A device and method for manufacturing a preform root for a wind turbine blade

Abstract

The application relates to a device and a method for preparing a prefabricated blade root for a wind power blade, and belongs to the technical field of wind power generation. The device comprises an outer convex surface structure, a plate-shaped flange connecting piece and a cover structure. The plate-shaped flange connecting piece is provided with three rows of connecting holes which are respectively connected with the outer convex surface structure, a threaded sleeve used by the prefabricated blade root product and the cover structure. The outer convex surface structure and the cover structure are both provided with step faces which are distributed in a stepped manner to form a prefabricated blade root with a stepped double bonding surface. The outer convex surface structure can effectively avoid the occurrence of wrinkles in the fiber woven fabric and simultaneously avoid the use of glue spraying. The device and the method for preparing the prefabricated blade root for the wind power blade can prepare the prefabricated blade root with less defects, better interlayer performance and stronger interface bonding.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and to a prefabricated blade root used on wind turbine blades, particularly an apparatus and method for preparing prefabricated blade roots for wind turbine blades, which can produce prefabricated blade roots with fewer defects, better interlayer performance, and stronger interfacial adhesion. Background Technology

[0002] In recent years, with the continuous improvement of technologies in the wind power industry, the size and performance of wind turbine blades have also been continuously improving. Wind turbine blades are a crucial component of wind turbine generators, and their structure and performance directly affect the efficiency and lifespan of these generators. To improve the production efficiency and quality of wind turbine blades, prefabricated components such as blade roots, pultruded plates, prefabricated webs, and prefabricated trailing edge main beams have begun to be used. Prefabricated components refer to parts that are manufactured before the wind turbine blade mold. They can be produced using different processes, such as manual lay-up, vacuum-assisted resin transfer molding (VARTM), and prepreg. The use of prefabricated components significantly reduces the time spent in the mold for the blade shell, improves production efficiency, and reduces production costs. Furthermore, the production process of prefabricated components allows for better quality control, reduces variability during manufacturing, and improves product consistency and reliability.

[0003] However, the use of prefabricated components also leads to reduced performance and increased defects at the interface between the prefabricated component and the fiber woven fabric. This is because there are problems such as interfacial stress concentration and poor interfacial adhesion between the prefabricated component and the fiber woven fabric. Interfacial stress concentration can cause cracks or delamination between the prefabricated component and the fiber woven fabric, reducing the strength and stiffness of the blade. Poor interfacial adhesion can cause air bubbles or voids between the prefabricated component and the fiber woven fabric, affecting the density and uniformity of the blade. These defects affect the durability and safety of wind turbine blades.

[0004] Currently, prefabricated blade roots for wind turbine blades are typically prepared using a negative mold: a release liner is laid first, followed by a continuous fiber woven fabric laid on top of the release liner according to design requirements. After laying a certain amount of continuous fiber woven fabric, staggered fiber woven fabric is laid to form a rough bonding surface. This method is prone to the following problems: (1) Due to the arc-shaped negative mold, the edge curvature of the negative mold is large, requiring more adhesive to fix the fiber woven fabric, which reduces the interlayer performance of the fiber woven fabric; (2) As the area connecting the blade and the hub, the prefabricated blade root needs to be laid with multiple layers of fiber woven fabric to withstand a large load, but areas with a large amount of fiber woven fabric are prone to wrinkling, leading to a decrease in the performance of the prefabricated blade root; (3) The prefabricated blade root only forms a rough bonding surface on its upper surface, resulting in a small bonding area that is prone to damage.

[0005] To address these issues, existing technologies often utilize male molds to form root preforms. The convex surface of the male mold effectively prevents the fiberglass cloth layer laid on the forming surface from slipping due to gravity, thus avoiding wrinkles in the fiberglass cloth layer. Because the fiberglass cloth layer does not slip, the adhesive application process can be simplified to some extent during molding, thereby avoiding any impact of adhesive application on the structural strength of the root preform. This ensures the high quality of root preforms formed using this mold.

[0006] However, the positive mold manufacturing process also has some shortcomings: for example, the manufacturing process of the positive mold is relatively complex and the production cost is relatively high; the size and shape of the positive mold are not as flexible as those of the negative mold; and the surface of the positive mold requires high control over the placement of the fabric and the molding process. Therefore, how to improve the manufacturing efficiency while further optimizing the mold structure and process of wind turbine blade root preforms, thereby further reducing manufacturing defects of the blade root preforms and maintaining good interlayer properties and strong interfacial adhesion, and improving the quality and performance of wind turbine blade preforms, is an urgent technical problem to be solved. Summary of the Invention

[0007] (a) Purpose of the invention

[0008] To overcome the problems existing in the preparation of prefabricated blade roots for wind turbine blades, especially the defects and shortcomings of the above-mentioned methods for preparing blade root prefabricated parts using traditional molds and processes, this invention provides an apparatus and method for preparing prefabricated blade roots for wind turbine blades. This method can prepare prefabricated blade roots with fewer defects, better interlayer performance, and stronger interfacial adhesion, thus ensuring the preparation quality and performance of wind turbine blade root prefabricated parts.

[0009] (II) Technical Solution

[0010] To achieve the above-mentioned objectives and solve the technical problems, the present invention provides the following technical solution:

[0011] The first objective of this invention is to provide an apparatus for preparing prefabricated blade roots for wind turbine blades, comprising at least a convex surface structural component, a plate-shaped flange connector, and a cover structural component. The convex surface structural component, the plate-shaped flange connector, and the cover structural component are fastened together by the connector to form a closed space for preparing the prefabricated blade roots. The invention is characterized in that…

[0012] The convex surface structure is an integral structure extending along an axis and having its outer wall surface formed into an outwardly convex shape. It includes a convex main body extending along the axis in the length direction and having a semi-cylindrical outer wall surface.

[0013] The bottom of the convex main body is symmetrically provided with a first platform connecting part that extends along the length direction and is strip-shaped on the left and right sides in the width direction. The planar top surface of each first platform connecting part is formed as a connecting surface, and a plurality of surface connecting holes extending perpendicular to the top surface are distributed at intervals along the length direction on the top surface of each first platform connecting part. Each surface connecting hole is used for mechanically fastening the convex structural component and the cover structural component.

[0014] Both end faces of the convex profile main body are semi-circular in shape along its length. The first end is formed as a flange fixed end, and the second end is formed as a free end. A plurality of first flange connection holes extending axially are distributed at intervals along the circumferential direction on the semi-circular end face of the first end. Each first flange connection hole is used for mechanically fastening the convex profile structural component and the plate flange connector.

[0015] The outer wall surface of the convex main body is provided with a plurality of axially extending semi-cylindrical stepped surfaces along its length from the first end to the second end, so that the outer wall surface of the convex main body is generally stepped. The first step surface is close to the first end in the length direction, and the last step surface is close to the second end in the length direction. The first step surface forms the innermost outer wall surface of the convex main body in the radial direction, and the last step surface forms the outermost outer wall surface of the convex main body in the radial direction. The radial depth of each step surface decreases sequentially from the first step surface to the last step surface. The axial extension length of each step surface is adapted to the length dimension of the fiber braided layer designed in the prefabricated blade root, and the radial depth of each step surface is adapted to the thickness dimension of the fiber braided layer designed in the prefabricated blade root.

[0016] The casing structure is an overall casing-like structure extending along an axis, including a casing main body extending along the axis in the length direction and having a semi-cylindrical inner wall surface, wherein,

[0017] The bottom of the main body of the casing is symmetrically provided on the left and right sides in the width direction with a second platform connecting part that extends along the length direction and is strip-shaped. The planar bottom surface of each second platform connecting part is formed as a connecting surface, and a plurality of casing connecting holes extending perpendicular to the top surface are distributed at intervals along the length direction on each second platform connecting part. Each casing connecting hole corresponds one-to-one with the connecting holes of each convex surface structure and is mutually adapted to achieve a fast connection between the casing structure and the convex surface structure through a connector.

[0018] Of the two ends along the length of the casing structure, one end is formed as a flange fixed end, and the other end is formed as a free end. A plurality of connecting bosses are spaced circumferentially on the outer wall surface of the flange fixed end. Each connecting boss has an axially extending second flange connecting hole. Each second flange connecting hole is used for mechanically fastening the casing structure to the plate-shaped flange connector.

[0019] At least two connecting holes are provided on the top of the main body of the cover. At least one connecting hole is connected to an external vacuum pumping device through a pipe to form a vacuum pumping connecting hole, and at least one connecting hole is connected to an external injection system through a pipe to form a resin injection hole.

[0020] The plate-shaped flange connector is a semi-circular plate structure with three rows of connecting holes arranged radially from the inside to the outside on its semi-circular plate surface. The connecting holes in each row are evenly spaced along the semi-circular circumference. The inner row of connecting holes corresponds one-to-one with the first flange connecting holes in the convex surface structure and is adapted to each other, used to achieve a fastening connection between the convex surface structure and the plate-shaped flange connector through the connector. The middle row of connecting holes corresponds one-to-one with the blade root bolt sleeves pre-embedded in the prefabricated blade root and is adapted to each other, used to provide positioning support for the blade root bolt sleeves during the prefabricated blade root preparation process through the connector. The outer row of connecting holes corresponds one-to-one with the second flange connecting holes in the cover structure and is adapted to each other, used to achieve a fastening connection between the cover structure and the plate-shaped flange connector through the connector.

[0021] Preferably, the plate flange connector and the cover structure are made of alloy steel, and the convex surface structure is made of fiber composite material.

[0022] Preferably, in the convex surface structure, the number of stepped surfaces provided on the outer wall surface of the convex surface main body is consistent with the number of staggered layers of fiber braided fabric laid on the radial inner surface of the prefabricated leaf root.

[0023] Preferably, in the convex surface structure, the final step surface of the convex surface main body is provided with a first sealing strip extending along its entire circumference on the wall surface near the second end in the axial direction, and the first step surface is provided with a second sealing strip extending along its entire length on the top surface of each platform connection. The first sealing strip and the second sealing strip are integrated to form a circumferentially closed sealing strip enclosure area, so as to realize that after the convex surface structure, the plate flange connection and the cover structure are mechanically connected, a sealed space is formed to prevent gas and resin leakage that may occur during the vacuum injection preparation of precast leaf roots.

[0024] Furthermore, in the plate flange connector, the area where each of the middle row connecting holes is fixedly connected to the bolt sleeve in the precast blade root is sealed with a vacuum membrane to prevent gas and resin leakage that may occur during the vacuum injection preparation of the precast blade root.

[0025] Furthermore, in the plate flange connector, there is a radial distance between the middle row of connecting holes and the outer row of connecting holes. A third sealing strip is provided on the inner wall surface of the flange plate between the radial distances, extending along its entire semicircular direction. After the convex surface structure, the plate flange connector, and the cover structure are mechanically connected, the third sealing strip is located on the inner side of the cover structure in the radial direction to prevent possible leakage between the plate flange connector and the cover structure.

[0026] Furthermore, the first sealing strip, the second sealing strip, and the third sealing strip are all fixedly installed on the corresponding wall surfaces by adhesive bonding.

[0027] Furthermore, in the plate-shaped flange connector, the radial distance between the middle row of connecting holes and the outer row of circular holes should meet the suitability requirements for the blade fiber laying process, the vacuum system laying process, and the subsequent blade mold installation and prefabrication of blade roots.

[0028] Preferably, the roughness Ra of the first end face of the convex surface structure and the inner wall surface of the plate flange connector that is fixedly connected to and directly attached to the first end face are both set to no more than 6.3, so that they can make full contact with each other to form a closed space.

[0029] Furthermore, in the plate-shaped flange connector, the inner row of connecting holes are all positioned higher than the top surface of the first platform connecting part in the convex surface structure, so that the plate-shaped flange connector and the end face of each first platform connecting part are in full contact to form a closed space.

[0030] Furthermore, in the convex surface structure, each platform connection part has a number of support pads of selectable thickness distributed at intervals along its length on its top surface. The thickness of the support pads is set according to the design content of the fiber braid in the prefabricated leaf root.

[0031] Furthermore, in the convex surface structure, the support pad provided on the top surface of each platform connection part is disposed inside the corresponding second sealing strip in the width direction.

[0032] Preferably, in the convex surface structure, a heating system for curing and heating during the preparation of preformed leaf roots is provided below or inside the convex surface main body.

[0033] Preferably, in the housing structure, the inner wall surface of the housing body is provided with a plurality of axially extending semi-cylindrical stepped surfaces along its length from the flange fixed end to the free end, so that the inner wall surface of the housing body is generally stepped. The first step surface is adjacent to the flange fixed end in the length direction, and the last step surface is adjacent to the free end in the length direction. The radial depth of each step surface decreases sequentially from the first step surface to the last step surface. Furthermore, the axial extension length of each step surface is adapted to the length dimension of the fiber braided fabric layer designed in the prefabricated blade root, and the radial depth of each step surface is adapted to the thickness dimension of the fiber braided fabric layer designed in the prefabricated blade root.

[0034] Furthermore, in the casing structure, the number of stepped surfaces provided on the inner wall surface of the casing body is consistent with the number of staggered layers of fiber woven fabric laid on the radial outer surface of the prefabricated leaf root.

[0035] Furthermore, in the housing structure, the axial extension termination positions of each step surface provided on the inner wall surface of the housing body are staggered with the axial extension termination positions of each step surface in the convex surface structure, so as to delay the formation of cracks in the misaligned area and the formation of a "bridging phenomenon" in the vertical direction.

[0036] Preferably, in the housing structure, the air extraction communication hole is provided on the side near the flange fixing end of the housing structure, and the resin injection hole is provided on the side near the free end of the housing structure.

[0037] Furthermore, in the housing structure, valves for controlling the opening and closing of the pipeline are provided on the connecting pipe between the air extraction hole and the external vacuum pumping equipment, and on the connecting pipe between the resin injection hole and the external injection system.

[0038] Preferably, in the housing structure, at least one lifting ring is provided directly above the main body of the housing, and the lifting ring is used to facilitate the installation and disassembly of the housing structure with the convex surface structure and the plate flange connector.

[0039] The second objective of this invention is to provide a method for preparing prefabricated blade roots for wind turbine blades. Based on the apparatus for preparing prefabricated blade roots for wind turbine blades provided by the first objective, the method is characterized in that it includes at least the following steps:

[0040] SS1. Apply a release agent to all surfaces of the convex surface structural member, plate flange connector, and housing structural member used to form an enclosed space;

[0041] SS2. After the release agent dries, based on the first flange connection hole in the convex surface structure and the inner row of connection holes in the plate flange connector, a fast connection between the convex surface structure and the plate flange connector is achieved through the connector.

[0042] SS3. After the release agent dries, a release cloth is laid on the outer wall surface of the outer convex main body of the outer convex structure. The release cloth covers all step surfaces. When laying the release cloth, it should be in full contact with all outer wall surfaces of the outer convex main body and be tightly adhered to it so as to facilitate the demolding of the prefabricated blade root in subsequent steps.

[0043] SS4. Lay fiber woven fabric on the outer wall surface of the main body of the convex surface according to the design requirements. The staggered fiber woven fabric should be adapted to the various steps. The fiber woven fabric should be smoothed during the laying process, without the need to spray adhesive.

[0044] SS5. After laying the fiber woven fabric on the outer wall surface of the main body of the convex surface, lay and place the release cloth, release film, and flow guide net on top of the fiber woven fabric in sequence;

[0045] SS6. Seal strips are laid around the periphery of the convex surface structure and in the area between the middle row connection holes and the outer row connection holes of the plate flange connector, and a vacuum membrane is laid in the area where the middle row connection holes of the plate flange connector are fixedly connected to the bolt sleeve in the prefabricated blade root for sealing.

[0046] SS7. Several support pads are provided at intervals along the length direction on the top surface of each platform connection part in the convex surface structure, and each support pad is placed inside the corresponding sealing strip to facilitate control of the fiber content of the prefabricated leaf root;

[0047] SS8. Based on the surface connection hole in the convex surface structural component and the cover connection hole in the cover structural component, a fast connection between the convex surface structural component and the cover structural component is achieved through a connector;

[0048] SS9. Based on the second flange connection hole in the cover structure and the outer connection hole of the plate flange connector, a fast connection between the cover structure and the plate flange connector is achieved through a connector;

[0049] SS10. After completing the mechanical connection between the convex surface structural component, the plate flange connector, and the cover structural component to form a closed space, use the air extraction communication hole on the top of the cover structural component to connect an external vacuum pumping device to pump air from the closed space. After reaching a certain vacuum level, use the resin injection hole on the top of the cover structural component to connect an external resin injection system for vacuum injection. After the resin injection is completed, turn off the resin injection system and the vacuum pumping device.

[0050] SS11. The convex surface structure is heated using a heating system to heat and cure the resin introduced into the enclosed space;

[0051] SS12. After the prefabricated blade root is heated and cured, remove all connecting parts to separate the convex surface structural parts, plate flange connecting parts, and cover structural parts, and prepare the prefabricated blade root.

[0052] Preferably, in step SS3 above, adhesive is sprayed to ensure a tight fit between the release cloth and the various stepped surfaces on the convex main body.

[0053] Preferably, in step SS5 above, the release cloth laid out should completely cover the woven fiber material underneath; when placing the guide net, it should be laid symmetrically from the highest point of the outer wall surface of the main body of the convex surface to both sides; the position of the isolation membrane should be adapted to the guide net, and the size of the isolation membrane should be slightly larger than that of the guide net.

[0054] Preferably, in step SS5 above, the guide net is arc-shaped with an angle of 30°~60°.

[0055] (iii) The technical effects that the invention can achieve compared with the prior art.

[0056] The apparatus and method for preparing prefabricated blade roots for wind turbine blades of the present invention form a closed space through an outwardly convex structural component, a plate-shaped flange connector, and a cover structure. A prefabricated blade root with a double bonding surface is formed by laying a fiber woven fabric on the stepped surface of the outwardly convex structural component. Compared with existing methods for preparing prefabricated blade roots using negative molds, the outwardly convex structural component of the present invention not only effectively prevents the fiber woven fabric from slipping and eliminates the need for adhesive spraying for fixation, but also allows the fiber woven fabric to spread effectively along the outwardly convex structural component due to its own gravity, reducing the frequency of wrinkles in areas with more fiber woven fabric. This results in prefabricated blade roots with fewer defects and better interlayer performance. The stepped surface and staggered laying method in the outwardly convex structural component form a double bonding surface, improving the interfacial adhesion between the prefabricated blade root and the blade. Attached Figure Description

[0057] Figure 1This is a schematic diagram of the overall structure of the device for preparing prefabricated blade roots for wind turbine blades according to the present invention.

[0058] Figure 2 This is a schematic diagram of the externally convex surface structural component and the plate-shaped flange connector in this invention.

[0059] Figure 3 This is a schematic diagram of the external structure of the cover structure in this invention.

[0060] Figure 4 This is a schematic diagram of the internal structure of the cover structure in this invention.

[0061] Figure 5 This is a schematic diagram of the process for preparing prefabricated blade roots for wind turbine blades according to the present invention.

[0062] Figure 6 This is a schematic diagram of the fiber weave fabric laying in this invention.

[0063] Explanation of reference numerals in the attached figures:

[0064] 10. Outwardly convex profile structural component; 11. Outwardly convex profile main body; 12. First platform connecting part; 13. Profile connecting hole; 14. First flange connecting hole; 15. Stepped surface; 16. First sealing strip; 17. Second sealing strip; 20. Plate flange connecting component; 21. Inner row connecting hole; 22. Middle row connecting hole; 23. Outer row connecting hole; 30. Cover structural component; 31. Cover main body; 32. Second platform connecting part; 33. Cover connecting hole; 34. Second flange connecting hole; 35. Stepped surface; 36. Air extraction connecting hole; 37. Resin injection hole; 38. Lifting ring; 40. Fiber woven fabric; 50. Release cloth. Detailed Implementation

[0065] To better understand the present invention, the following embodiments further illustrate the content of the invention, so that the advantages and features of the invention can be more easily understood by those skilled in the art. It should be noted that the following descriptions are merely preferred embodiments of the present invention, but the content of the invention is not limited to the following embodiments. In fact, various modifications and variations can be made to the present invention without departing from the scope or spirit of the invention, which will be apparent to those skilled in the art. For example, features shown or described as part of one embodiment can be used with another embodiment to produce yet another embodiment. Therefore, it is intended that such modifications and variations be included within the scope of the appended claims and their equivalents.

[0066] like Figure 1As shown, the apparatus for preparing prefabricated blade roots for wind turbine blades of the present invention includes a convex surface structure 10, a plate flange connector 20, and a cover structure 30. The plate flange connector 20 and the cover structure 30 are preferably made of alloy steel, and the convex surface structure 10 is preferably made of fiber composite material.

[0067] like Figure 2 As shown, the convex surface structure 10 is an overall structure that extends along the axis and has its outer wall surface formed into an outwardly convex surface, including a convex surface main body 11 that extends along the axis in the length direction and has a semi-cylindrical outer wall surface.

[0068] In the convex surface structural component 10, a first platform connecting portion 12 extending in a strip shape along the length direction is symmetrically provided on the left and right sides of the bottom of the convex surface main body 11 in the width direction. The planar top surface of each first platform connecting portion 12 is formed as a connecting surface. The top surfaces of the first platform connecting portions 12 on both sides are provided with profile connecting holes 13 (preferably threaded holes) adapted to the cover structural component 30 at intervals along the length direction. The two end faces of the convex surface main body 11 in the length direction are both semi-circular, wherein the first end is formed as a flange fixed end and the second end is formed as a free end. A plurality of first flange connecting holes 14 (preferably threaded holes) extending axially are provided at intervals along the circumferential direction on the semi-circular end face of the first end. Each first flange connecting hole 14 is used for mechanical fastening connection between the convex surface structural component 10 and the plate flange connecting component 20.

[0069] The outer wall surface of the convex main body 11 is provided with a plurality of axially extending semi-cylindrical stepped surfaces 15 along its length from the first end to the second end, so that the outer wall surface of the convex main body 11 is generally stepped. The first step surface is close to the first end in the length direction, and the last step surface is close to the second end in the length direction. The first step surface forms the innermost outer wall surface of the convex main body 11 in the radial direction, and the last step surface forms the outermost outer wall surface of the convex main body 11 in the radial direction. The radial depth of each step surface decreases sequentially from the first step surface to the last step surface. The axial extension length of each step surface is adapted to the length dimension of the fiber braided fabric layer designed in the prefabricated blade root, and the radial depth of each step surface is adapted to the thickness dimension of the fiber braided fabric layer designed in the prefabricated blade root. The number of each step surface is consistent with the number of staggered layers of the fiber braided fabric layer designed on the radial inner surface of the prefabricated blade root.

[0070] In addition, the final step surface of the convex main body 11 near the second end in the axial direction and the first step surface near the first end in the axial direction are provided with a first sealing strip 16 extending along its entire circumference. The top surface of each platform connection 12 is provided with a second sealing strip 17 extending along its entire length. The first sealing strip 16 and the second sealing strip 17 are integrated to form a sealing strip enclosure area that is closed in the circumference. This is used to realize that after the convex structural component 10, the plate flange connector 20 and the cover structural component 30 are mechanically connected, a sealed space is formed to prevent gas and resin leakage that may occur during the vacuum injection preparation of precast blade roots.

[0071] Each platform connection 12 has several support pads of selectable thickness spaced apart along its length on its top surface. The thickness of the support pads is set according to the design content of the fiber braid in the prefabricated blade root. The support pads on the top surface of each platform connection 12 are positioned inside the corresponding second sealing strip 17 in the width direction.

[0072] As a preferred example, in the convex surface structure 10, a heating system for curing and heating during the preparation of preformed leaf roots is provided below or inside the convex surface main body 11.

[0073] like Figure 3 , 4 As shown, the cover structure 30 is an overall cover-shaped structure extending along the axis, including a cover main body 31 extending along the axis in the length direction and having a semi-cylindrical inner wall surface. The bottom of the cover main body 31 has a second platform connecting part 32 extending in the length direction and being strip-shaped on the left and right sides in the width direction. The planar bottom surface of each second platform connecting part 32 is formed as a connecting surface, and a plurality of cover connecting holes 33 extending perpendicular to the top surface are distributed at intervals along the length direction on each second platform connecting part 32. Each cover connecting hole 33 corresponds one-to-one with each surface connecting hole 13 in the convex surface structure 10 and is adapted to each other, so as to realize the fast connection between the cover structure 30 and the convex surface structure 10 through the connector.

[0074] One end of the cover structure 30 is formed as a flange fixed end and the other end is formed as a free end. Several connecting bosses are distributed at intervals along the circumferential direction on the outer wall surface of the flange fixed end. Each connecting boss is provided with a second flange connecting hole 34 extending along the axial direction. Each second flange connecting hole 34 is used for mechanical fastening connection between the cover structure 30 and the plate flange connector 20.

[0075] Furthermore, in the housing structure 30, a number of axially extending semi-cylindrical stepped surfaces 35 are sequentially machined on the inner wall surface of the housing body 31 along its length from the flange fixed end to the free end, making the inner wall surface of the housing body 31 generally stepped. The first step surface is adjacent to the flange fixed end in the length direction, and the last step surface is adjacent to the free end in the length direction. The radial depth of each step surface decreases sequentially from the first step surface to the last step surface. The axial extension length of each step surface is adapted to the length dimension of the fiber braided fabric layer designed in the prefabricated blade root, and the radial depth of each step surface is adapted to the thickness dimension of the fiber braided fabric layer designed in the prefabricated blade root. The number of each step surface is consistent with the number of staggered layers of the fiber braided fabric layer designed on the radial outer surface of the prefabricated blade root. Furthermore, the step surfaces provided on the inner wall surface of the main body 31 of the cover are staggered in the axial direction at their axial extension cut-off positions from the step surfaces in the convex surface structure 10, so as to delay the formation of cracks in the staggered area and the formation of a "bridging phenomenon" in the vertical direction.

[0076] At least two connecting holes are provided on the top of the main body 31 of the housing. At least one connecting hole is connected to an external vacuum pumping device via a pipeline to form a vacuum connecting hole 36, and at least one connecting hole is connected to an external injection system via a pipeline to form a resin injection hole 37. The vacuum connecting hole 36 is located near the flange fixed end of the housing structural member 30, and the resin injection hole 37 is located near the free end of the housing structural member 30. Valves for controlling the on / off of the pipelines are provided on the connecting pipelines between the vacuum connecting hole 36 and the external vacuum pumping device, and on the connecting pipelines between the resin injection hole 37 and the external injection system. At least one lifting ring 38 is provided on the top of the main body 31 of the housing to facilitate the installation and disassembly of the housing structural member 30 with the convex surface structural member 10 and the plate flange connector 20.

[0077] like Figure 2 As shown, the plate flange connector 20 is a semi-circular plate structure. Three rows of connecting holes are arranged radially from the inside to the outside on the semi-circular plate surface. Each row of connecting holes is evenly spaced along the semi-circular circumference. The inner row of connecting holes 21 corresponds one-to-one with and is adapted to each of the first flange connecting holes 14 in the convex surface structure 10, used to achieve a tight connection between the convex surface structure 10 and the plate flange connector 20 through the connector. The middle row of connecting holes 22 corresponds one-to-one with and is adapted to each of the blade root bolt sleeves pre-embedded in the precast blade root, used to provide positioning support for the blade root bolt sleeves during the precast blade root preparation process through the connector. The outer row of connecting holes 23 corresponds one-to-one with and is adapted to each of the second flange connecting holes 34 in the cover structure 30, used to achieve a tight connection between the cover structure 30 and the plate flange connector 20 through the connector.

[0078] Furthermore, in the plate flange connector 20, the areas where each of the middle row connection holes 22 is fixed to the bolt sleeve in the precast blade root are sealed with a vacuum membrane to prevent gas and resin leakage that may occur during the vacuum infusion preparation of the precast blade root. There is a radial distance between the middle row connection holes 22 and the outer row connection holes 23. A third sealing strip extending along its entire semicircular direction is provided on the inner wall surface of the flange plate between the radial distances. After the convex profile structure 10, the plate flange connector 20, and the cover structure 30 are mechanically connected, the third sealing strip is located on the inner side of the cover structure 30 in the radial direction to prevent leakage that may occur between the plate flange connector 20 and the cover structure 30. The radial distance between the middle row connection holes 22 and the outer row circular holes 23 should meet the suitability requirements of the blade fiber laying process, the vacuum system laying process, and the subsequent blade mold installation of the precast blade root process. The inner connecting holes 21 are all positioned higher than the top surface of the first platform connecting part 12 in the convex surface structure 10, so that the plate flange connector 20 and the end face of each first platform connecting part 12 are in full contact, so as to form a closed space.

[0079] A release agent is applied to the outer shell of the convex surface structural component 10, the inner side of the plate flange connector 20, and the inner side of the cover structural component 30. The area where the release agent is applied should not exceed the area enclosed by the sealing strip, and should not be less than the area where the release cloth is laid. After the release agent dries, the convex surface structural component 10 and the plate flange connector 20 are fixedly connected through the inner row connection hole 21. The middle row connection hole 22 and the outer row connection hole 23 of the plate flange connector 20 have a certain distance to facilitate the laying of the sealing strip. The distance between the middle row connection hole 22 and the outer row connection hole 23 should also be suitable for the blade mold installation process of prefabricated blade roots, the blade fiber laying process, and the vacuum system laying process. The surface roughness (Ra) of the fixed side of the plate flange connector 20 and the convex surface structural component 10 should not exceed 6.3 to ensure sufficient contact. The circular holes of the plate flange connector 20 are all higher than the male mold platform, and the end face of the plate flange connector 20 is completely fitted with the end face of the platform of the convex surface structure 10, so as to form a closed space.

[0080] The depth of the stepped surface on the outer side of the convex surface structural component 10 decreases sequentially in the horizontal direction from the fixed end with the plate flange connector 20. The horizontal spacing of each step surface in the convex surface structural component 10 is adapted to the design layup length of the precast blade root, the vertical spacing of each step surface is adapted to the design layup thickness of the precast blade root, and the number of each step surface is consistent with the number of staggered layers in the design layup of the precast blade root. The platform of the convex surface structural component 10 should have a sufficient area to place a gasket of a certain thickness in order to control the fiber content of the precast blade root. A release cloth 50 is laid on the outer surface of the convex structural component 10. The release cloth 50 should cover all stepped surfaces of the convex structural component 10 and preferably make full contact with the platform of the convex structural component 10 to facilitate the demolding of the precast blade root. The release cloth 50 should fit tightly against the groove of the convex structural component 10. If applicable, adhesive can be sprayed to make the release cloth fit against the groove of the convex structural component 10 to avoid resin enrichment in the groove area. Sufficient area should be reserved on the side of the convex structural component 10 away from the fixing part of the plate flange connector 20 to facilitate the laying of sealing strips.

[0081] Based on the above-described apparatus for preparing prefabricated blade roots for wind turbine blades, the present invention, when preparing prefabricated blade roots for wind turbine blades, such as... Figure 5 , 6As shown, firstly, a release agent is applied to all surfaces of the convex profile structure 10, the plate flange connector 20, and the housing structure 30 used to form the enclosed space. After the release agent dries, a fastening connection between the convex profile structure 10 and the plate flange connector 20 is achieved through a connector, based on the first flange connection hole 14 in the convex profile structure 10 and the inner connection hole 21 of the plate flange connector 20. Next, a release cloth is laid on the outer wall surface of the convex profile main body 11 of the convex profile structure 10, covering all stepped surfaces. When laying the release cloth, it should be ensured to fully contact and tightly adhere to all outer wall surfaces of the convex profile main body 11 to facilitate the demolding of the prefabricated blade roots in subsequent steps. Then, according to the design requirements of the precast blade root, fiber woven fabric 40 is laid on the outer wall surface of the convex main body 11. The staggered fiber woven fabric 40 should be adapted to the various stepped surfaces 15 in the convex structural component 10. During the laying process, the fiber woven fabric 40 is smoothed to facilitate conforming the fiber woven fabric 40 to the outer surface of the convex structural component 10. No adhesive is required during the laying process; the fiber woven fabric 40 can achieve a good bonding effect by its own weight. After the fiber woven fabric 40 is laid, a release cloth 50, a release film, and a flow guide net are placed on top of the fiber woven fabric 40 in sequence. The release cloth 50 should completely cover the fiber woven fabric 40 and should be tightly bonded to the staggered structure of the fiber woven fabric. If applicable, adhesive can be sprayed to make the release cloth 50 bond to the staggered structure of the fiber woven fabric 40 to avoid the formation of resin-rich areas in the staggered structure region. The flow guide net is symmetrically laid out on both sides from the highest point of the convex surface structure 40. The flow guide net and the release cloth 50 are attached in an arc shape with an angle between 30° and 60°. The release membrane is laid between the release cloth 50 and the flow guide net, and its laying position is adapted to the flow guide net. The size of the release membrane should be slightly larger than the flow guide net to facilitate the demolding of the precast blade roots. The flow guide net can also be replaced by a material with equivalent function, such as a dense mesh net.

[0082] A sealing strip is laid on the side of the convex surface structural component 10 away from the fixed side of the plate flange connector 20 and the platform, and in the area between the middle row connection hole 22 and the outer row connection hole 23 of the plate flange connector 20. When applicable, a support gasket of a certain thickness is placed inside the sealing strip to control the fiber content of the precast blade root. The convex surface structural component 10 and the cover structural component 30 are fixed vertically through the platform threaded hole, and the plate flange connector 20 and the cover structural component 30 are fixedly connected horizontally through the outer row connection hole 23 and the second flange connection hole 34. The inner side of the casing structure 30 is provided with stepped surfaces 35. The depth of each stepped surface 35 decreases sequentially from the flange fixing end along one side. The horizontal spacing of each stepped surface 35 is adapted to the designed layup length of the precast blade root, the vertical spacing of each stepped surface 35 is adapted to the designed layup thickness of the precast blade root, and the number of each stepped surface 35 is consistent with the number of staggered layers in the designed layup of the precast blade root. The cut-off positions of the stepped surfaces 35 of the casing structure 30 are distributed at intervals with the cut-off positions of the stepped surfaces on the outer side of the convex surface structure 10 to delay the formation of a "bridging phenomenon" in the vertical direction due to cracks in the staggered layer area. Other areas, such as the area where the middle row connection hole 21 is fixed to the precast blade root threaded sleeve, are sealed with a vacuum membrane to prevent air leakage. The casing structure 30 can also use a vacuum membrane instead, requiring at least two injection blocks to be placed in the designated area, at least one injection block for air extraction and at least one injection block for resin injection.

[0083] A vacuum pipe is inserted into the top circular hole of the casing structure 30 on the side away from the plate flange connector 20 and connected to a vacuum device for evacuation. After the enclosed space formed by the convex surface structure 10, the plate flange connector 20, and the casing structure 30 reaches a certain vacuum level, a grouting system is connected to the circular hole at the other end for vacuum grouting. After grouting is completed, the grouting system and vacuum device are shut off. A heating system is installed below the convex surface structure 10 for curing; the heating system can also be embedded in the male mold. After the precast blade root has cured, the bolts fixing the inner row connection hole 21 and the outer row connection hole 23 are removed. The bolts fixing the middle row connection hole 22 do not need to be removed. A crane is used to separate the casing structure 30 from the convex surface structure 10 and the plate flange connector 20 by passing through the lifting ring in the middle area of ​​the casing structure 30. The blade negative mold is laid with a certain amount of material according to the design requirements. The release cloth 50 on the upper and lower surfaces of the precast blade root is removed. The precast blade root is flipped over and placed in the corresponding position of the blade negative mold. The outer connecting hole 23 of the plate flange connector 20 is fixedly connected with the bolt hole that matches the blade negative mold. The corresponding material is then laid according to the design requirements.

[0084] It should be noted that, in addition to the prefabricated blade root, the female mold used for the prefabricated trailing edge main beam and shell in the wind turbine blade can also be equivalently replaced with a male mold for vacuum injection preparation.

[0085] The objectives of this invention have been fully and effectively achieved through the above embodiments. All equivalent or simple variations made to the structures, features, and principles described in this patent concept are included within the protection scope of this patent. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this invention or exceed the scope defined in these claims, all of which should fall within the protection scope of this invention.

Claims

1. An apparatus for preparing prefabricated blade roots for wind turbine blades, comprising at least a convex surface structural component, a plate-shaped flange connector, and a cover structural component, wherein the convex surface structural component, the plate-shaped flange connector, and the cover structural component are fastened together by the connector to form a closed space for preparing the prefabricated blade root, characterized in that, The convex surface structure is an integral structure extending along an axis and having its outer wall surface formed into an outwardly convex shape. It includes a convex main body extending along the axis in the length direction and having a semi-cylindrical outer wall surface. The bottom of the convex main body is symmetrically provided with a first platform connecting part that extends along the length direction and is strip-shaped on the left and right sides in the width direction. The planar top surface of each first platform connecting part is formed as a connecting surface, and a plurality of surface connecting holes extending perpendicular to the top surface are distributed at intervals along the length direction on the top surface of each first platform connecting part. Each surface connecting hole is used for mechanically fastening the convex structural component and the cover structural component. Both end faces of the convex profile main body are semi-circular in shape along its length. The first end is formed as a flange fixed end, and the second end is formed as a free end. A plurality of first flange connection holes extending axially are distributed at intervals along the circumferential direction on the semi-circular end face of the first end. Each first flange connection hole is used for mechanically fastening the convex profile structural component and the plate flange connector. The outer wall surface of the convex main body is provided with a plurality of axially extending semi-cylindrical stepped surfaces along its length from the first end to the second end, so that the outer wall surface of the convex main body is generally stepped. The first step surface is close to the first end in the length direction, and the last step surface is close to the second end in the length direction. The first step surface forms the innermost outer wall surface of the convex main body in the radial direction, and the last step surface forms the outermost outer wall surface of the convex main body in the radial direction. The radial depth of each step surface decreases sequentially from the first step surface to the last step surface. The axial extension length of each step surface is adapted to the length dimension of the fiber braided layer designed in the prefabricated blade root, and the radial depth of each step surface is adapted to the thickness dimension of the fiber braided layer designed in the prefabricated blade root. The casing structure is an overall casing-like structure extending along an axis, including a casing main body extending along the axis in the length direction and having a semi-cylindrical inner wall surface, wherein, The bottom of the main body of the casing is symmetrically provided on the left and right sides in the width direction with a second platform connecting part that extends along the length direction and is strip-shaped. The planar bottom surface of each second platform connecting part is formed as a connecting surface, and a plurality of casing connecting holes extending perpendicular to the top surface are distributed at intervals along the length direction on each second platform connecting part. Each casing connecting hole corresponds one-to-one with the connecting holes of each convex surface structure and is mutually adapted to achieve a fast connection between the casing structure and the convex surface structure through a connector. Of the two ends along the length of the casing structure, one end is formed as a flange fixed end, and the other end is formed as a free end. A plurality of connecting bosses are spaced circumferentially on the outer wall surface of the flange fixed end. Each connecting boss has an axially extending second flange connecting hole. Each second flange connecting hole is used for mechanically fastening the casing structure to the plate-shaped flange connector. The inner wall surface of the main body of the casing is sequentially machined with several axially extending semi-cylindrical stepped surfaces along its length from the flange fixed end to the free end, making the overall inner wall surface of the main body of the casing stepped. The first step surface is adjacent to the flange fixed end in the length direction, and the last step surface is adjacent to the free end in the length direction. The radial depth of each step surface decreases sequentially from the first step surface to the last step surface. Furthermore, the axial extension length of each step surface matches the length of the fiber braided fabric layer designed in the prefabricated blade root, and the radial depth of each step surface matches the thickness of the fiber braided fabric layer designed in the prefabricated blade root. The number of each step surface matches the number of staggered layers of the fiber braided fabric layer designed on the radially outer surface of the prefabricated blade root. Moreover, the axial extension termination positions of each step surface on the inner wall surface of the main body of the casing are staggered with the axial extension termination positions of each step surface in the convex profile structure. At least two connecting holes are provided on the top of the main body of the cover. At least one connecting hole is connected to an external vacuum pumping device through a pipe to form a vacuum pumping connecting hole, and at least one connecting hole is connected to an external injection system through a pipe to form a resin injection hole. The plate-shaped flange connector is a semi-circular plate structure with three rows of connecting holes arranged radially from the inside to the outside on its semi-circular plate surface. The connecting holes in each row are evenly spaced along the semi-circular circumferential direction. The inner row of connecting holes corresponds one-to-one with the first flange connecting holes in the convex surface structure and is adapted to each other, used to achieve a fast connection between the convex surface structure and the plate-shaped flange connector through the connector. The middle row of connecting holes corresponds one-to-one with the blade root bolt sleeves embedded in the prefabricated blade root and is adapted to each other, used to achieve positioning and support of the blade root bolt sleeves through the connector during the prefabricated blade root preparation process. The outer row of connecting holes corresponds one-to-one with the second flange connecting holes in the cover structure and is adapted to each other, used to achieve a fast connection between the cover structure and the plate-shaped flange connector through the connector. In the convex surface structure, the number of stepped surfaces provided on the outer wall surface of the convex surface main body is consistent with the number of staggered layers of fiber braided fabric laid on the radial inner surface of the prefabricated leaf root.

2. The apparatus for preparing prefabricated blade roots for wind turbine blades according to claim 1, characterized in that, The plate flange connector and the cover structure are both made of alloy steel, and the convex surface structure is made of fiber composite material.

3. The apparatus for preparing prefabricated blade roots for wind turbine blades according to claim 1, characterized in that, In the convex surface structure, the final step surface of the convex surface main body is provided with a first sealing strip extending along its entire circumference on the wall surface near the second end in the axial direction, and the first step surface is provided with a second sealing strip extending along its entire length on the top surface of each platform connection. The first sealing strip and the second sealing strip are integrated to form a circumferentially closed sealing strip enclosure area, so as to realize that after the convex surface structure, the plate flange connection and the cover structure are mechanically connected, a sealed space is formed to prevent gas and resin leakage that may occur during the vacuum injection preparation of precast leaf roots.

4. The apparatus for preparing prefabricated blade roots for wind turbine blades according to claim 3, characterized in that, In the plate flange connector, the area where each of the middle row connection holes is fixedly connected to the bolt sleeve in the precast blade root is sealed with a vacuum membrane to prevent gas and resin leakage that may occur during the vacuum injection preparation of the precast blade root.

5. The apparatus for preparing prefabricated blade roots for wind turbine blades according to claim 3, characterized in that, In the plate flange connector, there is a radial distance between the middle row of connecting holes and the outer row of connecting holes. A third sealing strip is provided on the inner wall surface of the flange plate between the radial distances, extending along its entire semicircular direction. After the convex surface structure, the plate flange connector, and the cover structure are mechanically connected, the third sealing strip is located on the inner side of the cover structure in the radial direction to prevent possible leakage between the plate flange connector and the cover structure.

6. The apparatus for preparing prefabricated blade roots for wind turbine blades according to claim 5, characterized in that, The first sealing strip, the second sealing strip, and the third sealing strip are all fixedly installed on the corresponding wall surface by adhesive.

7. The apparatus for preparing prefabricated blade roots for wind turbine blades according to claim 5, characterized in that, In the plate-shaped flange connector, the radial distance between the middle row connecting holes and the outer row connecting holes should meet the suitability requirements of the blade fiber laying process, the vacuum system laying process, and the subsequent blade mold installation and prefabrication process.

8. The apparatus for preparing prefabricated blade roots for wind turbine blades according to claim 1, characterized in that, The roughness Ra of the first end face of the convex surface structure and the inner wall surface of the plate flange connector that is fixedly connected to and directly attached to the first end face are both set to no more than 6.3, so that they can make full contact with each other to form a closed space.

9. The apparatus for preparing prefabricated blade roots for wind turbine blades according to claim 8, characterized in that, In the plate-shaped flange connector, the inner row of connecting holes are all positioned higher than the top surface of the first platform connecting part in the convex surface structure, so that the plate-shaped flange connector and the end face of each first platform connecting part are in full contact to form a closed space.

Images