Offshore wind turbine foundation truss and protection construction method thereof

Abstract

The offshore wind turbine foundation truss comprises a truss body, the truss body comprises truss pile legs, the upper ends of the truss pile legs are connected with truss guide pipe legs, the upper ends of the truss guide pipe legs are connected to the lower surface of a supporting platform, and the lower end of a wind turbine tower drum is fixed to the upper surface of the supporting platform. A first connecting pipe frame, a second connecting pipe frame and a third connecting pipe frame are sequentially arranged between every two adjacent truss guide pipe legs from top to bottom. An ECC bonding layer and an FRP protective layer are arranged at a connecting node; a POZD material layer is arranged on the outer surface of the truss main body; the truss guide pipe leg comprises a guide pipe leg outer layer and a guide pipe leg inner layer, a guide pipe leg interlayer is arranged between the guide pipe leg outer layer and the guide pipe leg inner layer, and the guide pipe leg interlayer is filled with oil rock page waste residue concrete. The FRP protective layers are arranged at the connecting joints, the POZD material layers are arranged outside the truss body, and the truss guide pipe legs are filled with the oil rock page waste residue concrete, so that the overall corrosion resistance and load resistance can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine truss protection, and in particular to an offshore wind turbine foundation truss and a protection construction method thereof. Background Art

[0002] Offshore wind turbines and their foundations play a vital role in modern renewable energy systems. As the global demand for clean energy increases, offshore wind power, as a renewable and efficient form of energy, has gradually become an important way to achieve energy transformation and carbon reduction goals. Offshore wind turbines utilize the vast wind energy resources in the ocean, which can effectively reduce dependence on traditional fossil fuels, thereby reducing greenhouse gas emissions and alleviating the pressure of global warming.

[0003] The foundation structure design of offshore wind turbines is particularly critical. It not only needs to withstand complex loads from multiple directions such as wind, waves and currents, but also needs to have good corrosion resistance to adapt to the harsh marine environment. As a common structural form, the truss foundation has become an ideal choice for offshore wind turbines due to its superior mechanical properties and economy. Through reasonable foundation design, the stability and anti-overturning ability of the wind turbine can be effectively improved, ensuring its safe operation under extreme climatic conditions.

[0004] In addition, the design and construction of offshore wind turbines and their foundations directly affect the economic benefits and sustainability of wind power projects. Efficient foundation structures can reduce construction and maintenance costs, extend the service life of wind turbines, and improve overall power generation efficiency, thereby maximizing economic benefits. Therefore, with the continuous advancement and development of offshore wind power technology, in-depth research on the design principles and applications of offshore wind turbines and their foundations will provide solid technical support and theoretical basis for promoting the widespread application of renewable energy.

[0005] The joints of existing wind turbine trusses are not strong enough to withstand complex loads from multiple directions such as wind, waves and currents. Although FRP node reinforcement technology can enhance the strength of pipe connection nodes, it is mostly used for the connection of pipes, beams and columns on land.

[0006] In addition, oil shale waste residue concrete is a material that uses waste residue from oil shale extraction as part or all of the aggregate and admixture to replace traditional natural sand and gravel for concrete production. This type of concrete utilizes industrial waste, improves resource utilization efficiency, and can reduce pollution caused by waste residue stacking. At the same time, it can also reduce the cost of concrete and reduce the mining of natural sand and gravel resources. At the same time, the addition of oil shale waste residue can improve the compressive strength and durability of concrete.

[0007] POZD material is a polymer material developed through the catalytic reaction of isocyanate groups and epoxy resins. It has a macromolecular structure (see Figure 1), the molecular chains are intertwined and hydrogen-bonded, which significantly improves the elasticity, strength and overall performance of the material. At the same time, the generation of polyisocyanamide oxazolidinone greatly improves its toughness and explosion resistance. Compared with traditional polymer materials, POZD materials enhance the tensile and tearing properties of the material through molecular structure design and the use of special raw materials, and its three-dimensional network structure significantly improves the tear strength.

[0008] The material is green and environmentally friendly, and is in a plastic state at room temperature, which is convenient for transportation and construction. After being sprayed with professional equipment, it can reach 100% strength within 24 hours. It is suitable for any curved surface, inclined surface and vertical surface, and the construction is not affected by the ambient temperature and humidity. In addition, POZD material has good thermal stability, corrosion resistance and aging resistance, and can withstand short-term thermal shock of 350°C. It has excellent anti-corrosion performance, is resistant to corrosion by acids, alkalis, salts and oils, and has passed a 5000-hour neutral salt spray test.

[0009] If POZD material spraying is applied to the solution of offshore wind turbine truss foundation, it will have significant engineering advantages. First of all, POZD material, with its excellent toughness, explosion resistance and excellent corrosion resistance, can effectively improve the anti-dumping ability of the truss foundation and ensure the structural stability under extreme climatic conditions such as wind and waves. Secondly, the flow plastic state of POZD material makes its construction convenient. It can reach 100% strength within 24 hours after spraying. It can adapt to the complex marine environment and is not affected by temperature and humidity, which provides good conditions for offshore construction. In addition, POZD material significantly improves the durability of the foundation through the design of special molecular structure, and it is expected to extend the service life of the foundation and reduce the subsequent maintenance costs. However, there is no solution in the prior art to apply FRP node reinforcement technology, oil shale waste slag concrete and POZD material to the offshore wind turbine foundation truss.

[0010] Therefore, the art is in urgent need of a new offshore wind turbine foundation truss and a protective construction method thereof to solve the above-mentioned problems. Summary of the invention

[0011] The purpose of the present invention is to provide an offshore wind turbine foundation truss and a protective construction method thereof to solve the problems existing in the above-mentioned prior art. An FRP protective layer is provided on the connection node, a POZD material layer is provided on the outside of the truss body, and the truss duct legs are filled with oil shale waste slag concrete, which can not only effectively improve the connection strength of the connection node and the corrosion resistance of the truss body, extend its service life, but also significantly enhance its ability to resist lateral load impact.

[0012] To achieve the above object, the present invention provides the following solutions:

[0013] The present invention discloses an offshore wind turbine foundation truss, comprising a truss main body and a wind turbine tower, wherein the truss main body comprises a plurality of truss pile legs, the upper end of each of the truss pile legs is connected to a truss conduit leg, the upper ends of the truss conduit legs are commonly connected to the lower surface of a support platform, the lower end of the wind turbine tower is fixed to the upper surface of the support platform, and a first connecting pipe rack, a second connecting pipe rack and a third connecting pipe rack are sequentially arranged between two adjacent truss conduit legs from top to bottom;

[0014] The connection points between the first connecting pipe rack, the second connecting pipe rack and the third connecting pipe rack and the truss duct leg are all connecting nodes, and the connecting nodes are provided with an ECC bonding layer and an FRP protective layer, and the FRP protective layer is located on the outside of the ECC bonding layer;

[0015] The outer surface of the truss pile leg, the outer surface of the truss conduit leg, the outer surface of the support platform, the outer surface of the first connecting pipe rack, the outer surface of the second connecting pipe rack and the outer surface of the third connecting pipe rack are all provided with a POZD material layer;

[0016] The truss duct leg includes a duct leg outer layer and a duct leg inner side, the duct leg outer layer is located on the outside of the duct leg inner layer, a duct leg interlayer is formed between the duct leg outer layer and the duct leg inner layer, and the duct leg interlayer is filled with oil shale waste concrete.

[0017] Preferably, the truss pile legs and the truss conduit legs are each provided with four.

[0018] Preferably, the truss legs are steel pipe structures, the outer diameter of the truss legs is 2850 mm, and the wall thickness of the truss legs is 75 mm.

[0019] Preferably, the diameter of the outer layer of the conduit leg is 1750 mm, and the wall thickness of the outer layer of the conduit leg is 50 mm;

[0020] The diameter of the inner layer of the catheter leg is 750 mm, and the wall thickness of the inner layer of the catheter leg is 50 mm.

[0021] Preferably, the first connecting pipe rack comprises two cross-connected first connecting steel pipes, the diameter of the first connecting steel pipe is 600 mm, and the wall thickness of the first connecting steel pipe is 25 mm;

[0022] The second connecting pipe rack includes two cross-connected second connecting steel pipes, the diameter of the second connecting steel pipe is 700 mm, and the wall thickness of the second connecting steel pipe is 37.5 mm;

[0023] The third connecting pipe rack includes two cross-connected third connecting steel pipes, the diameter of the third connecting steel pipe is 850 mm, and the wall thickness of the third connecting steel pipe is 50 mm.

[0024] Preferably, the thickness of the POZD material layer is 5 mm.

[0025] Preferably, the support platform is a rectangular steel plate structure, and the thickness of the support platform is 1000 mm.

[0026] Preferably, the upper end diameter of the wind turbine tower is 5500 mm, and the lower end diameter of the wind turbine tower is 8000 mm.

[0027] The present invention discloses a construction method for an offshore wind turbine foundation truss, including a construction method for a connection node and a spraying method for a POZD material layer;

[0028] The construction method of the connection node includes the following steps:

[0029] S1. Construction preparation:

[0030] Material preparation, selection of appropriate FRP materials;

[0031] S2. Connection node cleanup:

[0032] Surface treatment: Before setting the FRP protective layer, the surface of the connection node needs to be cleaned to remove oil, dust and rust;

[0033] S3. Preparation of FRP protective layer:

[0034] Material cutting: Cut the FRP material into required specifications according to the shape and size of the connection node, ensuring that each layer of material is uniform;

[0035] Pre-preg treatment, immersing the cut FRP material in resin to ensure it is fully saturated;

[0036] S4. Paste FRP protective layer:

[0037] Apply adhesive evenly on the cleaned surface of the connection node;

[0038] Laying the FRP protective layer, pasting the impregnated FRP protective layer to the connection nodes layer by layer;

[0039] S5. Curing and inspection:

[0040] During the curing process, the ambient temperature and humidity are controlled according to the characteristics of the adhesive used to ensure that the FRP protective layer can be cured within the specified time;

[0041] Quality inspection: After curing is completed, quality inspection is carried out to check the bonding strength between the FRP protective layer and the substrate as well as the appearance quality;

[0042] S6. Post-processing:

[0043] Surface protection: applying protective coating on the outside of the FRP protective layer to enhance weather resistance and aesthetics;

[0044] Regular inspection: After construction is completed, the FRP protective layer should be inspected regularly to ensure its long-term effectiveness;

[0045] The spraying method of the POZD material layer comprises the following steps:

[0046] S1. Substrate treatment:

[0047] First, clean the truss body to remove oil and impurities, and use organic solvents to clean it to ensure that the base surface is clean; the welds and welding slag parts need to be polished to ensure that the surface is smooth and without sharp protrusions; the surface of the truss body is sandblasted using a sandblasting process to ensure that the surface roughness is suitable for painting; for parts that cannot be sandblasted, use a grinding wheel to manually polish; finally, use compressed air to clean the truss body after sandblasting to remove dust and rust residue to ensure the quality of painting;

[0048] S2. Selection of primer:

[0049] Choose epoxy resin as primer, and POZD material spraying should be carried out within 8 hours after the primer is applied;

[0050] S3. Inspection of spraying equipment:

[0051] Before spraying, check the normal working status of the spraying equipment, set the pressure and heating temperature of the pipeline, start the pipeline heater 30 minutes in advance, and fully stir the POZD material for 30 minutes to ensure uniform mixing;

[0052] S4, POZD material spraying:

[0053] Test spraying is carried out on a dry test spraying surface to observe the normality of the POZD material layer. A horizontal and vertical cross spraying method is adopted to ensure that the thickness of the POZD material layer is uniform and continuous. When spraying the next POZD material layer, it covers more than 50% of the previous POZD material layer to ensure the consistency of the spraying thickness.

[0054] Compared with the prior art, the present invention has achieved the following technical effects:

[0055] The present invention sets a POZD material layer on the outside of the truss body, sets an FRP protective layer at the connection node, and the truss duct leg is filled with oil shale waste slag concrete. By comparing the offshore wind turbine foundation trusses that are not sprayed with POZD materials and the truss duct legs that use different concretes, it is found that the oil shale waste slag concrete truss after setting an FRP protective layer at the connection node and spraying POZD material is significantly better than the unsprayed truss in performance. This improvement is reflected in many aspects such as the anti-overturning ability, toughness and corrosion resistance of the truss body. Studies have shown that spraying POZD materials and setting an FRP protective layer at the connection nodes effectively enhance the structural stability and durability of the truss body, and each connection node is not easy to crack, and can better adapt to the harsh conditions of the marine environment, thereby extending its service life and reducing maintenance costs. At the same time, the use of oil shale waste slag concrete is in line with the strategy of sustainable development compared to traditional concrete, effectively protects sand and stone resources, and saves costs, providing a new idea for offshore wind turbine protection.

[0056] The experimental results show that the lateral load resistance of the new truss body with a 5mm thick POZD material layer and an FRP protective layer at the connection nodes and CFDST (internal filling of oil shale waste concrete) is far superior to the same type of unsprayed new truss. This improvement not only enhances the stability of the structure, avoids cracking and other problems, reduces the potential risk of failure, but also extends the service life of the new truss body and reduces maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] 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 will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0058] Figure 1 It is a schematic diagram of the three-dimensional network structure of POZD material;

[0059] Figure 2 It is a front view of the offshore wind turbine foundation truss of Example 1;

[0060] Figure 3 It is a top view of the offshore wind turbine foundation truss of Example 1;

[0061] Figure 4 It is a cross-sectional view of a truss duct leg in an offshore wind turbine foundation truss in Example 1;

[0062] Figure 5 This is a schematic diagram of the connection nodes in the offshore wind turbine foundation truss of Example 1;

[0063] In the figure: 1-truss body; 101-truss pile leg; 102-truss duct leg; 103-support platform; 104-first connecting pipe rack; 105-second connecting pipe rack; 106-third connecting pipe rack; 2-wind turbine tower. DETAILED DESCRIPTION

[0064] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] The purpose of the present invention is to provide an offshore wind turbine foundation truss and a protective construction method thereof to solve the problems existing in the above-mentioned prior art. An FRP protective layer is provided on the connection node, a POZD material layer is provided on the outside of the truss body, and the truss duct legs are filled with oil shale waste slag concrete, which can not only effectively improve the connection strength of the connection node and the corrosion resistance of the truss body, extend its service life, but also significantly enhance its ability to resist lateral load impact.

[0066] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0067] Embodiment 1

[0068] like Figure 2-Figure 5 As shown, the present invention provides an offshore wind turbine foundation truss, including a truss body 1 and a wind turbine tower 2. The specific structure of the truss body 1 is as follows Figure 2 As shown, the truss body 1 includes a plurality of truss legs 101, which are main supporting members for supporting the various components above them. The upper end of each truss leg 101 is connected to a truss duct leg 102, and the upper ends of the truss duct legs 102 are commonly connected to the lower surface of a supporting platform 103. The lower end of the wind turbine tower 2 is fixed to the upper surface of the supporting platform 103. A first connecting pipe rack 104, a second connecting pipe rack 105 and a third connecting pipe rack 106 are arranged in sequence from top to bottom between two adjacent truss duct legs 102. The first connecting pipe rack 104, the second connecting pipe rack 105 and the third connecting pipe rack 106 are used to enhance the connection strength of two adjacent truss duct legs 102 so that they are connected as a whole.

[0069] The main difference from the prior art is that Figure 5As shown, the connection points of the first connecting pipe rack 104, the second connecting pipe rack 105 and the third connecting pipe rack 106 with the truss duct leg 102 are all connection nodes. ECC bonding layer and FRP protective layer are provided at the connection nodes, wherein the ECC bonding layer is ECC material (i.e., fiber-reinforced cement-based composite material), and the FRP protective layer is FRP cloth (i.e., fiber-reinforced composite material). The FRP protective layer is located on the outside of the ECC bonding layer. Figure 5 The shaded area in the figure is the FRP protective layer. During actual reinforcement, the ECC material is first applied to the nodes and then the FRP cloth is applied externally.

[0070] The reason why this embodiment does not use organic glues such as epoxy resin as concrete-FRP interface adhesives is that organic glues such as epoxy resins are prone to aging, which limits the service life of the reinforced structure. At the same time, compared with the high-strength characteristics of FRP materials, the FRP-concrete interface is relatively weak, and the peeling of the FRP-concrete interface often causes the reinforcement system to fail prematurely, especially the impact condition has high requirements for the deformation performance of the components, and the interface damage phenomenon is more obvious, which seriously limits the reinforcement effect of the FRP material. The purpose of using ECC material as an adhesive in this embodiment is that the ECC material exhibits good ductility and toughness under both dynamic and static loads, while the FRP material has high strength and high stiffness, which can provide additional bearing capacity and stiffness, and both materials have good durability. Through the composite reinforcement method, the advantages of ECC materials and FRP materials complement each other to achieve the purpose of improving the mechanical and deformation properties of the structure.

[0071] The outer surface of the truss pile leg 101, the outer surface of the truss duct leg 102, the outer surface of the support platform 103, the outer surface of the first connecting pipe rack 104, the outer surface of the second connecting pipe rack 105 and the outer surface of the third connecting pipe rack 106 (i.e., the outer surface of the truss body 1) are all provided with a POZD material layer. In the marine environment, the truss body 1 faces complex hydrodynamic loads and wind loads. Traditional trusses are often prone to displacement, deformation and instability under extreme conditions. The POZD material layer effectively disperses the external impact force and reduces the stress concentration of the structure by improving the surface strength and toughness. At the same time, the POZD material layer has good adhesion and flexibility, which can adapt to the dynamic deformation of the truss body 1 caused by waves and wind, ensuring the stability and safety of the structure in long-term operation.

[0072] In addition, the truss duct leg 102 includes a duct leg outer layer and a duct leg inner layer, the duct leg outer layer is located outside the duct leg inner layer, and the duct leg interlayer is between the duct leg outer layer and the duct leg inner layer. It should be noted that Figure 4 As shown, the interlayer of the conduit leg is filled with oil shale waste concrete.

[0073] In the design experiment of the truss duct leg 102, pre-mixed oil shale waste slag concrete and ordinary concrete were poured into the interlayers of the two duct legs respectively, and the proportions are shown in the following table (of course, in actual use, various parameters can be adjusted appropriately as needed). Group A in the following table is the ordinary concrete component, and Group B is the oil shale waste slag concrete component. By comparing and analyzing the impact strength of the truss duct leg 102 under different types of concrete pouring conditions, the influence of concrete type on the impact resistance of the duct leg is explored. Through the comparison of different types of concrete, it is finally concluded that the actual use effect of the oil shale waste slag concrete is better, the structural strength is higher, and the load resistance capacity is stronger.

[0074]

[0075] In this embodiment, if Figure 2-Figure 3 As shown, there are four truss legs 101 and four truss duct legs 102, and the four truss legs 101 are respectively located at the four vertices of the rectangle. The lower end of each truss duct leg 102 is respectively fixed to the upper end of a truss leg 101 opposite thereto, and the four truss duct legs 102 gradually move toward the center thereof from bottom to top.

[0076] In this embodiment, with regard to the specific dimensions of the truss leg 101 , the truss leg 101 is a steel pipe structure, the outer diameter of the truss leg 101 is 2850 mm, and the wall thickness of the truss leg 101 is 75 mm.

[0077] In this embodiment, with regard to the specific dimensions of the truss duct leg 102, the diameter of the outer layer of the duct leg (ie, the outer diameter) is 1750 mm, and the wall thickness of the outer layer of the duct leg is 50 mm.

[0078] The diameter (ie outer diameter) of the inner layer of the catheter leg is 750 mm, and the wall thickness of the inner layer of the catheter leg is 50 mm.

[0079] In this embodiment, the first connecting pipe rack 104 includes two cross-connected first connecting steel pipes, in other words, the two first connecting steel pipes are in an X shape, and both ends of each first connecting pipe are connected to two adjacent truss conduit legs 102. The diameter of the first connecting steel pipe is 600 mm, and the wall thickness of the first connecting steel pipe is 25 mm.

[0080] Similarly, the second connecting pipe rack 105 includes two cross-connected second connecting steel pipes, that is, the two second connecting steel pipes are in an X shape, and both ends of each second connecting pipe are connected to two adjacent truss conduit legs 102. The diameter of the second connecting steel pipe is 700 mm, and the wall thickness of the second connecting steel pipe is 37.5 mm.

[0081] Similarly, the third connecting pipe rack 106 includes two cross-connected third connecting steel pipes, that is, the two third connecting steel pipes are in an X shape, and both ends of each third connecting pipe are connected to two adjacent truss conduit legs 102. The diameter of the third connecting steel pipe is 850 mm, and the wall thickness of the third connecting steel pipe is 50 mm.

[0082] It can be seen that the sizes of the first connecting pipe rack 104 , the second connecting pipe rack 105 and the third connecting pipe rack 106 gradually increase from top to bottom, which is also caused by the fact that the spacing between adjacent truss conduit legs 102 also gradually increases from top to bottom.

[0083] In addition, the above-mentioned specific dimensions of each component in the truss body 1 only provide a specific embodiment. In actual use, the specific dimensions of each component can also be adjusted according to actual conditions and are not limited to this one.

[0084] In this embodiment, the thickness of the POZD material layer is 5 mm.

[0085] In this embodiment, the support platform 103 is a rectangular steel plate structure, which serves as the bearing structure of the wind turbine tower 2 , and the thickness of the support platform 103 is 1000 mm.

[0086] In this embodiment, the wind turbine tower 2 is a conical structure with a small top and a large bottom, the upper end diameter of the wind turbine tower 2 is 5500mm, and the lower end diameter of the wind turbine tower 2 is 8000mm. Of course, the sizes of the support platform 103 and the wind turbine tower 2 can also be adjusted according to actual conditions, and are not limited to this one.

[0087] Embodiment 2

[0088] This embodiment provides a construction method for an offshore wind turbine foundation truss, based on the offshore wind turbine foundation truss disclosed in the first embodiment, including a construction method for connecting nodes and a spraying method for a POZD material layer. The specific contents of the two methods are as follows:

[0089] The construction method of the connection node includes the following steps:

[0090] S1. Construction preparation:

[0091] Material preparation: select suitable FRP materials to ensure they meet the design requirements.

[0092] S2. Connection node cleanup:

[0093] Surface treatment: Before setting the FRP protective layer, the surface of the truss node must first be thoroughly cleaned (sandpaper or other methods can be used) to remove oil, dust, rust and other impurities to improve the bonding strength between the FRP protective layer and the substrate (ie, the truss body 1).

[0094] S3. Preparation of FRP protective layer:

[0095] Material cutting: FRP materials are cut into required specifications according to the shape and size of the connection nodes, ensuring that each layer of material is uniform.

[0096] Prepreg treatment: immerse the cut FRP material in resin to ensure it is fully saturated; alternatively, prepreg material can be used for direct laying.

[0097] S4. Paste FRP protective layer:

[0098] Apply adhesive evenly on the cleaned surface of the connection node to ensure that the coverage area of ​​the adhesive meets the design requirements.

[0099] Laying the FRP protective layer, paste the impregnated FRP protective layer onto the connection nodes layer by layer, taking care to eliminate bubbles between each layer and keep the material flat and fitted.

[0100] S5. Curing and inspection:

[0101] During the curing process, the ambient temperature and humidity are controlled according to the characteristics of the adhesive used to ensure that the FRP protective layer can be cured within the specified time.

[0102] Quality inspection: After curing is completed, quality inspection is carried out to check the bonding strength between the FRP protective layer and the substrate as well as the appearance quality to ensure that there are no obvious defects.

[0103] S6. Post-processing:

[0104] Surface protection: Apply protective coating to the outside of the FRP protective layer to enhance weather resistance and aesthetics.

[0105] Regular inspection: After construction is completed, the FRP protective layer should be inspected regularly to ensure its long-term effectiveness.

[0106] Through the above construction methods, FRP materials can effectively improve the structural performance of the connection nodes and extend their service life. In actual construction, the construction specifications should be strictly followed to ensure the optimization of the FRP protective layer effect.

[0107] The spraying method of the POZD material layer comprises the following steps:

[0108] S1. Substrate treatment:

[0109] First, the surface of the truss is thoroughly cleaned to remove oil and impurities, and is cleaned with organic solvents such as xylene and acetone to ensure that the base surface is clean. Welds and welding slag and other parts need to be polished to ensure that the surface is smooth and free of sharp protrusions. According to the "Construction Specifications for Steel Structure Coating Engineering" (GB 50214-2019), the surface treatment is carried out to Sa2.5 level by sandblasting to ensure that the surface roughness is suitable for coating. For parts that cannot be sandblasted, use a grinding wheel to manually polish to St3 level to ensure that the roughness after treatment meets the requirements. Finally, use oil-free and water-free compressed air to thoroughly clean the truss after sandblasting to remove dirt such as dust and rust residue to ensure the quality of coating.

[0110] S2. Selection of primer:

[0111] Choose epoxy resin as the primer, and the POZD material should be sprayed within 8 hours after the primer is applied. According to relevant specifications, if the coating (i.e. POZD material layer) is more than 48 hours apart, the primer needs to be reapplied to ensure good adhesion. The selection of primer and the construction time are crucial to the bonding strength of subsequent coatings.

[0112] S3. Inspection of spraying equipment:

[0113] Before spraying, check the normal working status of the main machine, spray gun and other auxiliary equipment, set the pressure and heating temperature of the pipeline, and start the pipeline heater 30 minutes in advance. Stir the POZD material for 30 minutes to ensure uniform mixing and achieve the standard of no floating color, no blooming and no precipitation.

[0114] S4, POZD material spraying:

[0115] Test spraying is performed on a dry test spraying surface to observe the normality of the POZD material layer. A horizontal and vertical cross-spraying method is used to ensure that the thickness of the POZD material layer is uniform and continuous. When spraying the next layer of POZD material, it covers more than 50% of the previous layer of POZD material to ensure the consistency of the spraying thickness. The interval between spraying each layer of POZD material should not exceed 3 hours. If this time is exceeded, the coating needs to be polished and a layer of closed primer should be applied before spraying. At the same time, the root of the truss body 1 is pre-sprayed to form a reinforcement layer. The thickness of the POZD material layer should be set to be greater than or equal to 2 mm to meet the protection requirements.

[0116] This embodiment applies new materials to the new truss body 1 of the offshore wind turbine. With its excellent physical and chemical properties, POZD material performs well in improving the structural strength, toughness and corrosion resistance of the truss. By optimizing the spraying process, it is ensured that the POZD material can evenly and fully cover the outer surface of the truss body 1, thereby forming an effective protective layer and enhancing its durability in the marine environment. In order to verify the improvement of the performance of the offshore wind turbine truss by spraying POZD material, this study used ABAQUS finite element analysis software for numerical simulation. The simulation results show that compared with the new truss without POZD spraying, the bearing capacity and stability of the truss after spraying are significantly improved.

[0117] Each component of the truss body 1 is fixed by welding. The welding method is used to connect each node, which can achieve a tighter and stronger combination, reduce the weaknesses of the connection parts, and effectively improve the overall bearing capacity and durability of the structure. In addition, the welding process has good seismic performance, can effectively absorb and disperse external loads, and enhance the adaptability of the structure in a dynamic environment. This overall design not only improves the safety and stability of the truss body 1, but also reduces maintenance requirements, prolongs the service life, and provides reliable protection for the long-term operation of offshore wind turbines.

[0118] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An offshore wind turbine foundation truss, characterized in that: It comprises a truss body and a wind turbine tower, wherein the truss body comprises a plurality of truss legs, the upper end of each truss leg is connected to a truss conduit leg, the upper ends of the truss conduit legs are commonly connected to the lower surface of a support platform, the lower end of the wind turbine tower is fixed to the upper surface of the support platform, and a first connecting pipe rack, a second connecting pipe rack and a third connecting pipe rack are sequentially arranged between two adjacent truss conduit legs from top to bottom; The connection points between the first connecting pipe rack, the second connecting pipe rack and the third connecting pipe rack and the truss duct leg are all connecting nodes, and the connecting nodes are provided with an ECC bonding layer and an FRP protective layer, and the FRP protective layer is located on the outside of the ECC bonding layer; The outer surface of the truss pile leg, the outer surface of the truss conduit leg, the outer surface of the support platform, the outer surface of the first connecting pipe rack, the outer surface of the second connecting pipe rack and the outer surface of the third connecting pipe rack are all provided with a POZD material layer; The truss duct leg includes a duct leg outer layer and a duct leg inner side, the duct leg outer layer is located on the outside of the duct leg inner layer, a duct leg interlayer is formed between the duct leg outer layer and the duct leg inner layer, and the duct leg interlayer is filled with oil shale waste concrete.

2. The offshore wind turbine foundation truss according to claim 1, characterized in that: The truss pile legs and the truss conduit legs are each provided with four.

3. The offshore wind turbine foundation truss according to claim 1, characterized in that: The truss legs are steel pipe structures, the outer diameter of the truss legs is 2850 mm, and the wall thickness of the truss legs is 75 mm.

4. The offshore wind turbine foundation truss according to claim 1, characterized in that: The diameter of the outer layer of the conduit leg is 1750 mm, and the wall thickness of the outer layer of the conduit leg is 50 mm; The diameter of the inner layer of the catheter leg is 750 mm, and the wall thickness of the inner layer of the catheter leg is 50 mm.

5. The offshore wind turbine foundation truss according to claim 1, characterized in that: The first connecting pipe rack includes two cross-connected first connecting steel pipes, the diameter of the first connecting steel pipe is 600 mm, and the wall thickness of the first connecting steel pipe is 25 mm; The second connecting pipe rack includes two cross-connected second connecting steel pipes, the diameter of the second connecting steel pipe is 700 mm, and the wall thickness of the second connecting steel pipe is 37.5 mm; The third connecting pipe rack includes two cross-connected third connecting steel pipes, the diameter of the third connecting steel pipe is 850 mm, and the wall thickness of the third connecting steel pipe is 50 mm.

6. The offshore wind turbine foundation truss according to claim 1, characterized in that: The thickness of the POZD material layer is 5 mm.

7. The offshore wind turbine foundation truss according to claim 1, characterized in that: The support platform is a rectangular steel plate structure, and the thickness of the support platform is 1000 mm.

8. The offshore wind turbine foundation truss according to claim 1, characterized in that: The upper end diameter of the wind turbine tower is 5500 mm, and the lower end diameter of the wind turbine tower is 8000 mm.

9. A construction method for an offshore wind turbine foundation truss, characterized in that: An offshore wind turbine foundation truss according to any one of claims 1 to 8, comprising a construction method for connecting nodes and a spraying method for a POZD material layer; The construction method of the connection node includes the following steps: S1. Construction preparation: Material preparation, selection of appropriate FRP materials; S2. Connection node cleanup: Surface treatment: Before setting the FRP protective layer, the surface of the connection node needs to be cleaned to remove oil, dust and rust; S3. Preparation of FRP protective layer: Material cutting: Cut the FRP material into required specifications according to the shape and size of the connection node, ensuring that each layer of material is uniform; Pre-preg treatment, immersing the cut FRP material in resin to ensure it is fully saturated; S4. Paste FRP protective layer: Apply adhesive evenly on the cleaned surface of the connection node; Laying the FRP protective layer, pasting the impregnated FRP protective layer to the connection nodes layer by layer; S5. Curing and inspection: During the curing process, the ambient temperature and humidity are controlled according to the characteristics of the adhesive used to ensure that the FRP protective layer can be cured within the specified time; Quality inspection: After curing is completed, quality inspection is carried out to check the bonding strength between the FRP protective layer and the substrate as well as the appearance quality; S6. Post-processing: Surface protection: applying protective coating on the outside of the FRP protective layer to enhance weather resistance and aesthetics; Regular inspection: After construction is completed, the FRP protective layer should be inspected regularly to ensure its long-term effectiveness; The spraying method of the POZD material layer comprises the following steps: S1. Substrate treatment: First, clean the truss body to remove oil and impurities, and use organic solvents to clean it to ensure that the base surface is clean; the welds and welding slag parts need to be polished to ensure that the surface is smooth and without sharp protrusions; the surface of the truss body is sandblasted using a sandblasting process to ensure that the surface roughness is suitable for painting; for parts that cannot be sandblasted, use a grinding wheel to manually polish; finally, use compressed air to clean the truss body after sandblasting to remove dust and rust residue to ensure the quality of painting; S2. Selection of primer: Choose epoxy resin as primer, and POZD material spraying should be carried out within 8 hours after the primer is applied; S3. Inspection of spraying equipment: Before spraying, check the normal working status of the spraying equipment, set the pressure and heating temperature of the pipeline, start the pipeline heater 30 minutes in advance, and fully stir the POZD material for 30 minutes to ensure uniform mixing; S4, POZD material spraying: Test spraying is carried out on a dry test spraying surface to observe the normality of the POZD material layer. A horizontal and vertical cross spraying method is adopted to ensure that the thickness of the POZD material layer is uniform and continuous. When spraying the next POZD material layer, it covers more than 50% of the previous POZD material layer to ensure the consistency of the spraying thickness.

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