Outer tank for onshore LNG (Liquefied Natural Gas) storage tank and outer tank construction method

Abstract

The invention relates to the technical field of natural gas storage facilities, in particular to an outer tank for an onshore LNG (Liquefied Natural Gas) storage cabin and an outer tank construction method. The outer tank comprises a storage cabin bearing platform arranged at the bottom of the outer tank and used for evenly distributing loads to a foundation; the storage cabin wall body is vertically arranged above the storage cabin bearing platform and is rigidly connected with the storage cabin bearing platform; the storage cabin dome is located at the top of the storage cabin wall body, and a cavity used for containing an inner tank is defined by the storage cabin dome, the storage cabin bearing platform and the storage cabin wall body; wherein the multiple storage cabin wall bodies are arranged on the storage cabin bearing platform in parallel at intervals, one storage cabin dome is correspondingly arranged between every two adjacent storage cabin wall bodies, and the multiple cavities are formed; and the storage cabin bearing platform, the storage cabin wall body and the storage cabin dome adopt reinforced concrete structures. According to the invention, the plurality of chambers capable of placing the inner tanks are formed by the plurality of storage tank walls arranged at intervals and the storage tank domes located on the adjacent storage tank walls, so that the total volume is increased, and the occupied area is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas storage and installation, and in particular to an outer tank for an onshore LNG storage tank and a method for constructing the outer tank. Background Art

[0002] At present, LNG storage facilities on land are an important part of the LNG (liquefied natural gas) supply chain. LNG storage facilities are not only used to receive and store LNG delivered from offshore LNG carriers, but also serve as a transfer station to supply LNG to urban areas or industrial areas in large cities. Common onshore LNG storage tanks include single-containment tanks, double-containment tanks, full-containment tanks, and membrane tanks. Among them, full-containment tanks are safer and are widely used in domestic LNG storage facilities.

[0003] However, since full containment tanks usually adopt a vertical cylindrical structure and the outer tank of the full containment tank is an independent structure, each full containment tank is equipped with a separate outer tank. As the tank capacity continues to increase, the thickness of the outer tank, the dome span, etc. must also increase accordingly, resulting in a significant increase in structural loads, and the material performance is close to the limit, which in turn limits the development of large-scale storage tanks. In addition, the safe spacing of the outer tank must be considered in the layout of the storage tank, resulting in a large footprint of onshore LNG storage tanks, requiring special land use approval, which also limits the development of large-scale storage tanks. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention proposes an outer tank for an onshore LNG storage tank and an outer tank construction method, so as to achieve the purpose of increasing the total volume and reducing the dome span and structural load by optimizing the outer tank structure.

[0005] In a first aspect, the present invention provides an outer tank for an onshore LNG storage tank, the outer tank comprising: The tank cap is installed at the bottom of the outer tank to distribute the load evenly on the foundation; A storage tank wall is vertically arranged above the storage tank pedestal and rigidly connected to the storage tank pedestal; A tank dome, located on the top of the tank wall, and enclosing with the tank cap and the tank wall to form a chamber for accommodating the inner tank; Wherein, a plurality of the storage tank walls are arranged on the storage tank support platform in parallel and at intervals, and a storage tank dome is correspondingly arranged between adjacent storage tank walls to form a plurality of the chambers; The storage tank cap, the storage tank wall and the storage tank dome adopt reinforced concrete structure.

[0006] According to an outer tank for an onshore LNG storage tank provided by the present invention, the tank wall includes an edge wall and a middle wall, the edge wall is exclusively occupied by the chamber and a heat insulation layer is arranged on one side thereof, and the middle wall is shared by adjacent chambers and a heat insulation layer is arranged on both sides thereof.

[0007] According to an outer tank for an onshore LNG storage tank provided by the present invention, the middle wall is provided with channels penetrating through both sides thereof for communicating with adjacent chambers.

[0008] According to the present invention, an outer tank for an onshore LNG storage tank also includes a seismic joint located between adjacent chambers. The seismic joint extends in a vertical direction and passes through from the bottom surface of the storage tank pedestal to the top surface of the intermediate wall to improve seismic resistance.

[0009] According to an outer tank for an onshore LNG storage tank provided by the present invention, a prestressed system is arranged in the tank wall, and the prestressed system is composed of a plurality of steel strands extending in a horizontal straight direction and a plurality of steel strands extending in a vertical straight direction which are cross-arranged.

[0010] According to an outer tank for an onshore LNG storage tank provided by the present invention, the length of the horizontally extending steel strand is shorter than the length of the vertically extending steel strand, so as to reduce the prestress loss.

[0011] According to an outer tank for an onshore LNG storage tank provided by the present invention, a heating system is provided inside the intermediate wall, and / or a heating system is provided inside the storage tank support platform; It is used to ensure that the intermediate wall and the storage tank support are within the design temperature range under normal working conditions.

[0012] According to an outer tank for an onshore LNG storage tank provided by the present invention, the tank wall is made of low-temperature resistant concrete and low-temperature resistant steel bars to ensure that it can withstand loads under low-temperature conditions.

[0013] According to an outer tank for an onshore LNG storage tank provided by the present invention, a pile foundation is arranged at the lower part of the storage tank cap, or the storage tank cap is seated on bedrock.

[0014] In a second aspect, the present invention provides a method for constructing an outer tank for an onshore LNG storage tank, which is used to construct the outer tank for an onshore LNG storage tank described in any one of the above; First, the storage tank wall and the storage tank dome are constructed respectively; Secondly, a slide rail is arranged on the top of the storage tank wall; Then, the storage tank dome is placed on the slide rails, and the storage tank dome is moved to a predetermined installation position through the slide rails.

[0015] The above one or more technical solutions in the present invention have at least one of the following technical effects: A plurality of chambers for placing inner tanks are formed by a plurality of tank walls arranged at intervals and tank domes located on adjacent tank walls, which not only reduces the distance between adjacent inner tanks and saves floor space, but also reduces the dome span of the outer tank and reduces the structural load, thereby achieving the purpose of optimizing the outer tank structure, increasing the volume and reducing the manufacturing cost.

[0016] In addition to the technical problems solved by the present invention, the technical features of the technical solutions constituted, and the advantages brought about by the technical features of these technical solutions described above, other technical features of the present invention and the advantages brought about by these technical features will be further explained in conjunction with the accompanying drawings or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only 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.

[0018] Figure 1 A schematic structural diagram of an outer tank for an onshore LNG storage tank provided in an embodiment of the present invention.

[0019] Figure 2 A schematic structural diagram of another outer tank for an onshore LNG storage tank provided in an embodiment of the present invention.

[0020] Figure 3 A partially enlarged schematic diagram of the structure of the middle wall provided in an embodiment of the present invention.

[0021] Figure 4 A partial side view of an intermediate wall with a hole provided in an embodiment of the present invention.

[0022] Reference numerals: 1. Storage tank foundation; 2. Storage tank wall; 21. Edge wall; 22. Middle wall; 3. Chamber; 4. Storage tank dome; 5. Prestressed system; 6. Channel; 7. Seismic joint; 8. Insulation layer. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. 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.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of 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.

[0025] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" 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 an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0026] In the embodiments of 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.

[0027] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0028] In the present invention, LNG is the abbreviation of liquefied natural gas (Liquefied Natural Gas). LNG refers to natural gas mainly composed of methane that is processed and cooled to about -162 degrees Celsius (-260 degrees Fahrenheit) under normal pressure to be converted into a liquid state.

[0029] Currently, LNG (liquefied natural gas) carriers are the main means of transporting imported LNG (liquefied natural gas). LNG storage facilities on land are an important part of the LNG (liquefied natural gas) supply chain.

[0030] Onshore LNG storage tanks are not only used to receive and store LNG delivered from offshore LNG carriers, but also serve as transfer stations to supply LNG to urban areas or industrial areas in large cities. Common onshore LNG storage tanks include single-containment tanks, double-containment tanks, full-containment tanks, and membrane tanks. Among them, full-containment tanks are more secure and are widely used in domestic LNG storage facilities.

[0031] However, since full containment tanks usually adopt a vertical cylindrical structure and the outer tank of the full containment tank is an independent structure, each full containment tank is equipped with a separate outer tank. As the tank capacity continues to increase, the thickness of the outer tank, the dome span, etc. must also increase accordingly, resulting in a significant increase in structural loads, and the material performance is close to the limit, which in turn limits the development of large-scale storage tanks. In addition, the safe spacing of the outer tank must be considered in the layout of the storage tank, resulting in a large footprint of onshore LNG storage tanks, requiring special land use approval, which also limits the development of large-scale storage tanks.

[0032] In order to solve the above problems, an outer tank for an onshore LNG storage tank is introduced in an embodiment of the present invention.

[0033] like Figure 1 and Figure 2 As shown, the outer tank mainly includes a storage tank base 1, a storage tank wall 2 and a storage tank dome 4.

[0034] The tank cap 1 is arranged at the bottom of the outer tank to distribute the load evenly on the foundation. The tank wall 2 is vertically arranged above the tank cap 1. The tank wall 2 is rigidly connected to the tank cap 1.

[0035] The tank dome 4 is located on the top of the tank wall 2. The tank dome 4, the tank support 1 and the tank wall 2 form a chamber 3 for accommodating an inner tank.

[0036] In particular, a plurality of the storage tank walls 2 are arranged in parallel and at intervals on the storage tank support 1. A storage tank dome 4 is correspondingly arranged between adjacent storage tank walls 2, forming a structure in which a plurality of the chambers 3 are arranged in parallel.

[0037] The storage tank base 1, the storage tank wall 2 and the storage tank dome 4 are of reinforced concrete structure.

[0038] In the present embodiment, a plurality of chambers 3 for placing inner tanks are formed by a plurality of storage tank walls 2 arranged at intervals and storage tank domes 4 located on adjacent storage tank walls 2, which not only reduces the distance between adjacent inner tanks and saves floor space, but also reduces the dome span of the outer tank and reduces the structural load, thereby achieving the purpose of optimizing the outer tank structure, increasing the volume and reducing the manufacturing cost.

[0039] Furthermore, the storage tank wall 2 includes an edge wall 21 and a middle wall 22. The edge wall 21 is exclusively occupied by the chamber 3 and a heat insulation layer 8 is arranged on one side thereof. The middle wall 22 is shared by adjacent chambers 3 and a heat insulation layer 8 is arranged on both sides thereof.

[0040] Specifically, the outer tank is in a cubic structure. Several chambers 3 are arranged inside the outer tank for placing the inner tank. Compared with a full-containment tank with a separate outer tank, the LNG storage tank in this embodiment does not need to consider the spacing between the outer tanks, which not only saves floor space, but also reduces the amount of work required to build the outer tank, and also greatly reduces the span of the dome.

[0041] Based on the above embodiment, in another embodiment of the present invention, an outer tank for an onshore LNG storage tank is introduced.

[0042] like Figure 2 As shown, the outer tank mainly includes a tank cap 1, a tank wall 2 and a tank dome 4. The tank cap 1 is arranged at the bottom of the outer tank. The tank wall 2 is vertically arranged above the tank cap 1. The tank dome 4 is located on the top of the tank wall 2.

[0043] Specifically, a plurality of the storage tank walls 2 are arranged in parallel and at intervals on the storage tank support 1. One storage tank dome 4 is correspondingly arranged between adjacent storage tank walls 2. The support points at both ends of the storage tank dome 4 are arranged across the adjacent storage tank walls 2 to form a structure in which a plurality of the chambers 3 are arranged in parallel. The storage tank domes 4 are arranged one by one with the chambers 3 to avoid the situation in which one storage tank dome 4 crosses over a plurality of storage tank walls 2, thereby greatly reducing the span of the storage tank dome 4.

[0044] Furthermore, the storage tank wall 2 includes an edge wall 21 and a middle wall 22. The edge wall 21 is exclusively occupied by the chamber 3. The middle wall 22 is shared by adjacent chambers 3. The middle wall 22 is provided with channels 6 running through both sides thereof for connecting adjacent chambers 3.

[0045] Based on the above embodiment, in another embodiment of the present invention, an outer tank for an onshore LNG storage tank is introduced.

[0046] like Figure 3 As shown, the outer tank is also provided with an anti-seismic seam 7 for improving the anti-seismic performance. The anti-seismic seam 7 is located between the adjacent chambers 3, which can ensure the safety of the outer tank structure.

[0047] Specifically, the seismic seam 7 is extended in the vertical direction, and passes through from the bottom surface of the storage tank support 1 to the top surface of the middle wall 22 .

[0048] Furthermore, the tank wall 2 is made of low-temperature resistant concrete and low-temperature resistant steel bars to ensure that it can withstand loads under low-temperature conditions. For example, when the inner tank installed in the outer tank leaks natural gas, the tank wall 2 at the leaking position will be in an extremely low temperature environment due to the gasification of natural gas. The tank wall 2 made of low-temperature resistant materials can still withstand a large load, avoiding structural damage and causing more serious accidents.

[0049] Furthermore, a pile foundation is provided at the bottom of the storage tank cap 1. Alternatively, the storage tank cap 1 is located on bedrock. Specifically, since the LNG storage tank is used to store a huge amount of liquefied natural gas, the stability and safety of the structure are extremely high, so foundation settlement should be avoided.

[0050] When the bearing capacity of the foundation is insufficient, it is necessary to build a pile foundation first, and build the storage tank cap 1 on the pile foundation, so that the load can be transferred to a deeper and more stable soil or rock layer through the pile foundation to ensure the structural stability of the LNG storage tank.

[0051] Alternatively, if the bedrock depth is not large, the bedrock can be directly trimmed and the tank cap 1 can be built on the bedrock. The tank cap 1 should have sufficient strength and rigidity to bear the entire load of the upper tank. For example, a ground-mounted structure can be used. In addition, a heating system can be installed inside the tank cap 1 to ensure that the tank cap 1 is within the design temperature range under normal working conditions.

[0052] Based on the above embodiment, in another embodiment of the present invention, an outer tank for an onshore LNG storage tank is introduced.

[0053] like Figure 1 , Figure 2 and Figure 4 As shown, a prestressing system 5 is arranged in the tank wall 2. The prestressing system 5 is composed of a plurality of steel strands extending in a horizontal straight direction and a plurality of steel strands extending in a vertical straight direction.

[0054] Furthermore, the length of the horizontally extending steel strand is shorter than the length of the vertically extending steel strand, which is used to reduce the prestress loss. In the prestress system 5, the prestress can be linear prestress, and each layer of the wall is separately provided with a steel strand, and the length of the single horizontal prestress is relatively small, which reduces the prestress loss of the annular storage tank.

[0055] Specifically, a prestressing system 5 is arranged inside the tank wall 2 to improve the tensile performance of the wall. Since the wall structure is a vertical wall, the prestressing system 5 can be arranged in a linear manner. Compared with the traditional vertical cylindrical wall, the linear prestressing system 5 has less friction resistance of steel strands and a shorter length of horizontal steel strands, so the prestressing loss is smaller.

[0056] Furthermore, the middle wall 22 is provided with holes 6 penetrating through both sides thereof, for connecting the adjacent chambers 3. The prestressed system 5 at the hole 6 should be interrupted to ensure the connection function of the middle wall 22.

[0057] Based on the above embodiment, in another embodiment of the present invention, an outer tank for an onshore LNG storage tank is introduced.

[0058] like Figure 2 As shown, the outer tank mainly includes a tank cap 1, a tank wall 2 and a tank dome 4. The tank cap 1 is arranged at the bottom of the outer tank. The tank wall 2 is vertically arranged above the tank cap 1. The tank dome 4 is located on the top of the tank wall 2.

[0059] Specifically, a plurality of the tank walls 2 are arranged in parallel and at intervals on the tank support 1, forming a structure in which a plurality of the chambers 3 are arranged in parallel. The tank wall 2 includes an edge wall 21 and an intermediate wall 22. The edge wall 21 is exclusively occupied by the chamber 3. The intermediate wall 22 is shared by the adjacent chambers 3, and can bear the internal tank load of the chambers 3 on both sides, so that the force is more reasonable.

[0060] In particular, a heat tracing system is provided inside the intermediate wall 22 to ensure that the intermediate wall 22 is within the design temperature range under normal working conditions. And / or, a heat tracing system is provided inside the storage tank support 1 to ensure that the storage tank support 1 is within the design temperature range under normal working conditions.

[0061] On the other hand, in another embodiment of the present invention, a method for constructing an outer tank for an onshore LNG storage tank is introduced.

[0062] The use of this method to construct the outer tank can reduce the construction difficulty and the amount of work. The tank dome 4 can be built separately and then assembled with the tank wall 2. The tank dome 4 can also be cast together with the tank wall 2 to form an integrated structure.

[0063] The method of splicing and assembling with the tank wall 2 is: first, respectively construct the tank wall 2 and the tank dome 4. The tank wall 2 adopts a reinforced concrete structure. The chamber 3 enclosed by the tank dome 4 and the tank wall 2 is in a cubic form and is used to install the inner tank.

[0064] Secondly, a slide rail is arranged on the top of the storage tank wall 2. Then, the storage tank dome 4 is placed on the slide rail, so that the two end support points of the storage tank dome 4 are straddled on two adjacent storage tank walls 2, and the storage tank dome 4 is moved to a predetermined installation position by the slide rail.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An outer tank for an onshore LNG storage tank, characterized in that: include: A tank cap (1) is arranged at the bottom of the outer tank and is used to distribute the load evenly on the foundation; A storage tank wall (2) is vertically arranged above the storage tank support platform (1) and is rigidly connected to the storage tank support platform (1); A tank dome (4) is located on the top of the tank wall (2) and, together with the tank support (1) and the tank wall (2), forms a chamber (3) for accommodating an inner tank; Wherein, a plurality of the storage tank walls (2) are arranged in parallel and at intervals on the storage tank support platform (1), and a storage tank dome (4) is correspondingly provided between adjacent storage tank walls (2), so as to form a plurality of the chambers (3); The storage tank base (1), the storage tank wall (2) and the storage tank dome (4) are made of reinforced concrete structures.

2. The outer tank for an onshore LNG storage tank according to claim 1, characterized in that: The storage tank wall (2) comprises an edge wall (21) and an intermediate wall (22); the edge wall (21) is exclusively occupied by the chamber (3) and a heat insulation layer is arranged on one side thereof; the intermediate wall (22) is shared by adjacent chambers (3) and a heat insulation layer (8) is arranged on both sides thereof.

3. The outer tank for an onshore LNG storage tank according to claim 2, characterized in that: The middle wall (22) is provided with channels (6) penetrating through two sides thereof, for communicating with adjacent chambers (3).

4. The outer tank for an onshore LNG storage tank according to claim 2 or 3, characterized in that: It also includes an anti-seismic joint (7) located between adjacent chambers (3), wherein the anti-seismic joint (7) extends in a vertical direction and passes through from the bottom surface of the storage tank support platform (1) to the top surface of the intermediate wall (22), so as to improve anti-seismic performance.

5. The outer tank for an onshore LNG storage tank according to any one of claims 1 to 3, characterized in that: A prestressed system (5) is arranged in the tank wall (2), and the prestressed system (5) is composed of a plurality of steel strands extending in a horizontal straight direction and a plurality of steel strands extending in a vertical straight direction that are cross-arranged.

6. The outer tank for an onshore LNG storage tank according to claim 5, characterized in that: The length of the horizontally extending steel strands is shorter than that of the vertically extending steel strands to reduce prestress loss.

7. The outer tank for an onshore LNG storage tank according to claim 6, characterized in that: A heating system is provided inside the intermediate wall (22), and / or a heating system is provided inside the storage tank support platform (1); It is used to ensure that the intermediate wall (22) and the storage tank support platform (1) are within the design temperature range under normal working conditions.

8. The outer tank for an onshore LNG storage tank according to any one of claims 1 to 3, characterized in that: The storage tank wall (2) is made of low-temperature resistant concrete and low-temperature resistant steel bars to ensure that it can withstand loads under low-temperature conditions.

9. The outer tank for an onshore LNG storage tank according to any one of claims 1 to 3, characterized in that: A pile foundation is arranged at the bottom of the storage tank cap (1), or the storage tank cap (1) is seated on bedrock.

10. A method for constructing an outer tank for an onshore LNG storage tank, characterized in that: Used to construct an outer tank for an onshore LNG storage tank as described in any one of claims 1 to 9; First, the storage tank wall (2) and the storage tank dome (4) are constructed respectively; Secondly, a slide rail is arranged on the top of the storage tank wall (2); Then, the storage tank dome (4) is placed on the slide rail, and the storage tank dome (4) is moved to a predetermined installation position via the slide rail.

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