Paving method for preventing wind turbine blade trailing edge corner cloth layer from hanging in the air and wind turbine blade

Abstract

The present invention relates to a method for preventing the fabric layer at the trailing edge corner of a wind turbine blade from hanging in the air, and a blade formed using the method. The method comprises the following steps: 1) providing a filling layer at the trailing edge corner of an empty mold, wherein the filling layer is in the form of a circular arc groove extending along the length of the blade, and the outer circumferential surface of the circular arc groove is in close contact with the mold corner. At the edge of the filling layer, the inner and outer circular surfaces of the filling layer are smoothly connected along the inner circumferential direction of the circular arc groove via a chamfered inclined surface; 2) starting to lay the fabric layer layer by layer in the mold provided with the filling layer, and compacting the fabric layer at the mold corner during each layer laying; 3) laying auxiliary materials for pouring in the mold, and then placing a corner-conforming rubber strip tooling at the mold corner; 4) laying a vacuum bag film to establish a vacuum system, and performing pressure-maintaining pouring, so that the corner-conforming rubber strip tooling can continuously compact the mold corner during pouring. The present invention can eliminate hanging, cavities, resin-rich and bubbles during the molding of the trailing edge corner.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine blade production and manufacturing, and in particular to a method for preventing a cloth layer at a corner of a trailing edge of a wind turbine blade from being suspended in the air, and a wind turbine blade manufactured thereby. Background Art

[0002] With the development of the times, the government and enterprises are increasingly focusing on renewable energy research. Wind power generation is one of the main directions of new energy development. Wind turbine blades are essential components for wind turbine power generation. The quality and reliability of blades directly affect the stability and lifespan of wind turbine operation. Wind turbine blades consist of a windward side (PS side) and a leeward side (SS side). Due to the special shape of the trailing edge corner of the blade, the fiberglass cloth layer does not easily fit the mold during production, which easily forms cavities. After infusion, resin-rich or air bubbles form on the blade exterior or within the cloth layer, affecting blade quality and reliability. Defects are difficult to identify. Repairs not only cause quality loss but also affect blade production schedule. Summary of the Invention

[0003] In order to solve the resin-rich and bubble defects at the trailing edge corner of a wind turbine blade caused by the hanging of the cloth layer at the trailing edge corner, the present invention proposes a laying method for preventing the cloth layer at the trailing edge corner of a wind turbine blade from hanging.

[0004] The purpose of the present invention and the solution to the technical problem are achieved by adopting the following technical solutions. According to the present invention, a method for laying cloth layers at the corner of the trailing edge of a wind turbine blade to prevent them from hanging in the air comprises the following steps: 1) providing a filling layer at the corner of the trailing edge of an empty mold, wherein the filling layer is in the form of an arc groove extending along the length of the blade, and the outer circumferential surface of the arc groove is closely attached to the mold corner. At the edge of the filling layer, the inner and outer circumferential surfaces of the filling layer are smoothly connected by a chamfered inclined surface along the inner circumferential direction of the arc groove; 2) laying the cloth layers layer by layer in the mold provided with the filling layer to complete the laying of the cloth layers, and compacting the cloth layers at the mold corner during each laying process; 3) laying auxiliary materials for pouring in the mold provided with the completed cloth layers, and then placing a corner-conforming rubber strip tooling at the mold corner, wherein the corner-conforming rubber strip tooling has a shape that fits the mold corner; and 4) laying a vacuum bag film to establish a vacuum system, and performing pressure-maintained pouring, so that the corner-conforming rubber strip tooling can continuously compact the mold corner under the action of the vacuum pressure during pouring.

[0005] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0006] In the aforementioned laying method for preventing the cloth layer from hanging in the corner of the trailing edge of the wind turbine blade, in step 4), the pressure is maintained during pouring by bonding the vacuum film bag to the mold flange through a sealing strip.

[0007] The aforementioned laying method for preventing the cloth layer from hanging in the air at the corner of the trailing edge of the wind turbine blade is characterized in that the filling layer has a thickness of 1.8-3.6 mm, and the length of the outer circular surface of the filling layer is 200-300 mm, and in the circumferential direction of the filling layer, there is a staggered layer of 25-50 mm between the two ends of the inner circular surface and the outer circular surface; in the extension direction of the filling layer, there is a staggered layer of 250-500 mm between the two ends of the inner circular surface and the outer circular surface.

[0008] The aforementioned laying method for preventing the cloth layer at the corner of the trailing edge of the wind turbine blade from hanging in the air, the filling layer is composed of 3-6 layers of narrow glass fiber cloth, and adjacent layers of narrow glass fiber cloth have a staggered layer of 5-10mm in the circumferential direction of the filling layer and a staggered layer of 50-100mm in the extension direction of the filling layer.

[0009] In the aforementioned laying method for preventing the cloth layer from hanging in the air at the corner of the trailing edge of the wind turbine blade, adjacent layers of narrow strips of glass fiber cloth are fixed by spraying glue.

[0010] In the aforementioned laying method for preventing the cloth layer from hanging in the air at the corner of the trailing edge of the wind turbine blade, the filling layer can be demoulded integrally with the mold and reused.

[0011] Compared with the prior art, the present invention has obvious advantages and beneficial effects. By means of the above technical solution, the present invention can achieve considerable technological advancement and practicality, and has wide industrial application value. It has at least the following advantages:

[0012] The present invention adds a filling layer at the mold corner of an empty mold, so that a transition structure approximately having a large radius is formed at the mold corner, eliminating the space between the cloth layer and the mold corner when the cloth layer is laid, and preventing the cloth layer from being suspended in the air at the mold corner; the present invention also uses special tooling to roll the cloth layer laid at the mold corner, further eliminating the gap between adjacent cloth layers at the mold corner and between the cloth layer and the mold and the filling layer. Finally, the present invention also provides a corner-shaped rubber strip tooling at the laid mold corner, so that the tooling can press the mold corner under the action of vacuum during vacuum infusion, thereby completing a trailing edge corner structure with no suspended cloth layer, no cavity, and no resin-rich corner and no bubbles through layer-by-layer design. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the composition of the wind turbine blade of the present invention;

[0014] Figure 2 for Figure 1 A magnified view of the mid-trailing edge corner;

[0015] Figure 3 This is a schematic diagram of the blade trailing edge corner mold of the present invention;

[0016] Figure 4 Schematic diagram of the trailing edge corner paving and compacting mold of the present invention;

[0017] Figure 5 This is a schematic diagram of the paving and compaction of the trailing edge corner of the present invention;

[0018] Figure 6 This is a schematic diagram of the state in which vacuum perfusion is to be performed on the trailing edge corner of the present invention;

[0019] Figure 7 Schematic diagram of a blade trailing edge corner mold according to another embodiment of the present invention.

[0020]

Main component symbol description

[0021] 1. Windward side of blade, 2. Leeward side of blade, 3. Trailing edge corner, 31. Mold, 32. Filling layer, 4. Handle, 5. Pressing part, 6. Auxiliary materials, 7. Corner profile rubber strip tooling, 8. Vacuum bag film, 9. Mold flange, 10. Sealing strip, 11. Glue injection pipeline, 12. Chamfered surface. DETAILED DESCRIPTION

[0022] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation method, structure, characteristics and effects of the laying method for preventing the cloth layer at the trailing edge corner of a wind turbine blade from being suspended in the air proposed by the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0023] See also Figure 1 , which is a schematic diagram of the composition of a wind turbine blade. The wind turbine blade is mainly composed of a blade windward surface 1 and a blade leeward surface 2 bonded together using an adhesive. At the trailing edge of the blade, the connection between the blade leeward surface 2 and the blade windward surface 1 forms a trailing edge corner 3 with a cross-section that is almost at a right angle. When the blade leeward surface 2 is formed through a mold, the position on the mold 31 used to form the trailing edge corner 3 also has a corresponding mold corner. As a result, after the glass fiber cloth layer is laid on the mold 31, it is difficult to fit the mold corner because the glass fiber itself is prone to loosening and twisting. As a result, there is a gap between the glass fiber cloth layer and the mold 31 at the mold corner, which affects the molding quality and causes quality defects.

[0024] See also Figure 3-6 Before laying all the glass fiber cloth, the present invention first lays several layers of glass fiber cloth in staggered layers at the mold corner of the empty mold 31, so that a filling layer 32 is formed in the mold corner. The filling layer 32 has an arc groove structure that extends along the length of the blade. The multiple layers of glass fiber cloth are staggered in the length and width of the blade to form chamfered surfaces. The chamfered surfaces achieve a smooth transition between the arc inner surface of the filling layer 32 and the mold 31, forming a structure similar to a large-diameter fillet at the mold corner. This allows the subsequently laid glass fiber cloth to fit tightly against the mold and the filling layer 32, preventing it from being suspended. The arc outer peripheral surface of the filling layer 32 fits tightly within the mold corner.

[0025] In this embodiment, the filling layer 32 has a thickness of 1.8-3.6 mm, and the circumference L of the outer circular surface of the filling layer 32 is 200-300 mm. In the circumferential direction of the filling layer 32 (blade width direction), there is a 25-50 mm staggered layer between the two ends of the inner circular surface of the filling layer and the outer circular surface, and the first chamfered slope 12 is formed at the staggered layer; in the extension direction of the filling layer 32 (blade length direction), there is a 250-500 mm staggered layer between the two ends of the inner circular surface of the filling layer 32 and the outer circular surface, and the second chamfered slope is formed at the staggered layer.

[0026] In this embodiment, the filling layer is composed of 3-6 layers of narrow glass fiber cloth, and the narrow glass fiber cloth is preferably biaxial glass fiber cloth, and adjacent layers of narrow glass fiber cloth form a 50-100 mm staggered layer in the length direction of the wind turbine blade, and there is a 5-10 mm staggered layer in the width square of the wind turbine blade. The staggered layer arrangement can ensure a uniform transition between the inner arc surface of the filling layer 32 and the mold, so that subsequent cloth layers can fit closely to the mold and the filling layer, and can also avoid the formation of step accumulation of cloth layers to cause stress concentration.

[0027] In the embodiment of the present invention, the first layer of narrow strips of glass fiber cloth is fixedly bonded to the corners of the mold using spray glue, and adjacent layers of narrow strips of glass fiber cloth are fixedly bonded using spray glue to prevent movement.

[0028] The filling layer 32 composed of narrow strips of fiberglass cloth in the embodiment of the present invention can not only eliminate the overhang between the trailing edge corner and the mold when the shell is laid, but also can be integrally formed with the shell laying layer during infusion molding, thereby achieving structural reinforcement of the trailing edge corner of the blade.

[0029] In another embodiment of the present invention, the filling layer 32 is made of other materials. It cannot absorb the epoxy resin poured during molding, nor is it integrally molded with the shell fabric layer. It is only used as a structure to fill the suspended space. The filling layer 32 is also reusable. The filling layer 32 can be integrally molded with the mold to form an improved mold that can eliminate the suspended space. It can also be glued and fixed to the corner of the mold to supplement the defects of the existing mold. Figure 7 .

[0030] The setting of the filling layer 32 of the present invention forms a transition structure similar to a large-diameter rounded corner at the corner of the mold, so that when the cloth is laid, the fiberglass cloth can better fit the mold and the filling layer, reducing the space generated by hanging at the corner of the mold. In order to further prevent the generation of hanging at the corner of the mold, the present invention also compacts the cloth at the corner of the mold through a compacting tool. The compacting tool includes a handle 4 for applying force and a clamping part 5 connected to the end of the handle 4. The clamping part 5 has a shape that can fit with the corner of the mold. Specifically, the clamping part 5 is a structure that is small at the bottom and large at the top, and the side surfaces connecting the upper and lower end faces of the clamping part 5 are all inclined surfaces, thereby making the clamping part 5 "boat-shaped", and the upper end face of the clamping part 5 is connected and fixed to the handle 4, and the lower end face and the inclined side wall can fit with the corner of the mold. The material used to prepare the handle 4 has a certain strength. Preferably, the handle 4 is a steel pipe, and the clamping part 5 is also made of steel.

[0031] After completing the arrangement of the filling layer 32 at the corner of the mold, the present invention begins to lay the shell. When laying each layer of fiberglass cloth, the above-mentioned compacting tool is used to press the fiberglass cloth at the rear edge corner so that the fiberglass cloth at this location is close to the mold and the filling layer 32 to prevent it from being suspended.

[0032] When pressing the fiberglass cloth at the corner of the mold, the operator holds the handle 4 and uses the pressing part 5 at the front end to roll the cloth layer along the corner of the mold, so that the different layers of fiberglass cloth laid on the mold 31 are tightly fitted at the corner of the mold, achieving non-overhanging laying.

[0033] In an embodiment of the present invention, an angle α is formed between the handle 4 of the compacting tool and the upper end surface of the pressing part 5. Preferably, the angle α is 70-80 degrees, which makes it easier for the compacting tool to apply force when rolling the cloth layer. Specifically, the two inclined surfaces connecting the upper end surface and the wide side of the bottom surface of the compacting part 5 can fit with the chamfers at both ends of the width direction of the filling layer 32, and the bottom of the compacting part 5 can enter the inner arc surface of the filling layer 32, so that when the compacting tool is used to roll the cloth at the corner, the compacting part can fit the fiberglass cloth with the inner arc surface of the filling layer 32, the chamfered surface and the chamfer of the mold, without any hanging.

[0034] After the fiberglass cloth layer is laid and the corners are compacted, the present invention sequentially lays auxiliary materials 6 on the laid fiberglass cloth layer, places corner-shaped rubber strip tooling 7, establishes vacuum, and maintains pressure for infusion. Specifically, the auxiliary materials 6 for blade infusion are first laid on the laid cloth layer, and then the corner-shaped rubber strip tooling 7 is placed at the corner of the mold, so that the corner-shaped rubber strip tooling 7 is attached to the auxiliary materials 6 located at the corner of the mold. At this time, the corner of the mold is sequentially provided with a filling layer 32, a fiberglass cloth layer, auxiliary materials 6, and corner-shaped rubber strip tooling 7 from bottom to top. Finally, a vacuum system is established by laying a vacuum bag film 8, and the vacuum bag film 8 is adhered to the mold flange 9 through a sealing strip 10 for pressure maintenance. Then, an infusion device is used to inject epoxy resin into the vacuum system through the glue injection pipe 11 on the vacuum bag film 8 for infusion molding. The corner-shaped rubber strip tooling 7 fits the corner of the trailing edge mold and can continuously compact the fiberglass cloth layer and auxiliary material 6 at the corner of the trailing edge mold under the action of vacuum pressure, further eliminating the overhang of the corner cloth layer and solving the problems of cavity, overhang, resin-rich corners and bubbles in the corner cloth layer of the trailing edge of the blade.

[0035] In the embodiment of the present invention, the cross section of the corner-shaped rubber strip tooling 7 is triangular, and one side angle of the triangle is substantially consistent with the corner of the blade mold, and can completely fit the corner of the blade mold.

[0036] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preventing the cloth layer at the trailing edge corner of a wind turbine blade from hanging in the air, characterized in that: The following steps are involved: 1) A filling layer is provided at the corner of the mold for forming the trailing edge corner of the blade in the empty mold. The filling layer has an arc groove structure extending along the length direction of the blade, and the outer circumferential surface of the arc groove is close to the mold corner. At the edge of the filling layer, the inner and outer circular surfaces of the filling layer are smoothly connected by a chamfered inclined surface along the inner circumferential direction of the arc groove. The filling layer has a thickness of 1.8-3.6 mm, and the length of the outer circular surface of the filling layer is 200-300 mm. In the circumferential direction of the filling layer, there is a 25-50 mm stagger between the two ends of the inner circular surface and the outer circular surface; in the extension direction of the filling layer, there is a 250-500 mm stagger between the two ends of the inner circular surface and the outer circular surface; the filling layer is composed of 3-6 layers of narrow glass fiber cloth, and adjacent layers of narrow glass fiber cloth have a 5-10 mm stagger in the circumferential direction of the filling layer and a 50-100 mm stagger in the extension direction of the filling layer; the filling layer can be demoulded integrally with the mold and reused; 2) Start laying the fabric layer by layer in the mold with the filling layer, and complete the laying of the fabric layer. When laying each layer, compact the fabric layer at the corner of the mold; 3) Lay the auxiliary materials for pouring in the mold where the fabric layer is laid, and then place the corner-shaped rubber strip tooling at the corner of the mold. The corner-shaped rubber strip tooling has a shape that fits the corner of the mold; 4) Lay the vacuum bag film to establish a vacuum system, and perform pressure-maintaining infusion so that the corner-shaped rubber strip tooling can continuously compact the mold corners under the action of vacuum pressure during infusion.

2. The method for preventing the wind turbine blade trailing edge corner from hanging in the air according to claim 1, characterized in that: In step 4), the vacuum bag film is bonded to the mold flange by a sealing strip to achieve pressure maintenance during pouring.

3. The method for preventing the wind turbine blade trailing edge corner from hanging in the air according to claim 1, characterized in that: Adjacent layers of narrow strips of fiberglass cloth are bonded and fixed by spraying glue.

4. The method for preventing the wind turbine blade trailing edge corner from hanging in the air according to claim 1, characterized in that: In step 2), the fabric layer is rolled and pressed by a compacting tool whose end can fit into the corner of the mold.

5. A wind turbine blade, characterized by: The method is described in any one of claims 1 to 4.

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