METHOD FOR CONNECTING TWO SECTIONS OF A STRUCTURE, ESPECIALLY OF A WIND TURBINE, AND CONNECTION TOOL

Abstract

A method is provided for connecting two tubular or conical sections of a structure, especially of a wind turbine, by joining respective circular ends of the outer walls of these sections by welding, including the steps: positioning the two sections in such a way, that the circular ends are adjacent to each other, positioning a first part of a connection tool adjacent to the circular ends of the two sections, positioning a second part of the connection tool in such a way that the first and second part of the connection tool form a ring-shaped housing, blocking access to the circular ends from the outside of the sections, and using a welding head of the connection tool arranged within the ring-shaped housing to join the outer walls.

Claims

1. A method for connecting two tubular or conical sections of a structure by joining respective circular ends of the outer walls of these sections by welding, comprising: positioning the two sections in such a way, that the circular ends are adjacent to each other; positioning a first part of a connection tool adjacent to the circular ends of the two sections; positioning a second part of the connection tool in such a way that the first and second part of the connection tool form a ring-shaped housing, blocking access to the circular ends from the outside of the sections; and using a welding head of the connection tool arranged within the ring-shaped housing to join the outer walls of the sections by welding.

2. The method according to claim 1, wherein the first and second part of the connection tool are connected by a mechanism, wherein the position of the second part relative to the first part is modified by an actuator to position the second part to form the ring-shaped housing.

3. The method according to claim 1, wherein the first and second part of the connection tool form a track for the welding head running essentially parallel to the circular ends of the two sections after the second part is positioned to form the ring-shaped housing, wherein the welding head moved along that track to form a welding seam joining the walls of the sections.

4. The method according to claim 1, wherein the temperature and/or humidity in the ring-shaped housing are modified by an environment control means of the connection tool prior to the joining of the outer walls by welding.

5. The method according to claim 1, wherein the connection tool is used to apply an added layer to and/or to treat the outer surface of the walls and/or the welding seam and/or to acquiring sensor data concerning the walls and/or the welding seam and/or the added layer in a respective additional processing step performed while the ring-shaped housing is formed by the first and second part of the connection tool.

6. The method according to claim 1, wherein the connection tool is used to connect several pairs of sections of structures, wherein at least two of the pairs have different diameters of the respective circular ends of the outer walls to be joined, wherein a seal between the ring-shaped housing and the respective outer walls and/or a radial position of the welding head and/or of a device used in the additional processing step or in at least one of the additional processing steps are chosen depending on the diameter of the respective circular ends to be connected.

7. The method according to claim 1, wherein an initial gap between the ends of the outer walls and/or an angle between the outer walls of the sections after the positioning of the two sections reduced by actuating the or an actuator of the connection tool.

8. The method according to claim 1, wherein the first part of the connection tool is positioned using a wheeled and/or tracked transport or a ship, and/or in that the sections are positioned in such a way that the longitudinal direction of the sections extends in the horizontal or vertical direction during the welding.

9. A connection tool for connecting two tubular or conical sections of a structure by joining respective circular ends of the outer walls of these sections by welding, comprising: a first and second part of the connection tool, each forming a segment of a ring-shaped housing, the first and second part being connected by a mechanism pivoting the second part with respect to the first part to open and close the ring-shaped housing, wherein the closed ring-shaped housing blocks access to the circular ends from the outside of the sections when the complete circumference of each axial end of the ring-shaped housing contacts the outer wall of a respective one of the sections; a welding head; a track for the welding head running along the inside of the ring-shaped housing, when the ring-shaped housing is closed; and an actuator for moving the welding head along the track to create a welding seam connecting the sections.

10. The connection tool according to claim 9, wherein the axial ends of the ring-shaped housing are formed using at least one elastic seal.

11. The connection tool according to claim 9, wherein the connection tool comprises an environment control means for modifying the temperature and/or the humidity in the closed ring-shaped housing.

12. The connection tool according to claim 9, wherein it comprises a respective device for applying an added layer to and/or for treating the outer surface of the walls and/or the welding seam and/or for acquiring sensor data concerning the walls and/or the welding seam and/or the added layer in a respective additional processing step.

13. The connection tool according to claim 12, wherein it comprises a control unit that is configured to control the actuator and the welding head to join the outer walls by welding in a welding step and to control the respective device in the respective additional processing step performed before and/or after the welding step.

14. The connection tool according to claim 13, wherein the control unit is configured to evaluate at least part of the sensor data and to generate a report based on this evaluation.

15. The connection tool according to claim 1, wherein it comprises a further mechanism for adjusting the radial position of the welding head and/or the device or at least one of the devices in the at least one processing step.

16. The method of claim 1, wherein the structure is a wind turbine.

17. The connection tool of claim 9, wherein the structure is a wind turbine.

Description

BRIEF DESCRIPTION

[0064] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0065] FIG. 1 shows an arrangement of two conical sections of a wind turbine and an embodiment of a connection tool at two different times while an embodiment of the method is performed; and

[0066] FIG. 2 shows an arrangement of two conical sections of a wind turbine and an embodiment of a connection tool at two different times while an embodiment of the method is performed.

DETAILED DESCRIPTION

[0067] A method for connecting two conical sections 1, 2 of a structure, especially a wind turbine, will be discussed with reference to FIGS. 1 and 2 that show the state of a connection tool 6 during different steps of the method. In the example two sections 1, 2 of a wind turbine tower are connected. Initially the sections 1, 2 that should be connected are placed on supports 3, 4 and positioned in such a way that the circular ends 11, 12 of the outer walls 13, 14 of these sections 1, 2 are adjacent. A first part 7 of the connection tool 6 is then positioned adjacent to the circular ends 11, 12 to allow access to the region where a welding seam is to be placed. In the example shown in FIGS. 1 and 2 the first part 7 of the connection tool 6 is attached to a wheeled transport 5 via a lifting platform 10. The transport 5 can be a self-propelled modular transport that essentially allows an arbitrary movement within the horizontal plane. By lowering the first part 7, then positioning the transport 5 below the relevant area and then lifting the first part 7, the first part 7 can place in such a way that an elastic seal 16 contacts the outside of the outer walls 13, 14 of the sections 1, 2.

[0068] The connection tool 6 can then be closed by positioning a second part 8 of the connection tool 6 in such a way that the first and second part 7, 8 of the connection tool 6 form a ring-shaped housing 19, blocking access to the circular ends 11, 12 from the outside of the sections 1, 2. When the second part 8 is positioned as shown in FIG. 2, the elastic seal 15 of the second part 8 also contacts the outer walls 13, 14 of the sections 1, 2. The interface between the respective section 1, 2 and the connection tool 6 is therefore sealed on both radial ends, essentially avoiding an exchange of fluid and/or air in these areas. Except for a controlled exchange of fluid and/or air by the environmental control means 20 of the connection tool 6 or other devices 26, 27 used within the connection tool 6, such an exchange is therefore only possible via a rather small gap between the circular ends 11, 12 of the outer walls 13, 14 of the sections 1, 2.

[0069] The first and second part 7, 8 of the connection tool 6 are connected via a mechanism 33, namely a hinge 9, and the second part 8 can be pivoted with respect to the first part 7 by an actuator 18 that is controlled by the control unit 17. By moving the second part 8 from the position shown in FIG. 1 to the position shown in FIG. 2, an alignment of the sections 1, 2 can be further improved by correcting minor misalignments due to forces exerted by the closing of the connection tool 6.

[0070] Alternatively, a further modification of the alignment of the sections 1, 2 would be possible by using additional actuators not shown in the example.

[0071] Once the ring-shaped housing 19 is formed by closing the connection tool 6, as shown in FIG. 2, controlled conditions can be created within an inner volume 21 of the ring-shaped housing 19 by the environment control means 20. The environment control means 20 can comprise a heater and an ability to exchange the air within the ring-shaped housing 19, especially for feeding in dry air to control humidity within the ring-shaped housing 19.

[0072] Once a controlled environment is provided it would in principle be possible to directly use a welding head 22 to form a welding seam along the circumference of the ends 11, 12 of the outer walls 13, 14 of the sections 1, 2 to connect the sections 1, 2 by welding. To achieve this the welding head 22 can be moved along a track 23 by an actuator 24 as indicated in FIG. 2 by the arrow 25. The sections of the track 23 running within the first and second parts 7, 8 of the connection tools 6 are shown in FIG. 1. The track itself is not shown in FIG. 2 for reasons of clarity. The actuator 24 and the welding head 22 itself can be controlled by the control unit 17.

[0073] In an embodiment, additional processing steps are performed while the ring-shaped housing 19 is closed. Typically, additional processing steps are used before and after the welding step. To allow for these additional processing steps additional devices 26, 27 are arranged within a ring-shaped housing 19. For reasons of clarity and simplicity only two additional devices 26, 27 are shown in the figures. To allow for an access to the surface of the sections 1, 2 from all directions, the devices 26, 27 can be places on additional tracks 28, 29 of the connection tool 6. The devices 26, 27 can be devices for surface processing, e.g., a nozzle for sandblasting or applying a coat of paint or tools for grinding the surfaces of the sections 1, 2 prior to the welding or for grinding down the welding seam to provide an optimal surface shape in the area of the welding seam. In an embodiment, at least one of the devices 26, 27 can be a sensor, e.g., an ultrasound sensor, an x-ray sensor or a camera, to acquire sensor data about the state of the surfaces of the sections 1, 2 and/or the welding seam and/or an additional layer, e.g., a coat of paint applied to the surfaces 1, 2 and the welding seam.

[0074] The control unit 17 can control the devices 26, 27, the welding head 22 and the actuator 24 as well as additional actuators for moving the devices 26, 27 to perform a series of processing steps and a welding step. It is possible to automatically perform the sequence of steps once the ring-shaped housing 19 is closed and certain environment conditions are established. It is also possible that a user 30 can interact with the connection tool 6, e.g., via a mobile device 31, to decide if certain processing steps should be repeated, change the parametrization of certain processing steps, check certain acquired sensor data, etc. To support the user 30 it is possible to provide intermediate reports depending on acquired sensor data via the control unit 17.

[0075] In an example the processing sequence can comprise a first surface preparation, e.g., by sandblasting and/or grinding using the devices 26, then an automatic welding with the welding head 22 and then a further surface treatment, e.g., a coating of the surface by an antioxidant paint using the device 27. Prior to each of these steps and after the surface treatment sensor data can be acquired by additional devices to gather information about an initial state of the outer surface of the sections 1, 2 in the welding area, the state of this area after a cleaning of the surface, the quality of the weld, a thickness of an applied coat, etc. This data can at least partially be evaluated by the control unit 17 and the control unit 17 can generate a report that can be provided to a user 30, e.g., via the mobile device 31.

[0076] Once all relevant processing steps are finished the connection tool 6 can be opened with the actuator 18 and then removed using the transport 5.

[0077] When the connection tool 6 is used to perform multiple welding operations along a conical tower of a wind turbine or when the connection tool 6 is to be used for different types of towers, foundations, etc., it should be adjustable for different diameters of the ends 11, 12 of the outer walls 13, 14 to be connected. Small variations in the diameter can be compensated by different degrees of compression of the elastic seals 15, 16. The radial position of the welding head 22 can be adjusted by a mechanism 32. The adjustment can be manual. For example, the mechanism 32 can be a telescoping holder for the welding head 22 and the length of the telescopic holder 32 can be manual adjusted. In an embodiment, the adjustment is however performed by an actuator that is part of the mechanism 32. In this case the radial position can then be automatically adjusted, e.g., by recognizing which sections 1, 2 are to be connected by a video camera or other sensors of the connection tool 6 and automatically adjusting the radial position of the welding head 22 accordingly. Similar approaches can be used to adjust the radial positions of the devices 26, 27.

[0078] If the diameters of the open ends 11, 12 of the walls 13, 14 to be connected vary strongly, e.g., in a range of 7, 5 m and 10 m, it might be advantageous to replace the elastic seals 15, 16 with different elastic seals 15, 16 to create a better fit for a wide variety of possible diameters.

[0079] The use of a wheeled transport and the performance of the welding while the sections 1, 2 are lying horizontally are purely exemplary. Alternatively, the connection tool 6 might be mounted to a ship, especially via a crane, a robotic arm or similar devices to allow a controlled placement of the first section 7. This might be necessary to perform offshore welding tasks. The welding might also be performed while the sections are vertical, e.g., to connect a tower section to an already mounted monopile.

[0080] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0081] For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.