A gas-liquid combined dome structure for a type B LNG fuel tank of a dual-fuel ultra-large container ship

Abstract

The present invention discloses a gas-liquid combined dome structure for a B-type LNG fuel tank of a dual-fuel ultra-large container ship, wherein the gas-liquid combined dome structure is located at a position above the top of the B-type LNG fuel tank, in the center and close to the stern end, and its main peripheral structure includes a surrounding wall (2) and a top cover plate (3), and has a horizontally arranged through-tank interlayer (4) and a vertical passage shaft wall (5) inside, and these main structures are welded to the top plate (1) of the B-type LNG fuel tank, and the whole is located above the cross-shaped strong structure composed of the longitudinal girder and the transverse strong frame at the top of the B-type LNG fuel tank. The gas-liquid combined dome structure provided by the present invention realizes the layout requirements of all through-tank pipes and the inspection and passage requirements of personnel and equipment in the LNG fuel tank within a limited space, and minimizes the redundant structure while ensuring the strength of the dome structure itself, and has a very large practical value.

Description

Technical Field

[0001] The present invention relates to the field of ship design, and in particular to a gas-liquid combined dome structure of a B-type LNG fuel tank for a dual-fuel ultra-large container ship. Background Art

[0002] The liquid cargo tanks of conventional large LNG carriers usually have a large single-tank capacity and a large size. Due to the relevant requirements of the IGC specifications, it is usually necessary to set up an air dome and a liquid dome. Considering that the ship has more stern trim states, the air dome is usually set at the front end of the tank, and the liquid dome is set at the rear end of the tank. Type B LNG fuel tanks usually have a much smaller capacity than the liquid cargo tanks of large LNG carriers, and their size is also relatively small. In addition, the LNG fuel tanks of container ships are usually arranged under the island in the superstructure. Due to the limited space layout, it is not convenient to arrange another air dome at the front end of the tank. Moreover, since the length of the fuel tank is not too long, the influence of the tilt angle caused by the stern trim is limited. In order to meet the relevant requirements of the IGC specifications, the air dome can be considered to be moved back to a position similar to that of the liquid dome. Therefore, the concept of a combined air-liquid dome structure was born.

[0003] Because the Type B cabin is an independent cabin, the overall layout and structural type of the combined dome need to be comprehensively considered in combination with the structural type of the Type B cabin itself and the structural type of the surrounding hull. After the gas dome and the liquid dome are combined into one, there are a large number of through-cabin pipes and fittings inside. At the same time, the layout of personnel and equipment maintenance passages must also be considered. Therefore, how to reasonably arrange and design the structure in a limited space is a challenging key technology. Summary of the Invention

[0004] The purpose of this invention is to design a combined gas-liquid dome structure for a Type B LNG fuel tank on a dual-fuel ultra-large container ship, taking into account multiple factors within the current technological landscape. This structure is designed to meet maintenance requirements within a limited space, reduce redundant structures, and improve construction efficiency.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A gas-liquid composite dome structure for a Type B LNG fuel tank on a dual-fuel ultra-large container ship is located in the center of the top of the Type B LNG fuel tank, near the stern. Its main peripheral structure includes a perimeter wall and a roof plate, and its interior includes a horizontally arranged through-tank interlayer and a vertical passageway wall structure. This main structure is welded to the Type B LNG fuel tank roof plate and sits above a cross-shaped strong structure consisting of a central longitudinal girder and transverse strong frames at the top of the Type B LNG fuel tank. The gas-liquid composite dome structure is constructed entirely of 9Ni steel, providing excellent cryogenic performance.

[0007] Preferably, the enclosure wall is square, with all four corners chamfered to effectively prevent stress concentration in the welds and reduce the risk of cracking. Brackets are provided on the front and rear end walls of the enclosure wall, on the opposite side of the Type B LNG fuel tank roof, for reverse reinforcement. The end walls of the enclosure wall align perfectly with the longitudinal ribs on the top of the Type B LNG fuel tank. Vertical reinforcement ribs are provided on both the enclosure wall and the passageway wall. The ends of the vertical reinforcement ribs on the enclosure wall are bracketed, while the ends of the vertical reinforcement ribs on the passageway wall are beveled, thereby enhancing the load-bearing capacity of the enclosure wall and the passageway wall.

[0008] Preferably, the top cover plate is larger than the range of the surrounding wall as a whole, and the four corners of the edge are also arc chamfered. The top cover plate is provided with a manhole and a hanging port composite hatch and a hatch cover at the position of the channel wall, which is convenient for personnel maintenance and replacement of equipment such as pumps. The edge of the top cover plate is a drooping annular T-row structure, which is convenient for installing a fixed sealing ring between the hull structure.

[0009] Preferably, the cabin-penetrating interlayer is located within a certain range below the top cover plate, and the specific height can be adjusted according to the actual situation. The cabin-penetrating interlayer and the top cover plate are provided with a number of horizontal reinforcing ribs, the ends of which are in the form of elbow plates, which can enhance the bearing capacity of the cabin-penetrating interlayer and the top cover plate.

[0010] The top cover plate and the through-tank interlayer are provided with a variety of pipe holes of different sizes, wherein the pipe holes of different sizes include gas pipe holes, spray pipe holes, bottom injection pipe holes, top injection pipe holes, BOG discharge pipe holes, BOG emergency discharge pipe holes, 0% sampling pipe holes, 50% sampling pipe holes, 100% sampling pipe holes, safety valve discharge pipe holes and instrument pipe holes.

[0011] Preferably, the 0% sampling tube hole, the 50% sampling tube hole and the 100% sampling tube hole among the tube holes are combined into one large hole on the top cover plate.

[0012] Based on the above technical solution, the gas-liquid combined dome structure of the present invention has achieved the following positive and beneficial effects through practical application:

[0013] The gas-liquid combined dome structure provided by the present invention makes it possible to meet the layout requirements of all through-tank pipes and the maintenance and access requirements of personnel and equipment in the LNG fuel tank within a limited space, while ensuring the strength of the dome structure itself while minimizing redundant structures. The special design of the edge of the top cover plate of the dome structure makes it easy to install a fixed sealing ring between it and the hull structure to ensure elastic sealing and avoid the risk of ultra-low temperature gas leakage from here, which has very great practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1The diagram is a longitudinal layout diagram of a gas-liquid combined dome structure of a Type B LNG fuel tank for a dual-fuel ultra-large container ship according to the present invention.

[0015] Figure 2 The present invention is a schematic diagram of the transverse arrangement of a gas-liquid combined dome structure of a Type B LNG fuel tank for a dual-fuel ultra-large container ship.

[0016] Figure 3 This is a diagram of the roof of a Type B LNG fuel tank in the area where the present invention is applied.

[0017] Figure 4 For the present invention Figure 3 The "AA" view.

[0018] Figure 5 For the present invention Figure 4 “A1-A1” direction view.

[0019] Figure 6 For the present invention Figure 3 "BB" direction view.

[0020] Figure 7 For the present invention Figure 6 "B1-B1" view.

[0021] Figure 8 For the present invention Figure 3 "CC" direction view.

[0022] Figure 9 For the present invention Figure 3 "DD" direction view.

[0023] Figure 10 For the present invention Figure 9 The "D1-D1" view of

[0024] Figure 11 For the present invention Figure 3 EE view of the .

[0025] Figure 12 For the present invention Figure 3 FF view of the .

[0026] Figure 13 For the present invention Figure 8 "GG" direction view.

[0027] Figure 14 For the present invention Figure 13 The "G1-G1" view.

[0028] Figure 15 For the present invention Figure 8 "HH" direction view.

[0029] The specific meanings of the numbers in the figure are: 1 is the top plate of Type B LNG fuel tank, 2 is the surrounding wall, 3 is the top cover plate, 4 is the through-tank interlayer, 5 is the passage wall, 6 is the drooping annular T-row structure, 7 is the vertical reinforcement rib, 8 is the horizontal reinforcement rib, 9 is the manhole and hanging port composite hatch and hatch cover, P is the gas pipe hole, L is the spray pipe hole, E1 is the bottom injection pipe hole, E2 is the top injection pipe hole, Z1 is the BOG discharge pipe hole, Z2 is the BOG emergency discharge pipe hole, N1 is the 0% sampling pipe hole, N2 is the 50% sampling pipe hole, K is the 100% sampling pipe hole, J is the safety valve discharge pipe hole, and R is the instrument pipe hole. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions and advantages of the present invention more clear, embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0031] It should be clear that the embodiments described are only part of the embodiments of the present invention and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] For the newly designed dual-fuel ultra-large container ship with B-type LNG fuel tank, the LNG fuel tank N is located below the superstructure area of ​​the ultra-large container ship's mid-island and below the main deck K. The LNG fuel tank N adopts a B-type independent tank body. The LNG fuel tank is full-width and its length is the length of the superstructure area plus half the length of the cargo hold, that is, the length of the LNG fuel tank N is approximately the length of the superstructure plus the length of one bay. The height of the LNG fuel tank is the distance from the inner bottom plate of the ship to the isolated empty space below the second deck. The hull inner shell on both sides of the fuel tank area on the dual-fuel ultra-large container ship adopts a large slope type. The bottom sides of the B-type LNG fuel tank also adopt a large slope type parallel to the hull inner shell on both sides. Various types of supports are provided between the LNG fuel tank N and the hull inner shell.

[0033] like Figure 1 and Figure 2 As shown, the fuel tank area of ​​the dual-fuel ultra-large container ship is also equipped with a gas-liquid combined dome M, an LNG storage and conversion transition room, a gas preparation room, an isolation chamber, and an LNG filling station. The gas-liquid combined dome M is installed on the top of the LNG fuel tank N near the aft end. The gas-liquid combined dome is located in the center of the cross-section of the LNG fuel tank N. The gas-liquid combined dome M extends through the isolation chamber into the LNG storage and conversion transition room. The LNG storage and conversion transition room is located directly above the gas-liquid combined dome.

[0034] like Figure 3-Figure 15As shown in FIG. 1 , the gas-liquid combined dome structure of the present invention is located at the center of the top of the B-type LNG fuel tank near the stern end. Its main peripheral structure includes a surrounding wall 2 and a top cover plate 3. Inside, there are horizontally arranged through-tank interlayers 4 and vertical passage shaft walls 5. These main structures are welded to the top plate 1 of the B-type LNG fuel tank. The whole structure is located above the cross-shaped strong structure composed of the longitudinal girder and the transverse strong frame at the top of the B-type LNG fuel tank, as shown in FIG. Figure 3 、 Figure 8 and Figure 11 All materials of the gas-liquid combined dome structure are 9Ni steel, which has excellent ultra-low temperature performance.

[0035] like Figure 9 、 Figure 10 and Figure 12 As shown, the enclosure wall 2 is made into a square shape as a whole, and the four corners are made into arc chamfers, which can effectively prevent stress concentration in the weld and reduce the risk of cracks. The front and rear end walls of the enclosure wall 2 are provided with brackets on the reverse side of the top plate of the B-type LNG fuel tank to strengthen the reverse side. The positions of the end walls on both sides of the enclosure wall 2 are just aligned with the longitudinal bones on the top of the B-type LNG fuel tank, as shown in FIG. Figure 4-Figure 7 The surrounding wall 2 and the passage wall 5 are both provided with vertical reinforcing ribs 7, wherein the ends of the vertical reinforcing ribs 7 on the surrounding wall 2 are made into toggle-type, while the ends of the vertical reinforcing ribs 7 on the passage wall 5 are made into bevel-type, which can enhance the bearing capacity of the surrounding wall 2 and the passage wall 5.

[0036] The top cover plate 3 is larger than the range of the surrounding wall 2 as a whole, and the four corners of the edge are also in the form of arc chamfers. The top cover plate 3 is provided with a manhole and a hanging port composite hatch and a hatch cover 9 at the position of the channel well wall 5, which is convenient for personnel maintenance and replacement of equipment such as pumps. The edge of the top cover plate 3 is a drooping annular T-row structure 6, which is convenient for installing a fixed sealing ring between the hull components, such as Figure 13 and Figure 14 shown.

[0037] The through-cabin interlayer 4 is located within a certain range below the top cover plate 3, and the specific height can be adjusted according to the actual situation. The through-cabin interlayer 4 and the top cover plate 3 are both provided with a number of horizontal reinforcing ribs 8, the ends of which are all in the form of brackets, which can enhance the load-bearing capacity of the through-cabin interlayer 4 and the top cover plate 3. Figure 13 、 Figure 14 and Figure 15 shown.

[0038] The top cover plate 3 and the through-tank interlayer 4 are both provided with a variety of pipe holes of varying sizes. These include a gas pipe hole P, a spray pipe hole L, a bottom injection pipe hole E1, a top injection pipe hole E2, a BOG discharge pipe hole Z1, a BOG emergency discharge pipe hole Z2, a 0% sampling pipe hole N1, a 50% sampling pipe hole N2, a 100% sampling pipe hole K, a safety valve discharge pipe hole J, and an instrument pipe hole R. The 0% sampling pipe hole N1, the 50% sampling pipe hole N2, and the 100% sampling pipe hole K are combined into one large hole on the top cover plate 3, as shown in FIG. Figure 8 and Figure 9 shown.

[0039] The installation process of the gas-liquid combined dome structure of the B-type LNG fuel tank for a dual-fuel ultra-large container ship of the present invention is roughly as follows:

[0040] The gas-liquid composite dome structure is constructed independently from the Type B fuel tank, utilizing a reverse-engineering method to ensure precise alignment with the Type B fuel tank. First, the hatch openings and all penetrations are cut in the corresponding locations on the top cover plate 3 and the through-tank interlayer 4. The enclosure wall 2 and the passageway wall 5 are then welded and installed on the machined top cover plate 3 using reverse-engineering welding. Next, all horizontal reinforcements 8 are installed on the top cover plate 3, followed by the through-tank interlayer 4 and its horizontal reinforcements 8. Finally, vertical reinforcements 7 are installed on the enclosure wall 2 and the passageway wall 5. Finally, the pendulous annular T-shaped structure 6 is installed at the edge of the top cover plate 3. This completes the construction of the gas-liquid composite dome module.

[0041] The reverse reinforcing bracket and flat steel are pre-installed at the corresponding position below the top plate 1 of the Type B fuel tank. Then the gas-liquid combined dome structure module is turned over and hoisted as a whole to the corresponding position above the top of the Type B fuel tank to ensure that the corresponding components are aligned up and down. After the butt welding is completed, the entire gas-liquid combined dome structure is fully installed.

[0042] The gas-liquid combined dome structure provided by the present invention makes it possible to meet the layout requirements of all through-tank pipes and the maintenance and access requirements of personnel and equipment in the LNG fuel tank within a limited space, while ensuring the strength of the dome structure itself while minimizing redundant structures. The special design of the edge of the top cover plate of the dome structure makes it easy to install a fixed sealing ring between it and the hull structure to ensure elastic sealing and avoid the risk of ultra-low temperature gas leakage from here.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solutions of the present invention. They should all be included in the scope of the technical solutions for which protection is sought in the present invention.

Claims

1. A gas-liquid combined dome structure for a type B LNG fuel tank of a dual-fuel ultra-large container ship, characterized in that: The gas-liquid combined dome structure is located at the center of the top of the B-type LNG fuel tank near the stern end, and its main peripheral structure includes a surrounding wall (2) and a top cover plate (3), and has a horizontally arranged through-tank interlayer (4) and a vertical passage shaft wall (5) inside. These main structures are welded to the top plate (1) of the B-type LNG fuel tank, and are located above the cross-shaped strong structure composed of the longitudinal girder and the transverse strong frame at the top of the B-type LNG fuel tank as a whole. The top cover plate (3) is provided with a manhole and a hanging port composite hatch and a hatch cover (9) at a position within the range of the passage shaft wall (5). The manhole and the hanging port composite hatch and the hatch cover (9) are used for personnel maintenance and equipment replacement. The through-tank interlayer (4) is located below the top cover plate (3), and the top cover plate (3) and the through-tank interlayer (4) are both provided with a variety of pipe holes of different sizes; The enclosure wall (2) is square in shape as a whole, and the four corners are formed into arc chamfered shapes. The front and rear end walls of the enclosure wall (2) are provided with brackets on the reverse side of the top plate (1) of the B-type LNG fuel tank to strengthen the reverse side. The end walls on the left and right sides of the enclosure wall (2) are aligned with the longitudinal ribs on the top of the B-type LNG fuel tank. The surrounding wall (2) and the channel wall (5) are both provided with vertical reinforcing ribs (7), wherein the ends of the vertical reinforcing ribs (7) on the surrounding wall (2) are made into a bracket type, and the ends of the vertical reinforcing ribs (7) on the channel wall (5) are made into a bevel type; The top cover plate (3) is larger than the surrounding wall (2) as a whole, and the four corners of the edge of the top cover plate (3) are also in the form of circular chamfers. The edge of the top cover plate (3) is a drooping annular T-row structure (6), and a sealing ring is installed and fixed between the annular T-row structure (6) and the hull component; A plurality of horizontal reinforcing ribs (8) are provided on the cabin penetration interlayer (4) and the top cover plate (3), and the end of the cabin penetration interlayer (4) is in the form of a toggle plate.

2. The gas-liquid combined dome structure of a type B LNG fuel tank for a dual-fuel ultra-large container ship according to claim 1, characterized in that: All materials used to make the gas-liquid combined dome structure are 9Ni steel.

3. The gas-liquid combined dome structure of a type B LNG fuel tank for a dual-fuel ultra-large container ship according to claim 1, characterized in that: The pipe holes include a gas pipe hole (P), a spray pipe hole (L), a bottom injection pipe hole (E1), a top injection pipe hole (E2), a BOG discharge pipe hole (Z1), a BOG emergency discharge pipe hole (Z2), a 0% sampling pipe hole (N1), a 50% sampling pipe hole (N2), a 100% sampling pipe hole (K), a safety valve discharge pipe hole (J) and an instrument pipe hole (R).

4. The gas-liquid combined dome structure of a type B LNG fuel tank for a dual-fuel ultra-large container ship according to claim 3, characterized in that: The 0% sampling tube hole (N1), the 50% sampling tube hole (N2) and the 100% sampling tube hole (K) are combined into one large hole on the top cover plate (3).

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