JP2024166721A - Low temperature above ground liquefied gas tank, method for constructing low temperature above ground liquefied gas tank - Google Patents

Abstract

To provide a low-temperature ground type liquefied gas tank capable of sufficiently enduring large load applied to a coupling part of a side wall and a roof and a construction method for the low-temperature ground type liquefied gas tank.SOLUTION: A low-temperature ground type liquefied gas tank 1 includes: a concrete side wall 20 formed to have a cylindrical shape; a metallic membrane 30 provided on a radial inner side of the side wall 20 and forming a storage space A of low-temperature liquefied gas 2; and a metal roof 40 covering an upper side of the storage space A. A shoulder part 22 projecting to the radial inner side is provided on an upper end part 20a of the side wall 20, and the roof 40 is fixed to the lower surface side of the shoulder part 22.SELECTED DRAWING: Figure 2

Description

The present invention relates to a low-temperature above-ground liquefied gas tank and a method for constructing a low-temperature above-ground liquefied gas tank.

The following Patent Document 1 discloses an aboveground cryogenic tank for storing low-temperature liquefied gas such as LNG (liquefied natural gas), LPG (liquefied petroleum gas), liquid nitrogen, etc. This cryogenic tank has a double shell structure consisting of an inner tank made entirely of metal and having a flat bottom and a cylindrical shape with a spherical roof, and an outer tank made of prestressed concrete side walls and a metallic spherical roof fixed to the side walls, and is configured by filling the space between the inner tank and the outer tank with a cold insulation material such as granular perlite or a material for mitigating cold and heat resistance.
Furthermore, Patent Document 2 listed below discloses an above-ground cryogenic tank in which a ring plate is attached around the entire inner periphery of the upper part of a cylindrical concrete body and the peripheral edge of the roof panel is fixed to the ring plate.

JP 2002-267099 A Japanese Patent Application Publication No. 8-338598

In conventional cryogenic tanks, as the tank size increases and the liquid head pressure increases, the thickness of the metal inner tank side plates becomes thicker to withstand the liquid pressure, but there is a limit to how thick the plates can be from the standpoint of strength and weldability.To solve this problem, a structure is sometimes adopted in which the side walls are made of prestressed concrete and a metal spherical roof is fixed to the side walls.
Even in the outer vessel of a conventional cryogenic tank, the metallic spherical roof is fixed to a prestressed concrete side wall, but the acting internal pressure is about 0.5 kPa. In this structure, a high internal gas pressure (e.g., about 20 kPa) due to the cryogenic liquefied gas acts on the joint between the side wall and the metallic spherical roof. This causes a problem in that a large load is applied to the joint between the side wall and the roof of the cryogenic tank.
In addition, in a conventional underground cryogenic tank for storing low-temperature liquefied gas, a structure in which a metallic spherical roof is fixed to a concrete side wall buried underground may be adopted. In this case, the outer end of the spherical roof is made of a thick plate, and is embedded in the side wall by about 1 m, as in the ring plate shown in FIG. 1 of Patent Document 2. However, in this case, this embedded part causes a lot of interference with the reinforcing bars in the concrete side wall, making assembly very complicated and restricting the arrangement of the reinforcing bars. Furthermore, when a concrete side wall is adopted in an above-ground cryogenic tank, the side wall needs to withstand the liquid head pressure from the inside, so it is necessary to place circumferential PC steel members and vertical PC steel members in the side wall, and it is assumed that it will be even more difficult to solve this interference problem.

The present invention was made in consideration of the above circumstances, and provides a low-temperature above-ground liquefied gas tank and a method for constructing a low-temperature above-ground liquefied gas tank that can fully withstand the load on the joint between the concrete side wall and the metal roof, and can significantly reduce interference between the outer edge of the metal roof and structures inside the side wall.

The low-temperature above-ground liquefied gas tank according to the first aspect of the present invention comprises a cylindrical concrete side wall, a metal membrane provided on the radially inner side of the side wall to form a storage space for low-temperature liquefied gas, and a metal roof covering the upper part of the storage space, with a shoulder portion protruding radially inward at the upper end of the side wall, and the roof fixed to the underside of the shoulder portion.

In addition, in a second aspect of the present invention, in the low-temperature above-ground liquefied gas tank of the first aspect, the roof may be fixed to the underside of the shoulder portion via a stud bolt.

In a third aspect of the present invention, in the low-temperature above-ground liquefied gas tank of the second aspect, the shoulder portion may include a support plate fixed to the inner wall of the side wall, a fixing plate fixed to the support plate and extending obliquely upward toward the radially inner side of the side wall, the stud bolt provided on the upper surface side of the fixing plate, and a concrete body poured into the upper surface side of the fixing plate and embedding the stud bolt, and the roof may be fixed to the fixing plate.

The method for constructing a low-temperature above-ground liquefied gas tank according to the fourth aspect of the present invention comprises forming a cylindrical concrete side wall, forming a metal membrane on the radially inner side of the side wall to form a storage space for low-temperature liquefied gas, forming a shoulder protruding radially inward at the upper end of the side wall, and fixing a metal roof covering the upper part of the storage space to the underside of the shoulder.

According to the above-mentioned aspect of the present invention, it is possible to provide a low-temperature above-ground liquefied gas tank that can adequately withstand the large load applied to the joint between the side wall and the roof, and a method for constructing a low-temperature above-ground liquefied gas tank.

FIG. 1 is a schematic diagram of a low-temperature ground-based liquefied gas tank according to one embodiment. FIG. 2 is a close-up view of a side wall and roof joint according to one embodiment. FIG. 2 is an explanatory diagram showing a process of connecting a roof to the upper end of a side wall in a method of constructing a low-temperature above-ground liquefied gas tank according to one embodiment. FIG. 2 is an explanatory diagram showing a process of connecting a roof to the upper end of a side wall in a method of constructing a low-temperature above-ground liquefied gas tank according to one embodiment. FIG. 2 is an explanatory diagram showing a process of connecting a roof to the upper end of a side wall in a method of constructing a low-temperature above-ground liquefied gas tank according to one embodiment.

One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a low-temperature ground-based liquefied gas tank 1 according to one embodiment.
As shown in Fig. 1, the low-temperature above-ground liquefied gas tank 1 generally includes a base plate 10, a side wall 20, a membrane 30, and a roof 40. A low-temperature liquefied gas 2 is stored in a storage space A inside the low-temperature above-ground liquefied gas tank 1.

The base plate 10 is made of concrete and is formed in a circular plate shape. A bottom liner and a cold insulation structure (cold insulation material, cold resistance mitigation material, etc.) (not shown) are provided on the upper surface of the base plate 10.

The side wall 20 is formed in a cylindrical shape on the outer periphery of the base slab 10. The side wall 20 is made of concrete, for example, a prestressed concrete (PC) wall. A side liner (not shown) and a cold insulation structure 50 (see FIG. 2 described later) are provided on the inner wall of the side wall 20. An external staircase 21 is provided on the outer wall of the side wall 20.

The membrane 30 is provided on the radially inner side of the side wall 20, and forms a storage space A for the low-temperature liquefied gas 2. The membrane 30 is formed in a bottomed cylindrical shape that covers the inner wall of the side wall 20 and the upper surface of the base plate 10. The membrane 30 is formed from multiple thin stainless steel plates made of metal, and the membrane 30 is provided with a lattice-like corrugation (pleats).

The roof 40 is a metallic spherical roof formed into an upwardly convex dome shape, and covers the top of the storage space A. The roof 40 is provided with a cold insulation structure (not shown). The roof 40 is also provided with a roof staircase 41. As shown in FIG. 2, the roof 40 is fixed to the upper end 20a of the side wall 20.

FIG. 2 is an enlarged view of the joint between the side wall 20 and the roof 40 according to one embodiment.
2, a shoulder 22 that protrudes radially inward is provided at the upper end 20a of the side wall 20. The roof 40 is fixed to the lower surface side of the shoulder 22. The shoulder 22 is provided in an annular shape in the circumferential direction along the upper end 20a of the side wall 20.

The underside of the shoulder 22 extends diagonally upward toward the radial inside of the side wall 20 (the center of the tank). A thick fixing plate 23 is provided on the underside of the shoulder 22, and the outer edge of the roof 40 is fixed via the fixing plate 23. The upper surface 22a of the shoulder 22 is flat (horizontal) so that rainwater does not accumulate.

Next, a method for constructing the low-temperature above-ground liquefied gas tank 1 having the above-mentioned configuration will be described with reference to Figures 3 to 5.
3 to 5 are explanatory diagrams showing a process of joining the roof 40 to the upper end 20a of the side wall 20 in a method of constructing a low-temperature above-ground liquefied gas tank 1 according to one embodiment. In Fig. 3 to 5, circumferential PC steel members 61, vertical PC steel members 62, and large-diameter vertical reinforcing bars 63 are shown as structural members within the side wall 20. Note that the circumferential reinforcing bars along the large-diameter vertical reinforcing bars 63 are not shown.

In this method, first the base plate 10 is formed, and then the cylindrical side wall 20 is formed on the outer periphery of the base plate 10. As shown in FIG. 3, a support plate 24 is fixed to the inner wall of the upper end portion 20a of the side wall 20. The support plate 24 is a thick metal plate and is equipped with multiple stud bolts 25.

Next, the fixing plate 23 is fixed to the upper end of the support plate 24 by welding or the like. The fixing plate 23 is supported by the support plate 24 in a position in which it extends diagonally upward toward the radial inside of the side wall 20.

The upper surface of the fixing plate 23 is provided with a number of stud bolts 26 and a frame fixing rib 27 for pouring a concrete body 29A (see FIG. 4) described later. The lower surface of the fixing plate 23 is provided with a roof fixing rib 28 for fixing a steel member 42 (such as a main rafter or a sub-rafter) extending radially from the center of the roof 40 in the radial direction.

The radially outer end of the fixing plate 23 is embedded in the inner wall of the side wall 20 together with the stud bolts 25 of the support plate 24. The embedded length of the radially outer end of the fixing plate 23 is shorter than the embedded length of the stud bolts 25 of the support plate 24. The radially outer end of the fixing plate 23 and the stud bolts 25 of the support plate 24 have a length and a circumferential arrangement that do not interfere with the circumferential PC steel 61, vertical PC steel 62, and large diameter vertical reinforcing bars 63 that apply prestress to the side wall 20.

Next, in this method, as shown in FIG. 4, a concrete pouring frame (not shown) is attached to the frame fixing ribs 27 of the fixing plate 23, and a concrete body 29A in which the stud bolts 26 are embedded is poured on the upper surface side of the fixing plate 23. The concrete body 29A protrudes radially inward from the side wall 20 to form a shoulder 22. Once the shoulder 22 is formed, the roof 40 constructed on the base slab 10 is raised by air raising or the like, and the outer periphery of the roof 40 is fixed to the fixing plate 23 by welding or the like.

Next, in this method, as shown in FIG. 5, concrete body 29B is poured into the recess between concrete body 29A and roof 40, and the upper surface 22a of shoulder 22 is made into a flat surface that connects with upper end 20a of side wall 20. A roof corridor board (not shown) can be laid on this flat surface. Then, an inclined water-repellent board 43 is fixed by welding or the like so as to straddle the joint between concrete body 29B and roof 40, to prevent rainwater from seeping in through the joint.

Inside the low-temperature above-ground liquefied gas tank 1, a corrugated membrane 30 is formed. Once the membrane 30 is completed, an airtight test is performed. After that, through cold insulation work, painting work, piping work, etc., the low-temperature above-ground liquefied gas tank 1 shown in Figure 1 can be constructed.

As described above, the low-temperature ground-type liquefied gas tank 1 according to this embodiment includes a cylindrical concrete side wall 20, a metal membrane 30 provided on the radially inner side of the side wall 20 to form a storage space A for the low-temperature liquefied gas 2, and a metal roof 40 covering the upper part of the storage space A. The upper end 20a of the side wall 20 is provided with a shoulder 22 that protrudes radially inward, and the roof 40 is fixed to the underside of the shoulder 22. With this configuration, the shoulder 22 can adequately withstand the internal pressure acting when storing the low-temperature liquefied gas 2. Therefore, the low-temperature ground-type liquefied gas tank 1 can adequately withstand the large load applied to the joint between the side wall 20 and the roof 40.

In addition, in this embodiment, the roof 40 is fixed to the underside of the shoulder portion 22 via the stud bolts 26. With this configuration, the load of the roof 40 can be fully supported by the shoulder portion 22 via the stud bolts 26.

In this embodiment, the shoulder 22 includes a support plate 24 fixed to the inner wall of the side wall 20, a fixing plate 23 fixed to the support plate 24 and extending diagonally upward toward the radial inside of the side wall 20, a stud bolt 26 provided on the upper surface side of the fixing plate 23, and a concrete body 29A poured into the upper surface side of the fixing plate 23 and embedding the stud bolt 26, and the roof 40 is fixed to the fixing plate 23. With this configuration, even if the side wall 20 is a PC wall, the roof 40 can be fixed to the upper end 20a of the side wall 20 without interfering with the structures (circumferential PC steel 61, vertical PC steel 62, and large diameter vertical reinforcing bar 63) that apply prestress to the side wall 20.

The method for constructing a low-temperature above-ground liquefied gas tank 1 according to this embodiment includes forming a concrete side wall 20 into a cylindrical shape, forming a metal membrane 30 that forms a storage space A for low-temperature liquefied gas 2 on the radially inner side of the side wall 20, forming a shoulder 22 that protrudes radially inward on the upper end 20a of the side wall 20, and fixing a metal roof 40 that covers the upper part of the storage space A to the underside of the shoulder 22. With this configuration, a low-temperature above-ground liquefied gas tank 1 that can adequately withstand a large load applied to the joint between the side wall 20 and the roof 40 can be constructed.

Although preferred embodiments of the present invention have been described and illustrated above, it should be understood that these are illustrative of the present invention and should not be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. Thus, the present invention should not be considered as limited by the foregoing description, but rather by the scope of the claims.

Reference Signs List 1...Low temperature above-ground liquefied gas tank, 2...Low temperature liquefied gas, 10...Foundation plate, 20...Side wall, 20a...Upper end, 21...External stairs, 22...Shoulder, 22a...Upper surface, 23...Fixing plate, 24...Support plate, 25...Stud bolt, 26...Stud bolt, 27...Frame fixing rib, 28...Roof fixing rib, 29A...Concrete body, 29B...Concrete body, 30...Membrane, 40...Roof, 41...Roof stairs, 42...Steel frame member, 43...Drain board, 50...Cold insulation structure, 61...Circumferential PC steel material, 62...Vertical PC steel material, 63...Large diameter vertical reinforcing bar, A...Storage space

Claims (4)

A cylindrical concrete side wall;
A metallic membrane provided on the radially inner side of the side wall and forming a storage space for low-temperature liquefied gas;
A metal roof covering the storage space from above;
The side wall has an upper end provided with a shoulder protruding radially inward,
The roof is fixed to the underside of the shoulder portion.
Low temperature above-ground liquefied gas tank. The roof is fixed to the underside of the shoulder portion via a stud bolt.
2. The low-temperature above-ground liquefied gas tank according to claim 1. The shoulder portion is
A support plate fixed to an inner wall of the side wall;
a fixing plate fixed to the support plate and extending obliquely upward toward the radially inner side of the side wall;
The stud bolt is provided on the upper surface side of the fixing plate;
A concrete body is poured on the upper surface side of the fixing plate and embeds the stud bolt,
The roof is fixed to the fixing plate.
3. The low-temperature above-ground liquefied gas tank according to claim 2. The concrete side walls are formed into a cylindrical shape,
A metallic membrane is formed on the radially inner side of the side wall to form a storage space for low-temperature liquefied gas;
A shoulder portion is formed at an upper end of the side wall, the shoulder portion protruding radially inward;
A metal roof is fixed to the underside of the shoulder portion to cover the storage space from above.
How to construct a cryogenic above-ground liquefied gas tank.

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