Dome structure for B-type cabin and installation method thereof

Abstract

The application discloses a dome structure for a B-type cabin and a mounting method thereof, and the dome structure comprises a coaming and a dome top plate, the lower end of the coaming is fixedly connected with the opening edge of the top of the B-type cabin, the upper end of the coaming is fixedly connected with the dome top plate, the dome top plate covers the upper end of the coaming, a ring-shaped flexible sealing piece is arranged along the periphery of the dome top plate, an outer support plate is fixedly arranged on the deck along the hole edge of a first mounting hole, the upper end of the flexible sealing piece is fixed at the edge of the dome top plate, the lower end of the flexible sealing piece is fixed on the dome top plate, the distance between the end of the dome top plate and the top end of the outer support plate is 200-300 mm in the horizontal direction and 200-300 mm in the height direction, and the distance between the upper end and the lower end of the flexible sealing piece in the natural state is greater than the straight-line distance between the end of the dome top plate and the top end of the outer support plate. The application enlarges the activity range of the flexible sealing piece. The mounting method in the application avoids the welding operation in the region and eliminates the safety hazard.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding technology, and in particular to a dome structure for a Type B cabin and its installation method. Background Technology

[0002] Containment systems are the core systems of offshore LNG storage and transportation equipment. Their main function is to isolate and safely store cryogenic cargoes such as liquefied natural gas, ethane, and ethylene from the ship's hull. As a stand-alone containment system, Type B tanks can be used on cryogenic liquid cargo carriers, such as LNG carriers or LNG carriers, and can also be used as fuel tanks on LNG-powered ships.

[0003] The dome structure of the Type B LNG compartment, serving as a passageway for the hoisting of liquid cargo equipment and personnel, typically protrudes from the top plate of the compartment and penetrates the ship's deck. After penetrating the deck, the dome structure needs to connect with the hull to form a sealed space, ensuring the airtightness of the space between the Type B LNG compartment and the ship (cargo hold area) to prevent cryogenic gas leakage. During the loading and unloading of cryogenic LNG, the tank itself undergoes thermal expansion and contraction deformation, and the dome above it will also experience relative movement and displacement with the surrounding hull structure. The space between the Type B LNG compartment and the hull's inner shell must remain sealed, and the dome is the only potential leakage point in this sealed space. Therefore, in addition to meeting basic functional requirements, the connection design between the Type B LNG compartment dome and the surrounding hull structure must ensure both airtightness and resistance to relative displacement changes in all directions. Furthermore, due to the extremely high structural precision requirements around the dome, the segmented construction of the large-opening main deck around it must significantly reduce the area of ​​open flame near the externally insulated Type B LNG compartment.

[0004] For example, Chinese patent CN202211404573.1 discloses a gas-liquid combined dome structure and its preparation method suitable for B-type cabins, which uses a flexible connection to connect the dome structure to the ship's deck. However, the dome structure disclosed in this patent has a limited range of movement, only moving vertically. Furthermore, the dome structure in this patent is prone to collision with the ship's structure during hoisting, and the insulating material is easily ignited during the welding process, posing a high safety hazard. Summary of the Invention

[0005] In view of the deficiencies in the existing technology, this application provides a dome structure for a Type B cabin and its installation method to solve the above-mentioned technical problems.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A dome structure for a Type B cargo hold includes a second mounting hole through the top plate of the cargo tank and a first mounting hole through the deck. The first mounting hole and the second mounting hole are arranged opposite to each other. Both the first mounting hole and the second mounting hole are rectangular in shape, and the size of the first mounting hole is larger than the size of the second mounting hole. The dome structure includes a surrounding panel and a dome top plate. The surrounding panel is connected end-to-end to form a rectangular annular wall. The surrounding panel is installed along the second mounting hole. The annular wall formed by the surrounding panel is at least 200mm away from the edge of the second mounting hole in the horizontal direction. The lower end of the surrounding panel is fixedly connected to the edge of the opening at the top of the B-type cabin, and the upper end of the surrounding panel is fixedly connected to the dome top plate. The dome top plate covers the upper end of the surrounding panel and is higher than the deck. An outer support plate is fixedly installed on the deck along the edge of the first mounting hole. The outer support plate is connected end-to-end to form a circular wall. The outer support plate is perpendicular to the deck, and the annular wall formed by the outer support plate is at least 200mm away from the edge of the first mounting hole in the horizontal direction. The distance between the edges is not less than 15mm. The top of the outer support plate is fixed with an installation plate parallel to the deck. An annular flexible seal is provided along the periphery of the dome top plate. The upper end of the flexible seal is fixed to the edge of the dome top plate by a connector, and the lower end of the flexible seal is fixed to the dome top plate by a connector. On the same vertical section, the distance between the end of the dome top plate and the top of the outer support plate is 200~300mm in the horizontal direction and 200~300mm in the vertical direction. In the natural state, the distance between the upper and lower ends of the flexible seal is greater than the straight distance between the end of the dome top plate and the top of the outer support plate.

[0007] In one embodiment, the second mounting hole is a rectangular opening with a rounded chamfer, the cross-section of the enclosure is a rectangle with a rounded chamfer, the radius of the rounded chamfer is greater than 500 mm, the flexible seal is made of expanded rubber, the distance between the upper and lower ends of the flexible seal is not less than 600 mm, and a manhole is provided on the dome top plate.

[0008] In one embodiment, an inner support plate is also provided along the edge of the dome top plate. The inner support plate is connected end to end to form a ring wall. The cross-section of the inner support plate is a hook shape with an arc and bending towards the wall. The inner support plate includes an arc segment and an inclined plate segment. One end of the arc segment is fixedly connected to the edge of the dome top plate, and the other end of the arc segment is fixedly connected to one end of the inclined plate segment.

[0009] In one embodiment, the upper end of the flexible seal is fixed to the dome top plate or to the inclined plate section.

[0010] In one embodiment, the connector at the upper end of the flexible seal includes a stud welded to the dome top plate or the inclined plate section, the stud being perpendicular to the dome top plate or the inclined plate section, and the stud being fitted with a nut, an elastic washer, a rigid washer and a sealing block.

[0011] In one embodiment, the mounting plate is divided into an inner region and an outer region by an outer support plate, and the lower end of the flexible seal is fixed to the inner region of the mounting plate or to the outer region of the mounting plate.

[0012] In one embodiment, when the fixing point of the lower end of the flexible seal is located in the inner region of the mounting plate, the connector connecting the lower end of the flexible seal to the top plate includes a stud welded to the mounting plate, the stud being perpendicular to the mounting plate, and a nut, an elastic washer, a rigid washer, a sealing block, and the flexible seal being sequentially fitted on the stud from top to bottom; when the fixing point of the lower end of the flexible seal is located in the outer region of the mounting plate, bolt holes are provided in the outer region of the mounting plate, and a nut, an elastic washer, a rigid washer, a sealing block, and the flexible seal are sequentially fitted on the stud on the upper side of the mounting plate from top to bottom, while an elastic washer and a rigid washer are fitted on the bolt on the lower side of the mounting plate from bottom to top.

[0013] In one embodiment, a water-retaining cover plate is fixedly installed along the edge of the dome top plate. The water-retaining cover plates are connected end to end to form a ring wall. The cross-section of the water-retaining cover plate is inverted L-shaped. The water-retaining cover plate includes a horizontal section and a vertical section. One end of the horizontal section is fixedly connected to the edge of the dome top plate, and the other end of the horizontal section is fixedly connected to the vertical section. The length of the horizontal section is greater than the horizontal distance between the end of the dome top plate and the top of the outer support plate. The length of the vertical section is greater than or equal to the vertical distance between the end of the dome top plate and the top of the outer support plate.

[0014] In one embodiment, when the upper ends of both the water-blocking cover and the flexible seal are fixed to the dome top plate, the water-blocking cover and the flexible seal share the same stud. When the water-blocking cover and the flexible seal are fixed to the dome top plate, the stud fixing the water-blocking cover is fitted with a nut, a rigid washer, the water-blocking cover and an elastic washer, a nut, an elastic washer, a rigid washer and a sealing block in sequence from the outside to the inside. When the water-blocking cover is fixed to the dome top plate and the upper end of the flexible seal is fixed to the inclined plate section, the connecting member fixing the water-blocking cover includes a stud welded to the top plate, and the stud fixing the water-blocking cover is fitted with a nut, a rigid washer, the water-blocking cover and an elastic washer in sequence from top to bottom.

[0015] In one embodiment, multiple vertical reinforcing ribs are evenly distributed vertically on the cofferdam. Two first transverse reinforcing ribs are fixedly installed along the width direction and two first longitudinal reinforcing ribs are fixedly installed along the length direction on the lower surface of the cargo tank top plate. The first transverse reinforcing ribs are positioned along the width direction edge of the second mounting hole, and the first longitudinal reinforcing ribs are positioned along the length direction edge of the second mounting hole. The ends of the first transverse and first longitudinal reinforcing ribs are fixedly connected to form a rectangle. Two second transverse reinforcing ribs and two third transverse reinforcing ribs are fixedly installed along the width direction on the lower surface of the deck, and two second longitudinal reinforcing ribs and two third longitudinal reinforcing ribs are fixedly installed along the length direction. The third transverse reinforcing ribs are positioned along the width direction edge of the first mounting hole, and the third longitudinal reinforcing ribs are positioned along the length direction edge. The third transverse reinforcing ribs are located directly below the outer support plate. Both the second transverse and second longitudinal reinforcing ribs are connected to the edge of the first mounting hole. At a fixed distance, the ends of the second transverse stiffener and the second longitudinal stiffener are fixedly connected to form a rectangle. The two ends of the third longitudinal stiffener are vertically fixed to the second transverse stiffener and the two ends of the third transverse stiffener are vertically fixed to the third longitudinal stiffener. A local stiffener is provided between the second transverse stiffener and the third transverse stiffener. A local stiffener is provided between the second longitudinal stiffener and the third longitudinal stiffener. The local stiffener between the second transverse stiffener and the third transverse stiffener is perpendicular to the second transverse stiffener. The two ends of the local stiffener between the second transverse stiffener and the third transverse stiffener are fixedly connected to the second transverse stiffener and the third transverse stiffener, respectively. The local stiffener between the second longitudinal stiffener and the third longitudinal stiffener is perpendicular to the second longitudinal stiffener. The two ends of the local stiffener between the second longitudinal stiffener and the third longitudinal stiffener are fixedly connected to the second longitudinal stiffener and the third longitudinal stiffener, respectively.

[0016] This application also provides a method for installing the dome structure for a Type B cabin as described above, comprising the following steps: Step 1: Weld studs onto the inclined plate section of the inner support plate, weld studs onto the edge of the dome top plate, weld the inner support plate onto the dome top plate, and assemble the top plate reinforcing ribs on the dome top plate. Step 2: Form the enclosure into a rectangular ring wall; Step 3: Weld the dome top plate to the upper end of the enclosure panel to form a complete dome component; Step 4: Fix the lower end of the cofferdam in the dome component to the opening edge of the top of the B-type tank, and weld vertical reinforcing ribs on the cofferdam. Weld the first transverse reinforcing rib and the first longitudinal reinforcing rib on the lower surface of the top plate of the liquid cargo tank. Step 5: Weld the liquid cargo tank dome sections to other liquid cargo tank sections to form the liquid cargo tank assembly section, and hoist the liquid cargo tank assembly section into the designated position in the dry dock for installation; Step 6: Weld an outer support plate to the upper surface of the deck, weld an mounting plate to the top of the outer support plate, weld a second transverse stiffener, a third transverse stiffener, a second longitudinal stiffener, and a third longitudinal stiffener to the lower surface of the deck, weld a local stiffener between the second transverse stiffener and the third transverse stiffener, and weld a local stiffener between the second longitudinal stiffener and the third longitudinal stiffener to form the hull deck section. Step 7: Hoist the hull deck sections into the designated positions in the dry dock for installation. The dome structure passes through the first mounting hole in the middle of the deck. At this time, studs can be welded to the inner area of ​​the mounting plate, or bolt holes can be opened on the outer area of ​​the mounting plate, and detachable bolts can be installed in the bolt holes. Step 8: Fix the upper end of the flexible seal to the internal support plate using studs, nuts, rigid washers, elastic washers, and sealing blocks; or fix the upper end of the flexible seal to the dome top plate using studs, nuts, rigid washers, elastic washers, and sealing blocks. Step 9: Fix the lower end of the flexible seal to the inner area of ​​the mounting plate using studs, nuts, rigid washers, elastic washers, and sealing blocks; or, on the outer area of ​​the mounting plate, fix the lower end of the flexible seal to the outer area of ​​the mounting plate using studs, rigid washers, elastic washers passing through the mounting plate and the flexible seal, and using sealing blocks, rigid washers, elastic washers, and nuts, which facilitates construction. Step 10: Secure the water-blocking cover to the dome top plate using studs, nuts, rigid washers, and elastic washers.

[0017] Compared with the prior art, this application has at least the following beneficial effects: This invention connects the deck and the dome top plate with a flexible seal, turning the gap space between the liquid cargo tank and the hull into a closed space. Through reasonable gasket settings, the airtightness of the gap space is ensured, preventing possible leakage of low-temperature gas. In this invention, the distance between the end of the dome top plate and the top of the outer support plate is set to 200~300mm in the horizontal direction and 200~300mm in the vertical direction, thereby expanding the range of motion of the flexible seal. In this invention, the inner and outer support plates are misaligned in both the horizontal and vertical directions. This design allows for easy hoisting of the complete hull deck section from above even after the dome section, including the inner support plate, is installed. This effectively ensures the integrity of the section.

[0018] The present invention reduces the damage to the flexible seal 5 by the edge of the dome top plate 2 by the setting of the rounded inner support plate, thereby extending the service life of the dome structure of the B-type cabin.

[0019] More advantageously, since the outer layer of the pre-installed dome sections is covered with insulating material, which is flammable and highly susceptible to ignition due to welding of nearby structures, the dome structure installation method of this invention achieves the complete hoisting of the hull deck sections, thereby completely avoiding welding operations in this area and eliminating safety hazards.

[0020] This invention, through the use of a water-blocking cover, can effectively reduce the direct impact of rainwater and ocean waves on flexible sealing materials, thereby reducing damage or aging of flexible seals and improving the safety of the dome structure.

[0021] In existing technologies, after the hull deck sections are hoisted and installed, the space behind the internal support plate used to fix the flexible seals is very small, making construction inconvenient. This invention addresses this by pre-welding studs to the internal support plate, allowing for quick and easy installation of the sealing connection components from only one side. Similarly, pre-welding studs to the dome deck facilitates single-sided installation of the flood barrier. Attached Figure Description

[0022] Figure 1 This is a stern-side view of the dome structure used for Type B cabins in an embodiment of this application; Figure 2 This is a top view of the dome structure used in the B-type cabin in the embodiments of this application; Figure 3 This is a schematic diagram of the tight connection components in the embodiments of this application. Figure 1 ; Figure 4 This is a schematic diagram of the tight connection components in the embodiments of this application. Figure 2 ; Figure 5 This is a schematic diagram of the tight connection components in the embodiments of this application. Figure 3 ; Figure 6 This is a schematic diagram of the tight connection components in the embodiments of this application. Figure 4 .

[0023] Reference numerals: 1. Enclosure; 101. Vertical stiffener; 102. Horizontal stiffener; 103. First longitudinal stiffener; 2. Dome top plate; 201. Manhole; 202. Top plate stiffener; 203. Inner support plate; 3. Deck; 301. First mounting hole; 302. Local stiffener; 303. Outer support plate; 304. Mounting plate; 305. Second longitudinal stiffener; 306. Second horizontal stiffener; 307. Third horizontal stiffener; 308. Third longitudinal stiffener; 4. Liquid cargo tank top plate; 5. Flexible seal; 6. Connector; 601. Stud; 602. Nut; 603. Elastic gasket; 604. Rigid gasket; 605. Sealing block; 606. Bolt; 7. Water barrier cover. Detailed Implementation

[0024] 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.

[0025] 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.

[0026] 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."

[0027] 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 connection or internal connection between two components. They can be direct connection or indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0028] 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.

[0029] like Figure 1-6 As shown, this application provides a dome structure for a Type B cargo hold. The dome structure has a second mounting hole on the top plate 4 of the cargo tank and a first mounting hole 301 on the deck 3. The first mounting hole 301 and the second mounting hole are arranged opposite to each other. Both the first mounting hole 301 and the second mounting hole are rectangular in shape. The size of the first mounting hole 301 is larger than the size of the second mounting hole. The dome structure includes a surrounding panel 1 and a dome top plate 2. The surrounding panel 1 is an annular wall with a rectangular cross-section. The surrounding panel 1 is installed along the second mounting hole. The annular wall formed by the surrounding panel 1 is at least 200mm away from the edge of the second mounting hole in the horizontal direction. The lower end of the surrounding panel 1 is fixedly connected to the edge of the opening at the top of the B-type cabin. The upper end of the surrounding panel 1 is fixedly connected to the dome top plate 2. The dome top plate 2 covers the upper end of the surrounding panel 1 and is higher than the deck 3. An outer support plate 303 is fixedly installed on the deck 3 along the edge of the first mounting hole 301. The outer support plates 303 are connected end to end to form an annular wall. The outer support plates 303 are perpendicular to the fixed deck 3. The annular wall formed by the outer support plates 303 is at least 200mm away from the edge of the first mounting hole in the horizontal direction. The distance between the holes is not less than 15mm. The top of the outer support plate 303 is fixed with an installation plate 304 parallel to the deck 3. An annular flexible seal 5 is provided along the periphery of the dome top plate 2. The upper end of the flexible seal 5 is fixed to the edge of the dome top plate 2 by a connector 6, and the lower end of the flexible seal 5 is fixed to the installation plate 304 by a connector 6. On the same vertical section, the distance between the end of the dome top plate 2 and the top of the outer support plate 303 in the horizontal direction is 200~300mm, and the distance in the height direction is 200~300mm. In the natural state, the distance between the upper and lower ends of the flexible seal 5 is greater than the straight distance between the end of the dome top plate 2 and the top of the outer support plate 303.

[0030] The second mounting hole is a rectangular opening with rounded chamfers. The cross-section of the enclosure plate 1 is also rectangular with rounded chamfers to reduce local stress concentration. The radius of the rounded chamfers is greater than 500 mm. The flexible seal 5 is made of expanded rubber, and the distance between the upper and lower ends of the flexible seal 5 is not less than 600 mm. A manhole 201 is provided on the dome top plate 2. The manhole 201 serves as a passage for personnel to enter the liquid cargo tank and a material hoisting port.

[0031] An inner support plate 203 is also provided along the edge of the dome top plate 2. The inner support plate 203 is connected end to end to form a ring wall. The cross-section of the inner support plate 203 is a hook shape with an arc and bending towards the wall plate 1. The inner support plate 203 includes an arc segment and an inclined plate segment. One end of the arc segment is fixedly connected to the edge of the dome top plate 2, and the other end of the arc segment is fixedly connected to one end of the inclined plate segment.

[0032] The upper end of the flexible seal 5 is fixed to the dome top plate 2 (as shown in the attached document). Figure 4 and attached Figure 6 (as shown) or fixed to the inclined plate section (as attached) Figure 3 and attached Figure 5 (As shown). By setting the inner support plate 203, the damage to the flexible seal 5 by the edge of the dome top plate 2 can be reduced when the flexible seal 5 is extended, thus extending the service life of the dome structure of the B-type cabin.

[0033] The connector 6 connecting the upper end of the flexible seal 5 includes a stud 601 welded to the dome top plate 2 or the inclined plate section. The stud 601 is perpendicular to the dome top plate 2 or the inclined plate section. The components sleeved on the stud 601 include a nut 602, an elastic washer 603, a rigid washer 604, and a sealing block 605.

[0034] Mounting plate 304 is divided by outer support plate 303 into an inner region near dome top plate 2 and an outer region away from dome top plate 2. The lower end of flexible seal 5 is fixed to the inner region of mounting plate 304 (as shown in the attached figure). Figure 3 and attached Figure 4 (as shown) or fixed to the outer area of ​​the mounting plate 304 (as shown in the attached figure). Figure 5 and attached Figure 6 (As shown).

[0035] When the fixing point of the lower end of the flexible seal 5 is located in the inner area of ​​the mounting plate 304, the connecting member 6 connecting the lower end of the flexible seal 5 and the mounting plate 304 includes a stud 601 welded to the mounting plate 304. The stud 601 is perpendicular to the mounting plate 304, and a nut 602, an elastic washer 603, a rigid washer 604, a sealing block 605, and the flexible seal 5 are sequentially sleeved on the stud 601 from top to bottom. When the fixing point at the lower end of component 5 is located in the outer region of mounting plate 304, bolt holes are provided in the outer region of mounting plate 304. The connecting component 6 connecting the lower end of flexible seal 5 to mounting plate 304 includes bolts 606 passing through bolt holes. The studs on the upper side of mounting plate 304 are fitted with nuts 602, elastic washers 603, rigid washers 604, sealing blocks 605 and flexible seal 5 from top to bottom. The bolts 606 on the lower side of mounting plate 304 are fitted with elastic washers 603 and rigid washers 604 from bottom to top.

[0036] A water-retaining cover 7 is also fixedly installed along the edge of the dome top plate 2. The water-retaining cover 7 is connected end to end to form a ring wall. The cross-section of the water-retaining cover 7 is inverted L-shaped. The water-retaining cover 7 includes a horizontal section and a vertical section. One end of the horizontal section is fixedly connected to the edge of the dome top plate 2, and the other end of the horizontal section is fixedly connected to the vertical section. The length of the horizontal section is greater than the horizontal distance between the end of the dome top plate 2 and the top of the outer support plate 303. The length of the vertical section is greater than or equal to the vertical distance between the end of the dome top plate 2 and the top of the outer support plate 303. The water-retaining cover 7 can spatially enclose the flexible seal 5. By setting the water-retaining cover 7, the effect of rainwater and waves on the flexible seal 5 can be reduced, thereby delaying material damage or aging and preventing damage to the flexible seal 5 by external forces.

[0037] When the upper ends of the water-blocking cover plate 7 and the flexible sealing element 5 are both fixed on the dome top plate 2, the water-blocking cover plate 7 and the flexible sealing element 5 share the same stud 601; when the water-blocking cover plate 7 and the flexible sealing element 5 are fixed on the dome top plate 2, the stud fixing the water-blocking cover plate 7 is fitted with a nut 602, a rigid washer 604, the water-blocking cover plate 7 and an elastic washer 603, a nut 602, an elastic washer 603, a rigid washer 604 and a sealing block 605 in sequence from the outside to the inside; when the water-blocking cover plate 7 is fixed on the dome top plate 2 and the upper end of the flexible sealing element 5 is fixed on the inclined plate section, the connecting part 6 for fixing the water-blocking cover plate 7 includes the stud 601 welded on the top plate, and the stud fixing the water-blocking cover plate 7 is fitted with a nut 602, a rigid washer 604, the water-blocking cover plate 7 and an elastic washer 603 in sequence from top to bottom.

[0038] To improve the structural strength of the dome structure, multiple vertical reinforcing ribs 101 are evenly distributed vertically on the cofferdam 1. Two first transverse reinforcing ribs 102 are fixedly installed on the lower surface of the cargo tank top plate 4 along the width direction (Y direction) and two first longitudinal reinforcing ribs 103 are fixedly installed along the length direction (X direction). The first transverse reinforcing ribs 102 are installed along the width direction of the second mounting hole, and the first longitudinal reinforcing ribs 103 are installed along the length direction of the second mounting hole. The ends of the first transverse reinforcing ribs 102 and the first longitudinal reinforcing ribs 103 are fixedly connected to form a rectangle. Two second transverse stiffeners 306 and two third transverse stiffeners 307 are fixedly installed along the width direction (Y direction) and two second longitudinal stiffeners 305 and two third longitudinal stiffeners 308 are fixedly installed along the length direction (X direction) of the lower surface of deck 3. The third transverse stiffeners 307 are set along the width direction edge of the first mounting hole 301, and the third longitudinal stiffeners 308 are set along the length direction edge. The third transverse stiffeners 307 are located directly below the outer support plate 303. The second transverse stiffeners 306 and the second longitudinal stiffeners 305 are both a certain distance from the edge of the first mounting hole 301. The ends of the second transverse stiffeners 306 and the second longitudinal stiffeners 305 are fixedly connected to form a rectangle. The two ends of the third longitudinal stiffeners 308 are vertically fixed to the second transverse stiffeners 306, and the two ends of the third transverse stiffeners 307 are vertically fixed to the third longitudinal stiffeners 306. On 8, a local reinforcing rib 302 is provided between the second transverse reinforcing rib 306 and the third transverse reinforcing rib 307, and a local reinforcing rib 302 is provided between the second longitudinal reinforcing rib 305 and the third longitudinal reinforcing rib 308. The local reinforcing rib 302 between the second transverse reinforcing rib 306 and the third transverse reinforcing rib 307 is perpendicular to the second transverse reinforcing rib 306. The two ends of the local reinforcing rib 302 between the second transverse reinforcing rib 306 and the third transverse reinforcing rib 307 are fixedly connected to the second transverse reinforcing rib 306 and the third transverse reinforcing rib 307, respectively. The local reinforcing rib 302 between the second longitudinal reinforcing rib 305 and the third longitudinal reinforcing rib 308 is perpendicular to the second longitudinal reinforcing rib 305. The two ends of the local reinforcing rib 302 between the second longitudinal reinforcing rib 305 and the third longitudinal reinforcing rib 308 are fixedly connected to the second longitudinal reinforcing rib 305 and the third longitudinal reinforcing rib 308, respectively.

[0039] This embodiment also provides an installation method for the dome structure used in the B-type cabin described above, including the following steps: Step 1: Weld studs 601 onto the inclined plate section of the inner support plate 203, weld studs 601 onto the edge of the dome top plate 2, weld the inner support plate 203 onto the dome top plate 2, and assemble the top plate reinforcing ribs 202 onto the dome top plate 2. Step 2: Form the enclosure panel 1 into a rectangular ring wall; Step 3: Weld the dome top plate 2 to the upper end of the enclosure plate 1 to form a complete dome component; Step 4: Fix the lower end of the cofferdam 1 in the dome component to the opening edge of the top of the B-type compartment, and weld the vertical reinforcing rib 101 on the cofferdam 1. Weld the first transverse reinforcing rib 102 and the first longitudinal reinforcing rib 103 on the lower surface of the top plate 4 of the liquid cargo compartment.

[0040] Step 5: Weld the liquid cargo tank dome sections to other liquid cargo tank sections to form the liquid cargo tank assembly section, and hoist the liquid cargo tank assembly section into the designated position in the dry dock for installation; Step 6: Weld an outer support plate 303 to the upper surface of the deck 3, weld an mounting plate 304 to the top of the outer support plate 303, weld a second transverse stiffener 306, a third transverse stiffener 307, a second longitudinal stiffener 305, and a third longitudinal stiffener 308 to the lower surface of the deck 3, weld a local stiffener 302 between the second transverse stiffener 306 and the third transverse stiffener 307, and weld a local stiffener 302 between the second longitudinal stiffener 305 and the third longitudinal stiffener 308 to form a hull deck section. Step 7: Hoist the hull deck sections into the designated positions in the dry dock for installation. The dome structure passes through the first mounting hole 301 in the middle of the deck 3. At this time, studs 601 can be welded to the inner area of ​​the mounting plate 304, or bolt holes can be opened in the outer area of ​​the mounting plate 304, and detachable studs 601 can be installed in the bolt holes. Step 8: Fix the upper end of the flexible seal 5 to the internal support plate 203 using studs 601, nuts 602, rigid washers 604, elastic washers 603, and sealing blocks 605; or fix the upper end of the flexible seal 5 to the dome top plate 2 using studs 601, nuts 602, rigid washers 604, elastic washers 603, and sealing blocks 605. Step 9: Fix the lower end of the flexible seal 5 to the inner area of ​​the mounting plate 304 using studs 601, nuts 602, rigid washers 604, elastic washers 603, and sealing blocks 605; or, on the outer area of ​​the mounting plate 304, fix the lower end of the flexible seal 5 to the outer area of ​​the mounting plate 304 using studs 601, rigid washers 604, elastic washers 603 passing through the mounting plate 304 and the flexible seal 5, and then fix the lower end of the flexible seal 5 to the outer area of ​​the mounting plate 304 using sealing blocks 605, rigid washers 604, elastic washers 603, and nuts 602, which facilitates construction. Step 10: Fix the water-blocking cover 7 to the dome top plate 2 using studs 601, nuts 602, rigid washers 604 and elastic washers 603.

[0041] 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 them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A dome structure for a Type B cabin, characterized in that, The dome structure has a second mounting hole on the top plate of the liquid cargo tank and a first mounting hole on the deck. The first mounting hole and the second mounting hole are arranged opposite to each other. Both the first mounting hole and the second mounting hole are rectangular in shape, and the size of the first mounting hole is larger than the size of the second mounting hole. The dome structure includes a surrounding panel and a dome top plate. The surrounding panel is connected end-to-end to form a rectangular annular wall. The surrounding panel is installed along the second mounting hole. The annular wall formed by the surrounding panel is at least 200mm away from the edge of the second mounting hole in the horizontal direction. The lower end of the surrounding panel is fixedly connected to the edge of the opening at the top of the B-type cabin, and the upper end of the surrounding panel is fixedly connected to the dome top plate. The dome top plate covers the upper end of the surrounding panel and is higher than the deck. An outer support plate is fixedly installed on the deck along the edge of the first mounting hole. The outer support plate is connected end-to-end to form a rectangular annular wall and is vertically fixed to the deck. The annular wall formed by the outer support plate is at least 200mm away from the edge of the first mounting hole in the horizontal direction. The distance between the top and bottom of the outer support plate is not less than 15mm. A mounting plate parallel to the deck is fixed to the top of the outer support plate. An annular flexible seal is provided along the periphery of the dome top plate. The upper end of the flexible seal is fixed to the edge of the dome top plate by a connector, and the lower end of the flexible seal is fixed to the mounting plate at the top of the outer support plate by a connector. On the same vertical section, the distance between the end of the dome top plate and the top of the outer support plate is 200~300mm in the horizontal direction and 200~300mm in the vertical direction. In its natural state, the distance between the upper and lower ends of the flexible seal is greater than the straight-line distance between the end of the dome top plate and the top of the outer support plate.

2. The dome structure according to claim 1, characterized in that, The second mounting hole is a rectangular opening with rounded chamfers. The cross-section of the enclosure is a rectangle with rounded chamfers, and the radius of the rounded chamfers is greater than 500 mm. The flexible seal is made of expanded rubber, and the distance between the upper and lower ends of the flexible seal is not less than 600 mm. A manhole is provided on the dome top plate.

3. The dome structure according to claim 1, characterized in that, An inner support plate is also provided along the edge of the dome top plate. The inner support plate is connected end to end to form a ring wall. The cross-section of the inner support plate is a hook shape with an arc and bending towards the wall. The inner support plate includes an arc segment and an inclined plate segment. One end of the arc segment is fixedly connected to the edge of the dome top plate, and the other end of the arc segment is fixedly connected to one end of the inclined plate segment.

4. The dome structure according to claim 3, characterized in that, The upper end of the flexible seal is fixed to the dome top plate or to the inclined plate section.

5. The dome structure according to claim 4, characterized in that, The connector at the upper end of the flexible seal includes a stud welded to the dome top plate or the inclined plate section, the stud being perpendicular to the dome top plate or the inclined plate section, and the stud being fitted with a nut, an elastic washer, a rigid washer and a sealing block.

6. The dome structure according to claim 5, characterized in that, The mounting plate is divided into an inner area and an outer area by the outer support plate. The lower end of the flexible seal is fixed to the inner area of ​​the mounting plate or to the outer area of ​​the mounting plate.

7. The dome structure according to claim 6, characterized in that, When the fixing point of the lower end of the flexible seal is located in the inner area of ​​the mounting plate, the connecting component between the lower end of the flexible seal and the mounting plate includes a stud welded to the mounting plate. The stud is perpendicular to the mounting plate, and a nut, an elastic washer, a rigid washer, a sealing block, and the flexible seal are sequentially fitted on the stud from top to bottom. When the fixing point of the lower end of the flexible seal is located in the outer area of ​​the mounting plate, bolt holes are provided in the outer area of ​​the mounting plate. The connecting component between the lower end of the flexible seal and the mounting plate includes a bolt passing through the bolt hole. The stud on the upper side of the mounting plate is sequentially fitted with a nut, an elastic washer, a rigid washer, a sealing block, and the flexible seal from top to bottom. The bolt on the lower side of the mounting plate is fitted with an elastic washer and a rigid washer from bottom to top.

8. The dome structure according to claim 7, characterized in that, A water-retaining cover plate is also fixedly installed along the edge of the dome top plate. The water-retaining cover plate is connected end to end to form a ring wall. The cross-section of the water-retaining cover plate is inverted L-shaped. The water-retaining cover plate includes a horizontal section and a vertical section. One end of the horizontal section is fixedly connected to the edge of the dome top plate, and the other end of the horizontal section is fixedly connected to the vertical section. The length of the horizontal section is greater than the horizontal distance between the end of the dome top plate and the top of the outer support plate. The length of the vertical section is greater than or equal to the vertical distance between the end of the dome top plate and the top of the outer support plate.

9. The dome structure according to claim 8, characterized in that, When the upper ends of both the water-blocking cover and the flexible seal are fixed to the dome top plate, the water-blocking cover and the flexible seal share the same stud. When the water-blocking cover and the flexible seal are fixed to the dome top plate, the stud fixing the water-blocking cover is fitted with a nut, a rigid washer, the water-blocking cover and an elastic washer, a nut, an elastic washer, a rigid washer and a sealing block in sequence from the outside to the inside. When the water-blocking cover is fixed to the dome top plate and the upper end of the flexible seal is fixed to the inclined plate section, the connecting parts for fixing the water-blocking cover include the stud on the welded top plate, and the stud fixing the water-blocking cover is fitted with a nut, a rigid washer, the water-blocking cover and an elastic washer in sequence from top to bottom.

10. The dome structure according to claim 9, characterized in that, The bulkhead has multiple vertically evenly distributed reinforcing ribs. On the lower surface of the cargo tank top plate, two first transverse reinforcing ribs are fixedly installed along the ship's width direction, and two first longitudinal reinforcing ribs are fixedly installed along the ship's length direction. The first transverse reinforcing ribs are positioned along the width direction of the second mounting holes, and the first longitudinal reinforcing ribs are positioned along the length direction of the second mounting holes. The ends of the first transverse and first longitudinal reinforcing ribs are fixedly connected to form a rectangle. On the lower surface of the deck, two second transverse reinforcing ribs and two third transverse reinforcing ribs are fixedly installed along the ship's width direction, and two second longitudinal reinforcing ribs and two third longitudinal reinforcing ribs are fixedly installed along the ship's length direction. The third transverse reinforcing ribs are positioned along the width direction of the first mounting holes, and the third longitudinal reinforcing ribs are positioned along the length direction of the first mounting holes. The third transverse reinforcing ribs are located directly below the outer support plate. Both the second transverse and second longitudinal reinforcing ribs are spaced a certain distance from the edges of the first mounting holes. The ends of the second transverse stiffener and the second longitudinal stiffener are fixedly connected to form a rectangle. The two ends of the third longitudinal stiffener are vertically fixed to the second transverse stiffener and the two ends of the third transverse stiffener are vertically fixed to the third longitudinal stiffener. A local stiffener is provided between the second transverse stiffener and the third transverse stiffener. A local stiffener is provided between the second longitudinal stiffener and the third longitudinal stiffener. The local stiffener between the second transverse stiffener and the third transverse stiffener is perpendicular to the second transverse stiffener. The two ends of the local stiffener between the second transverse stiffener and the third transverse stiffener are fixedly connected to the second transverse stiffener and the third transverse stiffener, respectively. The local stiffener between the second longitudinal stiffener and the third longitudinal stiffener is perpendicular to the second longitudinal stiffener. The two ends of the local stiffener between the second longitudinal stiffener and the third longitudinal stiffener are fixedly connected to the second longitudinal stiffener and the third longitudinal stiffener, respectively.

11. An installation method for a dome structure for a Type B cabin as described in claim 10, comprising the following steps: Step 1: Weld studs onto the inclined plate section of the inner support plate, weld studs onto the edge of the dome top plate, weld the inner support plate onto the dome top plate, and assemble the top plate reinforcing ribs on the dome top plate. Step 2: Form the enclosure into a rectangular ring wall; Step 3: Weld the dome top plate to the upper end of the enclosure panel to form a complete dome component; Step 4: Fix the lower end of the cofferdam in the dome component to the opening edge of the top of the B-type tank, and weld vertical reinforcing ribs on the cofferdam. Weld the first transverse reinforcing rib and the first longitudinal reinforcing rib on the lower surface of the top plate of the liquid cargo tank. Step 5: Weld the liquid cargo tank dome sections to other liquid cargo tank sections to form the liquid cargo tank assembly section, and hoist the liquid cargo tank assembly section into the designated position in the dry dock for installation; Step 6: Weld an outer support plate to the upper surface of the deck, weld an mounting plate to the top of the outer support plate, weld a second transverse stiffener, a third transverse stiffener, a second longitudinal stiffener, and a third longitudinal stiffener to the lower surface of the deck, weld a local stiffener between the second transverse stiffener and the third transverse stiffener, and weld a local stiffener between the second longitudinal stiffener and the third longitudinal stiffener to form the hull deck section. Step 7: Hoist the hull deck sections into the designated positions in the dry dock for installation. The dome structure passes through the first mounting hole in the middle of the deck. At this time, studs can be welded to the inner area of ​​the mounting plate, or bolt holes can be opened on the outer area of ​​the mounting plate, and detachable bolts can be installed in the bolt holes. Step 8: Fix the upper end of the flexible seal to the internal support plate using studs, nuts, rigid washers, elastic washers, and sealing blocks; or fix the upper end of the flexible seal to the dome top plate using studs, nuts, rigid washers, elastic washers, and sealing blocks. Step 9: Fix the lower end of the flexible seal to the inner area of ​​the mounting plate using studs, nuts, rigid washers, elastic washers, and sealing blocks; or, on the outer area of ​​the mounting plate, fix the lower end of the flexible seal to the outer area of ​​the mounting plate using studs, rigid washers, elastic washers passing through the mounting plate and the flexible seal, and using sealing blocks, rigid washers, elastic washers, and nuts, which facilitates construction. Step 10: Secure the water-blocking cover to the dome top plate using studs, nuts, rigid washers, and elastic washers.

Images