KR20230030271A - Barrier sructure of liquified gas storage tank - Google Patents

Abstract

The present invention relates to a barrier structure of a liquefied gas storage tank for protecting a hull from liquefied gas leaking from a tank body, comprising: a leakage liquefied gas discharge pipe for discharging leaked liquefied gas through a heat insulating layer formed outside the tank body; a leakage support installed at a lower part of the tank body to collect the liquefied gas discharged through the leakage liquefied gas discharge pipe; and a flexible pipe installed between an upper discharge pipe and a lower discharge pipe formed by dividing the leakage liquefied gas discharge pipe up and down.

Description

Barrier structure of liquefied gas storage tank {BARRIER SRUCTURE OF LIQUIFIED GAS STORAGE TANK}

The present invention relates to a liquefied gas storage tank, and more particularly, to a barrier structure of a liquefied gas storage tank capable of protecting a hull by preventing liquefied gas leaked from the liquefied gas storage tank from contacting the hull.

Due to recent strengthening of environmental pollution regulation standards for ships, interest in eco-friendly and highly efficient gas fuels such as liquefied natural gas (LNG) or liquefied petroleum gas (LPG) is increasing.

Liquefied natural gas (hereinafter referred to as 'LNG') is liquefied by cooling methane obtained by refining natural gas collected from gas fields. It is a fuel made into a liquid by compressing it at room temperature.

This liquefied gas is transported in a gaseous state through onshore or offshore gas pipelines, or transported to a distant consumer while being stored in a liquid state in a transport ship.

In particular, LNG is obtained by cooling natural gas to a very low temperature (about -163 ° C), and its volume is reduced to about 1/600 of that of gaseous natural gas, so it is very suitable for long-distance transportation through sea.

A liquefied gas storage tank that can withstand the extremely low temperature of LNG is used for LNG carriers to load and unload liquefied gas to destinations on land by operating the sea with LNG, or for LNG RV (Regasification Vessel) that regasifies and unloads LNG in the form of natural gas. (commonly referred to as a 'cargo hold') is provided

In addition, LNG FPSO (Floating, Production, Storage and Offloading) used to directly liquefy and store produced natural gas at sea, and transport stored LNG to LNG carriers when necessary, and store LNG unloaded from LNG carriers at sea. A liquefied gas storage tank installed in an LNG carrier or an LNG RV may also be included in an offshore structure such as an LNG Floating Storage and Regasification Unit (FSRU) that vaporizes LNG as needed and supplies it to an onshore consumer.

These liquefied gas storage tanks can be classified into a membrane type and an independent type depending on whether the cargo load directly acts on the insulation.

Membrane storage tanks are divided into No 96 type and Mark III type, and stand-alone storage tanks can be divided into Type A, Type B, and Type C according to the regulations of the International Maritime Organization (IMO), among which Type B Independent storage tanks can be generally divided into spherical type tanks and prismatic type tanks.

The membrane type storage tank is directly connected to the hull structure and is not separated from the hull structure, and has a structure in which a primary barrier and a secondary barrier are stacked on the inner wall of the hull. As the membrane type tank is directly connected to the hull, the load of the liquefied gas stored inside is transmitted to the hull without the storage tank supporting it.

On the other hand, the independent storage tank is manufactured in a form that is separated from the structure of the hull and mounted on the hull, and has a structure in which an insulating material is surrounded by an outer wall of the storage tank. As the independent storage tank is separated from the hull and supported by a supporting structure (vertical support structure, key structure, etc.) provided inside the hull, the load of the liquefied gas stored inside directly acts on the storage tank.

Unlike membrane-type storage tanks, independent storage tanks do not have a complex barrier structure, and are relatively advantageous in terms of structural stability against sloshing compared to membrane-type storage tanks. It has the advantage of facilitating maintenance.

Republic of Korea Patent Publication No. 10-2010-0106741 “Protective device for independent liquefied gas storage tank”

In such an independent storage tank, leakage of liquefied gas on the outer wall of the tank can cause fatal damage to the hull, which is vulnerable to cryogenic temperatures. Barriers must be installed to

In the case of Type B independent storage tanks, safety standards for gas carriers (IGC code; International code for the construction and equipment of ships carrying liquefied gases in bulk) or safety standards for gas-fueled ships (IGF code: international code of safety for ships using gases or other low-flashpoint fuels), a partial secondary barrier is required.

The partial secondary barrier is provided separately from the storage tank in the form of a drip tray. Thus, it serves to protect the leaked liquefied gas from affecting the temperature of the hull.

1 is a view schematically showing a part of the barrier structure of a spherical liquefied gas storage tank according to the prior art, and FIG. 2 is a view schematically showing a lower barrier structure of a prismatic liquefied gas storage tank in the prior art.

As shown in FIGS. 1 and 2, in the Type B independent storage tank, liquefied gas leaked in the direction of gravity can move along the leak path 30 formed between the tank body 10 and the heat insulating layer 20, It can be moved to the leakage support 50 through the leakage liquid passage 40 penetrating the heat insulating layer 20 from the lower part of the tank body 10 .

As described above, the Type B independent storage tank is divided into spherical and prismatic storage tanks, and the spherical storage tank has a single leak support 50 disposed in the lower center (see FIG. 1), and the prismatic storage It is common for the tank to install the leak support 50 at a plurality of designated locations including the bottom of the floor (see FIG. 2).

This is because the prismatic storage tank has a relatively flat lower part, unlike the spherical storage tank, and leaked liquefied gas can flow in a specific direction depending on the longitudinal or transverse slope (heel, or trim) of the hull. .

On the other hand, the liquefied gas storage tank is empty according to the temperature difference between the liquefaction temperature of the liquefied gas and the room temperature (ambient temperature) when the storage tank is emptied by loading low-temperature or cryogenic liquefied gas or unloading the loaded liquefied gas. It can contract or relax.

3 is a view showing the relative positional movement of a plurality of leak supports and a liquefied gas storage tank provided at the bottom of a prismatic storage tank as an example, FIG. 3 (a) is a tank contraction center (Center of Contraction) (CC) It is a view showing the case of being eccentric from the center of the tank (Center of Tank) (CT) as an example, and FIG. is the drawing shown.

For reference, in (a) and (b) of FIG. 3 , solid lines indicate the position of the tank body 10 before deformation of the liquefied gas storage tank, and dotted lines indicate the tank body moved to the center of contraction when the liquefied gas storage tank is deformed. (10) may mean the position.

As shown in FIG. 3, the prismatic storage tank is capable of moving the relative position of the tank body 10 and the leak support 50 installed on the hull from the lower part of the tank body 10 during contraction and relaxation due to the cryogenic environment. This may occur, and there is a concern that the leaked liquefied gas may flow into the hull when leaking of the liquefied gas occurs as the positions of the tank body 10 and the leak support 50 are displaced.

In a liquefied gas storage tank according to the prior art, when a leak of liquefied gas occurs, the size of the leak support is designed by estimating the amount leaked for 15 days. The size of the pedestal is excessively increased, which may result in an increase in construction costs.

In addition, the leaking liquefied gas flowing to the leak support is vaporized and evaporated due to the temperature difference between the outside air and the like. can affect

The present invention is provided with a leak support for blocking contact of the liquefied gas leaked from the liquefied gas storage tank with the hull, but reducing the risk due to the relative positional movement of the storage tank from the hull when the liquefied gas storage tank is contracted or relaxed. It is an object of the present invention to provide a barrier structure for a liquefied gas storage tank capable of protecting the hull.

In addition, it provides a leaking liquefied gas treatment system and method of a liquefied gas storage tank that can secure the stability of the hull by blocking the drop in hull temperature due to the vaporization of liquefied gas flowing into the leak support or the transfer of cold air to the inside of the hull. to do for a different purpose.

According to one aspect of the present invention, as a barrier structure of a liquefied gas storage tank for protecting a hull from liquefied gas leaking from a tank body, a leak for discharging liquefied gas leaked through a heat insulating layer formed on the outside of the tank body liquefied gas discharge pipe; Leak support installed at the lower part of the tank body to collect the liquefied gas discharged through the leak liquefied gas discharge pipe; And a barrier structure of a liquefied gas storage tank including a flexible pipe installed between an upper discharge pipe and a lower discharge pipe formed by dividing the leaky liquefied gas discharge pipe up and down may be provided.

The leakage support may be provided in a box shape in which the lower discharge pipe is coupled to an upper end and sealed.

In addition, the leak support is provided to be spaced apart from the heat insulation layer at the lower portion of the tank body, and the flexible pipe may be positioned between the leak support and the heat insulation layer.

In addition, an external heat insulating material formed on an outer surface of the leak support may be further included.

In addition, one or more water leakage supports may be provided at a lower portion of the tank body.

In addition, the liquefied gas storage tank may be an IMO Type B independent storage tank.

According to another aspect of the present invention, the tank body for accommodating liquefied gas therein; a heat insulating layer formed outside the tank body to insulate the liquefied gas stored inside the tank body; Leakage liquefied gas discharge pipe for discharging liquefied gas leaked through the heat insulating layer from the lower portion of the tank body; Leakage stand installed on the support structure supporting the tank body to collect the liquefied gas discharged through the leaky liquefied gas discharge pipe; And a liquefied gas storage tank including a flexible pipe installed between the upper discharge pipe and the lower discharge pipe formed by dividing the leaky liquefied gas discharge pipe up and down may be provided.

A leak path for moving the leaked liquefied gas to the leaked liquefied gas discharge pipe may be formed between the tank body and the heat insulating layer.

In addition, the heat insulating layer may be formed by attaching a plurality of heat insulating panels to the outer surface of the tank body or by spraying a spray foam type heat insulating material.

In the present invention, in order to block contact of liquefied gas leaked from the tank body with the hull, a leaky liquefied gas discharge pipe and a leak support are provided at the bottom of the tank body, but the leaked liquefied gas discharge pipe is divided up and down, and a flexible pipe is placed therebetween. By installing, it is possible to stably collect the leaked liquefied gas regardless of the relative positional movement of the hull and the tank body.

In addition, since the leak support is not installed on the hull and is connected to the tank body by a fixing means, even when the relative position of the hull and the tank body is moved, it moves together with the tank body, so that the leak liquefied gas discharge pipe and the leak support are not misaligned. and can prevent leaked liquefied gas from flowing into the hull.

In addition, by providing a passage for external discharge of the leaked liquefied gas moved to the leak pedestal disposed inside the partitioned space of the hull, the hull is prevented from being cooled due to vaporization of the leaked liquefied gas and transfer of cold air to the inside of the hull. and can have the effect of securing the stability of the hull accordingly.

1 is a view schematically showing a part of the barrier structure of a spherical liquefied gas storage tank according to the prior art.
Figure 2 is a view schematically showing the lower barrier structure of the prismatic liquefied gas storage tank in the prior art.
3 is a view showing the relative positional movement of a plurality of leak support and liquefied gas storage tank provided at the bottom of the prismatic storage tank as an example.
4 is a view schematically showing a portion of a barrier of a liquefied gas storage tank according to an embodiment of the present invention.
Figure 5 is a view schematically showing a state in which the tank body is contracted and moved due to the liquefied gas stored inside the tank body shown in FIG.
6 is a view schematically showing a barrier structure of a liquefied gas storage tank according to another embodiment of the present invention.
7 is a view showing that the leak support is installed in close contact with the heat insulation layer formed on the lower part of the tank body in the barrier structure of the liquefied gas storage tank according to another embodiment of the present invention.
8 is a view schematically showing a leakage liquefied gas treatment system of a liquefied gas storage tank including a plurality of leak support.
9 is a view schematically showing a modified example of a leaking liquefied gas treatment system of a liquefied gas storage tank according to an embodiment of the present invention.

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

First, in adding reference numerals to components of each drawing, it should be noted that the same components have the same numerals as much as possible even if they are displayed on different drawings.

In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

Preferred embodiments of the present invention will be described below, but the technical spirit of the present invention is not limited or limited thereto and can be modified and implemented in various ways by those skilled in the art, of course.

In the description of the present invention, liquefied gas is generally liquefied, such as cryogenic (approximately -163 ° C) LNG (Liquified Natural Gas), LPG (Liquefied Petroleum Gas) or liquefied ethylene gas (Liquefied Ethylene Gas). It may include all gaseous fuels stored as , and liquefied gas may mean liquefied gas as well as liquefied gas in a liquid state.

In the description of the present invention, liquefied gas is generally liquefied, such as cryogenic (approximately -163 ° C) LNG (Liquified Natural Gas), LPG (Liquefied Petroleum Gas) or liquefied ethylene gas (Liquefied Ethylene Gas). It may include all gaseous fuels stored as , and liquefied gas may mean liquefied gas as well as liquefied gas in a liquid state.

The present invention relates to a barrier structure of a liquefied gas storage tank for protecting a hull from liquefied gas leaking from a tank body. It can be applied, preferably, it can be applied to an IMO Type B stand-alone storage tank having a partial secondary barrier by forming a heat insulating layer on the outside of the tank body, but having a leakage support for temporarily storing liquefied gas leaked from the lower part of the tank body. there is.

4 is a view schematically showing a portion of a barrier of a liquefied gas storage tank according to an embodiment of the present invention, and FIG. 5 is a contraction movement of the tank body due to the liquefied gas stored inside the tank body shown in FIG. 4 It is a diagram schematically showing the state.

In this embodiment, the tank body 110 may be made of an alloy resistant to low temperatures such as aluminum alloy, SUS (Steel Use Stainless), or 9% nickel alloy, preferably. can be made of a high-Mn steel material that can withstand cryogenic temperatures due to its low price and excellent resistance to corrosion at low temperatures.

In addition, in the heat insulating layer 120 formed outside the tank body 110, a plurality of insulating panels made of polyurethane are attached to the outer surface of the tank body 110 or a spray foam type insulating material is used. It can be formed by spraying.

A leak path 130 may be formed between the tank body 110 and the heat insulating layer 120 to move the leaked liquefied gas in a direction of gravity (downward direction).

To this end, a leveling wedge (not shown) for forming the leak path 130 may be installed on the outer surface of the tank body 110 before forming the heat insulating layer 120 .

Referring to FIG. 4, the barrier structure of the liquefied gas storage tank according to an embodiment of the present invention includes a leakage path 130 formed between the tank body 110 and the heat insulating layer 120 at the bottom of the tank body 110 and It may include a leaking liquefied gas discharge pipe 140 for discharging the leaked liquefied gas through communication and a leak support 150 for collecting the liquefied gas discharged through the leaking liquefied gas discharge pipe 140.

The leaking liquefied gas discharge pipe 140 may be provided through the heat insulating layer 120 formed on the outside of the tank body 110, and guide the liquefied gas leaking from the tank body 10 to the leak support 150 to be described later. can play a role in

In this embodiment, it may be preferable that the leaking liquefied gas discharge pipe 140 protrudes from the heat insulation layer 120 formed on the lower portion of the tank body 110.

The leak support 150 may be provided at a lower portion of the tank body 110 to be spaced apart from the heat insulation layer 120, and a partial secondary barrier that protects the hull by collecting the liquefied gas discharged through the leak liquefied gas discharge pipe 140. can play a role as

The leakage support 150 of this embodiment may be provided in the form of a box in which the leaky liquefied gas discharge pipe 140 is coupled to the upper end and sealed while having an open top.

In this embodiment, the leak support 150 may be fixed to the bottom surface of the hull by welding or bolting, and an external heat insulating material 160 may be formed on the outer surface of the leak support 150.

The external insulator 160 may serve to insulate the liquefied gas flowing into the leak tray 150 so that the cold air of the liquefied gas collected in the leak tray 150 is not transmitted to the hull.

The barrier structure of the liquefied gas storage tank according to an embodiment of the present invention is provided in a box shape in which the leak support 150 is sealed at the bottom of the tank body 10, so that the liquefied gas flowing into the leak support 150 is vaporized. It is possible to block the supply to the inner space of the hull, and to prevent the hull from being cooled due to the vaporized liquefied gas, which affects the safety of the hull.

In this embodiment, the leaking liquefied gas discharge pipe 140 and the leaking support 150 may be preferably made of a material that can withstand the cryogenic temperature caused by the liquefied gas, the same as or similar to the tank body 110. there is.

On the other hand, as described above, the liquefied gas storage tank is mainly designed as a spherical and prismatic storage tank. can be applied

Specifically, in the spherical storage tank, the leaking liquefied gas discharge pipe 140 and the leak support 150 may be provided singly at the lower center of the tank body 110, and in the prismatic storage tank, the tank body 110 A plurality of leaky liquefied gas discharge pipes 140 and leak support 150 may be installed at designated locations such as corners, including the lowermost end.

Here, in the case of a spherical storage tank, even if the tank body 10 shrinks, it may be possible to stably collect the leaked liquefied gas through the adiabatic leak support 50 formed in the lower center of the tank body 10, but the angular In the storage tank, since the relative position of the tank body 10 and the leak support 50 installed in the hull may occur at the bottom of the tank body 10 during contraction and relaxation due to the cryogenic environment, the tank body 10 ) There is a concern that the leaked liquefied gas may flow to the hull when a leak of liquefied gas occurs due to the displacement of the position of the leak support 50.

The barrier structure of the liquefied gas storage tank according to an embodiment of the present invention may further include a flexible pipe 170 connected to the leaking liquefied gas discharge pipe 140.

Specifically, the leaky liquefied gas discharge pipe 140 of this embodiment is divided up and down, and may consist of an upper discharge pipe 141 and a lower discharge pipe 143, between the upper discharge pipe 141 and the lower discharge pipe 143. An association 170 may be installed.

Here, the leaky liquefied gas discharge pipe 140 is divided up and down, the upper discharge pipe 141 is fixedly installed in the lower part of the tank body 110, and the lower discharge pipe 143 is coupled to the open upper part of the leak support 150. It can be.

The flexible pipe 170 of this embodiment is flexible and can be freely bent, and both ends in the longitudinal direction are provided in the form of flanges, and the upper discharge pipe 141 and the lower discharge pipe are formed through bolting or other known fastening methods. (143).

That is, as it is divided into an upper discharge pipe 141 and a lower discharge pipe 143, damage to the leaking liquefied gas discharge pipe 140 can be prevented even when the tank body 110 relative to the hull moves, and the flexible pipe 170 Through this, the upper discharge pipe 141 and the lower discharge pipe 143 are always in communication so that the leaked liquefied gas can be stably collected.

In this embodiment, the flexible pipe 170 is a material that is excellent in corrosion resistance and corrosion resistance and is not damaged or damaged even at the temperature of liquefied gas (in the case of LNG, -163 ℃ or less), for example, can be used in a cryogenic environment It may be provided with SUS material.

In this embodiment, the leak support 150 is provided to be spaced apart from the heat insulation layer 120 at the bottom of the tank body 110, the flexible pipe 160 of the present embodiment is the leakage support 150 and the heat insulation layer 120 It may be desirable to be located in between.

In this embodiment, the dotted line shown in FIG. 5 may mean that the tank body 110 contracts and moves due to the liquefied gas stored inside the tank body 110 .

As shown in FIG. 5, the flexible pipe 170 of this embodiment, even if the positions of the upper discharge pipe 141 and the lower discharge pipe 143 are displaced due to contraction or relaxation of the tank body 110, the upper discharge pipe 141 And the lower discharge pipe 143 can be always in communication, and the leaking liquefied gas discharged through the upper discharge pipe 141 is stably inside the leak support 150 through the flexible pipe 170 and the lower discharge pipe 143. can be collected.

The barrier structure of the liquefied gas storage tank according to an embodiment of the present invention is a leaking liquefied gas discharge pipe 140 at the bottom of the tank body 110 in order to block contact of the liquefied gas leaked from the tank body 110 with the hull. ) and a leak support 150, but by dividing the leaking liquefied gas discharge pipe 140 up and down and installing the flexible pipe 170 therebetween, leakage regardless of the relative positional movement of the hull and the tank body 110 Stable collection of liquefied gas may be possible.

6 is a view schematically showing a barrier structure of a liquefied gas storage tank according to another embodiment of the present invention, and FIG. 7 is a tank body in which a leak support is provided in a barrier structure of a liquefied gas storage tank according to another embodiment of the present invention. It is a drawing showing that it is installed in close contact with the heat insulating layer formed on the lower part of.

6 and 7, the barrier structure of the liquefied gas storage tank according to another embodiment of the present invention is similar to the above-described embodiment, the tank body 210 and the insulation layer ( 220) and a leaking liquefied gas discharge pipe 240 for discharging the leaked liquefied gas in communication with the leak path 230 formed between the leaking liquefied gas discharge pipe 240 and a leak support for collecting the liquefied gas discharged through the leaking liquefied gas discharge pipe 240 ( 250) may be included.

The dotted lines shown in FIGS. 6 and 7 may mean that the tank body 110 shrinks and moves due to the liquefied gas stored in the tank body 110 .

In this embodiment, the leaking liquefied gas discharge pipe 240 may be formed to extend downward through the heat insulating layer 220 from the lower portion of the tank body 210, and the leak support 250 has an upper open form. The leakage liquefied gas discharge pipe 240 may be provided in a box shape that is coupled to the upper end and sealed.

In addition, it may be desirable to form an external heat insulating material 260 on the outer surface of the leak tray 250 so that the cold air of the liquefied gas collected in the leak tray 250 is not transferred to the hull.

On the other hand, the barrier structure of the liquefied gas storage tank of this embodiment may further include a fixing means 270 for fixing the leak support 250 to the tank body 210.

That is, unlike the above-described embodiment, the leakage support 250 of the present embodiment is connected to the tank body 210 rather than a structure fixed to the hull, even if the relative position movement of the hull and the tank body 210 occurs. As the positions of the leaking liquefied gas discharge pipe 240 and the leaking stand 250 are not displaced, it is possible to prevent the leaked liquefied gas from flowing into the hull.

Referring to FIGS. 5 and 6 , a plurality of support structures 280 may be provided at the bottom of the tank body 210 in order to link with a supporting structure (not shown) supporting the tank body 210. The structure 280 may be attached to the outer surface of the tank body 210 by penetrating the heat insulating layer 220 formed outside the tank body 210 .

The fixing means 270 of this embodiment may have one end connected to at least one of the plurality of support structures 280 formed below the tank body 210, and the other end connected to the leak support 250 to the tank body ( 210) may serve to allow the leak support 250 to move together during contraction and relaxation.

The other end of the fixing means 270 may be directly connected to the leak support 250 by penetrating the external insulation 260 formed on the outer surface of the leak support 250, or may be directly connected to the leak support 250 and the outer surface of the leak support 250. Since the external insulator 260 formed in is connected to one structure, it may be connected to the external insulator 260 formed on the outer surface of the leak support 250.

In this embodiment, it may be preferable that the fixing means 270 is made of the same or similar material as the leak support 250 in order to prevent heat transfer to the tank body 210 .

The leakage support 250 of this embodiment is connected to the tank body 210 and is provided to be spaced apart from the bottom surface of the hull, so that it may be desirable to minimize the effect on the stability of the hull by being transferred to the hull by cold air. .

In addition, the leak support 250 may be provided to be spaced apart from the heat insulating layer 220 at the lower part of the tank body 210 by the fixing means 270 (see FIG. 6), and may be installed in close contact with the heat insulating layer 220. It may also be (see Fig. 7).

According to this embodiment, the leakage support 250 is connected to the tank body 210 without being installed on the hull, so that the leaked liquefied gas is moved together with the tank body 210 when the tank body 210 is deformed. It can be prevented from flowing into the hull without moving into the leak support 250.

On the other hand, as described above in the prior art, the leaking liquefied gas flowing to the leak support is vaporized and evaporated due to the temperature difference with the outside air. When the vaporized liquefied gas is continuously supplied to the hull space, the hull is cooled and Deviations from the design temperature may affect the stability of the hull.

The present invention is to secure the stability of the hull by preventing the hull temperature from falling due to the vaporization of the liquefied gas flowing into the leak support.

8 is a diagram schematically showing a leak liquefied gas treatment system of a liquefied gas storage tank including a plurality of leak supports, and FIG. 9 is a leak liquefied gas treatment system of a liquefied gas storage tank according to an embodiment of the present invention. It is a drawing schematically showing a modified example.

Referring to FIG. 8, the leakage liquefied gas treatment system according to an embodiment of the present invention may include a plurality of leak supports 310 for collecting liquefied gas leaked from a liquefied gas storage tank (not shown), , At least a portion of the leaking liquefied gas collected into the leak support 310 may be configured to be vaporized and discharged to the outside.

In this embodiment, the dotted line shown in FIG. 8 may mean a partitioned space of the hull, and the plurality of leak supports 310 of this embodiment are inside the partitioned space of the hull for the installation of the liquefied gas storage tank. can be placed.

The leakage support 310 may be provided to have a sufficient size in order to stably collect the leaked liquefied gas even when the storage tank is moved relative to the hull.

The leakage support 310 of this embodiment may be provided in a box shape in which the leakage liquefied gas discharge pipe 140 is coupled to the upper end and sealed, and an external insulation 160 is formed on the outer surface to supply cryogenic liquefied gas to the hull. It can be prevented from affecting the stability of the hull (see Figs. 4 to 5).

The leaked liquefied gas treatment system of this embodiment, similar to the above-described embodiment, includes a flexible pipe 170 connected to the leaked liquefied gas discharge pipe 140, regardless of the relative movement of the hull and the storage tank. It may be provided so that it can move to the leak support 310.

Alternatively, a fixing means 270 for fixing the leak support 310 to the storage tank may be further included so that the leak support 310 is connected to the storage tank rather than a structure supported by the hull (FIGS. 6 to 6). see Figure 7).

A leaking liquefied gas treatment system of a liquefied gas storage tank according to an embodiment of the present invention includes a bridge line 320 connecting a plurality of leak supports 310 and a leaked liquefied gas in communication with the bridge line 320 It may further include an external discharge line 330 for discharging to the outside.

The bridge line 320 may be provided to sequentially connect the plurality of leak support 310, and form a single flow path through which the leaked liquefied gas moves, finally leaking with the external discharge line 330. It can serve as a passage through which liquefied gas is discharged to the outside.

Meanwhile, the leaked liquefied gas treatment system according to an embodiment of the present invention may further include a pressure relief valve 340 installed on the external discharge line 330.

The pressure relief valve 340 of this embodiment is for adjusting the internal pressure of the leak pedestal 310 and the bridge line 320 communicating with the external discharge line 330, and is opened at the maximum allowable pressure of each component. It may be desirable to be provided.

8 is a view showing a modified example of a leaking liquefied gas treatment system of a liquefied gas storage tank according to an embodiment of the present invention. A separate manifold connection line 350 is provided at each of the pedestals 310, and a manifold discharge line 360 is connected at a point where a plurality of manifold connection lines 350 join to release the leaked liquefied gas to the outside. It can be configured to discharge.

The leakage liquefied gas treatment system of this modified example, similar to the above-described embodiment, may be provided with a pressure relief valve 370 installed on the manifold discharge line 360 to be opened at the maximum allowable pressure of each component. there is.

The leakage liquefied gas treatment system of the liquefied gas storage tank according to an embodiment of the present invention is provided with a passage for external discharge of the leaked liquefied gas moved to the leak support inside the partitioned space of the hull, thereby vaporizing the leaked liquefied gas. And it is possible to prevent the hull from being cooled due to the transfer of cold air to the inside of the hull, and thus, the stability of the hull can be secured.

The present invention can be applied to any offshore structure used while floating in the sea where flow occurs, and can be applied to ships such as liquefied gas carriers or LNG Regasification Vessel (LNG RV) that transport LNG or LPG, as well as LNG FPSOs. (Floating, Production, Storage and Offloading) and offshore plants such as LNG Floating Storage and Regasification Unit (FSRU).

The above description is merely an example of the technical idea of the present invention, and those skilled in the art can make various modifications, changes, and substitutions without departing from the essential characteristics of the present invention. will be.

The embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings.

In addition, the protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

110: tank body
120: heat insulation layer
130: Leak path
140: leaking liquefied gas discharge pipe
150: Drip tray
160: external insulation
170: Flexible pipe

Claims (11)

As a barrier structure of a liquefied gas storage tank to protect the hull from liquefied gas leaking from the tank body,
A leaky liquefied gas discharge pipe for discharging leaked liquefied gas through the heat insulating layer formed outside the tank body;
Leak support installed at the lower part of the tank body to collect the liquefied gas discharged through the leak liquefied gas discharge pipe; and
A barrier structure of a liquefied gas storage tank comprising a flexible pipe installed between an upper discharge pipe and a lower discharge pipe formed by dividing the leaky liquefied gas discharge pipe up and down. According to claim 1,
The leak support is a barrier structure of a liquefied gas storage tank provided in a box shape in which the lower discharge pipe is coupled to the upper end and sealed. According to claim 1,
The leak support is provided to be spaced apart from the insulation layer at the lower part of the tank body,
The flexible pipe is a barrier structure of a liquefied gas storage tank located between the leak support and the heat insulation layer. According to claim 1,
A barrier structure of a liquefied gas storage tank in which a leak path is formed between the tank body and the heat insulating layer for the leaked liquefied gas to move to the leaked liquefied gas discharge pipe. According to claim 1,
The barrier structure of the liquefied gas storage tank further comprising an external heat insulating material formed on the outer surface of the leak support. According to claim 1,
The leak support is a barrier structure of a liquefied gas storage tank provided with one or more at the lower part of the tank body. According to claim 1,
The liquefied gas storage tank is a barrier structure of a liquefied gas storage tank, which is an IMO Type B independent storage tank. A tank body accommodating liquefied gas therein;
a heat insulating layer formed outside the tank body to insulate the liquefied gas stored inside the tank body;
Leakage liquefied gas discharge pipe for discharging liquefied gas leaked through the heat insulating layer from the lower portion of the tank body;
Leakage stand installed on the support structure supporting the tank body to collect the liquefied gas discharged through the leaky liquefied gas discharge pipe; and
A liquefied gas storage tank comprising a flexible pipe installed between an upper discharge pipe and a lower discharge pipe formed by dividing the leaky liquefied gas discharge pipe up and down. According to claim 8,
The leak support is a liquefied gas storage tank provided in the form of a box in which the lower discharge pipe is coupled to the upper end and sealed. According to claim 8,
A liquefied gas storage tank in which a leak path is formed between the tank body and the heat insulating layer for the leaked liquefied gas to move to the leaked liquefied gas discharge pipe. The method of claim 9 or 10,
The insulating layer is a liquefied gas storage tank formed by attaching a plurality of insulating panels to the outer surface of the tank body or spraying a spray foam type insulating material.

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