KR102361517B1 - Insulation System For Membrane Type in LNG Storage Tank - Google Patents

Abstract

The present invention relates to an insulation system for a liquefied gas cargo hold, wherein the thickness of the primary insulation layer is set within 10% of the thickness of the secondary insulation layer, and a cross-shaped fixing unit capable of fixing the membrane and the primary insulation layer together (membrane and insulation) securing unit) and improving the fixing structure of the primary insulation layer and the membrane sealing structure, it is possible to maintain structural rigidity and insulation performance while realizing weight reduction and slimming, as well as simplifying the cargo hold manufacturing process to improve workability and increase production cost can save

Description

Insulation system for liquefied gas cargo hold {Insulation System For Membrane Type in LNG Storage Tank}

The present invention relates to a thermal insulation system for a liquefied gas cargo hold, and more specifically, the thickness of the primary insulating layer is set within 10% of the thickness of the secondary insulating layer, and the cross-shaped fixing that can fix the membrane and the primary insulating layer together It relates to an insulation system for a liquefied gas cargo hold in which the fixing structure of the primary insulation layer and the membrane sealing structure are improved by installing a membrane and insulation securing unit.

In general, natural gas is transported in a gaseous state through land or sea gas pipelines, or stored in an LNG carrier as liquefied natural gas (hereinafter, abbreviated as LNG) and transported to remote consumers. .

LNG is obtained by cooling natural gas to a cryogenic temperature of approximately -163°C, and its volume is reduced to approximately 1/600 compared to that of natural gas in gaseous state, so it is very suitable for long-distance transportation by sea.

An LNG carrier for loading and unloading LNG to and from an onshore customer by navigating the sea, or an LNG RV (regasification vessel) that regasifies the stored LNG and unloads it into natural gas after arriving at an onshore demand by operating the sea is equipped with a storage tank that can withstand the cryogenic temperature of liquefied natural gas, that is, a cargo hold.

Recently, the demand for floating offshore structures such as LNG FPSO (floating, production, storage and offloading) and LNG FSRU (floating storage and regasification unit) is gradually increasing. A cargo hold to be installed is provided.

The LNG FPSO is a floating offshore structure used to liquefy produced natural gas directly at sea and store it in a cargo hold, and to transfer the LNG stored in the cargo hold to an LNG carrier when necessary.

An LNG FSRU is a floating offshore structure that stores LNG unloaded from an LNG carrier at sea far from land in a cargo hold, then vaporizes the LNG as needed and supplies it to onshore consumers.

As described above, cargo holds for storing LNG in a cryogenic state are installed in offshore structures such as LNG carriers, LNG RVs, LNG FPSOs, and LNG FSRUs that transport or store liquid cargo such as LNG at sea.

Cargo holds can be classified into an independent tank type and a membrane type depending on whether the load of the cargo acts directly on the insulation material.

In general, membrane type cargo holds are divided into GTT NO 96 type and TGZ Mark Ⅲ type, etc., and independent tank type cargo holds are divided into MOSS type and IHI-SPB type.

Membrane-type cargo holds have different insulation materials and structures depending on the type of special metal plate. GTT NO96 uses a thin plate made of Invar (an alloy with a very low coefficient of thermal expansion with iron and nickel as the main components), and MARK III uses stainless steel. Use a thin sheet of material.

The cargo hold of the GTT NO 96 type has first and second membranes made of Invar steel with a thickness of 0.5 to 1.5 mm, and first and second heat insulating walls made of plywood box and perlite, etc. They are alternately stacked and installed inside the hull.

The insulation system of the GTT NO 96 cargo hold consists of two layers of insulation boxes made of invar steel (36% nickel steel), pearlite and plywood, and plywood is used as a material for insulation boxes.

The thermal insulation system of the conventional liquefied gas cargo hold will be described as follows.

The heat insulation system of a conventional liquefied gas cargo hold includes a primary membrane and a secondary membrane made of 0.5-0.7 mm thick Invar steel; a primary insulating layer and a secondary insulating layer made of plywood box and perlite; a heat insulating layer fixing unit for fixing the first heat insulating layer and the second heat insulating layer; A membrane fixing unit for fixing the primary membrane and the secondary membrane is provided.

1 is a cross-sectional view showing a membrane fixing unit in a conventional thermal insulation system.

Referring to FIG. 1 , a tongue fixing groove 1a is formed in a thermal insulation layer for a membrane securing unit in a conventional thermal insulation system.

The lower end of the tongue 3 for fixing the membrane is inserted into the tongue fixing groove 1a, and the upper end of the tongue 3 for fixing the membrane is configured to protrude above the heat insulating layer.

A hole (3a) for position adjustment is formed at the upper end of the tongue (3) for fixing the membrane. A membrane 4 is laminated on the upper surface of the heat insulating layer 1 , and the membrane 4 is seam welded to the membrane fixing tongue 3 . The position adjustment hole 3a is used to adjust the level of the membrane 4 by moving the membrane fixing tongue 3 up and down.

However, in the conventional insulation system of a liquefied gas cargo hold, since a separate height adjustment operation is required to match the level of the membrane 4 during the membrane sealing welding operation, there is a problem in that workability is deteriorated.

In addition, in order to maintain the insulation performance of the insulation layer, due to the technical limitation of maintaining a certain thickness without reducing the thickness of the insulation layer, there is a problem in that the manufacturing workability of the insulation system of the cargo hold is lowered and the production cost is increased.

US Patent No. 6,035,795 US Patent Publication No. 2003-0000949 Korean Patent Publication No. 10-2000-0011347 Korean Patent Publication No. 10-2000-0011346

The present invention is to solve the above-described problems, and the thickness of the primary insulation layer is set within 10% of the thickness of the secondary insulation layer, and a cross-shaped fixing unit capable of fixing the membrane and the primary insulation layer together (membrane and insulation securing) unit) to improve the fixed structure and membrane sealing structure of the primary insulation layer, while realizing weight reduction and slimming, while maintaining structural rigidity and insulation performance, as well as simplifying the cargo hold manufacturing process to improve workability and reduce production costs An object of the present invention is to provide an insulation system for a liquefied gas cargo hold that can be saved.

In order to achieve the above object, the insulation system of the liquefied gas cargo hold of the present invention is a secondary insulation layer for secondary insulation of the cargo hold based on the inner wall of the hull; a secondary membrane made of Invar steel disposed on the secondary heat insulating layer; a first insulating layer disposed on the secondary membrane to primarily insulate the cargo hold; a primary membrane made of Invar steel disposed on the primary heat insulating layer; a first securing unit for fixing the first membrane, the second membrane, and the first heat insulating layer; and a second fixing unit configured to differently set a spring constant according to a deformation condition of the inner wall of the hull of the cargo hold to fix the secondary heat insulating layer.

The insulation system of the present invention is laminated in the order of the secondary insulation layer, the secondary membrane, the primary insulation layer, and the primary membrane from the inner wall of the hull (the inner wall of the tank).

The thickness of the first heat insulating layer may be formed within 10% of the thickness of the second heat insulating layer. The first fixing unit is installed between the boundary portions between the primary insulating layers and in the slits of the secondary insulating layers.

The first fixing unit may include: a vertically unbent member inserted between the boundary portions between the first heat insulation layers and into the slits of the second heat insulation layer and positioned vertically, the end portion being positioned to protrude relative to the second heat insulation layer; "L consisting of a first fixing part fixed to both sides of the vertical unbent member and inserted into the slit, and a second fixing part fixed to the secondary heat insulating layer after being bent from the first fixing part in the horizontal direction. "Shaped second bending member; a second fastening member fastened in a fastening hole formed in the second fixing part of the "L"-shaped second bending member to fix the "L"-shaped second bending member to the secondary heat insulating layer; First bent "L" shape consisting of a first fixing part fixed to both sides of the vertically unbent member, and a second fixing part fixed to the primary heat insulating layer after being bent from the first fixing part in the horizontal direction absence; and a first fastening member fastened in a fastening hole formed in the second fixing part of the "L"-shaped first bending member to fix the "L"-shaped first bending member to the first heat insulating layer; .

A stepped groove is formed in the second heat insulating layer, the second fixing part of the "L"-shaped second bending member is seated in the stepped groove, and a stepped groove is formed in the first heat insulating layer, and the "L" in the stepped groove The second fixing part of the first curved member may be seated.

The first fixing part of the "L"-shaped second bending member is bent and inserted into the slit and welded to the vertical non-bending member, and the first fixing part of the "L"-shaped first bending member is bent toward the liquefied gas. After being suture-welded to the vertical non-bending member.

The secondary membrane may be wrapped and welded to the second fixing part of the "L"-shaped second bending member or seam-welded to the vertical non-bending member of the "L"-shaped second bending member.

The primary membrane may be wrap-welded to the second fixing portion of the “L”-shaped first bending member or suture-welded to the first fixing portion of the “L”-shaped first bending member.

A chamfer for preventing interference with the "L"-shaped second bending member is formed at a corner of the upper end of the secondary heat insulating layer, and a chamfer for preventing interference with the primary membrane is formed at an edge of the lower end of the primary insulating layer An addition may be formed.

The second fixing unit may include: a stud bolt fixed to the inner wall of the hull on which the secondary heat insulation layer is installed; a nut fastened to the stud bolt for fixing the secondary heat insulating layer; an elastic body fitted to the stud bolt and adjusting the degree of elasticity according to the degree of deformation of the inner wall of the hull of the secondary heat insulating layer; a compression fixing mold inserted into the stud bolt and stacked on the elastic body to prevent local damage to the secondary heat insulating layer; and a reference plate for height adjustment according to the degree of deformation of the inner wall of the hull of the secondary heat insulating layer.

A filling plug may be installed in a space between the secondary heat insulating layers positioned above the compression fixing mold.

As described above, the thickness of the primary insulation layer is set to less than 10% of the thickness of the secondary insulation layer, and a cross-shaped fixing unit (membrane and insulation securing unit) capable of fixing the membrane and the primary insulation layer together is installed. By improving the fixed structure of the insulation layer and the sealing structure of the membrane, it is possible to achieve weight reduction and slimming while maintaining structural rigidity and thermal insulation performance, as well as simplifying the cargo hold manufacturing process to improve workability and significantly reduce production costs.

1 is a cross-sectional view showing a membrane fixing unit in a conventional thermal insulation system;
Figure 2 is a perspective view showing the insulation system of the liquefied gas cargo hold according to the present invention;
Figure 3 is a longitudinal sectional view showing the first fixing unit in the insulation system of the liquefied gas cargo hold according to the present invention;
Figure 4 is a longitudinal sectional view showing the second fixing unit in the insulation system of the liquefied gas cargo hold according to the present invention;

Hereinafter, with reference to the accompanying drawings, it will be described in detail with respect to the insulation system of the liquefied gas cargo hold according to a preferred embodiment of the present invention.

Figure 2 is a perspective view showing the insulation system of the liquefied gas cargo hold according to the present invention, Figure 3 is a longitudinal cross-sectional view showing the first fixing unit in the insulation system of the liquefied gas cargo hold according to the present invention, Figure 4 is liquefied gas according to the present invention It is a longitudinal cross-sectional view showing the second fixing unit in the insulation system of a gas cargo hold.

2 to 4 , the thermal insulation system according to the present invention includes a secondary thermal insulation layer 130 , a secondary membrane 140 , a primary thermal insulation layer 110 , a primary membrane 120 , and a first fixing unit (first). securing) 150 , and a second fixing unit (Secondary securing) 170 .

The secondary insulation layer 130, the secondary membrane 140, the primary thermal insulation layer 110, and the primary membrane 120 are arranged (stacked) in this order from the hull inner wall (refer to FIG. 1).

The secondary heat insulation layer 130 serves to insulate the cargo hold secondarily, and is fixed by maintaining a predetermined interval with the inner wall 1 of the hull with a resin (not shown) interposed inside the hull. The secondary heat insulating layer 130 may be formed of a polyurethane foam reinforced with glass fiber, or a sandwich type of plywood, an insulating material, or a composite structure.

The secondary membrane 140 is made of Invar steel and is sealed and welded on the secondary heat insulating layer 130 . As the welding method, both lapping welding and seam welding are possible.

The primary insulating layer 110 serves to primarily insulate the cargo hold and is fixedly installed at a position covering the secondary membrane 140 .

The primary insulating layer 110 and the secondary insulating layer 130 have different cross-sectional areas and heights. The width of the primary thermal insulation layer may be ½ of the secondary thermal insulation layer, and the length may be doubled.

The thickness of the primary insulating layer 110 may be formed within 10% of the thickness of the secondary insulating layer 130, preferably 5-10%.

The present invention can improve the fixing structure of the primary insulating layer and the sealing structure of the membrane by making the primary insulating layer a minimum thickness while maintaining the strength of the primary insulating layer.

The primary insulating layer 110 is a single-piece structure in which a plurality of plywoods are laminated in the thickness direction, or a plurality of laminated plywoods and an insulating material, for example, glass wool, a density of 40 to 50 kg/m 3 low-density polyurethane foam It may be composed of a composite structure composed of an insulating material of the material.

The primary membrane 120 is made of Invar steel and is sealed and welded on the primary heat insulating layer 110 . The welding method can be either wrapping welding or sealing welding.

The first fixing unit 150 serves to fix the primary membrane 120 , the secondary membrane 140 , and the primary heat insulating layer 110 together. It may be made of Invar steel and has a cross-shaped structure can be

And the second fixing unit 170 serves to fix the secondary heat insulating layer 130 by differently setting the elasticity (spring constant) according to the deformation condition of the inner wall (1) of the hull of the cargo hold.

Hereinafter, the configuration of the first fixing unit 150 will be described in detail with reference to FIG. 3 .

The first fixing unit 150 is installed between the boundary portions between the first heat insulating layers 110 and in the slits S of the second heat insulating layer 130 . Here, the boundary part refers to a gap between the unit primary insulating layers, and the slit of the secondary insulating layer refers to a long groove formed in the insulating layer in order to prevent deformation due to a difference in the expansion rate between the plywood and the insulating material.

The first fixing unit 150 includes a vertical non-bending member 151 , an “L”-shaped second bending member 152 , a second fastening member 153 , an “L”-shaped first bending member 154 , and a first fixing unit 150 . 1 includes a fastening member 155 .

The vertical non-bend member 151 is vertically positioned by being inserted into the slit S of the second heat insulating layer 130 and between the boundaries between the first heat insulating layers, and the upper end portion is positioned to protrude relatively than the first heat insulating layer 110 . Here, the expression of the upper end portion has been described with reference to FIG. 3 , and the expression of the upper side may be changed to the lower side or the side according to the position of the cargo hold.

The "L"-shaped second bending member 152 has an "L"-shaped bent shape and is fixed to both sides of the vertical non-bending member 151, and includes a first fixing part 152a and a second fixing part 152b. ) can be composed of Here, since the description of the first fixing part 152a and the second fixing part 152b is only arbitrarily determined for convenience of explanation, it is not necessarily divided into two parts, and can be divided into more parts. Of course.

The first fixing part 152a may be inserted into the slit S and fixed by suture welding to the vertical non-bending member 151 . The second fixing part 152b is bent from the first fixing part 152a in the horizontal direction and then fixed to the secondary heat insulating layer 130 . A stepped groove 130a is formed in the secondary heat insulating layer 130 , and the second fixing part 152b of the "L"-shaped second bending member 152 is seated in the stepped groove 130a. The reason for providing the stepped groove 130a is to make the level of the second fixing part 152b and the secondary heat insulating layer 130 the same to seal and weld the secondary membrane 140 flat.

A fastening hole H is formed in the second fixing part 152b, and a second fastening member 153, for example, a rivet or bolt is fastened in the fastening hole H.

The secondary membrane 140 may be wrapped and welded to the second fixing part 152b of the "L"-shaped second bending member 152 or suture-welded to the vertical non-bending member 151 .

A chamfer 130b for preventing interference with the "L"-shaped second bending member 152 may be formed at an upper edge of the secondary heat insulating layer 130 .

In addition, the "L"-shaped first bending member 154 has an "L"-shaped bent shape and is fixed to both sides of the vertical non-bending member 151, the first fixing part 154a and the second fixing part (154b).

The first fixing part 154a is fixed by suture welding to both sides of the vertical unbent member 151 . The first fixing part 151a may be welded upward. The second fixing part 154b is bent from the first fixing part 154a in the horizontal direction and then fixed to the primary heat insulating layer 110 . A stepped groove 110a is formed in the primary heat insulating layer 110 , and the second fixing part 154b of the "L"-shaped first bending member 154 is seated in the stepped groove 110a. The reason for providing the stepped groove 110a is to make the level of the second fixing part 154b and the primary heat insulating layer 110 the same to seal and weld the primary membrane 120 flat. A fastening hole H is formed in the second fixing part 154b, and a first fastening member 155, for example, a rivet or bolt is fastened in the fastening hole H.

The primary membrane 120 may be wrapped welded to the second fixing part 154b of the "L"-shaped first bent member 154 or suture welded to the vertical non-bend member 151 .

A chamfer 110b for preventing interference with the "L"-shaped second bending member 152 may be formed at the lower edge of the primary heat insulating layer 110 .

Hereinafter, the configuration of the second fixing unit 170 will be described in detail with reference to FIG. 4 .

Referring to FIG. 4 , the insulation system according to the present invention includes a second insulation securing unit 170 .

The second fixing unit (secondary insulation securing) 170 can be fixed by setting a spring constant differently according to the deformation condition of the inner wall of the hull 1 of the cargo hold, and as an example, a stud bolt (stud bolt). ) 171 , a nut 172 , an elastic body (washer spring) 173 , a mold for compression fixing 174 , and a reference wedge 175 .

In other words, the stud bolt (stud bolt) 171 is fixed to the hull inner wall (1) in which the secondary heat insulation layer (130) is installed. The fixing method of the stud bolt 171 may be fixed by a conventional fastening means, for example, welding.

A nut 172 is fastened to the stud bolt 171 for fixing the secondary heat insulating layer 130 .

The elastic body (washer spring) 173 is fitted to the stud bolt 171 , and is configured to adjust the elasticity according to the degree of deformation of the hull inner wall 1 of the secondary heat insulating layer 130 . In order to adjust the elasticity, the elastic body 173 may be replaced with a 3-stage or 5-stage type.

The compression fixing mold 174 is inserted into the stud bolt 171 to prevent local damage to the secondary heat insulating layer 130 and is configured to be stacked on the elastic body 173, and high-density PUF, compressed wood, etc. may be used.

A reference wedge 175 is fixed to the hull inner wall 1 , and a stud bolt 171 is vertically fixed to the reference plate 175 . The reference plate 175 is configured to be able to adjust the height according to the degree of deformation of the inner wall 1 of the hull of the secondary heat insulating layer 130 .

A filling plug 176 is installed on the upper portion of the compression fixing mold 174 , and the filling plug 176 fills the through portion H where the stud bolt 171 is installed and prevents damage to the secondary heat insulating layer 130 . plays a role

The insulation system of the liquefied gas cargo hold configured in this way forms the thickness of the first insulation layer 110 within 10% of the thickness of the second insulation layer 130, and the width of the first insulation layer is ½ of the second insulation layer, and the length is doubled. formed and provided with a first fixing unit that is a cross-type invar connection between the slit of the secondary insulating layer and the boundary between the primary insulating layer, the primary membrane, the secondary membrane, and the primary insulating layer are fixed together By doing so, it is possible to maintain structural rigidity and thermal insulation performance while realizing weight reduction and slimming, as well as simplify the cargo hold manufacturing process to improve workability and significantly reduce production costs.

In the thermal insulation system of the present invention, after fixing the first bending member with a rivet or screw, etc. to the primary insulating layer, which is relatively thinner than the secondary insulating layer, the vertical non-bending extending to a position higher than the primary membrane installation position (elevation) By suture welding with the member, it is possible to either permanently fix it or temporarily fix the primary bent member to the primary insulating layer and then to fix it by suture welding with the vertical unbent member.

In the insulation system of the present invention, since the edge of the vertical unbent member in the continuous installation direction is suture-welded with the primary and secondary membranes, there is no need for separate height adjustment during welding for sealing the membrane, so the sealing operation is very easy. It has the advantage of improving performance.

In the insulation system of the present invention, when sealing the secondary membrane, it can be used as a fixing point for sealing welding with an adjacent membrane, and a fixing structure penetrating the secondary membrane is not required for installation and fixing of the primary insulation layer, Due to the relatively thin primary heat insulating layer, it is possible to fix using the first fixing unit, which is a cross-shaped invar connection structure of the present invention.

Meanwhile, referring to FIG. 4 , in the insulation system according to the preferred embodiment of the present invention, the secondary insulation securing 170 has a spring constant according to the deformation condition of the inner wall 1 of the hull of the cargo hold. It can be fixed by setting it differently.

That is, in order to adjust the elasticity, the elastic body 173 may be appropriately replaced with three or five stages according to design conditions. A reference wedge 175 is fixed to the hull inner wall 1 and a stud bolt 171 is vertically fixed to the reference plate 175. The height can be adjusted according to the degree of deformation. Although not shown in the drawings, the reference wedge 175 may be integrally formed with the stud bolt 171 .

As described above, in the present invention, as described above, the thickness of the primary insulating layer is set within 10% of the thickness of the secondary insulating layer, and a cross-shaped fixing unit capable of fixing the membrane and the primary insulating layer together. and insulation securing unit) to improve the fixing structure of the primary insulation layer and the sealing structure of the membrane, while realizing weight reduction and slimming, it is possible to maintain structural rigidity and insulation performance, as well as to simplify the cargo hold manufacturing process and improve workability. Production cost can be significantly reduced.

Although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto, and the technical spirit of the present invention and the claims described below by those of ordinary skill in the art to which the present invention pertains. Various modifications and variations are possible within an equal range. For example, the insulation system of the present invention is not limited to the cargo hold of a liquefied gas carrier, and it is of course also applicable to all storage tanks for storing liquefied gas.

In addition, the expression of the upper side in the description of the present invention has been described with reference to FIG. 5 shown on the side of the bottom longitudinal bulkhead, and the lower side or side may be changed according to the cargo hold installation position due to the characteristics of the cargo hold.

1: hull inner wall
110: primary insulation layer
110a: step groove
110b: chamfer part
120: primary membrane
130: secondary insulation layer
130a: stepped groove
130b: chamfer part
140: secondary membrane
150: first securing unit (first securing)
151: vertical unbent member
152: "L" shape second bending member
152a: first fixing part
152b: second fixing part
153: second fastening member
154: "L" shape first bending member
154a: first fixing part
154b: second fixing part
155: first fastening member
170: second securing unit (secondary securing)
171: stud bolt (stud bolt)
172: nut (nut)
173: elastic body
174: mold for compression fixing
175: reference wedge
176: filling plug
H: fastening hole
S: slit

Claims (10)

a secondary insulation layer for secondary insulation of the cargo hold based on the inner wall of the hull;
a secondary membrane made of Invar steel disposed on the secondary heat insulating layer;
a first insulating layer disposed on the secondary membrane to primarily insulate the cargo hold;
a primary membrane made of Invar steel disposed on the primary heat insulating layer;
a first securing unit installed between a boundary portion between the primary insulating layers and in a slit of the secondary insulating layer to fix the primary and secondary membranes and the primary insulating layer; and
Including; a second fixing unit for fixing the secondary heat insulating layer;
The first fixing unit,
a vertically unbent member inserted between the boundary portions between the first heat insulation layers and into the slits of the second heat insulation layer and positioned vertically, the end portion being positioned to protrude relative to the second heat insulation layer;
"L consisting of a first fixing part fixed to both sides of the vertical unbent member and inserted into the slit, and a second fixing part fixed to the secondary heat insulating layer after being bent from the first fixing part in the horizontal direction. "Shaped second bending member;
a second fastening member fastened in a fastening hole formed in the second fixing part of the "L"-shaped second bending member to fix the "L"-shaped second bending member to the secondary heat insulating layer;
First bent "L" shape consisting of a first fixing part fixed to both sides of the vertically unbent member, and a second fixing part fixed to the primary heat insulating layer after being bent from the first fixing part in the horizontal direction absence; and
A liquefied gas cargo hold comprising a; of thermal insulation system. The method according to claim 1,
The insulation system of the liquefied gas cargo hold, characterized in that the thickness of the first insulation layer is formed within 10% of the thickness of the second insulation layer. The method according to claim 1,
The second fixing unit is a liquefied gas cargo hold insulation system, characterized in that by setting a different elasticity (spring constant) according to the deformation condition of the inner wall of the hull of the cargo hold to fix the secondary insulation layer. delete The method according to claim 1,
A stepped groove is formed in the secondary heat insulation layer, and the second fixing part of the "L"-shaped second bending member is seated in the stepped groove,
A stepped groove is formed in the first insulating layer, and the second fixing part of the "L"-shaped first bending member is seated in the stepped groove. The method according to claim 1,
The first fixing part of the "L"-shaped second bending member is bent and inserted into the slit and suture-welded to the vertical non-bending member,
The insulation system of a liquefied gas cargo hold, characterized in that the first fixing part of the "L"-shaped first bending member is bent to the liquefied gas side and then seam welded to the vertical non-bending member. The method according to claim 1,
The secondary membrane is wrap-welded to the second fixing part of the "L"-shaped second bending member or seam-welded to the vertical non-bending member of the "L"-shaped second bending member. of thermal insulation system. The method according to claim 1,
The primary membrane is a liquefied gas cargo hold, characterized in that the wrap-welded to the second fixing part of the "L"-shaped first bending member or seam-welded to the first fixing part of the "L"-shaped first bending member. of thermal insulation system. The method according to claim 1,
A chamfer for preventing interference with the "L"-shaped second bending member is formed at the edge of the upper end of the secondary heat insulating layer, and a chamfer is formed at the lower end of the primary heat insulating layer to prevent interference with the primary membrane. Insulation system of the liquefied gas cargo hold, characterized in that the addition is formed. 4. The method according to claim 3,
The second fixing unit,
stud bolts fixed to the inner wall of the hull on which the secondary insulation layer is installed;
a nut fastened to the stud bolt for fixing the secondary heat insulating layer;
an elastic body fitted to the stud bolt and adjusting the degree of elasticity according to the degree of deformation of the inner wall of the hull of the secondary heat insulating layer;
a compression fixing mold inserted into the stud bolt and stacked on the elastic body to prevent local damage to the secondary heat insulating layer; and
The insulation system of a liquefied gas cargo hold comprising a reference plate for height adjustment according to the degree of deformation of the inner wall of the hull of the secondary insulation layer.

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