Method for Forming a Connection Between Two Pipe Segments of Different Widths and a Correspondingly Produced Connection

Abstract

The invention relates to a method for forming a connection between two pipe segments of different widths, preferably of a tower-like structure, in particular of a wind turbine. In order to be able to connect pipe segments of different widths more easily, reliably and cost-effectively to one another, it is provided that the wider pipe segment is pushed with one end partially over an end of the narrower pipe segment , that the pipe segments are positioned apart from one another by forming an annular gap between the pipe segments, that in the annular gap between the two pipe segments a separating layer extending in the longitudinal direction of the pipe segments and/or in the radial direction is provided, that the annular gap adjacent to the separating layer and at least one side of the separating layer is at least partially cast with a casting compound, that during the hardening of the casting compound the casting compound forms a firm connection on one side of the separating layer with only one of the pipe segments and/or the casting compound forms a firm connection on the other side of the casting compound , only with the other pipe segment and that the pipe segments after the hardening of the casting compound are separated again along the separating layer with the assigned separate connecting elements in particular formed by the hardened casting compound.

Claims

1. A method for forming a connection between two pipe segments of different widths, preferably of a tower-like structure, in particular of a wind turbine, in which the wider pipe segment is pushed with one end partially over an end of the narrower pipe segment, in which the pipe segments are positioned at a distance from one another, forming an annular gap between the pipe segments, in which a separating layer extending in the longitudinal direction of the pipe segments and/or in the radial direction is provided in the annular gap between the two pipe segments, in which the annular gap is cast at least partially with a casting compound adjacent to the separating layer and to at least one side of the separating layer, in which, when the casting compound hardens, the casting compound forms a firm connection on one side of the separating layer with only one of the pipe segments and/or the casting compound on the other side of the casting compound only with the other pipe segment, and in which the pipe segments after the hardening of the casting compound are separated again along the separating layer with the associated separate connecting elements, in particular formed by the hardened casting compound.

2. The method according to claim 1, in which, after separating the pipe segments along the separating layer, the separated pipe segments are reconnected in such a way that at least the separate connecting elements formed from the already hardened casting compound form a form-fitting connection and/or a force-fitting connection in the longitudinal direction of the pipe segments.

3. the method according to claim 1, in which steel pipe segments or reinforced concrete are used as pipe segments and/or in which cylindrical or conical pipe segments are used as pipe segments at least in the region of the annular gap and/or in which pipe segments of an offshore structure are used as pipe segments and/or in which tower segments of a wind turbine, in particular of an offshore wind turbine, are used as pipe segments.

4. The method according to claim 1, in which the pipe segments are positioned concentrically to one another, forming an annular gap between the pipe segments.

5. The method according to claim 1, in which a film, preferably a plastic film, in particular a film made of polyvinyl chloride and/or polytetrafluoroethylene is used as a separating layer and/or in which the separating layer is formed at least partially by a metal, for example in the form of aluminium, iron or steel, and/or a carbon fibre fabric and/or a glass fibre fabric and/or a fibre-reinforced composite material and/or in which the separating layer is replaced or supplemented by an expanding separating layer, in particular made of bentonite mats, after the manufacture of the at least one connecting element.

6. The method according to claim 1, in which the separating layer is arranged cylindrically at least in sections in the annular gap and in which, preferably, at least the cylindrical section of the separating layer extends at least substantially concentrically to the inner pipe segment and/or to the outer pipe segment.

7. The method according to claim 1, in which in the annular gap between the two pipe segments, a separating layer is provided which at least substantially closes the annular gap tin the longitudinal direction of the pipe segments.

8. The method according to claim 1, in which the separating layer is formed at least in sections conically and/or obliquely in the radial direction to the longitudinal direction of the pipe segments in which, preferably, the separating layer is provided at least in the conical section on the inner edge of the annular gap in the longitudinal direction of the pipe segments closer to the end of the inner pipe segment assigned to the annular gap than to the outer edge of the annular gap and/or on the outer edge of the annular gap in the longitudinal direction of the pipe segments closer to the end of the outer pipe segment assigned to the annular gap than to the inner edge of the annular gap.

9. The method according to claim 1, in which the annular gap is at least partially cast with casting compound when the outer pipe segment is heated and/or when the inner pipe segment is cooled and/or are reinserted into each other after the casting compound has hardened and/or in which the hardened connecting elements are separated from one another along the separating layer when the outer pipe segment is heated and/or when the inner pipe segment is cooled.

10. The method according to claim 9, in which the cooled outer pipe segment and/or inner pipe segment cooled to a temperature below 20° C., preferably below 15° C., in particular below 10° C. and/or in which the heated outer pipe segment and/or inner pipe segment is heated to a temperature above 20° C., preferably above 30° C., in particular above 40° C.

11. The method according to claim 1, in which the outer pipe segment and/or inner pipe segment has at least one thrust rib in the region of the annular gap and in which, preferably, the at least one thrust rib provided at least substantially circumferentially and in which, further preferably, the at least one thrust rib is provided to be at least substantially annular.

12. The method according to claim 1, in which a grout and/or a casting mortar is used as the casting compound and in which, preferably, a grout which expands during hardening, a substance known as expansive grout, is used and in which, further preferably, a grout with alkali silica reactive aggregates, additions of bentonite, calcium sulphate aluminate cements and/or aluminate is used.

13. A connection of two pipe segments of different widths, preferably of a tower-like structure, in particular of a wind turbine, with an annular gap between overlapping ends of a wider outer pipe segment and a narrower inner pipe segment, preferably using the method according to claim 1, a connecting element is firmly connected to the outer circumferential side of the inner pipe segment in the annular gap, in that a different connecting element is firmly connected to the inner circumferential side of the outer pipe segment in the annular gap, in that at least one of the connecting elements is formed by a hardened casting compound and in that at least the two connecting elements connect the pipe segments in a longitudinal direction of the pipe segments in a form-fitting and/or force-fitting manner.

14. The connection according to claim 13, wherein the separating layer is provided between the connecting elements for producing the connection and in that, preferably, the separating layer is a film, preferably a plastic film, in particular a film made of polyvinyl chloride and/or polytetrafluoroethylene.

15. The connection according to claim 13, the connecting elements in the annular gap are designed at least substantially cylindrically and/or at least substantially conically at least in sections.

16. The connection according to claim 13, the pipe segments are designed cylindrically or conically at least in the region of the annular gap and/or in that the pipe segments are pipe segments of an offshore structure and/or in that the pipe segments are tower segments of a wind turbine, in particular of an offshore wind turbine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The invention is explained in greater detail below by means of a drawing merely depicting exemplary embodiments. In the drawings:

[0039] FIG. 1 shows a schematic side view of an offshore wind turbine,

[0040] FIGS. 2A-F show schematic sectional views of method steps of a first method according to the invention for forming a first connection according to the invention and

[0041] FIGS. 3A-F show schematic sectional views of method steps of a first method according to the invention for forming a first connection according to the invention.

DESCRIPTION OF THE INVENTION

[0042] FIG. 1 shows an offshore wind turbine W. The wind turbine W comprises a monopile foundation F formed by a foundation pile P in the form of a metal pipe embedded in the seabed M. The foundation pile P protrudes above sea level S and is connected there via a connection to tower T of wind turbine W, which carries nacelle G and rotor O of wind turbine W. In the present wind turbine W, the lower part of the tower T is designed as a cylindrical pipe segment 1 and the upper part of the foundation pile P is designed as a cylindrical pipe segment 2. Both pipe segments 1, 2 are designed as steel pipes. In addition, the diameter of the upper pipe segment 1 is larger than the diameter of the lower pipe segment 2, so that the upper pipe segment 1 can be pushed with its lower end onto the lower pipe segment 2 with its upper end.

[0043] FIGS. 2A-F show step-by-step how the connection 3 is formed between the two pipe segments 1, 2. At the end of the narrower pipe segment 2, a separating layer 4 extending in the longitudinal direction L is initially applied in the form of a plastic film, as shown in FIG. 2A. Now, the ends of the two pipe segments 1, 2 assigned to one another are pushed together in sections in the longitudinal direction L of the pipe segments 1, 2, as shown in FIG. 2B. These are concentric pipe segments 1, 2 with a circular cross-section. In this way, an annular gap 5 is formed in the radial direction R. In the next step, the separating layer 4 is connected to the end of the other pipe segment 1 and namely in such a way that the separating layer 4 takes on a conical shape at least in sections, as shown in FIG. 2C. In this way, the separating layer 4 separates two regions 6, 7 of the annular gap 5 from one another. The region 6 open in a downwards direction is sealed by a ring 8 or a seal, such as what is known as a grout seal, and the two regions 6, 7 are cast at least partially adjacent to the separating layer 4 and to both sides of the separating layer 4 with a casting compound 9, which then hardens in the annular gap 5, wherein the casting compound 9 forms two separate connecting elements 10, 11 which are firmly connected to the respectively assigned pipe segment 1, 2, as shown in FIG. 2D. In order to strengthen this connection 3, in each case a plurality of thrust ribs 12 is provided on the outer side of the narrower, inner pipe segment 2 and on the inner side of the wider, outer pipe segment 1, which surround the inner side or the outer side of the respective pipe segment 1, 2 in a circular manner. However, the pipe segments 1, 2 and assigned connecting elements 10, 11 can be separated from one another again along the separating layer 4 by pulling the pipe segments 1, 2 back out of one another in the longitudinal direction L of the same, as shown in FIG. 2E.

[0044] Now, the pipe segments 1, 2 can be moved separately to the installation location of the offshore wind turbine W and re-inserted there as before in order to join a connection 3 of the offshore wind turbine W, as shown in FIG. 2F. Since the same pipe segments 1, 2 are used for this as for forming the connecting elements 10, 11 from the casting compound 9 and the pipe segments 1, 2 are also turned against each other again as for forming the connecting elements 10, 11 from the casting compound 9, a defined and very precise connection 3 is obtained. The two pipe segments 1, 2 are held in a form-fitting manner in the longitudinal direction L of the pipe segments 1, 2 via the two connecting elements 10, 11. Twisting is prevented as a result of the dead weight of the upper pipe segment 1, 2 by a force-fitting connection of the connection 3.

[0045] The orientation of the pipe segments 1, 2 to be connected can also be reversed. If the narrower pipe segment 2 is to be the upper pipe segment and the wider pipe segment 1 the lower pipe segment, the connection 3 can be established in the same way. The arrangement of the pipe segments 1, 2 in the longitudinal direction L must only be reversed relative to one another when the connection 3 is finally joined. Alternatively or additionally, the orientation of the pipe segments 1, 2 to be connected can also be reversed before the insertion of the separating layer 4 and/or the at least one casting compound 9. It would therefore be possible to insert the narrower pipe segment 2 into the wider pipe segment 1 from above.

[0046] FIGS. 3A-F show step-by-step how an alternative connection 20 is formed between two pipe segments 21, 22 of different widths. At the end of the narrower pipe 22, a ring 23 is first detachably fastened, which circumferentially holds a separating layer 24 extending in the longitudinal direction L in the form of a plastic film, as shown in FIG. 3A. Further down, another ring 25 is held on the plastic film. Now, the ends of the two pipe segments 21, 22 assigned to one another are pushed together in sections in the longitudinal direction L of the pipe segments 21, 22, as shown in FIG. 3B. These are concentric pipe segments 21, 22 with a circular cross-section.

[0047] In this way, an annular gap is formed in the radial direction R, as shown in FIG. 3C. The separating layer 24 forms a cylindrical section 26 in the annular gap 27, wherein the two rings 23, 25 ensure that the separating layer 24 is spaced apart from both pipe segments 21, 22 in the cylindrical section 26. In addition, the rings 23, 25 close the annular gap 27 upwards and downwards so that the regions 28, 29 on both sides of the separating layer 24 are closed and can be filled with casting compound 30, which then hardens in the annular gap 27, wherein the casting compound 30 forms two separate connecting elements 31, 32, which are firmly connected to the respectively assigned pipe segment 21, 22, as shown in FIG. 3D. In order to strengthen this connection 20, in each case a plurality of thrust ribs 33 is provided on the outer side of the narrower, inner pipe segment 22 and on the inner side of the wider, outer pipe segment 21, which surround the inner side or the outer side of the respective pipe segment 21, 22 in a circular manner. However, the pipe segments 21, 22 and assigned connecting elements 31, 32 can be separated from one another again along the separating layer 24 by pulling the pipe segments 21, 22 back out of one another in the longitudinal direction L of the same, as shown in FIG. 3E.

[0048] Now, the pipe segments 21, 22 can be moved separately to the installation location of the offshore wind turbine W and re-inserted there as before in order to join a connection 20 of the offshore wind turbine W, as shown in FIG. 3F. Since the same pipe segments 21, 22 are used for this as for forming the connecting elements 31, 32 from the casting compound 30 and the pipe segments 21, 22 are also turned against each other again as for forming the connecting elements 31, 32 from the casting compound 30, a defined and very precise connection 20 is obtained. In the longitudinal direction L, the pipe segments 21, 22 are held against one another in particular as a result of a force-fitting connection. This is caused by the expansive casting compound 30. The casting compound 30 expands for a certain time after the principle hardening. Consequently, the connecting elements 31, 32 expand after joining the connection 20. The corresponding connecting elements 31, 32 are increasingly pressed against each other as a result of the expansion in the joined state, which results in a strong force-fitting connection.

[0049] Whether the narrower pipe segment 2 is inserted from above into the wider pipe segment 1 or vice versa in the manufacture of the connection and/or in the subsequent installation of the pipe segments 1, 2 is fundamentally of secondary importance.

LIST OF REFERENCE NUMERALS

[0050] 1.2 Pipe segment

[0051] 3 Connection

[0052] 4 Separating layer

[0053] 5 Annular gap

[0054] 6, 7 Regions

[0055] 8 Ring

[0056] 9 Casting compound

[0057] 10, 11 Connecting element

[0058] 12 Thrust ribs

[0059] 20 Connection

[0060] 21, 22 Pipe segments

[0061] 23 Ring

[0062] 24 Separating layer

[0063] 25 Ring

[0064] 26 Cylindrical section

[0065] 27 Annular gap

[0066] 28, 29 Region

[0067] 30 Casting compound

[0068] 31, 32 Connecting element

[0069] 33 Thrust ribs

[0070] F Foundation

[0071] G Nacelle

[0072] L Longitudinal direction

[0073] M Seabed

[0074] O Rotor

[0075] P Foundation pile

[0076] R Radial direction

[0077] S Sea level

[0078] T Tower

[0079] W Wind turbine