A wave suppression and drag reduction device for a deep-sea mining vessel's moon pool

Abstract

This utility model relates to the field of marine engineering technology, specifically to a wave suppression and drag reduction device for a moon pool on a deep-sea mining vessel. The technical solution includes: an arc-shaped bevel formed on the rear wall of the moon pool; and a guide plate, which is positioned below the arc-shaped bevel and fixedly connected to the side wall of the moon pool. The guide plate has an airfoil-shaped cross-section along the length of the hull, forming a narrow channel between the guide plate and the arc-shaped bevel. This utility model has the advantages of simple structure and significant wave suppression and drag reduction effect.

Description

Technical Field

[0001] This utility model relates to the field of marine engineering technology, specifically to a wave suppression and drag reduction device for a deep-sea mining vessel's moon pool. Background Technology

[0002] As surface support equipment for seabed mining, deep-sea mining vessels are crucial technological tools. Currently, they are typically converted from oil drilling ships, utilizing their existing moon pools and positioning systems to assist in mining operations. However, the presence of the moon pool significantly impacts the drag performance of the mining vessel. Existing research indicates that a high-pressure zone forms behind the rectangular moon pool during navigation, significantly increasing drag, which can exceed 20% at high speeds. Furthermore, the moon pool also introduces slamming and wave-like effects from the water movement within it, which are detrimental to the structural safety of the vessel.

[0003] Currently, domestic research on moon pools largely focuses on their impact on the navigation performance of mining vessels, while research on moon pool wave suppression and drag reduction devices is still in its developmental stage. Patent application CN105416521A proposes a platform moon pool drag reduction device, including vibration damping chambers and anti-sway chambers, damping blocks, wave-blocking columns, and wave-absorbing blocks. Its complex structure makes practical engineering applications difficult. Patent application CN112937754A proposes an integrated moon pool drag reduction device, including a base plate, a top cover, and a truss structure connecting the base plate and the top cover. The base plate's shape matches the bottom opening of the moon pool, and the top cover's shape matches the top opening of the moon pool, to reduce drag and increase deck cargo area. However, for mining vessels that need to lower or lower survey equipment through the moon pool, this device obstructs the passage and hinders surveying and other operations. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this utility model provides a wave suppression and drag reduction device for a deep-sea mining vessel's moon pool, which has the advantages of simple structure and significant wave suppression and drag reduction effect.

[0005] The above-mentioned objective of this utility model is achieved through the following technical solution:

[0006] This utility model provides a wave suppression and drag reduction device for a deep-sea mining vessel's moonpool, comprising:

[0007] An arc-shaped bevel is opened on the rear wall of the moon pool;

[0008] And a guide vane, which is located below the arc-shaped bevel and fixedly connected to the side wall of the moon pool. The cross-section of the guide vane along the length of the hull is airfoil-shaped, and a narrow channel is formed between the guide vane and the arc-shaped bevel.

[0009] By adopting the above technical solution, a low-pressure zone is formed near the rear wall of the moon pool through a narrow channel, and the water flow is accelerated. The low-pressure zone achieves the dual effect of wave suppression and drag reduction.

[0010] Furthermore, the outer edge of the arc-shaped bevel is parabolic in shape.

[0011] By adopting the above technical solution, the narrow channel formed is wider at both ends and narrower in the middle, which avoids the water at the back wall of the moon pool moving upward and causing waves.

[0012] Furthermore, the guide vane is inclined along the width direction of the hull, and the guide vane portion is disposed in the space below the arc-shaped bevel.

[0013] By adopting the above technical solution, the flow guide plate can be avoided from occupying the bottom space of the moon pool.

[0014] Furthermore, the lower end of the guide vane is higher than the bottom plate of the hull.

[0015] By adopting the above technical solution, it is possible to avoid increasing the projected area in the direction of water flow during navigation, which would increase resistance.

[0016] Furthermore, the angle of attack of the guide vane is denoted as ∠β, where 23°≤∠β≤28°.

[0017] By adopting the above technical solution, a narrow passage can be better formed in conjunction with the curved bevel, and it has a significant drag reduction effect.

[0018] Furthermore, the angle of attack of the guide plate is ∠β=25°.

[0019] By adopting the above technical solution, the drag reduction effect of the narrow channel formed by the guide plate and the arc-shaped bevel is optimal.

[0020] Furthermore, the length of the guide plate is the distance between the two side walls of the pool.

[0021] By adopting the above technical solution, the guide plate is completely in contact with the side wall of the moon pool, avoiding the formation of other channels.

[0022] Furthermore, a fixed bracket is provided between the guide plate and the rear wall of the moon pool.

[0023] By adopting the above technical solution, the guide plate can be set up stably, avoiding damage caused by excessive deflection due to the action of fluid on the guide plate.

[0024] Furthermore, two fixing brackets are provided.

[0025] By adopting the above technical solution, the connection between the guide plate and the rear wall of the moon pool is made more stable.

[0026] Furthermore, the cross-section of the fixed bracket along the length of the hull is a symmetrical teardrop shape.

[0027] By adopting the above technical solution, the impact of the fixed support on the flow field inside the moon pool can be reduced.

[0028] In summary, this utility model has at least one of the following beneficial technical effects: the wave suppression and drag reduction device of this utility model forms a low-pressure zone near the rear wall of the moon pool through a narrow channel and accelerates the water flow, thereby achieving the dual effect of wave suppression and drag reduction by utilizing the low-pressure zone; the structure is simple and does not occupy the bottom area of ​​the moon pool, avoiding interference with other operating equipment in the moon pool, and is highly practical. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of this embodiment;

[0030] Figure 2 yes Figure 1 Schematic diagram of the cross section at point AA;

[0031] Figure 3 yes Figure 2 Enlarged view of a section at point C;

[0032] Figure 4 yes Figure 1 Schematic diagram of the cross section at point BB;

[0033] Figure 5 yes Figure 4 Enlarged view of a section at point D;

[0034] Figure 6 yes Figure 2 Another diagram showing a magnified view of a section at point C;

[0035] Figure 7 yes Figure 3 A schematic diagram of the cross-section of the fixed bracket along EE.

[0036] In the diagram, 1. Hull; 11. Front wall of the moon pool; 12. Rear wall of the moon pool; 13. Side wall of the moon pool; 2. Curved bevel; 3. Deflector plate; 4. Narrow passage; 5. Fixed support. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to the accompanying drawings.

[0038] To facilitate understanding of this utility model by those skilled in the art, the specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0039] To facilitate understanding of the technical solution of this utility model, the bow direction of the deep-sea mining vessel is taken as the front end, the stern direction as the rear end, the moon pool wall near the bow direction is the front wall 11 of the moon pool, the moon pool wall near the stern direction is the rear wall 12 of the moon pool, and the moon pool walls on both sides are the side walls 13 of the moon pool.

[0040] Reference Figure 1-7 This utility model discloses a wave suppression and drag reduction device for a moon pool on a deep-sea mining vessel, comprising an arc-shaped bevel 2 and a guide plate 3. A narrow channel 4 is formed between the arc-shaped bevel 2 and the guide plate 3. When water flows into the moon pool from the bow direction, the narrow channel 4 formed between the arc-shaped bevel 2 and the guide plate 3 can accelerate the water flow and create a low-pressure zone.

[0041] An arc-shaped bevel 2 is formed on the rear wall 12 of the moon pool. The arc-shaped bevel 2 extends from the rear wall 12 towards the rear end, and its outer edge is parabolic. Taking the highest point of the arc-shaped bevel 2 as the origin, the horizontal direction pointing towards the rear end is the Y-axis, and the vertical direction pointing towards the moon pool opening is the X-axis. The equation of the parabola is y = (x / 30)^2 * 33.33, where -4500 ≤ x ≤ 0. The angle between the line connecting the two ends of the arc-shaped bevel 2 along the length of the hull and the horizontal direction is ∠α, where 20° ≤ ∠α ≤ 35°. In this embodiment, ∠α = 28°.

[0042] The guide vane 3 is inclined along the width of the hull, and part of the guide vane 3 is located in the space below the arc-shaped bevel 2, thus avoiding occupying the bottom space of the moon pool. The lower end of the guide vane 3 is higher than the bottom plate of the mining vessel, which can avoid increasing the projected area of ​​the water flow direction during navigation and thus increasing resistance. In order to cooperate with the arc-shaped bevel 2 to form a narrow channel 4, the guide vane 3 is set with a large angle of attack ∠β, that is, the angle of attack ∠β between the chord length direction and the bottom plane of the ship is set to 23°~28°. To achieve the best drag reduction effect, the guide vane 3 in this embodiment is set with an angle of attack ∠β=25°.

[0043] The deflector 3 has an airfoil-shaped cross-section along the length of the deep-sea mining vessel. The trailing edge of the deflector 3 tends towards the rear wall 12 of the moon pool, while the leading edge of the deflector 3 is inclined upwards relative to the trailing edge and tends towards the front wall 11 of the moon pool. To prevent the airfoil deflector 3 from stalling due to a large angle of attack, thus affecting its wave suppression and drag reduction effect in the low-pressure area, the leading edge radius of the airfoil is increased, along with its maximum thickness and trailing edge angle. In this embodiment, the leading edge radius of the airfoil deflector 3 is 5.4% of the chord length, the maximum thickness is 16.4% of the chord length, and the trailing edge angle is 28°.

[0044] The two ends of the guide plate 3 are fixedly connected to the side wall 13 of the moon pool. To increase the connection between the guide plate 3 and the side wall 13 of the moon pool, they are fixed by welding.

[0045] The fluid within the moon pool causes excessive deflection of the guide plate 3, which is detrimental to its long-term use. Therefore, a fixed bracket 5 is installed between the guide plate 3 and the rear wall 12 of the moon pool to connect the guide plate 3 to the hull. Specifically, one end of the fixed bracket 5 is connected to the guide plate 3, and the other end is connected to the arc-shaped bevel 2 on the rear wall 12 of the moon pool. In this embodiment, two fixed brackets 5 are provided, and the two fixed brackets 5 are equally spaced. The cross-section of the fixed bracket 5 along the length of the hull is a symmetrical teardrop shape to reduce the influence of the fixed bracket 5 on the flow field within the moon pool. The fixed bracket 5 is fixed to the guide plate 3 by welding.

[0046] The implementation principle of this embodiment is as follows: a narrow channel 4 is formed between the arc-shaped bevel 2 and the guide plate 3, thereby reducing the pressure in the high-pressure zone behind the moon pool and decreasing the pressure gradient. When the water flows from the bow into the moon pool and then through the narrow channel 4, the low-pressure zone formed can achieve a drag reduction effect. Since the low-pressure zone is located near the bottom plate of the ship on the rear wall 12 of the moon pool, it also helps to reduce the upward waves caused by the upward movement of water in the rear of the moon pool. Therefore, it has a dual effect of drag reduction and wave suppression. The above device has a simple structure and does not require frequent maintenance. Moreover, part of the guide plate 3 is located in the space below the arc-shaped bevel 2, which hardly occupies the bottom area of ​​the moon pool and avoids interference with other operating equipment in the moon pool, making it highly practical.

[0047] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model.

[0048] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0049] The embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A wave dampening and drag reducing device for a moon pool of a deep sea mining vessel, characterized in that, include: An arc-shaped bevel (2) is opened on the rear wall of the moon pool (12); And a guide plate (3), which is located below the arc-shaped bevel (2) and fixedly connected to the side wall (13) of the moon pool. The cross section of the guide plate (3) along the length of the hull is airfoil-shaped, and a narrow channel (4) is formed between the guide plate (3) and the arc-shaped bevel (2).

2. The moonpool wave suppression and drag reduction device for a deep-sea mining vessel according to claim 1, characterized in that: The outer edge of the arc-shaped bevel (2) is parabolic in shape.

3. The deep-sea mining vessel moonpool wave suppression and drag reduction device according to claim 1, characterized in that: The guide plate (3) is inclined along the width direction of the hull, and part of the guide plate (3) is located in the space below the arc-shaped bevel (2).

4. The wave suppression and drag reduction device for a deep-sea mining vessel according to claim 3, characterized in that: The lower end of the guide plate (3) is higher than the bottom plate of the hull.

5. A wave suppression and drag reduction device for a deep-sea mining vessel according to any one of claims 1-3, characterized in that: The angle of attack of the guide plate (3) is denoted as ∠β, where 23°≤∠β≤28°.

6. The moonpool wave suppression and drag reduction device for a deep-sea mining vessel according to claim 1, characterized in that: The angle of attack of the guide plate (3) is ∠β=25°.

7. The moonpool wave suppression and drag reduction device for a deep-sea mining vessel according to claim 6, characterized in that: The length of the guide plate (3) is the distance between the two side walls (13) of the pool.

8. The moonpool wave suppression and drag reduction device for a deep-sea mining vessel according to claim 1, characterized in that: A fixed bracket (5) is provided between the guide plate (3) and the rear wall (12) of the moon pool.

9. A wave suppression and drag reduction device for a deep-sea mining vessel according to claim 8, characterized in that: There are two fixed brackets (5).

10. A wave suppression and drag reduction device for a deep-sea mining vessel according to claim 9, characterized in that: The fixed bracket (5) has a symmetrical teardrop-shaped cross section along the length of the hull.

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