Three-layer metal LNG full-capacity storage tank structure

Abstract

A three-layer metal LNG full-capacity storage tank structure comprises a main container, a secondary container and an outer container which are arranged on a foundation platform (1), annular gaps are formed between a main container barrel (2) and a secondary container barrel (3) and between the secondary container barrel (3) and an outer container barrel (4), a first combined elastic layer (21) is arranged on the outer wall of the main container barrel (2), and a second combined elastic layer (22) is arranged on the outer wall of the outer container barrel (4). A first pearlife heat insulation layer (22) is arranged in an annular gap between the first combined elastic layer (21) and the secondary container barrel (3), a second combined elastic layer (31) is arranged on the outer wall of the secondary container barrel (3), and a second pearlife heat insulation layer (32) is arranged in an annular gap between the second combined elastic layer (31) and the outer container barrel (4). According to the structure, under the condition that the main container leaks, the low daily evaporation rate can be maintained, safety is high, leaked LNG and BOG flash steam can be contained, the fireproof interval of the storage tank is reduced, investment is relatively low, and the construction period is short.

Description

Technical Field

[0001] The utility model relates to the technical field of low-temperature storage equipment, and in particular to a three-layer metal LNG full-capacity storage tank structure. Background Art

[0002] In recent years, my country has attached great importance to ecological environment construction and encouraged the construction of a clean, low-carbon, safe and efficient energy system to reduce the greenhouse effect and promote a virtuous ecological cycle.

[0003] According to their functions and properties, liquefied natural gas (LNG) stations can be roughly divided into LNG receiving stations, LNG emergency peak-shaving stations, LNG storage and distribution stations, LNG gasification stations (including conventional gasification stations, bottle gasification stations and skid-mounted gasification stations, etc.), LNG liquefaction plants, LNG vehicle refueling stations, LNG ship refueling stations and combined stations of the above stations, etc. LNG storage tanks, as the core equipment to realize the functions of LNG stations, play a vital role in the safety performance of the entire station.

[0004] At present, LNG storage tanks are mainly divided into three types: single-containment tanks, double-containment tanks and full-containment tanks. Full-containment tanks consist of inner tanks and outer tanks. The inner tank is a steel self-supporting structure used to store low-temperature flammable liquids; the outer tank is an independent self-supporting closed structure with a dome, which is used to withstand gas phase pressure and insulation materials, and can accommodate low-temperature flammable liquids overflowing from the inner tank. Its material is generally steel or concrete. Among the above three types of above-ground storage tanks, full-containment tanks are the safest.

[0005] The most widely used full containment tank is the bimetallic full containment tank. For the bimetallic full containment tank structure, when the inner tank containing the cryogenic medium leaks, the outer tank must contain all the cryogenic medium liquid leaked from the inner tank and the vapor after the leaked liquid is vaporized. Although the existing bimetallic full containment tank structure can contain all the liquid leaked from the inner tank, due to the direct contact between the outer tank pipe wall and the outside atmosphere, there is a problem of too fast vaporization speed of the leaked liquid, and the controllability of the leakage condition is poor. There are other types of bimetallic full containment tanks, which adopt an outer insulation layer outside the outer tank wall and a double-layer metal bottom at the bottom of the outer tank wall. The outer insulation layer of this structure is often damaged by moisture without the protection of the outer tank and cannot achieve the insulation effect, and the use and maintenance cost is high. In addition, there are full-containment concrete outer tanks and storage tanks with concrete tops and inner steel plates. They have advantages such as being sturdy, durable, leak-free, maintenance-free, and high pressure-bearing, but they require large investments and have a long construction period, and are only suitable for 100,000 m 3 Large-scale LNG receiving station projects with storage capacity of 100MW and above. Utility Model Content

[0006] In order to address the deficiencies in the prior art, the utility model provides a three-layer metal LNG full-containment storage tank structure, which is an all-metal structure, and has interlayer cold insulation between the main container and the secondary container and between the secondary container and the outer container. The LNG liquid is stored in the main container, and the outer container is used to contain evaporated gas and cold insulation materials. When the main container leaks, the secondary container is used to effectively store the LNG liquid, so that it can maintain a low daily evaporation rate, has better structural safety, can better contain leaked LNG and BOG flash gas, reduces the fire protection distance of the storage tank, has relatively low investment, and has a short construction period.

[0007] As conceived above, the utility model adopts the following technical solutions:

[0008] A three-layer metal LNG full-volume storage tank structure, characterized in that it comprises a main container, a secondary container and an outer container arranged on a foundation base (1); an annular gap is arranged between the main container cylinder (2) and the secondary container cylinder (3), and between the secondary container cylinder (3) and the outer container cylinder (4); the outer wall of the main container cylinder (2) is provided with a first combined elastic layer (21); a first pearl sand insulation layer (22) is arranged in the annular gap between the first combined elastic layer (21) and the secondary container cylinder (3); the outer wall of the secondary container cylinder (3) is provided with a second combined elastic layer (31); a second pearl sand insulation layer (32) is arranged in the annular gap between the second combined elastic layer (31) and the outer container cylinder (4).

[0009] Preferably, the bottom of the outer container cylinder (4) is provided with an outer container bottom plate (7) which is sealed and connected thereto, and the outer container bottom plate (7) is arranged closely above the foundation pedestal (1); the bottom of the secondary container cylinder (3) is provided with a secondary container bottom plate (6) which is fixedly and sealed and connected thereto, and the secondary container bottom plate (6) is located above the outer container bottom plate (7); a bottom cement board layer (71), a foam glass brick insulation layer (72) and an intermediate cement board layer (73) are arranged between the outer container bottom plate (7) and the secondary container bottom plate (6) from bottom to top; the bottom of the main container cylinder (2) is provided with a main container bottom plate (5) which is fixedly and sealed and connected thereto, and the main container bottom plate (5) is located above the secondary container bottom plate (6), and an upper cement board layer (61) is arranged between the secondary container bottom plate (6) and the main container bottom plate (5).

[0010] Preferably, a pearl sand reinforced concrete ring beam (8) is provided in the pressure-bearing annular area directly below the cylinder wall of the main container cylinder (2) and the secondary container cylinder (3), and the outer side of the pearl sand reinforced concrete ring beam (8) extends outward to the outside of the secondary container cylinder (3), and the inner side extends inward to the inside of the main container cylinder (2).

[0011] Preferably, the pearl sand reinforced concrete ring beam (8) is placed between the middle cement board layer (73) and the foam glass brick insulation layer (72), and an asphalt waterproofing membrane layer (75) is provided between the pearl sand reinforced concrete ring beam (8) and the middle cement board layer (73).

[0012] Preferably, the foam glass brick insulation layer (72) comprises a lower foam glass brick insulation layer (721) and an upper foam glass brick insulation layer (722), and an asphalt waterproofing membrane layer (75) is provided between the two.

[0013] Preferably, an asphalt waterproofing membrane layer (75) is provided between the lower foam glass brick insulation layer (721) and the pearl sand reinforced concrete ring beam (8), and between the upper foam glass brick insulation layer (722) and the middle cement board layer (73).

[0014] Preferably, a cold primer layer (74) is provided between the lower foam glass brick insulation layer (721) and the bottom cement board layer (71).

[0015] Preferably, n main container tie straps (23) are evenly arranged on the outer wall of the main container cylinder (2) along its axial direction, wherein n≥40, and the spacing between two adjacent main container tie straps (23) is 1-1.5m. One end of each main container tie strap (23) is fixedly connected to the outer wall of the main container cylinder (2), and the other end thereof is anchored in the foundation pedestal (1).

[0016] Preferably, m outer container draw straps (41) are evenly arranged on the outer wall of the outer container cylinder (4) along its axial direction, wherein m≥60, and the spacing between two adjacent outer container draw straps (41) is 0.8-1.2m, and one end of each outer container draw strap (41) is fixedly connected to the outer wall of the outer container cylinder (4), and the other end thereof is anchored in the foundation pedestal (1).

[0017] Preferably, an elastic compensation joint (9) is provided at the opening at the upper end of the secondary container bottom plate (6), and the lower end of the elastic compensation joint (9) is fixedly and sealedly connected to the opening of the secondary container bottom plate (6).

[0018] Preferably, the first combined elastic layer (21) and the second combined elastic layer (31) comprise an inner cotton cloth layer (a), an elastic cotton layer (b), an outer cotton cloth layer (c) and a glass fiber cloth layer (d) which are sequentially arranged from inside to outside.

[0019] Preferably, the top of the outer container barrel (4) is sealed and connected to the outer top cover (10), and a suspended top plate (20) is suspended below the outer top cover (10) via a suspension rod (101), and the suspended top plate (20) is sealed and connected to the top of the main container barrel (2).

[0020] Preferably, a glass fiber wool layer (201) is provided above the suspended ceiling plate (20), and a circumferentially arranged annular baffle (202) is provided on the outer edge of the glass fiber wool layer (201).

[0021] The technical solution of the utility model has the following advantages:

[0022] A. The utility model provides a flat-bottomed ceiling, vertical three-layer metal wall, fully inclusive structure storage tank. LNG liquid is stored in the main container. There are gaps between the outer container and the secondary container, and between the secondary container and the main container. When the main container leaks, the cryogenic liquid enters the secondary container for storage. Since the secondary container blocks the leaked liquid from contacting the outer container, the outer container cannot contact the cryogenic liquid and cryogenic gas under normal working conditions and leakage conditions. Unlike the main container and the secondary container, which are made of stainless steel, the outer container can be made of ordinary carbon steel or low-alloy steel structure, which can greatly reduce the project cost. The outer container is used to hold evaporating gas and cold-insulating materials.

[0023] B. Under the full liquid level leakage condition, the storage tank of the utility model can maintain a low daily evaporation rate because there is a complete interlayer cold insulation between the inner container and the secondary container, as well as between the secondary container and the outer container. Its process system can still operate smoothly without taking measures such as safety discharge.

[0024] C. The utility model ensures that in case of leakage of the main container, the secondary container can store all the LNG liquid, and the evaporated gas is discharged through the venting pipeline. The internal positive pressure and interlayer vacuum load do not need to be considered when designing the main container. When an overpressure or vacuum accident occurs in the storage tank, the inner tank of the main container will not be affected in any way, which is safer.

[0025] D. The utility model uses an interlayer storage tank to store LNG evaporated gas, which does not require an interlayer nitrogen sealing system, can save supporting valves and daily operating costs, and the operation and control system are simpler.

[0026] E. In the utility model, the main container cylinder, the main container bottom plate, the secondary container cylinder and the secondary container bottom plate are all made of stainless steel S30408 ​​and placed on the insulation layer pearl sand reinforced concrete ring beam. The main function of the secondary container is to store LNG leaked from the main container in an accident state to prevent LNG from leaking into the environment. The outer container cylinder and the outer container bottom plate are made of low alloy steel Q345R. The function of the outer container is to store the evaporated gas from the main container, support the insulation layer materials of the main container and the secondary container, and maintain the airtightness of the structure, and can be vented. The outer container cylinder is equipped with multiple reinforcing ribs to strengthen the structure to ensure that it can withstand sufficient pressure and maintain the stability of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is a structural cross-sectional view of a three-layer metal LNG full-capacity storage tank of the utility model;

[0029] Figure 2 for Figure 1 Enlarged view of structure I;

[0030] Figure 3 for Figure 1 Enlarged view of the middle structure II;

[0031] Figure 4 This is a schematic diagram of the structure of the first combined elastic layer in the utility model;

[0032] Figure 5 This is a schematic diagram of the structure of the second combined elastic layer in the utility model;

[0033] Figure 6 This is a schematic diagram of the main container drawstring structure in the utility model;

[0034] Figure 7 for Figure 6 Enlarged view of structure III.

[0035] The following are marked in the figure:

[0036] 1-foundation bearing platform; 2-main container cylinder, 21-first combined elastic layer, 22-first pearl sand insulation layer, 23-main container drawstring; 3-secondary container cylinder, 31-second combined elastic layer, 32-second pearl sand insulation layer; 4-outer container cylinder, 41-outer container drawstring; 5-main container bottom plate; 6-secondary container bottom plate, 61-upper cement board layer; 7-outer container bottom plate, 71-bottom cement board layer, 72-foam glass brick insulation layer, 721-lower foam glass brick insulation layer, 722-upper foam glass brick insulation layer, 73-middle cement board layer, 74-cold primer layer, 75-asphalt waterproofing membrane layer; 8-pearl sand reinforced concrete ring beam; 9-elastic compensation joint; 10-outer top cover, 101-suspender rod; 20-suspended top plate, 201-glass fiber wool layer, 202-annular baffle;

[0037] a-inner cotton layer; b-elastic cotton layer; c-outer cotton layer; d-glass fiber layer. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and 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 therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] like Figure 1-Figure 2As shown, the utility model provides a three-layer metal LNG full-containment storage tank structure, including a main container cylinder 2, a secondary container cylinder 3 and an outer container cylinder 4 arranged on a foundation pedestal 1, the main container cylinder 2 and the secondary container cylinder 3 are both stainless steel structures, the outer container cylinder 4 is a carbon steel or low alloy steel structure, and an annular gap is provided between the main container cylinder 2 and the secondary container cylinder 3, and between the secondary container cylinder 3 and the outer container cylinder 4. The outer wall of the main container cylinder 2 is provided with a first combined elastic layer 21, and the annular gap between the first combined elastic layer 21 and the secondary container cylinder 3 is filled with pearl sand to form a first pearl sand insulation layer 22, and the outer wall of the secondary container cylinder 3 is provided with a second combined elastic layer 31, and the annular gap between the second combined elastic layer 31 and the outer container cylinder 4 is filled with pearl sand to form a second pearl sand insulation layer 32. In the utility model, the main container is a self-supporting, steel, single-wall tank that does not store product evaporation gas. The main container is entirely located on the bottom insulation layer. The width of the interlayer space between the main container cylinder 2 and the secondary container cylinder 3 is 800-1000mm, and the interlayer space is filled with dense pearl sand to keep the storage tank with good insulation performance. A first combined elastic layer 21 with a thickness of 200mm is hung on the outer wall plate of the main container cylinder 2 to absorb the lateral extrusion force of the first pearl sand insulation layer 22 on the main container cylinder 2 during the initial pre-cooling and equipment warming up (storage tank safety maintenance, etc.) of the main container. The first pearl sand insulation layer 22 is set to isolate the transfer of cold in the direction of the side wall of the main container. The width of the interlayer space between the secondary container cylinder 3 and the outer container cylinder 4 is 1000-1200mm, and the interlayer space is filled with dense pearl sand to keep the storage tank with good insulation performance. A second combined elastic layer 31 with a thickness of 200mm is hung on the outer wall plate of the secondary container cylinder 3. The second combined elastic layer 31 and the second pearl sand insulation layer 32 form the insulation material layer of the secondary container cylinder 3 .

[0042] Furthermore, if Figure 2 As shown, an outer container bottom plate 7 is provided at the bottom of the outer container cylinder 4, and the outer container bottom plate 7 is arranged closely above the foundation pedestal 1, and is fixedly and sealedly connected to the outer container cylinder 4 by welding. A secondary container bottom plate 6 is provided at the bottom of the secondary container cylinder 3, and is fixedly and sealedly connected to the outer container cylinder 4 by welding. The secondary container bottom plate 6 is located above the outer container bottom plate 7. A bottom cement board layer 71, a foam glass brick insulation layer 72, and an intermediate cement board layer 73 are provided in sequence from bottom to top between the outer container bottom plate 7 and the secondary container bottom plate 6. A main container bottom plate 5 is provided at the bottom of the main container cylinder 2, and is fixedly and sealedly connected to the main container cylinder 2 by welding. The main container bottom plate 5 is located above the secondary container bottom plate 6, and an upper cement board layer 61 is provided between the secondary container bottom plate 6 and the main container bottom plate 5.

[0043] A pearl sand reinforced concrete ring beam 8 is provided in the pressure-bearing annular area directly below the cylinder wall of the main container cylinder 2 and the secondary container cylinder 3. The outer side of the pearl sand reinforced concrete ring beam 8 extends outward to the outside of the secondary container cylinder 3 and is flush with the outer side of the middle cement board layer 73. The inner side of the pearl sand reinforced concrete ring beam 8 extends inward to the inner side of the main container cylinder 2. The pearl sand reinforced concrete ring beam 8 is located below the edge of the middle cement board layer 73, and the foam glass brick insulation layer 72 is below the pearl sand reinforced concrete ring beam 8.

[0044] The foam glass brick insulation layer 72 includes a lower foam glass brick insulation layer 721 and an upper foam glass brick insulation layer 722. The pearl sand reinforced concrete ring beam 8 is located above the lower foam glass brick insulation layer 721 and outside the upper foam glass brick insulation layer 722. The thickness of the pearl sand reinforced concrete ring beam 8 is consistent with the thickness of the upper foam glass brick insulation layer 722.

[0045] A cold primer layer 74 is provided between the bottom cement board layer 71 and the lower foam glass brick insulation layer 721, and an asphalt waterproof membrane layer 75 is provided between the lower foam glass brick insulation layer 721 and the upper foam glass brick insulation layer 722, between the lower foam glass brick insulation layer 721 and the pearl sand reinforced concrete ring beam 8, and between the upper foam glass brick insulation layer 722, the pearl sand reinforced concrete ring beam 8 and the middle cement board layer 73.

[0046] The bottom of the main container of the utility model is insulated by foam glass bricks + pearl sand reinforced concrete ring beam. Pearl sand reinforced concrete ring beam 8 is installed below the edge plate of the main container bottom plate 5. Before the installation of the entire bottom insulation layer, an upper cement board layer 61 is poured on the secondary container bottom plate 6 to form a leveling layer, which is used to ensure the unevenness of the tank foundation and the bottom plate during laying. A layer of cold primer is applied on the upper cement board layer 61, and waterproof asphalt glass cloth is laid between the foam glass brick layers (overlapping is not allowed). The gap between the upper foam glass brick insulation layer 722 and the pearl sand reinforced concrete ring beam 8 does not exceed 20mm, and all gaps must be filled with compressed glass fiber wool. An asphalt waterproof roll material layer 75 is set on the upper part of the foam glass brick insulation layer 72 to form a leveling layer.

[0047] In the utility model, ordinary strength foam glass bricks are laid between the main container bottom plate 5 and the outer container bottom plate 7 as the bottom insulation layer and to bear the weight of the main container and the medium. Pearlescent sand reinforced concrete ring beam 8 (the steel bars are stainless steel) is used to distribute the load in the annular area with high pressure just below the main container cylinder 2 and the secondary container cylinder 3. High-density foam glass bricks are used at the bottom of the concrete ring beam, and the thickness of the foam glass bricks is 800mm.

[0048] like Figure 2 , Figure 6As shown, n main container tie straps 23 are evenly arranged on the outer wall of the main container cylinder 2 along its axial direction, where n≥40, and the spacing between two adjacent main container tie straps 23 is 1-1.5m; m outer container tie straps 41 are evenly arranged on the outer wall of the outer container cylinder 4 along its axial direction, where m≥60, and the spacing between two adjacent outer container tie straps 41 is 0.8-1.2m. One end of each main container tie strap 23 is fixedly connected to the outer wall of the main container cylinder 2, and the other end thereof passes through the secondary container bottom plate 6, the middle cement board layer 73, the pearl sand reinforced concrete ring beam 8, the lower foam glass brick insulation layer 721, the bottom cement board layer 71 and the outer container bottom plate 7 in sequence and is then anchored in the foundation pedestal 1. One end of each outer container tie strap 41 is fixedly connected to the outer wall of the outer container cylinder 4, and the other end thereof is anchored in the foundation pedestal 1. The utility model forms anchoring devices for the main container and the outer container by arranging a main container tie strap 23 and an outer container tie strap 41, and reliably connects them with the pre-buried anchoring device of the foundation, so that the main container and the outer container are fastened to the foundation pedestal of the storage tank to prevent the equipment from tilting and lifting under the action of working load and external force (such as wind load, earthquake load, etc.).

[0049] like Figure 7 As shown, an elastic compensation joint 9 is provided at the opening at the upper end of the secondary container bottom plate 6 for installing the main container drawstring 23. The elastic compensation joint 9 is sleeved on the outside of the main container drawstring 23. The lower end of the elastic compensation joint 9 is fixedly and sealedly connected to the corresponding opening of the secondary container bottom plate 6 by welding, and the upper end thereof is fixedly and sealedly connected to the main container drawstring 23 by welding.

[0050] like Figure 4 , Figure 5 As shown, the first combined elastic layer 21 and the second combined elastic layer 32 include an inner cotton layer a, an elastic cotton layer b, an outer cotton layer c and a glass fiber layer d arranged sequentially from the inside to the outside. The combined elastic layer and the corresponding pearl sand insulation layer together form the insulation structure of the tank wall.

[0051] like Figure 1 , Figure 3 As shown, a suspended ceiling plate 20 is provided on the top of the main container cylinder 2, and the suspended ceiling plate 20 is sealed and connected to the main container cylinder 2. The suspended ceiling plate 20 is suspended below the outer top cover 10 by a suspension rod 101. A glass fiber wool layer 201 is laid on the suspended ceiling plate 20. The single-layer thickness of the glass fiber wool layer 201 shall not be less than 100 mm. 10 layers of glass fiber wool are laid on the suspended ceiling plate. The total thickness after laying is 800 mm, so as to maintain good insulation performance within the top space of the main container; four sets of suspended ceiling vents are arranged on the suspended ceiling plate 20, which are used to balance the gas phase pressure between the inside of the main container and the space above the suspended ceiling plate 20.

[0052] In order to ensure the seal between the upper part of the main container cylinder 2 and the suspended ceiling and prevent the pearlescent sand from entering the main container, the LNG storage tank is designed with a suspended ceiling sealing structure. All structural parts of the suspended ceiling seal shall not form a fixed structure with the main container cylinder and accessories, and no less than 3 layers of compressed elastic cotton shall be filled between the main container cylinder and the suspended ceiling activity space. In order to ensure that the pearlescent sand above the suspended ceiling does not enter the suspended ceiling space, glass fiber cloth is used to isolate the entire circle of the glass fiber cotton layer 201 along the edge of the suspended ceiling, and it is reinforced with wire mesh to form an annular baffle 202. The lower end of the annular baffle 202 is fixedly connected to the suspended ceiling plate 20, and its upper end extends upward to the bottom of the outer top cover 10, while considering the personnel passage.

[0053] Under the condition of full liquid level leakage, the storage tank can maintain a low daily evaporation rate because there is a complete interlayer between the inner container and the secondary container, and between the secondary container and the outer container, and its process system can still operate smoothly without taking measures such as safety discharge. The utility model ensures that in the case of leakage of the main container, the secondary container can store all the LNG liquid, and the evaporated gas is discharged through the venting pipeline. The main container does not need to consider the internal positive pressure and interlayer vacuum load when designing. When the storage tank is over-pressurized or vacuum accident occurs, the inner tank of the main container will not be affected in any way, and the safety is higher.

[0054] Anything not described in the present invention is applicable to the prior art.

[0055] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present utility model.

Claims

1. A three-layer metal LNG full-capacity storage tank structure, characterized in that: The invention comprises a main container, a secondary container and an outer container arranged on a base support (1); an annular gap is arranged between the main container cylinder (2) and the secondary container cylinder (3), and between the secondary container cylinder (3) and the outer container cylinder (4); the outer wall of the main container cylinder (2) is provided with a first combined elastic layer (21); a first pearl sand heat insulation layer (22) is arranged in the annular gap between the first combined elastic layer (21) and the secondary container cylinder (3); the outer wall of the secondary container cylinder (3) is provided with a second combined elastic layer (31); a second pearl sand heat insulation layer (32) is arranged in the annular gap between the second combined elastic layer (31) and the outer container cylinder (4).

2. A three-layer metal LNG full-containment storage tank structure according to claim 1, characterized in that: The bottom of the outer container cylinder (4) is provided with an outer container bottom plate (7) which is sealed and connected thereto. The outer container bottom plate (7) is arranged closely above the foundation support platform (1). The bottom of the secondary container cylinder (3) is provided with a secondary container bottom plate (6) which is fixedly and sealed and connected thereto. The secondary container bottom plate (6) is located above the outer container bottom plate (7). A bottom cement board layer (71), a foam glass brick insulation layer (72) and an intermediate cement board layer (73) are arranged in sequence from bottom to top between the outer container bottom plate (7) and the secondary container bottom plate (6). The bottom of the main container cylinder (2) is provided with a main container bottom plate (5) which is fixedly and sealed and connected thereto. The main container bottom plate (5) is located above the secondary container bottom plate (6). An upper cement board layer (61) is arranged between the secondary container bottom plate (6) and the main container bottom plate (5).

3. A three-layer metal LNG full-capacity storage tank structure according to claim 1, characterized in that: A pearlescent sand reinforced concrete ring beam (8) is provided in the pressure-bearing annular area directly below the cylinder walls of the main container cylinder (2) and the secondary container cylinder (3); the outer side of the pearlescent sand reinforced concrete ring beam (8) extends outward to the outside of the secondary container cylinder (3), and the inner side extends inward to the inside of the main container cylinder (2).

4. A three-layer metal LNG full-capacity storage tank structure according to claim 3, characterized in that: The pearl sand reinforced concrete ring beam (8) is placed between the middle cement board layer (73) and the foam glass brick insulation layer (72), and an asphalt waterproofing coiled material layer (75) is provided between the pearl sand reinforced concrete ring beam (8) and the middle cement board layer (73).

5. A three-layer metal LNG full-containment storage tank structure according to claim 2, characterized in that: The foam glass brick insulation layer (72) comprises a lower foam glass brick insulation layer (721) and an upper foam glass brick insulation layer (722), and an asphalt waterproofing coiled material layer (75) is provided between the two.

6. A three-layer metal LNG full-capacity storage tank structure according to claim 5, characterized in that: An asphalt waterproofing coiled material layer (75) is provided between the lower foam glass brick insulation layer (721) and the pearlescent sand reinforced concrete ring beam (8), and between the upper foam glass brick insulation layer (722) and the middle cement board layer (73).

7. A three-layer metal LNG full-capacity storage tank structure according to claim 5, characterized in that: A cold primer layer (74) is provided between the lower foam glass brick insulation layer (721) and the bottom cement board layer (71).

8. The three-layer metal LNG full-containment storage tank structure according to claim 1 is characterized in that: The outer wall of the main container cylinder (2) is evenly provided with n main container tie straps (23) along its axial direction, wherein n≥40, and the spacing between two adjacent main container tie straps (23) is 1-1.5m. One end of each main container tie strap (23) is fixedly connected to the outer wall of the main container cylinder (2), and the other end thereof is anchored in the foundation pedestal (1).

9. A three-layer metal LNG full-containment storage tank structure according to claim 1, characterized in that: The outer wall of the outer container cylinder (4) is evenly provided with m outer container drawstrings (41) along its axial direction, wherein m≥60, and the spacing between two adjacent outer container drawstrings (41) is 0.8-1.2m. One end of each outer container drawstring (41) is fixedly connected to the outer wall of the outer container cylinder (4), and the other end thereof is anchored in the foundation pedestal (1).

10. A three-layer metal LNG full-containment storage tank structure according to claim 2, characterized in that: An elastic compensation joint (9) is provided at the opening of the upper end of the secondary container bottom plate (6), and the lower end of the elastic compensation joint (9) is fixedly and sealedly connected to the opening of the secondary container bottom plate (6).

11. A three-layer metal LNG full-containment storage tank structure according to claim 1, characterized in that: The first combined elastic layer (21) and the second combined elastic layer (31) comprise an inner cotton cloth layer (a), an elastic cotton layer (b), an outer cotton cloth layer (c) and a glass fiber cloth layer (d) which are sequentially arranged from the inside to the outside.

12. A three-layer metal LNG full-containment storage tank structure according to claim 1, characterized in that: The top of the outer container cylinder (4) is sealed to the outer top cover (10), a suspended top plate (20) is suspended below the outer top cover (10) via a suspension rod (101), and the suspended top plate (20) is sealed to the top of the main container cylinder (2).

13. The three-layer metal LNG full-containment storage tank structure according to claim 12 is characterized in that: A glass fiber cotton layer (201) is provided above the suspended ceiling plate (20), and a circumferentially arranged annular baffle (202) is provided on the outer edge of the glass fiber cotton layer (201).

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