KR20230166519A - Membrane sheet arrangement structure of liquefied gas insulation system - Google Patents

Abstract

An insulation layer consisting of a plurality of insulation panels arranged on the inner wall of the hull; The membrane sheet arrangement structure of the liquefied gas insulation system includes a barrier disposed on the upper part of the insulation layer and composed of a plurality of membrane sheets connected, and is arranged so that the central axis of the membrane sheet and the central axis of the insulation panel coincide. It begins.

Description

Membrane sheet arrangement structure of liquefied gas insulation system}

The present invention relates to a membrane sheet arrangement structure of a liquefied gas insulation system. More specifically, in constructing an insulation system inside a storage tank storing cryogenic liquefied gas, the effective use of a membrane sheet installed to keep the liquefied gas airtight is provided. It proposes a layout structure.

Liquefied Natural Gas (LNG) is obtained by cooling natural gas to a cryogenic temperature of approximately -163°C. Its volume is reduced to approximately 1/600 of that in gaseous form, making it very suitable for long-distance transportation by sea. Suitable.

Structures for transporting or storing LNG, such as LNG carriers (LNGCs) that transport LNG at sea and unload it at land destinations, have specially designed storage tanks (commonly referred to as 'cargo holds') to withstand the extremely low temperatures of LNG. ) is installed.

In general, in order to safely store cryogenic LNG, LNG storage tanks are composed of an insulation system consisting of one or more barriers made of metal membranes and an insulation layer surrounding the barrier. Depending on whether the load of the cargo acts directly on the insulation, the membrane type can be used. It can be divided into (membrane type) and independent type.

A membrane-type storage tank is a tank manufactured as one piece with the hull structure. It has a double seal structure (or double insulation structure) in which the secondary insulation layer, secondary barrier, primary insulation layer, and primary barrier are sequentially stacked on the inner wall of the hull. An insulation system is constructed. Representative membrane-type storage tanks include GTT's NO 96 type and MARK Ⅲ type.

The NO 96 type storage tank consists of insulation boxes filled with insulation materials such as perlite powder or glass wool inside a plywood box, and the primary and secondary insulation layers are composed of each It is a structure in which an invar steel (36% nickel steel) membrane with a thickness of 0.5 to 0.7 mm is installed on the top of the insulation layer to form a barrier.

The NO 96 type storage tank has almost the same level of liquid tightness and strength as the primary barrier and the secondary barrier, so when the primary barrier leaks, the secondary barrier alone can safely support the cargo for a considerable period of time. It is composed of an insulated box. The advantage is that the insulation layer can have high compressive strength and rigidity, and the automation rate of welding is high.

The MARK Ⅲ type storage tank consists of primary and secondary insulation layers made of insulation panels made by attaching wood plywood to the upper and lower surfaces of polyurethane foam (PUF), with a thickness of approximately 1.2 mm on top of the primary insulation layer. A thick stainless steel (SUS) membrane is installed to form a primary barrier, and a composite material called triplex is installed on top of the secondary insulation layer to form a secondary barrier.

The MARK Ⅲ type storage tank is advantageous in terms of BOR (Boil-Off Rate) due to the excellent insulation effect of the insulation panel based on polyurethane foam insulation, but is vulnerable to thermal deformation or hull deformation due to the flexible nature of the insulation panel. has Therefore, it is difficult to apply the Invar steel membrane with a low heat contraction coefficient used in the NO 96 type to the MARK Ⅲ type storage tank. Instead, it has a structure that absorbs heat shrinkage deformation by forming a primary barrier with a stainless steel membrane with corrugated corrugations.

In addition, the stainless steel membrane with corrugations has a protruding structure, making it difficult to install between the first and second insulation layers. Therefore, in the current MARK Ⅲ type storage tank, the secondary barrier is called a triplex instead of a metal membrane. It is composed of composite materials. However, the MARK III type storage tank in which the secondary barrier is composed of a triplex composite material has the disadvantage of being vulnerable to watertightness compared to the insulation system in which both the primary and secondary barriers are composed of metal barriers.

In the above, the insulation system in which the insulation layer consists of insulation boxes, such as the NO 96 type storage tank, is called a box type insulation system. In distinction from this, the insulation layer is based on polyurethane foam insulation, such as the MARK Ⅲ type storage tank. An insulation system composed of one insulation panel is also called a panel type insulation system.

Meanwhile, the insulation layer is made up of insulation panels made based on polyurethane foam insulation, which basically takes a panel-type structure, but instead of installing a barrier between the first and second insulation layers, two barriers are built in succession over the entire insulation layer. The KC-1 insulation system has been developed and is known. The specific structure of the KC-1 insulation system is clearly shown in Republic of Korea Patent Publication No. 10-0644217 (November 10, 2006).

However, the KC-1 insulation system has a risk in that the insulation panels that make up the insulation layer are not connected. The KC-1 insulation system, in which the insulation panels are not connected to each other, may have the disadvantage of panel-type insulation systems being vulnerable to thermal deformation or hull deformation. In addition, the KC-1 insulation system is structurally very vulnerable to external deformation because the members installed between the first and second barriers are connected to the inner wall of the hull, and heat loss through the connection with the hull is also significant, which is a fatal problem. There is a downside.

Meanwhile, referring to Figure 17, the existing commercialized panel-type insulation system is designed to form a barrier by connecting a plurality of membrane sheets (MS) through welding, usually in a cross shape on the insulation panel (IP). The insulation system is constructed so that the edge portion of the membrane sheet (MS) is welded onto the installed anchor strip (AS), and therefore the corner portion of the membrane sheet (MS) is separated from the central axis of the insulation panel (IP) disposed below. It is located at an offset point, that is, has a structure in which the vertical edge of the insulation panel (IP) and the vertical edge of the membrane sheet (MS) are arranged in a misaligned manner.

In this way, in the existing insulation system, the structure in which the membrane sheet (MS) and the insulation panel (IP) are arranged misaligned with each other is based on design variables such as the maximum producible size of the membrane sheet (MS) and the producible width of the insulation panel (IP). In addition to considering the structural characteristics of the existing insulation layer, it was an inevitable arrangement.

However, this conventional membrane sheet arrangement has a disadvantage in terms of structural strength considering the cryogenic heat shrinkage direction of the insulation panel (IP). The liquefied gas insulation system has the special feature of being installed in a cryogenic environment, and each member that makes up the liquefied gas insulation system shrinks by the heat contraction coefficient toward the neutral axis of each member in the cryogenic environment. As in the prior art, a membrane sheet (MS ) and the insulation panel (IP) are arranged misaligned with each other, because the shrinkage direction of the membrane sheet (MS) and the shrinkage direction of the insulation panel (IP) are formed differently, greater stress is concentrated in the welded portion of the membrane, resulting in a structural disadvantage. It works well.

In addition, if only the heat shrinkage due to cryogenic temperatures is considered, it may be at a level that can be tolerated at the welded portion of the membrane, but when looking at the insulation system as a whole, it experiences various loads such as sloshing load, hull deformation, and fatigue load that occur inside the storage tank. Placing the membrane sheet and the insulation panel (IP) misaligned with each other is not an optimal arrangement.

The present invention seeks to present a new type of liquefied gas insulation system that can take advantage of both the panel-type insulation system, which has excellent insulation performance, and the double metal barrier structure, which is strong against water and is structurally advantageous.

In other words, the present invention enables the application of a double metal barrier structure to a panel-type insulation system that is advantageous in terms of BOR by applying a polyurethane foam-based insulation material, thereby providing superior performance compared to existing products in terms of both insulation performance and structural stability. The purpose is to provide an improved liquefied gas insulation system that can be equipped.

In addition, in order to solve the problem that structural weaknesses occurred due to the membrane sheets and insulation panels being arranged misaligned with each other in the existing insulation system, the present invention theoretically changes the central axis of the membrane sheet constituting the barrier to the center of the insulation panel without any deformation. Another technical task is to effectively prevent stress from concentrating in the membrane weld zone and improve the overall structural performance of the insulation system by arranging it in line with the axis.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

According to one aspect of the present invention for achieving the above object, an insulation layer consisting of a plurality of insulation panels arranged on the inner wall of the hull; The membrane sheet arrangement structure of the liquefied gas insulation system includes a barrier disposed on the upper part of the insulation layer and composed of a plurality of membrane sheets connected, and is arranged so that the central axis of the membrane sheet and the central axis of the insulation panel coincide. can be provided.

The insulating layer further includes a bridge panel disposed between the adjacent insulating panels, and the membrane sheet has an edge fixed to an anchor strip provided on the bridge panel, and the edges of the adjacent membrane sheets overlap each other. Can be welded.

The insulation panel includes a lower insulation board made in the shape of a hexahedron and fixed to the inner wall of the hull, and an upper insulation board made in the shape of a hexahedron having a smaller flat cross-sectional area than the lower insulation board and laminated on top of the lower insulation board, The bridge panel may be disposed in the space between the upper insulation boards that are adjacent to each other while covering the boundaries of the lower insulation boards that are adjacent to each other.

The central axes of the lower insulation board and the upper insulation board may coincide.

The membrane sheet may have the same plan size as the lower insulation panel, and may be arranged so that the vertical edge of the membrane sheet corresponds to the vertical edge of the lower insulation panel.

The liquefied gas insulation system according to the present invention is basically a panel-type insulation system in which the insulation layer is composed of an insulation panel based on polyurethane foam insulation, and can have excellent insulation performance compared to a box-type insulation system.

In addition, the liquefied gas insulation system according to the present invention realizes double airtightness by a double metal barrier continuously installed on the upper part of the insulation layer, so the disadvantage of the conventional MARK III storage tank being vulnerable to watertightness can be complemented, and thus excellent Not only does it have insulation performance, but it also ensures high reliability of the insulation system.

The liquefied gas insulation system according to the present invention has a structure in which a plurality of insulation panels arranged in succession are connected by a bridge panel, so that the insulation layer can behave flexibly against thermal deformation or hull deformation, and a double barrier installed on the top of the insulation layer. And since the support members between the barriers have a structure that is not connected to the hull, heat intrusion from the outside can be minimized.

In addition, the liquefied gas insulation system according to the present invention is characterized in that the wrinkles formed on the primary barrier protrude toward the inside of the storage tank, and the wrinkles formed on the secondary barrier protrude toward the outside of the storage tank, that is, toward the hull. According to the structure of the present invention, interference due to wrinkles does not occur between the first and second barriers, so the structure or shape of the inter-barrier structure placed in the space can be simplified, and the installation structure of the inter-barrier structure As is greatly simplified, the constructability of the liquefied gas storage tank can be expected to be greatly improved and the total drying period can be shortened.

In addition, the present invention applies an arrangement structure in which the central axis of the membrane sheet constituting the barrier is theoretically aligned with the central axis of the insulation panel, which is theoretically free of deformation, thereby effectively preventing stress from concentrating on the membrane weld zone and ultimately providing insulation. It can have a positive effect of improving the overall structural performance of the system.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

Figure 1 is a diagram showing an insulation system in which the wrinkles of the first and second barriers installed adjacent to each other are all directed toward the inside of the storage tank.
Figure 2 is a cross-sectional view of the liquefied gas storage tank insulation system according to the present invention.
Figure 3 is a perspective view showing the liquefied gas storage tank insulation system according to the present invention.
Figure 4 is a perspective view showing the insulation panel constituting the insulation layer in the liquefied gas storage tank insulation system according to the present invention.
Figure 5 is a side view of the insulation panel according to the present invention.
Figure 6 is a view showing a bridge panel being installed between a plurality of insulation panels in the liquefied gas storage tank insulation system according to the present invention.
Figure 7 is a diagram showing that a secondary barrier is installed on the top of the insulation layer in the liquefied gas storage tank insulation system according to the present invention.
Figure 8 is a diagram showing the supporting plywood installed between the first and second barriers in the liquefied gas storage tank insulation system according to the present invention.
Figure 9 is a plan view of the supporting plywood according to the present invention.
Figure 10 is a diagram showing that supporting plywood is installed on the upper part of the insulation layer and secondary barrier in the liquefied gas storage tank insulation system according to the present invention.
Figure 11 is a plan view showing the installation structure of the supporting plywood according to the present invention.
Figure 12 is a diagram showing the fixing structure of the first supporting plywood according to the present invention.
Figure 13 is a diagram showing the fixing structure of the second supporting plywood according to the present invention.
Figure 14 is a diagram showing that the primary barrier is installed on the top of the insulation layer, secondary barrier, and supporting plywood in the liquefied gas storage tank insulation system according to the present invention.
Figure 15 is a view to explain the effect of absorbing wrinkle deformation of the primary barrier by the structure of the supporting plywood according to the present invention.
Figure 16 is a diagram showing the membrane sheet arrangement structure according to the present invention.
Figure 17 is a diagram showing a membrane sheet arrangement structure according to the prior art.

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

Matters expressed in the drawings attached to this specification may be somewhat different from the form actually implemented in schematic drawings to easily explain the embodiments of the present invention, and the sizes of each component shown in the drawings are for explanatory purposes. It can be exaggerated or reduced and does not mean the size that is actually applied.

Additionally, the terms used herein are merely used to describe specific embodiments and are not intended to limit the invention. For example, in this specification, “including” a certain component does not mean excluding other components, but may further include other components, unless specifically stated to the contrary.

In addition, it should be understood that saying that a component is 'connected' to another component includes direct connection as well as indirect connection, and that other components may exist between the two components. Singular expressions may be interpreted to include plural expressions unless the context clearly indicates otherwise.

The liquefied gas storage tank described in this specification includes LNG, a representative liquefied gas, LPG (Liquefied petroleum gas), LEG (Liquefied Ethane Gas), Liquefied Ethylene Gas, Liquefied Propylene Gas, etc. It may include all storage tanks that store various types of liquefied gases that can be liquefied at low temperatures and stored/transported.

In this specification, the terms 'primary' and 'secondary' for liquefied gas storage tanks are used to indicate whether the liquefied gas is primarily sealed or insulated based on the liquefied gas stored inside the storage tank, or secondarily sealed. Or, it was used as a standard for whether or not it was insulated.

In addition, the terms 'upper', 'top' or 'top' conventionally applied to liquefied gas storage tanks refer to the direction toward the inside of the tank regardless of the direction of gravity, and similarly, the terms 'lower' and 'lower' Alternatively, 'down' refers to the direction towards the outside of the tank, regardless of the direction with respect to gravity.

Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention with reference to the accompanying drawings. The embodiments described below are provided so that those skilled in the art can easily understand the technical idea of the present invention, and the present invention is not limited thereto.

Figure 1 is a diagram showing an insulation system in which the wrinkles of the first and second barriers installed adjacent to each other are all directed toward the inside of the storage tank. Figure 2 is a cross-sectional view showing the liquefied gas storage tank insulation system according to the present invention, and Figure 3 is a perspective view showing the liquefied gas storage tank insulation system according to the present invention. Figure 4 is a perspective view showing the insulation panel constituting the insulation layer in the liquefied gas storage tank insulation system according to the present invention, and Figure 5 is a side view of the insulation panel according to the invention. Figure 6 is a view showing a bridge panel being installed between a plurality of insulation panels in the liquefied gas storage tank insulation system according to the present invention. Figure 7 is a diagram showing that a secondary barrier is installed on the top of the insulation layer in the liquefied gas storage tank insulation system according to the present invention. Figure 8 is a diagram showing the supporting plywood installed between the first and second barriers in the liquefied gas storage tank insulation system according to the present invention, and Figure 9 is a plan view of the supporting plywood according to the present invention. Figure 10 is a view showing that supporting plywood is installed on the upper part of the insulation layer and secondary barrier in the liquefied gas storage tank insulation system according to the present invention, and Figure 11 is a plan view showing the installation structure of the supporting plywood according to the present invention. It is a drawing. Figure 12 is a diagram showing the fixing structure of the first supporting plywood according to the present invention, and Figure 13 is a diagram showing the fixing structure of the second supporting plywood according to the present invention. Figure 14 is a diagram showing that the primary barrier is installed on the top of the insulation layer, secondary barrier, and supporting plywood in the liquefied gas storage tank insulation system according to the present invention. Figure 15 is a view to explain the effect of absorbing wrinkle deformation of the primary barrier by the structure of the supporting plywood according to the present invention. And Figure 16 is a diagram showing the membrane sheet arrangement structure according to the present invention.

As described above, the present invention seeks to provide a liquefied gas insulation system in which a double metal barrier is installed on the upper part of an insulation layer based on a polyurethane foam-based insulation material. At this time, the double metal barrier is composed of a primary membrane that provides primary airtightness while in direct contact with the liquefied gas, and a secondary membrane that provides secondary airtightness when the primary barrier leaks. You can.

In addition, as the present invention uses an insulation panel with relatively flexible properties, it is intended to apply stainless steel or low-temperature steel with similar properties as the material for both the primary and secondary barriers, and each of the primary and secondary barriers includes We aim to create a structure that can absorb heat shrinkage caused by cryogenic liquefied gas by forming corrugations.

At this time, one can simply consider a method of forming the wrinkles formed on the primary barrier and the secondary barrier in an upward direction, that is, toward the inside of the storage tank, and this structure can be seen in Figure 1.

Referring to Figure 1, a secondary barrier 20 and a primary barrier 30 are sequentially placed on the top of the insulation layer 10, and between the secondary barrier 20 and the primary barrier 30, two barriers ( A spacer 40 is installed to support between 20 and 30 and space them apart at regular intervals. The secondary barrier 20 and the primary barrier 30 may be made of a membrane made of stainless steel, and may each include a plurality of wave-shaped wrinkles 21 and 31 formed to absorb heat shrinkage due to cryogenic temperatures. there is.

However, as shown in FIG. 1, both the secondary wrinkles 21 formed on the secondary barrier 20 and the primary wrinkles 31 formed on the primary barrier 30 are directed upward (inside the storage tank). If it is formed to face the direction (direction), interference due to the secondary wrinkles 21 occurs in the space between the secondary barrier 20 and the primary barrier 30, and this interference with the secondary wrinkles 21 In order to avoid this, the spacer 40 must be divided into multiple pieces and placed in the space between the secondary wrinkles 21.

That is, the spacer 40, which is installed as an inter-barrier structure to support and separate the primary barrier 30 and the secondary barrier 20, is adjusted to correspond to the space between the secondary wrinkles 21 formed in large numbers. Since it must be manufactured, it not only creates design constraints, but also increases the amount of materials and installation man-hours, which can reduce constructability.

In addition, the space between adjacent spacers 40 is a space where the secondary wrinkles 21 formed in the secondary barrier 20 should be placed, and can be left empty or left empty after the secondary wrinkles 21 are placed. You can consider inserting an insulating material such as glass wool into the space, but even if additional insulating material is installed, it is difficult to completely prevent heat loss due to convection through the space.

In order to solve the above problems, the present invention has the wrinkles formed on the secondary barrier facing downward (outward direction of the storage tank) and the wrinkles formed on the primary barrier facing upward (inside direction of the storage tank). We would like to propose a liquefied gas insulation system with an improved structure that does not cause wrinkle interference in the space between the first and second barriers. Hereinafter, a preferred embodiment of the liquefied gas insulation system according to the present invention will be described with reference to FIGS. 2 to 16.

Referring to Figures 2 and 3, the liquefied gas insulation system according to the present invention includes an insulation layer 100 installed on the inner wall of the hull (H), a secondary barrier 200 installed continuously on the upper side of the insulation layer 100, and It may be configured to include a primary barrier 300. A supporting plywood 400 may be installed between the secondary barrier 200 and the primary barrier 300 as an inter-barrier structure to separate and support the two barriers 200 and 300.

As will be explained in more detail later, the secondary barrier 200 and the primary barrier 300 may each be composed of a stainless steel membrane, and may include a plurality of corrugated wrinkles 200c, which are formed to absorb heat contraction caused by cryogenic liquefied gas. 300c) may be included. The secondary wrinkles 200c formed on the secondary barrier 200 protrude downward, i.e. toward the outside of the storage tank, and the primary wrinkles 300c formed on the primary barrier 300 protrude upward, i.e. toward the outside of the storage tank. It may protrude in a direction toward the inside.

The insulation layer 100 has the main insulation function in this insulation system, that is, the function of preventing heat intrusion from the outside of the storage tank, and is made of an insulation material such as polyurethane foam or reinforced polyurethane foams (R-PUF). It may be composed of a plurality of insulation panels 110 and bridge panels 120 manufactured based on it.

The insulation panel 110 and bridge panel 120 that make up the insulation layer 100 include polyurethane foam or reinforced polyurethane foam insulation, and are made of plywood or fiber reinforcement to provide mechanical rigidity to the flexible insulation material. Materials such as plastics (Fiber Reinforced Plastics (FRP)) may be provided in a composite form.

More specifically, the insulation layer 100 includes an insulation panel 110 manufactured as a roughly 'convex' shaped module including a lower insulation board 111 and an upper insulation board 112, and adjacent insulation panels ( It may include a bridge panel 120 disposed between 110).

The specific structure of the insulation panel 110 can be seen in FIGS. 4 and 5. Referring to Figures 4 and 5, the insulation panel 110 may be provided in a form in which an upper insulation board 112 with a smaller cross-sectional area is stacked on top of a lower insulation board 111 having a rectangular parallelepiped shape.

The upper insulation board 112 may be fixed to the upper surface of the lower insulation board 111 by adhesive. At this time, the upper insulation board 112 may be arranged so that its center coincides with the lower insulation board 111, and therefore a portion of the upper edge of the lower insulation board 111 is exposed. The area exposed at the edge of the lower insulation board 111 is covered by a bridge panel 120, which will be described later. The length from each corner of the upper insulation board 112 to each corner of the lower insulation board 111 in the corresponding direction may be formed to be the same.

The lower insulation board 111 has a lower plate 111b made of plywood or fiber-reinforced plastic attached to the lower surface of the lower insulation 111i, which is manufactured by processing polyurethane foam or reinforced polyurethane foam insulation into a rectangular parallelepiped shape. can be provided. The lower plate 111b serves to provide mechanical rigidity to the lower insulating material 111i, which has flexible properties.

The upper insulation board 112 has an upper plate 112t made of plywood or fiber-reinforced plastic attached to the upper surface of the upper insulation 112i, which is manufactured by processing polyurethane foam or reinforced polyurethane foam insulation into an approximately rectangular parallelepiped shape. It can be provided in the form Here, the shape of the upper insulation board 112 is expressed as 'approximately' a rectangular parallelepiped because a receiving groove 112g is formed in the upper part of the upper insulation board 112 to accommodate the secondary wrinkles 200c, which will be described later. This is because it cannot be viewed as an exact cube.

Looking in detail at the processing form of the upper insulation board 112, a receiving groove 112g is formed in the upper part of the upper insulation board 112 to provide a space for receiving the secondary wrinkles 200c. A plurality of receiving grooves 112g are formed side by side at regular intervals in each direction along the longitudinal and width directions of the upper insulation board 112 in response to the secondary wrinkle 200c structure formed in the secondary barrier 200. It can be. Accordingly, a plurality of receiving grooves 112g are formed in a grid shape on the upper surface of the upper insulation board 112. The drawing shows that the receiving groove (112g) is processed into a 'V' shape, but it would also be possible to process the receiving groove (112g) into a 'U' shape to correspond to the shape of the secondary wrinkle 200c.

Additionally, the receiving groove 112g may include a chamfer shape formed along the upper edge of the upper insulation board 112. The receiving groove 112g formed in a chamfered shape on the upper edge of the upper insulation board 112 is located opposite to the receiving groove formed in a chamfered shape along the upper edge of the bridge panel 120, which will be described later, and provides a space between the two. A 'V' or 'U' shaped wrinkle receiving space may be formed in the space.

The upper plate 112t located at the top of the upper insulation board 112 can be divided into a plurality of segments by forming the receiving groove 112g. As will be described later, the flat portion of the secondary barrier 200 is placed on the upper plate 112t, and the secondary wrinkles 200c protruding downward are accommodated in the receiving groove 112g formed between them.

Additionally, a slit (112s) extending vertically downward from the center of the receiving groove (112g) may be formed in the upper insulation board (112). The slits 112s are provided to alleviate the stress concentration phenomenon caused by the load occurring on the insulation layer 100, especially the thermal load, and a plurality of slits 112s are formed along the longitudinal and width directions of the upper insulation board 112. You can. The slit 112s formed along the longitudinal direction and the slit 112s formed along the width direction are orthogonal to each other.

By processing the slit (112s), the upper insulation board (112) can be divided into a number of parts with separate heat contraction behavior, and the heat contraction behavior for each part is achieved separately, thereby structurally liquefying the liquefied gas insulation system. Stability can be improved.

In the present invention, all components of the insulation panel 110 can be joined by adhesive. The lower insulation material 111i and the lower plate 111b constituting the lower insulation board 111 are bonded to each other by adhesive, and the upper insulation material 112i and the upper plate 112t constituting the upper insulation board 112 are bonded together. They are coupled to each other, and the lower surface of the upper insulation board 112 may be fixed to the upper surface of the lower insulation board 111 by adhesive.

However, the case of the first fixing device 113 installed at the upper center of the upper insulation board 112 is an exception. The first fixing device 113 is mechanically fastened and fixed to the center of the upper plate 112t located in the center among the multiple segments present on the upper part of the upper insulation board 112. You can. The first fixing device 113 is a configuration for fixing the supporting plywood 400, which will be described later, in more detail.

The insulation panel 110 can be modularized and manufactured as an integrated unit including the lower insulation board 111 and the upper insulation board 112, and a plurality of insulation panels 110 manufactured as modules are placed on the inner wall of the hull (H). The insulation layer 100 can be formed by arranging the bridge panels 120 in the space between them in succession.

Referring to Figure 6, the plurality of insulation panels 110 may be arranged in rows and rows so that the lower insulation board 111 is adjacent to each other along the horizontal and longitudinal directions of the storage tank. At this time, considering the installation tolerance, the adjacent lower insulation boards 111 can be placed with a predetermined gap between them.

Meanwhile, as described above, the upper insulation board 112 has a smaller flat cross-sectional area than the lower insulation board 111, so an empty space is created between the adjacent upper insulation boards 112, and the present invention provides the space A structure is applied to connect neighboring insulation panels 110 to each other by placing a bridge panel 120 thereon.

The liquefied gas insulation system according to the present invention is a structure in which both the primary barrier 300 and the secondary barrier 200 are located on the upper side of the insulation layer 100, that is, the insulation layer 100 is located on the barriers 200 and 300. It is a structure that is not separated by In this structure, if the insulation layer 100 is formed as a single layer, structural weakness may occur due to vertical load due to hull deformation. In addition, as described above, a predetermined gap occurs between adjacent lower insulation boards 111 in consideration of installation tolerance, and the gap that occurs within the insulation system is a space where convection occurs and is a space where heat loss can occur. .

In order to compensate for the above weaknesses, the present invention consists of a double layer insulation panel 110 including a lower insulation board 111 and an upper insulation board 112, and a lower insulation board 111 constituting the lower insulation layer. By arranging the vertical edges of the upper insulation board 112 and the bridge panel 120, which constitute the upper insulation layer, to be offset from each other, stable behavior of the insulation layer 100 is possible and heat loss through the boundary between the panels can also be effectively blocked. Implement the structure.

Continuing to refer to FIG. 6, the bridge panel 120 is disposed between the upper insulation boards 112 of neighboring insulation panels 110, and thus will be arranged while covering the boundaries of the neighboring lower insulation boards 111. You can.

The bridge panel 120 may have a shape similar to that of the upper insulation board 112. The bridge panel 120 may be provided with a top plate (member number not assigned) attached to the upper surface of polyurethane foam or reinforced polyurethane foam insulation (member number not assigned) made of plywood or fiber-reinforced plastic. . In addition, a receiving groove (member number not assigned) to accommodate the secondary wrinkles 200c formed in the secondary barrier 200 and a slit (member number not assigned) to relieve stress concentration are formed in the bridge panel 120. It can be.

In this embodiment, the bridge panel 120 includes a transverse bridge panel 120A disposed laterally between upper insulation boards 112 adjacent to each other in the longitudinal direction, and upper insulation boards adjacent to each other in the width direction ( 112), a longitudinal bridge panel (120B) disposed longitudinally between them, and an intersection bridge panel ( It can be provided in three forms, including 120C).

The transverse bridge panel 120A may have the same shape as the portion located within the gap between the slits 112s formed in the width direction of the upper insulation board 112, and the longitudinal bridge panel 120B may be an upper insulation board ( It may have the same shape as the portion located within the gap between the slits 112s formed in the longitudinal direction in 112). In addition, the intersection bridge panel 120C may have the same shape as the portion located within the gap between the slits 112s formed in the longitudinal direction and within the gap between the slits 112s formed in the width direction.

According to this, the width of the horizontal bridge panel (120A) and the longitudinal bridge panel (120B) may be formed to be the same as the spacing of the slits (112s) formed in the upper insulation board (112). Additionally, the length of the horizontal bridge panel 120A and the length of the longitudinal bridge panel 120B may be formed to be the same as the width and length of the upper insulation board 112, respectively. In addition, both the width and length of the intersection bridge panel 120C may be formed to be the same as the spacing of the slits 112s.

However, the present invention is not limited thereto. Not only can the size of the horizontal bridge panel (120A) and the vertical bridge panel (120B) be made smaller or larger, but either the horizontal bridge panel (120A) or the vertical bridge panel (120B) can be used at the intersection. It can also be configured by integrating with the bridge panel (120C). In addition, the effect of reducing material quantity can be maximized by unifying all three types of bridge panels (120A, 120B, and 120C) into the same size and appropriately arranging them in the space between the upper insulation boards 112.

For reference, in the drawing, in order to distinguish the upper insulation board 112 and the bridge panel 120, the gap formed between the upper insulation board 112 and the bridge panel 120 is a slit (112s) formed in the upper insulation board 112. ) is shown larger than the width, but it is preferable that the gap formed between the upper insulation board 112 and the bridge panel 120 and the width of the slit 112s formed in the upper insulation board 112 are formed at the same level.

The bridge panel 120 may further include a secondary anchor strip 121 for fixing the secondary barrier 200. The secondary anchor strip 121 is a strip-shaped metal plate with a predetermined width, and can be mechanically fastened to the upper plate of the bridge panel 120 using rivets, screws, staples, etc. In addition, the secondary anchor strip 121 may be seated and fixed in a groove formed on the upper surface of the upper plate of the bridge panel 120, and the upper surface of the secondary anchor strip 121 is the upper surface of the upper plate of the bridge panel 120. It can form the same plane as .

The secondary anchor strip 121 installed on the lateral bridge panel 120A and the longitudinal bridge panel 120B may be installed along the center line along the longitudinal direction of each panel 120A and 120B. The secondary anchor strip 121 installed on the intersection bridge panel 120C can maintain continuity with the anchor strip 121 provided on the adjacent transverse bridge panel 120A and longitudinal bridge panel 120B. It can be provided in the shape of the character ten (十).

Meanwhile, as a receiving groove for receiving the secondary wrinkles 200c is formed on the upper part of the bridge panel 120, the upper plate of the bridge panel 120 is divided into a plurality of segments that are not connected to each other, and thus the upper plate The secondary anchor strip 121 installed in has a structure that is not connected but is disconnected at regular intervals. Disconnecting the secondary anchor strip 121 in this way is an intended structure of the present invention to increase the structural stability of the insulation system by more effectively preventing heat contraction of the secondary barrier 200.

A second fixing device 122 for fixing the supporting plywood 400, which will be described later, may be installed at the upper center of the intersection bridge panel 120C among the bridge panels 120. The second fixing device 122 may be fixed by welding to the center of the ten-shaped anchor strip 121 provided on the intersection bridge panel 120C. Details of the second fixing device 122 will be described later along with the first fixing device 113.

The present invention implements a liquefied gas insulation system with a double metal barrier structure by successively installing the secondary barrier 200 and the primary barrier 300 on the upper side of the insulation layer 100. That is, the present invention eliminates the process of installing a barrier between the upper and lower insulation layers in a conventional insulation system, forms an overall thick insulation layer 100, and then installs a double barrier 200, 300 thereon.

The primary and secondary barriers 300 and 200 serve to seal (liquid-tight/air-tight) the liquefied gas contained within the storage tank. The primary barrier 300 performs a primary sealing function by directly contacting the cryogenic liquefied gas contained within the storage tank, and the secondary barrier 200 performs a secondary sealing function when the primary barrier 300 leaks. It must be designed to enable tightness and support of liquefied gas for a considerable period of time even if leakage of the primary barrier 300 occurs.

The first and second barriers 300 and 200 may be made of a metal material with strong low-temperature brittleness to cope with stress changes caused by the extremely low temperature of the liquefied gas contained inside the storage tank, for example, stainless steel or Invar steel. Alternatively, low-temperature steel such as aluminum alloy may be used.

As described above, in the present invention, due to the nature of the structure of the panel-type insulation system in which the insulation layer 100 has flexible properties, the primary and secondary barriers 300 and 200 are made of stainless steel material that can easily respond to stress changes. It is preferable that the primary and secondary barriers 300 and 200 made of stainless steel membranes may each include a plurality of wavy wrinkles 300c and 200c to cope with heat shrinkage due to cryogenic temperatures.

Referring to FIG. 7, the secondary barrier 200 may be provided with a plurality of membrane sheets airtightly connected to each other. The unit membrane sheet constituting the secondary barrier 200 is prepared as an approximately rectangular metal sheet with a predetermined length and width, and the edges of adjacent membrane sheets are overlapping and welded to form airtightness at the corresponding level. .

The secondary wrinkles 200c formed on the secondary barrier 200 may be formed to protrude downward, that is, toward the outside of the storage tank. A plurality of secondary wrinkles 200c formed in the secondary barrier 200 may be formed side by side along the length and width directions of the membrane sheet, with longitudinal wrinkles extending in the longitudinal direction and transverse wrinkles extending in the width direction. Wrinkle intersections may be formed in areas where wrinkles intersect. In addition, when welding adjacent membrane sheets, the wrinkles formed on each membrane sheet are connected to each other, so that a plurality of wrinkles extending along the transverse and longitudinal directions can form a grid inside the storage tank.

The secondary barrier 200 may be fixed by a secondary anchor strip 121 installed on the top of the insulation layer 100. In the liquefied gas insulation system according to the present invention, it has been described above that among the components constituting the insulation layer 100, the secondary anchor strip 121 is installed only on the upper surface of the bridge panel 120, and as shown in Figure 7, the insulation layer The edges of the membrane sheets constituting the secondary barrier 200 may be fixed by welding on the secondary anchor strips 121 arranged in a grid form on the upper part of the 100. At this time, the edges of neighboring membrane sheets are overlapped and welded to each other.

According to the structure of the present invention as described above, the size of the membrane sheet constituting the secondary barrier 200 can be manufactured to the same or similar level as the lower insulation board 111 of the insulation panel 110, and the installation location can also be It may be formed at a position corresponding to the lower insulation board 111.

The characteristics and effects of the membrane arrangement structure according to the present invention will be briefly described with reference to FIG. 16. The portion indicated by the dotted line in FIG. 16 is an easily understandable division of the area where the insulation panel 110 is placed.

As explained with reference to FIG. 17 in the background technology, the conventional design structure in which the membrane sheet (MS) and the insulation panel (IP) are arranged misaligned with each other is structurally disadvantageous and may be a factor that impedes the stability of the liquefied gas insulation system.

However, the present invention allows the edge of the membrane sheet constituting the secondary barrier 200 to be welded to the secondary anchor strip 121 installed on the bridge panel 120 disposed between the insulation panels 110, thereby forming the insulation panel 110. ) and the central axes of the membrane sheets placed on it can be aligned with each other, thereby providing an insulation system with excellent structural stability.

More specifically, in the present invention, the membrane sheet constituting the secondary barrier 200 is arranged to coincide with the central axis of the insulation panel 110, which has no structural deformation when considering heat shrinkage, and therefore is similar to the conventional membrane arrangement structure ( Compared to Figure 17), less stress is generated in the welds between membrane sheets, which is expected to have a positive effect on improving the structural performance of the insulation system.

Meanwhile, there are fixing devices 113 and 122 on the top of the insulation layer 100 for fixing the supporting plywood 400, which will be described later, and the fixing devices 113 and 122 penetrate the secondary barrier 200. It includes studs that protrude upward. In order to allow such a protruding structure, there is a through hole in the center of the membrane sheet constituting the secondary barrier 200 in the present invention for the studs of the first fixing device 113 installed at the upper center of the insulation panel 110 to pass through. This can be formed. In addition, in order to allow the studs of the second fixing device 122 installed at the upper center of the intersection bridge panel 120C to protrude, the four corners of the membrane sheet constituting the secondary barrier 200 are cut diagonally. It can have a shape.

The first fixing device 113 is inserted and fixed to the upper part of the upper insulation board 112 and may include a metal fastening part (e.g., base socket) to which the lower end of the stud is fastened, and is located in the center of the secondary barrier 200. The formed through hole can be airtightly welded onto the metal fastening part. The upper surface of the metal fastening part may be flush with the upper surface of the upper insulation board 112, and more specifically, the upper surface of the upper plate 112t.

In addition, the diagonal portion formed at the corner of the membrane sheet constituting the secondary barrier 200 is airtight on the secondary anchor strip 121 installed in a cross shape on the upper surface of the intersection bridge panel 120C. It may be welded, and a portion of the diagonal portion may be overlap-welded with a neighboring membrane sheet to maintain airtightness at the level of the secondary barrier 200.

Meanwhile, the secondary barrier 200 and the primary barrier 300, which are continuously installed on the top of the insulation layer 100, may expand and contract under the influence of the cryogenic temperature of the liquefied gas, so the two barriers 200 and 300 They must be structured so that they do not come into contact with each other, and an insulation system needs to be constructed to prevent them from being influenced by each other as much as possible.

To this end, the present invention separates the first and second barriers (300, 200) at a predetermined interval and uses a supporting fly between the secondary barrier (200) and the primary barrier (300) for the purpose of minimizing mutual influence. Install wood (400). The specific structure of the supporting plywood 400 can be seen in Figures 8 and 9.

Supporting plywood 400 is made of plywood in the form of a plate or plate having a predetermined thickness, and the two barriers are separated by separating the primary barrier 300 to the upper side of the secondary barrier 200 by the thickness. (200, 300) plays a role in minimizing the influence of each other and promoting structural stability. However, in the present invention, the material of the supporting plywood 400 is not limited to plywood. Any material that can be used at extremely low temperatures and can function as a load-bearing structural material (for example, a composite material such as fiber-reinforced plastic) can be used as an alternative.

The supporting plywood 400 includes a first supporting plywood 410 forming a large frame, and a second supporting plywood 420 inserted into the through portion 413 formed in the center of the first supporting plywood 410. ) can be manufactured with two members including.

The first supporting plywood 410 is installed on a first support plate 411 having a rectangular cross-section and a predetermined thickness, and the upper surface of the first support plate 411, and the primary barrier 300 is welded. It may include a first primary anchor strip 412 fixed by. A square-shaped penetrating portion 413 is formed in the center of the first support plate 411.

The first support plate 411 is preferably a plate made of plywood, and the penetration portion 413 extends the first support plate 411 in the thickness direction to provide a space for the second supporting plywood 420 to be installed. It is a hole formed by penetrating.

The first primary anchor strip 412 is a strip-shaped metal plate with a predetermined width, and may be installed along the longitudinal center line and the width direction center line of the first support plate 411. The first primary anchor strip 412 is seated in a groove formed on the upper surface of the first support plate 411 and can be mechanically fastened and fixed by rivets, screws, staples, etc., and the first primary anchor strip 412 The upper surface may be flush with the upper surface of the first support plate 411.

The second supporting plywood 420 is installed on the second support plate 421, which has a square cross-section and the same thickness as the first supporting plywood 410, and the upper surface of the second support plate 421. The car barrier 300 may include a second primary anchor strip 422 that is fixed by welding.

Like the first support plate 411, the second support plate 421 may also be made of a ply material. The second support plate 421 may have a square (more preferably square) cross-section corresponding to the shape of the penetrating portion 413 formed in the central portion of the first supporting plywood 410, and the penetrating portion 413 It can be inserted and installed within the space.

The second primary anchor strip 422 is a strip-shaped metal plate with a predetermined width. The second support plate 421 is provided to maintain continuity with the first primary anchor strip 412 provided on the first support plate 411. The table may be provided in the shape of the character 十. The second primary anchor strip 422 is seated in a groove formed on the upper surface of the second support plate 421 and can be mechanically fastened and fixed by rivets, screws, staples, etc., and the second primary anchor strip 422 The upper surface may be flush with the upper surface of the second support plate 421.

According to the structure of the present invention described above, when viewed based on the supporting plywood 400 including the first and second supporting plywood 410, 420, the primary anchor strips 412, 422 cross the center. When the separation layer, which is provided in the shape of (十) and is composed of a plurality of supporting plywood 400, is viewed as a whole, there are a number of primary anchor strips 412 and 422 extending along the horizontal and longitudinal directions of the storage tank. It can form a grid.

Meanwhile, as shown in FIG. 1, both the secondary wrinkles 21 formed on the secondary barrier 20 and the primary wrinkles 31 formed on the primary barrier 30 are directed upward (inside the storage tank). direction), the spacer 40 that separates the two barriers 20 and 30 is divided into multiple pieces to avoid interference with the secondary wrinkle 21, thereby increasing the amount of material and installation man-hours. I mentioned above that there is a problem.

In addition, in the structure shown in Figure 1, in order to prevent overlap between the secondary wrinkles 21 and the primary wrinkles 31, the two barriers 20 and 30 must be spaced apart to the extent that they are not affected by sloshing. The thickness of the spacer 40 increases by the corresponding separation distance, which ultimately leads to an increase in cost. In particular, due to the nature of membrane-type insulation systems applied to cryogenic environments, specific materials that do not become brittle and fractured at cryogenic temperatures must be used rather than general materials, which inevitably leads to greater economic losses.

On the other hand, the liquefied gas insulation system according to the present invention, which forms the secondary wrinkles 200c formed on the secondary barrier 200 downward, has 2 in the space between the secondary barrier 200 and the primary barrier 300. No interference occurs due to the secondary wrinkles 200c. Therefore, the present invention has the great advantage that the unit area of the supporting plywood 400 can be increased without the need to consider the spacing of the secondary wrinkles 200c, and the thickness of the supporting plywood 400 can also be flexibly changed by the designer. It can be expected to have economic effects such as improved productivity and reduced costs due to reduced installation man-hours.

The supporting plywood 400 can be manufactured to be at least larger than the interval between the wrinkles 200c and 300c of the barriers 200 and 300. More preferably, the supporting plywood 400 can be manufactured to the same or similar size as the lower insulation board 111 of the insulation panel 110, and the installation location is also at a position corresponding to the lower insulation board 111. can be formed in The installation structure of the supporting plywood 400 will be examined in more detail later.

However, if the size of the supporting plywood 400 is only vaguely large, structural problems may occur, so the present invention seeks to respond to this by machining a slit 414 on the supporting plywood 400.

As mentioned in explaining the structure of the secondary anchor strip 121 described above, the anchor strip to which the barrier is fixed by welding has a disconnected structure so that the wrinkles spread during heat contraction of the barrier and the amount of heat contraction can be well controlled. It is desirable to have it in place.

For this purpose, the present invention can process a slit 414 on the first supporting plywood 410 to cut off the first primary anchor strip 412. Here, the slit 414 extends in a direction perpendicular to the first primary anchor strip 412 and can be seen as a thin hole penetrating the first support plate 411. In order to prevent the first support plate 411 from being damaged due to the heat contraction behavior of the primary barrier 300, it is preferable that the slit 414 completely penetrates the first support plate 411.

Meanwhile, the penetrating portion 413 formed in the center of the first support plate 411 serves to disconnect the first primary anchor strip 412 and the first primary anchor strip 412 and the second primary anchor strip 422. Therefore, separate slits are formed on the first primary anchor strip 412 installed along the width direction of the first support plate 411 and the second primary anchor strip 422 installed on the second support plate 412. It may not be processed. However, the present invention is not limited to this, and it is of course possible to additionally process slits on the first primary anchor strip 412 installed along the width direction in consideration of structural design.

The slits 414 can be formed at regular intervals, and by processing the slits 414, the supporting plywood 400 can be divided into numerous zones that can move independently based on the slits 414. In addition, the second supporting plywood 420 can operate independently of the first supporting plywood 410 by forming the penetrating portion 413.

Referring to FIG. 15 for a moment, when the primary barrier 300 is thermally contracted, each section divided by the slit 414 and the penetration portion 413 in the supporting plywood 400 behaves independently, thereby forming the primary barrier 300. Thermal contraction can be controlled more effectively, and thus the structural stability of the insulation system can be improved. This same effect appears in the secondary barrier 200 that is welded and fixed on the secondary anchor strip 121 having a disconnected structure.

Meanwhile, additional slits 414 may be further processed along the edge of the first support plate 411. The slits 414 formed on the inside and edge of the first support plate 411 allow the supporting plywood 400 to flexibly respond to heat contraction between the first and second barriers 300 and 200.

The slit 414 formed on the edge of the first support plate 411 has an extension direction that is offset from the slit 414 formed on the inside of the first support plate 411 in order to cut off the first primary anchor strip 412. The position may be determined to form.

Additionally, a hole 414h may be formed at the end of the slit 414 for the purpose of preventing cracks from occurring or growing due to heat shrinkage. The hole 414h may have a circular or oval shape with a diameter larger than the width of the slit 414, and, like the slit 414, may be formed to completely penetrate the first support plate 411. In the case of the slit 414 that cuts off the first primary anchor strip 412, it is formed at both ends and in the case of the slit 414 formed at the edge of the first support plate 411, it is formed on the inside of the first support plate 411. A hole 414h may be formed at each facing end.

As described above, the present invention is a supporting plywood that allows the supporting plywood 400 to be as large as the insulation panel 110 as much as possible while simultaneously responding flexibly to the heat shrinkage behavior of the primary barrier 300 installed thereon. It is characterized by providing an optimized structure and arrangement of the wood 400.

Next, we will look at the installation and fixing structure of the supporting plywood 400 with reference to FIGS. 10 and 11.

Referring to Figures 10 and 11, the first supporting plywood 410 is fixed at each of the four corners by the second fixing device 122 provided on the intersection bridge panel 120C, and the second supporting plywood ( In the case of 420), the supporting plywood 400 can be installed on the upper part of the secondary barrier 200 by being fixed by the first fixing device 113 provided on the insulation panel 110.

That is, the supporting plywood 400 can be fixed at five points, including the four corners of the first supporting plywood 410 and the central part of the second supporting plywood 420, as shown in Figures 12 and 12 below. Refer to 13 to look at the fixed structure at each point in more detail.

First, referring to FIG. 12, the corner portion of the first supporting plywood 410 may be fixed by a second fixing device 122 provided on the intersection bridge panel 120C (not shown in FIG. 12). In the drawing, two other first supporting plywoods 410 are shown adjacent to each other, and a fixing plate (p) and a fixing nut (n) are fastened to the studs constituting the second fixing device 122 to provide the first supporting plywood 410. Fixing may be done in the form of holding the corner of the plywood 410.

The fixing plate (p) may be made of plywood like the first supporting plywood 410, and may have a stepped shape so as to pressurize and support the corner portion of the first supporting plywood 410. In addition, in order to maintain flatness when installing the primary barrier 300, it is desirable for the fixing plate (p) and the upper surface of the first supporting plywood 410 to be on the same plane, so that the first supporting plywood 410 Step processing may be performed on the corner portion so that the fixing plate (p) can be seated.

Next, referring to FIG. 13, the second supporting plywood 420 may be fixed at the center by the first fixing device 113 provided on the insulation panel 110 (not shown in FIG. 13). To this end, a fastening hole 420h penetrating upward and downward may be formed at the center position of the second supporting plywood 420 so that the stud of the first fixing device 113 can be inserted.

A single first supporting plywood 410 is shown in the drawing. After the first supporting plywood 410 is first installed, an empty space is created in the center of the first supporting plywood 410 due to the penetration part 413, and the first fixing device 113 is located in the space. At this time, as the stud of the first fixing device 113 is inserted into the fastening hole 420h, the second supporting plywood 420 is inserted into the penetration part 413, and the fixing nut (n) is fastened to the top of the stud. 2 The supporting plywood 420 can be fixed.

Here, the second supporting plywood 420 is fixed in such a way that it directly holds the first supporting plywood 410, and for this purpose, step processing is performed on the through portion 413 of the first supporting plywood 410. In response to this, step processing may also be performed on the lower surface of the second supporting plywood 420.

Meanwhile, in the case of the first supporting plywood 410, the first primary anchor strip 412 does not affect fixation, but in the case of the second supporting plywood 420, after the fixing nut (n) is fastened, the upper part thereof Since the second primary anchor strip 422 must be covered, the second primary anchor strip 422 can be assembled in the field after fixing the second supporting plywood 420 to the first fixing device 113. will be.

A plurality of supporting plywood 400 installed in the same manner as above is arranged in succession to form a separation layer that separates the first and second barriers 300 and 200 from each other. At this time, since no interference due to wrinkles occurs in the space between the first and second barriers (300, 200), it is possible to place the supporting plywood (400) tightly without any gaps, thereby preventing heat loss due to convection. A very effective structure can be implemented.

A primary barrier 300 is installed on the upper part of the separation layer composed of a plurality of supporting plywood 400. The primary barrier 300 may be arranged to be spaced apart from the upper side of the secondary barrier 200 by a height corresponding to the thickness of the supporting plywood 400.

The primary barrier 300 has a similar structure to the secondary barrier 200 described above, except that the direction of the wrinkles protrudes toward the inside of the storage tank and there is no through hole for penetration of the fixing device. .

More specifically, referring to FIG. 14, the primary barrier 300 may be provided with a plurality of membrane sheets that are airtightly connected to each other. The unit membrane sheet constituting the primary barrier 300 is prepared as an approximately rectangular metal sheet with a predetermined length and width, and the edges of adjacent membrane sheets are overlapping and welded to form airtightness at the corresponding level. .

The primary wrinkles 300c formed on the primary barrier 300 may be formed to protrude upward, that is, toward the inside of the storage tank. A plurality of primary wrinkles 300c formed in the primary barrier 300 may be formed in parallel along the length and width directions of the membrane sheet, with longitudinal wrinkles extending in the longitudinal direction and transverse wrinkles extending in the width direction. Wrinkle intersections may be formed in areas where wrinkles intersect. In addition, when welding adjacent membrane sheets, the wrinkles formed on each membrane sheet are connected to each other, so that a plurality of wrinkles extending along the transverse and longitudinal directions can form a grid inside the storage tank.

The primary barrier 300 may be fixed by primary anchor strips 412 and 422 installed on the upper part of the supporting plywood 400. As shown in FIG. 14, a membrane sheet constituting the primary barrier 300 on primary anchor strips 412 and 422 arranged in a grid form on the upper part of a separation layer composed of a plurality of supporting plywood 400. The edges can be fixed by welding. At this time, the edges of neighboring membrane sheets are overlapped and welded to each other.

Since there is no separate protruding structure on the upper part of the supporting plywood 400, there is no through hole in the membrane sheet constituting the primary barrier 300. However, in order to structurally avoid four membrane sheets overlapping at the same time, diagonal processing may also be performed on the four corners of the membrane sheet constituting the primary barrier 300. The diagonal portion formed at the corner of the membrane sheet constituting the primary barrier 300 is airtight on the second primary anchor strip 422 installed in a cross shape on the upper surface of the second supporting plywood 420. It can be welded properly, and some of the diagonal portions can be overlap-welded with neighboring membrane sheets to maintain airtightness at the level of the primary barrier 300.

Meanwhile, the second supporting plywood 420, where the corner of the membrane sheet constituting the primary barrier 300 is located, is a first fixing device 113 that penetrates the center of the membrane sheet constituting the secondary barrier 200. ) is fixed by. Therefore, when viewed in the vertical direction, the corner of the membrane sheet constituting the primary barrier 300 is located at the center of the membrane sheet constituting the secondary barrier 200, that is, the first and second barriers 300 and 200 ) It can be seen that the membrane sheets that make up are arranged misaligned with each other.

In addition, referring again to FIG. 2, in the insulation system according to the present invention, the primary wrinkle 300c formed on the primary barrier 300 and the secondary wrinkle 200c formed on the secondary barrier 200 have a pitch ( pitch) intervals may be designed differently.

As shown in FIG. 1, when both the wrinkles 31 formed on the primary barrier 30 and the wrinkles 21 formed on the secondary barrier 30 are formed upward, the two wrinkles 21 and 31 can be arranged to overlap each other, but in the case where the secondary wrinkles 200c formed in the secondary barrier 200 are configured downward as presented in a preferred embodiment of the present invention, the heat insulating layer 100 is formed. Processing is required on the panel portion. In this case, processing of approximately 50 mm or more occurs, which means a decrease in insulation performance. In addition, when the secondary wrinkle 200c is configured downward, it must be in a smooth curved shape rather than an elliptical shape for automatic welding, so the range that needs to be processed may be wider. Automatic welding is performed in a direction tangent to the corrugation waveform. When the curve is large, it is difficult for automatic welding to follow the welding line due to the steep slope, resulting in a high defect rate. Therefore, it is advantageous in terms of automatic welding for the wrinkles to have a smooth curved shape.

Accordingly, the present invention is intended to minimize the processing range for accommodating the secondary wrinkles (200c) and satisfy the smooth 'corrugation profile' condition that enables automatic welding. Specifically, by reducing the gap between the secondary wrinkles (200c), the wrinkles are reduced. Configure to reduce profile size. Here, 'profile' refers to the shape and size of the wrinkle waveform. The smaller the height of the wrinkle and the gentler the curve, the more advantageous it is for automatic welding.

That is, as the pitch interval of the wrinkles becomes smaller, the amount of heat shrinkage decreases, and the size of the wrinkle waveform to absorb this can be configured to be small. Therefore, the present invention adjusts the pitch interval of the wrinkles 200c formed in the secondary barrier 200 to By making it relatively small compared to the primary barrier 300, the profile size of the wrinkles is reduced, thereby implementing a structure advantageous for automatic welding.

As a result, as shown in FIG. 2, the secondary wrinkles 200c formed on the secondary barrier 200 and the primary wrinkles 300c formed on the primary barrier 300 are arranged to be offset from each other in the vertical direction. At this time, the misalignment between the primary wrinkles 300c and the secondary wrinkles 200c is not formed randomly, and the wrinkle spacing can be determined by considering the number per unit length of the insulation panels 110 constituting the insulation layer 100. there is.

According to the structure of the present invention in which the primary wrinkles (300c) and the secondary wrinkles (200c) are arranged to be offset from each other, the processing range of the panel constituting the insulation layer 100 is minimized by reducing the profile of the secondary wrinkles (200c). This has the effect of facilitating automatic welding of the secondary barrier 200. In addition, it is superior in terms of manufacturing performance compared to the case where the spacing between the primary and secondary wrinkles 300c and 200c is configured to be the same, and there is an advantage that the designer can flexibly change the performance of the secondary barrier 200.

In addition, in order to solve the problem of lowering the BOR performance of the insulation system due to processing of the panels constituting the insulation layer 100, wrinkle insulation that functions as an insulation material in the wrinkles 200c and 300c formed on the barriers 200 and 300 (not shown) may be placed.

As described above, when the panel is processed for the placement of the secondary wrinkles 200c formed downward, the insulation performance may be reduced accordingly, so the reduced insulation performance is compensated by placing wrinkle insulation (not shown) on the wrinkle profile area. It is done.

Wrinkle insulation (not shown) is filled by filling the empty space of the wrinkles (200c, 300c) using glass wool, or a solid foam insulation such as polyurethane foam can be placed in a simple form. is possible.

The wrinkle insulation (not shown) disposed within the secondary wrinkle 200c functions to restore some of the insulation performance lost due to panel processing of the insulation layer 100, and utilizes the empty space in the wrinkle profile portion that may inevitably occur. This can play a role in improving the BOR performance of the insulation system.

In addition, in the case of pleated insulation (not shown) disposed within the primary corrugation 300c, it not only functions to improve the BOR performance of the insulation system, but also directly and indirectly improves the buckling strength of the primary barrier 300. It will be of help to you. When considering this aspect of buckling strength, it may be better to have some strength, such as polyurethane foam, as a wrinkle insulation (not shown) disposed within the primary barrier 300c.

Below, we will look at the construction method of the liquefied gas insulation system according to the present invention in a sequential process.

(1) First, the work of installing the insulation layer 100 on the inner wall of the hull (H) is performed. At this time, the installation of the insulation layer 100 may be carried out in the order of installing the bridge panel 120 in the space between the installation of the insulation panel 110.

(2) Once the installation of the insulation layer 100 is completed, the work of installing the secondary barrier 200 on the top of the insulation layer 100 is performed. Specifically, a plurality of membrane sheets constituting the secondary barrier 200 are secondary anchor strips 121 installed on the upper surface of the insulation layer 100, and more specifically, secondary anchor strips installed on the bridge panel 120. (121) It can be overlap-welded on top to form a sealing structure.

(3) After installation of the secondary barrier 200, the work of installing the supporting plywood 400 on the upper part of the secondary barrier 200 is performed. In the present invention, the supporting plywood 400 includes a first supporting plywood 410 with a penetrating part 413 formed in the center and a second supporting plywood 420 inserted into the penetrating part 413. It may be composed of branch members, and the corner portions of the first supporting plywood 410 and the second supporting plywood 420 each have a central portion that protrudes upward through the secondary barrier 200. A second fixing device ( 122) and may be fastened to the studs of the first fixing device 113.

Here, the liquefied gas insulation system according to the present invention does not generate a wrinkle interference structure between the primary barrier 300 and the secondary barrier 200, so the unit area of the supporting plywood 400 is large and is placed tightly. You can do it. This is directly related to the effect of being structurally stable and effectively blocking heat loss due to convection. In addition, due to the absence of the wrinkle interference structure, the shape and installation structure of the supporting plywood 400 can be greatly simplified, which will ultimately have the effect of greatly improving the constructability of the liquefied gas storage tank and shortening the total drying period. You can.

(4) Finally, the first barrier 300 installation work is performed. Specifically, a plurality of membrane sheets constituting the primary barrier 300 are overlap-welded on the primary anchor strips 412 and 422 installed on the upper surface of the supporting plywood 400 to form a sealing structure, and finally, a double An insulation system with a metal barrier structure can be implemented.

It is obvious to those skilled in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. Accordingly, such modifications or variations should be considered to fall within the scope of the claims of the present invention.

100: insulation layer
110: Insulation panel
111: Lower insulation board
111i: Lower insulation material
111b: lower plate
112: Upper insulation board
112i: Top insulation
112t: upper plate
112g: receiving groove
112s: slit
113: first fixture
120: Bridge panel
120A: Horizontal bridge panel
120B: Longitudinal bridge panel
120C: Intersection bridge panel
121: Secondary anchor strip
122: second fixture
200: Secondary barrier
200c: 2nd wrinkle
300: Primary barrier
300c: 1st wrinkle
400: Supporting plywood
410: 1st supporting plywood
411: first support plate
412: Primary anchor strip
413: Penetrating part
414: slit
414h: hall
420: 2nd supporting plywood
420h: fastening hole
421: second support plate
422: Day 2 anchor strip

Claims (5)

An insulation layer consisting of a plurality of insulation panels arranged on the inner wall of the hull;
It is disposed on top of the insulation layer and includes a barrier composed of a plurality of membrane sheets connected,
Arranged so that the central axis of the membrane sheet and the central axis of the insulation panel coincide,
Membrane sheet arrangement structure of liquefied gas insulation system. In claim 1,
The insulation layer further includes a bridge panel disposed between the neighboring insulation panels,
The edge of the membrane sheet is fixed to an anchor strip provided on the bridge panel, and the edges of the adjacent membrane sheets are overlapped and welded to each other,
Membrane sheet arrangement structure of liquefied gas insulation system. In claim 2,
The insulation panel includes a lower insulation board made in the shape of a hexahedron and fixed to the inner wall of the hull, and an upper insulation board made in the shape of a hexahedron having a smaller flat cross-sectional area than the lower insulation board and laminated on top of the lower insulation board,
The bridge panel is characterized in that it is disposed in the space between the upper insulation boards that are adjacent to each other while covering the boundaries of the lower insulation boards that are adjacent to each other.
Membrane sheet arrangement structure of liquefied gas insulation system. In claim 3,
Characterized in that the central axes of the lower insulation board and the upper insulation board coincide.
Membrane sheet arrangement structure of liquefied gas insulation system. In claim 4,
The membrane sheet has the same planar size as the lower insulation panel,
Characterized in that the vertical edge of the membrane sheet is disposed at a position corresponding to the vertical edge of the lower insulation panel,
Membrane sheet arrangement structure of liquefied gas insulation system.

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