Negative pressure barrel and offshore wind power foundation

Abstract

The invention discloses a negative pressure barrel and an offshore wind power foundation, and relates to the technical field of offshore wind power foundations, the offshore wind power foundation comprises a draught fan supporting frame and the negative pressure barrel, the negative pressure barrel comprises a barrel body and a limiting piece, a sliding groove is formed in the outer wall of the barrel body in the axis direction of the barrel body, an expansion piece and a pull rod are arranged in the sliding groove, and the expansion piece comprises a fixing part and an expansion part; the fixing part is fixedly connected with the sliding groove, the pull rod is slidably connected with the sliding groove and comprises a protruding part, and the limiting piece is connected with the pull rod. The negative pressure barrel is provided with an expansion piece, a pull rod, a limiting piece and other structures, after the limiting piece abuts against the seabed, the pull rod is limited to descend, a protruding part pushes an expansion part to extend out of a sliding groove to abut against the groove wall of the seabed, the side friction resistance between the negative pressure barrel and soil is increased, the uplift bearing capacity is remarkably improved, and the negative pressure barrel is convenient to recycle; the limiting piece is supported by the seabed, the bearing area of the seabed to the negative pressure barrel can be effectively increased, and then the vertical bearing capacity, the horizontal resistance and the anti-overturning bending moment of the negative pressure barrel foundation are improved.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power foundation technology, and in particular to a negative pressure tank and an offshore wind power foundation. Background Technology

[0002] In the offshore wind power sector, barrel foundations are widely used as support structures for wind turbines. They typically utilize a barrel attached to the seabed to provide stable support for the wind turbine above. In existing technologies, some barrel foundations rely solely on negative pressure suction to connect to the seabed. While this method facilitates foundation recovery, it has significant drawbacks. Due to the lack of additional fixing structures, their pull-out resistance is poor, resulting in insufficient stability under external loads such as wave impacts and wind forces, making it difficult to ensure the long-term reliable operation of the wind turbine. To address the aforementioned stability issues, some barrel foundations undergo grouting via the suction pipe after installation. This grouting seals the suction pipe, preventing seawater infiltration and potential loosening of the negative pressure tank. It also seals the top layer inside the negative pressure tank, filling it with a loose mixture of seawater and gravel. Furthermore, after solidification, it increases the overall weight of the negative pressure tank, enhancing stability during use. However, this approach introduces new problems. Once sealed with grout, the negative pressure tank becomes difficult to remove from the seabed by injecting air or seawater from above. This significantly increases the difficulty and cost of recycling the barrel foundation, hindering the sustainable development and resource recycling of offshore wind power foundations. Therefore, a new type of offshore wind power foundation structure that improves foundation stability while facilitating recycling is urgently needed. Summary of the Invention

[0003] To address the problems of poor pull-out resistance, insufficient stability, and difficult recycling of existing cylindrical foundations, this invention provides a negative pressure tank and an offshore wind power foundation containing it. The aim is to improve the pull-out bearing capacity, vertical bearing capacity, horizontal resistance, and overturning moment resistance of the negative pressure tank, enhance foundation stability, and solve the problem of difficult recycling of the negative pressure tank, thereby reducing recycling costs.

[0004] To achieve the above objectives, in a first aspect, the present invention provides a negative pressure tank, comprising a tank body and a limiting member. The tank body has an open-bottomed chamber inside, and a drain hole communicating with the chamber is opened at the top of the tank body. A groove is formed on the outer wall of the tank body along its axial direction, and an expansion plate and a pull rod are provided in the groove. The expansion plate includes a fixed part and an expansion part. The fixed part is fixedly connected to the groove, and the pull rod is slidably connected to the groove. The pull rod includes a protrusion that contacts and engages with the expansion part and is used to push the expansion part to move away from the center of the tank body to extend out of the groove. The limiting member is connected to the pull rod. When the tank body penetrates the seabed to a first depth, the limiting member abuts against the seabed and provides an upward supporting force to the pull rod to limit the pull rod from descending with the tank body, thereby increasing the pressure between the protrusion and the expansion part, so that the expansion part tends to extend out of the groove away from the center of the tank body. The tank body will eventually descend to a second depth. During the process of the tank body moving from the first depth to the second depth, the protrusion pushes the expansion part to extend out of the groove and abut against the groove wall of the seabed.

[0005] Furthermore, the expansion plate has a first arc surface that conforms to the outer wall of the barrel, and the pull rod has a second arc surface that conforms to the outer wall of the barrel.

[0006] Furthermore, the expansion plate and the tie rod together fill the chute. Based on this, the bottoms of the protrusion and the expansion plate can be flush with each other and both abut against the bottom of the chute; or the bottom of the protrusion can be lower than the bottom of the expansion plate, with the bottom of the protrusion abutting against the bottom of the chute, and the second arc surface distributed in two segments, with the first arc surface located between the two segments of the second arc surface. This allows the expansion plate and the tie rod to seal the chute, keeping the outer wall of the barrel cylindrical, thus avoiding increased resistance when penetrating the seabed.

[0007] Furthermore, the grooves are evenly distributed on the outer wall of the barrel, and the limiting member is sleeved on the barrel, with the top of the limiting member lower than the top of the barrel.

[0008] Furthermore, the protrusion includes a first inclined surface facing the expansion portion, and the expansion portion includes a second inclined surface facing the protrusion, with the first inclined surface and the second inclined surface abutting against each other.

[0009] Furthermore, the expansion plate is provided with a bending groove, the opening of which faces the inside of the barrel, and the bending groove is located at the junction of the fixing part and the expansion part.

[0010] Furthermore, a valve is installed on the drain hole to control the opening and closing of the drain hole.

[0011] Furthermore, a movable connecting seat is fixed to the limiting member, and a fixed connecting seat is fixed to the top of the barrel. The movable connecting seat and the fixed connecting seat are connected by a bolt assembly. The movable connecting seat has a movable lower connecting hole and a movable upper connecting hole, with the movable lower connecting hole located below the movable upper connecting hole. The fixed connecting seat has a fixed lower connecting hole and a fixed upper connecting hole, with the fixed lower connecting hole located below the fixed upper connecting hole. The movable lower connecting hole is aligned with the fixed lower connecting hole, and the bolts of the bolt assembly pass through both the movable and fixed lower connecting holes. This ensures that the tie rod and expansion plate are fixedly connected to the barrel, preventing the expansion plate from extending outwards from the groove due to relative movement between the tie rod and the expansion plate during penetration. When the barrel penetrates the seabed to the second depth, the movable upper connecting hole is aligned with the fixed upper connecting hole, and the bolts of the bolt assembly pass through both the movable and fixed upper connecting holes. This ensures that the tie rod and the expanded expansion plate are fixedly connected to the barrel, allowing the protrusion to stably abut against the expansion part, and the expansion part to stably abut against the inner wall of the penetration hole on the seabed.

[0012] Furthermore, the limiting member can be fixedly connected to the pull rod, or it can be connected to the pull rod via an elastic member. When connected via an elastic member, the pull rod also includes a horizontal extension, with the upper end of the elastic member connected to the bottom of the horizontal extension and the lower end of the elastic member connected to the upper end of the limiting member. By setting the elastic member, an elastic buffering effect can be achieved. When the pull rod rises relative to the expansion plate, if the hardness of the contact point between the expansion part and the seabed penetration hole is too high, the expansion part may not be able to smoothly embed into the inner wall of the seabed penetration hole, potentially causing the pull rod to break. Setting the elastic member as a spring allows for relative movement between the limiting member and the barrel body, and also allows the protrusion to apply a certain compressive force to the expansion part, causing the expansion part to deform and increasing the pressure between the expansion part and the inner wall of the seabed penetration hole, thereby improving the vertical pull-out bearing capacity.

[0013] Secondly, the present invention also provides an offshore wind power foundation, including a wind turbine support frame and any of the aforementioned negative pressure tanks, wherein the wind turbine support frame is fixedly connected to the top of the tank. Different types of wind turbine support frames can be selected according to actual needs to connect one or more negative pressure tanks, forming a single-tank or multi-tank foundation. For a single-tank foundation, the wind turbine support frame is placed at the center of the top of the tank; for a multi-tank foundation, each leg of the wind turbine support frame is connected to the top of each tank.

[0014] Compared with existing technologies, this technical solution has at least one of the following beneficial effects: 1. The negative pressure tank, by setting up expansion plates, tie rods and limiting components, restricts the descent of the tie rod after the limiting components come into contact with the seabed during the process of the tank penetrating the seabed. The protrusion pushes the expansion part to extend out of the groove and abut against the seabed groove wall, which increases the lateral friction resistance between the negative pressure tank and the soil and significantly improves the pull-out bearing capacity. 2. The limiting component is supported by the seabed, which effectively increases the support area of ​​the seabed for the negative pressure tank, thereby improving the vertical bearing capacity, horizontal resistance and overturning moment of the negative pressure tank foundation, greatly enhancing the foundation stability and reducing the probability of negative pressure tank failure. 3. The negative pressure tank of this invention is used in offshore wind power foundations, which eliminates the need for grouting and sealing, thus solving the problem of difficult recycling of negative pressure tanks in the prior art and significantly reducing recycling costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an explosion of a negative pressure tank according to an embodiment of the present invention; Figure 2 This is a perspective view of a negative pressure tank according to an embodiment of the present invention; Figure 3 This is a front view of a negative pressure tank according to an embodiment of the present invention; Figure 4 for Figure 3 Sectional view along line AA; Figure 5 for Figure 3 Sectional view along line BB; Figure 6 for Figure 4 A magnified view of a section at point C; Figure 7 This is a partial schematic diagram of a negative pressure tank according to an embodiment of the present invention (the expansion part extends out of the groove). Figure 8 This is a partial schematic diagram of a negative pressure tank according to another embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of an offshore wind power foundation according to an embodiment of the present invention; In the diagram, 1. Barrel body; 11. Chamber; 12. Drain hole; 13. Slide groove; 14. Flange; 2. Expansion plate; 21. Fixing part; 22. Expansion part; 221. Second inclined surface; 23. First arc surface; 24. Bending groove; 3. Tie rod; 31. Protrusion; 311. First inclined surface; 32. Second arc surface; 33. Horizontal extension part; 4. Limiting element; 5. Valve; 6. Movable connecting seat; 61. Movable lower connecting hole; 62. Movable upper connecting hole; 7. Fixed connecting seat; 71. Fixed lower connecting hole; 72. Fixed upper connecting hole; 8. Elastic element; 9. Fan support frame. Detailed Implementation

[0016] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0017] Please see Figures 1 to 7 This application provides a negative pressure tank, including a tank body 1 and a limiting member 4. The tank body 1 is cylindrical, and has an open chamber 11 at the bottom. A drain hole 12 communicating with the chamber 11 is provided at the top of the tank body 1. The drain hole 12 is used to discharge liquid and / or gas from the chamber 11. During installation, the material inside the tank body 1 can be pumped out through the drain hole 12, creating a negative pressure in the chamber 11. This negative pressure pushes the tank body 1 into the seabed, laying the foundation for a stable connection with the seabed and facilitating the installation of the negative pressure tank.

[0018] In this embodiment, to improve the pull-out bearing capacity of the negative pressure tank after it penetrates the seabed, a groove 13 is formed on the outer wall of the tank body 1 along its axial direction. An expansion plate 2 and a pull rod 3 are provided within the groove 13. The expansion plate 2 includes a fixing part 21 and an expansion part 22. The fixing part 21 is fixedly connected to the groove 13; specifically, the two side walls of the fixing part 21 are fixedly connected to the inner wall of the groove 13 by welding. The pull rod 3 is slidably connected to the groove 13. The pull rod 3 includes a protrusion 31 that contacts and engages with the expansion part 22 and is used to push the expansion part 22 away from the center of the tank body 1 to extend out of the groove 13. For example, the expansion plate 2 is made of a corrosion-resistant alloy material with good toughness and a certain strength, such as a nickel-copper alloy. Its good toughness ensures that the expansion plate 2 deforms under the push of the protrusion 31, while its sufficient strength ensures that the expansion part 22 will not easily break or be damaged under stress when it comes into contact with the seabed tank wall, thus stably increasing the side friction resistance. The thickness of the expansion plate 2 is 5-8 mm, preferably 6 mm. An expansion plate 2 that is too thin cannot withstand large pressure and is prone to excessive deformation or even breakage under stress. An expansion plate that is too thick will affect its flexibility, making it difficult to deform and extend into the groove 13 under the push of the protrusion 31. A thickness range of 5-8 mm for the expansion plate 2 balances its strength requirements and deformation capacity, ensuring its normal operation during the insertion and recovery of the negative pressure tank. A hardness of HB150-200 for the expansion plate 2 is more suitable. This hardness range ensures that the expansion plate 2 has sufficient hardness to resist the compression of the seabed and maintain a stable contact with the seabed trench wall, while also being not so hard that it cannot deform smoothly under the action of the protrusion 31 of the tie rod 3, thus ensuring the effectiveness and reliability of the pull-out structure.

[0019] For example, the pull rod 3 is made of high-strength stainless steel, such as 316L stainless steel. 316L stainless steel not only has excellent corrosion resistance, maintaining stable performance even after long-term immersion in seawater, but also possesses high strength and good machinability. During the operation of the negative pressure tank, the pull rod 3 needs to withstand the supporting force of the limiting member 4 and the force pushing the expansion part 22. The high strength of 316L stainless steel ensures that the pull rod 3 will not deform or break under stress, while its good machinability facilitates the manufacture of structures such as protrusions 31 with specific shapes and sizes. Depending on the specifications of different negative pressure tanks and stress analysis, the thickness of the pull rod 3 is generally 8-12mm, preferably 9mm. A suitable thickness ensures the structural stability of the pull rod 3 during force transmission, preventing failure due to insufficient strength caused by insufficient thickness, while also avoiding unnecessary weight and cost increases due to excessive thickness, which could affect the overall installation and recycling operation of the negative pressure tank. The hardness of the pull rod 3 is HRC30-35. This hardness range ensures that the pull rod 3 has a certain rigidity to push the expansion part 22, while also having a certain toughness, preventing brittle fracture due to excessive local stress during relative movement with the expansion part 22, thus guaranteeing the reliability of the pull rod 3 throughout the entire negative pressure tank operation and recycling process.

[0020] For example, the barrel 1 is mainly made of Q345R pressure vessel steel plate. This steel has good comprehensive mechanical properties, high strength, and can withstand the impact force when the barrel 1 penetrates the seabed and various external forces it experiences in the seabed. Simultaneously, its excellent weldability facilitates the manufacturing and processing of the barrel 1, ensuring its sealing performance and overall structural strength. In a marine environment, Q345R steel, after being coated with an anti-corrosion coating, can effectively resist seawater erosion and extend the service life of the barrel 1. The thickness of the barrel 1 is determined according to the size of the negative pressure tank and the design pressure it withstands; in this embodiment, the thickness of the barrel 1 is set to 25mm. For larger sizes or negative pressure tanks requiring higher pressure, the thickness of the barrel 1 is increased accordingly. Sufficient thickness ensures that the barrel 1 will not deform or crack under negative pressure, maintaining the structural integrity of the barrel 1, ensuring the stable penetration of the negative pressure tank into the seabed, and providing reliable support. The hardness of the barrel 1 is HB180-230. This hardness ensures that the barrel 1 has both sufficient strength to withstand external loads and sufficient toughness. When subjected to complex external forces such as wave impacts and seabed compression, it will not suffer brittle fracture due to excessive hardness, thus guaranteeing the safe use of the negative pressure tank in harsh marine environments. The height of the barrel 1 is 1-6 times its outer diameter; in this embodiment, the height of the barrel 1 is set to 1.2 times its outer diameter.

[0021] In this embodiment, considering that different stress conditions may occur when the expansion part 22 contacts the inner wall of the seabed penetration hole due to differences in seabed geological hardness, in order to prevent the tie rod 3 from breaking due to excessive force, and to ensure that the expansion part 22 can effectively contact the seabed to improve pull-out resistance, a limiting member 4 is provided and connected to the tie rod 3 through an elastic member 8. To facilitate the connection of the elastic member 8, the tie rod 3 also includes a horizontal extension part 33, with the upper end of the elastic member 8 connected to the bottom of the horizontal extension part 33, and the lower end of the elastic member 8 connected to the upper end of the limiting member 4. By incorporating the elastic element 8, a buffering effect is achieved. When the pull rod 3 rises relative to the expansion plate 2, if the hardness of the contact point between the expansion part 22 and the seabed penetration hole is too high, the expansion part 22 may not be able to smoothly embed into the inner wall of the seabed penetration hole, potentially causing the pull rod 3 to break. The elastic element 8, being a spring, allows for relative movement between the limiting element 4 and the barrel 1, and also allows the protrusion 31 to apply a certain compressive force to the expansion part 22, causing it to deform and increasing the pressure between the expansion part 22 and the inner wall of the seabed penetration hole, thereby improving the vertical pull-out bearing capacity. The elastic connection structure between the limiting element 4 and the pull rod 3 improves the adaptability of the negative pressure barrel to different seabed geological conditions, enhancing the structural safety and reliability.

[0022] For example, in this embodiment, the elastic element 8 is set as a spring or a rubber elastomer. Specifically, the spring can be a nickel-based alloy spring or a titanium alloy spring. Both nickel-based alloy springs and titanium alloy springs have excellent resistance to seawater corrosion and will not easily rust in a marine environment. Their high strength and good fatigue resistance can ensure that the elastic force can still be reliably provided after being subjected to multiple elastic tensile and compressive deformations in the structure of the tie rod 3 and the expansion plate 2.

[0023] In this embodiment, the side of the expansion plate 2 facing the center of the barrel 1 is attached to the pull rod 3, and the side of the pull rod 3 facing the center of the barrel 1 is attached to the groove 13. In this way, when the barrel 1 penetrates the seabed to the first depth, there is no gap between the barrel 1, the expansion plate 2 and the pull rod 3. The barrel 1 will radially support the expansion plate 2 and the pull rod 3, so as to prevent the expansion plate 2 and the pull rod 3 from being deformed by the seabed pressure.

[0024] When the barrel 1 penetrates the seabed to the first depth, the limiting member 4 abuts against the seabed and provides upward support to the tie rod 3, preventing the tie rod 3 from descending with the barrel 1. This increases the pressure between the protrusion 31 and the expansion part 22, causing the expansion part 22 to tend to extend the groove 13 away from the center of the barrel 1. The barrel 1 eventually penetrates the seabed to the second depth, which is below the first depth. During the movement of the barrel 1 from the first depth to the second depth, the protrusion 31 pushes the expansion part 22 to extend the groove 13 and abut against the seabed groove wall, increasing the lateral friction resistance between the negative pressure barrel and the soil. This significantly improves the pull-out bearing capacity of the negative pressure barrel, enabling it to better withstand external loads and ensuring the stability of the offshore wind power foundation.

[0025] In some embodiments, please refer to Figure 1 , Figure 6 and Figure 7 To minimize resistance between the barrel 1 and the seabed during the insertion of the negative pressure barrel into the seabed and avoid insertion difficulties due to structural protrusions, the expansion plate 2 is designed with a first arc surface 23 that conforms to the outer wall of the barrel 1, and the tie rod 3 is designed with a second arc surface 32 that conforms to the outer wall of the barrel 1. The expansion plate 2 and the tie rod 3 together fill the groove 13. Based on this, the bottoms of the protrusion 31 and the expansion portion 22 can be flush with each other and both abut against the bottom of the groove 13; or, please refer to Figure 8 The bottom of the protrusion 31 is lower than the bottom of the expansion part 22, and the bottom of the protrusion 31 abuts against the bottom of the groove 13. The second arc surface 32 is distributed in two segments, with the first arc surface 23 located between the two segments of the second arc surface 32. This structure allows the expansion plate 2 and the pull rod 3 to close the groove 13, and the first arc surface 23, the second arc surface 32, and the outer wall of the barrel 1 together form a cylinder. This effectively reduces the frictional resistance between the barrel 1 and the seabed when penetrating into the seabed, allowing the negative pressure barrel to penetrate into the seabed to the specified depth more smoothly.

[0026] In some embodiments, please refer to Figure 1 In order to make the negative pressure tank more evenly stressed in the seabed and ensure its stability, the sliding groove 13 is evenly distributed on the outer wall of the tank body 1. At the same time, in order to ensure that the limiting member 4 can both limit the descent of the pull rod 3 and not affect the overall structure of the tank body 1 and the installation process, the limiting member 4 is in the shape of a ring plate and is sleeved on the tank body 1, with the top of the limiting member 4 lower than the top of the tank body 1.

[0027] Understandably, the even distribution of the grooves 13 ensures that the force exerted by the expansion plates 2 and the tie rods 3 on the barrel 1 is uniform, avoiding excessive local stress. The number of grooves 13 can be flexibly set. In this embodiment, four grooves 13 are provided. In other embodiments, two, three, or more than four grooves 13 can also be provided. The annular and positional design of the limiting member 4 allows it to stably contact the seabed and support the tie rods 3 without interfering with the top structure of the barrel 1 and the installation of equipment, further improving the stability and applicability of the negative pressure barrel on the seabed.

[0028] In some embodiments, please refer to Figure 1 , Figure 6 and Figure 7 In order to make the process of the protrusion 31 pushing the expansion part 22 to extend out of the groove 13 smoother and improve the force transmission efficiency between the two, the protrusion 31 is provided to include a first inclined surface 311 facing the expansion part 22, and the expansion part 22 includes a second inclined surface 221 facing the protrusion 31, with the first inclined surface 311 and the second inclined surface 221 in contact.

[0029] It should be noted that the design of the first inclined surface 311 and the second inclined surface 221 fitting together allows the force of the protrusion 31 to be more effectively transmitted to the expansion part 22 when the pull rod 3 and the expansion plate 2 move relative to each other, pushing the expansion part 22 to rotate smoothly upward and extend the groove 13 to abut against the seabed wall.

[0030] In some embodiments, please refer to Figure 6 and Figure 7 To facilitate the deformation of the expansion portion 22 under stress and allow it to extend smoothly into the groove 13, a bending groove 24 is provided on the expansion plate 2. The opening of the bending groove 24 faces the inside of the barrel 1, and the bending groove 24 is located at the junction of the fixing portion 21 and the expansion portion 22. In this embodiment, the deformation of the bending groove 24 is set to a semi-circle. In other embodiments, it can also be set to a V-shape, rectangle, or other shapes. The setting of the bending groove 24 reduces the strength at the junction of the fixing portion 21 and the expansion portion 22, making it easier for the expansion portion 22 to rotate away from the center of the barrel 1 at the bending groove 24, thereby extending into the groove 13.

[0031] In some embodiments, please refer to Figures 1 to 4 Since it is necessary to control the formation and release of negative pressure inside the barrel 1, a valve 5 is installed on the drain hole 12 to control the opening and closing of the drain hole 12.

[0032] By switching valve 5 on and off, the discharge and entry of liquid and gas inside tank 1 can be controlled, thereby controlling the generation and elimination of negative pressure, facilitating the installation and subsequent maintenance of the negative pressure tank. In other embodiments, a separate pipe connected to drain hole 12 and vacuum pump can be provided, with valve 5 installed on the pipe.

[0033] In some embodiments, please refer to Figure 6 and Figure 7 To ensure the relative fixation of the tie rod 3, expansion plate 2, and barrel 1 during the insertion of the negative pressure barrel, and to ensure the stable contact of the expansion plate 2 with the seabed after complete insertion, a movable connecting seat 6 is fixed on the limiting component 4, and a fixed connecting seat 7 is fixed on the top of the barrel 1. The movable connecting seat 6 and the fixed connecting seat 7 are connected by a bolt assembly. The bolt assembly includes bolts and nuts.

[0034] The movable connecting seat 6 has a movable lower connecting hole 61 and a movable upper connecting hole 62, with the movable lower connecting hole 61 located below the movable upper connecting hole 62. The fixed connecting seat 7 has a fixed lower connecting hole 71 and a fixed upper connecting hole 72, with the fixed lower connecting hole 71 located below the fixed upper connecting hole 72.

[0035] The movable lower connecting hole 61 is aligned with the fixed lower connecting hole 71. The bolts of the bolt assembly pass through the movable lower connecting hole 61 and the fixed lower connecting hole 71. This ensures that the pull rod 3 and the expansion plate 2 are fixedly connected to the barrel 1, preventing the pull rod 3 and the expansion plate 2 from moving relative to each other during the insertion process, which would cause the expansion plate 2 to extend and expand outward from the groove 13.

[0036] When the barrel 1 penetrates the seabed to the second depth, the movable upper connection hole 62 aligns with the fixed upper connection hole 72. The bolts of the bolt assembly pass through the movable upper connection hole 62 and the fixed upper connection hole 72, ensuring that the tie rod 3 and the expanded expansion plate 2 are fixedly connected to the barrel 1. This allows the protrusion 31 to stably abut against the expansion part 22, and the expansion part 22 to stably abut against the inner wall of the penetration hole in the seabed. This connection structure design ensures the structural stability and reliability of the negative pressure barrel at different installation stages.

[0037] To facilitate the alignment of the movable upper connection hole 62 with the fixed upper connection hole 72, a flange 14 is provided at the top of the barrel 1. When the barrel 1 descends to the point where the flange 14 abuts against the limiting member, the barrel 1 can no longer descend relative to the limiting member. At this time, the movable upper connection hole 62 and the fixed upper connection hole 72 are aligned, which makes it easier to determine the relative position of the movable upper connection hole 62 and the fixed upper connection hole 72, and makes it easier for the bolts of the bolt assembly to pass through the movable upper connection hole 62 and the fixed upper connection hole 72.

[0038] Please see Figure 9 An embodiment of the present invention also provides an offshore wind power foundation, including a wind turbine support frame 9 and the aforementioned negative pressure tank, wherein the wind turbine support frame 9 is fixedly connected to the top of the tank body 1.

[0039] Different types of fan support frames 9 can be selected according to actual needs to connect one or more negative pressure tanks to form a single-tank foundation or a multi-tank foundation.

[0040] For a single-barrel foundation, place the fan support frame 9 at the center of the top of the barrel 1; for a multi-barrel foundation, connect each leg of the fan support frame 9 to the top of each barrel 1.

[0041] With the movable lower connecting hole 61 and the fixed lower connecting hole 71 aligned, the bolts of the bolt assembly are passed through the movable lower connecting hole 61 and the fixed lower connecting hole 71, and nuts are installed on the bolts to fix the limiting member 4 to the barrel 1, so that the negative pressure barrel is in the installation state.

[0042] After the offshore wind turbine foundation of this invention is accurately hoisted to the designated position by the installation vessel, the self-weight of the offshore wind turbine foundation causes the barrel 1 to penetrate into the seabed to a certain depth. A seabed penetration hole is formed between the barrel 1 and the seabed. Next, the valve 5 of the drainage hole 12 is opened and the seawater and air inside the barrel 1 are extracted using an external vacuum pump, creating a negative pressure in the chamber 11. Under the action of negative pressure, the barrel 1 continues to penetrate into the seabed until it reaches the first depth. At this point, the limiting member 4 comes into contact with the seabed. Since the limiting member 4 is annular and sleeved on the barrel 1, its contact area with the seabed is large, resulting in high resistance.

[0043] When the barrel 1 penetrates the seabed to the first depth, the negative pressure suction is paused, and then the bolt assembly is removed, allowing the limiting member 4 to move relative to the barrel 1. Then, suction of the barrel 1 continues, and the barrel 1 moves to the second depth under negative pressure. However, the limiting member 4, due to its large contact area and high resistance with the seabed, cannot penetrate the seabed. At this point, the pull rod 3 tends to move relative to the expansion plate 2. If the limiting member 4 is connected to the pull rod 3 via the elastic member 8, the elastic member 8 is gradually compressed. When the elastic member 8 is compressed to a certain extent, the pressure required to continue compressing the elastic member 8 is greater than the force required by the protrusion 31 to push the expansion part 22 to deform and extend the groove 13. Therefore, the protrusion 31 pushes the expansion part 22 to extend out of the groove 13. The first inclined surface 311 of the protrusion 31 fits into the second inclined surface 221 of the expansion part 22. During relative movement, the cooperation between the first inclined surface 311 and the second inclined surface 221 facilitates the expansion part 22 to move away from the center of the barrel body 1. The setting of the bending groove 24 facilitates the deformation of the expansion part 22.

[0044] When the fixed upper connection hole 72 moves to the position aligned with the movable upper connection hole 62, the protrusion 31 moves close to the fixed part 21. At this time, the deformation of the expansion part 22 is also at its maximum, and the barrel 1 is in a state of complete penetration into the seabed. Subsequently, the bolts of the bolt assembly are passed through the movable upper connection hole 62 and the fixed upper connection hole 72, so that the tie rod 3 and the expanded expansion piece 2 are both fixedly connected to the barrel 1. This makes the protrusion 31 stably abut against the expansion part 22, and makes the expansion part 22 stably abut against the inner wall of the penetration hole in the seabed.

[0045] If the hardness of the contact area between the expansion part 22 and the seabed penetration hole is too high, and the expansion part 22 cannot be smoothly embedded into the inner wall of the seabed penetration hole, then under the action of the elastic element 8, an upward pulling force will be applied to the tie rod 3, causing the protrusion 31 to apply a certain compressive force to the expansion part 22, increasing the pressure between the expansion part 22 and the inner wall of the seabed penetration hole, thereby improving the vertical pull-out bearing capacity. Furthermore, since the limiting element 4 is supported by the seabed, the supporting area of ​​the seabed on the negative pressure tank can be increased, thereby improving the vertical bearing capacity, horizontal resistance, and overturning moment resistance of the negative pressure tank foundation, thus better reducing the probability of negative pressure tank failure.

[0046] Finally, close valve 5 and seal drain hole 12 to complete the installation of the offshore wind turbine foundation.

[0047] The specific working process for recycling the negative pressure tank of the present invention is as follows: First, unscrew the bolt assembly between the movable connecting seat 6 and the fixed connecting seat 7, allowing the barrel 1 to move relative to the limiting member 4. Then, apply downward pressure to the pull rod 3 using a tool or negative pressure, causing the protrusion 31 to descend relative to the expansion part 22, and the protrusion 31 no longer supports the expansion part 22.

[0048] Subsequently, valve 5 of drain hole 12 is opened, allowing seawater or air from the outside to freely enter the barrel 1. As fluid flows in, the pressure inside the barrel 1 gradually increases until it reaches equilibrium with the external environmental pressure. Once the pressure inside the barrel 1 is balanced, gas or liquid is introduced into drain hole 12, increasing the pressure inside chamber 11. After the expansion part 22 loses the support of protrusion 31, the pressure between it and the seabed penetration hole decreases. When the pressure inside the barrel 1 increases to a certain level, the barrel 1 will overcome resistance, including friction between the expansion part 22 and the seabed penetration hole, and move upward. During the upward movement of the barrel 1, under the squeezing force of the seabed on the expansion part 22, the expansion part 22 will gradually retract into the chute 13, returning to or approaching its initial state, releasing the contact with the seabed chute wall, further reducing the recovery resistance, until the barrel 1 detaches from the seabed.

[0049] Alternatively, after the internal pressure of the tank 1 is balanced, the lifting equipment on the installation vessel is used to connect the slings to the wind turbine support frame 9 or the negative pressure tank. The lifting equipment is then started, and an upward pulling force is slowly applied. Since there is only a small friction between the negative pressure tank and the seabed at this time, the negative pressure tank can be smoothly pulled out of the seabed and lifted onto the installation vessel under the action of the lifting force, completing the entire recovery process.

[0050] The above recycling process makes full use of the structural design of the negative pressure tank, avoids the recycling problems caused by traditional grouting and sealing, reduces the difficulty and cost of recycling, and has a clear and reasonable operation process, which is suitable for practical engineering applications.

[0051] The offshore wind power foundation of this invention is generally suitable for sea areas with a water depth of 20-80m. Within this water depth range, the negative pressure tank can be stably penetrated into the seabed and provide reliable support through its own structural design and negative pressure principle. At the same time, it also facilitates the installation and recovery of the foundation by equipment such as installation ships.

[0052] In terms of geology, soft soil is more suitable, including silt, silty soil, silty clay, etc. Under these soft soil conditions, the negative pressure bucket can penetrate into the seabed relatively smoothly under its own weight and negative pressure. Moreover, after the expansion plate 2 extends, it can form effective lateral friction resistance with the soft soil, which improves the pull-out resistance and overall stability of the foundation.

[0053] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

[0055] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature referred to as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

Claims

1. A negative pressure tank, comprising a tank body (1), wherein the tank body (1) has an open-bottomed chamber (11) inside, and a drain hole (12) communicating with the chamber (11) is provided at the top of the tank body (1), characterized in that, A groove (13) is provided on the outer wall of the barrel (1) along its axial direction. An expansion plate (2) and a pull rod (3) are provided in the groove (13). The expansion plate (2) includes a fixing part (21) and an expansion part (22). The fixing part (21) is fixedly connected to the groove (13), and the pull rod (3) is slidably connected to the groove (13). The pull rod (3) includes a part that contacts and cooperates with the expansion part (22) and is used to push the expansion part (22) to move away from the center of the barrel (1) to extend out of the groove. The protrusion (31) of the barrel (1) also includes a limiting member (4), which is connected to the pull rod (3). When the barrel (1) penetrates the seabed to the first depth, the limiting member (4) abuts against the seabed and provides an upward supporting force to the pull rod (3) to limit the pull rod (3) from falling with the barrel (1), thereby increasing the pressure between the protrusion (31) and the expansion (22), so that the expansion (22) tends to extend the groove (13) away from the center of the barrel (1).

2. The negative pressure tank according to claim 1, characterized in that, The expansion plate (2) has a first arc surface (23) that matches the outer wall of the barrel (1), and the pull rod (3) has a second arc surface (32) that matches the outer wall of the barrel (1).

3. The negative pressure tank according to claim 2, characterized in that, The expansion plate (2) and the pull rod (3) together fill the groove (13).

4. The negative pressure tank according to claim 1, characterized in that, The groove (13) is evenly distributed on the outer wall of the barrel (1), and the limiting member (4) is sleeved on the barrel (1), with the top of the limiting member (4) lower than the top of the barrel (1).

5. The negative pressure tank according to claim 1, characterized in that, The protrusion (31) includes a first inclined surface (311) facing the expansion portion (22), and the expansion portion (22) includes a second inclined surface (221) facing the expansion portion (22), with the first inclined surface (311) and the second inclined surface (221) fitting together.

6. The negative pressure tank according to claim 1, characterized in that, The expansion plate (2) is provided with a bending groove (24), the opening of the bending groove (24) faces the inside of the barrel (1), and the bending groove (24) is located at the junction of the fixing part (21) and the expansion part (22).

7. The negative pressure tank according to claim 1, characterized in that, A valve (5) is installed on the drain hole (12) to control the opening and closing of the drain hole (12).

8. The negative pressure tank according to claim 1, characterized in that, The limiting member (4) is fixed with a movable connecting seat (6), and the top of the barrel (1) is fixed with a fixed connecting seat (7). The movable connecting seat (6) and the fixed connecting seat (7) are connected by a bolt assembly. The movable connecting seat (6) has a movable lower connecting hole (61) and a movable upper connecting hole (62). The movable lower connecting hole (61) is located below the movable upper connecting hole (62). The fixed connecting seat (7) has a fixed lower connecting hole (71) and a fixed upper connecting hole (72). The fixed lower connecting hole (71) is located below the fixed upper connecting hole (72). The movable lower connecting hole (61) and the fixed lower connecting hole (71) are aligned. The bolt of the bolt assembly passes through the movable lower connecting hole (61) and the fixed lower connecting hole (71). When the barrel (1) penetrates the seabed to the second depth, the movable upper connecting hole (62) and the fixed upper connecting hole (72) are aligned.

9. The negative pressure tank according to claim 1, characterized in that, The limiting member (4) is connected to the pull rod (3) through the elastic member (8). The pull rod (3) also includes a horizontal extension (33). The upper end of the elastic member (8) is connected to the bottom of the horizontal extension (33), and the lower end of the elastic member (8) is connected to the upper end of the limiting member (4).

10. An offshore wind power foundation, characterized in that, It includes a fan support frame (9) and a negative pressure tank as described in any one of claims 1 to 9, wherein the fan support frame (9) is fixedly connected to the top of the tank body (1).

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