KR102608693B1 - Lower barrier structure of independence type storage tank - Google Patents

Abstract

A lower barrier structure of an independent storage tank that performs insulation and sealing functions around a tank supporter supporting the independent storage tank is disclosed.
The lower barrier structure includes a heat insulation layer 24 installed around the tank support 30 supporting the tank body 22 of the independent storage tank; a cover member 40 installed below the heat insulating layer; a sealing member (46) sealing the gap between the tank support and the cover member; may include. The cover member 40 may include a first extension part 42 extending parallel to the lower surface of the insulating layer and a second extension part 44 extending parallel to the side surface of the tank support.

Description

Lower barrier structure of an independent storage tank {LOWER BARRIER STRUCTURE OF INDEPENDENCE TYPE STORAGE TANK}

The present invention relates to a lower barrier structure of an independent storage tank for storing liquefied gases such as LNG or LPG. More specifically, the present invention relates to insulation and insulation around the tank supporter installed at the bottom of the independent storage tank and supporting the independent storage tank. It relates to a lower barrier structure that performs a sealing function.

Natural gas is transported in a gaseous state through gas pipelines on land or at sea, or is stored in an LNG transport ship in the form of liquefied liquefied natural gas (LNG) or liquefied petroleum gas (LPG) and transported to distant consumers. Liquefied natural gas is obtained by cooling natural gas to extremely low temperatures (approximately -163°C), and its volume is reduced to approximately 1/600 compared to gaseous natural gas, making it very suitable for long-distance transportation by sea.

Liquefied gas carriers that carry liquefied gas such as LNG or LPG and sail the sea to unload the liquefied gas shipped from the production site at the point of demand have a storage tank (commonly called a 'cargo hold') that can withstand the extremely low temperature of the liquefied gas. Includes.

In addition to liquefied gas carriers, storage tanks that can accommodate liquefied gas can also be installed in floating plants such as LNG FPSO (Floating, Production, Storage and Offloading) and LNG FSRU (Floating Storage and Regasification Unit).

Recently, in order to curb environmental pollution, the number of ships (LNG propulsion ships) propelled by engines using LNG, a clean fuel, has been increasing, and these LNG propulsion ships also have liquefied gas storage tanks that can store LNG as fuel. It is mounted. In addition, as the number of LNG propulsion ships increases, LNG bunkering ships that can visit LNG propulsion ships to supply fuel have been developed, and fuel supply ships also have liquefied gas storage tanks installed inside the hull.

In this way, ships such as LNG carriers, LNG RVs, LNG propulsion ships, and fuel supply ships that transport or store liquefied gas such as LNG as cargo or store it as fuel, or in floating plants such as LNG FPSO and LNG FSRU, contain LNG, etc. A liquefied gas storage tank is installed to store liquefied gas at extremely low temperatures.

Liquefied gas storage tanks can be classified into independent type and membrane type depending on whether the load of the cargo acts directly on the insulation material. Typically, membrane-type storage tanks are divided into GT NO 96 type and TGZ Mark III type, and independent storage tanks can be divided into MOSS type and SPB type.

Independent storage tanks can be classified into type A, type B, type C, etc. according to the classification criteria in the IMO IGC code. Among them, in general, in the case of IMO type A tanks, there is a problem that it is impossible to implement a secondary barrier for cryogenic cargo such as LNG with the steel used in the hull. Additionally, in the case of the IMO type C tank, it is a pressure vessel type tank, so it is difficult to manufacture a large capacity tank.

Considering this, the IMO type B tank is attracting attention as an independent storage tank used to transport or store cryogenic liquefied gas such as LNG. In general, among independent storage tanks, IMO type B tanks are made by attaching a relatively hard insulating panel such as polyurethane to the outside of the tank body made of metal with good characteristics at extremely low temperatures such as stainless steel and aluminum alloy, and the inner bottom of the hull. It is placed on a plurality of tank supports arranged in. The structure of a tank support body for supporting an independent storage tank is described in Japanese Patent Laid-Open No. 60-26900, Japanese Patent Laid-Open No. 7-52870, and Korean Patent No. 10-189306.

Figure 1 shows an example of a stand-alone storage tank.

As illustrated in FIG. 1, the independent storage tank 20 may be installed in a space formed inside the hull 10. The independent storage tank 20 is made of a metal material that can withstand extremely low temperatures and includes a tank body 22 that functions as a primary sealing wall, and an insulation layer 24 installed to surround the outside of the tank body 22. ) and a drip tray installed outside the insulating layer 24 to perform the function of a secondary sealing wall by collecting and temporarily storing the leaked liquid when a liquefied gas leak occurs from the tank body 22.

The drip tray is usually placed between the independent storage tank 20 and the bottom of the interior space of the hull 10, and is especially placed at a location where leaked liquid from the tank body 22 can flow down and collect.

The independent storage tank 20 is seated and supported on a plurality of tank supports 30 arranged at the bottom of the interior space of the hull 10. Each tank support 30 is in contact with the tank body 22 and supports the tank body 22, and the heat insulating layer 24 is not formed at the position where the tank support 30 is disposed, as shown in FIG. 1 As shown, the tank support 30 is formed to penetrate the insulation layer 24.

As described above, the independent storage tank 20 is installed inside the hull by being supported by a plurality of tank supports 30, and the tank support 30 includes a wooden block 32 made of wood. . As such, since the material of the insulation layer 24 surrounding the outside of the tank body 22 and the material of the tank support 30 are different from each other, the portion between the insulation layer 24 and the tank support 30 is a barrier system, that is, an insulation layer. And it may be the most vulnerable part in forming the sealing layer.

In order to form the insulation layer 24 around the tank support 30, foam molding is performed on site while spraying or injecting polyurethane and then the surface is finished, or a panel manufactured to a certain size is attached and then connected to the tank support. There is a method of sealing the gap with the panel using sealing tape.

Figure 2 is an enlarged partial cross-sectional view showing the surroundings of the tank support 30 of an independent storage tank, showing the lower barrier structure of the independent storage tank forming the insulation layer 24 by attaching an insulation panel around the tank support 30. It is showing. Referring to FIG. 2, an insulation panel is installed around the tank support 30 to support the tank body 22 of an independent storage tank to form an insulation layer 24, and the insulation layer 24 and the tank support 30 are connected to each other. By sealing the gap existing between the two with the sealing tape 26, the lower barrier structure of the independent storage tank is formed.

The lower barrier structure of such an independent storage tank is affected by thermal deformation as the loading and unloading of liquefied gas is repeated, and is inevitably affected by shaking inevitably applied to the storage tank during navigation, so it is made of different materials. It is very likely that leaks will occur in the immediate vicinity of the support structure and insulation.

The present invention is intended to solve the problems described above, and aims to provide a lower barrier structure of an independent storage tank that can stably perform insulation and sealing functions around the tank supporter supporting the independent storage tank.

According to one aspect of the present invention for achieving the above object, it is a lower barrier structure of an independent storage tank that performs insulation and sealing functions around a tank supporter supporting the independent storage tank, and supports the tank body of the independent storage tank. an insulation layer installed around the tank support; a cover member installed below the heat insulating layer; a sealing member sealing the gap between the tank support and the cover member; It includes a lower part of the independent storage tank, wherein the cover member includes a first extension part extending parallel to the lower surface of the insulation layer, and a second extension part extending parallel to the side of the tank support. Barrier structures may be provided.

The sealing member is made in the form of a tape, and the sealing member is attached across the second extension portion of the cover member and the side of the tank support so as to seal the entire gap between the tank support and the cover member. You can.

The cover member may further include an opening formed in the first extension portion to allow the tank supporter to pass through the first extension portion.

The second extension part may be formed to extend by bending downward from an edge of the opening.

The cover member may be made of a material with a higher thermal deformation coefficient than the tank support.

According to another aspect of the present invention, there is provided an independent storage tank capable of storing liquefied gas, comprising: a tank body made of a metal material capable of withstanding extremely low temperatures; an insulating layer installed to surround the outside of the tank body; a tank supporter supporting the tank body; a lower barrier structure that performs insulation and sealing functions around the tank support; The lower barrier structure includes a cover member installed below the heat insulating layer around the tank supporter, and a sealing member sealing the gap between the tank supporter and the cover member, wherein the cover member includes, An independent storage tank may be provided, comprising a first extension part extending parallel to the lower surface of the heat insulating layer, and a second extension part extending parallel to the side of the tank support.

The cover member is attached to the tank support before forming the insulating layer, and the insulating layer can be formed by spraying or injecting an insulating material around the tank support where the cover member is installed.

The insulation layer is formed by arranging a plurality of insulation panels on the outside of the tank body, and the cover member may be attached to the lower surface of the insulation panel after the insulation panels are arranged around the tank support body.

According to the present invention, a lower barrier structure of an independent storage tank that can stably perform insulation and sealing functions around the tank supporter supporting the independent storage tank can be provided.

According to the lower barrier structure of the independent storage tank according to the present invention, stable insulation and sealing can be achieved even in adjacent areas between the support structure and the insulation material made of different materials.

Figure 1 is a schematic cross-sectional view of a ship equipped with an independent storage tank.
Figure 2 is a partial cross-sectional view showing an enlarged view around the tank support of an independent storage tank.
Figure 3 is a partial cross-sectional view showing the lower barrier structure of an independent storage tank around the tank support body according to one embodiment of the present invention.
Figure 4 is a perspective view for explaining a cover member included in the lower barrier structure of an independent storage tank according to an embodiment of the present invention.

Hereinafter, the lower barrier structure of an independent storage tank according to a preferred embodiment of the present invention will be described in detail with reference to the drawings.

Figure 3 shows a partial cross-sectional view showing the lower barrier structure of the independent storage tank around the tank support according to an embodiment of the present invention, and Figure 4 shows the lower part of the independent storage tank according to an embodiment of the present invention. A perspective view is shown to explain the coupling method of the cover member and support structure included in the barrier structure.

As shown in Figure 3, the lower barrier structure of an independent storage tank according to an embodiment of the present invention includes a heat insulation layer ( 24), a cover member 40 installed below the heat insulating layer 24, and a sealing member 46 that seals the gap between the tank support 30 and the cover member 40.

According to one embodiment of the present invention, the cover member 40 includes a first extension portion 42 extending parallel to the lower surface of the heat insulating layer 24, and a second extending portion extending parallel to the side of the tank support 30. It includes 2 extensions (44).

The sealing member 46 may be in the form of a tape, and is connected to the second extension portion 44 of the cover member 40 and the tank support so as to seal the entire gap between the tank support 30 and the cover member 40. It is attached across the side of (30).

As described above with reference to FIG. 1, an independent storage tank equipped with a lower barrier structure according to an embodiment of the present invention may be installed in a space formed inside the hull. Similar to the independent storage tank shown in FIG. 1, the independent storage tank with a lower barrier structure according to an embodiment of the present invention is a tank made of a metal material that can withstand extremely low temperatures and functions as a primary sealing wall. A body 22, a heat insulating layer 24 installed to surround the outside of the tank body 22, and a leaking liquid provided on the outside of the heat insulating layer 24 when liquefied gas leaks from the tank body 22. It includes a drip tray (not shown) that performs the function of a secondary sealing wall by collecting and temporarily storing.

A plurality of drip trays can be appropriately placed in required locations. The drip tray is, for example, disposed between the tank body of an independent storage tank and the bottom of the interior space of the hull, and is especially disposed at a location where leaked liquid from the tank body can flow down and collect.

The independent storage tank is seated and supported on a plurality of tank supports 30 arranged at the bottom of the interior space of the hull. Each tank supporter 30 is in contact with the tank body 22 and supports the tank body 22, and the heat insulating layer 24 is not installed at the position where the tank supporter 30 is disposed. As shown in FIG. 3, the tank support 30 penetrates the heat insulation layer 24 and comes into contact with the tank body 22.

The tank support 30 may include, for example, an upper block (i.e., wooden block 32) in contact with the tank body 22 and a lower block (not shown) supporting the upper block. The upper block (wooden block 32) can be fixed in position by the upper fixing member 22a installed on the tank body 22, and the lower block can be fixed on the lower fixing member (not shown) installed on the bottom of the inner space of the hull. The position can be fixed by If necessary, a sliding member (not shown) may be interposed between these upper and lower blocks to enable relative sliding movement.

Referring to FIGS. 3 and 4, the tank support 30 is shown as being made of a wooden block 32 having a hexahedral shape. However, the tank support 30 may not be made only of the wooden block 32. The shape of the wooden block may have a shape other than a hexahedron. Additionally, the side of the wooden block may have a flat surface or a step as shown in FIGS. 3 and 4.

The insulation layer 24 disposed on the outside of the tank body 22 is foam-molded by spraying or injecting polyurethane directly onto the external surface of the tank body 22 at the storage tank manufacturing site. It can be formed by doing. In this case, the cover member 40 can serve as a frame for polyurethane foam molding, and for this purpose, the cover member 40 can be attached to the tank support 30 before forming the heat insulating layer.

Alternatively, the insulation layer 24 disposed on the outside of the tank body 22 may be formed, for example, by arranging a plurality of insulation panels on the outside of the tank body 22. The insulation panel may be manufactured in advance at a separate location to have a certain size and thickness, then transported to the storage tank construction site and attached to the tank body 22. The insulating panel may be made of an insulating material, for example, polyurethane (or reinforced polyurethane), and has at least one surface of the insulating material (e.g., insulating material) to prevent damage to the insulating material and to facilitate manufacturing and handling. A material with higher strength than the insulating material may be integrally attached to the upper and lower surfaces of the material. In this case, the cover member 40 may be attached to the lower surface of the insulation panel after the insulation panel is arranged around the tank support.

As described above, the cover member 40 is installed below the heat insulating layer 24 around the tank support body 30. In detail, the cover member 40 includes a first extension portion 42 extending parallel to the lower surface of the heat insulating layer 24 while contacting the lower surface of the heat insulating layer 24, and a side surface of the tank support 30 ( That is, it includes a second extension portion 44 extending parallel to the side of the tank support 30 while contacting the side of the wooden block.

The first extension 42 of the cover member 40 has an opening through which the tank support 30 can pass. Although the opening 40a is shown in FIG. 4 as being formed in a square shape, the opening 40a is not limited to the shape shown. For example, the opening 40a may have a shape corresponding to the shape of the wooden block 32 of the tank support 30 at the point where the cover member 40 is attached.

The second extension portion 44 is bent approximately vertically along the edge of the opening 40a formed in the first extension portion 42 and extends downward. The first extension portion 42 and the second extension portion 44 of the cover member 40 are formed integrally.

The cover member 40 may be made of a material with a higher thermal deformation coefficient than the wooden block of the tank support 30. In detail, the cover member 40 has a heat contraction coefficient greater than that of the wooden block, so when liquefied gas is shipped to the storage tank, the amount of shrinkage of the cover member may be greater than the amount of shrinkage of the wooden block. It is manufactured so that Accordingly, when the temperature drops by loading the liquefied gas into the storage tank, the cover member 40, especially the second extension portion 44 of the cover member 40, can be more strongly adhered to the side of the wooden block 32. , leaks can be prevented more reliably.

The cover member 40 may be made of a material that can withstand the load due to heat shrinkage, and is particularly preferably flexible enough to bear the load due to heat shrinkage in a low-temperature environment.

As described above, the sealing member 46 is attached to seal the gap between the tank support 30, that is, the wooden block 32, and the cover member 40. In order to seal the entire gap between the wooden block of the tank support 30 and the cover member 40, the tape-shaped sealing member 46 is connected to the second extension 44 of the cover member 40 and the tank support ( It is attached entirely to the side of the wooden block in 30).

The sealing member 46 may be made of any material, as long as it can seal the gap between the second extension 44 of the cover member 40 and the wooden block 32 of the tank support 30. It does not have to be in the form of tape.

As such, in the detailed description of the present invention, specific embodiments have been described, but of course, various modifications are possible without departing from the technical spirit of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims described below as well as equivalents to these claims.

22: tank body (of the independent storage tank), 24: heat insulation layer (of the independent storage tank), 30: tank support, 32: wooden block (of the tank support), 40: cover member, 40a: opening, 42: first extension Part, 44: second extension part, 46: sealing member.

Claims (8)

It is a lower barrier structure of an independent storage tank that performs insulation and sealing functions around the tank support that supports the independent storage tank,
a heat insulation layer installed around the tank supporter supporting the tank body of the independent storage tank;
a cover member installed below the heat insulating layer around the tank supporter and covering a space between the heat insulating layer and the tank supporter;
a sealing member sealing the gap between the tank support and the cover member;
Includes,
The cover member includes a first extension part extending parallel to the lower surface of the heat insulating layer, and a second extension part extending downward from the first extension part parallel to a side surface of the tank support,
The first extension portion and the second extension portion are formed integrally,
The sealing member is in the form of a tape,
The sealing member is a lower barrier of an independent storage tank, characterized in that it is attached across a second extension portion of the cover member and a side surface of the tank support so as to seal the entire gap between the tank support and the cover member. structure. delete In claim 1,
The cover member further includes an opening formed in the first extension portion to allow the tank support to pass through the first extension portion. In claim 3,
A lower barrier structure of an independent storage tank, wherein the second extension portion is formed to extend by bending downward from an edge of the opening. In claim 1,
A lower barrier structure of an independent storage tank, wherein the cover member is made of a material with a higher thermal deformation coefficient than the tank support. As an independent storage tank that can store liquefied gas,
a tank body made of a metal material capable of withstanding extremely low temperatures;
an insulating layer installed to surround the outside of the tank body;
a tank supporter supporting the tank body;
a lower barrier structure that performs insulation and sealing functions around the tank support;
Includes,
The lower barrier structure includes a cover member installed below the insulating layer around the tank supporter and covering the space between the insulating layer and the tank supporter, and a sealing member sealing the gap between the tank supporter and the cover member,
The cover member includes a first extension part extending parallel to the lower surface of the heat insulating layer, and a second extension part extending downward from the first extension part parallel to a side surface of the tank support,
The first extension portion and the second extension portion are formed integrally,
The sealing member is in the form of a tape,
The sealing member is attached to a second extension portion of the cover member and a side surface of the tank support so as to seal the entire gap between the tank support and the cover member. In claim 6,
The cover member is attached to the tank support before forming the insulation layer, and the insulation layer is formed by spraying or injecting an insulation material around the tank support on which the cover member is installed. In claim 6,
The insulation layer is formed by arranging a plurality of insulation panels on the outside of the tank body, and the cover member is attached to the lower surface of the insulation panel after the insulation panels are arranged around the tank support body. An independent storage tank .

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