Method for repairing a wind turbine blade with a pre-buried root

Abstract

The present disclosure provides a wind turbine blade embedded root repair method, comprising: determining a blade damage area of a blade to be repaired at a root in a wind wheel; drilling a hole at the blade damage area and a position corresponding to a UD block to obtain at least two glue injection holes; injecting glue into the glue injection holes; heating and curing the glue; wherein the depth of the glue injection hole is greater than the depth of the blade damage area, the diameter of the glue injection hole is less than the width of the UD block, and the glue injection hole and the bolt sleeve are distributed along the circumference of the root; the depth direction of the blade damage area and the glue injection hole are both parallel to the thickness direction of the root. The wind turbine blade embedded root repair method provided by the present disclosure can complete in-situ repair without disassembling the wind turbine blade, effectively reducing the repair difficulty of the embedded root, and improving the repair efficiency of the embedded root.

Description

Technical Field

[0001] This disclosure relates to the field of wind turbine blade maintenance technology, and in particular to a maintenance method for wind turbine blades with pre-embedded blade roots. Background Technology

[0002] As wind turbine blades become larger, the load on the blade roots is increasing, making the connection between the blade roots and the turbine hub more prone to failure. Failure of the blade root connection may cause the blade to fall off.

[0003] In related technologies, wind turbine blades typically employ pre-embedded blade roots, such as... Figure 1 As shown, the embedded blade root includes: an outer skin 01, an inner skin 02, and a blade root embedded component 03. The blade root embedded component 03 includes a bolt sleeve 031, a UD (Unidirectional Block) block 032, and a sealing block. The UD block 032 can also be called a unidirectional block, and the sealing block can be a foam block. The sealing block seals the end of the bolt sleeve 031 near the tip of the wind turbine blade. Multiple bolt sleeves 031 are arranged at intervals along the circumference of the blade root, and the UD block 032 is located between two adjacent bolt sleeves 031, with the outer wall of the UD block 032 fitting against the outer wall of the bolt sleeve 031. The blade root embedded component 03 is connected between the outer skin 01 and the inner skin 02. The outer skin 01 includes multiple layers of fiber cloth, and the inner skin 02 includes multiple layers of fiber cloth. The embedded blade root is connected to the wind turbine hub by connecting bolts, with the connecting bolts and bolt sleeves 031 threaded together.

[0004] Based on the above structure, the connection failures of the embedded blade roots mainly include: connection bolt failure and embedded blade root delamination failure. Among them, embedded blade root delamination failure includes at least one of the following: connection failure between the embedded blade root component 03 and the outer skin 01, connection failure between the embedded blade root component 03 and the inner skin 02, interlayer failure of the outer skin 01, and interlayer failure of the inner skin 02.

[0005] In related technologies, when the pre-embedded blade root fails due to layering, it is necessary to disassemble the wind turbine blade to repair the pre-embedded blade root, which makes the repair of the pre-embedded blade root more difficult and less efficient. Summary of the Invention

[0006] In view of this, the purpose of this disclosure is to provide a maintenance method for pre-embedded blade roots of wind turbine blades, thereby reducing the maintenance difficulty of pre-embedded blade roots and improving the maintenance efficiency of pre-embedded blade roots.

[0007] To achieve the above objectives, this disclosure provides the following technical solutions:

[0008] This disclosure provides a maintenance method for pre-embedded blade roots in wind turbine blades, including:

[0009] Identify the damaged area at the blade root of the blade to be repaired in the wind turbine, wherein the blade to be repaired is connected to the hub of the wind turbine;

[0010] At least two injection holes are made at the location corresponding to the UD block in the blade damage area.

[0011] Inject adhesive into the injection hole;

[0012] The adhesive is cured by heating;

[0013] The depth of the glue injection hole is greater than the depth of the blade damage area, the diameter of the glue injection hole is smaller than the width of the UD block, and the glue injection holes and bolt sleeves are distributed circumferentially along the blade root; the depth directions of the blade damage area and the glue injection holes are both parallel to the thickness direction of the blade root.

[0014] In some possible embodiments, the glue injection holes are at least two layers, with any two layers distributed in the vertical direction; in two adjacent layers, the glue injection holes of one layer and the glue injection holes of the other layer are distributed in a staggered manner along the circumference of the leaf root.

[0015] In some possible embodiments, the injection holes are at least two layers, with any two layers distributed along the vertical direction; injecting adhesive into the injection holes includes: injecting adhesive into each layer of injection holes sequentially from bottom to top along the vertical direction;

[0016] Alternatively, there may be at least three injection holes, one of which is a first injection hole and at least two of which are second injection holes, with the second injection holes distributed around the periphery of the first injection hole; injecting adhesive into the injection holes includes: injecting adhesive into the first injection hole until adhesive overflows from each of the second injection holes.

[0017] In some possible embodiments, the maintenance method for the pre-embedded blade roots of the wind turbine blades further includes, prior to heating and curing the adhesive:

[0018] After the injection hole is filled with adhesive, the injection hole is sealed.

[0019] In some possible embodiments, heating to cure the adhesive includes:

[0020] The heating element is placed over the damaged area of ​​the blade, and the heating element extends beyond the boundary of the damaged area of ​​the blade at the surface of the blade root.

[0021] The heating assembly and the blade to be repaired are fixedly connected;

[0022] The leaf roots are heated to cure the adhesive.

[0023] In some possible embodiments, after securing the heating assembly and the blade to be repaired, and before heating the blade root, the heating and curing of the adhesive further includes:

[0024] Cover the heating assembly with the insulation material;

[0025] The insulation component and the blade to be repaired are fixedly connected, or the insulation component and the heating assembly are fixedly connected.

[0026] In some possible embodiments, determining the blade damage area at the blade root of the blade to be repaired in the wind turbine includes:

[0027] Determine the boundary of the leaf damage area on the leaf root surface and determine the depth of the leaf damage area;

[0028] Mark the boundary of the damaged area on the blade root surface on the blade to be repaired.

[0029] In some possible embodiments, the distance between the injection hole and the boundary is greater than zero and not greater than 50 mm.

[0030] In some possible embodiments, the wind turbine blade pre-embedded blade root repair method further includes, before determining the blade damage area at the blade root of the blade to be repaired in the wind turbine rotor:

[0031] Rotate the blade to be repaired so that the root of the blade is facing upwards and the tip is facing downwards in the vertical direction.

[0032] In some possible embodiments, the maintenance method for the pre-embedded blade roots of the wind turbine blades further includes, after heating and curing the adhesive:

[0033] At least one of the first reinforcing plate and the second reinforcing plate is fixed to the leaf root;

[0034] The first reinforcing plate is located on the side of the outer skin away from the inner skin, and the first reinforcing plate covers the projection of the blade damage area on the outer skin; the second reinforcing plate is located on the side of the inner skin away from the outer skin, and the second reinforcing plate covers the projection of the blade damage area on the inner skin.

[0035] In some possible embodiments, fixing at least one of the first reinforcing plate and the second reinforcing plate to the leaf root includes:

[0036] A hole is made at the leaf root and at the position corresponding to the UD block to obtain a connecting hole. The connecting hole penetrates the outer skin, inner skin and UD block of the leaf root along the thickness direction of the leaf root.

[0037] An anchor that mates with the connection hole is used to fix at least one of the first reinforcing plate and the second reinforcing plate to the blade root.

[0038] In some possible embodiments, fixing at least one of the first reinforcing plate and the second reinforcing plate to the leaf root further includes:

[0039] After drilling a hole at the blade root and at the position corresponding to the UD block, and before fixing at least one of the first reinforcing plate and the second reinforcing plate to the blade root using the anchor, adhesive is used to bond at least one of the first reinforcing plate and the second reinforcing plate to the blade root;

[0040] After the first reinforcing plate and the second reinforcing plate are fixed to the blade root using the anchor, the maintenance method for the pre-embedded blade root of the wind turbine blade further includes: heating and curing the adhesive.

[0041] In some possible embodiments, both the first reinforcing plate and the second reinforcing plate are reinforcing plates;

[0042] Fixing at least one of the first reinforcing plate and the second reinforcing plate to the leaf root further includes:

[0043] After drilling a hole at the blade root and at the position corresponding to the UD block, and before bonding the reinforcing plate to the blade root with adhesive, the surface of the reinforcing plate in contact with the blade root is roughened.

[0044] In some possible embodiments, fixing at least one of the first reinforcing plate and the second reinforcing plate to the leaf root further includes:

[0045] After drilling a hole at the blade root and at the position corresponding to the UD block, and before bonding the reinforcing plate to the blade root with adhesive, the outer skin and inner skin at the blade root are sanded.

[0046] In some possible embodiments, the lengths of both the first reinforcing plate and the second reinforcing plate are greater than the length of the bolt sleeve, and the widths of the first reinforcing plate and the second reinforcing plate along the circumferential direction of the blade root are both greater than the width of the blade damage area along the circumferential direction of the blade root.

[0047] In some possible embodiments, the first reinforcing plate is one; or, the first reinforcing plate includes at least two first sub-plates, the width of the first sub-plate along the circumferential direction of the blade root is greater than the width of the UD block, and the width of the first sub-plate along the circumferential direction of the blade root is less than the distance between the axes of two adjacent bolt sleeves.

[0048] The second reinforcing plate is one; or, the second reinforcing plate includes at least two second sub-plates, the width of the second sub-plates along the circumferential direction of the blade root is greater than the width of the UD block, and the width of the second sub-plates along the circumferential direction of the blade root is less than the distance between the central axes of two adjacent bolt sleeves.

[0049] In some possible embodiments, a first chamfer is provided on the front end of the first reinforcing plate away from the outer skin and on the rear end of the first reinforcing plate away from the outer skin, and a second chamfer is provided on the front end of the second reinforcing plate away from the inner skin and on the rear end of the second reinforcing plate away from the inner skin.

[0050] The maintenance method for pre-embedded blade roots of wind turbine blades disclosed herein directly identifies the damaged area of ​​the blade at the blade root on the wind turbine and performs adhesive injection repair. The identification of the damaged area, drilling, adhesive injection, and heat curing of the adhesive are not affected by the connection structure between the blade to be repaired and the hub. Therefore, maintenance can be carried out on-site at the wind power generation device, and in-situ repair can be completed without disassembling the wind turbine blade. Compared with related technologies that disassemble the wind turbine blade to repair the pre-embedded blade root, it is not necessary to disassemble the wind turbine blade (the blade to be repaired), which effectively reduces the maintenance difficulty of the pre-embedded blade root and improves the maintenance efficiency.

[0051] The technical features mentioned above, as well as those shown individually in the accompanying drawings, can be combined arbitrarily, provided that the combined technical features are not contradictory. All feasible combinations of features are the technical content explicitly described herein. Any one of the multiple sub-features contained in the same statement can be applied independently, without necessarily being applied together with other sub-features. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments and related technologies of this disclosure, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0053] Figure 1 A partial structural diagram of the root of a wind turbine blade provided for related technologies;

[0054] Figure 2 This is a schematic diagram of the structure of a wind power generation device provided in an embodiment of this disclosure;

[0055] Figure 3 A schematic diagram showing the first and second reinforcing plates fixed in the maintenance method for the pre-embedded blade root of the wind turbine blade provided in this embodiment of the present disclosure;

[0056] Figure 4 A schematic diagram of the structure of the wind turbine blade pre-embedded blade root maintenance method provided in this embodiment of the present disclosure, wherein the first reinforcing plate has a first chamfer and the second reinforcing plate has a second chamfer;

[0057] Figure 5 This is a schematic diagram showing the bolt installation process in the maintenance method for wind turbine blade pre-embedded blade roots provided in this embodiment of the disclosure.

[0058] Figure 6 This is a schematic diagram showing the distribution of connection holes in the maintenance method for wind turbine blade pre-embedded blade roots provided in this embodiment of the disclosure;

[0059] Figure 7 This is a schematic diagram showing another distribution of the connection holes in the maintenance method for pre-embedded blade roots of wind turbine blades provided in this embodiment of the disclosure;

[0060] Figure 8 This is a schematic diagram of the glue injection nozzle in the maintenance method for pre-embedded blade roots of wind turbine blades provided in this embodiment of the disclosure;

[0061] Figure 9 A schematic flowchart illustrating a maintenance method for wind turbine blades with pre-embedded blade roots provided in an embodiment of this disclosure;

[0062] Figure 10 Another schematic flowchart of the maintenance method for pre-embedded blade roots of wind turbine blades provided in this embodiment of the present disclosure;

[0063] Figure 11 This is a schematic diagram of a process for heating and curing adhesive in a maintenance method for pre-embedded blade roots of wind turbine blades provided in an embodiment of this disclosure;

[0064] Figure 12 Another schematic diagram of the process for heating and curing adhesive in the maintenance method for pre-embedded blade roots of wind turbine blades provided in this embodiment of the disclosure;

[0065] Figure 13 Another schematic flowchart of the maintenance method for pre-embedded blade roots of wind turbine blades provided in this embodiment of the present disclosure;

[0066] Figure 14 This is a schematic diagram illustrating the process of fixing at least one of the first reinforcing plate and the second reinforcing plate to the blade root in the maintenance method for pre-embedded blade roots of wind turbine blades provided in the embodiments of this disclosure.

[0067] The annotations in the attached figures are explained as follows:

[0068] 01 Outer skin, 02 Inner skin, 03 Leaf root embedded part, 031 Bolt sleeve, 032 UD block;

[0069] 100 wind turbine rotors, 1 wind turbine blade, 1a blade under maintenance, 2 hubs;

[0070] 11 Blade root, 111 Outer skin, 112 Inner skin, 113 Blade root embedded part, 1131 Bolt sleeve, 1132 UD block; 12 Injection hole, 12a First injection hole, 12b Second injection hole; 13 Connecting hole, 14 First reinforcing plate, 141 First chamfer, 15 Second reinforcing plate, 151 Second chamfer, 16 Anchor, 17 Blade tip;

[0071] A represents the damaged area of ​​the leaf, and L represents the boundary.

[0072] 200 support bodies;

[0073] 300 is the glue nozzle, 301 is the first end face, and 302 is the second end face. Detailed Implementation

[0074] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments.

[0075] In the description of the embodiments of this disclosure, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," "third," and "fourth" may explicitly or implicitly include one or more of that feature.

[0076] In the description of the embodiments disclosed herein, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, "linking" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. "Fixed connection" refers to a connection where the relative positional relationship remains unchanged after connection. "Rotary connection" refers to a connection where the two parts can rotate relative to each other after connection. "Sliding connection" refers to a connection where the two parts can slide relative to each other after connection.

[0077] The directional terms used in the embodiments of this disclosure, such as "inner" and "outer," are merely for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this disclosure, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure. Furthermore, unless otherwise stated in this disclosure, "a plurality of" refers to two or more.

[0078] In the description of embodiments of this disclosure, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0079] In the description of the embodiments disclosed herein, "and / or" is merely a way of describing the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0080] The terms "parallel" and "perpendicular" used in this disclosure refer to "basically parallel" and "basically perpendicular" in actual operation. "Basically parallel" can be understood as parallelism with a certain degree of error, and similarly, "basically perpendicular" can be understood as perpendicularity with a certain degree of error.

[0081] To facilitate understanding of the maintenance method for pre-embedded blade roots of wind turbine blades provided in the embodiments of this disclosure, the wind power generation device will be described first below.

[0082] like Figure 2 As shown, the wind power generation device includes a wind turbine 100 and a support body 200.

[0083] The wind turbine 100 is located on top of the support body 200, and the support body 200 supports the wind turbine 100.

[0084] The wind turbine 100 includes wind turbine blades 1 and a hub 2. The root 11 of the wind turbine blade 1 is connected to the hub 2 by connecting bolts. The hub 2 is rotatably mounted to drive the wind turbine blade 1 to rotate. The tip 17 of the wind turbine blade 1 is farther away from the hub 2 than the root 11.

[0085] like Figure 3 As shown, the blade root 11 includes an outer skin 111, an inner skin 112, and a blade root embedded part 113. It can be understood that the blade root 11 is an embedded blade root.

[0086] The outer skin 111 may include multiple layers of fiber cloth, and the inner skin 112 may include multiple layers of fiber cloth. The outer skin 111 may be referred to as part of the shell of the blade root 11, and the inner skin 112 may be referred to as part of the shell of the blade root 11.

[0087] The blade root embedded part 113 is located between the outer skin 111 and the inner skin 112. It can be understood that, in the thickness direction of the blade root 11 (wind turbine blade 1), the blade root embedded part 113 is located between the outer skin 111 and the inner skin 112.

[0088] The leaf root embedded part 113 includes multiple bolt sleeves 1131, multiple UD (Unidirectional Block) blocks 1132 and sealing blocks (not shown in the figure).

[0089] The axial direction of the bolt sleeve 1131 is parallel to the length direction of the blade root 11, that is, the axial direction of the bolt sleeve 1131 is parallel to the length direction of the wind turbine blade 1. The connecting bolts mentioned above are inserted through the bolt sleeve 1131.

[0090] Block 1132 of UD can be referred to as a one-way block. The sealing block can be a foam block or other types, and this disclosure does not limit the specific type.

[0091] Bolt sleeves 1131 are arranged circumferentially along the blade root 11. UD blocks 1132 are located between two adjacent bolt sleeves 1131, and the outer wall of UD blocks 1132 is in contact with the outer wall of bolt sleeves 1131. A sealing block seals the end of the bolt sleeve 1131 near the blade tip. The embedded blade root is connected to the wind turbine hub by connecting bolts.

[0092] Connection failures between the blade root embedded part 113 and the outer skin 111, between the blade root embedded part 113 and the inner skin 112, between the layers of the outer skin 111, or between the layers of the inner skin 112 can all be referred to as blade root delamination failures. The area of ​​blade root delamination failure can be referred to as the blade damage area. The wind turbine blade embedded root repair method provided in this embodiment can repair blade roots that have experienced the above-mentioned blade root delamination failures.

[0093] like Figure 9 As shown in the embodiments of this disclosure, the maintenance method for wind turbine blades with embedded blade roots includes:

[0094] S1: Identify the damaged area at the blade root of the blade to be repaired in the wind turbine;

[0095] S2: Make holes in the blade damage area and at the position corresponding to the UD block to obtain at least two glue injection holes;

[0096] S3: Inject adhesive into the injection hole;

[0097] S4: Heat-curing adhesive.

[0098] In S1 above, during the process of determining the blade damage area, the blade 1a to be repaired is connected to the hub 2 and is not detached from the hub 2. The blade damage area includes at least one of the following: the connection failure area between the blade root embedded part 113 and the outer skin 111; the connection failure area between the blade root embedded part 113 and the inner skin 112; the connection failure area between the layers of the outer skin 111; and the connection failure area between the layers of the inner skin 112. In the connection failure area between the blade root embedded part 113 and the outer skin 111, there is a gap between the blade root embedded part 113 and the outer skin 111; in the connection failure area between the blade root embedded part 113 and the inner skin 112, there is a gap between the blade root embedded part 113 and the inner skin 112; in the connection failure area between the layers of the outer skin 111, there is a gap between the layers of the outer skin 111; and in the connection failure area between the layers of the inner skin 112, there is a gap between the layers of the inner skin 112.

[0099] In some possible embodiments, S1 may include: performing non-destructive testing on the blade 1a to be repaired to determine the blade damage area at the blade root 11.

[0100] Non-destructive testing may include at least one of ultrasonic testing, X-ray testing, and infrared thermography. This disclosure does not limit the specific method of non-destructive testing.

[0101] In S1 above, determining the leaf damage area specifically includes: determining the boundary L of the leaf damage area on the leaf root 11 surface and determining the depth of the leaf damage area.

[0102] It is understandable that determining the boundary L of the leaf damage area on the leaf root 11 surface means determining the boundary L of the leaf damage area on the outer skin 111 surface. Figure 6 The boundary L of the blade damage zone A is shown.

[0103] To facilitate subsequent drilling, S1 further includes marking the boundary between the damaged area of ​​the blade and the surface of the blade root on the surface of the blade to be repaired. For example, as shown... Figure 6 As shown, the boundary L of the damaged area A on the surface of the leaf root 11 can be marked with lines. The lines can be dashed lines, dotted lines, or other types; this embodiment does not limit the specific type.

[0104] In the above embodiments, the marked boundary L provides a precise basis for the planning of subsequent drilling positions, ensuring that all repair actions are concentrated and cover the blade damage area A, thereby avoiding omission of some areas of the blade damage area A or over-repair.

[0105] In the above step S2, the depth of the glue injection hole 12 is greater than the depth of the blade damage area. It can be understood that the glue injection hole 12 penetrates the blade damage area and extends to the undamaged area of the blade root 11. In this way, it can be ensured that the glue injection hole 12 can penetrate all delamination interfaces, establish a channel for the subsequently injected glue solution directly to the deepest damage layer, thereby ensuring that the glue solution can be injected into any position of the blade damage area in the depth direction, and then realizing full-thickness repair from the inside to the outside.

[0106] It should be noted that the depth of the blade damage area refers to the length of the blade damage area in the thickness direction of the blade root 11. Both the depth of the glue injection hole 12 and the depth of the blade damage area are parallel to the thickness direction of the blade root 11, and the thickness direction of the blade root 11 is parallel to the thickness direction of the blade 1a to be repaired.

[0107] In the above embodiment, the depth direction of the glue injection hole 12 is parallel to the thickness direction of the blade root 11, so that the injected glue solution can permeate and diffuse along the interlayer delamination gap through the shortest and most direct path, which improves the filling efficiency of the glue solution and the permeation saturation of the interlayer gap.

[0108] In the above step S2, the diameter of the glue injection hole 12 is smaller than the width of the UD block 1132, so as to ensure that the glue injection hole 12 is completely located inside the UD block 1132, thereby avoiding damage to the adjacent bolt sleeve 1131. It can be understood that the projection of the glue injection hole 12 along the thickness direction of the blade root 11 and the projection of the UD block 1132 along the thickness direction of the blade root 11 have an overlapping portion, and the glue injection hole 12 does not pass through the bolt sleeve 1131. Combined with Figure 4 and Figure 5 as shown, in the circumferential direction of the blade root 11, the spacing d1 between two adjacent glue injection holes 12 is greater than the spacing d2 between two adjacent UD blocks 1132. It can be understood that the spacing d2 between two adjacent UD blocks 1132 refers to the maximum spacing between two adjacent UD blocks 1132. The minimum spacing between two adjacent UD blocks 1132 is d3.

[0109] As mentioned above, there is a gap in the blade damage area A, and the gap communicates any two glue injection holes 12.

[0110] In order to ensure that the repair range covers the entire blade damage area A, the distance d4 between the glue injection hole 12 and the boundary L should satisfy: 0<d4≤50mm, so as to ensure that the glue solution can fully wet the edge of the blade damage area A, so that the injected glue solution has a sufficient flow range to fully permeate and block the fine cracks at the boundary of the blade damage area A, and can also avoid a large amount of glue solution loss to the undamaged area caused by the glue injection hole 12 being too far outward, thereby ensuring the repair efficiency and material utilization rate.

[0111] By way of example, the value range of d4 is 10mm-30mm.

[0112] In some other possible embodiments, the value range of d4 may also be other, and is not limited to the above embodiments.

[0113] In some possible embodiments, the injection holes 12 are at least two layers, with any two layers of injection holes 12 distributed vertically; in adjacent layers, the injection holes 12 of one layer and the injection holes 12 of the other layer are staggered in the circumferential direction of the blade root 11. It is understood that in adjacent layers, the projections of the injection holes 12 along the thickness direction of one layer and the projections of the injection holes 12 along the thickness direction of the other layer are spaced apart in the circumferential direction of the blade root 11. This allows the three injection holes 12 to be arranged in a triangular pattern. After injection into one injection hole 12, it facilitates the flow of adhesive to other injection holes and also facilitates venting from other injection holes. For example, if there are burrs at the bolt sleeve 1131, the burrs will increase the flow resistance of the adhesive, further highlighting the advantages of the above-mentioned distribution structure of the injection holes 12. Moreover, after curing, the injected adhesive forms an interwoven anchoring structure, which can effectively resist interlaminar shear and tearing under complex alternating loads, greatly improving the integrity and fatigue resistance of the repair area.

[0114] As mentioned above, the gap in the blade damage area A will connect any two glue injection holes 12. During the process of injecting glue into the glue injection hole 12 in S3 above, the air in the gap in the blade damage area A and the air in the glue injection hole 12 will be expelled.

[0115] In S3 above, the adhesive can be epoxy resin, polyurethane resin, modified acrylic resin, or other types, and this embodiment does not limit this. For example, the type of adhesive can be selected according to the temperature of the environment where the leaf root 11 is located.

[0116] In S3 above, adhesive can be injected into the adhesive injection hole 12 using an adhesive injection device. For example... Figure 8 As shown, the dispensing nozzle 300 of the dispensing equipment has a first end face 301 and a second end face 302 along the axial direction of the dispensing nozzle 300. The dispensing nozzle 300 gradually narrows from the second end face 302 to the first end face 301. The diameter R1 of the first end face 301 is smaller than the diameter of the dispensing hole 12 to ensure that the dispensing nozzle 300 can be inserted into the dispensing hole 12. The diameter R2 of the second end face 302 is larger than the diameter R of the dispensing hole 12. The dispensing nozzle 300 can form an effective seal on the dispensing hole 12 to ensure that the dispensing nozzle 300 blocks the dispensing hole 12, thereby preventing the glue from overflowing back from the dispensing hole 12 during the dispensing process, causing waste and pollution.

[0117] The injection pressure is set according to actual needs, and this embodiment does not limit it.

[0118] In the above-mentioned S3, adhesive is injected into the injection hole 12 in two ways: layered injection and central radial injection.

[0119] like Figure 6 As shown, in some possible embodiments, when the glue injection holes 12 are at least two layers and any two layers are distributed in a vertical direction, injecting glue into the glue injection holes 12 includes: injecting glue into each layer of glue injection holes 12 sequentially from bottom to top in a vertical direction.

[0120] For example, glue is first injected into the bottommost glue injection hole 12. After the bottommost glue injection hole 12 is filled, glue is then injected into the glue injection hole 12 of the next layer.

[0121] For example, two adjacent injection holes 12 are respectively a lower layer hole and an upper layer hole; injection of adhesive into each injection hole 12 from bottom to top in the vertical direction includes:

[0122] Inject adhesive into the lower layer holes;

[0123] After the lower layer holes are filled with adhesive, inject adhesive into the upper layer holes.

[0124] It should be noted that "filling the injection hole 12" means that no more glue can be injected into the injection hole 12, or that glue has overflowed from the upper injection hole 12. "No more glue can be injected into the lower injection hole 12," or that glue has overflowed from the upper injection hole 12, indicates that the damaged area below the lower hole and the damaged area between the upper and lower holes have been completely filled with glue. Then, glue is injected into the upper holes until the upper holes are full of glue, indicating that the damaged area above the upper holes has been filled with glue.

[0125] The glue injection holes 12 in the same layer can be injected with glue simultaneously, or the glue injection holes 12 in the same layer can be injected with glue one by one. This disclosure does not limit this.

[0126] In the above embodiments, the bottom-to-top glue injection sequence cleverly utilizes the self-weight of the glue and the principle of air venting to drive and expel the air in the holes and the gaps between layers from bottom to top. This can eliminate the air pockets and cavities inside the damaged area A of the blade, thereby achieving a full and dense glue injection effect.

[0127] like Figure 7As shown, in some other possible embodiments, there are at least three injection holes 12. One injection hole 12 is a first injection hole 12a, which can be referred to as the central hole. At least two injection holes 12 are second injection holes 12b, which can be referred to as peripheral holes. The second injection holes 12b are distributed around the first injection hole 12a. In this case, adhesive is injected into the injection holes 12, including into the first injection hole 12a, until adhesive overflows from each of the second injection holes 12b, indicating that each injection hole 12 is filled with adhesive. This central injection method allows for injection with the fewest possible injection points, and the peripheral injection holes 12 allow for accurate determination of whether the damaged area A of the blade is filled with adhesive, thereby improving repair efficiency.

[0128] The second injection hole 12b can be two, three, or at least four, and this disclosure does not limit this.

[0129] like Figure 10 As shown, in some possible embodiments, the maintenance method for pre-embedded blade roots of wind turbine blades before heating and curing the adhesive further includes:

[0130] S3': After filling the injection hole with adhesive, seal the injection hole.

[0131] In the above S3', after one injection hole 12 is filled with glue, the injection hole 12 is sealed, and then glue is injected into the next injection hole 12.

[0132] In the above S3', a sealing element can be used to seal the glue injection hole 12. The sealing element can be a resin rod or other types. This embodiment does not limit the type of sealing element.

[0133] In the above embodiments, by sealing the injection hole 12, the adhesive pressure inside the damaged area A of the blade can be maintained, which can prevent adhesive backflow or leakage and leave cavity defects, thereby improving the repair effect. After heating and curing the adhesive, the sealing component and the cured adhesive can be fused together. For example, the sealing component and the injected adhesive can be made of the same material.

[0134] In step S4 above, the adhesive is heated to cure. Specifically, the adhesive is heated until its degree of curing is within a set range, for example, until the degree of curing is greater than 90%. After the adhesive has cured, the repair of the damaged area of ​​the blade can be completed.

[0135] In step S4 above, an electric heating device, an infrared heating device, a hot air circulation heating device, an induction heating device, or other heating devices can be used to heat and cure the adhesive. After the heating and curing process is complete, the heating device should be removed.

[0136] like Figure 11 As shown, in some possible embodiments, the above-described S4 includes:

[0137] S41: Cover the damaged area of ​​the blade with the heating element;

[0138] S42: Fixed connection between heating assembly and blade to be repaired;

[0139] S43: Heat the leaf roots to heat and cure the adhesive.

[0140] In S41 above, the edge of the heating component and the boundary L of the blade damage area A on the surface of the blade root 11 can be aligned; or, the heating component can extend beyond the boundary of the blade damage area on the surface of the blade root 11. This ensures that heat can be evenly conducted to the entire blade damage area A, improving the heating effect of the heating component, thereby improving the curing efficiency of the adhesive and thus improving maintenance efficiency; it can also prevent incomplete curing of the blade damage area A due to insufficient temperature, thereby preventing the formation of new weak points.

[0141] For example, the distance of the heating assembly beyond the boundary L of the blade damage zone can be greater than 200 mm.

[0142] The heating element can be an electric blanket, a water-heated blanket, or other types of heating elements; this embodiment does not limit this.

[0143] In S42 above, tape, straps, or other components can be used to securely connect the heating assembly and the blade 1a to be maintained. It is understood that the tape, straps, or other components can all be adapted to the heating temperature of the heating assembly.

[0144] In the above S42, by fixing the heating component, the heating efficiency can be further improved, and it can also resist the interference of the external environment, especially low temperature and strong wind weather.

[0145] like Figure 12 As shown, in some possible embodiments, between S42 and S43, the above-mentioned S4 further includes:

[0146] S42': Cover the heating assembly with the insulation material;

[0147] S43': Fixed connection between insulation component and blade to be repaired, or fixed connection between insulation component and heating component.

[0148] In the above S42', the insulation component can be a cotton quilt, aluminum foil, or other insulation components, etc., and this embodiment does not limit it.

[0149] In S42' above, the edge of the insulation component and the edge of the heating component can be aligned; or, the edge of the insulation component can extend beyond the edge of the heating component to improve the insulation effect of the insulation component, thereby improving the curing efficiency of the adhesive and thus improving maintenance efficiency.

[0150] For example, the distance of the insulation element extending beyond the edge of the heating component can be greater than 200 mm or other values, and this disclosure does not limit this.

[0151] In the above S43', tape, straps or other components can be used to fix the insulation component and the blade 1a to be repaired, or to fix the insulation component and the heating component.

[0152] In the above embodiments, the insulation component can significantly reduce the heat loss from the heating assembly to the outside air, thereby creating a stable and uniform curing environment. This accelerates the curing process of the adhesive, ensuring that the adhesive reaches the set degree of curing at the preset temperature. Consequently, the mechanical properties and durability of the repaired adhesive layer meet long-term operational requirements. Therefore, incorporating insulation components can improve the curing effect, thereby enhancing the repair efficiency.

[0153] The maintenance method for the pre-embedded blade root of the wind turbine blade provided in this embodiment directly determines the blade damage area A at the blade root of the blade 1a to be repaired on the wind turbine 100 and performs glue injection repair. The determination of the blade damage area A, drilling, glue injection, and heat curing of the glue are not affected by the connection structure between the blade 1a to be repaired and the hub, so that maintenance can be carried out on-site at the wind power generation device. In-situ repair can be completed without disassembling the wind turbine blade 1. Compared with the related technology of disassembling the wind turbine blade to repair the pre-embedded blade root, it is not necessary to disassemble the wind turbine blade 1 (blade 1a to be repaired), which effectively reduces the maintenance difficulty of the pre-embedded blade root and improves the maintenance efficiency. Moreover, since it is not necessary to disassemble the wind turbine blade 1 (blade 1a to be repaired), it is not necessary to disassemble the equipment, which effectively reduces the maintenance cost of the pre-embedded blade root.

[0154] In the maintenance method for pre-embedded blade roots of wind turbine blades provided in this embodiment, an injection hole 12 is opened at the position corresponding to the blade damage area A and the UD block 1132. By limiting the diameter of the injection hole 12 to be smaller than the width of the UD block 1132, and by distributing the injection hole 12 and the bolt sleeve 1131 at intervals along the circumference of the blade root 11, the bolt sleeve 1131 (core load-bearing component) of the blade root 11 is effectively avoided. This avoids the risk of damaging the bolt sleeve 1131 by opening the hole and eliminates the risk of the adhesive clogging the bolt sleeve 1131, thereby ensuring the reliability of the connection between the wind turbine blade 1 and the hub 2. It also preserves a sufficiently complete load-bearing material at the edge of the UD block 1132, thereby avoiding excessive weakening of the strength of the UD block 1132 structure due to the opening. By opening at least two injection holes 12, the injection and venting are realized. During the injection, the adhesive is driven to flow fully and fill orderly in the blade damage area A, continuously expelling interlayer air and residual air bubbles, and finally forming a dense and continuous adhesive layer, eliminating local bonding defects caused by residual air cavitation.

[0155] In the maintenance method for the pre-embedded blade root of the wind turbine blade provided in this embodiment, by injecting adhesive into the injection hole 12 and heating to cure the adhesive, the adhesive can fully fill the delamination area (connecting the damaged area) between the blade root pre-embedded part 113 and the outer skin 111, the delamination area (connecting the damaged area) between the blade root pre-embedded part 113 and the inner skin 112, the delamination area of ​​the outer skin 111 itself, and the delamination area of ​​the inner skin 112 itself under pressure. The cured adhesive re-establishes the connection between each structural layer, effectively repairing the blade damage area A at the blade root 11, thereby ensuring the interlayer shear strength and overall mechanical properties of the blade root 11, and ensuring that the repaired blade root can meet the load-bearing requirements under working conditions. Moreover, the injection holes 12 are distributed to avoid the formation of a cross-sectional weakening zone by densely opening holes on the UD block 1132, maintaining the uniformity and continuity of the circumferential stiffness of the blade root 11, so that the repaired blade root 11 will not generate new fatigue danger points due to the concentration of openings when subjected to bending and torsional alternating loads.

[0156] Therefore, the maintenance method for the pre-embedded blade root of wind turbine blades provided in this embodiment can be performed without disassembling the blade. Through the ingenious design of the opening position, size and glue injection curing, efficient and high-quality in-situ repair of the delamination damage of the pre-embedded blade root is achieved, which significantly reduces the maintenance difficulty and maintenance cost of the delamination failure of the pre-embedded blade root.

[0157] To facilitate the maintenance of the blade 1a to be maintained, before S1, the maintenance method of the pre-embedded blade root of the wind turbine blade also includes locking the blade 1 of the wind turbine 100. It can be understood that all blades 1 are locked so that the blade 1a to be maintained is in a locked state.

[0158] Locking the blades 1 of the wind turbine 100 is specifically achieved by locking the blades 1 of the wind turbine 100 using a blade locking device. The blade locking device is a part of the structure of the wind power generation device. The specific structure of the blade locking device is selected according to the actual situation, and this application embodiment does not limit it.

[0159] The blade root 11 is typically equipped with a blade baffle (not shown in the figure), which is perpendicular to the length of the blade root 11. To facilitate the identification of the damaged area A on the blade and to perform other maintenance operations (drilling, injecting adhesive, and curing adhesive, etc.), the blade baffle provides a platform for the maintenance personnel. Based on this, such as Figure 10 As shown, prior to S1, the maintenance method for the pre-embedded blade roots of the wind turbine blades also includes:

[0160] S1': Rotate the blade to be repaired so that the blade root faces upward and the blade tip faces downward.

[0161] It should be noted that when the blade root 11 of the blade to be repaired 1a is pointing upward and the blade tip 17 is pointing downward, it means that in the vertical direction, the blade root of the blade to be repaired is pointing upward and the blade tip is pointing downward. Figure 2 The blade 1a to be repaired is shown with its root 11 pointing upwards and its tip 17 pointing downwards. The length direction of the blade 1a to be repaired can be parallel to the vertical direction, or the length direction of the blade 1a to be repaired can be at an angle to the vertical direction, which is greater than zero degrees and less than 90 degrees.

[0162] In the above S1', rotating the blade 1a to be maintained can be achieved by rotating the wind turbine 100.

[0163] In the above S1', by rotating the blade 1a to be repaired to a set position (the blade root 11 facing upwards and the blade tip 17 facing downwards), the blade baffle is set approximately horizontally or parallel to the horizontal direction. This allows the maintenance personnel to operate on the blade root baffle, which is beneficial for subsequent operations such as determining the blade damage area of ​​the blade root 11, opening holes, injecting adhesive, and curing adhesive, thereby improving the convenience and safety of operation. Moreover, with the blade root 11 facing upwards and the blade tip 17 facing downwards, it is easy for the adhesive to flow during the adhesive injection process, which is conducive to the adhesive fully wetting the blade damage area A.

[0164] In the above embodiments, the maintenance method for pre-embedded blade roots of wind turbine blades further includes: with the blade 1 of the wind turbine 100 locked, first rotate the blade to be maintained so that the blade root of the blade to be maintained faces upward and the blade tip faces downward, and then lock the blade 1 of the wind turbine 100.

[0165] like Figure 10 As shown, in some possible embodiments, after S4 above, the maintenance method for the pre-embedded blade root of the wind turbine blade further includes:

[0166] S5: Fix at least one of the first reinforcing plate and the second reinforcing plate to the leaf root.

[0167] The first reinforcing plate 14 is located on the side of the outer skin 111 away from the inner skin 112, and the first reinforcing plate 14 covers the projection of the blade damage area A on the outer skin 111; the second reinforcing plate 15 is located on the side of the inner skin 112 away from the outer skin 111, and the second reinforcing plate 15 covers the projection of the blade damage area A on the inner skin 112.

[0168] In the above embodiments, by thickening and reinforcing the outer skin 111 with the first reinforcing plate 14 and the inner skin 112 with the second reinforcing plate 15, the stiffness of the blade root 11 can be effectively improved, thereby improving the load-bearing capacity of the blade root 11. For example, the blade root 11 can completely restore or even exceed the load-bearing capacity of the original structure, thus meeting the high load-bearing operation requirements of the blade root.

[0169] In the above embodiments, the first reinforcing plate 14 and the second reinforcing plate 15 can both be metal plates or non-metal plates, and this disclosure does not limit this. For example, the first reinforcing plate 14 and the second reinforcing plate 15 are non-metal plates, and the first reinforcing plate 14 and the second reinforcing plate 15 can be glass fiber prepreg, carbon fiber prepreg (for higher stiffness requirements), wet-laid glass fiber cloth, or adhesive composite board, etc.

[0170] To facilitate the first reinforcing plate 14 covering the projection of the blade damage area A onto the outer skin 111, the length of the first reinforcing plate 14 is greater than the length of the bolt sleeve 1131, and the width of the first reinforcing plate 14 along the circumference of the blade root 11 is greater than the width of the blade damage area A along the circumference of the blade root 11. Correspondingly, to facilitate the second reinforcing plate 15 covering the projection of the blade damage area A onto the inner skin 112, the length of the second reinforcing plate 15 is greater than the length of the bolt sleeve 1131, and the width of the second reinforcing plate 15 along the circumference of the blade root 11 is greater than the width of the blade damage area A along the circumference of the blade root 11.

[0171] In some possible embodiments, there may be only one first reinforcing plate 14, thereby reducing the installation steps of the first reinforcing plate 14 and improving maintenance efficiency. Correspondingly, there may also be only one second reinforcing plate 15, which can reduce the installation steps of the second reinforcing plate 15 and improve maintenance efficiency.

[0172] In some other possible embodiments, the first reinforcing plate 14 includes at least two first sub-plates. The width of the first sub-plates along the circumference of the blade root 11 is greater than the width of the UD block 1132, and the width of the first sub-plates along the circumference of the blade root 11 is less than the distance between the axes of two adjacent bolt sleeves 1131. This allows the first sub-plates to be manufactured as standard parts, and the first sub-plates can be combined into the first reinforcing plate 14 for the maintenance of different wind turbine blades 1, improving the versatility of the first sub-plates. It is understood that the number of first sub-plates required for the maintenance of different wind turbine blades 1 may be the same or different. Correspondingly, the second reinforcing plate 15 includes at least two second sub-plates. The width of the second sub-plates along the circumference of the blade root 11 is greater than the width of the UD block 1132, and the width of the second sub-plates along the circumference of the blade root 11 is less than the distance between the central axes of two adjacent bolt sleeves 1131. This allows the second sub-plates to be manufactured as standard parts, and the second sub-plates can be combined into the second reinforcing plate 15 for the maintenance of different wind turbine blades 1, improving the versatility of the second sub-plates. It is understandable that the number of second plates required for the maintenance of different wind turbine blades 1 may be the same or different.

[0173] An embodiment in which the first reinforcing plate 14 is a single plate and an embodiment in which the second reinforcing plate 15 is a single plate can be implemented in combination; or, an embodiment in which the first reinforcing plate 14 is a single plate and an embodiment in which the second reinforcing plate 15 includes at least two second sub-plates can be implemented in combination; or, an embodiment in which the first reinforcing plate 14 includes at least two first sub-plates and an embodiment in which the second reinforcing plate 15 includes at least two second sub-plates can be implemented in combination.

[0174] like Figure 4 As shown, in some possible embodiments, a first chamfer 141 is provided on the front end of the first reinforcing plate 14 away from the outer skin 111 and on the rear end of the first reinforcing plate 14 away from the outer skin 111.

[0175] It should be noted that, Figure 4 The image shows that a first chamfer 141 is provided on the front end of the first reinforcing plate 14, away from the outer skin 111. Figure 4 The first chamfer 141 on the rear end of the first reinforcing plate 14 away from the outer skin 111 is not shown in the figure.

[0176] In the above embodiments, the first chamfer 141 at the front and rear ends of the first reinforcing plate 14 can effectively smooth the geometric abrupt changes of the entire structural cross section; when the wind turbine blade 1 is in operation, the first chamfer 141 can significantly reduce the aerodynamic drag and wind noise at the edge of the first reinforcing plate 14; moreover, the first reinforcing plate 14 with the first chamfer 141 can smoothly transfer the load, thereby reducing the peel stress and shear stress peak at the edge of the first reinforcing plate 14, and thus preventing the front and rear ends of the first reinforcing plate 14 from debonding and warping due to stress concentration.

[0177] like Figure 4 As shown, in some possible embodiments, a second chamfer 151 is provided on the front end of the second reinforcing plate 15 away from the inner skin 112 and on the rear end of the second reinforcing plate 15 away from the inner skin 112.

[0178] It should be noted that, Figure 4 The image shows that a second chamfer 151 is provided on the front end of the second reinforcing plate 15, away from the inner skin 112. Figure 4 The second chamfer 151 on the rear end of the second reinforcing plate 15 away from the inner skin 112 is not shown in the figure.

[0179] In the above embodiments, the second chamfer 151 at the front and rear ends of the second reinforcing plate 15 can effectively smooth the geometric abrupt changes of the entire structural cross section; when the wind turbine blade 1 is in operation, the second chamfer 151 can significantly reduce the aerodynamic drag and wind noise at the edge of the second reinforcing plate 15; moreover, the second reinforcing plate 15 with the second chamfer 151 can smoothly transfer the load, thereby reducing the peel stress and shear stress peak at the edge of the second reinforcing plate 15, and thus preventing the front and rear ends of the second reinforcing plate 15 from debonding and warping due to stress concentration.

[0180] The size of the first chamfer 141 and the second chamfer 151 is designed according to the actual situation. For example, the chamfer ratio of the first chamfer 141 is less than 1:5, and the chamfer ratio of the second chamfer 151 is less than 1:5.

[0181] like Figure 13 As shown, in some possible embodiments, prior to S5, the maintenance method for pre-embedded blade roots of wind turbine blades further includes:

[0182] S5': Make the first and second reinforcing plates.

[0183] The first reinforcing plate 14 and the second reinforcing plate 15 can be manufactured according to actual needs. For example, you can refer to the previous description of the first reinforcing plate 14 and the second reinforcing plate 15.

[0184] For example, S5' can be between S4 and S5, or S5' can be before S4, as long as S5' is before S5.

[0185] The fixing method of the first reinforcing plate 14 and the second reinforcing plate 15 can be selected according to the actual situation. For example... Figure 14 As shown, in some possible embodiments, the above-described S5 includes:

[0186] S51: Make a hole at the leaf root and at the position corresponding to the UD block to obtain a connection hole;

[0187] S52: At least one of the first reinforcing plate and the second reinforcing plate is fixed to the blade root using anchors that mate with the connecting holes.

[0188] In the above S51, such as Figure 5 As shown, the connecting hole 13 penetrates the outer skin 111, the inner skin 112, and the UD block 1132 along the thickness direction of the blade root 11. There can be one or at least two connecting holes 13. When there are at least two connecting holes 13, any two connecting holes 13 are spaced apart along the length direction of the blade root 11.

[0189] In the above S52, such as Figure 5 As shown, the anchor 16 passes through the first reinforcing plate 14, the connecting hole 13, and the second reinforcing plate 15.

[0190] In the above S52, the anchor 16 can be a bolt anchor, a blind rivet, an adhesive-filled anchor, a threaded pin, or other anchoring components, and this embodiment does not limit this.

[0191] In the above embodiments, at least one of the first reinforcing plate 14 and the second reinforcing plate 15 is fixed by the anchor 16, and the first reinforcing plate 14 and the second reinforcing plate 15 are connected to the original structure as a whole. This can reduce the probability of the first reinforcing plate 14 being peeled off and the second reinforcing plate 15 being peeled off, thereby improving the reliability of the blade 1a to be repaired after repair.

[0192] like Figure 14 As shown, in order to improve the fit between the first reinforcing plate 14 and the outer skin 111, and the fit between the second reinforcing plate 15 and the inner skin 112, between S51 and S52, the above-mentioned S5 further includes:

[0193] S52': At least one of the first reinforcing plate and the second reinforcing plate is bonded to the leaf root using adhesive.

[0194] Based on the above embodiments, after S52, S5 further includes:

[0195] S53: Heat-curing adhesive.

[0196] It should be noted that S52' may include using adhesive to bond the first reinforcing plate 14 to the blade root 11, and S52 may include using an anchor 16 that mates with the connecting hole 13 to fix the first reinforcing plate 14 to the blade root 11; or, S52' may include using adhesive to bond the second reinforcing plate 15 to the blade root 11, and S52 may include using an anchor 16 that mates with the connecting hole 13 to fix the second reinforcing plate 15 to the blade root 11; or, S52' may include using adhesive to bond the first reinforcing plate 14 to the blade root 11 and using adhesive to bond the second reinforcing plate 15 to the blade root 11, and S52 may include using an anchor 16 that mates with the connecting hole 13 to fix the first reinforcing plate 14 to the blade root 11 and using an anchor 16 that mates with the connecting hole 13 to fix the second reinforcing plate 15 to the blade root 11.

[0197] The adhesive can be epoxy or other types, and this disclosure does not limit the specific type of adhesive used.

[0198] In the above embodiments, by bonding the first reinforcing plate 14 and the second reinforcing plate 15, the connection reliability and stability between the first reinforcing plate 14 and the blade root 11, and the connection reliability and stability between the second reinforcing plate 15 and the blade root 11 can be improved. This can further reduce the probability of the first reinforcing plate 14 being peeled off and the probability of the second reinforcing plate 15 being peeled off, thereby improving the reliability of the blade 1a after repair. The combination of the anchor 16 and the adhesive forms a double fixing structure. Under vibration and alternating loads, the double fixing structure can also effectively suppress the further expansion of delamination damage, thereby improving the overall stiffness and fatigue life of the blade root after repair.

[0199] It should be noted that the first reinforcing plate 14 is one type of reinforcing plate, and the second reinforcing plate 15 is another type of reinforcing plate.

[0200] like Figure 14 As shown, to improve the bonding effect, between S51 and S52', the above-mentioned S5 further includes:

[0201] S51': Roughen the surface of the reinforcing plate that contacts the blade root.

[0202] For example, the surface of the first reinforcing plate 14 that contacts the blade root 11 is roughened. For instance, the first reinforcing plate 14 has a first surface that contacts the blade root 11, and the first surface of the first reinforcing plate 14 is roughened.

[0203] For example, the surface of the second reinforcing plate 15 that contacts the blade root 11 is roughened. For instance, the second reinforcing plate 15 has a second surface that contacts the blade root 11, and the second surface of the second reinforcing plate 15 is roughened.

[0204] When the reinforcing plate is a metal plate, the roughening treatment can be knurling, sandblasting, or other treatment methods; when the reinforcing plate is made of resin-based fiber-reinforced material, the roughening treatment can be sandblasting, release cloth treatment, or other treatment methods.

[0205] In the above embodiments, by roughening the surface of the reinforcing plate in contact with the leaf root 11, the roughened surface can form a strong mechanical bond with the subsequently applied adhesive, improving the shear and peel resistance of the interface, thereby improving the bonding effect and thus improving the maintenance effect.

[0206] like Figure 14 As shown, in some possible embodiments, between S51 and S52', the above-mentioned maintenance method for pre-embedded blade roots of wind turbine blades further includes:

[0207] S51'': Grind the outer and inner skin at the leaf root.

[0208] S51'' can be before S51' or S51'' can be after S51'.

[0209] In the above embodiments, grinding the surfaces of the outer skin 111 and the inner skin 112 can remove the oxide layer and expose fresh fibers, which is beneficial to improving the bonding effect of the first reinforcing plate 14 and the bonding effect of the second reinforcing plate 15.

[0210] In the maintenance method for pre-embedded blade roots of wind turbine blades provided in this embodiment, the blade 1a to be maintained is directly maintained on the wind turbine 100 without disassembling the wind turbine blade 1, which significantly reduces the maintenance difficulty, shortens the maintenance cycle, and reduces the maintenance cost; at the same time, through reasonable hole design and reinforcement measures, the load-bearing capacity of the repaired blade root 11 is improved.

[0211] The maintenance method for the pre-embedded blade root of the wind turbine blade provided in this embodiment addresses the problem of delamination failure of the pre-embedded blade root. It uses injection holes 12 to fill the delamination area. After the injection curing, at least one of the outer skin 111 and inner skin 112 of the blade root 11 is thickened and reinforced to improve the structural rigidity of the blade root 11. The reinforced plate is anchored to the original blade root structure through anchors 16, realizing the synergistic repair of injection filling, rigidity enhancement and anti-peeling, which can effectively improve the maintenance effect of the blade root 11.

[0212] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles used, and is not intended to limit this disclosure. The described embodiments are only a part of the embodiments of this disclosure, and not all of them. Various modifications and variations can be made to this disclosure by those skilled in the art. The scope of protection in this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalent features without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions provided in this disclosure.

Claims

1. A maintenance method for wind turbine blades with pre-embedded blade roots, characterized in that, include: Determine the blade damage area (A) at the blade root (11) of the blade (1a) to be repaired in the wind turbine (100); the blade (1a) to be repaired is in a state of being connected to the hub (2) of the wind turbine (100); At least two injection holes (12) are made at the location corresponding to the blade damage area (A) and UD block (1132). Inject adhesive into the injection hole (12); The adhesive is cured by heating; The depth of the glue injection hole (12) is greater than the depth of the blade damage area (A), the diameter of the glue injection hole (12) is smaller than the width of the UD block (1132), and the glue injection hole (12) and the bolt sleeve (1131) are distributed circumferentially along the blade root (11); the depth direction of the blade damage area (A) and the glue injection hole (12) are both parallel to the thickness direction of the blade root (11).

2. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 1, characterized in that, The glue injection holes (12) are at least two layers, with any two layers distributed in the vertical direction; in two adjacent layers, the glue injection holes (12) of one layer and the glue injection holes (12) of the other layer are staggered along the circumferential direction of the leaf root (11).

3. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 1, characterized in that, The glue injection hole (12) has at least two layers, and any two layers are distributed in the vertical direction; injecting glue into the glue injection hole (12) includes: injecting glue into each layer of the glue injection hole (12) in the vertical direction from bottom to top; Alternatively, there may be at least three injection holes (12), one of which is a first injection hole (12a) and at least two of which are second injection holes (12b), with the second injection holes (12b) distributed around the first injection hole (12a); injecting adhesive into the injection holes (12) includes: injecting adhesive into the first injection hole (12a) until adhesive overflows from each of the second injection holes (12b).

4. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 1, characterized in that, Before the adhesive is heated and cured, the maintenance method for the pre-embedded blade root of the wind turbine blade also includes: After the glue injection hole (12) is filled with glue, the glue injection hole (12) is sealed.

5. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 1, characterized in that, Heating and curing the adhesive includes: The heating assembly is placed over the damaged area (A) of the blade, and the heating assembly extends beyond the boundary (L) of the damaged area (A) of the blade to the surface of the leaf root (11). The heating assembly and the blade to be repaired (1a) are fixedly connected. The leaf root (11) is heated to heat-cure the adhesive.

6. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 5, characterized in that, After the heating assembly and the blade to be repaired (1a) are fixedly connected, and before the blade root (11) is heated and cured, the process of heating and curing the adhesive further includes: Cover the heating assembly with the insulation material; The insulation component and the blade to be repaired (1a) are fixedly connected, or the insulation component and the heating assembly are fixedly connected.

7. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 1, characterized in that, Identify the blade damage area (A) at the blade root (11) of the blade (1a) to be repaired in the wind turbine (100), including: Determine the boundary (L) of the leaf damage area (A) on the surface of the leaf root (11), and determine the depth of the leaf damage area (A); Mark the boundary (L) of the damaged area (A) of the blade (1a) on the surface of the blade root (11).

8. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 7, characterized in that, The distance between the injection hole (12) and the boundary (L) is greater than zero and not greater than 50 mm.

9. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 1, characterized in that, Before determining the blade damage zone (A) at the blade root (11) of the blade to be repaired in the wind turbine (100), the maintenance method of pre-embedded blade root of the wind turbine blade also includes: Rotate the blade (1a) to be repaired so that the root (11) of the blade (1a) to be repaired in the vertical direction is facing upward and the tip (17) is facing downward.

10. The maintenance method for wind turbine blades with pre-embedded blade roots according to any one of claims 1-9, characterized in that, After the adhesive has been heated and cured, the maintenance method for the pre-embedded blade roots of the wind turbine blades also includes: At least one of the first reinforcing plate (14) and the second reinforcing plate (15) is fixed to the leaf root (11); The first reinforcing plate (14) is located on the side of the outer skin (111) away from the inner skin (112), and the first reinforcing plate (14) covers the projection of the blade damage area (A) on the outer skin (111); the second reinforcing plate (15) is located on the side of the inner skin (112) away from the outer skin (111), and the second reinforcing plate (15) covers the projection of the blade damage area (A) on the inner skin (112).

11. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 10, characterized in that, Fixing at least one of the first reinforcing plate (14) and the second reinforcing plate (15) to the leaf root (11) includes: A hole is made at the leaf root (11) and at the position corresponding to the UD block (1132) to obtain a connecting hole (13). The connecting hole (13) penetrates the outer skin (111), inner skin (112) and UD block (1132) of the leaf root (11) along the thickness direction of the leaf root (11). At least one of the first reinforcing plate (14) and the second reinforcing plate (15) is fixed to the leaf root (11) using an anchor (16) that mates with the connecting hole (13).

12. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 11, characterized in that, Fixing at least one of the first reinforcing plate (14) and the second reinforcing plate (15) to the leaf root (11) further includes: After the hole is made at the leaf root (11) and at the position corresponding to the UD block (1132), and before at least one of the first reinforcing plate (14) and the second reinforcing plate (15) is fixed to the leaf root (11) using the anchor (16), at least one of the first reinforcing plate (14) and the second reinforcing plate (15) is bonded to the leaf root (11) using adhesive. After the first reinforcing plate (14) and the second reinforcing plate (15) are fixed to the blade root (11) using the anchor (16), the maintenance method for the pre-embedded blade root of the wind turbine blade further includes: heating and curing the adhesive.

13. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 12, characterized in that, Both the first reinforcing plate (14) and the second reinforcing plate (15) are reinforcing plates; Fixing at least one of the first reinforcing plate (14) and the second reinforcing plate (15) to the leaf root (11) further includes: After making a hole at the leaf root (11) and at the position corresponding to the UD block (1132), and before bonding the reinforcing plate to the leaf root (11) with adhesive, the surface of the reinforcing plate in contact with the leaf root (11) is roughened.

14. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 12, characterized in that, Fixing at least one of the first reinforcing plate (14) and the second reinforcing plate (15) to the leaf root (11) further includes: After making a hole at the leaf root (11) and at the position corresponding to the UD block (1132), and before bonding the reinforcing plate to the leaf root (11) with adhesive, the outer skin (111) and inner skin (112) at the leaf root (11) are sanded.

15. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 10, characterized in that, The lengths of the first reinforcing plate (14) and the second reinforcing plate (15) are both greater than the length of the bolt sleeve (1131). The width of the first reinforcing plate (14) along the circumference of the leaf root (11) and the width of the second reinforcing plate (15) along the circumference of the leaf root (11) are both greater than the width of the blade damage area (A) along the circumference of the leaf root (11).

16. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 10, characterized in that, The first reinforcing plate (14) is one; or, the first reinforcing plate (14) includes at least two first sub-plates, the width of the first sub-plate along the circumferential direction of the leaf root (11) is greater than the width of the UD block (1132), and the width of the first sub-plate along the circumferential direction of the leaf root (11) is less than the distance between the axes of two adjacent bolt sleeves (1131). The second reinforcing plate (15) is one; or, the second reinforcing plate (15) includes at least two second sub-plates, the width of the second sub-plates along the circumferential direction of the leaf root (11) is greater than the width of the UD block (1132), and the width of the second sub-plates along the circumferential direction of the leaf root (11) is less than the distance between the central axes of two adjacent bolt sleeves (1131).

17. The maintenance method for wind turbine blades with pre-embedded blade roots according to claim 10, characterized in that, The first reinforcing plate (14) has a first chamfer (141) on the front end away from the outer skin (111) and a second chamfer (151) on the rear end away from the outer skin (111).

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