A method of repair for shear web excursion in a wind turbine blade

Abstract

The application discloses a repairing method for shear web offset in a fan blade, which comprises the following steps: cutting the part of the main beam beam head connected with the shear web to be repaired from the shear web to be repaired; preparing a prefabricated shear web same as the shear web to be repaired according to the cut shear web to be repaired; installing the prefabricated shear web on the main beam beam head corresponding to the shear web to be repaired; and finally, completing the repairing of the shear web offset in the fan blade by overlapping the part of the shear web to be repaired which is not cut with the prefabricated shear web. The prefabricated shear web can support the upper and lower main beam beam heads and bear the shear load of the fan blade by overlapping the part of the shear web to be repaired which is not cut with the prefabricated shear web after the prefabricated shear web is installed on the main beam beam head corresponding to the shear web to be repaired, and the stability of the fan blade and the shear web to be repaired is provided.

Description

Technical Field

[0001] This invention belongs to the field of wind turbine blade technology, specifically relating to a method for repairing shear web offset within wind turbine blades. Background Technology

[0002] Currently, the internal structure of wind turbine blades mainly consists of two upper and lower half-shells, two unidirectional main beam caps, and a C-shaped shear web. The main beam caps are mostly made of unidirectional fiberglass and bear the main bending loads on the blade. The shear web, as the connecting component between the upper and lower beam caps, is bonded to the beam caps with structural adhesive, providing structural support for the blade. It is also made of biaxial fiberglass cloth to bear shear loads and improve blade stability. To ensure that the load can be smoothly transferred through the relatively weak structural adhesive bonding surface, the shear web and the beam caps must overlap sufficiently.

[0003] During the forming process of wind turbine blades, the shear web inevitably deviates from the main beam due to factors such as equipment and processes. If the shear web deviates from the main beam cap, the blade stability deteriorates, leading to failure before its design life. Therefore, repairing wind turbine blades with shear webs deviating from the main beam cap is of great significance. Summary of the Invention

[0004] To address the technical problems existing in the prior art, the present invention provides a method for repairing shear web offset within wind turbine blades.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A method for repairing shear web misalignment within a wind turbine blade includes:

[0007] The portion of the shear web to be repaired that deviates from the main beam cap to which it is connected is cut off from the shear web to be repaired.

[0008] Based on the cut-off shear web to be repaired, prepare a prefabricated shear web identical to the shear web to be repaired;

[0009] The prefabricated shear web is installed on the main beam cap corresponding to the shear web to be repaired;

[0010] The uncut portion of the shear web to be repaired is overlapped with the prefabricated shear web to complete the repair of the shear web misalignment within the wind turbine blade.

[0011] Furthermore, when cutting off the portion of the shear web to be repaired that deviates from the main beam cap from the shear web to be repaired, the following steps are included:

[0012] Cut the lightning protection wire at the root of the shear web to be repaired, and tear the lightning protection wire off the shear web to be repaired.

[0013] Use a cutting machine to completely cut off the shear web to be repaired, which is offset from the position of the main beam cap;

[0014] Use a grinder to grind the flange edge and residual mold adhesive remaining on the shear web to be repaired, so as to ensure that the ground area on the inner skin surface of the wind turbine blade forms a smooth transition with the surrounding area.

[0015] Use a vacuum cleaner to clean the flange edge and the sanded surface of the residual mold adhesive on the shear web to be repaired.

[0016] Furthermore, when preparing a prefabricated shear web identical to the shear web to be repaired based on the cut-off shear web, the process includes:

[0017] For the cut-off shear-resistant web to be repaired, select the web mold corresponding to the shear-resistant web to be repaired;

[0018] By preparing a prefabricated shear web using the web mold, a prefabricated shear web identical to the shear web to be repaired can be obtained.

[0019] Furthermore, when installing the precast shear web onto the main beam cap corresponding to the shear web to be repaired, the following steps are included:

[0020] The wind turbine blades are then placed back into the corresponding blade housing mold.

[0021] Place the prefabricated shear-resistant web according to the marked lines determined on the blade-shaped shell mold;

[0022] After positioning the prefabricated shear web inside the wind turbine blade, the prefabricated shear web is bonded to the main beam cap connected to the shear web to be repaired.

[0023] Furthermore, when positioning the prefabricated shear-resistant web within the wind turbine blade, the following steps are included:

[0024] The prefabricated shear web is placed on the central axis of the main beam cap connected to the shear web to be repaired.

[0025] Mark the precast shear web on the main beam cap that is connected to the shear web to be repaired, so that the precast shear web can be bonded to the mark on the main beam cap.

[0026] Furthermore, when bonding the precast shear web to the main beam cap connected to the shear web to be repaired, the following steps are included:

[0027] Use mold-fitting adhesive to fill the gap between the marking lines on the precast shear web and the main beam cap, ensuring that there is a certain amount of adhesive left between the marking lines on the precast shear web and the main beam cap. Hand lay two layers of multi-axis fabric on the inner and outer sides of the front and rear edges of the precast shear web.

[0028] Furthermore, when overlapping the uncut portion of the shear web to be repaired with the prefabricated shear web, the following steps are included:

[0029] Use molding compound to fill the gaps and joints at the overlap between the shear web to be repaired and the prefabricated shear web, so that the overlap joint becomes a sloping transition;

[0030] Five layers of two-axis fabric are hand-laid on the outer sides of the front and rear edges of the lap joint, wherein the width of each of the two-axis fabrics is 60cm, and the axial lengths of the two-axis fabrics are 100cm, 85cm, 70cm, 55cm and 40cm respectively.

[0031] Furthermore, after overlapping the uncut portion of the shear web to be repaired with the prefabricated shear web, the blade shell mold is closed, and the blade shell mold is heated to 75°C and kept at that temperature for more than 8 hours until the Tg value of the mold-closing adhesive is found to be qualified.

[0032] Furthermore, after completing the repair of the shear web misalignment within the wind turbine blades, the process also includes:

[0033] The lightning protection wire is connected to the root of the precast shear-resistant web by bolts;

[0034] Test the conductivity of the lightning protection wire on the precast shear-resistant web to ensure that its resistance is <50mΩ.

[0035] This invention provides a method for repairing shear web misalignment within a wind turbine blade. The method involves cutting off the portion of the shear web to be repaired that deviates from the main beam cap to which it is connected; preparing a prefabricated shear web identical to the cut-off portion; installing the prefabricated shear web onto the main beam cap corresponding to the shear web; and finally, overlapping the uncut portion of the shear web to be repaired with the prefabricated shear web to complete the repair of the shear web misalignment within the wind turbine blade. This invention involves installing a prefabricated shear web identical to the shear web to be repaired onto the main beam cap corresponding to the shear web to be repaired, and then overlapping the uncut portion of the shear web to be repaired with the prefabricated shear web. This allows the prefabricated shear web to support the upper and lower main beam caps and bear the shear load of the wind turbine blades, thereby providing consistent stability between the wind turbine blades and the shear web to be repaired. This ensures the quality of wind turbine blade repair while effectively reducing blade maintenance costs.

[0036] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0037] Figure 1 A flowchart illustrating a method for repairing shear web offset within a wind turbine blade, provided as an exemplary embodiment of the present invention;

[0038] Figure 2 A schematic flowchart of another method for repairing shear web offset within a wind turbine blade, provided as an exemplary embodiment of the present invention;

[0039] Figure 3 A schematic flowchart illustrating another method for repairing shear web offset within a wind turbine blade, provided as an exemplary embodiment of the present invention;

[0040] Figure 4 A schematic flowchart of another method for repairing shear web offset within a wind turbine blade, provided as an exemplary embodiment of the present invention;

[0041] Figure 5 A schematic flowchart illustrating yet another method for repairing shear web offset within a wind turbine blade, provided as an exemplary embodiment of the present invention;

[0042] Figure 6 A schematic diagram of the shear web to be repaired and the prefabricated web after overlapping, provided as an exemplary embodiment of the present invention;

[0043] In the picture:

[0044] 1-Precast shear web, 2-Shear web to be repaired, 3-Overlap surface, 4-Hand lay-up two-axis fabric at the connection with the main beam cap. Detailed Implementation

[0045] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0046] This invention provides a method for repairing shear web misalignment within wind turbine blades, see [link to relevant documentation]. Figure 1 It includes the following steps:

[0047] S100: Cut off the portion of the shear web to be repaired that deviates from the main beam cap to which it is connected;

[0048] S200. Based on the cut-off shear web to be repaired, prepare a prefabricated shear web identical to the shear web to be repaired.

[0049] S300. Install the precast shear web onto the main beam cap corresponding to the shear web to be repaired.

[0050] S400. Overlap the uncut portion of the shear web to be repaired with the prefabricated shear web to complete the repair of the shear web misalignment within the wind turbine blade.

[0051] See Figure 6 By installing a prefabricated shear web identical to the shear web to be repaired onto the main beam cap corresponding to the shear web to be repaired, and then overlapping the uncut portion of the shear web to be repaired with the prefabricated shear web, the prefabricated shear web can support the upper and lower main beam caps and bear the shear load of the wind turbine blades. This provides consistent stability between the wind turbine blades and the shear web to be repaired, thereby ensuring the repair quality of the wind turbine blades while effectively reducing the maintenance cost of the blades.

[0052] As a preferred embodiment, see Figure 2 When cutting off the portion of the shear web to be repaired that deviates from the main beam cap from the shear web to be repaired, the following is included:

[0053] S101. Cut the lightning protection wire at the root of the shear web to be repaired and tear the lightning protection wire off the shear web to be repaired.

[0054] S102. Use a cutting machine to completely cut off the shear web of the main beam that is off-center from the position of the main beam cap;

[0055] S103. Use a grinder to grind the flange edge and residual mold adhesive remaining on the shear web to be repaired, so as to ensure that the ground area on the inner skin surface of the wind turbine blade forms a smooth transition with the surrounding area.

[0056] S104. Use a vacuum cleaner to clean the flange edge and the sanded surface of the residual mold adhesive on the shear web to be repaired.

[0057] The shear web to be repaired is cut along the smallest possible oblique section, and both the inner and outer sides of the oblique section are ground into rough surfaces so that it can overlap with the precast shear web.

[0058] As a preferred embodiment, see Figure 3 When preparing a prefabricated shear web identical to the shear web to be repaired based on the cut-off shear web, the process includes:

[0059] S201. For the cut-off shear web to be repaired, select the web mold corresponding to the shear web to be repaired.

[0060] S202. By preparing a prefabricated shear web using a web mold, a prefabricated shear web identical to the one to be repaired can be obtained.

[0061] The specific preparation method of the prefabricated shear web includes:

[0062] (1) Select a web mold corresponding to the shear web to be repaired, mark the length on the web mold, attach a wooden strip with a thickness of 4mm-5mm and a width of about 80mm along the inner side of the flange edge of the web mold, or a rubber strip with a certain strength, and ensure that the rubber strip does not deform during the vacuuming and pressure holding process.

[0063] (2) Clean the web mold and apply release agent to the production area. Keep it at 15-50℃ for 35-15 minutes until the release agent forms a film.

[0064] (3) Lay a layer of release cloth in the bonding area between the precast shear web and the main beam head opposite to the web mold, and in the reinforcement area of ​​the precast shear web, wherein the width of the release cloth is 140mm-145mm.

[0065] (4) Lay four layers of biaxial fiber cloth, PVC core material, and four layers of biaxial fiber cloth in sequence on the web mold;

[0066] (5) Lay a layer of 0.3m*0.3m release cloth at the bonding position between the pre-set shear web and the main beam cap corresponding to the web mold, then lay the isolation film as a whole, and then arrange the guide net, the air extraction system and the glue injection system in sequence. Finally, perform glue injection molding and curing. After curing, clean the auxiliary materials.

[0067] (6) After curing, remove the mold, mark the position and cut the mark on the surface of the pre-set shear web according to the length mark and flange width on the web mold, cut the leaf root section and flange edge according to the mark line marked when removing the mold, and finally grind the inner surface of the rear edge and front edge of the pre-set shear web to form a slope, thus completing the preparation of the pre-set shear web.

[0068] As a preferred embodiment, see Figure 4 When installing the precast shear web onto the main beam cap corresponding to the shear web to be repaired, it includes:

[0069] S301. Place the fan blades back into the corresponding blade housing mold;

[0070] S302. Place the prefabricated shear web according to the marking lines determined on the blade shell mold;

[0071] S303. After positioning the precast shear web inside the wind turbine blade, bond the precast shear web to the main beam cap connected to the shear web to be repaired.

[0072] By connecting the upper and lower main beam caps on the wind turbine blades with prefabricated shear-resistant webs, the prefabricated shear-resistant webs support the upper and lower main beam caps and bear the shear load of the wind turbine blades, thereby providing stability that is consistent between the wind turbine blades and the shear-resistant webs to be repaired.

[0073] For specific details, see [link / reference] Figure 5 Positioning the prefabricated shear-resistant web within the wind turbine blade includes:

[0074] S303a. Place the precast shear web on the central axis of the main beam cap connected to the shear web to be repaired.

[0075] S303b. Mark the bonding lines between the precast shear web and the main beam cap connected to the shear web to be repaired, so that the precast shear web can be bonded to the marking lines on the main beam cap.

[0076] Furthermore, when bonding the precast shear web to the main beam cap connected to the shear web to be repaired, the following steps are included:

[0077] The mold-fitting adhesive is used to fill the gap between the marked lines on the precast shear web and the main beam cap, ensuring that there is a certain amount of adhesive left between the marked lines on the precast shear web and the main beam cap. Two layers of multi-axis fabric are hand-laid on both the inner and outer sides of the front and rear edges of the precast shear web. The mold-fitting adhesive may contain chopped strand mat scraps.

[0078] When overlapping the uncut portion of the shear web to be repaired with the precast shear web, the following is included:

[0079] Use molding compound to fill the gaps and joints at the overlap between the shear web to be repaired and the precast shear web, so that the overlap joint becomes a sloping transition.

[0080] Five layers of two-axis fabric are hand-laid on the outer edges of the front and rear edges of the lap joint. The width of each two-axis fabric is 60cm, and the axial lengths of the two-axis fabric are 100cm, 85cm, 70cm, 55cm, and 40cm, respectively.

[0081] As another preferred embodiment, after overlapping the uncut portion of the shear web to be repaired with the prefabricated shear web, the blade shell mold is closed, and the blade shell mold is heated to 75°C and kept at that temperature for more than 8 hours until the Tg value of the mold adhesive is found to be qualified.

[0082] As another preferred embodiment, after repairing the shear web misalignment within the wind turbine blades, the method further includes:

[0083] The lightning protection wire is connected to the root of the precast shear-resistant web by bolts;

[0084] Test the conductivity of the lightning protection wire on the precast shear-resistant web to ensure that its resistance is <50mΩ.

[0085] The above embodiments are merely typical examples used to explain the present invention and are not intended to limit the present invention in any way. Any modifications or changes made to the present invention under the same inventive spirit should be included within the scope of protection intended by the present invention. That is, those skilled in the art can make different shapes to achieve equivalent or similar effects without departing from the basic principles of the present invention, but all such changes should be considered as not departing from the scope of the patent described above.

Claims

1. A method for repairing shear web misalignment within a wind turbine blade, characterized in that, include: The portion of the shear web to be repaired that deviates from the main beam cap to which it is connected is cut off from the shear web to be repaired. Based on the cut-off shear web to be repaired, prepare a prefabricated shear web identical to the shear web to be repaired; The prefabricated shear web is installed on the main beam cap corresponding to the shear web to be repaired; The uncut portion of the shear web to be repaired is overlapped with the prefabricated shear web to complete the repair of the shear web misalignment within the wind turbine blade.

2. The method for repairing shear web misalignment within a wind turbine blade according to claim 1, characterized in that, When cutting off the portion of the shear web to be repaired that deviates from the main beam cap from the shear web to be repaired, the following steps are included: Cut the lightning protection wire at the root of the shear web to be repaired, and tear the lightning protection wire off the shear web to be repaired. Use a cutting machine to completely cut off the shear web to be repaired, which is offset from the position of the main beam cap; Use a grinder to grind the flange edge and residual mold adhesive remaining on the shear web to be repaired, so as to ensure that the ground area on the inner skin surface of the wind turbine blade forms a smooth transition with the surrounding area. Use a vacuum cleaner to clean the flange edge and the sanded surface of the residual mold adhesive on the shear web to be repaired.

3. The method for repairing shear web misalignment within a wind turbine blade according to claim 1, characterized in that, When preparing a prefabricated shear web identical to the shear web to be repaired based on the cut-off shear web, the process includes: For the cut-off shear-resistant web to be repaired, select the web mold corresponding to the shear-resistant web to be repaired; By preparing a prefabricated shear web using the web mold, a prefabricated shear web identical to the shear web to be repaired can be obtained.

4. The method for repairing shear web misalignment within a wind turbine blade according to claim 1, characterized in that, When installing the precast shear web onto the main beam cap corresponding to the shear web to be repaired, the following steps are included: The wind turbine blades are then placed back into the corresponding blade housing mold. Place the prefabricated shear-resistant web according to the marked lines determined on the blade-shaped shell mold; After positioning the prefabricated shear web inside the wind turbine blade, the prefabricated shear web is bonded to the main beam cap connected to the shear web to be repaired.

5. A method for repairing shear web misalignment within a wind turbine blade according to claim 4, characterized in that, Positioning the prefabricated shear-resistant web within the wind turbine blade includes: The prefabricated shear web is placed on the central axis of the main beam cap connected to the shear web to be repaired. Mark the precast shear web on the main beam cap that is connected to the shear web to be repaired, so that the precast shear web can be bonded to the mark on the main beam cap.

6. A method for repairing shear web misalignment within a wind turbine blade according to claim 5, characterized in that, When bonding the precast shear web to the main beam cap connected to the shear web to be repaired, the following steps are included: Use mold-fitting adhesive to fill the gap between the marking lines on the precast shear web and the main beam cap, ensuring that there is a certain amount of adhesive left between the marking lines on the precast shear web and the main beam cap. Hand lay two layers of multi-axis fabric on the inner and outer sides of the front and rear edges of the precast shear web.

7. A method for repairing shear web misalignment within a wind turbine blade according to claim 6, characterized in that, When overlapping the uncut portion of the shear web to be repaired with the prefabricated shear web, the following steps are included: Use molding compound to fill the gaps and joints at the overlap between the shear web to be repaired and the prefabricated shear web, so that the overlap joint becomes a sloping transition; Five layers of two-axis fabric are hand-laid on the outer sides of the front and rear edges of the lap joint, wherein the width of each of the two-axis fabrics is 60cm, and the axial lengths of the two-axis fabrics are 100cm, 85cm, 70cm, 55cm and 40cm respectively.

8. A method for repairing shear web misalignment within a wind turbine blade according to claim 7, characterized in that, After overlapping the uncut portion of the shear web to be repaired with the prefabricated shear web, the blade shell mold is closed, and the blade shell mold is heated to 75°C and kept at that temperature for more than 8 hours until the Tg value of the mold adhesive is found to be qualified.

9. A method for repairing shear web misalignment within a wind turbine blade according to claim 8, characterized in that, After completing the repair of the shear web misalignment within the wind turbine blades, the following steps are also included: The lightning protection wire is connected to the root of the precast shear-resistant web by bolts; Test the conductivity of the lightning protection wire on the precast shear-resistant web to ensure that its resistance is <50mΩ.

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