KR100924099B1 - Cargo containment system of lng ship and construction method thereof - Google Patents

Abstract

The present invention discloses a cargo hold of a LNG carrier and its construction method. According to the present invention, the first barrier layer is formed by combining a plurality of metal plates in which LNG is loaded and a bent portion is formed therein. Rigid bodies are further bonded to the surfaces of the plurality of metal plates that form the first barrier layer or to portions where the metal plates are respectively joined. The first heat insulating layer is formed of a first heat insulating material fixed to an outer surface of the first barrier layer. The second barrier layer is fixed to the outer surface of the first heat insulating layer, and a bent portion is formed. The second barrier layer is composed of several layers of metal plates or a sandwich structure in which metal sheets and fiber-reinforced composite materials are laminated. The second heat insulating layer is formed of a second heat insulating material fixed to an outer surface of the second barrier layer. The outer cover layer is fixed to the outer surface of the second heat insulating layer. The outer cover layer is composed of several layers of metal plates or a sandwich structure in which metal sheets and fiber-reinforced composite materials are laminated.

1st barrier layer, 1st heat insulation layer, 2nd barrier layer, 2nd heat insulation layer, outer cover layer, rigid body, LNG

Description

Cargo hold and construction method of liquefied natural gas transport ship {CARGO CONTAINMENT SYSTEM OF LNG SHIP AND CONSTRUCTION METHOD THEREOF}

The present invention relates to a cargo hold of a LNG carrier and its construction method, and in particular, can reduce the construction time, improve the convenience and reliability of construction, reduce the thermal stress caused by LNG and the flow of LNG The present invention relates to a cargo hold of an LNG carrier and a construction method thereof which can reduce damage caused by a barrier.

In general, as shown in FIG. 1, the LNG carrier has a space separated by the outer wall 1 and the inner wall 2 of the hull, and a cargo hold 3 for storing LNG is installed inside the inner wall 2. . The cargo hold 3 is provided with a passage 4 for installing a pump tower for loading and unloading LNG. Such cargo holds are of membrane type and spherical type. Membrane type is the most widely used because of its larger loading capacity and easier manufacturing than the spherical type. These membrane-type cargo holds include the Gaz Transport and Technigaz systems developed by Gaz Transport and Technigaz (France).

The Gaz Transport system uses Invar steel (36% nickel steel) with very low thermal expansion as the primary and secondary barriers, and is used as a thermal insulation box by filling pearlite between the barriers. In contrast, the Technics system (Mark-III system, GTT) uses a grid of corrugated stainless steel sheet as a primary barrier to absorb expansion and contraction due to thermal deformation. In addition, the triple barrier (Triplex) in which the glass fiber composite material is bonded to both sides of the aluminum foil is used as the secondary barrier, and the polyurethane foam is filled between the barriers and used as the heat insulating material. The Boil-Off Rate (BOR) of the two systems is known to be similar, but because of the low cost, ease of construction, and excellent thermal insulation of polyurethane foams compared to Invar membranes, Technics Systems This is the preferred trend.

However, since the grid-shaped corrugated stainless steel sheet constituting the primary barrier of the Technics system has a large rigidity, thermal stress is largely generated in the weld due to heat shrinkage at low temperatures. In addition, since the glass fiber composite material constituting the secondary barrier is constructed by adhesion, the construction reliability is not high. In addition, since the adhesion must be completed within the pot life of the adhesive, the construction convenience is inferior. In addition, due to fatigue due to repeated thermal stress generated during LNG storage, there is a problem in that breakage of the adhesive interface is advanced and leakage occurs at the adhesive part.

The present invention has been proposed to solve the above-mentioned problems, and an object of the present invention is to provide a cargo hold of the LNG carrier and its construction method that can reduce the air and improve the convenience and reliability of construction.

It is another object of the present invention to provide a cargo hold of a LNG carrier and a construction method thereof which can reduce thermal stress caused by LNG and reduce damage of a barrier caused by the flow of LNG.

The cargo hold of the LNG carrier according to the first aspect of the present invention for achieving the above object comprises: a first barrier layer in which LNG is loaded inside and a plurality of metal plates having a bent portion are coupled; A first heat insulating layer formed of a first heat insulating material fixed to an outer surface of the first barrier layer; A second barrier layer fixed to an outer surface of the first heat insulating layer and having a bent portion; A second heat insulating layer formed of a second heat insulating material fixed to an outer surface of the second barrier layer; And an outer cover layer fixed to an outer surface of the second heat insulating layer.

The plurality of metal plates forming the first barrier layer are respectively joined by welding or adhesive. Rigid bodies may be further bonded to the surfaces of the plurality of metal plates or portions to which the metal plates are respectively joined to form the first barrier layer. The rigid body is composed of a curved body having an arc shape or a beam having an I shape, and a plurality of curved portions or holes are formed on the surface of the rigid body. The first barrier layer has a polygonal or circular cross-sectional shape. The first barrier layer is composed of several layers of metal plates or a polymer resin mixed with metal powder is coated on the surface of the metal plates. The first barrier layer is provided with a passage for installing a pump tower for loading and unloading LNG.

The first insulation consists of phenol foam or urethane foam. The first insulation is preferably made of a porous insulation having a plurality of open pores or a plurality of closed pores.

The second barrier layer is composed of several layers of metal plates or a sandwich structure in which metal sheets and fiber-reinforced composite materials are laminated.

The second insulation consists of phenolic foam or urethane foam. The second insulator consists of a porous insulator having a plurality of open pores or a plurality of closed pores.

The outer cover layer is composed of several layers of metal plates or a sandwich structure in which metal sheets and fiber-reinforced composite materials are laminated.

In another configuration, the cargo hold of the LNG carrier according to the first aspect of the present invention includes a first barrier layer in which LNG is loaded therein and a plurality of metal plates having a bent portion are coupled; A first heat insulating layer formed of a first heat insulating material fixed to an outer surface of the first barrier layer; A second barrier layer covered on an outer surface of the first heat insulating layer and having a bent portion; A second heat insulating layer formed of a second heat insulating material fixed to an outer surface of the second barrier layer; It includes an outer cover layer covered on the outer surface of the second heat insulating layer, a composite material is laminated or a polymer film is applied to the surface of the second heat insulating layer in contact with the second heat insulating layer and the outer cover layer. In addition, a composite material may be laminated or a polymer film may be coated on a surface of the first heat insulating layer in contact with the first heat insulating layer and the second barrier layer.

The LNG carrier according to the second aspect of the present invention includes a hull formed of an inner wall and an outer wall; It characterized in that it comprises a cargo hold according to the first aspect of the invention described above fixed to the inner wall. The anchor is fixed to the inner wall, the insertion portion is formed in a shape corresponding to the position corresponding to the anchor in the cargo hold.

The anchor has a single shape of a circle column, a cone column, a polygonal column, a polygonal column, or a staircase structure combining the shapes of the circle column, the cone column, the polygonal column, and the polygonal column. The anchor is formed of a polymer insulator or fiber reinforced composite material layer or a combination of the polymer insulator and fiber reinforced composite material layer. A metal layer is attached to the anchor so that the anchor and the cargo hold can be welded. Anchors are formed with bends or holes.

Support means may be further included between the inner wall and the cargo hold. The support means consists of a metal support having a low friction coefficient and the outer surface of the cargo hold is in sliding contact on the surface of the metal support. The metal support may have two or more degrees of freedom. On the surface of the metal support in contact with the outer surface of the cargo hold, a composite layer having a low friction coefficient is laminated or coated with Teflon. In another configuration, the support means consists of an air bag, and a composite layer having a low friction coefficient is laminated or Teflon coated on the surface of the air bag in contact with the outer surface of the cargo hold. In another configuration, the support means may be a liquid filled between the inner wall and the cargo hold. It is preferable that a liquid is a liquid which mixed metal, a polymer, and a ceramic.

According to a third aspect of the present invention, there is provided a method of constructing a cargo hold of an LNG carrier, comprising: combining a plurality of metal plates having bends to form a first barrier layer; Fixing the first heat insulating material to the outer surface of the first barrier layer to form a first heat insulating layer; Fixing a second barrier layer having a bent portion to an outer surface of the first heat insulating layer; Fixing a second heat insulating material to an outer surface of the second barrier layer to form a second heat insulating layer; And fixing the outer cover layer to an outer surface of the second heat insulating layer.

The plurality of metal plates forming the first barrier layer are respectively joined by welding or adhesive. The rigid body may be further bonded to the surfaces of the plurality of metal plates forming the first barrier layer or to portions where the metal plates are respectively bonded. The first barrier layer is formed of a plurality of metal plates or coated with a polymer resin mixed with metal powder on the surface of the metal plate.

The second barrier layer and the outer cover layer may be formed of a plurality of metal plates or a sandwich structure in which a metal thin plate and a fiber reinforced composite material are laminated.

The first insulator and the second insulator are constructed with insulation having open pores, and the space between the first barrier layer and the second barrier layer and the space between the second barrier layer and the outer cover layer are vacuumed using a vacuum pump. Keep it.

The gas is cooled by using vaporization heat of LNG to be vaporized or by using a separate cooling device, and bubbles are formed by discharging the cooled gas into the LNG through a pipe installed inside the first barrier layer and communicating with the outside of the cargo hold. .

The gas pressure between the first barrier layer and the second barrier layer is maintained at or above atmospheric pressure to prevent sagging in the first barrier layer due to the load of LNG.

On the other hand, the construction method of the cargo hold of the LNG carrier according to the present invention is characterized in that the cargo hold is produced outside the production of the hull of the LNG carrier, and then mounted inside the hull of the LNG carrier.

According to the cargo hold and the construction method of the LNG carrier of the present invention as described above, since the cargo hold can be manufactured from the outside of the hull separately from the manufacture of the hull, there is an effect that can reduce the air and improve the convenience and reliability of construction. .

In addition, since the cargo hold is formed so that the barrier of the cargo hold can be shrunk without directly contacting the inner wall of the hull, there is an effect that can reduce the thermal stress by the LNG.

In addition, the barrier of the cargo hold is formed to minimize the flow of LNG has the effect of reducing the breakage of the barrier due to the flow of LNG.

Hereinafter, with reference to the accompanying drawings, the cargo hold and the construction method of the LNG carrier according to a preferred embodiment of the present invention will be described in detail as follows.

First, the cargo hold of the LNG carrier according to the first aspect of the present invention will be described with reference to FIGS. 2 to 10.

2 shows a portion of the first barrier layer of the cargo hold of an LNG carrier. Referring to Figure 2, the first barrier layer 10 is a plurality of metal plate 12, such as stainless steel suitable for loading the cryogenic LNG is coupled to form a polygonal or circular cross-sectional shape. The plurality of metal plates 12 are each joined by welding or adhesive. When the metal plate 12 shrinks due to the cryogenic LNG, a bent portion 12a is formed in the metal plate 12 in order to reduce thermal stress applied to the joint portion joined by welding or adhesive. In addition, the rigid body 14 may be provided on the surface of the plurality of metal plates 12 or the portions where the metal plates 12 are coupled to each other so as to reduce the deformation of the first barrier layer 10 by the self load of the metal plate 12. Further combined. For example, the rigid body 14 may be formed of a curved body 14a having an arc cross section as shown in FIG. 3, and a beam 14b having an I shape as shown in FIG. 4. It can be formed into). The rigid body 14 not only reduces the deformation of the first barrier layer 10 due to the self load of the metal plate 12, but also moves the hull inside the first barrier layer 10 on which the LNG is loaded. It serves as a partition wall to suppress the flow of LNG by (Sloshing). As such, a plurality of bends or holes may be formed on the surface of the rigid body 14 to effectively suppress LNG flow.

As shown in FIGS. 5 and 6, the first barrier layer 10 has a passage 16 for installing a pump tower for loading and unloading LNG therein. In addition, the first barrier layer 10 may be formed of a plurality of layers of metal plates or a polymer resin mixed with metal powder may be applied to the surface of the metal plates in order to suppress radiation due to a temperature difference with the outside when loading LNG. have.

7 shows a first heat insulating layer of a cargo hold of an LNG carrier. Referring to FIG. 7, the first heat insulating layer 20 is formed of a first heat insulating material that is bonded to the outer surface of the first barrier layer 10 or fixed by mechanical fastening such as bolt fastening. The 1st heat insulation layer 20 is for ensuring heat insulation performance in order to suppress that LNG is vaporized around the 1st barrier layer 10. The first heat insulating material is made of a material having high heat insulating performance and excellent strength and rigidity, such as phenolic foam or urethane foam. The first insulation may be formed of a porous insulation having a plurality of open pores or a plurality of closed pores. In general, the factors influencing the thermal insulation performance of the insulation is conduction by the gas inside the insulation, conduction by the materials constituting the insulation, radiation and convection. Among them, the most influential factor in the insulation performance of the low density polymer insulation is conduction by the gas inside the insulation. Therefore, the first heat insulating layer 20 may be constructed of a heat insulating material having open pores, and may form a vacuum environment to remove the gas inside the first heat insulating layer 20 to remove conduction by the gas.

8 shows a second barrier layer of the cargo hold of an LNG carrier. Referring to FIG. 8, the second barrier layer 30 is formed by welding a plurality of metal plates 32 as in the first barrier layer 10. The bends 32a are formed in the plurality of metal plates 32. The plurality of metal plates 32 are fixed to the outer surface of the first heat insulating layer 20 by adhesion of an adhesive, for example, polyurethane and epoxy resin. The plurality of metal plates 32 may be fixed to the outer surface of the first heat insulating layer 20 by fastening bolts as necessary. The second barrier layer 30 may be formed of a metal layer of several layers or may have a sandwich structure in which a metal thin plate and a fiber reinforced composite material are stacked. As the fiber reinforced composite material, a composite material in which fibers having a low coefficient of thermal expansion such as glass fibers are laminated may be used. In the space where the first heat insulating layer 20 between the first barrier layer 10 and the second barrier layer 30 is constructed, if a vacuum state is maintained using a vacuum pump, conduction by gas inside the heat insulating material does not occur. Therefore, high heat insulation performance can be ensured. In this case, heat conduction due to radiation may be large, but radiation may be suppressed by constructing a plurality of layers of the metal plate 32 of the second barrier layer 30 formed on the surface of the first heat insulating layer 20. On the other hand, the first barrier layer 10 may maintain the gas pressure between the first barrier layer 10 and the second barrier layer 30 above atmospheric pressure in order to prevent sagging that may occur due to the load of LNG. . Accordingly, the stress acting on the first barrier layer 10 and the second barrier layer 30 may be minimized by minimizing the pressure difference generated based on the first barrier layer 10.

9 shows a second insulating layer of the cargo hold of an LNG carrier. Referring to FIG. 9, the second heat insulating layer 40 is formed of a second heat insulating material adhered to the outer surface of the second barrier layer 30 or fixed by mechanical fastening. The 2nd heat insulation layer 40 is for ensuring the heat insulation performance for suppressing vaporization of LNG around the 2nd barrier layer 30. The second heat insulating material is made of phenol foam or urethane foam like the first heat insulating material. The second heat insulating material is preferably formed of a porous heat insulating material having a plurality of open pores or a plurality of closed pores.

10 shows the outer cover layer of the cargo hold of the LNG carrier. Referring to FIG. 10, the outer cover layer 50 is fixed to the outer surface of the second heat insulating layer 40. The outer cover layer 50 may be made of a plurality of layers of metal plate 52 or a sandwich structure in which a metal foil and a fiber-reinforced composite material are laminated in order to prevent thermal conduction by radiation. As the fiber reinforced composite material, a composite material in which fibers having a low coefficient of thermal expansion such as glass fibers are laminated may be used.

11 shows a modification of the cargo hold of an LNG carrier according to the first aspect of the present invention. Referring to FIG. 11, in order to reduce friction between the contact surface of the second heat insulating layer 40 and the outer cover layer 50 and to facilitate heat deformation, the second heat insulating layer 40 and the outer cover layer 50 are not fastened. Instead, the composite material is laminated on the surface of the second heat insulating layer 40 in contact with the outer cover layer 50 or a low friction polymer film F such as a Teflon film is applied. Accordingly, when the barrier shrinks due to the temperature difference, the second heat insulating layer 40 slides on the outer cover layer 50 because the amount of heat shrinkage is greater than that of the outer cover layer 50. That is, the second heat insulating layer 40 and the outer cover layer 50 is made of a structure that is not fastened to each other. Similarly, a composite material may be laminated on the surface of the first heat insulating layer 20 in contact with the first heat insulating layer 20 and the second barrier layer 30, or a low friction polymer film F such as a Teflon film may be applied. Can be. In this case, the composite material laminated on one surface of the first heat insulating layer 20 and the second heat insulating layer 40 may use a composite material made of a self lubricating material such as carbon fiber and a polymer resin. In addition, the polymer film may be a low friction polymer film such as Teflon (Teflon), polyethylene (Polyethylene), nylon (Nylon), or may be used with lubricating oil on the friction surface to reduce friction.

Meanwhile, the LNG carrier according to the second aspect of the present invention will be described with reference to FIGS. 12 to 27.

12 shows an anchor fixed to the inner wall of the LNG carrier. Referring to FIG. 12, the hull 60 is formed of an outer wall 62 and an inner wall 64 installed inside the outer wall 62, and the inner wall 64 of the LNG carrier according to the first aspect of the present invention described above. The cargo hold 70 is fixed. That is, as shown in FIGS. 12 to 14, the anchor 66 is fixed to the bottom surface of the inner wall 64, and the insertion portion 72 is formed on the bottom surface of the cargo hold 70 in a shape corresponding to the anchor 66. As a result, the anchor 66 is inserted into the insertion unit 72 so that the cargo hold 70 is fixed to the inner wall 64. The anchor 66 has an inclined shape and can be self-aligned when the cargo hold 70 is fixed to the inner wall 64. The shape, position and number of the anchors 66 may be adjusted according to the shape and size of the barrier layer and the inner wall 64 of the cargo hold 70. In addition, a metal layer is attached to the anchor 66 so that the anchor 66 and the cargo hold 70 can be welded. As shown in FIGS. 15 and 16, the metal layer includes a first metal layer 66a welded to the first barrier layer 10 and a second metal layer 66b welded to the second barrier layer 30.

17 and 18 show modifications of the anchor. Referring to FIG. 17, the anchor 67 may be formed of a fiber reinforced composite layer or a polymer insulator or a combination of the fiber reinforced composite layer 68 and the polymer insulator 69. The higher the metal occupies in the anchor 67, the lower the thermal insulation performance due to the high thermal conductivity of the metal. Therefore, the metal part can be constructed by welding the inner wall of the hull and the metal plate of the cargo hold while minimizing the exposed metal. . To this end, the first fiber layer 68a and the second metal layer 68b are formed in the fiber reinforced composite layer 68 to be welded to the cargo hold. The fiber reinforced composite layer 68 may be formed by molding a material impregnated with a polymer resin such as carbon fiber or glass fiber. In addition, holes 68c may be formed in the fiber-reinforced composite layer 68 to improve heat insulation performance and reduce weight, as shown in FIG. 18, and a bent portion may be formed.

19 and 20 show examples in which a metal layer is attached to the anchor 67. The first metal layer 68a to be welded with the first barrier layer and the second metal layer 68b to be welded with the second barrier layer are bonded to the composite material layer 68 by single overlap bonding as shown in FIG. 19, or It may be bonded by double overlap bonding as shown in FIG. 20 to enhance adhesion.

21 shows various shapes of anchors fixed to the inner wall of the LNG Carrier. The anchor may have a single shape of a circle column, a cone column, a polygonal column, or a polygonal column, or may have a staircase structure combining a column column, a cone column, a polygonal column, and a polygonal column.

22 shows a first example of the supporting means fixed to the inner wall of the LNG carrier to support the cargo hold. When the cargo hold 70 is directly fastened and fixed to the inner wall 64 of the hull 60, damage may occur to the cargo hold 70 due to the deformation of the hull 60. Means may be appropriately mounted to the inner wall 64 of the hull 60 depending on the shape and size of the cargo hold 70. Referring to Figure 22, the support means is made of a metal support 82 having a low friction coefficient, the outer surface of the cargo hold 70 is in sliding contact on the surface of the metal support 82. Accordingly, when the cargo hold 70 is shrunk by cryogenic LNG, the entire thermal barrier layer of the cargo hold 70 can be radially shrunk, resulting in small thermal stress.

23 and 24 show a second example of the support means fixed to the inner wall of the LNG carrier to support the cargo hold. Referring to FIGS. 23 and 24, the support means includes a metal support 82 and a composite material layer 82a stacked on an upper surface of the metal support 82. The composite material layer 82a may be formed by impregnating a polymer resin in carbon fiber, glass fiber, or aramid. In the composite material layer 82a having a low friction coefficient in contact with the outer surface of the cargo hold 70, wear particles due to sliding may occur, and thus a plurality of grooves in the longitudinal direction are formed at regular intervals. This groove allows wear particles to come off the contact surface to reduce wear. In another configuration, Teflon may be coated on the upper surface of the metal support 82.

FIG. 25 shows a third example of the support means fixed to the inner wall of the LNG Carrier to support the cargo hold. Referring to Figure 25, the support means is made of an air bag 84, the composite material layer 84a having a low coefficient of friction is laminated or coated with Teflon on the surface of the air bag 84 in contact with the outer surface of the cargo hold 70 Can be. Since the airbag 84 may be deformed according to the internal pressure, the airbag 84 may be continuously supported even when the barrier layer of the cargo hold 70 is deformed, and due to the flow of LNG loaded into the barrier layer of the cargo hold 70 When an impact is applied to the barrier layer, it is attenuated to prevent the barrier from being broken. As in the above-described example, a plurality of longitudinal grooves may be formed in the composite material layer 84a at a predetermined interval.

FIG. 26 shows a fourth example of the support means fixed to the inner wall of the LNG Carrier to support the cargo hold. Referring to Figure 26, the support means consists of a metal support 86 having two degrees of freedom. The two-degrees-of-freedom metal support 86 has a first member 86a fixed to the inner wall, a second member 86b formed to linearly move with respect to the first member 86a, and a second member fixed to the cargo hold. And a third member 86c formed to perform a linear movement in a direction perpendicular to the linear movement direction of 86b). On the contact surfaces of the first member 86a, the second member 86b, and the third member 86c, a composite material layer having a low friction coefficient may be laminated or coated with Teflon. The two degrees of freedom metal support 86 can be changed according to the shape of the cargo hold and the shape and load of the inner wall of the hull.

27 shows a fifth example of the support means fixed to the inner wall of the LNG carrier to support the cargo hold. Referring to FIG. 27, the support means consists of a liquid 88 filled between the inner wall 64 and the cargo hold 70. Low friction forces must be maintained between the inner wall 64 and the cargo hold 70 to facilitate heat shrinkage of the cargo hold 70 that occurs at cryogenic temperatures. To this end, by filling the space between the inner wall 64 and the cargo hold 70 with the lubricating liquid 88, a uniform buoyancy acts on the cargo hold 70 to disperse the load acting on the inner wall 64, thereby providing frictional force. Can be reduced. Accordingly, the heat shrinkage of the cargo hold 70 can be facilitated to minimize the occurrence of thermal stress. At this time, the liquid 88 can be applied to any liquid, it is preferable to use a liquid excellent in lubrication action. In addition, the liquid 88 may use a liquid in which powder, polyhedron, or spherical metal, polymer, and ceramic are mixed.

On the other hand, Figure 28 is a flow chart for the construction method of the cargo hold of the LNG carrier according to the third aspect of the present invention. 2 and 28, the plurality of metal plates 12 having the bent portion 12a are combined to form the first barrier layer 10 (S10). The plurality of metal plates 12 forming the first barrier layer 10 are joined to each other by welding or adhesive. Rigid bodies 14 may be further bonded to the surfaces of the plurality of metal plates 12 that form the first barrier layer 10 or to portions where the metal plates 12 are coupled to each other, as shown in FIGS. 2 to 4. It may be (S12). In addition, the first barrier layer 10 may be formed of a plurality of metal plates or may be coated with a polymer resin mixed with metal powder on the surface of the metal plate (S14).

In the next step, as shown in FIG. 7, the first insulating layer 20 is formed on the outer surface of the first barrier layer 10 by adhering or fixing the first insulating material by mechanical fastening (S20). It is preferable to construct a 1st heat insulating material with the heat insulating material which has open pore.

Next, as shown in FIG. 8, the second barrier layer 30 having the bent portion 32a is fixed to the outer surface of the first heat insulating layer 20 (S30). The second barrier layer 30 is formed of a metal layer of several layers or a sandwich structure in which a metal foil and a fiber reinforced composite material are laminated. The space between the first barrier layer 10 and the second barrier layer 30 is maintained in a vacuum state using a vacuum pump.

Next, as shown in FIG. 9, the second insulating layer 40 is formed on the outer surface of the second barrier layer 30 by adhering or fixing the second insulating material by mechanical fastening (S40). It is preferable to construct a 2nd heat insulating material with the heat insulating material which has open pore.

Lastly, as shown in FIG. 10, the outer cover layer 50 is fixed to the outer surface of the second heat insulating layer 40 (S50). The outer cover layer 50 is formed of multiple layers of metal plates or a sandwich structure in which a metal sheet and a fiber reinforced composite material are laminated. The space between the second barrier layer 30 and the outer cover layer 50 is to maintain the vacuum state using a vacuum pump.

FIG. 29 is a view illustrating a method for forming bubbles in LNG loaded inside the first barrier layer in the method of constructing the cargo hold of the LNG carrier according to the third aspect of the present invention.

When liquid LNG flows due to external force and impacts the barrier layer of the cargo hold 70, damage may occur to the barrier layer. In order to minimize this, as shown in FIG. 2, a method of forming bubbles G in LNG loaded inside the first barrier layer 10 may be used, in addition to further coupling the rigid body 14. Referring to Figure 29, using the vaporization heat of the vaporized LNG or a separate cooling device to cool the gas, the tube installed in the interior of the first barrier layer 10 and communicated with the outside of the cargo hold 70 (T) Bubble (G) is formed by discharging the gas cooled through the inside of the LNG. Accordingly, the bubble G is deformed by the flow of LNG to absorb the flow energy, thereby reducing the flow of LNG. Such bubbles (G) may prevent the barrier layer of the cargo hold 70 from being damaged by acting as a buffer to absorb impact energy applied by the LNG flow to the first barrier layer 10.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in the art.

1 is a cross-sectional view showing the structure of an LNG carrier according to the prior art,

2 is a perspective view showing a part of the first barrier layer of the cargo hold of the LNG carrier according to the first aspect of the present invention;

3 is a cross-sectional view showing an example of the rigid body further coupled to the first barrier layer of the cargo hold of the LNG carrier according to the first aspect of the present invention;

4 is a cross-sectional view showing another example of a rigid body further coupled to the first barrier layer of the cargo hold of the LNG carrier according to the first aspect of the present invention;

5 is a perspective view showing a state in which LNG is loaded inside the first barrier layer of the cargo hold of the LNG carrier according to the first aspect of the present invention;

6 is a perspective view showing a modification of the first barrier layer of the cargo hold of the LNG carrier according to the first aspect of the present invention,

7 is a perspective view showing a first heat insulating layer of the cargo hold of the LNG carrier according to the first aspect of the present invention;

8 is a perspective view showing a second barrier layer of the cargo hold of the LNG carrier according to the first aspect of the present invention;

9 is a perspective view showing a second heat insulating layer of the cargo hold of the LNG carrier according to the first aspect of the present invention,

10 is a perspective view showing the outer cover layer of the cargo hold of the LNG carrier according to the first aspect of the present invention,

11 is a cross-sectional view showing a modified example of the cargo hold of the LNG carrier according to the first aspect of the present invention;

12 is a perspective view showing a state in which the anchor is fixed to the inner wall of the LNG carrier according to the second aspect of the present invention,

13 is a cross-sectional view showing a state in which the anchor is fixed to the inner wall of the LNG carrier and the insertion portion is inserted into the cargo hold according to the second aspect of the present invention,

14 is a cross-sectional view showing a state in which the anchor is inserted into the insertion portion of FIG.

15 is an enlarged cross-sectional view of a portion A of FIG. 14;

16 is a perspective view of the anchor of FIG. 15,

17 is a perspective view showing a modification of the anchor,

18 is a perspective view showing another modified example of the anchor,

19 is a cross-sectional view showing an example in which a metal layer is bonded to an anchor;

20 is a sectional view showing another example in which a metal layer is attached to an anchor;

21 is a perspective view showing various shapes of an anchor fixed to an inner wall of an LNG carrier according to a second aspect of the present invention;

22 is a cross-sectional view showing a first example of the support means fixed to the inner wall of the LNG carrier according to the second aspect of the present invention for supporting the cargo hold;

23 is a cross-sectional view showing a second example of the support means fixed to the inner wall of the LNG carrier according to the second aspect of the present invention for supporting the cargo hold;

24 is an enlarged cross-sectional view of a portion B of FIG. 23;

25 is a cross-sectional view showing a third example of the support means fixed to the inner wall of the LNG carrier according to the second aspect of the present invention for supporting the cargo hold;

26 is a sectional view showing a fourth example of the support means fixed to the inner wall of the LNG carrier according to the second aspect of the present invention for supporting the cargo hold;

27 is a sectional view showing a fifth example of the support means fixed to the inner wall of the LNG carrier according to the second aspect of the present invention for supporting the cargo hold;

28 is a flowchart illustrating a construction method of a cargo hold of an LNG carrier according to a third aspect of the present invention;

29 is a cross-sectional view showing a method of forming bubbles in the LNG loaded in the first barrier layer in the method for constructing the cargo hold of the LNG carrier according to the third aspect of the present invention.

Explanation of symbols on the main parts of the drawings

10: first barrier layer 12: metal plate

12a: bend 14: rigid body

14a: bend 14b: I beam

16: passage 20: first insulating layer

30 second barrier layer 32 metal plate

32a: bend 40: second heat insulating layer

50: outer cover layer 52: metal plate

52a: bend 60: hull

62: outer wall 64: inner wall

66 anchor 66a first metal layer

66b: second metal layer 67: anchor

68: composite layer 69: polymer insulation

70: cargo hold 72: insert

80: support means 82: metal support

82a: composite material layer 84: airbag

84a: composite layer 86: 2 degrees of freedom metal support

88: liquid G: bubble

T: Cooling gas inlet pipe

Claims (37)

LNG is loaded therein, and the first barrier layer is formed by combining a plurality of metal plates having a bent portion; A first heat insulating layer formed of a first heat insulating material fixed to an outer surface of the first barrier layer; A second barrier layer fixed to an outer surface of the first heat insulating layer and having a bent portion; A second heat insulating layer formed of a second heat insulating material fixed to an outer surface of the second barrier layer; Cargo hold of the LNG carrier comprising an outer cover layer fixed to the outer surface of the second heat insulating layer. The method of claim 1, A plurality of metal plates forming the first barrier layer is cargo hold of the LNG carrier, respectively, are joined by welding or adhesive. The method according to claim 1 or 2, A cargo hold of an LNG carrier in which a rigid body is further coupled to a surface of the plurality of metal plates forming the first barrier layer or a portion to which the metal plates are respectively coupled. The method of claim 3, wherein The rigid body is made of a curved body having an arc shape or a beam having an I-shaped cross-sectional shape, the cargo hold of the LNG carrier is formed with a plurality of bent portions or holes on the surface of the rigid body. The method of claim 1, The first barrier layer is a cargo hold of the LNG carrier consisting of a polygonal or circular cross-sectional shape. The method of claim 1, The first barrier layer is composed of a plurality of metal plates or cargo surface of the LNG carrier is coated with a polymer resin mixed with metal powder on the surface of the metal plate. The method of claim 1, The cargo hold of the LNG carrier is formed in the first barrier layer is a passage for installing a pump tower for loading and unloading LNG. The method of claim 1, The first insulation is a cargo hold of LNG carrier consisting of phenol foam or urethane foam. The method according to claim 1 or 8, The first insulation is a cargo hold of the LNG carrier consisting of a porous insulation having a plurality of open pores or a plurality of closed pores. The method of claim 1, The second barrier layer is a cargo hold of an LNG carrier consisting of a metal layer of several layers or a sandwich structure in which a metal sheet and a fiber-reinforced composite material are laminated. The method of claim 1, The second insulation is a cargo hold of LNG carrier consisting of phenol foam or urethane foam. The method according to claim 1 or 11, wherein The second insulator is a cargo hold of the LNG carrier consisting of a porous insulation having a plurality of open pores or a plurality of closed pores. The method of claim 1, The outer cover layer is made of multiple layers of metal plates or cargo hold of the LNG carrier consisting of a sandwich structure in which the metal sheet and the fiber-reinforced composite material is laminated. LNG is loaded therein, and the first barrier layer is formed by combining a plurality of metal plates having a bent portion; A first heat insulating layer formed of a first heat insulating material fixed to an outer surface of the first barrier layer; A second barrier layer covered on an outer surface of the first heat insulating layer and having a bent portion; A second heat insulating layer formed of a second heat insulating material fixed to an outer surface of the second barrier layer; An outer cover layer covered on an outer surface of the second heat insulation layer, The cargo hold of the LNG carrier in which a composite material is laminated or a polymer film is coated on a surface of the second heat insulating layer that the second heat insulating layer and the outer cover layer contact. The method of claim 14, The cargo hold of the LNG carrier in which a composite material is laminated or a polymer film is applied to a surface of the first heat insulating layer in contact with the first heat insulating layer and the second barrier layer. A hull formed by an inner wall and an outer wall, and a cargo hold fixed to the inner wall, The cargo hold is formed of a first barrier layer formed by combining a plurality of metal plates having LNG loaded therein and a bent portion, a first heat insulating layer formed of a first heat insulating material fixed to an outer surface of the first barrier layer, and the first heat insulating layer. A second barrier layer fixed to an outer surface of the second barrier layer formed with a bent portion, a second heat insulating layer formed of a second heat insulating material fixed to an outer surface of the second barrier layer, and an outer cover layer fixed to an outer surface of the second heat insulating layer. LNG ship. The method of claim 16, An anchor is fixed to the inner wall, the LNG carrier is an insertion portion is formed in a shape corresponding to the position corresponding to the anchor in the cargo hold. The method of claim 17, The anchor has a single shape of any one of the column, conical column, polygonal column, polygonal column, or LNG vessel consisting of a staircase structure combining the shape of the column, conical column, polygonal column, polygonal column. The method of claim 17 or 18, The anchor is an LNG carrier formed of a polymer insulating material or a fiber reinforced composite material layer or formed by combining a polymer insulating material and a fiber reinforced composite material layer. The method of claim 19, LNG carrier to which a metal layer is bonded to the anchor so that the anchor and the cargo hold can be welded. The method of claim 19, LNG anchor in which the bent portion or hole is formed. The method of claim 16, LNG carrier further comprising a support means between the inner wall and the cargo hold. The method of claim 22, The support means is made of a metal support having a low coefficient of friction, the LNG carrier that the outer surface of the cargo hold on the surface of the metal support sliding contact. The method of claim 23, The metal support is an LNG carrier having two or more degrees of freedom. The method of claim 23, An LNG carrier having a low friction coefficient composite material layer laminated or Teflon coated on the surface of the metal support in contact with the outer surface of the cargo hold. The method of claim 22, The support means is composed of an air bag, the LNG carrier in which a composite layer having a low friction coefficient is laminated or Teflon coated on the surface of the air bag in contact with the outer surface of the cargo hold. The method of claim 22, The support means is a LNG carrier is a liquid filled between the inner wall and the cargo hold. The method of claim 27, LNG is a liquid that is a mixture of metal, polymer, ceramic. Combining a plurality of metal plates having bends to form a first barrier layer; Fixing a first heat insulating material to an outer surface of the first barrier layer to form a first heat insulating layer; Fixing a second barrier layer having a bent portion to an outer surface of the first heat insulation layer; Fixing a second heat insulating material to an outer surface of the second barrier layer to form a second heat insulating layer; Construction method of the cargo hold of the LNG carrier comprising fixing the outer cover layer on the outer surface of the second heat insulating layer. The method of claim 29, Construction method of the cargo hold of the LNG carrier is coupled to each of the plurality of metal plate forming the first barrier layer using a welding or adhesive. The method of claim 29 or 30, A method of constructing a cargo hold of an LNG Carrier further coupling a rigid body to a surface of a plurality of metal plates forming the first barrier layer or a portion to which the metal plates are respectively coupled. The method of claim 29, The first barrier layer is formed of multiple layers of metal plates or coating method of the cargo hold of the LNG carrier to apply a polymer resin mixed with metal powder on the surface of the metal plate. The method of claim 29, And the second barrier layer and the outer cover layer are formed of metal layers of several layers or a sandwich structure in which metal thin plates and fiber-reinforced composite materials are laminated. The method of claim 29, The first heat insulating material and the second heat insulating material are constructed of a heat insulating material having open pores, and the space between the first barrier layer and the second barrier layer and the space between the second barrier layer and the outer cover layer are vacuum pumped. Construction method of cargo holds of LNG ships to maintain a vacuum state using. The method of claim 29, Cooling the gas by using the vaporization heat of the vaporized LNG or using a separate cooling device, and by forming a bubble by discharging the cooled gas into the LNG through a tube installed inside the first barrier layer and communicated with the outside of the cargo hold. Construction method of cargo holds of LNG carriers. The method of claim 29, A method of constructing a cargo hold of an LNG carrier in which a gas pressure between the first barrier layer and the second barrier layer is maintained at or above atmospheric pressure to prevent sagging in the first barrier layer due to the load of LNG. delete

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