KR102538602B1 - LNG Storage Tanks including Bridge Structure to Prevent Membrane Damage - Google Patents

Abstract

Disclosed is a liquefied natural gas storage tank including a bridge structure for preventing membrane damage. The present invention is a liquefied natural gas storage tank comprising a heat insulating wall in which a plurality of heat insulating panels are arranged and a sealing wall installed on top of the heat insulating wall, forming a stepped portion along the circumference of the upper edge of the heat insulating panel, and adjacent to each other By installing a bridge plate so as to span between the step portions to reinforce the lower support structure of the sealing wall and reduce the rapid vertical step that occurs between the insulation panels.

Description

LNG Storage Tanks including Bridge Structure to Prevent Membrane Damage}

The present invention relates to a liquefied natural gas storage tank including a bridge structure for preventing membrane damage, and more particularly, by reinforcing the lower support structure of the membrane by a bridge structure connecting adjacent insulation panels to prevent damage to the membrane. It relates to a liquefied natural gas storage tank including a bridge structure for preventing membrane damage.

Natural gas is transported in a gaseous state through onshore or offshore gas pipelines, or transported to a distant consumer while stored in an LNG carrier in a state of liquefied natural gas (LNG). LNG is obtained by cooling natural gas to a very low temperature (approximately -163 ° C), and its volume is reduced to approximately 1/600 of that of gaseous natural gas, so it is very suitable for long-distance transportation through sea.

A storage tank (commonly referred to as a 'cargo hold') that can withstand the cryogenic temperature of LNG is installed in a structure for transporting or storing LNG, such as an LNG carrier for loading and unloading LNG to a place on land by operating the sea with LNG.

The LNG storage tank can be classified into an independent tank type and a membrane type depending on whether the cargo load directly acts on the insulation material. Normally, membrane type storage tanks are divided into GTT NO 96 type and MARK Ⅲ type, etc., and independent tank type storage tanks are divided into MOSS type and IHI-SPB type.

The NO 96 type storage tank has primary and secondary sealing walls made of Invar (36% nickel steel) membranes with a thickness of 0.5 to 0.7 mm, and insulators such as perlite powder in a plywood box. It includes primary and secondary insulation walls provided in the form of a filled insulation box.

In the NO 96 type storage tank, the primary sealing wall and the secondary sealing wall have almost the same level of liquid tightness and strength, so that cargo can be safely supported only by the secondary sealing wall for a considerable period of time when the primary sealing wall leaks.

In addition, since the NO 96 type storage tank has an insulation wall filled with insulation inside a wooden box, it can have higher compressive strength and rigidity than the MARK Ⅲ type storage tank, and has a high automation rate due to easy welding.

The MARK Ⅲ type storage tank has a primary sealing wall made of a stainless steel (SUS) membrane with a thickness of 1.2 mm, a secondary sealing wall made of triplex, and a top or bottom surface of polyurethane foam. It includes primary and secondary insulation walls provided with insulation panels bonded with wood plywood.

The primary sealing wall of the MARK Ⅲ type storage tank has corrugated corrugations to absorb thermal contraction by LNG in a cryogenic state, and since these corrugated corrugations absorb deformation of the membrane, large stress does not occur in the membrane.

The MARK Ⅲ type storage tank has disadvantages in terms of installation/manufacturing due to the low welding automation rate of the primary sealing wall with corrugated corrugations. The insulation effect of the foam is excellent and it is widely used.

The technical problem to be achieved by the present invention is to provide a thermal insulation structure of a liquefied natural gas storage tank, which prevents damage to the membrane by reinforcing the lower support structure of the membrane by a bridge structure connecting adjacent insulation panels.

In order to achieve the above object, the present invention is a liquefied natural gas storage tank comprising an insulating wall formed by arranging a plurality of insulating panels and a sealing wall installed on top of the insulating wall, the upper end of the insulating panel Steps formed along the edge circumference; And a bridge plate seated so as to span each step formed in the insulation panels adjacent to each other and connecting the insulation panels adjacent to each other, wherein the bridge plate has an upper surface identical to an upper surface of the insulation panel. Arranged to achieve a plane, it provides a liquefied natural gas storage tank comprising a bridge structure for preventing damage to the membrane, characterized in that for supporting the lower portion of the sealing wall.

The sealing wall is formed by continuously welding a plurality of unit membranes, and the edge of the unit membrane is displaced from the edge of the insulating panel, so that a middle portion of the unit membrane may be supported by the bridge plate.

The bridge plate is made of a plurality of unit plates and is continuously arranged along the edge of the insulation panel, and each unit plate may be disposed within a gap between slits formed on an upper portion of the insulation panel. .

At least one end of both ends of the bridge plate may be fixed to a stepped portion formed on the insulation panel.

And in the present invention, the heat insulation wall is composed of a secondary insulation wall made of a plurality of secondary insulation panels arranged on the inner wall of the hull, and a plurality of primary insulation panels, and the primary insulation panel disposed on top of the secondary insulation panel A heat insulating wall, wherein the sealing wall includes a secondary sealing wall installed between the secondary insulating wall and the primary insulating wall, and a primary sealing wall installed on top of the primary insulating wall, , The bridge plate may include a secondary bridge plate connecting between the secondary insulation panels adjacent to each other and a primary bridge plate connecting between the primary insulation panels adjacent to each other.

The secondary bridge plate may be fixed to at least one of the secondary insulation panels adjacent to each other, and the primary bridge plate may be fixed to all of the primary insulation panels adjacent to each other.

The primary and secondary insulation panels include an insulation material made of polyurethane foam and an upper plywood made of plywood attached to the top of the insulation material, and the secondary sealing wall includes a plurality of invar strakes Is made by being continuously welded to a tongue member installed on the upper part of the secondary insulation panel, the edge of the invar strake is displaced from the edge of the secondary insulation panel, by the secondary bridge plate A middle portion of the invar strake may be supported.

The primary sealing wall is made by continuously welding a plurality of stainless steel (SUS) membranes to an anchor strip provided on the upper portion of the primary insulation panel, and the edge of the stainless steel membrane is the primary insulation panel. Displaced from the edge of the insulation panel, the middle portion of the stainless steel membrane may be supported by the primary bridge plate.

In addition, in order to achieve the above object, the present invention is a liquefied natural gas storage tank comprising an insulating wall formed by arranging a plurality of insulating panels, and a sealing wall installed on top of the insulating wall, of the insulating panel By forming a stepped portion along the circumference of the upper end and installing a bridge plate so as to span between the adjacent stepped portions, reinforcing the lower support structure of the sealing wall and reducing the rapid vertical step occurring between the insulating panels Characterized in that, it provides a liquefied natural gas storage tank comprising a bridge structure for preventing membrane damage.

The present invention provides an improved panel type insulation system capable of configuring a secondary sealing wall with a flat invar membrane while configuring the insulation wall with an insulation panel made of polyurethane foam.

Therefore, in the present invention, in installing the secondary sealing wall on the upper part of the secondary insulation wall, automation of welding is possible, so productivity is improved, and the primary and secondary insulation walls are provided with insulation panels made of polyurethane foam, thereby insulating It has the effect of improving performance.

In addition, in the liquefied natural gas storage tank including a bridge structure for preventing membrane damage according to the present invention, the lower support structure of the sealing wall is reinforced by a bridge plate connecting between neighboring insulation panels, so that a specific part of the membrane It has the effect of preventing the phenomenon of stress concentration on

In addition, in the present invention, as the height difference between the insulation panels is made as continuous as possible by the bridge plate connecting the insulation panels adjacent to each other, stress is applied to the discontinuous portion of the membrane due to the load caused by the deformation of the hull. concentration can be avoided.

1 is a perspective view schematically showing the thermal insulation structure of a liquefied natural gas storage tank according to the present invention.
2 is a perspective view of a secondary insulation panel of a liquefied natural gas storage tank according to the present invention.
Figure 3 is a perspective view of the primary insulation panel of the liquefied natural gas storage tank according to the present invention.
Figure 4 is a view for explaining the problem of the insulation structure to which the bridge structure between the insulation panels is not applied, (a) shows the stress concentration phenomenon of the membrane according to the load of the cargo, (b) is due to the deformation of the hull It shows the stress concentration phenomenon of the membrane according to one load.
Figure 5 is an exploded perspective view showing the insulation structure of the liquefied natural gas storage tank according to the present invention to which the bridge structure between the insulation panels is applied.
6 is an internal perspective view schematically showing the structure of a secondary insulation wall to which a bridge structure between insulation panels according to the present invention is applied.
Figure 7 is a side cross-sectional view of the secondary insulation wall viewed from the direction A of Figure 6;
8 is an internal perspective view schematically showing the structure of a primary insulating wall to which a bridge structure between insulating panels according to the present invention is applied.
9 is a cross-sectional side view of the primary heat insulating wall viewed from the direction B of FIG. 8 .

In order to fully understand the present invention and the advantages in operation 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 members.

In the present invention, the use of the terms 'primary' and 'secondary' refers to whether the function is to primarily seal or insulate the LNG based on the LNG stored in the storage tank, or to seal or insulate the LNG secondarily. It is used as a criterion for distinguishing whether or not it is.

Further, by convention, the terms 'upper' or 'above' applied to elements of a tank refer to a direction toward the inside of the tank, regardless of the direction to gravity, and likewise, the terms 'lower' or 'down' to a gravity force. Regardless of the direction, it points toward the outside of the tank.

In addition, the term 'longitudinal edge' used herein refers to an edge extending along the longitudinal direction of the insulation panel, and the term 'longitudinal edge' refers to an edge extending along the width direction of the insulation panel.

1 is a perspective view schematically showing the insulation structure of a liquefied natural gas storage tank according to the present invention, Figure 2 is a perspective view of a secondary insulation panel of a liquefied natural gas storage tank according to the present invention, Figure 3 is a perspective view according to the present invention It is a perspective view of the primary insulation panel of the liquefied natural gas storage tank.

Referring to Figures 1 to 3, the liquefied natural gas storage tank according to the present invention, the secondary insulation wall 100 consisting of a plurality of secondary insulation panels 110 arranged on the inner wall of the hull (H), and the secondary A primary insulation wall 300 composed of a secondary sealing wall 200 installed on the insulation wall 100 and a plurality of primary insulation panels 310 arranged on the secondary sealing wall 200, and 1 It has a structure including a primary sealing wall 400 installed on the secondary insulation wall 300.

The primary and secondary insulation panels 310 and 110 may be manufactured as a unit panel having a width and length of approximately 1:3 in the form of a melt, preferably approximately 1m × 3m in size. However, the present invention is not limited thereto.

The secondary insulation panel 110 may be provided as a sandwich panel in which plywood plywood 112 and 113 are bonded to both the upper and lower surfaces or the upper and lower surfaces of an insulator 111 made of polyurethane foam (PUF).

Similarly, the primary insulating panel 310 may also be provided as a sandwich panel in which plywood plywood 312 and 313 are bonded to the upper and/or lower surfaces of the insulating material 311 made of polyurethane foam.

As will be described later, the primary and secondary insulation panels 310 and 110 have higher strength than general polyurethane foam in order to configure the secondary sealing wall 200 as a flat invar membrane. It is preferably made of highly reinforced polyurethane foam (Rigid Polyurethane Foam, RPUF).

The secondary insulation panel 110 may be fixed to the inner wall of the hull (H) by adhesives or studs such as mastic, and the primary insulation panel 310 is between the secondary insulation panel 110 and the By being coupled to the fixing device (S1) provided on the upper portion of the secondary insulation panel 110 in a state where the secondary sealing wall 200 is interposed, it may be fixed in close contact with the upper portion of the secondary sealing wall 200.

The secondary sealing wall 200 may be made of an Invar membrane. Specifically, a band-shaped metal plate called invar strake is continuously welded to a tongue member installed on top of the secondary insulation panel 110, so that the secondary sealing wall 200 is It may be installed on the upper part of the secondary insulation wall (100).

Through-holes may be formed in the secondary sealing wall 200 so that stud bolts included in the fixing device S1 provided on the upper portion of the secondary insulation panel 110 pass through.

The liquefied natural gas storage tank according to the present invention is prepared as a panel type insulation system in which the insulation walls 100 and 300 are formed in the form of insulation panels in which wood plywood is attached to the upper and / or lower surfaces of polyurethane foam. However, it is characterized in that the secondary sealing wall 200 is composed of a flat invar membrane in a flat form.

In general, since flat invar membranes have a low coefficient of heat shrinkage, they are not suitable for panel-type insulation systems in which an insulation panel is made of polyurethane foam. In order to apply the flat invar membrane, the insulating wall supporting the membrane should be composed of an insulating box with low heat shrinkage and high rigidity, like a conventional NO 96 type storage tank.

However, in the present invention, by providing a structure for reinforcing the rigidity of the secondary insulation wall 100, while providing the secondary insulation wall 100 in the form of an insulation panel (made of polyurethane foam) rather than an insulation box, secondary sealing It is possible to construct the wall 200 as a flat invar membrane.

Specifically, the present invention reinforces the rigidity of the secondary insulation wall 100 by installing a transverse connector (not shown) supporting both ends of the secondary sealing wall 200 at the corner of the storage tank. do.

The transverse connector is a lattice-type structure installed along the edges of the front and rear walls of the storage tank, and one end is welded to an anchoring bar provided on the inner wall of the hull to be fixed to the corner of the storage tank, The other end serves to transmit various loads applied to them to the hull by supporting each end of the primary sealing wall 400 and the secondary sealing wall 200.

The transverse connector is preferably made of an invar material with high rigidity, and an insulation box with high rigidity may be interposed between the inside of the transverse connector and between the transverse connector and the hull to support the transverse connector. there is. The insulation box may be provided in the form of filling an insulation material such as perlite powder inside the plywood box.

In the present invention, since part of the load applied to the primary and secondary sealing walls (400, 200) is transferred to the hull and resolved by the transverse connecting body installed at the corner of the storage tank, it is provided with a flat invar membrane It is possible to configure the secondary insulation wall 100 supporting the secondary sealing wall 200 as an insulation panel having weaker rigidity than the insulation box.

Therefore, in the present invention, in installing the secondary sealing wall 200 on the upper part of the secondary insulation wall 100, the welding line can be formed in a straight line, and thus the welding can be automated, thereby improving productivity. has the effect of

In addition, according to the present invention, as the first and second heat insulating walls 300 and 100 are made of polyurethane foam, heat insulating performance is also excellent. The liquefied natural gas storage tank according to the present invention, compared to the conventional NO 96 type storage tank in which the insulation wall is provided in the form of an insulation box, the thickness of the primary insulation wall is approximately 40% or more, and the thickness of the secondary insulation wall It is possible to achieve the same insulating effect while reducing by about 20% or more.

The primary sealing wall 400 directly contacts and seals LNG, and may be provided with a stainless steel (SUS) membrane formed with a plurality of corrugated corrugations toward the inside of the storage tank to absorb shrinkage caused by cryogenic temperatures.

The primary sealing wall 400 may be formed of a plurality of unit membranes having a size corresponding to the unit panel of the primary insulation panel 310, and a plurality of unit membranes are provided on top of the primary insulation panel 310 By being welded to the anchor strip (anchor strip, 316) without gaps, the primary sealing wall 400 can be installed on top of the primary insulation wall (300).

Anchor strip 316 may be provided with a metal plate of invar material, after being inserted into the groove formed in the primary upper plywood 312 of the primary insulation panel 310 made of plywood, rivets or screws It may be mechanically fastened by a fastening member such as a screw.

Here, since the fixing part (S2) coupled with the fixing device (S1) is formed at the vertical edge of the primary insulation panel 310 as described later, the anchor strip 316 is the upper surface of the primary insulation panel 310 It is preferable to be placed on the inside rather than at the corner.

In the present invention, it is suggested that the anchor strip 316 is provided in a strip shape in two directions orthogonal to each other as a preferred embodiment, and the strip in the two directions is the center line in the width direction and the center line in the longitudinal direction of the primary insulation panel 310 may be extended accordingly.

Edges of the unit membranes constituting the primary sealing wall 400 are bonded to the anchor strip 316 by welding, and at this time, the edges of adjacent unit membranes may be overlap-welded in a state where the edges of the unit membranes overlap each other.

One unit membrane constituting the primary sealing wall 400 may be disposed so as to span over the four primary insulation panels 310 .

On the other hand, the present invention is characterized by having a structure in which the secondary insulation panel 110 and the primary insulation panel 310 disposed thereon cross each other.

As shown in the drawing, the primary insulation panel 310 may be arranged offset from each other so that the corner portion is placed in the center of the secondary insulation panel 110, and accordingly, one primary insulation panel 310 is lower It is arranged so as to span the upper surface of the four secondary insulation panels 110 disposed on.

For the cross arrangement of the primary insulation panel 310 and the secondary insulation panel 110, the fixing device (S1) provided for coupling between them will be disposed inside the corner from the top of the secondary insulation panel 110. can

One fixing device (S1) is disposed at the center of the secondary insulation panel 110, and the remaining fixing devices are spaced apart from the fixing device (S1) disposed at the center by the same distance in the longitudinal direction of the panel in the front and rear directions. (S1) may be arranged respectively.

At this time, the distance (L1) from the fixing device (S1) disposed at the center of the secondary insulation panel 110 to the fixing device (S1) disposed to be spaced apart from the front and rear is the width direction of the secondary insulation panel (110). It may be arranged so as to be twice the distance (L2) from the edge to the adjacent fixture (S1).

The fixing device (S1) is disposed on the center line (C) in the width direction on the secondary insulation panel 110, the displacement of the fixing device (S1) in the width direction by the stress acting on the panel can be minimized .

In addition, the slits 114 are formed at positions spaced apart by the same distance from the front and rear of each fixing device S1, so that the displacement of the fixing device S1 in the longitudinal direction due to the stress acting on the panel is minimized. It can be.

The interval between the slits 114 formed on the secondary insulation panel 110 may be formed constant, and as shown in the drawing, the slit 114 is attached to the top of the secondary insulation panel 110 2 It may also be formed together with the car upper plywood 112.

The fixing unit (S2) provided on the primary insulation panel 310 for coupling with the fixing device (S1) may be disposed at the side end vertical corner portion including the four corners of the primary insulation panel 310. Fixing part (S2) may be spaced apart to have the same interval along the longitudinal direction of the primary insulation panel (310).

The fixing part (S2) may be provided with a groove having a semicircular or fan-shaped cross section, and a stud provided in the fixing device (S1) is inserted into the fixing part (S2) by fastening a nut to the fixing part. By pressing (S2), the primary insulation panel 310 may be fixedly installed on the secondary insulation panel 110.

In the present invention, a preferred embodiment in which three fixing devices (S1) are provided on the upper portion of the secondary insulating panel 110 and eight fixing parts (S2) are provided at the vertical corners of the primary insulating panel 310. is presented as

According to this embodiment, the fixing unit (S1) disposed in the center of the secondary insulation panel 110 is coupled to the fixing portion (S2) formed on the four primary insulation panels 310 at once, secondary insulation The fixing unit (S1) disposed spaced apart from the center in the panel 110 is coupled to the fixing part (S2) formed on the two primary insulation panels 310 at once.

In this way, the primary insulation panels 310 adjacent to each other may share the fixing device (S1) disposed therebetween, and in this embodiment, three fixing devices (S1) in one secondary insulation panel 110 ) Just by providing, it is possible to secure 8 points or points of support of the primary insulation panel 310.

That is, the present invention is to secure the support point of the primary insulation panel 310 to the maximum even with a small number of fixing devices (S1) by the cross arrangement of the secondary insulation panel 110 and the primary insulation panel 310. It is possible, and thus the stability of the support structure is improved, as well as the productivity of the insulation panel is improved.

Unexplained numeral 115 is an insertion groove for inserting a tongue to which an invar strake constituting the secondary sealing wall 200 is welded, and a non-explained numeral 315 is a protrusion of the tongue inserted into the insertion groove and welded thereto It is an accommodation groove for accommodating the bent portion of the secondary sealing wall 200 to be.

In addition, non-explained numeral 314 is a slit formed in the transverse and longitudinal directions while having regular intervals on the top of the primary insulation panel 310 to disperse the concentration of stress due to heat shrinkage.

As described above, the liquefied natural gas storage tank according to the present invention is different from the conventional NO 96 type storage tank in that an insulation panel to which polyurethane foam is applied is applied outside the corner portion of the storage tank.

In the conventional NO 96 type storage tank, the secondary sealing wall is supported by a highly rigid insulation box, and the heat shrinkage of the insulation box is not large, so that the vertical step or the gap between the insulation boxes in the horizontal direction is properly controlled. However, there is still a gap between the insulation boxes, and there is no structure supporting the secondary sealing wall in this part. In the conventional NO 96 type storage tank, the pressure acting on the gap is not large, but if the primary sealing wall is damaged and the load of LNG acts, the corresponding part is inevitably weakened.

On the other hand, in the present invention, in that the heat insulating walls 300 and 100 supporting the primary sealing wall 400 and the secondary sealing wall 200 are composed of the insulating panels 310 and 110 made of polyurethane foam, Since the amount of heat shrinkage of the insulating walls 300 and 100 is greater under low temperature conditions than that of the NO 96 type storage tank, deformation in the vertical and horizontal directions is greater.

Therefore, when the insulation panels 110 and 310 constituting the insulation walls 100 and 300 are thermally contracted by the cryogenic temperature of LNG, as shown in (a) of FIG. 4, between the insulation panels 110 and 310 adjacent to each other A larger gap occurs, and in this state, when the sealing walls 200 and 400, that is, the membrane receives the load of the cargo (LNG), a phenomenon in which stress is concentrated in a specific region occurs.

In addition, as shown in (b) of FIG. 4, a vertical step difference may occur between neighboring insulation panels 310 and 110 due to a load caused by deformation of the hull, and stress is generated in the discontinuous portion of the membrane caused by the height step difference. this can be focused.

In the liquefied natural gas storage tank according to the present invention, the deformation in the vertical direction of the insulation walls 300 and 100 is relieved to some extent by the configuration in which the primary insulation panel 310 and the secondary insulation panel 110 are intersected with each other It can be, but it's not a perfect solution.

If stress concentration is excessively applied to the membrane, the sealing walls 200 and 400 may be damaged, leading to serious problems such as breakage of airtightness. Therefore, countermeasures are required.

Hereinafter, the structure of the liquefied natural gas storage tank including the bridge structure for preventing damage to the membrane according to the present invention provided to solve the problem pointed out in FIG. 4 will be described.

Figure 5 is an exploded perspective view showing the insulation structure of the liquefied natural gas storage tank according to the present invention to which the bridge structure between the insulation panels is applied.

6 is an internal perspective view schematically showing the structure of a secondary insulation wall to which a bridge structure between insulation panels according to the present invention is applied, and FIG. 7 is a side cross-sectional view of the secondary insulation wall viewed from the direction A in FIG.

In addition, Figure 8 is an internal perspective view schematically showing the structure of the primary insulation wall to which the bridge structure between the insulation panels according to the present invention is applied, Figure 9 is a side cross-sectional view of the primary insulation wall viewed from the direction B of Figure 8.

For reference, in FIGS. 6 and 8 , dots are marked on the first and second bridge plates 320 and 120 in order to clearly distinguish between the configurations.

5, the liquefied natural gas storage tank according to the present invention, the secondary bridge plate 120 connecting between the secondary insulation panels 110 adjacent to each other, and the primary insulation panels 310 adjacent to each other A primary bridge plate 320 connecting between them may be further included.

The primary and secondary bridge plates 320 and 120 may be made of plywood, which is the same material as the upper plywood 312 and 112 of the insulation panels 310 and 110. However, the present invention is not limited thereto, and the first and second bridge plates 320 and 120 may be provided as metal plates, of course.

First, referring to FIGS. 5 to 7, looking in detail at the bridge structure applied to the secondary insulation wall 100, the secondary bridge plate 120 is arranged to span between the secondary insulation panels 110 adjacent to each other. It can be seen that the structure is

Secondary insulation panels 110 adjacent to each other have upper edges connected to each other by a secondary bridge plate 120, and a stepped portion in which the secondary bridge plate 120 is seated at the upper edge of the secondary insulation panel 110. can be formed

Specifically, the secondary insulation panel 110 is formed stepwise along the circumference of the secondary upper plywood 112 and may include a stepped portion on which the secondary bridge plate 120 is seated. The upper surface of the secondary bridge plate 120 may form the same plane as the upper surface of the secondary upper plywood 112 .

Since the secondary sealing wall 200 is installed to span the upper portion of the secondary insulation panels 110 adjacent to each other, two disposed to span the stepped portion formed at the upper edge of the secondary insulation panels 110 adjacent to each other. The secondary bridge plate 120 supports the middle portion of the secondary sealing wall 200 .

In addition, the secondary bridge plate 120 is arranged in the longitudinal direction of the storage tank and the longitudinal secondary bridge plate 121 connecting the longitudinal edges of the neighboring secondary insulation panels 110 to each other, and the storage tank It may include a transverse secondary bridge plate 122 that is arranged in the transverse direction and connects the width direction edges of the neighboring secondary insulation panels 110 to each other.

The longitudinal secondary bridge plate 121 is made of a plurality of unit plates, and may be continuously arranged along the longitudinal edge of the secondary insulation panel 110 .

The unit plate constituting the longitudinal secondary bridge plate 121 may be disposed within the interval between the slits 114 formed in the secondary insulation panel 110. That is, each unit plate may be disposed between the slits 114 and the slits 114, and for this purpose, the unit plate may be manufactured with a length corresponding to or shorter than the interval between the slits 114.

This is to ensure that the effect of the slit 114 dispersing the thermal stress on the secondary insulation panel 110 is not hindered by the longitudinal secondary bridge plate 120.

Similarly, the transverse secondary bridge plate 122 is also made of a plurality of unit plates, and may be continuously arranged along the width direction edge of the secondary insulation panel 110, wherein each unit plate is a secondary insulation panel It may be disposed within the gap between the insertion grooves 115 formed in (110).

The secondary bridge plate 120 may be fixed to the stepped portion formed on the edge of the upper end of the secondary insulation panel 110 by screws or rivets.

At this time, in the case of the secondary insulation panel 110, since heat shrinkage occurs relatively smaller than the primary insulation panel 310, at least one of both ends of the secondary bridge plate 120 may be fixed.

Preferably, the short side of the secondary insulation panel 110, that is, the transverse secondary bridge plate 122 arranged along the edge in the width direction, both ends are both fixed to the stepped portion of the secondary insulation panel 110 on both sides It may be, the long side of the secondary insulation panel 110, that is, the longitudinal secondary bridge plate 121 arranged along the longitudinal edge, only one of both ends is fixed to the stepped portion of the secondary insulation panel 110 can

Next, referring to FIGS. 5, 8 and 9, it can be seen that the bridge structure applied to the primary insulation wall 300 is provided in a similar form to the bridge structure applied to the secondary insulation wall 100 described above. there is.

That is, the primary insulation panels 310 adjacent to each other have upper edges connected to each other by the primary bridge plate 320, and the primary bridge plate 320 is seated on the upper edge of the primary insulation panel 310. A stepped portion may be formed.

Specifically, the primary insulation panel 310 may include a stepped portion formed along the circumference of the primary upper plywood 312 so that the primary bridge plate 320 is seated, and at this time, the stepped portion is seated The upper surface of the primary bridge plate 320 may form the same plane as the upper surface of the primary upper plywood 312 .

Since the unit membrane of the primary sealing wall 400 is installed to span the upper portion of the primary insulation panels 310 adjacent to each other, it spans the stepped portion formed at the upper edge of the primary insulation panels 310 adjacent to each other. The disposed primary bridge plate 320 supports the middle portion of the primary sealing wall 400 .

In addition, the primary bridge plate 320 is arranged in the longitudinal direction of the storage tank and the longitudinal primary bridge plate 321 connecting the longitudinal edges of the neighboring primary insulation panels 310 to each other, and the storage tank It may include a transverse primary bridge plate 322 which is arranged in the transverse direction and connects the width direction edges of the neighboring primary insulation panels 310 to each other.

The longitudinal primary bridge plate 321 and the transverse primary bridge plate 322 may be made of a plurality of unit plates, and each unit plate is formed in a grid shape on top of the primary insulation panel 310 It may be disposed within the gap between the slits 314 to be.

The primary bridge plate 320 may be fixed by fastening members such as screws or rivets to the stepped portion formed on the upper edge of the primary insulation panel 310 .

At this time, the primary insulation panel 310 is exposed to a lower temperature than the secondary insulation panel 110, and the lower panel is not bonded by bonding, so heat shrinkage occurs significantly. Therefore, it is preferable that both ends of the primary bridge plate 320 are fixed to both ends of the stepped portion of both primary insulation panels 310 in order to serve to control the heat shrinkage of the panel.

On the other hand, as shown in Figure 8, by providing an anchor strip on the primary bridge plate 320 connected to the anchor strip 316 provided on the primary insulation panel 310, the continuity of the anchor strip 316 can keep this.

Non-explained numeral 130 is a flat joint made of glass wool inserted into the space between the secondary insulation panels 110. Although not shown in the drawing, such a flat joint 130 may be inserted into the space formed between the primary insulation panels 310.

In the liquefied natural gas storage tank including a bridge structure for preventing membrane damage according to the present invention, the sealing walls 200 and 400 are connected by bridge plates 120 and 320 connecting adjacent insulation panels 110 and 310 to each other. ) By reinforcing the lower support structure, there is an effect of preventing stress from being concentrated on a specific part of the membrane.

In addition, according to the present invention, as the height difference between the insulation panels 110 and 310 is made as continuous as possible by the bridge plates 120 and 320 connecting between the insulation panels 110 and 310 adjacent to each other, It is possible to prevent stress from being concentrated on a discontinuous portion of the membrane due to a load due to deformation.

The present invention is not limited to the described embodiments, and it is obvious 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. Therefore, it should be said that such modifications or variations fall within the scope of the claims of the present invention.

100: secondary insulation wall 110: secondary insulation panel
111: secondary insulation 112: secondary upper plywood
113: secondary lower plywood 114: slit
115: insertion groove 120: secondary bridge plate
121: longitudinal secondary bridge plate 122: transverse secondary bridge plate
200: secondary sealing wall
300: primary insulation wall 310: primary insulation panel
311: primary insulation 312: primary upper plywood
313: primary lower plywood 314: slit
315: receiving groove 316: anchor strip
320: primary bridge plate 321: longitudinal primary bridge plate
322: transverse primary bridge plate
400: primary sealing wall
S1: Fixing device S2: Fixing part

Claims (9)

An insulation wall comprising a secondary insulation wall made of a plurality of secondary insulation panels arranged on the inner wall of the hull and a primary insulation wall made of a plurality of primary insulation panels and disposed on top of the secondary insulation wall, and the above In the liquefied natural gas storage tank including a sealing wall including a secondary sealing wall installed between the secondary insulation wall and the primary insulation wall and a primary sealing wall installed on top of the primary insulation wall,
a stepped portion formed along a circumference of an upper edge of the insulation panel; and
It is seated so as to span each step formed in the insulation panels adjacent to each other and connects the insulation panels that are adjacent to each other, but the upper surface is arranged to form the same plane as the upper surface of the insulation panel to support the lower portion of the sealing wall. Including a bridge plate to
The bridge plate,
A secondary bridge plate connecting the secondary insulation panels adjacent to each other; and
Including a primary bridge plate connecting between the primary insulation panels adjacent to each other,
A liquefied natural gas storage tank with a bridge structure to prevent membrane damage. The method of claim 1,
The sealing wall is made by continuously welding a plurality of unit membranes,
The edge of the unit membrane is displaced from the edge of the insulating panel, and the middle portion of the unit membrane is supported by the bridge plate.
A liquefied natural gas storage tank with a bridge structure to prevent membrane damage. The method of claim 1,
The bridge plate is made of a plurality of unit plates and is continuously arranged along the edge of the insulation panel,
Characterized in that each of the unit plates is disposed within a gap between slits formed on an upper portion of the insulation panel,
A liquefied natural gas storage tank with a bridge structure to prevent membrane damage. The method of claim 1,
The bridge plate is characterized in that at least one end of both ends is fixed to the stepped portion formed on the insulation panel,
A liquefied natural gas storage tank with a bridge structure to prevent membrane damage. delete The method of claim 1,
The secondary bridge plate is fixed to at least one of the secondary insulation panels adjacent to each other,
Characterized in that the primary bridge plate is fixed to all of the primary insulation panels adjacent to each other,
A liquefied natural gas storage tank with a bridge structure to prevent membrane damage. The method of claim 1,
The primary and secondary insulation panels include an insulation material made of polyurethane foam and an upper plywood made of plywood attached to the top of the insulation material,
The secondary sealing wall is made by continuously welding a plurality of invar strakes to a tongue member installed on top of the secondary insulation panel,
Characterized in that the edge of the invar strake is displaced from the edge of the secondary insulation panel, and the middle portion of the invar strake is supported by the secondary bridge plate.
A liquefied natural gas storage tank with a bridge structure to prevent membrane damage. The method of claim 7,
The primary sealing wall is made by continuously welding a plurality of stainless steel (SUS) membranes to an anchor strip provided on top of the primary insulation panel,
Characterized in that the edge of the stainless steel membrane is displaced from the edge of the primary insulation panel, and the middle portion of the stainless steel membrane is supported by the primary bridge plate.
A liquefied natural gas storage tank with a bridge structure to prevent membrane damage. delete

Images