Control method for layering of wind power blade mold closing seam

Abstract

The invention discloses a control method for layering of a wind power blade mold closing seam, which comprises the following steps of: respectively forming grooves in a front edge mold closing seam and a rear edge mold closing seam, adjacent to a blade root point, of a blade mold, embedding silica gel in the grooves, and enabling the top surface of the silica gel to be flush with the surface of the blade mold or to have an exposure height a which is less than 5h; wherein h is the thickness of the single-layer cloth liner. Silica gel is added to the front edge and the rear edge of the root of the blade mold, buffering is formed between the blade and the mold during blade mold closing on the premise that pneumatic molded surfaces of the front edge and the rear edge of the blade are not damaged and the power generation efficiency of the blade is not affected, a laminated structure of a mold closing seam of the front edge and the rear edge of the blade is protected, and therefore the layering defect of the mold closing seam is relieved or even eliminated. Besides, the silica gel can be recycled and only needs to be replaced once with the manufacturing time of 20-30 leaves as a period, and compared with glass fibers, resin and labor consumed by cloth liners, the manufacturing cost of the leaves is reduced.

Description

Technical Field

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

[0002] Among the multiple processes in wind turbine blade manufacturing, one process is the mold closing process, which is to turn the mold over and turn the windward side of the blade to the leeward side, so as to combine the two parts of the blade into a complete blank. In this process, the windward side of the blade will be turned 180 degrees with the drive of the mold, and its leading and trailing edges will be squeezed.

[0003] At present, the mainstream blade lengths in the wind power market are generally above 90 meters, the blade root base circle exceeds 3 meters, and the blade root weight generally exceeds 10 tons. Therefore, the leading and trailing edge laminated structures of wind power blades are very likely to form delamination defects under such extrusion. In theory, the longer the wind power blade is and the larger the blade root base circle is, the more likely it is to have the above-mentioned delamination defects.

[0004] The leading edge of the wind turbine blade mentioned above refers to the leading edge when it meets the wind flow. Its main function is to reduce the resistance of wind to the blade, and it can also change the direction and speed of the wind flow.

[0005] The trailing edge of the wind turbine blade mentioned above refers to the edge when it separates from the wind flow. Its main function is to reduce the negative pressure formed by the wind behind the blade, thereby reducing the suction of the wind on the blade.

[0006] The current methods for controlling delamination defects in the industry are mainly: Figure 1 As shown, a pad is placed at the front and rear edge joints of the blade mold near the blade root point, and the pad is torn off after the blade is demoulded. The benefits of this control method are: on the one hand, it can alleviate the extrusion effect caused by the surface difference between the prefabricated blade root and the skin mold, and on the other hand, it can reduce the severity of the delamination defect at the joint position of the blade body structure.

[0007] As blades are designed to be longer and longer, the weight of the blade roots is also increasing. Therefore, the padding methods are usually divided into the following situations:

[0008] (1) Blades with a length of 50-80 m and 20-30 layers of blade root reinforcement

[0009] The blade root reinforcement layer is a main component of the blade root and is mainly composed of glass fiber to enhance the blade root stiffness.

[0010] For blades of this length class, the fiberglass structure of the blade root mold seam is usually sufficient to withstand the extrusion when the mold is turned over. Therefore, cloth is only placed within a range of 5-8m from the root to the end point of the blade. There are 1-3 layers of cloth, and the width of the cloth is 100-200mm, which is evenly divided along the mold seam.

[0011] (2) Blades with a length of 80-100 m and 30-50 layers of blade root reinforcement

[0012] The blade root reinforcement layer of blades within this range will extend from the blade root to 15-25m away from the blade root. The blade root weight is also heavier than that of blades below 80m. The fiberglass structure at the blade mold seam position can no longer withstand the extrusion when the mold is flipped. Therefore, the end point of the pad cloth extends to 2-10m away from the blade root. The number of pad cloth layers is 3-4, and the width of the pad cloth is 100-200mm, evenly divided along the mold seam.

[0013] (3) Blades with a length of more than 100 m and more than 50 layers of blade root reinforcement

[0014] The padding cloth can no longer eliminate the mold seam delamination defects on 100-meter-class blades, but can only be used to reduce the severity of the defects. The end point of the padding cloth is usually at the 15-30m position, the number of layers is usually 4-5, and the width of the padding cloth is 100-200mm, evenly divided along the mold seam.

[0015] The current solution of padding the mold seam with fiberglass cloth actually replaces the blade body structure with the cloth to withstand the extrusion when the blade is molded and flipped. In this way, even if delamination defects occur, they will occur on the previously laid cloth, and the cloth will be torn off after the blade is demoulded.

[0016] This solution has certain limitations. First, the number of layers of the pad is preferably within 5. If it exceeds 5 layers, it will damage the aerodynamic surface of the leading and trailing edges of the blade, affecting the power generation efficiency of the blade. Since the number of layers of the pad is too small, the pad solidifies with the blade during the infusion process. When the mold is turned over during the mold closing process, the blade is still in hard contact with the mold, and it cannot be guaranteed that the delamination defects are completely on the pad. After the blade is demolded and the pad is torn off, there will still be delamination defects remaining in the main structure of the blade; secondly, the pad is disposable and needs to be replaced after each blade is demolded. In addition, since the current blade structure layer is mainly composed of epoxy resin and glass fiber, the presence of the pad will also increase the amount of epoxy resin used, increasing the manufacturing cost of the blade.

[0017] If grooves are directly cut in the mold and more than 5 layers of padding are laid, the padding will solidify with the blades to form fiberglass, making it difficult to remove the padding from the mold. In addition, if the padding is not cleaned in time, it will be ineffective and will cause stratification of the mold seam in subsequent products. Summary of the invention

[0018] The technical problem to be solved by the present invention is to provide a method for controlling the stratification of the mold seam of a wind turbine blade in view of the deficiencies of the above-mentioned prior art. The method for controlling the stratification of the mold seam of a wind turbine blade is achieved by adding silicone to the leading and trailing edges of the root of the blade mold. When the blade is molded, a buffer is formed between the blade and the mold without damaging the aerodynamic surfaces of the leading and trailing edges of the blade, thereby protecting the laminated structure of the mold seam of the leading and trailing edges of the blade, thereby reducing or even eliminating the stratification defects of the mold seam.

[0019] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0020] A method for controlling the stratification of a wind turbine blade mold seam, wherein grooves are respectively provided at the leading edge mold seam and the trailing edge mold seam near the blade root point of the blade mold, silicone is embedded in the grooves, and the top surface of the silicone is flush with the surface of the blade mold or has an exposed height a, and a<5h; wherein h has a value range of 0.6-0.8mm.

[0021] The Shore hardness of silicone is 20-40HD.

[0022] The cross section of each groove is V-shaped, including an edge prism groove and a cavity groove; wherein the edge prism groove is opened on the side surface of the edge prism, and the cavity groove is opened on the side surface of the cavity.

[0023] The silicone has a V-shaped cross section, and includes an edge prism protection silicone and a cavity protection silicone that are integrally arranged; wherein the edge prism protection silicone is embedded in the edge prism groove, and the cavity protection silicone is embedded in the cavity groove.

[0024] Both the edge prism groove and the cavity groove are tapered grooves with the bottom surface inclined toward the mold seam, and the tapered groove has a maximum depth D at the mold seam.

[0025] The taper angle range of the edge prism groove and the cavity groove is 10 to 30 degrees, so that the change of silicone thickness forms a smooth transition from the mold seam to the prism edge and from the mold seam to the mold cavity.

[0026] The top surface of the silicone is flush with the surface of the blade mold, and the maximum depth D of the tapered groove is equal to the maximum thickness H of the silicone.

[0027] Both the leading edge mold seam and the trailing edge mold seam have root points that match the blade root. The silicone starts from the root point, and the embedding length along the length of the cavity is L; the width of the edge prism protection silicone is a fixed value w1, and the width of the cavity protection silicone is w2, then H, L and w2 will be adjusted according to the different blade structure and length.

[0028] For blades with a length of 50-80m and 20 to 30 blade root reinforcement layers, H = 1 to 2mm, L = 1 to 2mm, and w2 = 50H.

[0029] For blades with a length of 80-100 m and 30 to 50 blade root reinforcement layers, H = 1 to 3 mm, L = 5 to 10 mm, and w2 = 50H.

[0030] For blades with a length of more than 100m and more than 50 blade root reinforcement layers, H = 3-5mm, L = 10-20mm, and w2 = 80H.

[0031] The present invention has the following beneficial effects:

[0032] 1. The hardness of the silicone itself will not change with the curing of the blade. Therefore, when the mold is turned over, the blade and the mold will maintain soft contact, which will form a buffer between the blade and the mold to reduce the damage to the blade caused by the extrusion force during the mold turning, thereby preventing the defect of mold seam delamination.

[0033] 2. Since the top surface of the silicone is flush with the surface of the blade mold or has an exposed height a, and a<5h; where h is in the range of 0.6 to 0.8 mm; that is, the exposed height of the top surface of the silicone does not exceed the thickness of five layers of padding, it will not damage the aerodynamic surfaces of the leading and trailing edges of the blade and will not affect the power generation efficiency of the blade.

[0034] 3. Since both the edge prism groove and the cavity groove are conical grooves with the bottom surface inclined toward the mold seam, the thickness of the edge prism protective silicone and the cavity protective silicone gradually increases toward the mold seam.

[0035] 4. Silicone can be recycled and only needs to be replaced once every 20 to 30 blades. Compared with the glass fiber, resin and labor consumed by the pad, the production cost of the blades is reduced.

[0036] 5. By using silicone to control the lamination defects of the mold seam, the material and labor costs consumed in rework and repair of subsequent processes can be reduced, and the turnover time of subsequent processes can also be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The schematic diagram shows the structure of using a pad cloth to control the delamination defect of the mold seam in the prior art.

[0038] Figure 2 A top view showing the use of silicone to control mold seam delamination defects in the present invention.

[0039] Figure 3 Shows Figure 2 Schematic diagram of the local cross section at midpoint A.

[0040] Figure 4 A partial dimensioning schematic diagram of the blade mold in the present invention is shown.

[0041] Among them are:

[0042] 10. Blade mold;

[0043] 11. Cavity; 12. Front edge mold seam; 13. Trailing edge mold seam; 14. Edge ridge; 15. Mold seam; 16. Blade root point;

[0044] 20. Groove; 30. Silicone; 31. Edge prism protection silicone; 32. Cavity protection silicone;

[0045] 40. Cloth pad. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

[0047] In the description of the present invention, it should be understood that the terms "left side", "right side", "upper part", "lower part" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "First", "second" and the like do not indicate the importance of the components, and therefore cannot be understood as limiting the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution, and do not limit the scope of protection of the present invention.

[0048] like Figure 1 , Figure 2 and Figure 3 As shown, the blade mold 10 has a cavity 11 and edge prisms 14 located on both sides of the cavity. The boundary between the cavity and the two edge prisms forms two mold seams 15, namely a leading edge mold seam 12 and a trailing edge mold seam 13.

[0049] The leading edge mold seam and the trailing edge mold seam are both provided with blade root points 16 that match with the blade roots.

[0050] like Figure 2 and Figure 3 As shown, a method for controlling the layering of the mold seam of a wind turbine blade is provided, wherein grooves 20 are respectively provided at the leading edge mold seam and the trailing edge mold seam near the blade root point of the blade mold, and silicone 30 is embedded in the grooves.

[0051] The cross section of each groove is V-shaped, including an edge prism groove and a cavity groove; wherein the edge prism groove is opened on the side surface of the edge prism, and the cavity groove is opened on the side surface of the cavity.

[0052] Both the edge prism groove and the cavity groove are tapered grooves with the bottom surface inclined toward the mold seam, and the tapered groove has a maximum depth D at the mold seam.

[0053] The taper angle range of the edge prism groove and the cavity groove is 10 to 30 degrees, so that the change of silicone thickness forms a smooth transition from the mold seam to the prism edge and from the mold seam to the mold cavity, preventing stress concentration and causing damage to the blade during mold turning.

[0054] The silicone has a V-shaped cross section, and includes an edge prism protection silicone 31 and a cavity protection silicone 32 that are integrally arranged; wherein the edge prism protection silicone is embedded in the edge prism groove, and the cavity protection silicone is embedded in the cavity groove.

[0055] The Shore hardness of silicone is 20-40HD. The hardness of silicone itself will not change as the blade is cured and formed. Therefore, when the mold is turned over, the blade and the mold will maintain soft contact, which will form a buffer between the blade and the mold to reduce the damage to the blade caused by the extrusion force during the mold turning.

[0056] The top surface of the silica gel is flush with the surface of the blade mold or has an exposed height a, and a<5h; wherein the value range of h is 0.6-0.8mm.

[0057] In this embodiment, the top surface of the silicone is preferably flush with the surface of the blade mold, so that the maximum depth D of the tapered groove is equal to the maximum thickness H of the silicone. Therefore, the silicone and the blade mold are formed as a whole, and the V-shaped vertex line of the silicone forms a new mold joint.

[0058] like Figure 2 As shown in the figure, the silicone starts from the blade root point, and the embedding length along the length direction of the cavity is L; Figure 4 As shown, the width of the edge prism protective silicone is a fixed value w1, preferably 50 mm; the width of the cavity protective silicone is w2, then H, L and w2 will be adjusted according to the different blade structures and lengths.

[0059] For blades with a length of 50-80m and 20 to 30 blade root reinforcement layers, H = 1 to 2mm, L = 1 to 2mm, and w2 = 50H.

[0060] For blades with a length of 80-100 m and 30 to 50 blade root reinforcement layers, H = 1 to 3 mm, L = 5 to 10 mm, and w2 = 50H.

[0061] For blades with a length of more than 100m and more than 50 blade root reinforcement layers, H = 3-5mm, L = 10-20mm, and w2 = 80H.

[0062] The preferred embodiments of the present invention are described in detail above; however, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A method for controlling the stratification of the die seam of a wind turbine blade, characterized in that: Grooves are respectively provided at the leading edge mold seam and the trailing edge mold seam near the blade root point of the blade mold, and silicone is embedded in the grooves. The top surface of the silicone is flush with the surface of the blade mold or has an exposed height a, and a<5h; wherein h ranges from 0.6 to 0.8 mm.

2. The method for controlling the stratification of the die seam of a wind turbine blade according to claim 1, characterized in that: The Shore hardness of silicone is 20-40HD.

3. The method for controlling the stratification of the die seam of a wind turbine blade according to claim 1, characterized in that: The cross section of each groove is V-shaped, including an edge prism groove and a cavity groove; wherein the edge prism groove is opened on the side surface of the edge prism, and the cavity groove is opened on the side surface of the cavity; The silicone has a V-shaped cross section, and includes an edge prism protection silicone and a cavity protection silicone that are integrally arranged; wherein the edge prism protection silicone is embedded in the edge prism groove, and the cavity protection silicone is embedded in the cavity groove.

4. The method for controlling the stratification of the die seam of a wind turbine blade according to claim 3, characterized in that: Both the edge prism groove and the cavity groove are tapered grooves with the bottom surface inclined toward the mold seam, and the tapered groove has a maximum depth D at the mold seam.

5. The method for controlling the stratification of the die seam of a wind turbine blade according to claim 4, characterized in that: The taper angle range of the edge prism groove and the cavity groove is 10 to 30 degrees, so that the change of silicone thickness forms a smooth transition from the mold seam to the prism edge and from the mold seam to the mold cavity.

6. The method for controlling the stratification of the die seam of a wind turbine blade according to claim 4, characterized in that: The top surface of the silicone is flush with the surface of the blade mold, and the maximum depth D of the tapered groove is equal to the maximum thickness H of the silicone.

7. The method for controlling the stratification of the die seam of a wind turbine blade according to claim 6, characterized in that: Both the leading edge mold seam and the trailing edge mold seam have root points that match the blade root. The silicone starts from the root point, and the embedding length along the length of the cavity is L; the width of the edge prism protection silicone is a fixed value w1, and the width of the cavity protection silicone is w2, then H, L and w2 will be adjusted according to the different blade structure and length.

8. The method for controlling the delamination of the die seam of a wind turbine blade according to claim 7, characterized in that: For blades with a length of 50-80m and 20 to 30 blade root reinforcement layers, H = 1 to 2mm, L = 1 to 2mm, and w2 = 50H.

9. The method for controlling the stratification of the die seam of a wind turbine blade according to claim 7, characterized in that: For blades with a length of 80-100 m and 30 to 50 blade root reinforcement layers, H = 1 to 3 mm, L = 5 to 10 mm, and w2 = 50H.

10. The method for controlling the delamination of the die seam of a wind turbine blade according to claim 7, characterized in that: For blades with a length of more than 100m and more than 50 blade root reinforcement layers, H = 3-5mm, L = 10-20mm, and w2 = 80H.

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