A segmented composite wind turbine blade connected in a hybrid connection manner

Abstract

The present invention relates to a wind turbine blade structure design technology, and aims to provide a segmented composite material wind turbine blade that is connected in a hybrid connection manner. In adjacent blade segments, the relative connection end faces are connected through a plurality of groups of monomer connection configurations with the same structure: a bolt sleeve is embedded in the main body of the skin on one side, and the stud bolt is fastened and installed in the bolt sleeve with one end thereof; a mounting groove is provided on the surface of the main body of the skin on the other side, and a through hole is provided between the mounting groove and the connection end face on this side, and a smooth sleeve is embedded in the through hole; the other end of the stud bolt is exposed in the mounting groove after passing through the smooth sleeve; there is an adhesive layer between the two connection end faces, and the end of the stud bolt exposed in the installation groove is locked by a nut, so that the two connection end faces are tightly fitted with the adhesive layer. The bolts connected by the embedded metal sleeve of the present invention have a lower load coefficient, and the adjacent blade segments are connected by the adhesive layer, which can reduce the number of mechanical structures used, and has the most significant commercial value.

Description

Technical Field

[0001] The invention relates to the field of wind turbine blade structure design, and in particular to a segmented composite material wind turbine blade connected in a hybrid connection manner. Background Art

[0002] At present, the structure of large wind turbine blades is in the form of skin main beam. The skin is mainly reinforced by biaxial composite material layer, which provides aerodynamic shape and bears most of the shear load. The trailing edge cavity is wide and adopts sandwich structure to improve its anti-instability ability. The main beam is mainly reinforced by unidirectional composite material layer and is the main load-bearing structure of the blade. The web is a sandwich structure, which supports the main beam.

[0003] At present, the diameter and output power of wind turbine blades at home and abroad are constantly increasing. The blade length can reach 108m, and the rated power has exceeded 9.5MW. The blades are constantly developing in the direction of large-scale, lightweight and low-cost. The larger the size of the wind turbine, the lower the unit energy cost of wind power generation, which is also the main reason for the continuous increase in the size of wind turbines. However, the increase in blade size will bring huge challenges to service safety, transportation, installation and manufacturing processes. Segmented connection and modular design are important solutions to solve the difficulties in manufacturing and transportation of large blades.

[0004] At present, there are three main ways to connect segmented blades, namely adhesive connection, mechanical connection and hybrid connection. Mechanical connection is easy to install and test, safe and reliable, but it is heavy, costly and easy to cause stress concentration, and its commercial value is not outstanding. Adhesive connection increases weight less, is suitable for connecting special-shaped, heterogeneous, thin-walled and complex parts, and can obtain a smooth aerodynamic shape, but the strength of the adhesive bonding interface is weak, and the fracture failure mechanism is complex. Since the adhesive structure is prone to debonding failure, the defects of the segmented connection structure based on strength and damage tolerance at home and abroad are: the design method is immature, the strength complementarity of fastener connection and adhesive connection is insufficient, the design service life (generally 20 years) cannot be guaranteed, and the coordination between weight and strength is not strong. Even the more mature GE segmented design connection structure has experienced multiple fracture accidents. Therefore, it is necessary to propose a new hybrid connection technology. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a segmented composite material wind turbine blade that is connected in a hybrid connection manner.

[0006] To solve the technical problem, the solution of the present invention is:

[0007] Provided is a segmented composite material wind turbine blade connected in a hybrid connection manner, comprising at least two blade segments, wherein adjacent blade segments are connected via opposite connection end faces; the opposite connection end faces are connected via a plurality of groups of monomer connection configurations having the same structure, wherein the specific structure of the monomer connection configuration is as follows:

[0008] A bolt sleeve is buried in the skin main body of the connecting end face on one side, and a stud bolt is fastened and installed in the bolt sleeve with one end thereof; a mounting groove is provided on the surface of the skin main body of the connecting end face on the other side, and a through hole is provided between the mounting groove and the connecting end face on this side, in which a smooth sleeve is buried; the other end of the stud bolt is exposed in the mounting groove after passing through the smooth sleeve; an adhesive layer is provided between the two connecting end faces, and the end of the stud bolt exposed in the mounting groove is locked by a nut, so that the two connecting end faces are tightly fitted with the adhesive layer.

[0009] As a preferred solution of the present invention, the plurality of groups of monomer connection configurations are arranged in parallel along the circumferential direction at the connection end surfaces of adjacent blade segments, and adjacent monomer connection configurations are arranged in reverse directions.

[0010] As a preferred solution of the present invention, the adjacent blade segments are connected with an inclined surface, and the angle between the relative connecting end surface and the blade axis is in the range of 10-45°.

[0011] As a preferred solution of the present invention, both ends of the stud bolt are processed with external threads, and the bolt sleeve is a hollow cylindrical metal sleeve with internal threads; the smooth sleeve is a hollow cylindrical metal sleeve without internal threads, and its inner diameter is larger than the outer diameter of the stud bolt.

[0012] As a preferred solution of the present invention, the optical sleeve is pre-embedded in the through hole, one end of which is flush with the side wall of the installation groove, and the other end is butted against the end of the bolt sleeve.

[0013] As a preferred solution of the present invention, outer surfaces of the skin bodies of adjacent blade segments have a consistent aerodynamic shape at the connecting end surfaces.

[0014] As a preferred solution of the present invention, the length of the stud bolt is 800-1000 mm, and the diameter is 40-64 mm; the embedded depth of the bolt sleeve is 25-50 mm, and the length of the smooth sleeve is 400-500 mm.

[0015] As a preferred embodiment of the present invention, the effective component of the adhesive layer is any one of the following: epoxy resin, ethyl formate, cyclopentadiene, methyl methacrylate, vinyl ester, polyester.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention can realize segmented manufacturing, segmented transportation and on-site assembly of wind turbine blades, greatly reducing transportation and manufacturing costs;

[0018] 2. The present invention provides a mounting groove in the blade connection area, which does not damage the blade shape and can ensure that adjacent blade segments have continuous and good aerodynamic characteristics;

[0019] 3. The present invention adopts a method of alternately arranging bolt sleeves and smooth sleeves along the circumference of the airfoil profile, which can alleviate the adverse effect of the installation groove on the structural strength of the composite blade;

[0020] 4. The present invention adopts the form of embedded metal sleeves. The bolts of this connection form have a lower load coefficient, which is beneficial to the connection strength and reliability of the bolts.

[0021] 5. The present invention connects adjacent blade segments through an adhesive layer, which can reduce the number of mechanical structures used and reduce the weight of the segmented blades.

[0022] 6. The present invention adopts a hybrid connection method, which can combine the advantages of the two connection methods, reduce the weight of the segmented blades while ensuring the connection strength, and has the most significant commercial value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the overall schematic diagram of the blade;

[0024] Figure 2 It is a schematic diagram of the segmented blade connection configuration;

[0025] Figure 3 A partial cross-sectional view of the segmented blade connection configuration.

[0026] In the figure: 1 wind turbine blade; 2 blade segment close to the blade root; 3 blade segment close to the blade tip; 4 skin body; 5 stud bolt; 6 bolt sleeve; 7 smooth sleeve; 8 mounting groove; 9 nut; 10 adhesive layer. DETAILED DESCRIPTION

[0027] The present invention will be described in detail below through specific implementation schemes in conjunction with the accompanying drawings.

[0028] like Figure 1-3As shown, the wind turbine blade 1 provided by the present invention comprises a blade segment 2 near the blade root and a blade segment 3 near the blade tip, and the opposite connecting end faces of the two are connected by a plurality of groups of monomer connecting configurations with the same structure. The specific structure of the monomer connecting configuration is as follows: a bolt sleeve 6 is buried in the skin body 4 of the connecting end face on one side, and a stud bolt 5 is fastened and installed in the bolt sleeve 6 with one end thereof. A mounting groove 8 is provided on the surface of the skin body of the connecting end face on the other side, and a through hole is provided between the mounting groove 8 and the connecting end face on this side, and a smooth sleeve 7 is buried in the through hole; the other end of the stud bolt 5 is exposed in the mounting groove 8 after passing through the smooth sleeve 7; there is an adhesive layer 10 between the two connecting end faces, and the end of the stud bolt 5 exposed in the mounting groove 8 is locked by a nut 9, so that the two connecting end faces are closely fitted with the adhesive layer 10, thereby realizing a close connection between the two blade segments.

[0029] like Figure 2 As shown, several groups of monomer connection configurations are arranged in parallel along the circumferential direction at the connection end faces of adjacent blade segments, and the adjacent monomer connection configurations are arranged in reverse. That is, at the connection end face of a certain blade segment, the bolt sleeve 6 and the smooth sleeve 7 are arranged alternately, which can alleviate the adverse effect of the installation groove on the structural strength of the composite blade.

[0030] like Figure 1 As shown, after the complete wind turbine blade 1 is manufactured as a whole, it is cut obliquely along the line aa in the span direction, or modular manufacturing is adopted with the same design scheme, and each blade segment is manufactured separately in the blade mold. The adjacent blade segments are connected with an oblique surface to increase the docking area and the number of installations of the monomer connection configuration, thereby improving the connection strength. The angle between the relative connection end surface and the blade axis is in the range of 10-45°.

[0031] The stud bolt 5 has external threads at both ends, and the bolt sleeve 6 is a hollow cylindrical metal sleeve with internal threads; the smooth sleeve 7 is a hollow cylindrical metal sleeve without internal threads, and its inner diameter is larger than the outer diameter of the stud bolt 5. The smooth sleeve 7 is embedded in the through hole, one end of which is flush with the side wall of the installation groove 8 and the other end is connected to the end of the bolt sleeve 6 to enhance the stability of the installation. As an optional example, the length of the stud bolt is 800-1000mm and the diameter is 40-64mm; the embedded depth of the bolt sleeve is 25-50mm, and the length of the smooth sleeve is 400-500mm.

[0032] The adhesive layer 10 is provided on the connecting end surface between the blade segments, which can relatively reduce the use of the metal material mechanical connection structure and reduce the overall weight of the blade. As an example, the effective component of the adhesive layer can be any one of the following: epoxy resin, ethyl formate (including polyurethane), cyclopentadiene (including dicyclopentadiene), methyl methacrylate, vinyl ester, polyester.

[0033] Since the monomer connection configuration and adhesive layer adopted by the present invention are located between adjacent blade segments after installation, the outer shape of the skin body is not damaged. After being connected into a blade as a whole, the blade surface has a consistent aerodynamic shape even at the end surface where the connection is completed.

[0034] Installation instructions for the example:

[0035] The bolt sleeve 6 and the smooth sleeve 7 are pre-buried at the two connection end faces before the product leaves the factory, so only bolt installation and glue application operations need to be performed at the equipment installation site.

[0036] First, place the blade segments 2 and 3 along the blade axis, and fasten one end of the stud bolt 5 in the bolt sleeve 6. Apply glue on the connecting end faces of the blade segments 2 and 3, and dock them after a period of rest, and pass each stud bolt 5 through the smooth sleeve 7. Then install and fasten the nut 9 in the installation groove 8 to complete the blade installation procedure.

[0037] Finally, it should be noted that the above examples are only specific examples of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A segmented composite wind turbine blade connected in a hybrid connection manner, comprising at least two blade segments, wherein adjacent blade segments are connected via opposite connection end faces; characterized in that: The relative connection end faces are connected by a plurality of groups of monomer connection configurations with the same structure, and the specific structure of the monomer connection configuration is as follows: A bolt sleeve is embedded in the skin body of the connecting end face on one side, and a stud bolt is fastened and installed in the bolt sleeve with one end thereof; a mounting groove is provided on the surface of the skin body of the connecting end face on the other side, and a through hole is provided between the mounting groove and the connecting end face on this side, and a smooth sleeve is embedded in the through hole; the other end of the stud bolt is exposed in the mounting groove after passing through the smooth sleeve; an adhesive layer is provided between the two connecting end faces, and the end of the stud bolt exposed in the mounting groove is locked by a nut, so that the two connecting end faces are closely fitted with the adhesive layer; The plurality of groups of monomer connection configurations are arranged in parallel along the circumferential direction at the connection end surfaces of adjacent blade segments, and the adjacent monomer connection configurations are arranged in reverse directions; The adjacent blade segments are connected with an inclined surface, and the angle between the relative connecting end surface and the blade axis is in the range of 10-45°; The stud bolt has external threads at both ends, and the bolt sleeve is a hollow cylindrical metal sleeve with internal threads; the smooth sleeve is a hollow cylindrical metal sleeve without internal threads, and its inner diameter is larger than the outer diameter of the stud bolt; The optical sleeve is pre-embedded in the through hole, one end of which is flush with the side wall of the installation groove, and the other end is butted against the end of the bolt sleeve; The outer surfaces of the skin bodies of the adjacent blade segments have a consistent aerodynamic shape at the connecting end surfaces.

2. The segmented composite wind turbine blade according to claim 1, characterized in that: The length of the stud bolt is 800-1000mm, and the diameter is 40-64mm; the embedded depth of the bolt sleeve is 25-50mm, and the length of the smooth sleeve is 400-500mm.

3. The segmented composite wind turbine blade according to claim 1, characterized in that: The effective component of the adhesive layer is any one of the following: epoxy resin, ethyl formate, cyclopentadiene, methyl methacrylate, vinyl ester, polyester.

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