Piston type suction anchor and its installation method and recovery method

Abstract

The present invention provides a piston-type suction anchor and its installation method and recovery method, which belong to the field of suction anchor technology. The piston-type suction anchor includes an anchor barrel assembly and a piston assembly limiting flexible member. The anchor barrel assembly includes a barrel skirt and a top cover. The top cover is fixedly connected to the side wall of the barrel skirt through its edge, so that a first accommodation space with a bottom opening is formed between the top cover and the barrel skirt; the piston assembly includes a plate-like member, which is radially arranged inside the barrel skirt, so that the first accommodation space is divided into a second accommodation space and a third accommodation space by the plate-like member; a moving pair is formed between the plate-like member and the inner wall of the barrel skirt; wherein the pressure between the piston assembly and the barrel skirt can be adjusted; one end of the limiting flexible member is fixedly connected to the bottom surface of the top cover, and the other end of the limiting flexible member is fixedly connected to the top surface of the plate-like member. The installation method of the piston-type suction anchor and the recovery method of the piston-type suction anchor can enable the suction anchor to be installed and recovered. Its installation and recovery efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of suction anchors, in particular to a piston-type suction anchor and an installation method and a recovery method thereof. Background Art

[0002] A suction anchor is a type of marine engineering equipment designed to create a stable anchoring point on the seabed or other surfaces. The geological conditions of the seabed significantly influence the deployment and retrieval process of a suction anchor. Before installing a suction anchor, a detailed survey of the seabed's geological conditions is typically required to ensure the selection of an appropriate anchoring solution and equipment configuration, thereby maximizing the success and safety of the operation. For highly permeable seabeds, measures are often taken or the use of suction anchors is avoided as much as possible. Summary of the Invention

[0003] In view of this, the present invention provides a piston-type suction anchor and an installation method and a recovery method thereof, which can achieve efficient installation and recovery of the suction anchor, thereby being more suitable for practical use.

[0004] In order to achieve the above first purpose, the technical solution of the piston-type suction anchor provided by the present invention is as follows:

[0005] The piston-type suction anchor provided by the present invention comprises an anchor cylinder assembly (1), a piston assembly (2) and a position-limiting flexible member (12).

[0006] The anchor cylinder assembly (1) comprises a cylinder skirt (4) and a top cover (3).

[0007] The top cover (3) is fixedly connected to the side wall of the tube skirt (4) via its edge, so that a first accommodating space with a bottom opening is formed between the top cover (3) and the tube skirt (4);

[0008] The piston assembly (2) comprises a plate-shaped member (8),

[0009] The plate-shaped member (8) is radially arranged inside the tube skirt (4), so that the first accommodating space is divided into a second accommodating space (10) and a third accommodating space by the plate-shaped member (8), wherein the second accommodating space (10) is the accommodating space between the top cover (3), the tube skirt (4) and the plate-shaped member (8), and the third accommodating space is the accommodating space between the plate-shaped member (8), the tube skirt (4) and the bottom opening; a moving pair is formed between the plate-shaped member (8) and the inner wall of the tube skirt (4); wherein the pressure between the piston assembly (2) and the tube skirt (4) can be adjusted;

[0010] One end of the position-limiting flexible member (12) is fixedly connected to the bottom surface of the top cover (3), and the other end of the position-limiting flexible member (12) is fixedly connected to the top surface of the plate-shaped member (8).

[0011] The piston-type suction anchor provided by the present invention can also be further implemented by adopting the following technical measures.

[0012] Preferably, the piston-type suction anchor further comprises a flexible bag (9),

[0013] The flexible bag (9) is arranged between the plate-shaped member (8) and the tube skirt (4), so that the plate-shaped member (8) forms a moving pair through the flexible bag (9) and the inner wall of the tube skirt (4).

[0014] Preferably, the volume of the flexible bag (9) can be changed. By changing the mass of the content of the flexible bag (9), the pressure between the piston assembly (2) and the anchor cylinder assembly (1) can be changed, so that the friction between the piston assembly (2) and the anchor cylinder assembly (1) can be adjusted.

[0015] Preferably, the piston-type suction anchor further comprises a water pump (13),

[0016] The water pump (13) is in communication with the flexible bag (9), and water can be pumped into the flexible bag (9) or pumped out of the flexible bag (9) through the water pump (13).

[0017] When the mass of water in the flexible bag (9) increases, the pressure between the flexible bag (9) and the anchor cylinder assembly (1) increases, so that the friction between the piston assembly (2) and the anchor cylinder assembly (1) increases;

[0018] When the mass of water in the flexible bag (9) decreases, the pressure between the flexible bag (9) and the anchor cylinder assembly (1) decreases, so that the friction between the piston assembly (2) and the anchor cylinder assembly (1) decreases.

[0019] Preferably, the piston-type suction anchor further comprises a first valve,

[0020] The first valve is used to control the opening and closing of the water pump (13), and / or the pumping direction, and / or the opening size.

[0021] Preferably, the piston-type suction anchor further comprises a pressure-resistant flexible cable (14) and a waterproof electrical connector (6).

[0022] The water pump (13) is fixedly mounted on the plate-shaped member (8), and the waterproof electrical connector (6) is fixedly mounted on the top cover (4).

[0023] One end of the pressure-resistant flexible cable (14) is electrically connected to the waterproof electrical connector (6), and the other end of the pressure-resistant flexible cable (14) is electrically connected to the first valve, so that the first valve can be remotely controlled.

[0024] Preferably, the piston-type suction anchor further comprises a second valve (5),

[0025] The second valve (5) is arranged on the top cover (3); when the second valve (5) is in an open state, the second accommodating space (10) can communicate with the outside through the second valve (5).

[0026] Preferably, the second valve (5) comprises a plurality of second valves (5), and the plurality of second valves (5) are evenly arranged on the top cover (3).

[0027] Preferably, the piston-type suction anchor further comprises a third valve (15),

[0028] The third valve (15) is arranged at the bottom of the plate-shaped member (8); when the third valve (15) is in an open state, the second accommodating space (10) is communicated with the third accommodating space through the third valve (15).

[0029] Preferably, the piston-type suction anchor further comprises a remote-controlled unmanned submersible, which is used as a control terminal of the valve.

[0030] In order to achieve the above second purpose, the technical solution of the installation method of the piston-type suction anchor provided by the present invention is as follows:

[0031] The installation method of the piston-type suction anchor provided by the present invention comprises the following steps:

[0032] Positioning the piston-type suction anchor on the seabed on the sea surface;

[0033] Embedding the piston-type suction anchor into the seabed using the piston-type suction anchor's own weight;

[0034] Increasing the pressure between the piston assembly (2) and the tube skirt (4) so ​​that the second accommodating space (10) is closed;

[0035] Carry out suction sinking.

[0036] The installation method of the piston-type suction anchor provided by the present invention can also be further implemented by adopting the following technical measures.

[0037] Preferably, during the suction penetration, if the penetration speed does not reach the expected speed, the installation method of the piston-type suction anchor further comprises the following steps:

[0038] The pressure between the piston assembly (2) and the tube skirt (4) is reduced, so that the friction between the piston assembly (2) and the tube skirt (4) is appropriately reduced, thereby increasing the penetration speed of the piston-type suction anchor.

[0039] In order to achieve the third object above, the technical solution of the recovery method of the piston-type suction anchor provided by the present invention is as follows:

[0040] The recovery method of the piston-type suction anchor provided by the present invention comprises the following steps:

[0041] The pressure between the piston assembly (2) and the tube skirt (4) is increased, and water is injected into the second accommodating space (10), so that the pressure difference between the inside and outside of the second accommodating space (10) increases. Under the action of the pressure difference between the inside and outside, the piston-type suction anchor is gradually pulled out to achieve the recovery of the piston-type suction anchor.

[0042] The recovery method of the piston-type suction anchor provided by the present invention can be further implemented by adopting the following technical measures.

[0043] Preferably, the recovery method of the piston-type suction anchor further comprises the following steps:

[0044] The pressure between the piston assembly (2) and the tube skirt (4) is reduced, and the pressure between the piston assembly (2) and the tube skirt (4) is reduced, so that the piston assembly (2) and the tube skirt (4) are separated.

[0045] The following technical measures may be used to further implement the installation method of the piston-type suction anchor provided by the present invention and the recovery method of the piston-type suction anchor provided by the present invention.

[0046] Preferably, during the step of increasing the pressure between the piston assembly (2) and the tube skirt (4) so ​​that the second accommodating space (10) is closed, the pressure between the flexible bag (9) and the tube skirt (4) is increased by increasing the volume of the flexible bag (9).

[0047] Preferably, the increasing of the volume of the flexible bag (9) is achieved by increasing the mass of the contents of the flexible bag (9).

[0048] Preferably, the mass of the contents of the flexible bladder (9) is increased by pumping water into the flexible bladder (9).

[0049] Preferably, during the step of reducing the pressure between the piston assembly (2) and the tube skirt (4), the pressure between the flexible bag (9) and the tube skirt (4) is reduced by reducing the volume of the flexible bag (9).

[0050] Preferably, the reducing the volume of the flexible bag (9) is achieved by reducing the mass of the contents of the flexible bag (9).

[0051] Preferably, the mass of the contents of the flexible bladder (9) is reduced by pumping water out of the flexible bladder (9).

[0052] In the piston-type suction anchor provided by the embodiment of the present invention, the pressure between the piston assembly 2 and the tube skirt 4 can be adjusted. According to f=μ·N (where f is friction, μ is sliding friction coefficient, and N is pressure), it can be seen that when the pressure between the contact surfaces of the two objects increases, the sliding friction will also increase; when the pressure between the contact surfaces of the two objects decreases, the sliding friction will also decrease. On this basis, the piston-type suction anchor provided by the embodiment of the present invention is designed to be adjustable in size through the pressure between the piston assembly 2 and the tube skirt 4. By changing the pressure between the piston assembly 2 and the tube skirt 4, the friction between the moving pair formed between the piston assembly 2 and the tube skirt 4 can be achieved, thereby achieving efficient installation and recovery under the conditions of the piston-type suction anchor provided by the embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0054] Attachment Figure 1 A schematic diagram of the three-dimensional structure of a piston-type suction anchor provided by an embodiment of the present invention in a typical direction (wherein the tube skirt 4 is partially cut away);

[0055] Attachment Figure 2 A schematic diagram of the three-dimensional structure of the piston suction anchor provided by an embodiment of the present invention in another typical direction (wherein the skirt 4 is partially cut away, and the cut away portion is larger than the attached portion). Figure 1 the section of the ribs);

[0056] Description of reference numerals:

[0057] 1-anchor cylinder assembly, 2-piston assembly, 3-top cover, 4-cylinder skirt, 5-second valve, 6-waterproof electrical connector, 7-top cover hanging ear, 8-plate-shaped member, 9-flexible bag, 10-second accommodating space, 11-plate-shaped member hanging ear, 12-limiting flexible member, 13-water pump, 14-pressure-resistant flexible cable, 15-third valve. DETAILED DESCRIPTION

[0058] In view of this, the present invention provides a piston-type suction anchor and an installation method and a recovery method thereof, which can achieve efficient installation and recovery of the suction anchor, thereby being more suitable for practical use.

[0059] After arduous efforts, the inventor discovered that:

[0060] The working principle of a piston-type suction anchor is to form a closed volume and adjust the internal pressure to enable it to move relative to the seabed or other surfaces. When the internal pressure drops to a level lower than the external water pressure of the surrounding environment, the suction anchor will be sucked into the seabed due to the pressure difference, thus achieving anchoring. Conversely, if the suction anchor needs to be recovered, it can be pushed out of the seabed by increasing its internal pressure to a level higher than the external water pressure. This design allows the suction anchor to be easily deployed and recovered when needed, and is suitable for a variety of marine engineering applications, including but not limited to offshore wind power generation, marine exploration and stabilization of seabed facilities.

[0061] The geological conditions of the seabed have a significant impact on the deployment and recovery process of the suction anchor. A hard or dense seabed, such as a consolidated clay layer or dense sand, can provide a higher internal and external pressure difference, but it will also increase the resistance of the suction anchor during penetration or withdrawal; while a loose or low-modulus seabed, such as loose sand or under-consolidated silty sediments, may cause the suction anchor to quickly balance the pressure difference during the penetration and withdrawal process due to the high permeability of the seabed, and cannot overcome the resistance generated by the movement of the suction anchor, affecting the installation and recovery efficiency of the suction anchor. In addition, the unevenness of the seabed may also affect the penetration efficiency and anchoring force of the suction anchor. Therefore, before installing the suction anchor, it is usually necessary to conduct a detailed investigation of the geological conditions of the seabed to ensure the selection of appropriate anchoring schemes and equipment configurations, thereby improving the success rate and safety of the operation. For seabeds with high permeability, some measures are often taken or the use of suction anchors in this area is avoided as much as possible.

[0062] To further illustrate the technical means and effectiveness of the present invention in achieving its intended objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, describes in detail a piston-type suction anchor, its installation method, and its recovery method, including its specific implementation, structure, features, and effectiveness. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0063] The term "and / or" in this article is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B, specifically understood as: A and B may be included at the same time, A may exist alone, or B may exist alone, and any of the above three situations may exist.

[0064] Piston suction anchor

[0065] See attached Figure 1 and attached Figure 2 The piston-type suction anchor provided by the embodiment of the present invention includes an anchor barrel assembly 1, a piston assembly 2 and a limiting flexible member 12. The anchor barrel assembly 1 includes a barrel skirt 4 and a top cover 3, and the top cover 3 is fixedly connected to the side wall of the barrel skirt 4 through its edge, so that a first accommodation space with a bottom opening is formed between the top cover 3 and the barrel skirt 4. The piston assembly 2 includes a plate-like member 8, and the plate-like member 8 is radially arranged inside the barrel skirt 4, so that the first accommodation space is divided into a second accommodation space 10 and a third accommodation space by the plate-like member 8, wherein the second accommodation space 10 is the accommodation space between the top cover 3, the barrel skirt 4 and the plate-like member 8, and the third accommodation space is the accommodation space between the plate-like member 8, the barrel skirt 4 and the bottom opening; a moving pair is formed between the plate-like member 8 and the inner wall of the barrel skirt 4; wherein the pressure between the piston assembly 2 and the barrel skirt 4 can be adjusted. One end of the limiting flexible part 12 is fixedly connected to the bottom surface of the top cover 3, and the other end of the limiting flexible part 12 is fixedly connected to the top surface of the plate-like part 8. In this embodiment, one end of the limiting flexible part 12 is fixedly connected to the top cover 3 through the top cover hanging ear 7, and the other end of the limiting flexible part 12 is fixedly connected to the plate-like part 8 through the plate-like part hanging ear 11. When the plate-like part 8 moves upward along the inner wall of the tube skirt 4, so that the distance between the top cover 4 and the plate-like part 8 is shortened, the limiting flexible part 12 can be in a relatively relaxed state, so as not to hinder the plate-like part 8 from moving along the tube skirt toward the top cover 4; when the plate-like part moves downward along the inner wall of the tube skirt 4, so that the distance between the top cover 4 and the plate-like part 8 is increased, the limiting flexible part 12 can be gradually straightened until a pulling force is applied to the plate-like part 8, thereby avoiding the plate-like part 8 from falling off the tube skirt 4 after moving downward along the tube skirt 4 to the bottom opening of the anchor tube assembly 1, resulting in the consequence that it cannot be recovered. The position-limiting flexible member 12 may be a steel chain.

[0066] In the piston-type suction anchor provided by the embodiment of the present invention, the pressure between the piston assembly 2 and the tube skirt 4 can be adjusted. According to f=μ·N (where f is friction, μ is sliding friction coefficient, and N is pressure), it can be seen that when the pressure between the contact surfaces of the two objects increases, the sliding friction will also increase; when the pressure between the contact surfaces of the two objects decreases, the sliding friction will also decrease. On this basis, the piston-type suction anchor provided by the embodiment of the present invention is designed to be adjustable in size through the pressure between the piston assembly 2 and the tube skirt 4. By changing the pressure between the piston assembly 2 and the tube skirt 4, the friction between the moving pair formed between the piston assembly 2 and the tube skirt 4 can be achieved, thereby achieving efficient installation and recovery under the conditions of the piston-type suction anchor provided by the embodiment of the present invention.

[0067] Among them, the piston-type suction anchor also includes a flexible bag 9. The flexible bag 9 is arranged between the plate-like member 8 and the tube skirt 4, so that the plate-like member 8 forms a moving pair through the flexible bag 9 and the inner wall of the tube skirt 4. In this case, by adjusting the volume of the flexible bag 9, the contact environment between the edge of the plate-like member 8 and the tube skirt 4 can be changed. When the volume of the flexible bag 9 increases, the gap between the plate-like member 8 and the tube skirt 4 is filled more fully by the flexible bag 9, and the pressure between the flexible bag 9 and the tube skirt 4 increases, thereby increasing the friction between the piston assembly 2 and the tube skirt 4 and reducing the ability of the piston assembly 2 to move axially along the tube skirt 4; when the volume of the flexible bag 9 decreases, the gap between the plate-like member 8 and the tube skirt 4 is filled less densely by the flexible bag 9, and the pressure between the flexible bag 9 and the tube skirt 4 decreases, thereby reducing the friction between the piston assembly 2 and the tube skirt 4 and enhancing the ability of the piston assembly 2 to move axially along the tube skirt 4.

[0068] The volume of the flexible bladder 9 can be changed. By changing the mass of the contents of the flexible bladder 9, the pressure between the piston assembly 2 and the anchor barrel assembly 1 can be changed, so that the friction between the piston assembly 2 and the anchor barrel assembly 1 can be adjusted. In this case, when it is necessary to increase the friction between the piston assembly 2 and the anchor barrel assembly 1, the mass of the contents is added to the flexible bladder 9, which increases the pressure between the flexible bladder 9 and the barrel skirt 4, thereby increasing the friction between the flexible bladder 9 and the barrel skirt 4; when it is necessary to reduce the friction between the piston assembly 2 and the anchor barrel assembly 1, the mass of the contents is removed from the flexible bladder 9, which reduces the pressure between the flexible bladder 9 and the barrel skirt 4, thereby reducing the friction between the flexible bladder 9 and the barrel skirt 4.

[0069] The piston-type suction anchor also includes a water pump 13. The water pump 13 is connected to the flexible bladder 9 and can pump water into or out of the bladder 9. When the mass of water in the bladder 9 increases, the pressure between the bladder 9 and the anchor barrel assembly 1 increases, increasing the friction between the piston assembly 2 and the anchor barrel assembly 1. When the mass of water in the bladder 9 decreases, the pressure between the bladder 9 and the anchor barrel assembly 1 decreases, reducing the friction between the piston assembly 2 and the anchor barrel assembly 1. In this case, pumping water into the bladder 9 using the water pump 13 increases the mass of the contents within the bladder 9, thereby increasing the friction between the bladder 9 and the barrel skirt 4. Pumping water out of the bladder 9 using the water pump 13 reduces the mass of the contents within the bladder 9, thereby reducing the friction between the bladder 9 and the barrel skirt 4. This system utilizes local materials, saving costs and improving efficiency.

[0070] Among them, the piston-type suction anchor also includes a first valve. The first valve is used to control the opening and closing of the water pump 13, and / or the direction of water pumping, and / or the size of the opening. In this case, the first valve can be a normally closed solenoid valve, which can realize the valve opening when a high level is input to it; because in the embodiment of the present invention, the water pump 13 pumps water into the flexible capsule 9 and pumps water out of the flexible capsule 9 in a two-way action mode, the normally closed solenoid valve should also have the function of converting the working direction of the water pump 13; in addition, in order to adjust the flow rate of water pumped into the flexible capsule 9 and pumped out of the flexible capsule 9, the normally closed solenoid valve should also have the function of adjusting the size of the opening.

[0071] The piston-type suction anchor also includes a pressure-resistant flexible cable 14 and a waterproof electrical connector 6. The water pump 13 is fixed to the plate-like member 8, and the waterproof electrical connector 6 is fixed to the top cover 4. One end of the pressure-resistant flexible cable 14 is electrically connected to the waterproof electrical connector 6, and the other end of the pressure-resistant flexible cable 14 is electrically connected to the first valve, enabling remote control of the first valve. One end of the pressure-resistant flexible cable 14 is electrically connected to the waterproof electrical connector 6, and the other end of the pressure-resistant flexible cable 14 is electrically connected to the first valve, which is the valve of the water pump 13, and the water pump 13 is fixedly connected to the plate-like member 8. When the plate-like member 8 moves upward along the inner wall of the tube skirt 4, so that the distance between the top cover 4 and the plate-like member 8 is shortened, the pressure-resistant flexible cable 14 can be in a relatively relaxed state, so as not to hinder the plate-like member 8 from moving along the tube skirt toward the top cover 4; when the plate-like member moves downward along the inner wall of the tube skirt 4, so that the distance between the top cover 4 and the plate-like member 8 increases, the pressure-resistant flexible cable 14 can be gradually straightened until a pulling force is applied to the plate-like member 8, and can work together with the limiting flexible member 12 to prevent the plate-like member 8 from falling off the tube skirt 4 after moving downward along the tube skirt 4 to the bottom opening of the anchor tube assembly 1, resulting in the inability to be recovered. In addition, since there is an electrical connection between the high-voltage flexible cable 14 and the first valve, the electrical connection itself is subject to relatively small tension. The safest way is to ensure that the high-voltage flexible cable is never in a tensile state, which would cause the electrical connection to fail. In this embodiment, when the limiting flexible member 12 is in a stretched and tensile state, the high-voltage flexible cable 14 is still in a relaxed state.

[0072] The piston-type suction anchor further includes a second valve 5. The second valve 5 is disposed on the top cover 3. When the second valve 5 is open, the second accommodating space 10 is connected to the outside world through the second valve 5. In this case, the second accommodating space 10 can be depressurized while the second valve 5 is open.

[0073] The second valve 5 includes a plurality of valves 5, which are evenly arranged on the top cover 3. In this case, the pressure relief efficiency of the second accommodating space 10 can be improved, and the stability and safety of the second accommodating space 10 during the pressure relief process can be ensured.

[0074] The piston-type suction anchor also includes a third valve 15. The third valve 15 is located at the bottom of the plate-like member 8. When the third valve 15 is open, the second accommodating space 10 communicates with the third accommodating space through the third valve 15. In this case, the third valve 15 can also be opened to release pressure from the second accommodating space 10. Because the third valve 10 is located at the bottom of the plate-like member 8, it can utilize the weight of the water in the second accommodating space 10 to release pressure, resulting in higher pressure relief efficiency.

[0075] The piston-type suction anchor also includes a remotely operated unmanned vehicle (ROV), which is used as a control terminal for the valve. The piston-type suction anchor provided by the embodiment of the present invention can be used in underwater operations. By remotely controlling the ROV, unmanned operation is possible, making the operation safer and more reliable.

[0076] Installation method of piston suction anchor

[0077] The installation method of the piston-type suction anchor provided in an embodiment of the present invention comprises the following steps:

[0078] Step S1: locating the position of the piston-type suction anchor on the seabed on the sea surface;

[0079] Step S2: embedding the piston-type suction anchor into the seabed using its own weight;

[0080] Step S3: increasing the pressure between the piston assembly 2 and the tube skirt 4 so that the second accommodating space 10 is closed;

[0081] Step S4: performing suction-type sinking.

[0082] The installation method of the piston-type suction anchor provided in the embodiment of the present invention realizes installation in a high-permeability seabed. Compared with traditional suction anchors, it is considered that during the installation process of the suction anchor, due to the excessively high permeability of the seabed, the difference between the pressure inside the anchor and the pressure outside the anchor is small, and the problem of friction resistance and end resistance between the anchor skirt and the soil during installation and recovery cannot be overcome. Due to the obstruction of the piston assembly 2, the water in the seabed cannot quickly enter the second accommodating space 10, and a sufficiently large pressure difference can be generated between the inside and outside of the piston-type suction anchor provided in the embodiment of the present invention to overcome the friction resistance between the tube skirt 4 and the soil. The piston-type suction anchor provided in the embodiment of the present invention enhances the functionality and applicability of the suction anchor structure in marine engineering, and meets the current needs of the installation, construction and development of offshore wind farms, offshore platforms and suction embedded plate anchors (SEPLA).

[0083] If the penetration rate does not reach the expected level during suction penetration, the installation method of the piston suction anchor may further include the following steps:

[0084] Step S5: reducing the pressure between the piston assembly 2 and the tube skirt 4 so that the friction between the piston assembly 2 and the tube skirt 4 can be appropriately reduced, thereby increasing the penetration speed of the piston-type suction anchor.

[0085] In the step of increasing the pressure between the piston assembly 2 and the tube skirt 4 so that the second accommodating space 10 is closed, the pressure between the flexible bag 9 and the tube skirt 4 is increased by increasing the volume of the flexible bag 9.

[0086] The volume of the flexible bag 9 is increased by increasing the mass of the content of the flexible bag 9 .

[0087] The mass of the content of the flexible bag 9 is increased by pumping water into the flexible bag 9 .

[0088] In the step of reducing the pressure between the piston assembly 2 and the tube skirt 4 , the pressure between the flexible bag 9 and the tube skirt 4 is reduced by reducing the volume of the flexible bag 9 .

[0089] The reduction of the volume of the flexible bag 9 is achieved by reducing the mass of the content of the flexible bag 9 .

[0090] The mass of the content of the flexible bag 9 is reduced by pumping water out of the flexible bag 9 .

[0091] Recovery method of piston suction anchor

[0092] The recovery method of the piston-type suction anchor provided by the present invention comprises the following steps:

[0093] Step S1: Increase the pressure between the piston assembly 2 and the tube skirt 4, and inject water into the second accommodating space 10, so that the pressure difference between the inside and outside of the second accommodating space 10 increases. Under the action of the internal and external pressure difference, the piston suction anchor is gradually pulled out to realize the recovery of the piston suction anchor.

[0094] The recovery method of the piston-type suction anchor provided in the embodiment of the present invention realizes installation in a high-permeability seabed. Compared with traditional suction anchors, it is considered that during the recovery process of the suction anchor, due to the excessively high permeability of the seabed, the difference between the pressure inside the anchor and the pressure outside the anchor is small, and the problem of friction resistance and end resistance between the anchor skirt and the soil during installation and recovery cannot be overcome. Due to the obstruction of the piston assembly 2, the water in the seabed cannot quickly enter the second accommodating space 10, and a sufficiently large pressure difference can be generated between the inside and outside of the piston-type suction anchor provided in the embodiment of the present invention to overcome the friction resistance between the tube skirt 4 and the soil. The piston-type suction anchor provided in the embodiment of the present invention enhances the functionality and applicability of the suction anchor structure in marine engineering, and meets the current needs of the installation, construction and development of offshore wind farms, offshore platforms and suction embedded plate anchors (SEPLA).

[0095] The recovery method of the piston-type suction anchor further comprises the following steps:

[0096] Step S2: reducing the pressure between the piston assembly 2 and the tube skirt 4. The pressure between the piston assembly 2 and the tube skirt 4 is reduced, so that the piston assembly 2 and the tube skirt 4 are separated.

[0097] In the step of increasing the pressure between the piston assembly 2 and the tube skirt 4 so that the second accommodating space 10 is closed, the pressure between the flexible bag 9 and the tube skirt 4 is increased by increasing the volume of the flexible bag 9.

[0098] The volume of the flexible bag 9 is increased by increasing the mass of the content of the flexible bag 9 .

[0099] The mass of the content of the flexible bag 9 is increased by pumping water into the flexible bag 9 .

[0100] In the step of reducing the pressure between the piston assembly 2 and the tube skirt 4 , the pressure between the flexible bag 9 and the tube skirt 4 is reduced by reducing the volume of the flexible bag 9 .

[0101] The reduction of the volume of the flexible bag 9 is achieved by reducing the mass of the content of the flexible bag 9 .

[0102] The mass of the content of the flexible bag 9 is reduced by pumping water out of the flexible bag 9 .

[0103] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0104] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A piston suction anchor, characterized in that: It comprises an anchor cylinder assembly (1), a piston assembly (2) and a position-limiting flexible member (12). The anchor cylinder assembly (1) comprises a cylinder skirt (4) and a top cover (3). The top cover (3) is fixedly connected to the side wall of the tube skirt (4) via its edge, so that a first accommodating space with a bottom opening is formed between the top cover (3) and the tube skirt (4); The piston assembly (2) comprises a plate-shaped member (8), The plate-shaped member (8) is radially arranged inside the tube skirt (4), so that the first accommodating space is divided into a second accommodating space (10) and a third accommodating space by the plate-shaped member (8), wherein the second accommodating space is the accommodating space between the top cover (3), the tube skirt (4) and the plate-shaped member (8), and the third accommodating space is the accommodating space between the plate-shaped member (8), the tube skirt (4) and the bottom opening; a moving pair is formed between the plate-shaped member (8) and the inner wall of the tube skirt (4); wherein the pressure between the piston assembly (2) and the tube skirt (4) can be adjusted; One end of the position-limiting flexible member (12) is fixedly connected to the bottom surface of the top cover (3), and the other end of the position-limiting flexible member (12) is fixedly connected to the top surface of the plate-shaped member (8); Also included is a flexible bladder (9), The flexible bag (9) is arranged between the plate-shaped member (8) and the tube skirt (4), so that the plate-shaped member (8) forms a moving pair through the flexible bag (9) and the inner wall of the tube skirt (4); The volume of the flexible bag (9) can be changed. By changing the mass of the contents of the flexible bag (9), the pressure between the piston assembly (2) and the anchor cylinder assembly (1) can be changed, so that the friction between the piston assembly (2) and the anchor cylinder assembly (1) can be adjusted. Also includes a water pump (13), The water pump (13) is in communication with the flexible bag (9), and water can be pumped into the flexible bag (9) or pumped out of the flexible bag (9) through the water pump (13). When the mass of water in the flexible bag (9) increases, the pressure between the flexible bag (9) and the anchor cylinder assembly (1) increases, so that the friction between the piston assembly (2) and the anchor cylinder assembly (1) increases; When the mass of water in the flexible bag (9) decreases, the pressure between the flexible bag (9) and the anchor cylinder assembly (1) decreases, so that the friction between the piston assembly (2) and the anchor cylinder assembly (1) decreases.

2. The piston-type suction anchor according to claim 1, characterized in that: Also includes a first valve, The first valve is used to control the opening and closing of the water pump (13), and / or the pumping direction, and / or the opening size.

3. The piston-type suction anchor according to claim 2, characterized in that: It also includes a pressure-resistant flexible cable (14), a waterproof electrical connector (6), The water pump (13) is fixedly mounted on the plate-shaped member (8), and the waterproof electrical connector (6) is fixedly mounted on the top cover (3). One end of the pressure-resistant flexible cable (14) is electrically connected to the waterproof electrical connector (6), and the other end of the pressure-resistant flexible cable (14) is electrically connected to the first valve, so that the first valve can be remotely controlled.

4. The piston-type suction anchor according to claim 1, characterized in that: Also includes a second valve (5), The second valve (5) is arranged on the top cover (3); when the second valve (5) is in an open state, the second accommodating space (10) can communicate with the outside through the second valve (5).

5. The piston-type suction anchor according to claim 4, characterized in that: The second valve (5) comprises a plurality of valves, and the plurality of second valves (5) are evenly arranged on the top cover (3).

6. The piston-type suction anchor according to claim 1, characterized in that: Also includes a third valve (15), The third valve (15) is arranged at the bottom of the plate-shaped member (8); when the third valve (15) is in an open state, the second accommodating space (10) is communicated with the third accommodating space through the third valve (15).

7. The piston-type suction anchor according to any one of claims 2, 5 and 6, characterized in that: It also includes a remote-controlled unmanned submarine, which is used as a control terminal for the valve.

8. The method for installing a piston-type suction anchor according to any one of claims 1 to 7, characterized in that: The following steps are involved: Positioning the piston-type suction anchor on the seabed on the sea surface; Embedding the piston-type suction anchor into the seabed using the piston-type suction anchor's own weight; Increasing the pressure between the piston assembly (2) and the tube skirt (4) so ​​that the second accommodating space (10) is closed; Carry out suction sinking.

9. The installation method of the piston-type suction anchor according to claim 8, characterized in that: During suction penetration, if the penetration speed does not meet expectations, the installation method of the piston-type suction anchor further includes the following steps: The pressure between the piston assembly (2) and the tube skirt (4) is reduced, so that the friction between the piston assembly (2) and the tube skirt (4) is appropriately reduced, thereby increasing the penetration speed of the piston-type suction anchor.

10. The method for recovering a piston-type suction anchor according to any one of claims 1 to 7, characterized in that: The following steps are involved: The pressure between the piston assembly (2) and the tube skirt (4) is increased, and water is injected into the second accommodating space (10), so that the pressure difference between the inside and outside of the second accommodating space (10) increases. Under the action of the pressure difference between the inside and outside, the piston-type suction anchor is gradually pulled out to achieve the recovery of the piston-type suction anchor.

11. The method for recovering a piston-type suction anchor according to claim 10, characterized in that: The following steps are also included: The pressure between the piston assembly (2) and the tube skirt (4) is reduced, and the pressure between the piston assembly (2) and the tube skirt (4) is reduced, so that the piston assembly (2) and the tube skirt (4) are separated.

12. The method according to claim 8 or 10, characterized in that The piston-type suction anchor is the piston-type suction anchor described in claim 2. During the step of increasing the pressure between the piston assembly (2) and the tube skirt (4) so ​​that the second accommodating space (10) is closed, the pressure between the flexible bag (9) and the tube skirt (4) is increased by increasing the volume of the flexible bag (9).

13. The method according to claim 12, characterized in that The piston-type suction anchor is the piston-type suction anchor according to claim 3, and the increase in the volume of the flexible bag (9) is achieved by increasing the mass of the content of the flexible bag (9).

14. The method according to claim 13, characterized in that The piston-type suction anchor is the piston-type suction anchor according to claim 4, and the mass of the content of the flexible bag (9) is increased by pumping water into the flexible bag (9).

15. The method according to claim 9 or 11, characterized in that The piston-type suction anchor is the piston-type suction anchor described in claim 2. During the step of reducing the pressure between the piston assembly (2) and the tube skirt (4), the pressure between the flexible bag (9) and the tube skirt (4) is reduced by reducing the volume of the flexible bag (9).

16. The method according to claim 15, characterized in that The piston-type suction anchor is the piston-type suction anchor according to claim 3, and the reduction of the volume of the flexible bag (9) is achieved by reducing the mass of the content of the flexible bag (9).

17. The method according to claim 16, characterized in that The piston-type suction anchor is the piston-type suction anchor according to claim 4, and the mass of the contents of the flexible bag (9) is reduced by pumping water out of the flexible bag (9).

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