KR20110050182A - Cargo tank for liquefied gas and ship having the same - Google Patents

Abstract

PURPOSE: A storage tank for liquefied gas and a ship therewith are provided to reduce the amount of reinforcing members by improving the structural strength of a sandwich plate. CONSTITUTION: A storage tank for liquefied gas comprises sandwich plates(110) and section steel. The sandwich plates are arranged to divide a space for storing liquefied gas. The section shape steel is allowed in between the sandwich plate. The section steel is inserted between the sandwich plates and connects the sandwich plates each other. A flow path is formed in the section steel in a longitudinal direction in order to flow gas. Each sandwich plate comprises a core layer(113) and an adhesive layer(116). The core layers are arranged between metal layers(111) and have a honeycomb structure with the same expansion coefficient as the metal layers. The adhesive layers are inserted between the metal layers and the core layers.

Description

Cargo Tank For Liquefied Gas and Ship having the Same

The present invention relates to a liquefied gas storage container and a vessel having the same.

Inside the LNG vessel carrying liquefied gas, a cargo hold which is a container for storing liquefied gas is provided. These cargo holds are divided into membrane and self-supporting methods, depending on their structure.

1 is a perspective view showing a standalone liquefied gas storage container according to the prior art. FIG. 2 is an enlarged view of a portion A of FIG. 1.

1 and 2, the conventional independent liquefied gas storage container 10 is installed in the hull 20, the outer wall portion having a polyhedral shape in the hull 20 and a space for liquefied gas storage therein (1), a plurality of transformer members (2) installed on the inner surface of the outer wall portion (1) to be spaced apart by a predetermined interval along the longitudinal direction of the cargo hold, upper and lower portions on the upper, lower portion of the inner surface of the outer wall (1) Each of the vertical bulkhead 3 attached to each other to divide the inner space of the outer wall portion 1, the inner surface of the outer wall portion 1 and one side of the vertical partition wall (3) has a 'A' or 'T' shape It consists of the reinforcing material 4 and the heat insulating material 5 surrounding the outer surface of the outer wall part 1.

In this case, since the liquefied gas of the (extreme) low temperature of -45 to -196 degrees Celsius is stored in the liquefied gas storage container 10, the outer wall portion 1, the trans member 2, the vertical bulkhead 3 and The reinforcing materials 4 are all made of (extreme) low temperature steel.

In addition, in case the liquefied gas of low temperature (extreme) flows out of the liquefied gas storage container 10 due to damage of the liquefied gas storage container 10, the double barrier is located outside the liquefied gas storage container 10. The wall 6 of the hull 20, which functions as a wall, is also made of (extreme) low temperature steel similarly to the outer wall portion 1, the trans member 2, the vertical bulkhead 3, and the reinforcing material 4.

However, according to this prior art, the wall of the hull is used as a double barrier, so that not only the outer wall of the liquefied gas storage vessel but also the wall of the hull must be made of (extreme) low temperature steel, and thus the cost of manufacturing the LNG vessel as a whole There is a problem that increases.

In addition, the liquefied gas storage container according to the prior art, the outer wall portion is made of a single layer, a large number of reinforcement for the rigid reinforcement must be installed on the inner surface of the outer wall portion, and as a result the manufacturing cost and time of the LNG vessel is increased There was also a problem.

The present invention is a sandwich plate itself can perform the function of the double barrier, the structural rigidity can be improved to reduce the number of reinforcement, liquefied gas storage container that can be prevented by the freezing of moisture in the air and It is to provide a vessel provided with this.

According to one aspect of the invention, a plurality of sandwich plates (sandwich plate) arranged to partition the space for storing the liquefied gas, sandwiched between the sandwich plate to connect the sandwich plates to each other, the gas flow inside the sandwich plate And a through-hole formed in the section steel such that the flow paths are connected to each other, and the sandwich plate includes a pair of metal layers and a honeycomb having a coefficient of thermal expansion equal to that of the metal layer. A liquefied gas storage container is provided that includes a core layer of a comb structure and an adhesive layer interposed between the metal layer and the core layer to adhere the metal layer and the core layer.

The core layer may include a partition wall extending along the thickness direction of the metal layer, and a plurality of cells formed by partitioning the space between the metal layers by the partition wall.

The section steel consists of a pair of flanges, each joined to a metal layer, and a web disposed between the flanges and a web disposed perpendicularly to the flange, the plurality of flow paths are partitioned from each other by a web, and the through holes are formed in the web. Can be.

The section steel may have a cross-sectional shape of any one of 'I', 'II' and 'III'.

The shaped steel may have the same coefficient of thermal expansion as the metal layer and the core layer.

The metal layer, core layer and the shaped steel may have the same thermal conductivity.

The metal layer, core layer and the shaped steel may be made of the same material.

The metal layer, the core layer and the shaped steel may be made of a material including aluminum (Al) or stainless steel.

The thickness of the core layer may be greater than the thickness of each of the metal layers.

The thickness of each of the adhesive layers may be less than the thickness of each of the metal layers.

In addition, according to another aspect of the invention, there is provided a vessel comprising the liquefied gas storage container described above.

According to the invention, the sandwich plate itself can perform the function of a double barrier. In addition, the structural rigidity of the sandwich plate is improved, thereby reducing the number of reinforcements to be installed. And damage due to freezing of moisture in the air can be prevented.

An embodiment of a liquefied gas storage container and a vessel having the same according to the present invention will be described in detail with reference to the accompanying drawings. In the following description with reference to the accompanying drawings, the same or corresponding components are given the same reference numbers. Duplicate description thereof will be omitted.

3 is a trial showing a liquefied gas storage container 100 according to an embodiment of the present invention. 4 is a partially enlarged view illustrating a portion B of FIG. 3.

According to the present embodiment, as shown in FIGS. 3 and 4, a sandwich comprising a pair of metal layers 111 and 112, a core layer 113, and a pair of adhesive layers 116 and 117. A connecting member 120 comprising a sandwich plate 110, a pair of flanges 121 and 122, three webs 123, a flow path 124, and a through hole 125, A liquefied gas storage container 100 is provided that includes a reinforcement 130 and a heat insulator 160.

According to the present embodiment as described above, since the sandwich plate 110 includes a pair of metal layers 111 and 112, the sandwich plate 110 itself functions as a double barrier, and thus, the hull 170 as in the prior art. Unlike the case of using a double barrier, since the hull 170 does not need to be made of (extreme) low temperature steel, the overall manufacturing cost of the LNG vessel can be significantly reduced.

In addition, since the honeycomb core layer 113 is inserted between the pair of metal layers 111 and 112, structural stiffness relative to the weight of the sandwich plate 110 may be improved, and thus, a reinforcement installed to reinforce rigidity. The quantity of 130 can be reduced by more than 40%.

In addition, as the number of the reinforcement 130 is reduced in this way, the internal structure of the liquefied gas storage container 100 may be simplified to minimize the occurrence of fatigue cracking, and the overall manufacturing cost and time of the LNG vessel may also be significantly reduced. .

Hereinafter, each configuration will be described in more detail with reference to FIGS. 3 to 9.

As shown in FIG. 3, a plurality of sandwich plates 110 are arranged inside the hull 170, and the plurality of sandwich plates 110 surrounds this space to partition a space for storing liquefied gas. Has a polyhedron shape.

The sandwich plate 110 includes a pair of metal layers 111 and 112, a core layer 113, and a pair of adhesive layers 116 and 117, as shown in FIGS. 5 to 7.

5 is a perspective view showing a sandwich plate 110 according to an embodiment of the present invention. 6 is an exploded perspective view showing a sandwich plate 110 according to an embodiment of the present invention. 7 is a perspective view showing the core layer 113 of the sandwich plate 110 according to an embodiment of the present invention.

As shown in FIG. 5, the pair of metal layers 111 and 112 are spaced apart from each other by a predetermined distance. The thickness of each of the metal layers 111 and 112 may be, for example, 3 mm, and may be formed to a thickness greater than that.

As such, the sandwich plate 110 forms a double structure in which the metal layers 111 and 112 are arranged in pairs, and when the liquefied gas storage container 100 of the LNG vessel is configured, the hull 170 may be removed. The sandwich plate 110 itself may function as a double barrier.

The core layer 113 is disposed between the metal layers 111 and 112 and has a honeycomb structure, as shown in FIGS. 5 to 7. As shown in FIG. 5, the core layer 113 is interposed in a space between the pair of metal layers 111 and 112 spaced apart from each other, so that the structural rigidity of the sandwich plate 110 may be significantly improved relative to its weight. have.

The core layer 113 of the honeycomb structure includes a partition wall 114 and a plurality of cells 115 partitioned thereby, as shown in FIGS. 6 and 7. Here, the partition wall 114 extends in the vertical direction along the thickness direction of the metal layers 111 and 112, and the space between the metal layers 111 and 112 is divided and partitioned into partitions by the partition wall 114. A plurality of cells 115 arranged in a lattice structure may be formed.

More specifically, as shown in FIGS. 6 and 7, the plurality of partition walls 114 are disposed in the thickness direction of the metal layers 111 and 112, that is, in a direction perpendicular to the surfaces of the metal layers 111 and 112, The metal layers 111 and 112 are repeatedly bent along the length direction. Since the plurality of partition walls 114 are disposed to face each other, a space may be formed therein and a plurality of cells 115 having a hexagonal cross section may be formed.

Since the partition wall 114 is disposed perpendicularly to the metal layers 111 and 112, the sandwich plate 110 may further improve stiffness with respect to a load acting perpendicularly to the metal layers 111 and 112. In addition, since flexural strength may also be improved due to the presence of spaces in the plurality of cells 115 of the core layer 113, the overall structural rigidity of the sandwich plate 110 may be improved.

Therefore, when the liquefied gas storage container 100 of the LNG vessel is configured using the sandwich plate 110, the number of reinforcement 130 installed to compensate for structural rigidity can be significantly reduced as compared with the conventional art. .

The thickness t1 of the core layer 113 may be set larger than the thickness t2 of each of the metal layers 111 and 112, as illustrated in FIGS. 5 to 7. Thus, by setting the thickness t1 of the core layer 113 to be larger than the thickness t2 of the metal layers 111 and 112, the rigidity and the bending strength with respect to the vertical load of the sandwich plate 110 may be further improved. As shown in the comparison table of FIG. 8, when the thickness t1 of the core layer 113 is increased, the structural rigidity of the sandwich plate 110 is significantly increased compared to the increase.

8 is a comparison table showing physical properties according to the thickness of the core layer 113 of the sandwich plate 110 according to an embodiment of the present invention.

8A illustrates a case in which the core layer 113 is not used, and FIG. 8B illustrates a case in which the thickness of the core layer 113 is twice the thickness of each metal layer 111 and 112. (C) is the case where the thickness of the core layer 113 is six times the thickness of each of the metal layers 111 and 112. Hereinafter, with reference to (a) of FIG. 8, (b) and (c) of FIG. 8 will be compared and explained, respectively.

FIG. 8B illustrates a case where the core layer 113 having twice the thickness of each metal layer 111 and 112 is used, and stiffness and flexural strength with respect to the vertical load of the sandwich plate 110 are compared with those of FIG. 8A. Represents 7-fold and 3.5-fold increase, respectively.

On the contrary, in FIG. 8C, the core layer 113 having six times the thickness of each of the metal layers 111 and 112 is used. The stiffness and bending strength of the sandwich plate 110 are 37 times higher than that of the vertical load. Since it is 9.2 times increased, it can be seen from this result that when the thickness of the core layer 113 is increased, the structural rigidity of the sandwich plate 110 is significantly increased compared to the increase degree.

In the case of FIGS. 8B and 8C, the weight of the sandwich plate 110 is increased by 3% and 6%, respectively, as compared with FIG. 8A, and thus, the core layer 113. By this interposition, it can be seen that the structural rigidity of the sandwich plate 110 is significantly improved relative to its weight.

On the other hand, the core layer 113 has the same thermal expansion coefficient and thermal conductivity as the metal layers 111 and 112. That is, the core layer 113 and the metal layers 111 and 112 may be made of a material having the same thermal characteristics, and may be made of, for example, the same material including aluminum (Al) or stainless steel. .

As such, since the core layer 113 and the metal layers 111 and 112 are made of a material having the same thermal expansion coefficient and thermal conductivity, the sandwich plate 110 is heated by welding when the liquefied gas storage container 100 is manufactured, or When the sandwich plate 110 is cooled by the (extreme) cryogenic liquefied gas inside the liquefied gas storage container 100, thermal stress generated at the bonding interface between the metal layers 111 and 112 and the core layer 113 may be minimized. As a result, breakage of the liquefied gas storage container 100 may be minimized.

Conventionally, sandwich plates with elastomers having self-adhesive properties between metal plates were used for fabricating the structure, but such sandwich plates had a problem in that the elastomer melted due to welding heat for bonding, and the elastomer and the metal plate were separated. Due to the difference in thermal properties, there is a problem of premature fatigue failure as the working stress or thermal stress generated at the bonding interface between them increases, which makes it difficult to apply such a sandwich plate to a liquefied gas storage container.

However, according to the present embodiment, by inserting the core layer 113 having the same thermal characteristics (coefficient of thermal expansion, thermal conductivity) between the metal layers 111 and 112, instead of the conventional elastomer core, heating by welding or Even with cooling by the liquefied gas, since the thermal stress between the metal layers 111 and 112 and the core layer 113 can be minimized, a stable liquefied gas storage container 100 with minimized fatigue damage can be implemented.

On the other hand, as shown in Figure 7, each cell 115 may be formed with an inlet and an outlet so that gas, such as nitrogen, for example to flow. Thus, through the proper arrangement of the partition wall 114, the inlet and outlet ports for flowing gas between the plurality of cells 115 or between the cell 115 and the outside is formed, so that the inside of the core layer 113, that is, each So-called nitrogen purging (N ₂ purging), which fills the inside of the cell 115 with, for example, nitrogen gas, becomes possible.

Since the liquefied gas injected into the liquefied gas storage container 100 is a (extreme) low temperature of, for example, -45 to -196 degrees Celsius, when air is introduced into the core layer 113 of the honeycomb structure, moisture in the air freezes. Since the liquefied gas storage container 100 may be damaged, such breakage may be prevented by filling a gas such as nitrogen into each cell 115 of the core layer 113 through nitrogen purging.

As shown in FIGS. 5 to 7, the pair of adhesive layers 116 and 117 are interposed between the pair of metal layers 111 and 112 and the core layer 113, respectively. The layer 113 is bonded. That is, as shown in FIG. 6, by placing a pair of adhesive layers 116 and 117 between the upper and lower surfaces of the core layer 113 and the metal layers 111 and 112, respectively, and heating and compressing them. The sandwich plate 110 may be manufactured.

In this case, the thickness t3 of each of the adhesive layers 116 and 117 is smaller than the thickness t2 of each of the metal layers 111 and 112. For example, the thin adhesive layers 116 and 117 in the form of a film may be formed. Can be used.

3 and 9, the connection member 120 is interposed between the sandwich plates 110 to connect the sandwich plates 110 to each other. 9 is a partially enlarged view illustrating a part of a liquefied gas storage container 100 according to an embodiment of the present invention.

The connection member 120 is a means for coupling the plurality of sandwich plates 110 arranged in a polyhedron shape inside the hull 170 so as to partition a space for storing liquefied gas to each other. Friction Stir Welding (FSW) Is bonded to the metal plate of each sandwich plate 110, and a friction stir welding line 140 is formed by the welding. Such a friction stir welding method will be described later in more detail in the presenting method of manufacturing the liquefied gas storage container 100 with reference to FIGS. 12 to 16.

In this case, the connection member 120 also has the same thermal characteristics as the metal layers 111 and 112 and the core layer 113, that is, the same coefficient of thermal expansion and the same thermal conductivity. That is, the connection member 120 is made of the same material as the metal layers 111 and 112 and the core layer 113, for example, may be made of a material containing aluminum or stainless steel.

As described above, the connection member 120 has the same thermal characteristics (coefficient of thermal expansion and thermal conductivity) as those of the metal layers 111 and 112 and the core layer 113, and thus, when the liquefied gas storage container 100 is manufactured. When the sandwich plate 110 and the connecting member 120 are heated by welding, or the sandwich plate 110 and the connecting member 120 are cooled by the (extreme) cryogenic liquefied gas inside the liquefied gas storage container 100. In addition, thermal stress generated between the sandwich plate 110 and the connection member 120 may be minimized. Accordingly, breakage of the liquefied gas storage container 100 may be minimized.

On the other hand, the connection member 120 is formed with a flow path 124 to enable gas flow with the inside of the core layer 113. That is, the flow path 124 is connected to the connection member 120 inserted between the sandwich plates 110 in order to flow the nitrogen gas charged in the core layer 113 between the sandwich plates 110 by the nitrogen purging described above. Is formed.

As such, the flow path 124 is formed in the connection member 120, so that gases such as nitrogen may flow between the core layers 113 of the sandwich plates 110, so that nitrogen purging can be performed more easily and effectively. As a result, moisture in the air introduced into the core layer 113 may freeze, thereby preventing the liquefied gas storage container 100 from being damaged.

In this case, as shown in FIG. 9, the connection member 120 may include a flow path along the longitudinal direction to enable gas flow to the inside of the sandwich plate 110, that is, the inside of the cell 115 of the core layer 113. 124 is formed.

This shaped steel consists of flanges 121, 122 and web 123. The flanges 121 and 122 form a pair, and the pair of flanges 121 and 122 are joined to the pair of metal layers 111 and 112 by friction stir welding, respectively. A web 123 disposed perpendicular to the flanges 121 and 122 is interposed between the pair of flanges 121 and 122.

As such, when the steel is used as the connecting member 120, and the flanges 121 and 122 of the steel are joined to the pair of metal layers 111 and 112, respectively, the longitudinal flow path 124 is formed by the structure of the steel itself. Since it can be secured, manufacturing cost and time for forming the flow path 124 can be reduced.

As shown in FIG. 9, the shaped steel may include three webs 123 and may have a 'III' shaped cross section. In this case, the space between the sandwich plates 110 may be defined by the three webs 123. May be divided into four and divided into four to form a total of four flow paths 124 along the longitudinal direction of the section steel.

As illustrated in FIG. 9, the plurality of flow paths 124 may be connected to each other by the through holes 125. That is, a plurality of through holes 125 are formed in each web 123 of the shaped steel, and the through holes 125 enable the flow of gas such as nitrogen between the four flow paths 124.

3 and 9, the reinforcement 130 is bonded to the surface of the connecting member 120 to reinforce the rigidity of the liquefied gas storage container 100. That is, the reinforcement 130 is bonded to the connection member 120 rather than the surface of the sandwich plate 110 to reinforce the rigidity of the liquefied gas storage container 100. The reinforcement 130 is installed in the connection member 120 by fillet welding, and the fillet welding line 150 is formed according to the welding.

When the reinforcing material 130 is installed in the connection member 120 as described above, the separation distance between the bonding portion to which the reinforcing material 130 is bonded and the adhesive layers 116 and 117 is formed on the surface of the sandwich plate 110. It is increased compared to the case where is bonded. Therefore, melting of the adhesive layers 116 and 117 by welding for bonding the reinforcement 130 may be prevented.

In addition, when the shaped steel is used as the connecting member 120, since the web 123 of the shaped steel also serves as a cooling fin, melting of the adhesive layers 116 and 117 due to the above-described welding heat may be more effectively prevented. In this case, since the shaped steel itself has rigidity, deformation due to the above-described welding can be minimized.

Meanwhile, in the present embodiment, since the core layer 113 is formed in a honeycomb structure as described above, the rigidity of the sandwich plate 110 is increased, the quantity of the reinforcement 130 installed may be reduced by about 40%.

As shown in FIG. 3, the heat insulating material 160 is disposed to surround the outer surfaces of the plurality of sandwich plates 110 joined to each other by the connecting member 120, and stored inside the liquefied gas storage container 100. It insulates the liquefied gas from the outside.

Hereinafter, the liquefied gas storage container 100 according to another embodiment of the present invention will be described.

10 and 11 are partially enlarged views showing a part of a liquefied gas storage container 100 according to another embodiment of the present invention.

In the present embodiment, the sandwich plate 110, the metal layers 111 and 112, the core layer 113, the adhesive layers 116 and 117, the connection member 120, the flanges 121 and 122, the flow path 124, and through The hole 125, the reinforcing material 130, the friction stir welding line 140, the fillet welding line 150, and the heat insulating material 160 all have the same structure and function as the above-described embodiment, but the number of webs 123 is different. The specific shape of the connection member 120 according to the present embodiment is different.

That is, in the present embodiment, as shown in Figure 10, the number of web 123 is one, the shape steel having a cross-section of the 'I' shape can be used as the connecting member 120. As such, as the number of webs 123 is one, the space between the sandwich plates 110 may be divided into two so that a total of two flow paths 124 may be formed along the length direction of the connection member 120.

In the present embodiment, as shown in Figure 11, the number of web 123 is two so that the section steel having a 'II'-shaped cross section may be used as the connecting member 120. In this case, since the number of webs 123 is two, the space between the sandwich plates 110 is divided into three, so that a total of three flow paths 124 are formed along the longitudinal direction of the connection member 120. Can be.

Hereinafter, a ship according to another embodiment of the present invention will be described.

According to this embodiment, an LNG vessel including a hull (170 in FIG. 3) and a liquefied gas storage container (100 in FIG. 3) installed inside the hull (170 in FIG. 3) is presented.

In the case of the present embodiment, the specific configuration and function of the liquefied gas storage container (100 of FIG. 3) is the same or similar to the above-described embodiment, so a detailed description thereof will be omitted.

Hereinafter, a method of manufacturing a liquefied gas storage container 100 according to another embodiment of the present invention will be described.

12 is a flowchart illustrating a method of manufacturing a liquefied gas storage container (100 of FIG. 3) according to another embodiment of the present invention. 13 to 16 are partial enlarged views showing each step of the method for manufacturing a liquefied gas storage container (100 of FIG. 3) according to another embodiment of the present invention.

According to the present embodiment, as shown in FIGS. 12 to 16, providing a sandwich plate 210 (S110), arranging the connecting member 220 (S120), and a metal layer by friction stir welding ( A method of manufacturing a liquefied gas storage container (100 of FIG. 3) including a step (S130) of joining 211 and 212 and a connection member 220, and a step (S140) of joining the reinforcing material 230 is provided.

According to this embodiment, by joining the metal layers 211 and 212 and the connecting member 220 by friction stir welding, the heat generated during welding is reduced to melt the deformation of the adhesive layers 216 and 217 and deformation of the welded portion. This can be minimized, and the bead femininity due to welding is small, and the fatigue strength can be improved.

Hereinafter, each process will be described in more detail with reference to FIGS. 12 to 16.

In the present embodiment, the sandwich plate 210, the metal layers 211 and 212, the core layer 213, the adhesive layers 216 and 217, the connecting member 220, the flanges 221 and 222, the web 223, the flow path 224, the through hole 225, the reinforcing material 230, the friction stir welding line 240, the structure of the fillet welding line 250, and the function thereof, the liquefied gas storage container (see the embodiment described above) 3, the sandwich plate 110, the metal layers 111 and 112, the core layer 113, the adhesive layers 116 and 117, the connecting member 120, the flanges 121 and 122, the web 123, and the like. Since the flow path 124, the through hole 125, the reinforcing material 130, the friction stir welding line 140, and the fillet welding line 150 are the same as or similar to each other, a detailed description thereof will be omitted. The manufacturing process of the liquefied gas storage container (100 of FIG. 3) will be described below.

First, as shown in FIG. 13, a core layer of a honeycomb structure having a heat expansion coefficient disposed between the pair of metal layers 211 and 212 and the metal layers 211 and 212 and having the same thermal expansion coefficient as the metal layers 211 and 212 ( 213 and a plurality of sandwich plates 210 interposed between the metal layers 211 and 212 and the core layer 213, and adhesive layers 216 and 217 for adhering the metal layers 211 and 212 to the core layer 213. (S110).

As a step of providing the sandwich plate 210 presented in the above-described embodiments, the sandwich plate 210 may be formed between the upper and lower surfaces of the core layer 213 and the metal layers 211 and 212 as described above. After arranging the pair of adhesive layers 216 and 217, respectively, the metal layers 211 and 212, the adhesive layers 216 and 217, and the core layer 213 may be manufactured by heating and compressing them.

Next, as shown in FIG. 14, the connection member 220 is disposed between the sandwich plates 210 (S120). The plurality of sandwich plates 210 are arranged in a polyhedron shape to partition an internal space for storing liquefied gas. In order to couple these sandwich plates 210, a section steel, which is a connecting member 220, is disposed between the sandwich plates 210.

In this case, as shown in FIG. 14, the sections are arranged such that the sides of the flanges 221 and 222 of the section steel and the sides of the metal layers 211 and 212 abut each other, and the core layer 213 is formed according to the shape of the sections. A flow path 224 capable of gas flow with the gas is formed.

Next, as shown in FIG. 15, the metal layers 211 and 212 and the connection member 220 are bonded by friction stir welding (S130). Friction stir welding is a method of joining the joined material by plastically flowing a local region of the joined material by frictional heat between the rotating tool and the joined material, and by this welding, the friction stir welding line 240 as shown in FIG. 15. ) Is formed.

By bonding the metal layers 211 and 212 and the flanges 221 and 222 of the connection member 220 by such a friction stir welding method, heat generated during welding may be reduced, and thus, the adhesive layers 216 and 217 may be reduced. Deformation of the melting and welding sites can be minimized. In addition, when the friction stir welding is performed, the welded portion is formed flat, so that the bead height of the weld is small, and thus the fatigue strength of the welded portion can be improved.

Next, as shown in FIG. 16, the reinforcing material 230 is bonded to the surface of the connecting member 220 (S140). In the process of joining the reinforcement 230 to the upper and lower surfaces of the connecting member 220 by the fillet welding method, the fillet welding line 250 is connected to the joining portion of the reinforcing member 230 and the connecting member 220 by such welding. Is formed.

As mentioned above, although an embodiment of the present invention has been described, those of ordinary skill in the art may add, change, delete or add components within the scope not departing from the spirit of the present invention described in the claims. The present invention may be modified and changed in various ways, etc., which will also be included within the scope of the present invention.

1 is a perspective view showing a standalone liquefied gas storage container according to the prior art.

FIG. 2 is an enlarged view of a portion A of FIG. 1; FIG.

3 is a perspective view showing a liquefied gas storage container according to an embodiment of the present invention.

4 is a partially enlarged view illustrating a portion B of FIG. 3.

5 is a perspective view showing a sandwich plate according to an embodiment of the present invention.

Figure 6 is an exploded perspective view showing a sandwich plate according to an embodiment of the present invention.

7 is a perspective view showing a core layer of a sandwich plate according to an embodiment of the present invention.

Figure 8 is a comparison table showing the physical properties according to the thickness of the core layer of the sandwich plate according to an embodiment of the present invention.

9 is a partially enlarged view showing a portion of a liquefied gas storage container according to an embodiment of the present invention.

10 and 11 are partially enlarged views showing a part of a liquefied gas storage container according to another embodiment of the present invention.

12 is a flow chart showing a liquefied gas storage container manufacturing method according to another embodiment of the present invention.

13 to 16 is a partially enlarged view showing each step of the liquefied gas storage container manufacturing method according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: liquefied gas storage container 110: sandwich plate

111, 112: metal layer 113: core layer

114: partition wall 115: cell

116, 117: adhesive layer 120: connecting member

121, 122: flange 123: web

124: Euro 125: Through hole

130: reinforcing material 140: friction stir welding line

150: fillet welding line 160: heat insulating material

170: hull

210: sandwich plate 211, 212: metal layer

213: core layer 216, 217: adhesive layer

220: connection member 221, 222: flange

223 web 224 euro

225: through hole 230: reinforcing material

240: friction stir welding line 250: fillet welding line

Claims (11)

A plurality of sandwich plates arranged to partition a space for storing liquefied gas; A section steel interposed between the sandwich plates to connect the sandwich plates to each other and having a plurality of flow paths formed in a length direction to enable gas flow to the inside of the sandwich plate; And It includes a through hole formed in the section steel so that the flow path is connected to each other, The sandwich plate, A pair of metal layers; A core layer of a honeycomb structure disposed between the metal layers and having the same coefficient of thermal expansion as the metal layer; And And an adhesive layer interposed between the metal layer and the core layer to bond the metal layer and the core layer. The method of claim 1, The core layer, A partition wall extending along the thickness direction of the metal layer; And And a plurality of cells formed by partitioning the space between the metal layers by the partition wall. The method of claim 1, The section steel consists of a pair of flanges joined to the metal layer, respectively, and a web disposed vertically to the flange between the flanges, The plurality of flow paths are partitioned from each other by the web, The through hole is a liquefied gas storage container, characterized in that formed in the web. The method of claim 3, The section steel has a liquefied gas storage container, characterized in that it has a cross-sectional shape of any one of 'I', 'II' and 'III'. The method according to any one of claims 1 to 4, The section steel has a coefficient of thermal expansion equal to that of the metal layer and the core layer. The method of claim 5, The metal layer, the core layer and the section steel have the same thermal conductivity, liquefied gas storage container. The method of claim 6, The metal layer, the core layer and the section steel is liquefied gas storage container, characterized in that made of the same material. The method of claim 7, wherein The metal layer, the core layer and the section steel is a liquefied gas storage container, characterized in that made of a material containing aluminum (Al) or stainless steel (stainless steel). The method according to any one of claims 1 to 4, The thickness of the core layer is a liquefied gas storage container, characterized in that greater than the thickness of each of the metal layer. 10. The method of claim 9, The thickness of each of the adhesive layer is smaller than the thickness of each of the metal layer liquefied gas storage container. Ship comprising the liquefied gas storage container according to any one of claims 1 to 4.

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