KR20230027590A - Insulation system for liquefied gas storage tank having double metallic barrier structure - Google Patents

Abstract

An insulation system for a liquefied gas storage tank having a double metal barrier structure is disclosed. The insulation system of a liquefied gas storage tank having a double metal barrier structure according to the present invention includes a heat insulation layer installed on an inner wall of a hull; Secondary barriers and primary barriers installed adjacently on top of the heat insulating layer and spaced apart from each other in the vertical direction; and a barrier-to-wall structure installed between the second barrier and the first barrier, wherein the barrier-to-wall structure includes: a plurality of supporting members spaced apart from the second barrier upwardly and supporting the first barrier; And including a connecting member connecting between support members disposed adjacent to each other, the influence of the adjacent first and second barriers on each other by loads applied from inside/outside of the liquefied gas storage tank is minimized, and between barriers The installation structure of the structure is simplified, which has the effect of greatly improving the efficiency and workability of the installation work.

Description

Insulation system of liquefied gas storage tank with double metal barrier structure {INSULATION SYSTEM FOR LIQUEFIED GAS STORAGE TANK HAVING DOUBLE METALLIC BARRIER STRUCTURE}

The present invention relates to an insulation system for a liquefied gas storage tank having a double metal barrier structure, and more particularly, to minimize the influence of the first and second barriers installed continuously adjacent to the upper side of the insulation layer to each other. , It relates to an insulation system for a liquefied gas storage tank having characteristics in the shape and installation structure of a structure between barriers installed between two barriers.

Liquefied Natural Gas (hereinafter referred to as 'LNG') is obtained by cooling natural gas to a cryogenic temperature of approximately -163°C, and its volume is reduced to approximately 1/600 of that in gaseous state, so it is very suitable for long-distance transportation through sea. Suitable.

Structures for transporting or storing LNG, such as LNG carriers (LNGC) for loading and unloading LNG at sea, are equipped with specially designed storage tanks (commonly referred to as 'cargo holds') to withstand the cryogenic temperatures of LNG. ) is installed.

In general, an LNG storage tank consists of an insulation system consisting of one or more barriers made of metal membranes and an insulation layer surrounding the barriers to safely store cryogenic LNG, and independent ( It can be divided into an independent type storage tank and a membrane type storage tank.

The membrane-type storage tank is a tank manufactured integrally with the hull structure, and has a double sealing structure (or double insulation structure) in which a secondary insulation layer, a secondary barrier, a primary insulation layer, and a primary barrier are sequentially stacked on the inner wall of the hull. 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 is composed of insulation boxes in which the primary and secondary insulation layers are filled with an insulation material such as perlite powder or glass wool inside a plywood box, It has a structure in which a barrier is formed by installing an invar steel (36% nickel steel) membrane having a thickness of 0.5 to 0.7 mm on top of each heat insulating layer.

In the NO 96 type storage tank, the first and second barriers have almost the same liquid-tightness and strength, so that in case of leakage of the first barrier, the second barrier can safely support the cargo for a considerable period of time. The heat insulation layer can have high compressive strength and rigidity, and has the advantage of high automation rate of welding.

The MARK Ⅲ type storage tank is composed of insulation panels in which the insulation layer is made of polyurethane foam (PUF) with wood plywood attached to the upper and lower surfaces, and the top of the primary insulation layer is made of stainless steel with a thickness of approximately 1.2 mm. (Stainless steel, SUS) membrane is installed to form a primary barrier, and a composite material called triplex is used 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) because the insulation panel based on polyurethane foam insulation is excellent, but it is vulnerable to thermal deformation or deformation of the hull due to the flexible nature of the insulation panel. have Therefore, in the MARK Ⅲ type storage tank, it is not easy to apply the Invar steel membrane used in the NO 96 type, and the first barrier is formed using a stainless steel membrane with corrugated parts to absorb heat shrinkage.

In addition, since the stainless steel membrane with corrugated corrugated parts includes a protruding structure, it is difficult to install it between the first and second insulation layers. Therefore, in the current MARK Ⅲ type storage tank, a composite called triplex is used instead of a metal membrane to It forms a secondary barrier, which has the disadvantage of being vulnerable to watertightness in comparison to an insulation system in which both the primary and secondary barriers are made of metal.

An insulation system in which the insulation layer is composed of insulation boxes, such as the NO 96 type storage tank, is called a box type insulation system. An insulation system composed of insulation panels is also referred to as a panel type insulation system.

On the other hand, as in the MARK Ⅲ type storage tank, the insulation layer is composed of insulation panels manufactured based on polyurethane foam insulation, so it basically takes the structure of a panel-type insulation system, without installing a barrier between the 1st and 2nd insulation layers. The KC-1 insulation system, in which two barriers are placed in two stages on top of the insulation layer, has been developed and known.

However, since the KC-1 insulation system is not connected to each other, the panel-type insulation system, as described above, is vulnerable to thermal deformation or hull deformation. In addition, in the KC-1 insulation system, the members installed between the first and second barriers are fixed to the fastening structure already installed on the second barrier, but the members between the barriers are very vulnerable to external deformation and repair is difficult after installation. It has the problem of being impossible.

The present invention provides an insulation system for a liquefied gas storage tank capable of minimizing the influence of each other by loads applied to the adjacent primary and secondary barriers by implementing two barriers capable of airtightness on the upper side of the insulation layer. intended to provide

In particular, the present invention is to secure structural stability in installing a barrier structure between two barriers so that the adjacent first and second barriers are not affected by each other by loads applied from the inside and outside of the liquefied gas storage tank. At the same time, the installation structure of the inter-barrier structure that enables easy response to the sloshing load is presented in detail.

In addition, the present invention greatly improves the efficiency and workability of the installation work by simplifying the installation structure of the inter-barrier structure installed between the first and second barriers, and ultimately promotes the effect of shortening the drying period of the liquefied gas storage tank want to do

According to one aspect of the present invention for achieving the above object, a heat insulating layer installed on the inner wall of the hull; Secondary barriers and primary barriers that are continuously and adjacently installed on the top of the heat insulating layer and are spaced apart from each other in the vertical direction; and an inter-barrier structure installed between the secondary barrier and the primary barrier, wherein the inter-barrier structure includes: a plurality of supporting members spaced apart from the secondary barrier upwardly and supporting the primary barrier; And it can be provided with a thermal insulation system for a liquefied gas storage tank having a double metal barrier structure, including a connection member connecting between the support members disposed adjacent to each other.

The secondary barrier includes a plurality of wrinkles formed in the transverse and longitudinal directions of the storage tank to absorb heat shrinkage caused by cryogenic temperatures, and the support member is provided in the form of a plate or block having a predetermined thickness. It can be placed in the intervals between the intersecting folds in the form of a grid on the barrier.

Both edge ends of the connection member may be fixed to upper edge portions of the support member adjacent to each other, and a stepped portion may be formed at the upper edge portion of the support member so that the edge end portion of the connection member may be seated.

The barrier-to-wall structure may further include a reinforcing material that is detachably coupled to an upper portion of the connecting member and accommodated in the wrinkles formed on the primary barrier to reinforce the rigidity of the wrinkles and prevent deformation.

The thickness of the support member may be greater than the height of the wrinkles formed on the secondary barrier so that the connection member can be disposed at a position higher than the wrinkles of the secondary barrier.

The connecting member is provided as a plate in the form of a flat plate, and a slit may be formed on the support member as a structure for absorbing thermal contraction in the in-plane direction of the connecting member provided in a flat plate shape.

The connection member may include a pleated structure protruding downward to itself absorb heat shrinkage in the in-plane direction.

The structure between the barriers may be manufactured as an integral set structure in which at least two or more support members are connected by the connecting member and the reinforcing member is coupled to the upper portion of the connecting member and installed on top of the secondary barrier. there is.

The insulation system for a liquefied gas storage tank according to the present invention basically has a panel-type insulation system in which an insulation layer is formed based on a polyurethane foam insulation material, so that it can have excellent insulation performance compared to a box-type insulation system.

In addition, the insulation system of the liquefied gas storage tank according to the present invention can compensate for the conventional disadvantage of being vulnerable to watertightness by implementing double airtightness by the first and second barriers successively installed on the upper side of the heat insulation layer. In addition to having excellent insulation performance, reliability and structural stability of the insulation system can be secured.

In particular, the insulation system of the liquefied gas storage tank according to the present invention is provided in a form in which a plurality of support members installed between the first and second barriers are connected to each other, so that it is possible to secure structural stability against the load applied to the barriers, , it is possible to minimize the influence of the adjacent primary and secondary barriers on each other by loads applied from inside/outside of the liquefied gas storage tank.

In addition, in the insulation system of a liquefied gas storage tank according to the present invention, a reinforcing member for reinforcing sloshing is additionally provided on a connecting member connecting adjacent support members to each other, so that the support member connection structure including the reinforcing member is a support member. It can have two functions of fixing and at the same time structurally reinforcing the barrier to withstand the sloshing load, thereby minimizing the influence of the adjacent primary and secondary barriers on each other by the applied load and There is an effect that can be responded to.

In addition, in the insulation system of a liquefied gas storage tank according to the present invention, a plurality of support members are connected by a connecting member to install an inter-barrier structure integrally configured at once, so the installation structure is simplified and the installation work is simplified. Efficiency and workability are greatly improved, and ultimately, the drying period of the liquefied gas storage tank can be shortened.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood from the description below.

1 is a side cross-sectional view showing a part of an insulation system for a liquefied gas storage tank according to the present invention.
2 is a view showing a set configuration of a structure between barriers installed between first and second barriers in the insulation system for a liquefied gas storage tank according to the present invention.
3 is a view showing a modified example of a connecting member as a structure for responding to heat shrinkage in the insulation system of a liquefied gas storage tank according to the present invention.

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

Matters represented in the drawings accompanying this specification may be somewhat different from the form actually implemented as a schematic drawing to easily explain the embodiments of the present invention, and the size of each component shown in the drawings is for explanation. They may be exaggerated or reduced and are not meant to be of actual size.

Terms used in this specification are only used to describe specific embodiments and are not intended to limit the present invention. For example, in the present specification, 'including' a certain component means that other components may be further included, rather than excluding other components unless otherwise stated.

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

The liquefied gas storage tank described herein includes LNG, which is 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 for storing various types of liquefied gas that can be liquefied at a low temperature and stored/transported.

In this specification, the use of the terms 'primary' and 'secondary' for the liquefied gas storage tank means that the liquefied gas is primarily sealed or insulated based on the liquefied gas stored inside the storage tank. Or it is used as a criterion for whether to insulate.

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

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. 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 thereby.

1 is a side cross-sectional view showing a part of an insulation system for a liquefied gas storage tank according to the present invention, and FIG. 2 is a structure between barriers installed between first and second barriers in the insulation system for a liquefied gas storage tank according to the present invention. This is a diagram showing the configuration of the set. And Figure 3 is a view showing a modified example of the connection member as a structure for responding to heat shrinkage in the insulation system of the liquefied gas storage tank according to the present invention.

Referring to FIG. 1, the insulation system of a liquefied gas storage tank having a double metal barrier structure according to the present invention includes a heat insulation layer 100 installed on the inner wall of a hull and a heat insulation layer 100 continuously installed on the upper side of the heat insulation layer 100. It includes a secondary barrier 200 and a primary barrier 300.

The heat insulation layer 100 serves the main insulation function in this insulation system, that is, the function of preventing heat intrusion from the outside of the storage tank, and uses an insulation material such as polyurethane foam or reinforced polyurethane foams (R-PUF). Based on this, it can be provided with a structure similar to the above-described panel type insulation system.

Specifically, the heat insulating layer 100 may include a heat insulating material such as polyurethane foam or reinforced polyurethane foam, and plywood or fiber reinforced plastics (FRP: Fiber Reinforced Plastics ) The same material may be provided in a composite form.

More specifically, the heat insulating layer 100 may be formed by arranging a plurality of heat insulating panels, the core of which is made of polyurethane foam or reinforced polyurethane foam heat insulating material, on the inner wall of the hull in succession. At this time, the first and second barriers (300, 200 ) Since this insulation system in which all are located on the upper side of the heat insulation layer 100 has a structure in which the insulation layer is not separated by the barrier, when the insulation layer 100 is formed as a single layer, convection flows at the boundary between the insulation panels constituting the insulation layer 100. Heat loss may occur due to hull deflection, and structural weakness may occur even in vertical deformation of the insulation panel due to hull deflection.

In order to compensate for this, in the present insulation system, the heat insulation layer 100 is preferably formed in a multi-layer structure of at least two layers, and the vertical edges of the insulation panels constituting the lower insulation layer and the insulation panels constituting the upper insulation layer cross each other so that they are offset from each other. Arrangement is good in terms of structural stability or prevention of heat loss through the boundary between insulation panels. In the drawings accompanying this specification, it may be understood that only a partial structure of the upper layer of the heat insulating layer 100 is shown.

This insulation system implements a double metal barrier structure by continuously installing the secondary barrier 200 and the primary barrier 300 on the upper side of the thermal insulation layer 100. That is, the present invention eliminates the process of installing a barrier (secondary barrier) between the upper and lower insulation layers in the conventional insulation system, forms a thick insulation layer 100 as a whole (multi-layer structure as necessary), and then doubles the It is to install barriers (200, 300).

In this insulation system, the barriers 200 and 300 serve to seal (liquid-tight/tight-tight) the liquefied gas contained in the storage tank. Here, the primary barrier 300 is in direct contact with the cryogenic liquefied gas contained in the storage tank to perform a primary sealing function, and the secondary barrier 200 is a secondary barrier when the primary barrier 300 leaks. As a sealing function, even if leakage of the primary barrier 300 occurs, it should be designed to be liquid-tight and support the liquefied gas for a considerable period of time.

The barriers 200 and 300 may be made of a metal material with strong low-temperature brittleness so as to respond to stress changes caused by cryogenic temperatures of the liquefied gas accommodated inside the storage tank, such as stainless steel, invar steel, or aluminum alloy. Low temperature steel may be used.

In this insulation system, it is more preferable that the barriers 200 and 300 are made of stainless steel that can easily respond to stress changes due to the nature of the insulation layer 100 having a flexible panel-type structure. The barriers 200 and 300 made of membranes may include a plurality of corrugations to cope with thermal contraction caused by cryogenic temperatures.

The wrinkles may be formed on the barriers 200 and 300 in a form that rises toward the inside of the storage tank, and a plurality of transverse wrinkles extending along the transverse direction of the storage tank and a plurality of longitudinal wrinkles extending along the longitudinal direction It is formed in the form of crossing each other, and when viewed from above, it can form an approximate lattice form.

The barrier walls 200 and 300 may be formed by continuously connecting a plurality of membrane sheets provided as unit units. The membrane sheet may be provided as a substantially rectangular metal sheet having a predetermined length and width, and when a plurality of membrane sheets are arranged in succession, the edges of the membrane sheets adjacent to each other are overlapped and welded to form a sealing structure of the barriers 200 and 300. can be formed.

A plurality of wrinkles formed on the barriers 200 and 300 may be formed side by side along the lengthwise and widthwise directions of the membrane sheet, and the wrinkles of the adjacent membrane sheets are connected to each other so that the inside of the storage tank is formed along the longitudinal and transverse directions. A large number of elongated pleats may be arranged in a lattice shape.

The secondary barrier 200 may be fixed by a membrane fixing unit (not shown) installed on top of the heat insulating layer 100 . The membrane fixing part (not shown) may be, for example, a metal band member such as an anchor strip installed on the upper surface of the heat insulating layer 100, and the edge of the membrane sheet constituting the secondary barrier 200 is the anchor strip. It can be welded on and firmly fixed to the top of the heat insulating layer (100).

On the secondary barrier 200, there is a through hole so that the stud bolt of the fixing device 500 installed on the top of the heat insulating layer 100 can pass through for fixing the support member 410 and the primary barrier 300, which will be described later. The sealing of the secondary barrier 200 may be maintained by welding the periphery of the through-hole to the fixing device 500 side in a state where the stud bolt passes through.

On the other hand, since the secondary barrier 200 and the primary barrier 300 installed continuously adjacent to the upper side of the heat insulating layer 100 may undergo expansion and contraction under the influence of the cryogenic temperature of the liquefied gas, the primary and secondary barriers ( 300, 200) should be provided in a spaced structure so as not to contact each other, and it is necessary to configure the insulation system in a way to prevent the possibility of being influenced by each other as much as possible.

To this end, the two barriers 200 and 300 are spaced apart from each other at a predetermined interval between the secondary barrier 200 and the primary barrier 300 of the present insulation system, and between the barriers for the purpose of minimizing mutual influence. A structure 400 may be installed.

The barrier-to-wall structure 400 includes a support member 410 for supporting and spaced the first barrier 300 upward from the second barrier 200, and a connecting member connecting between the support members 410 adjacent to each other. 420, and a reinforcing member 430 installed on the connection member 420 to reinforce the wrinkles formed in the primary barrier 300 against the sloshing load generated in the storage tank.

The support member 410 seeks structural stability by spacing the two barriers 200 and 300, which can have different degrees of thermal contraction, to achieve structural stability, and is provided in the form of a plate or block having a predetermined thickness. It may be disposed between the barrier 200 and the primary barrier 300 .

As shown in the drawing, the support member 410 may be installed in a flat area between the gaps where wrinkles are formed on the secondary barrier 200. At this time, the support member 410 may be disposed to correspond within all intervals between the wrinkles formed on the secondary barrier 200, but if the load applied to the primary barrier 300 can be endured to an acceptable level, the wrinkles are formed. It goes without saying that only a portion of the remaining areas excluding the portion may be arranged at predetermined intervals.

As the material of the support member 410, one that can be used in a cryogenic state and can serve as a load-bearing structural material, for example, a composite material such as plywood or fiber-reinforced plastic can be used, or high-density and high-strength poly It is also possible to use urethane foam.

The support member 410 may be fixed by a fixing device 500 installed on top of the heat insulating layer 100 in a state disposed within the crease gap on the secondary barrier 200 . To this end, a fastening hole penetrating in the thickness direction may be formed in the support member 410 so that the stud bolts of the fixing device 500 can pass through, and the stud bolts of the fixing device 500 may pass through the secondary barrier 200. After sequentially passing through the through hole of the support member 410 and the fastening hole of the support member 410, the support member 410 may be fixed by fastening a fixing member such as a nut.

In the present insulation system, the support member 410 may be installed on the upper part of the secondary barrier 200 while at least two or more of the neighboring components are connected by a connecting member 420 to be described later, and thus all support members 410 does not have to be individually fixed, and it is okay even if only a part is fixed. That is, in the present insulation system, the fixing device 500 does not need to be provided to correspond to all of the plurality of support members 410, respectively.

The connection member 420 connects the support members 410 adjacent to each other to achieve structural stability and at the same time make it possible to install a plurality of support members 410 at once, and also of the reinforcing member 430 described later. It is to provide installation space.

The connection member 420 is provided as a thin plate in the form of a flat plate, and both edge ends thereof may be fixed to upper edge portions of the support member 410 adjacent to each other. A stepped portion for seating the edge end of the connecting member 420 may be formed at the upper corner of the support member 410, and a rivet or It may be fixed by mechanical fastening or adhesive method using screws, staples, and the like.

On the other hand, since the connection member 420 should not interfere with the wrinkles of the secondary barrier 200 located on the lower side, the overall thickness of the support member 410 including the stepped portion is greater than the wrinkles of the secondary barrier 200. should be built high. More specifically, in this insulation system, the thickness of the support member 410 is preferably formed within a range of more than 1 time and less than 2 times the height of the wrinkles of the secondary barrier 200.

In this way, as the connecting member 420 is positioned higher than the wrinkles of the secondary barrier 200, the connecting member 420 can be configured as a plane without the need for separate molding or processing. A slit 411 may be formed on the support member 410 described above for the purpose of responding to the in-plane direction heat shrinkage of the 420 . The slit 411 is a narrow gap processed from the upper surface of the support member 410 to a certain depth along the thickness direction, and is applied to the support member 410 by heat shrinkage of the connection member 420 and the primary barrier 300 It can play a role in dispersing the stress.

Alternatively, instead of forming the slit 411 in the supporting member 410, the shape of the connecting member 420 is modified to include a pleated structure as shown in FIG. 3 to absorb heat shrinkage stress in the connecting member 420 itself. It is also possible to do At this time, the wrinkles formed on the connecting member 420 may protrude downward, and may be formed symmetrically on both sides based on the wrinkles formed on the secondary barrier 200.

In addition, forming the slit 411 in the support member 410 and transforming the shape of the connection member 420 to include a corrugated structure are of course also possible.

The reinforcing material 430 is installed on the upper part of the connection member 420 and is accommodated in the wrinkles formed in the primary barrier 300 covered thereafter to reinforce the wrinkle rigidity of the primary barrier 300 and function to prevent deformation. . The reinforcing material 430 reinforces the resistance of the pleats of the primary barrier 300 against the sloshing load generated in the storage tank, and supports the inner surface of the pleats during thermal contraction of the primary barrier 300 due to cryogenic temperatures so that the wrinkles collapse. You can prevent that from happening.

Although the cross section of the reinforcing material 430 is shown as a hexagon in the drawing, the cross-sectional shape of the reinforcing material 430 may be formed to correspond to the inner shape of the wrinkles of the primary barrier 300, and the wrinkles of the primary barrier 300 Of course, it can be deformed into any shape as long as it reinforces the structure and prevents deformation.

The present invention is characterized in that the insulation system is configured so that sloshing reinforcement is easily performed by simply coupling the reinforcing member 430 to the connecting member 420. Specifically, the reinforcing member 430 may be coupled to the upper surface of the connecting member 420 using various detachable fastening methods, and examples of such fastening methods include an interference fitting method and a hook coupling method. The hook coupling method may refer to a method in which a protrusion formed on one of the connecting member 420 and the reinforcing member 430 is inserted into a groove formed on the other one and then held.

On the other hand, referring to FIG. 2, in the inter-barrier structure 400 of the present insulation system including the support member 410, the connection member 420, and the reinforcing member 430, at least two or more support members 410 are disposed therebetween. It can be manufactured as a kind of set structure fastened by the connecting member 420 connecting the.

In addition, the inter-barrier structure 400 is provided in a state in which the reinforcing member 430 is coupled to the upper portion of the connecting member 420, and the three components of the supporting member 410, the connecting member 420 and the reinforcing member 430 are combined into one. When a set of at least two or more sets can be manufactured as an integral structure that is repeatedly connected, the installation of these set structures can be done at once.

This is a method for simplifying the installation structure of the inter-barrier structure 400 installed between the second barrier 200 and the first barrier 300 and reducing the number of hours required, and is connected to a plurality of support members 410. It can be understood as modularizing and installing the member 420 and the reinforcing member 430 beyond a certain standard.

In the drawing, it is shown that the set configuration consisting of the support member 410, the connection member 420, and the reinforcing member 430 is connected side by side side by side, but such a set configuration can be connected in the front and rear directions based on the drawing. It should be understood, therefore, that the barrier-to-wall structure 400 can be manufactured as a structure having five and a half rows as the set configurations are arranged in the longitudinal and transverse directions.

The primary barrier 300 may be spaced apart from the upper side of the secondary barrier 200 by a height corresponding to the thickness of the support member 410 by installing the structure 400 between the barriers.

As described in the second barrier 200, the first barrier 300 may be formed of a structure in which a plurality of membrane sheets provided as unit units are continuous, and the membrane sheet is a rectangular metal sheet having a predetermined length and width. As it may include wrinkles raised toward the inside of the storage tank. At this time, the sealing structure of the primary barrier 300 may be formed by overlapping and welding the edges of the membrane sheets adjacent to each other.

In addition, a membrane fixing part (not shown) such as an anchor strip may be installed on the upper surface of the support member 410 similarly to that installed on the top of the heat insulating layer 100, and a plurality of constituting the primary barrier 300 The edges of the membrane sheet may be welded on the anchor strip to be firmly fixed to the top of the support member 410.

Hereinafter, the construction method of the insulation system of the liquefied gas storage tank according to the present invention will be reviewed in sequential steps.

1) First, an operation of installing the heat insulating layer 100 on the inner wall surface of the hull is performed.

2) When the installation of the heat insulating layer 100 is completed, an operation of installing the secondary barrier 200 on the upper part of the heat insulating layer 100 is performed. At this time, a plurality of membrane sheets may be overlapped and welded on a membrane fixing part (eg, an anchor strip) provided on the upper surface of the heat insulating layer 100 to form the secondary barrier 200 .

3) After installation of the secondary barrier 200, an operation of installing the support member 410 fastened with the connection member 420 as the inter-barrier structure 400 on the upper portion of the secondary barrier 200 is performed. At this time, the connection member 420 may be provided in a state in which the reinforcing member 430 is coupled thereto, and the support member 410 is fixed by the fixing device 500 provided on the upper surface of the heat insulating layer 100. In this step, at least two or more support members 410 are provided as an integral set structure connected by a connecting member 420, and as the installation is performed, the number of hours required for installation may be reduced.

4) When the installation of the inter-barrier structure 400 on the upper part of the secondary barrier 200 is completed, the installation of the primary barrier 300 is finally performed. A plurality of membrane sheets constituting the primary barrier 300 are welded and fixed to a membrane fixing part (eg, anchor strip) separately installed on the upper surface of the support member 410 similarly to the secondary barrier 200, or Alternatively, fixation may be performed using the upper end of the fixing device 500 .

The insulation system for a liquefied gas storage tank according to the present invention basically has a panel-type insulation system in which an insulation layer is formed based on a polyurethane foam insulation material, so that it can have excellent insulation performance compared to a box-type insulation system.

In addition, the insulation system of the liquefied gas storage tank according to the present invention can compensate for the conventional disadvantage of being vulnerable to watertightness by implementing double airtightness by the first and second barriers successively installed on the upper side of the heat insulation layer. In addition to having excellent insulation performance, reliability and structural stability of the insulation system can be secured.

In particular, the insulation system of the liquefied gas storage tank according to the present invention is provided in a form in which a plurality of support members installed between the first and second barriers are connected to each other, so that it is possible to secure structural stability against the load applied to the barriers, , it is possible to minimize the influence of the adjacent primary and secondary barriers on each other by loads applied from inside/outside of the liquefied gas storage tank.

In addition, in the insulation system of a liquefied gas storage tank according to the present invention, a reinforcing member for reinforcing sloshing is additionally provided on a connecting member connecting adjacent support members to each other, so that the support member connection structure including the reinforcing member is a support member. It can have two functions of fixing and at the same time structurally reinforcing the barrier to withstand the sloshing load, thereby minimizing the influence of the adjacent primary and secondary barriers on each other by the applied load and There is an effect that can be responded to.

In addition, in the insulation system of a liquefied gas storage tank according to the present invention, a plurality of support members are connected by a connecting member to install an inter-barrier structure integrally configured at once, so the installation structure is simplified and the installation work is simplified. Efficiency and workability are greatly improved, and ultimately, the drying period of the liquefied gas storage tank can be shortened.

In addition, the insulation system of the liquefied gas storage tank according to the present invention avoids the structure in which the double metal barrier is connected to the inner wall of the hull, thereby preventing the behavior due to the deformation of the hull from being directly transmitted to the barrier, and the conventional insulation system In the case where the first and second barriers are connected to the inner wall of the hull through metal fixtures, there is no concern about the problem of heat loss.

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

100: heat insulation layer
200: Second barrier
300: primary barrier
400: Inter-barrier structure
410: support member
420: connecting member
430: stiffener
500: fixture

Claims (8)

Insulation layer installed on the inner wall of the hull;
Secondary barriers and primary barriers that are continuously and adjacently installed on the top of the heat insulating layer and are spaced apart from each other in the vertical direction; and
Including an inter-barrier structure installed between the secondary barrier and the primary barrier,
The structure between the barriers,
a plurality of support members for supporting and spacing the primary barrier upwardly from the secondary barrier; and
Including a connecting member connecting between the support members disposed adjacent to each other,
Insulation system of liquefied gas storage tank with double metal barrier structure. The method of claim 1,
The secondary barrier includes a plurality of wrinkles formed in the transverse and longitudinal directions of the storage tank to absorb heat shrinkage caused by cryogenic temperatures,
Characterized in that the support member is provided in the form of a plate or block having a predetermined thickness and disposed within the interval between the intersecting wrinkles in a lattice form on the secondary barrier,
Insulation system of liquefied gas storage tank with double metal barrier structure. The method of claim 2,
Both edge ends of the connection member are fixed to the upper edge portions of the support member adjacent to each other,
Characterized in that a stepped portion is formed at the upper corner of the support member so that the edge end of the connection member can be seated.
Insulation system of liquefied gas storage tank with double metal barrier structure. The method of claim 3,
The structure between the barriers,
Further comprising a reinforcing material that is detachably coupled to the upper portion of the connecting member and accommodated in the wrinkles formed in the primary barrier to reinforce the rigidity of the wrinkles and prevent deformation.
Insulation system of liquefied gas storage tank with double metal barrier structure. The method of claim 3,
Characterized in that the thickness of the support member is formed greater than the height of the wrinkles formed on the secondary barrier so that the connecting member can be disposed at a position higher than the wrinkles of the secondary barrier.
Insulation system of liquefied gas storage tank with double metal barrier structure. The method of claim 5,
The connecting member is provided as a plate in the form of a flat plate,
Characterized in that a slit is formed on the support member as a structure for absorbing the in-plane direction heat shrinkage of the connecting member provided in the form of a flat plate,
Insulation system of liquefied gas storage tank with double metal barrier structure. The method of claim 3,
Characterized in that the connecting member includes a pleated structure protruding downward to absorb the in-plane heat shrinkage by itself.
Insulation system of liquefied gas storage tank with double metal barrier structure. The method of claim 4,
The structure between the barriers is manufactured as an integral set structure in which at least two or more support members are connected by the connecting member and the reinforcing member is coupled to the upper portion of the connecting member and installed on top of the secondary barrier. characterized by,
Insulation system of liquefied gas storage tank with double metal barrier structure.

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