Liquid cargo ship structure design method and vessel

Abstract

This invention relates to the field of shipbuilding technology, and more particularly to a structural design method and a vessel for a liquid cargo ship. The structural design method for the liquid cargo ship includes the following steps: an independent liquid cargo tank is located in the ship's hold; a first strong rib and a plurality of second strong ribs are fixedly installed within the independent liquid cargo tank along its length. The first strong rib includes an upper rib and a lower rib. The lower rib and the plurality of second strong ribs are arranged at equal intervals along the length of the independent liquid cargo tank, and the upper rib and the lower rib are arranged alternately. The inner wall surface of the ship's hold is provided with a first strong frame and a plurality of second strong frames at intervals; a plurality of anti-buoyancy seats are provided at intervals on the upper surface of the independent liquid cargo tank; and a plurality of support seats are provided on the bottom plate of the ship's hold. This invention enables the load on the anti-buoyancy seats and support seats to tend to be even, thereby simplifying the design, reducing construction difficulty, and reducing construction costs.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding technology, and in particular to a structural design method for a liquid cargo ship and the ship itself. Background Technology

[0002] Liquefied gas (LPG) cargo on liquefied gas carriers is typically housed in independent cargo tanks. Large independent cargo tanks are generally Type A or Type B. An independent cargo tank is a separate container placed within the ship's hold; its metal structure is not connected to the ship's hull. To prevent movement within the tank and potential damage to the tank or the ship, a restraining system is in place. This system consists of multiple support seats, each with a laminated wood surface. The ship and tank contact each other through this laminated wood. Support seats can be categorized based on their restraining direction and function, primarily including support seats and anti-buoyancy seats. Support seats are positioned between the ship's double bottom plate and the tank's bottom to support the independent cargo tank. Anti-buoyancy seats are positioned between the tank's shoulder and the ship's inner hull plate above it, with a gap at the anti-buoyancy seat. If the ship's hold is breached and flooded, the anti-buoyancy seat will prevent the independent cargo tank from continuing to rise and damaging the ship above it.

[0003] Multiple strong ribs are installed within the independent cargo tanks. Each strong rib is located in a plane perpendicular to the ship's length and is arranged at equal intervals along the ship's length. The strong ribs form a complete closed-loop structure. Hull compartments also have corresponding strong frames to the strong ribs of the independent cargo tanks, allowing for the placement of support seats between them to transfer loads. The strong frames of the compartments are arranged at equal intervals along the length of the hull. The inner hull of the compartments has numerous longitudinal ribs to support the compartment bulkheads. These longitudinal ribs pass through and are fixedly connected to the strong frames, which in turn provide support to the longitudinal ribs.

[0004] The distance from the transverse bulkhead of the ship's hold to the nearest first strong frame is equal to the interval between the other strong frames. However, the first strong rib of the independent cargo tank is set correspondingly to the first strong frame of the ship's hold and is located on the same cross section. The distance from the first strong rib of the independent cargo tank to the rear wall of the independent cargo tank is greater than half of the spacing between the strong ribs, which makes the load-bearing range of the first strong rib exceed that of the other strong ribs, resulting in a larger load on the support base below it.

[0005] When a ship's hold is breached and flooded, if the independent cargo tanks contain little or no cargo, they will float. At this point, the anti-buoyancy supports on top of the independent cargo tanks will press against the ship's structure, restricting movement and providing stability. The load is distributed among multiple longitudinally arranged anti-buoyancy supports. Under this load, the top of the ship's structure will arch slightly upwards. The compression is minimal in the middle of the hold, while it is greatest near the transverse bulkheads. This results in the anti-buoyancy supports near the transverse bulkheads bearing the greatest load, leading to a significant uneven load distribution. This necessitates substantial reinforcement of the anti-buoyancy supports near the transverse bulkheads, as well as the nearby independent cargo tank structure and the ship's overall structure. Conversely, the structure in the middle of the hold suffers from excessive strength, resulting in inconsistent structural design and increased construction complexity.

[0006] The hull near the anti-buoyancy seat has longitudinal ribs. The first strong frame of the hull deforms upward under the load of the anti-buoyancy seat, but the transverse bulkhead does not deform. The longitudinal ribs between the two are bent. The greater the load of the anti-buoyancy seat, the more severe the bending of the longitudinal ribs, which leads to an increase in the required strength of the longitudinal ribs. Larger specifications are required, which increases the cost and construction difficulty. The welding quality is less reliable, and the scrap rate increases.

[0007] Therefore, a structural design method and a vessel for liquid cargo ships are needed to solve the above problems. Summary of the Invention

[0008] The purpose of this invention is to provide a structural design method and vessel for liquid cargo ships, which can make the load on the buoyancy arrestor and the support seat more even, thereby simplifying the design, reducing the difficulty of construction, and reducing the construction cost.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] The structural design methodology for liquid cargo ships includes the following steps:

[0011] The independent liquid cargo tank is located in the ship's hold, and the length direction of the independent liquid cargo tank is consistent with the length direction of the ship's hull;

[0012] A first strong rib and a plurality of second strong ribs are fixedly installed within the independent cargo tank along its length. The first strong rib includes an upper rib and a lower rib. The lower rib and the plurality of second strong ribs are arranged at equal intervals along the length of the independent cargo tank at a predetermined distance. The upper rib and the lower rib are both located between the second strong rib closest to the end wall of the independent cargo tank and the end wall. The upper rib and the lower rib are arranged alternately, and the distance between the upper rib and the transverse bulkhead of the tank is equal to the predetermined distance, while the distance between the lower rib and the transverse bulkhead of the tank is less than the predetermined distance.

[0013] The inner wall of the cabin is provided with a first strong frame and a plurality of second strong frames at intervals. The first strong frame includes an upper strong frame body and a lower strong frame body. The upper strong frame body is arranged opposite to the upper rib, and the lower strong frame body is arranged opposite to the lower rib. The plurality of second strong frames are arranged opposite to the plurality of second strong ribs one by one.

[0014] Multiple anti-buoyancy seats are spaced apart on the upper surface of the independent cargo tank, and the multiple anti-buoyancy seats are arranged opposite to the upper rib and the multiple second strong ribs;

[0015] Multiple support seats are provided on the bottom plate of the ship's hold, and the multiple support seats are correspondingly provided with the lower strong frame and the multiple second strong frames. The support seats are used to support the independent liquid cargo tank.

[0016] Furthermore, a horizontal truss structure is fixedly provided on the end wall. The horizontal truss structure is arranged horizontally, and the upper rib is located at the upper end of the horizontal truss structure and is welded to the horizontal truss structure.

[0017] Furthermore, the lower rib is located at the lower end of the horizontal truss structure, and the lower rib is welded to the horizontal truss structure.

[0018] Furthermore, the horizontal truss structure extends along the independent cargo tank to the second strong rib closest to the end wall, and the horizontal truss structure is welded to the second strong rib.

[0019] Furthermore, the support base is used to support a first laminated wood at one end of the independent liquid cargo tank.

[0020] Furthermore, a second layer of pressed wood is provided at the upper end of the anti-buoyancy seat.

[0021] Furthermore, the second strong rib is ring-shaped.

[0022] Furthermore, the independent cargo tank is prismatic, frustum-shaped, or a combination of prismatic and frustum-shaped.

[0023] Furthermore, the independent cargo tanks are symmetrical about the mid-longitudinal plane of the hull.

[0024] The vessel includes an independent liquid cargo tank and a hull. The liquid cargo tank is located in the hull's compartment. Both the independent liquid cargo tank and the hull are designed using the liquid cargo ship structural design method described above.

[0025] The beneficial effects of this invention are:

[0026] This invention provides a structural design method for a liquid cargo ship. An independent liquid cargo tank is located within the ship's hold. A first strong rib and multiple second strong ribs are fixedly installed along the length of the independent liquid cargo tank. The first strong rib includes an upper rib and a lower rib. The lower rib and multiple second strong ribs are arranged at equal intervals along the length of the independent liquid cargo tank. Both the upper and lower ribs are located between the second strong rib closest to the end wall of the independent liquid cargo tank and the end wall. The upper and lower ribs are staggered, and the distance between the upper rib and the transverse bulkhead of the ship's hold is equal to the predetermined distance, while the distance between the lower rib and the transverse bulkhead of the ship's hold is less than the predetermined distance. Based on the first and second strong ribs, first and second strong frames are arranged in the ship's hold, along with corresponding anti-buoyancy seats and support seats. Through the above method, the first strong rib is not a complete closed-loop structure; the upper and lower ribs are misaligned, reducing the rigidity of the upper rib. When its anti-buoyancy seat is under stress, the upper rib is more prone to deformation, thus reducing the distributed load. This reduces the need for reinforcement structures at this anti-buoyancy seat, lightening the structural weight, reducing welding difficulty, and decreasing construction workload. The lower rib is closer to the end wall; when loading cargo, the load-bearing capacity and lever arm of the lower rib's support seat are reduced, decreasing the load on this support seat. This also reduces the need for corresponding reinforcement structures, lowering welding difficulty, reducing costs, and decreasing construction workload. Furthermore, the reduced load on the anti-buoyancy seat closest to the end wall means that, with the total load remaining constant, the load on other anti-buoyancy seats increases, resulting in more even stress distribution. This alleviates the material waste caused by the low load on the anti-buoyancy seat located in the middle, and also reduces the types of anti-buoyancy seats, facilitating construction. The load on the support closest to the end wall is reduced. With the total load remaining unchanged, the load on other supports increases, the force is more evenly distributed, and the material waste caused by the low load on the support in the middle is alleviated. At the same time, the types of supports can be reduced, avoiding the use of multiple supports of different strengths due to very uneven loads, thereby simplifying the design and reducing the difficulty of construction.

[0027] The present invention provides a ship comprising an independent liquid cargo tank and a hull. The liquid cargo tank is located in the hull compartment, which can make the load on the anti-buoyancy seat and the support seat tend to be even, thereby simplifying the design, reducing the construction difficulty and reducing the construction cost. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of an independent liquid cargo tank and the hull along the length of the ship in this invention;

[0030] Figure 2 This is a diagram showing the arrangement of the horizontal truss structure and the upper ribs in this invention;

[0031] Figure 3 This is a diagram showing the arrangement of the horizontal truss structure and the lower ribs in this invention.

[0032] In the picture:

[0033] 1. Hull; 11. Transverse bulkhead; 12. Bottom plate; 13. Upper strong frame; 14. Lower strong frame; 15. Second strong frame; 2. Independent cargo tank; 21. End bulkhead; 22. Upper rib; 23. Lower rib; 24. Second strong rib; 3. Buoyancy stop; 31. Second laminated timber; 4. Horizontal girder structure; 5. Support base; 51. First laminated timber. Detailed Implementation

[0034] Before explaining any implementation of this application in detail, it should be understood that this application is not limited to its application to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0035] In this application, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0036] In this application, the terms "connection," "combination," "coupling," and "installation" can refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the need for an intermediary, while an indirect connection refers to two parts or components each being connected to at least one intermediary, with the connection achieved through the intermediary. Furthermore, "connection" and "coupling" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.

[0037] In this application, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0038] In this application, the directional terms "upper," "lower," "left," "right," "front," and "rear" are used to describe the orientation and positional relationships shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when an element is mentioned as being connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as upper side, lower side, left side, right side, front side, and rear side not only represent positive orientation but can also be understood as lateral orientation. For example, "below" can include directly below, lower left, lower right, lower front, and lower rear.

[0039] In the design and construction of liquid cargo ship structures, in order to make the load on the buoyancy arrestor and support seats more even, thereby simplifying the design, reducing construction difficulty, and reducing construction costs, such as... Figures 1-3 As shown, this invention provides a structural design method for liquid cargo ships. The structural design method for liquid cargo ships includes the following steps:

[0040] Independent cargo tank 2 is located in the ship's hold, and the length direction of independent cargo tank 2 is consistent with the length direction of hull 1;

[0041] A first strong rib and a plurality of second strong ribs 24 are fixedly installed inside the independent cargo tank 2 along the length direction of the independent cargo tank 2. The first strong rib includes an upper rib 22 and a lower rib 23. The lower rib 23 and the plurality of second strong ribs 24 are arranged at equal intervals along the length direction of the independent cargo tank 2 at a predetermined distance. The upper rib 22 and the lower rib 23 are both located between the second strong rib 24 closest to the end wall 21 of the independent cargo tank 2 and the end wall 21. The upper rib 22 and the lower rib 23 are arranged alternately, and the distance between the upper rib 22 and the transverse bulkhead 11 of the tank is equal to the predetermined distance, while the distance between the lower rib 23 and the transverse bulkhead 11 of the tank is less than the predetermined distance.

[0042] The inner wall of the cabin is provided with a first strong frame and a plurality of second strong frames 15 at intervals. The first strong frame includes an upper strong frame body 13 and a lower strong frame body 14. The upper strong frame body 13 is arranged opposite to the upper rib 22, and the lower strong frame body 14 is arranged opposite to the lower rib 23. The plurality of second strong frames 15 are arranged opposite to the plurality of second strong ribs 24 one by one.

[0043] Multiple anti-buoyancy seats 3 are spaced apart on the upper end face of the independent cargo tank 2, and the multiple anti-buoyancy seats 3 are arranged opposite to the upper rib 22 and multiple second strong ribs 24.

[0044] Multiple support seats 5 are provided on the bottom plate 12 of the ship's hold. The multiple support seats 5 are correspondingly provided with the lower strong frame 14 and multiple second strong frames 15. The support seats 5 are used to support the independent liquid cargo tank 2.

[0045] Based on the first and second strong ribs 24, the first and second strong frames 15 are arranged in the hull, along with corresponding anti-buoyancy seats 3 and support seats 5. In this manner, the first strong rib is not a complete closed-loop structure; the upper rib 22 and lower rib 23 are misaligned, reducing the rigidity of the upper rib 22. When the anti-buoyancy seat 3 is under load, the upper rib 22 is more prone to deformation, thus reducing the distributed load. This reduces the need for reinforcement of the anti-buoyancy seat 3, lightening the structural weight, reducing welding difficulty, and decreasing construction workload. The lower rib 23 is closer to the end wall 21. When loading cargo, the load-bearing capacity and lever arm of the support seat of the lower rib 23 are reduced, decreasing the load on the support seat. This also reduces the need for corresponding reinforcement, lowering welding difficulty, reducing cost, and decreasing construction workload. Furthermore, the load on the anti-buoyancy seat 3 closest to the end wall 21 is reduced. With the total load remaining constant, the load on the other anti-buoyancy seats 3 increases, resulting in more even force distribution. This alleviates the material waste caused by the low load on the anti-buoyancy seat 3 located in the middle, and also reduces the number of types of anti-buoyancy seats 3, facilitating construction. Similarly, the load on the support seat 5 closest to the end wall 21 is reduced. With the total load remaining constant, the load on the other support seats increases, resulting in more even force distribution. This also alleviates the material waste caused by the low load on the support seat located in the middle, and also reduces the number of types of support seats, avoiding the need to use multiple support seats of different strengths due to highly uneven loads. This simplifies the design and reduces construction difficulty.

[0046] Furthermore, a horizontal truss structure 4 is fixedly installed on the end wall 21. The horizontal truss structure 4 is arranged horizontally, and the upper rib 22 is located at the upper end of the horizontal truss structure 4 and is welded to the horizontal truss structure 4. By setting the horizontal truss structure 4, it is convenient to support and install the upper rib 22, improve the strength of the upper rib 22, and thus ensure that the structural strength of the end of the independent liquid cargo tank 2 meets the requirements.

[0047] Furthermore, the lower rib 23 is located at the lower end of the horizontal truss structure 4, and is welded to the horizontal truss structure 4. The horizontal truss structure 4 facilitates the support and installation of the lower rib 23, increasing its strength and ensuring that the structural strength of the end of the independent cargo tank 2 meets requirements. Moreover, by connecting the upper rib 22 and the lower rib 23 together through the horizontal truss structure 4, the upper rib 22 and the lower rib 23 form a complete structure, guaranteeing the structural strength of the end of the independent cargo tank 2.

[0048] Furthermore, the horizontal truss structure 4 extends along the independent cargo tank 2 to the second strong rib 24 closest to the end wall 21, and the horizontal truss structure 4 is welded to the second strong rib 24. This arrangement facilitates the installation of the horizontal truss structure 4 and ensures the strength of the installed horizontal truss structure 4.

[0049] Furthermore, a first laminated timber 51 is provided at one end of the support base 5 to support the independent liquid cargo tank 2. By providing the first laminated timber 51, direct contact between the support base 5 and the tank body of the independent liquid cargo tank 2 is avoided, and the first laminated timber 51 can also act as a buffer. Since the support base 5 bears the load evenly, the variety of specifications of the first laminated timber 51 is reduced, making procurement easier and avoiding installation difficulties caused by excessive weight of the first laminated timber 51 in certain locations.

[0050] Furthermore, a second layer of pressurized timber 31 is installed on the upper end of the anti-buoyancy base 3. By installing the second layer of pressurized timber 31, when the hull 1 is damaged and the independent cargo tank 2 floats, direct rigid collision between the tank body of the independent cargo tank 2 and the upper hull structure is avoided, while also serving as a buffer. Moreover, due to the adoption of this design method, the anti-buoyancy base 3 is subjected to uniform force when the independent cargo tank 2 floats, the variety of specifications of the second layer of pressurized timber 31 is reduced, making procurement easier and avoiding installation difficulties caused by excessive weight of the second layer of pressurized timber 31 in certain locations.

[0051] Furthermore, the second reinforcing rib 24 is ring-shaped. Using a ring-shaped second reinforcing rib 24 ensures the structural integrity of the second reinforcing rib 24 and guarantees its load-bearing capacity.

[0052] Furthermore, the independent cargo tank 2 can be prismatic, frustum-shaped, or a combination of prismatic and frustum-shaped. The first screenshot shows the shape of the independent cargo tank 2 being selected based on actual needs.

[0053] Furthermore, the independent cargo tank 2 is symmetrical about the mid-longitudinal plane of the hull 1. By designing the independent cargo tank 2 as a symmetrical structure, it is easier to manufacture and at the same time, it can ensure that the independent cargo tank 2 is subjected to uniform stress.

[0054] By improving the independent cargo tank 2 and the hull, the weight of the hull structure is reduced, allowing for the loading of more cargo with the same displacement. Furthermore, with improved stress distribution, the independent cargo tank 2 can be designed to be larger within the same construction capacity. This larger capacity reduces the transportation cost per unit of cargo, thereby improving the overall operational economy of the vessel.

[0055] This embodiment also provides a ship, including an independent cargo tank 2 and a hull 1. The cargo tank is located in the hull 1. Both the independent cargo tank 2 and the hull 1 are designed using the above-mentioned cargo ship structural design method, which can make the load on the anti-buoyancy seat 3 and the support seat tend to be average, thereby simplifying the design, reducing the construction difficulty and reducing the construction cost.

[0056] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A structural design method for liquid cargo ships, characterized in that, Includes the following steps: The independent cargo tank (2) is located in the ship's hold, and the length direction of the independent cargo tank (2) is consistent with the length direction of the hull (1); A first strong rib and a plurality of second strong ribs (24) are fixedly installed inside the independent cargo tank (2) along its length. The first strong rib includes an upper rib (22) and a lower rib (23). The lower rib (23) and the plurality of second strong ribs (24) are arranged at equal intervals at a predetermined distance along the length of the independent cargo tank (2). The upper rib (22) and the lower rib (23) are both located between the second strong rib (24) closest to the end wall (21) of the independent cargo tank (2) and the end wall (21). The upper rib (22) and the lower rib (23) are arranged alternately. The distance between the upper rib (22) and the transverse bulkhead (11) of the tank is equal to the predetermined distance, and the distance between the lower rib (23) and the transverse bulkhead (11) of the tank is less than the predetermined distance. The inner wall of the cabin is provided with a first strong frame and a plurality of second strong frames (15) at intervals. The first strong frame includes an upper strong frame body (13) and a lower strong frame body (14). The upper strong frame body (13) is arranged opposite to the upper rib (22), and the lower strong frame body (14) is arranged opposite to the lower rib (23). The plurality of second strong frames (15) are arranged opposite to the plurality of second strong ribs (24) one by one. Multiple anti-buoyancy seats (3) are provided at intervals on the upper end face of the independent liquid cargo tank (2), and the multiple anti-buoyancy seats (3) are arranged opposite to the upper rib (22) and the multiple second strong ribs (24); Multiple support seats (5) are provided on the bottom plate (12) of the ship's compartment. The multiple support seats (5) are correspondingly provided with the lower strong frame (14) and the multiple second strong frames (15). The support seats (5) are used to support the independent liquid cargo tank (2).

2. The liquid cargo ship structural design method according to claim 1, characterized in that, A horizontal truss structure (4) is fixedly provided on the end wall (21). The horizontal truss structure (4) is arranged horizontally. The upper rib (22) is located at the upper end of the horizontal truss structure (4) and is welded to the horizontal truss structure (4).

3. The liquid cargo ship structural design method according to claim 2, characterized in that, The lower rib (23) is located at the lower end of the horizontal truss structure (4), and the lower rib (23) is welded to the horizontal truss structure (4).

4. The liquid cargo ship structural design method according to claim 2, characterized in that, The horizontal truss structure (4) extends along the independent cargo tank (2) to the second strong rib (24) closest to the end wall (21), and the horizontal truss structure (4) is welded to the second strong rib (24).

5. The liquid cargo ship structural design method according to claim 1, characterized in that, The support base (5) is used to support the first laminated wood (51) at one end of the independent liquid cargo tank (2).

6. The liquid cargo ship structural design method according to claim 1, characterized in that, The upper end of the anti-buoyancy seat (3) is provided with a second layer of pressed wood (31).

7. The liquid cargo ship structural design method according to claim 1, characterized in that, The second strong rib (24) is ring-shaped.

8. The liquid cargo ship structural design method according to claim 1, characterized in that, The independent liquid cargo tank (2) is prismatic, frustum-shaped or a combination of prismatic and frustum-shaped.

9. The liquid cargo ship structural design method according to claim 1, characterized in that, The independent cargo tank (2) is symmetrical about the mid-longitudinal plane of the hull (1).

10. A ship, characterized in that, It includes an independent liquid cargo tank (2) and a hull (1), wherein the independent liquid cargo tank is located in the hull (1), and both the independent liquid cargo tank (2) and the hull (1) are designed using the liquid cargo ship structural design method as described in any one of claims 1-9.

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