A method for preventing the root layer of wind turbine blades from turning white

Abstract

The present invention discloses a method for preventing partial stratification and whitening at the root of a wind turbine blade, comprising: during a layering process, spraying glue on the inside of a mold, laying a perforated isolation membrane on the inside surface of the mold in the areas on the leading and trailing edges of the blade root, and sequentially laying a first fiberglass cloth, a second fiberglass cloth, and a release cloth; flipping excess widthwise portions over to the end faces of the mold so that layers are laid on the inside, outside, and ends of the mold; then sequentially fixing the perforated isolation membrane, the first fiberglass cloth, the second fiberglass cloth, and the release cloth with glue; manufacturing the wind turbine blade, cooling the blade to below 40°C after complete curing, and demolding the blade; and removing the perforated isolation membrane, the first fiberglass cloth, the second fiberglass cloth, and the release cloth after the demolded blade cools to room temperature. The present invention can effectively solve the problem of partial stratification and whitening at the root of wind turbine blades, improve the production efficiency and quality of wind turbine blades, and save operating costs for wind turbine blade manufacturers.

Description

Technical Field

[0001] The invention belongs to the field of wind power and wind turbine blade manufacturing, and particularly relates to a method for preventing the root portion of a wind turbine blade from becoming stratified and white. Background Art

[0002] Wind turbine blades are essential components for converting wind energy into kinetic energy. High-quality manufacturing is crucial for reliable wind turbine operation, and the load-bearing at the root of a wind turbine blade is a key factor affecting the lifespan and safe operation of the wind turbine. The root area of a wind turbine blade has a complex structure and multiple layers of fiberglass cloth, making it difficult to manufacture. Therefore, the quality of the root molding significantly impacts the performance of the wind turbine blade.

[0003] Currently, after demolding, wind turbine blades commonly experience delamination and whitening of the fiberglass reinforced plastic (FRP) at the outer edges of the leading and trailing edges of the root. This problem typically involves 10-20 layers. Due to the large circular transition radius in this area, repairing these layers is difficult and labor-intensive. Furthermore, if the repair fails to meet process requirements, the blade root strength will be reduced, affecting the operational quality and performance of the wind turbine blade. Prolonged repairs also occupy workstations, hindering product flow and delivery, and increasing operating costs for wind turbine blade manufacturers. Therefore, after thoroughly analyzing the causes of this problem, it became crucial to find a method that is easy to operate, highly feasible, low-cost, and effective in preventing the delamination of the wind turbine blade root. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem of root fiberglass stratification and whitening that has not been effectively solved for a long time in the manufacture of wind turbine blades, and to provide a method for preventing the root layer whitening of wind turbine blades that is easy to operate, has high process feasibility, low cost and good effect. This method reduces the defect of root layer whitening of wind turbine blades, improves the production efficiency and quality of wind turbine blades, and saves operating costs for wind turbine blade manufacturing companies.

[0005] In order to achieve the above object, the technical solution adopted in the present invention is:

[0006] A method for preventing the root of a wind turbine blade from becoming stratified and whitening, comprising:

[0007] During the layup process, glue is sprayed on the inside of the mold. A perforated barrier film is laid on the inside surface of the mold in the areas on the leading and trailing edges of the blade root. The first fiberglass cloth, the second fiberglass cloth, and the release cloth are then laid in sequence. The excess width is flipped over to the end face of the mold, ensuring that the inside, outside, and ends of the mold are all covered with layers. The perforated barrier film, the first fiberglass cloth, the second fiberglass cloth, and the release cloth are then fixed in place with glue in sequence.

[0008] To make wind turbine blades, after the wind turbine blades are completely cured, they are cooled to below 40° for demoulding;

[0009] After the demoulded wind turbine blade cools to room temperature, the perforated isolation film, the first glass fiber cloth, the second glass fiber cloth and the demoulding cloth are torn off.

[0010] As a further improvement of the present invention, the perforated isolation membrane, the first glass fiber cloth, the second glass fiber cloth and the release cloth are fixed by spraying glue.

[0011] As a further improvement of the present invention, on the inner side of the mold, the widths of the perforated isolation membrane, the first glass fiber cloth, and the second glass fiber cloth are staggered in sequence, the width b of the release cloth and the second glass fiber cloth are the same, the width difference between the first glass fiber cloth and the second glass fiber cloth is L4, the width of the perforated isolation membrane is greater than that of the first glass fiber cloth, the width difference is L5, and L4 is equal to L5.

[0012] As a further improvement of the present invention, on the outside of the mold, the first glass fiber cloth, the second glass fiber cloth and the release cloth are staggered layer by layer toward the inside of the mold, and the staggered widths are L1, L2, and L3 respectively. L1, L2, and L3 are equal, and the width a of the release cloth is greater than the width of the glass fiber cloth when the wind turbine blade substrate is turned over to the end face of the mold.

[0013] As a further improvement of the present invention, the perforated isolation membrane is made of ETFE high-temperature resistant film; the first glass fiber cloth and the second glass fiber cloth are made of biaxial or triaxial glass fiber cloth; and the release cloth is made of high-temperature resistant release cloth with a unit gram weight greater than 105g.

[0014] As a further improvement of the present invention, before laying the isolation membrane with holes on the inner side of the mold, the first glass fiber cloth, the second glass fiber cloth and the release cloth, the mold should be preheated to a preset temperature before the laying process is carried out.

[0015] As a further improvement of the present invention, when the wind turbine blade is demoulded, a cutting machine is used to cut off the excess fiberglass on the leading and trailing edge sides in the axial direction according to the spacing; when a sling is used for demoulding, the excess fiberglass on the mold end face is cut into a slot with the width of the sling in the leading and trailing edge areas of the blade root.

[0016] As a further improvement of the present invention, before the layer laying process, the following steps are further included:

[0017] Clean the inner side and end face of the leading and trailing edges of the root area of the wind turbine blade mold, and apply the release agent evenly in a circular motion.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention provides a method for preventing partial whitening at the root of a wind turbine blade. Prior to blade production, a laying process is performed. A perforated isolation film, a first layer of fiberglass cloth, a second layer of fiberglass cloth, and a release cloth are sequentially laid on the blade mold. This allows for rapid demolding later, utilizing conventional materials used in wind turbine blade production. The overall solution requires no new equipment or tooling. The method specifies the mold preheating temperature, the laying process, and the demolding temperature for the wind turbine blade. The method is primarily applicable to the leading and trailing edges of the wind turbine blade root. After cleaning the mold and evenly applying a release agent, the perforated isolation film is laid. Two layers of fiberglass cloth and the release cloth are then laid in sequence. Each layer is flipped over onto the mold end face as required. Spray adhesive is used to secure the layers, ensuring that all layers fit perfectly within the mold. During demolding, the wind turbine blade should be cooled and the sling support area should be individually cut. After the blade temperature drops to room temperature, the perforated isolation film, two layers of fiberglass cloth, and the release cloth are removed. The present invention does not require the addition of new equipment and tooling, has high process feasibility, is easy to operate, and has low cost. Multiple process tests have shown that this method can effectively solve the problem of partial whitening of the root layers of wind turbine blades, improve the production efficiency and quality of wind turbine blades, and save operating costs for wind turbine blade manufacturing companies. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the inner layer structure of the mold of the present invention;

[0023] Figure 3 It is a schematic diagram of the outer layer structure of the mold of the present invention.

[0024] Among them, 1-wind turbine blade manufacturing mold; 2-perforated isolation membrane; 3-first glass fiber cloth; 4-second glass fiber cloth; 5-release cloth; 6-wind turbine blade substrate; a-end face release cloth width; b-inner side release cloth width; L1, L2, L3-end face staggered width; L4, L5-inner side staggered width. DETAILED DESCRIPTION

[0025] As described in the background technology, the purpose of the present invention is to solve the problem of root fiberglass stratification and whitening that has not been effectively solved for a long time in the manufacturing of wind turbine blades, and to provide a method for preventing the root layer whitening of wind turbine blades that is easy to operate, has high process feasibility, low cost and good effect, so as to reduce the defect of root layer whitening of wind turbine blades, improve the production efficiency of wind turbine blades and save operating costs for wind turbine blade manufacturing companies.

[0026] The present invention will be described in further detail below with reference to the accompanying drawings.

[0027] like Figure 1 As shown, a method for preventing the root layer of a wind turbine blade from turning white is provided. The method mainly specifies the temperature control, laying process and demoulding method of the wind turbine blade. It includes:

[0028] During the layup process, glue is sprayed on the inside of the mold. A perforated barrier film 2 is laid on the inside surface of the mold in the areas on the leading and trailing edges of the blade root. The first fiberglass cloth 3, the second fiberglass cloth 4, and the release cloth 5 are then laid in sequence. The excess width is folded over to the end faces of the mold, ensuring that the inside, outside, and ends of the mold are all covered with layers. Finally, glue is used to secure the perforated barrier film 2, the first fiberglass cloth 3, the second fiberglass cloth 4, and the release cloth 5 in sequence.

[0029] To make wind turbine blades, after the wind turbine blades are completely cured, they are cooled to below 40° for demoulding;

[0030] After the demoulded wind turbine blade cools to room temperature, the perforated isolation film 2, the first glass fiber cloth 3, the second glass fiber cloth 4 and the demoulding cloth 5 are torn off.

[0031] The laying area primarily includes the mold's inner side and end faces. The laying method involves first cleaning the inside and end faces of the wind turbine blade mold. Apply release agent evenly to the area in a circular motion. Then, evenly spray glue onto the mold's inner surface. Next, lay the perforated isolation film 2, first fiberglass cloth 3, second fiberglass cloth 4, and release cloth 5 in that order. A small amount of glue is sprayed between the perforated isolation film 2, first fiberglass cloth 3, second fiberglass cloth 4, and release cloth 5 to secure them.

[0032] As a preferred solution, after the inner side of the mold is laid and fixed, the porous isolation film 2, the first glass fiber cloth 3, the second glass fiber cloth 4 and the release cloth 5 are laid layer by layer according to the Figure 1 and Figure 3 As shown, it is laid along the end face of the mold and to the outside of the mold.

[0033] As a preferred solution, Figure 2 As shown, the inside of the mold, from closest to the mold toward the outside, is composed of a perforated isolation membrane 2, a first glass fiber cloth 3, a second glass fiber cloth 4, and a release cloth 5. Inside the mold, the widths of the perforated isolation membrane 2, the first glass fiber cloth 3, and the second glass fiber cloth 4 are staggered. The release cloth 5 and the second glass fiber cloth 4 have the same width b. The width difference between the first glass fiber cloth 3 and the second glass fiber cloth 4 is L4. The width of the perforated isolation membrane 2 is greater than that of the first glass fiber cloth 3 by a width difference of L5, with L4 being equal to L5.

[0034] The release cloth 5 and the second glass fiber cloth 4 have the same width b, which is 15 cm, and L4 is equal to L5, which is about 5 cm.

[0035] As a preferred solution, Figure 3As shown, on the outside of the mold, the first glass fiber cloth 3, the second glass fiber cloth 4, and the release cloth 5 are staggered inwards, with staggered widths L1, L2, and L3, respectively. L1, L2, and L3 are equal, and the width a of the release cloth 5 is greater than the width of the glass fiber cloth when the wind turbine blade base 6 is flipped over to the mold end face. On the inside, the layers are flipped over to the mold end face, with the first glass fiber cloth 3, the second glass fiber cloth 4, and the release cloth 5 staggered inwards, with staggered widths L1, L2, and L3 equal, approximately 3 cm. The width a of the release cloth 5 is approximately 5 cm, greater than the width of the glass fiber cloth when the wind turbine blade base 6 is flipped over to the mold end face.

[0036] As a preferred solution, the inside and end surfaces of the mold, especially the end surfaces, should be kept absolutely clean. Any residual structural adhesive and other impurities on the mold surface should be scraped clean with a metal tool to ensure that each layer in this method can be fully bonded to the mold.

[0037] As a preferred solution, the perforated isolation membrane 2 is made of ETFE high-temperature resistant film; the first glass fiber cloth 3 and the second glass fiber cloth 4 are made of biaxial or triaxial glass fiber cloth. In order to achieve the purpose of convenient operation, it is not recommended to use uniaxial glass fiber cloth; the release cloth 5 is made of high-temperature resistant release cloth with a unit gram weight greater than 105g.

[0038] As a preferred solution, the mold should be preheated to 30° before laying the perforated isolation film 2, first fiberglass cloth 3, second fiberglass cloth 4, and release cloth 5. Each layer is fixed with spray glue to ensure interlayer adhesion.

[0039] As a preferred option, after the wind turbine blade is post-cured, the mold should be cooled to below 40° before opening and flipping the upper shell mold to avoid excessively high temperature when opening the mold, which may cause adhesion and stress between the fiberglass and the mold.

[0040] As a preferred option, when demolding wind turbine blades, a cutting machine should be used to cut off excess fiberglass on the leading and trailing edges at 2m intervals in the axial direction to prevent localized adhesion between the shell and the mold, which could cause delamination and whitening of the blade root due to stress. When using a sling for demolding, a slot the width of the sling should also be cut off from the excess fiberglass on the mold end face at the leading and trailing edges of the blade root to prevent delamination and whitening of the fiberglass on the outer edges of the leading and trailing edges of the blade root due to external stress.

[0041] As a preferred solution, when the perforated isolation film 2, the first glass fiber cloth 3, the second glass fiber cloth 4 and the demoulding cloth 5 are torn off after the wind turbine blade is demoulded, it should be ensured that the temperature of the wind turbine blade substrate 6 has dropped to room temperature.

[0042] The present invention is described in detail below with reference to specific embodiments and accompanying drawings.

[0043] Example 1

[0044] A method for preventing the root layer of a wind turbine blade from turning white comprises the following steps:

[0045] Step a: Material preparation:

[0046] Before the wind turbine blades are manufactured, the perforated isolation film, biaxial or triaxial fiberglass cloth, and release cloth are cut into certain sizes and set aside.

[0047] Step b: Clean the mold

[0048] Clean the inner side and end surface of the leading and trailing edges of the wind turbine blade mold root area, and apply the release agent evenly in a circular motion;

[0049] Step c: Lamination process

[0050] First, spray glue on the inside of the mold. Then, apply a perforated barrier film to the mold's inner surface within a 5m radius of the leading and trailing edges of the blade root. Next, lay two layers of fiberglass cloth and one layer of release cloth, securing the two layers with glue. Fold the excess widthwise to the mold's end faces, and then secure the perforated barrier film, two layers of fiberglass cloth, and release cloth with glue. Ensure each layer fits perfectly within the mold to avoid any loose ends.

[0051] Step d: After the wind turbine blade is completely cured, it is demoulded and cooled to below 40°C.

[0052] Step e: Demolding: After the wind turbine blade cools to room temperature, the perforated isolation film, the two layers of fiberglass cloth, and the demoulding cloth are removed.

[0053] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will appreciate that they may revise the technical solutions described in the foregoing embodiments or substitute equivalents for some of the technical features. Any revisions, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preventing the root layer of a wind turbine blade from turning white, characterized in that: include: In the layering process, glue is sprayed on the inner side of the mold, and a perforated isolation film (2) is laid on the inner surface of the mold in the area of the leading edge and trailing edge of the blade root, and the first glass fiber cloth (3), the second glass fiber cloth (4) and the release cloth (5) are laid in sequence; the excess part in the width direction is turned over to the end face of the mold so that the inner side, the outer side and the end of the mold are all layered, and then the perforated isolation film (2), the first glass fiber cloth (3), the second glass fiber cloth (4) and the release cloth (5) are fixed in sequence with glue; To make wind turbine blades, after the wind turbine blades are completely cured, they are cooled to below 40° for demoulding; After the demoulded wind turbine blade cools to room temperature, the perforated isolation film (2), the first glass fiber cloth (3), the second glass fiber cloth (4) and the demoulding cloth (5) are torn off; On the inner side of the mold, the widths of the perforated isolation membrane (2), the first glass fiber cloth (3), and the second glass fiber cloth (4) are staggered in sequence, the demoulding cloth (5) and the second glass fiber cloth (4) have the same width b, the width difference between the first glass fiber cloth (3) and the second glass fiber cloth (4) is L4, the width of the perforated isolation membrane (2) is greater than that of the first glass fiber cloth (3), the width difference is L5, and L4 is equal to L5; On the outside of the mold, the first glass fiber cloth (3), the second glass fiber cloth (4) and the demoulding cloth (5) are staggered layer by layer toward the inside of the mold, and the staggered widths are L1, L2, and L3 in sequence, and L1, L2, and L3 are equal. The width a of the demoulding cloth (5) is greater than the width of the glass fiber cloth when the wind turbine blade base (6) is turned over to the end face of the mold; The perforated isolation film (2) is made of ETFE high-temperature resistant film; the first glass fiber cloth (3) and the second glass fiber cloth (4) are made of biaxial or triaxial glass fiber cloth; the release cloth (5) is made of a release cloth with a high-temperature resistant unit weight greater than 105g; Before laying the mold inner-side perforated isolation membrane (2), the first glass fiber cloth (3), the second glass fiber cloth (4) and the release cloth (5), the mold should be preheated to a preset temperature before the laying process is carried out.

2. The method for preventing the root layer of a wind turbine blade from turning white according to claim 1, characterized in that: The perforated isolation membrane (2), the first glass fiber cloth (3), the second glass fiber cloth (4) and the release cloth (5) are fixed by spraying glue.

3. The method for preventing the root layer of a wind turbine blade from turning white according to claim 1, characterized in that: When demoulding the wind turbine blade, a cutting machine is used to cut off the excess fiberglass on the leading and trailing edge sides in the axial direction according to the spacing; when demoulding with a sling, the excess fiberglass on the mold end surface is cut into slots with the width of the sling at the leading and trailing edge areas of the blade root.

4. The method for preventing the root layer of a wind turbine blade from turning white according to claim 1, characterized in that: Before the laying process, it also includes: Clean the inner side and end face of the leading and trailing edges of the root area of the wind turbine blade mold, and apply the release agent evenly in a circular motion.

Images