Rail structure and design method of a fuel tank side cargo tank bulkhead of a container ship

Abstract

This invention relates to the field of shipbuilding technology, and more particularly to a guide rail structure and design method for a cargo hold bulkhead on the side of a container ship's fuel tank. The guide rail structure for the cargo hold bulkhead on the side of a container ship's fuel tank includes vertically arranged guide rails on the bulkhead. Each guide rail comprises a connecting plate fixedly mounted on the bulkhead and angle steel located on the connecting plate. The guide rail is segmented, including a deformation zone corresponding to the center of the fuel tank and regular zones at other locations. Larger angle steels are installed in the deformation zone, and smaller angle steels are installed in the regular zones. A transition plate connects the large and small angle steels. The width of the connecting plate is equal to the sum of the widths of the corresponding angle steel limbs, ensuring that the sides of the angle steels furthest from the cargo hold bulkhead are arranged at equal heights. This solves the problem in existing container ships where bulkhead deformation after fuel filling causes the guide rails on the bulkhead to deform, resulting in containers getting stuck on the guide rails.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding technology, and in particular to a guide rail structure and design method for the bulkhead of the fuel tank side cargo hold of a container ship. Background Technology

[0002] Large dual-fuel container ships typically have an LNG fuel storage tank midway through the hull, with cargo holds located on its sides. To facilitate container loading and unloading, vertically arranged guide rails are installed on the bulkheads. These guide rails are generally made of angle steel, arranged from top to bottom, with two angle steels on each side of the bulkhead arranged in pairs, facing each other within each pair, thus defining the movement path of the containers. Containers are lowered and lifted vertically under the constraint of these guide rails. The low temperature and high pressure of the LNG fuel tank cause deformation of the fore and aft cargo hold bulkheads adjacent to the LNG tank. This deformation is typically around 40-50 mm, forming a parabolic shape along the height of the bulkhead, bulging towards the cargo hold, with the maximum deformation usually occurring at the midpoint of the bulkhead height. This deformation of the cargo hold bulkheads naturally causes deformation of the guide rails, causing them to deform towards the container side, thus compressing the container and making it difficult to load or unload. Summary of the Invention

[0003] In view of this, the present invention provides a guide rail structure for the fore and aft cargo hold bulkheads of the LNG fuel tank of a container ship, in order to solve the problem in the prior art where the bulkheads of container ships deform after the fuel tanks are filled with fuel, causing the guide rails on the bulkheads to deform as well, resulting in the containers getting stuck on the guide rails.

[0004] A guide rail structure for a cargo hold bulkhead on the side of a container ship's fuel tank includes a cargo hold bulkhead located on the side of the fuel tank. Guide rails are vertically arranged on the bulkhead, each guide rail comprising a connecting plate fixedly mounted on the bulkhead and angle steel on the connecting plate. The connecting plate is arranged perpendicular to the bulkhead. The guide rails are arranged in pairs, with two angle steels in each pair arranged opposite each other to form an L-shaped track between the two angle steels. The guide rails are segmented, including a deformation zone corresponding to the center of the fuel tank and regular zones at other locations. Larger angle steels are installed in the deformation zone, and smaller angle steels are installed in the regular zones. A transition plate connects the large and small angle steels. The width of the connecting plate is equal to the sum of the widths of the corresponding angle steel limbs, ensuring that the sides of the angle steels furthest from the cargo hold bulkhead are arranged at equal heights.

[0005] Furthermore, the angle steel is an equilateral angle steel.

[0006] Furthermore, the bottom end of the large angle steel is 75-150 cm from the bottom of the cargo hold.

[0007] Furthermore, the top of the large angle steel is flush with the top of the fuel tank.

[0008] Furthermore, the transition plate is in the shape of a right trapezoid.

[0009] The beneficial effects of the guide rail structure for the cargo hold bulkhead on the fuel tank side of a container ship in this invention are as follows: The guide rail structure in this invention, by setting connecting plates and angle steel, easily forms a guide rail capable of limiting the container's position. Since the cargo hold bulkhead is susceptible to deformation, the use of connecting plates also avoids direct contact between the angle steel limbs and the bulkhead, reducing the risk of the guide rail structure detaching from the bulkhead during deformation. The use of angle steel to form the rail facilitates the limiting of the container. Distinguishing between the deformation zone and the normal zone allows for targeted design; the guide rail in the deformation zone deforms towards the container side, thus... To avoid contact between the guide rail and the container, and to increase the distance between the guide rail and the container side when it is not deformed, larger angle steel is used. To increase the distance between the angle steel and the container side wall, when using large angle steel, the size of the connecting plate is reduced, so that the side of the angle steel away from the cargo hold wall is arranged at the same height. Thus, after the fuel tank is filled with fuel, even after the guide rail deforms, there is still a sufficient gap between the guide rail and the container. This solves the problem in the existing technology where the container ship's bulkhead deforms after the fuel tank is filled with fuel, causing the guide rail on the bulkhead to deform and the container to get stuck on the guide rail.

[0010] A method for constructing guide rails for the cargo hold bulkhead of the fuel tank on a container ship includes: calculating the theoretical deformation value of the cargo hold bulkhead adjacent to the fuel tank based on the fuel tank dimensions and set fuel storage temperature and pressure values; selecting the specifications of the angle steel for the deformation zone based on the theoretical deformation value, wherein the leg width of the angle steel is not less than the sum of the theoretical deformation value and the leg width of the conventional angle steel; dividing the guide rail into a deformation zone corresponding to the center of the fuel tank and a conventional zone at other locations along the vertical extension direction of the cargo hold bulkhead; installing larger angle steel in the deformation zone and smaller angle steel in the conventional zone; installing a connecting plate between the angle steel and the cargo hold bulkhead, the width of the connecting plate being equal to the sum of the leg widths of the corresponding angle steel; and installing a transition plate between the large and small angle steels; finally, installing the guide rails according to the designed dimensions.

[0011] Furthermore, the bottom end of the large angle steel is 75-150 cm from the bottom of the cargo hold.

[0012] Furthermore, the top of the large angle steel is flush with the top of the fuel tank.

[0013] Furthermore, after the guide rail is installed, a trial lift is carried out before fuel is added to the fuel tank. After the lift test is completed, fuel is added to the fuel tank. After fuel is added, the actual deformation is measured. If the actual deformation is greater than the theoretical deformation, the connecting plate is corrected.

[0014] The beneficial effects of the guide rail construction method for the cargo hold bulkhead on the fuel tank side of a container ship in this invention are as follows: This invention facilitates the estimation of deformation by calculating theoretical deformation values, and the deformation of the guide rail is obtained based on the theoretical deformation, thus making it easy to determine the clearance distance. The use of angle steel to form the rail facilitates the restraint of the container. By distinguishing between the deformation zone and the normal zone, targeted design is possible. The guide rail in the deformation zone deforms towards the container side. To avoid contact between the guide rail and the container, the distance between this area and the container side when it is not deformed is increased by using larger-sized angle steel. To increase the distance between the angle steel and the container sidewall, when using large-sized angle steel, the size of the connecting plate is reduced, so that the side of the angle steel away from the cargo hold bulkhead is arranged at the same height. Therefore, after fuel is added to the fuel tank and the guide rail deforms, there is still sufficient clearance between the guide rail and the container. This solves the problem in the prior art where, due to the deformation of the bulkhead after fuel is added to the fuel tank, the guide rail on the bulkhead deforms accordingly, causing the container to get stuck on the guide rail. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the arrangement of the fuel tank and cargo hold in an embodiment of the guide rail structure of the cargo hold bulkhead on the fuel tank side of a container ship in this invention. Figure 2 This is a schematic diagram of the guide rail structure in an embodiment of the guide rail structure of the cargo hold bulkhead on the fuel tank side of a container ship in this invention. Figure 3 This is an enlarged schematic diagram of the guide rail structure in an embodiment of the guide rail structure of the cargo hold bulkhead on the fuel tank side of a container ship in this invention. Figure 4 This is an enlarged schematic diagram of the guide rail structure from another perspective in an embodiment of the guide rail structure of the cargo hold bulkhead on the fuel tank side of a container ship in this invention.

[0017] Figure 5 This is a schematic diagram showing the connection between the connecting plate and the angle steel of the guide rail structure of the cargo hold bulkhead on the fuel tank side of a container ship in this invention.

[0018] The labels in the diagram mean the following: 1. Fuel tank; 2. Cargo hold; 21. Cargo hold bulkhead; 22. Deformation zone; 31. Connecting plate; 32. Transition plate; 33. Small angle steel; 34. Large angle steel. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0020] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0021] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms and should not be construed as indicating or implying relative importance. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0022] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "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 invention 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 invention.

[0023] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0024] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.

[0025] To better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings.

[0026] In Embodiment 1 of the present invention, the guide rail structure (hereinafter referred to as the guide rail structure) of the cargo hold bulkhead on the fuel tank side of a container ship: like Figure 1 As shown, in this embodiment, the guide rail structure includes a cargo hold bulkhead 21 located on the side of the fuel tank 1. A guide rail is vertically arranged on the cargo hold bulkhead 21. The guide rail includes a connecting plate 31 fixedly mounted on the bulkhead and angle steel on the connecting plate 31. The angle steels are arranged in pairs, with the two angle steels in the same pair facing each other, thus forming a track capable of limiting the container's position. Since the guide rail is located near the fuel tank 1, after fuel is added to the fuel tank 1, the cargo hold bulkhead 21 will deform along with the fuel tank 1, with the deformation direction towards the interior space of the cargo hold 2. The angle steel includes two mutually perpendicular limbs, thus forming an L-shaped track. One limb is perpendicular to the cargo hold bulkhead 21 and is denoted as the guide side, while the other limb is parallel to the cargo hold bulkhead 21 and is denoted as the reference side. During the deformation of the cargo hold bulkhead 21, the reference side will deform towards the container. If the initial distance between the reference side and the container is too small, it will cause the reference side to contact the container after deformation, resulting in difficulty in loading and unloading the container.

[0027] like Figure 2 , Figure 3 and Figure 4As shown, in this embodiment, to address this issue, the guide rail is segmented, including a deformation zone 22 located at the center of fuel tank 1 and conventional zones on either side of the deformation zone 22. The deformation zone 22, being closer to the center of fuel tank 1, undergoes more deformation during deformation. The conventional zones, being farther from the center, experience only slight deformation or no deformation. Therefore, the reference edge of the deformation zone 22 needs to maintain a larger initial distance from the container, while the reference edge of the conventional zones can maintain a smaller initial distance. In this embodiment, a larger angle steel is used in the deformation zone 22, and a smaller angle steel is used in the conventional zones. The angle steel in the deformation zone 22 is designated as large angle steel 34, and the angle steel in the conventional zones is designated as small angle steel 33. Both large angle steel 34 and small angle steel 33 are equilateral angle steels with the same length of reference edge and guide edge. In this embodiment, large angle steel 34 uses L200*200*16 angle steel, and small angle steel 33 uses L150*150*15 angle steel. Furthermore, the deformation zone 22 needs to be positioned according to the location of the fuel tank 1. In this embodiment, the bottom of the deformation zone 22 is 1m away from the floor of the cargo hold 2, and the top of the deformation zone 22 is flush with the top of the fuel tank 1, making both the upper and lower sides of the deformation zone 22 conventional areas. These conventional areas on both sides allow the guide rail to match with other components; for example, using standard-sized angle steel at the lower end is necessary to cooperate with the stacking cone at the bottom of the cargo hold 2. Also, since this part does not involve significant deformation, using smaller angle steel saves material and reduces the weight of the guide rail structure. Through testing, on a certain ship type, the distance between the reference edge and the bulkhead was reduced from 171.5mm to 121.5mm. This means that even if deformation occurs, the increased distance between the reference edge and the container sidewall prevents contact.

[0028] like Figure 3 and Figure 5 As shown, in order to increase the distance between the reference edge of the large angle steel 34 and the container, the length of the connecting plate 31 is changed in this embodiment. Different connecting plates 31 are used for the deformation zone 22 and the regular zone. A smaller connecting plate 31 is used in the deformation zone 22, and a larger connecting plate 31 is used in the regular zone. Since the width of the guide edge differs by 50mm, the connecting plate 31 is used to make up for this length difference. That is, the width of the connecting plate 31 in the deformation zone 22 is 50mm smaller than that in the regular zone, thereby aligning the guide edges in the deformation zone 22 and the regular zone.

[0029] The guide edges of the large angle steel 34 and the small angle steel 33 are aligned with each other. Due to the difference in leg width, the distances between the reference edges of the large angle steel 34 and the small angle steel 33 and the cargo hold 2 wall are not the same. To achieve an effective connection between the large angle steel 34 and the small angle steel 33, a transition plate 32 is also provided between them. The transition plate 32 is a right-angled trapezoid, with its upper base aligned with the reference edge of the small angle steel 33 and its lower base aligned with the reference edge of the large angle steel 34. The connecting plate 31 corresponding to the transition plate 32 is also adaptively adjusted to provide an installation foundation for the large angle steel 34 and the small angle steel 33 respectively. It is worth noting that the connecting plate 31 can be arranged vertically or horizontally, serving as the installation foundation for the angle steel after arrangement. The transition plate 32 can be pre-trimmed into this right-angled trapezoidal shape before installation, or a rectangular plate can be placed between the large angle steel 34 and the small angle steel 33 first, and then the excess part can be cut off, such as... Figure 4 As shown in the shaded area.

[0030] In an embodiment of the method for constructing guide rails for the cargo hold bulkhead on the fuel tank side of a container ship (hereinafter referred to as the guide rail construction method) of the present invention: The final product constructed in this embodiment is the same as the guide rail in the above-mentioned guide rail structure. Specifically, during the construction process, the key points to focus on are the division of the deformation zone and the conventional zone, as well as the selection of the specifications of the large angle steel in the deformation zone.

[0031] Specifically, during the actual construction process, the theoretical deformation must first be determined. The theoretical deformation is calculated based on the temperature and pressure values ​​of the LNG tank and the hull structure. This calculation can be performed using analytical formulas of elasticity or finite element analysis (FEM), or other methods. This embodiment employs FEM, creating finite element models of the fuel tank and cargo tank in the software, and then applying pressure to conduct a simulation experiment. The specific method of FEM is a conventional technique and will not be elaborated upon here. It is worth noting that, to simplify the calculation, only the location of the maximum deformation is calculated, not the overall deformation of the cargo tank walls.

[0032] Next, the specifications of the large angle steel are selected based on the calculated theoretical deformation. When selecting, it is necessary to ensure that the size difference between the upper limbs of the large angle steel and the small angle steel is greater than the theoretical deformation, so that the container can maintain a certain distance from the reference edge when deformation occurs.

[0033] Next, installation is required. According to the guide rail structure layout diagram, the guide rail structure is installed on the cargo hold bulkhead. The installation must meet the requirements of lateral and longitudinal tolerances of -7 to +7 mm. Longitudinal tolerance refers to the allowable deviation in distance between guide rails on two bulkheads within the same cargo hold, while lateral tolerance is the allowable deviation in distance between two guide rails on the same bulkhead. Specifically, during installation, the connecting plate is first welded and fixed to the cargo hold bulkhead. The connecting plate is arranged laterally. Then, large and small angle steels are welded onto the connecting plate. It is worth noting that a single large angle steel can be used within the deformation zone, but for ease of hoisting and transportation, multiple large angle steels can be used, each welded to the connecting plate and assembled together to form the guide rail structure within the deformation zone.

[0034] After the guide rail structure is installed, a container hoisting test is conducted before refueling in the fuel tank. The container is hoisted into the cargo hold along the rails. At this point, the cargo hold does not deform, determining whether the container can be hoisted in normally. Then, refueling is performed. After refueling, the cargo hold walls deform, and this deformation is compared to the theoretical deformation. Since a margin is usually included in the calculation, the actual deformation is generally less than the theoretical deformation. Measuring the actual deformation aims to verify that the deformation of the cargo hold walls is within the theoretical deformation range. After refueling, another container hoisting test is conducted to verify whether the guide rail structure in this embodiment can meet the loading and unloading requirements of the container under deformation conditions. If any discrepancies are found, the connecting plates are locally modified. The verification method is relatively simple, requiring no special tools, only the container hoisting test.

[0035] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A guide rail structure for the bulkhead of the cargo hold on the side of the fuel tank of a container ship, characterized in that: The cargo hold bulkhead, located on the side of the fuel tank, has vertically arranged guide rails. Each guide rail includes a connecting plate fixed to the bulkhead and angle steel on the connecting plate. The connecting plate is perpendicular to the bulkhead. The guide rails are arranged in pairs, with two angle steels in each pair arranged opposite each other to form an L-shaped track between the two angle steels. The guide rails are segmented, including a deformation zone corresponding to the center of the fuel tank and regular zones at other locations. Larger angle steels are installed in the deformation zone, while smaller angle steels are installed in the regular zones. A transition plate connects the large and small angle steels. The width of the connecting plate is equal to the sum of the widths of the corresponding angle steel limbs, ensuring that the sides of the angle steels furthest from the cargo hold bulkhead are arranged at the same height.

2. The guide rail structure for the cargo hold bulkhead on the fuel tank side of a container ship according to claim 1, characterized in that: The angle steel is an equilateral angle steel.

3. The guide rail structure for the cargo hold bulkhead on the fuel tank side of a container ship according to claim 1 or 2, characterized in that: The bottom of the large angle steel is 75-150 cm from the bottom of the cargo hold.

4. The guide rail structure for the cargo hold bulkhead on the fuel tank side of a container ship according to claim 3, characterized in that: The top of the large angle steel is flush with the top of the fuel tank.

5. The guide rail structure for the cargo hold bulkhead on the fuel tank side of a container ship according to claim 1 or 2, characterized in that: The transition plate is in the shape of a right trapezoid.

6. A method for constructing guide rails for the bulkhead of the cargo hold on the side of the fuel tank of a container ship, characterized in that: Calculate the theoretical deformation value of the cargo hold wall adjacent to the fuel tank based on the size of the fuel tank and the set fuel storage temperature and pressure values. Select the specifications of the angle steel in the deformation zone based on the theoretical deformation value. The leg width of the angle steel shall not be less than the sum of the theoretical deformation value and the leg width of the conventional angle steel. The guide rail is divided into a deformation zone corresponding to the center of the fuel tank and a regular zone along the vertical extension direction of the cargo hold wall. Larger angle steels are installed in the deformation zone, and smaller angle steels are installed in the regular zone. A connecting plate is installed between the angle steels and the cargo hold side wall, and the width of the connecting plate is equal to the sum of the widths of the corresponding angle steels. A transition plate is installed between the large and small angle steels. Finally, the guide rail is installed according to the designed dimensions.

7. The method for constructing guide rails for the cargo hold bulkhead on the fuel tank side of a container ship according to claim 5, characterized in that: The bottom of the large angle steel is 75-150 cm from the bottom of the cargo hold.

8. The method for constructing guide rails for the cargo hold bulkhead on the fuel tank side of a container ship according to claim 6, characterized in that: The top of the large angle steel is flush with the top of the fuel tank.

9. The method for constructing guide rails for the cargo hold bulkhead on the fuel tank side of a container ship according to any one of claims 5-7, characterized in that: After the guide rail is installed, a trial lift is carried out before fuel is added to the fuel tank. After the lift test is completed, fuel is added to the fuel tank. After fuel is added, the actual deformation is measured. If the actual deformation is greater than the theoretical deformation, the connecting plate is corrected.

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