Carbonized cork wood core material for wind power blade and preparation method and application thereof

Abstract

The invention discloses a carbonized balsa wood core material for a wind power blade and a preparation method and application of the carbonized balsa wood core material, and relates to the technical field of wind power blades. According to the technical scheme, the preparation method of the carbonized balsa wood core material for the wind power blade comprises the following steps that round balsa wood is cut and processed into battens, then the battens are sequentially subjected to carbonization treatment and drying treatment, and then the battens are squared to form a BLOCK blank; and the BLOCK green body is sequentially subjected to flat cutting repairing, sanding, four-edge cutting, surface treatment, grooving and punching, dicing, chamfering and sleeve cutting, and the carbonized balsa wood core material for the wind power blade is obtained. According to the carbonized balsa wood core material prepared through the preparation method of the carbonized balsa wood core material for the wind power blade, on the premise that the inherent advantages of low density and high specific strength of balsa wood are reserved, the moisture content is stably controlled to be 6%-8% for a long time, the dry shrinkage rate is smaller than or equal to 2%, and the carbonized balsa wood core material can meet the service requirement of the wind power blade.

Description

Technical Field

[0001] This application relates to the field of wind turbine blade technology, and in particular to a carbonized balsa wood core material for wind turbine blades, its preparation method, and its application. Background Technology

[0002] As a core pillar of the global clean energy transition, wind power is seeing its single-unit capacity upgrade to 15MW and above, with blade lengths exceeding 120 meters. This places stringent demands on the lightweight, high dimensional stability, and weather resistance of sandwich core materials. Industry data shows that core materials account for 30-40% of blade weight, and their performance directly determines blade stiffness, fatigue life, and manufacturing costs, while market demand continues to rise. Currently, mainstream core materials are mainly PET foam, PVC foam, PMI foam, and composite honeycomb materials. However, these wood-free core materials have inherent technical bottlenecks, making it difficult to simultaneously meet the comprehensive requirements of low density, high specific strength, resistance to damp heat, and low cost.

[0003] To address the challenge of adapting core materials for large wind turbine blades, the industry has developed two core technology routes: foam-based and honeycomb-based. PET foam has become the mainstream choice for small and medium-sized blades due to its controllable cost and good processability. However, key components of wind turbine blades above 8MW still rely on imported PMI foam, which costs 3-5 times more than PET foam. PVC foam has poor resistance to damp heat aging, with a strength retention rate of ≤70% after 1000 hours at 85℃ / 85%RH, and it easily releases corrosive gases, leading to its gradual market obsolescence. While honeycomb composite materials offer excellent mechanical properties, their processing cycle is long (15-20 days), resulting in low molding efficiency and difficulty in meeting the demands of large-scale blade production. Furthermore, aramid honeycomb is expensive and only used in niche applications such as ultra-large blades. In addition, the high density of emerging engineering plastic structural components limits the weight reduction effect of blades, while carbon fiber reinforced PEEK core materials are still in the laboratory verification stage, with excessively high costs hindering industrialization. In addition, although natural balsa wood has attracted attention for its low density and high specific strength, it has always had the inherent defect of extremely high moisture content and a strong ability to absorb moisture and return to moisture. During processing and transportation, the moisture content is prone to rebound, which can cause serious defects such as bubbles, bursting, whitening, and delamination when the blade is cast and molded. It cannot meet the stringent requirements of wind turbine blades for low moisture content of core material, so it has not been effectively applied in the field of wind turbine blades for a long time.

[0004] To address the aforementioned technical shortcomings, there is an urgent need to improve existing technologies. Summary of the Invention

[0005] In view of this, this application provides a carbonized balsa wood core material for wind turbine blades, its preparation method and application. This carbonized balsa wood core material for wind turbine blades retains the inherent advantages of balsa wood, such as low density and high specific strength, while maintaining a stable moisture content of 6% to 8% and a shrinkage rate of ≤2%, which can meet the service requirements of wind turbine blades.

[0006] In the first aspect, this application discloses a method for preparing carbonized balsa wood core material for wind turbine blades, the technical solution of which is as follows:

[0007] A method for preparing carbonized balsa wood core material for wind turbine blades includes the following steps:

[0008] After the balsa wood logs are cut and processed into strips, they are carbonized and dried in sequence, and then assembled to form a BLOCK blank.

[0009] The BLOCK blank is sequentially subjected to flat cutting and repair, sanding, four-sided cutting, surface treatment, grooving and drilling, cutting into blocks, chamfering, and nesting to obtain carbonized balsa wood core material for wind turbine blades.

[0010] The method for preparing carbonized balsa wood core material for wind turbine blades provided in this application has a coherent, simple, and controllable process route. It retains the natural advantages of balsa wood, such as low density and high specific strength, while improving the inherent defects of natural balsa wood, such as easy moisture absorption and dampness, through carbonization and drying treatment, thereby improving the dimensional stability of the core material. The preparation process provided in this application does not require complex equipment, and the processing flow is highly efficient and adaptable to large-scale production. This reduces the core material preparation cost and environmental pressure, while meeting the comprehensive performance requirements of wind turbine blades for the core material.

[0011] Optionally, the carbonization process is carried out in an atmospheric pressure air environment, specifically including the following steps: a first heat preservation at a first temperature, then raising the temperature to a second temperature, a second heat preservation at the second temperature, then raising the temperature to a third temperature, and a third heat preservation at the third temperature.

[0012] Optionally, the first temperature is 60~80℃, and the first heat preservation time is 12~24h.

[0013] Optionally, the second temperature is 125~135℃, and the second heat preservation time is 24~36h.

[0014] Optionally, the third temperature is 140~180℃, and the third heat preservation time is 48~72h.

[0015] Optionally, the heating rate from the first temperature to the second temperature is 0.5~1.0℃ / min.

[0016] Optionally, the heating rate from the second temperature to the third temperature is 0.3~0.5℃ / min.

[0017] This application utilizes a limited carbonization process with a gradient heating mode of low temperature, medium temperature, and medium-high temperature to gradually release moisture and volatile components from the balsa wood. This avoids cell wall thermal degradation, cracking, or structural loosening caused by sudden temperature increases, thus preserving the natural porous structure and mechanical properties of balsa wood to the greatest extent. The first temperature stage, low-temperature insulation, achieves initial dehydration and preheating of the balsa wood; the second temperature stage, medium-temperature insulation, promotes the initial decomposition of some hydrophilic groups in the wood components; and the third temperature stage, medium-high temperature insulation, deepens the carbonization reaction, reduces remaining hydrophilic groups, and forms a stable fiber cross-linked structure. This improves the core problems of natural balsa wood, such as easy moisture absorption and dimensional instability. Furthermore, the temperature range, holding time, and heating rate parameters specified in this application can be precisely achieved using conventional carbonization kiln equipment, avoiding product performance fluctuations caused by ambiguous parameters in traditional carbonization processes. This ensures the performance consistency of carbonized balsa wood core materials from different batches, thus adapting to the material stability requirements of large-scale wind turbine blade production. Moreover, the gradient heating and segmented holding design not only ensures the sufficiency of the carbonization reaction but also avoids the energy waste and excessively long production cycle caused by single high-temperature, long-term carbonization. While improving the core material performance, it controls production energy consumption and time costs, enhancing the industrial feasibility of the technology.

[0018] Optionally, the drying process is carried out at a temperature of 50-70°C for 2-4 hours.

[0019] Optionally, the surface treatment specifically includes the following steps:

[0020] After the carbonized balsa wood core material with four sides cut is dried in hot air at 50~70℃ for 3~5 minutes, the composite sealing surface treatment agent is evenly coated onto the surface of the core material using roller coating, brush coating or spray coating methods, with a coating amount of 0.2~0.5 kg / m². 2 After coating, the light intensity is 800~1200mW / cm. 2 The surface is irradiated with ultraviolet light for 10-30 seconds to complete the surface treatment.

[0021] Optionally, the preparation method of the composite sealing surface treatment agent includes the following steps:

[0022] Glycidyl methacrylate, acrylamide, benzoyl peroxide and N,N-dimethylformamide were mixed and stirred to react. Then γ-aminopropyltriethoxysilane was added to carry out a ring-opening reaction to obtain an organic intermediate.

[0023] The activated metakaolin, dilute nitric acid, deionized water and anhydrous ethanol were mixed and reacted to obtain metakaolin-based aluminosilicate inorganic sol.

[0024] The organic intermediate, metakaolin-based aluminosilicate inorganic sol, γ-glycidyl etheroxypropyltrimethoxysilane and photoinitiator are mixed and subjected to ultrasonic grafting reaction to obtain the composite sealing surface treatment agent.

[0025] Optionally, the mass-to-volume ratio of glycidyl methacrylate, acrylamide, benzoyl peroxide, N,N-dimethylformamide and γ-aminopropyltriethoxysilane is (50~70) g : (20~30) g : (0.5~1.5) g : (150~200) mL : (25~35) g.

[0026] Optionally, the mass-to-volume ratio of the activated metakaolin, dilute nitric acid, deionized water and anhydrous ethanol is (8~15) g: (80~100) mL: (30~50) mL: (20~30) mL, and the volume concentration of the dilute nitric acid is 5%~10%.

[0027] Optionally, the mass-to-volume ratio of the organic intermediate, metakaolin-based aluminosilicate inorganic sol, γ-glycidoxypropyltrimethoxysilane, and photoinitiator is (95~105) g: (130~150) mL: (1~3) g: (1~3) g, wherein the photoinitiator is selected from one or both of 1-hydroxycyclohexylphenyl ketone or 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0028] Optionally, the stirring reaction temperature is 70~80℃, the time is 3~5h, and the rotation speed is 100~200r / min; the ring-opening reaction temperature is 80~100℃, and the time is 2~4h.

[0029] Optionally, the ring-opening reaction is carried out at a temperature of 80-100°C for 2-4 hours.

[0030] Optionally, the mixing reaction is carried out at a temperature of 60-70°C for 1-2 hours.

[0031] Optionally, the ultrasonic grafting reaction power is 250~350W, the temperature is 25~35℃, and the time is 30~50min.

[0032] Secondly, this application provides a carbonized balsa wood core material for wind turbine blades, which is prepared by the preparation method of carbonized balsa wood core material for wind turbine blades described in the aforementioned scheme. The carbonized balsa wood core material has a moisture content of 6%~8%, a parallel compressive strength ≥10MPa, a perpendicular compressive strength ≥0.75MPa, a shear strength ≥2.0MPa, a shear modulus ≥160MPa, and a shrinkage rate ≤2%.

[0033] Thirdly, this application provides a wind turbine blade, the technical solution of which is as follows:

[0034] A wind turbine blade includes a carbonized balsa wood core material, wherein the carbonized balsa wood core material is the same as the carbonized balsa wood core material for wind turbine blades described in the aforementioned scheme.

[0035] This application provides a carbonized balsa wood core material for wind turbine blades, its preparation method, and its application. Through a low-to-medium temperature, multi-stage carbonization process, the moisture content of the balsa wood is stably controlled at 6%–8%. This retains the advantages of balsa wood's low density and high specific strength while solving the problems of natural balsa wood's moisture absorption and the high cost and insufficient stability of existing wood-based core materials. Therefore, compared to existing technologies, the technical solution provided in this application has the advantages of stable and controllable moisture content, excellent comprehensive mechanical properties, strong weather resistance, manufacturing costs suitable for large-scale production, and a combination of environmental protection and practical value. Detailed Implementation

[0036] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific implementation methods described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0037] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0038] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both mean: a, b, c, a~b (i.e., a and b), a~c, b~c, or a~b~c, where a, b, and c can be single or multiple.

[0039] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0040] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0041] Example 1

[0042] This embodiment provides a wind turbine blade, wherein the wind turbine blade includes carbonized balsa wood core material.

[0043] The method for preparing the carbonized balsa wood core includes the following steps:

[0044] After the balsa wood logs are cut and processed into strips, they are carbonized and dried in sequence, and then assembled to form a BLOCK blank.

[0045] After the BLOCK blank is successively flat-cut, repaired, sanded, and four-sided cut, the carbonized balsa core material with four-sided cut is placed in a 50℃ hot air dryer for 3 minutes. Then, a composite sealing surface treatment agent is evenly applied to the core material surface by brushing, with a coating amount of 0.2 kg / m². 2 After coating, at a light intensity of 800mW / cm 2 After irradiating with ultraviolet light for 10 seconds, the surface is treated, then grooved, drilled, cut into blocks, chamfered, and nested to obtain carbonized balsa wood core material for wind turbine blades.

[0046] The carbonization process is carried out in an atmospheric pressure air environment and specifically includes the following steps: a first heat preservation at a first temperature, then heating to a second temperature, a second heat preservation at the second temperature, then heating to a third temperature, and a third heat preservation at the third temperature;

[0047] The first temperature is 60℃, and the first heat preservation time is 12h;

[0048] The second temperature is 125℃, and the second heat preservation time is 24 hours;

[0049] The third temperature is 140℃, and the third heat preservation time is 48h;

[0050] The heating rate from the first temperature to the second temperature is 0.5℃ / min;

[0051] The heating rate from the second temperature to the third temperature is 0.3℃ / min;

[0052] The drying process is carried out at a temperature of 50°C for 2 hours.

[0053] The preparation method of the composite sealing surface treatment agent includes the following steps:

[0054] 50g glycidyl methacrylate, 20g acrylamide, 0.5g benzoyl peroxide and 150mL N,N-dimethylformamide were mixed and stirred at 70℃ and 100r / min for 3h. Then 25g γ-aminopropyltriethoxysilane was added and the ring-opening reaction was carried out at 80℃ for 2h to obtain an organic intermediate.

[0055] 8g of activated metakaolin, 80mL of 5% dilute nitric acid, 30mL of deionized water and 20mL of anhydrous ethanol were mixed and reacted to obtain metakaolin-based aluminosilicate inorganic sol.

[0056] 95g of organic intermediate, 130mL of metakaolin-based aluminosilicate inorganic sol, 1g of γ-glycidyl etheroxypropyltrimethoxysilane and 1g of 1-hydroxycyclohexylphenyl ketone were mixed and ultrasonically grafted at 250W and 25℃ for 30min to obtain the composite sealing surface treatment agent.

[0057] Example 2

[0058] This embodiment provides a wind turbine blade, wherein the wind turbine blade includes carbonized balsa wood core material.

[0059] The method for preparing the carbonized balsa wood core includes the following steps:

[0060] After the balsa wood logs are cut and processed into strips, they are carbonized and dried in sequence, and then assembled to form a BLOCK blank.

[0061] After the BLOCK blank is successively flat-cut, repaired, sanded, and four-sided cut, the carbonized balsa wood core material with four-sided cut is placed in a 70℃ hot air dryer for 5 minutes. Then, a composite sealing surface treatment agent is evenly coated onto the core material surface using a roller coating method, with a coating amount of 0.5 kg / m². 2 After coating, at a light intensity of 1200mW / cm 2 After irradiating with ultraviolet light for 30 seconds, the surface is treated, then grooved, drilled, cut into blocks, chamfered, and nested to obtain carbonized balsa wood core material for wind turbine blades.

[0062] The carbonization process is carried out in an atmospheric pressure air environment and specifically includes the following steps: a first heat preservation at a first temperature, then heating to a second temperature, a second heat preservation at the second temperature, then heating to a third temperature, and a third heat preservation at the third temperature;

[0063] The first temperature is 80℃, and the first heat preservation time is 24h;

[0064] The second temperature is 135℃, and the second heat preservation time is 36 hours;

[0065] The third temperature is 180℃, and the third heat preservation time is 72h;

[0066] The heating rate from the first temperature to the second temperature is 1.0℃ / min;

[0067] The heating rate from the second temperature to the third temperature is 0.5℃ / min;

[0068] The drying process is carried out at a temperature of 70°C for 4 hours.

[0069] The preparation method of the composite sealing surface treatment agent includes the following steps:

[0070] 70g glycidyl methacrylate, 30g acrylamide, 1.5g benzoyl peroxide and 200mL N,N-dimethylformamide were mixed and stirred at 80℃ and 200r / min for 5h. Then 35g γ-aminopropyltriethoxysilane was added and the ring-opening reaction was carried out at 100℃ for 4h to obtain an organic intermediate.

[0071] 15g of activated metakaolin, 100mL of 10% dilute nitric acid, 50mL of deionized water and 30mL of anhydrous ethanol were mixed and reacted to obtain metakaolin-based aluminosilicate inorganic sol.

[0072] 100g of organic intermediate, 150mL of metakaolin-based aluminosilicate inorganic sol, 3g of γ-glycidyl etheroxypropyltrimethoxysilane and 3g of 2-hydroxy-2-methyl-1-phenyl-1-propanone were mixed and ultrasonically grafted at 350W and 35℃ for 50min to obtain the composite sealing surface treatment agent.

[0073] Example 3

[0074] This embodiment provides a wind turbine blade, wherein the wind turbine blade includes carbonized balsa wood core material.

[0075] The method for preparing the carbonized balsa wood core includes the following steps:

[0076] After the balsa wood logs are cut and processed into strips, they are carbonized and dried in sequence, and then assembled to form a BLOCK blank.

[0077] After the BLOCK blank is successively flat-cut, repaired, sanded, and four-sided cut, the carbonized balsa wood core material with four-sided cut is placed in a 60℃ hot air dryer for 4 minutes. Then, a composite sealing surface treatment agent is evenly applied to the surface of the core material by spraying, with a coating amount of 0.4 kg / m². 2 After coating, at a light intensity of 1000mW / cm 2After irradiating with ultraviolet light for 20 seconds, the surface is treated, then grooved, drilled, cut into blocks, chamfered, and nested to obtain carbonized balsa wood core material for wind turbine blades.

[0078] The carbonization process is carried out in an atmospheric pressure air environment and specifically includes the following steps: a first heat preservation at a first temperature, then heating to a second temperature, a second heat preservation at the second temperature, then heating to a third temperature, and a third heat preservation at the third temperature;

[0079] The first temperature is 70℃, and the first heat preservation time is 18h;

[0080] The second temperature is 130℃, and the second heat preservation time is 30h;

[0081] The third temperature is 160℃, and the third heat preservation time is 60h;

[0082] The heating rate from the first temperature to the second temperature is 0.75℃ / min;

[0083] The heating rate from the second temperature to the third temperature is 0.4℃ / min;

[0084] The drying process is carried out at a temperature of 60°C for 3 hours.

[0085] The preparation method of the composite sealing surface treatment agent includes the following steps:

[0086] 60g glycidyl methacrylate, 25g acrylamide, 1g benzoyl peroxide and 175mL N,N-dimethylformamide were mixed and stirred at 75℃ and 150r / min for 4h. Then 30g γ-aminopropyltriethoxysilane was added and the ring-opening reaction was carried out at 90℃ for 3h to obtain an organic intermediate.

[0087] 13g of activated metakaolin, 90mL of 8% dilute nitric acid, 40mL of deionized water and 25mL of anhydrous ethanol were mixed and reacted to obtain metakaolin-based aluminosilicate inorganic sol.

[0088] 98g of organic intermediate, 140mL of metakaolin-based aluminosilicate inorganic sol, 2g of γ-glycidyl etheroxypropyltrimethoxysilane and 2g of 1-hydroxycyclohexylphenyl ketone were mixed and ultrasonically grafted at 300W and 30℃ for 40min to obtain the composite sealing surface treatment agent.

[0089] Comparative Example 1

[0090] This comparative example provides a wind turbine blade, wherein the wind turbine blade comprises carbonized balsa wood core material.

[0091] The method for preparing the carbonized balsa wood core includes the following steps:

[0092] After the balsa wood is cut into strips, it is kept at 130℃ for 108 hours, then dried at 60℃ for 3 hours, and then assembled to form a BLOCK blank.

[0093] After the BLOCK blank is successively flat-cut, repaired, sanded, and four-sided cut, the carbonized balsa wood core material with four-sided cut is placed in a 60℃ hot air dryer for 4 minutes. Then, a composite sealing surface treatment agent is evenly applied to the surface of the core material by spraying, with a coating amount of 0.4 kg / m². 2 After coating, at a light intensity of 1000mW / cm 2 After irradiating with ultraviolet light for 20 seconds, the surface is treated, then grooved, drilled, cut into blocks, chamfered, and nested to obtain carbonized balsa wood core material for wind turbine blades.

[0094] The preparation method of the composite sealing surface treatment agent includes the following steps:

[0095] 60g glycidyl methacrylate, 25g acrylamide, 1g benzoyl peroxide and 175mL N,N-dimethylformamide were mixed and stirred at 75℃ and 150r / min for 4h. Then 30g γ-aminopropyltriethoxysilane was added and the ring-opening reaction was carried out at 90℃ for 3h to obtain an organic intermediate.

[0096] 13g of activated metakaolin, 90mL of 8% dilute nitric acid, 40mL of deionized water and 25mL of anhydrous ethanol were mixed and reacted to obtain metakaolin-based aluminosilicate inorganic sol.

[0097] 98g of organic intermediate, 140mL of metakaolin-based aluminosilicate inorganic sol, 2g of γ-glycidyl etheroxypropyltrimethoxysilane and 2g of 1-hydroxycyclohexylphenyl ketone were mixed and ultrasonically grafted at 300W and 30℃ for 40min to obtain the composite sealing surface treatment agent.

[0098] Comparative Example 2

[0099] This comparative example provides a wind turbine blade, wherein the wind turbine blade is composed of carbonized balsa wood core material, a reinforcing layer and a matrix layer, the reinforcing layer is carbon fiber fabric and the matrix layer is prepared from epoxy resin.

[0100] The method for preparing the carbonized balsa wood core includes the following steps:

[0101] After the balsa wood logs are cut and processed into strips, they are carbonized and dried in sequence, and then assembled to form a BLOCK blank.

[0102] The BLOCK blank is sequentially subjected to flat cutting and repair, sanding, four-sided cutting, grooving and drilling, cutting into blocks, chamfering and nesting to obtain carbonized balsa wood core material for wind turbine blades.

[0103] The carbonization process is carried out in an atmospheric pressure air environment and specifically includes the following steps: a first heat preservation at a first temperature, then heating to a second temperature, a second heat preservation at the second temperature, then heating to a third temperature, and a third heat preservation at the third temperature;

[0104] The first temperature is 70℃, and the first heat preservation time is 18h;

[0105] The second temperature is 130℃, and the second heat preservation time is 30h;

[0106] The third temperature is 160℃, and the third heat preservation time is 60h;

[0107] The heating rate from the first temperature to the second temperature is 0.75℃ / min;

[0108] The heating rate from the second temperature to the third temperature is 0.4℃ / min;

[0109] The drying process is carried out at a temperature of 60°C for 3 hours.

[0110] The core properties (moisture content, shrinkage rate, and mechanical strength) of the carbonized balsa wood core material in the wind turbine blades prepared in Examples 1-3 and Comparative Examples 1-2, as well as the overall weather resistance (resistance to damp heat aging strength retention rate) of the blades, were tested. The test results are shown in Table 1.

[0111] Table 1

[0112] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Moisture content (%) of carbonized balsa wood core 6.2 7.8 7.0 9.5 7.1 Shrinkage rate of carbonized balsa wood core (%) 1.3 1.8 1.5 3.7 1.6 Parallel compressive strength (MPa) of carbonized balsa wood core 10.5 12.3 11.4 8.2 11.2 Vertical compressive strength (MPa) of carbonized balsa wood core 0.82 0.95 0.88 0.61 0.86 Shear strength (MPa) of carbonized balsa wood core 2.2 2.5 2.3 1.7 2.2 Shear modulus (MPa) of carbonized balsa wood core 168 185 176 142 173 Leaf resistance to damp heat aging retention rate (85℃ / 85%RH, 1000h, %) 88.6 91.2 89.8 76.3 79.5

[0113] The technical solutions provided by the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for preparing carbonized balsa wood core material for wind turbine blades, characterized in that, Includes the following steps: After the balsa wood logs are cut and processed into strips, they are carbonized and dried in sequence, and then assembled to form a BLOCK blank. The BLOCK blank is sequentially subjected to flat cutting and repair, sanding, four-sided cutting, surface treatment, grooving and drilling, cutting into blocks, chamfering, and nesting to obtain carbonized balsa wood core material for wind turbine blades.

2. The method for preparing carbonized balsa wood core material for wind turbine blades according to claim 1, characterized in that, The carbonization process is carried out in an atmospheric pressure air environment and specifically includes the following steps: a first heat preservation at a first temperature, then raising the temperature to a second temperature, a second heat preservation at the second temperature, then raising the temperature to a third temperature, and a third heat preservation at the third temperature.

3. The method for preparing carbonized balsa wood core material for wind turbine blades according to claim 2, characterized in that, The first temperature is 60~80℃, and the first heat preservation time is 12~24h; and / or The second temperature is 125~135℃, and the second heat preservation time is 24~36h; and / or The third temperature is 140~180℃, and the third heat preservation time is 48~72h.

4. The method for preparing carbonized balsa wood core material for wind turbine blades according to claim 2, characterized in that, The heating rate from the first temperature to the second temperature is 0.5~1.0℃ / min; and / or The heating rate from the second temperature to the third temperature is 0.3~0.5℃ / min.

5. The method for preparing carbonized balsa wood core material for wind turbine blades according to claim 1, characterized in that, The drying process is carried out at a temperature of 50-70°C for 2-4 hours.

6. The method for preparing carbonized balsa wood core material for wind turbine blades according to claim 1, characterized in that, The surface treatment specifically includes the following steps: After the carbonized balsa wood core material with four sides cut is dried in hot air at 50~70℃ for 3~5 minutes, the composite sealing surface treatment agent is evenly coated onto the surface of the core material using roller coating, brush coating or spray coating methods, with a coating amount of 0.2~0.5 kg / m². 2 After coating, the light intensity is 800~1200mW / cm. 2 The surface is irradiated with ultraviolet light for 10-30 seconds to complete the surface treatment.

7. The method for preparing carbonized balsa wood core material for wind turbine blades according to claim 6, characterized in that, The preparation method of the composite sealing surface treatment agent includes the following steps: Glycidyl methacrylate, acrylamide, benzoyl peroxide and N,N-dimethylformamide were mixed and stirred to react. Then γ-aminopropyltriethoxysilane was added to carry out a ring-opening reaction to obtain an organic intermediate. The activated metakaolin, dilute nitric acid, deionized water and anhydrous ethanol were mixed and reacted to obtain metakaolin-based aluminosilicate inorganic sol. The organic intermediate, metakaolin-based aluminosilicate inorganic sol, γ-glycidyl etheroxypropyltrimethoxysilane and photoinitiator are mixed and subjected to ultrasonic grafting reaction to obtain the composite sealing surface treatment agent.

8. The method for preparing carbonized balsa wood core material for wind turbine blades according to claim 7, characterized in that, The mass-to-volume ratio of glycidyl methacrylate, acrylamide, benzoyl peroxide, N,N-dimethylformamide, and γ-aminopropyltriethoxysilane is (50~70) g : (20~30) g : (0.5~1.5) g : (150~200) mL : (25~35) g; and / or The mass-to-volume ratio of the activated metakaolin, dilute nitric acid, deionized water, and anhydrous ethanol is (8~15) g : (80~100) mL : (30~50) mL : (20~30) mL, and the volume concentration of the dilute nitric acid is 5%~10%; and / or The organic intermediate, metakaolin-based aluminosilicate inorganic sol, γ-glycidyl etheroxypropyltrimethoxysilane, and photoinitiator have a mass-to-volume ratio of (95~105) g:(130~150) mL:(1~3) g:(1~3) g, wherein the photoinitiator is selected from one or both of 1-hydroxycyclohexylphenyl ketone or 2-hydroxy-2-methyl-1-phenyl-1-propanone; and / or The stirring reaction temperature is 70~80℃, the time is 3~5h, and the rotation speed is 100~200r / min; the ring-opening reaction temperature is 80~100℃, and the time is 2~4h; and / or The ring-opening reaction is carried out at a temperature of 80-100°C for 2-4 hours; and / or The mixing reaction is carried out at a temperature of 60-70°C for 1-2 hours; and / or The ultrasonic grafting reaction power is 250~350W, the temperature is 25~35℃, and the time is 30~50min.

9. A carbonized balsa wood core material for wind turbine blades, characterized in that, The carbonized balsa wood core material for wind turbine blades is prepared by the preparation method of any one of claims 1 to 8, wherein the carbonized balsa wood core material has a moisture content of 6% to 8%, a parallel compressive strength ≥10MPa, a vertical compressive strength ≥0.75MPa, a shear strength ≥2.0MPa, a shear modulus ≥160MPa, and a shrinkage rate ≤2%.

10. A wind turbine blade, characterized in that, It includes carbonized balsa wood core material, wherein the carbonized balsa wood core material is the carbonized balsa wood core material for wind turbine blades as described in claim 9.