the hub 7. This is realized by means of pitch drives 8, said pitch drives 8 being part of a pitch system (not shown). The pitch system controls the rotor speed to given set points. By means of pitch-drives 8, the rotor blades 6 may be moved about a rotor blade 6 axes into different pitch positions, said rotor blade 6 axis extending in an axial di-rection of the rotor blades 6. Each rotor blade 6 is connected to the hub 7 via its pitch-drive 8. The nacelle 3 is covered by a nacelle cover 9, which has a nacelle cover interface 10. The hub 7 is covered by a spinner 11.

Fig. 2 shows a hybrid tower 2, wherein an upper section of the hybrid tower 2 is designed as a tubular section 12 and a lower section of the hy-brid tower 2 is designed as a lattice section 13. The tubular section 12 and the lattice section 13 are connected with each other by means of an adapter arrangement 14. The lattice section 13 comprises at least three, in this embodiment four, corner bars 15 which are connected to each other by a number of cross girders 16 and cross braces 17 and the corner bars 15 are arranged in an angle a to a longitudinal axis 18 of the hybrid tower 2 as shown in Fig. 3. The corner bars 15 are designed for dissipating the bending moments acting perpendicularly to the tower axis 18 as well as for dissipating forces acting in the tower axis 18. The cross braces 17 of the lattice section 13 are designed for dissipating torsional moments act-ing around the tower axis as well as for dissipating forces acting perpen-dicularly to the tower axis 18. The corner bars 15 are arranged with an inclination angle to the tower axis 18. The tubular section 12 is connected to the lattice section 13 via the adapter arrangement 14. For the tubular section 12 already existing tubular segments 19 from the known tubular section 12 can be used; here, for instance, the two uppermost segments 19 of the known tubular section 12 are used. The adapter arrangement 14 is arranged on the level of the tip of the one rotor blade 6 located in the lowermost position. Hence the hybrid tower 2 is designed very slimly in the section of the rotor 5 so that it is ensured that the rotor blades 6 can freely move in relation to the hybrid tower 2 even at high deflection of the rotor blades 6. Below the rotor 5 the width of the lattice section 13 can be freely increased so that a large platform and thus a stable standing of the hybrid tower 2 can be guaranteed.

Fig. 3 depicts a detailed view of a first embodiment of the adapter ar-rangement 14 of the hybrid tower 2 according to Fig. 2 arranged at the top of the lattice section 13. The adapter arrangement 14 comprises a transi-tion piece 20, a plurality of adapter plates 21 and a plurality of connection bars designed as corner bars 15. In the shown embodiment the number of corner bars 15 is equal to the number of adapter plates 21. Further the transition piece 20 has a cylindrical cross section. Due to this design the transition piece 20 and each of the corner bars 15 include an angle ß. Each of the adapter plates 21 is designed such a way to compensate the space between the transition piece 20 and the corner bars 15 at least part-ly. However, each of the adapter plates 21 lies flush on the surface of the transition piece 20 so that the adapter plates 21 at least partially overlap the transition piece 20 in longitudinal direction of the hybrid tower 2 and the adapter plates 21, in assembled state of the adapter arrangement 14, are connected with the corner bars 15 of the lattice section 13, and wherein the transition piece 20, in assembled state of the adapter ar-rangement 14, is connected with the tubular section 12. Therefore, as can be seen in Fig. 4, the adapter plate 21 having a first area 22 for fastening of the corner bars 15 and a second area 23 for fastening the transition piece 20. The adapter plates 21 can be mounted via screws (not shown). The bores 24 therefore are arranged at the first and second area 22, 23.

Fig. 5 depicts a detailed view of a second embodiment of the adapter ar-rangement 14a of the hybrid tower 2 according to Fig. 2 arranged at the top of the lattice section 13. Components described before which have the same functions, but differs under constructions, are numbered with an “a”.

The second embodiment of the adapter arrangement 14a differs from the first embodiment by the fact that the adapter plates 21a have another de-sign. As shown in Fig. 6, the second area 23a of the adapter plate 21a, from an orthogonal view to a longitudinal axis of the adapter plate 21a, so that the adapter plate 21a basically forms a double Y-form. For this the second area 23a having a narrowing 25 in direction to the first area 22. This narrowing 25 has his maximum at approximately two-thirds of the length of the adapter plate 21a. Then a third area 26 for connecting the adapter plate 21a with the transition piece 20 follows. Therefore bores 24 are arranged at the third area 26. At the area of the narrowing 25 the adapter plate 21a has no contact with the transition piece 20. Further the adapter plate 21a comprises a reinforcement element 27.

Fig. 7 shows another embodiment of the adapter plate 21a, which have additional reinforcement elements 28.

Fig. 8 depicts a detailed view of a third embodiment of the adapter ar-rangement 14b of the hybrid tower 2 according to Fig. 2 arranged at the top of the lattice section 13). Components described before which have the same functions, but differs under constructions, are numbered with a “b”.

The third embodiment of the adapter arrangement 14b differs from the foresaid embodiments by the fact that the adapter plates 21b can be welded with the transition piece 20. Therefore – as can be seen in Fig. 9 – the second area 23b has no bores. The second area 23b lies flush at the surface of the transition piece 20. In this position the adapter plate 21b can be welded with the transition piece 20 for forming a stable connec-tion. The first area 22 is designed in the same way as described in the foresaid embodiments.

Fig. 10 depicts a detailed view of a fourth embodiment of the adapter ar-rangement 14c of the hybrid tower 2 according to Fig. 2 arranged at the top of the lattice section 13. Components described before which have the same functions, but differs under constructions, are numbered with a “c”.

The main different of this embodiment to foresaid embodiments is that each of the adapter plate 21c is executed in two parts 21c-1, 21c-2. These two parts 21c-1, 21c-2 are symmetrical along a longitudinal axis 29, as shown in Fig. 11. Further, the two parts are casted parts. In the shown embodiment the two parts 21c-1, 21c-2 can be mounted via screws (not shown) to the transition piece 20. However, in a not shown embodiment the two parts 21c-1, 21c-2 of the adapter plate 21c can be welded with the transition piece 20.

Fig. 11 shows a rear view of the two parts 21c-1, 21c-2 of the adapter plate 21c. Both parts have the same design. In the following the first part is numbered with “-1” and the second part is numbered with “-2”.

For mounting the two parts 21c-1, 21c-2 with the corner bars 15, each of the parts 21c-1, 21c-2 having a first area 22c-1, 22c-2. In the shown em-bodiment each of the first areas 22c-1, 22c-2 is mounted to the corner bars via screws (not shown). Therefore, at each of the first area 22c-1, 22c-2 a plurality of bores 30-1, 30-2 is arranged. The edge area of each part 21c-1, 21c-2 of the adapter plate 21c has a double-Y like shape with a second area 23c-1, 23c-2, a third area 26c-1, 26c-2 and a narrowing ar-ea 25c-1, 25c-2 between them. At each of these areas a plurality of bores 31-1, 31-2 are arranged for mounting the second area 23c-1, 23c-2, the third area 26c-1, 26c-2 and the narrowing area 25c-1, 25c-2 to the transi-tion piece 20.

LIST OF REFERENCE SIGNS

1 wind turbine
2 hybrid tower
3 nacelle
4 drive train chain
5 rotor
6 rotor blades
7 hub
8 pitch drives
9 nacelle cover
10 nacelle cover interface
11 spinner
12 tubular section
13 lattice section
14 adapter arrangement (first embodiment)
14a adapter arrangement (second embodiment)
14b adapter arrangement (third embodiment)
14c adapter arrangement (fourth embodiment)
15 corner bar
16 cross girders
17 cross braces
18 tower axis
19 tubular segments
20 transition piece
21 adapter plates (first em-bodiment)
21a adapter plates (second embodiment)
21b adapter plates (third em-bodiment)
21c adapter plates (fourth embodiment)
21c-1 first part of adapter plate
21c-2 second part of adapter plate
22 first area
22c-1 first area of first part
22c-2 first area of second part
23 second area
23b second area (without bores)
23c-1 second area of first part
23c-2 second area of second part
24 bores
25 narrowing area
25c-1 narrowing area of first part
25c-2 narrowing area of sec-ond part
26 third area
26c-1 third area of first part
26c-1 third area of second part
27 reinforcement element
28 additional reinforcement element
29 longitudinal axis of adapter plate
30-1 bores of first part
30-2 bores of second part
31-1 bores of first part
31-2 bores of second part
a angle of corner bars
ß angle between transition piece and the connection bar