KR102150458B1 - 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 Invar steel (INVAR, 36% Ni) having a small heat shrinkage is used as the primary and secondary membranes, and the primary insulation layer is plywood, insulation, composite, etc. It is composed of a composite form combined with, and has a thickness within 20% of the thickness of the second insulating layer, and the second insulating layer is composed of a polyurethane foam reinforced with glass fiber and a sandwich form of plywood or flour and composite materials. The transverse corner portion of the cargo hold is a structure in which a fixed inbar structure connecting the primary and secondary membranes is provided in order to transmit the load of the cargo hold to the inner wall of the hull.
According to the present invention, it is possible to implement light weight and slimmer, improve insulation performance and structural rigidity, as well as simplify the cargo hold manufacturing process and reduce production cost.

Description

Insulation System For Membrane Type in LNG Storage Tank}

The present invention relates to a membrane-type insulation system for a cargo hold of a liquefied gas carrier and a liquefied gas fuel container, and more specifically, Invar (36% Ni) having a small amount of heat contraction is used as the primary and secondary membranes, The first insulating layer is composed of a composite form of plywood, insulating material, and composite material, and has a thickness within 20% of the thickness of the second insulating layer, and the second insulating layer is polyurethane foam and ply reinforced with glass fiber. Liquefied gas cargo hold which is composed of a sandwich of wood or plywood and a composite material, and is equipped with a fixed inbar structure connecting the primary and secondary membranes to transfer the load of the cargo hold to the inner wall of the hull at the transverse corner of the cargo hold. Of the insulation system.

In general, natural gas is transported in gaseous form through gas pipes on land or at sea, or stored in LNG carriers 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 about -163°C, and its volume is reduced to about 1/600 compared to that of gaseous natural gas, so it is very suitable for long-distance transportation through sea.

LNG carriers for loading and unloading LNG to a land demander by loading LNG or an LNG regasification vessel (RV) that regasifies the stored LNG and unloads it in natural gas after arriving at a land demander by operating the sea with LNG. Is equipped with a storage tank, that is, a cargo hold, capable of withstanding the cryogenic temperatures of liquefied natural gas.

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, and these floating offshore structures are also used by LNG carriers and LNG RVs. A cargo hold to be installed is provided.

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

LNG FSRU is a floating offshore structure that stores LNG unloaded from LNG carriers at sea far from land in a cargo hold and then vaporizes LNG as necessary and supplies it to land demanders.

In this way, cargo holds for storing LNG in cryogenic conditions 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 hold can be classified into independent tank type and membrane type depending on whether the load of cargo directly acts on the insulation material.

Usually, the membrane type cargo hold is divided into GTT NO 96 type and TGZ Mark Ⅲ type, and the independent tank type cargo hold is divided into MOSS type and IHI-SPB type.

Membrane-type cargo holds have different insulation and structure depending on the type of special metal plate.GTT NO96 type uses a thin plate made of Invar (a very low thermal expansion alloy composed mainly of iron and nickel), and MARK III type is stainless steel. Use a thin plate of material.

The cargo hold of GTT NO 96 type is a first and second membrane made of Invar steel with a thickness of 0.5 to 1.5 mm, and a first and second insulation wall made of plywood box and perlite, etc. They are alternately stacked and installed inside the hull.

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

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

The insulation system of the liquefied gas cargo hold includes a primary membrane and a secondary membrane made of Invar steel having a thickness of 0.5 to 0.7 mm; Plywood box (plywood box) and perlite (perlite) consisting of a primary insulating layer and a secondary insulating layer; A heat insulating layer fixing part for fixing the first heat insulating layer and the second heat insulating layer; A membrane fixing part for fixing the primary membrane and the secondary membrane is provided.

However, in the conventional liquefied gas cargo hold insulation system, there is a technical limitation in reducing the thickness of the primary insulation layer in order to maintain the insulation performance of the primary insulation layer. In other words, when the thickness of the first heat insulating layer is made too thin, a problem occurs in heat insulation performance, and a technical problem occurs in fixing the first heat insulating layer.

Since the thickness of the primary insulation layer cannot be made thin due to technical limitations as in the prior art, the configuration of the fixing portion of the primary insulation layer is also complicated, resulting in a problem of lowering the overall cargo hold manufacturing workability and increasing manufacturing cost.

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

The present invention is to solve the above-described problem, the thickness of the primary insulation layer is set within 30% of the thickness of the secondary insulation layer, and the liquefied gas load is different depending on the installation location of the cargo hold, so a relatively large load is required. The primary insulation layer of the monolithic structure is arranged in the area, and the primary insulation layer of the composite is arranged in the location where the load is relatively small but large insulation is required, thereby implementing the slimming of the primary insulation layer and improving the insulation performance and structural rigidity. The purpose of this is to provide an insulation system for a liquefied gas cargo hold that can improve workability and reduce production costs by simplifying the cargo hold manufacturing process.

In order to achieve the above object, the insulation system for a liquefied gas cargo hold according to the present invention comprises: a second 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 second membrane to primarily insulate the cargo hold; And a primary membrane made of Invar steel disposed on the primary insulation layer, wherein the primary insulation layer has a monolithic structure in which a plurality of plywoods are stacked in the thickness direction or a composite structure composed of a plurality of plywoods and an insulation material. The transverse corner of the cargo hold is provided with a fixed inbar structure connecting the primary and secondary membranes in order to transmit the load of the cargo hold to the inner wall of the hull.

In the thermal insulation system of the present invention, a secondary thermal insulation layer, a secondary membrane, a primary thermal insulation layer, and a primary membrane are sequentially stacked from the hull inner wall (tank inner wall).

The thickness of the first insulating layer may be formed within 30% of the thickness of the second insulating layer.

The fixed Invar structure is made of Invar steel, and the cross section may be configured in a grid shape. The fixed invar structure may be a structure connected to either the primary membrane or the secondary membrane of the cargo hold.

The first heat insulating layer may be composed of either the monolithic structure or the composite structure having different loads of liquefied gas that can withstand according to the internal installation position of the cargo hold.

The primary insulating layer of a monolithic structure may be disposed at the corner of the top longitude studio, the upper surface of the side longitude studio bulkhead, and the outer edge of the top longitude studio bulkhead.

The primary insulation layer of the composite structure may be disposed in the center of the bottom longitude studio bulkhead, the front transverse bulkhead, the rear transverse bulkhead, a side longitude studio bulkhead, and the top longitude studio bulkhead. have.

The first heat insulating layer may have a step (stepped) formed at the intersection of four corners.

The first insulating layer of the composite structure may have a configuration in which glass wool is inserted between the plywoods of the upper and lower parts.

The second heat insulating layer may be composed of a polyurethane foam reinforced with glass fiber, or a sandwich of plywood, heat insulation, and composite structure.

The first heat insulating layer may be disposed to cover the boundary between the second heat insulating layers so as to prevent a step difference between the second heat insulating layers and block heat loss.

The insulation system for a liquefied gas cargo hold according to the present invention further includes a secondary insulation layer fixing unit for fixing the secondary insulation layer, wherein the secondary insulation layer fixing unit is elasticity according to the deformation condition of the inner wall of the hull of the cargo hold. ) Can be set differently to be fixed.

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

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

The insulation system for a liquefied gas cargo hold according to the present invention further includes a first insulation layer fixing unit for fixing the first insulation layer, and the first insulation layer fixing unit may be configured in a form that does not penetrate the first insulation layer. . That is, the first insulating layer fixing unit may be configured to be located at the intersection of four corners of the four primary insulating layers.

The first heat insulating layer fixing unit is fixed to the upper portion of the second heat insulating layer and the support having a fastening hole; A stud bolt fastened in the fastening groove and installed vertically; A metal plate fitted into the stud bolts and fixing the four primary heat insulating layers by simultaneously catching the steps of the four primary heat insulating layers at a corner intersection; A washer interposed on the stud bolt to fix the metal plate; And a nut fastened to the stud bolt.

The insulation system for a liquefied gas cargo hold according to the present invention further includes a secondary membrane fixing unit for fixing the secondary membrane, wherein the secondary membrane fixing unit comprises: a tongue fixing groove formed at an upper end of the second insulation layer; And a tongue engaging the tongue fixing groove to fix the secondary membrane.

The insulation system for a liquefied gas cargo hold according to the present invention further includes a first membrane fixing unit for fixing the primary membrane, wherein the first membrane fixing unit includes a tongue fixing groove formed at an upper end of the first insulation layer; And a tongue engaging the tongue fixing groove to fix the primary membrane.

The transverse corner of the cargo hold may be provided with a primary membrane or a fixed invar structure connecting the secondary membrane in order to transmit the load of the cargo hold to the inner wall of the hull.

The fixing invar structure may be made of Invar steel and may have a grid shape in cross section, and the fixing invar structure may be a structure connected to either the primary membrane or the secondary membrane of the cargo hold. .

The fixed inbar structure connected to the secondary membrane is fixed to the anchor flat bar of the transverse bulkhead from the side of the transverse bulkhead of the cargo hold, and is located in a horizontal direction and connected to the secondary membrane of the bottom longitudinal bulkhead. A bending member; A first primary bending member positioned at the longitudinal bulkhead, fixed to a lower end of the unfolded member, bent, and having an end fixed to the anchor flat bar of the transverse bulkhead; A third bending member having both ends fixed to the non-bending member and the first primary bending member to form a lattice-shaped invar tube space; A second primary bending member fixed at a position opposite to the first primary bending member based on the non-bending member; A third primary bending member fixed at a position opposite to the third bending member based on the non-bending member; And a fourth primary bending member fixed at a position opposite to the third bending member based on the first primary bending member.

A corrugated buffer member may be installed at a position connecting the secondary membrane and the fourth primary bending member, and at a position connecting the secondary membrane and the third primary bending member.

In addition, the fixed inbar structure connected to the primary membrane is welded to the anchor flat bar of the transverse bulkhead from the side of the transverse bulkhead of the cargo hold, and is located in a horizontal direction and is connected to the primary membrane of the Longitudinal bulkhead. A non-bending member; A first primary bending member positioned at the bottom longitudinal bulkhead, fixed to a lower end of the non-bending member and then bent, and an end portion fixed to an anchor flat bar of the transverse bulkhead; A second primary bending member fixed at a position opposite to the first primary bending member based on the non-bending member; A third primary bending member that is welded to the first primary bending member and then connected to the primary membrane of the longitudinal bulkhead; A first secondary bending member fixed between the second primary bending member and the non-bending member; And a fourth primary bending member fixed at a position opposite to the first secondary bending member based on the second primary bending member.

A corrugated buffer member may be installed at a position connecting the primary membrane and the fourth primary bending member, and at a position connecting the primary membrane and the first secondary bending member.

As described above, the thickness of the primary insulation layer is set to within 30% of the thickness of the secondary insulation layer, and the liquefied gas load is different depending on the internal installation location of the cargo hold. The insulation layer is arranged, and the first insulation layer of the composite is arranged in a location where the load is relatively small but large insulation is required, so that the first insulation layer can be slimmed and the insulation performance and structural rigidity can be improved, as well as the cargo hold manufacturing process. This simplification can improve workability and reduce production cost.

1 is a perspective view showing a general liquefied gas cargo hold
2 is an exploded view of the liquefied gas cargo hold of FIG. 1
3 is a cut-away perspective view showing a part of the insulation system of a liquefied gas cargo hold according to a preferred embodiment of the present invention
4 is a longitudinal cross-sectional view of an insulation system for a liquefied gas cargo hold according to a preferred embodiment of the present invention
Figure 5 is an extract of the main part of Figure 3
6 is a perspective view showing the primary insulating layer of a single body structure
7 is a longitudinal cross-sectional view showing the primary insulating layer of a single body structure
Figure 8 is a perspective view showing the first insulating layer of the composite structure
9 is a longitudinal cross-sectional view showing the first insulating layer of the composite structure
10 is a view in which the primary insulation layer of a single body structure or a composite structure is arranged according to the internal installation position of the cargo hold
11 is a view showing another example of the arrangement of the primary insulating layer of a monolithic structure or a composite structure
12 is a longitudinal sectional view showing a secondary insulating layer fixing unit
13 is an enlarged view of A in FIG. 4
14 is an enlarged view of B of FIG. 4
15 is a view showing an invar structure for fixing the structure connected to the secondary membrane
16 is a cross-sectional view showing in detail the inbar structure for fixing of FIG. 15
17 is a cross-sectional view showing an invar structure for fixing the structure connected to the primary membrane

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

1 is a perspective view showing a general liquefied gas cargo hold, and FIG. 2 is an exploded view showing the liquefied gas cargo hold of FIG.

1 and 2, a general liquefied gas cargo hold may be formed in an octagonal structure inside the hull, and the top longitude studio bulkhead 10 and the bottom longitude studio bulkhead 20 above and below the cargo hold, respectively. ) Are arranged symmetrically.

The front transverse bulkhead 30 and the rear transverse bulkhead 40 are arranged symmetrically at the front and rear of the cargo hold. Side Longitudinal bulkheads 50 and 60 are arranged symmetrically on the port side and starboard side of the cargo hold, respectively.

Top Longitudinal Corner (70) between the Top Longitudinal Bulkhead (10) and the Front Transverse Bulkhead (30), and between the Top Longitudinal Bulkhead (10) and the Rear Transverse Bulkhead (40) Is placed.

Between the bottom longitudinal bulkhead 20 and the front transverse bulkhead 30, between the bottom longitudinal bulkhead 20 and the rear transverse bulkhead 40, the bottom longitudinal corner part 80 Is placed.

In the cross section of the side long-terminal bulkhead 50 and the top long-distance bulkhead 10, the cross section of the side long-terminal bulkhead 50 and the bottom long-term bulkhead 20 Bus corner portions 90 are formed.

In addition, at the intersection of the side longitude studio bulkhead 60 and the top longitude studio bulkhead 10, the cross section of the side longitude studio bulkhead 60 and the top longitude studio bulkhead 10 In the transverse corner portion 90 is formed.

On the other hand, Figure 3 is a cut-away perspective view showing a part of the insulation system of a liquefied gas cargo hold according to a preferred embodiment of the present invention, Figure 4 is a longitudinal sectional view of the insulation system of a liquefied gas cargo hold according to a preferred embodiment of the present invention, and 5 is an excerpt of the main part of FIG. 3.

Referring to Figures 3 to 5, the liquefied gas cargo hold of the present invention is provided with a heat insulation system for heat insulation of the liquefied gas (斷熱).

The thermal insulation system of the present invention is disposed on the side of the liquefied gas of the cargo hold to primarily insulate the cargo hold, the first insulating layer 110, made of Invar steel and laminated on the first insulating layer 110, 1 A secondary insulation layer 130 disposed between the secondary insulation layer 110 and the inner wall 1 of the hull to secondaryly insulate the cargo hold, a secondary membrane 140 made of Invar steel and laminated on the secondary insulation layer 130, The primary insulation layer fixing unit 150 for fixing the primary insulation layer 110, the secondary insulation layer fixing unit 160 for fixing the secondary insulation layer 130, and the primary fixing the primary membrane 120 It includes a membrane fixing unit 170, and a secondary membrane fixing unit 180 for fixing the secondary membrane 140. In the thermal insulation system of the present invention, the secondary thermal insulation layer 130, the secondary membrane 140, the primary thermal insulation layer 110, and the primary membrane 120 are sequentially stacked (arranged) from the hull inner wall 1 as a reference.

In the heat insulating system of the present invention, the thickness of the first heat insulating layer 110 is formed within 30% of the thickness of the second heat insulating layer 130, but the first heat insulating layer 110 may be composed of a single body structure or a composite structure.

That is, the thickness of the first insulating layer 110 may be formed within 30%, preferably 10-20% of the thickness of the second insulating layer 130, the first insulating layer (110: 110a, 110b) is a plurality of It is composed of a monolithic structure in which plywoods are stacked in the thickness direction, or a composite structure composed of a plurality of plywoods and an insulation material, for example, glass wool, and an insulation material made of a low density polyurethane foam material. I can. Here, for convenience of explanation, a single-body heat insulating layer among the first heat insulating layers 110 is 110a, and a first heat insulating layer of a composite structure is 110b.

FIG. 6 is a perspective view showing a first heat insulating layer of a monolithic structure, and FIG. 7 is a longitudinal sectional view showing the first heat insulating layer of a monolithic structure.

6 and 7, a plurality of, for example, four sheet-shaped plywoods may be formed in a structure in which a plurality of, for example, four sheet-shaped plywoods are stacked in a thickness direction. The first heat insulating layer 110a having a monolithic structure may have a step 111 formed at four corner intersections.

FIG. 8 is a perspective view showing the first heat insulating layer of the composite structure, and FIG. 9 is a longitudinal sectional view showing the first heat insulating layer of the composite structure.

8 and 9, the first heat insulating layer 110b of the composite structure may be formed in a structure in which sheet-shaped plywoods are stacked in the thickness direction at the upper and lower portions, and an insulating material is installed between the plywoods. . The first insulating layer 110b of the composite structure may have a step 111 formed at four corner intersections.

On the other hand, the liquid gas (LNG) carried inside the insulation system of the cargo hold is operated in a state that is full or almost empty.When the cargo is loaded, the inner surface of the cargo hold receives the hydrostatic pressure of the liquid cargo (+adds the acceleration of the ship). . At this time, the maximum static load is 2~3 bar level. However, since the impact force of the liquid cargo acts on the inner surface of the cargo hold by the shaking of the liquid cargo, it is preferable to reinforce the part where the sloshing load acts.

10 is a view showing an example of the arrangement of the primary insulation layer of a single-piece structure or a composite structure according to the internal installation position of the cargo hold.

As shown in FIG. 10, the arrangement of the first heat insulating layer 110 may be set differently depending on the position of the cargo hold. That is, the first insulating layer 110a of a single body structure or the first insulating layer 110b of a composite structure may be selectively disposed depending on the internal installation position of the cargo hold.

It is limited to the LNG carrier shown in FIG. 10, and is limited when there is a limit on the loading height of liquid cargo.

The first insulating layer 110a of a single body structure may be disposed on the top longitude studio corner part 70, the upper side of the side longitude studio bulkhead 50, and the outer edge of the top longitude studio bulkhead 10. .

In addition, the first insulating layer 110b of the composite structure is the upper side of the bottom longitudinal bulkhead 20, the front transverse bulkhead 30, the rear transverse bulkhead 40, and the side longitudinal bulkhead 50. It may be disposed at a central portion of the secondary, side longitudinal bulkhead 60, and the top longitudinal bulkhead 10.

11 is a view showing another example of the arrangement of the primary heat insulating layer of a monolithic structure or a composite structure.

Referring to FIG. 11, when there is no restriction on the loading height of liquid cargo, such as LNG FSRU, LNG FPSO, LNG Fuel tank, LNG Bunkering vessel, it is preferable to reinforce the entire area excluding the bottom of the cargo hold. That is, in the bottom longitudinal bulkhead 20, the first insulating layer 110a of a monolithic structure may be disposed, and the first insulating layer 110b of a composite structure may be disposed on the remaining bulkheads 10,30-80. .

Referring to Figures 4 to 6, a more detailed look at the arrangement structure of the first insulating layer 110 and the second insulating layer 130 are as follows.

The primary insulation layer 110 is located in the center of the secondary insulation layer 130, and the primary insulation layer 110 is adjacent to each other based on the intersection of the four corners of the primary insulation layer 110 located in the center of the outer edge of the secondary insulation layer 130. It may be arranged so that four corner intersection points between the insulating layer 110 are formed.

Since the first heat insulating layer 110 is disposed to cover the boundary between the second heat insulating layers 130, it prevents a step difference between the second heat insulating layers 130 and blocks heat loss. Here, the boundary between the secondary insulating layers 130 means a gap (or gap) between the secondary insulating layers 130 adjacent to each other.

The secondary insulating layer 130 may be formed of a polyurethane foam reinforced with glass fiber, or a sandwich of plywood, insulation, or composite structure.

In addition, Figure 12 is a longitudinal cross-sectional view showing a secondary heat insulating layer fixing unit.

12, the secondary insulation securing unit 160 can be fixed by setting a spring constant differently according to the deformation condition of the inner wall 1 of the cargo hold. For example, a stud bolt (161), a nut (162), an elastic body (washer spring) 163, a compression fixing mold (164), and a reference wedge (165) It may include.

In other words, the stud bolt 161 is fixed to the inner wall 1 of the hull on which the secondary heat insulating layer 130 is installed. The fixing method of the stud bolt 161 may be fixed by conventional fastening means, for example, welding.

The nut 162 is fastened to the stud bolt 161 to fix the secondary heat insulating layer 130.

The elastic body (washer spring) 163 is fitted to the stud bolt 161 and is configured to adjust the degree of elasticity according to the degree of deformation of the inner wall 1 of the hull of the secondary heat insulating layer 130. In order to adjust the elasticity, the elastic body 163 may be replaced with a third or fifth stage.

The compression fixing mold 164 is configured to be inserted into the stud bolt 161 and laminated on the elastic body 163 in order to prevent local damage to the secondary heat insulating layer 130, and high-density PUF, compressed wood, and the like may be used.

A reference wedge 165 is fixed to the inner wall 1 of the hull, and a stud bolt 161 is vertically fixed to the reference plate 165. The reference plate 165 is configured to adjust the height according to the degree of deformation of the inner wall 1 of the secondary heat insulating layer 130.

A filling plug 166 is installed on the upper part of the compression fixing mold 164, and the filling plug 166 fills the inside of the through portion H where the stud bolt 161 is installed, and prevents damage to the secondary insulating layer 130 Plays a role.

In addition, FIG. 13 is an enlarged view of part A of FIG. 4.

Referring to FIG. 13, the primary insulation securing unit 150 may be configured in a form that does not penetrate the primary insulation layer 110, and the four primary insulation layers 110 adjacent to each other It is configured to be located at the intersection of the square.

That is, the primary heat insulating layer fixing unit 150 includes a stud bolt 151, a base socket 152, a metal plate 153, a nut 154, and a washer 155 as an example. Include.

Looking at the configuration of the primary heat insulating layer fixing unit 150 in more detail as follows.

It is configured to utilize the through part (hole) (H) constructed in the center of the secondary insulation layer 130 to fix the primary insulation layer 110, and the lower part of the base socket 152 (Hole) It is inserted into (H), the upper end of the support (Base Socket) 152 may be fixed with a rivet (or screw) (R) on the upper portion of the secondary heat insulating layer 130. A fastening hole 152a may be formed in the support 152 for fixing rivets or screws. A secondary membrane 140 is positioned on the base socket 152.

The stud bolt 151 is fastened in the fastening groove 152a of the base socket 152, and for fastening the stud bolt 151, a female thread is formed on the inner circumferential surface of the fastening groove 152a, and the female threaded part In correspondence with, a male thread may be formed on the outer peripheral surface of the stud bolt 151. The fastening structure of the female screw part and the male screw part corresponds to a publicly known technique, so it will not be shown in the drawings.

The metal plate (Setting Plate) 153 has a rectangular shape and serves to fix the four primary heat insulating layers 110 by being simultaneously caught on the steps 111 of the four primary heat insulating layers 110 at the corner intersections.

In order to fix the metal plate 153, the nut 154 is fastened to the stud bolt 151 through a washer 155. The washer 155 serves to equalize the fastening force when fastening the nut 154 to the metal plate 153.

The filling plug 156 is positioned on the metal plate 153, and the plywood is positioned at the same height as the level of the primary insulating layer 110 on the filling plug 156.

In addition, FIG. 14 is an enlarged view of B of FIG. 4.

As shown in FIG. 14, the secondary membrane securing unit 180 includes a tongue securing groove 181 formed on the upper end of the second insulating layer 130, and the secondary membrane ( It includes a tongue (182) that is coupled to the tongue fixing groove (181) to fix the 140).

In addition, as shown in FIG. 14, the primary membrane securing unit 170 includes a tongue fixing groove 171 formed on the upper end of the primary insulating layer 110, and the primary membrane 120. It includes a tongue 172 that is coupled to the tongue fixing groove 171 to fix it.

In addition, the insulation system of the present invention is a fixed inbar connecting the secondary membrane 140 or the primary membrane 120 in order to transmit the load of the cargo hold to the inner wall 1 of the hull to the transverse corner 90 of the cargo hold. Structures 190 and 290 are provided.

The fixed Invar structures 190 and 290 are made of Invar steel, and may have a cross-section in a grid shape.

The fixed invar structures 190 and 290 may be a structure connected to the primary membrane 120 of the cargo hold (see FIGS. 15 and 16) or a structure connected to the secondary membrane 140 (see FIG. 17). .

Hereinafter, the fixed invar structure will be described in detail.

FIG. 15 is a view showing an invar structure for fixing of a structure connected to a secondary membrane, and FIG. 16 is a cross-sectional view of the invar structure for fixing in detail.

15 and 16, the inbar structure 190 for fixing is a non-bending member 191, a first primary bending member 192, a third bending member 193, a second primary bending member 194, A third primary bending member 195 and a fourth primary bending member 196 are included. Fixing of these members may be performed by conventional fastening means, for example seam welding.

The non-bending member 191 is fixed to the anchor flat bar 91 of the transverse bulkhead 90 at the side of the transverse bulkhead 90 of the cargo hold, and is positioned in the horizontal direction so that the bottom longitudinal bulkhead 40 It is connected to the primary membrane 120.

The first primary bending member 192 is located in the Longitudinal bulkhead, and is bent after being fixed to the lower end of the non-bending member 191, and the end is fixed to the anchor flat bar 92 of the transverse bulkhead 90 do.

The third bending member 193 has both ends fixed to the non-bending member 191 and the first primary bending member 192, respectively, to form a lattice-shaped Invar tube space.

The second primary bending member 194 is fixed at a position opposite to the first primary bending member 192 based on the non-bending member 191.

The third primary bending member 195 is fixed at a position opposite to the third bending member 193 with respect to the non-bending member 191.

The fourth primary bending member 196 is fixed at a position opposite to the third bending member 193 with respect to the first primary bending member 192.

When the deformation of the secondary membrane is large at the location where the secondary membrane 140 and the fourth primary bending member 196 are connected, and at the location where the secondary membrane 140 and the third primary bending member 195 are connected In contrast, a pleated buffer member (B) may be installed.

Meanwhile, FIG. 17 is a cross-sectional view showing an Invar structure for fixing the structure connected to the primary membrane.

As shown in FIG. 17, the invar structure 290 for fixing according to another example of the present invention shows a structure connected to the secondary membrane 140, and includes a non-bending member 291 and a first primary bending member ( 292), a second primary bending member 293, a third primary bending member 294, a fourth primary bending member 296, and a first secondary bending member 295. Fixing of these members may be performed by conventional fastening means, for example seam welding.

The non-bending member 291 is welded to the anchor flat bar 91 of the transverse bulkhead 90 at the transverse bulkhead 90 of the cargo hold, and is positioned in the horizontal direction, so that the secondary of the Longitudinal bulkhead 20 It is connected to the membrane 140.

The first primary bending member 292 is located at the bottom longitudinal bulkhead 90, and is bent after being fixed to the lower end of the non-bending member 291, and the end is an anchor of the bottom longitudinal bulkhead 90 It is fixed to the flat bar 92.

The second primary bending member 293 is fixed at a position opposite to the first primary bending member 292 with respect to the non-bending member 291.

The third primary bending member 294 is welded to the second primary bending member 293 and then connected to the primary membrane 120 of the Longitudinal bulkhead 20.

The first secondary bending member 295 is fixed between the third primary bending member 294 and the non-bending member 291.

The fourth primary bending member 296 is fixed to a position facing the first secondary bending member 295 with respect to the third primary bending member 294.

When the deformation of the primary membrane is large at the location where the first membrane 120 and the third primary bending member 294 are connected, and at the location where the first membrane 120 and the fourth primary bending member 296 are connected In contrast, a pleated buffer member (B) may be installed.

The effect of the insulation system of the liquefied gas cargo hold configured as described above will be described as follows.

As shown in Figure 4, the heat insulation system according to a preferred embodiment of the present invention, based on the inner wall of the hull (1), the secondary insulation layer 130, the secondary membrane 140, the primary insulation layer 110, and 1 The primary membrane 120 is sequentially stacked.

In the heat insulation system according to a preferred embodiment of the present invention, the thickness of the first heat insulation layer 110 is formed within 30% of the thickness of the second heat insulation layer 130, but the first heat insulation layer 110 is composed of a single body structure or a composite structure. I can.

The primary insulation layer has a thin design, so even if the total insulation thickness of the insulation system changes, the thickness of the primary insulation layer remains constant. Due to the thin primary insulating layer, it is possible to achieve economic efficiency such as manufacturing and installation, such as weight reduction.

In addition, the heat insulation system according to the preferred embodiment of the present invention may set different degrees of load in the arrangement of the first heat insulation layer 110. That is, in consideration of a load that can be endured according to the internal installation position of the cargo hold, the first insulating layer 110a of a monolithic structure or the first insulating layer 110b of a composite structure may be selectively disposed.

In this way, the first insulating layer 110a of a single body structure in which the thickness of the first insulating layer 110 is formed within 30% of the thickness of the second insulating layer 130, and the load of liquefied gas that can withstand is different depending on the internal installation position of the cargo hold. Alternatively, by appropriately arranging the first heat insulating layer 110b of the composite structure, it is possible to achieve weight reduction and slimming, and improve structural rigidity and heat insulation performance.

In addition, as shown in FIGS. 3 to 5, in the heat insulating system according to the preferred embodiment of the present invention, the first heat insulating layer 110 is disposed to cover the boundary between the second heat insulating layers 130, so that the second heat insulating layer ( 130) It can prevent the gap between the gaps and effectively block heat loss.

In addition, referring to FIG. 12, in the heat insulation system according to a preferred embodiment of the present invention, the secondary insulation securing unit 160 has a spring constant according to the deformation condition of the inner wall 1 of the cargo hold. ) Can be set differently and fixed.

That is, in order to adjust the elasticity, the elastic body 163 may be appropriately replaced according to design conditions in three stages or five stages. The reference wedge 165 is fixed to the inner wall 1 of the hull, and the stud bolts 161 are vertically fixed to the reference plate 165, so that the inner wall of the hull 1 of the secondary insulation layer 130 The height can be adjusted according to the degree of deformation. Although not shown in the drawing, the reference wedge 165 may be integrally formed with the stud bolt 161.

In addition, referring to FIG. 13, in the heat insulation system according to a preferred embodiment of the present invention, there is an effect that the primary insulation securing unit 150 does not penetrate the primary insulation layer 110. . That is, in order to fix the first insulating layer 110, the through part (hole) H installed in the center of the second insulating layer 130 can be used, and the rectangular metal plate 153 crosses the corners. It serves to fix the four primary heat insulating layers 110 by being simultaneously caught in the step 111 of the four primary heat insulating layers 110 at the point. The washer 155 serves to equalize the fastening force when fastening the nut 154 to the metal plate 153.

In addition, as shown in Figs. 15 to 17, in the thermal insulation system of the present invention, in order to transmit the load of the cargo hold to the transverse corner 90 of the cargo hold to the inner wall 1 of the hull, the secondary membrane 140 or 1 Invar structures 190 and 290 for fixing to connect the car membrane 120 are provided.

In the thermal insulation system of the present invention, since the first thermal insulation layer 110 is formed to be less than 30% thicker than the secondary thermal insulation layer 130, an invar structure for fixing that connects the primary and secondary membranes to the inner wall of the hull of the cargo hold ( The shape of the anchoring invar structure) can be improved to a simple structure connected to any one of the first and second membranes, rather than a structure connected to both the first and second membranes, unlike the conventional one. Due to these technical features, it is possible to install only once by welding on each installation surface in a confined space when installing the fixed inbar structure, and it can be manufactured by sealing welding with relatively high welding speed. While facilitating it, it can play its part smoothly.

As described above, the present invention relates to a fixing method for the first insulation layer of the insulation system, and the first insulation layer is a lightweight insulation layer having a thinner thickness compared to the second insulation layer, and a structure capable of fixing the first insulation layer can be simplified. In addition, both the fixing structure penetrating the secondary membrane or the fixing structure not penetrating the secondary membrane can be applied, and the fixing structure can be installed using a penetration part constructed to fix the secondary insulating layer. In addition, a fixing structure in the form of penetrating the membrane located in the center of one secondary insulation layer is fixed at the intersection of the four corners of the primary insulation layer, and the fixing structure penetrates the secondary membrane and is placed on top of the secondary insulation layer. A support part fixed with rivets or screws, a stud bolt connected to the support part, a metal plate member that can fix the intersection of the four corners of the primary insulation layer, a nut that can fix the metal plate member, and a metal plate with nuts. It is composed of a washer that can equalize the fastening force when it is fixed, and an insert-type insulation material that can fill the space that occurs when the primary membrane is installed on the upper part of the fixing structure, and to withstand the external force received by the primary membrane. A plywood cover is installed.

In the present invention, the thickness of the primary insulation layer is set within 30% of the thickness of the secondary insulation layer, and according to the internal installation position of the cargo hold according to the liquefied gas load that the cargo hold can withstand, the primary insulation layer of a single body structure or a composite structure is appropriately used. By arranging, it is possible to achieve lighter weight and slimming, while improving thermal insulation performance and structural rigidity, as well as simplifying the cargo hold manufacturing process and significantly reducing production costs.

Although the present invention has been described through 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 technical field to which the present invention pertains. Various modifications and variations are possible within the uniform range. For example, the heat insulation system of the present invention is not limited to the cargo hold of a liquefied gas carrier, and can be applied equally to all storage tanks for storing liquefied gas.

In addition, the first heat insulating layer 110 of the present invention can be applied equally to the flat portion (10-60) of the cargo hold, and to the transverse corner portion 90 and the longitude corner portions 70 and 80.

1: hull inner wall
110: first insulating layer
110a: 1st heat insulating layer of monolithic structure
110b: the first insulating layer of the composite structure
111: step
120: primary membrane
130: secondary insulating layer
140: secondary membrane
150: primary insulation layer fixing unit
151: stud bolt
152: Base Socket
152a: fastening hole
153: Setting Plate
154: nut
155: washer
160: secondary insulation layer fixing unit
161: stud bolt
162: nut
163: elastic body
164: compression fixing mold
165: reference wedge
166: filling plug
170: primary membrane fixing unit
171: tongue fixing groove
172: tongue
180: secondary membrane fixing unit
181: tongue fixing groove
182: tongue
190: fixed inbar structure
191: non-bending member
192: first primary bending member
193: 3rd bending member
194: second primary bending member
195: third primary bending member
196: fourth primary bending member
B: corrugated cushioning member
H: penetration
R: rivet

Claims (11)

A second 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 second membrane to primarily insulate the cargo hold; And
A primary membrane made of Invar steel disposed on the primary insulating layer; And
Includes; a fixed inbar structure installed at the transverse corner of the cargo hold and connected to the primary membrane and the secondary membrane to transmit the load of the cargo hold to the inner wall of the hull,
The secondary insulating layer is composed of a sandwich of reinforced polyurethane foam and plywood,
The first insulating layer is composed of a structure in which a plurality of plywoods provided in a sheet shape are stacked in the thickness direction, and has a thickness of 30% or less compared to that of the second insulating layer,
As the thickness of the first heat insulating layer is reduced compared to the second heat insulating layer, the fixing invar structure is connected to each of the inner walls of the hull adjacent to each other at the corner portion by only one member to be connected from the first membrane and the second membrane. Insulation system of a liquefied gas cargo hold, characterized in that it is possible to integrate the transmitted load and transmit it to the inner wall of the hull. The method according to claim 1,
The fixed inbar structure,
A non-bent member whose one end is fixed to an anchor flat bar provided on one of the inner walls of the hull adjacent to each other at the transverse corner of the cargo hold, and the other end is connected to the primary or secondary membrane;
A first primary bending member whose one end portion is fixed to an anchor flat bar provided on another inner wall of the hull inner wall adjacent to each other at the transverse corner portion of the cargo hold, and the other end is fixed to the non-bending member; And
And a plurality of bending members coupled to the non-bending member or the first primary bending member to be connected to the remaining primary and secondary membranes not connected to the non-bending member. Insulation system of gas hold. The method according to claim 1,
Insulation system of a liquefied gas cargo hold, characterized in that a space portion is formed inside the first heat insulating layer except for plywood disposed at the top and bottom ends, and an insulation material made of glass wool or polyurethane foam is disposed in the space portion. A second 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 second membrane to primarily insulate the cargo hold;
A primary membrane made of Invar steel disposed on the primary insulating layer; And
Includes; a fixed inbar structure installed at the transverse corner of the cargo hold and connected to the primary membrane and the secondary membrane to transmit the load of the cargo hold to the inner wall of the hull,
The primary insulating layer is composed of a single-body structure in which a plurality of plywoods are stacked in the thickness direction or a composite structure composed of a plurality of plywoods and an insulating material,
The fixed inbar structure,
A non-bending member fixed to an anchor flat bar provided in a transverse bulkhead of the cargo hold and connected to the primary membrane installed in a horizontal direction;
A first primary bending member fixed to a lower end of the non-bending member, and having an end portion fixed to an anchor flat bar provided in the longitudinal bulkhead of the cargo hold;
A second primary bending member fixed to a position opposite to the first primary bending member with respect to the non-bending member and connected to the primary membrane installed in a vertical direction;
A third primary bending member fixed to an upper end of the non-bending member and connected to the secondary membrane installed in a vertical direction;
A fourth primary bending member fixed to the side of the first primary bending member and connected to the secondary membrane installed in a horizontal direction; And
And a third bending member having both ends fixed to the non-bending member and the first primary bending member to form a lattice-shaped invar tube space. The method of claim 4,
Insulation of a liquefied gas cargo hold, characterized in that a corrugated buffer member is installed at a position connecting the secondary membrane and the fourth primary bending member, and at a position connecting the secondary membrane and the third primary bending member system. A second 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 second membrane to primarily insulate the cargo hold;
A primary membrane made of Invar steel disposed on the primary insulating layer; And
Includes; a fixed inbar structure installed at the transverse corner of the cargo hold and connected to the primary membrane and the secondary membrane to transmit the load of the cargo hold to the inner wall of the hull,
The primary insulating layer is composed of a single-body structure in which a plurality of plywoods are stacked in the thickness direction or a composite structure composed of a plurality of plywoods and an insulating material,
The fixed inbar structure,
A non-bending member fixed to the anchor flat bar provided in the transverse bulkhead of the cargo hold and connected to the secondary membrane installed in a horizontal direction;
A first primary bending member fixed to a lower end of the non-bending member, and having an end portion fixed to an anchor flat bar provided in the longitudinal bulkhead of the cargo hold;
A second primary bending member fixed at a position opposite to the first primary bending member based on the non-bending member and connected to the secondary membrane installed in a vertical direction;
A third primary bending member fixed to a side of the second primary bending member and connected to the primary membrane installed in a horizontal direction;
A fourth primary bending member fixed to an upper end of the third primary bending member and connected to the primary membrane installed in a vertical direction; And
And a secondary bending member fixed between the second primary bending member and the non-bending member. The method of claim 6,
Heat insulation of a liquefied gas cargo hold, characterized in that a corrugated buffer member is installed at a position connecting the primary membrane and the fourth primary bending member and at a position connecting the primary membrane and the third primary bending member system. The method of claim 3,
A composite structure in which a space is formed in the interior of the single-body structure consisting of only a plurality of plywoods and a plurality of plywood stacked structures by dividing the zone according to the degree of the load acting inside the cargo hold. Insulation system of a liquefied gas cargo hold, characterized in that the first heat insulating layer is selectively arranged. The method of claim 8,
The first insulation layer of a monolithic structure is disposed at the corner of the top longe studio, the upper side of the side longe studio bulkhead, and the outer edge of the top longe tutorial bulkhead,
The primary insulation layer of the composite structure is the bottom longitude studio bulkhead, the front transverse bulkhead, the rear transverse bulkhead, the upper part of the side longitude studio bulkhead, the side longitude studio bulkhead, and the top longitude studio bulkhead. Insulation system of liquefied gas cargo hold, characterized in that disposed in the central portion of the head. The method according to claim 1,
The first insulating layer is fixed by a fixing device provided at the upper center of the second insulating layer at a corner portion, and accordingly, four corner intersection points of the first insulating layer are formed in the upper center of the second insulating layer, and the 1 Insulation system of a liquefied gas cargo hold, characterized in that the secondary insulation layer is disposed to cover the boundary between the secondary insulation layers. delete

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