KR102291928B1 - Insulation Wall Securing Structure of LNG Storage Tank - Google Patents

Abstract

The present invention is a double barrier structure comprising a secondary insulating wall composed of a plurality of secondary insulating panels fixed to the inner wall of a hull, and a primary insulating wall composed of a plurality of primary insulating panels fixed to an upper portion of the secondary insulating panel. A liquefied natural gas storage tank, comprising: a corner fixing device for fixing each corner of a secondary insulation panel to an inner wall of a hull; and a center fixing device installed through the center of the secondary insulation panel and fixing each corner of the primary insulation panel to the inner wall of the hull, wherein the secondary insulation panel is supported by mastic on the inner wall of the hull. , Mastic is applied between the kraft paper laid on the inner wall of the hull and the secondary insulation panel, and the secondary insulation panel is supported on the inner wall of the hull in a non-adhesive manner. It provides a fixed structure.

Description

Insulation Wall Securing Structure of LNG Storage Tank

The present invention relates to a structure for fixing the insulation wall of a liquefied natural gas storage tank, and more particularly, by fixing the primary insulation wall laminated on the upper portion of the secondary insulation wall to the inner wall of the hull, the structural stability of the insulation system is improved, It relates to a structure for fixing the insulation wall of a liquefied natural gas storage tank, which greatly improves the ease of installation of the insulation system by giving freedom to all fixing devices for fixing the primary and secondary insulation walls.

In general, liquefied natural gas (hereinafter referred to as 'LNG') is obtained by cooling natural gas containing methane as a main component to an ultra-low temperature state of -162 ° C. Since it is reduced to 1/600, it is very suitable for long-distance transport by sea.

LNG storage tanks (commonly referred to as 'cargo holds') that can withstand the cryogenic temperature of LNG are installed on LNG carriers, etc.

The LNG storage tank can be classified into an independent type and a membrane type depending on whether the load of cargo acts directly on the insulation. In general, membrane-type storage tanks are divided into GT NO 96 type and TGZ MARK Ⅲ type, and independent storage tanks are divided into MOSS type and SPB type.

In general, the membranous storage tank has a double barrier structure in which the secondary insulating wall, the secondary sealing wall, the primary insulating wall and the primary sealing wall 240 are sequentially stacked in the inner direction of the storage tank from the inner wall of the hull. Hereinafter, the structures of the NO 96 type storage tank and the MARK Ⅲ type storage tank classified as membrane type storage tanks will be described in detail.

1 is a view showing a conventional insulation system of a NO 96 type storage tank, Figure 2 is a view showing a structure of fixing the insulation wall of the conventional NO 96 type storage tank.

'NO 96 type storage tank', as shown in FIG. 1, the primary and secondary sealing walls 140 and 120 made of an invar (36% nickel steel) membrane, and perlite (perlite) inside the wooden box It has a structure including primary and secondary insulating walls in which a plurality of insulating boxes 130 and 110 in the form of filling insulators such as powder are arranged.

In the NO 96 storage tank, a predetermined gap is formed in consideration of the installation tolerance between the secondary insulation boxes 110, which are components of the secondary insulation wall, and a rigid gap insulation material to fill the gap. (not shown) is installed in such a way that it is fitted.

In the NO 96 storage tank, since the primary and secondary sealing walls 140 and 120 have almost the same airtightness and strength, when the primary sealing wall 140 leaks, only the secondary sealing wall 120 for a considerable period of time can be safely supported, and as the primary and secondary insulation walls are provided in a box type, high compressive strength and rigidity can be obtained. In addition, since the primary and secondary sealing walls 140 and 120 are made of a flat type without corrugation, automation of welding is possible.

On the other hand, referring to FIGS. 1 and 2 , the primary and secondary insulating walls in the NO 96 storage tank are simultaneously fixed to the inner wall of the hull (H) by a coupler-type fixing device 150 .

Specifically, the insulation wall fixing device 150 of the NO 96 type storage tank is fixed to the base socket 151 fixedly installed on the inner wall of the hull (H) by welding, and the lower end is fixed to the nut accommodated in the base socket 151, The coupler rod 152 extending upward, the coupler rod 152 is inserted through, and the setting plate for the secondary insulation box is supported by the secondary supporter 111 installed at the lower end of the side of the secondary insulation box 110 . (153), and the second fixing nut 154 that is fastened to the upper end of the coupler rod 152 to press and fix the setting plate 153 for the secondary insulation box downward, and the setting plate 153 for the secondary insulation box. ), the lower end is fixed to the plywood wedge 155 installed on the upper part, the setting plate 156 for the color stud installed on the upper part of the plywood wedge 155, and the setting plate 156 for the color stud, and upward The extended collar stud 157 and the collar stud 157 are inserted therethrough, and the setting plate 158 for the primary insulation box is supported by the primary supporter 131 installed at the lower side of the side of the primary insulation box 130 . ) and a primary fixing nut 159 fastened to the upper end of the collar stud 157 to press and fix the setting plate 158 for the primary insulation box downward.

That is, the secondary insulation box 110 constituting the secondary insulation wall is fixed to the inner wall of the hull (H) by a structure in which the setting plate 153 for the secondary insulation box is supported on the upper end of the secondary support 111 . The primary insulation box 130 constituting the primary insulation wall is a secondary insulation box 110 by a structure in which the setting plate 158 for the primary insulation box is supported on the upper end of the primary support 131 . is fixed on top of

In the conventional NO 96 storage tank, the insulating boxes 130 and 110 constituting the primary and secondary insulating walls are fixed to the inner wall of the hull (H) by a fixing device 150 at each corner. That is, at the point where the four insulation boxes 130 and 110 meet, the corner portions of each insulation box 130 and 110 are fixed at the same time by one fixing device 150 .

At this time, the setting plate 153 for the secondary insulation box and the setting plate 158 for the primary insulation box of the fixing device 150 vertically support the secondary support 111 and the primary support 131, respectively. The insulation box 110 and the primary insulation box 130 are fixed to the inner wall of the hull (H).

However, the coupler method applied to the conventional NO 96 storage tank can be a structurally rigid support structure, but there is a problem in that a cold spot or a loss in thermal performance occurs because the structure is connected from the inner wall of the hull. .

Figure 3 is a view showing the conventional insulation system of the MARK Ⅲ type storage tank, Figure 4 is a view showing the structure of fixing the insulation wall of the conventional MARK Ⅲ type storage tank.

The 'MARK Ⅲ type storage tank' is, as shown in FIG. 3, a primary sealing wall 240 made of a stainless steel (SUS) membrane, and a secondary sealing wall 220 made of a triplex composite material. And, it has a structure including primary and secondary thermal insulation walls formed by arranging a plurality of insulating panels 230 and 210 in the form of bonding wooden plywood to the upper or lower surface of the polyurethane foam (PUF).

At this time, the primary insulating panel 230 is provided in a smaller size than the secondary insulating panel 210 and disposed on the secondary insulating panel 210, and in the space between the neighboring primary insulating panels 230, a bridge panel is provided. 231 may be disposed.

The bridge panel 231 is a supple triplex attached to the upper surface of the secondary sealing wall 220 provided as a rigid triplex using an adhesive such as wpoxy glue (supple triplex 221). It can be attached again using an adhesive on the top of the.

In the NO 96 storage tank, a flat joint 211 made of Rigid Insulation (PVC series) material is inserted into the space between the secondary insulation panels 210, which are components of the secondary insulation wall, and the secondary insulation panel A foam plug 212 is inserted into the through-hole formed for fixing with the stud to be described later at 210 to close the secondary insulating wall.

The primary sealing wall 240 in direct contact with cryogenic LNG in the MARK III storage tank has corrugated corrugations to absorb heat shrinkage caused by cryogenic temperatures, and absorbs deformation of the membrane in these corrugated corrugations, so that the inside of the membrane is No great stress is generated.

However, in the MARK Ⅲ type storage tank, the welding of the primary sealing wall 240 having a corrugated corrugation is complicated, so the welding automation rate is low, and it is difficult to secure the reliability of the secondary sealing wall 220 made of a triplex.

Meanwhile, referring to FIG. 4 , in the MARK Ⅲ type storage tank, the primary and secondary thermal insulation walls are fixed by a bonding method.

Specifically, the secondary thermal insulation panel 210 constituting the secondary thermal insulation wall is directly fixed to the inner wall of the hull (H) by adhesion with resin and studs. And the secondary sealing wall 220 is fixed to the upper part of the secondary insulating panel 210 by an adhesive, and the primary insulating panel 230 constituting the primary insulating wall on the upper surface of the secondary sealing wall 220 is It is likewise fixed by an adhesive.

In the conventional MARK Ⅲ type storage tank, the secondary insulation panel 210 constituting the secondary insulation wall is fixed to the inner wall of the hull (H) by applying eight studs per unit panel. A through hole is formed at the edge of the secondary insulation panel 210 so that the stud can be inserted, and after the stud is arranged to be inserted into the through hole, the secondary insulation panel 210 is installed in the hull by fastening a nut to the stud. (H) It is fixed to the inner wall. After the fixing by the studs is completed, the foam plug 212 is inserted into the empty space of the through hole to seal the space.

In the MARK Ⅲ type storage tank to which the insulation wall is fixed by the bonding method as described above, the upper portion of the primary insulation panel 230 is located close to cryogenic LNG and heat-shrink. The insulation panel 210 is not stable against heat shrinkage as it is fixed to the side of the secondary sealing wall 220 by an adhesive, and since the secondary sealing wall 220 is made of a triplex composite material, concerns about stability such as LNG leakage is more problematic.

As described above, in addition to the bonding method applied to the MARK Ⅲ type storage tank, in the SCA/MARK V type storage tank, the primary insulating wall is not fixed by bonding, but is fixed to a fixing device installed on the upper part of the secondary insulating wall. A securing device method is also used.

However, the securing device method applied to the SCA/MARK V-type storage tank is a structure in which the fixing device installed on the upper part of the secondary insulating wall holds the bottom plate of the primary insulating wall by bolting. There is a problem in that the plywood near the fixing device becomes weak against the sloshing load.

The technical problem to be achieved by the present invention is to provide a structure for fixing the insulating wall of a liquefied natural gas storage tank in which structural stability and ease of installation are significantly improved compared to the prior art.

In order to achieve the above object, the present invention is a secondary insulation wall consisting of a plurality of secondary insulation panels fixed to the inner wall of the hull, and a plurality of primary insulation panels fixed to the upper portion of the secondary insulation panel 1 In the liquefied natural gas storage tank of a double barrier structure including a primary insulating wall, a corner fixing device for fixing each corner of the secondary insulating panel to the inner wall of the hull; and a center fixing device installed through the central portion of the secondary insulation panel and fixing each corner portion of the primary insulation panel to the inner wall of the hull, wherein the secondary insulation panel is mastic to the inner wall of the hull. ), the mastic is applied between the kraft paper laid on the inner wall of the hull and the secondary insulation panel, and the secondary insulation panel is non-adhesive supported on the inner wall of the hull. It can provide a structure for fixing the insulating wall of the liquefied natural gas storage tank.

The center fixing device may include a second base socket fixed to the inner wall of the hull by welding; a second coupler rod having a lower end fixed to the second base socket and extending upwardly through the central portion of the secondary insulation panel; a socket plate fastened to the upper end of the second coupler rod and supported by the upper plate of the secondary insulation panel; and a collar stud having a lower end fixed to the socket plate and extending upward. an elastic member through which the collar stud is inserted and supported by the lower plate of the primary insulation panel; a second setting plate supported by the elastic member; and a second fixing nut fastened to the upper end of the collar stud to press and fix the second setting plate downward.

The elastic member is provided with any one of plywood, polymer plastic, and an elastic body, and may function to absorb the deformation of the hull.

The socket plate may include a socket member fastened to an upper end of the second coupler rod in a screw-coupled manner; and a plate member having an enlarged diameter provided at the upper end of the socket member and supported by the upper plate of the secondary heat insulating panel, wherein the plate member is seated in a groove formed in the upper center of the secondary heat insulating panel, An upper portion of the secondary insulation panel may be fixed.

The corner fixing device may include: a first base socket fixed to the inner wall of the hull by welding; a first coupler rod having a lower end fixed to the first base socket and extending upward; a fixing pad through which the first coupler rod is inserted and supported by the lower plate of the secondary insulation panel; a first setting plate through which the first coupler rod is inserted and supported by the fixing pad; and a first fixing nut fastened to the upper end of the first coupler rod to press and fix the first setting plate downward.

The fixing pad may be made of any one of plywood, polymer plastic, and an elastic body.

The first base socket and the second base socket may have a degree of freedom of 1 to 5° in a direction perpendicular to the inner wall of the hull.

A void space is formed at each corner of the primary insulating panel to expose a portion of the lower plate to support the elastic member, and a point where four primary insulating panels fixed at the same time by the center fixing device meet In the space formed by the void space, a corner insulating material may be inserted and disposed.

The corner insulation has a density of 30 to 210 kg / m ³ , polyvinyl chloride (PVC), polyurethane foam (PUF), fiber-reinforced polyurethane foam (R-PUF), any one of EPS (Expanded Polystyrene) It may be prepared from the material of

A void space is formed in each corner portion of the secondary insulation panel to expose a portion of the lower plate to support the fixing pad, and the four secondary insulation panels fixed at the same time by the corner fixing device meet At the point, a corner insulating material may be inserted into the space formed by the void space.

The corner insulation has a density of 30 to 210 kg / m ³ , polyvinyl chloride (PVC), polyurethane foam (PUF), fiber-reinforced polyurethane foam (R-PUF), any one of EPS (Expanded Polystyrene) It may be prepared from the material of

In addition, another aspect of the present invention for achieving the above object is a liquefied natural gas storage tank of a double barrier structure in which a secondary insulation panel and a primary insulation panel are sequentially stacked on the inner wall of the hull, the secondary insulation panel The corner part is fixed to the inner wall of the hull by a silver corner fixing device, and the corner part is fixed to the inner wall of the hull by a center fixing device penetrating the center of the secondary insulating panel in the primary insulation panel, and the corner fixing device and the The center fixing device is connected to the inner wall of the hull by a base socket, respectively, and the base socket provided in the corner fixing device and the center fixing device has a degree of freedom of 1 to 5° with respect to the inner wall of the hull, the 2 The primary insulation panel is supported by mastic on the inner wall of the hull, and the mastic is applied between the kraft paper laid on the inner wall of the hull and the secondary insulation panel, and the secondary insulation panel is It is possible to provide a structure for fixing the insulation wall of the liquefied natural gas storage tank, characterized in that it is supported in a non-adhesive manner on the inner wall of the hull.

According to the present invention, since the primary insulation panel is fixed to the inner wall of the hull rather than being fixed in such a way as to be adhered to the upper portion of the secondary insulation panel, the structural stability of the insulation system is improved compared to the prior art.

In addition, according to the present invention, since each corner portion of the secondary insulation panel is fixed to the inner wall of the hull by the corner fixing device, and the upper part of the secondary insulation panel is additionally fixed by the center fixing device, the structural structure of the secondary insulation wall The stability is further improved, so it is possible to prepare for the occurrence of failure in the secondary insulation structure.

In addition, according to the present invention, since the secondary insulation panel is supported in a non-adhesive manner to the hull, and the base socket connected to the inner wall of the hull in the corner fixing device and the center fixing device has a degree of freedom, all fixings fixing/supporting the insulation wall The ease of installation (tolerances) is improved as the device has degrees of freedom.

In addition, the present invention applies a structure that absorbs the deformation of the hull to the corner fixing device and the center fixing device for fixing the secondary insulation panel and the primary insulation panel, effectively preventing the deformation or behavior of the hull from being transmitted to the insulation wall. can be prevented, and thus, ultimately, it is possible to prevent damage to the sealing wall installed on the upper portion of the insulating wall.

On the other hand, even if it is an effect not explicitly mentioned herein, it is added that the effects described in the following specification and their potential effects expected by the technical features of the present invention are treated as if they were described in the specification.

1 is a view showing an insulation system of a conventional NO 96 storage tank.
Figure 2 is a view showing the structure of the conventional NO 96 type storage tank insulated wall fixing.
3 is a view showing an insulation system of a conventional MARK Ⅲ type storage tank.
4 is a view showing the structure of fixing the insulation wall of the conventional MARK Ⅲ type storage tank.
5 is a side cross-sectional view schematically showing a thermal insulation system of a liquefied natural gas storage tank according to the present invention.
6 is a perspective view schematically showing a structure for fixing a thermal insulation wall of a liquefied natural gas storage tank according to an embodiment of the present invention.
7 is a side view schematically showing a structure for fixing a thermal insulation wall of a liquefied natural gas storage tank according to an embodiment of the present invention.
8 is a view showing the structure of a corner fixing device installed at the corner of the secondary insulating wall in the liquefied natural gas storage tank according to an embodiment of the present invention.
9 is a view showing the structure of the center fixing device installed in the center of the secondary insulating wall in the liquefied natural gas storage tank according to an embodiment of the present invention.
FIG. 10 is a view showing a modified embodiment of FIG. 9 .
11 is a perspective view schematically showing the insulating wall fixing structure of the liquefied natural gas storage tank according to another embodiment of the present invention.
12 is a view showing the structure of a corner fixing device installed at the corner of the secondary insulating wall in the liquefied natural gas storage tank according to another embodiment of the present invention.
13 is a perspective view schematically showing the insulating wall fixing structure of the liquefied natural gas storage tank according to another embodiment of the present invention.
14 is a view showing the structure of a corner fixing device installed at the corner of the secondary insulating wall in the liquefied natural gas storage tank according to another embodiment of the present invention.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. Like reference numerals in each figure indicate like elements.

In the present invention, the use of the terms 'primary' and 'secondary' refers to whether the function primarily seals or insulates the LNG based on the LNG stored in the storage tank, or the function to secondary seal or insulate the LNG. It is used as a criterion for classification.

Also, the terms 'upper' or 'above', as customarily applied to elements of a tank, refer to the direction towards the inside of the tank, irrespective of the direction to gravity; Regardless of the direction, it points toward the outside of the tank.

Before looking at the structure of fixing the insulating wall of the liquefied natural gas storage tank according to the present invention, let us first look at the overall insulating structure of the liquefied natural gas storage tank according to the present invention.

5 is a side cross-sectional view schematically showing a thermal insulation system of a liquefied natural gas storage tank according to the present invention.

5, the liquefied natural gas storage tank according to the present invention is a secondary insulating wall 10 disposed on the inner wall of the hull (H), a secondary sealing wall installed on the second insulating wall 10 ( 20), a primary insulating wall 30 disposed on the secondary sealing wall 20, and a double barrier in which the primary sealing wall 40 installed on the first insulating wall 30 is sequentially stacked ( double barrier) structure.

And in the transverse corner of the liquefied natural gas storage tank according to the present invention, it is installed on the inner hull along the edges of the front wall and the rear wall of the storage tank, the secondary sealing wall 20 is fixed and supported ten (十) ) shaped transverse connector (transverse connector, 50) is installed.

The transverse connector 50 is a structure that functions similarly to an invar tube installed at the corresponding position in a conventional NO 96 storage tank, but the conventional invar tube is provided in a grid structure to provide primary and secondary sealing Unlike all the walls are connected by welding, the transverse connector 50 of the present invention is different in that only the secondary sealing wall 20 is connected by welding because it is provided in a single ten-shape. .

The transverse connector 50 is fixed to the wall surface of the hull H by a connecting member such as an anchoring bar, and the end of the secondary sealing wall 20 is welded to the transverse connector 50 by sealed connected. The transverse connector 50 is made of an invar material, and serves to transmit various loads applied to the secondary sealing wall 20 to the hull H. Although only one lateral corner portion is shown in the drawings for convenience, the opposite lateral corner portion, which is not shown in the drawings, is also configured to have the same structure.

The secondary insulation wall 10 is a corner insulation box 320 installed in the transverse corner of the storage tank to support the transverse connector 50, and is installed in areas other than the corner portion of the storage tank. A secondary insulation panel 310 may be included.

The corner insulation box 320 is a structure installed between the transverse connector 50 and the hull H to support the transverse connector 50, and is made of plywood or a composite material. ) as the main member. Specifically, the corner insulation box 320 may be provided in the form of an insulation box in which an insulation material such as pearlite powder or glass wool is filled inside a box made of plywood or a composite material. As the composite material described in this embodiment, for example, fiber-reinforced plastic (GRP: Glass Reinforced Plastic) may be used.

The secondary insulation panel 310 may be provided in the form of an insulation panel in which fiber-reinforced polyurethane foam (R-PUF) and plywood (or composite material) are single or combined. More specifically, the secondary insulation panel 310 is a sandwich panel in which a protective plate made of plywood or a composite material is adhered to the upper surface, lower surface, or both upper and lower surfaces of a fiber-reinforced polyurethane foam (R-PUF) insulating material having a thickness. panel) can be manufactured.

The secondary heat insulation panel 310 may be manufactured as a unit panel in the form of a hexahedron or more polyhedron, and a plurality of them are arranged on the inner wall of the hull (H) along the transverse and longitudinal directions of the storage tank, corner insulation box The secondary thermal insulation wall 10 may be formed together with the 320 .

The secondary sealing wall 20 may be made of a flat invar membrane. Specifically, the secondary sealing wall 20 is a plurality of invar strakes having a band shape are continuously welded to a tongue member installed on the upper portion of the secondary insulation panel 310, so that the secondary It may be installed in close contact with the upper portion of the insulating wall (10).

On the other hand, since the flat invar membrane has a low coefficient of thermal contraction, it is not suitable for a panel type insulation system in which the insulation wall is made of polyurethane foam (PUF). Therefore, in order to apply the flat invar membrane, it was common that the insulating wall supporting the membrane, like the conventional NO 96 storage tank, was composed of an insulating box with low heat shrinkage and high rigidity.

However, the present invention supplements the rigidity of the secondary insulating wall 10 by the transverse connection body 50 installed in the transverse corner of the storage tank, thereby forming the secondary sealing wall 20 in a flat form. It makes it possible to construct a membrane.

That is, according to the present invention, part of the load applied to the secondary sealing wall 20 by the transverse connection body 50 installed in the transverse corner of the storage tank is transferred to the hull (H) and resolved, It is possible to apply a flat invar membrane as the secondary sealing wall 20 installed thereon while configuring the secondary insulating wall 10 in a panel type.

In addition, in the present invention, the use of fiber-reinforced polyurethane foam (R-PUF), which has higher rigidity than general polyurethane foam (PUF), is used as the insulation material of the secondary insulation panel 310 constituting the secondary insulation wall 10 in the present invention. , it is part of a plan for configuring the secondary sealing wall 20 as a flat invar membrane.

The primary insulating wall 30 may include a corner insulating block 340 disposed in a transverse corner of the storage tank, and a primary insulating panel 330 disposed in an area other than the corner of the storage tank. have.

The corner insulating block 340 may have a cross-sectional shape bent in an approximately 'L' shape according to the angle of each wall surface constituting the lateral corner of the storage tank.

Corner portion insulation block 340, like the secondary insulation panel 310 or the primary insulation panel 330 to be described later, fiber-reinforced polyurethane foam (R-PUF) and plywood (or composite material) are single or It may be provided in the form of a combined insulation panel, or may be provided in the form of a block of plywood (or composite material) single material.

A connection plate 341 made of stainless steel (SUS) or invar material may be installed on the upper portion of the corner insulation block 340 , and the end of the primary sealing wall 40 is welded to the connection plate 341 . It can be sealed at the corner of the storage tank. In this case, the wrinkle formed on the primary sealing wall 40 may be sealed using a closing member 41 such as an angle piece or an end cap.

The primary insulation panel 330, like the secondary insulation panel 310, fiber-reinforced polyurethane foam (R-PUF) and plywood (or composite material) may be provided in the form of a single or combined insulation panel. . In addition, the primary heat insulation panel 330 may be manufactured as a unit panel in the form of a hexahedron or more polyhedron, and a plurality of them are arranged on the secondary sealing wall 20 in the transverse and longitudinal directions of the storage tank, The primary insulating wall 30 may be formed together with the corner insulating block 340 .

The primary sealing wall 40 may be made of a stainless steel (SUS) membrane, and may include a plurality of corrugated corrugations to absorb shrinkage due to cryogenic temperatures. Specifically, the primary sealing wall 40 may be formed of a unit membrane sheet including corrugated corrugations, and a plurality of unit membrane sheets are voids in an anchor strip installed on the upper portion of the primary insulating panel 330 . By welding without, it can be installed in close contact with the upper portion of the primary heat insulating wall (30).

On the other hand, in order to promote the structural stability of the liquefied natural gas storage tank, the secondary insulating wall 10 and the primary insulating wall 30 must be fixed from the inner wall of the hull (H). Hereinafter, the 'fixed structure' of the secondary insulating wall 30 and the primary insulating wall 30 of the liquefied natural gas storage tank according to the present invention will be described in detail.

6 is a perspective view schematically showing a structure for fixing an insulating wall of a liquefied natural gas storage tank according to an embodiment of the present invention, and FIG. 7 is a structure for fixing an insulating wall of a liquefied natural gas storage tank according to an embodiment of the present invention It is a schematic side view. And Figures 8 and 9 show the structures of the corner fixing device installed at the corner of the secondary insulating wall and the center fixing device installed at the center of the secondary insulating wall in the liquefied natural gas storage tank according to an embodiment of the present invention, respectively. It is a drawing made

6 and 7, the liquefied natural gas storage tank according to an embodiment of the present invention is installed on the secondary insulating panel 310 constituting the secondary thermal insulation wall, and the secondary thermal insulation wall 1 It includes a primary thermal insulation panel 330 constituting the primary thermal insulation wall.

The liquefied natural gas storage tank according to this embodiment has the above-mentioned double barrier structure insulation system, but in order to clearly express the fixed structure of the secondary insulation panel 310 and the primary insulation panel 330, for convenience, the storage tank Structures and sealing walls installed at the corners are omitted from the illustration.

In this embodiment, the primary and secondary insulation panels 330 and 310 are sandwiches in which plywood plywood is attached to the upper and lower surfaces of polyurethane foam (PUF) or fiber-reinforced polyurethane foam (R-PUF). It may be provided in the form of a panel. However, the configuration of the primary and secondary thermal insulation panels 330 and 310 is not limited thereto, and insulating materials of various materials for a thermal insulation function, and upper and lower plates attached to the upper and lower surfaces of the insulator to give mechanical rigidity to the insulator are not limited thereto. Any form can be applied as long as it contains For example, it goes without saying that the present invention can also be applied to a type of insulation box in which an insulation material such as pearlite powder or glass wool is filled inside the plywood box.

In addition, although it is shown in the drawings that the width and length of the primary and secondary heat insulation panels 330 and 310 are provided in a 1:1 ratio, it is not limited thereto, and the length is not limited thereto, such as 1:2 or 1:3 ratio. The panel may be provided as an integer multiple of the width.

As shown in FIGS. 6 and 7 , in the present embodiment, the primary insulating panel 330 and the secondary insulating panel 310 may be cross-arranged (displaced) so that their edges are shifted from each other. More specifically, the corner portion of the primary thermal insulation panel 330 may be arranged to lie in the center of the secondary thermal insulation panel 310 disposed below.

In this embodiment, by interposing the primary insulating panel 330 and the secondary insulating panel 310, the effect of minimizing heat loss that may occur due to convection or the like in the gap between the insulating panels 330 and 310 is achieved. can do.

On the other hand, the liquefied natural gas storage tank according to an embodiment of the present invention may include a heat insulating wall fixing device for fixing the secondary insulating panel 310 and the primary insulating panel 330 to the inner wall of the hull (H). In this case, the insulation wall fixing device includes a corner fixing device 350 for fixing each corner of the secondary insulation panel 310 to the inner wall of the hull (H), and passing through the center of the secondary insulation panel 310 for the primary It includes a center fixing device 360 for fixing each corner portion of the insulation panel 330 to the inner wall of the hull (H).

The structures of the corner fixing device 350 and the center fixing device 360 are shown in detail in FIGS. 8 and 9 , respectively.

Referring to Figure 8, the corner fixing device 350 of this embodiment, the first base socket 351 fixed by welding to the inner wall of the hull (H), the lower end is fixed to the first base socket 351, the upper The first coupler rod 352 extending to the A setting plate 353 and a first fixing nut 354 fastened to the upper end of the first coupler rod 352 to press and fix the first setting plate 353 downward, and a first setting plate 353 and It includes a first spring washer (355) interposed between the first fixing nut (354).

The first spring washer 355 serves to absorb the deformation of the hull due to the ballast pressure, etc. together with the secondary cleat 311 . As will be described later, the first spring washer 355 and the secondary cleat 311 may be replaced with an elastic member (not shown).

As shown in FIG. 6 , in the lower end of both edges along either side of the storage tank or the longitudinal direction of the storage tank in the secondary heat insulation panel 310 of this embodiment, the lower plate for coupling with the corner fixing device 350 . is formed to be partially exposed, and a secondary cleat 311 may be attached and installed on the exposed lower plate. The exposed end of the lower plate may be cut in a rounded shape to accommodate the base socket 351 .

A gap is formed between the secondary heat insulation panels 310 facing each other in a direction in which the lower plate is exposed, and a gap insulation material (not shown) may be inserted into the gap. As interstitial insulation, rigid insulation having a density of 30 to 60 kg/m ³ , glass wool (20 to 50 kg/m ³ ), polyurethane foam (30 to 60 kg/m ³ ), fiber reinforcement Polyurethane foam (100 ~ 200 kg/m ³ ), EPS (20 ~ 100 kg/m ³ ) Various insulating materials may be applied, and the above-mentioned materials may be mixed depending on the situation.

9, the center fixing device 360 of the present embodiment, the second base socket 361 fixed by welding to the inner wall of the hull (H), and the lower end is fixed to the second base socket 361, 2 A second coupler rod 362 extending upwardly through the center of the car insulation panel 310, is fastened to the upper end of the second coupler rod 362, and is supported by the upper plate of the secondary insulation panel 310 The socket plate 363, the lower end of which is fixed to the socket plate 363, and the collar stud 364 extending upward, and the collar stud 364 are inserted through and supported by the lower plate of the primary insulation panel 330. The second setting plate 366, which is an elastic member 365, the collar stud 364 is inserted through and supported by the elastic member 365, and the second setting plate fastened to the upper end of the collar stud 364 ( It includes a second fixing nut 367 for pressing and fixing the 366 downwards, and a second spring washer 368 interposed between the second setting plate 366 and the second fixing nut 367 .

In this embodiment, the socket plate 363 is provided so that the diameter is extended at the upper end of the socket member 363a fastened to the upper end of the second coupler rod 362 by a screw coupling method, and the socket member 363a is provided for secondary insulation. It may be configured to include a plate member 363b supported by the upper plate of the panel 310 .

A groove corresponding to the shape of the plate member 363b may be formed in the upper center of the upper plate of the secondary insulation panel 310 , and the plate member 363b is seated in the groove to form the secondary insulation panel 310 . The upper part can be fixed.

That is, in the present embodiment, the secondary insulation panel 310 has each corner part fixed to the inner wall of the hull (H) by the above-described corner fixing device 350, and the upper end part of the hull (H) by the center fixing device 360. ) is additionally fixed to the inner wall.

The plate member 363b may have a circular cross-section, or may have a polygonal cross-sectional shape to prevent rotation on the upper portion of the secondary heat insulation panel 310 .

In this embodiment, the elastic member 365 serves to absorb the deformation of the hull (H), and may be made of a material such as plywood, polymer plastic, or an elastic body, and includes a cleat and a spring washer. simultaneously play the role of Accordingly, the second spring washer 368 may be deleted by the installation of the elastic member 365 . Here, the polymer plastic may be a thermoplastic elastomer having both properties of rubber and plastic, for example, including materials such as UHMW-PE (ultra-high molecular polyethylene) and KOPEL® (TPC-ET). Therefore, various materials can be used.

Such an elastic member may also be applied to the above-described corner fixing device 350 . That is, in FIG. 8 , the secondary cleat 311 installed at the lower end of the side surface of the secondary thermal insulation panel 310 is deleted, and the elastic member between the lower plate and the first setting plate 353 of the secondary thermal insulation panel 310 is removed. By installing the hull (H) deformation from the secondary heat insulation panel 310 side may be absorbed.

The structure in which the elastic member is applied in the present embodiment may be selectively applied to at least one of the primary insulating panel 330 side and the secondary insulating panel 310 side. That is, the elastic member may be included in at least one of the center fixing device 360 and the corner fixing device 350 .

In the secondary insulation panel 310 of this embodiment, a through hole 312 may be formed in the center along the thickness direction so that the center fixing device 360 can be inserted therethrough, and the center fixing device in the through hole 312 . The empty space remaining after accommodating the configuration of 360 may be filled with an insulating material made of a flexible material. Representative examples of flexible insulating materials include Flexible Polyurethane Foam with Open Cells, Polyeter or Polyester type.

As shown in FIG. 6 , in the lower end of both edges along either the transverse or longitudinal direction of the storage tank in the primary heat insulation panel 330 of this embodiment, the lower plate for coupling with the center fixing device 360 . is formed to be exposed, and the above-described elastic member 365 may be supported on the exposed lower plate. The exposed end of the lower plate may be cut in a rounded shape to accommodate the collar stud 364 .

Similar to the secondary insulating panel 310, a gap is formed between the primary insulating panels 330 facing each other in the direction in which the lower plate is exposed, and in this gap, a gap insulating material (not shown) ) may be inserted. The above-mentioned materials may be applied as the gap insulation material.

The embodiment of FIG. 9 applies the elastic member 365 as a structure for absorbing deformation of the hull (H), and the elastic member 365 is a configuration included in the center fixing device 360, and the collar stud 364 is It is provided in such a way that it is inserted through. Here, since the elastic member 365 serves as a cleat + a spring washer at the same time, a second spring washer 367 interposed between the second setting plate 366 and the second fixing nut 367. is an optional element. That is, the elastic member 365 and the second spring washer 367 may be installed to absorb double hull (H) deformation, but the second spring washer 367 may be deleted.

On the other hand, in the modified embodiment shown in FIG. 10, the second setting plate 366 is installed at the lower end of the side of the primary heat insulation panel 330 without applying an elastic member as a structure for absorbing deformation of the hull (H). A method supported by the primary cleat 331 is applied. Therefore, in the embodiment of FIG. 10 , the second spring washer 367 should be necessarily installed.

11 is a perspective view schematically showing a structure for fixing a thermal insulation wall of a liquefied natural gas storage tank according to another embodiment of the present invention, and FIG. 12 is a secondary thermal insulation wall in a liquefied natural gas storage tank according to another embodiment of the present invention. It is a diagram showing the structure of a corner fixing device installed in a corner.

11 and 12, in the liquefied natural gas storage tank according to another embodiment of the present invention, in the method of fixing the secondary insulating panel 310 to the inner wall of the hull (H), the secondary insulating panel 310 ) to form a void space for accommodating the corner fixing device 350 in each corner portion, and to the first coupler rod 352 of the corner fixing device 350 with the fixing pad 356 and the first After inserting the setting plate 353 sequentially, a method of fastening the first fixing nut 354 is applied.

That is, unlike the method of installing the secondary cleats 311 at the lower side of the side of the secondary insulating panel 310 in the embodiment shown in Figs. A fixing pad 356 through which the first coupler rod 352 is inserted is disposed in the void space formed in the corner portion.

In the embodiment shown in FIGS. 6 to 8 , a portion of the lower plate is exposed at the lower end of both edges of the secondary heat insulation panel 310 in order to secure a space for installing the secondary cleat 311 , and thus the secondary A gap had to be formed between the insulating panels 310 .

On the other hand, according to the present embodiment, it is possible to form a void space only in the corner portion of the secondary thermal insulation panel 310, and accordingly, the space formed by the void space between the secondary thermal insulation panels 310 facing each other is reduced. No gap is formed except

Therefore, in this embodiment, as compared to the embodiment shown in FIGS. 6 to 8 , the processing of the secondary heat insulating panel 310 can be made to a minimum, and thus, ease of installation is improved.

In this embodiment, the fixing pad 356 is supported on a lower plate formed to be exposed at the corner of the secondary heat insulation panel 310 by a void space, as shown in FIG. 12 , and the upper first It is pressed by the setting plate 353 .

For example, the fixing pad 356 may be an elastic member replacing the secondary cleat 311 and the first spring washer 355 as described above. When the fixing pad 356 is provided with an elastic member (plywood, polymer plastic, elastic body, etc.), the first spring washer 355 may be deleted.

In addition, in this embodiment, at the point where the four secondary insulation panels 310 meet, the space formed by the void space, that is, the space where the corner portions of each secondary insulation panel 310 face each other, have a corner insulation material ( 357) may be insertedly disposed. Since a gap is not formed between the secondary insulation panels 310 except for the void space, the above-described gap insulation material is not applied in this embodiment.

Corner insulation 357, polyvinyl chloride (PVC), polyurethane foam (PUF), fiber-reinforced polyurethane foam (R-PUF), various insulation materials such as EPS (Expanded Polystyrene) may be applied, 30 to 210 It may be provided to have a density of kg/m ^{3 .} In general, an insulating material having a density of about 120 kg/m ³ is applied to an insulating panel, and a high-density insulating foam having a density increased to 170 to 210 kg/m ^{3 may be applied to the high sloshing area.} Therefore, in the above, the density range of the corner insulating material 357 is expressed in consideration of application to the high sloshing area.

The corner insulating material 357 may have a lower shape processed in the corner fixing device 350 to surround the components protruding to the inside of the lower plate of the secondary insulating panel 310 by minimizing heat transfer through the void space. It functions to prevent the occurrence of a cold spot on the back side of the hull (H).

On the other hand, the method of forming a void space only in the corner portion of the secondary insulation panel 310 and coupling it with the corner fixing device 350 may be equally applied to fixing the primary insulation panel 330 . That is, in order to support the above-described elastic member 365 , the lower plate may be exposed only at the corners of the primary heat insulating panel 330 , not at both edges of both sides.

13 is a perspective view schematically showing a structure for fixing an insulating wall of a liquefied natural gas storage tank according to another embodiment of the present invention, and FIG. 14 is a secondary insulation in a liquefied natural gas storage tank according to another embodiment of the present invention. It is a diagram showing the structure of the corner fixing device installed at the corner of the wall.

The liquefied natural gas storage tank according to another embodiment of the present invention shown in FIGS. 13 and 14 is that a plug 358 is added to the embodiment shown in FIGS. 11 and 12 described above. Therefore, in this embodiment, only the configuration of the plug 358, which is an added configuration, will be briefly described.

13 and 14 , the plug 358 blocks the upper portion of the void space formed by the four secondary insulation panels 310 facing each other, thereby inserting the corner insulation 357 into the space. serves to fix.

The plug 358 is disposed so as to span the corners of each secondary insulation panel 310 at the point where the four secondary insulation panels 310 meet, and is located at the end of the upper plate of the secondary insulation panel 310 . It may be seated in the formed groove to form the same plane as the upper surface of the secondary heat insulation panel 310 . In this case, the plug 358 may be fixed on the upper plate of each secondary insulation panel 310 using staples, screws, rivets, glue, or the like.

The method in which the plug 358 is additionally installed in this way may be equally applied to the primary heat insulation panel 330 as in the above-described embodiment.

On the other hand, in the liquefied natural gas storage tank according to the present invention including all of the above-described embodiments, the corner fixing device 350 is the first base socket 351 , and the center fixing device 360 is the second base socket 361 . ), it can be seen that each includes

The present invention, unlike the conventional MARK Ⅲ type storage tank (refer to FIG. 4) in which the studs for fixing the corners of the secondary insulation panel are directly fixed to the inner wall of the hull by welding, the corner fixing device 350 and the center A coupling method between the base sockets 351 and 361 and the coupler rods 352 and 362 is applied to the fixing device 360 .

In this case, the first base socket 351 and the second base socket 362 may have a degree of freedom of 1 to 5° (more preferably 3°) with respect to the vertical direction. Therefore, according to the present invention, since the fixing devices 350 and 360 installed for fixing the insulating wall have a degree of freedom with respect to the inner wall of the hull (H), a flexible behavior of the insulating wall with respect to the hull (H) is possible.

In addition, the liquefied natural gas storage tank according to the present invention, unlike the conventional MARK Ⅲ type storage tank (see FIG. 4) in which the secondary insulation panel is adhesively supported on the inner wall of the hull by mastic or resin, the hull (H) Laying kraft paper on the inner wall, and applying a bearing mastic between the kraft paper and the secondary insulation panel 310 is applied.

Therefore, in the present invention, since the secondary insulation panel 310 is separated from the inner wall of the hull (H) and supported in a non-adhesive manner, it is possible to avoid a direct effect due to the behavior or deformation of the hull, and accordingly, the behavior or deformation of the hull is 2 Transmission to the barrier insulation wall can be prevented more effectively.

According to the present invention as described above, the following effects can be achieved.

According to the present invention, since the primary insulation panel 330 is fixed to the inner wall of the hull (H) rather than being fixed in such a way as to be adhered to the upper portion of the secondary insulation panel 310, the structural stability of the insulation system is improved compared to the prior art. .

In addition, according to the present invention, each corner portion of the secondary insulation panel 310 is fixed to the inner wall of the hull (H) by the corner fixing device 350, and the secondary insulation panel ( Since the upper part of the 310) is additionally fixed, the structural stability of the secondary insulating wall is further improved, so that it is possible to prepare for the occurrence of failure in the secondary insulating structure.

In addition, according to the present invention, the secondary insulation panel 310 is supported on the hull in a non-adhesive manner, and the base socket 351 is connected to the inner wall of the hull (H) in the corner fixing device 350 and the center fixing device 360, 361) has a degree of freedom, so the ease of installation (tolerance) is improved because all fixing devices that fix/support the insulating wall have a degree of freedom.

In addition, the present invention applies a structure to absorb the deformation of the hull (H) to the corner fixing device 350 and the center fixing device 360 for fixing the secondary insulation panel 310 and the primary insulation panel 330 . By doing so, it is possible to effectively prevent the deformation or behavior of the hull (H) from being transmitted to the insulating wall, thus ultimately preventing the damage of the sealing wall installed on the top of the insulating wall.

The present invention is not limited to the described embodiments, and it is apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Accordingly, it should be said that such modifications or variations are included in the claims of the present invention.

310: secondary insulation panel
330: primary insulation panel
350: corner fixing device
351: first base socket 352: first coupler rod
353: first setting plate 354: first fixing nut
355: first spring washer
360: center fixing device
361: second base socket 362: second coupler rod
363: socket plate 364: collar stud
365: elastic member 366: second setting plate
367: second fixing nut 368: second spring washer

Claims (12)

Liquefied nature of a double barrier structure comprising a secondary insulating wall composed of a plurality of secondary insulating panels fixed to the inner wall of the hull, and a primary insulating wall composed of a plurality of primary insulating panels fixed to an upper portion of the secondary insulating panel In the gas storage tank,
a corner fixing device for fixing each corner of the secondary insulation panel to the inner wall of the hull; and
The lower end is fixed to the inner wall of the hull and is installed to penetrate the center of the secondary insulation panel, and includes a center fixing device for fixing each corner of the primary insulation panel to the inner wall of the hull,
The center fixing device comprises a socket plate supported by the upper plate of the secondary heat insulation panel, characterized in that the central upper end of the secondary heat insulation panel is additionally fixed to the inner wall of the hull by the socket plate,
Fixed structure of insulating wall of liquefied natural gas storage tank. The method according to claim 1,
The center fixing device,
a second base socket fixed to the inner wall of the hull by welding;
a second coupler rod having a lower end fixed to the second base socket and extending upwardly through the central portion of the secondary insulation panel;
the socket plate fastened to the upper end of the second coupler rod and supported by the upper plate of the secondary insulation panel; and
a collar stud having a lower end fixed to the socket plate and extending upwardly;
an elastic member through which the collar stud is inserted and supported by the lower plate of the primary insulation panel;
a second setting plate supported by the elastic member; and
It is fastened to the upper end of the collar stud comprising a second fixing nut for pressing and fixing the second setting plate downwardly,
Fixed structure of insulating wall of liquefied natural gas storage tank. 3. The method according to claim 2,
The elastic member is provided with any one of plywood, polymer plastic, and an elastic body, characterized in that it functions to absorb the deformation of the hull,
Fixed structure of insulating wall of liquefied natural gas storage tank. 3. The method according to claim 2,
The socket plate is
a socket member fastened to the upper end of the second coupler rod by a screw coupling method; and
and a plate member provided to have an expanded diameter at the upper end of the socket member and supported by the upper plate of the secondary heat insulation panel,
The plate member is seated in a groove formed in the upper center of the secondary insulation panel to fix the upper portion of the secondary insulation panel,
Fixed structure of insulating wall of liquefied natural gas storage tank. 3. The method according to claim 2,
The corner fixing device,
a first base socket fixed to the inner wall of the hull by welding;
a first coupler rod having a lower end fixed to the first base socket and extending upward;
a fixing pad through which the first coupler rod is inserted and supported by the lower plate of the secondary insulation panel;
a first setting plate through which the first coupler rod is inserted and supported by the fixing pad; and
It is fastened to the upper end of the first coupler rod comprising a first fixing nut for pressing and fixing the first setting plate downwardly,
Fixed structure of insulating wall of liquefied natural gas storage tank. 6. The method of claim 5,
The fixing pad, characterized in that made of any one material of plywood, polymer plastic, and elastic body,
Fixed structure of insulating wall of liquefied natural gas storage tank. 6. The method of claim 5,
The first base socket and the second base socket, characterized in that it has a degree of freedom of 1 to 5 ° in a direction perpendicular to the inner wall of the hull,
Fixed structure of insulating wall of liquefied natural gas storage tank. 3. The method according to claim 2,
A void space is formed in each corner of the primary heat insulating panel so that a portion of the lower plate is exposed to support the elastic member,
At the point where the four primary insulation panels fixed at the same time by the center fixing device meet, a corner insulation material is inserted into the space formed by the void space, characterized in that,
Fixed structure of insulating wall of liquefied natural gas storage tank. 9. The method of claim 8,
The corner insulation has a density of 30 to 210 kg / m ³ , polyvinyl chloride (PVC), polyurethane foam (PUF), fiber-reinforced polyurethane foam (R-PUF), any one of EPS (Expanded Polystyrene) characterized in that it is provided with a material of
Fixed structure of insulating wall of liquefied natural gas storage tank. 6. The method of claim 5,
A void space is formed at each corner of the secondary heat insulation panel so that a part of the lower plate is exposed to support the fixing pad,
At a point where the four secondary insulation panels fixed at the same time by the corner fixing device meet, a corner insulation material is inserted into a space formed by the void space, characterized in that,
Fixed structure of insulating wall of liquefied natural gas storage tank. 11. The method of claim 10,
The corner insulation has a density of 30 to 210 kg / m ³ , polyvinyl chloride (PVC), polyurethane foam (PUF), fiber-reinforced polyurethane foam (R-PUF), any one of EPS (Expanded Polystyrene) characterized in that it is provided with a material of
Fixed structure of insulating wall of liquefied natural gas storage tank. In the liquefied natural gas storage tank of a double barrier structure in which a secondary insulation panel and a primary insulation panel are sequentially stacked on the inner wall of the hull,
The secondary insulation panel has a corner portion fixed to the inner wall of the hull by a corner fixing device, and the primary insulation panel has a corner portion fixed to the inner wall of the hull by a center fixing device penetrating the center of the secondary insulation panel,
The corner fixing device and the center fixing device are connected to the inner wall of the hull by a base socket, respectively, and the base socket provided in the corner fixing device and the center fixing device has a degree of freedom of 1 to 5° with respect to the inner wall of the hull. has,
The center fixing device includes a socket plate supported by the upper plate of the secondary insulating panel, characterized in that the center upper end as well as the corner part of the secondary insulating panel is additionally fixed to the inner wall of the hull,
Fixed structure of insulating wall of liquefied natural gas storage tank.

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