KR100747378B1 - Lng vessel with a pressure decreasing apparatus arranged on a turret - Google Patents

Abstract

An LNG vessel with a pressure decreasing apparatus arranged on a turret is provided to prevent damage to the interior of the turret by discharging an explosion pressure outside the turret by a cover even when an explosion is generated in the turret. A cover is provided in an LNG regasification ship. A pressure decreasing apparatus includes a cover opened to discharge pressure due to an explosion outside a turret when the explosion is generated due to leakage of natural gas and the pressure in the turret increases. The cover includes a frame(31) and a plurality of opening members(32,42). The opening members are attached to the frame and are opened if the explosion occurs in the interior of the turret.

Description

LNG ship with pressure reducing device installed on turret

1 is a schematic diagram schematically showing an LNG regasification system installed in an LNG regasification vessel according to the present invention;

2 is a view showing a turret of an LNG regasification vessel in which a pressure reducing device according to the present invention is installed;

3 is a partially enlarged cross-sectional view of the pressure reducing device;

4A and 4B are plan views of a pressure reducing device according to various embodiments of the present disclosure.

<Description of Symbols for Major Parts of Drawings>

2: ship 3: turret

4: buoy 6: subsea terminal

10: offshore LNG regasification system 21: connector

30, 40: cover as pressure reducing device 31: frame

32, 42: opening member

The present invention relates to an LNG vessel, and more particularly, to an LNG regasification system for regasifying Liquified Natural Gas (LNG) and supplying natural gas in a regasified gas state to an onshore requirement. The present invention relates to an LNG vessel having a pressure reducing device installed in a turret of a LNG regasification vessel.

In recent years, the consumption of natural gas is rapidly increasing worldwide. Natural gas is transported in a gaseous state through onshore or offshore gas piping, or to a remote consumer while stored in an LNG carrier (especially an LNG carrier) in the form of liquefied natural gas. Liquefied natural gas is obtained by cooling natural gas to cryogenic temperature (approximately -163 ℃), and its volume is reduced to about 1/600 than natural gas in gas state, so it is very suitable for long distance transportation through sea.

The LNG Carrier is designed to unload liquefied natural gas to the land requirements by loading the liquefied natural gas into the sea, and for this purpose, an LNG storage tank (commonly referred to as a 'cargo') that can withstand the cryogenic temperature of the liquefied natural gas. It includes. Normally, such LNG transport ships unload liquefied natural gas in LNG storage tanks as they are liquefied, and the unloaded LNG is regasified by LNG regasification facilities installed on land and then transported through gas piping to consumers of natural gas. do.

Such onshore LNG regasification facility is known to be economically advantageous when installed in a place where there is a demand for natural gas because the natural gas market is well formed. However, in the case of natural gas demand where the demand for natural gas is seasonal, short-term or periodic, it is economically disadvantageous to install LNG regasification facilities on land due to the high installation cost and management cost.

In particular, if a land LNG regasification facility is destroyed due to a natural disaster or the like, even if an LNG carrier arrives at a required destination, the LNG cannot be regasified. Holding it.

As a result, for example, an offshore LNG regasification system has been developed in which an LNG regasification facility is provided on an LNG carrier to regasify liquefied natural gas at sea and supply natural gas obtained through regasification to the land. In addition, the prior art associated with such an offshore LNG regasification system include Korean Patent No. 0569621 (ExxonMobil Oil Corporation, Method and System for Gasification of Liquefied Natural Gas on a Ship), and US Patent No. 6,546,739 (Exmar Offshore Company, Method and apparatus for offshore LNG regasification, US Pat. No. 6,578,366 (Moss Maritime AS, Device for evaporation of liquefied natural gas), US Pat. No. 6,688,114 (El Paso Corporation LNG CARRIER, US Pat. No. 6,598,408, El Paso Corporation, Method and apparatus for transporting LNG), Korean Patent No. 0467963 (Kang Do-wook, Al & G Alv operation method), US Patent No. 6,945,049 (Hamworthy KSE as, Regasification system and method), Korean Patent No. 0504237 (Daewoo Shipbuilding & Marine Engineering) Co., Ltd., a vessel equipped with shielding means to block the bottom opening, Korea Patent No. 0474522 (Daewoo Shipbuilding & Marine Engineering Co., Ltd. System), Korean Patent Publication No. 2003 -0090686 (Life Hoeg Unt.A.S., Ship and Unloading System), US Patent Publication No. 2005-0061002A (Shipboard regasification for LNG carriers with alternate propulsion plants), Korean Patent Publication No. 2004-0105801 (Excelate Energy Limited Partnership, Improved LNG Carrier), and Korean Utility Registration No. 0410836 (Samsung Heavy Industries Co., Ltd., Liquefied Natural Gas Regasification System).

The conventional LNG regasification vessel is equipped with a facility such as a vaporizer in the vessel for regasification of the liquefied natural gas stored in the LNG storage tank, and in addition, the piping in the system to supply the regasified natural gas to the land requirements And a connecting device for connecting the gas piping to the land requirements, and a ship position maintaining device for maintaining the position of the ship while the natural gas is unloaded.

In order to connect the piping of LNG regasification ship and the pipe of the land, a structure called a turret is provided in the ship, and since the ship is floating while floating on the sea, the turret connecting the ship's pipe and the land pipe to each other The inventors have found that there is a risk of leakage of natural gas regasified from the vessel and supplied to the land.

If natural gas leaks between pipes and the concentration of natural gas is more than 3%, it will meet the conditions for explosion. As such, when an explosion occurs in a turret that is in a sealed state due to an explosion condition, serious damage may be caused to the hull around the turret.

The present invention is to solve such a problem, an object of the present invention, even if an explosion occurs due to the leakage of natural gas in the turret provided in the vessel for connecting the piping of the LNG regasification vessel and the land piping, It is to provide a pressure reducing device of the turret that can guide the explosion pressure toward the top of the turret to release the outside of the turret to prevent damage to the inside of the turret, further to prevent damage to the hull.

According to an aspect of the present invention for achieving the above object, as a cover provided in the turret provided in the LNG regasification ship to connect the piping of the LNG regasification ship and the land of the LNG regasification vessel provided with a marine LNG regasification system, When the explosion occurs due to the leakage of gas to increase the pressure in the turret, the cover is installed on the turret of the LNG regasification vessel, characterized in that it comprises a cover that is open to release the pressure due to the explosion outside the turret A pressure reducing device is provided.

Here, the cover is preferably made of a frame and a plurality of opening members attached to the frame and opened when an explosion occurs in the turret.

In addition, the plurality of opening members may be arranged such that one end is fixed to the frame and the other end is overlapped on another opening member, whereby the opening member is normally provided with sea water or rain water of the turret. While preventing the flow into the inside, when the explosion occurs inside the turret, the other end side of the opening member is bent upward to open the turret.

Alternatively, the plurality of opening members may be arranged such that one end thereof is opened and closed by a hinge to the frame, and the other end thereof is arranged to overlap on another opening member, whereby the opening member is normally seawater. While preventing rain water from flowing into the turret, when the explosion occurs inside the turret, the turret is opened by turning about the hinge.

In addition, the opening member is preferably arranged to be gradually lowered toward the periphery from the center of the cover.

In addition, the cover is preferably detachably mounted on the top of the turret.

In addition, according to another aspect of the present invention, in order to connect the piping of the LNG regasification vessel provided with an offshore LNG regasification system and the land piping, a cover is installed on the turret provided in the LNG regasification vessel, the interior of the turret When the explosion occurs due to the leakage of natural gas in the air, the pressure reduction method is provided in the turret of the LNG regasification vessel, characterized in that the cover is opened by the explosion pressure to release the explosion pressure to the outside of the turret.

(Example)

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

1 shows an offshore LNG regasification system provided in an LNG regasification vessel according to an embodiment of the present invention. As shown in Fig. 1, the system 10 of the present embodiment is installed on a ship 2, and after re-gasification of the liquefied natural gas into a natural gas in a gas state with the ship 2 mooring at sea. This is supplied to the land requirements (not shown) via the subsea terminal 6.

Although the system 10 of the present embodiment has been described as being installed in an LNG regasification vessel having a transport function of liquefied natural gas, the system of the present embodiment is applied to another offshore floating structure on the sea which receives liquefied natural gas from an LNG carrier and regasifies it. 10 may be installed.

The system 10 of the present embodiment includes an LNG storage tank 11, a suction drum 12 for temporarily storing liquefied natural gas drawn up from the LNG storage tank 11, and the suction drum 12. A plurality of high pressure pumps 13 (only one is shown in FIG. 1) for pressurizing the supplied liquefied natural gas to a high pressure, and the liquefied natural gas which is boosted and supplied from each of the plurality of high pressure pumps 13 to provide a heat exchange medium. And a plurality of vaporizers 14 for regasification.

As the heat exchange medium, sea water or fresh water may be used, or an intermediate heat exchange medium (eg, propane, ethane, ammonia, etc.) may be used together (see US Patent No. 6,945,049).

In order to supply the regasified natural gas to the land (that is, unloading), the gas pipe of the ship and the land pipe (especially the pipe installed on the land quay) using the gas pipe of the seabed, or directly without the sea gas pipe. A method of connecting the same may be used.

In the present embodiment, the method using the subsea gas piping 7, and inter alia, the buoy 4 of the seabed is connected to the turret 3 of the ship, so that the LNG regasification system 10 and the subsea terminal 6 on the ship are connected. The Submerged Turret Loading (STL) method, which is a method of connecting between the buoy 4 and the riser 9, is used. However, this STL scheme may be modified in various forms and is not intended to limit the present invention.

2 shows a state in which the buoy 4 is coupled to the bottom of the turret 3 provided on the vessel 2. As shown in FIG. 2, the turret 3 has a generally circular or elliptical tubular shape, and the lower diameter of the turret 3 is enlarged relative to the upper diameter so that the buoy 4 can be engaged.

As described above, the buoy 4 moored below the sea level is coupled to the lower end of the turret 3 of the ship, and then the top of the connector 21 and the buoy 4, which are ends of the LNG regasification system 10 on the ship. By connecting the connection between the LNG regasification system 10 on the ship and the land side pipe.

At this time, since the ship inevitably flows due to the wave, the natural gas leaks between the pipe connection points inside the turret 3, that is, between the connector 21 and the buoy 4, and an explosion may occur.

Since the covers 30 and 40 are covered at the top of the turret 3 to prevent the inflow of seawater or rainwater due to the waves, the inside of the turret 3 is almost sealed, so the explosion pressure is increased when an explosion occurs. There is a possibility that it will act on the inner wall surface and the hull of the turret 3 as it is.

According to the present invention, since the cover (30, 40) has a structure that can be opened when an explosion occurs in the turret (3), the damage inside the turret by releasing the pressure inside the turret increased by the explosion to the outside It serves as a pressure reducing device inside the turret that can prevent and further prevent damage to the hull.

As shown in FIG. 3, the lids 30 and 40 as the pressure reducing device include a frame 31 and a plurality of opening members 32 and 42 attached to the frame 31. The two opening members 32 and 42 are arranged attached to the frame 31 in the form of tile roofs or scales.

The opening members 32 and 42 may be bent upward when the explosion occurs in the turret 3 to open the top of the turret 3.

One end side of the opening members 32 and 42 is attached to the frame 31 by a method such as pressure welding, and the other end side thereof is overlapped on the other opening members 32 and 42. As described above, the plurality of opening members 32 and 42 are arranged to overlap each other, so that seawater or rainwater due to waves can be prevented from flowing into the turret 3.

In addition, the opening members 32 and 42 are arranged to have a sloped shape that gradually decreases toward the periphery from the center point or the center line passing through the center of the cover 30 and 40 so that the sea water or the rain water flows down naturally. It is preferable. In addition, it is preferable that the frame 31 is formed to be gradually lowered toward the periphery of the cover 30 and 40 so that the opening members 32 and 42 may be inclined as described above.

The frame 31 is preferably made of a material such as a hollow pipe having a suitable strength so as not to be damaged during an explosion, and may have a rounded shape of a lower surface so that the explosion pressure does not directly affect.

The opening members 32 and 42 are preferably made of a material having corrosion resistance against seawater, for example, stainless steel (SUS316, etc.), and may have a thickness that can be bent upward when an explosion occurs in the turret 3. For example, it is preferable to have thickness of about 0.5-1t.

When the thickness of the opening members 32 and 42 is thinner than 0.5t, deformation may occur when a load is applied, such as an operator or the like, on the covers 30 and 40, which is not preferable. , 42) thicker than 1 ton is not preferable because there is a fear that the upper part of the turret (3) may not be opened during the explosion.

4A and 4B show top views of lids 30 and 40 in accordance with various embodiments of the present invention. Cover 30 according to the embodiment shown in Figure 4a is made of the opening member 32 is arranged symmetrically to the left and right, the cover 40 according to the embodiment shown in Figure 4b is the opening member 42 is radial It is arranged as

Here, depending on how the opening members 32 and 42 are arranged, the shape of each of the opening members 32 and 42 may be deformed into a rectangle or a fan shape, but the arrangement of the opening members 32 and 42 may be changed. The present invention is not limited by the shape or shape.

In addition, for the convenience of repairing or replacing the various equipment in the turret (3), the cover (30, 40) is detachably mounted on the top of the turret (3) by a bolt (not shown) or the like. desirable.

In addition, when the explosion occurs in the turret 3 has been described as opening the upper portion of the turret by bending the opening members 32 and 42 welded to the frame 31, the opening members 32 and 42 have been described. In addition to being fixed to the frame 31, it may be provided to be opened and closed by a hinge (not shown) or the like.

While the invention has been described above with reference to specific embodiments, various modifications, changes or modifications may be made in the art within the spirit of the invention and the appended claims, and thus the foregoing description and drawings illustrate It should be construed as illustrating the present invention, not limiting the technical spirit of the invention.

According to the present invention as described above, even if an explosion occurs due to the leakage of natural gas in the turret provided in the vessel for connecting the piping of the LNG regasification vessel and the land piping, the explosion pressure is directed toward the upper end of the turret There is provided a cover as a pressure reducing device capable of releasing to the outside of the turret.

Therefore, according to the present invention, even if an explosion occurs inside the turret, the explosion pressure can be released to the outside of the turret by the cover, it is possible to prevent damage to the inside of the turret, and further to prevent damage to the hull.

Claims (7)

As a cover installed in the turret provided in the LNG regasification ship to connect the piping of the LNG regasification ship equipped with an offshore LNG regasification system and the onshore piping, Installed in the turret of the LNG regasification vessel, characterized in that it includes a cover that is open to release the pressure due to the explosion to the outside of the turret when the explosion caused by the leakage of natural gas is increased Pressure reducing device. The method according to claim 1, The cover is installed on the frame and the turret of the LNG regasification vessel, characterized in that consisting of a plurality of opening members attached to the frame and opened when the explosion occurs inside the turret. The method according to claim 2, The plurality of opening members are arranged such that one end is fixed to the frame and the other end is superimposed on another opening member, Accordingly, the opening member prevents sea water or rainwater from flowing into the turret during normal use, and when the explosion occurs inside the turret, the other end of the opening member is bent upward to open the turret. A pressure reducing device installed on the turret of the LNG regasification vessel characterized in that. The method according to claim 2, A plurality of the opening member is arranged so that one end side can be opened and closed by a hinge to the frame, the other end side is arranged to overlap on another opening member, Accordingly, the opening member prevents sea water or rainwater from flowing into the turret during normal use, and when the explosion occurs inside the turret, turns the hinge around the hinge to open the turret. Pressure reducing device installed on turret of regasification vessel. The method according to claim 3 or 4, The opening member is a pressure reducing device installed in the turret of the LNG regasification vessel, characterized in that arranged to be gradually lowered toward the periphery from the center of the cover. The method according to any one of claims 1 to 4, The cover is a pressure reducing device installed on the turret of the LNG regasification ship, characterized in that detachably mounted on the top of the turret. In order to connect the piping of the LNG regasification vessel with the offshore LNG regasification system and the land piping, a cover is installed on the turret provided in the LNG regasification vessel, and an explosion may occur due to the leakage of natural gas inside the turret. When the cover is opened by the explosion pressure to release the explosion pressure to the outside of the turret.

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