Dome protection device of low-temperature liquefied gas film storage tank

Abstract

The invention relates to the technical field of liquid cargo storage devices, and discloses a low-temperature liquefied gas film storage tank dome protection device which comprises a vacuum heat insulation box arranged on the side wall face of a dome, a first heat insulation box attached to the vacuum heat insulation box and a bonding layer for bonding the vacuum heat insulation box and the first heat insulation box. The connecting bolt is hollow in the axial direction, the vacuum heat insulation box shell is vacuumized through the connecting bolt and is sealed to form a vacuum heat insulation structure, and meanwhile the connecting bolt is used for connecting the first heat insulation box and the vacuum heat insulation box into a whole. A good heat insulation effect is achieved through vacuum heat insulation of the vacuum heat insulation box, meanwhile, vacuumizing operation is completed through the connecting bolts, the first heat insulation box can be fixed to the surface of the vacuum heat insulation box through the subsequent connecting bolts, and the problem that the vacuum heat insulation box is damaged due to the fact that liquefied gas makes contact with the vacuum heat insulation box is solved; stable heat insulation of the vacuum heat insulation box is ensured, and gasification of liquefied natural gas in the film tank is reduced.

Description

Technical Field

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

[0002] As a clean and efficient energy source, liquefied natural gas is mainly stored and transported through cryogenic atmospheric storage tanks or pressure storage tanks. There are mainly two ways of transporting liquefied natural gas: by sea and by land. In the sea transportation mode, it is mainly transported by LNG ships.

[0003] For the transportation of liquefied natural gas, an LNG ship is provided with a liquid cargo hold thin film, an insulation layer, a dome deck and a dome. Among them, the liquid cargo hold thin film is used to directly store liquefied natural gas, which is formed by splicing and welding corrugated plates. The corrugated structure is used to absorb the cold shrinkage generated when the thin film loads cryogenic liquefied gas. The insulation layer is arranged outside the liquid cargo hold thin film to isolate the liquid cargo hold thin film 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 deck is a deck structure at the top of the liquid cargo hold, mainly used to support the dome structure and related operating equipment, and as a platform for staff to operate and maintain the liquid cargo hold. The dome protrudes above the deck and is used as a support structure for structures such as pump towers and as an inlet and outlet for liquid cargo.

[0004] As a part of the liquid cargo hold, the dome has a liquid cargo storage area at its lower part and an external space at its upper part. It needs to have good heat insulation performance to reduce the heat exchange between liquid natural gas and the external space. Usually, glass wool is filled at the side wall surface of the gas dome. Glass wool has good heat insulation ability and good deformation ability, which is convenient for filling in the protruding space formed by the gas dome to fill the protruding space and ensure the heat insulation effect. At the same time, an insulation box made of polyurethane is arranged below the glass wool. An insulation layer is arranged on the side of the insulation box away from the side wall surface, and nitrogen is filled in the insulation layer for heat insulation. The existing dome insulation structure mainly insulates heat through the insulation layer of the liquid cargo hold and the glass wool at the top. However, when the glass wool filling area contracts due to cold, voids will be generated, resulting in cold leakage. As a result, there is still a relatively large amount of flash steam in the liquefied natural gas due to poor heat insulation performance. Summary of the Invention

[0005] In view of one or more of the above defects or improvement requirements in the prior art, the present invention provides a dome protection device for a cryogenic liquefied natural gas thin-film storage tank to solve the problem that the heat insulation effect at the dome of the existing thin-film tank is poor, resulting in a relatively large amount of liquefied natural gas vaporizing into flash steam.

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

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

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

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

[0010] A connecting bolt, wherein the connecting bolt is arranged on a side of the vacuum insulation box facing the first insulation box, and the connecting bolt is passed through a side wall of the first insulation box to fix the vacuum insulation box to the first insulation box;

[0011] Among them, 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 by 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 connection plate extends from one side of the vacuum thermal insulation box toward the first thermal insulation box, and the connection plate is arranged flush with the bottom of the vacuum thermal insulation box;

[0013] The connecting plate is overlapped with a skirt 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 is vertically extended and arranged for welding connection with the corrugated plate.

[0014] As a further improvement of the present invention, 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.

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

[0016] A first flange plate is provided at one end of the overlap portion away from the connecting plate, and a second insulating pad is provided at one side of the connecting plate away from the skirt plate; a second flange plate is provided at one 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 insulating pad and the second insulating pad are all provided with through holes, the first screw is inserted into the through hole, the nut is arranged at the end of the first flange plate away from the overlapping portion, and the nut is threadably matched 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 in contact with 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 pressing bolt are all made of stainless steel.

[0020] As a further improvement of the present invention, the bonding layer is formed by curing resin glue, and the bonding 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 heat insulation boxes are further provided below the vacuum heat insulation box, and a plurality of the second heat insulation boxes are all attached to the side wall surface of the dome;

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

[0023] As a further improvement of the present invention, the length of the overlapping part in the horizontal direction is greater than the length of the connecting plate. A plurality of plywood boards are arranged side by side at one end of the connecting plate facing the welding part. The plywood boards are arranged below the overlapping part, and the plywood boards are adhesively connected to the second heat 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 heat insulation box. The stud is hollow along the axial direction, and the stud communicates with the inside of the vacuum heat insulation box;

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

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

[0028] Generally speaking, compared with the prior art, the beneficial effects of the above technical solutions conceived by the present invention include:

[0029] (1) The dome protection device for the low-temperature liquefied gas thin-film storage tank of the present invention forms a heat insulation area on the side wall surface of the dome by arranging a vacuum heat insulation box, and uses the vacuum structure to prevent heat exchange between the liquefied natural gas inside the thin-film tank and the external environment, so as to achieve a good heat insulation effect. Secondly, the first heat insulation box can form a heat insulation buffer between the vacuum heat insulation box and the liquefied natural gas, preventing the vacuum heat insulation box made of carbon steel from losing its bearing capacity due to excessive cold and ensuring the vacuum heat insulation effect of the vacuum heat insulation box. Moreover, in addition to fixing the first heat insulation box on the side wall of the vacuum heat insulation box, the connecting bolts themselves also serve as a communication channel, enabling the vacuum heat insulation box to be evacuated through the vacuum channels on the connecting bolts, making the vacuum heat insulation box have the function of heat isolation to reduce the gasification of the liquefied natural gas in the thin-film tank.

[0030] (2) The dome protection device for the low-temperature liquefied gas thin-film storage tank of the present invention, based on the stable structure of the vacuum heat insulation box, extends a connecting plate structure at the side wall of the vacuum heat insulation box, and presses and fixes the skirt plate and the connecting plate through a pressing mechanism to achieve non-welded connection between the two. The stable box structure of the vacuum heat insulation box provides good support for the fixation of the skirt plate and the connecting plate, and effectively reduces the structural fatigue damage caused by cyclic loads. In this application, by pressing and fixing the skirt plate and the connecting plate instead of welding, the problem of stress concentration at the welding point caused by inconsistent shrinkage of the two under low-temperature conditions is avoided, ensuring the mechanical properties and low-temperature resistance characteristics of the skirt plate structure and improving the connection stability between the corrugated plate and the skirt plate.

[0031] (3) The dome protection device for the low-temperature liquefied gas thin-film storage tank of the present invention sets a first isolation pad between the skirt plate and the connecting plate. The first isolation pad can isolate carbon penetration between the skirt plate and the connecting plate and has good sealing performance, ensuring the sealing effect of the connection structure formed by the skirt plate, the connecting plate, the first isolation pad and the pressing mechanism. After the skirt plate and the corrugated plate are welded, a complete shielding layer is formed as a whole, avoiding the risk of leakage of liquefied natural gas inside the corrugated plate to the external insulation layer. Brief Description of the Drawings

[0032] Figure 1 is a schematic cross-sectional structure diagram of the dome protection device for the low-temperature liquefied gas thin-film storage tank in the embodiment of the present invention;

[0033] Figure 2 is Figure 1 an enlarged schematic diagram at A in

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

[0035] Figure 4 is a schematic structure diagram of the skirt plate in the embodiment of the present invention;

[0036] Figure 5 It is a schematic cross-sectional structure diagram of the connecting bolt in the 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 bolt; 105, connecting plate; 106, skirt plate; 107, pressing mechanism; 108, first isolation pad; 109, second isolation pad; 110, second insulation box; 111, corrugated plate;

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

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

[0041] 1071, first screw; 1072, nut; 1073, first flange plate; 1074, second flange plate. Detailed implementation manners

[0042] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can 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", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention.

[0044] In addition, unless otherwise specified, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0047] Example:

[0048] See also Figures 1 to 5 The dome protection device of the cryogenic liquefied gas film storage tank in the preferred embodiment of the present invention comprises 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. 1 is toward the side of the first thermal insulation box 102, and the connecting bolt 104 is penetrated on the side wall of the first thermal insulation box 102 to fixedly connect the vacuum thermal insulation box 101 with the first thermal insulation box 102; and the connecting bolt 104 is hollow along the axial direction, one end of the connecting bolt 104 is communicated with the inside of the vacuum thermal insulation box 101, and the other end is connected to the first thermal insulation box 102, and after the vacuum thermal insulation box 101 is evacuated by the connecting bolt 104, the hollow channel of the connecting bolt 104 is closed to form a vacuum thermal insulation structure.

[0049] Specifically, for the dome protection device of the low-temperature liquefied gas thin-film storage tank of the present invention, a vacuum insulation box 101 is provided on the side wall surface of the dome. The vacuum structure forms an insulation area on the side wall surface of the dome to prevent heat exchange between the liquefied natural gas inside the thin-film tank and the external environment, thus achieving a good heat insulation effect. Secondly, a first insulation box 102 is provided 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 prevent supercooled liquefied natural gas from directly contacting the vacuum insulation box 101. The vacuum insulation box 101 is an integral structure with the side wall and the top surface of the dome, and the side wall of the dome structure is usually made of carbon steel, so that the dome has better strength to adapt to the support and placement of a pump tower, 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 first insulation box 102 is provided in this application to prevent the vacuum insulation box 101 from being damaged by cold. Furthermore, in this application, a connecting bolt 104 is provided on the side of the vacuum insulation box 101 facing the first insulation box 102. In addition to fixing the first insulation box 102 on the side wall of the vacuum insulation box 101, the connecting bolt 104 itself also serves as a communication channel, so that the vacuum insulation box 101 can be evacuated through the vacuum channel on the connecting bolt 104, enabling the vacuum insulation box 101 to have a heat insulation effect and reducing the gasification of the liquefied natural gas in the thin-film tank.

[0050] Further, as an alternative embodiment of the present invention, a connecting plate 105 extends from one side of the vacuum insulation box 101 facing the first insulation box 102, and the connecting plate 105 is arranged flush with the bottom of the vacuum insulation box 101; and a skirt plate 106 is lapped on the connecting plate 105. The skirt plate 106 includes a lapping portion 1061 and a welding portion 1062 which are connected to each other. The lapping portion 1061 and the connecting plate 105 are horizontally stacked, and the lapping portion 1061 and the connecting plate 105 are connected by a pressing mechanism 107. The welding portion 1062 extends vertically and is used for welding connection with the corrugated plate 111. In addition to the heat insulation and sealing treatment at the dome structure, it also bears the structure for welding the corrugated plate 111. The corrugated plate 111, as a component of the thin-film tank, has good shrinkage performance to adapt to the expansion problem caused by the gasification of liquefied natural gas. In the prior art, an L-shaped member is welded on the top surface of the dome structure. There is a certain gap between the L-shaped member and the dome side wall, and glass wool is filled in the gap for heat insulation. Then, taking the L-shaped member as a fulcrum, the corrugated plate 111 is connected to the L-shaped member to connect the corrugated plate 111 and the dome structure into an integrated closed adiabatic structure to prevent heat exchange between the liquefied natural gas in the thin-film tank and the dome side wall. Generally, the L-shaped member is connected to the dome and is made of the same material as the dome for easy welding connection with the dome; while the corrugated plate 111 is usually made of stainless steel and needs to have good low-temperature resistance and good ductility. In the prior art, the corrugated plate 111 and the L-shaped member are usually welded together. However, the carbon content of the carbon steel L-shaped member and the stainless steel corrugated plate 111 is different, and their material properties are different, resulting in differences in anti-bending and shrinkage performance. During the long-term use of the thin-film tank, stress concentration is likely to occur at the connection position between the L-shaped member and the corrugated plate 111. At the same time, the carbon in the L-shaped member will penetrate into the stainless steel, affecting the mechanical properties and low-temperature resistance of the corrugated plate 111 itself, and ultimately causing leakage of the thin-film tank. Based on this, based on the stable structure of the vacuum insulation box 101, a connecting plate 105 structure is extended from the side wall of the vacuum insulation box 101, and the skirt plate 106 and the connecting plate 105 are pressed and fixed through the pressing mechanism 107 to achieve 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 liquefied natural gas expands and causes the corrugated plate 111 to squeeze the skirt plate 106, the skirt plate 106 can conduct the force to the vacuum insulation box 101, so that the skirt plate 106 is stably arranged. By pressing and fixing the skirt plate 106 and the connecting plate 105 in this application, the welded connection between the two is avoided, the problem of stress concentration at the welding point caused by inconsistent shrinkage of the two under low-temperature conditions is avoided, the carbon penetration between the two is slowed down, the mechanical properties and low-temperature resistance of the skirt plate 106 structure are ensured, and the connection stability between the corrugated plate 111 and the skirt plate 106 is improved.

[0051] Furthermore, as an alternative embodiment of the present invention, a first isolation pad 108 is further provided between the skirt plate 106 and the connection plate 105, and the first isolation pad 108 is a polytetrafluoroethylene winding pad. The polytetrafluoroethylene winding pad is made of stainless steel and polytetrafluoroethylene helically wound together, and it has good strength and toughness, and has the characteristics of pressure resistance and low temperature resistance. By providing the first isolation pad 108 between the skirt plate 106 and the connection plate 105, the first isolation pad 108 can isolate carbon penetration between the skirt plate 106 and the connection plate 105. At the same time, with good compressive and heat insulation capabilities, the connection structure formed by the skirt plate 106, the connection plate 105, the first isolation pad 108 and the pressing mechanism 107 has good sealing performance. After the skirt plate 106 and the corrugated plate 111 are welded, the skirt plate 106 and the connection plate 105 connected by crimping also have good sealing performance, avoiding the leakage of liquefied natural gas inside the corrugated plate 111 to the external insulation layer.

[0052] Furthermore, as an alternative embodiment of the present invention, the pressing mechanism 107 includes a pressing bolt, the pressing bolt includes a first screw 1071 and a nut 1072. A first flange plate 1073 is provided at one end of the overlapping portion 1061 away from the connection plate 105, and a second isolation pad 109 is further provided on the side of the connection plate 105 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 away from the connection plate 105; through holes are correspondingly formed on the first flange plate 1073, the overlapping portion 1061, the connection plate 105, the second flange plate 1074, the first isolation pad 108 and the second isolation pad 109, and the first screw 1071 and the nut 1072 cooperate to tighten and fix each structure. Through the tightening and cooperation form of the first screw 1071 and the nut 1072, the stable connection between the skirt plate 106 and the connection plate 105 can be realized, and the setting of the first isolation pad 108 and the second isolation pad 109 can prevent the skirt plate 106 and the connection plate 105 from contacting, eliminating the possibility of carbon penetration between the two.

[0053] Furthermore, as an alternative embodiment of the present invention, the through hole on the connection plate 105 in the present application is larger than the diameter of the first screw 1071, so that the connection plate 105 and the first screw 1071 are not in contact. In the present application, the first isolation pad 108 and the second isolation pad 109 are provided on both sides of the connection plate 105 to isolate the connection plate 105 from the skirt plate 106 and the pressing mechanism 107, avoiding carbon penetration between the connection plate 105 and the skirt plate 106, and the non-contact between the first screw 1071 and the connection plate 105 can avoid the indirect contact between the connection plate 105 and the skirt plate 106.

[0054] Furthermore, as an alternative embodiment of the present invention, the connecting plate 105 in the present application is made of carbon steel, and the skirt plate 106, the first flange plate 1073, the second flange plate 1074, and the compression bolts are all made of stainless steel. The first isolation pad 108 and the second isolation pad 109 isolate both sides of the connecting plate 105, and then the skirt plate 106 and the connecting plate 105 are fixed through the first flange plate 1073 and the compression bolts, which can not only avoid carbon penetration between the skirt plate 106 and the connecting plate 105, but also achieve stable connection between the two, ensuring the seal at the connection between the two.

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

[0056] Furthermore, as an alternative embodiment of the present invention, a plurality of second heat insulation boxes 110 are further provided below the vacuum heat insulation box 101, and the plurality of second heat insulation boxes 110 are all attached to the side wall surface of the dome; at the same time, the skirt plate 106 is in an L shape, the overlapping portion 1061 is located at the upper end surface of the second heat insulation box 110, and the welding portion 1062 is located at the side wall surface of the second heat insulation box 110. The side wall surface of the dome usually needs to cooperate with the heat insulation box structure to form an insulating layer. In the present application, a plurality of second heat insulation boxes 110 are arranged on the side wall surface of the dome. On the one hand, it plays a heat insulation role, and on the other hand, it can serve as an overlapping structure of the skirt plate 106 to support the skirt plate 106. When the corrugated plate 111 expands, it will squeeze the skirt plate 106. The upper and lower surfaces of the skirt plate 106 are respectively in contact with the first heat insulation box 102 and the second heat insulation box 110, and the side wall surface of the skirt plate 106 is in contact with the side wall of the second heat insulation box 110. The force on the skirt plate 106 is distributed to the two heat insulation boxes, avoiding the force on the skirt plate 106 from being 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 between the skirt plate 106 and the connecting plate 105.

[0057] Further, as an alternative embodiment of the present invention, the length of the overlapping portion 1061 in the horizontal direction is greater than the length of the connecting plate 105. A plywood board is arranged side by side at one end of the connecting plate 105 facing the welding portion 1062. The plywood board is arranged below the overlapping portion 1061 and is adhesively connected to the second heat insulation box 110. The overlapping structure of the overlapping portion 1061 and the connecting plate 105 enables the two to be arranged in a laminated manner. The skirt plate 106 is an L-shaped member, and gaps are likely to appear at the connection position between the overlapping portion 1061 of the skirt plate 106 and the welding portion 1062, and it is likely to bend when stressed, and the connection position between the overlapping portion 1061 and the welding portion 1062 is likely to break. Therefore, in the part where the overlapping portion 1061 extends beyond the connecting plate 105, a plywood board is filled and arranged below. The plywood board is a flexible structure, which can fill the connection between the overlapping portion 1061 and the welding portion 1062 and has a certain energy absorption capacity. At the same time, the plywood board can be connected to the second heat insulation box 110 to form a stable lifting structure below the overlapping portion 1061 to bear the extrusion force received by the skirt plate 106 and improve the service life of the skirt plate 106.

[0058] Further, as an alternative embodiment of the present invention, the first heat insulation box 102 and the second heat insulation box 110 in the present application have the same structure, which specifically includes an external shell formed by plywood boards, and a polyurethane foam material is filled in the space formed by the plywood boards. The heat insulation box composed of plywood boards and polyurethane foam material has good heat insulation ability, can be used as a support structure, and will deform when pressed, preventing the film tank formed by the corrugated plate 111 from expanding excessively and avoiding rigid contact with the film tank.

[0059] Further, as an alternative 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 heat insulation box 101, and the stud 1041 is hollow along the axial direction and communicates with the inside of the vacuum heat insulation box 101; the second screw 1042 is threadedly matched with the hollow channel of the stud 1041, and a sealing ring 1043 is further arranged between the second screw 1042 and the stud 1041. The stud 1041 communicates with the inside of the vacuum heat insulation box 101 and is integrally formed with the side wall of the vacuum heat insulation box 101. After the inside of the vacuum heat insulation box 101 is evacuated through the stud 1041, a flexible sheet is first used to block the through hole of the stud 1041, and then the second screw 1042 with the sealing ring 1043 is screwed into the through hole of the stud 1041. The flexible sheet is squeezed into the inside of the vacuum heat 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 is matched with the stud 1041 and blocks the evacuated through hole, and the vacuum heat insulation box 101 is completed to be sealed.

[0060] Further, as an alternative embodiment of the present invention, after the vacuum insulation box 101 is evacuated, a rubber material can also be filled in the hollow channel of the stud 1041 for plugging, and then the hollow channel of the stud 1041 is closed by means of metal welding to achieve the sealing of the vacuum insulation box 101.

[0061] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dome protection device for a low-temperature liquefied gas thin-film 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, wherein the first thermal insulation box is attached to a side of the vacuum thermal insulation box away from the side wall of the dome; an adhesive layer, the adhesive layer being provided between the vacuum thermal insulation box and the first thermal insulation box; A connecting bolt, wherein the connecting bolt is arranged on a side of the vacuum insulation box facing the first insulation box, and the connecting bolt is passed through a side wall of the first insulation box to fix the vacuum insulation box to the first insulation box; Among them, 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 by the connecting bolt, the hollow channel of the connecting bolt is closed to form a vacuum insulation structure.

2. The low-temperature liquefied gas thin-film storage tank dome protection device according to claim 1, characterized in that, A connection plate extends from one side of the vacuum insulation box toward the first insulation box, and the connection plate is arranged flush with the bottom of the vacuum insulation box; The connecting plate is overlapped with a skirt 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 is vertically extended and arranged for welding connection with the corrugated plate.

3. The low-temperature liquefied gas thin-film storage tank dome protection device according to claim 2, wherein, A first insulating pad is also provided between the skirt plate and the connecting plate, and the first insulating pad is a polytetrafluoroethylene winding pad.

4. The low-temperature liquefied gas thin-film storage tank dome protection device according to claim 3, characterized in that, The clamping mechanism comprises a clamping bolt, and the clamping bolt comprises a first screw and a nut; A first flange plate is provided at one end of the overlap portion away from the connecting plate, and a second insulating pad is provided at one side of the connecting plate away from the skirt plate; a second flange plate is provided at one 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 insulating pad and the second insulating pad are all provided with through holes, the first screw is inserted into the through hole, the nut is arranged at the end of the first flange plate away from the overlapping portion, and the nut is threadably matched with the first screw.

5. The low-temperature liquefied gas thin-film storage tank dome protection device according to claim 4, wherein, 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.

6. The low-temperature liquefied gas thin-film storage tank dome protection device according to claim 5, 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.

7. The low-temperature liquefied gas thin-film storage tank dome protection device according to claim 1, characterized in that, The bonding layer is formed by curing a resin adhesive, and the bonding layer forms an annular protective structure after the resin adhesive is cured.

8. The low-temperature liquefied gas thin-film storage tank dome protection device according to claim 2, wherein A plurality of second thermal insulation boxes are also 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 overlap 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.

9. The low-temperature liquefied gas thin-film storage tank dome protection device according to claim 8, characterized in that, The length of the overlap portion in the horizontal direction is greater than the length of the connecting plate. The connecting plate has plywood arranged side by side at one end facing the welding portion. The plywood is arranged below the overlap portion, and the plywood is adhesively connected to the second thermal insulation box.

10. The low-temperature liquefied gas thin-film storage tank dome protection device according to claim 1, wherein The connecting bolt comprises 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 connected to the inside of the vacuum insulation box; The second screw is threadedly matched with the hollow channel of the stud, and a sealing ring is further provided between the second screw and the stud.

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