KR20230011512A - Insulation structure of cargo tank - Google Patents

Abstract

An insulation structure of a liquefied gas storage tank is disclosed. One embodiment of the present invention comprises: a foam insulation layer covering the outer surface of a storage tank containing liquefied gas; a leakage channel formed on the inner surface of the foam insulation layer in contact with the outer surface of the storage tank and provided as a passage through which the liquefied gas leaking from the storage tank moves; a plurality of barriers provided to surround the outside of the foam insulation layer; a plurality of supports supporting the plurality of barriers spaced apart from the outer surface of the foam insulation layer; and a powder insulation material filled between the outer surface of the foam insulation layer and the inner surface of the plurality of barriers. At least some of the plurality of barriers may be provided with a drip tray connected to the leakage channel to collect the leaked liquefied gas. Accordingly, insulation performance can be maintained.

Description

Insulation structure of liquefied gas storage tank {INSULATION STRUCTURE OF CARGO TANK}

The present invention relates to a heat insulating structure of a liquefied gas storage tank, and more particularly, to a heat insulating structure of a liquefied gas storage tank capable of effectively insulating low-temperature liquefied gas to promote stable accommodation and storage.

Liquefied gas is made into a liquid by cooling or compressing a gas, and is a phase change to a liquid by cooling a gas at room temperature for the convenience of transportation and storage. One of the widely used and important resources among liquefied gases is liquefied natural gas (LNG). Liquefied natural gas refers to a colorless and transparent ultra-low temperature liquid that reduces the volume to 1/600 by cooling natural gas, whose main component is methane, to about -162 ° C.

Recently, as liquefied natural gas is used as an important energy resource, efficient transportation methods capable of transporting liquefied natural gas in large quantities from production areas to various demand areas have been reviewed. As part of these efforts, a liquefied gas transport ship capable of transporting a large amount of liquefied natural gas through the sea has been developed.

A liquefied gas storage tank capable of withstanding cryogenic temperatures is installed in a liquefied gas transport vessel to store and store liquefied natural gas. Since liquefied natural gas has a vapor pressure higher than atmospheric pressure and has a boiling temperature of ultra-low temperature, the liquefied gas storage tank must be made of a material that can withstand ultra-low temperatures, and has a unique insulation structure that is resistant to other thermal stress and heat shrinkage and can prevent heat intrusion. will need

Storage tanks are classified into independent type and membrane type depending on whether the cargo load is directly applied to the insulation structure. Among them, the independent storage tank has a relatively simple structure and can stably accommodate liquefied natural gas, so it is adopted and used in various liquefied gas transport ships. In the stand-alone storage tank, a storage tank is installed in a storage tank accommodation space formed on the hull of a floating offshore structure such as a ship structurally, and an insulation structure is installed between the outer surface of the storage tank and the storage tank accommodation space.

At this time, when a storage tank with a large specification is adopted in order to increase the loading capacity of the storage tank, the space between the outer surface of the storage tank and the storage tank accommodation space is narrowed, making it difficult to install the insulation structure. In addition, when a relatively thick insulation structure is adopted to improve insulation performance, or when the distance between the outer surface of the storage tank and the storage tank receiving space is widened to facilitate the installation of the insulation structure, a storage tank with a small size specification Since it must be adopted, there is a problem in that the loading amount of the storage tank is reduced.

Accordingly, studies are required to effectively insulate the low-temperature liquefied gas such as liquefied natural gas loaded in the storage tank to stably accommodate and store the liquefied gas, and to increase the liquefied gas load in the storage tank.

Republic of Korea Patent Publication No. 10-2014-0106137 (2014. 09. 03. Publication)

The present embodiment is intended to provide a thermal insulation structure for a liquefied gas storage tank capable of maintaining a stable structure in response to thermal deformation of the storage tank and maintaining insulation performance.

This embodiment is to provide a heat insulation structure of a liquefied gas storage tank that can effectively insulate the loaded liquefied gas.

This embodiment is to provide a heat insulation structure of a liquefied gas storage tank that can be quickly and easily installed.

The present embodiment is to provide a thermal insulation structure of a liquefied gas storage tank capable of increasing the loading of the liquefied gas in the storage tank while stably insulating the liquefied gas.

The present embodiment is intended to provide a thermal insulation structure for a liquefied gas storage tank that can improve space utilization of a floating offshore structure such as a ship in which the storage tank is installed.

The present embodiment is to provide a heat insulation structure of a liquefied gas storage tank that can prevent leakage of liquefied gas and safety accidents caused by leakage of liquefied gas.

This embodiment is intended to provide a heat insulation structure of a liquefied gas storage tank that can promote efficiency in installation and operation with a simple structure.

According to one aspect of the present invention, the foam insulation layer covering the outer surface of the storage tank for accommodating liquefied gas; a leakage channel formed on an inner surface of the foam insulation layer in contact with an outer surface of the storage tank and provided as a passage through which liquefied gas leaking from the storage tank moves; a plurality of barriers provided to surround the outside of the foam insulation layer; a plurality of supports for supporting the plurality of barrier walls by separating them from the outer surface of the foam insulation layer; and a powder insulating material filled between an outer surface of the foam insulation layer and an inner surface of the plurality of barrier walls, wherein at least a portion of the plurality of barrier walls is connected to the leakage channel and includes a drip tray configured to collect leaked liquefied gas. A heat insulation structure of the gas storage tank may be provided.

The drip tray may be provided with an insulation structure of a liquefied gas storage tank integrally provided with the barrier wall.

The drip tray may be provided with an insulation structure of a liquefied gas storage tank including a protrusion provided on the outside of the barrier wall and a drain passage provided on the inside of the protrusion.

The drip tray may be provided with a heat insulating structure of a liquefied gas storage tank including a discharge port penetrating the protruding portion to communicate with the outside of the drain passage and an opening/closing member opening and closing the at least one discharge port.

The insulation structure of the liquefied gas storage tank may further include a connection discharge pipe having a connection passage having one side communicating with the leakage channel and the other side communicating with the drain passage.

The insulation structure of the liquefied gas storage tank according to the present embodiment has an effect of maintaining a stable structure and maintaining insulation performance in response to thermal deformation of the storage tank.

The insulation structure of the liquefied gas storage tank according to the present embodiment has an effect of promoting stable handling of the liquefied gas by effectively insulating the loaded liquefied gas.

The heat insulation structure of the liquefied gas storage tank according to this embodiment has the effect of quickly and easily performing the installation work.

The heat insulation structure of the liquefied gas storage tank according to the present embodiment has an effect of increasing the loading capacity of the liquefied gas storage tank while stably insulating the liquefied gas.

The insulation structure of the liquefied gas storage tank according to the present embodiment has an effect of improving space utilization of floating offshore structures such as ships in which the storage tank is installed.

The heat insulation structure of the liquefied gas storage tank according to the present embodiment has an effect of preventing leakage of liquefied gas and preventing safety accidents caused by leakage of liquefied gas in advance.

The heat insulation structure of the liquefied gas storage tank according to this embodiment has an effect of improving the efficiency of installation and operation as a simple structure.

1 is a lateral cross-sectional view showing a thermal insulation structure of a liquefied gas storage tank according to an embodiment of the present invention.
FIG. 2 is an enlarged view of portion A of FIG. 1 .
FIG. 3 is an enlarged view of part B of FIG. 1 .
Figure 4 is a perspective view showing a partially cut away portion A of Figure 1;
5 is a perspective view of part B of FIG. 1 viewed from the lower side of the storage tank.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are presented to sufficiently convey the spirit of the present invention to those skilled in the art. The present invention may be embodied in other forms without being limited to only the embodiments presented herein. In the drawings, in order to clarify the present invention, illustration of parts irrelevant to the description may be omitted, and the size of components may be slightly exaggerated to aid understanding.

1 is a lateral cross-sectional view showing a thermal insulation structure 100 of a liquefied gas storage tank according to an embodiment of the present invention.

The liquefied gas accommodated in the liquefied gas storage tank 10 according to this embodiment may be liquefied natural gas phase-changed into a cryogenic liquid for the convenience of transportation and storage. However, it is not limited to this, and if liquefied ethane gas, liquefied hydrocarbon gas, liquefied propane gas, liquefied hydrogen gas, etc. are cooled to a low temperature and liquefied, and then shipped and handled inside the storage tank 10, it should be understood the same as the same technical concept. do.

In addition, referring to FIG. 1 , the storage tank 10 to which the heat insulating structure 100 according to the present embodiment is applied may be mounted on floating offshore structures 1 of various types and methods. For example, the floating offshore structure 1 may be composed of a liquefied gas carrier, FPSO (Floating Production Storage and offloading), LNG FSRU (Floating Storage and Regasification Unit), etc., and needs to accommodate and store low-temperature liquefied gas It can be applied to the hull (1) of various offshore structures.

The hull 1 of the floating offshore structure may be composed of a double hull structure composed of an outer plate and an inner plate, and the inside of the hull 1 includes a storage tank 10, a support structure 20, and an insulation structure to be described later. A storage tank accommodating space 2 in which the 100 or the like is installed and disposed may be formed. The storage tank accommodating space 2 may be partitioned by an inner wall of the hull 1, and the storage tank 10 may be fixed and supported inside the storage tank accommodating space 2 by the support structure 20.

The storage tank 10 is provided to accommodate and store liquefied gas therein, and may be fixed and supported by a plurality of support structures 20 and disposed inside the storage tank accommodating space 2 . The storage tank 10 may be made of an independent type tank in which the load of the liquefied gas loaded therein directly acts on the inner surface of the storage tank 10 rather than the insulation structure 100, and aluminum steel, stainless steel and It can be made of special steel for cryogenic use such as 35% nickel steel. On the upper side of the storage tank 10, a liquid dome (not shown) may be provided in which various pipes for supplying liquefied gas to the inside of the storage tank 10 or unloading liquefied gas from the storage tank 10 are installed. there is.

A plurality of support structures 20 are distributed at regular intervals between the inner wall of the hull 1 and the outer surface of the storage tank 10 to stably fix and support the storage tank 10 in the storage tank receiving space 2. It can be arranged and provided. For example, as shown in FIG. 1 , a plurality of support structures 20 may be disposed on the top, bottom, and top of the outer surface of the storage tank 10, respectively, but are not limited to the number and location. The support structure 20 stably endures the load of the storage tank 10 and the liquefied gas accommodated therein, while the cold heat of the liquefied gas is transferred to the storage tank receiving space 2 or external heat is transferred to the inside of the storage tank 10. It may be made of a material such as plywood having low thermal conductivity so as not to be transmitted.

An insulating structure 100 is provided on the outer surface of the storage tank 10 to insulate the liquefied gas accommodated in the storage tank 10 from external heat.

FIG. 2 is an enlarged view of part A of FIG. 1, FIG. 3 is an enlarged view of part B of FIG. 1, FIG. 4 is a perspective view partially cut away of part A of FIG. 1, and FIG. It is a perspective view looking at part B of 1 from the lower side of the storage tank.

1 to 5, the heat insulation structure 100 of the liquefied gas storage tank according to an embodiment of the present invention includes a foam insulation layer 110 covering the outer surface of the storage tank 10 in which liquefied gas is accommodated, A leak channel 120 formed on the inner surface of the foam insulation layer 110 to be recessed or hollow so that liquefied gas leaking into the storage tank 10 moves, a plurality of barriers 130 provided on the outside of the foam insulation layer 110, A plurality of supports 140 supporting the plurality of barriers 130 in a state of being spaced apart from the outer surface of the foam insulation layer 110, and a powder insulation material 150 filled between the foam insulation layer 110 and the plurality of barriers 130 may be provided, including

The foam insulation layer 110 may be provided to cover the outer surface of the storage tank 10 . The foam insulation layer 110 may include polyurethane having heat insulation or heat preservation properties, and may be provided by spraying or coating the outer surface of the storage tank 10 using a spray gun or the like. The foam insulation layer 110 sprayed or applied to the outer surface of the storage tank 10 adheres to the outer surface of the storage tank 10 and expands. foam) can be semi-permanently fixed and placed on the outer surface of the storage tank 10.

A leakage channel 120 serving as a passage through which liquefied gas leaked from the storage tank 10 moves may be provided between the outer surface of the storage tank 10 and the inner surface of the foam insulation layer 110 .

The leakage channel 120 may be recessed on the inner surface of the foam insulation layer 110 in contact with the outer surface of the storage tank 10, or may be hollow by removing at least a portion thereof. In addition, the leakage channel 120 stably collects the leakage liquid generated in various parts of the storage tank 10 and guides it to the drip tray 170 provided on the lower side of the storage tank 10. ) It may be formed in a lattice shape or mesh shape on the inner surface of.

The leakage channels 120 are densely formed on the outer surface of the storage tank 10 as a whole, connected and communicated with each other, and can flow downward due to their own weight. At this time, at least a part of the leakage channel 120 at the lower side of the storage tank 10 communicates with the connection passage 181 of the connection discharge pipe 180, and flows into the leakage channel 120 at the lower side of the storage tank 10. The liquefied gas may be moved to and collected in the drain passage 172 of the drip tray 170 through the connection passage 181 .

The leakage channel 120 may be provided using a fiber material (Fiber, 121). After the fiber material 121 is first applied in a grid or mesh shape on the outer surface of the storage tank 10, the above-described foam insulation layer 110 is subsequently formed on the outer surface of the storage tank 10, thereby forming a leakage channel. (120) can be formed. The fiber material 121 may be provided with various types of fibers that sublimate or vaporize when heated. Accordingly, the leak channel 120 may be formed by heating and sublimating or vaporizing the fiber material 121 by receiving the heat of the foam insulation layer 110 that is subsequently sprayed and applied. Alternatively, the fiber material 121 may be provided with a fiber having a property of shrinking when heated, and is heated by the foam insulation layer 110 that is subsequently sprayed and applied, and the fiber material 121 shrinks, thereby reducing the leakage channel 120. may be formed.

A plurality of barrier walls 130 are disposed on the outside of the foam insulation layer 110 to surround the foam insulation layer 110, and are supported at a predetermined distance from the outer surface of the foam insulation layer 110 by a support 140 described below. It can be. A powder insulator 150 described below may be filled in the separation space G formed between the outer surface of the foam insulation layer 110 and the inner surface of the barrier 130 .

The plurality of barriers 130 may be fixed and supported on the outer surface of the support 140 to be described later, and each barrier 130 is fastened or bonded to the support 140 or between unit barriers 130 adjacent to each other. By being fixed by overlap welding, the separation space (G) in which the powder insulator 150 is filled inside can be sealed from the outside. The plurality of barriers 130 may be made of various materials if they can stably accommodate and hold the powder insulator 150, but stable operation through the same thermal expansion as the storage tank 10 even when cryogenic liquefied gas leaks It may be made of the same material as the storage tank 10 such as aluminum steel, stainless steel and 35% nickel steel to enable this.

The plurality of barriers 130 may include a first barrier 130a without the drip tray 170 and a second barrier 130b with the drip tray 170 .

Preferably, the first barrier 130a is provided in a plate shape and may be provided on the upper side and both sides of the storage tank 10, and may be partially provided on the lower side of the storage tank 10. In addition, the second barrier 130b may include a drip tray 170 for discharging leaked liquefied gas to the outside, and is partially or entirely provided on the lower side of the storage tank 10. It can be.

The drip tray 170 may be integrally formed with the second barrier 130b and formed as a part of the second barrier 130b.

The drip tray 170 may be preferably provided at the corner and center of the second barrier 130b, respectively. In addition, the portion where the drip tray 170 is formed on the second barrier 130b accommodates cryogenic liquefied gas, so it can be coated with a material that can withstand cryogenic temperatures or made of a separate material. Drip tray 170 ) is the projection 171 provided on the outside of the second barrier 130b, the drain passage 172 provided inside the projection 171, and the drain passage 172 to communicate with the outside. It may include a discharge port 173 formed through and an opening/closing member 174 opening and closing the discharge port 173.

The protruding portion 171 is a portion protruding outward from the second barrier 130b, and may provide a space in which the drain passage 172 is formed. For example, the protruding portion 171 may protrude in a semicircular shape from a plate shape and extend in one direction.

A discharge port 173 for discharging liquefied gas by communicating with the outside of the drain passage 172 may be formed on one side of the protrusion 171 .

The drain passage 172 is a space recessed inside the protrusion 171 to accommodate liquefied gas introduced through the connection passage 181, and is provided with a partition from the powder insulator 150.

The drain passage 172 communicates with a portion of the leakage channel 120 through the connection passage 181 of the connection discharge pipe 180 . As described above, since the leakage channels 120 are provided in a lattice shape and connected to each other, even if the drain passage 172 is connected to a part of the leakage channel 120 through the connection passage 181, the entire direction of the storage tank 10 Liquefied gas leaking from can be collected.

Therefore, the liquefied gas leaking from the storage tank 10 flows along the leakage channel, but flows to the lower side of the storage tank 10 due to its own weight, is collected in the drip tray 170 through the connection passage 181, and discharge port 173 It is provided that it can be discharged to the outside through.

The connection discharge pipe 180 is provided between the powder insulators 150 and has a connection passage 181 in which one side communicates with the leakage channel 120 and the other side communicates with the drain passage 172 .

For example, the connection discharge pipe 180 is provided in the form of a pipe and has a connection passage 181 inside, one end passing through the foam insulation layer 110 to communicate with the leak channel 120, and the other end passing through the drain passage 172 can be connected with

However, the shape of the connection discharge pipe 180 is not limited to this, and various modifications are possible as long as the leakage channel 120 and the drain passage 172 can be connected to transfer the leaked liquefied gas, and it should be understood the same.

A plurality of supports 140 may be provided to support the barrier 130 by separating it from the outer surface of the foam insulation layer 110 . A plurality of supports 140 may be formed to extend along the longitudinal direction of the storage tank 10 for stable installation and support of the barrier 130, and each support 140 extends from the outer surface of the storage tank 10 to the outside. It may include a vertical portion 141 extending in a direction and a horizontal portion 142 extending or expanding from an outer end of the vertical portion 141 to both sides. That is, the cross-sectional shape of the support 140 may be provided in a 'T' shape.

The barrier 130 is supported at a predetermined distance from the outer surface of the foam insulation layer 110 by the vertical portion 141 of the support 140, so that the powder is placed between the outer surface of the foam insulation layer 110 and the inner surface of the barrier 130. A separation space G filled with the heat insulating material 150 may be formed. In addition, the barrier 130 is installed in contact with the outer surface of the horizontal portion 142 extending in the lateral direction from the vertical portion 141, so that the support area of the barrier 130 increases, so that a plurality of barriers 130 are formed. It can be fixed and supported more stably.

The inner end of the support 140 may be fixed and supported by a stud bolt 160 fixed to the storage tank 10 by welding or the like, and at least a part of the inner end is inserted into the foam insulation layer 110 to additionally can be supported In addition, the support 140 may be provided by including a polyurethane foam having insulation or heat retention so that external heat is not transferred to the liquefied gas inside the storage tank 10 through the support 140 .

The powder insulator 150 is filled in the separation space G formed between the outer surface of the foam insulation layer 110 and the inner surface of the barrier 130 to insulate the liquefied gas contained in the storage tank 10. The powder insulator 150 is configured in the form of an independent powder and can be provided by filling the space between the outer surface of the foam insulation layer 110 and the inner surface of the barrier 130 by a filling pump (not shown) or the like. The powder insulator 150 may include at least one of glass bubbles and perlite having excellent thermal insulation properties. In this way, the structure of the liquefied gas storage tank 10 can be simplified because the powder insulator 150 in powder form can be quickly filled instead of stacking and installing a separate insulation layer on the storage tank 10, , the time consumed in manufacturing and installation can be reduced.

On the other hand, although not shown in the drawing, for structural stability of the liquefied gas storage tank 10, the separation space G between the outer surface of the foam insulation layer 110 and the inner surface of the barrier 130 is filled with the powder insulation material 150 The inert gas may be continuously supplied and discharged by an air pump (not shown), and a gas detector (not shown) may be provided on a required position of the heat insulating structure 100 to detect leakage of liquefied gas.

The present invention has been described with reference to an embodiment shown in the accompanying drawings, but this is only exemplary, and those skilled in the art can make various modifications and equivalent other embodiments therefrom. You will understand. Therefore, the true scope of the present invention should be defined only by the appended claims.

100: insulation structure 110: foam insulation layer
120: leakage channel 130: barrier
130a: first barrier 130b: second barrier
140: support 141: vertical part
142: horizontal portion 150: powder insulation
170: drip tray 171: protrusion
172: drain passage 173: discharge port
174: opening and closing member 180: connection discharge pipe
181: connection flow

Claims (5)

A foam insulation layer covering the outer surface of the storage tank for accommodating liquefied gas;
a leakage channel formed on an inner surface of the foam insulation layer in contact with an outer surface of the storage tank and provided as a passage through which liquefied gas leaking from the storage tank moves;
a plurality of barriers provided to surround the outside of the foam insulation layer;
a plurality of supports for supporting the plurality of barrier walls by separating them from the outer surface of the foam insulation layer; and
Including a powder insulation material filled between the outer surface of the foam insulation layer and the inner surface of the plurality of barriers,
At least some of the plurality of barriers
A heat insulation structure of a liquefied gas storage tank having a drip tray connected to the leak channel to collect the leaked liquefied gas. According to claim 1,
The drip tray
Insulation structure of the liquefied gas storage tank provided integrally with the barrier. According to claim 2,
The drip tray
A heat insulating structure for a liquefied gas storage tank having a protrusion provided on the outside of the barrier and a drain passage provided on the inside of the protrusion. According to claim 3,
The drip tray
A heat insulating structure for a liquefied gas storage tank comprising a discharge port penetrating the protruding portion to communicate with the outside of the drain passage and an opening and closing member for opening and closing the at least one discharge port. According to claim 4,
The insulation structure of the liquefied gas storage tank further comprising a; connection discharge pipe having a connection passage having one side communicating with the leakage channel and the other side communicating with the drain passage.

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