TOWER CRANE FOR ERECTING A WIND TURBINE, AND METHOD FOR ERECTING SAID TOWER CRANE

Abstract

A rotating tower crane for erecting a wind turbine, having a tower and a tower substructure, which is connected to the tower and is intended for supporting the tower, wherein the tower substructure has a supporting cross frame, which has three or more, preferably four, legs, extending from the tower. It is proposed that each leg has fastened on it, on the ground side, a load-distributor plate, which is not connected to the foundation, wherein the load-distributor plates together form the ballast of the tower.

Claims

1. A rotating tower crane for erecting a wind turbine on a foundation, the rotating tower crane comprising: a tower; and a tower substructure coupled to the tower and configured to support the tower, the tower substructure having a supporting cross frame that includes at least three legs extending from the tower, the at least three legs having ends and load-distributor plates coupled to the ends, the load-distributor plates being on the foundation or a ground surface without being fixed to the foundation and together forming the ballast of the tower.

2. The rotating tower crane according to claim 1, wherein the tower substructure has a levelling device and wherein the levelling device has four cylinders, the four cylinders being separately activatable.

3. The rotating tower crane according to claim 2, wherein the levelling device includes at least one of: force-measuring sensors configured to sense the forces acting on the four cylinders, pressure sensors configured to sense fluid pressure acting on the four cylinders, an inclination sensor, or at least one sensor for each of the four cylinders, each of the at least one sensors being configured to sense a cylinder stroke.

4. The rotating tower crane according to claim 2, wherein the levelling device has an electronic control device.

5. The rotating tower crane according to claim 4, wherein the electronic control device is configured to activate one or more of the four cylinders in dependence on at least one of the following variables: an angle of inclination of the tower, a force acting on the respective cylinder, fluid pressure acting on the respective cylinder, or a cylinder stroke covered by the respective cylinder.

6. The rotating tower crane according to claim 4, wherein the electronic control device is configured to establish a control recommendation for activating one or more of the four cylinders and to generate a signal indicative of the control recommendation, wherein the control recommendation depends on at least one of the following variables: angle of inclination of the tower, force acting on the cylinders, fluid pressure acting on the cylinders, or cylinder stroke covered by the cylinders.

7. The rotating tower crane according to claim 6, wherein the levelling device has a display unit configured to display one or more of the following variables: angular position of the tower, loading on one or more of the four cylinders, operating mode of the levelling device, fault messages, system pressures, position of one of the four cylinders on the supporting cross frame, one of the four cylinders recommended for activation, or the control recommendation.

8. The rotating tower crane according to claim 1, wherein adjacent legs of the supporting cross frame, in a zero position, are oriented in relation to one another at an angle of 90°, and one or more of the legs are arranged in an articulated manner on the supporting cross frame such that the one or more legs are deflected out of the zero position by an adjustment angle.

9. The rotating tower crane according to claim 8, wherein the adjustment angle ranges from +/−10°.

10. The rotating tower crane according to claim 1, comprising at least one stay cable configured to fasten the rotating tower crane at a first height H.sub.1, at a second height and at a third height of a tower of a wind turbine to be erected, wherein the stay cable has in each case one or more pneumatically or hydraulically actuated telescopic retaining arms configured to be moved between a retracted position and an extended position and in the extended position configured to be connected to the tower in a reversibly releasable manner by a coupling.

11. A method comprising: erecting a rotating tower crane for erecting a wind turbine, wherein the erecting the rotating tower crane comprises: forming a foundation for the wind turbine; positioning two load-distributor plates on the foundation without fixing the two load-distributor plates to the foundation; positioning one or more, load-distributor plates alongside the foundation on a ground surface without fixing the one or more load-distributor plates to the ground surface; connecting the two load-distributor plates and the one or more load-distributor plates to the tower by a supporting cross frame having three or more legs; and erecting the tower, wherein the two load-distributor plates and the one or more load-distributor plates form the ballast of the tower.

12. A method comprising: positioning two first load-distributor plates above a foundation for a wind turbine, wherein the first load-distributor plates are not fixed to the foundation; positioning two second load-distributor plates alongside the foundation on a ground surface, wherein the second load-distributor plates are not fixed to the ground surface; connecting the first and second load-distributor plates to the tower by a supporting cross frame having three or more legs; erecting the tower; and levelling the tower by a levelling device.

13. The method according to claim 12, wherein the levelling comprises one or more of the following: sensing an angle of inclination of the tower; sensing a force acting on one or more cylinders of the levelling device; sensing a fluid pressure acting on the one or more cylinders; sensing a cylinder stroke of the one or more cylinders; and actuating the one or more cylinders in dependence on one or more of the sensed angle, sensed force, sensed fluid pressure, and sensed cylinder stroke in order to orient the tower vertically.

14. The method according to claim 13, wherein the levelling comprises one or more of the following: establishing a recommendation for activating the one or more cylinders in dependence on at least one of the following variables on a display unit: angle of inclination of the tower, force acting on the one or more cylinders, fluid pressure acting on the one or more cylinders, and cylinder stroke covered by the one or more cylinders, the method further comprising generating a signal indicative of the recommendation, and displaying one or more of the following variables: angular position of the tower, loading on the one or more cylinders, operating mode of the levelling device, fault messages, system pressures, position of the one or more cylinders on the supporting cross frame, and the recommendation.

15. The method according to claim 12, wherein positioning two first load-distributor plates and positioning two second load-distributor plates includes positioning the first and second load-distributor plates, such that centers of mass of the first and second load-distributor plates are arranged on a common circular path.

16. The method according to claim 15, wherein the common circular path has a radius R.sub.K, which is defined by the equation $R_K=x.Math.\frac{R_A+R_I}{2},$ where x ranges from 0.8 to 1.4.

17. The method according to claim 15, comprising: deflecting the legs out of a zero position by an adjustment angle such that the bottom points of the legs are arranged on the common circular path.

18. The method according to claim 15, wherein the common circular path is concentrically with the center axis of the wind-turbine tower.

19. The method according to claim 15, wherein the common circular path is in a range from +/−10°.

20. The rotating tower crane according to claim 4, wherein the electronic control device is a programmable controller configured to activate the one or more cylinders.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0029] The invention will be described in more detail hereinbelow by way of a preferred exemplary embodiment and with reference to the accompanying figures, in which:

[0030] FIG. 1 shows a schematic side view of a rotating tower crane during the operation of erecting a wind turbine according to a first exemplary embodiment,

[0031] FIG. 2 shows a schematic illustration of a detail of the rotating tower crane from FIG. 1, and

[0032] FIGS. 3a-c show schematic plan views of the rotating tower crane according to FIGS. 1 to 2 in different operating positions.

DETAILED DESCRIPTION

[0033] FIG. 1 depicts a rotating tower crane 1. The rotating tower crane is a so-called top-slewing crane, having a stationary tower 3 constructed on, and supported by, a tower substructure 5. The tower substructure 5 has a total of four legs 7 intended for supporting purposes. The legs 7 of the tower 1 are connected at their bottom regions 9 in each case to a load-distributor plate 11a, b. The load-distributor plates 11a, b stand on the ground region 200, wherein two 11b of the four load-distributor plates stand on the ground, with no connection to the ground, alongside a foundation 101 of a wind turbine 100 which is to be erected, and two further load-distributor plates 11a are arranged above the foundation 101, with no connection to the foundation 101.

[0034] The wind turbine 100 has a multiplicity of tower segments 103, which are raised one after the other, and positioned on the tower segments beneath, by the rotating tower crane 1. The wind turbine 100 has a center axis S.sub.W, whereas the tower has a center axis S.sub.T.

[0035] At a height H.sub.1, the rotating tower crane 1 has a first stay cable 13, by means of which the rotating tower crane 1 is fastened on the tower of the wind turbine 100. The fact that the tower segments 103 are already braced to the foundation 101 at this height H.sub.1 provides the rotating tower crane 1 with additional stability.

[0036] In view of the tendency towards wind-turbine towers of increasing height, provided is, from a certain height H.sub.2, for example above 140 m, for a second bracing means, by brace 15, to be fitted between the rotating tower crane 1 and the tower of the wind turbine 100. It is potentially possible, in the case of towers increasing to further heights, which, for the sake of simplicity, is not illustrated here, for further bracing means to be fitted.

[0037] FIG. 2 illustrates, schematically, the bearing region of one of the load-distributor plates 11 on the ground region 200. The tower substructure 5, and with it the rotating tower crane 1 as a whole, has to be oriented vertically in order for the rotating tower crane 1 to operate safely. For this purpose, the rotating tower crane 1 has a levelling device 20. The levelling device 20 has a cylinder 17, for example a hydraulic cylinder, preferably for each load-distributor plate 11a, b and each leg 7 of the tower substructure 5. The cylinder 17 is connected for signal-transfer purposes to an electronic control device 25, preferably a programmable controller, and can be activated thereby. Furthermore, the cylinder 17 is connected to a pressure sensor 21, which, for its part, is connected for signal-transfer purposes to the electronic control device 25. The tower substructure 5 preferably also bears, for the levelling device 20, an inclination sensor 19, which is connected for signal-transfer purposes to the electronic control device 25.

[0038] An absolute encoder 23 for establishing the cylinder stroke covered by the cylinder is preferably provided either on the tower substructure 5 or, as an alternative to the variant shown, directly on the cylinder 17. This absolute encoder may be, for example, an optical sensor. It is also the case that the absolute encoder 23 is connected for signal-transfer purposes to the electronic control device 25.

[0039] The electronic control device 25, for its part, is connected for signal-transfer purposes, optionally by cables or wirelessly, to a display unit 27 and an operating element 29. The electronic control device 25 is intended, in dependence on the pressures established for the cylinder 17, and/or on the inclination established, and/or on the cylinder strokes covered, to establish an adjustment recommendation for the cylinders 17 and to transmit this to the display unit 27. It is possible for the operator, preferably by means of the operating element 29, to input a command which follows the recommendation, or to input a differing command manually. As an alternative, the electronic control device 25 is set up preferably to execute the alignment operation autonomously, provided this complies with legal requirements.

[0040] The electronic control device preferably has a control module, which is programmed to enable or to block, depending on the legal requirements at the site of the rotating tower crane 1, the autonomous levelling function following input of a password.

[0041] FIGS. 3a-c show a further aspect of the invention. FIGS. 3a-c illustrate a plan view of the positioning of the rotating tower crane 1 relative to the wind turbine 100, in particular relative to the foundation 101 thereof.

[0042] The foundation 101 has an outer circumference of radius R.sub.A and a skid of radius R.sub.I.

[0043] In FIG. 3b, the legs 7 of the rotating tower crane 1 are arranged in a zero position. In this zero position, respectively adjacent legs, in the horizontal plane illustrated, define an essentially right angle, preferably precisely a right angle, in relation to one another. The load-distributor plates 11a, and with them the legs 7, are arranged such that they are located, preferably by way of their center of mass, above the foundation 101 on a common circular path K. The radius R.sub.K of the circular path K has preferably been established as referred to above.

[0044] This positioning results in the rotating tower crane 1 being spaced apart by a distance C, as measured from its center axis S.sub.T to the center axis S.sub.W of the wind turbine 100.

[0045] On account of the zero position, the direct distance between the bottom regions of the legs 7 is always equal and assumes the value E.

[0046] In comparison with the zero position according to FIG. 3b, the rotating tower crane in FIG. 3a is used for a wind turbine 100 of which the foundation 101—and also the tower—have a smaller diameter than in FIG. 3b. In the state which is shown in FIG. 3a, the legs 7, rather than being located in the zero position, have been deflected by an angle α. As a result, the bottom regions of the legs 7 on the load-distributor plates 11a, and with them the load-distributor plates 11a themselves, are closer together than in FIG. 3b and so are spaced apart from one another by the distance A, which is smaller than distance E. The load-distributor plates 11a, however, are likewise arranged on a common circular path K of radius R.sub.K, said circular path having been determined as referred to above. As a result of this, and of the legs 7 being adjusted by the angle α, it is also possible for the distance between the rotating tower crane 1 and the wind turbine 100 in the state according to FIG. 3a to be essentially equal to the distance which has been set in FIG. 3b. The center axis S.sub.T of the rotating tower crane 1 is spaced apart by the distance CC from the center axis S.sub.W of the wind turbine 100 in FIG. 3a.

[0047] FIG. 3c depicts the other extreme in relation to FIGS. 3b and 3a. The wind turbine 100 according to FIG. 3c has a larger foundation diameter 101 and, with this, a larger tower diameter at the base. Here, then, the legs 7 and the load-distributor plates 11a have been deflected out of the zero position in the direction opposite to that in FIG. 3a, to be precise by an angle β. This means, then, that the distance F between the bottom regions of the legs 7 and the load-distributor plates 11a is larger than the value E in FIG. 3b, whereas the distance between the load-distributor plates 11a and 11b and the respective bottom regions of the legs 7, which are connected to said load-distributor plates, is smaller and assumes a value G. For the case where the angle β is equal to angle α, value G corresponds to the value A, while the value F corresponds to the value B.

[0048] It is also the case in the exemplary embodiment according to FIG. 3c that the load-distributor plates 11a are arranged, preferably by way of their center of mass, on a common circular path K of radius R.sub.K, which has been established as referred to above. It is thus made possible, even in the case of a relatively large foundation, as shown here in FIG. 3c, to set essentially the same distance between the rotating tower crane 1 and the wind turbine 100. The distance in this case between the center axis S.sub.T of the rotating tower crane 1 and the center axis S.sub.W of the wind turbine 100 is equal to the value C′.

[0049] In order to provide a reference point for the range of use of the rotating tower crane, it can be assumed that the installation height of the tower of the wind turbine 100 in FIG. 3a is approximately 100 m, whereas the tower height of the wind turbine 100 in FIG. 3b is approximately 125 m, and the tower height of the wind turbine 100 in FIG. 3c is approximately 150 m. The distances C, C′ and C″ are each approximately 9.5 m. The radii R.sub.A, in the three exemplary embodiments, are between approximately 10.70 m (FIG. 3a) and 13 m (FIG. 3c). The values for R.sub.I are between approximately 4.70 m (FIG. 3a) and approximately 8.50 m (FIG. 3c). The values for the distances A to F fluctuate between approximately 15 m (A, G) and approximately 20.5 (B, F).

[0050] The load-distributor plates 11 weigh, by way of example, approximately 20 t each.

[0051] It would optionally also be possible for the load-distributor plates to have a unit weight, for example, ranging from approximately 10 t to approximately 40 t, for example approximately 24.5 t, so that, in the case of less pronounced or in the case of more pronounced transverse loads, etc., it is still the case that sufficient ballasting is provided for rotating tower cranes of the order of magnitude presented.