A liquefied gas carrier

Abstract

The application provides a liquefied gas ship, comprising: a ship shell comprising a ship side plate; a liquid cargo tank arranged in the ship shell, and a contraction area being arranged between the liquid cargo tank and the ship shell in a ship width direction, the distance between the side surface of the two ends of the liquid cargo tank in the ship width direction and the ship side plate being 0.2-0.3 times the distance from the ship side plate to the ship centerline in the longitudinal direction; a fuel supply tank arranged in the contraction area, and an isolation tank arranged between the fuel supply tank and the liquid cargo tank, and a cargo filling tank arranged at the top of the fuel supply tank, the cargo filling tank being arranged below the main deck plane. The arrangement of the liquefied gas ship effectively utilizes the ship space.

Description

Technical Field

[0001] This invention relates to the field of ship design, and in particular to a liquefied gas carrier. Background Technology

[0002] In the design of liquefied gas carriers, multiple cargo tanks are often arranged in parallel to reduce stability risks by increasing the number of tanks. However, this also increases costs and fuel consumption. At the same time, in order to meet the requirements of low-carbon power, existing ships sometimes need to be equipped with additional independent fuel tanks, further encroaching on cargo space.

[0003] Driven by both the global shipping industry's low-carbon transformation and the growth of energy trade, increasing the cargo capacity of liquefied gas carriers has become a core trend in the industry's development. The demand for low-carbon power using clean fuels is also increasing. How to effectively utilize hull space and increase cargo capacity while setting up fuel tanks, and at the same time achieve the goal of being as lightweight and cost-effective as possible, has become an urgent problem to be solved in this field. Summary of the Invention

[0004] In view of the shortcomings of the aforementioned related technologies, the purpose of this invention is to provide a liquefied gas carrier to solve the above problems.

[0005] To achieve the above and other related objectives, the present invention provides a liquefied gas carrier, comprising: a ship hull, including side plates; a cargo tank disposed within the ship hull, wherein the cargo tank has a contraction zone between itself and the ship hull in the width direction, and the distance between the sides of the cargo tank at both ends in the width direction and the side plates is 0.2-0.3 times the distance from the side plates to the longitudinal centerline of the ship; a fuel supply tank disposed in the contraction zone, wherein an isolation compartment is provided between the fuel supply tank and the cargo tank, and a cargo bunkering tank is provided on top of the fuel supply tank, wherein the cargo bunkering tank is configured to be lower than the main deck plane.

[0006] Optionally, the liquid cargo tank includes a perimeter structure, an internal structure, and a sway-damping bulkhead. The perimeter structure contains a liquid cargo loading space, the internal structure is located within the perimeter structure, and the sway-damping bulkhead is located within the liquid cargo loading space to reduce the impact force of liquid cargo swaying.

[0007] Optionally, the perimeter structure includes a bottom plate, a top plate, side plates, a front wall, and a rear wall, wherein the bottom plate, the top plate, the two side plates, the front wall, and the rear wall enclose a liquid cargo loading space.

[0008] Optionally, the perimeter structure includes an air chamber and a liquid collection well. The air chamber is located on the top plate and is used to balance the pressure in the chamber. The liquid collection well is located on the bottom plate and is used to collect and gather residual liquid, leaked liquid, or sewage that is difficult to drain from the chamber.

[0009] Optionally, the internal structure includes a central longitudinal wall, a transverse frame, and a horizontal truss. The central longitudinal wall is arranged along the length of the liquid cargo tank and is connected to the top plate and the bottom plate to divide the liquid cargo loading space into two compartments. The periphery of the transverse frame is connected to the bottom plate, the top plate, the side plates, and the central longitudinal wall, respectively. The horizontal truss is arranged horizontally and its two sides are connected to the side plates and the central longitudinal wall, respectively.

[0010] Optionally, the upper half of the sway-controlling bulkhead is a hollow structure, and the lower half of the sway-controlling bulkhead is a plate structure with multiple spaced holes.

[0011] Optionally, the cargo tank includes a cross brace, the two ends of which are respectively connected to the side plate and the central longitudinal wall.

[0012] Optionally, the cargo tank includes a cross brace, the two ends of which are respectively connected to the horizontal girder and the central longitudinal wall.

[0013] Optionally, a gusset structure is provided between the cross brace and the horizontal truss, and the cross-sectional area of ​​the end of the cross brace that connects to the central longitudinal wall is larger than the cross-sectional area of ​​the middle part of the cross brace.

[0014] Optionally, the interior of the isolation chamber is lined with impact-resistant and fire-resistant material, the thickness of which is not less than 10mm.

[0015] As described above, the liquefied gas carrier of the present invention has the following beneficial effects: The present invention provides a contraction area in the width direction of the liquid cargo tank at the bow / stern to accommodate the fuel supply tank, and at the same time, an isolation compartment is provided between the liquid cargo tank and the fuel supply tank. The present invention effectively utilizes the space of the hull, realizes the coordinated arrangement of the fuel supply tank and the liquid cargo tank, and reduces the ship's operating costs. Attached Figure Description

[0016] Figure 1 The image shown is a front view of the liquid cargo tank in an embodiment of the present invention.

[0017] Figure 2 The diagram shown is a side view of the liquid cargo tank in an embodiment of the present invention.

[0018] Figure 3 The diagram shown is a schematic representation of the horizontal frame in an embodiment of the present invention.

[0019] Figure 4 The diagram shown is a schematic representation of the horizontal truss in an embodiment of the present invention.

[0020] Figure 5 The diagram shown is a schematic representation of the oscillation control bulkhead in an embodiment of the present invention.

[0021] Figure 6 The diagram shown is a schematic representation of the cross brace in an embodiment of the present invention.

[0022] Figure 7 The image shown is a front view schematic diagram of an LPG carrier in an embodiment of the present invention.

[0023] Figure 8 The image shown is a top view of an LPG carrier as described in an embodiment of the present invention.

[0024] Figure 9 The image shown is a side view of an LPG carrier as described in an embodiment of the present invention.

[0025] Component designation explanation

[0026] 1. Cargo tank; 101. Bottom plate; 102. Top plate; 103. Side plate; 104. Forward bulkhead; 105. Aft bulkhead; 106. Gas chamber; 107. Liquid collection well; 110. Mid-longitudinal bulkhead; 111. Transverse frame; 112. Horizontal girder; 121. Anti-sway bulkhead; 122. Cross brace; 2. Hull; 21. Cavity; 3. Fuel supply tank; 4. Separation compartment; 5. Cargo bunkering tank. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0028] In the detailed description of embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0029] For ease of description, spatial relation terms such as “below,” “under,” “lower than,” “below,” “above,” and “upper” may be used herein to describe the relationship between one element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the drawings for the device in use or operation. Furthermore, when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or there may be one or more layers in between. The phrase “between” as used herein includes both endpoint values.

[0030] In the context of this application, the structure described above the first feature may include embodiments in which the first and second features are formed in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0031] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0032] like Figure 1 As shown, this embodiment provides an independent liquid cargo tank 1, which includes a perimeter structure, an internal structure, a sloshing-damping bulkhead 121, and cross bracing 122. The perimeter structure includes a bottom plate 101, a top plate 102, side plates 103, a front wall 104, a rear wall 105, a gas chamber 106, and a collection well 107. The bottom plate 101, top plate 102, two side plates 103, front wall 104, and rear wall 105 form the shell of the liquid cargo tank 1, and the interior of the shell is the liquid cargo loading space. It is understood that the plates are selected from materials with good low-temperature toughness, such as 9-nickel steel or austenitic stainless steel, according to the temperature characteristics of the liquid cargo being loaded. The plate thickness is determined after strength verification based on the tank capacity, design pressure, and specification requirements.

[0033] Gas chamber 106 is located on top plate 102, typically in the highest area of ​​top plate 102. Its function is to collect gases generated by the evaporation of liquid cargo and to balance the pressure inside the tank by connecting to external systems, preventing the risk of overpressure. Liquid collection well 107 is located on bottom plate 101. Liquid collection well 107 is used to collect and gather residual liquid, leaked liquid, or sewage that is difficult to drain from the tank.

[0034] The internal structure serves to enhance the overall rigidity and load-bearing capacity of the cargo tank 1, ensuring that the tank does not become unstable or excessively deformed under internal liquid pressure and hull motion loads. The internal structure includes a central longitudinal wall 110, transverse frames 111, and horizontal girders 112. The central longitudinal wall 110 is a vertical wall extending along the length of the cargo tank 1, located at the midpoint of its width. The top of the central longitudinal wall 110 connects to the top plate 102, and the bottom connects to the bottom plate 101. The central longitudinal wall 110 divides the cargo loading space of the cargo tank 1 into two compartments, left and right. It is understood that the central longitudinal wall 110 itself is a plate frame structure, with horizontal and vertical stiffeners that can be arranged on the plate as needed.

[0035] The transverse frame 111 is a circumferential frame structure installed within the cargo tank 1. Through its own structure, it can transmit forces, effectively resisting external forces and preventing deformation or damage to the cargo tank structure. Multiple transverse frames 111 can be installed, spaced apart along the length of the cargo tank 1. The periphery of each transverse frame 111 is connected to the bottom plate 101, top plate 102, side plates 103, and central longitudinal wall 110. The transverse frame 111 adopts a plate frame form with a high proportion of openings. The openings are mostly oval or round, and the opening ratio is optimized according to the stress requirements, sufficient to resist lateral loads while reducing its own weight.

[0036] The horizontal girder 112 is a horizontal component set along the length of the ship. It can be divided into the top horizontal girder 112 and the bottom horizontal girder 112, which are located at a certain height below the top plate 102 and above the bottom plate 101, respectively. Its two ends are connected to the side plate 103 and the central longitudinal wall 110. It is used to bear the longitudinal bending moment and prevent the side plate 103 from bulging outward or inward.

[0037] The anti-sloshing bulkhead 121 is a plate-frame structure. Its two sides are connected to the side plates 103 and the central longitudinal wall 110, respectively. The upper half of the anti-sloshing bulkhead 121 is a perforated structure, while the lower half is a plate structure with multiple holes. These holes can be circular, oblong, or rectangular, and are distributed in a specific arrangement. When the liquid tank is not full, the liquid inside will slosh violently with the ship's movements (such as rolling and pitching). This sloshing generates enormous impact forces, which may damage the bulkhead structure or cause hull stability fluctuations in severe cases. The anti-sloshing bulkhead 121 modulates the inherent sloshing frequency of the liquid inside the tank by changing the effective width of the free surface and the fluid movement path, causing it to avoid the main energy frequency band of the ship's movement and preventing harmful resonance. Simultaneously, the openings on the bulkhead generate eddies and friction during liquid flow, gradually dissipating the kinetic energy of the liquid movement and reducing the impact force to a level that the structure can withstand.

[0038] The horizontal brace 122 is horizontally positioned, with its two sides connected to the side plate 103 and the central longitudinal wall 110, respectively. The horizontal brace 122 can be in the form of a tubular strut, box girder, or perforated plate frame, with its axis generally horizontal. One connection method is to weld both ends of the horizontal brace 122 to the side plate 103 and the central longitudinal wall 110, respectively; another connection method is to weld one end of the horizontal brace 122 to the horizontal girder 112 and the other end to the central longitudinal wall 110. The horizontal brace 122 can also be located above the horizontal girder 112, with a height of 1100mm-1500mm. The number of horizontal braces 122 is determined by the tank capacity and calculated load, but there must be at least one horizontal brace 122. When there is only one horizontal brace 122, it is located in the middle of the height direction of the cargo tank 1. When the dimensions of the cabin are large, two or more horizontal braces 122 can be installed along the height direction to ensure that the side plate 103 does not experience elastic instability under full load and partial load conditions.

[0039] As the size of the cabin changes, the number and arrangement of the sway-controlling bulkheads 121 and cross braces 122 can be changed accordingly to meet the requirements for sway control and structural strength.

[0040] To avoid excessive local stress, a burr structure is provided between the cross brace 122 and the horizontal truss 112 when both ends of the cross brace 122 are connected to the horizontal truss 112 and the central longitudinal wall 110, respectively. The burr structure can be understood as similar to a reinforcing rib, and its dimensions in the height direction of the cargo tank 1 are 15mm-50mm. The cross-sectional area of ​​the end of the cross brace 122 connected to the central longitudinal wall 110 is larger than the cross-sectional area of ​​the middle part of the cross brace 122.

[0041] To support the cargo tank 1, a support structure is installed on its exterior. This support structure is segmented along the ship's length and is welded and fixed to the bottom plate 101, top plate 102, and side plate 103 of the cargo tank 1, forming an integrated vertical load-bearing frame. This frame effectively withstands the static pressure of the cargo, the dynamic load of the cargo sloshing, and the overall longitudinal bending moment of the hull, thus improving the overall load-bearing capacity and safety of the cargo tank 1 structure. The support structure includes a first frame and a second frame. The first frame is a high-percentage, open-hole structural frame used to provide rigid, weak support. Its opening size and cross-sectional area account for no less than 80%, significantly reducing the structural weight while ensuring basic structural rigidity, achieving a lightweight design.

[0042] The second frame is divided into two types. The first type is used to provide strong rigidity support, and its opening size and cross-sectional area ratio are not less than 50%. This frame is divided into a lower support surface and an upper support surface. The lower support surface can effectively resist the impact load generated by the sloshing of liquid cargo, while the upper support surface further reduces the structural weight by optimizing the opening design, taking into account both load-bearing performance and lightweight requirements. The second type is used to provide strong rigidity support, and its opening size, lower support surface, and upper support surface cross-sectional area ratio are all not less than 80%. This frame is divided into a lower support surface and an upper support surface, which can effectively hold and constrain the bottom plate 101, outer plate, and side plate 103 structure, ensuring the overall structural rigidity of the liquid tank, suppressing structural deformation, and improving the structural stability and reliability of the liquid cargo tank 1.

[0043] This embodiment also discloses a liquefied gas carrier employing the aforementioned cargo tank 1. The liquefied gas carrier includes the cargo tank 1, the hull 2, and the fuel supply tank 3. The hull 2 ​​includes side plates. The lateral dimensions of the cargo tank 1 are arranged along the width direction of the ship, and the distance between the bow / stern sides of the cargo tank 1 and the side plates is 0.2-0.3 times the distance from the side plates to the longitudinal centerline of the ship.

[0044] The fuel supply tank 3 is located in the area between the liquid cargo tank 1 and the ship's outer shell 2 after the liquid cargo tank 1 is laterally retracted. A fireproof and explosion-proof isolation compartment 4 is provided between the fuel supply tank 3 and the liquid cargo tank 1. The interior of the isolation compartment 4 is lined with impact-resistant and fireproof material with a thickness of not less than 10mm.

[0045] When multiple liquid cargo tanks 1 are arranged, each liquid cargo tank 1 is arranged sequentially at intervals along the longitudinal direction of the ship. The lateral coverage of adjacent liquid cargo tanks 1 does not overlap with each other, and each liquid cargo tank 1 has a corresponding fuel tank in its lateral contraction area. An independent fireproof isolation compartment 4 is set between adjacent fuel tanks.

[0046] Fuel supply tank 3 is equipped with fuel delivery pipelines and a liquid level monitoring device. The pipelines are made of oil-resistant and corrosion-resistant materials, and the liquid level monitoring device is electrically connected to the ship's central control system.

[0047] A cargo refueling tank 5 is located atop the fuel supply tank 3, and this cargo refueling tank 5 is below the main deck level. Multiple cargo pipes are installed inside the cargo refueling tank 5, and all bulkheads of the cargo refueling tank 5 are composed of cryogenic steel. The cargo refueling tank 5 has outward-facing openings.

[0048] In order to orderly reduce the maximum bending moment and shear force of the ship, while ensuring the required ballast water volume and the orderly controllability of the maximum bending moment, stepped concave cavities 21 are provided at the top of the bow and stern ends of the hull 2.

[0049] The novel structural design of the large-scale cargo tank 1 in this embodiment achieves a continuous distribution of longitudinal and transverse structures within a single, independent tank space, thus fulfilling the three core requirements of "maximizing tank capacity, coordinating with fuel tanks, and ensuring tank stability in case of damage." Furthermore, by replacing some of the sloshing-damping bulkheads 121 in the relatively long, independent cargo tank 1 with transverse braces 122, the transverse braces 122, in conjunction with the retained sloshing-damping bulkheads 121, effectively reduce the sloshing impact of the liquid. They also connect the sidewalls of the cargo tank 1, reducing deformation of the sidewalls during loading and ensuring the structural stability of the cargo tank 1 and the navigational stability of the ship. Moreover, the transverse brace 122 structure is lighter than the traditional sloshing-damping bulkhead 121, reducing the number of components and the overall weight of the cargo tank 1, thereby saving on shipbuilding costs.

[0050] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A liquefied gas carrier, characterized in that, include: The hull of a ship, including the outer plating on the sides; The liquid cargo tank is located inside the hull of the ship, and the liquid cargo tank has a contraction area between itself and the hull in the width direction. The distance between the sides of the liquid cargo tank at both ends of the bow and stern and the outer plating of the ship's side is 0.2-0.3 times the distance from the outer plating of the ship's side to the longitudinal centerline of the ship. A fuel supply tank is located in the contraction zone, and an isolation compartment is provided between the fuel supply tank and the liquid cargo tank. A cargo refueling tank is provided on the top of the fuel supply tank, and the cargo refueling tank is configured to be lower than the main deck plane.

2. The liquefied gas carrier according to claim 1, characterized in that: The liquid cargo tank includes a perimeter structure, an internal structure, and a sloshing-damping bulkhead. The perimeter structure contains a liquid cargo loading space, the internal structure is located within the perimeter structure, and the sloshing-damping bulkhead is located within the liquid cargo loading space to reduce the impact force of liquid cargo sloshing.

3. The liquefied gas carrier according to claim 2, characterized in that: The perimeter structure includes a bottom plate, a top plate, side plates, a front wall, and a rear wall, which together form a liquid cargo loading space.

4. The liquefied gas carrier according to claim 3, characterized in that: The perimeter structure includes an air chamber and a liquid collection well. The air chamber is located on the top plate and is used to balance the pressure of the chamber. The liquid collection well is located on the bottom plate and is used to collect and gather residual liquid, leaked liquid, or sewage that is difficult to drain from the chamber.

5. The liquefied gas carrier according to claim 3, characterized in that: The internal structure includes a central longitudinal wall, a transverse frame, and a horizontal truss. The central longitudinal wall is arranged along the length of the liquid cargo tank and is connected to the top plate and the bottom plate to divide the liquid cargo loading space into two compartments. The periphery of the transverse frame is connected to the bottom plate, the top plate, the side plates, and the central longitudinal wall, respectively. The horizontal truss is arranged horizontally and its two sides are connected to the side plates and the central longitudinal wall, respectively.

6. The liquefied gas carrier according to claim 2, characterized in that: The upper half of the sway-controlling chamber wall has a hollow structure, while the lower half of the sway-controlling chamber wall has a plate structure with multiple spaced holes.

7. The liquefied gas carrier according to claim 5, characterized in that: The liquid cargo tank includes a cross brace, the two ends of which are connected to the side plate and the central longitudinal wall, respectively.

8. The liquefied gas carrier according to claim 5, characterized in that: The cargo tank includes a cross brace, the two ends of which are connected to the horizontal girder and the central longitudinal wall, respectively.

9. The liquefied gas carrier according to claim 8, characterized in that: A gusset structure is provided between the cross brace and the horizontal truss, and the cross-sectional area of ​​the end of the cross brace that connects to the middle longitudinal wall is greater than the cross-sectional area of ​​the middle part of the cross brace.

10. The liquefied gas carrier according to claim 1, characterized in that: The interior of the isolation chamber is lined with impact-resistant and fireproof material, and the thickness of the fireproof material is not less than 10mm.

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