Patent Description:
Wind turbine blade is the core component of wind turbine to convert natural wind energy into electricity. With the intensification of market competition, wind turbine blades begin to develop in the direction of large size and light weight.

In the related technologies known to the inventor, the manufacture of wind turbine blades mostly uses molds for processing. However, with the development of large-scale wind power blades, ordinary molds can no longer meet the manufacturing needs. The inventors began to study the manufacturing technology of modular wind turbine blades. The modular fabrication, on the one hand, can reduce the footprint of the mold and the production difficulty, on the other hand, can also reduce the difficulty of transportation and installation of wind turbine blades.

Compared with the manufacture of one-piece blades, how to ensure the strength of the connection points of modular blade segments has become an urgent problem to be solved.

The information disclosed in this background section is only intended to deepen the understanding of the overall background of the present disclosure, and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art known to those skilled in the art.

<CIT> discloses a method of assembling a wind turbine blade including forming a preform pressure surface member and a preform suction surface member. The method also includes forming at least one of a leading edge and a trailing edge. <CIT> discloses a blade shell part for a wind turbine blade and a wind turbine blade, as well as a method of manufacturing a wind turbine blade. The blade shell part is made of a composite structure comprising a reinforcement material embedded in a polymer matrix, and the blade shell part extending from a tip end to a root end. <CIT> discloses a wind power generation apparatus including a wind turbine blade that has a blade body and a receptor mounted on a tip of the blade body. <CIT> discloses a rotor blade of a wind turbine with a first rotor blade segment and a second rotor blade segment. The rotor blade has a hollow space surrounded by a shell. The first rotor blade segment is connected with the second rotor blade segment by a bolt connection. The bolt connection has a first connection of the first rotor blade segment, a second connection of the second rotor blade segment, and a bolt establishing a bolted joint between the first connection and the second connection. <CIT> discloses an adhesive machine for constructing segmented rotor blades having at least three prefabricated rotor blade parts containing a first accommodating region for receiving a first prefabricated rotor blade part, a second accommodating region for receiving a second prefabricated rotor blade part and a third accommodating region for receiving a third prefabricated rotor blade part. <CIT> discloses a fan blade and aerogenerator. The fan blade comprises a blade tip section and a blade root section. The tip section includes a first link end. The root section includes a second connection end.

In view of at least one of the above technical problems, the present disclosure provides a modular blade connection method and tooling, which improves the connection strength of a first module and a second module by extending a bonding flange into the second module and thickening the connection between the first module and the bonding flange.

The present disclosure is advantageous in that it facilitates the control the bonding quality of the double-sided overlapping of the modular blade by means of the bonding flange extending from the first module toward the inside of the second module, and facilitates the improvement of the fatigue resistance at the assembling position by means of the first reinforcement formed by the increased thickness of the first module and the second reinforcement formed by the overflow of the structural adhesive module, while reducing the influence on the aerodynamic performance of the blade.

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the accompanying drawings to be used in the description of the embodiments or prior art will be briefly described below. It is obvious that the accompanying drawings in the following description are only some of the embodiments recorded in the present disclosure, and other accompanying drawings can be obtained according to these accompanying drawings without creative work for those of ordinary skill in the art.

The technical solutions in the embodiments of the present disclosure will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments.

It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the another element or an intermediate element may also be present. It should be noted that when an element is referred to as being "connected to" another element, it can be directly on the another element or an intermediate element may also be present. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not mean that they are the only mode of implementation.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art of the present disclosure. The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the present disclosure. The term "and/or" as used herein includes any and all combinations of one or more of the related listed items.

<FIG> illustrate a modular blade connection structure (not form a part of the invention), comprising: a first module <NUM>, a second module <NUM> and a structural adhesive module <NUM>.

As shown in <FIG>, the first module <NUM> and the second module <NUM> are provided opposite each other, and the first module <NUM> is provided on an end face thereof with a bonding flange <NUM> extending towards the second module <NUM>, the bonding flange <NUM> extending into the second module <NUM>. In some embodiments of the present disclosure, the bonding flange <NUM> is directly processed and formed at the end of the first module <NUM>, and the instability of the segmented connection can be reduced by integral molding. Referring to <FIG> and <FIG>, in the butting process, it is necessary to abut the first module <NUM> and the second module <NUM> so that the bonding flange <NUM> enters the inside of the second module <NUM>. As shown in <FIG>, when the first module <NUM> and the second module <NUM> are butt joint, there is a gap between the butting surface of the first module <NUM> and the butting surface of the second module <NUM>, and between the bonding flange <NUM> and an inner wall of the second module <NUM>, a structural adhesive module <NUM> is filled in the gap and cured by extrusion. It should be noted that the gap here is to facilitate the description of the structural adhesive module <NUM>, and is not a limitation on the way the structural adhesive module <NUM> is formed. In the embodiment of the present disclosure, the structural adhesive is applied to the butting surfaces and the bonding flange <NUM> before the first module <NUM> is butt joint to the second module <NUM>. Of course, in other embodiments of the present disclosure, it is possible to leave a gap in advance and then inject the structural adhesive into the gap.

As shown in <FIG>, in the embodiment of the present disclosure, the first module <NUM> and the second module <NUM> are flush in outer surface. The thickness of the first module <NUM> at the starting end of the bonding flange <NUM> extends towards the inner surface to form a first reinforcement 10a, and the structural adhesive module <NUM> extends inside the second module <NUM> in a direction away from the bonding flange <NUM> to form a second reinforcement 30a. By providing the first reinforcement 10a, the support strength of the bonding flange <NUM> is improved, and the stress concentration at the flange can be reduced when the first module <NUM> and the second module <NUM> are connected to form the whole. Moreover, in the embodiment of the present disclosure, the provision of the second reinforcement 30a formed by the overflow of structural adhesive can further improve the bonding strength between the bonding flange <NUM> and the second module <NUM> on the one hand, and can reduce the stress concentration at the butt joint as a whole after the structural adhesive is cured when the stress is applied.

In the above disclosure, it facilitates the control the bonding quality of the double-sided overlapping of the modular blade by means of the bonding flange <NUM> extending from the first module <NUM> toward the inside of the second module <NUM>, and facilitates the improvement of the fatigue resistance at the assembling position by means of the first reinforcement 10a formed by the increased thickness of the first module <NUM> and the second reinforcement 30a formed by the overflow of the structural adhesive module <NUM>, while reducing the influence on the aerodynamic performance of the blade.

In some embodiments of the present disclosure, reference is made to <FIG>, the first reinforcement 10a gradually increases in thickness from a direction away from the bonding flange <NUM> to a direction towards the bonding flange <NUM>. In this way, the thickness of the first module <NUM> at the position near the bottom of the bonding flange <NUM> is maximized, which can not only ensure the structural strength of the bonding flange <NUM>, but also reduce the blade manufacturing cost and improve its economic practicality. Continuing with reference to <FIG>, in the embodiment of the present disclosure, the second reinforcement 30a gradually decreases in thickness in a direction away from the bonding flange <NUM>. In this way, a form of symmetry with the first reinforcement 10a is basically achieved, which on the one hand can improve the force balance at the joint, and on the other hand, it is also convenient to secure the subsequent processing process to further improve the connection strength of the first module <NUM> and the second module <NUM>.

In the embodiment of the present disclosure, in order to facilitate processing, both the first reinforcement 10a and the second reinforcement 30a are inclined in a straight line, as shown in <FIG>, and the inclination ratio of the two in the thickness direction and the butt joint length direction ranges from <NUM>:<NUM> to <NUM>:<NUM>. Such structural configuration can not only ensure the connection strength, but also can reduce the manufacturing cost and the manufacturing difficulty to meet the high-quality and low-cost requirements of segmental manufacturing of wind turbine blades.

As shown in <FIG>, in the embodiment of the present disclosure, the first reinforcement 10a, the bottom of the bonding flange <NUM> within the second module <NUM>, and the second reinforcement 30a are further covered with a composite reinforcement layer. The bottom here refers to the inner wall after the first module <NUM> and the second module <NUM> are connected. In the embodiment of the present disclosure, the specific material of the composite reinforcement layer is carbon fiber cloth or glass fiber cloth. The composite reinforcement layer further improves the overall support performance and tensile properties of the butting surfaces as a whole.

In the embodiment of the present disclosure, there is also provided a modular blade connection method applied to the modular blade connection structure described above, comprising the steps described in details below.

At step S10, a first module <NUM> and a second module <NUM> are prepared. Here, the first module <NUM> and the second module <NUM> are separately prepared in a mould. In some embodiments of the present disclosure, the first module <NUM> and the second module <NUM> are manufactured by segment splicing. In this way, each segment can be transported to the site for installation after the preparation is completed, so as to improve the convenience in the preparation process of the wind turbine blades.

At step S20, a structural adhesive is applied to the butting surfaces of the first module <NUM> and the second module <NUM>. In the embodiment of the present disclosure, the butting surface is the surface corresponding to the gap as shown in <FIG>, specifically the side and outer surface of the flange and the end surface of the second module <NUM> towards the first module <NUM> and the inner surface of the second module <NUM>.

At step S30, the first module <NUM> and the second module <NUM> are butt to a set position, and a set pressure is applied along the adjoining direction of the first module <NUM> and the second module <NUM>. Here, the sequence of the butting and force application is not limited, because generally the structural adhesive is extruded during the butting process, and a certain deformation will occur. The general sequence is to butt the modules first, and then extrude according to the set pressure until the first module <NUM> and the second module <NUM> reach the set position.

At step S40, when the pressure along the adjoining direction reaches a stop holding pressure, a set pressure is applied on both sides in the thickness direction to cause the structural adhesive at the end of the bonding flange <NUM> to overflow until the curing is completed. Since the structural adhesive has some fluidity before curing, it will overflow from the butting surface when extruding the first module <NUM> and the second module <NUM>. When the structural adhesive overflows, it means that the interior has been filled with structural adhesive, and thus the amount of structural adhesive can be determined to meet the demand. If no structural adhesive overflow is found, it means that the amount of adhesive applied is not enough and needs to be replenished.

The first module <NUM> is thickened near the bonding flange <NUM> to form a first reinforcement 10a when preparing the first module <NUM>.

When the pressure is applied in the thickness direction so that the structural adhesive at the end of the bonding flange <NUM> overflows, the overflowing structural adhesive is scraped in the direction away from the flange to form a second reinforcement 30a. Here, the structure has been described in detail above, and the structure as well as its effect can be understood with reference to the above description.

In the embodiment of the present disclosure, when the first module <NUM> is prepared, the first reinforcement 10a is configured to gradually increase in thickness in a direction towards the bonding flange when preparing the first module, and the second reinforcement 30a is configured to decrease in thickness in a direction away from the bonding flange <NUM> when the second reinforcement 30a is formed by scraping. This is also described in detail above, and its function and effect will not be described in detail here. However, it should be noted that after the structural adhesive overflows, it is scraped before it is cured to form a structure with gradually decreasing thickness.

As shown in <FIG>, if the structural adhesive overflows from the outside of the butting surfaces of the first module <NUM> and the second module <NUM> after curing by applying pressure in the thickness direction, the overflow structural adhesive is polished to eliminate defects. Since the overflow portion has cured, it affects the flatness of the outer surface between the first module <NUM> and the second module <NUM>. In order to improve the overall appearance of flatness as well as to provide a good basis for subsequent processing, in the embodiment of the present disclosure, the overflow portion needs to be polished and trimmed. With continued reference to <FIG>, in the embodiment of the present disclosure, after curing is complete and defects are eliminated, the inside of the butting surface of the first module <NUM> is covered with a composite reinforcement layer. Of course, if no defects are created, the composite reinforcement layer can be applied directly. Here, the application does not only refer to the application onto the inside of the butting surface, but also the application onto the outside of the butting surface.

In the embodiment of the present disclosure, there is also provided a modular blade connection tooling applied to the modular blade connection structure described above.

As shown in <FIG> and <FIG>, the tooling comprises an internal pressing mechanism provided at both ends thereof with an extrusion block in contact with part of the first reinforcement 10a and part of the inner wall of the bonding flange <NUM>. The extrusion block follows the inner wall of the first module and the second module, and the internal pressing mechanism is configured to apply pressure in opposite directions. It should be noted here that this part of tooling is used only when pressure is applied in the thickness direction. The pressure application in the adjoining direction is carried out by means of a prior art pressure application structure, such as a hydraulic cylinder, pneumatic cylinder, or other existing pressure application mechanism.

Claim 1:
A modular blade connection method applied to a modular blade connection structure comprising a first module (<NUM>), a second module (<NUM>) and a structural adhesive module (<NUM>); wherein the first module (<NUM>) and the second module (<NUM>) are provided opposite each other, and the first module (<NUM>) is provided on an end face thereof with a bonding flange (<NUM>) extending towards the second module (<NUM>), the bonding flange (<NUM>) extending into the second module (<NUM>); wherein the modular blade connection method comprises the following steps:
preparing the first module (<NUM>) and the second module (<NUM>);
applying a structural adhesive to the butting surface of the first module (<NUM>) and the butting surface of the second module (<NUM>), wherein the butting surface being the surface corresponding to the gap defined by the side and outer surface of the flange and the end surface of the second module (<NUM>) towards the first module (<NUM>) and the inner surface of the second module (<NUM>);
butting the first module (<NUM>) and the second module (<NUM>) to a set position, and applying a set pressure along the adjoining direction of the first module (<NUM>) and the second module (<NUM>);
when the pressure along the adjoining direction reaches a stop holding pressure, applying a set pressure on both sides in the thickness direction to cause the structural adhesive at the end of the bonding flange (<NUM>) to overflow until the curing is completed;
wherein the first module (<NUM>) is thickened near the bonding flange (<NUM>) to form a first reinforcement (10a) when preparing the first module (<NUM>); and
wherein when the pressure is applied in the thickness direction so that the structural adhesive at the end of the bonding flange (<NUM>) overflows, the overflowing structural adhesive is scraped in the direction away from the flange to form a second reinforcement (30a).