Liquefied gas storage tank and vessel comprsing the same

Abstract

The present invention relates to a liquefied gas storage tank (1) and a vessel comprising same, wherein the liquefied gas storage tank (1) of the present invention comprises a corner block (CB) which is arranged at a corner where a first surface and a second surface at different angles meet each other and form a storage space for accommodating liquefied gas. The corner block (CB) comprises: a lower block (LB) which is provided inside the first and second surfaces and includes a single board; an upper block (UB) which is bonded to a secondary barrier (4) of the lower block (LB); and an upper connecting block (UBB) which is on the upper surfaces of neighboring lower blocks (LB), is bonded to the secondary barriers (4), and connects the lower blocks (LB). The upper block (UB) comprises: a first inner fixing unit (3b1) and a second inner fixing unit (3b2) which are respectively provided inside the first surface and inside the second surface and bonded to the secondary barriers (4), each of the first inner fixing unit (3b1) and second inner fixing unit (3b2) having a structure in which a primary inner plywood (31b), a primary corner insulating material (32b), and a primary outer plywood (33b) are stacked; and an inner bent portion (3b3) which is installed at a corner space portion between the first inner fixing unit (3b1) and the second inner fixing unit (3b2). The inner bent portion (3b3) has both side surfaces that are perpendicular to the secondary barrier (4) and have reduced length compared with the total height of each of the first and second inner fixing units (3b1, 3b2). FIG. 28

Description

Liquefied gas storage tank and vessel containing same

[0001] The present invention relates to a liquefied gas storage tank and a vessel including the same.

[0002] With recent technological developments, liquefied gases such as liquefied natural gas (LNG) and liquefied petroleum gas (LPG) are widely used as replacements for gasoline and diesel.

[0003] In addition, LNG carriers, LNG RVs (Regasification Vessels), LNG FPSOs (Floating, Production, Storage and Offloading), and LNG FSRUs (Floating Storage and Regasification Units) that transport or store liquefied gases such as LNG at sea are equipped with storage tanks (so-called "cargo holds") to store LNG in a cryogenic liquid state.

[0004] Furthermore, liquefied gas storage tanks can generate boil-off gas (BOG) due to external heat intrusion. Reducing the boil-off rate (BOR), the rate at which BOG evaporates, through insulation design is a key technology in liquefied gas storage tank design. Furthermore, because liquefied gas storage tanks are exposed to various loads, such as sloshing, ensuring the mechanical strength of the insulation panels can also be essential.

[0005] Considering these points, active research is being conducted to secure the mechanical strength of insulation panels at right-angled or obtuse-angled corners of liquefied gas storage tanks, improve insulation performance, and reduce stresses caused by various loads such as sloshing, deformation of the hull, and temperature changes.

[0006] The present invention was created to solve the problems of the prior art as described above, and the purpose of the present invention is to provide a liquefied gas storage tank and a ship including the same, which can reduce the low-temperature burden, sloshing burden, and stress burden of the corner secondary barrier by improving the structure of the corner block.

[0007] According to one aspect of the present invention, a liquefied gas storage tank includes a corner block that is arranged at a corner portion where first and second surfaces having different angles meet to form a storage space for accommodating liquefied gas, wherein the corner block includes a lower block provided on the inner side of the first and second surfaces and made of a single board, an upper block bonded to a secondary barrier wall of the lower block, and an upper connecting block bonded to the secondary barrier wall on an upper surface of the lower block that is arranged adjacent to each other to connect the lower blocks, wherein the upper block includes an inner first fixing part and an inner second fixing part that are respectively provided on the inner side of the first surface and the second surface and bonded to the secondary barrier wall, and have a structure in which an inner primary plywood, a corner primary insulation material, and an outer primary plywood are laminated; And it includes an inner bending part installed in a corner space portion between the inner first fixing part and the inner second fixing part, and the inner bending part may have a height of both sides perpendicular to the secondary barrier that is reduced compared to the total height of each of the inner first and second fixing parts.

[0008] Specifically, the inner bending portion is provided with a first protrusion on both sides, and the first protrusion extends a certain length from the inner bending portion inserted into the corner space portion created by the inner first and second fixing portions to the outside of the space, and has a cross-sectional shape similar to the inner bending portion, but a curved portion in contact with the secondary barrier extends in the same line from the curved portion of the inner bending portion, and both side surfaces perpendicular to the secondary barrier may have a first step with both side surfaces of the inner bending portion.

[0009] Specifically, the upper connecting block is provided on the inner side of the first surface and the second surface, respectively, and is bonded to the secondary barrier, and has a corner first connecting fixing part and a corner second connecting fixing part having a structure in which a corner first connecting plywood, a corner connecting insulation material, and a corner second connecting plywood are laminated; And it includes a corner connecting bending part installed in the corner space part between the first corner connecting fixing part and the second corner connecting fixing part, and the corner connecting bending part has a height of both side surfaces perpendicular to the secondary barrier that is reduced compared to the total height of each of the first and second corner connecting fixing parts, and a second protrusion part is provided on both side surfaces, and the second protrusion part extends a certain length out of the space from the corner connecting bending part inserted into the corner space part created by the first and second corner connecting fixing parts, and has a cross-sectional shape similar to the corner connecting bending part, and a curved portion in contact with the secondary barrier extends in the same line from the curved portion of the corner connecting bending part, and the both side surfaces perpendicular to the secondary barrier can extend to have a second step from both side surfaces of the corner connecting bending part.

[0010] Specifically, when the upper connecting block is installed between the adjacent upper blocks, the first and second protrusions come into contact with each other, so that a step space is created between the inner first and second fixing parts and the corner first and second connecting fixing parts, and a stuffing piece is inserted and installed in the step space, and the stuffing piece has a (+) tolerance so as to completely seal the step space, and can be formed in a shape corresponding to the shape of the step space.

[0011] Specifically, the first and second inner fixing parts are provided symmetrically based on the direction of dividing the corner portion equally, and the first side that is in close contact with both sides of the inner bending portion is perpendicular to the second barrier, and the second side that extends from the first side toward the storage space extends in the same direction as the dividing direction, and the upper block further includes a corner inner packing material that is inserted and installed in a space created between the first side that is in close contact with both sides of the inner bending portion and the second side that faces each other, and the corner inner packing material can be formed to have a (+) tolerance so as to be able to seal the space when inserted into the space between the second sides.

[0012] According to another aspect of the present invention, a liquefied gas storage tank includes a corner block disposed at a corner portion where first and second surfaces having different angles meet to form a storage space for accommodating liquefied gas, wherein the corner block comprises: a lower block provided on the inner side of the first and second surfaces and made of a single board; an integrated upper block bonded to a secondary barrier of the lower block and made of a single board; an upper connection block bonded to the secondary barrier exposed between the integrated upper blocks disposed adjacent to each other; and a barrier fixing member installed on an upper surface of the integrated upper block and fixing a primary barrier, wherein the integrated upper block comprises: one outer primary plywood provided on the inner side of the first surface and the second surface respectively and bonded to the secondary barrier; one corner primary insulation material laminated on the outer primary plywood; And it is composed of one inner primary plywood laminated on the corner primary insulation material, and the barrier fixing member can be formed by installing a plurality of unit barrier fixing members in parallel and adjacent to each other on one inner primary plywood.

[0013] Specifically, the integrated upper block includes a plurality of upper slits formed at a certain depth at the upper portion, and the plurality of upper slits are formed through the inner primary plywood to at least a portion of the corner primary insulation material to prepare for shrinkage or expansion stress of the corner primary insulation material, and the plurality of unit barrier fixing members can be formed at corresponding positions between the plurality of unit barrier fixing members to be linked to shrinkage or expansion of the corner primary insulation material.

[0014] Specifically, the integrated upper block includes a plurality of upper slits formed at a certain depth at the upper portion; and a plurality of lower slits formed at a certain depth at the lower portion, and the plurality of upper slits and the plurality of lower slits may be formed at mutually staggered positions.

[0015] Specifically, the outer primary plywood has a plurality of first grooves formed on the lower surface thereof to be bonded to the secondary barrier, and the plurality of first grooves are formed in a direction perpendicular to the corners of the storage tank so as to ensure that the adhesive is squeezed out into a non-bonded area when the outer primary plywood is bonded to the secondary barrier with an adhesive, and the non-bonded area is set in a plurality in the middle portion including the edge portions on both sides of the outer primary plywood, and each of the plurality of non-bonded areas is set at a constant interval and width in a direction perpendicular to the corners of the storage tank, and can be set at a position corresponding to between the plurality of unit barrier fixing members.

[0016] Specifically, the plurality of first grooves may be formed along the boundary portions on both sides of the plurality of non-adhesive regions and may be arranged to be staggered with the plurality of upper slits.

[0017] According to another aspect of the present invention, a liquefied gas storage tank includes a corner block which is arranged at a corner portion where first and second surfaces having different angles meet to form a storage space for accommodating liquefied gas, wherein the corner block includes a lower block provided on the inner side of the first and second surfaces and made of a single board, an upper block bonded to a secondary barrier wall of the lower block, and an upper connecting block bonded to the secondary barrier wall on an upper surface of the lower block which is arranged adjacent to the lower block to connect the lower blocks, wherein the upper connecting block includes a corner first connecting fixing part and a corner second connecting fixing part which are respectively provided on the inner side of the first surface and the second surface and bonded to the secondary barrier wall, and have a structure in which a corner first connecting plywood, a corner connecting insulation material, and a corner second connecting plywood are laminated; And it includes a corner connecting bending part installed in a corner space portion between the first corner connecting fixing part and the second corner connecting fixing part, and the corner connecting bending part may have a height of both sides perpendicular to the second barrier that is reduced compared to the total height of each of the first and second corner connecting fixing parts.

[0018] Specifically, the corner connecting bend portion has a second protrusion provided on both sides, and the second protrusion extends a certain length outward from the corner connecting bend portion inserted into the corner space portion created by the first and second corner connecting fixing parts, and has a cross-sectional shape similar to the corner connecting bend portion, but a curved portion in contact with the secondary barrier extends in the same line from the curved portion of the corner connecting bend portion, and both side surfaces perpendicular to the secondary barrier may have a second step with both side surfaces of the corner connecting bend portion.

[0019] Specifically, the first and second corner connecting fixing parts are provided symmetrically based on the direction of dividing the corner portion equally, and the first side that is in close contact with both sides of the corner connecting bend portion is perpendicular to the second barrier, and the second side that extends from the first side toward the storage space extends in the same direction as the dividing direction, and the upper connecting block further includes a corner inner packing material that is inserted and installed in a space created between the first side that is in close contact with both sides of the corner connecting bend portion and the second side that faces each other, and the corner inner packing material can be formed to have a (+) tolerance so as to be able to seal the space in a state where it is inserted into the space between the second sides.

[0020] Specifically, the second corner connecting plywood may have a second groove formed on the lower surface thereof to be bonded to the second barrier, and the second groove may be formed in a horizontal direction with respect to the corner side of the storage tank so as to ensure that the adhesive is squeezed out to a non-bonded area when the second corner connecting plywood is bonded to the second barrier with an adhesive.

[0021] Specifically, the second groove may be formed in a portion adjacent to the rear edge of the corner second connecting plywood so as to ensure that the adhesive is squeezed out to the corner connecting bend portion, which is a non-adhesive area.

[0022] The liquefied gas storage tank according to the present invention and the vessel equipped with the same can reduce the low-temperature burden, sloshing burden, and stress burden of the corner secondary barrier by improving the structure of the corner block.

[0023] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith form the inner first and second fixing members for holding the corner primary barrier fixing member in the corner block not only with plywood but also with a combination of polyurethane foam insulation, thereby improving the insulation performance, reducing the weight, and reducing the cost compared to the existing structure composed only of plywood.

[0024] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith have the same, by configuring the corner primary insulation wall of the corner block connected to the flat primary insulation wall of the flat block and the corner secondary insulation wall of the corner block connected to the flat secondary insulation wall of the flat block to have the same or similar thickness, so that the thickness of the corner primary insulation wall is relatively thicker than before (however, the thickness of the corner secondary insulation wall is a thickness that can maintain mechanical strength at a certain level), so that the low-temperature burden and sloshing burden of the corner secondary wall can be reduced, and damage to the corner secondary wall can be prevented, and the low-temperature burden of the corner secondary wall can be reduced, thereby preventing brittle fracture of the hull.

[0025] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith have a corner primary insulation wall configured to be relatively thicker than before, so that the length of the portion of the corner secondary barrier that is not bonded to the corner secondary barrier can be increased, and not only can the probability of damage to the corner secondary barrier including the corner connection barrier be further reduced due to the increased flexibility of the corner secondary barrier, but also the corner secondary barrier can easily absorb hull deformation and further reduce low-temperature stress.

[0026] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith space the inner first fixing part and the inner second fixing part provided on the inner sides of the first and second sides at different angles by a certain distance, and provide an inner intermediate fixing part between the inner first and second fixing parts, so that the bending angle of the corner primary barrier can be alleviated by the inner intermediate fixing part, thereby reducing the sloshing burden on the corner primary barrier and increasing the mechanical strength of the corner portion.

[0027] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith form a chamfer at the corner where the outer first fixing part and the outer second fixing part, which are respectively fixed to the first and second surfaces at different angles, face each other, and fill the chamfer with low-density polyurethane foam, thereby further increasing the insulation performance at the corner portion by the low-density polyurethane foam.

[0028] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith form a step at the corner where the outer first fixing part and the outer second fixing part, which are respectively fixed to the first and second surfaces at different angles, face each other, and fill the step portion with glass wool, thereby improving the flexibility of the corner secondary barrier including the corner connecting barrier formed on the upper part of the glass wool, thereby further preventing damage to the corner secondary barrier.

[0029] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith space apart the first outer fixing part and the second outer fixing part, which are fixed to the first and second surfaces at different angles, by a predetermined distance, and provide an outer intermediate fixing part between the first and second outer fixing parts, so that the gaps formed between the first outer fixing part and the outer intermediate fixing part and between the second outer fixing part and the outer intermediate fixing part respectively can prevent damage to the corner secondary barrier fixed to the outer fixing part by relieving the shrinkage or expansion stress due to the temperature of the outer fixing part compared to a conventional single gap.

[0030] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped with the same form a chamfer at the corner where the outer first fixing part and the outer second fixing part, which are respectively fixed to the first surface and the second surface at different angles, face each other, and a corner secondary barrier is installed along the surface of the outer first and second fixing parts including the chamfer portion, so that the corner secondary barrier protrudes outward and is bent, thereby increasing the length of the non-bonded portion to the corner secondary insulation wall, and thus the flexibility of the corner secondary barrier increases, thereby further reducing the probability of damage to the corner secondary barrier including the corner connecting barrier, and the corner secondary barrier can easily absorb hull deformation and further reduce low-temperature stress.

[0031] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith are configured such that a plurality of corner primary insulation walls including inner primary plywood forming a step with the corner primary insulation material are arranged on the corner secondary insulation wall, and neighboring corner primary insulation materials are arranged adjacently, thereby facilitating the installation handling of the barrier fixing member through the step portion between the adjacent inner primary plywoods, and since the packing material only needs to be installed in the step portion, the consumption of the packing material can be reduced.

[0032] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith are configured such that the inner bend of the corner primary insulation wall is formed of an inner first half-bend that is bonded to the inner first fixing part and an inner second half-bend that is bonded to the inner second fixing part, and the space between the inner first and second half-bends is finished with a corner inner packing material having a (+) tolerance, thereby blocking the heat convection path in the inner bend and preventing the heat convection phenomenon.

[0033] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith reduce the size of the inner bend (or corner connecting bend) of the corner primary insulation wall to about half of the size of the inner first and second fixing parts (or corner first and second connecting fixing parts) of the corner primary insulation wall (or corner connecting insulation wall), so that the area reduced due to temperature change is reduced compared to the existing inner bend formed to the same height as the inner first and second fixing parts, and thus the space where heat convection occurs in the inner bend (or corner connecting bend) (non-bonded area between the inner bend and the secondary wall in the corner part) is reduced, thereby reducing the heat convection phenomenon.

[0034] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped with the same reduce the size of the inner bend (or corner connecting bend) of the corner primary insulation wall to about half of the size of the inner first and second fixing parts (or corner first and second connecting fixing parts) of the corner primary insulation wall (or corner connecting insulation wall), and thereby finish the space portion created between the remaining half of the inner first and second fixing parts (or corner first and second connecting fixing parts) with a corner inner packing material, and insert the inner corner packing material into the inner bend (or corner connecting bend) to a certain depth, thereby further reducing the heat convection phenomenon in the inner bend (or corner connecting bend).

[0035] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith can reduce the heat convection phenomenon by configuring an integrated upper block in which a plurality of unit upper blocks are integrated into one, compared to the existing upper block in which a plurality of unit upper blocks are arranged in parallel and adjacent to each other, thereby omitting the heat convection path that occurs between the existing unit upper blocks.

[0036] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped with the same have a structure in which both sides of a reduced-sized inner bend and a reduced-sized corner connecting bend are protruded, and when an upper connecting block is installed between adjacent integrated upper blocks, the space created by the protruding structures of the inner bend and the corner connecting bend is closed with a stuffing piece, so that the heat convection path created between the integrated upper block and the upper connecting block forms a curved path by the protruding structure and the stuffing piece, thereby reducing the heat convection phenomenon.

[0037] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith can alleviate shrinkage and expansion stress of the integrated upper block by installing a plurality of unit barrier fixing members on the upper surface of each portion corresponding to a plurality of unit upper blocks constituting the existing upper block in the integrated upper block, forming an upper slit of a certain depth in the upper portion of the integrated upper block exposed between the plurality of unit barrier fixing members, and forming a lower slit of a certain depth in the lower portion of the integrated upper block so as to be staggered with the upper slit. In addition, the liquefied gas storage tank according to the present invention and the vessel equipped with the same form a plurality of first grooves in a direction perpendicular to the corner side of the storage tank on the outer primary plywood of the integrated upper block connected to the corner secondary barrier, and by forming them in a portion adjacent to both edges of the outer primary plywood and a portion on both sides of the boundary of a non-bonded area set in a plurality in the middle portion, it is possible to prevent bonding failure of the integrated upper block having a larger bonding area than that of a conventional upper block.

[0038] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped therewith form a plurality of first grooves in the outer primary plywood of the integrated upper block, so that when bonding the outer primary plywood to the secondary barrier with adhesive, it is possible to confirm that the adhesive is squeezed out into the non-bonded area and to prevent the adhesive from excessively penetrating into the non-bonded area.

[0039] In addition, the liquefied gas storage tank according to the present invention and the vessel equipped with the same form a second groove in a horizontal direction with respect to the corner side of the storage tank in the corner second connecting plywood of the upper connecting block connected to the corner connecting barrier, and by forming the second groove in a portion adjacent to the rear edge of the corner second connecting plywood, not only can it be directly confirmed with the naked eye that the adhesive in the bonding area is squeezed out to the non-bonding area, but also the adhesive is squeezed out and bonded to the non-bonding section beyond the second groove, thereby preventing the non-bonding section of the corner from being reduced and the load applied to the secondary barrier from becoming larger, thereby preventing a bonding failure of the upper connecting block.

[0040] FIG. 1 is a cross-sectional view of a portion of a planar portion for explaining a liquefied gas storage tank according to a first embodiment of the present invention.

[0041] FIG. 2 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a first embodiment of the present invention.

[0042] FIG. 3 is a drawing showing the results of a structural analysis of a corner portion of a liquefied gas storage tank according to the first embodiment of the present invention.

[0043] FIG. 4 is a drawing showing another structural analysis result for a corner portion of a liquefied gas storage tank according to the first embodiment of the present invention.

[0044] Figure 5 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a second embodiment of the present invention.

[0045] Figure 6 is a drawing showing the results of structural analysis of a corner portion of a liquefied gas storage tank according to a second embodiment of the present invention.

[0046] Fig. 7 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a third embodiment of the present invention.

[0047] Figure 8 is a drawing showing the results of structural analysis of a corner portion of a liquefied gas storage tank according to a third embodiment of the present invention.

[0048] Fig. 9 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a fourth embodiment of the present invention.

[0049] FIG. 10 is a drawing showing the results of a structural analysis of a corner portion of a liquefied gas storage tank according to the fourth embodiment of the present invention.

[0050] Fig. 11 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a fifth embodiment of the present invention.

[0051] Fig. 12 is a drawing showing the results of structural analysis of a corner portion of a liquefied gas storage tank according to the fifth embodiment of the present invention.

[0052] Fig. 13 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to the sixth embodiment of the present invention.

[0053] Figure 14 is a drawing showing the results of structural analysis of a corner portion of a liquefied gas storage tank according to the sixth embodiment of the present invention.

[0054] Fig. 15 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to the seventh embodiment of the present invention.

[0055] Figure 16 is a drawing showing the results of structural analysis of a corner portion of a liquefied gas storage tank according to the seventh embodiment of the present invention.

[0056] Fig. 17 is a partial front view of a corner portion for explaining a liquefied gas storage tank according to the eighth embodiment of the present invention.

[0057] Fig. 18 is a partial front view of a corner portion for explaining a liquefied gas storage tank according to the ninth embodiment of the present invention.

[0058] Fig. 19 is a side view for explaining the unit upper block constituting the upper block of Fig. 18.

[0059] Figure 20 is an exploded view of the unit upper block of Figure 19.

[0060] Figure 21 is a drawing for explaining the process of assembling the unit upper block of Figure 20.

[0061] Fig. 22 is a side view for explaining the upper connection block of Fig. 18.

[0062] Fig. 23 is a partial front view of a corner portion for explaining a liquefied gas storage tank according to the tenth embodiment of the present invention.

[0063] Fig. 24 is a partially exploded perspective view of a corner portion for explaining a liquefied gas storage tank according to the tenth embodiment of the present invention.

[0064] Figure 25 is a front view for explaining the integrated upper block of Figure 23.

[0065] Fig. 26 is a front view illustrating another embodiment of the integrated upper block of Fig. 25.

[0066] Figure 27 is a side view of the integrated upper block of Figure 25.

[0067] Figure 28 is a cross-sectional view taken along line A-A' of Figure 25.

[0068] Fig. 29 is a perspective view for explaining the upper connecting block of Fig. 23.

[0069] Fig. 30 is a front view for explaining the upper connecting block of Fig. 23.

[0070] Figure 31 is a cross-sectional view taken along line B-B' of Figure 30.

[0071] Fig. 32 is a cross-sectional view illustrating another embodiment of the integrated upper block of Fig. 25.

[0072] Figure 33 is an exploded view of the integrated upper block of Figure 32.

[0073] FIGS. 34 to 37 are drawings for comparing and explaining the temperature of the convection path and the secondary barrier, which vary depending on the structure of the corner primary insulation wall and the corner connecting insulation wall in the liquefied gas storage tank according to the tenth embodiment of the present invention and the liquefied gas storage tank according to the comparative example.

[0074] The purpose, specific advantages, and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments, taken in conjunction with the accompanying drawings. It should be noted that, in this specification, reference numerals are assigned to components in each drawing, and that, where possible, identical components are assigned the same reference numerals, even if they appear in different drawings. Furthermore, in describing the present invention, detailed descriptions of related known technologies will be omitted if they are deemed to unnecessarily obscure the gist of the present invention.

[0075] In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention.

[0076] Additionally, terms including ordinal numbers such as first, second, etc. may be used to describe various components, but the components are not limited by the terms. The terms are used solely to distinguish one component from another. In addition, among the terms used throughout the specification, it is to be noted that the term "outside" refers to the outside of the tank with respect to the liquefied gas storage tank, and the term "inside" refers to the inside of the tank with respect to the liquefied gas storage tank.

[0077] Hereinafter, in this specification, liquefied gas may be used to mean all gaseous fuels that are generally stored in a liquid state, such as LNG or LPG, ethylene, ammonia, etc., and cases where the state is not liquid due to heating or pressurization may also be expressed as liquefied gas for convenience. This can also be applied to boil-off gas. In addition, LNG may be used to mean not only NG (Natural Gas) in a liquid state, but also LNG in a supercritical state, etc., for convenience, and boil-off gas may be used to mean not only boil-off gas in a gaseous state but also liquefied boil-off gas.

[0078] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0079] FIG. 1 is a cross-sectional view of a portion of a planar portion for explaining a liquefied gas storage tank according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a first embodiment of the present invention, FIG. 3 is a drawing showing the results of a structural analysis of a corner portion of a liquefied gas storage tank according to a first embodiment of the present invention, and FIG. 4 is a drawing showing another result of a structural analysis of a corner portion of a liquefied gas storage tank according to a first embodiment of the present invention.

[0080] It should be noted that the vessel equipped with the liquefied gas storage tank (1) described below is a concept encompassing not only merchant ships transporting cargo from a point of origin to a destination, but also marine structures floating at a certain point in the sea to perform specific tasks, although not illustrated. Furthermore, it should be noted that the liquefied gas storage tank (1) in the present invention includes any type of tank that stores liquefied gas.

[0081] A liquefied gas storage tank (1) is installed on a ship and can store liquefied gas such as LNG, which is a cryogenic substance (approximately -160°C to -170°C), and may include a flat structure and a corner structure. For example, the transverse walls in the front-rear direction of the liquefied gas storage tank (1), the floor between the transverse walls, the vertical walls, and the ceiling may correspond to a flat structure. In addition, for example, the structure where the transverse walls, the floor, the vertical walls, and the ceiling of the liquefied gas storage tank (1) meet may correspond to a corner structure. Here, the corner structure may include an obtuse corner structure or a right-angle corner structure. When the thickness of the first insulation wall (3) or the second insulation wall (5) changes, a change in the obtuse corner structure or the right-angle corner structure may be accompanied.

[0082] The planar structure of the liquefied gas storage tank (1) can be formed by a combination of a plurality of planar blocks, as illustrated in Fig. 1, and the corner structure of the liquefied gas storage tank (1) can be formed by a combination of a plurality of corner blocks, as illustrated in Fig. 2. These plurality of planar blocks can be connected to a plurality of corner blocks at corner portions of the liquefied gas storage tank (1).

[0083] As illustrated in FIGS. 1 and 2, a liquefied gas storage tank (1) may be configured to include a primary barrier (2) in contact with the liquefied gas, a primary insulation wall (3) installed on the outside of the primary barrier (2), a secondary barrier (4) installed on the outside of the primary insulation wall (3), and a secondary insulation wall (5) arranged on the outside of the secondary barrier (4). The liquefied gas storage tank (1) may be supported on a hull (7) by mastic (6) installed between the secondary insulation wall (5) and the hull (7).

[0084] In the above, the primary barrier wall (2) may be formed of a flat primary barrier wall (2a) of a flat block and a corner primary barrier wall (2b) of a corner block, the primary insulation wall (3) may be formed of a flat primary insulation wall (3a) of a flat block and a corner primary insulation wall (3b) of a corner block, the secondary barrier wall (4) may be formed of a flat secondary barrier wall (41a) of a flat block and a corner secondary barrier wall (41b) of a corner block, and the secondary insulation wall (5) may be formed of a flat secondary barrier wall (5a) of a flat block and a corner secondary barrier wall (5b) of a corner block.

[0085] In the above, the secondary barrier (4) of the flat block and the corner block may include a flat connecting barrier (42a) or a corner connecting barrier (42b) that connects the flat secondary barrier (41a) that is adjacently placed or the corner secondary barrier (41b) that is adjacently placed when a plurality of flat blocks or a plurality of corner blocks are adjacently placed.

[0086] In order to optimize the insulation performance and storage capacity of such a liquefied gas storage tank (1), it may be necessary to optimize the thickness of the primary insulation wall (3) and the secondary insulation wall (5). For example, when polyurethane foam is used as the main material of the primary insulation wall (3) and the secondary insulation wall (5), the total thickness of the primary insulation wall (3) and the secondary insulation wall (5) combined may be in the range of 250 mm to 500 mm, and in the present embodiment, the thickness of the primary insulation wall (3) and the thickness of the secondary insulation wall (5) may be the same or similar in the flat block and the corner block.

[0087] That is, in comparison with the existing liquefied gas storage tank, where the thickness of the first insulation wall in the flat block and the corner block is about 1 / 3 thinner than the thickness of the second insulation wall, in this embodiment, the thickness of the first insulation wall (3) and the thickness of the second insulation wall (5) in the flat block and the corner block are the same or similar, and the reason for this will be explained later.

[0088] Referring to Fig. 1, the planar portion of the liquefied gas storage tank (1) according to the first embodiment of the present invention will first be described. The planar portion of the liquefied gas storage tank (1) is formed by a combination of a plurality of planar blocks, and it is to be noted in advance that the configuration of the planar blocks of the liquefied gas storage tank (1) described below is equally applicable not only to the first embodiment but also to the second to eighth embodiments described below.

[0089] As illustrated in FIG. 1, the flat block of the liquefied gas storage tank (1) is arranged on a flat portion on a first surface or a second surface at different angles that forms a storage space for accommodating liquefied gas, and may include a flat primary barrier (2a) made of a metal material, a flat primary insulation wall (3a) arranged on the outside of the flat primary barrier (2a), a flat secondary barrier (41a) provided on the outside of the flat primary insulation wall (3a), and a flat secondary insulation wall (5a) arranged on the outside of the flat secondary barrier (41a).

[0090] The flat primary barrier (2a) is arranged on a flat portion of the first or second surface at different angles to form a receiving space for receiving liquefied gas, which is a cryogenic substance, and may be made of a metal material. For example, the metal material may be stainless steel, but is not limited thereto. The flat primary barrier (2a), together with the flat secondary barrier (41a), can prevent liquefied gas from leaking to the outside.

[0091] The flat primary barrier (2a) can be fixedly connected to the upper portion of the flat primary insulating wall (3a) by a metal strip (not shown) and installed so as to be in direct contact with the liquefied gas, which is an extremely low-temperature substance stored in the liquefied gas storage tank (1).

[0092] This flat primary barrier (2a) seals the flat primary insulating wall (3a) and the corner primary barrier (2b) shown in Fig. 2 when the flat block and the corner block shown in Fig. 2 are placed adjacent to each other and connected.

[0093] The flat primary insulation wall (3a) is designed to withstand impact from the outside or impact due to liquefied gas sloshing from the inside while blocking heat intrusion from the outside, and can be installed between the flat primary insulation wall (2a) and the flat secondary insulation wall (41a).

[0094] The flat primary insulation wall (3a) may have a structure in which a flat primary plywood (31a) and a flat primary insulation material (32a) are sequentially laminated on the outside of the flat primary barrier (2a), and may be formed to a thickness that is the sum of the thickness of the flat primary plywood (31a) and the thickness of the flat primary insulation material (32a), for example, a thickness of 160 mm to 250 mm, but is not limited thereto.

[0095] A flat primary plywood (31a) can be installed between a flat primary barrier (2a) and a flat primary insulation material (32a).

[0096] The flat primary insulation material (32a) can be formed of a material with excellent insulation performance and mechanical strength so as to withstand impact from the outside or impact caused by liquefied gas sloshing from the inside while blocking heat intrusion from the outside.

[0097] The flat primary insulation material (32a) can be formed of polyurethane foam between the flat primary plywood (31a) and the flat secondary barrier wall (4a), and occupies most of the thickness of the flat primary insulation wall (3a).

[0098] The flat primary insulation wall (3a) is a part of a flat block together with the flat secondary insulation wall (41a) and the flat secondary insulation wall (5a). The flat primary insulation wall (3a) forming the flat block may have a width smaller than the width of the flat secondary insulation wall (5a), which is another part of the flat block. As a result, a part of the flat secondary insulation wall (41a) may be exposed on both sides of the flat primary insulation wall (3a). When a plurality of flat blocks are arranged adjacently, a flat connecting insulation wall (33a) may be installed in the space between the adjacent flat primary insulation walls (3a), i.e., the space where the flat secondary wall (41a) is exposed.

[0099] The flat connecting insulation wall (33a) is arranged between adjacent flat primary insulation walls (3a) when flat blocks are arranged adjacent to each other, and can be provided in the form of a flat connecting plywood (331a) and a flat connecting insulation material (332a) that are identical or similar to the flat primary insulation wall (3a) being laminated, and has a thickness identical or similar to the flat primary insulation wall (3a).

[0100] This flat connecting insulation wall (33a) is installed to block heat intrusion from the outside by sealing the space created between adjacent flat secondary insulation walls (5a) when a plurality of flat blocks are placed adjacently together with the flat connecting barrier (42a).

[0101] A flat secondary barrier (41a) can be installed between a flat primary insulation wall (3a) and a flat secondary insulation wall (5a), and together with the flat primary barrier (2a), can prevent liquefied gas from leaking to the outside.

[0102] The flat secondary barrier (41a) is a part of a flat block together with the flat primary insulation wall (3a) and the flat secondary insulation wall (5a), and when the flat blocks are placed adjacently, the neighboring flat secondary barriers (41a) can be connected by a flat connecting barrier (42a).

[0103] A flat connecting wall (42a) can connect a neighboring flat secondary wall (41) that is exposed to the outside when flat blocks are placed adjacently, and a flat connecting insulating wall (33a) can be installed on the top.

[0104] The flat secondary insulation wall (5a) can be designed to withstand external impact or impact due to liquefied gas sloshing from within while blocking external heat intrusion together with the flat primary insulation wall (3a) and the flat connecting insulation wall (33a). In addition, the flat secondary insulation wall (5a) can be installed between the flat secondary barrier (4a) and the hull (7), and can be configured to include a flat secondary insulation material (51a) and a flat secondary plywood (52a).

[0105] The flat secondary insulation wall (5a) may have a structure in which a flat secondary insulation material (51a) and a flat secondary plywood (52a) are sequentially laminated on the outside of the flat secondary wall (41a), and may be formed to have a total thickness of the combined thickness of the flat secondary insulation material (51a) and the flat secondary plywood (52a), for example, 150 mm to 240 mm, which is the same as or similar to the thickness of the flat primary insulation wall (3a), but is not limited thereto.

[0106] The flat secondary insulation material (51a) can be formed of a material with excellent insulation performance and mechanical strength so as to withstand impact from the outside or impact caused by liquefied gas sloshing from the inside while blocking heat intrusion from the outside.

[0107] The flat secondary insulation material (51a) can be formed of polyurethane foam between the flat secondary barrier (41a) and the flat secondary plywood (52a), and occupies most of the thickness of the flat secondary insulation wall (5a).

[0108] A flat secondary plywood (52a) can be installed between the flat secondary insulation (51a) and the hull (7).

[0109] As described above, the flat block of the liquefied gas storage tank (1) according to the present embodiment can be configured so that the flat connecting insulation wall (33a) included in the flat primary insulation wall (3a) has a thickness that is the same as or similar to the thickness of the flat secondary insulation wall (5a). In connection with this configuration, the flat connecting insulation (332a) of the flat connecting insulation wall (33a) can be configured so that the flat connecting insulation (332a) of the flat connecting insulation wall (33a) has a thickness that is 90% to 110% of the thickness of the flat secondary insulation (51a), so that the flat connecting insulation (332a) of the flat connecting insulation wall (33a) has a thickness that is the same as or similar to the thickness of the flat secondary insulation (51a).

[0110] That is, in comparison with the conventional liquefied gas storage tank, in which the thickness of the first insulation wall in the flat block is about 1 / 3 thinner than the thickness of the second insulation wall, in this embodiment, the thickness of the flat first insulation wall (3a) and the thickness of the flat second insulation wall (5a) in the flat block are configured to be the same or similar, and this is to prevent damage due to low-temperature stress of the flat second insulation wall (41a).

[0111] In general, the flat secondary barrier (41a) and the flat secondary insulation wall (5a) have different shrinkage amounts depending on the temperature to which they are exposed. In the case of the flat secondary barrier (41a) and the flat secondary insulation wall (5a), the thinner the flat connection insulation wall (33a) becomes, the more it can be affected by the cold heat of the ultra-low temperature liquefied gas. In addition, in this case, the temperature itself decreases, so the shrinkage itself increases, which increases the stress at low temperatures, and there is a problem that the flat secondary barrier (41a) is at a higher risk of being damaged. This problem can occur particularly frequently in the flat connection barrier (42a) that interconnects the flat secondary barriers (41a) by bonding, etc., below the flat connection insulation wall (33a). Below the flat connecting insulation wall (33a), the flat connecting barrier (42a) is connected to a flat secondary barrier (41a) of a plurality of flat blocks whose ends are arranged adjacent to each other. This is because the ends of the flat connecting barrier (42a) can be deformed to move away from or closer to each other as the flat secondary insulation wall (5a) of the flat block shrinks.

[0112] In this embodiment, by forming the flat primary insulation wall (3a) and the flat secondary insulation wall (5a) including the flat connection insulation wall (33a) to have the same or similar thickness, the thickness of the flat primary insulation wall (3a) including the flat connection insulation wall (33a) is relatively thicker compared to the conventional one, so that the ultra-low temperature burden of the flat secondary wall (41a) and especially the flat connection wall (42a) is reduced, and further, since the thickness of the flat secondary insulation wall (5a) is relatively thinner compared to the conventional one, the shrinkage itself is reduced, thereby reducing the stress at low temperatures. As a result, the risk of damage to the secondary wall (4) in the area where a plurality of flat blocks are adjacently arranged is relatively lowered compared to the conventional one.

[0113] Referring to FIG. 2, a corner portion of a liquefied gas storage tank (1) according to a first embodiment of the present invention will be described. The corner portion of the liquefied gas storage tank (1) may be formed by a combination of a plurality of corner blocks. The corner structure of the liquefied gas storage tank (1) described below is described as an example of an obtuse corner structure forming an angle of 135 degrees, but is not limited to the numerical value.

[0114] As illustrated in Fig. 2, the corner block of the liquefied gas storage tank (1) is arranged at a corner portion where first and second sides of different angles meet to form a storage space for accommodating liquefied gas, and may include a corner primary insulation wall (3b) arranged on the outside of the corner primary insulation wall (2b) while fixing a corner primary barrier (2b) made of a metal material, a corner secondary insulation wall (41b) provided on the outside of the corner primary insulation wall (3b), and a corner secondary insulation wall (5b) arranged on the outside of the corner secondary insulation wall (41b). Here, the corner primary insulation wall (3b) may further include an inner bent portion (3b3).

[0115] The corner primary barrier (2b) is positioned at a corner where the first or second surfaces at different angles meet to form a space for containing liquefied gas, which is a cryogenic substance, and may be made of a metal material. The corner primary barrier (2b), together with the corner secondary barrier (41b), can prevent liquefied gas from leaking to the outside.

[0116] The corner primary barrier (2b), although not shown in Fig. 2, may be fixedly connected to the upper portion of the corner primary insulation wall (3b) by a barrier fixing member installed in various ways, such as by bonding or bolting, so as to be installed in direct contact with the liquefied gas, which is an extremely low-temperature substance stored in the liquefied gas storage tank (1). Accordingly, the corner primary barrier (2b) mentioned below may be used to mean a barrier fixing member, etc.

[0117] This corner primary barrier (2b) can seal the corner primary insulating wall (3b) and the flat primary barrier (2a) illustrated in FIG. 1 when the corner block and the flat block illustrated in FIG. 1 are arranged adjacent to each other and connected, and is fixed to the inner primary plywood (31b) of the inner first fixing member (3b1) and the inner primary plywood (31b) of the inner second fixing member (3b2), and can be arranged to be bent at a certain angle, for example, 135 degrees, on the inner surface of the insulation material (3b31) of the inner bending member (3b3).

[0118] The corner primary insulation wall (3b) is designed to withstand impact from the outside or impact due to liquefied gas sloshing from the inside while blocking heat intrusion from the outside, and can be installed between the corner primary insulation wall (2b) and the corner secondary insulation wall (41b).

[0119] The corner primary insulation wall (3b) is provided on the inner side of each of the first and second sides, and may include an inner first fixing part (3b1) and an inner second fixing part (3b2) configured with a structure in which an inner primary plywood (31b), a corner primary insulation material (32b), and an outer primary plywood (33b) are sequentially laminated on the outer side of the corner primary barrier (2b).

[0120] Here, the inner first fixing part (3b1) may be fixed to the outer first fixing part (5b1) and provided on the inner side of the first surface, and the inner second fixing part (3b2) may be fixed to the outer second fixing part (5b2) and provided on the inner side of the second surface.

[0121] Additionally, the corner first insulation wall (3b) may include an inner bend (3b3) formed by filling an insulation material (3b31) between the inner first fixing part (3b1) and the inner second fixing part (3b2).

[0122] The thickness of the corner primary insulation wall (3b) may be the sum of the thickness of the inner primary plywood (31b), the thickness of the corner primary insulation material (32b), and the thickness of the outer primary plywood (33b) and may be the same as the thickness of the flat primary insulation wall (3a) described above (for example, a thickness of 160 mm to 250 mm).

[0123] The inner primary plywood (31b) can be installed between the corner primary barrier (2b) and the corner primary insulation (32b).

[0124] In this embodiment, as described above, since the primary insulation wall (3) in the flat block and corner block is formed to be relatively thicker than the thickness of the existing primary insulation wall, the thickness of the inner primary plywood (31b) constituting the corner primary insulation wall (3b) of the corner block can be reduced, and the remaining thickness can be replaced with a corner primary insulation material (32b) formed of polyurethane foam.

[0125] The thickness of the inner primary plywood (31b) of the present embodiment may be 20 mm to 80 mm.

[0126] In this way, in this embodiment, the inner first and second fixing members (3b1, 3b2) for holding the corner primary barrier (2b) in the corner block are not formed solely of plywood having a thickness of approximately 92 mm as in the past, but are formed in combination with a corner primary insulation material (32b) of polyurethane foam, thereby improving the insulation performance, reducing the weight, and reducing the cost compared to the existing plywood-only structure.

[0127] The corner primary insulation material (32b) can be placed between the inner primary plywood (31b) and the outer primary plywood (33b), and can be formed of high-density polyurethane foam, which is a material with excellent insulation performance and mechanical strength, so as to withstand impact from the outside or impact due to liquefied gas sloshing from the inside while blocking heat intrusion from the outside.

[0128] The outer primary plywood (33b) can be placed between the corner primary insulation (32b) and the corner secondary barrier (41b), and can be fixed to the corner secondary barrier (41b).

[0129] The outer primary plywood (33b) can be formed to a thickness of 6.5 mm to 15 mm.

[0130] As described above, the corner primary insulation wall (3b) of the present embodiment is configured with a structure in which the inner primary plywood (31b), the corner primary insulation material (32b), and the outer primary plywood (33b) are sequentially laminated, so that the heat shrinkage of the corner primary insulation material (32b) is held by the inner primary plywood (31b) and the outer primary plywood (33b) having high strength, thereby preventing the heat shrinkage of the corner primary insulation material (32b) from being directly applied to the secondary barriers (4, 41b, 42b) between the outer first and second fixing members (5b1, 5b2), and by providing the corner primary insulation material (32b) as an intermediate layer, it is easy to manage the tolerance of the inner primary plywood (31b) and the outer primary plywood (33b) that are sensitive to humidity. Can be.

[0131] Each of the inner first and second fixing parts (3b1, 3b2) composed of the corner first insulation wall (3b) is fixed to each of the outer first and second fixing parts (5b1, 5b2) composed of the corner second insulation wall (41b) and the corner second insulation wall (5b). The width of each of the inner first and second fixing parts (3b1, 3b2) may be smaller than the width of each of the outer first and second fixing parts (5b1, 5b2). Accordingly, when a plurality of corner blocks are adjacently arranged along the side of the corner portion where the first and second sides at different angles face each other, an inner bent part (3b3) may be formed in the space portion between the adjacently arranged inner first and second fixing parts (3b1, 3b2), i.e., in the space portion where the corner second insulation wall (41b) is exposed.

[0132] The inner bend (3b3) can be formed by filling with insulation (3b31).

[0133] The insulation material (3b31) of the inner folded portion (3b3) may be low-density polyurethane foam, and a secondary wall (4) formed by stacking a corner secondary wall (41b) and a corner connecting wall (42b) may be provided on the outer surface folded at a certain angle, for example, 135 degrees.

[0134] The insulation material (3b31) of the inner bending portion (3b3) can block heat intrusion from the outside by sealing the space created between the outer first and second fixing portions (5b1, 5b2) that are adjacently arranged when a plurality of corner blocks are arranged adjacently together with the corner connection barrier (42b).

[0135] The corner secondary barrier (41b) can be provided on the outside of the corner primary insulation wall (3b). The corner secondary barrier (41b) can be installed between the corner primary insulation wall (3b) and the corner secondary insulation wall (5b), and together with the corner primary barrier (2b), can prevent liquefied gas from leaking to the outside.

[0136] The corner secondary barrier (41b) is a part of the corner block together with the corner primary insulation wall (3b) and the corner secondary insulation wall (5b), and when the corner blocks are placed adjacently, the neighboring corner secondary barriers (41b) between the outer first and second fixed members (5b1, 5b2) can be connected by the corner connecting barrier (42b).

[0137] The corner connecting wall (42b) can connect the adjacent corner secondary wall (41) exposed to the outside when the corner blocks are arranged adjacently, and the insulation material (3b31) of the inner bending portion (3b3) is installed on the upper portion, so that the space portion created between the insulation material (3b31) of the inner bending portion (3b3) and the outer first and second fixing portions (5b1, 5b2) arranged adjacently can be sealed to block heat intrusion from the outside. In the present embodiment, the corner connecting wall (42b) can be formed to extend not only between the inner first and second fixing portions (3b1, 3b2), but also to a length that overlaps at least the inner first and second fixing portions (3b1, 3b2).

[0138] At the point where the outer first and second fixed parts (5b1, 5b2) meet, the secondary wall (4) in which the corner secondary wall (41b) and the corner connecting wall (42b) are laminated can be arranged to be bent.

[0139] The corner secondary insulation wall (5b) may be arranged on the outer side of the corner secondary barrier (41b). The corner secondary insulation wall (5b) may be designed to withstand impact from the outside or impact caused by liquefied gas sloshing from the inside while blocking heat intrusion from the outside together with the corner primary insulation wall (3b) and the insulation material (3b31) of the inner bend (3b3). In addition, the corner secondary insulation wall (5b) may be installed between the corner secondary barrier (4b) and the hull (7), and may be configured to include an inner secondary plywood (51b), a corner secondary insulation material (52b), and an outer secondary plywood (53b).

[0140] The corner secondary insulation wall (5b) is fixed to the inner side of the first side and the second side, respectively, and may include an outer first fixing part (5b1) and an outer second fixing part (5b2) configured with a structure in which an inner secondary plywood (51b), a corner secondary insulation material (52b), and an outer secondary plywood (53b) are sequentially laminated on the outer side of the corner secondary barrier wall (2b).

[0141] Here, the outer first fixing part (5b1) can be fixed to the inner side of the first surface, and the outer second fixing part (5b2) can be fixed to the inner side of the second surface.

[0142] The side surface where the outer first fixing portion (5b1) fixed to the first surface and the outer second fixing portion (5b2) fixed to the second surface face each other may be inclined in a direction (ED) that divides the corner portion evenly. In this embodiment, the corner portion is described as being evenly divided, but this is not limited to this, and since it may not be even depending on the corner position, it goes without saying that the corner portion may be inclined in a direction (ED) that divides it unevenly.

[0143] The total thickness of the corner secondary insulation wall (5b) including the thickness of the inner secondary plywood (51b), the thickness of the corner secondary insulation material (52b), and the thickness of the outer secondary plywood (53b) may be equal to the thickness of the flat secondary insulation wall (5a) described above (for example, a thickness of 150 mm to 240 mm).

[0144] The inner secondary plywood (51b) can be placed between the corner secondary barrier (2b) and the corner secondary insulation (51b), and the corner secondary barrier (2b) can be fixed. The inner secondary plywood (51b) can be formed to a thickness of 6.5 mm to 15 mm.

[0145] The corner secondary insulation material (52b) can be formed of a material with excellent insulation performance and mechanical strength so as to withstand impact from the outside or impact caused by liquefied gas sloshing from the inside while blocking heat intrusion from the outside.

[0146] The corner secondary insulation material (52b) can be formed of polyurethane foam between the inner secondary plywood (51b) and the outer secondary plywood (53b), and occupies most of the thickness of the corner secondary insulation wall (5b).

[0147] The outer secondary plywood (53b) can be installed between the corner secondary insulation (52b) and the hull (7). The outer secondary plywood (53b) can be formed to a thickness of 6.5 mm to 25 mm.

[0148] In the liquefied gas storage tank (1) according to the above-described embodiment, since the thickness of the primary insulation wall (3) is relatively thicker than before, the secondary barrier (4) moves toward the hull (7) in the corner block as well as the flat block, thereby increasing the radius of curvature. In this case, as the radius of curvature of the secondary barrier (4) at the corner portion increases, the length of the portion where the secondary barrier (4) is not bonded to the secondary insulation wall (5) also increases. This means that the flexibility of the secondary barrier (4) in the obtuse corner structure increases, and as a result, the secondary barrier (4) in the obtuse corner structure easily absorbs deformation of the peripheral portion, for example, hull deformation, and also reduces low-temperature stress. In the present embodiment, the length of the non-bonded portion may be, for example, 0 mm to 100 mm, preferably 50 mm to 100 mm.

[0149] As described above, in the obtuse corner structure of the present invention, the stress applied to the existing secondary wall (4) at low temperatures can be reduced compared to the obtuse corner structure of the primary insulation wall (3) formed with a relatively thin thickness. In addition, since the non-bonded portion increases, it is also easy to absorb hull deformation.

[0150] This was proven through the structural analysis results for the corner portion of the liquefied gas storage tank (1) according to the embodiment shown in FIGS. 3 and 4.

[0151] The structural analysis was performed under the conditions of 20°C at the hull location and -163°C at the primary barrier, and the heat transfer analysis was performed using the resulting temperature distribution.

[0152] In addition, the results obtained by the structural analysis of the liquefied gas storage tank (1) according to the present embodiment are compared with the existing liquefied gas storage tank, in which the thickness of the first insulation wall in the flat block and the corner block is about 1 / 3 thinner than the thickness of the second insulation wall, the fixing members corresponding to the first and second inner fixing members (3b1, 3b2) are composed of only plywood, and the length of the non-bonded portion is 50 mm. In this existing liquefied gas storage tank, the stress value in the YY direction of the bent portion of the second barrier was about 66.8984 MPa, and the temperature was about -135.857°C.

[0153] The stress value in the YY direction obtained as a result of the structural analysis is the stress value at the corner, and the lower it is, the less stress there is. The temperature is the temperature at the corner, and the higher the temperature, the less stress there is (represents the value changed after installation at room temperature of 25℃).

[0154] It should be noted in advance that the above conditions apply equally not only to this embodiment but also to the structural analysis of the liquefied gas storage tank (1) according to the second to seventh embodiments described below.

[0155] Figure 3 shows the results of structural analysis of the YY direction stress value and temperature distribution of the secondary barrier (4, 41b, 42b) at the part where the outer first and second fixed parts (5b1, 5b2) face each other and are bent when the length of the non-bonded part in this embodiment is 50 mm. The YY direction stress value was 37.155 MPa and the temperature was -57.940°C. These figures show that the stress in the YY direction of the bent portion of the secondary barrier of the existing liquefied gas storage tank is about 66.8984 MPa and the temperature is about -135.857℃, and compared to this, the stress in the secondary barrier (4, 41b, 42b) according to the present embodiment is much lower, which means that the influence of cold heat from the cryogenic material, such as damage due to low-temperature stress, is reduced in the secondary barrier (4, 41b, 42b) of the present embodiment compared to the existing one.

[0156] Fig. 4 is a result of structural analysis of the YY direction stress value and temperature distribution of the secondary barrier (4, 41b, 42b) at the part where the outer first and second fixed parts (5b1, 5b2) face each other and are bent when the length of the non-bonded part in this embodiment is 97 mm. The YY direction stress value was 12.084 MPa and the temperature was -59.025°C. These figures show that the stress in the YY direction of the bent portion of the secondary barrier of the existing liquefied gas storage tank is about 66.8984 MPa and the temperature is about -135.857℃, and compared to this, the stress in the secondary barrier (4, 41b, 42b) according to the present embodiment is much lower, which means that the influence of cold heat from the cryogenic material, such as damage due to low-temperature stress, is reduced in the secondary barrier (4, 41b, 42b) of the present embodiment compared to the existing one.

[0157] Through this, the present embodiment forms the inner first and second fixing members (3b1, 3b2) for holding the fixing member to which the corner first barrier (2b) is fixed in the corner block not only with plywood, but also with a combination of polyurethane foam insulation (3b31), thereby improving the insulation performance compared to the existing one composed only of plywood, reducing the weight, and reducing the cost.

[0158] In addition, in this embodiment, the thickness of the corner first insulation wall (3b) of the corner block connected to the flat first insulation wall (3a) of the flat block and the corner second insulation wall (5b) of the corner block connected to the flat second insulation wall (5a) of the flat block are configured to be the same or similar, so that the thickness of the corner first insulation wall (3b) is relatively thicker than before (however, the thickness of the corner second insulation wall (5b) is a thickness that can maintain mechanical strength at a certain level), so that the low-temperature burden and sloshing burden of the secondary walls (4, 41b, 42b) between the outer first and second fixed parts (5b1, 5b2) can be reduced, and damage to the secondary walls (4, 41b, 42b) can be prevented, and the low-temperature burden of the secondary walls (4, 41b, 42b) can be reduced, thereby preventing brittle fracture of the hull (7).

[0159] In addition, in this embodiment, since the thickness of the corner primary insulation wall (3b) is configured to be relatively thicker than before, the length of the portion of the secondary barrier (4, 41b, 42b) that is not bonded to the corner secondary insulation wall (5b) can be increased, so that the flexibility of the secondary barrier (4, 41b, 42b) can be increased, and not only can the probability of damage to the secondary barrier (4, 41b, 42b) be further reduced, but also the secondary barrier (4, 41b, 42b) can easily absorb hull deformation and the low-temperature stress can be further reduced.

[0160] FIG. 5 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a second embodiment of the present invention, and FIG. 6 is a drawing showing the results of a structural analysis of a corner portion of a liquefied gas storage tank according to a second embodiment of the present invention.

[0161] The planar structure of the liquefied gas storage tank (1) of the present embodiment may be formed by a combination of a plurality of planar blocks, as illustrated in the aforementioned Fig. 1, and the corner structure of the liquefied gas storage tank (1) may be formed by a combination of a plurality of corner blocks, as illustrated in Fig. 5. These plurality of planar blocks may be connected to a plurality of corner blocks at corner portions of the liquefied gas storage tank (1).

[0162] In the liquefied gas storage tank (1) of the present embodiment, the configuration of the flat block is the same as or similar to the configuration described above with reference to FIG. 1. That is, the flat block of the liquefied gas storage tank (1) of the present embodiment, as illustrated in FIG. 1, is arranged in a flat portion on a first surface or a second surface at different angles that forms a storage space for accommodating liquefied gas, and may include a flat primary barrier (2a) made of a metal material, a flat primary insulating wall (3a) arranged on the outside of the flat primary barrier (2a), a flat secondary barrier (41a) provided on the outside of the flat primary insulating wall (3a), and a flat secondary insulating wall (5a) arranged on the outside of the flat secondary barrier (41a).

[0163] Accordingly, to avoid redundant explanation, a detailed description of the flat block configuration of the liquefied gas storage tank (1) is omitted here. Hereinafter, the configuration of the corner block of the liquefied gas storage tank (1) of the present embodiment will be specifically described with reference to FIGS. 1 and 5.

[0164] As illustrated in FIGS. 1 and 5, a liquefied gas storage tank (1) may be configured to include a primary barrier (2) in contact with the liquefied gas, a primary insulation wall (3) installed on the outside of the primary barrier (2), a secondary barrier (4) installed on the outside of the primary insulation wall (3), and a secondary insulation wall (5) arranged on the outside of the secondary barrier (4). The liquefied gas storage tank (1) may be supported on a hull (7) by mastic (6) installed between the secondary insulation wall (5) and the hull (7).

[0165] In the above, the primary barrier wall (2) may be formed of a flat primary barrier wall (2a) of a flat block and a corner primary barrier wall (2b) of a corner block, the primary insulation wall (3) may be formed of a flat primary insulation wall (3a) of a flat block and a corner primary insulation wall (3b) of a corner block, the secondary barrier wall (4) may be formed of a flat secondary barrier wall (41a) of a flat block and a corner secondary barrier wall (41b) of a corner block, and the secondary insulation wall (5) may be formed of a flat secondary insulation wall (5a) of a flat block and a corner secondary insulation wall (5b) of a corner block. In the present embodiment, as described in the first embodiment, the thickness of the primary insulation wall (3) and the thickness of the secondary insulation wall (5) in the flat block and the corner block may be the same or similar.

[0166] In the above, the secondary barrier (4) of the flat block and the corner block may include a flat connecting barrier (42a) or a corner connecting barrier (42b) that connects the flat secondary barrier (41a) that is adjacently placed or the corner secondary barrier (41b) that is adjacently placed when a plurality of flat blocks or a plurality of corner blocks are adjacently placed.

[0167] As illustrated in Fig. 5, the corner portion of the liquefied gas storage tank (1) according to the second embodiment of the present invention may be formed by a combination of a plurality of corner blocks. The corner structure of the liquefied gas storage tank (1) described below may be an obtuse corner structure forming a certain angle, for example, an angle of 135 degrees.

[0168] The corner block of the liquefied gas storage tank (1) is arranged at a corner portion where first and second sides of different angles meet to form a storage space for accommodating liquefied gas, and may include a corner primary barrier (2b) made of metal, a corner primary insulation wall (3b) arranged on the outside of the corner primary barrier (2b), a corner secondary barrier (41b) provided on the outside of the corner primary insulation wall (3b), and a corner secondary insulation wall (5b) arranged on the outside of the corner secondary barrier (41b).

[0169] The corner primary barrier (2b) is positioned at a corner where the first or second surfaces at different angles meet to form a space for containing liquefied gas, which is a cryogenic substance, and may be made of a metal material. The corner primary barrier (2b), together with the corner secondary barrier (41b), can prevent liquefied gas from leaking to the outside.

[0170] The corner primary barrier (2b) of this embodiment is basically the same or similar to the first embodiment described above, and thus a detailed description thereof is omitted here. However, since the corner primary barrier (2b) of this embodiment has a different configuration of the corner primary insulating wall (3b) from the first embodiment, the angle at which it is bent may vary, which will be mentioned below when describing the corner primary insulating wall (3b).

[0171] The corner primary insulation wall (3b) is designed to withstand external impact or impact due to liquefied gas sloshing from the inside while blocking heat intrusion from the outside, and can be installed between the corner primary insulation wall (2b) and the corner secondary insulation wall (41b). The configuration of the corner primary insulation wall (3b) of the present embodiment is the same or similar to that of the first embodiment described above, except that the outer primary plywood (33b) is omitted and the configuration of the inner folded portion (3b3) formed by filling the insulation material (3b31) is different. Here, the description will be made mainly of the different configuration.

[0172] The corner primary insulation wall (3b) is provided on the inner side of the first side and the second side, and may include an inner first fixing part (3b1) and an inner second fixing part (3b2) configured to have a structure in which an inner primary plywood (31b) and a corner primary insulation material (32b) are sequentially laminated on the outer side of the corner primary barrier (2b). Here, the inner primary plywood (31b) and the corner primary insulation material (32b) of the present embodiment may be the same as or similar to those of the first embodiment described above, and thus, a detailed description thereof will be omitted to avoid redundant explanation.

[0173] The inner first fixing part (3b1) may be fixed to the outer first fixing part (5b1) and provided on the inner side of the first surface, and the inner second fixing part (3b2) may be fixed to the outer second fixing part (5b2) and provided on the inner side of the second surface.

[0174] Additionally, the corner first insulation wall (3b) may include an inner intermediate fixing part (3b12) provided between the inner first fixing part (3b1) and the inner second fixing part (3b2).

[0175] The inner intermediate fixing member (3b12) may include a corner intermediate insulation (32b12) fixed to a corner connecting wall (42b) connecting adjacent corner secondary walls (41b), and an inner intermediate plywood (31b12) arranged on the inner side of the corner intermediate insulation (32b12) and to which the corner primary wall (2b) is fixed.

[0176] The inner intermediate plywood (31b12) can be formed with the same or similar structure as the inner primary plywood (31b), and the corner primary barrier (2b) can be fixed together with the inner primary plywood (31b).

[0177] This inner intermediate plywood (31b12) may be parallel to a direction perpendicular to the direction of equal division (ED) when the corner portion is divided equally. However, it goes without saying that the inner intermediate plywood (31b12) may not be parallel to a direction perpendicular to the direction of dividing the corner portion (ED) when the corner portion is divided unequally.

[0178] The corner intermediate insulation (32b12) may be formed of the same or similar material as the corner primary insulation (32b). The corner intermediate insulation (32b12) may be formed of high-density polyurethane foam.

[0179] This corner intermediate insulation (32b12) can block heat intrusion from the outside by sealing the space created between the outer first and second fixing parts (5b1, 5b2) that are adjacently arranged when a plurality of corner blocks are adjacently arranged together with the corner connection barrier (42b). In the present embodiment, the corner connection barrier (42b) can be formed to extend to a length that overlaps not only the inner first and second fixing parts (3b1, 3b2) but also at least the inner first and second fixing parts (3b1, 3b2).

[0180] Since the inner intermediate plywood (31b12) is provided between the inner first fixing part (3b1) and the inner second fixing part (3b2), the corner primary barrier (2b) is fixed to the inner primary plywood (31b) of the inner first fixing part (3b1), the inner intermediate plywood (31b12) of the inner intermediate fixing part (3b12), and the inner primary plywood (31b) of the inner second fixing part (3b2), and can be provided to be bent in an angle range of 150 to 160 degrees between the inner first fixing part (3b1) and the inner intermediate fixing part (3b12) and between the inner intermediate fixing part (3b12) and the inner second fixing part (3b2).

[0181] Through this, the present embodiment provides a certain distance between the inner first fixing part (3b1) and the inner second fixing part (3b2) provided on the inner sides of the first and second sides at different angles, and provides an inner intermediate fixing part (3b12) between the inner first and second fixing parts (3b1, 3b2), thereby alleviating the bending angle of the corner primary barrier (2b) by the inner intermediate fixing part (3b12), thereby reducing the sloshing burden on the corner primary barrier (2b) and increasing the mechanical strength of the corner portion.

[0182] The corner secondary barrier (41b) can be installed between the corner primary insulation wall (3b) and the corner secondary insulation wall (5b), and when the corner blocks are arranged adjacently, the neighboring corner secondary barriers (41b) between the outer first and second fixing members (5b1, 5b2) can be connected by the corner connection barrier (42b), and together with the corner primary barrier (2b), the liquefied gas can be prevented from leaking to the outside. The corner secondary barrier (41b) of the present embodiment is the same as or similar to the first embodiment described above, and thus, a detailed description thereof is omitted to avoid redundant explanation.

[0183] The corner secondary insulation wall (5b) may be configured to include an inner secondary plywood (51b), a corner secondary insulation material (52b), and an outer secondary plywood (53b). The corner secondary insulation wall (5b) may include an outer first fixing part (5b1) and an outer second fixing part (5b2) which are respectively fixed to the inner sides of the first side and the second side, and are configured to have a structure in which the inner secondary plywood (51b), the corner secondary insulation material (52b), and the outer secondary plywood (53b) are sequentially laminated on the outer side of the corner secondary barrier wall (2b).

[0184] The corner secondary insulation wall (5b) of this embodiment is identical or similar to the first embodiment described above, and thus a detailed description thereof is omitted to avoid redundant description.

[0185] Fig. 6 is a result of structural analysis of the YY direction stress value and temperature distribution of the secondary barrier (4, 41b, 42b) at the portion where the first and second outer fixing members (5b1, 5b2) face each other and are bent, and the YY direction stress value was 10.982 MPa and the temperature was -67.914℃. When these figures are compared with the YY direction stress value of about 66.8984 MPa and the temperature of about -135.857℃ at the bent portion of the secondary barrier of the existing liquefied gas storage tank, it can be seen that the stress is much less in the secondary barrier (4, 41b, 42b) according to the present embodiment, which means a reduction in the influence of cold heat from the cryogenic material, such as damage due to low-temperature stress, in the secondary barrier (4, 41b, 42b) of the present embodiment compared to the existing one.

[0186] FIG. 7 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a third embodiment of the present invention, and FIG. 8 is a drawing showing the results of a structural analysis of a corner portion of a liquefied gas storage tank according to a third embodiment of the present invention.

[0187] The planar structure of the liquefied gas storage tank (1) of the present embodiment may be formed by a combination of a plurality of planar blocks, as illustrated in the aforementioned Fig. 1, and the corner structure of the liquefied gas storage tank (1) may be formed by a combination of a plurality of corner blocks, as illustrated in Fig. 7. These plurality of planar blocks may be connected to a plurality of corner blocks at corner portions of the liquefied gas storage tank (1).

[0188] In the liquefied gas storage tank (1) of the present embodiment, the configuration of the flat block is the same as or similar to the configuration described above with reference to FIG. 1. That is, the flat block of the liquefied gas storage tank (1) of the present embodiment, as illustrated in FIG. 1, is arranged in a flat portion on a first surface or a second surface at different angles that forms a storage space for accommodating liquefied gas, and may include a flat primary barrier (2a) made of a metal material, a flat primary insulating wall (3a) arranged on the outside of the flat primary barrier (2a), a flat secondary barrier (41a) provided on the outside of the flat primary insulating wall (3a), and a flat secondary insulating wall (5a) arranged on the outside of the flat secondary barrier (41a).

[0189] Accordingly, to avoid redundant explanation, a detailed description of the flat block configuration of the liquefied gas storage tank (1) is omitted here. Hereinafter, the configuration of the corner block of the liquefied gas storage tank (1) of the present embodiment will be specifically described with reference to FIGS. 1 and 7.

[0190] As illustrated in FIGS. 1 and 7, a liquefied gas storage tank (1) may be configured to include a primary barrier (2) in contact with the liquefied gas, a primary insulation wall (3) installed on the outside of the primary barrier (2), a secondary barrier (4) installed on the outside of the primary insulation wall (3), and a secondary insulation wall (5) arranged on the outside of the secondary barrier (4). The liquefied gas storage tank (1) may be supported on a hull (7) by mastic (6) installed between the secondary insulation wall (5) and the hull (7).

[0191] In the above, the primary barrier wall (2) may be formed of a flat primary barrier wall (2a) of a flat block and a corner primary barrier wall (2b) of a corner block, the primary insulation wall (3) may be formed of a flat primary insulation wall (3a) of a flat block and a corner primary insulation wall (3b) of a corner block, the secondary barrier wall (4) may be formed of a flat secondary barrier wall (41a) of a flat block and a corner secondary barrier wall (41b) of a corner block, and the secondary insulation wall (5) may be formed of a flat secondary insulation wall (5a) of a flat block and a corner secondary insulation wall (5b) of a corner block. In the present embodiment, as described in the first embodiment, the thickness of the primary insulation wall (3) and the thickness of the secondary insulation wall (5) in the flat block and the corner block may be the same or similar.

[0192] In the above, the secondary barrier (4) of the flat block and the corner block may include a flat connecting barrier (42a) or a corner connecting barrier (42b) that connects the flat secondary barrier (41a) that is adjacently placed or the corner secondary barrier (41b) that is adjacently placed when a plurality of flat blocks or a plurality of corner blocks are adjacently placed.

[0193] As illustrated in Fig. 7, the corner portion of the liquefied gas storage tank (1) according to the third embodiment of the present invention may be formed by a combination of a plurality of corner blocks. The corner structure of the liquefied gas storage tank (1) described below may be an obtuse corner structure forming a certain angle, for example, an angle of 135 degrees.

[0194] In this embodiment, unlike the drawing, the position of the corner primary insulation wall (3b) can be positioned so as to expose the corner secondary barrier (41b) constructed on the corner secondary insulation wall (5b) at the center of the corner. Accordingly, it is also possible to finish the exposed corner secondary barrier (41b) by interconnecting it with a corner connecting barrier (42b), or to construct the corner connecting barrier (42b) so that the corner primary insulation wall (3b) connects the adjacent corner secondary barriers (41b) and then stack it on the corner secondary barrier (41b) / corner connecting barrier (42b). In this embodiment, the corner connecting barrier (42b) can be formed to extend not only between the inner first and second fixing members (3b1, 3b2), but also to overlap at least the inner first and second fixing members (3b1, 3b2).

[0195] The corner block of the liquefied gas storage tank (1) is arranged at a corner portion where first and second sides of different angles meet to form a storage space for accommodating liquefied gas, and may include a corner primary barrier (2b) made of metal, a corner primary insulation wall (3b) arranged on the outside of the corner primary barrier (2b), a corner secondary barrier (41b) provided on the outside of the corner primary insulation wall (3b), and a corner secondary insulation wall (5b) arranged on the outside of the corner secondary barrier (41b).

[0196] The corner primary barrier (2b) is positioned at a corner where the first or second surfaces at different angles meet to form a space for containing liquefied gas, which is a cryogenic substance, and may be made of a metal material. The corner primary barrier (2b), together with the corner secondary barrier (41b), can prevent liquefied gas from leaking to the outside.

[0197] The corner primary barrier (2b) of this embodiment is basically the same or similar to the first embodiment described above, and thus a detailed description thereof is omitted here.

[0198] The corner primary insulation wall (3b) is designed to withstand external impact or impact due to liquefied gas sloshing from the inside while blocking external heat intrusion, and can be installed between the corner primary insulation wall (2b) and the corner secondary insulation wall (41b). The configuration of the corner primary insulation wall (3b) of the present embodiment is the same or similar to that of the first embodiment described above, except that the outer primary plywood (33b) is omitted. Here, the description will focus on the different configuration.

[0199] The corner primary insulation wall (3b) is provided on the inner side of the first side and the second side, and may include an inner first fixing part (3b1) and an inner second fixing part (3b2) configured to have a structure in which an inner primary plywood (31b) and a corner primary insulation material (32b) are sequentially laminated on the outer side of the corner primary barrier (2b). Here, the inner primary plywood (31b) and the corner primary insulation material (32b) of the present embodiment may be the same as or similar to those of the first embodiment described above, and thus, a detailed description thereof will be omitted to avoid redundant explanation.

[0200] The inner first fixing part (3b1) may be fixed to the outer first fixing part (5b1) and provided on the inner side of the first surface, and the inner second fixing part (3b2) may be fixed to the outer second fixing part (5b2) and provided on the inner side of the second surface.

[0201] In addition, the corner first insulation wall (3b) may include an inner bend (3b3) formed by filling an insulation material (3b32) between the inner first fixing part (3b1) and the inner second fixing part (3b2). The insulation material (3b32) of the inner bend (3b3) of the present embodiment may be the same as or similar to that of the first embodiment described above, and thus, a detailed description thereof is omitted to avoid redundant explanation.

[0202] The corner secondary barrier (41b) can be installed between the corner primary insulation wall (3b) and the corner secondary insulation wall (5b), and when the corner blocks are arranged adjacently, the adjacent corner secondary barriers (41b) between the outer first and second fixing members (5b1, 5b2) can be connected by a corner connection barrier (42b), and together with the corner primary barrier (2b), the liquefied gas can be prevented from leaking to the outside. The corner secondary barrier (41b) of the present embodiment may have a basic configuration identical or similar to that of the first embodiment described above. However, the corner secondary barrier (41b) including the corner connecting barrier (42b) of the present embodiment may have a different arrangement relationship as some of the configurations of the corner secondary insulating wall (5b) are different from those of the first embodiment described above, which will be mentioned below when explaining the corner secondary insulating wall (5b).

[0203] The corner secondary insulation wall (5b) may be configured to include an inner secondary plywood (51b), a corner secondary insulation material (52b), and an outer secondary plywood (53b). The corner secondary insulation wall (5b) may include an outer first fixing part (5b1) and an outer second fixing part (5b2) which are respectively fixed to the inner sides of the first side and the second side, and are configured to have a structure in which the inner secondary plywood (51b), the corner secondary insulation material (52b), and the outer secondary plywood (53b) are sequentially laminated on the outer side of the corner secondary barrier wall (2b).

[0204] The above-described outer first fixing portion (5b1) and outer second fixing portion (5b2) may be provided such that the facing sides thereof are inclined in a direction (ED) that divides the corner portions evenly. In this embodiment, the corner portions are described as being equally divided, but this is not limited thereto, and since they may not be even depending on the corner position, it goes without saying that the corner portions may be inclined in a direction (ED) that divides them unevenly.

[0205] The outer first fixing part (5b1) and the outer second fixing part (5b2) may have chamfers formed at the corners facing each other.

[0206] Additionally, the corner secondary insulation wall (5b) may include an outer bend (5b3) including an insulation material (5b31) filled between the chamfer portions of the outer first fixing portion (5b1) and the outer second fixing portion (5b2). The insulation material (5b31) of the outer bend (5b3) may be low-density polyurethane foam.

[0207] By providing an insulation material (5b31) of an outer bending portion (5b3) in the chamfered portions of the outer first fixing portion (5b1) and the outer second fixing portion (5b2), a corner secondary barrier (41b) encompassing a corner connecting barrier (42b) is fixed to the inner secondary plywood (51b) of the outer first fixing portion (5b1), the insulation material (5b31) of the outer bending portion (5b3), and the inner secondary plywood (51b) of the outer second fixing portion (5b2), and can be provided to be bent at a predetermined angle, for example, 135 degrees, on the inner side of the insulation material (5b31) of the outer bending portion (5b3).

[0208] Through this, the present embodiment forms a chamfer at the corner where the outer first fixing part (5b1) and the outer second fixing part (5b2), which are fixed to the first and second surfaces at different angles, respectively, face each other, and an insulating material (5b31) of the outer bending part (5b3) made of low-density polyurethane foam is provided in the chamfer, thereby further increasing the insulating performance at the corner portion by the low-density polyurethane foam.

[0209] Fig. 8 is a structural analysis result of the YY direction stress value and temperature distribution of the secondary barrier (4, 41b, 42b) at the portion where the first and second outer fixing members (5b1, 5b2) face each other and are bent, and the YY direction stress value was 12.003 MPa and the temperature was -64.358℃. When these figures are compared with the YY direction stress value of about 66.8984 MPa and the temperature of about -135.857℃ at the bent portion of the secondary barrier of the existing liquefied gas storage tank, it can be seen that the stress is much less in the secondary barrier (4, 41b, 42b) according to the present embodiment, which means a reduction in the influence of cold heat from the cryogenic material, such as damage due to low-temperature stress, in the secondary barrier (4, 41b, 42b) of the present embodiment compared to the existing one.

[0210] FIG. 9 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a fourth embodiment of the present invention, and FIG. 10 is a drawing showing the results of a structural analysis of a corner portion of a liquefied gas storage tank according to a fourth embodiment of the present invention.

[0211] The planar structure of the liquefied gas storage tank (1) of the present embodiment may be formed by a combination of a plurality of planar blocks, as illustrated in the aforementioned Fig. 1, and the corner structure of the liquefied gas storage tank (1) may be formed by a combination of a plurality of corner blocks, as illustrated in Fig. 9. These plurality of planar blocks may be connected to a plurality of corner blocks at corner portions of the liquefied gas storage tank (1).

[0212] In the liquefied gas storage tank (1) of the present embodiment, the configuration of the flat block is the same as or similar to the configuration described above with reference to FIG. 1. That is, the flat block of the liquefied gas storage tank (1) of the present embodiment, as illustrated in FIG. 1, is arranged in a flat portion on a first surface or a second surface at different angles that forms a storage space for accommodating liquefied gas, and may include a flat primary barrier (2a) made of a metal material, a flat primary insulating wall (3a) arranged on the outside of the flat primary barrier (2a), a flat secondary barrier (41a) provided on the outside of the flat primary insulating wall (3a), and a flat secondary insulating wall (5a) arranged on the outside of the flat secondary barrier (41a).

[0213] Accordingly, to avoid redundant explanation, a detailed description of the flat block configuration of the liquefied gas storage tank (1) is omitted here. Hereinafter, the configuration of the corner block of the liquefied gas storage tank (1) of the present embodiment will be specifically described with reference to FIGS. 1 and 9.

[0214] As illustrated in FIGS. 1 and 9, a liquefied gas storage tank (1) may be configured to include a primary barrier (2) in contact with the liquefied gas, a primary insulation wall (3) installed on the outside of the primary barrier (2), a secondary barrier (4) installed on the outside of the primary insulation wall (3), and a secondary insulation wall (5) arranged on the outside of the secondary barrier (4). The liquefied gas storage tank (1) may be supported on a hull (7) by mastic (6) installed between the secondary insulation wall (5) and the hull (7).

[0215] In the above, the primary barrier wall (2) may be formed of a flat primary barrier wall (2a) of a flat block and a corner primary barrier wall (2b) of a corner block, the primary insulation wall (3) may be formed of a flat primary insulation wall (3a) of a flat block and a corner primary insulation wall (3b) of a corner block, the secondary barrier wall (4) may be formed of a flat secondary barrier wall (41a) of a flat block and a corner secondary barrier wall (41b) of a corner block, and the secondary insulation wall (5) may be formed of a flat secondary insulation wall (5a) of a flat block and a corner secondary insulation wall (5b) of a corner block. In the present embodiment, as described in the first embodiment, the thickness of the primary insulation wall (3) and the thickness of the secondary insulation wall (5) in the flat block and the corner block may be the same or similar.

[0216] In the above, the secondary barrier (4) of the flat block and the corner block may include a flat connecting barrier (42a) or a corner connecting barrier (42b) that connects the flat secondary barrier (41a) that is adjacently placed or the corner secondary barrier (41b) that is adjacently placed when a plurality of flat blocks or a plurality of corner blocks are adjacently placed.

[0217] As illustrated in Fig. 9, the corner portion of the liquefied gas storage tank (1) according to the fourth embodiment of the present invention may be formed by a combination of a plurality of corner blocks. The corner structure of the liquefied gas storage tank (1) described below may be an obtuse corner structure forming a certain angle, for example, an angle of 135 degrees.

[0218] In this embodiment, unlike the drawing, the position of the corner primary insulation wall (3b) can be positioned so as to expose the corner secondary barrier (41b) constructed on the corner secondary insulation wall (5b) at the center of the corner. Accordingly, it is also possible to finish the exposed corner secondary barrier (41b) by interconnecting it with a corner connecting barrier (42b), or to construct the corner connecting barrier (42b) so that the corner primary insulation wall (3b) connects the adjacent corner secondary barriers (41b) and then stack it on the corner secondary barrier (41b) / corner connecting barrier (42b). In this embodiment, the corner connecting barrier (42b) can be formed to extend not only between the inner first and second fixing members (3b1, 3b2), but also to overlap at least the inner first and second fixing members (3b1, 3b2).

[0219] The corner block of the liquefied gas storage tank (1) is arranged at a corner portion where first and second sides of different angles meet to form a storage space for accommodating liquefied gas, and may include a corner primary barrier (2b) made of metal, a corner primary insulation wall (3b) arranged on the outside of the corner primary barrier (2b), a corner secondary barrier (41b) provided on the outside of the corner primary insulation wall (3b), and a corner secondary insulation wall (5b) arranged on the outside of the corner secondary barrier (41b).

[0220] The corner primary barrier (2b) is positioned at a corner where the first or second surfaces at different angles meet to form a space for containing liquefied gas, which is a cryogenic substance, and may be made of a metal material. The corner primary barrier (2b), together with the corner secondary barrier (41b), can prevent liquefied gas from leaking to the outside.

[0221] The corner primary barrier (2b) of this embodiment is basically the same or similar to the first embodiment described above, and thus a detailed description thereof is omitted here.

[0222] The corner primary insulation wall (3b) is designed to withstand external impact or impact due to liquefied gas sloshing from the inside while blocking external heat intrusion, and can be installed between the corner primary insulation wall (2b) and the corner secondary insulation wall (41b). The configuration of the corner primary insulation wall (3b) of the present embodiment is the same or similar to that of the first embodiment described above, except that the outer primary plywood (33b) is omitted and the configuration of the inner bending portion (3b3) is different. Here, the different configuration will be mainly described.

[0223] The corner primary insulation wall (3b) is provided on the inner side of the first side and the second side, and may include an inner first fixing part (3b1) and an inner second fixing part (3b2) configured to have a structure in which an inner primary plywood (31b) and a corner primary insulation material (32b) are sequentially laminated on the outer side of the corner primary barrier (2b). Here, the inner primary plywood (31b) and the corner primary insulation material (32b) of the present embodiment may be the same as or similar to those of the first embodiment described above, and thus, a detailed description thereof will be omitted to avoid redundant explanation.

[0224] The inner first fixing part (3b1) may be fixed to the outer first fixing part (5b1) and provided on the inner side of the first surface, and the inner second fixing part (3b2) may be fixed to the outer second fixing part (5b2) and provided on the inner side of the second surface.

[0225] In addition, the corner primary insulation wall (3b) may include an outer insulation material (3b33) provided on a corner secondary barrier (41b) that is filled between the inner first fixing part (3b1) and the inner second fixing part (3b2) and includes a corner connecting barrier (42b), and an inner bending part (3b3) including an inner insulation material (3b34) provided between the outer insulation material (3b33) and the corner primary barrier (2b).

[0226] The outer insulation (3b33) of the inner folded portion (3b3) may be glass wool, and a secondary wall (4) may be provided on the outer surface folded at a certain angle, for example, 135 degrees, in which a corner secondary wall (41b) and a corner connecting wall (42b) are laminated.

[0227] The inner insulation (3b34) of the inner fold (3b3) may be low-density polyurethane foam, and a corner primary barrier (2b) may be provided on the inner surface bent at a certain angle, for example, 135 degrees.

[0228] The thickness of each of the outer insulation material (3b33) and the inner insulation material (3b34) of the inner bending portion (3b3) can be freely determined.

[0229] The corner secondary barrier (41b) can be installed between the corner primary insulation wall (3b) and the corner secondary insulation wall (5b), and when the corner blocks are arranged adjacently, the adjacent corner secondary barriers (41b) between the outer first and second fixing members (5b1, 5b2) can be connected by a corner connection barrier (42b), and together with the corner primary barrier (2b), the liquefied gas can be prevented from leaking to the outside. The corner secondary barrier (41b) of the present embodiment may have a basic configuration identical or similar to that of the first embodiment described above. However, the corner secondary barrier (41b) including the corner connecting barrier (42b) of the present embodiment may have a different arrangement relationship as some of the configurations of the corner primary insulation wall (3b) and the corner secondary insulation wall (5b) are different from those of the first embodiment described above, which will be mentioned below when explaining the corner secondary insulation wall (5b).

[0230] The corner secondary insulation wall (5b) may be configured to include an inner secondary plywood (51b), a corner secondary insulation material (52b), and an outer secondary plywood (53b). The corner secondary insulation wall (5b) may include an outer first fixing part (5b1) and an outer second fixing part (5b2) which are respectively fixed to the inner sides of the first side and the second side, and are configured to have a structure in which the inner secondary plywood (51b), the corner secondary insulation material (52b), and the outer secondary plywood (53b) are sequentially laminated on the outer side of the corner secondary barrier wall (2b).

[0231] The above-described outer first fixing portion (5b1) and outer second fixing portion (5b2) may be provided such that the facing sides thereof are inclined in a direction (ED) that divides the corner portions evenly. In this embodiment, the corner portions are described as being equally divided, but this is not limited thereto, and since they may not be even depending on the corner position, it goes without saying that the corner portions may be inclined in a direction (ED) that divides them unevenly.

[0232] The outer first fixing part (5b1) and the outer second fixing part (5b2) may have steps formed at the corners facing each other.

[0233] In addition, the corner secondary insulation wall (5b) may include an outer bend (5b3) including an insulation material (5b312) that is filled between the step portion of the outer first fixing part (5b1) and the outer second fixing part (5b2). The insulation material (5b32) of the outer bend (5b3) may be glass wool, which is the same material as the outer insulation material (3b33) of the inner bend (3b3).

[0234] By providing an insulation material (5b32) of an outer bending portion (5b3) at a step portion between an outer first fixing portion (5b1) and an outer second fixing portion (5b2), a corner secondary barrier (41b) encompassing a corner connecting barrier (42b) is fixed to the inner secondary plywood (51b) of the outer first fixing portion (5b1), the insulation material (5b32) of the outer bending portion (5b3), and the inner secondary plywood (51b) of the outer second fixing portion (5b2), and can be provided to be bent at a predetermined angle, for example, 135 degrees, on the inner side of the insulation material (5b32) of the outer bending portion (5b3).

[0235] In this way, the present embodiment forms a step at the corner where the outer first fixing part (5b1) and the outer second fixing part (5b2), which are respectively fixed to the first and second surfaces at different angles, face each other, and an insulation material (5b32) of an outer folded part (5b3) made of glass wool is provided at the step portion, and an outer insulation material (3b33) of an inner folded part (5b3) made of glass wool is provided with a corner secondary barrier (41b) that includes a corner connecting barrier (42b) interposed therebetween, thereby improving the flexibility of the corner secondary barrier (41b) that includes the corner connecting barrier (42b) formed between the glass wools, thereby further preventing damage to the corner secondary barrier (41b) that includes the corner connecting barrier (42b).

[0236] Fig. 10 is a structural analysis result of the YY direction stress value and temperature distribution of the secondary barrier (4, 41b, 42b) at the portion where the first and second outer fixing members (5b1, 5b2) face each other and are bent, and the YY direction stress value was 12.003 MPa and the temperature was -64.358℃. When these figures are compared with the YY direction stress value of about 66.8984 MPa and the temperature of about -135.857℃ at the bent portion of the secondary barrier of the existing liquefied gas storage tank, it can be seen that the stress is much less in the secondary barrier (4, 41b, 42b) according to the present embodiment, which means a reduction in the influence of cold heat from the cryogenic material, such as damage due to low-temperature stress, in the secondary barrier (4, 41b, 42b) of the present embodiment compared to the existing one.

[0237] FIG. 11 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a fifth embodiment of the present invention, and FIG. 12 is a drawing showing the results of a structural analysis of a corner portion of a liquefied gas storage tank according to a fifth embodiment of the present invention.

[0238] The planar structure of the liquefied gas storage tank (1) of the present embodiment may be formed by a combination of a plurality of planar blocks, as illustrated in the aforementioned Fig. 1, and the corner structure of the liquefied gas storage tank (1) may be formed by a combination of a plurality of corner blocks, as illustrated in Fig. 11. These plurality of planar blocks may be connected to a plurality of corner blocks at corner portions of the liquefied gas storage tank (1).

[0239] In the liquefied gas storage tank (1) of the present embodiment, the configuration of the flat block is the same as or similar to the configuration described above with reference to FIG. 1. That is, the flat block of the liquefied gas storage tank (1) of the present embodiment, as illustrated in FIG. 1, is arranged in a flat portion on a first surface or a second surface at different angles that forms a storage space for accommodating liquefied gas, and may include a flat primary barrier (2a) made of a metal material, a flat primary insulating wall (3a) arranged on the outside of the flat primary barrier (2a), a flat secondary barrier (41a) provided on the outside of the flat primary insulating wall (3a), and a flat secondary insulating wall (5a) arranged on the outside of the flat secondary barrier (41a).

[0240] Accordingly, to avoid redundant explanation, a detailed description of the flat block configuration of the liquefied gas storage tank (1) is omitted here. Hereinafter, the configuration of the corner block of the liquefied gas storage tank (1) of the present embodiment will be specifically described with reference to FIGS. 1 and 11.

[0241] As illustrated in FIGS. 1 and 11, a liquefied gas storage tank (1) may be configured to include a primary barrier (2) in contact with the liquefied gas, a primary insulation wall (3) installed on the outside of the primary barrier (2), a secondary barrier (4) installed on the outside of the primary insulation wall (3), and a secondary insulation wall (5) arranged on the outside of the secondary barrier (4). The liquefied gas storage tank (1) may be supported on a hull (7) by mastic (6) installed between the secondary insulation wall (5) and the hull (7).

[0242] In the above, the primary barrier wall (2) may be formed of a flat primary barrier wall (2a) of a flat block and a corner primary barrier wall (2b) of a corner block, the primary insulation wall (3) may be formed of a flat primary insulation wall (3a) of a flat block and a corner primary insulation wall (3b) of a corner block, the secondary barrier wall (4) may be formed of a flat secondary barrier wall (41a) of a flat block and a corner secondary barrier wall (41b) of a corner block, and the secondary insulation wall (5) may be formed of a flat secondary insulation wall (5a) of a flat block and a corner secondary insulation wall (5b) of a corner block. In the present embodiment, as described in the first embodiment, the thickness of the primary insulation wall (3) and the thickness of the secondary insulation wall (5) in the flat block and the corner block may be the same or similar.

[0243] In the above, the secondary barrier (4) of the flat block and the corner block may include a flat connecting barrier (42a) or a corner connecting barrier (42b) that connects the flat secondary barrier (41a) that is adjacently placed or the corner secondary barrier (41b) that is adjacently placed when a plurality of flat blocks or a plurality of corner blocks are adjacently placed.

[0244] As illustrated in Fig. 11, the corner portion of the liquefied gas storage tank (1) according to the fifth embodiment of the present invention may be formed by a combination of a plurality of corner blocks. The corner structure of the liquefied gas storage tank (1) described below may be an obtuse corner structure forming a certain angle, for example, an angle of 135 degrees.

[0245] In this embodiment, unlike the drawing, the position of the corner primary insulation wall (3b) can be positioned so as to expose the corner secondary barrier (41b) constructed on the corner secondary insulation wall (5b) at the center of the corner. Accordingly, it is also possible to finish the exposed corner secondary barrier (41b) by interconnecting it with a corner connecting barrier (42b), or to construct the corner connecting barrier (42b) so that the corner primary insulation wall (3b) connects the adjacent corner secondary barriers (41b) and then stack it on the corner secondary barrier (41b) / corner connecting barrier (42b). In this embodiment, the corner connecting barrier (42b) can be formed to extend not only between the inner first and second fixing members (3b1, 3b2), but also to overlap at least the inner first and second fixing members (3b1, 3b2).

[0246] The corner block of the liquefied gas storage tank (1) is arranged at a corner portion where first and second sides of different angles meet to form a storage space for accommodating liquefied gas, and may include a corner primary barrier (2b) made of metal, a corner primary insulation wall (3b) arranged on the outside of the corner primary barrier (2b), a corner secondary barrier (41b) provided on the outside of the corner primary insulation wall (3b), and a corner secondary insulation wall (5b) arranged on the outside of the corner secondary barrier (41b).

[0247] The corner primary barrier (2b) is positioned at a corner where the first or second surfaces at different angles meet to form a space for containing liquefied gas, which is a cryogenic substance, and may be made of a metal material. The corner primary barrier (2b), together with the corner secondary barrier (41b), can prevent liquefied gas from leaking to the outside.

[0248] The corner primary barrier (2b) of this embodiment is basically the same or similar to the first embodiment described above, and thus a detailed description thereof is omitted here.

[0249] The corner primary insulation wall (3b) is designed to withstand external impact or impact due to liquefied gas sloshing from the inside while blocking external heat intrusion, and can be installed between the corner primary insulation wall (2b) and the corner secondary insulation wall (41b). The configuration of the corner primary insulation wall (3b) of the present embodiment is the same or similar to that of the first embodiment described above, except that the outer primary plywood (33b) is omitted. Here, the description will focus on the different configuration.

[0250] The corner primary insulation wall (3b) is provided on the inner side of the first side and the second side, and may include an inner first fixing part (3b1) and an inner second fixing part (3b2) configured to have a structure in which an inner primary plywood (31b) and a corner primary insulation material (32b) are sequentially laminated on the outer side of the corner primary barrier (2b). Here, the inner primary plywood (31b) and the corner primary insulation material (32b) of the present embodiment may be the same as or similar to those of the first embodiment described above, and thus, a detailed description thereof will be omitted to avoid redundant explanation.

[0251] The inner first fixing part (3b1) may be fixed to the outer first fixing part (5b1) and provided on the inner side of the first surface, and the inner second fixing part (3b2) may be fixed to the outer second fixing part (5b2) and provided on the inner side of the second surface.

[0252] In addition, the corner first insulation wall (3b) may include an inner bend (3b3) formed by filling an insulation material (3b35) between the inner first fixing part (3b1) and the inner second fixing part (3b2). The insulation material (3b35) of the inner bend (3b3) of the present embodiment may be the same as or similar to that of the first embodiment described above, and thus, a detailed description thereof is omitted to avoid redundant explanation.

[0253] The corner secondary barrier (41b) can be installed between the corner primary insulation wall (3b) and the corner secondary insulation wall (5b), and when the corner blocks are arranged adjacently, the adjacent corner secondary barriers (41b) between the outer first and second fixing members (5b1, 5b2) can be connected by a corner connection barrier (42b), and together with the corner primary barrier (2b), the liquefied gas can be prevented from leaking to the outside. The corner secondary barrier (41b) of the present embodiment may have a basic configuration identical or similar to that of the first embodiment described above. However, the corner secondary barrier (41b) including the corner connecting barrier (42b) of the present embodiment may have a different arrangement relationship as some of the configurations of the corner secondary insulating wall (5b) are different from those of the first embodiment described above, which will be mentioned below when explaining the corner secondary insulating wall (5b).

[0254] The corner secondary insulation wall (5b) may be configured to include an inner secondary plywood (51b), a corner secondary insulation material (52b), and an outer secondary plywood (53b). The corner secondary insulation wall (5b) may include an outer first fixing part (5b1) and an outer second fixing part (5b2) which are respectively fixed to the inner sides of the first side and the second side, and are configured to have a structure in which the inner secondary plywood (51b), the corner secondary insulation material (52b), and the outer secondary plywood (53b) are sequentially laminated on the outer side of the corner secondary barrier wall (2b).

[0255] The inner first fixing part (3b1) may be fixed to the outer first fixing part (5b1) and provided on the inner side of the first surface, and the inner second fixing part (3b2) may be fixed to the outer second fixing part (5b2) and provided on the inner side of the second surface.

[0256] In addition, the corner secondary insulation wall (5b) is provided between the outer first fixing part (5b1) and the outer second fixing part (5b2), and may include an outer intermediate fixing part (5b12) on which a folded portion of the corner secondary barrier (41b) encompassing the corner connecting barrier (42b) is secured.

[0257] The outer intermediate fixing member (5b12) may include an outer intermediate plywood (51b12) fixed to the first side and the second side, an outer intermediate insulation material (52b12) provided on the inner side of the outer intermediate plywood (51b12), and an inner intermediate insulation material (53b12) provided on the inner side of the outer intermediate insulation material (52b12) and on which a bent portion of a corner secondary barrier (41b) encompassing a corner connecting barrier (42b) is secured.

[0258] The outer intermediate plywood (51b12) is positioned on the same line as the inner secondary plywood (51b) and may have the same configuration.

[0259] The outer intermediate insulation (52b12) may be polyurethane foam.

[0260] The inner intermediate insulation (53b12) may be glass wool.

[0261] An outer intermediate fixing part (5b1) is provided between the outer first fixing part (5b1) and the outer second fixing part (5b2), in which an outer intermediate plywood (51b12), an outer intermediate insulation material (52b12), and an inner intermediate insulation material (53b12) are laminated, so that a corner secondary barrier (41b) encompassing a corner connecting barrier (42b) is fixed to the inner secondary plywood (51b) of the outer first fixing part (5b1), the inner intermediate insulation material (53b12) of the outer intermediate fixing part (5b12), and the inner secondary plywood (51b) of the outer second fixing part (5b2), and can be provided to be bent at a predetermined angle, for example, an angle of 135 degrees, on the inner side of the inner intermediate insulation material (53b12) of the outer intermediate fixing part (5b12).

[0262] Through this, the present embodiment provides an outer intermediate fixing part (5b12) between an outer first fixing part (5b1) and an outer second fixing part (5b2) which are fixed to the first and second surfaces at different angles, respectively, and the flexibility of the corner secondary barrier (41b) encompassing the corner connecting barrier (42b) formed on the upper part of the inner intermediate insulation (53b12) of the outer intermediate fixing part (5b12) made of glass wool is improved, so that damage to the corner secondary barrier (41b) encompassing the corner connecting barrier (42b) can be further prevented.

[0263] In addition, the present embodiment provides a corner connecting barrier (42b) that includes a corner fixed to the outer fixing portion (5b1), which is fixed to the first side and the second side at different angles, by spacing apart a certain distance between the outer first fixing portion (5b1) and the outer second fixing portion (5b2), and by providing an outer intermediate fixing portion (5b12) between the outer first and second fixing portions (5b1, 5b2), thereby relieving the shrinkage or expansion stress due to temperature in the outer fixing portions (5b1, 5b2, 5b12) having two gaps compared to the existing outer fixing portion having one gap. Damage to the secondary barrier (41b) can be prevented.

[0264] Fig. 12 is a structural analysis result of the YY direction stress value and temperature distribution of the secondary barrier (4, 41b, 42b) at the portion where the first and second outer fixing members (5b1, 5b2) face each other and are bent, and the YY direction stress value was 13.101 MPa and the temperature was -74.480℃. When these figures are compared with the YY direction stress value of about 66.8984 MPa and the temperature of about -135.857℃ at the bent portion of the secondary barrier of the existing liquefied gas storage tank, it can be seen that the stress is much less in the secondary barrier (4, 41b, 42b) according to the present embodiment, which means a reduction in the influence of cold heat from the cryogenic material, such as damage due to low-temperature stress, in the secondary barrier (4, 41b, 42b) of the present embodiment compared to the existing one.

[0265] FIG. 13 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a sixth embodiment of the present invention, and FIG. 14 is a drawing showing the results of a structural analysis of a corner portion of a liquefied gas storage tank according to a sixth embodiment of the present invention.

[0266] The planar structure of the liquefied gas storage tank (1) of the present embodiment may be formed by a combination of a plurality of planar blocks, as illustrated in the aforementioned Fig. 1, and the corner structure of the liquefied gas storage tank (1) may be formed by a combination of a plurality of corner blocks, as illustrated in Fig. 13. These plurality of planar blocks may be connected to a plurality of corner blocks at corner portions of the liquefied gas storage tank (1).

[0267] In the liquefied gas storage tank (1) of the present embodiment, the configuration of the flat block is the same as or similar to the configuration described above with reference to FIG. 1. That is, the flat block of the liquefied gas storage tank (1) of the present embodiment, as illustrated in FIG. 1, is arranged in a flat portion on a first surface or a second surface at different angles that forms a storage space for accommodating liquefied gas, and may include a flat primary barrier (2a) made of a metal material, a flat primary insulating wall (3a) arranged on the outside of the flat primary barrier (2a), a flat secondary barrier (41a) provided on the outside of the flat primary insulating wall (3a), and a flat secondary insulating wall (5a) arranged on the outside of the flat secondary barrier (41a).

[0268] Accordingly, to avoid redundant explanation, a detailed description of the flat block configuration of the liquefied gas storage tank (1) is omitted here. Hereinafter, the configuration of the corner block of the liquefied gas storage tank (1) of the present embodiment will be specifically described with reference to FIGS. 1 and 13.

[0269] As illustrated in FIGS. 1 and 13, a liquefied gas storage tank (1) may be configured to include a primary barrier (2) in contact with the liquefied gas, a primary insulation wall (3) installed on the outside of the primary barrier (2), a secondary barrier (4) installed on the outside of the primary insulation wall (3), and a secondary insulation wall (5) arranged on the outside of the secondary barrier (4). The liquefied gas storage tank (1) may be supported on a hull (7) by mastic (6) installed between the secondary insulation wall (5) and the hull (7).

[0270] In the above, the primary barrier wall (2) may be formed of a flat primary barrier wall (2a) of a flat block and a corner primary barrier wall (2b) of a corner block, the primary insulation wall (3) may be formed of a flat primary insulation wall (3a) of a flat block and a corner primary insulation wall (3b) of a corner block, the secondary barrier wall (4) may be formed of a flat secondary barrier wall (41a) of a flat block and a corner secondary barrier wall (41b) of a corner block, and the secondary insulation wall (5) may be formed of a flat secondary insulation wall (5a) of a flat block and a corner secondary insulation wall (5b) of a corner block. In the present embodiment, as described in the first embodiment, the thickness of the primary insulation wall (3) and the thickness of the secondary insulation wall (5) in the flat block and the corner block may be the same or similar.

[0271] In the above, the secondary barrier (4) of the flat block and the corner block may include a flat connecting barrier (42a) or a corner connecting barrier (42b) that connects the flat secondary barrier (41a) that is adjacently placed or the corner secondary barrier (41b) that is adjacently placed when a plurality of flat blocks or a plurality of corner blocks are adjacently placed.

[0272] As illustrated in Fig. 13, the corner portion of the liquefied gas storage tank (1) according to the sixth embodiment of the present invention may be formed by a combination of a plurality of corner blocks. The corner structure of the liquefied gas storage tank (1) described below may be an obtuse corner structure forming a certain angle, for example, an angle of 135 degrees.

[0273] The corner block of the liquefied gas storage tank (1) is arranged at a corner portion where first and second sides of different angles meet to form a storage space for accommodating liquefied gas, and may include a corner primary barrier (2b) made of metal, a corner primary insulation wall (3b) arranged on the outside of the corner primary barrier (2b), a corner secondary barrier (41b) provided on the outside of the corner primary insulation wall (3b), and a corner secondary insulation wall (5b) arranged on the outside of the corner secondary barrier (41b).

[0274] The corner primary barrier (2b) is positioned at a corner where the first or second surfaces at different angles meet to form a space for containing liquefied gas, which is a cryogenic substance, and may be made of a metal material. The corner primary barrier (2b), together with the corner secondary barrier (41b), can prevent liquefied gas from leaking to the outside.

[0275] The corner primary barrier (2b) of this embodiment is basically the same or similar to the first embodiment described above, and thus a detailed description thereof is omitted here.

[0276] The corner primary insulation wall (3b) is designed to withstand external impact or impact due to liquefied gas sloshing from the inside while blocking external heat intrusion, and can be installed between the corner primary insulation wall (2b) and the corner secondary insulation wall (41b). The configuration of the corner primary insulation wall (3b) of the present embodiment is the same or similar to that of the first embodiment described above, except that the outer primary plywood (33b) is omitted and the outer shape of the insulation material (3b31) of the inner folded portion (3b3) is different. Here, the description will be made mainly of the different configuration.

[0277] The corner primary insulation wall (3b) is provided on the inner side of the first side and the second side, and may include an inner first fixing part (3b1) and an inner second fixing part (3b2) configured to have a structure in which an inner primary plywood (31b) and a corner primary insulation material (32b) are sequentially laminated on the outer side of the corner primary barrier (2b). Here, the inner primary plywood (31b) and the corner primary insulation material (32b) of the present embodiment may be the same as or similar to those of the first embodiment described above, and thus, a detailed description thereof will be omitted to avoid redundant explanation.

[0278] The inner first fixing part (3b1) may be fixed to the outer first fixing part (5b1) and provided on the inner side of the first surface, and the inner second fixing part (3b2) may be fixed to the outer second fixing part (5b2) and provided on the inner side of the second surface.

[0279] In addition, the corner primary insulation wall (3b) may include an inner bend (3b3) formed by filling an insulation material (3b36) between the inner first fixing part (3b1) and the inner second fixing part (3b2). The insulation material (3b36) of the inner bend (3b3) of the present embodiment may be the same as or similar to that of the first embodiment described above. However, the shape of the outer surface of the insulation material (3b36) of the inner bend (3b3) of the present embodiment may change depending on the configuration of the outer first and second fixing parts (5b1, 5b2).

[0280] That is, the insulation material (3b36) of the inner bending portion (3b3) of the present embodiment has a shape in which the outer surface protrudes outward relative to the inner first fixing portion (3b1) or the inner second fixing portion (3b2), because a chamfer is formed at the corner where the outer first fixing portion (5b1) and the outer second fixing portion (5b2) face each other.

[0281] The corner secondary barrier (41b) can be installed between the corner primary insulation wall (3b) and the corner secondary insulation wall (5b), and when the corner blocks are arranged adjacently, the adjacent corner secondary barriers (41b) between the outer first and second fixing members (5b1, 5b2) can be connected by the corner connecting barrier (42b), and together with the corner primary barrier (2b), the liquefied gas can be prevented from leaking to the outside. In the present embodiment, the corner connecting barrier (42b) can be formed to extend to a length that overlaps not only the inner first and second fixing members (3b1, 3b2), but also at least the inner first and second fixing members (3b1, 3b2).

[0282] The corner secondary barrier (41b) of this embodiment may have a basic configuration identical or similar to that of the first embodiment described above. However, the corner secondary barrier (41b) encompassing the corner connecting barrier (42b) of this embodiment may have a different arrangement relationship as some of the configurations of the corner secondary insulation wall (5b) are different from those of the first embodiment described above, which will be mentioned below when describing the corner secondary insulation wall (5b).

[0283] The corner secondary insulation wall (5b) may be configured to include an inner secondary plywood (51b), a corner secondary insulation material (52b), and an outer secondary plywood (53b). The corner secondary insulation wall (5b) may include an outer first fixing part (5b1) and an outer second fixing part (5b2) which are respectively fixed to the inner sides of the first side and the second side, and are configured to have a structure in which the inner secondary plywood (51b), the corner secondary insulation material (52b), and the outer secondary plywood (53b) are sequentially laminated on the outer side of the corner secondary barrier wall (2b).

[0284] The above-described outer first fixing portion (5b1) and outer second fixing portion (5b2) may be provided such that the facing sides thereof are inclined in a direction (ED) that divides the corner portions evenly. In this embodiment, the corner portions are described as being equally divided, but this is not limited thereto, and since they may not be even depending on the corner position, it goes without saying that the corner portions may be inclined in a direction (ED) that divides them unevenly.

[0285] The outer first fixing part (5b1) and the outer second fixing part (5b2) may have chamfers formed at the corners facing each other.

[0286] In the present embodiment, the inner secondary plywood (51b) may be composed of a peripheral plywood (51b1) that is parallel to the outer secondary plywood (53b) and is fixed on the corner secondary insulation material (52b), and an inclined plywood (51b2) that is connected to the peripheral plywood (51b1) and is fixed on the corner secondary insulation material (52b) of the chamfered portion. Accordingly, unlike the first embodiment described above, the corner primary insulation material (32b) may be provided on the peripheral plywood (51b1), and the insulation material (3b36) of the inner bent portion (3b3) may be provided on the inclined plywood (51b2).

[0287] By providing inclined plywood (51b2) and insulation material (3b36) of the inner bending portion (3b3) in the chamfered portions of the outer first fixing portion (5b1) and the outer second fixing portion (5b2), the corner secondary barrier (41b) encompassing the corner connecting barrier (42b) can be fixed to the surrounding plywood (51b1) of the outer first fixing portion (5b1), the inclined plywood (5b2) of the outer first fixing portion (5b1), the inclined plywood (5b2) of the outer second fixing portion (5b2), and the surrounding plywood (51b1) of the outer second fixing portion (5b2).

[0288] Additionally, the corner secondary barrier (41b) encompassing the corner connecting barrier (42b) can be bent to protrude outward so as to be seated in the chamfered portions of the outer first fixing member (5b1) and the outer second fixing member (5b2).

[0289] That is, the corner secondary barrier (41b) encompassing the corner connecting barrier (42b) may be arranged to be bent outward between the peripheral plywood (51b1) of the outer first fixing portion (5b1) and the inclined plywood (51b2) of the outer first fixing portion (5b1), bent inward between the inclined plywood (51b2) of the outer first fixing portion (5b1) and the inclined plywood (51b2) of the outer second fixing portion (5b2), and bent outward between the inclined plywood (51b2) of the outer second fixing portion (5b2) and the peripheral plywood (51b1) of the outer second fixing portion (5b2).

[0290] In this embodiment, a chamfer is formed at the corner where the outer first fixing part (5b1) and the outer second fixing part (5b2) which are fixed to the first and second surfaces at different angles, respectively, face each other, and a corner secondary barrier (41b) including a corner connecting wall (42b) is installed along the surface of the outer first and second fixing parts (5b1, 5b2) including the chamfer portion, so that the corner secondary barrier (41b) including the corner connecting wall (42b) protrudes outward and increases the length of the non-bonded portion to the corner secondary insulating wall (5b), thereby further reducing the probability of damage to the corner secondary barrier (41b) including the corner connecting wall (42b) due to the increased flexibility of the corner secondary barrier (41b) including the corner connecting wall (42b). The secondary barrier (41b) can easily absorb hull deformation and further reduce low-temperature stress.

[0291] Fig. 14 is a structural analysis result of the YY direction stress value and temperature distribution of the secondary barrier (4, 41b, 42b) at the portion where the first and second outer fixing members (5b1, 5b2) face each other and are bent, and the YY direction stress value was 7.197 MPa and the temperature was -53.710℃. When these figures are compared with the YY direction stress value of about 66.8984 MPa and the temperature of about -135.857℃ at the bent portion of the secondary barrier of the existing liquefied gas storage tank, it can be seen that the stress is much less in the secondary barrier (4, 41b, 42b) according to the present embodiment, which means a reduction in the influence of cold heat from the cryogenic material, such as damage due to low-temperature stress, in the secondary barrier (4, 41b, 42b) of the present embodiment compared to the existing one.

[0292] FIG. 15 is a cross-sectional view of a corner portion for explaining a liquefied gas storage tank according to a seventh embodiment of the present invention, and FIG. 16 is a drawing showing the results of a structural analysis of a corner portion of a liquefied gas storage tank according to a seventh embodiment of the present invention.

[0293] As illustrated in FIG. 15, the liquefied gas storage tank (1) of the present embodiment may be the same or similar to the liquefied gas storage tank (1) of the first embodiment described above in other configurations except for the configuration of the inner bending portion (3b3). Accordingly, to avoid redundant description of the same configuration, a detailed description will be omitted, and the description will be focused on the different configurations.

[0294] The configuration of the corner first insulation wall (3b) of this embodiment is the same or similar to that of the first embodiment described above, except that the configuration of the part where the inner bend (3b3) filled with insulation material (3b31) is arranged is different. Here, the description will be focused on the different configuration.

[0295] The corner first insulation wall (3b) of the present embodiment may include a vacuum insulation panel (3b37) filled in the inner bending portion (3b3) between the inner first fixing portion (3b1) and the inner second fixing portion (3b2).

[0296] In the present embodiment, since the inner first fixing part (3b1) and the inner second fixing part (3b2) are non-structural members, it is easy to construct a vacuum insulation panel (3b37), which is a structural member, between the inner first fixing part (3b1) and the inner second fixing part (3b2). The vacuum insulation panel (3b37) has excellent insulation performance among various insulation materials such as polyurethane foam, and can improve insulation performance at corners.

[0297] Fig. 16 is a structural analysis result of the YY direction stress value and temperature distribution of the secondary barrier (4, 41b, 42b) at the portion where the first and second outer fixing members (5b1, 5b2) face each other and are bent, and the YY direction stress value was 12.084 MPa and the temperature was -59.025℃. When these figures are compared with the YY direction stress value of about 66.8984 MPa and the temperature of about -135.857℃ at the bent portion of the secondary barrier of the existing liquefied gas storage tank, it can be seen that the stress is much less in the secondary barrier (4, 41b, 42b) according to the present embodiment, which means a reduction in the influence of cold heat from the cryogenic material, such as damage due to low-temperature stress, in the secondary barrier (4, 41b, 42b) of the present embodiment compared to the existing one.

[0298] Fig. 17 is a partial front view of a corner portion for explaining a liquefied gas storage tank according to the eighth embodiment of the present invention.

[0299] The planar structure of the liquefied gas storage tank (1) of the present embodiment may be formed by a combination of a plurality of planar blocks, as illustrated in the aforementioned Fig. 1, and the corner structure of the liquefied gas storage tank (1) may be formed by a combination of a plurality of corner blocks, as illustrated in Fig. 17. These plurality of planar blocks may be connected to a plurality of corner blocks at corner portions of the liquefied gas storage tank (1).

[0300] In the liquefied gas storage tank (1) of the present embodiment, the configuration of the flat block is the same as or similar to the configuration described above with reference to FIG. 1. That is, the flat block of the liquefied gas storage tank (1) of the present embodiment, as illustrated in FIG. 1, is arranged in a flat portion on a first surface or a second surface at different angles that forms a storage space for accommodating liquefied gas, and may include a flat primary barrier (2a) made of a metal material, a flat primary insulating wall (3a) arranged on the outside of the flat primary barrier (2a), a flat secondary barrier (41a) provided on the outside of the flat primary insulating wall (3a), and a flat secondary insulating wall (5a) arranged on the outside of the flat secondary barrier (41a).

[0301] Accordingly, to avoid redundant explanation, a detailed description of the flat block configuration of the liquefied gas storage tank (1) is omitted here. Hereinafter, the configuration of the corner block of the liquefied gas storage tank (1) of the present embodiment will be specifically described with reference to FIGS. 1 and 17.

[0302] As illustrated in FIG. 1 and FIG. 17, a liquefied gas storage tank (1) may be configured to include a primary barrier (2) in contact with the liquefied gas, a primary insulation wall (3) installed on the outside of the primary barrier (2), a secondary barrier (4) installed on the outside of the primary insulation wall (3), and a secondary insulation wall (5) arranged on the outside of the secondary barrier (4). The liquefied gas storage tank (1) may be supported on a hull (7) by mastic (6) installed between the secondary insulation wall (5) and the hull (7).

[0303] In the above, the primary barrier wall (2) may be formed of a flat primary barrier wall (2a) of a flat block and a corner primary barrier wall (2b) of a corner block, the primary insulation wall (3) may be formed of a flat primary insulation wall (3a) of a flat block and a corner primary insulation wall (3b) of a corner block, the secondary barrier wall (4) may be formed of a flat secondary barrier wall (41a) of a flat block and a corner secondary barrier wall (41b) of a corner block, and the secondary insulation wall (5) may be formed of a flat secondary insulation wall (5a) of a flat block and a corner secondary insulation wall (5b) of a corner block. In the present embodiment, as described in the first embodiment, the thickness of the primary insulation wall (3) and the thickness of the secondary insulation wall (5) in the flat block and the corner block may be the same or similar.

[0304] In the above, the secondary barrier (4) of the flat block and the corner block may include a flat connecting barrier (42a) or a corner connecting barrier (42b) that connects the flat secondary barrier (41a) that is adjacently placed or the corner secondary barrier (41b) that is adjacently placed when a plurality of flat blocks or a plurality of corner blocks are adjacently placed.

[0305] As illustrated in Fig. 17, the corner portion of the liquefied gas storage tank (1) according to the eighth embodiment of the present invention can be formed by a combination of a plurality of corner blocks.

[0306] The corner block of the liquefied gas storage tank (1) is arranged at a corner portion where first and second sides of different angles meet to form a storage space for accommodating liquefied gas, and may include a corner primary barrier (2b) made of metal, a corner primary insulation wall (3b) arranged on the outside of the corner primary barrier (2b), a corner secondary barrier (41b) provided on the outside of the corner primary insulation wall (3b), and a corner secondary insulation wall (5b) arranged on the outside of the corner secondary barrier (41b).

[0307] The corner primary barrier (2b) is arranged at a corner portion where the first or second surfaces at different angles meet to form a receiving space for receiving liquefied gas, which is a cryogenic substance, and may be made of a metal material. The corner primary barrier (2b), together with the corner secondary barrier (41b), can prevent the liquefied gas from leaking to the outside. The corner primary barrier (2b) of the present embodiment is basically the same as or similar to the first embodiment described above, and thus a detailed description thereof is omitted here.

[0308] The corner primary barrier (2b) can be fixed to the barrier fixing member (21b).

[0309] The barrier fixing member (21b) may be installed on the upper part of the corner primary insulation wall (3b) made of metal. In the case of the corner primary insulation wall (3b), a plurality of such members may be arranged along the edge of the corner portion on the corner secondary insulation wall (5b), and accordingly, the barrier fixing member (21b) may be independently installed on each of the plurality of corner primary insulation walls (3b).

[0310] The corner primary insulation wall (3b) is designed to withstand impact from the outside or impact due to liquefied gas sloshing from the inside while blocking heat intrusion from the outside, and can be installed between the corner primary insulation wall (2b) and the corner secondary insulation wall (41b).

[0311] The corner primary insulation wall (3b) is provided on the inner side of each of the first and second sides, and may include a corner primary insulation material (32b) fixed to the corner secondary barrier wall (2b), and an inner primary plywood (31b) that is arranged on the inner side of the corner primary insulation material (32b) and forms a step with the corner primary insulation material (32b) and to which the corner primary barrier wall (2b) is fixed.

[0312] A corner first insulation wall (3b) in which the inner first plywood (31b) and the corner first insulation material (32b) are sequentially laminated can be arranged in multiple numbers along the edge of the corner portion on the corner second insulation wall (5b).

[0313] In this embodiment, the corner primary insulation wall (3b) is described as being composed of an inner primary plywood (31b) and a corner primary insulation material (32b), but it is obvious that it may be the same as or similar to the corner primary insulation wall (3b) according to at least one of the first to seventh embodiments described above.

[0314] The above-described plurality of corner first-block insulation walls (3b) are arranged adjacent to each other on top of the corner second-block insulation walls (5b), but the gap between the plurality of corner first-block insulation walls (3b) can be minimized so that separate insulation material filling, such as glass wool, between the plurality of corner first-block insulation walls (3b) is omitted.

[0315] When multiple corner primary insulation walls (3b) are arranged in this way, a step space is created between the corner primary insulation material (32b) and the inner primary plywood (31b) that forms a step. The corner block of the present embodiment includes an inner first packing material (3b4) that fills the step space of the corner primary insulation walls (3b) that are arranged adjacent to each other and on which the corner primary barrier wall (2b) is secured.

[0316] The inner first packing material (3b4) may be polyurethane foam or glass wool.

[0317] A plurality of corner primary insulation walls (3b) are configured as part of a corner block together with a corner secondary insulation wall (41b) and a corner secondary insulation wall (5b). The total width of the plurality of corner primary insulation walls (3b) forming the corner block may be smaller than the width of the corner secondary insulation wall (5b), which is another component of the corner block. As a result, a part of the corner secondary insulation wall (41b) may be exposed on the outermost side of the plurality of corner primary insulation walls (3b). When a plurality of corner blocks are arranged adjacently along the edge of a corner portion, a corner connecting insulation wall (34b) may be installed in the space between the outermost corner primary insulation walls (3b) that are arranged adjacently, i.e., in the space where the corner secondary wall (41b) is exposed.

[0318] The corner connecting insulation wall (34b) is arranged between the outermost corner first insulation walls (3b) adjacent to each other when corner blocks are arranged adjacent to each other. It can be provided in the form of a corner connecting insulation material (341b) and a corner connecting plywood (342b) that are identical or similar to the corner first insulation wall (3b) being laminated, and has a thickness identical or similar to the corner first insulation wall (3b).

[0319] This corner connection insulation wall (34b) is installed to block heat intrusion from the outside by sealing the space created between adjacent corner secondary insulation walls (5b) when a plurality of corner blocks are placed adjacently along the edge of the corner portion, together with the corner connection barrier (42b).

[0320] When a plurality of corner blocks are placed adjacently along the corner portion in this way, a space is created between the corner connecting insulation (42b) and the corner primary insulation (32b) and between the corner connecting plywood (342b) and the inner primary plywood (31b), and the inner second packing material (3b5) on which the corner primary barrier (2b) is installed is filled in this space, thereby completing the construction of the corner primary insulation wall (3b).

[0321] The inner second packing material (3b5) may be polyurethane foam or glass wool.

[0322] The corner secondary barrier (41b) can be installed between the corner primary insulation wall (3b) and the corner secondary insulation wall (5b), and together with the corner primary barrier (2b), can prevent liquefied gas from leaking to the outside.

[0323] The corner secondary barrier (41b) is a part of the corner block together with the corner primary insulation wall (3b) and the corner secondary insulation wall (5b), and when the corner blocks are placed adjacently, the neighboring corner secondary barriers (41b) can be sealed and connected through the corner connection barrier (42b).

[0324] The corner connecting wall (42b) can connect the adjacent corner secondary wall (41) that is exposed to the outside when the corner blocks are placed adjacently, and a corner connecting insulating wall (34b) can be installed on the upper part.

[0325] The corner secondary insulation wall (5b) may be configured to include an inner secondary plywood (51b), a corner secondary insulation material (52b), and an outer secondary plywood (53b). The corner secondary insulation wall (5b) may be fixed to the inner sides of the first side and the second side, respectively, and may be configured to have a structure in which the inner secondary plywood (51b), the corner secondary insulation material (52b), and the outer secondary plywood (53b) are sequentially laminated on the outer side of the corner secondary barrier (2b).

[0326] When a plurality of corner blocks are placed adjacently along the edge of a corner portion, the space created between the adjacent corner secondary insulation walls (5b) can be filled with an outer packing material (5b4).

[0327] The outer packing material (5b4) may be polyurethane foam or glass wool.

[0328] The corner secondary insulation wall (5b) of this embodiment may be identical or similar to the corner secondary insulation wall (5b) according to at least one of the first to seventh embodiments described above, and thus, a detailed description thereof is omitted here to avoid redundant description.

[0329] In this embodiment, a plurality of corner primary insulation walls (3b) including inner primary plywood (31b) forming a step with a corner primary insulation material (32b) are arranged on a corner secondary insulation wall (5b), and neighboring corner primary insulation materials (32b) are arranged adjacently, thereby facilitating the installation handling of the barrier fixing member (21b) through the step portion between the adjacent inner primary plywoods (31b). In addition, since the packing material (3b4) only needs to be installed on the step portion, the consumption of the packing material can be reduced.

[0330] FIG. 18 is a partial front view of a corner portion for explaining a liquefied gas storage tank according to a ninth embodiment of the present invention, FIG. 19 is a side view for explaining a unit upper block constituting the upper block of FIG. 18, FIG. 20 is an exploded view of the unit upper block of FIG. 19, FIG. 21 is a drawing for explaining a process of assembling the unit upper block of FIG. 20, and FIG. 22 is a side view for explaining an upper connecting block of FIG. 18.

[0331] As illustrated in Fig. 18, a corner portion of a liquefied gas storage tank (1) according to the ninth embodiment of the present invention may be formed by a combination of a plurality of corner blocks (CB). The primary structure of the corner block (CB) may include a lower block (LB) fixed to the hull (7) and formed of a single board, an upper block (UB) formed by a plurality of unit upper blocks (UB1, UB2, UB3, UB4) bonded on the lower block (LB) and arranged in parallel and adjacent to each other, and an upper connecting block (UBB) bonded to a secondary barrier (4) exposed between the upper blocks (UB) that connect the lower blocks (LB) arranged adjacently. The upper block (UB) of this embodiment is described as being formed by four first to fourth unit upper blocks (UB1, UB2, UB3, UB4) arranged in parallel and adjacent to each other, but is not limited thereto and may of course be formed of at least two or more unit upper blocks.

[0332] The corner block (CB) of this embodiment can be arranged at a corner portion where the first and second surfaces of different angles meet to form a storage space for receiving liquefied gas, as in the first to eighth embodiments described above, and although not shown, when the corner block (CB) is arranged, a corner primary barrier (2b) made of a metal material is formed on the upper block (UB) and the upper connection block (UBB) as described above to complete the corner portion of the liquefied gas storage tank (1) having a storage space for hermetically receiving liquefied gas, which is an extremely low-temperature substance.

[0333] The liquefied gas storage tank (1) of the present embodiment is completed by connecting a corner block (CB) formed in the corner portion and a flat block formed in the flat portion, wherein the flat block may be a flat block having the structure shown in FIG. 1 of the first embodiment described above, but is not limited thereto.

[0334] In addition, the corner block (CB) of the present embodiment will be described in detail below by dividing it into a lower block (LB), an upper block (UB), and an upper connection block (UBB), but it is not limited thereto and can of course be the same as or similar to the structure of any one of the first to eighth embodiments described above.

[0335] As illustrated in FIG. 18, the lower block (LB) may have an upper block (UB) and an upper connection block (UBB) installed on the upper surface, and may be composed of a corner secondary barrier (41b) bonded to the lower surface of the upper block (UB), a corner connection barrier (42b) bonded to the lower surface of the upper connection block (UBB) connecting the neighboring corner secondary barrier (41b) that is exposed to the outside when the upper block (UB) is not installed when the lower block (LB) is placed adjacent to it, and a corner secondary insulation wall (5b) including an inner secondary plywood (51b), a corner secondary insulation material (52b), and an outer secondary plywood (53b).

[0336] The sub-block (LB) of this embodiment may be identical or similar to the configuration according to at least one of the first to eighth embodiments described above, and thus, a detailed description thereof is omitted here to avoid redundant description.

[0337] The upper block (UB) may be formed by a plurality of unit upper blocks, for example, first to fourth unit upper blocks (UB1, UB2, UB3, UB4), arranged in parallel and adjacent to each other, so that the lower surface may be bonded to the lower block (LB) and the upper surface may be fixed to the barrier fixing member (21b).

[0338] Each of the first to fourth unit upper blocks (UB1, UB2, UB3, UB4) has a basic structure consisting of a corner first insulation wall (3b) arranged on the outside of a barrier fixing member (21b), as illustrated in FIGS. 18, 19, 20, and 21.

[0339] In the above, the corner primary insulation wall (3b) is provided on the inner side of the first side and the second side, and may include an inner first fixing part (3b1) and an inner second fixing part (3b2) configured to have a structure in which an inner primary plywood (31b), a corner primary insulation material (32b), and an outer primary plywood (33b) are sequentially laminated on the outer side of the barrier fixing part (21b). The inner first fixing part (3b1) and the inner second fixing part (3b2) may be provided symmetrically based on a direction (ED) that equally divides the corner portion.

[0340] In addition, the corner first insulation wall (3b) is installed in the corner space between the inner first fixing part (3b1) and the inner second fixing part (3b2), and may include an inner bending part (3b3) made of insulation material.

[0341] The inner bend portion (3b3) of the present embodiment may be formed by dividing into an inner first half bend portion (3b3') and an inner second half bend portion (3b3"), unlike a conventional integrated inner bend portion, as shown in FIGS. 19, 20, and 21.

[0342] That is, the inner first half-bent portion (3b3') and the inner second half-bent portion (3b3") may have a triangular shape that is obtained by symmetrically cutting the existing integrated inner bend portion along the direction (ED) that divides the corner portion equally.

[0343] The inner first half-bent portion (3b3') of the above-mentioned triangular shape can be bonded to the side of the inner first fixed portion (3b1) by the first bonding portion (3b6) with the side perpendicular to the corner connecting wall (42b) of the secondary wall (4).

[0344] In addition, the inner second half-bent portion (3b3") of the triangular shape can be bonded to the side of the inner second fixed portion (3b2) by the second bonding portion (3b7) with the side perpendicular to the corner connecting wall (42b) of the secondary wall (4).

[0345] The assembly process of the upper block (UB) of the above-described embodiment is as follows.

[0346] First, each of the inner first fixing part (3b1), inner second fixing part (3b2), inner first half-bent part (3b3'), and inner second half-bent part (3b3"), which are separated into four pieces, are prepared.

[0347] The inner first fixed portion (3b1) and the inner first half-bent portion (3b3') are bonded together using the first bonding portion (3b6).

[0348] The inner second fixed portion (3b2) and the inner second half-bent portion (3b3") are bonded together using the second bonding portion (3b7).

[0349] The inner first half-bent portion (3b3') and the inner first fixed portion (3b1) bonded together are bonded together to the secondary barrier (4) using an adhesive (10).

[0350] The inner second half-bent portion (3b3") and the inner second fixed portion (3b2) bonded together are bonded to the secondary barrier (4) using an adhesive (10).

[0351] The assembly is completed by inserting and installing the corner first inner packing material (3b8) into the space created between the inner first half-bent portion (3b3') and the inner second half-bent portion (3b3") by bonding to the secondary barrier (4).

[0352] As described above, the corner first insulation wall (3b) of the present embodiment can be assembled and installed at the corner portion in a state where the inner first and second half-bent portions (3b3', 3b3") are bonded to the inner first and second fixing portions (3b1, 3b2) by the first and second bonding portions (3b6, 3b7). At this time, the outer first plywood (53b) of the inner first and second fixing portions (3b1, 3b2) can be fixed to the corner connecting wall (42b) of the secondary barrier (4) by an adhesive (10), and the bottom of the inner first and second half-bent portions (3b3', 3b3") that are horizontal to the corner connecting wall (42b) is placed in a non-adhesive state with respect to the corner connecting wall (42b).

[0353] In the assembled state as described above, a space is inevitably created between the inclined surface of the inner first half-bent portion (3b3') and the inclined surface of the inner second half-bent portion (3b3"), which are opposite each other. In order to prevent heat convection occurring through this space, the corner first insulation wall (3b) of the present embodiment may further include a corner first inner packing material (3b8) that seals the space between the inner first and second half-bent portions (3b3', 3b3").

[0354] The first inner corner packing material (3b8) can be formed of a vacuum insulation material using glass wool as its main raw material.

[0355] In addition, the corner first inner packing material (3b8) can be formed to have a (+) tolerance so that the space can be completely sealed when inserted into the space between the first and second inner half-bent portions (3b3', 3b3").

[0356] In this embodiment, the outer primary plywood (53b) of the inner first and second fixing portions (3b1, 3b2) must be in a bonded state with the corner connecting barrier (42b) of the secondary barrier (4), and the bottom surface of the inner first and second half-bent portions (3b3', 3b3") must be in a non-bonded state with the corner connecting barrier (42b). In order to secure sufficient bonding strength by the adhesive (10) in the bonded area while preventing the adhesive (10) from spreading to the non-bonded area, it is necessary to provide a means for confirming the squeeze-out of the adhesive (10).

[0357] In this embodiment, a chamfer (CF) can be formed at the right-angled corner portion where the side and bottom of the inner first and second half-bend portions (3b3', 3b3") meet as a means of checking squeeze-out.

[0358] As shown in Fig. 19, this chamfer (CF) forms a space on the side of the outer primary plywood (53b) of the inner first and second fixing members (3b1, 3b2) when the corner primary insulation wall (3b) is installed in the corner portion, thereby making it possible to visually confirm that the adhesive (10) is squeezed out.

[0359] The barrier fixing member (21b) can be installed on the upper part of the corner first insulation wall (3b) made of metal.

[0360] As shown in FIGS. 18 and 19, the barrier fixing member (21b) is fixedly installed on the inner primary plywood (31b) forming the inner first fixing member (3b1) and the inner second fixing member (3b2) after the upper block (UB) composed of the first to fourth unit upper blocks (UB1, UB2, UB3, UB4) is bonded along the edge of the corner portion to the lower block (LB). The inner first fixing member (3b1) and the inner second fixing member (3b2) can be fixed.

[0361] The barrier fixing member (21b) can be independently installed on the upper portion of each of the first to fourth unit upper blocks (UB1, UB2, UB3, UB4).

[0362] Through this, the present embodiment configures the inner bend (3b3) of the corner first insulation wall (3b) with an inner first half bend (3b3') bonded to the inner first fixing part (3b1) and an inner second half bend (3b3') bonded to the inner second fixing part (3b2), so that even if the inner first and second half bends (3b3', 3b3") expand or contract, the heat convection path between the inner first fixing part (3b1) and the inner first half bend (3b3') and between the inner second fixing part (3b2) and the inner second half bend (3b3") can be blocked, thereby preventing the heat convection phenomenon in the inner bend (3b3).

[0363] In addition, in this embodiment, by finishing the space between the first and second inner half-bends (3b3', 3b3") with a corner first inner packing material (3b8) having a (+) tolerance, even if the first and second inner half-bends (3b3', 3b3") expand or contract, the heat convection path between the first and second inner half-bends (3b3', 3b3") can be blocked, thereby preventing the heat convection phenomenon in the inner bend (3b3).

[0364] In addition, in this embodiment, by forming a chamfer (CF) at the right-angled corner portion where the side and bottom of the inner first and second half-bent portions (3b3', 3b3") meet, when the outer first plywood (53b) of the inner first and second fixed portions (3b1, 3b2) is bonded to the corner connecting barrier (42b) of the secondary barrier (4) with an adhesive (10), it is possible to directly visually confirm that the adhesive (10) in the bonding area is squeezed out to the non-bonding area, thereby preventing a bonding failure.

[0365] The upper connecting block (UBB) of the present embodiment can be bonded to the upper surface of the adjacent lower blocks (LB) to connect the lower blocks (LB). The upper connecting block (UBB) can be installed in the space exposed between the upper block (UB) formed by the first to fourth unit upper blocks (UB1, UB2, UB3, UB4) being arranged adjacent to each other and in parallel, and the upper block (UB) arranged adjacent thereto.

[0366] The upper connecting block (UBB) may be formed of a corner connecting insulation wall (34b) arranged on the outside of the barrier fixing member (21b), as shown in FIG. 18 and FIG. 22.

[0367] The corner connecting insulation wall (34b) of the upper connecting block (UBB) is designed to withstand impact from the outside or impact due to liquefied gas sloshing from the inside while blocking heat intrusion from the outside together with the corner primary insulation wall (3b), and can be installed between the barrier fixing member (21b) and the corner connecting insulation wall (42b).

[0368] In the above, the corner connecting insulation wall (34b) is provided on the inner side of the first side and the second side, and may include a corner first connecting fixing part (34b1) and a corner second connecting fixing part (34b2) configured in a structure in which a corner first connecting plywood (342b), a corner connecting insulation material (341b), and a corner second connecting plywood (343b) are sequentially laminated on the outer side of the barrier fixing part (21b). The corner first connecting fixing part (34b1) and the corner second connecting fixing part (34b2) may be provided symmetrically based on a direction (ED) that equally divides the corner portion.

[0369] In addition, the corner connecting insulation wall (34b) is installed in the corner space between the first corner connecting fixing part (34b1) and the second corner connecting fixing part (34b2), and may include a corner connecting bending part (34b3) made of insulating material.

[0370] The corner connecting bend (34b3) of the present embodiment, as illustrated in FIG. 22, may be formed by dividing into a first corner half bend (34b3') and a second corner half bend (34b3"), unlike the existing integrated inner bend.

[0371] The corner first half-bend portion (34b3') can be bonded to the side of the corner first connection fixing portion (34b1) by the first bonding portion (34b6) on a side perpendicular to the corner connection barrier (42b) of the secondary barrier (4).

[0372] In addition, the side of the second half-bent corner (34b3"), which is perpendicular to the corner connecting wall (42b) of the secondary barrier (4), can be bonded to the side of the second connecting fixing part (34b2) by the second bonding part (34b7).

[0373] The corner connecting insulation wall (34b) of the present embodiment may further include a corner second inner packing material (34b8) that seals the space between the first and second corner half-bent portions (34b3', 34b3").

[0374] Each of the corner first half-bent portion (34b3'), the corner second half-bent portion (34b3"), and the corner second inner packing material (34b8) of the upper connecting block (UBB) described above may be structurally identical or similar to each of the inner first half-bent portion (3b3'), the inner second half-bent portion (3b3"), and the corner first inner packing material (3b8) of the upper block (UB) described above, with only the drawing symbols and names being different, and thus, a detailed description thereof is omitted here to avoid redundant description.

[0375] FIG. 23 is a front view of a part of a corner portion for explaining a liquefied gas storage tank according to a tenth embodiment of the present invention, FIG. 24 is an exploded perspective view of a part of a corner portion for explaining a liquefied gas storage tank according to a tenth embodiment of the present invention, FIG. 25 is a front view for explaining the integrated upper block of FIG. 23, FIG. 26 is a front view for explaining another embodiment of the integrated upper block of FIG. 25, FIG. 27 is a side view of the integrated upper block of FIG. 25, FIG. 28 is a cross-sectional view taken along line A-A' of FIG. 25, FIG. 29 is a perspective view for explaining the upper connection block of FIG. 23, FIG. 30 is a front view for explaining the upper connection block of FIG. 23, FIG. 31 is a cross-sectional view taken along line B-B' of FIG. 30, and FIG. 32 is a cross-sectional view for explaining another embodiment of the integrated upper block of FIG. 25, and FIG. 33 is an exploded view of the integrated upper block of FIG. 32, and FIGS. 34 to 37 are drawings for comparing and explaining the temperature of the convection path and the secondary barrier that vary depending on the structure of the corner primary insulation wall and the corner connecting insulation wall in the liquefied gas storage tank according to the tenth embodiment of the present invention and the liquefied gas storage tank according to the comparative example.

[0376] As illustrated in FIGS. 23 and 24, the corner portion of the liquefied gas storage tank (1) according to the tenth embodiment of the present invention may be formed by a combination of a plurality of corner blocks (CB). The primary structure of the corner block (CB) may include a lower block (LB) fixed to the hull (7) and formed of a single board, an integrated upper block (UUB) bonded onto the lower block (LB) and formed of a single board having a width narrower than the front-rear, left-right, and right widths of the lower block (LB), and an upper connection block (UBB) bonded to a secondary barrier (4) exposed between the integrated upper blocks (UUB) and connecting the lower blocks (LB) arranged adjacently.

[0377] The corner block (CB) of this embodiment will be described in detail below, dividing it into a lower block (LB), an integrated upper block (UUB), and an upper connecting block (UBB). However, this embodiment may have the same or similar configuration as the ninth embodiment described above or the first to eighth embodiments described above, and in such cases, a detailed description will be omitted to avoid redundant explanation.

[0378] As illustrated in FIG. 23, the lower block (LB) may have an integrated upper block (UUB) and an upper connecting block (UBB) installed on the upper surface, and may be composed of a corner secondary barrier (41b) bonded to the lower surface of the integrated upper block (UUB), a corner connecting barrier (42b) bonded to the lower surface of the upper connecting block (UBB) connecting the adjacent corner secondary barrier (41b) that is exposed to the outside when the integrated upper block (UUB) is not installed when the lower block (LB) is placed adjacent to it, and a corner secondary insulation wall (5b) including an inner secondary plywood (51b), a corner secondary insulation material (52b), and an outer secondary plywood (53b).

[0379] The sub-block (LB) of this embodiment may be identical or similar to the configuration according to at least one of the first to ninth embodiments described above, and thus, a detailed description thereof is omitted here to avoid redundant description.

[0380] The integrated upper block (UUB) is bonded onto the lower block (LB) and may be formed of a single board having a width narrower than the front-rear, left-right, and right width of the lower block (LB).

[0381] Specifically, the integrated upper block (UUB) can be formed as a single board by integrating multiple unit upper blocks, unlike the existing upper block in which multiple unit upper blocks are arranged in parallel and adjacent to each other. Here, the existing upper block can be formed as the upper block (UB) of the ninth embodiment described above in which four first to fourth unit upper blocks (UB1, UB2, UB3, UB4) are arranged in parallel and adjacent to each other, and the integrated upper block (UUB) of the present embodiment can be formed as a single board having the same width as the front-back, left-right, and right width of the existing upper block (UB) in which the first to fourth unit upper blocks (UB1, UB2, UB3, UB4) are arranged in parallel and adjacent to each other.

[0382] In this embodiment, the integrated upper block (UUB) is described as being formed with the integrated size of four first to fourth unit upper blocks (UB1, UB2, UB3, UB4), but it is not limited thereto and it is obvious that at least two or more unit upper blocks may be formed with the integrated size.

[0383] The above-described integrated upper block (UUB) may be formed of a corner primary insulation wall (3b) including an inner first fixing unit (3b1) and an inner second fixing unit (3b2) which are formed of a single board structure in which one inner primary plywood (31b), one corner primary insulation material (32b), and one outer primary plywood (33b) are sequentially laminated on the outside of a barrier fixing unit (21b) composed of a plurality of unit barrier fixing units (21b1, 21b2, 21b3, 21b4), as illustrated in FIGS. 23, 24, 25, 26, and 27. The inner first fixing unit (3b1) and the inner second fixing unit (3b2) may be provided symmetrically with respect to a direction (ED) that equally divides the corner portion.

[0384] The first and second inner fixing members (3b1, 3b2) configured with the above-described single board structure can be fixed by a plurality of unit barrier fixing members (21b1, 21b2, 21b3, 21b4), as will be described later.

[0385] Through this, the present embodiment configures an integrated upper block (UUB) in which a plurality of unit upper blocks (UB1, UB2, UB3, UB4) are integrated into one, compared to an existing upper block (UB) in which a plurality of unit upper blocks (UB1, UB2, UB3, UB4) are arranged in parallel and adjacent to each other, thereby omitting the thermal convection path that occurs between the existing unit upper blocks (UB1, UB2, UB3, UB4), thereby reducing the thermal convection phenomenon.

[0386] The above-mentioned corner first insulation wall (3b) is installed in the corner space between the inner first fixing part (3b1) and the inner second fixing part (3b2), and may include an inner bending part (3b3) made of insulating material.

[0387] The inner bending portion (3b3) of the present embodiment may have a size reduced to about half the size of the inner first and second fixing portions (3b1, 3b2) of the corner first insulation wall (3b), as shown in FIGS. 25, 27, and 28, and may have a symmetrical shape based on the direction (ED) that divides the corner portion equally.

[0388] Hereinafter, the inner bending portion (3b3) with a reduced size is described as being applied to an integrated upper block (UUB) in which a plurality of unit upper blocks (UB1, UB2, UB3, UB4) are integrated into one, but it is not limited thereto and can of course be applied to an existing upper block (UB) in which a plurality of unit upper blocks (UB1, UB2, UB3, UB4) are arranged in parallel and adjacent to each other.

[0389] Specifically, the inner bending portion (3b3) with a reduced size may have a height of the two sides perpendicular to the corner connecting wall (42b) of the secondary wall (4) on the inner side of the first and second surfaces, which is about half of the total height of each of the inner first and second fixing portions (3b1, 3b2), for example, a height reduced to a size within a range of 40% to 60% of the total height of the inner first and second fixing portions (3b1, 3b2).

[0390] As described above, the side shapes of the first and second inner fixing members (3b1, 3b2) may change as the size of the inner bending member (3b3) is reduced.

[0391] Specifically, the first and second inner fixing portions (3b1, 3b2) of the present embodiment are provided symmetrically with respect to the direction (ED) that divides the corner portion equally, and the first side that is in close contact with both sides of the inner folded portion (3b3) of which size is reduced is perpendicular to the corner connecting wall (42b) of the secondary barrier (4), and the second side that extends inward (toward the storage space) from the first side that is perpendicular can extend in the same direction as the division direction (ED).

[0392] As described above, the corner first insulation wall (3b) of the present embodiment can be assembled by fixing the outer first plywood (53b) of the inner first and second fixing parts (3b1, 3b2) to the corner connecting wall (42b) of the second barrier wall (4) by adhesive (10) while the second side of the inner first fixing part (3b1) and the second side of the inner second fixing part (3b2) are facing each other, and inserting and installing a reduced-size inner bending part (3b3) into the corner space created by the inner first and second fixing parts (3b1, 3b2).

[0393] In the assembled state as described above, a space is inevitably created between the first side of the inner first and second fixing parts (3b1, 3b2) that are in close contact with both sides of the inner bending part (3b3) whose size is reduced, and the second side of the inner first and second fixing parts (3b1, 3b2) that face each other. In order to prevent a heat convection phenomenon occurring through this space, the corner first insulation wall (3b) of the present embodiment may further include a corner inner packing material (3b8) that seals the space between the second sides of the inner first and second fixing parts (3b1, 3b2).

[0394] The corner inner packing material (3b8) can be formed of a vacuum insulation material using glass wool as its main raw material.

[0395] In addition, the corner inner packing material (3b8) can be formed to have a (+) tolerance so that the space can be completely sealed when inserted into the space between the second side surfaces of the inner first and second fixing members (3b1, 3b2).

[0396] The above-mentioned inner corner packing material (3b8) can be configured to be inserted to a certain depth into the inner folded portion (3b3) whose size has been reduced, as shown in FIGS. 32 and 33.

[0397] In order for the corner inner packing material (3b8) to be inserted into the inner folded portion (3b3) to a certain depth, an insertion groove (SH) of a certain depth can be formed in the inner folded portion (3b3) of this embodiment in the same direction as the splitting direction (ED) at the point where both sides meet.

[0398] The insertion groove (SH) is formed in a direction corresponding to the corner of the storage tank, and its depth may be less than half the thickness of the inner bend (3b3), but is not limited thereto.

[0399] Through this, the present embodiment can not only reduce the space where heat convection occurs (the non-bonded area between the inner bend and the secondary barrier at the corner) by reducing the size of the inner bend (3b3), but also form the corner inner packing material (3b8) between the second sides of the inner first and second fixing parts (3b1, 3b2) while the first and second sides of the inner first and second fixing parts (3b1, 3b2), which can be considered as heat convection paths, so that the reduction area due to temperature change is reduced compared to the existing inner bend formed at the same height as the inner first and second fixing parts (3b1, 3b2), thereby reducing the heat convection phenomenon.

[0400] In addition, the present embodiment can further reduce the heat convection phenomenon in the inner bend (3b3) by inserting the inner corner packing material (3b8) into the inner bend (3b3) to a certain depth.

[0401] The inner bending portion (3b3) with a reduced size according to the present embodiment may be provided with a first protrusion (PT1) on both sides, as shown in FIG. 24 and FIG. 27.

[0402] The first protrusion (PT1) can extend a certain length outside the space from the inner bending portion (3b3) inserted into the corner space portion created by the inner first and second fixing portions (3b1, 3b2).

[0403] The first protrusion (PT1) has a cross-sectional shape similar to that of the inner fold (3b3), but the curved portion that comes into contact with the corner connecting wall (42b) of the secondary barrier (4) extends along the same line from the curved portion of the inner fold (3b3), and the two side surfaces perpendicular to the corner connecting wall (42b) of the secondary barrier (4) can be extended to have a first step (ST1) with the two side surfaces of the inner fold (3b3).

[0404] That is, the first protrusion (PT1) of the present embodiment is formed to have a first step (ST1) with respect to the inner bend (3b3) by being smaller than the size of the inner bend (3b3), so that the heat convection path forms a curved path by the first step (ST1), thereby preventing the heat convection phenomenon, which will be described later.

[0405] The integrated upper block (UUB) of the present embodiment may include a plurality of upper slits (SL1) formed at a certain depth at the top to prepare for shrinkage and expansion stress of the corner first insulation wall (3b) having a single board structure, as shown in FIGS. 23, 24, and 25.

[0406] The upper slit (SL1) may have a depth less than half the thickness of the corner first insulation wall (3b) forming the integrated upper block (UUB), for example, a depth within the range of 30% to 50%, so as to maximize alleviation of temperature-induced shrinkage or expansion stress applied to the corner first insulation wall (3b).

[0407] It is preferable that the upper slit (SL1) be formed through the inner primary plywood (31b), which is the upper layer of the corner primary insulation wall (3b), and at least to a part of the middle layer, the corner primary insulation material (32b), to prepare for shrinkage or expansion stress of the corner primary insulation material (32b).

[0408] The above-mentioned upper slit (SL1) is formed with a depth corresponding to a thickness less than half of the thickness of the corner first insulation wall (3b), so that not only can the shrinkage or expansion stress due to temperature applied to the corner first insulation wall (3b) be alleviated to the greatest extent possible, but also the heat convection space can be reduced, and cold air can be prevented from being transmitted from the corner block (CB) to the flat block by the insulation material (not shown) constructed between the flat first insulation wall (3a) of the flat block illustrated in FIG. 1 and the corner first insulation wall (3b) of the corner block (CB) of the present embodiment.

[0409] The upper slit (SL1) of the present embodiment can be formed at a corresponding position between a plurality of unit barrier fixing members (21b1, 21b2, 21b3, 21b4) installed on the upper surface of the integrated upper block (UUB) of each of the plurality of unit upper blocks (UB1, UB2, UB3, UB4) forming the existing upper block (UB), and it is to be understood that the upper slit is not limited to this position and can be formed at any position spaced apart by a certain distance.

[0410] In addition, the integrated upper block (UUB) of the present embodiment may include a plurality of lower slits (SL2) formed at a certain depth at the bottom to prepare for shrinkage and expansion stress of the corner first insulation wall (3b) having a single-board structure, as illustrated in FIG. 26.

[0411] The lower slit (SL2) may have a depth less than half the thickness of the corner primary insulation wall (3b) forming the integrated upper block (UUB), for example, a depth within the range of 30% to 50%, so as to maximize alleviation of temperature-induced shrinkage or expansion stress applied to the corner primary insulation wall (3b).

[0412] It is preferable that the lower slit (SL2) be formed through the outer primary plywood (53b), which is the lower layer of the corner primary insulation wall (3b), and extend to at least a portion of the middle layer, the corner primary insulation material (32b), to prepare for shrinkage or expansion stress of the corner primary insulation material (32b).

[0413] The lower slit (SL2) of the present embodiment may be formed at a position that is intersected with the upper slit (SL1), but is not limited to this position and may be formed at any position spaced a certain distance apart.

[0414] Through this, the present embodiment forms an upper slit (SL1) of a certain depth on the upper side of the integrated upper block (UUB), and forms a lower slit (SL2) of a certain depth on the lower side of the integrated upper block (UUB) so as to be staggered from the upper slit (SL1), thereby enabling the contraction and expansion stress of the integrated upper block (UUB) to be alleviated by the upper and lower slits (SL1, SL2).

[0415] In addition, the integrated upper block (UUB) of the present embodiment is bonded to the upper portion of the corner secondary barrier (4) with an adhesive (10). Since the bonding area is wider than that of a conventional upper block, a squeeze-out confirmation means needs to be provided to confirm the squeeze-out of the adhesive (10) so as to secure sufficient adhesive strength by the adhesive (10) in the bonding area while preventing the adhesive (10) from spreading to the non-bonding area.

[0416] In this embodiment, as shown in FIGS. 24, 25, and 26, when bonding the outer primary plywood (53b) onto the secondary barrier (4) with an adhesive (10), a plurality of first grooves (GV1) can be formed in the outer primary plywood (53b) of the integrated upper block (UUB) as a means of ensuring that the adhesive (10) is squeezed out into the non-bonded area and preventing the adhesive (10) from excessively penetrating into the non-bonded area.

[0417] In the above, the non-adhesive area can be set in multiple numbers in the middle portion, including the edge portions on both sides of the outer primary plywood (53b).

[0418] Each of the plurality of non-bonded areas can be set at a certain interval and width in a direction perpendicular to the corner of the storage tank. For example, the plurality of non-bonded areas can be set at a position corresponding to between the plurality of unit barrier fixing members (21b1, 21b2, 21b3, 21b4) installed on the upper surface of the integrated upper block (UUB) of each of the plurality of unit upper blocks (UB1, UB2, UB3, UB4) forming the existing upper block (UB), and of course, the non-bonded areas are not limited to these positions and can be set at any position spaced apart by a certain distance.

[0419] In this embodiment, the reason why multiple non-bonded areas are set in the outer primary plywood (53b) bonded to the secondary barrier (4) by the adhesive (10) is that since the outer primary plywood (53b) has a larger area than before, bonding partially rather than bonding all parts with the adhesive (10) can reduce the bonding failure rate of the adhesive (10).

[0420] A plurality of first grooves (GV1) can be formed in a direction perpendicular to the corner of the storage tank on the outer primary plywood (53b).

[0421] Specifically, a plurality of first grooves (GV1) can be formed along the boundary portions on both sides of each of the plurality of non-adhesive areas.

[0422] When the above-described plurality of non-adhesive areas are set to corresponding positions between the plurality of unit barrier fixing members (21b1, 21b2, 21b3, 21b4), the plurality of first grooves (GV1) are arranged to be staggered with respect to the plurality of upper slits (SL1), which may be advantageous in terms of mechanical strength compared to being arranged on the same line.

[0423] On the integrated upper block (UUB) configured as described above, a barrier fixing member (21b) composed of a plurality of unit barrier fixing members (21b1, 21b2, 21b3, 21b4) can be installed, as illustrated in FIGS. 23, 24, 25, and 26. Hereinafter, the barrier fixing member (21b) is described as being composed of four first, second, third, and fourth unit barrier fixing members (21b1, 21b2, 21b3, 21b4), but is not limited thereto.

[0424] Each of the first, second, third, and fourth unit barrier fixing members (21b1, 21b2, 21b3, 21b4) can be installed adjacent to each other and parallel to the upper portion of the corner first insulation wall (3b) forming an integrated upper block (UUB) made of metal, and can be bent at a predetermined angle on the inner side of the first and second sides, for example, can be bent at the same angle as the angle formed by the first and second sides at different angles forming a storage space for accommodating liquefied gas.

[0425] In this embodiment, the first, second, third, and fourth unit barrier fixing members (21b1, 21b2, 21b3, 21b4) can be installed on one integrated upper block (UUB).

[0426] That is, since the integrated upper block (UUB) of the present embodiment is configured as a single board structure in which one inner primary plywood (31b), one corner primary insulation material (32b), and one outer primary plywood (33b) are sequentially laminated, the first, second, third, and fourth unit barrier fixing members (21b1, 21b2, 21b3, 21b4) are installed in parallel on one inner primary plywood (31b), whereas in the case of the existing upper block (UB) composed of a plurality of unit upper blocks (UB1, UB2, UB3, UB4), each unit barrier fixing member is installed independently for each unit upper block, which is structurally different.

[0427] Each of the above-mentioned first, second, third, and fourth unit barrier fixing members (21b1, 21b2, 21b3, 21b4) can be arranged at intervals considering the shrinkage and expansion stress of the corner first insulation wall (3b), and the number of units arranged can vary depending on the size of the integrated upper block (UUB) made of a single board.

[0428] In addition, the first, second, third, and fourth unit barrier fixing members (21b1, 21b2, 21b3, 21b4) can be linked to the contraction or expansion of the corner first insulation material (32b) when the plurality of upper slits (SL1) described above are formed at corresponding positions between the first, second, third, and fourth unit barrier fixing members (21b1, 21b2, 21b3, 21b4).

[0429] In general, the barrier fixing member is provided with a reinforcing member such as a stiffener along the edge of the back surface so that the upper block (UB) can be firmly fixed (tightness) by holding the upper part of the corner primary insulation wall. However, in the case of the first, second, third, and fourth unit barrier fixing members (21b1, 21b2, 21b3, 21b4) according to the present embodiment, since they are placed on one inner primary plywood (31b) whose upper part is flat, the back surface cannot but be flat.

[0430] Accordingly, each of the first, second, third, and fourth unit barrier fixing members (21b1, 21b2, 21b3, 21b4) can be installed on the upper portion of the corner first insulation wall (3b) using a plurality of connecting members (211b) provided on the back surface, as illustrated in Fig. 28. The connecting members (211b) can be formed of stud bolts and nuts.

[0431] Hereinafter, the assembly process of fixing the inner first fixing part (3b1) and the inner second fixing part (3b2) formed as an integrated upper block (UUB) using the first, second, third, and fourth unit barrier fixing parts (21b1, 21b2, 21b3, 21b4) will be described. Since the first, second, third, and fourth unit barrier fixing parts (21b1, 21b2, 21b3, 21b4) are each configured identically, the first unit barrier fixing part (21b1) will be described below as an example.

[0432] The first assembly process is to bond the outer primary plywood (33b) of the inner first and second fixing parts (3b1, 3b2) having a plurality of first holes (81) to the outer surface of the corner primary insulation material (32b) of the inner first and second fixing parts (3b1, 3b2) having a plurality of second holes (82), and to bond the inner primary plywood (31b) of the inner first and second fixing parts (3b1, 3b2) having a plurality of third holes (83) to the inner surface of the corner primary insulation material (32b) having a plurality of second holes (82), thereby completing the assembly of the inner first and second fixing parts (3b1, 3b2), and to insert the corner inner packing material (3b8) into the space between the inner first and second fixing parts (3b1, 3b2). Here, in the case of the inner corner packing material (3b8), the (+) tolerance can be maintained by fixing it using the connecting member (211b) while it is installed by pressing between the inner first and second fixing parts (3b1, 3b2) in the secondary assembly process described later.

[0433] Here, the first, second, and third holes (81, 82, 83) can be formed on an extension line of a position corresponding to each of a plurality of connecting members (211b) provided in the first unit barrier fixing member (21b1). The first and second holes (81, 82) have the same size and have a hole shape that is connected by bonding the outer primary plywood (33b) and the corner primary insulation material (32b), and can be sealed by inserting a foam plug (9) into this connecting hole, and the third hole (83) can be formed in a size into which the connecting member (211b) can be inserted.

[0434] In the second assembly process, while the outer primary plywood (33b), the corner primary insulation material (32b), and the inner primary plywood (31b) are bonded together, the first unit barrier fixing member (21b1) is pressed against the upper surface of the inner primary plywood (31b) so that a plurality of joining members (211b) are inserted into a plurality of third holes (83) formed in the inner primary plywood (31b).

[0435] The third assembly process is to fix the first unit barrier fixing member (21b1) to the upper surface of the inner primary plywood (31b) by bolting the connecting member (211b) through the connecting hole formed by the plurality of first and second holes (81, 82).

[0436] In the fourth assembly process, while the first unit barrier fixing member (21b1) is fixed to the inner primary plywood (31b), a foam plug (9) is inserted into a communication hole formed by a plurality of first and second holes (81, 82). Here, the foam plug (9) has a size corresponding to the communication hole and may be made of the same or similar material as the corner primary insulation material (32b).

[0437] Afterwards, the assembly process of the integrated upper block (UUB) is completed by inserting a reduced-size inner bending part (3b3) into the corner space between the inner first fixing part (3b1) and the inner second fixing part (3b2) formed by the bonded structure of the outer primary plywood (33b), the corner primary insulation material (32b), and the inner primary plywood (31b).

[0438] As described above, the integrated upper block (UUB) of the present embodiment has a structure in which an outer primary plywood (33b) having a plurality of first holes (81), a corner primary insulation material (32b) having a plurality of second holes (82), and an inner primary plywood (31b) having a plurality of third holes (83) are first bonded together, and then the first, second, third, and fourth unit barrier fixing members (21b1, 21b2, 21b3, 21b4) can be bolted together.

[0439] In this embodiment, the inner bending part (3b3) with a reduced size is described as being installed at the end of the assembly process, but it is of course possible to install it between the first and second assembly processes.

[0440] As shown in Fig. 28, a corner outer packing material (5b5) can be inserted and installed in the space between the outer first fixing part (5b1) and the outer second fixing part (5b2), and can be finished with a plywood filler (PF) of a certain length.

[0441] The upper connecting block (UBB) of the present embodiment can be bonded to the upper surface of the adjacent lower block (LB) to connect the lower blocks (LB), as illustrated in FIG. 23.

[0442] The upper connecting block (UBB) can be installed in the space exposed between the integrated upper block (UUB) having a single board structure in which the existing first to fourth unit upper blocks (UB1, UB2, UB3, UB4) are integrated, and the integrated upper block (UUB) having the same structure and positioned adjacent to it.

[0443] The upper connecting block (UBB) may be formed of a corner connecting insulation wall (34b) placed on the outside of the barrier fixing member (21b).

[0444] The corner connecting insulation wall (34b) of the upper connecting block (UBB) is designed to withstand impact from the outside or impact due to liquefied gas sloshing from the inside while blocking heat intrusion from the outside together with the corner primary insulation wall (3b) of the integrated upper block (UUB), and can be installed between the barrier fixing member (21b) and the corner connecting insulation wall (42b).

[0445] These corner connecting insulation walls (34b), as shown in FIGS. 29 and 30, are provided on the inner sides of the first and second sides, respectively, and may include a corner first connecting fixing member (34b1) and a corner second connecting fixing member (34b2) configured in a structure in which a corner first connecting plywood (342b), a corner connecting insulation material (341b), and a corner second connecting plywood (343b) are sequentially laminated on the outer side of the barrier fixing member (21b).

[0446] In this embodiment, the corner connecting insulation wall (34b) of the upper connecting block (UBB) may be structurally identical or similar to the corner primary insulation wall (3b) of the integrated upper block (UUB) described above, with only the drawing symbol and size being different.

[0447] The above-mentioned corner connecting insulation wall (34b) is installed in the corner space between the first corner connecting fixing part (34b1) and the second corner connecting fixing part (34b2), and may include a corner connecting bending part (34b3) made of insulating material.

[0448] The corner connecting bend (34b3) of the present embodiment may have a shape identical to or similar to the inner bend (3b3) of the corner first insulation wall (3b), as illustrated in FIGS. 29 and 30, and accordingly, the side shapes of the first corner connecting fixing part (34b1) and the second corner connecting fixing part (34b2) may also be identical to or similar to the side shapes of the inner first and second fixing parts (3b1, 3b2). A corner connecting bend (34b3) having a reduced size may be inserted and installed in the corner space created by the first and second corner connecting fixing parts (34b1, 34b2) having the above-described side shapes.

[0449] That is, the corner connecting bend (34b3) has a height that is reduced compared to the total height of each of the first and second connecting fixing parts (34b1, 34b2) of the corners, with respect to the secondary barrier (4), for example, the height of each of the two sides of the corner connecting bend (34b3) may have a height within a range of 40% to 60% of the total height of each of the first and second connecting fixing parts (34b1, 34b2).

[0450] In addition, a corner inner packing material (34b4) is inserted and installed in the space between the first and second corner connecting fixing parts (34b1, 34b2). The corner inner packing material (34b4) may be the same as or similar to the corner inner packing material (3b8) inserted and installed in the space between the first and second inner fixing parts (3b1, 3b2).

[0451] That is, the upper connection block (UBB) is different from the integrated upper block (UUB) only in the size of the corner side of the storage tank and the horizontal direction, but the corner connection insulation wall (34b), the corner connection bend (34b3), and the corner inner packing material (34b4) may be the same as or similar to the corner primary insulation wall (3b), the inner bend (3b3), and the corner inner packing material (3b8) of the integrated upper block (UUB), so a detailed description is omitted here to avoid redundant explanation.

[0452] Through this, the present embodiment can reduce the space where heat convection occurs (the non-bonded area between the corner connecting bend and the secondary barrier at the corner) by reducing the size of the corner connecting bend (34b3), and by forming the corner inner packing material (34b4) in the space between the first and second corner connecting fixing parts (34b1, 34b2), which can be considered a heat convection path, the area affected by temperature change is reduced compared to the existing corner connecting bend formed at the same height as the first and second corner connecting fixing parts (34b1, 34b2), thereby reducing the heat convection phenomenon.

[0453] In addition, the present embodiment can further reduce the heat convection phenomenon at the corner connecting bend (34b3) by having the corner inner packing material (34b4) inserted into the corner connecting bend (34b3) to a certain depth.

[0454] The corner connecting bending portion (34b3) with a reduced size according to the present embodiment may be provided with a second protrusion (PT2) on both sides, as shown in FIGS. 29 and 30.

[0455] The second protrusion (PT2) can extend a certain length outside the space from the corner connecting bending portion (34b3) inserted into the corner space portion created by the first and second corner connecting fixing portions (34b1, 34b2).

[0456] The second protrusion (PT2) has a cross-sectional shape similar to that of the corner connecting portion (34b3), but the curved portion that comes into contact with the corner connecting portion (42b) of the secondary barrier (4) extends in the same line from the curved portion of the corner connecting portion (34b3), and the two side surfaces perpendicular to the corner connecting portion (42b) of the secondary barrier (4) can be extended to have a second step (ST2) with the two side surfaces of the corner connecting portion (34b3).

[0457] That is, the second protrusion (PT2) of the present embodiment is formed to have a first step (ST1) with respect to the corner connecting bend (34b3) by being smaller than the size of the corner connecting bend (34b3), so that the heat convection path forms a curved path by the second step (ST2), thereby preventing the heat convection phenomenon, which will be described later.

[0458] The second protrusion (PT2) provided in the above-described corner connecting bend (34b3) may be identical to or similar to the first protrusion (PT1) provided in the above-described inner bend (3b3), and as illustrated in FIGS. 23 and 24, when the upper connecting block (UBB) is installed between the adjacent integrated upper blocks (UUB), it comes into contact with the first protrusion (PT1), and a step space may be created between the inner first and second fixing parts (3b1, 3b2) and the corner first and second connecting fixing parts (34b1, 34b2) by the first and second protrusions (PT1, PT2).

[0459] In this embodiment, in order to prevent heat convection from occurring through the step space created by the first and second protrusions (PT1, PT2), the space is finished with a stuffing piece (SP).

[0460] The stuffing piece (SP) can be inserted into the step space created by the second protrusion (PT2) provided in the corner connecting bend (34b3) and the first protrusion (PT1) provided in the inner bend (3b3), as shown in FIGS. 23 and 24.

[0461] The stuffing piece (SP) may have a shape corresponding to the shape of the step space, and may be formed of a material identical or similar to the inner bend (3b3) or the corner connecting bend (34b3), for example, low-density polyurethane foam, or may be formed of a vacuum insulation material using glass wool as the main raw material.

[0462] In addition, the stuffing piece (SP) can be formed to a thickness of 30 mm so as to completely seal the step space created by the first and second protrusions (PT1, PT2) when the step space is, for example, 20 mm.

[0463] When the stuffing piece (SP) is inserted, the heat convection path generated on both sides of the stuffing piece (SP) and the heat convection path generated at the contact point of the first and second protrusions (PT1, PT2) form a curved path.

[0464] Through this, the present embodiment provides a first protrusion (PT1) on a reduced-size inner bend (3b3), provides a second protrusion (PT2) on a reduced-size corner connecting bend (34b3), and closes the step space created by the first and second protrusions (PT1, PT2) with a stuffing piece (SP), so that the heat convection path generated between the integrated upper block (UUB) and the upper connecting block (UBB) forms a curved path by the protruding structure and the stuffing piece (SP), thereby reducing the heat convection phenomenon.

[0465] Meanwhile, when the temperature of the primary barrier (2) is -196 degrees and the temperature of the hull (7) is 10 degrees, the case where the inner bend (3b3) and the corner connecting bend (34b3) of the present embodiment are applied and the case where the inner bend (3b3) and the corner connecting bend (34b3) of the existing size are applied, the results of the CFD analysis showed that in the case of the present embodiment, the heat flux was 8.73 W / ㎡, the average temperature of the secondary barrier (4) was -90.15 degrees, and the average temperature of the hull (7) was 8.79 degrees, while in the case of the existing embodiment, the heat flux was 12.95 W / ㎡, the average temperature of the secondary barrier (4) was -145.19 degrees, and the average temperature of the hull (7) was 8.20 degrees. In terms of this condensation, it was found that the present embodiment was superior to the existing one.

[0466] In addition, the upper connecting block (UBB) of the present embodiment needs to be provided with a squeeze-out confirmation means that can confirm the squeeze-out of the adhesive (10) when bonding the upper portion of the corner secondary barrier (4) with an adhesive (10).

[0467] In this embodiment, as shown in FIGS. 24, 29, and 31, when bonding the corner second connecting plywood (343b) onto the secondary barrier (4) with an adhesive (10), a second groove (GV2) can be formed in the corner second connecting plywood (343b) of the upper connecting block (UBB) as a means of ensuring that the adhesive (10) is squeezed out into the non-bonded area.

[0468] The second groove (GV2) may be formed in a horizontal direction with respect to the corner edge of the storage tank in the corner second connecting plywood (343b), which is an adhesive area, but may be formed in a portion adjacent to the rear edge of the corner second connecting plywood (343b) so that the adhesive (10) can be squeezed out to the corner connecting bend (34b3), which is a non-adhesive area.

[0469] Through this, the present embodiment forms a second groove (GV2) horizontally with the corner edge of the storage tank in the corner second connecting plywood (343b) of the upper connecting block (UBB) connected to the corner connecting barrier (42b), and forms it in a portion adjacent to the rear edge of the corner second connecting plywood (343b), which is the bonding area, so that not only can it be directly confirmed with the naked eye that the adhesive (10) is squeezed out to the corner connecting bend (34b3), which is the non-bonding area, but also, as the adhesive (10) is squeezed out and bonded beyond the second groove (GV2) to the non-bonding area, the non-bonding area of ​​the corner is reduced, thereby preventing the load applied to the secondary barrier (4) from becoming larger, thereby preventing a bonding failure of the upper connecting block (UBB).

[0470] Hereinafter, with reference to FIGS. 34 to 37, the convection path and the resulting temperature difference depending on the structure of the corner block (CB) in the liquefied gas storage tank (1) according to the present embodiment and the liquefied gas storage tank (1') according to the comparative example will be compared and explained. Here, FIG. 34 (a) illustrates the application of the corner block (CB) in the liquefied gas storage tank (1) according to the present embodiment, and FIG. 34 (b) illustrates the application of the corner block (CB) in the liquefied gas storage tank (1') according to the comparative example.

[0471] The liquefied gas storage tank (1') according to the comparative example may be, for example, the liquefied gas storage tank of the aforementioned ninth embodiment illustrated in FIG. 18.

[0472] In the liquefied gas storage tank (1) according to the present embodiment and the liquefied gas storage tank (1') according to the comparative example, the flat primary insulation wall (3a) may have the same or different structure, but below, regardless of the structure of the flat primary insulation wall (3a), the convection path and the resulting temperature difference due to the structural difference of the corner block (CB) will be compared and explained.

[0473] Figures 35 (a) and 36 illustrate the first and second convection paths (CP1, CP2) and the first and second convection blocking paths (CBP1, CBP2) in the liquefied gas storage tank (1) according to the present embodiment.

[0474] The first convection path (CP1) is a path corresponding to the non-bonded area between the inner bend (3b3) formed at half the height of the total height of each of the first and second inner fixing parts (3b1, 3b2) and the secondary barrier (4), and between the corner connecting bend (34b3) formed at half the height of the total height of each of the first and second corner connecting fixing parts (34b1, 34b2) and the secondary barrier (4).

[0475] The second convection path (CP2) is a path corresponding to the upper slit (SL1) formed with a depth corresponding to less than half the thickness of the corner first insulation wall (3b).

[0476] The first convection blocking path (CBP1) is a blocking path corresponding to a stuffing piece (SP) inserted into a step space formed by a first protrusion (PT1) provided in an inner bend (3b3) and a second protrusion (PT2) provided in a corner connecting bend (34b3).

[0477] The second convection blocking path (CBP2) is a blocking path corresponding to the corner inner packing material (3b8, 34b4) inserted into the space between the inner first and second fixing parts (3b1, 3b2) and the corner first and second connecting fixing parts (34b1, 34b2).

[0478] Figure 35 (b) illustrates the third and fourth convection paths (CP3, CP4) in the liquefied gas storage tank (1') according to a comparative example.

[0479] The third convection path (CP3) is a path corresponding to the non-bonded area between the inner bend (3b3) formed with the same height as the total height of each of the first and second inner fixing parts (3b1, 3b2) and the secondary barrier (4), and between the corner connecting bend (34b3) formed with the same height as the total height of each of the first and second corner connecting fixing parts (34b1, 34b2) and the secondary barrier (4).

[0480] As shown in FIGS. 34, 35, and 36, it can be seen that the convection areas of the first and second convection paths (CP1, CP2) of the liquefied gas storage tank (1) of the present embodiment are reduced compared to the third and fourth convection paths (CP3, CP4) of the liquefied gas storage tank (1') of the comparative example.

[0481] In addition, as shown in (b) of FIG. 35, in the case of the liquefied gas storage tank (1') according to the comparative example, convection occurs between the upper primary barrier (2) and the lower secondary barrier (4), but as shown in (a) of FIG. 35, in the case of the liquefied gas storage tank (1) of the present embodiment, convection is blocked by the inner corner packing material (3b8), so that the temperature drop occurs less in the secondary barrier (4) of the liquefied gas storage tank (1) of the present embodiment compared to the liquefied gas storage tank (1') according to the comparative example.

[0482] Due to this difference in convection path, a temperature difference occurs in the secondary barrier (4) of each of the liquefied gas storage tank (1) of the present embodiment and the liquefied gas storage tank (1') of the comparative example, which will be explained with reference to (a), (b), and (c) of FIGS. 36 and 37.

[0483] Temperature measurement conditions were measured by changing the positions of the first, second, and third temperature sensors (TL1, TL2, TL3) under conditions where the temperature of the first barrier (2) was -196 degrees and the temperature of the hull (7) was 10 degrees. Although not shown, temperature sensors were also attached to the same positions in the liquefied gas storage tank (1') of the comparative example to measure the temperature.

[0484] As shown in (a) of Figures 36 and 36, at the location where the first temperature sensor (TL1) is attached, the liquefied gas storage tank (1) of the present embodiment was measured at -43.4 degrees, and the liquefied gas storage tank (1') of the comparative example was measured at -130.1 degrees.

[0485] As shown in (b) of Figures 36 and 36, at the location where the second temperature sensor (TL2) is attached, the liquefied gas storage tank (1) of the present embodiment was measured at -66.5 degrees, and the liquefied gas storage tank (1') of the comparative example was measured at -154.6 degrees.

[0486] As shown in (c) of Figures 36 and 36, at the location where the first temperature sensor (TL1) is attached, the liquefied gas storage tank (1) of the present embodiment was measured at -80.3 degrees, and the liquefied gas storage tank (1') of the comparative example was measured at -164.7 degrees.

[0487] These results can be seen to be due to the convection path of the liquefied gas storage tank (1) of the present embodiment being narrower and reduced compared to the liquefied gas storage tank (1') of the comparative example, as described above.

[0488] The present invention is not limited to the embodiments described above, and may include a combination of the above embodiments or a combination of at least one of the above embodiments and a known technology as another embodiment.

[0489] Although the present invention has been described in detail through specific examples, this is intended to specifically explain the present invention, and the present invention is not limited thereto, and it will be apparent that modifications and improvements can be made by those skilled in the art within the technical spirit of the present invention.

[0490] All simple modifications or changes of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be made clear by the appended claims.

[0491] [Explanation of symbols]

[0492] 1: Liquefied gas storage tank 2: Primary barrier

[0493] 2a: Flat primary barrier 2b: Corner primary barrier

[0494] 21b: Barrier fixing member 21b1: First unit barrier fixing member

[0495] 21b2: Second unit barrier fixing device 21b3: Third unit barrier fixing device

[0496] 21b4: 4th unit barrier fixing member 211b: Joint member

[0497] 3: Primary insulation wall 3a: Flat primary insulation wall

[0498] 31a: Flat primary plywood 32a: Flat primary insulation

[0499] 33a: Flat joint insulation wall 331a: Flat joint plywood

[0500] 332a: Flat joint insulation 3b: Corner primary insulation wall

[0501] 3b1: Medial first fixation part 3b2: Medial second fixation part

[0502] 31b: Inner primary plywood 32b: Corner primary insulation

[0503] 33b: Outer primary plywood 3b12: Inner intermediate fixing part

[0504] 31b12: Inner middle plywood 32b12: Corner middle insulation

[0505] 34b: Corner joint insulation wall 34b1: Corner first joint fixing part

[0506] 34b2: Corner second connection fixing member 341b: Corner connection insulation

[0507] 342b: Corner first connection plywood 343b: Corner second connection plywood

[0508] 34b3: Corner joint bend 34b3': Corner first half bend

[0509] 34b3": Corner second half-bend 34b4: Corner inner packing material

[0510] 3b3: Inner bend 3b3': Inner first half bend

[0511] 3b3": Inner second half-bend 3b31: Insulation

[0512] 3b32: Insulation 3b33: Outer insulation

[0513] 3b34: Inner insulation 3b35: Insulation

[0514] 3b36: Insulation 3b37: Vacuum Insulation Panel

[0515] 3b4: Inner first packing material 3b5: Inner second packing material

[0516] 3b6, 34b6: First bonding section 3b7, 34b7: Second bonding section

[0517] 3b8, 34b8: 1st and 2nd corner inner packing material 4: 2nd barrier

[0518] 41a: Flat secondary barrier 42a: Flat connecting barrier

[0519] 41b: Corner secondary barrier 42b: Corner connecting barrier

[0520] 5: Secondary insulation wall 5a: Flat secondary insulation wall

[0521] 51a: Flat secondary insulation 52a: Flat secondary plywood

[0522] 5b: Corner secondary insulation wall 5b1: Outer first fixed part

[0523] 5b2: Outer second fixing member 51b: Inner second plywood

[0524] 51b1: Perimeter plywood 51b2: Inclined plywood

[0525] 52b: Corner secondary insulation 53b: Outer secondary plywood

[0526] 5b12: Outer mid-fixed part 51b12: Outer mid-plywood

[0527] 52b12: Outer intermediate insulation 53b12: Inner intermediate insulation

[0528] 5b3: Outer bend 5b31: Insulation

[0529] 5b32: Insulation 5b4: Outer packing material

[0530] 5b5: Corner outer packing material 6: Mastic

[0531] 7: Hull 81: First hole

[0532] 82: Hole 2 83: Hole 3

[0533] 9: Foam plug 10: Adhesive

[0534] CB: Corner block CBP1: First convection blocking path

[0535] CBP2: Second convection blocking path CP1: First convection path

[0536] CP2: Second convection path CP3: Third convection path

[0537] CP4: Fourth convection path CF1: First chamber

[0538] CF2: Second chamfer ED: Split direction

[0539] GV1: First groove GV2: Second groove

[0540] LB: Sub-block PF: Plywood filler

[0541] PT1: First protrusion PT2: Second protrusion

[0542] SH: Insertion groove SL1: Upper slit

[0543] SL2: Lower slit SP: Stuffing piece

[0544] UB: Upper block UB1: First unit upper block

[0545] UB2: Upper block of the second unit UB3: Upper block of the third unit

[0546] UB4: Upper block of the fourth unit UBB: Upper connecting block

[0547] UUB: Integrated upper block ST1: First stage

[0548] ST2: Second step SS: Step space

[0549] TL1: First temperature sensor TL2: Second temperature sensor

[0550] TL3: Third temperature sensor

Claims

1. A liquefied gas storage tank including a corner block that is arranged at a corner portion where first and second sides of different angles meet to form a storage space for accommodating liquefied gas. The above corner block is, It is composed of a lower block provided on the inner side of the first and second surfaces and made of a single board, an upper block bonded to the secondary barrier of the lower block, and an upper connecting block bonded to the secondary barrier on the upper surface of the lower block arranged adjacent to each other to connect the lower blocks. The above upper block is, An inner first fixing part and an inner second fixing part, each provided on the inner side of the first side and the second side and bonded to the second barrier, having a structure in which an inner first plywood, a corner first insulation material, and an outer first plywood are laminated; and Including an inner bending part installed in a corner space portion between the inner first fixing part and the inner second fixing part, The above inner bending part is, A liquefied gas storage tank having a height of both sides perpendicular to the secondary barrier that is reduced compared to the total height of each of the first and second inner fixed sections.

2. In the first paragraph, the inner bending portion is A first protrusion is provided on both sides, The above first protrusion is, A certain length is extended from the inner bending portion inserted into the corner space portion created by the inner first and second fixed portions to the outside of the space, The cross-sectional shape is similar to the inner bend portion, but the curved portion in contact with the secondary barrier extends in the same line from the curved portion of the inner bend portion, A liquefied gas storage tank in which both sides perpendicular to the above secondary barrier are extended to have a first step difference from both sides of the inner bending portion.

3. In the second paragraph, the upper connecting block, A corner first connecting fixing part and a corner second connecting fixing part, each provided on the inner side of the first side and the second side and bonded to the second barrier, having a structure in which a corner first connecting plywood, a corner connecting insulation material, and a corner second connecting plywood are laminated; and Includes a corner connecting bending part installed in the corner space between the first corner connecting fixing part and the second corner connecting fixing part, The above corner connecting bend is, The vertical side heights of the above secondary barrier have a height that is reduced compared to the total height of each of the first and second corner connecting fixing parts, A second protrusion is provided on both sides, The above second protrusion is, A corner connecting bending part inserted into the corner space portion created by the first and second connecting fixing parts above extends a certain length outside the space, The cross-sectional shape is similar to the above corner connecting bend, but the curved portion in contact with the second barrier extends in the same line from the curved portion of the above corner connecting bend, A liquefied gas storage tank in which both sides perpendicular to the above secondary barrier are extended to have a second step with both sides of the above corner connecting portion.

4. In the third paragraph, the first and second protrusions are When the upper connecting block is installed between the adjacent upper blocks, a step space is created between the inner first and second fixing parts and the corner first and second connecting fixing parts by mutual contact, A stuffing piece is inserted and installed in the above step space, The above stuffing piece is, A liquefied gas storage tank having a (+) tolerance so as to completely seal the above-mentioned stepped space and formed in a shape corresponding to the shape of the above-mentioned stepped space.

5. In the first paragraph, the inner first and second fixing parts, It is arranged symmetrically based on the direction of dividing the corner portion equally, and the first side that is in close contact with both sides of the inner bending portion is perpendicular to the second barrier, and the second side that extends from the first side toward the storage space extends in the same direction as the dividing direction. The above upper block is, It further includes a corner inner packing material inserted and installed in a space created between the first side that is in close contact with both sides of the inner bending portion and the second side that faces each other. The inner packing material of the above corner is A liquefied gas storage tank formed to have a (+) tolerance so as to seal the space while being inserted into the space between the above second sides.

6. A liquefied gas storage tank including a corner block that is arranged at a corner portion where the first and second sides at different angles meet to form a storage space for accommodating liquefied gas. The above corner block is, A lower block provided on the inner side of the first and second surfaces and made of a single board; An integrated upper block made of a single board and bonded to the secondary barrier of the above lower block; An upper connecting block bonded to the secondary barrier exposed between the adjacently arranged integrated upper blocks; and It is installed on the upper surface of the above integrated upper block and includes a barrier fixing member that fixes the first barrier, The above integrated upper block is, One outer primary plywood provided on the inner side of each of the first side and the second side and bonded to the secondary barrier; One corner primary insulation laminated on the outer primary plywood; and It is composed of one inner primary plywood laminated on the above corner primary insulation material, The above barrier fixing member is, A liquefied gas storage tank in which a plurality of unit barrier fixing members are installed in parallel and adjacent to each other on one of the inner primary plywoods.

7. In paragraph 6, the integrated upper block, It includes a plurality of upper slits formed at a certain depth at the top, The above plurality of upper slits are, In order to prepare for shrinkage or expansion stress of the corner primary insulation, it is formed through the inner primary plywood to at least a part of the corner primary insulation, A liquefied gas storage tank formed at a corresponding position between the plurality of unit barrier fixing members so that the plurality of unit barrier fixing members are linked to the contraction or expansion of the corner primary insulation material.

8. In paragraph 1, the integrated upper block, A plurality of upper slits formed at a certain depth at the top; and It includes a plurality of lower slits formed at a certain depth at the bottom, The above plurality of upper slits and the above plurality of lower slits are, Liquefied gas storage tanks formed in mutually staggered positions.

9. In paragraph 7, the outer primary plywood is A plurality of first grooves are formed on the lower surface that is bonded to the above secondary barrier, The above plurality of first grooves are, When bonding the above outer primary plywood to the above secondary barrier with adhesive, it is formed in a direction perpendicular to the corner of the storage tank to ensure that the adhesive is squeezed out to the non-adhesive area. The above non-adhesive area is, It is set in multiple pieces in the middle part including the edge parts on both sides of the above outer primary plywood, Each of the above plurality of non-adhesive areas, A liquefied gas storage tank, which is set at a constant interval and width in the vertical direction from the corner of the storage tank, and is set at a corresponding position between the plurality of unit barrier fixing members.

10. In the 9th paragraph, the plurality of first grooves, It is formed along the boundary portions on both sides of the above-mentioned plurality of non-adhesive areas, A liquefied gas storage tank arranged in an alternating manner with the above plurality of upper slits.

11. A liquefied gas storage tank including a corner block that is arranged at a corner portion where the first and second sides at different angles meet to form a storage space for accommodating liquefied gas. The above corner block is, It is composed of a lower block provided on the inner side of the first and second surfaces and made of a single board, an upper block bonded to the secondary barrier of the lower block, and an upper connecting block bonded to the secondary barrier on the upper surface of the lower block arranged adjacent to each other to connect the lower blocks. The above upper connecting block is, A corner first connecting fixing part and a corner second connecting fixing part, each provided on the inner side of the first side and the second side and bonded to the second barrier, having a structure in which a corner first connecting plywood, a corner connecting insulation material, and a corner second connecting plywood are laminated; and Includes a corner connecting bending part installed in the corner space between the first corner connecting fixing part and the second corner connecting fixing part, The above corner connecting bend is, A liquefied gas storage tank having a height of both sides perpendicular to the secondary barrier that is reduced compared to the total height of each of the first and second corner connecting fixing parts.

12. In the 11th paragraph, the corner connecting bending part is A second protrusion is provided on both sides, The above second protrusion is, A corner connecting bending part inserted into the corner space portion created by the first and second connecting fixing parts above extends a certain length outside the space, The cross-sectional shape is similar to the above corner connecting bend, but the curved portion in contact with the second barrier extends in the same line from the curved portion of the above corner connecting bend, A liquefied gas storage tank in which both sides perpendicular to the above secondary barrier are extended to have a second step with both sides of the above corner connecting portion.

13. In the 11th paragraph, the first and second corner connecting fixing parts, It is arranged symmetrically based on the direction of dividing the corner portion equally, and the first side that is in close contact with both sides of the corner connecting bend is perpendicular to the second barrier, and the second side that extends from the first side toward the storage space extends in the same direction as the dividing direction. The above upper connecting block is, It further includes a corner inner packing material inserted and installed in a space created between the first side that is in close contact with both sides of the corner connecting bend and the second side that faces each other. The inner packing material of the above corner is A liquefied gas storage tank formed to have a (+) tolerance so as to seal the space while being inserted into the space between the above second sides.

14. In the 11th paragraph, the second corner connecting plywood, A second groove is formed on the lower surface where the second barrier is bonded, The above second groove is, A liquefied gas storage tank formed in a horizontal direction with a corner side of the storage tank so as to ensure that the adhesive is squeezed out into the non-bonded area when bonding the above corner second plywood to the above secondary barrier with an adhesive.

15. In the 14th paragraph, the second groove, A liquefied gas storage tank formed adjacent to the rear edge of the second corner connecting plywood so as to ensure that the adhesive is squeezed out through the corner connecting bend, which is a non-adhesive area.