Method for controlling layering of mold closing seam of wind power blade and wind power blade

Abstract

The invention discloses a method for controlling layering of a mold closing seam of a wind power blade and the wind power blade. The method comprises the steps that a PTFE film is pasted into a cavity from a prismatic table of a mold at the position of the mold closing seam, then glass fiber cloth and porous films are sequentially and alternately laid on the surface of the PTFE film, a foam material repairing strip is used on one layer of glass fiber cloth in a matched mode, a blocking interface is created, and the blocking interface is formed; and finally, pouring and demolding to finish the operation. During cooling shrinkage, the product is firstly separated from an interface, so that concentrated stress is prevented from directly acting on the product, and the purposes of controlling layering of a wind power blade die closing seam and improving blade quality are achieved. The method has the advantages of low popularization cost, wide audience, easiness in operation, wide application range and the like, and is suitable for popularization and application.

Description

Technical Field

[0001] The invention belongs to the technical field of wind turbine blade manufacturing, and in particular relates to a method for controlling the delamination of a die seam of a wind turbine blade and a wind turbine blade. Background Art

[0002] Wind turbine blades are the core components of wind turbines that convert natural wind energy into electricity for wind turbines. They are also the main basis for measuring the design and technical level of wind turbines. The quality of wind turbine blades will directly affect the power generation efficiency, stability and service life of the wind turbine. Due to the special operating environment of offshore wind turbine blades, large blades have undergone a comprehensive upgrade in structural design, which undoubtedly brings great difficulties to blade manufacturing and quality control. Different from the blade root mold seam stratification produced in small blades in the past, the blade root stratification defects produced by large blades have the characteristics of long length and deep layers. The currently commonly used solutions for controlling blade root stratification have the disadvantages of low applicability, poor effect, and low efficiency when applied to large blades. Blade root mold seam stratification seriously affects the production efficiency and product quality of blades, so the research of new technologies is imminent.

[0003] The traditional process currently has the following defects: (1) The traditional process directly lays an anti-delamination mat at the front and rear edge joints. The mat and the product are both glass fiber. After infusion and curing, they are fused with the product. During the cooling and shrinking process, the product and the mat are not separated first. The concentrated stress of the mold acts on the mat and also on the product itself. In addition, the large blades have deep layers of stratification, and the improvement effect as a sacrificial layer is not significant. (2) Traditional processes such as CN107415283A disclose a wind turbine blade molding defect control tool and control method, which fixes a PVC foam with a thickness of 15 mm at the joint position, mainly improving the inflection point of the glass fiber cloth layer at the joint position, increasing the stress concentration point, so that the layered glass fiber cloth layer is finally cut off. Although the problem of blade root stratification is completely solved, it also brings a huge amount of grinding to the subsequent process. Considering efficiency, quality and cost, this process has not been effectively promoted. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for controlling the delamination of the mold seam of a wind turbine blade and a wind turbine blade. In the laying stage, glass fiber cloth and porous membrane are laid alternately, and PVC foam is used on the last layer of pad cloth to create a barrier interface. During cooling and shrinkage, the product is first separated from the interface, thereby avoiding concentrated stress directly acting on the product itself, thereby achieving the purpose of controlling the delamination of the mold seam of the wind turbine blade and improving the quality of the blade.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for controlling the delamination of a wind turbine blade mold seam comprises the following steps:

[0007] Step 1) Lamination preparation: During the pre-production preparation of the lamination, after wiping off the dust on the front and rear edges, the PTFE film is pasted from the prism of the mold into the cavity at the mold seam position;

[0008] Step 2) Laying: After the PTFE membrane is pasted, glass fiber cloth and porous membrane are alternately laid on the surface of the PTFE membrane; the glass fiber cloth is completely attached to the mold, and a foam material repair strip is laid on one layer of the glass fiber cloth with the edges flush, and after fixing, the surface is covered with a porous membrane, and finally covered with a release cloth; wherein the PTFE membrane, glass fiber cloth, porous membrane and foam material repair strip together constitute an anti-delamination material; a structure in which the glass fiber cloth and porous membrane are alternately laid is a combined mat;

[0009] Step 3) Infusion: After the layering is completed, the product is pressure maintained. After the pressure maintenance is completed, the resin is introduced under negative pressure. After the infusion resin exceeds the inner edge, the heating curve curing can be started;

[0010] Step 4) Demolding: Cut off the foam material repair strip before demoulding, and then tear off the combined pad cloth and demoulding cloth on the surface during demoulding to complete the operation.

[0011] Preferably, the width of the PTFE membrane in step 1) in the mold cavity exceeds the width of the glass fiber cloth in step 2) in the mold cavity.

[0012] Preferably, in step 2), the glass fiber cloth and the porous membrane are laid in three layers.

[0013] Preferably, the lengths of the first two layers of glass fiber cloth laid out exceed the lengths of the corresponding porous membranes, and the length of the third layer of porous membrane exceeds the length of the second layer of glass fiber cloth.

[0014] Preferably, the foam material in step 2) is PVC or PET.

[0015] Preferably, the thickness of the foam material repair strip in step 2) is 2 to 3 mm.

[0016] Preferably, the foam material repair strip in step 2) is laid on the last layer of glass fiber cloth.

[0017] Preferably, after step 2) is completed, the anti-delamination material is bypassed when cleaning the remaining fabric on the prism.

[0018] Preferably, the combined mat cloth described in step 2) can be prefabricated in advance as needed; when laying the layers, first paste the PTFE membrane in the manner of step 1), then directly lay the combined mat cloth on the surface of the PTFE membrane, then peel off one layer of the porous membrane of the combined mat cloth, lay the foam material repair strips on the corresponding glass fiber cloth flush with the edges, and finally cover the surface of the combined mat cloth with a release cloth.

[0019] A wind turbine blade is prepared by adopting the above method.

[0020] The beneficial effects of the present invention are as follows:

[0021] (1) Low promotion cost: The method of the present invention involves low material cost; no polishing is required after curing, saving time and cost; no tooling is involved, saving tooling manufacturing cost.

[0022] (2) Widely applicable and easy to operate: The combined pad designed by the present invention can be sewn in advance and laid out as a whole during prenatal preparation, which is convenient to operate.

[0023] (3) Wide scope of application: The method of the present invention is applicable to any type of wind turbine blades, effectively solving the inapplicability of traditional solutions on large blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of controlling the delamination of the mold seam of a wind turbine blade;

[0025] In the figure: 1. PTFE membrane; 2. Fiberglass cloth; 3. Porous membrane; 4. Foam material repair strip; 5. Mold. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] A method for controlling the delamination of a wind turbine blade mold seam, the specific steps are as follows:

[0029] (1) Preparation for laying: When preparing for laying, use absorbent cotton cloth to wipe off the dust on the front and rear edges. Figure 1 As shown, at the mold seam position, the PTFE membrane 1 is pasted from the prism of the mold 5 into the cavity. The width of the PTFE membrane 1 in the cavity must exceed the width of the pad cloth (i.e., the fiberglass cloth 2 described below) in the cavity. A wallpaper knife can be used to cut the joint at the corner to ensure that it is firmly attached to the mold 5 and the surface is smooth and wrinkle-free. This PTFE membrane 1 serves as a non-stick coating to facilitate the separation of the product from the mold 5.

[0030] The PTFE membrane can be adjusted in position, and the relative position remains unchanged: from the perspective of positioning, the PTFE membrane needs to extend chordally beyond the widest layer of padding, and axially beyond the maximum length of the layer. The actual length and width can be adjusted according to the convenience of on-site employees and the size of the blade model.

[0031] (2) Laying: After the PTFE membrane 1 is pasted, the glass fiber cloth 2 and the porous membrane 3 are laid alternately on the surface of the PTFE membrane 1 using spray glue. Figure 1As shown, the laying layers of the glass fiber cloth 2 and the porous membrane 3 described in this embodiment are all three layers, the length of the first two layers of glass fiber cloth 2 laid needs to exceed the length of the corresponding porous membrane 3, and the third layer of porous membrane 3 needs to cover the second layer of glass fiber cloth 2 (that is, the length of the third layer of porous membrane 3 not only exceeds the third layer of glass fiber cloth 2, but also exceeds the second layer of glass fiber cloth 2). The process needs to be pressed by hand to make the glass fiber cloth 2 and the mold 5 completely close, and the foam material repair strip 4 is laid on the last layer of glass fiber cloth 2 with the edges and edges, and the surface is covered with the last layer of porous membrane 3 and demoulding cloth after fixing. The above-mentioned PTFE membrane 1, glass fiber cloth 2, porous membrane 3 and foam material repair strip 4 together constitute the anti-delamination material. After the normal laying is completed, when cleaning the remaining cloth of the prism, it is necessary to pay attention to bypassing the anti-delamination material to avoid its failure.

[0032] Positioning of glass fiber cloth and porous membrane: Lay them alternately from the mold prism to the cavity, and stagger them in sequence. The width inside the cavity can be determined according to the layer width. The main purpose is to allow the product to separate from the pad first during the cooling and shrinking process to avoid concentrated stress on the product itself.

[0033] The quantity and width of glass fiber cloth and porous membrane can be fine-tuned: the glass fiber cloth and porous membrane involved in this embodiment are both three-layered, and the width needs to exceed the layer width. The actual quantity and width of glass fiber cloth and porous membrane can be fine-tuned according to the blade model, severity of defects and on-site operability.

[0034] Thickness requirement of foam material repair strip: Fix PVC or PET repair strip on the last layer of glass fiber cloth, with thickness ranging from 2 to 3mm, which mainly acts as a buffer medium to slow down the stress at the mold seam during cooling and shrinkage process and directly act on the product surface.

[0035] Adjustment of the placement position of the foam material repair strip: In this embodiment, the foam material repair strip is placed above the last layer of fiberglass cloth. The actual order can be adjusted according to the proficiency of on-site operation and the difficulty of laying.

[0036] Through the barrier interface composed of the above materials, the product and the interface are separated first during the process of high-temperature solidification, cooling and shrinkage of the blade. The concentrated stress at the mold seam position cannot be transmitted to the product itself, thereby controlling the mold seam delamination.

[0037] In a preferred solution, the combined mat composed of the structure of alternately laid glass fiber cloth 2 and porous membrane 3 can be sewn in advance and laid as a whole during pre-production preparation. When laying, firstly stick the PTFE membrane 1 according to the above steps, then directly lay the prefabricated combined mat on the surface of the PTFE membrane 1, then peel off one layer of the porous membrane 3 of the combined mat according to actual needs, lay the foam material repair strip 4 on the corresponding glass fiber cloth 2 flush with the edges, and finally cover the surface of the combined mat with a release cloth.

[0038] (3) Infusion: After the layering is completed, the product is pressure maintained. After the pressure maintenance is completed, the resin is introduced under negative pressure. After the infused resin exceeds the inner edge, the heating curve curing can be started.

[0039] (4) Demolding: Before demolding, the foam material repair strip 4 is removed, and then the combined padding cloth and demolding cloth on the surface are torn off to complete the operation. Among the above-mentioned anti-delamination materials, the PTFE membrane 1 can be reused, and the foam material repair strip 4 has been removed before demolding, and only the glass fiber cloth 2 and the porous membrane 3 need to be torn off.

[0040] After the above operations, the stratification at the mold seam is good, and the number and length of stratification layers are greatly reduced.

[0041] The embodiments described above are only some embodiments of the present invention, rather than all embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. The scope of protection of the present invention shall be subject to the scope required by the claims. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work shall fall within the scope of protection of the present invention.

Claims

1. A method for controlling the delamination of the die seam of a wind turbine blade, characterized in that: The following steps are involved: Step 1) Lamination preparation: During the pre-production preparation of the lamination, after wiping off the dust on the front and rear edges, the PTFE film is pasted from the prism of the mold into the cavity at the mold seam position; Step 2) Laying: After the PTFE membrane is pasted, glass fiber cloth and porous membrane are alternately laid on the surface of the PTFE membrane; the glass fiber cloth is completely attached to the mold, and a foam material repair strip is laid on one layer of the glass fiber cloth with the edges flush, and after fixing, the surface is covered with a porous membrane, and finally covered with a release cloth; wherein the PTFE membrane, glass fiber cloth, porous membrane and foam material repair strip together constitute an anti-delamination material; a structure in which the glass fiber cloth and porous membrane are alternately laid is a combined mat; Step 3) Infusion: After the layering is completed, the product is pressure maintained. After the pressure maintenance is completed, the resin is introduced under negative pressure. After the infusion resin exceeds the inner edge, the heating curve curing can be started; Step 4) Demolding: Cut off the foam material repair strip before demoulding, and then tear off the combined pad cloth and demoulding cloth on the surface during demoulding to complete the operation.

2. A method for controlling the delamination of the die seam of a wind turbine blade according to claim 1, characterized in that: The width of the PTFE membrane in step 1) in the cavity exceeds the width of the glass fiber cloth in step 2) in the cavity.

3. The method for controlling the delamination of the die seam of a wind turbine blade according to claim 1, characterized in that: In step 2), the glass fiber cloth and the porous membrane are laid in three layers.

4. A method for controlling the delamination of the die seam of a wind turbine blade according to claim 3, characterized in that: The lengths of the first two layers of glass fiber cloth laid out exceed the lengths of the corresponding porous membranes, and the length of the third layer of porous membrane exceeds the length of the second layer of glass fiber cloth.

5. The method for controlling the delamination of the die seam of a wind turbine blade according to claim 1, characterized in that: Step 2) The foam material is PVC or PET.

6. The method for controlling the delamination of the die seam of a wind turbine blade according to claim 1, characterized in that: Step 2) The thickness of the foam material repair strip is 2 to 3 mm.

7. The method for controlling the delamination of the die seam of a wind turbine blade according to claim 1, characterized in that: Step 2) The foam material repair strip is laid on the last layer of glass fiber cloth.

8. The method for controlling the delamination of the die seam of a wind turbine blade according to claim 1, characterized in that: Step 2) After laying, bypass the anti-delamination material when cleaning the remaining fabric on the prism.

9. The method for controlling the delamination of the die seam of a wind turbine blade according to claim 1, characterized in that: The combined mat cloth of step 2) can be prefabricated in advance as required; when laying the layers, first paste the PTFE membrane in the manner of step 1), then directly lay the combined mat cloth on the surface of the PTFE membrane, then peel off one layer of the porous membrane of the combined mat cloth, lay the foam material repair strip on the corresponding glass fiber cloth flush with the edges, and finally cover the surface of the combined mat cloth with a release cloth.

10. A wind turbine blade, characterized in that: The method is prepared by the method according to any one of claims 1 to 8.

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