Modular manufacturing process of lightweight floating wind turbine platform filled with polyurethane material

Abstract

The present application relates to offshore wind power generation technology field, especially light weight floating wind power platform modular manufacturing process based on polyurethane material filling, the process comprises the following steps: step S1, the rotational molding preparation of hollow plastic sphere: using rotational molding process, linear low density polyethylene powder is used as raw material, and hollow plastic sphere is prepared; in the scheme, by dividing the frame into several standardized segmented bodies and performing the alternating operation of "putting-in, plugging, pouring and curing" one by one, the modular precise filling and efficient manufacturing of the large-size floating wind power platform buoyancy structure are realized by cooperating the composite structure of the rotational molding hollow plastic sphere and the polyurethane foam material and the segmented sealing pouring of the air bag type plugging equipment, the problems such as high mold cost, transportation difficulty, many filling defects and unreliable interface bonding in the traditional integral casting process are avoided, and the controllability of the manufacturing process, the quality traceability and the long-term service reliability of the platform are improved.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power technology, and in particular to a modular manufacturing process for lightweight floating wind power platforms based on polyurethane filling materials. Background Technology

[0002] Lightweight floating wind turbine platforms are core equipment for deep-sea wind energy development, and the balance between their buoyancy structure and overall weight directly determines the platform's engineering feasibility and economic viability. Polyurethane materials, due to their lightweight, high buoyancy, low water absorption, and excellent seawater corrosion resistance, have been incorporated into the buoyancy filling structure of floating wind turbine platforms. By filling the platform's steel frame with rigid polyurethane foam or composite foam materials, the overall weight of the platform can be effectively reduced, while buoyancy reserves can be increased.

[0003] However, traditional polyurethane filling processes typically employ a monolithic, one-time casting method, continuously pouring foaming material or filler into the entire frame, which then cures to form a complete filler. This method has the following drawbacks: First, monolithic filling requires extremely precise mold dimensions; large molds are expensive to manufacture and difficult to reuse. Furthermore, the extra-large fillers are inconvenient for factory production and land transportation, hindering the efficiency of engineering applications. Second, the flow path of the foaming material or filler within the frame during the one-time casting process is long and uncontrollable, easily leading to defects such as voids and air pockets within the filler. These defects are highly concealed and difficult to detect and repair after curing, severely affecting the structural integrity and buoyancy reliability of the filler. Third, traditional filling methods lack reliable interfacial bonding between the filler and the inner wall of the frame, making them prone to interfacial debonding and relative sliding under long-term alternating marine loads. This allows seawater to seep in along the interface, accelerating internal structural corrosion.

[0004] To address this, this invention proposes a modular manufacturing process for lightweight floating wind power platforms based on polyurethane material filling. By dividing the infill within the frame into several standardized segments and performing alternating "insertion-sealing-injection-curing" operations on each segment, combined with a composite structure of rotationally molded hollow plastic spheres and polyurethane foam material, and segmented sealing injection using an airbag-type sealing device, this process achieves modular, precise filling and efficient manufacturing of the buoyancy structure of large-size floating wind power platforms. It effectively solves prominent problems in traditional integral casting processes, such as high mold costs, transportation difficulties, numerous filling defects, and unreliable interface bonding, thereby improving the controllability of the manufacturing process, quality traceability, and long-term service reliability of the platform. Summary of the Invention

[0005] Technical problems to be solved: Overcoming the shortcomings of traditional polyurethane integral casting process for floating wind power platforms, such as high mold cost, difficulty in transporting ultra-large fillers, easy generation of internal voids by one-time casting, and unreliable bonding between filler and frame interface, a modular manufacturing process that can realize segmented prefabrication, segmented filling, and quality control is provided to achieve efficient and high-quality manufacturing of large-size floating wind power platforms.

[0006] To address the shortcomings of existing technologies, this invention provides a modular manufacturing process for lightweight floating wind power platforms based on polyurethane material filling, thereby solving the technical problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A modular manufacturing process for lightweight floating wind turbine platforms based on polyurethane filling material includes the following steps:

[0009] Step S1, preparation of hollow plastic spheres by rotational molding: Hollow plastic spheres are prepared using linear low-density polyethylene powder as raw material through rotational molding process;

[0010] Step S2, Segment Mold Preparation: Based on the platform frame length L and diameter R, design the segment mold. The mold length is L / N, where N is an integer and ranges from 3 to 8. The mold diameter is designed as R-2cm, with a 2cm gap reserved. The mold is designed as a split structure that is divided into two or more halves along the axial direction, and is equipped with a foam material injection port and an exhaust port.

[0011] Step S3, Segment preparation: Place the multiple hollow plastic spheres prepared in step S1 into the mold prepared in step S2. After closing the mold, inject rigid polyurethane foam raw material. The raw material foams and solidifies in the mold, anchoring the hollow plastic spheres to form standardized segmented bodies.

[0012] Step S4, End Sealing: Before filling the segmented body, the end of the platform frame is sealed using a sealing device to prevent filler from overflowing; the sealing device achieves radial fastening and sealing through airbag inflation;

[0013] Step S5, Segment placement: The segments prepared in step S3 are placed one by one into the platform frame. Assembly gaps are formed between the segments and the inner wall of the frame and between the end faces of adjacent segments. The sealing device is used to seal the side of the current segment near the open end to form a closed cavity.

[0014] Step S6, Filler Injection: Inject filler into the closed cavity formed in step S5. The filler is a two-component solvent-free micro-foamed polyurethane structural adhesive. After curing, it fills the gaps and fixes the segment to the inner wall of the frame.

[0015] Step S7, Repeated processing of the next segment: Repeat steps S5 and S6 to complete the placement, sealing, filling and curing of all segments in sequence;

[0016] Step S8, Final sealing of openings: After all segments have been filled and cured, the openings of the frame are sealed.

[0017] Step S9, Platform Frame Assembly: Assemble the completed platform frame sections to form a complete floating wind power platform structure.

[0018] In one possible implementation, the diameter of the hollow plastic sphere in step S1 is controlled between 10cm and 20cm, and the wall thickness is controlled between 2 and 5mm; during rotational molding, the heating temperature is controlled between 250 and 400℃, the ratio of revolution speed to rotational speed is 4:1, and the heating time is 10 to 30 minutes; the wall thickness uniformity error of the finished sphere is controlled within ±20%.

[0019] In one possible implementation, the rigid polyurethane foam described in step S3 has a closed-cell rate ≥92%, a water absorption rate ≤0.7%, a compressive strength ≥0.22 MPa, and a density of 40 kg / m³. 3 The bonding strength with polyethylene is ≥0.4MPa; the foaming temperature is controlled at 20~40℃, the foaming time is 10~30 minutes, and after curing for 1~2 hours, it is demolded and then cured at room temperature for 24~48 hours.

[0020] In one possible implementation, the sealing device in step S4 includes a main body, an annular rubber airbag located on the outside of the main body, an upper pressure plate and a lower pressure plate located at the upper and lower ends of the main body, and a hollow screw rod passing through the middle of the main body; the upper pressure plate and the lower pressure plate are threadedly connected to the hollow screw rod, and the clamping force is adjusted by rotating the nut; the airbag inflation pressure is 0.2~0.5MPa during use.

[0021] In one possible implementation, the gap between the end faces of adjacent segments in steps S5 and S6 is controlled at 2-4 cm; the filler has a shear strength ≥1.7 MPa on the stainless steel substrate in seawater and a micro-foaming rate of 5%-15%; the injection pressure is controlled at 0.3-0.8 MPa, the injection speed is 1-3 L / min, and the injection volume is reserved with a margin of 5%-10%; the curing conditions are room temperature curing for 24-72 hours or heating curing at 40-60℃ for 4-8 hours.

[0022] In one possible implementation, the selection of the N value in step S2 is determined based on the ease of movement and transportation of the segment body, so as to balance the relationship between the number of segment bodies and the size of a single segment body, so that the standardized mold can be reused and the segment bodies are easy to produce in the factory, transport by land and hoist on site.

[0023] Beneficial effects compared to existing technologies:

[0024] In this solution, a composite structure of rotationally molded hollow plastic spheres and in-situ foamed rigid polyurethane foam is used to form a lightweight segmented structure with synergistic force distribution between the sphere and the foam. This significantly reduces the structural weight while ensuring buoyancy redundancy safety, achieving lightweight manufacturing of large-size floating wind power platforms. By dividing the infill within the frame into several standardized segments and equipping them with reusable modular molds, the factory prefabrication and mass production of the segments are achieved. Mold reuse reduces manufacturing costs, and reasonable control of segment dimensions solves the engineering challenges of transporting and hoisting ultra-large components. The solution utilizes a process of "inserting one by one and sealing segment by segment." The alternating operation method of "plugging, segmented injection, and segmented curing," combined with airbag-type sealing equipment, achieves reliable sealing between the inner wall of the frame and the segmented bodies. This ensures uniform filling gaps and dense, void-free filler in each segment. The segments are continuously bonded axially to form a unified, integral filling structure, achieving modular, precise filling with a controllable and traceable process. By bonding the filling structure to the inner wall of the platform frame and implementing final end sealing, the filler and frame work together to bear the load, while isolating seawater from the internal structure. This significantly improves the platform's fatigue resistance, structural durability, and corrosion resistance. In summary, this process enables modular manufacturing of lightweight floating wind turbine platforms from materials to finished products, effectively reducing construction costs and difficulties in deep-sea wind turbine platforms. Attached Figure Description

[0025] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the segmented mold structure of the present invention;

[0028] Figure 3 This is a schematic diagram of the sealing device structure of the present invention;

[0029] Figure 4 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0030] Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention can also be implemented in various different forms, and therefore the present invention is not limited to the embodiments described below.

[0031] The technical solution in this application embodiment is to solve the problems mentioned in the background art, and the overall idea is as follows:

[0032] Please refer to Figures 1 to 4 As shown, this embodiment introduces a modular manufacturing process for a lightweight floating wind power platform based on polyurethane material filling, including the following steps:

[0033] Step S1: Preparation of hollow plastic spheres by rotational molding

[0034] Hollow plastic spheres are prepared using rotational molding. In rotational molding, a measured amount of powdered resin is loaded into a cold mold. The rotational molding machine drives the mold to slowly rotate and revolve around two mutually perpendicular axes. Simultaneously, an external heat source heats the mold, causing the resin powder to melt and, with its own weight, evenly coat the entire inner surface of the mold cavity. After cooling and demolding, a hollow product with uniform wall thickness, no edge waste, and no weld seams is obtained. Products with wall thicknesses ranging from 1 to 16 mm can be molded.

[0035] It uses imported linear low-density polyethylene powder as the molding raw material, with a melt flow rate controlled at 4~6 g / 10 min and a density of 0.92~0.94 g / cm³. 3 Melt flow rate is a key parameter of this process. If it is too high, the melt will be too fluid and result in uneven wall thickness. If it is too low, the melt will be difficult to coat evenly. Linear low-density polyethylene has excellent resistance to seawater corrosion, aging, and impact. It is not easily hydrolyzed or degraded in the marine environment and is non-toxic, odorless, and does not pollute the marine water.

[0036] The measured resin powder is loaded into a hollow spherical metal mold. The mold is made of cast aluminum alloy with a wall thickness of 5-8mm, which has good thermal conductivity and dimensional stability. After the mold is closed, it is tightened and an exhaust pipe is installed. The exhaust pipe is filled with glass fiber or steel wool to prevent the powder from overflowing during rotation.

[0037] The mold is placed in a heating furnace, and the heating temperature is controlled at 250~400℃. The mold rotates slowly along two axes with a revolution-to-rotation speed ratio of 4:1, so that the molten resin is evenly coated on the inner wall of the mold. The heating time is determined according to the size of the sphere and the wall thickness requirements, generally 10~30 minutes. The precise matching of rotation speed and heating temperature is the key to controlling the uniformity of wall thickness.

[0038] After heating, the mold is transferred to the cooling station and cooled by air cooling or water mist cooling. After cooling to room temperature, the mold is opened and the hollow sphere is taken out. The edge is trimmed to remove the flash and burrs. (5) Quality inspection: The wall thickness uniformity of the finished sphere is inspected and the error is controlled within ±20%. The appearance defects are inspected and the air pressure sealing is inspected.

[0039] The diameter of the spheres is controlled between 10cm and 20cm, with the specific size adjusted according to their location on the platform. Larger diameter spheres are used in areas with high buoyancy requirements to reduce the number of spheres per unit volume and the bonding interface, while smaller diameter spheres are used in areas with complex structures or limited space to improve filling density. The wall thickness is controlled between 2 and 5mm. Thicker walls result in higher pressure resistance but also greater weight; a balance must be struck between buoyancy and strength. The polyethylene hollow spheres, prepared using rotational molding, are seamless, have uniform wall thickness, and good sealing properties. Their hollow structure itself is an independent buoyancy unit, decomposing a large continuous float into several independent small buoyancy units. This effectively avoids the risk of overall buoyancy loss due to partial damage to a single float. Even if individual spheres break and leak water, the others can continue to provide buoyancy, significantly improving the platform's redundancy safety. Furthermore, the spheres exhibit uniform stress distribution and strong pressure resistance when subjected to external water pressure.

[0040] Step S2: Preparation of segmented molds

[0041] like Figure 2 As shown, the segmented mold is designed based on the length L and diameter R of the platform frame to be filled. The mold length is L / N, where N is an integer and generally ranges from 3 to 8. A large N value increases the number of segments and the workload of on-site assembly, while a small N value results in an excessively large individual segment that is inconvenient for transportation and hoisting. The specific selection must comprehensively consider the ease of movement and transportation of the segments. The mold diameter is designed to be R-2cm, with a 2cm gap. This gap mainly facilitates the smooth entry of the segments and allows for the filling of filler material in this gap and the intervals between the upper and lower segments to achieve connections between the segments and between the segments and the interior of the platform frame.

[0042] The mold is designed as a split metal mold that is divided into two or more halves along the axial direction to facilitate demolding. The mold is equipped with a foam material injection port and an exhaust port to ensure that the gas is smoothly discharged and the foam is densely filled during the foaming process. The mold material is selected from cast aluminum alloy or carbon steel, and the wall thickness is determined according to the size of the segment and is generally not less than 8mm to ensure that the mold does not deform under the foaming pressure.

[0043] Dividing the infill within the entire frame into several standardized segments is the core of modular manufacturing. Standardized segment dimensions allow for mold reuse, reducing mold manufacturing costs. Appropriate control over segment volume makes in-factory production, land transportation, and on-site hoisting feasible, avoiding the manufacturing and logistical challenges associated with oversized overall infill. The reserved 2cm gap fully considers the assembly tolerance between the segments and the frame, ensuring smooth insertion of the segments while providing sufficient flow space and bonding thickness for the infill, ensuring connection strength.

[0044] Step S3: Segmented body preparation

[0045] This step uses foam material to anchor multiple hollow plastic spheres together, forming standardized segmented bodies. The foam material is mainly used to fill the gaps between the hollow plastic spheres and to connect the spheres to form segmented bodies. Specifically:

[0046] The hollow plastic spheres prepared in step S1 are placed into the mold prepared in step S2. The spherical design of the hollow plastic spheres creates gaps between them, which can be used to fill the foam material and facilitate the flow of the foam material. After the mold is closed, polyurethane rigid foam raw material is injected through the injection port on the mold. The raw material undergoes a chemical reaction and expands in volume inside the mold, filling the gaps between the spheres and firmly anchoring each sphere. The foaming temperature is controlled at 20~40℃, and the foaming time is about 10~30 minutes. During the foaming process, the injection volume must be strictly controlled. Insufficient injection volume will cause the foam to fail to fill the cavity and form voids, while excessive injection volume will cause the foam to overflow or generate excessive internal pressure, resulting in mold deformation.

[0047] After foaming, continue to cure in the mold for 1-2 hours, then demold and remove the segment. The demolded segment needs to continue to mature at room temperature for 24-48 hours to ensure that the internal cross-linking reaction is fully completed and the performance is stable.

[0048] The selected rigid polyurethane foam material must meet the following requirements: closed-cell rate ≥ 92%, as the closed-cell structure ensures that each cell is independent and does not communicate with each other, which is key to preventing water penetration; water absorption rate (by volume) ≤ 0.7%; compressive strength ≥ 0.22 MPa; density 40 kg / m³. 3 The dimensions are approximately ±1%; dimensional stability (100℃, 7 days) ≤ ±1%; bond strength with polyethylene ≥ 0.4 MPa. This closed-cell structure makes it impermeable to any type of liquid, including water and solvents, making it particularly suitable for harsh marine environments.

[0049] The foaming material is in-situ foamed within the mold, utilizing its expansion properties to fill all irregular gaps between the spheres, forming a "sphere-foam" composite structure. This structure combines the advantages of both materials: firstly, the hollow spheres provide the primary source of buoyancy and a compressive strength framework; secondly, the foaming material fills the gaps, transfers loads, and constrains the displacement of the spheres. The interfacial bonding between the spheres and the foam makes the entire segment a cohesive whole, sharing the load under external forces, preventing relative displacement and concentrated stress on the spheres. Simultaneously, the closed-cell structure of the rigid polyurethane foam ensures that the entire segment has a low water absorption rate and high buoyancy retention during long-term seawater immersion.

[0050] Step S4, End sealing

[0051] The purpose of end sealing is to seal the ends of the platform frame before segment filling and filler injection, preventing filler overflow and ensuring connection strength. End sealing involves two cases:

[0052] Scenario 1: The platform frame is a hollow frame structure with closed ends. In this case, one end of the platform frame has been closed by welding the end plate during manufacturing. Before the filling operation, a pressure test is required to confirm that the end is closed and leak-free. The filling operation is carried out from the other end. After all the filling is completed, the open end is sealed.

[0053] Scenario 2: The platform frame is a through structure with openings at both ends. In this case, sealing equipment is needed to seal both ends separately.

[0054] like Figure 3 As shown, the sealing device includes a main body with a hollow screw that also serves as a filling channel for the filler in the middle. An annular rubber airbag is located on the outer side of the main body. An upper pressure plate and a lower pressure plate are respectively located at the upper and lower ends of the main body. The upper and lower pressure plates are threadedly connected to the hollow screw. The clamping force between the pressure plate and the frame end face can be adjusted by rotating the nut. The upper and lower pressure plates are available in various diameters and thicknesses, selected to match the diameter of the platform frame. The outer diameter of the pressure plate should be slightly smaller than the outer diameter of the frame to ensure it can enter the platform frame.

[0055] In use, the sealing device is inserted into the end of the frame, and the airbag is inflated by inflating it to a pressure of 0.2~0.5MPa. The side wall of the airbag presses against the inner wall of the platform frame to achieve radial fastening and sealing. The filling device is connected to the hollow screw port, and then the filler is injected into the platform frame through the hollow screw.

[0056] End sealing is a prerequisite for ensuring the quality of filler injection. If the end sealing is not tight, the injected filler will flow out before curing, which will not only waste materials, but also cause the filler inside the frame to not be filled completely, forming voids, which will seriously affect the bonding strength between the segment and the frame and the reliability of the overall structure. However, the dual sealing mechanism of radial expansion of the airbag and axial compression of the pressure plate achieves universal compatibility and reliable sealing for frames of different diameters.

[0057] Step S5: Place the segmented body in

[0058] The segments prepared and cured in step S3 are placed one by one into the platform frame. Since the diameter of each segment is 2 cm smaller than the inner diameter of the platform frame, the segments can easily enter the frame. This step is alternated with the subsequent filler injection and curing steps; that is, after placing one segment, its ends are sealed, then filler is injected and cured. After curing, the next segment is placed, and so on, until all segments are filled. Specifically:

[0059] Use a crane or electric hoist to lift the segment to the frame port; use guide cone sleeves or guide rollers to ensure that the segment enters smoothly along the frame axis, avoiding deviation and jamming; the segment is fed along the frame axis until it contacts the fixed previous segment or the sealing end, and the end face gap between the two is controlled within the range of 2~4cm; use temporary positioning fixtures (such as radial support rods or axial stops) to fix the current segment in the design position to prevent it from axial movement or radial displacement during subsequent sealing and grouting operations.

[0060] After the current segment is positioned, immediately seal the end of the segment near the open end. Insert the sealing device into the frame from the open end, positioning it near the end face of the segment near the open end, ensuring a 2cm to 4cm gap between the sealing device and the segment's near end face. Inflate the airbag to form a closed cavity between the segment and the open end. Inflate the airbag (0.2~0.5MPa) to make its sidewalls press against the inner wall of the platform frame, achieving radial fastening and sealing. This creates closed cavities at both ends of the annular gap between the current segment and the inner wall of the frame, and the end face gap between the current segment and the previous segment (or the sealing end). Connect the hollow screw port of the sealing device to the filling device to inject the filler.

[0061] Step S6: Filler Injection

[0062] After the current segment is positioned and a closed cavity is established on the side near the open end using a sealing device, the filler is injected, cured, and the sealing device is removed. Specifically:

[0063] The filler selected is a two-component, solvent-free micro-foamed polyurethane structural adhesive, which exhibits high adhesion to various materials such as metals, foams, and plastics. The cured adhesive layer possesses good elasticity, vibration resistance, impact resistance, fatigue resistance, abrasion resistance, and durability, as well as good resistance to hydrolysis, oil, solvents, oxidation, and ozone. In seawater, the shear strength against stainless steel substrates can reach over 1.7 MPa, and it retains over 80% of its initial strength even after accelerated aging. The micro-foaming characteristics of the filler cause it to slightly expand during curing (foaming rate 5%~15%), fully filling gaps of 2~4 cm, eliminating microcracks caused by shrinkage, and achieving self-adaptive full filling.

[0064] Connect the filling device to the hollow screw port extending from the sealing device, and inject the filler into the gap between the segment and the platform frame. The filling is done by pressure filling, with the filling pressure controlled at 0.3~0.8MPa and the filling speed controlled at 1~3L / min, to ensure that the filler fully fills all gaps and removes internal air.

[0065] The filler injection is carried out according to the preset injection volume, which is calculated and determined by multiplying the sum of the annular gap volume between the segment body and the inner wall of the frame and the end face gap volume between the segments body by a margin coefficient of 1.05~1.10. During the injection process, the injection is stopped when the injection volume reaches the preset value; then the injection equipment is separated from the hollow screw port.

[0066] After injection, during the micro-foaming curing process of the filler (curing at room temperature for 24-72 hours, or accelerating the curing process by heating at 40-60℃ for 4-8 hours), excess gas generated during foaming is naturally discharged through the hollow screw port, preventing excessive internal pressure or incomplete filling due to gas accumulation in the sealed cavity. During curing, the airbag of the sealing device is kept inflated to ensure the sealing of the cavity, while maintaining environmental stability and avoiding vibration, humidity, and drastic temperature fluctuations.

[0067] After the filler has fully cured and the venting is completed, the sealing device is depressurized to allow the airbag to shrink back to its original shape, releasing the radial compression seal between the airbag sidewall and the inner wall of the platform frame. The sealing device is then removed entirely from the frame opening, and any remaining filler on the surface is cleaned for reuse in the sealing operation of the next segment.

[0068] Step S7: Repeat processing of the next segment.

[0069] Repeat steps S5 and S6, sequentially inserting, sealing, injecting, and curing the next segment, until all N segments have been inserted, sealed, filled, and secured. Specifically:

[0070] The filling operation of each segment uses the previously cured segment as a positioning reference. When a new segment is inserted, the end face of the adjacent previous segment is used as a reference. By controlling the 2-4 cm end face gap between the two segments, it is ensured that all segments within the entire frame are evenly distributed axially. For the filling process of each segment, the filling pressure must be controlled at 0.3-0.8 MPa, and the filling speed must be controlled at 1-3 L / min to ensure that the filler fully fills all gaps. A 5%-10% margin should be reserved in the filling volume to ensure that all gaps are completely filled. After the filler has cured, the sealing device is removed, and the next segment is processed.

[0071] By processing each segment individually, the entire filling process achieves high controllability and quality traceability. The injection volume and curing status of each segment can be independently recorded and inspected. If any abnormality occurs in the filling of a segment (such as an abnormal increase in injection pressure or no filler flowing from the vent hole), it can be detected in time and remedial measures can be taken to avoid the accumulation of defects leading to overall rework. The reusability of the sealing equipment realizes a construction organization mode of "one tool for multiple uses, sealing segment by segment," reducing equipment costs. The cured filler serves to fix the segment within the frame, providing a stable "base" for the placement of subsequent segments and preventing the movement of already placed segments from affecting the gap control accuracy.

[0072] Step S8: Final closure of the open end

[0073] After all the segments have been placed, sealed, filled and cured, the final sealing treatment of the frame opening ends is carried out.

[0074] This step also has two scenarios:

[0075] Scenario 1: The platform frame is a hollow frame structure closed at both ends. In this case, the entire lightweight filling structure is already enclosed inside the platform frame. After filling, there is no need to close the ends separately; only welding or installing sealing plugs is required at the filling port.

[0076] Scenario 2: The platform frame is a through-structure with openings at both ends. After all segments are filled and cured, the last opening must be sealed with a sealing material. The sealing material should be a metal sheet of the same or compatible material as the platform frame, with a thickness not less than the frame wall thickness, and fixed to the frame end by welding or bolting. Before sealing, it must be confirmed that the filler in the last segment has completely cured. If welding is used, attention should be paid to the possibility that the heat-affected zone of the weld may cause thermal damage to the nearby cured filler. Segmented welding, heat input control, and heat insulation protection of the welding area should be adopted. After sealing, it is recommended to perform overall heating curing of the entire frame (50~60℃, 2~4 hours) to allow all fillers to complete final cross-linking and curing in a closed environment, further improving the bonding strength. Subsequently, a pneumatic or hydrostatic test should be conducted to confirm that the entire frame is sealed without leakage.

[0077] The final closure of the open end is necessary for both structural integrity and corrosion and waterproofing. After closure, the entire infill structure is completely sealed inside the frame, isolated from the external marine environment, preventing seawater from directly contacting the infill material and the inner wall of the frame, thus fundamentally eliminating the possibility of corrosion and water seepage. Overall heat curing allows the filler between each segment to achieve the optimal cross-linking density and adhesion performance in the closed environment, forming a unified whole infill.

[0078] Step S9: Platform framework assembly

[0079] The platform frame sections, after being filled with polyurethane material, will be assembled according to the design drawings. Specifically:

[0080] Frame connection: The various frame sections are connected into a complete floating wind power platform structure using welding, bolting, or connecting structural components. Welded connections offer high strength and permanence, but require a large amount of on-site welding work and are greatly affected by environmental factors; bolted connections facilitate disassembly and maintenance, but require protection against loosening and corrosion.

[0081] Overall inspection: The assembled platform undergoes dimensional accuracy re-inspection, non-destructive testing of welds, filling density testing, and overall buoyancy testing. Filling density testing can be performed using the tapping method (listening to the sound) or ultrasonic testing.

[0082] Installation of ancillary facilities: Installation of wind turbine tower foundations, mooring system connectors, cathodic protection systems, navigation lights, and other ancillary facilities;

[0083] Factory acceptance: After all inspection items are completed and qualified, the product is delivered for use or transported to the installation sea area.

[0084] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A modular manufacturing process for a lightweight floating wind power platform based on polyurethane material filling, characterized in that, The process includes the following steps: Step S1, preparation of hollow plastic spheres by rotational molding: Hollow plastic spheres are prepared using linear low-density polyethylene powder as raw material by rotational molding process; Step S2, Segment Mold Preparation: Based on the platform frame length L and diameter R, design the segment mold. The mold length is L / N, where N is an integer and ranges from 3 to 8. The mold diameter is designed as R-2cm, with a 2cm gap reserved. The mold is designed as a split structure that is divided into two or more halves along the axial direction, and is equipped with a foam material injection port and an exhaust port. Step S3, Segment preparation: Place the multiple hollow plastic spheres prepared in step S1 into the mold prepared in step S2. After closing the mold, inject rigid polyurethane foam raw material. The raw material foams and solidifies in the mold, anchoring the hollow plastic spheres to form standardized segmented bodies. Step S4, End Sealing: Before filling the segmented body, the end of the platform frame is sealed using a sealing device to prevent filler from overflowing; the sealing device achieves radial fastening and sealing through airbag inflation; Step S5, Segment placement: The segments prepared in step S3 are placed one by one into the platform frame. Assembly gaps are formed between the segments and the inner wall of the frame and between the end faces of adjacent segments. The sealing device is used to seal the side of the current segment near the open end to form a closed cavity. Step S6, Filler Injection: Inject filler into the closed cavity formed in step S5. The filler is a two-component solvent-free micro-foamed polyurethane structural adhesive. After curing, it fills the gaps and fixes the segment to the inner wall of the frame. Step S7, Repeated processing of the next segment: Repeat steps S5 and S6 to complete the placement, sealing, filling and curing of all segments in sequence; Step S8, Final sealing of openings: After all segments have been filled and cured, the openings of the frame are sealed. Step S9, Platform Frame Assembly: Assemble the completed platform frame sections to form a complete floating wind power platform structure.

2. The modular manufacturing process for a lightweight floating wind power platform based on polyurethane material filling as described in claim 1, characterized in that, In step S1, the diameter of the hollow plastic sphere is controlled between 10cm and 20cm, and the wall thickness is controlled between 2 and 5mm. During rotational molding, the heating temperature is controlled between 250 and 400℃, the ratio of revolution speed to rotation speed is 4:1, and the heating time is 10 to 30 minutes. The wall thickness uniformity error of the finished sphere is controlled within ±20%.

3. The modular manufacturing process for a lightweight floating wind power platform based on polyurethane material filling as described in claim 1, characterized in that, The rigid polyurethane foam described in step S3 has a closed-cell rate ≥92%, a water absorption rate ≤0.7%, a compressive strength ≥0.22MPa, and a density of 40kg / m³. 3 The bonding strength with polyethylene is ≥0.4MPa; the foaming temperature is controlled at 20~40℃, the foaming time is 10~30 minutes, and after curing for 1~2 hours, it is demolded and then cured at room temperature for 24~48 hours.

4. The modular manufacturing process for a lightweight floating wind power platform based on polyurethane material filling as described in claim 1, characterized in that, The sealing device described in step S4 includes a main body, an annular rubber airbag located on the outside of the main body, an upper pressure plate and a lower pressure plate located at the upper and lower ends of the main body, and a hollow screw rod passing through the middle of the main body; the upper pressure plate and the lower pressure plate are threadedly connected to the hollow screw rod, and the clamping force is adjusted by rotating the nut; the airbag inflation pressure is 0.2~0.5MPa when in use.

5. The modular manufacturing process for a lightweight floating wind power platform based on polyurethane material filling as described in claim 1, characterized in that, In steps S5 and S6, the gap between the end faces of adjacent segments is controlled at 2-4 cm; the filler has a shear strength ≥1.7 MPa on the stainless steel substrate in seawater and a micro-foaming rate of 5%-15%; the injection pressure is controlled at 0.3-0.8 MPa, the injection speed is 1-3 L / min, and the injection volume is reserved with a margin of 5%-10%; the curing conditions are room temperature curing for 24-72 hours or heating curing at 40-60℃ for 4-8 hours.

6. The modular manufacturing process for a lightweight floating wind power platform based on polyurethane material filling as described in claim 1, characterized in that, The selection of the N value in step S2 is determined based on the ease of movement and transportation of the segmented body, so as to balance the relationship between the number of segmented bodies and the size of a single segmented body, so that the standardized mold can be reused and the segmented bodies are easy to produce in the factory, transport by land and hoist on site.

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