A dome protection device for cryogenic liquefied gas membrane storage tank

Abstract

The present invention relates to the technical field of liquid cargo storage devices, and discloses a dome protective device for a cryogenic liquefied gas film storage tank, which includes a vacuum insulation box arranged on the side wall of the dome, a first insulation box attached to the vacuum insulation box, and an adhesive layer for bonding the vacuum insulation box and the first insulation box; connecting bolts, the connecting bolts are hollow along the axial direction, the vacuum insulation box shell is evacuated and sealed by the connecting bolts to form a vacuum insulation structure, and the connecting bolts are used to connect the first insulation box and the vacuum insulation box as a whole. The present invention achieves a good insulation effect through the vacuum insulation of the vacuum insulation box, and at the same time uses the connecting bolts to complete the vacuuming operation. The subsequent connecting bolts can also fix the first insulation box on the surface of the vacuum insulation box, avoiding the problem of damage to the vacuum insulation box caused by contact between liquefied gas and the vacuum insulation box, ensuring the stable insulation of the vacuum insulation box, and reducing the gasification of liquefied natural gas in the film tank.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid cargo storage devices, and in particular to a dome protection device for a cryogenic liquefied gas membrane storage tank. Background Art

[0002] As a clean and efficient energy source, liquefied natural gas (LNG) is primarily stored and transported in cryogenic, atmospheric pressure tanks or pressure tanks. LNG can be transported by sea or land. For sea transport, it is primarily transported by LNG carriers.

[0003] LNG ships are designed for the transportation of liquefied natural gas and are equipped with a cargo tank membrane, an insulation layer, a dome deck, and a dome. The cargo tank membrane is used to directly store liquefied natural gas and is made of corrugated plates welded together. The corrugated structure is used to absorb the shrinkage caused by the film when it is loaded with cryogenic liquefied gas. The insulation layer is provided on the outside of the cargo tank membrane to isolate the cargo tank membrane from the external environment, reduce the heat exchange between the liquid cargo natural gas and the external environment, and keep the temperature of the liquid cargo natural gas below the boiling point. The dome plywood is a deck structure on top of the cargo tank, which is mainly used to support the dome structure and related operating equipment, as well as a platform for staff to operate and maintain the cargo tank. The dome protrudes above the deck and is used as a support structure for structures such as pump towers, as well as an entrance and exit for liquid cargo.

[0004] As part of the cargo tank, the dome has a liquid cargo storage area at the bottom and an external space at the top. It needs to have good insulation performance to reduce the heat exchange between the liquid natural gas and the external space. Usually, the side walls of the gas dome are filled with glass wool. Glass wool has good insulation capacity and good deformation capacity, which makes it easy to fill the protruding space formed by the gas dome to fill the protruding space and ensure the insulation effect. At the same time, an insulation box made of polyurethane is arranged under the glass wool. An insulation layer is set on the side of the insulation box away from the side wall, and nitrogen is filled in the insulation layer for insulation. The existing dome insulation structure mainly uses the insulation layer of the liquid cargo tank and the glass wool on the top for insulation. However, when the glass wool filling area shrinks due to cold, gaps will be generated, resulting in cold leakage, resulting in a large amount of flash steam caused by the poor insulation performance of the liquefied natural gas. Summary of the Invention

[0005] In response to one or more of the above-mentioned defects or improvement needs in the prior art, the present invention provides a cryogenic liquefied natural gas membrane storage tank dome protection device to solve the problem that the insulation effect at the dome of the existing membrane tank is poor, resulting in a large amount of liquefied natural gas being vaporized into flash steam.

[0006] To achieve the above-mentioned object, the present invention provides a dome protection device for a cryogenic liquefied natural gas membrane storage tank, comprising:

[0007] A vacuum insulation box, which is arranged around the side wall of the dome;

[0008] a first thermal insulation box, the first thermal insulation box being attached to a side of the vacuum thermal insulation box away from the dome side wall;

[0009] an adhesive layer provided between the vacuum thermal insulation box and the first thermal insulation box;

[0010] Connecting bolts, the connecting bolts being provided on a side of the vacuum thermal insulation box facing the first thermal insulation box, the connecting bolts being passed through a side wall of the first thermal insulation box to securely connect the vacuum thermal insulation box to the first thermal insulation box;

[0011] Among them, the connecting bolt is hollow along the axial direction, one end of the connecting bolt is connected to the inside of the vacuum insulation box, and the other end is connected to the first insulation box. After the vacuum insulation box is evacuated through the connecting bolt, the hollow channel of the connecting bolt is closed to form a vacuum insulation structure.

[0012] As a further improvement of the present invention, a connecting plate extends from one side of the vacuum thermal insulation box toward the first thermal insulation box, and the connecting plate is arranged flush with the bottom of the vacuum thermal insulation box;

[0013] A skirt plate is overlapped on the connecting plate, and the skirt plate includes an overlapping portion and a welding portion that are connected to each other. The overlapping portion and the connecting plate are horizontally stacked, and the overlapping portion and the connecting plate are connected to each other through a clamping mechanism; the welding portion extends vertically and is used for welding connection with the corrugated plate.

[0014] As a further improvement of the present invention, a first insulating pad is provided between the skirt plate and the connecting plate, and the first insulating pad is a polytetrafluoroethylene wound pad.

[0015] As a further improvement of the present invention, the clamping mechanism includes a clamping bolt, and the clamping bolt includes a first screw and a nut;

[0016] A first flange plate is provided on one end of the overlap portion away from the connecting plate, and a second insulating pad is provided on the side of the connecting plate away from the skirt plate; a second flange plate is provided on the side of the second insulating pad away from the connecting plate;

[0017] The first flange plate, the overlapping portion, the connecting plate, the second flange plate, the first isolation pad and the second isolation pad are all provided with through holes, the first screw is passed through the through hole, the nut is provided at the end of the first flange plate away from the overlapping portion, and the nut is threadably engaged with the first screw.

[0018] As a further improvement of the present invention, the through hole on the connecting plate is larger than the diameter of the first screw, and the connecting plate is not connected to the first screw.

[0019] As a further improvement of the present invention, the connecting plate is made of carbon steel, and the skirt plate, the first flange plate, the second flange plate and the clamping bolts are all made of stainless steel.

[0020] As a further improvement of the present invention, the adhesive layer is formed by curing a resin glue, and the adhesive layer forms an annular protective structure after the resin glue is cured.

[0021] As a further improvement of the present invention, a plurality of second thermal insulation boxes are further provided below the vacuum thermal insulation box, and the plurality of second thermal insulation boxes are all attached to the side wall surface of the dome;

[0022] The skirt plate is L-shaped, the overlapping portion is located at the upper end surface of the second thermal insulation box, and the welding portion is located at the side wall surface of the second thermal insulation box.

[0023] As a further improvement of the present invention, the horizontal length of the overlapping portion is greater than the length of the connecting plate, and the connecting plate has plywood arranged side by side toward one end of the welding portion. The plywood is arranged below the overlapping portion, and the plywood is adhesively connected to the second thermal insulation box.

[0024] As a further improvement of the present invention, the connecting bolt includes a stud and a second screw,

[0025] The stud is fixedly connected to the side wall of the vacuum insulation box, the stud is hollow along the axial direction, and the stud is communicated with the interior of the vacuum insulation box;

[0026] The second screw is threadably matched with the hollow channel of the stud, and a sealing ring is provided between the second screw and the stud.

[0027] The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0028] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0029] (1) The dome protection device of the cryogenic liquefied gas membrane storage tank of the present invention is provided with a vacuum insulation box on the side wall of the dome, and a vacuum structure is used to form an insulation area on the side wall of the dome to prevent heat exchange between the liquefied natural gas inside the membrane tank and the external environment, thereby achieving a good insulation effect; secondly, the first insulation box can form an insulation buffer between the vacuum insulation box and the liquefied natural gas, thereby preventing the carbon steel vacuum insulation box from overcooling and losing its bearing capacity, thereby ensuring the vacuum insulation effect of the vacuum insulation box; furthermore, in addition to fixing the first insulation box to the side wall of the vacuum insulation box, the connecting bolt itself also serves as a connecting channel, so that the vacuum insulation box can be evacuated through the vacuum channel on the connecting bolt, so that the vacuum insulation box has a heat insulation effect, thereby reducing the gasification of the liquefied natural gas in the membrane tank.

[0030] (2) The dome protection device for cryogenic liquefied gas membrane storage tanks of the present invention is based on the stable structure of the vacuum insulation box. A connecting plate structure extends from the side wall of the vacuum insulation box, and the skirt plate and the connecting plate are pressed and fixed by a clamping mechanism to achieve a non-welded connection between the two. The stable box structure of the vacuum insulation box provides good support for the fixation of the skirt plate and the connecting plate, while effectively reducing the structural fatigue damage caused by cyclic loads. This application avoids the problem of stress concentration at the welding point caused by inconsistent shrinkage of the two under low temperature conditions by pressing and fixing the skirt plate and the connecting plate instead of welding them, thereby ensuring the mechanical properties and low-temperature resistance of the skirt plate structure and improving the connection stability between the corrugated plate and the skirt plate.

[0031] (3) The dome protective device for the cryogenic liquefied gas membrane storage tank of the present invention provides a first insulating pad between the skirt plate and the connecting plate. The first insulating pad can isolate the carbon penetration between the skirt plate and the connecting plate and has good sealing performance. The sealing effect of the connection structure formed by the skirt plate, the connecting plate, the first insulating pad and the clamping mechanism is ensured. After the skirt plate and the corrugated plate are welded, a complete shielding layer is formed as a whole, thereby avoiding the risk of liquefied natural gas inside the corrugated plate leaking to the external insulation layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 2 is a schematic cross-sectional view of a dome protection device for a cryogenic liquefied gas membrane storage tank according to an embodiment of the present invention;

[0033] Figure 2 yes Figure 1 A in the middle is an enlarged schematic diagram;

[0034] Figure 3 This is a schematic diagram of the cross-sectional structure of the connection between the skirt plate and the connecting plate in an embodiment of the present invention;

[0035] Figure 4 2 is a schematic structural diagram of a skirt plate according to an embodiment of the present invention;

[0036] Figure 5 It is a schematic diagram of the cross-sectional structure of the connecting bolt in an embodiment of the present invention.

[0037] In all the drawings, the same reference numerals represent the same technical features, specifically:

[0038] 101. Vacuum insulation box; 102. First insulation box; 103. Adhesive layer; 104. Connecting bolts; 105. Connecting plate; 106. Skirt plate; 107. Pressing mechanism; 108. First insulation pad; 109. Second insulation pad; 110. Second insulation box; 111. Corrugated plate;

[0039] 1041, stud; 1042, second screw; 1043, sealing ring;

[0040] 1061, overlapping portion; 1062, welding portion;

[0041] 1071. First screw; 1072. Nut; 1073. First flange plate; 1074. Second flange plate. DETAILED DESCRIPTION

[0042] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0043] In the description of the present invention, it should be understood that, unless otherwise specified, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0044] Furthermore, unless otherwise specified, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specified.

[0045] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0046] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0047] Example:

[0048] See Figures 1 to 5 The dome protection device for a cryogenic liquefied gas membrane storage tank in a preferred embodiment of the present invention includes a vacuum insulation box 101, which is arranged around the side wall of the dome; a first insulation box 102, which is attached to the side of the vacuum insulation box 101 away from the side wall of the dome; an adhesive layer 103, which is arranged between the vacuum insulation box 101 and the first insulation box 102; and a connecting bolt 104, which is arranged on the vacuum insulation box 101. On the side facing the first thermal insulation box 102, a connecting bolt 104 is provided through the side wall of the first thermal insulation box 102 to fixedly connect the vacuum thermal insulation box 101 to the first thermal insulation box 102; and the connecting bolt 104 is hollow along the axial direction, with one end of the connecting bolt 104 communicating with the interior of the vacuum thermal insulation box 101 and the other end connected to the first thermal insulation box 102. After the vacuum thermal insulation box 101 is evacuated by the connecting bolt 104, the hollow channel of the connecting bolt 104 is sealed to form a vacuum thermal insulation structure.

[0049] Specifically, the dome protection device of the low-temperature liquefied gas membrane storage tank of the present invention sets a vacuum insulation box 101 on the side wall of the dome, and uses a vacuum structure to form an insulation area on the side wall of the dome to avoid heat exchange between the liquefied natural gas inside the membrane tank and the external environment, so as to achieve a good insulation effect; secondly, the present application sets a first insulation box 102 on the side of the vacuum insulation box 101 close to the liquefied natural gas. The first insulation box 102 is used to form a gradient buffer between the liquefied natural gas and the vacuum insulation box 101 to avoid direct contact between the supercooled liquefied natural gas and the vacuum insulation box 101. The vacuum insulation box 101 is an integrated structure with the side walls and top surface of the dome, and the side walls of the dome structure are usually carbon steel structures, so that the dome has better strength to adapt to the support and placement of pump towers, etc. The vacuum insulation box 101 made of carbon steel has a shrinkage problem when encountering supercooled liquefied natural gas and is easily damaged. Therefore, the present application sets a first insulation box 102 to avoid damage to the vacuum insulation box 101 when it is cold. Furthermore, the present application provides a connecting bolt 104 on the side of the vacuum insulation box 101 facing the first insulation box 102. In addition to fixing the first insulation box 102 to the side wall of the vacuum insulation box 101, the connecting bolt 104 itself also serves as a connecting channel, so that the vacuum insulation box 101 can be evacuated through the vacuum channel on the connecting bolt 104, so that the vacuum insulation box 101 has a thermal insulation effect to reduce the gasification of liquefied natural gas in the membrane tank.

[0050] Furthermore, as an optional embodiment of the present invention, a connecting plate 105 extends from one side of the vacuum insulation box 101 toward the first insulation box 102. The connecting plate 105 is flush with the bottom of the vacuum insulation box 101. A skirt plate 106 is overlapped on the connecting plate 105. The skirt plate 106 includes an overlapping portion 1061 and a welding portion 1062 that are interconnected. The overlapping portion 1061 is horizontally stacked with the connecting plate 105. The overlapping portion 1061 and the connecting plate 105 are connected by a clamping mechanism 107. The welding portion 1062 extends vertically and is used for welding to the corrugated plate 111. In addition to providing thermal insulation and sealing, the dome structure also bears the structure of the welded corrugated plate 111. As a component of the membrane tank, the corrugated plate 111 has good shrinkage properties to accommodate the expansion problem caused by the gasification of liquefied natural gas. In the prior art, an L-shaped member is welded to the top surface of the dome structure. A certain gap exists between the L-shaped member and the side wall of the dome, and the gap is filled with glass wool for thermal insulation. Then, using the L-shaped member as a fulcrum, a corrugated plate 111 is attached to the L-shaped member to integrate the corrugated plate 111 with the dome structure, forming a closed, insulated structure. This prevents heat exchange between the liquefied natural gas (LNG) in the membrane tank and the dome's sidewalls. Typically, the L-shaped member connected to the dome is made of the same material as the dome, facilitating a welded connection. The corrugated plate 111 is typically made of stainless steel, which requires good low-temperature resistance and ductility. In the prior art, the corrugated plate 111 and L-shaped member are typically welded together. However, the carbon steel L-shaped member and the stainless steel corrugated plate 111 have different carbon contents, resulting in different material properties and resistance to bending and shrinkage. During long-term use of the membrane tank, stress concentration is likely to occur at the connection between the L-shaped member and the corrugated plate 111. Furthermore, the carbon in the L-shaped member can penetrate the stainless steel, affecting the mechanical properties and low-temperature resistance of the corrugated plate 111 itself, ultimately causing leakage in the membrane tank. Based on this, the present invention is based on the stable structure of the vacuum insulation box 101, and extends the connecting plate 105 structure at the side wall of the vacuum insulation box 101, and presses and fixes the skirt plate 106 and the connecting plate 105 through the pressing mechanism 107, thereby realizing a non-welded connection between the two. The stable box structure of the vacuum insulation box 101 provides good support for the fixation of the skirt plate 106 and the connecting plate 105. Even if the expansion of liquefied natural gas causes the corrugated plate 111 to squeeze the skirt plate 106, the skirt plate 106 can still transmit the force to the vacuum insulation box 101, so that the skirt plate 106 is stably arranged. The present application avoids the welding connection between the skirt plate 106 and the connecting plate 105 by pressing and fixing them, avoids the problem of stress concentration at the welding point caused by the inconsistent shrinkage of the two under low temperature conditions, slows down the carbon penetration between the two, ensures the mechanical properties and low temperature resistance of the skirt plate 106 structure, and improves the connection stability between the corrugated plate 111 and the skirt plate 106.

[0051] Furthermore, as an optional embodiment of the present invention, a first insulating pad 108 is provided between the skirt plate 106 and the connecting plate 105, and the first insulating pad 108 is a polytetrafluoroethylene wound pad. The polytetrafluoroethylene wound pad is made of a spiral composite of stainless steel and polytetrafluoroethylene, and has good strength and toughness, and has pressure resistance and low temperature resistance. By providing the first insulating pad 108 between the skirt plate 106 and the connecting plate 105, the first insulating pad 108 can isolate the carbon penetration between the skirt plate 106 and the connecting plate 105. At the same time, the good pressure resistance and heat insulation capabilities make the connection structure formed by the skirt plate 106, the connecting plate 105, the first insulating pad 108 and the clamping mechanism 107 have good sealing performance. After the skirt plate 106 and the corrugated plate 111 are welded, the skirt plate 106 and the connecting plate 105 connected by crimping also have good sealing performance, thereby preventing the liquefied natural gas inside the corrugated plate 111 from leaking to the external insulation layer.

[0052] Further, as an optional embodiment of the present invention, the clamping mechanism 107 includes a clamping bolt, which includes a first screw 1071 and a nut 1072. A first flange plate 1073 is provided at the end of the overlapping portion 1061 facing away from the connecting plate 105, and a second isolation pad 109 is also provided on the side of the connecting plate 105 facing away from the skirt plate 106; at the same time, a second flange plate 1074 is provided on the side of the second isolation pad 109 facing away from the connecting plate 105; corresponding through holes are provided on the first flange plate 1073, the overlapping portion 1061, the connecting plate 105, the second flange plate 1074, the first isolation pad 108 and the second isolation pad 109, and the first screw 1071 cooperates with the nut 1072 to tighten and fix each structure. By tightening the first screw 1071 and the nut 1072, a stable connection between the skirt plate 106 and the connecting plate 105 can be achieved, and the setting of the first isolation pad 108 and the second isolation pad 109 can prevent the skirt plate 106 from contacting the connecting plate 105, eliminating the possibility of carbon penetration between the two.

[0053] Furthermore, as an optional embodiment of the present invention, the through hole on the connecting plate 105 in the present application is larger than the diameter of the first screw 1071, so that the connecting plate 105 and the first screw 1071 do not contact each other. In the present application, a first insulating pad 108 and a second insulating pad 109 are provided on both sides of the connecting plate 105 to isolate the connecting plate 105 from the skirt plate 106 and the clamping mechanism 107, thereby preventing carbon penetration between the connecting plate 105 and the skirt plate 106. The lack of contact between the first screw 1071 and the connecting plate 105 can prevent indirect connection between the connecting plate 105 and the skirt plate 106.

[0054] Furthermore, as an optional embodiment of the present invention, the adapter plate 105 in this application is made of carbon steel, while the skirt plate 106, first flange plate 1073, second flange plate 1074, and compression bolts are all made of stainless steel. The first and second isolation pads 108 and 109 isolate the two sides of the adapter plate 105, and the first flange plate 1073 and compression bolts secure the skirt plate 106 to the adapter plate 105. This prevents carbon penetration between the skirt plate 106 and the adapter plate 105, while also ensuring a stable connection and a sealed seal at the joint.

[0055] Furthermore, as an optional embodiment of the present invention, the adhesive layer 103 in the present application is formed by curing a resin glue, and the adhesive layer 103 forms an annular protective structure after the resin glue is cured. The dome side wall is annular in structure as a whole. After the vacuum insulation box 101 and the first insulation box 102 are bonded, the resin glue bonded along the dome side wall is cured to form an annular adhesive layer 103. In addition to having a bonding effect, the adhesive layer 103 itself forms a solid structure, which can reduce heat transfer between the first insulation box 102 and the vacuum insulation box 101, and can serve as a load-bearing structure to form a protective structure between the first insulation box 102 and the vacuum insulation box 101.

[0056] Furthermore, as an optional embodiment of the present invention, a plurality of second thermal insulation boxes 110 are provided below the vacuum thermal insulation box 101, and the plurality of second thermal insulation boxes 110 are all attached to the side wall surface of the dome; at the same time, the skirt board 106 is L-shaped, the overlapping portion 1061 is located at the upper end surface of the second thermal insulation box 110, and the welding portion 1062 is located at the side wall surface of the second thermal insulation box 110. The side wall surface of the dome usually needs to cooperate with the thermal insulation box structure to form an insulating layer. In the present application, a plurality of second thermal insulation boxes 110 are arranged on the side wall surface of the dome, which, on the one hand, play a role of heat insulation, and on the other hand, can serve as an overlapping structure of the skirt board 106 to support the skirt board 106. When the corrugated plate 111 expands, it will squeeze the skirt plate 106. The upper and lower surfaces of the skirt plate 106 will respectively abut the first insulation box 102 and the second insulation box 110, and the side wall of the skirt plate 106 will abut the side wall of the second insulation box 110. The force on the skirt plate 106 is distributed to the two insulation boxes, avoiding the force of the skirt plate 106 to be transmitted to the connection with the connecting plate 105, avoiding stress concentration at the connection between the skirt plate 106 and the connecting plate 105, and improving the connection stability of the skirt plate 106 and the connecting plate 105.

[0057] Furthermore, as an optional embodiment of the present invention, the horizontal length of the overlap portion 1061 is greater than the length of the connecting plate 105, and plywood is arranged side by side at one end of the connecting plate 105 facing the welding portion 1062. The plywood is arranged below the overlap portion 1061, and the plywood is adhesively connected to the second thermal insulation box 110. The overlapping structure of the overlap portion 1061 and the connecting plate 105 allows the two to be arranged in a stacked manner. The skirt plate 106 is an L-shaped component, and a gap is easily formed at the connection between the overlap portion 1061 and the welding portion 1062 of the skirt plate 106. It is easy to bend when subjected to force, and the connection between the overlap portion 1061 and the welding portion 1062 is easy to break. Therefore, the portion of the overlap portion 1061 that is beyond the connecting plate 105 is filled with plywood. The plywood is a flexible structure that can fill the connection between the overlap portion 1061 and the welding portion 1062 and has a certain energy absorption capacity. At the same time, it can be connected to the second heat insulation box 110 through plywood to form a stable supporting structure under the overlapping portion 1061 to withstand the extrusion force exerted on the skirt board 106 and improve the service life of the skirt board 106.

[0058] Furthermore, as an optional embodiment of the present invention, the first and second thermally insulated boxes 102 and 110 herein have identical structures, specifically comprising an outer shell formed from plywood, with the space formed by the plywood filled with polyurethane foam. This combination of plywood and polyurethane foam provides excellent thermal insulation and serves as a support structure. It also deforms under pressure, preventing the membrane tank formed by the corrugated sheet 111 from excessively expanding and avoiding rigid contact with the membrane tank.

[0059] Furthermore, as an optional embodiment of the present invention, the connecting bolt 104 includes a stud 1041 and a second screw 1042. The stud 1041 is fixedly connected to the side wall of the vacuum insulation box 101, and the stud 1041 is hollow along the axial direction. The stud 1041 is connected to the interior of the vacuum insulation box 101; the second screw 1042 is threadedly matched with the hollow channel of the stud 1041, and a sealing ring 1043 is also provided between the second screw 1042 and the stud 1041. The stud 1041 is connected to the interior of the vacuum insulation box 101 and is integrally formed with the side wall of the vacuum insulation box 101. After the interior of the vacuum insulation box 101 is evacuated through the stud 1041, the through hole of the stud 1041 is first blocked with a flexible sheet, and then the second screw 1042 with a sealing ring 1043 is screwed into the through hole of the stud 1041. The flexible sheet is squeezed into the interior of the vacuum insulation box 101 under the extrusion force of the second screw 1042 and the internal vacuum negative pressure. The second screw 1042 with the sealing ring 1043 matches the stud 1041 and blocks the vacuumed through hole, and the vacuum insulation box 101 is sealed.

[0060] Furthermore, as an optional embodiment of the present invention, after the vacuum insulation box 101 is evacuated, the present application may also fill the hollow channel of the stud 1041 with rubber material to seal it, and then seal the hollow channel of the stud 1041 through metal welding to achieve the sealing of the vacuum insulation box 101.

[0061] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A dome protection device for a cryogenic liquefied gas membrane storage tank, characterized in that: include: A vacuum insulation box, which is arranged around the side wall of the dome; a first thermal insulation box, the first thermal insulation box being attached to a side of the vacuum thermal insulation box away from the dome side wall; an adhesive layer provided between the vacuum thermal insulation box and the first thermal insulation box; Connecting bolts, the connecting bolts being provided on a side of the vacuum thermal insulation box facing the first thermal insulation box, the connecting bolts being passed through a side wall of the first thermal insulation box to securely connect the vacuum thermal insulation box to the first thermal insulation box; The connecting bolt is hollow along the axial direction, one end of the connecting bolt is connected to the interior of the vacuum insulation box, and the other end is connected to the first insulation box. After the vacuum insulation box is evacuated through the connecting bolt, the hollow channel of the connecting bolt is closed to form a vacuum insulation structure. A connecting plate extends from one side of the vacuum thermal insulation box toward the first thermal insulation box, and the connecting plate is arranged flush with the bottom of the vacuum thermal insulation box; The connecting plate is overlapped with a skirt plate, and the skirt plate includes an overlapping portion and a welding portion connected to each other. The overlapping portion and the connecting plate are horizontally stacked, and the overlapping portion and the connecting plate are connected by a clamping mechanism, which is a clamping bolt; the welding portion extends vertically and is used for welding to the corrugated plate; A first insulating pad is further provided between the skirt plate and the connecting plate, and the first insulating pad is a polytetrafluoroethylene winding pad.

2. The dome protection device for cryogenic liquefied gas membrane storage tank according to claim 1 is characterized in that: The clamping bolt includes a first screw and a nut; A first flange plate is provided on one end of the overlap portion away from the connecting plate, and a second insulating pad is provided on the side of the connecting plate away from the skirt plate; a second flange plate is provided on the side of the second insulating pad away from the connecting plate; The first flange plate, the overlapping portion, the connecting plate, the second flange plate, the first isolation pad and the second isolation pad are all provided with through holes, the first screw is passed through the through hole, the nut is provided at the end of the first flange plate away from the overlapping portion, and the nut is threadably engaged with the first screw.

3. The dome protection device for cryogenic liquefied gas membrane storage tank according to claim 2, characterized in that: The through hole on the connecting plate is larger than the diameter of the first screw, and the connecting plate is not connected to the first screw.

4. The dome protection device for cryogenic liquefied gas membrane storage tank according to claim 3 is characterized in that: The connecting plate is made of carbon steel, and the skirt plate, the first flange plate, the second flange plate and the clamping bolts are all made of stainless steel.

5. The dome protection device for cryogenic liquefied gas membrane storage tank according to claim 1, characterized in that: The bonding layer is formed by curing a resin adhesive, and the bonding layer forms a ring-shaped protective structure after the resin adhesive is cured.

6. The dome protection device for cryogenic liquefied gas membrane storage tank according to claim 1, characterized in that: A plurality of second thermal insulation boxes are further provided below the vacuum thermal insulation box, and the plurality of second thermal insulation boxes are all attached to the side wall surface of the dome; The skirt plate is L-shaped, the overlapping portion is located at the upper end surface of the second thermal insulation box, and the welding portion is located at the side wall surface of the second thermal insulation box.

7. The dome protection device for a cryogenic liquefied gas membrane storage tank according to claim 6, characterized in that: The horizontal length of the overlap portion is greater than the length of the connecting plate. The connecting plate has plywood arranged side by side at one end toward the welding portion. The plywood is arranged below the overlap portion and is adhesively connected to the second thermal insulation box.

8. The dome protection device for cryogenic liquefied gas membrane storage tank according to claim 1, characterized in that: The connecting bolt includes a stud and a second screw, The stud is fixedly connected to the side wall of the vacuum insulation box, the stud is hollow along the axial direction, and the stud is communicated with the interior of the vacuum insulation box; The second screw is threadably matched with the hollow channel of the stud, and a sealing ring is provided between the second screw and the stud.

Images