Deformable integrated moon pool resistance reduction device

Abstract

The invention relates to the technical field of ocean engineering ships, and discloses a deformable integrated moon pool resistance reducing device which comprises a moon pool top cover and a moon pool bottom plate, the moon pool top cover is arranged above the moon pool bottom plate, an air bag is arranged on the bottom face of the moon pool top cover, the moon pool top cover and the moon pool bottom plate are connected through a steel cable, a winch is arranged on the top face of the moon pool top cover, and the winch is connected with the moon pool bottom plate through a steel cable. And the upper end of the steel cable is connected with the winch. According to the deformable integrated moon pool resistance reduction device, the top cover and the bottom plate which are connected through the hinge are arranged at the top and the bottom of the moon pool, the air bag matched with the shape of the moon pool is placed between the cover plate and the bottom plate, the ship body can be kept in a streamline shape at the moon pool through the bottom plate, and oscillation of liquid in the moon pool is reduced through the air bag; the combination of the two can effectively reduce the resistance of the ship during sailing, and can alleviate the vibration and noise problems of the ship body through the limitation of water oscillation of the air bag, so that the ship sails more stably.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore engineering vessels, and particularly relates to a deformable integrated moonpool drag reduction device. Background Art

[0002] A moonpool is a special structure in offshore engineering and ship design, usually referring to an opening vertically penetrating the hull inside a ship. The design of the moonpool allows the ship to carry out various underwater operations without damaging the hull integrity, such as placing and retrieving submersibles, remotely operated underwater vehicles (ROVs), subsea equipment, etc. The existence of the moonpool provides a direct access to the water surface for these operations, reducing the dependence on other parts of the ship and improving the safety and efficiency of the operations. It is widely used in marine exploration, deep-sea drilling, subsea facility maintenance, and scientific research missions.

[0003] However, since the moonpool opening will damage the hydrodynamic structure of the ship, resulting in turbulence and oscillation after water flows into the moonpool, this will increase the viscous drag and wave drag of the ship, thereby increasing fuel consumption and reducing the ship speed. The water body inside the moonpool may resonate with the ship's sailing speed or wave frequency, resulting in violent vibration of the water body. This not only increases the drag of the ship, but may also cause vibration of the hull, affecting the comfort of the crew and the safety of the hull structure.

[0004] To reduce the adverse effects caused by the moonpool, a closed moonpool can be adopted. The moonpool can be closed by a movable cover plate or hatch. These cover plates can be sealed when the moonpool is not in use to prevent seawater from flowing into the moonpool and reduce the influence of external water flow. The moonpool closing system adopts automatic control. Through a cover plate system driven by hydraulic or electric power, the crew can remotely operate the opening and closing of the moonpool. When drilling or equipment operation is required, the cover plate can be quickly opened to ensure the smooth deployment and operation of the equipment.

[0005] However, the design of a closed moonpool requires the ship hull to be equipped with additional complex mechanical equipment such as cover plates, hatches, and hydraulic systems to achieve the opening and closing of the moonpool. The integration and design of such a system require higher technical standards, increasing the complexity of the overall design. Due to the involvement of a large number of precision mechanical equipment, especially hydraulic drive devices and automatic control systems, the required materials and technical standards are relatively high, and the manufacturing and installation costs increase accordingly. Due to the complexity of the system, the maintenance cost is also relatively high. It is necessary to regularly inspect and maintain the hydraulic system, cover plate sealing structure, control system, etc. to ensure the reliability and safety of the moonpool during long-term use. The opening and closing system of the closed moonpool relies on mechanical devices and hydraulic systems. During long-term use, these systems may malfunction, resulting in the moonpool being unable to be opened and closed in time. In this case, the moonpool may not be able to operate normally, affecting the operation efficiency of the ship. Summary of the Invention

[0006] The technical problem to be solved by the present invention is that the existing closed moonpool has a complex structure, high installation and maintenance costs, and affects the operation efficiency.

[0007] To solve the above technical problem, the technical solution of the present invention is to provide a deformable integrated moonpool drag reduction device, including a moonpool top cover and a moonpool bottom plate. The moonpool top cover is arranged above the moonpool bottom plate. An airbag is provided on the bottom surface of the moonpool top cover. The moonpool top cover and the moonpool bottom plate are connected by steel cables. A winch is provided on the top surface of the moonpool top cover, and the upper end of the steel cable is connected to the winch.

[0008] Optionally, a plurality of longitudinal girders and transverse frames are arranged inside the moonpool bottom plate.

[0009] Optionally, the four peripheral edges of the moonpool bottom plate are wrapped with flexible wear-resistant materials.

[0010] Optionally, a pressure relief port composed of a flow deflector and a flow deflector cover plate is provided on the moonpool bottom plate.

[0011] Optionally, an arc transition is provided at the edge of the flow deflector cover plate.

[0012] Optionally, lifting points are provided on the bottom plate, the lower end of the steel cable is connected to the lifting points, an opening is provided on the moonpool top cover, and the upper end of the steel cable passes through the opening and is connected to the winch.

[0013] Optionally, the winch is a double-drum winch.

[0014] Optionally, a plurality of bolt holes are provided at the edge of the top surface of the moonpool top cover.

[0015] Optionally, a plurality of lifting points are provided on the top surface of the moonpool top cover.

[0016] Optionally, an inflation port for inflating and deflating the airbag is provided on the moonpool top cover.

[0017] In summary, the present invention has at least the following beneficial effects:

[0018] 1. The present invention designs a deformable integrated moonpool drag reduction device. By setting a top cover and a bottom plate connected by hinges at the top and bottom of the moonpool, and placing an airbag that fits the shape of the moonpool between the cover plate and the bottom plate, the bottom plate can keep the hull streamlined at the moonpool, and the airbag can also reduce the oscillation of the liquid in the moonpool. The combination of the two can effectively reduce the resistance during ship navigation. At the same time, by restricting the oscillation of the water body by the airbag, the vibration and noise problems of the hull can be reduced, making the ship navigation more stable.

[0019] 2. Compared with the existing methods of reducing resistance in the moonpool, the design, construction, and later maintenance of the present invention are relatively simple, the cost is lower, it does not occupy the internal space of the hull, and it has stronger applicability. By implementing the present invention, the resistance of the ship during navigation can be reduced. Especially during high-speed navigation, the reduction of resistance is beneficial to improving the fuel efficiency of the ship and reducing the fuel consumption level.

[0020] 3. After installing the top cover on the moonpool designed by the present invention, a larger deck area can be obtained. The non-watertight bottom plate of the moonpool can also reduce the manufacturing and maintenance costs. The top cover and the bottom plate are connected by steel cables, and the installation of the top cover and the bottom plate can be completed by only one hoisting. After being removed, the occupied deck space is small and does not affect the normal placement of goods and equipment on the deck. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of the deformable integrated moonpool drag reduction device of the present invention;

[0022] Figure 2 is a schematic installation structure diagram of the deformable integrated moonpool drag reduction device of the present invention;

[0023] Figure 3 is a schematic retracted structure diagram of the deformable integrated moonpool drag reduction device of the present invention;

[0024] Figure 4 is an enlarged schematic installation structure diagram of the deformable integrated moonpool drag reduction device of the present invention;

[0025] Figure 5 is an enlarged schematic retracted structure diagram of the deformable integrated moonpool drag reduction device of the present invention;

[0026] In the figure: 1. Moonpool top cover; 2. Hoisting point; 3. Opening; 4. Bolt hole; 5. Inflation port; 6. Airbag; 7. Steel cable; 8. Transverse frame; 9. Moonpool bottom plate; 10. Hoisting point; 11. Flexible wear-resistant material; 12. Longitudinal girder; 13. Winch; 14. Deflector cover plate; 15. Deflector; 17. Slide rail; 18. Stacking area. DETAILED DESCRIPTION OF THE INVENTION

[0027] The following will Figures 1-5 further describe the present invention in detail.

[0028] The present invention discloses a deformable integrated moonpool drag reduction device. Referring to Figure 1 , it includes a moonpool top cover 1 and a moonpool bottom plate 9. The moonpool top cover 1 is arranged above the moonpool bottom plate 9. An airbag 6 is provided on the bottom surface of the moonpool top cover 1. The moonpool top cover 1 and the moonpool bottom plate 9 are connected by a steel cable 7. A winch 13 is provided on the top surface of the moonpool top cover 1, and the upper end of the steel cable 7 is connected to the winch 13.

[0029] In a further embodiment, a plurality of longitudinal girders 12 and transverse frames 8 are provided inside the moonpool bottom plate 9 to enhance the strength of the moonpool bottom plate 9. The moonpool bottom plate 9 and the hull outer shell are smoothly transitioned to reduce resistance. The size of the moonpool bottom plate 9 is slightly smaller than the size of the moonpool to facilitate the arrangement and retraction of the device. The four peripheral edges of the moonpool bottom plate 9 are wrapped with a flexible wear-resistant material 11, which can reduce the gap between the moonpool bottom plate 9 and the ship's moonpool structure and also play a buffering role in the collision between the moonpool bottom plate 9 and the moonpool. A pressure relief opening composed of a deflector 15 and a deflector cover plate 14 is provided on the moonpool bottom plate 9. The edge of the deflector cover plate 14 is provided with an arc transition to prevent the deflector 15 from piercing the airbag 6 when the device is retracted.

[0030] In a further embodiment, lifting points 10 are provided on the bottom plate 9. The lower end of the steel cable 7 is connected to the lifting point 10. An opening 3 is provided on the moonpool top cover 1. The upper end of the steel cable 7 passes through the opening 3 and is connected to a winch 13. The winch 13 is a double-drum winch used to control the retraction and deployment of the moonpool bottom plate 9. A plurality of bolt holes 4 are provided at the top edge of the moonpool top cover 1 to fix the moonpool top cover 1 on the ship's deck. The number of bolt holes 4 can be adjusted according to the size of the moonpool. A plurality of lifting points 2 are provided on the top surface of the moonpool top cover 1 to facilitate the installation and removal of the drag reduction device by a crane on the ship. An inflation port 5 for inflating and deflating the airbag 6 is provided on the moonpool top cover 1. The airbag 6 is used to fill the gap between the liquid in the moonpool and the moonpool top cover 1, reduce the "oscillation" of the liquid in the moonpool, and thus reduce resistance.

[0031] As Figure 2 and Figure 4 shown, when the ship is sailing, the device of the present invention is installed in the moonpool. The installation process is that the crane lifts the device from the stacking area 18 through the lifting hole 2, moves it to above the moonpool through the slide rail 17, and then lowers the device. After that, the moonpool top cover 1 is fixed on the ship's deck through the bolt holes 4, and then the moonpool bottom plate 9 is lowered through the winch 13. While lowering the moonpool bottom plate 9, the airbag 6 is inflated through the inflation port 5. When the moonpool bottom plate 9 is lowered to be flush with the hull outer shell (which can be judged by the marks on the steel cable 7), the steel cable 7 is fixed through the winch 13. At this time, the drag reduction device is installed. The moonpool opening on the ship's hull realizes a streamlined transition through the moonpool bottom plate 9, and the "oscillation" of the liquid in the moonpool is also restricted by the airbag 6, reducing the resistance during ship navigation.

[0032] When the ship needs to perform operations through the moonpool, as Figure 3 and Figure 5 shown, it is necessary to first deflate the airbag 6 through the inflation port 5, and then raise the moonpool bottom plate 9 through the winch 13, which can reduce the height of the device and the deck space occupied by the device. After the bottom plate is raised to a predetermined height, the steel cable 7 is fixed through the winch 13, and then the bolts on the bolt holes 4 are unscrewed, and the device is lifted through the lifting hole 2 and moved to the corresponding position on the deck.

[0033] In this device, the bottom plate 9 is a non-watertight structure. At the same time, an airbag 6 is arranged above the water body in the moonpool, which can effectively reduce the oscillation of the water body inside the moonpool, and then reduce the resistance during ship navigation. Since there is an airbag 6 above the water body, the oscillation of the water body in the moonpool is restricted, which can reduce the vibration and noise problems of the hull and make the ship navigation more stable. At the same time, the design and construction of the non-watertight bottom plate 9 are relatively simple, reducing the related construction and maintenance costs; this device can adjust the distance between the moonpool top cover 1 and the moonpool bottom plate 9 through the steel cable 7, which can reduce the deck space occupied when the device is retracted. When the device is arranged in the moonpool, the moonpool top cover 1 can effectively increase the ship deck area.

[0034] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A deformable integrated moon pool drag reduction device, characterized in that: The invention comprises a moon pool top cover (1) and a moon pool bottom plate (9), wherein the moon pool top cover (1) is arranged above the moon pool bottom plate (9), an air bag (6) is arranged on the bottom surface of the moon pool top cover (1), the moon pool top cover (1) and the moon pool bottom plate (9) are connected by a steel cable (7), a winch (13) is arranged on the top surface of the moon pool top cover (1), and the upper end of the steel cable (7) is connected to the winch (13).

2. The deformable integrated moon pool drag reduction device according to claim 1, characterized in that: A plurality of longitudinal girders (12) and transverse ribs (8) are arranged in the moon pool bottom plate (9).

3. The deformable integrated moon pool drag reduction device according to claim 2, characterized in that: The edges of the moon pool bottom plate (9) are wrapped with flexible wear-resistant material (11).

4. The deformable integrated moon pool drag reduction device according to claim 1, characterized in that: The moon pool bottom plate (9) is provided with a pressure relief port consisting of a guide plate (15) and a guide plate cover plate (14).

5. The deformable integrated moon pool drag reduction device according to claim 4, characterized in that: The edge of the guide plate cover (14) is provided with an arc-shaped transition.

6. The deformable integrated moon pool drag reduction device according to claim 1, characterized in that: The bottom plate (9) is provided with a suspension point (10), the lower end of the steel cable (7) is connected to the suspension point (10), the moon pool top cover (1) is provided with an opening (3), and the upper end of the steel cable (7) passes through the opening (3) and is connected to a winch (13).

7. The deformable integrated moon pool drag reduction device according to claim 6, characterized in that: The winch (13) is a double-drum winch.

8. The deformable integrated moon pool drag reduction device according to claim 1, characterized in that: A plurality of bolt holes (4) are provided at the edge of the top surface of the moon pool cover (1).

9. The deformable integrated moon pool drag reduction device according to claim 1, characterized in that: A plurality of hanging points (2) are provided on the top surface of the moon pool cover (1).

10. The deformable integrated moon pool drag reduction device according to claim 1, characterized in that: The moon pool top cover (1) is provided with an inflation port (5) for inflating and deflation of the air bag (6).

Images