High-pulling-resistance spiral pile for mooring tension leg floating type draught fan

Abstract

The utility model provides a high-pulling-resistance screw pile for mooring a tension leg floating type draught fan. The high-pulling-resistance screw pile comprises a screw pile body, a screw rod and a pull rod, wherein screw blades are arranged on the screw pile body; the drill bit is arranged at the bottom end of the screw pile body; the mooring pile cap is arranged at the top end of the screw pile body, and a mooring rope for mooring is stored in the mooring pile cap; and the transmission connecting piece is mounted at the top of the mooring pile cap, is connected with an external power source, and transmits torque to the screw pile body and the drill bit. According to the scheme of the utility model, the spiral pile structure obviously improves the axial pulling resistance of the anchoring foundation. A piling method is not needed, use of large special equipment is avoided, the construction efficiency is greatly improved in the drilling construction process, and large-scale application is facilitated. The mooring rope and the mooring pile cap are connected together and stored in the pile cap, connection of the lower portion of the mooring rope is achieved on the land, the installation process is greatly simplified, and the installation efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of marine engineering technology, and in particular to a high pull-out helical pile for mooring tension leg floating wind turbines. Background Technology

[0002] Driven pile anchor foundations are widely used in marine engineering to provide restoring force and withstand pull-out forces for tension leg floating wind turbines. Their structure is a closed cylindrical steel structure. During offshore construction, a guide frame is first installed on the seabed. The impact force of an impact hammer drives the pile into the soil. The hammer's potential energy is converted into kinetic energy, applying instantaneous high pressure to the pile top, causing the pile to overcome soil resistance and sink. As hammering continues, the pile gradually sinks, the soil is continuously compressed, and the surrounding soil shifts, gradually bonding with the soil to form a stable foundation. Hammering stops when the pile reaches the design depth or meets the bearing capacity requirements. For TLP floating wind turbine foundations, which require anchor foundations to withstand pull-out forces, the bearing capacity of the driven pile foundation mainly comes from the pile's side skin friction.

[0003] Driven pile foundations are widely used in offshore oil and gas development and marine new energy development, with low soil requirements. Currently, their application in marine engineering mainly bears lateral loads. However, for TLP floating wind turbines, they mainly bear uplift loads. In this case, the bearing capacity provided by the driven pile foundation mainly comes from the side friction of the pile. To ensure sufficient side friction, it is necessary to increase the pile diameter and driving depth. This results in excessive steel consumption in the foundation structure, and the large pile foundations also require specialized equipment for offshore construction. The market resources for large floating cranes and large pile hammers are scarce, leading to high operating costs. Utility Model Content

[0004] The purpose of this utility model is to solve at least one technical problem in the background art and to provide a high pull-out helical pile for mooring tension leg floating wind turbines.

[0005] To achieve the above objectives, this utility model provides a high-pull-out helical pile for mooring tension leg floating wind turbines, comprising:

[0006] The helical pile body is equipped with helical blades;

[0007] The drill bit is located at the bottom end of the helical pile body;

[0008] A mooring cap is placed at the top of the helical pile body and stores mooring cables inside.

[0009] The transmission connector is installed on the top of the mooring pile cap and connected to an external power source to transmit torque to the helical pile body and the drill bit.

[0010] According to one aspect of the present invention, the helical pile body is composed of multiple pile body segments, each pile body segment is provided with helical blades, and each helical blade is arranged at intervals on the outer wall of the helical pile body.

[0011] According to one aspect of the present invention, the spiral pile body has a central cavity that extends through both the upper and lower ends.

[0012] According to one aspect of the present invention, the drill bit is a roller cone drill bit, and the roller cone drill bit is threadedly connected to the bottom end of the spiral pile body;

[0013] The roller cone drill bit consists of three self-rotating roller cones, with a hollow central part formed by the roller cones. During drilling, the displaced soil and mud are poured into the central cavity of the spiral pile body.

[0014] According to one aspect of the present invention, a quick-connect flange is provided at the top of the mooring pile cap, and the mooring pile cap is connected to the transmission connector through the quick-connect flange.

[0015] According to one aspect of the present invention, the transmission connecting member is composed of a multi-segment transmission structure with threaded connections at both ends.

[0016] According to the present invention, a drill bit-type device is arranged at the end of the helical pile body to effectively increase drilling efficiency. The device is connected to the inside of the pile body and can squeeze the drilled soil into the pile body. While greatly improving the installation efficiency of the helical pile, it protects the soil from damage to the maximum extent, so that the soil can maintain its original properties and provide sufficient bearing capacity.

[0017] This utility model addresses the mooring requirements of TLP-type floating foundations by utilizing a spiral structure. This changes the original driven pile's bearing capacity, which relies solely on side friction to resist uplift forces. The new spiral pile effectively utilizes the spiral structure, making its bearing capacity approach that of a "gravity" foundation. The soil gravity above the spiral structure can provide uplift bearing capacity, effectively improving the foundation's ability to resist uplift loads.

[0018] According to the present invention, the offshore installation process provided by this invention does not require special equipment such as large floating cranes, but only relies on existing resources, and the drilling-style installation process greatly improves installation efficiency. This invention innovatively connects the mooring cable and the pile cap together and stores them inside the pile cap, achieving the connection of the lower part of the mooring cable on land, greatly simplifying the installation process and improving installation efficiency. Attached Figure Description

[0019] Figures 1-4 The diagrams schematically illustrate the structural layout of various parts of a high-pull-out helical pile for mooring a tension leg floating wind turbine according to one embodiment of the present invention. Detailed Implementation

[0020] The present invention will now be discussed with reference to exemplary embodiments. It should be understood that the described embodiments are merely intended to enable those skilled in the art to better understand and thus implement the present invention, and are not intended to imply any limitation on the scope of the present invention.

[0021] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment".

[0022] Figures 1-4 The diagrams schematically illustrate the structural layout of various parts of a high-pull-out helical pile for mooring tension leg floating wind turbines according to one embodiment of the present invention. Figures 1-4 As shown, in this embodiment, the high-pull-out helical pile for mooring tension leg floating wind turbines includes:

[0023] 1. A spiral pile body, on which spiral blades 2 are arranged;

[0024] Drill bit 3 is located at the bottom end of the helical pile body 1;

[0025] The mooring cap 4 is set at the top of the helical pile body 1 and stores the mooring cable 9 inside.

[0026] The transmission connector 5 is installed on the top of the mooring pile cap 4 and connected to an external power source to transmit torque to the helical pile body 1 and the drill bit 3.

[0027] Furthermore, such as Figures 1-3 As shown, in this embodiment, the helical pile body 1 is composed of multiple pile body segments 7, which are connected by threads. Each pile body segment 7 has one or more helical blades 2, and the helical blades 2 are arranged at intervals on the outer wall of the helical pile body 1.

[0028] Furthermore, in this embodiment, the helical pile body 1 has a central cavity that extends through both the upper and lower ends.

[0029] Furthermore, such as Figure 3 As shown, in this embodiment, the drill bit 3 is a roller cone drill bit, which is threadedly connected to the bottom end of the helical pile body 1.

[0030] The roller cone drill bit consists of three self-rotating roller cones. The central part formed by the roller cones is hollow and connected to the central cavity of the spiral pile body 1. During the drilling process, the displaced soil and mud are poured into the central cavity of the spiral pile body 1 and then discharged.

[0031] Furthermore, such as Figure 1 As shown, in this embodiment, a quick-connect flange 6 is provided at the top of the mooring pile cap 4, and the mooring pile cap 4 is connected to the transmission connector 5 through the quick-connect flange 6.

[0032] Furthermore, such as Figure 4 As shown, in this embodiment, the transmission connector 5 can be composed of multiple transmission structures 8 connected by threaded ends.

[0033] According to the above-mentioned solution of this utility model, a drill bit-type device is arranged at the end of the helical pile body to effectively increase the drilling efficiency. The device is connected to the inside of the pile body and can squeeze the drilled soil into the inside of the pile body. While greatly improving the installation efficiency of the helical pile, it protects the soil from damage to the maximum extent, so that the soil can maintain its original properties and provide sufficient bearing capacity.

[0034] This utility model addresses the mooring requirements of TLP-type floating foundations by utilizing a spiral structure. This changes the original driven pile's bearing capacity, which relies solely on side friction to resist uplift forces. The new spiral pile effectively utilizes the spiral structure, making its bearing capacity approach that of a "gravity" foundation. The soil gravity above the spiral structure can provide uplift bearing capacity, effectively improving the foundation's ability to resist uplift loads.

[0035] Furthermore, the actual construction process of the high pull-out helical pile for mooring tension leg floating wind turbines based on the present invention is as follows:

[0036] Once the vessel is in position, the vessel lifts the guide frame and lowers it to the seabed.

[0037] The helical pile body 1 is assembled by using a pile gripper and a crane, and the drill bit 3 is installed at the bottom end of the helical pile body 1.

[0038] The spiral pile is formed by assembling the helical pile body 1, the mooring pile cap 4, and the transmission connector 5 using a pile gripper and a crane.

[0039] The spiral pile is lowered following the guide frame. After entering the guide frame and contacting the soil, it is left to stand still to complete the free standing of the spiral pile.

[0040] After the helical pile stabilizes by sinking under its own weight, drilling operations are carried out until the helical pile is drilled to the designed depth, thus completing the drilling operation.

[0041] Unload and retract the transmission connector, and remove the mooring cable stored in the mooring cap 4 to complete the wet storage of the mooring cable.

[0042] Taking a drilling vessel as an example, the SPMT transports the guide frame, the various sections of the helical pile body, and the various sections of the transmission connecting parts to the drilling vessel at the dock. The drilling vessel then sails to the construction site together with the floating crane vessel. The floating crane vessel lifts the guide frame and lowers it to the seabed.

[0043] The helical pile body 1 is assembled using a pile gripper and a crane:

[0044] The bottom section of the helical pile is held in place by a pile gripper. A crane is then used to connect the other section of the pile to the top drive. The top drive is aligned with the bottom section of the pile and the threads are tightened to complete the connection between the two sections. The pile gripper is then released, and the top drive lowers the connected section to the next connection height. The pile gripper is then tightened again to begin connecting the next section of the pile. This process is repeated until the assembly of the helical pile is complete.

[0045] By assembling the helical pile body 1, mooring pile cap 4, and transmission connector 5 using a pile gripper and a crane, a helical pile is formed as follows:

[0046] The helical pile body is gripped tightly by a pile gripper, and then the crane aligns the mooring pile cap 4 with the helical pile body. The connection between the mooring pile cap 4 and the transmission connector 5 is then completed via a quick-connect flange. The connection process for each section of the transmission connector 5 is the same as the connection process for the helical pile body.

[0047] After the helical pile stabilizes by its own weight, drilling operations are carried out until the helical pile is drilled to the designed depth, thus completing the drilling operation:

[0048] The top of the transmission structure of the top drive connecting transmission connector 5 drives the spiral pile body 1 and the drill bit 3 to rotate and drill. Drilling stops when the top of the transmission structure of the top drive connecting connector 5 approaches the upper part of the pile gripper that holds the spiral pile body 1. At this time, the transmission structure is held by the pile gripper. Then, the other transmission structure is connected to the previous transmission structure by the crane and the top drive. The operation is repeated until the spiral pile body is drilled to the designed depth, and the drilling operation is completed.

[0049] Unload and retract the transmission connector, and remove the mooring cable stored in the mooring cap 4 to complete the wet storage of the mooring cable.

[0050] The upper pile gripper clamps the transmission structure, and an underwater robot quickly releases the connecting flange. Then, the transmission structure is retrieved segment by segment using the reverse installation process, completing the retraction of the transmission structure. The mooring cable can be a new type of fiber cable, pre-coiled in the mooring pile cap. The mooring cable is pre-connected to the helical pile body. With the assistance of the underwater robot, the mooring cable is removed, completing its wet storage.

[0051] According to the above-described solution of this utility model, the offshore installation process provided by this utility model does not require special equipment such as large floating cranes, but only needs to rely on existing resources, and the drilling-style installation process greatly improves installation efficiency. This utility model innovatively connects the mooring cable and the pile cap together and stores them inside the pile cap, achieving the connection of the lower part of the mooring cable on land, greatly simplifying the installation process and improving installation efficiency.

[0052] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this utility model.

Claims

1. A high-pull-out helical pile for mooring tension leg floating wind turbines, characterized in that, include: The helical pile body (1) is provided with helical blades (2). A drill bit (3) is disposed at the bottom end of the helical pile body (1); A mooring cap (4) is set at the top of the helical pile body (1) and stores the mooring cable inside. The transmission connector (5) is installed on the top of the mooring pile cap (4) and connected to an external power source to transmit torque to the helical pile body (1) and the drill bit (3).

2. The high pull-out resistance helical pile for mooring tension leg floating wind turbines according to claim 1, characterized in that, The spiral pile body (1) is composed of multiple pile body segments, each pile body segment is provided with the spiral blades (2), and each spiral blade (2) is arranged at intervals on the outer wall of the spiral pile body (1).

3. The high pull-out resistance helical pile for mooring tension leg floating wind turbines according to claim 1, characterized in that, The spiral pile body (1) has a central cavity that runs through both the upper and lower ends.

4. The high pull-out resistance helical pile for mooring tension leg floating wind turbines according to claim 3, characterized in that, The drill bit (3) is a roller cone drill bit, which is threaded to the bottom end of the helical pile body (1); The roller cone drill bit consists of three self-rotating roller cones. The central part formed by the roller cones is hollow. During the drilling process, the displaced soil and mud are poured into the central cavity of the spiral pile body (1).

5. The high pull-out resistance helical pile for mooring tension leg floating wind turbines according to claim 1, characterized in that, The top of the mooring cap (4) is provided with a quick-connect flange (6), and the mooring cap (4) is connected to the transmission connector (5) through the quick-connect flange (6).

6. The high-pull-out helical pile for mooring tension leg floating wind turbines according to any one of claims 1-5, characterized in that, The transmission connector (5) is composed of a multi-segment transmission structure with threaded connections at both ends.

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