KR101257139B1 - LNG Carrier's Cargo Tank equiped with Anti-Sloshing Cap - Google Patents

Abstract

The present invention relates to a liquid cargo carrier cargo hold provided with a buoyancy cap for sloshing suppression, the object is to install a floating cap that moves up and down along the liquid level of the liquid cargo, slosh that can suppress and reduce sloshing in the cargo hold It is to provide a liquid cargo carrier cargo hold equipped with a buoyancy buoyancy cap.

A double bottom panel constituting the bottom of the cargo hold, a lower chamfer panel extending inclined upwardly outward of the double bottom panel, a vertical panel vertically installed from the lower chamfer panel, and inclined inwardly upward from the vertical panel In the cargo hold consisting of a double-window structure comprising an upper chamfer panel and a top panel connecting the upper chamfer panel; The support is installed in the cargo hold so as to be connected to the double bottom panel in the top panel, and the support is installed through the center or the required position, and the rotary wing is formed along the outer circumferential surface at the lower end of the floating cap, the liquid level of the liquid cargo in the cargo hold It is configured to include a buoyancy cap which is moved up and down by buoyancy according to the change of position, and when the flow of liquid cargo occurs, the sloshing phenomenon is suppressed and reduced by the buoyancy cap which floats along the liquid surface of the liquid cargo and rotates itself. .

Cargo hold, sloshing, liquid cargo, buoyancy cap, LNG

Description

LNG Carrier's Cargo Tank equiped with Anti-Sloshing Cap}

The present invention relates to a liquid cargo carrier cargo hold equipped with a buoyancy cap for sloshing suppression, by installing a buoyancy cap to move up and down along the liquid level of the liquid cargo stored in the cargo hold structural structure inside the storage tank due to the sloshing phenomenon of the liquid cargo The present invention relates to a liquid cargo carrier cargo hold provided with a buoyancy cap for suppressing sloshing to prevent damage.

In general, natural gas maintains its liquid state when it reaches a temperature of minus 163 ° C at atmospheric pressure, and thus can be stored in a liquid state in a storage tank having a thermal insulation function. Liquefied natural gas (LNG: Liquefied Natural Gas) stored in cargo tanks and transported at low temperatures (about -163 ° C) is concerned about the fragility of hulls caused by cryogenic temperatures. A special cargo hold is to be provided, and this special structure is used to block the movement of cryogenic liquefied natural gas and heat as a structural member of the hull or cargo hold. So-called membrane (Membrane) method of mediating the insulation is used a lot.

The membrane-type storage tank insulated structure is composed of a material that effectively blocks heat transfer and a metal panel having a liquefied natural gas sealing function. The metal material constituting the metal panel is made of a material resistant to low temperature brittleness, and the metal panel is liquefied natural. It is designed and manufactured to expand and contract in response to changes in temperature and load generated when gas is injected into or removed from a storage tank.

Currently, commercially available thermal insulation methods include an external insulation method and an internal insulation method, and the internal insulation method can control the temperature of the container enclosure similar to the outside temperature, thus limiting the use of materials such as the application of low-temperature materials. There is no advantage. As such an internal insulation method, a membrane-type insulation system of GTT, France, which has a double barrier structure based on the middle barrier structure (US Patent No. 484358) of McDonald Douglas, USA, is known.

However, offshore structures such as liquefied natural gas carriers (LNGC) operated at sea or floating liquefied natural gas storage evaporation units (FSRUs) that are anchored and operated in one place may be The entire structure is shaken, and the liquefied natural gas stored in the cargo hold flows with the shake of the structure itself. At this time, the flowing liquefied natural gas is to hit the inside of the cargo hold, this phenomenon is called the impact (Sloshing Impact) due to sloshing.

The possibility of damage inside the cargo hold due to such sloshing tends to increase as the cargo hold grows in size, thus limiting the size of such cargo hold. In particular, in the case of floating LNG storage vaporization facilities that are operated for a long time in a particular sea area, and in the case of a LNG carrier that operates in an area where the marine environment is bad, the restriction due to such sloshing is a very important design factor.

Therefore, there is a need for a cargo hold having a liquefied natural gas sludge reduction function that can be applied to a large cargo hold of a liquefied natural gas carrier or a floating liquefied natural gas storage vaporization facility for storing and operating liquefied natural gas.

Conventionally, in order to suppress sloshing in a cargo hold as described above, a method of installing an anti-sloshing bulkhead in a cargo hold (Patent No. 0785475), and a method of installing a specific surface structure at a corner portion of the cargo hold (US2007 / 0245941) , Method of forming a jaw having a gentle slope on the upper surface of the storage tank (Utility Model Registration No. 0333611), Method of forming a chamfer having a constant slope on the front and upper sides of the storage tank (Utility Model Registration 0340531) However, the conventional methods such as the modification of the structure for a specific part of the cargo hold, or the installation of a separate structure, and the resulting sloshing reduction is only partially shown the effect, overall sloshing It does not have a reduction function.

The present invention is to solve the above problems, the object is to install a floating cap that rotates simultaneously with the shanghai along the liquid surface of the liquid cargo, the buoyancy cap for sloshing suppression that can reduce the sloshing in the cargo hold To provide a liquid cargo carrier cargo hold installed.

Another object of the present invention is to provide a liquid cargo carrier cargo hold equipped with a buoyancy cap for sloshing suppression that can ensure the stability of the cargo hold through the reduction of the sloshing, and to realize the extra large size of the cargo hold.

Another object of the present invention is to provide a liquid cargo carrier cargo hold provided with a buoyancy cap for the sloshing suppression that can be offset by the rotation of the buoyancy cap when the sloshing flow occurs by having a rotary blade at the end of the buoyancy cap. will be.

Another object of the present invention is to provide a liquid cargo carrier cargo hold is installed with a buoyancy cap for the sloshing suppression can be firmly supported by connecting the bottom and top of the support to the hull.

A double bottom panel constituting the bottom of the cargo hold, a lower chamfer panel extending inclined upwardly outward of the double bottom panel, a vertical panel vertically installed from the lower chamfer panel, and inclined inwardly upward from the vertical panel In the cargo hold consisting of a double-window structure comprising an upper chamfer panel and a top panel connecting the upper chamfer panel;

The support is vertically installed in the cargo hold so as to be connected to the double bottom panel in the top panel, and the support is installed through the center, and a rotary wing is formed along the outer circumferential surface at the lower end thereof, and the liquid surface position of the liquid cargo in the cargo hold is changed. It is configured to include a buoyancy cap to move up and down by buoyancy, when the flow of liquid cargo (sloshing flow) occurs, the sloshing phenomenon is reduced by the buoyancy cap that rotates itself while floating along the liquid surface of the liquid cargo.

As described above, the present invention is movable up and down along a support installed in the cargo hold, and the buoyancy cap which can float on the liquid level of the liquid cargo in the cargo hold is installed in the cargo hold by the buoyancy cap which is rotated when the liquid cargo flow in the cargo hold is generated. It is possible to reduce the phenomenon of crushing, and to realize the enlargement of cargo holds.

In addition, the present invention is provided with a rotary blade at the lower end of the buoyancy cap, when the liquid cargo fluctuations, the buoyancy body is rotated by the rotary blade in the state in which the surface area of the liquid cargo reduced by the surface area of the buoyancy cap to the support and buoyancy cap By canceling the transmitted force, it is possible to reduce the cross-sectional area of the struts, and to simplify the connection structure with the bottom panel and the top panel of the cargo hold coupled with the struts, there are many effects.

1 is an exemplary view showing a configuration according to the present invention, Figure 2 is an exemplary view showing a coupled state of the struts according to the present invention, Figure 3 is an example attempt to show a configuration of the buoyancy cap according to the present invention, Figure 4 5 is an exemplary view showing a modified configuration of the buoyancy cap according to the present invention, Figure 5 shows an exemplary view showing a state in which a plurality of support and buoyancy cap is installed in the cargo hold, the present invention is a double bottom forming the bottom of the cargo hold A panel 110, a lower chamfer panel 120 extending obliquely upwardly above the double bottom panel 110, a vertical panel 130 installed vertically from the lower chamfer panel 120, and the vertical panel. In the cargo hold (100) consisting of a double-window structure comprising an upper chamfer panel (140) extending obliquely upward from the (130) and a top panel (150) connecting the upper chamfer panel (140);

The pillar 400 is installed in the cargo hold so as to be connected to the double bottom panel 110 in the top panel 150, and the pillar 400 is installed therethrough, and a rotary blade 410 is formed along the outer circumferential surface at the lower end thereof. The buoyancy cap 500 is configured to include a buoyancy cap 500 which is moved in accordance with the change of the liquid level of the liquid cargo 300 in the cargo hold. The sloshing phenomenon is suppressed and reduced by moving and rotating upward.

The support 400 is, as shown in Figure 1, the top and bottom are respectively fixed to the top panel 150 and the double bottom panel 110 by a gas tight connection 600, buoyancy cap 500 on the top Stopper 410 is prevented from rising.

The hermetic connection part 600 is connected to the top panel 150 at the same time as the double bottom panel 110 through the heat insulating structure 200 of the cargo hold, is penetrated through the heat insulating structure 200 of the cargo hold made of a double barrier structure. The stud bolt is positioned in the formed installation hole.

That is, as shown in FIG. 2, the hermetic connection part 600 passes through the primary barrier 230, the primary insulation plate 210, the secondary barrier 240, and the secondary insulation plate 220. One end of the stud bolt 610 is welded to the top panel, and the support 400 is connected to the other end of the stud bolt 610 that penetrates the heat insulation structure 200 and protrudes into the cargo hold.

At this time, the thermal insulation structure 200 of the cargo hold, that is, the primary barrier 230, the primary insulation plate 210, the secondary barrier 240 and the secondary insulation plate 220 is installed for the installation of the stud bolt 610 The hole 250 is formed, and the stud bolt 610 to be installed and the primary barrier 230 located at the top of the heat insulation structure 200 of the cargo hold are maintained to be airtight by welding as shown in FIG. 2. It is. In addition, the nut 620 and the strut 400 are also fixed by welding to maintain firmness and airtightness.

In addition, the installation hole 250 formed in the heat insulation structure 200 of the cargo hold is inserted and filled with a heat insulating material of the same material as the heat insulation plates 210 and 220. The installation of the heat insulating material according to the insertion of the heat insulating material and the welding of the stud bolt is made at the time of installation of the cargo hold heat insulating structure 200, and the installation of such heat insulating structure is well known technology means, and thus the detailed description thereof will be omitted.

Both ends of the support 400 are hermetically maintained on the top panel 150 and the bottom panel 110 by the hermetic connection part 600 as described above, and are firmly connected to each other.

The stopper 410 is to prevent the collision with the top panel due to the rise of the buoyancy cap 500, the stopper bolt, the plate-shaped stopper and the like is integrated in the support 400, buoyancy cap It is made of an elastic material for cushioning the impact upon contact with the 500, or the buffer is coated.

The buoyancy cap 500 is for suppressing sloshing, and is made of an engineering plastic material to float on the liquid surface 310 of the liquid cargo 300. Engineering plastic material as described above is used to select the engineering plastic material that can withstand the properties of the liquid cargo, such as cryogenic temperature. In addition, since the type of engineering plastics is widely known, a detailed description thereof will be omitted.

As shown in FIG. 3, the buoyancy cap 500 is a horizontal plate formed integrally with the insertion hole 510 and the insertion hole 510 through which a support passage is formed in the center so that the support post is inserted therethrough. 520 and a plurality of rotary blades 530 which are formed to be inclined downward along the outer circumferential surface of the horizontal plate 520. 3 shows a perspective view of the buoyancy cap, and a lower view shows a bottom perspective view of the buoyancy cap.

The rotary blade 530 is the wing body 531, the outer rotary wing 532 protruding in the outward direction of the buoyancy cap with respect to the wing body 531 and the buoyancy cap of the wing body 531 It consists of an inner rotary blade 533 formed to protrude in the inward direction. That is, the outer rotary blade 532 and the inner rotary blade 533 is formed to protrude in opposite directions with respect to the wing body 531.

In addition, the horizontal plate 520 is formed with a plurality of communication holes 521, the liquid cargo is moved to the upper and lower portions of the buoyancy cap 500 through the communication hole 521, the water surface 310 of the liquid cargo To increase the contact of the buoyancy cap 500 and to prevent the rotation and movement of the buoyancy cap 500 due to excessive buoyancy. The communication hole 521 as described above is formed to maintain equal intervals so as to be symmetrical to each other on the horizontal plate 520 for uniform movement of the buoyancy cap 500 (movement according to the equilibrium of the buoyancy cap).

In addition, as shown in Figure 4, the buoyancy cap is provided with only the outer rotary blade 532 or the inner rotary blade 533, it can prevent excessive rotation due to the fluid flow. Reference numeral 500a denotes a buoyancy cap having only the outer rotary blade 532, 500b shows a buoyancy cap having only the inner rotary blade 533, respectively.

The prop and buoyancy cap of the present invention made as described above is installed one or at least one in the cargo hold, when one support and the buoyancy cap is installed, the support is installed in the center of the cargo hold, as shown in FIG. When two props and abutment caps are installed, as shown in FIG. 5, they are spaced apart from the cargo hold. Reference numeral 500c denotes a miniaturized buoyancy cap.

In addition, when one buoyancy cap is installed in the cargo hold, the one buoyancy cap is as shown in Figure 1, the inclination angle (α) formed by the horizontal plate 520 and the rotary blade 530 of the buoyancy cap is the top panel It is preferably made to be smaller than or equal to the inclination angle (beta) formed by the 150 and the upper chamfer panel 140, the length of the rotary blade (L1) within 50% of the length (L2) of the upper chamfer panel 140. It is preferably formed. In addition, the diameter (H1) of the horizontal plate 520 of the buoyancy cap is preferably determined to be within 80% of the top panel 150 width length (H2).

In addition, the liquid cargo means liquefied natural gas and the like, the cargo hold means liquefied natural gas storage tank and the like. In addition, the present invention is applicable not only to LNG carriers but also to floating LNG storage vessels (FSRUs).

In addition, the present invention is applicable to both a heat insulating structure having a double barrier structure and a heat insulating structure having a membrane metal panel as well as a membrane type heat insulating system manufactured by GTT, France.

According to the present invention made as described above, the support is inserted into the insertion hole of the buoyancy cap, and the support is vertically installed in the cargo hold, and when the liquid cargo is stored in the cargo hold, the buoyancy cap is partially locked to the liquid level of the liquid cargo. It will float.

According to the present invention configured as described above, when an external force is generated, such as a rocking of a ship, the sloshing phenomenon is suppressed by the floating and self-rotation of the buoyancy cap floating in the liquid cargo liquid level.

In addition, the moment of lifting the buoyancy cap generated during the flow of the liquid cargo, and the shear force (Shear Force) to push the buoyancy cap to the left and right, but this is a buoyancy cap generated by converting the rotational force to the rotary wing of the buoyancy cap Since the external force is canceled due to the rotation of, the generation of force that can be generated between the support and the buoyancy cap is prevented, thereby simplifying the connection between the buoyancy cap and the support.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. Of course, such modifications are within the scope of the claims.

1 is an exemplary view showing a configuration according to the present invention

Figure 2 is an exemplary view showing a coupled state of the struts in accordance with the present invention

3 is an exemplary view showing the configuration of a buoyancy cap according to the present invention

Figure 4 is an exemplary view showing a modified configuration of the buoyancy cap according to the invention

5 is an exemplary view showing a state in which a plurality of struts and buoyancy cap is installed in the cargo hold

DESCRIPTION OF THE REFERENCE NUMERALS

(100): cargo hold (110): floor panel

120: lower chamfer panel 130: vertical panel

140: upper chamfer panel 150: top panel

(200): cargo hold insulation structure (210): primary insulation board

220: secondary insulation plate 230: primary barrier

(240): secondary barrier (250): mounting hole

300: liquid cargo 310: sleep

400: Shoring 410: Stopper

(500): buoyancy cap (510): insertion hole

(520): horizontal plate (521): communication hole

(530): Rotating Wings (531): Wing Body

(532): outer rotor (533): inner rotor

(600): airtight connection (610): stud bolt

620: Nut

Claims (10)

A double bottom panel constituting the bottom of the cargo hold, a lower chamfer panel extending inclined upwardly outward of the double bottom panel, a vertical panel vertically installed from the lower chamfer panel, and inclined inwardly upward from the vertical panel In the cargo hold consisting of a double-window structure comprising an upper chamfer panel and a top panel connecting the upper chamfer panel; A post installed in the cargo hold so as to be connected to the double bottom panel in the top panel; The prop is installed through, the rotary blade is formed along the outer circumferential surface at the lower end, it is configured to include a buoyancy cap that is moved to the top and rotates according to the change in the liquid level of the liquid cargo in the cargo hold, When the flow of the liquid cargo, the liquid cargo carrier cargo hold equipped with a sloshing suppression buoyancy cap, characterized in that the sloshing phenomenon is reduced by the buoyancy cap floating on the surface of the liquid cargo. The method of claim 1, The holding and buoyancy cap is a liquid cargo carrier cargo hold equipped with a buoyancy buoyancy cap for sloshing, characterized in that one or more installed in the cargo hold. The method according to claim 1 or 2; The struts are liquid cargo carrier cargo hold is installed buoyancy cap for sloshing suppression, characterized in that the stopper is further provided. The method according to claim 1 or 2; The strut is fixed to the top and bottom by a gas tight connection to the top panel and the double bottom panel, respectively, One end of the stud bolt is welded to the double bottom panel (or top panel) to be located in the installation hole formed through the heat insulation structure, and the support is connected to the other end protruding into the cargo hold by the nut through the heat insulation structure. The liquid cargo carrier cargo hold equipped with a buoyancy cap for sloshing suppression, characterized in that the insulation is inserted and filled in the installation hole is inserted into the stud bolt and the top of the insulation structure and the stud bolt is welded to maintain the airtightness and insulation of the cargo hold. The method according to claim 1 or 2; The buoyancy cap is formed in the center of the insertion hole through which the strut is inserted, the horizontal plate formed integrally with the insertion hole, and a plurality of rotary wings are formed inclined downward along the outer circumferential surface of the horizontal plate Cargo hold cargo hold equipped with a buoyancy cap for sloshing suppression. The method according to claim 5; Liquid cargo carrier cargo hold is installed in the horizontal plate is a buoyancy cap for suppressing sloshing characterized in that a plurality of communication holes are further formed. The method according to claim 5; The rotary wing is characterized by consisting of a wing body, an outer rotary wing protruding in the outward direction of the buoyancy cap based on the wing body, and an inner rotary wing formed to protrude in the inner direction of the buoyancy cap relative to the wing body. Cargo hold of liquid cargo ship with buoyancy cap for sloshing suppression. The method according to claim 5; The rotary wing is a liquid cargo carrier cargo hold equipped with a buoyancy cap buoyancy cap characterized in that consisting of a wing body, and an outer rotary wing protruding in the outward direction of the buoyancy cap based on the wing body. The method according to claim 5; The rotary wing is a liquid cargo carrier cargo hold equipped with a buoyancy cap buoyancy cap, characterized in that consisting of the wing body, and the inner rotary wing is formed to protrude in the inner direction of the buoyancy cap with respect to the wing body. The method according to claim 5; If one buoyancy cap is installed in the cargo hold, The buoyancy cap is the angle of inclination (α) formed by the horizontal plate and the rotary blade is less than or equal to the inclination angle (β) formed by the top panel and the upper chamfer panel, The length L1 of the rotary blade is formed within 50% of the length L2 of the upper chamfer panel, and the diameter H1 of the horizontal plate 520 of the buoyancy cap is 80 of the width H2 of the top panel 150. Liquid cargo carrier cargo hold equipped with a buoyancy cap for sloshing suppression, characterized in that formed within%.

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