Wind turbine generator blade and preparation method thereof

Abstract

The invention relates to the field of wind power generation equipment manufacturing, and discloses a wind turbine generator blade and a preparation method thereof. According to the method, a shell blade root prefabricated part, oblique angle cloth and an outer skin are sequentially laid on a shell mold, then a rear edge beam, a carbon fiber girder and a core material are laid, polyurethane resin is poured through a vacuum pouring method to form a blade shell, a carbon fiber web is installed, and the wind turbine generator blade is formed after mold closing and glue scraping. The method has the advantages of overall rapid forming and short manufacturing period; the girders and the webs are prefabricated and formed by adopting carbon fiber prepreg, so that the overall strength and rigidity of the blade are improved, and the weight is reduced. The wind turbine generator blade prepared by the method has better strength and rigidity and lighter weight, and is beneficial to actual use.

Description

Technical Field

[0001] The present invention relates to the field of wind power generation equipment manufacturing, and in particular to a wind turbine blade and a preparation method thereof. Background Art

[0002] Wind power generation is one of the main development directions in the field of new energy. Among them, wind turbine blades are the core components of wind turbines. Therefore, the manufacturing technology of wind turbine blades is also one of the core technologies of wind power generation systems. With the continuous increase in market demand for wind power generation, the requirements for the capacity of wind turbines are also getting higher and higher, which requires longer and longer wind turbine blades. However, the lengthening of wind turbine blades will increase the weight and stress area of ​​the blades, resulting in increased stress on the blades during operation, causing defects such as blade deformation and affecting the stability of wind power generation.

[0003] The components that affect the overall strength and rigidity of wind turbine blades mainly include beams, webs and shells. At present, the beams and webs of blades are mainly made of glass fiber materials, which are heavy and low in strength; the shell mainly adopts a structure of glass fiber cloth skin and epoxy resin infusion. The epoxy resin has low strength and poor compatibility with glass fiber, and has low fluidity and wettability during the preparation process, which makes the curing time long and requires the shell mold to be kept warm for a long time, which affects the quality of other components such as core materials, prolongs the process flow, and increases energy consumption and production costs. Therefore, it is necessary to improve the component materials and assembly methods of wind turbine blades, improve the strength and rigidity of each component of wind turbine blades, and reduce the weight of blades. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of poor overall strength and rigidity of wind turbine blades and heavy blades in the prior art, and a wind turbine blade and a method for preparing the same are proposed. The method comprises laying a shell blade root prefabricated part, an angled cloth and an outer skin on a shell mold in sequence, and then laying a trailing edge beam, a beam and a core material, and then infusing polyurethane resin by a vacuum infusion method to form a blade shell and installing a web, and then molding into a wind turbine blade after mold closing and glue scraping, which has the advantage of overall rapid molding; the beam and web are prefabricated with carbon fiber prepreg, which increases the overall strength and rigidity of the blade and reduces the weight. The wind turbine blade prepared by this method has good strength and rigidity and light weight, which is beneficial for practical use.

[0005] In order to achieve the above object, the present invention provides a method for preparing a wind turbine blade, the method comprising the following steps: (1) Clean the shell mold surface, then lay the shell blade root preform on the shell mold, and then lay the shell bevel cloth and outer skin; (2) Laying the trailing edge beam: positioning and laying the trailing edge beam continuous felt, and laying the trailing edge beam according to the positioning; (3) Laying the shell beam: positioning and laying the beam continuous felt, and laying the shell beam according to the positioning; (4) Laying the core material: Lay the core material from the core material boundary toward the blade root and blade tip; (5) Laying the shell inner skin: Laying the shell inner skin on the surface of the core material so that it covers the core material, and cutting off the portion of the shell inner skin that exceeds the core material; (6) Laying out shell auxiliary materials: Lay out release cloth in the beam area, front and rear edge bonding area, blade root annular area, lightning arrester, counterweight and bonding angle area, and then lay out the composite guide net, vacuum unit and glue injection pipeline in sequence; (7) Laying the shell vacuum bag film: The shell vacuum bag film includes a first layer of vacuum bag film and a second layer of vacuum bag film. First, the first layer of vacuum bag film is unfolded in the cavity of the shell mold where the shell needs to be poured and adheres to the inner wall of the cavity. Then, the first layer of vacuum bag film is pre-tightened to make the pressure in the first layer of vacuum bag film 40-50mbar. Then, the second layer of vacuum bag film is unfolded in the cavity of the shell mold where the shell needs to be poured and adheres to the inner wall of the cavity. Then, the second layer of vacuum bag film is pre-tightened to make the pressure in the second layer of vacuum bag film 40-50mbar. Finally, the shell vacuum bag film is air-tightly connected to the glue injection pipeline; (8) Shell pouring: After degassing, pour the polyurethane resin into the area to be poured into the shell; (9) Shell pre-curing: pre-curing the shell after the polyurethane resin is poured; (10) Web bonding: Multiple webs are bonded together and fixed through web connecting plates, and then hoisted to the web installation position and bonded and fixed; (11) Mold closing and glue scraping: Turn the shell mold over to try mold closing, then glue the counterweight box and connect the lightning protection wire, then remove the release cloth at each position and scrape glue.

[0006] Preferably, in step (1), the method for laying the shell blade root preform comprises: laying a demoulding cloth and a shell blade root preform on the shell mold in sequence, and then sealing the space between the shell mold and the shell blade root preform, and making the space in a vacuum state.

[0007] Preferably, in step (1), the angled cloth is a glass fiber cloth layer, and the method of laying the shell angled cloth and outer skin comprises: laying the glass fiber cloth layer in the shell mold, and then laying the outer skin large cloth, outer skin patch cloth, outer skin reinforcement layer, reinforcement cloth layer and outer skin continuous felt in sequence.

[0008] Preferably, the raw material for preparing the trailing edge beam includes at least one of carbon fiber, polyurethane and glass fiber.

[0009] Preferably, the raw material for preparing the core material includes at least one of PET, PBT, PE and PVC.

[0010] Preferably, in step (3), the shell beam is manufactured by pre-infusing carbon fiber prepreg into a beam mold, and the manufacturing method comprises the following steps: (3-1) Pretreatment of carbon fiber prepreg: keep the relative humidity of the environment no more than 75%, thaw the carbon fiber prepreg at 30-35°C for 12-24h, and make the temperature of the carbon fiber prepreg reach 20-35°C; (3-2) Laying the lower mold release cloth: unfold the lower mold release cloth to cover the bottom of the mold, adjust the axial position and the chordal position, and then fix the lower mold release cloth; (3-3) Laying carbon fiber prepreg: The carbon fiber prepreg is laid by a laying vehicle, and each layer of carbon fiber prepreg is cut after laying. After laying ten layers of carbon fiber prepreg, the surface temperature of the last laying area is tested and controlled to be 30-40°C; (3-4) Laying auxiliary materials on the beam: the auxiliary materials on the beam include an upper release cloth, an isolation film and a breathable felt, and the auxiliary materials on the beam are laid in the order of the upper release cloth, the isolation film and the breathable felt; (3-5) Laying vacuum system: the vacuum system includes a vacuum device, a vacuum continuous felt and a vacuum bag film; (3-6) Curing and demolding: Turn on the vacuum system and maintain the surface temperature of the beam after laying in step (3-5) not exceeding 110°C. After curing at 60-80°C for 6-8 hours, keep it at 100-110°C for 5-7 hours, then remove the auxiliary materials on the beam and perform demolding.

[0011] Preferably, in step (6), the glue injection pipeline comprises a glue injection ohmic tube and a glue injection seat, and the glue injection ohmic tube is connected to the glue injection seat.

[0012] Preferably, in step (8), the shell is poured by integral integral pouring or manual pouring.

[0013] Preferably, the conditions for the shell infusion include: a temperature of 40-45°C.

[0014] Preferably, in step (9), the pre-curing treatment conditions include: maintaining a constant temperature at 50-60°C for 1-3 hours, and then maintaining a constant temperature at 70-80°C for 0.5-3 hours.

[0015] Preferably, in step (10), the web is bonded by windward shell bonding or leeward shell bonding.

[0016] Preferably, in step (10), the web is manufactured by pre-infusing a web mold with carbon fiber prepreg, and the manufacturing method comprises the following steps: (10-1) Pretreatment of carbon fiber prepreg: Keep the relative humidity of the environment no more than 75%, thaw the carbon fiber prepreg at 30-35°C for 12-24h, and make the temperature of the carbon fiber prepreg reach 20-35°C; (10-2) Laying the lower mold release cloth: unfold the lower mold release cloth to cover the bottom of the mold, adjust the axial position and the chordal position, and then fix the lower mold release cloth; (10-3) Laying carbon fiber prepreg: The carbon fiber prepreg is laid by a laying vehicle, and each layer of carbon fiber prepreg is cut after laying. After laying ten layers of carbon fiber prepreg, the surface temperature of the last laying area is tested and controlled to be 30-40°C; (10-4) Laying the web auxiliary materials: the web auxiliary materials include an upper release cloth, an isolation film and a breathable felt, and the web auxiliary materials are laid in the order of the upper release cloth, the isolation film and the breathable felt; (10-5) Laying vacuum system: the vacuum system includes a vacuum device, a vacuum continuous felt and a vacuum bag film; (10-6) Curing and demolding: Turn on the vacuum system and maintain the surface temperature of the beam after laying in step (10-5) not exceeding 110°C. After curing at 60-80°C for 6-8 hours, keep it at 100-110°C for 6-8 hours, then remove the web auxiliary material and perform demolding.

[0017] A second aspect of the present invention provides a wind turbine blade prepared by the aforementioned method.

[0018] According to the preparation method of wind turbine blades of the present invention, the shell blade root prefabricated part, the bevel cloth and the outer skin are laid on the shell mold in sequence, and then the trailing edge beam, the main beam and the core material are laid, and then the polyurethane resin is poured into the blade shell by the vacuum infusion method to form the blade shell and the web is installed, and after mold closing and glue scraping, it is formed into a wind turbine blade, which has the advantage of overall rapid molding; the main beam and the web are prefabricated with carbon fiber prepreg, which increases the overall strength and rigidity of the blade and reduces the weight; polyurethane resin is used instead of traditional epoxy resin and the blade shell is formed by vacuum infusion, which utilizes the better wetting effect of polyurethane resin and the glass fiber cloth layer of the shell skin, can shorten the shell vacuum infusion molding time, avoid the change of the core material and other component materials caused by long-term heat preservation, and no post-curing is required, shortening the production cycle and saving energy consumption and cost.

[0019] The wind turbine blades prepared according to the method of the present invention adopt carbon fiber prepreg with better strength and lighter weight as raw materials to pre-prepare the beam and the web, and adopt polyurethane resin to prepare the blade shell by vacuum infusion, which effectively improves the strength and rigidity of the blades, reduces the weight of the blades, and shortens the production cycle, which is beneficial to practical use. DETAILED DESCRIPTION

[0020] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0021] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0022] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, unless otherwise specified, features defined as "first" and "second" may explicitly or implicitly include one or more of the features; "plurality" means two or more. The term "including" and any variation thereof means non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components and / or combinations thereof may exist or be added.

[0023] In addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internally connected between two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] The method for preparing a wind turbine blade of the present invention comprises the following steps: (1) Clean the shell mold surface, then lay the shell blade root preform on the shell mold, and then lay the shell bevel cloth and outer skin; (2) Laying the trailing edge beam: positioning and laying the trailing edge beam continuous felt, and laying the trailing edge beam according to the positioning; (3) Laying the shell beam: positioning and laying the beam continuous felt, and laying the shell beam according to the positioning; (4) Laying the core material: Lay the core material from the core material boundary toward the blade root and blade tip; (5) Laying the shell inner skin: Laying the shell inner skin on the surface of the core material so that it covers the core material, and cutting off the portion of the shell inner skin that exceeds the core material; (6) Laying out shell auxiliary materials: Lay out release cloth in the beam area, front and rear edge bonding area, blade root annular area, lightning arrester, counterweight and bonding angle area, and then lay out the composite guide net, vacuum unit and glue injection pipeline in sequence; (7) Laying the shell vacuum bag film: The shell vacuum bag film includes a first layer of vacuum bag film and a second layer of vacuum bag film. First, the first layer of vacuum bag film is unfolded in the cavity of the shell mold where the shell needs to be poured and adheres to the inner wall of the cavity. Then, the first layer of vacuum bag film is pre-tightened to make the pressure in the first layer of vacuum bag film 40-50mbar. Then, the second layer of vacuum bag film is unfolded in the cavity of the shell mold where the shell needs to be poured and adheres to the inner wall of the cavity. Then, the second layer of vacuum bag film is pre-tightened to make the pressure in the second layer of vacuum bag film 40-50mbar. Finally, the shell vacuum bag film is air-tightly connected to the glue injection pipeline; (8) Shell pouring: After degassing, pour the polyurethane resin into the area to be poured into the shell; (9) Shell pre-curing: pre-curing the shell after the polyurethane resin is poured; (10) Web bonding: Multiple webs are bonded together and fixed through web connecting plates, and then hoisted to the web installation position and bonded and fixed; (11) Mold closing and glue scraping: Turn the shell mold over to try mold closing, then glue the counterweight box and connect the lightning protection wire, then remove the release cloth at each position and scrape glue.

[0025] In the method described in the present invention, preferably, in step (1), the cleaning step includes: cleaning the surface of the shell mold to make the surface of the shell mold clean and smooth, and then applying a release agent on the product area.

[0026] In the method described in the present invention, preferably, in step (1), the method for laying the shell blade root preform includes: laying a demoulding cloth and a shell blade root preform on the shell mold in sequence, and then sealing the space between the shell mold and the shell blade root preform, and making the space in a vacuum state. In a specific embodiment of the present invention, the method for laying the shell blade root preform includes: laying a demoulding cloth on the shell mold and fixing it with spray glue; hoisting the shell blade root preform above the shell mold, positioning and laying it using the steel flange positioning point and the skin positioning groove, and installing the positioning pin; sealing the flange edge of the shell blade root preform and the flange edge of the shell mold with a sealing strip, and sealing the vacuum bag film, and then evacuating the space between the flange edge of the shell blade root preform and the shell mold, and maintaining the vacuum state of the space until the pre-curing of the blade shell is completed.

[0027] In the method of the present invention, preferably, in step (1), the angled cloth is a glass fiber cloth layer, and the method of laying the shell angled cloth and outer skin comprises: laying the glass fiber cloth layer in the shell mold, and then laying the outer skin large cloth, outer skin patch cloth, outer skin reinforcement layer, reinforcement cloth layer and outer skin continuous felt in sequence. In a specific embodiment of the present invention, the method of laying the shell angled cloth and outer skin comprises: unfolding the glass fiber cloth layer in the shell mold, laying the glass fiber cloth layer by manual laying or intelligent laying equipment, and then laying the outer skin large cloth, outer skin patch cloth, outer skin reinforcement layer and reinforcement cloth layer in sequence, and finally laying the outer skin continuous felt.

[0028] In the method of the present invention, preferably, the raw material for preparing the trailing edge beam includes at least one of carbon fiber, polyurethane and glass fiber. More preferably, the raw material for preparing the trailing edge beam includes carbon fiber and / or glass fiber.

[0029] In the method described in the present invention, under preferred circumstances, the method for laying the trailing edge beam includes: setting a positioning line and determining the starting and ending points of the trailing edge beam and the chord-to-front and rear edge by means of a positioning tool or an intelligent positioning device, and then laying a continuous felt for the trailing edge beam, so that the length of the continuous felt for the trailing edge beam exceeds the starting and ending points of the trailing edge beam and the chord-to-front and rear edge by 30-50 mm; and then hoisting the trailing edge beam above the shell mold, and laying the trailing edge beam according to the positioning of the starting and ending points of the trailing edge beam and the chord-to-front and rear edge.

[0030] In the method described in the present invention, preferably, in step (3), the method for laying the beam includes: setting a positioning line by means of a positioning tool or an intelligent positioning device, then cutting and laying the beam continuous felt according to the shape and size of the laying area, and then hoisting and laying the beam according to the positioning line.

[0031] In the method of the present invention, preferably, in step (3), the shell beam is manufactured by pre-infusing carbon fiber prepreg into a beam mold, and the manufacturing method comprises the following steps: (3-1) Pretreatment of carbon fiber prepreg: keep the relative humidity of the environment no more than 75%, thaw the carbon fiber prepreg at 30-35°C for 12-24h, and make the temperature of the carbon fiber prepreg reach 20-35°C; (3-2) Laying the lower mold release cloth: unfold the lower mold release cloth to cover the bottom of the mold, adjust the axial position and the chordal position, and then fix the lower mold release cloth; (3-3) Laying carbon fiber prepreg: The carbon fiber prepreg is laid by a laying vehicle, and each layer of carbon fiber prepreg is cut after laying. After laying ten layers of carbon fiber prepreg, the surface temperature of the last laying area is tested and controlled to be 30-40°C; (3-4) Laying auxiliary materials on the beam: the auxiliary materials on the beam include an upper release cloth, an isolation film and a breathable felt, and the auxiliary materials on the beam are laid in the order of the upper release cloth, the isolation film and the breathable felt; (3-5) Laying vacuum system: the vacuum system includes a vacuum device, a vacuum continuous felt and a vacuum bag film; (3-6) Curing and demolding: Turn on the vacuum system and keep the surface temperature of the beam after laying in step (3-5) not more than 110°C. After curing at 60-80°C for 6-8h, keep it at 100-110°C for 5-7h, then remove the auxiliary materials on the beam and perform demolding. More preferably, after curing at 65-78°C for 6.5-7.5h, keep it at 102-108°C for 5.5-6.5h, then remove the auxiliary materials on the beam and perform demolding. In the present invention, the above-mentioned curing conditions can make the Shore hardness of the resin part after curing not less than 65, which meets the strength requirements of wind turbine blades.

[0032] In the method of the present invention, preferably, the raw material for preparing the core material includes at least one of PET, PBT, PE and PVC. More preferably, the raw material for preparing the core material includes at least one of PET, PBT and PE. Most preferably, the raw material for preparing the core material includes PET and / or PE.

[0033] In the method described in the present invention, preferably, in step (4), the method for laying the core material comprises: laying the core material from the boundary of the core material toward the blade root and the blade tip, respectively, so that the core material and the contact side of the beam are close to the edge of the beam, and the chamfer near the shell parting surface is fixed by spraying glue, and after laying is completed, the core material is patted toward the laying starting point and the beam direction, so that the core materials and the core materials and the beam are tightly fitted to reduce gaps.

[0034] In the method described in the present invention, preferably, in step (6), the method of laying the composite flow guide net includes: unfolding the composite flow guide net in the shell mold cavity to cover the area from the front edge of the beam to the parting line in the rear edge of the mold. Lay the composite flow guide net along the front edge of the beam, touch the edge of the beam by hand to determine the edge of the beam, fix it in sections at a certain distance from the beam edge, and lay a supplementary composite flow guide net in the area with a larger width between the composite flow guide net and the parting line at the rear edge.

[0035] In the method described in the present invention, preferably, in step (6), the glue injection pipeline includes a glue injection ohmic tube and a glue injection seat, and the glue injection ohmic tube is connected to the glue injection seat.

[0036] In the method described in the present invention, preferably, in step (8), the shell is poured by integral integral pouring or manual pouring.

[0037] In the method of the present invention, preferably, in step (8), the conditions for the shell infusion include: a temperature of 40-45°C, more preferably 41-44°C.

[0038] In the method of the present invention, preferably, in step (9), the pre-curing treatment conditions include: constant temperature at 50-60°C for 1-3h, and then constant temperature at 70-80°C for 0.5-3h. More preferably, the pre-curing treatment conditions include: constant temperature at 50-60°C for 1-3h, and then constant temperature at 70-80°C for 0.5-3h. In the present invention, the above pre-curing conditions can make the Shore hardness of the resin part after curing not less than 65, which meets the strength requirements of wind turbine blades.

[0039] In the method of the present invention, preferably, in step (10), the web is bonded by windward shell bonding or leeward shell bonding.

[0040] In the method of the present invention, preferably, in step (10), the web is made by pre-infusing carbon fiber prepreg into a web mold, and the making method comprises the following steps: (10-1) Pretreatment of carbon fiber prepreg: Keep the relative humidity of the environment no more than 75%, thaw the carbon fiber prepreg at 30-35°C for 12-24h, and make the temperature of the carbon fiber prepreg reach 20-35°C; (10-2) Laying the lower mold release cloth: unfold the lower mold release cloth to cover the bottom of the mold, adjust the axial position and the chordal position, and then fix the lower mold release cloth; (10-3) Laying carbon fiber prepreg: The carbon fiber prepreg is laid by a laying vehicle, and each layer of carbon fiber prepreg is cut after laying. After laying ten layers of carbon fiber prepreg, the surface temperature of the last laying area is tested and controlled to be 30-40°C; (10-4) Laying web auxiliary materials: the auxiliary materials on the beam include an upper mold release cloth, an isolation membrane and a breathable felt, and the web auxiliary materials are laid in the order of the upper mold release cloth, the isolation membrane and the breathable felt; (10-5) Laying vacuum system: the vacuum system includes a vacuum device, a vacuum continuous felt and a vacuum bag film; (10-6) Curing and demolding: Turn on the vacuum system and keep the surface temperature of the beam after laying in step (10-5) not more than 110°C. After curing at 60-80°C for 6-8h, keep it at 100-110°C for 6-8h, then remove the auxiliary materials on the beam and perform demolding. More preferably, after curing at 65-75°C for 6.5-7.5h, keep it at 102-18°C for 6.5-7.5h, then remove the auxiliary materials on the beam and perform demolding. In the present invention, the above-mentioned curing conditions can make the Shore hardness of the resin part after curing not less than 65, which meets the strength requirements of wind turbine blades.

[0041] In a specific embodiment of the present invention, the method for preparing a wind turbine blade according to the present invention comprises the following steps: (1) Cleaning the shell mold: clean the surface of the shell mold to make it clean and smooth, and then apply a release agent on the product area; (2) Laying the shell blade root prefabricated part: Lay a demoulding cloth on the shell mold after the treatment in step (1) and fix it with spray glue, lift the shell blade root prefabricated part to the top of the shell mold, position it using the steel flange positioning points and the skin positioning grooves, and install the positioning pins; then seal the flange edge of the shell blade root prefabricated part and the flange edge of the shell mold with a sealing strip, and seal the vacuum bag film, then evacuate the space between the flange edge of the shell blade root prefabricated part and the shell mold, and maintain the vacuum state of the space until the pre-curing of the blade shell is completed; (3) Laying the bevel cloth and outer skin: The bevel cloth is a glass fiber cloth layer. The glass fiber cloth layer is spread in the shell mold after being processed in step (2). The glass fiber cloth layer is laid manually or by intelligent laying equipment. Then, the outer skin large cloth, outer skin patch cloth, outer skin reinforcement layer and reinforcement cloth layer are laid in sequence. Finally, the outer skin continuous felt is laid. (4) Laying the trailing edge beam: the raw material for preparing the trailing edge beam includes at least one of carbon fiber, polyurethane and glass fiber; setting the positioning line and determining the starting and ending points of the trailing edge beam and the chord to the front and rear edge by positioning tooling or intelligent positioning equipment, and then laying the trailing edge beam continuous felt, so that the length of the trailing edge beam continuous felt exceeds the starting and ending points of the trailing edge beam and the chord to the front and rear edge by 30-50 mm; then hoisting the trailing edge beam to the top of the shell mold, and laying the trailing edge beam according to the positioning of the starting and ending points of the trailing edge beam and the chord to the front and rear edge; (5) Laying the shell girder: Setting the positioning line by means of positioning tooling or intelligent positioning equipment, then cutting and laying the girder continuous felt according to the shape and size of the laying area, and then hoisting and laying the girder according to the positioning line; the shell girder is made by pre-infusing carbon fiber prepreg in a girder mold, and the manufacturing method comprises the following steps: (5-1) Pretreatment of carbon fiber prepreg: keep the relative humidity of the environment no more than 75%, thaw the carbon fiber prepreg at 30-35°C for 12-24h, and make the temperature of the carbon fiber prepreg reach 20-35°C; (5-2) Laying the lower mold release cloth: unfold the lower mold release cloth to cover the bottom of the mold, adjust the axial position and the chordal position, and then fix the lower mold release cloth; (5-3) Laying carbon fiber prepreg: The carbon fiber prepreg is laid by a laying vehicle, and each layer of carbon fiber prepreg is cut after laying. After laying ten layers of carbon fiber prepreg, the surface temperature of the last laying area is tested and controlled to be 30-40°C; (5-4) Laying auxiliary materials on the beam: the auxiliary materials on the beam include an upper release cloth, an isolation film and a breathable felt, and the auxiliary materials on the beam are laid in the order of the upper release cloth, the isolation film and the breathable felt; (5-5) Laying vacuum system: the vacuum system includes a vacuum device, a vacuum continuous felt and a vacuum bag film; (5-6) Curing and demoulding: Turn on the vacuum system and keep the surface temperature of the beam after laying in step (5-5) not more than 110°C. After curing at 60-80°C for 6-8h, keep it at 100-110°C for 5-7h, then remove the auxiliary materials on the beam and perform demoulding; (6) Laying the core material: The raw material for preparing the core material includes at least one of PET, PBT, PE and PVC; the method for laying the core material includes: laying the core material from the boundary of the core material toward the blade root and the blade tip, respectively, so that the contact side of the core material and the beam is close to the edge of the beam, using glue spray to fix the chamfer near the parting surface of the shell, and after laying, patting the core material toward the laying starting point and the beam direction, so that the core materials and the core materials and the beam are closely attached to each other and the gap is reduced; (7) Laying the shell inner skin: Laying the shell inner skin on the surface of the core material so that it covers the core material, and cutting off the portion of the shell inner skin that exceeds the core material; (8) Laying shell auxiliary materials: Lay release cloth in the beam area, front and rear edge bonding areas, blade root annular area, lightning arrester, counterweight and bonding angle area, and then lay the composite guide net, vacuum unit and glue injection pipeline in sequence; the method of laying the composite guide net includes: unfolding the composite guide net in the shell mold cavity, covering the area from the front edge of the beam to the parting line in the rear edge of the mold. Lay the straight edge of the composite guide net along the front edge of the beam, touch the edge of the beam by hand to determine the edge of the beam, fix it in sections at a certain distance from the beam edge, and lay a supplementary composite guide net in the area with a larger width between the rear edge composite guide net and the parting line; the glue injection pipeline includes a glue injection ohm tube and a glue injection seat, and the glue injection ohm tube is connected to the glue injection seat; (9) Laying the shell vacuum bag film: The shell vacuum bag film includes a first layer of vacuum bag film and a second layer of vacuum bag film. First, the first layer of vacuum bag film is unfolded in the cavity of the shell mold where the shell needs to be poured and adheres to the inner wall of the cavity. Then, the first layer of vacuum bag film is pre-tightened to make the pressure in the first layer of vacuum bag film 40-50mbar. Then, the second layer of vacuum bag film is unfolded in the cavity of the shell mold where the shell needs to be poured and adheres to the inner wall of the cavity. Then, the second layer of vacuum bag film is pre-tightened to make the pressure in the second layer of vacuum bag film 40-50mbar. Finally, the shell vacuum bag film is air-tightly connected to the glue injection pipeline; (10) Shell pouring: After degassing, the polyurethane resin is poured into the area to be poured into the shell. The shell pouring adopts one-piece integral pouring or manual pouring. The conditions of the shell pouring include: the temperature is 40-45°C; (11) Shell pre-curing: The shell after being infused with polyurethane resin is pre-cured, and the pre-curing conditions include: constant temperature at 50-60°C for 1-3 hours, and then constant temperature at 70-80°C for 0.5-3 hours; (12) Web bonding: multiple webs are bonded together and fixed through web connecting plates, and then hoisted to the web installation position and bonded and fixed. The web bonding method is windward shell bonding or leeward shell bonding. The web is made by pre-infusing carbon fiber prepreg in a web mold. The manufacturing method includes the following steps: (12-1) Pretreatment of carbon fiber prepreg: Keep the relative humidity of the environment no more than 75%, thaw the carbon fiber prepreg at 30-35°C for 12-24h, and make the temperature of the carbon fiber prepreg reach 20-35°C; (12-2) Laying the lower mold release cloth: unfold the lower mold release cloth to cover the bottom of the mold, adjust the axial position and the chordal position, and then fix the lower mold release cloth; (12-3) Laying carbon fiber prepreg: The carbon fiber prepreg is laid by a laying vehicle, and each layer of carbon fiber prepreg is cut after laying. After laying ten layers of carbon fiber prepreg, the surface temperature of the last laying area is tested and controlled to be 30-40°C; (12-4) Laying the web auxiliary materials: the web auxiliary materials include an upper release cloth, an isolation film and a breathable felt, and the web auxiliary materials are laid in the order of the upper release cloth, the isolation film and the breathable felt; (12-5) Laying vacuum system: the vacuum system includes a vacuum device, a vacuum continuous felt and a vacuum bag film; (12-6) Curing and demolding: Turn on the vacuum system and keep the surface temperature of the beam after laying in step (12-5) not more than 110°C, cure at 60-80°C for 6-8h, and then keep at 100-110°C for 6-8h, then remove the web auxiliary material and perform demolding; (13) Mold closing and glue scraping: Turn the shell mold over to try to close the mold, then glue the counterweight box and connect the lightning protection wire, and then remove the release cloth at each position and scrape glue.

[0042] According to the preparation method of wind turbine blades of the present invention, the shell blade root prefabricated part, the bevel cloth and the outer skin are laid on the shell mold in sequence, and then the trailing edge beam, the main beam and the core material are laid, and then the polyurethane resin is poured into the blade shell by the vacuum infusion method to form the blade shell and the web is installed, and after mold closing and glue scraping, it is formed into a wind turbine blade, which has the advantage of overall rapid molding; the main beam and the web are prefabricated with carbon fiber prepreg, which increases the overall strength and rigidity of the blade and reduces the weight; polyurethane resin is used instead of traditional epoxy resin and the blade shell is formed by vacuum infusion, which utilizes the better wetting effect of polyurethane resin and the glass fiber cloth layer of the shell skin, can shorten the shell vacuum infusion molding time, avoid the change of the core material and other component materials caused by long-term heat preservation, and no post-curing is required, shortening the production cycle and saving energy consumption and cost.

[0043] The present invention also provides a wind turbine blade prepared by the above method.

[0044] The wind turbine blades prepared according to the method of the present invention adopt carbon fiber prepreg with better strength and lighter weight as raw materials to pre-prepare the beam and the web, and adopt polyurethane resin to prepare the blade shell by vacuum infusion, which effectively improves the strength and rigidity of the blades, reduces the weight of the blades, and shortens the production cycle, which is beneficial to practical use.

[0045] The wind turbine blade and its preparation method of the present invention are further described by examples. The examples are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples and preparation examples.

[0046] The methods in the following examples and preparation examples, unless otherwise specified, are all conventional methods in the art. The experimental materials used in the following examples and preparation examples, unless otherwise specified, are all commercially available.

[0047] Preparation Example 1 The shell beam is made by pre-infusing carbon fiber prepreg in the beam mold: (1) Pretreatment of carbon fiber prepreg: keep the relative humidity of the environment no more than 75%, thaw the carbon fiber prepreg at 30°C for 24 hours, and make the temperature of the carbon fiber prepreg reach 35°C; (2) Laying the lower mold release cloth: unfold the lower mold release cloth to cover the bottom of the mold, adjust the axial position and the chordal position, and then fix the lower mold release cloth; (3) Laying carbon fiber prepreg: The carbon fiber prepreg is laid by a laying vehicle, and each layer of carbon fiber prepreg is cut after laying. After laying ten layers of carbon fiber prepreg, the surface temperature of the last laying area is tested and controlled to be 32°C. (4) Laying auxiliary materials on the beam: the auxiliary materials on the beam include an upper release cloth, an isolation film and a breathable felt. The auxiliary materials on the beam are laid in the order of the upper release cloth, the isolation film and the breathable felt; (5) Laying vacuum system: the vacuum system includes a vacuum device, a vacuum continuous felt and a vacuum bag film; (6) Curing and demolding: Turn on the vacuum system and maintain the surface temperature of the beam after laying in step (5) not exceeding 110°C. After curing at 70°C for 7 hours, keep it at 105°C for 6 hours, then remove the auxiliary materials on the beam and perform demolding.

[0048] Preparation Example 2 The web is made by pre-infusing carbon fiber prepreg into the web mold: (1) Pretreatment of carbon fiber prepreg: keep the relative humidity of the environment no more than 75%, thaw the carbon fiber prepreg at 35°C for 18 hours, and make the temperature of the carbon fiber prepreg reach 30°C; (2) Laying the lower mold release cloth: unfold the lower mold release cloth to cover the bottom of the mold, adjust the axial position and the chordal position, and then fix the lower mold release cloth; (3) Laying carbon fiber prepreg: The carbon fiber prepreg is laid by a laying vehicle, and each layer of carbon fiber prepreg is cut after laying. After laying ten layers of carbon fiber prepreg, the surface temperature of the last laying area is tested and controlled to be 35°C. (4) Laying the web auxiliary materials: The web auxiliary materials include an upper release cloth, an isolation film and a breathable felt. The web auxiliary materials are laid in the order of the upper release cloth, the isolation film and the breathable felt. (5) Laying vacuum system: the vacuum system includes a vacuum device, a vacuum continuous felt and a vacuum bag film; (6) Curing and demolding: Turn on the vacuum system and maintain the surface temperature of the beam after laying in step (5) not exceeding 110°C. After curing at 70°C for 7 hours, keep it at 105°C for 7 hours, then remove the web auxiliary material and perform demolding.

[0049] Example 1 (1) Clean the surface of the shell mold to make it clean and smooth, and then apply a release agent on the product area; (2) Lay a demoulding cloth on the shell mold after the treatment in step (1) and fix it with spray glue, lift the shell blade root prefabricated part to the top of the shell mold, position it using the steel flange positioning point and the skin positioning groove, and install the positioning pin; then seal the flange edge of the shell blade root prefabricated part and the flange edge of the shell mold with a sealing strip, and seal the vacuum bag film, then evacuate the space between the flange edge of the shell blade root prefabricated part and the shell mold, and maintain the vacuum state of the space until the pre-curing of the blade shell is completed; (3) Unfolding the glass fiber cloth layer in the shell mold after being processed in step (2), laying the glass fiber cloth layer using an intelligent cloth laying device, and then laying the outer skin large cloth, outer skin patch cloth, outer skin reinforcement layer and reinforcement cloth layer in sequence, and finally laying the outer skin continuous felt; (4) Setting the positioning line and determining the starting and ending points of the trailing beam and the chord to the front and rear edge by using the intelligent positioning equipment, and then laying the trailing beam continuous felt, so that the length of the trailing beam continuous felt exceeds the starting and ending points of the trailing beam and the chord to the front and rear edge by 30 mm; then hoisting the carbon fiber trailing beam to the top of the shell mold, and laying the trailing beam according to the positioning of the starting and ending points of the trailing beam and the chord to the front and rear edge; (5) Set the positioning line through positioning tooling or intelligent positioning equipment, then cut and lay the beam continuous felt according to the shape and size of the laying area, and then hoist and lay the shell beam according to the position of the positioning line; (6) Lay the PVC core material from the core material boundary toward the blade root and blade tip, respectively, so that the contact side of the PVC core material and the beam is close to the edge of the beam, and use glue spray to fix the chamfer near the shell parting surface. After laying, pat the PVC core material toward the laying starting point and the beam direction, so that the PVC core materials and the PVC core materials and the beam fit tightly together to reduce the gap; (7) Laying the inner skin of the shell on the surface of the PVC core material so that it covers the PVC core material, and cutting off the portion of the inner skin of the shell that exceeds the portion covering the PVC core material; (8) Lay demoulding cloth in the beam area, front and rear edge bonding area, blade root annular area, lightning arrester, counterweight, and bonding angle area, then unfold the composite guide net in the shell mold cavity, covering the front edge of the beam to the parting line area of ​​the rear edge of the mold. Lay the composite guide net along the front edge of the beam with a straight edge. Use your hand to touch the edge of the beam to determine the edge of the beam. Fix it in sections at a certain distance from the beam edge, and lay a supplementary composite guide net in the area with a large width between the composite guide net and the parting line at the rear edge; lay a vacuum unit between the guide net and the parting line and fix it with a sealing strip or network tape. The vacuum unit is axially spaced to arrange the exhaust port and guide it to the parting surface of the shell mold; arrange the injection ohm tube and the injection seat. Use glass fiber cloth or demoulding cloth to protect the lap position of the ohm tube and the injection seat. Ensure that the injection tube and the injection seat are connected, and the lap direction of the ohm tube is consistent; (9) The shell vacuum bag film includes a first layer of vacuum bag film and a second layer of vacuum bag film. First, the first layer of vacuum bag film is unfolded in the cavity of the shell mold where the shell needs to be poured and adheres to the inner wall of the cavity. Then, the first layer of vacuum bag film is pre-tightened so that the pressure in the first layer of vacuum bag film is 65 mbar. Then, the second layer of vacuum bag film is unfolded in the cavity of the shell mold where the shell needs to be poured and adheres to the inner wall of the cavity. Then, the second layer of vacuum bag film is pre-tightened so that the pressure in the second layer of vacuum bag film is 65 mbar. Finally, the shell vacuum bag film is air-tightly connected to the glue injection pipeline; (10) After degassing the polyurethane resin, it is injected into the area to be poured into the shell by an integrated integral pouring method, and the pouring temperature is 45°C; (11) Curing the shell after infusing the polyurethane resin at a constant temperature of 55°C for 2 hours, and then curing it at a constant temperature of 75°C for 2 hours; (12) The two webs are bonded and fixed by a web connecting plate, and then hoisted to the web installation position, and bonded and fixed by using the windward shell bonding method; (13) Reverse the shell mold to test mold, then glue the counterweight box and connect the lightning protection wire, then remove the release cloth at each position and scrape the glue.

[0050] The method for preparing the wind turbine blade of the present invention uses carbon fiber prepreg to preform the main beam and the web, and then uses vacuum infusion of polyurethane resin to prepare the blade shell, which has the advantage of overall rapid prototyping; the main beam and the web are preformed with carbon fiber prepreg, which increases the overall strength and rigidity of the blade and reduces the weight; polyurethane resin is used to replace the traditional epoxy resin infusion, which has a fast infusion speed and a short curing time, avoids long-term heat aging of the core material and other components, and does not need to undergo a post-curing process, shortening the production cycle. The wind turbine blade prepared by this method has good strength and rigidity and light weight, which is conducive to practical use.

[0051] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a wind turbine blade, characterized in that: The method comprises the following steps: (1) Clean the shell mold surface, then lay the shell blade root preform on the shell mold, and then lay the shell bevel cloth and outer skin; (2) Laying the trailing edge beam: positioning and laying the trailing edge beam continuous felt, and laying the trailing edge beam according to the positioning; (3) Laying the shell beam: positioning and laying the beam continuous felt, and laying the shell beam according to the positioning; (4) Laying the core material: Lay the core material from the core material boundary toward the blade root and blade tip; (5) Laying the shell inner skin: Laying the shell inner skin on the surface of the core material so that it covers the core material, and cutting off the portion of the shell inner skin that exceeds the core material; (6) Laying out shell auxiliary materials: Lay out release cloth in the beam area, front and rear edge bonding area, blade root annular area, lightning arrester, counterweight and bonding angle area, and then lay out the composite guide net, vacuum unit and glue injection pipeline in sequence; (7) Laying the shell vacuum bag film: The shell vacuum bag film includes a first layer of vacuum bag film and a second layer of vacuum bag film. First, the first layer of vacuum bag film is unfolded in the cavity of the shell mold where the shell needs to be poured and adheres to the inner wall of the cavity. Then, the first layer of vacuum bag film is pre-tightened to make the pressure in the first layer of vacuum bag film 40-50mbar. Then, the second layer of vacuum bag film is unfolded in the cavity of the shell mold where the shell needs to be poured and adheres to the inner wall of the cavity. Then, the second layer of vacuum bag film is pre-tightened to make the pressure in the second layer of vacuum bag film 40-50mbar. Finally, the shell vacuum bag film is air-tightly connected to the glue injection pipeline; (8) Shell pouring: After degassing, pour the polyurethane resin into the area to be poured into the shell; (9) Shell pre-curing: pre-curing the shell after the polyurethane resin is poured; (10) Web bonding: Multiple webs are bonded together and fixed through web connecting plates, and then hoisted to the web installation position and bonded and fixed; (11) Mold closing and glue scraping: Turn the shell mold over to try mold closing, then glue the counterweight box and connect the lightning protection wire, then remove the release cloth at each position and scrape glue.

2. The method according to claim 1, characterized in that In step (1), the method for laying the shell blade root preform comprises: laying a demoulding cloth and a shell blade root preform on the shell mold in sequence, and then sealing the space between the shell mold and the shell blade root preform and placing the space in a vacuum state.

3. The method according to claim 1, characterized in that In step (1), the angled cloth is a glass fiber cloth layer, and the method for laying the shell angled cloth and outer skin comprises: laying the glass fiber cloth layer in the shell mold, and then laying the outer skin large cloth, outer skin patch cloth, outer skin reinforcement layer, reinforcement cloth layer and outer skin continuous felt in sequence.

4. The method according to claim 1, characterized in that The raw material for preparing the trailing edge beam includes at least one of carbon fiber, polyurethane and glass fiber.

5. The method according to claim 1, characterized in that The raw material for preparing the core material includes at least one of PET, PBT, PE and PVC.

6. The method according to claim 1, characterized in that In step (3), the shell beam is manufactured by pre-infusing carbon fiber prepreg into a beam mold, and the manufacturing method includes the following steps: (3-1) Pretreatment of carbon fiber prepreg: keep the relative humidity of the environment no more than 75%, thaw the carbon fiber prepreg at 30-35°C for 12-24h, and make the temperature of the carbon fiber prepreg reach 20-35°C; (3-2) Laying the lower mold release cloth: unfold the lower mold release cloth to cover the bottom of the mold, adjust the axial position and the chordal position, and then fix the lower mold release cloth; (3-3) Laying carbon fiber prepreg: The carbon fiber prepreg is laid by a laying vehicle, and each layer of carbon fiber prepreg is cut after laying. After laying ten layers of carbon fiber prepreg, the surface temperature of the last laying area is tested and controlled to be 30-40°C; (3-4) Laying auxiliary materials on the beam: the auxiliary materials on the beam include an upper release cloth, an isolation film and a breathable felt, and the auxiliary materials on the beam are laid in the order of the upper release cloth, the isolation film and the breathable felt; (3-5) Laying vacuum system: the vacuum system includes a vacuum device, a vacuum continuous felt and a vacuum bag film; (3-6) Curing and demolding: Turn on the vacuum system and maintain the surface temperature of the beam after laying in step (3-5) not exceeding 110°C. After curing at 60-80°C for 6-8 hours, keep it at 100-110°C for 5-7 hours, then remove the auxiliary materials on the beam and perform demolding.

7. The method according to claim 1, characterized in that In step (6), the glue injection pipeline includes a glue injection ohmic tube and a glue injection seat, and the glue injection ohmic tube is connected to the glue injection seat.

8. The method according to claim 1, characterized in that In step (8), the shell is poured by integral integral pouring or manual pouring; Preferably, the conditions for the shell infusion include: a temperature of 40-45°C.

9. The method according to claim 1, characterized in that In step (9), the pre-curing treatment conditions include: maintaining a constant temperature at 50-60°C for 1-3 hours, and then maintaining a constant temperature at 70-80°C for 0.5-3 hours.

10. The method according to claim 1, characterized in that In step (10), the web is bonded by windward shell bonding or leeward shell bonding.

11. The method according to any one of claims 1 or 10, characterized in that: In step (10), the web is manufactured by pre-infusing carbon fiber prepreg into a web mold, and the manufacturing method comprises the following steps: (10-1) Pretreatment of carbon fiber prepreg: Keep the relative humidity of the environment no more than 75%, thaw the carbon fiber prepreg at 30-35°C for 12-24h, and make the temperature of the carbon fiber prepreg reach 20-35°C; (10-2) Laying the lower mold release cloth: unfold the lower mold release cloth to cover the bottom of the mold, adjust the axial position and the chordal position, and then fix the lower mold release cloth; (10-3) Laying carbon fiber prepreg: The carbon fiber prepreg is laid by a laying vehicle, and each layer of carbon fiber prepreg is cut after laying. After laying ten layers of carbon fiber prepreg, the surface temperature of the last laying area is tested and controlled to be 30-40°C; (10-4) Laying the web auxiliary materials: the web auxiliary materials include an upper mold release cloth, an isolation film, and a breathable felt, and the web auxiliary materials are laid in the order of the upper mold release cloth, the isolation film, and the breathable felt; (10-5) Laying vacuum system: the vacuum system includes a vacuum device, a vacuum continuous felt and a vacuum bag film; (10-6) Curing and demolding: Turn on the vacuum system and maintain the surface temperature of the beam after laying in step (10-5) not exceeding 110°C. After curing at 60-80°C for 6-8 hours, keep it at 100-110°C for 6-8 hours, then remove the web auxiliary material and perform demolding.

12. A wind turbine blade prepared according to the method according to any one of claims 1 to 11.