KR20110017179A - Cargo having sloshing reduction structure - Google Patents

Abstract

PURPOSE: A cargo with a sloshing reduction structure is provided to remarkably reduce sloshing energy generated by a movable space by reducing the width between inner walls of the cargo. CONSTITUTION: A cargo with a sloshing reduction structure comprises a damping block(110). The damping block reduces the width between inner walls of the cargo. The damping block is protruded from the inner bottom(102) of the cargo in order to reduce the sloshing of liquefied natural gas. The side walls(112) of the damping block are inclined in order to smoothly flow the liquefied natural gas. The center of the inner bottom of the damping block has a sloshing reduction structure.

Description

Cargo hold with sloshing reduction structure {CARGO HAVING SLOSHING REDUCTION STRUCTURE}

The present invention relates to a cargo hold having a sloshing reduction structure, and more particularly, to a sloshing phenomenon caused by the flow of fluid such as liquefied natural gas partially filled in the cargo hold during operation or berthing of the ship. A cargo hold with a sloshing reducing structure is also possible.

In general, liquefied natural gas (LNG) refers to a colorless, transparent cryogenic liquid whose natural gas, which contains methane as its main component, is cooled to -163 ° C and its volume is reduced to one hundredth.

As such liquefied natural gas has emerged as an energy resource, an efficient transportation method that can transport a large amount from the production base to the receiving site of the demand has been considered in order to use this gas as energy. LNG carriers have been shown.

LNG carriers are to be provided with cargo holds to store them for storage and transportation of liquefied liquefied natural gas at cryogenic conditions. In this case, the cargo hold is made of materials that can withstand ultra low temperatures, such as aluminum alloy, stainless steel, 35% nickel steel, etc., to store liquefied natural gas having a medium pressure higher than atmospheric pressure and a boiling temperature of -163 ° C. It is necessary to design a design that can cope with thermal stress and heat shrinkage, and to install an insulation structure to prevent thermal intrusion.

1 is a view schematically showing a LNG carrier having a cargo hold.

As shown in FIG. 1, the LNG carrier 1 has the exception of the power unit 7 which generates thrust used to propel the residential part 5 where the crew resides and the LNG carrier 1. A plurality of cargo holds 10 are formed in most hull zones.

Cargo hold 10 is a place for storing the liquefied natural gas transported by the liquefied natural gas carrier (1). In the space between the cargo hold 10 is a compartment of the cofferdam (9, Cofferdam) is arranged, and is provided with a device for heating the air therein is delivered from the cargo hold 10 that stores the cryogenic liquefied natural gas It serves to protect the hull bulkhead from cold.

Figure 2 is a cross-sectional view schematically showing the cargo hold structure of the conventional LNG carrier.

In the membrane-shaped cargo hold 10, generally, the secondary barrier 12 of the insulation panel, which is attached and fixed to the inside of the hull 11 by stud bolts (not shown), and is welded on the upper side of the secondary barrier 12. It is composed of the primary barrier 14 of the corrugation membrane (Corrugation Membrane) to be fixed to keep warm and sealed.

By the way, offshore structures such as LNG LNG carriers (LNGCs) or floating liquefied natural gas storage evaporation units (FSRUs) that are anchored and operated in one place may be damaged by sea conditions, such as waves or sea winds. The entire structure is shaken, and the liquefied natural gas stored in the cargo hold 10 is flowed together by the shaking of the structure itself. In particular, when the level of the liquefied natural gas is low liquid liquefied natural gas flows to hit the inside of the cargo hold 10, this phenomenon is referred to as a sloshing load (sloshing load).

The damage inside the cargo hold 10 due to such sloshing tends to increase as the size of the cargo hold 10 increases, which is a great constraint in designing the size of the cargo hold 10 in large size. In particular, in the case of floating LNG storage vaporization facilities that are operated for a long time in a specific sea area, and in the case of liquefied natural gas carriers that operate in bad sea environment, the restriction due to this sloshing is a very important design factor.

Therefore, there is a need for a cargo hold having a liquefied natural gas sloshing reduction function applicable to a liquefied natural gas carrier or a floating liquefied natural gas storage vaporization facility for storing and operating liquefied natural gas.

The present invention has been invented to solve the above problems, the object of the present invention is to provide a buffer block to the inner bottom of the cargo hold to greatly alleviate the sloshing energy during low liquid level, as a buffer block between the inner wall of the cargo hold. It is to provide a cargo hold that can reduce the width and greatly alleviate the sloshing energy generated by the large flow space.

In order to achieve the above object, according to the present invention, the buffer block protrudes from the inner bottom of the cargo hold to serve to reduce the width between the inner wall of the cargo hold to reduce the sloshing phenomenon of the flowing liquefied natural gas, A sidewall of the buffer block is provided with a sloshing reduction structure formed with an inclined surface so that the liquefied natural gas flows smoothly with the buffer block interposed therebetween.

And the buffer block is provided along the longitudinal direction in the center of the inner bottom, extending to the heat insulating material and the primary barrier constituting the cargo hold, or may be formed to protrude as a material resistant to cryogenic deformation.

According to the cargo hold provided with the sloshing reduction structure of the present invention, by protruding a buffer block that can reduce the sloshing phenomenon at low liquid level in the inner bottom of the cargo hold, the sloshing energy is greatly alleviated so that the dynamic load acting on the wall surface of the cargo hold. It has the effect of greatly reducing the safety of the cargo hold for loading liquefied natural gas.

Hereinafter, one embodiment of the present invention will be described in more detail with reference to the accompanying drawings so that those skilled in the art can easily practice, but this is only an example, the present invention is limited thereto. It doesn't happen.

3 is a front sectional view of a cargo hold provided with a sloshing reduction device according to an embodiment of the present invention, Figure 4 is a side view of a cargo hold provided with a sloshing reduction device according to an embodiment of the present invention.

As shown in FIG. 3, the cargo hold provided with the sloshing reduction structure of the present embodiment includes a cargo hold 100 filled with liquefied natural gas and a buffer formed at the inner inner bottom 102 side of the cargo hold 100. Block 110.

In this case, the cargo hold 100 may be a marine structure such as a liquefied natural gas carrier (LNGC) or a floating liquefied natural gas storage evaporation unit (FSRU) that is anchored and operated in one place.

The cargo hold 100 shows a membrane type in a basic form, but it may be applicable to a cargo hold or a modified cargo hold.

The buffer block 110 is installed to reduce the sloshing phenomenon due to the flow of the liquefied natural gas at the time of operation or anchored in the cargo hold 100 is filled with low liquefied natural gas, as shown in FIG. It is installed in the longitudinal direction along the center of the inner bottom 102 so as to reduce the width between the inner wall of the 100, by the impact applied to the buffer block 110 during the flow of liquefied natural gas in the low liquid state Since another sloshing phenomenon may occur, the side wall of the buffer block 110 may be formed as a gentle slope 112 with respect to both the longitudinal direction and the width direction.

The buffer block 110 is configured to extend to the heat insulating material and the primary, secondary barriers constituting the cargo hold 100, or the buffer block 110 can be formed to protrude as a heat insulating material resistant to cryogenic deformation.

Furthermore, the buffer block 110 may be formed in plural as another example.

The action of the cargo hold with the sloshing reduction structure made of such a structure is as follows.

The sloshing phenomenon may occur due to waves or tidal currents during operation or anchoring of the liquefied natural gas carrier. In the present invention, the liquefied natural gas flows before the flow pressure is applied to the side of the cargo hold 100. Flow pressure is applied to the buffer block 110 protruding to a predetermined length so as to divide the left and right.

That is, the buffer block 110 is installed protruding in the center of the cargo hold 100, serves to reduce the width between the inner wall surface of the cargo hold 100 to reduce the sloshing energy, the liquefied natural gas is reduced the flow pressure It may flow smoothly along the inclined surface 112 of the block 110.

Therefore, according to the above, the sloshing phenomenon is remarkably reduced through the buffer block 110 installed in the inner bottom 102 of the cargo hold 100, thereby ensuring more improved safety and reliability, the super large cargo hold ( 100) It may be possible to manufacture.

As described above as a specific embodiment of the cargo hold having a sloshing reduction structure according to the present invention, but this is only an example, the present invention is not limited thereto, and has the broadest range in accordance with the basic idea disclosed herein. Should be interpreted. Those skilled in the art can easily change the material, size, etc. of each component according to the application field, and can be combined / substituted the disclosed embodiments to implement a pattern of a timeless shape, but this also does not depart from the scope of the present invention will be. It will be apparent to those skilled in the art that various changes and modifications may be readily made without departing from the spirit and scope of the invention as defined by the appended claims.

1 is a view schematically showing a conventional LNG carrier having a cargo hold,

2 is a cross-sectional view schematically showing a cargo hold structure of a conventional LNG carrier;

3 is a front sectional view of a cargo hold provided with a sloshing reducing apparatus according to an embodiment of the present invention,

4 is a side view of a cargo hold equipped with a sloshing reducing device according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: cargo hold 102: inner bottom

110: buffer block 112: inclined surface

Claims (3)

The buffer block protrudes from the inner bottom of the cargo hold so as to reduce the width between the inner walls of the cargo hold and reduce the sloshing phenomenon of the liquefied natural gas flowing. A cargo hold having a sloshing reduction structure in which sidewalls of the buffer block are formed on an inclined surface to smoothly flow the liquefied natural gas with the buffer block interposed therebetween. The method of claim 1, The buffer block is, Cargo hold having a sloshing reduction structure is provided along the longitudinal direction in the center of the inner bottom. The method of claim 1, The buffer block is, A cargo hold provided with a heat insulating material constituting the cargo hold and a sloshing reduction structure which extends to the primary and secondary barriers or protrudes from a material resistant to cryogenic deformation.

Images