A method for recycling waste wind turbine blades

Abstract

The present invention provides a method for recycling waste wind turbine blades, and relates to the field of recycling waste wind turbine blades. The method comprises: mixing waste wind turbine blade materials within a preset size range with thermoplastic materials to obtain molding materials; molding the molding materials to obtain wind power supporting products. The method can not only greatly reduce solid waste, thereby solving the problem of ecological environmental pollution caused by waste wind turbine blades, but also make waste wind turbine blades into blade root platforms or manhole covers by molding, which can make full use of the residual mechanical properties and value of waste wind turbine blades as glass fiber composite materials, and realize the resource and high-value recycling of waste wind turbine blades. In addition, compared with the traditional method for manufacturing blade root platforms and manhole covers, the wind power supporting products such as blade root platforms and manhole covers made by this method can reduce the cost of raw materials because most of the raw materials are waste wind turbine blade materials.

Description

Technical Field

[0001] The present invention relates to the technical field of recycling waste wind turbine blades, and in particular to a method for recycling waste wind turbine blades. Background Art

[0002] In the prior art, wind turbine blades usually use glass fiber reinforced epoxy resin as raw material, which is a thermosetting composite material. After curing and molding, the original properties of the material cannot be restored, so it cannot be degraded. This is a huge threat to my country's ecological civilization construction. Traditional landfill and incineration treatments occupy a large amount of land resources, causing serious groundwater and air pollution, and do not give full play to the residual mechanical properties and value of glass fiber composite materials. Faced with a large number of retired blades in the future, their resource recovery and high-value reuse has become a difficult problem that the industry generally pays attention to. Therefore, it is of great significance to develop a low-cost and high-efficiency method for the regeneration of waste wind turbine blades and make them into high-value-added products that meet performance requirements. Summary of the invention

[0003] The purpose of the present invention is to provide a method for recycling waste wind turbine blades to solve the technical problems existing in the prior art that waste wind turbine blades seriously pollute the ecological environment and have low value utilization rate.

[0004] The method for recycling waste wind turbine blades provided by the present invention comprises:

[0005] Mixing waste wind turbine blade materials within a preset size range with thermoplastic materials to obtain molding materials;

[0006] The molding material is molded to obtain a wind power supporting product.

[0007] Furthermore, during mixing, the mixing temperature is controlled to be 150-200°C.

[0008] Furthermore, the thermoplastic material includes at least one of high-density polyethylene (HDPE), polypropylene (PP), polyethylene glycol terephthalate (PET) and polyurethane (PU).

[0009] Furthermore, the preset size range of the waste wind turbine blade material is a length less than or equal to 50 mm and a width less than or equal to 10 mm.

[0010] Furthermore, epoxy resin, curing agent, accelerator and low shrinkage additive are also mixed into the molding material.

[0011] Furthermore, the low shrinkage additive includes at least one of polystyrene (PS), polyethylene (PE) and polypropylene.

[0012] Furthermore, the thickness of the molding material is controlled to be 5-50 mm.

[0013] Furthermore, the waste wind turbine blade material is chopped fibers obtained by cutting waste wind turbine blades.

[0014] Furthermore, the compression molding of the molding material comprises: transferring the molding material into a mold, and preheating and prepressing the mold, the preheating temperature is 50-60° C., and the prepressing pressure is 6-10 MPa.

[0015] Furthermore, the compression molding of the molding material further includes: after the material is added into the mold, the mold is closed, the air is exhausted and pressure-maintaining and curing is performed, and during the pressure-maintaining and curing, the pressure in the mold is controlled to be 20-25Mpa.

[0016] The method for recycling waste wind turbine blades provided by the present invention can produce the following beneficial effects:

[0017] The method for recycling waste wind turbine blades provided by the present invention can make wind turbine blade root platforms or manhole covers and other wind turbine supporting products required by wind turbine blades by mixing waste wind turbine blade materials within a preset size range with thermoplastic materials, and molding the molding materials obtained by the mixing, which can not only greatly reduce solid waste, thereby solving the ecological environment pollution problem caused by waste wind turbine blades, but also make waste wind turbine blades into blade root platforms or manhole covers by molding, which can make full use of the residual mechanical properties and value of waste wind turbine blades as glass fiber composite materials, and realize the resource and high-value recycling of waste wind turbine blades. In addition, compared with the traditional method for manufacturing blade root platforms and manhole covers, the wind turbine supporting products such as blade root platforms and manhole covers made by this method can reduce the cost of raw materials because most of the raw materials are waste wind turbine blade materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0019] Figure 1 A flowchart of the method for recycling waste wind turbine blades provided by the present invention;

[0020] Figure 2 A detailed flow chart of the method for recycling waste wind turbine blades provided by the present invention for manufacturing wind turbine supporting products. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] This embodiment provides a method for recycling waste wind turbine blades. Figure 1 As shown, including:

[0023] S102, mixing the waste wind turbine blade material within a preset size range with the thermoplastic material to obtain a molding material.

[0024] Specifically, in this embodiment, during mixing, the prepared waste wind turbine blade material can be fluffed and then fully kneaded with the thermoplastic resin glue in an internal mixer until the resin is completely mixed, and then dried or air-dried to a proper viscosity, thereby obtaining the desired molding material. Among them, adding thermoplastic material can appropriately increase the fluidity and plasticity of the molding material, thereby making the molding material more evenly mixed and having a certain plasticity.

[0025] S104, molding the molding material to obtain wind power supporting products, such as blade root platforms and manhole covers required for manufacturing wind power blades.

[0026] The method for recycling waste wind turbine blades provided in this embodiment can make wind turbine blade root platforms or manhole covers and other wind turbine supporting products required by wind turbine blades by mixing waste wind turbine blade materials within a preset size range with thermoplastic materials and molding the molding materials obtained by mixing. This can not only greatly reduce solid waste, thereby solving the ecological and environmental pollution problem caused by waste wind turbine blades, but also make waste wind turbine blades into blade root platforms or manhole covers by molding, which can make full use of the residual mechanical properties and value of waste wind turbine blades as glass fiber composite materials, and realize the resource and high-value recycling of waste wind turbine blades. In addition, compared with the traditional method for manufacturing blade root platforms and manhole covers, the wind turbine supporting products such as blade root platforms and manhole covers made by this method can reduce the cost of raw materials because most of the raw materials are waste wind turbine blade materials.

[0027] Specifically, in this embodiment, the preset size range of the waste wind turbine blade material is a length of less than or equal to 50 mm and a width of less than or equal to 10 mm, and the waste wind turbine blade material is a chopped fiber obtained by cutting the waste wind turbine blades. Of course, the waste wind turbine blade material can also be obtained by other methods other than cutting. As long as its size is within the preset size range, it can be made into wind turbine supporting products such as blade root platforms or manhole covers using the method provided in this embodiment. This application does not impose specific restrictions on the method for obtaining waste wind turbine blade materials.

[0028] Specifically, in this embodiment, the thermoplastic material includes at least one of high-density polyethylene, polypropylene, polyethylene terephthalate and polyurethane.

[0029] Specifically, in this embodiment, epoxy resin, curing agent, accelerator and low shrinkage additive are also mixed in the molding material to ensure the fluidity of the molding material and the mechanical properties of the final product. The low shrinkage additive includes at least one of polystyrene, polyethylene and polypropylene, which is used to release internal stress through partial relaxation to compensate for polymerization shrinkage, thereby reducing the shrinkage rate.

[0030] Specifically, in this embodiment, during mixing, the mixing temperature is controlled to be 150-200° C. More specifically, the mixing temperature can be determined according to the strength requirements of the finished product. When manufacturing the manhole cover, since the strength requirements of the manhole cover are relatively low, the temperature of the internal mixer can be controlled to be 180° C.; and when manufacturing the blade root platform, since the strength requirements of the blade root platform are relatively high, the temperature of the internal mixer can be controlled to be 200° C.

[0031] Specifically, in this embodiment, the thickness of the molded material is controlled to be 5-50 mm. More specifically, the thickness of the molded material is controlled according to the thickness of the finished product. When manufacturing a manhole cover, the thickness of the molded material is controlled to be 9 mm; when manufacturing a blade root platform, the thickness of the molded material is controlled to be 36 mm.

[0032] After the molding material is obtained, it can be molded. Specifically, in this embodiment, the molding material is compression molded, including: transferring the molding material to a mold, and preheating and pre-pressing the mold, the preheating temperature is 50-60°C, and the pre-pressing pressure is 6-10Mpa.

[0033] Specifically, in this embodiment, the molding process also includes: before transferring the molding material into the mold, preheating the mold and applying a mold release agent to the mold to ensure that the finished product can be demolded smoothly. While the mold release agent is solidifying, the waste wind turbine blade material can be prepared; after the mold release agent is solidified, the material can be added into the mold.

[0034] Specifically, in this embodiment, the molding process also includes: after the material is added to the mold, the mold is closed, the air is exhausted, and pressure-maintaining curing is performed, and when the pressure-maintaining curing is performed, the pressure in the mold is controlled to be 20-25Mpa. More specifically, the mold closing process is completed in a hydraulic press, the molding material needs to fill the mold cavity, and the various components of the molding material (i.e., waste wind turbine blade materials and thermoplastic materials, epoxy resins, curing agents, accelerators, and low shrinkage additives) undergo sufficient curing reactions, and the molding temperature is controlled at 150-200°C. During the mold closing process, the degree of curing of the product can be guaranteed by controlling the pressure. Regardless of preheating, pre-pressing, or pressure holding, the curing speed can be controlled by controlling the temperature and pressure to reduce by-products in the curing process and reduce the volume shrinkage of the finished product.

[0035] When using the method for recycling waste wind turbine blades provided in this embodiment to manufacture manhole covers, waste wind turbine blades are used as the main raw materials, and a small amount of thermoplastic material, epoxy resin, curing agent, accelerator, and low shrinkage additive are added. The mixture is kneaded to obtain a molding material with a thickness of 9 mm, and then molded to obtain a finished product, which can be used in 70-80m-class wind turbine blades. Among them, the thermoplastic material is polypropylene film, the epoxy resin, curing agent, and accelerator are the corresponding materials for vacuum infusion molding, and the low shrinkage additive is polystyrene. Figure 2 , the specific process is:

[0036] S202, preheating the mold at a temperature of 50°C;

[0037] S204, applying a release agent to the mold to ensure that the manhole cover can be demoulded smoothly;

[0038] S206, preparing waste wind turbine blade materials: while the release agent is being cured, the waste wind turbine blades can be cut to obtain chopped fibers, wherein the chopped fibers have a length of 20-30 mm and a width of 1-10 mm;

[0039] S208, mixing: adding the waste wind turbine blade material, the polypropylene film thermoplastic material, the epoxy resin, the curing agent, the accelerator, and the low shrinkage additive into an internal mixer for mixing, and controlling the temperature of the internal mixer to be 180° C., and finally obtaining a molding material with a thickness of 9 mm;

[0040] S210, molding material metering: after the mixing is completed and before the material is added into the mold, the molding material required for manufacturing the manhole cover is metered out;

[0041] S212, adding materials to the mold and preheating and prepressing: after the release agent is cured, the measured molding material is transferred to the mold cavity and the mold is preheated and prepressed. The preheating temperature is 60°C, the pre-applied pressure is 8 MPa, and the fluidity of the molding material in the cavity needs to be checked during the preheating and prepressing process;

[0042] S214, mold closing; the molding process is completed in the hydraulic press 315T;

[0043] S216, exhaust;

[0044] S218, pressure holding and curing: control the molding temperature to 180°C and the pressure to 20Mpa;

[0045] S220, demoulding;

[0046] S222, product curing, cooling and post-processing to obtain the finished manhole cover;

[0047] S224, mold cleaning, after completion, the mold can be used to manufacture the next product.

[0048] When using the method for recycling waste wind turbine blades provided in this embodiment to manufacture the blade root platform, waste wind turbine blades are used as the main raw materials, and a small amount of thermoplastic material, epoxy resin, curing agent, accelerator, and low shrinkage additive are added. The mixture is kneaded to obtain a molding material with a thickness of 36 mm, and then molded to obtain a finished product, which can be used in 70-80m-class wind turbine blades. Among them, the thermoplastic material is a high-density polyethylene film, the epoxy resin, curing agent, and accelerator are the corresponding materials for vacuum infusion molding, and the low shrinkage additive is polystyrene. Figure 2 , the specific process is:

[0049] S202, preheating the mold at a temperature of 50°C;

[0050] S204, applying a mold release agent to the mold to ensure that the blade root platform can be smoothly demoulded;

[0051] S206, preparing waste wind turbine blade materials: while the release agent is being cured, the waste wind turbine blades can be cut to obtain chopped fibers, wherein the chopped fibers have a length of 20-30 mm and a width of 1-10 mm;

[0052] S208, mixing: adding the waste wind turbine blade material, high-density polyethylene film thermoplastic material, epoxy resin, curing agent, accelerator, and low shrinkage additive into an internal mixer for mixing, and controlling the temperature of the internal mixer to be 200° C., and finally obtaining a molding material with a thickness of 36 mm;

[0053] S210, molding material metering: after the mixing is completed and before the material is added into the mold, the molding material required for manufacturing the blade root platform is metered out;

[0054] S212, adding materials to the mold and preheating and prepressing: after the release agent is cured, the measured molding material is transferred to the mold cavity and the mold is preheated and prepressed. The preheating temperature is 60°C, the pre-applied pressure is 10 MPa, and the fluidity of the molding material in the cavity needs to be checked during the preheating and prepressing process;

[0055] S214, mold closing; the molding process is completed in the hydraulic press 315T;

[0056] S216, exhaust;

[0057] S218, pressure holding and curing: control the molding temperature to 200°C and the pressure to 25Mpa;

[0058] S220, demoulding;

[0059] S222, product curing, cooling and post-processing to obtain the finished blade root platform product;

[0060] S224, mold cleaning, after completion, the mold can be used to manufacture the next product.

[0061] The traditional blade root platform and manhole cover are used to close the inner cavity of the blade root, and can also be used as a hub debugging operation platform. The weight that the blade root platform and the manhole cover can bear is greater than or equal to 300kg. In the prior art, the manufacture of the blade root platform and the manhole cover uses an epoxy resin system, vacuum bag pressing or vacuum infusion method, and the fiber cloth is spliced ​​with two-axial cloth or three-axial cloth to ensure a smooth surface without flaws. When the outer circle of the root platform body is made, it is first made according to the whole circle, and then cut and formed according to the drawing. The two pieces of edge material cut off are still indispensable as part of the product. Use demoulding cloth to make a rough surface in the outermost 20cm area of ​​the inner surface and outer surface of the root platform to facilitate hand paste bonding. The above-mentioned blade root platform and manhole cover manufacturing process is relatively complicated, and the raw materials used need to be purchased from the market, which is costly. However, by using the waste wind turbine blade recycling method provided in this embodiment, the waste wind turbine blades are recycled into blade root platforms or manhole covers, which can greatly reduce costs.

[0062] The compression molding method is different from the vacuum bag pressing or vacuum infusion method. It is a molding method in which powdered, granular or fibrous raw materials are first placed into the mold cavity at the molding temperature, and then the mold is closed and pressurized to form and solidify it. Compression molding has the advantages of small loss of raw materials, relatively stable mechanical properties of finished products, high product dimensional accuracy, good repeatability, low cost of molding equipment, high production efficiency, and easy to realize automated production. The method for recycling waste wind turbine blades provided in this embodiment adjusts the material formula of waste wind turbine blades, fiber length, mixing and kneading time, controls the operating pressure and temperature, etc., through the compression molding method, controls the fluidity, shrinkage, and compressibility of the molding material, and ensures that the performance of the molded product of the waste wind turbine blade material meets the performance requirements of the blade root platform and the manhole cover.

[0063] Finally, it should be noted that, in this article, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0064] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to the embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for recycling waste wind turbine blades, wherein the waste wind turbine blades are made of glass fiber composite materials, characterized in that: include: After fluffing the waste wind turbine blade material within a preset size range, the waste wind turbine blade material is mixed with the thermoplastic material in an internal mixer to obtain a molding material; The preset size range of the waste wind turbine blade material is less than or equal to 50 mm in length and less than or equal to 10 mm in width; The molding material is compression molded to obtain a wind power supporting product.

2. The method for recycling waste wind turbine blades according to claim 1, characterized in that: During mixing, the mixing temperature is controlled at 150-200°C.

3. The method for recycling waste wind turbine blades according to claim 1, characterized in that: The thermoplastic material includes at least one of high-density polyethylene, polypropylene, polyethylene terephthalate, and polyurethane.

4. The method for recycling waste wind turbine blades according to any one of claims 1 to 3, characterized in that: The molding material is further mixed with epoxy resin, curing agent, accelerator and low shrinkage additive.

5. The method for recycling waste wind turbine blades according to claim 4, characterized in that: The low shrinkage additive includes at least one of polystyrene, polyethylene and polypropylene.

6. The method for recycling waste wind turbine blades according to any one of claims 1 to 3, characterized in that: The thickness of the molding material is controlled to be 5-50 mm.

7. The method for recycling waste wind turbine blades according to any one of claims 1 to 3, characterized in that: The waste wind turbine blade material is chopped fibers obtained by cutting waste wind turbine blades.

8. The method for recycling waste wind turbine blades according to any one of claims 1 to 3, characterized in that: The compression molding of the molding material comprises: transferring the molding material into a mold, and preheating and pre-pressing the mold, wherein the preheating temperature is 50-60° C. and the pre-pressing pressure is 6-10 MPa.

9. The method for recycling waste wind turbine blades according to claim 8, characterized in that: The compression molding of the molding material further includes: after the material is added into the mold, closing the mold, venting and performing pressure-maintaining and curing, and during the pressure-maintaining and curing, controlling the pressure in the mold to be 20-25 MPa.

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