KR20220049392A - Marine structure - Google Patents

Abstract

The present invention provides a marine structure floating in seawater. The marine structure comprises: a hull; a tank unit installed on the hull and storing fluid; and a controller for controlling the tank unit. The tank unit can include: a first tank in which a sloshing prevention member is installed; a plurality of second tanks having a structure different from the structure of the first tank; a plurality of fluid pipes for moving the fluid between the plurality of second tanks; and a plurality of valves installed on each of the plurality of fluid pipes. The controller can control the opening and closing of the valve selected from among the plurality of valves to maintain the amount of the fluid stored in the plurality of second tanks to be equal to or greater than a set upper limit value or equal to or less than a set lower limit value as the fluid stored in the tank unit is consumed. The present invention can minimize the manufacturing costs of the marine structure.

Description

Offshore structures {MARINE STRUCTURE}

The present invention relates to offshore structures.

According to recent technological development, liquefied gas such as liquefied natural gas (LNG) and liquefied petroleum gas (LPG) is widely used to replace gasoline or diesel.

Liquefied natural gas is liquefied by cooling methane obtained by refining natural gas collected from a gas field. It is a colorless and transparent liquid with few pollutants and high calorific value. On the other hand, liquefied petroleum gas is a fuel made into liquid by compressing the gas containing propane (C3H8) and butane (C4H10) together with petroleum from oil fields at room temperature. Liquefied petroleum gas, like liquefied natural gas, is colorless and odorless and is widely used as fuel for household, business, industrial, and automobile use.

Such liquefied gas is stored in a liquefied gas storage tank installed on the ground or stored in a liquefied gas storage tank provided in a transportation means sailing the ocean. Liquefied natural gas is reduced to a volume of 1/600 by liquefaction, and liquefied petroleum gas is reduced to a volume of 1/260 of propane and 1/230 of butane by liquefaction, which has the advantage of high storage efficiency.

For example, liquefied natural gas (LNG) is obtained by cooling natural gas to a cryogenic temperature (about -163 ℃), and since its volume is reduced to about 1/600 of that of natural gas in gaseous state, it is transported over a long distance by sea very suitable for

LNG carrier for loading and unloading LNG to onshore demand by operating the sea, or LNGRV (Regasification Vessel), which loads LNG and operates the sea to arrive at onshore demand, regasifies the stored LNG and unloads it into natural gas; LNG FPSO (Floating, Production, Storage and Offloading) is used to liquefy and store the produced natural gas directly at sea and, if necessary, transfer the stored LNG to an LNG carrier. After storing the LNG unloaded from the LNG carrier at sea An LNG FSRU (Floating Storage and Regasification Unit) that vaporizes LNG as needed and supplies it to onshore demand includes a storage tank (aka, 'cargo hold') that can withstand the cryogenic temperature of LNG.

In this way, in offshore structures such as LNG carriers, LNG RVs, LNG, FPSOs, LNG FSRUs, and FLNGs that transport or store liquefied gas such as LNG at sea, a storage tank for storing LNG in a cryogenic liquid state is installed. .

These storage tanks can be classified into independent type and membrane type depending on whether the load of cargo acts directly on the insulation material, and in general, membranous storage tanks are NO 96 type and Mark Ⅲ It is divided into two types, and the independent storage tank is divided into MOSS type and IHI-SPB type. In general, among the membranous storage tanks, the NO 96 storage tank is a primary barrier and a secondary barrier made of Invar steel (36% Ni), and a plywood box (Plywood Box) and perlite The primary and secondary insulating walls made of (Perlite) and the like are alternately laminated and installed on the inner surface of the hull, and the Mark Ⅲ type storage tank includes a primary barrier made of stainless steel membrane and A secondary barrier made of a triplex, a primary insulating wall and a secondary insulating wall made of polyurethane foam, etc. are alternately laminated and installed on the inner surface of the hull.

In addition, the independent storage tank is made by attaching a relatively hard insulation panel such as polyurethane to a tank body made of an alloy resistant to low temperature such as aluminum alloy or SUS, and 9% nickel, and a plurality of tanks arranged on the inner bottom of the hull placed on a support.

Even if the vessel is shaken by waves when the liquefied gas such as LNG or LPG is filled inside the storage tank, the impact caused by sloshing on the side wall and ceiling structure of the storage tank due to the flow of liquid seldom transmitted. Sloshing refers to a phenomenon in which a liquid material contained in a storage tank, ie, LNG, flows when a ship or a floating structure moves in various sea conditions. When there is an empty space inside the storage tank, that is, when a part of the space is filled with liquefied gas, the wall and ceiling of the storage tank are severely impacted by sloshing due to the flow of the fluid. In particular, sloshing occurs largely when the storage tank is filled with liquefied gas, about 10% to 70%.

Accordingly, in general, various structures that can prevent sloshing are installed in the storage tank. However, when installing various structures capable of preventing sloshing in the storage tank as described above, there is a problem of increasing the manufacturing cost of the storage tank.

An object of the present invention is to provide an offshore structure capable of minimizing the manufacturing cost of the offshore structure floating in seawater.

In addition, an object of the present invention is to provide an offshore structure capable of minimizing the manufacturing cost of the tank unit of the offshore structure.

In addition, an object of the present invention is to provide an offshore structure capable of minimizing the occurrence of sloshing in the tank, even if the sloshing prevention member is not installed in the tank.

The object of the present invention is not limited thereto, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

The present invention provides an offshore structure floating in seawater. Offshore structures include a hull; a tank unit installed on the hull and storing a fluid; and a controller for controlling the tank unit, wherein the tank unit includes: a first tank in which a sloshing prevention member is installed; a plurality of second tanks having a structure different from that of the first tank; a plurality of fluid pipes for moving the fluid between the plurality of second tanks; a plurality of valves installed in each of the plurality of fluid pipes; The controller is configured to control the valve selected from among the plurality of valves to maintain an amount of the fluid stored in the plurality of second tanks greater than or equal to a set upper limit value or less than or equal to a set lower limit value as the fluid stored in the tank unit is consumed. Opening and closing can be controlled.

According to an embodiment, when the fluid stored in the plurality of second tanks is consumed and the amount of the fluid stored in the plurality of second tanks reaches the set upper limit value, the controller is configured to select the plurality of second tanks. The opening and closing of the valve may be controlled such that the fluid stored in the second tank selected from among the plurality of second tanks is transferred to the remaining second tank.

According to an embodiment, the controller is configured to, when the fluid stored in the second tank selected from among a plurality of second tanks is consumed and the amount of the fluid stored in the selected second tank reaches the set upper limit value, the selected Opening and closing of the valve may be controlled so that the fluid stored in at least one of the second tanks is transferred to the remaining second tanks among the selected second tanks.

According to an embodiment, the controller is configured to maintain the amount of the fluid stored in the selected second tank more than the set upper limit value even if the fluid stored in the second tank selected from among the plurality of second tanks is consumed. Opening and closing of the valve may be controlled so that the fluid is delivered to the second tank selected from at least one of the second tanks.

According to an embodiment, the controller is configured to, when the fluid stored in the second tank selected from among a plurality of second tanks is consumed and the amount of the fluid stored in the selected second tank reaches the set upper limit value, the selected second tank The fluid stored in at least one of the two tanks is transferred to at least one of the remaining second tanks, and the opening and closing of the valve is controlled so that the amount of the fluid stored in the remaining second tank is less than or equal to the set lower limit value. can do.

According to an embodiment, the second tanks may be disposed inside the hull along the vertical direction.

According to an embodiment, the set upper limit value may be 70% of the amount of the fluid that the second tank can store at a maximum.

According to an embodiment, the set lower limit value may be 10% of the amount of the fluid that the second tank can maximum store.

According to an embodiment, the sloshing preventing member may not be installed in the second tank.

According to an embodiment of the present invention, it is possible to minimize the manufacturing cost of the offshore structure floating in seawater.

In addition, according to an embodiment of the present invention, it is possible to minimize the manufacturing cost of the tank unit of the offshore structure.

In addition, according to an embodiment of the present invention, even if the sloshing preventing member is not installed in the tank, it is possible to minimize the occurrence of sloshing in the tank.

Effects of the present invention are not limited to the above-described effects, and effects not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the present specification and accompanying drawings.

1 is a schematic view from above of an offshore structure according to an embodiment of the present invention.
Figure 2 is a schematic view of the marine structure of Figure 1 viewed from the side.
3 is a view showing a tank unit according to an embodiment of the present invention.
4 is a perspective view for explaining the basic configuration of the first tank.
5 is a side cross-sectional view of the first tank.
6 is a front cross-sectional view of the first tank.
7 is an enlarged view showing the main part of the boil-off gas passage formed in the bulkhead installed in the first tank.
8 is a perspective view for explaining the basic configuration of the second tank.
9 is a view showing a tank unit performing a preparation step in the fluid storage method according to an embodiment of the present invention.
10 is a view showing a tank unit that has performed the first step in the fluid storage method according to an embodiment of the present invention.
11 is a view showing a tank unit in which a second step is performed in the method for storing a fluid according to an embodiment of the present invention.
12 is a view showing a tank unit in which a third step is performed in the fluid storage method according to an embodiment of the present invention.
13 is a view showing a tank unit in which a fourth step is performed in the method for storing a fluid according to an embodiment of the present invention.
14 is a view showing a tank unit in which a fifth step is performed in the fluid storage method according to an embodiment of the present invention.
15 is a view showing a tank unit in which a sixth step is performed in the method for storing a fluid according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be implemented in several different forms and is not limited to the embodiments described herein. In addition, in describing a preferred embodiment of the present invention in detail, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions.

"Including" a certain component means that other components may be further included, rather than excluding other components, unless otherwise stated. Specifically, terms such as “comprise” or “have” are intended to designate that a feature, number, step, action, component, part, or combination thereof described in the specification is present, and includes one or more other features or It should be understood that the existence or addition of numbers, steps, operations, components, parts, or combinations thereof does not preclude the possibility of addition.

The singular expression includes the plural expression unless the context clearly dictates otherwise. In addition, shapes and sizes of elements in the drawings may be exaggerated for clearer description.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms may be used for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

When a component is referred to as being “connected” or “connected” to another component, it is understood that the other component may be directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle. Other expressions describing the relationship between components, such as "between" and "immediately between" or "neighboring to" and "directly adjacent to", etc., should be interpreted similarly.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted to have meanings consistent with the context of the related art, and are not to be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. .

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 15 .

1 is a schematic view of an offshore structure in accordance with an embodiment of the present invention viewed from the top, and FIG. 2 is a schematic view of the offshore structure of FIG. 1 as viewed from the side. 1 and 2 , an offshore structure 100 according to an embodiment of the present invention may include a hull 110 , a turret unit 130 , and a propulsion unit 150 .

A liquefied gas storage tank may be installed in the hull 110 . Liquefied gas such as LNG, LPG, or liquid nitrogen may be stored in the liquefied gas storage tank. That is, the offshore structure 100 may be a structure in which a liquefied gas storage tank is installed to transport or store liquefied gas at sea. For example, when the liquefied gas is LNG, it may be an LNG carrier, an LNG RV (Regasification Vessel), an LNG FPSO (Floating, Production, Storage and Offloading), or an LNG FSRU (Floating Storage and Regasification Unit).

A turret unit 130 may be installed in the hull 110 . The turret unit 130 may fix the position of the hull 110 on the seabed OF. The turret unit 130 may include a line fixing member 132 and a mooring line 134 . The line fixing member 132 may be installed on the hull 110 . The line fixing member 132 may be installed under the hull 110 . For example, the line fixing member 132 may be installed on the lower surface of the hull 110 to be submerged in seawater (SW). One end of the mooring line 134 may be connected to the line fixing member 132 . In addition, the other end of the mooring line 134 may extend to the seabed OF. For example, the other end of the mooring line 134 may be fixed to the seabed OF. In addition, a plurality of mooring lines 134 may be provided. The mooring lines 134 may be installed at the pivot center point C at which the hull 110 turns when viewed from above. Accordingly, when an external force is applied to the hull 110 by an external environment, the hull 110 may be rotated based on the pivot center point C when viewed from the top.

In the above-described example, mooring by a one-point mooring system such as the turret unit 130 has been described as an example, but the present invention is not limited thereto. For example, the hull 110 may be moored by a one-point mooring system such as a yoke mooring.

The propulsion unit 150 may generate thrust so that the hull 110 can be rotated based on the pivot center point (C). The propulsion unit 150 may be installed at the bow or stern of the hull 110 to adjust the bow angle of the hull 110 .

In addition, external forces such as waves (Wa), ocean currents (Cu), winds (Wi) may be transmitted to the hull 110 . The offshore structure 100 may include a controller 190 for controlling the propulsion unit 150 to maintain the bow angle at which the fluctuation of the hull 110 is minimized by the external force transmitted to the hull 110 . In addition, the offshore structure 100 may include a bow motion measurement system for measuring the degree of motion of the hull 110 and a wave measurement system for measuring the direction and wave height in which waves act. The controller may control the propulsion unit 150 by receiving the results measured by these bow motion measurement systems and wave measurement systems. Accordingly, according to the present invention, it is possible to actively control the bow angle of the hull 110 by operating the propulsion unit 150 by the controller 190 based on the results measured by various measurement systems. Accordingly, it is possible to maintain the operating state of various equipment installed in the hull 110 normally, and it is possible to minimize the occurrence of sloshing due to the liquefied gas stored in the storage tank.

When adjusting the bow angle of the hull 110 by the controller 190, it is not necessary to always match the bow angle with the direction of the wave (wave), and the bow angle may be within the allowed wave angle. This allowable wave angle can be automatically calculated in the controller as a predetermined value in consideration of wave characteristics (wave height, period, etc.).

In addition, the offshore structure 100 according to an embodiment of the present invention may include a tank unit. The tank unit can store liquefied gas such as LNG, LPG or liquid nitrogen. The fluid L that the tank unit stores may be such a liquefied gas. The tank unit may be installed on the hull 110 . The tank units 160 and 170 may include a first tank 160 and at least one or more second tanks 170 .

3 is a view showing a tank unit according to an embodiment of the present invention. Referring to FIG. 3 , the first tank 160 and the second tank 170 may have different internal structures. For example, the sloshing prevention member 165 to be described later may be installed in the first tank 160 , and the sloshing prevention member 165 may not be installed in the second tank 170 . A structure that the first tank 160 and the second tank 170 may have will be described later.

In addition, a plurality of second tanks 170 may be provided. For example, the second tank 170 may include tank 1 171 , tank 2 172 , tank 3 173 , tank 4 174 , tank 5 175 , and tank 6 176 . , and the 7th tank 177 may be included. In FIG. 3 , it has been described that the second tank 170 has seven tanks as an example, but the present invention is not limited thereto, and the number of the second tanks 170 may vary as needed.

Tank 1 171, Tank 2 172, Tank 3 173, Tank 4 174, Tank 5 175, Tank 6 176, and Tank 7 177 are , from the first tank 171 to the seventh tank 177 may be sequentially arranged in the direction from the bottom to the top. For example, the No. 1 tank 171 is disposed at the bottom, the No. 2 tank 172 is disposed thereon, the No. 3 tank 173 is disposed thereon, and the No. 4 tank 174 is disposed thereon. , on which the 5th tank 175 is disposed, the 6th tank 176 is disposed thereon, and the 7th tank 177 may be disposed thereon.

In addition, the tank unit may further include a plurality of fluid pipes (181, 182). For example, the fluid pipes 181 and 182 may provide a path for moving the fluid L between the plurality of second tanks 170 . For example, the fluid pipes 181 and 182 may include a first fluid pipe 181 and a second fluid pipe 182 . In addition, a first valve 183 may be installed in the first fluid pipe 181 . In addition, a second valve 184 may be installed in the second fluid pipe 182 . The first valve 183 and the second valve 184 may be an on/off valve or a flow control valve. The first fluid pipe 181 is a fluid movement path for transferring the fluid L from the second tank 170 of any one selected among the second tanks 170 to the second tank 170 disposed below it. can provide In addition, the second fluid pipe 182 is a fluid movement path for transferring the fluid L from any one of the second tanks 170 selected among the second tanks 170 to the second tank 170 disposed thereon. can provide For example, the first fluid pipe 181 may be provided between the No. 7 tank 177 and the No. 6 tank 176 . The first fluid pipe 181 may provide a fluid movement path for transferring the fluid from the 7th tank 177 to the 6th tank 176 . Since the fluid L flowing in the first fluid pipe 181 can flow downward by gravity, the installation of a pump is not required in the first fluid pipe 181 .

Also, the second fluid pipe 182 may be provided between the No. 7 tank 177 and the No. 6 tank 166 . The second fluid pipe 182 may provide a fluid movement path for transferring the fluid L from the sixth tank 176 to the seventh tank 177 . At this time, since the fluid L must move in the upward direction, the tank unit may further include a pump (not shown) capable of moving the fluid L in the upward direction. The pump may be installed in the second fluid pipe 182 .

In addition, the first fluid pipe 181 , the second fluid pipe 182 , the first valve 183 , the second valve 184 , and the pump may be provided between the adjacent second tanks 170 . . For example, the first fluid pipe 181 , the second fluid pipe 182 , the first valve 183 , the second valve 184 , and the pump are disposed between the first tank 171 and the second tank 172 . , between tank 2 172 and tank 3 173, between tank 3 173 and tank 4 174, between tank 4 174 and tank 5 175, 5 It may be installed between the No. tank 175 and the No. 6 tank 176 , and between the No. 6 tank 176 and the No. 7 tank 172 .

Also, the first tank 160 may be connected to the gas exhaust line 161a. The gas exhaust line 161a may exhaust the boil-off gas generated from the fluid L, which is a liquefied gas stored in the first tank 160 , to the outside of the first tank 160 .

Also, the second tank 170 may be connected to the gas discharge lines 171a, 172a, 173a, 174a, 175a, 176a, and 177a. For example, the first tank 171 is connected to the first gas discharge line 171a, the second tank 172 is connected to the second gas discharge line 172a, and the third tank 173 is the third gas. It is connected to the discharge line 173a, the fourth tank 174 is connected to the fourth gas discharge line 174a, the fifth tank 175 is connected to the third gas discharge line 175a, and the sixth tank Reference numeral 176 may be connected to the sixth gas discharge line 176a, and the seventh tank 177 may be connected to the third gas discharge line 177a. The gas discharge lines 171a, 172a, 173a, 174a, 175a, 176a, and 177a exhaust the boil-off gas generated from the fluid L, which is a liquefied gas stored in the second tank 170, to the outside of the second tank 170. can do.

The controller 190 may control the tank unit. For example, the controller 190 may control opening and closing of the first valve 181 and the second valve 182 . Also, the controller 190 may control a pump that may be installed in the second fluid pipe 182 . In addition, the tank unit has a first valve 181 based on a measurement value measured by a measurement member capable of measuring the amount of the fluid L stored in the first tank 160 and the second tank 170 . , and may control opening and closing of the second valve 182 and/or driving of the pump. In addition, when excessive sloshing occurs in the second tank 170 , the controller 190 evaporates in the gas exhaust line 160a rather than the gas exhaust lines 171a, 172a, 173a, 174a, 175a, 176a, 177a. The tank unit may be controlled so that the gas is exhausted and used as fuel required to operate the offshore structure 100 . That is, the controller 190 selects any one of the first tank 160 and the second tank 170 and uses the boil-off gas generated from the fluid L stored in the tank as a fuel required to operate the marine structure 100 . can be used as

4 is a perspective view for explaining the basic configuration of the first tank, FIG. 5 is a side cross-sectional view of the first tank, FIG. 6 is a front cross-sectional view of the first tank, and FIG. It is an enlarged view of the main part showing the boil-off gas passage.

4 to 7 , the first tank 160 may have a first storage space 161 . A first gas dome 162 may be provided at an upper portion of the first tank 160 . The first gas dome 162 may be provided to exhaust the boil-off gas generated from the fluid L stored in the first storage space 161 to the outside of the first tank 160 . The first gas dome 162 may be connected to the above-described gas exhaust line 161a.

In addition, a sloshing prevention member 165 may be installed in the first tank 160 . The sloshing prevention member 150 may be provided to reduce the flow of a liquefied cargo accommodated in the first storage space 161 of the first tank 160 , for example, a fluid L such as liquefied gas. The sloshing prevention member 165 may include a partition wall 165a installed at a predetermined height from the ceiling of the first tank 160 . The partition wall 165a may be structurally made of a metal material having very high rigidity against torsion. The bulkhead 165a may be provided at a height that can be partially submerged in the liquefied cargo accommodated in the first tank 160 . The height can be variously modified according to need.

In addition, an evaporation gas passage connected to the first gas dome 162 is formed in the partition wall 165a. For example, the evaporation gas passage may include an inlet 165b and an exhaust passage 165c connected to the inlet 165b and connected to the first gas dome 162 . Since the sloshing phenomenon is mainly caused by shaking in the left and right direction by waves or currents, the movement of the fluid L can be reduced by the partition wall 165a installed on the ceiling of the first tank 160, It is possible to mitigate the impact applied to the sidewall of (160). In general, the sloshing phenomenon occurs when the amount of the fluid (L) stored in the tank is at a level of 10% to 70% of the amount of the fluid (L) that the tank can store, but the sloshing prevention member 165 is By providing, the sloshing phenomenon hardly occurs even when the amount of the fluid (L) stored in the tank is at a level of 10% to 70% of the amount of the fluid (L) that the tank can store at the maximum. In addition, the configuration of the above-described sloshing preventing member 165 is only an example, and the sloshing preventing member 165 may be variously modified into various known sloshing preventing members.

8 is a perspective view for explaining the basic configuration of the second tank. Referring to FIG. 8 , the second tank 170 may have a structure substantially similar to that of the first tank 160 , except that the aforementioned sloshing prevention member 165 is not installed. For example, the second tank 170 may have a second storage space in which the fluid L is stored. In addition, the second tank 170 may be provided with a second gas dome 172 that performs a function similar to that of the first gas dome 162 . Gas discharge lines 171a, 172a, 173a, 174a, 175a, 176a, and 177a may be connected to the second gas dome 172 .

As described above, since the sloshing prevention member 165 is installed in the first tank 160 , the amount of the fluid L stored in the first tank 160 is the maximum fluid that the first tank 160 can store. Even in the case of 10% to 70% of the amount of (L), the sloshing phenomenon hardly occurs. However, in order to manufacture the first tank 160 , since the sloshing prevention member 165 needs to be additionally manufactured, the manufacturing cost of the first tank 160 is high. On the other hand, since the sloshing prevention member 165 is not installed in the second tank 170 in the second tank 170 , additional manufacturing of the sloshing prevention member 165 is not required. The manufacturing cost is low. On the other hand, when the amount of the fluid (L) stored in the second tank 170 is 10% to 70% of the amount of the fluid (L) that the second tank 170 can store at the maximum, the sloshing phenomenon occurs. do.

Accordingly, an embodiment of the present invention minimizes the occurrence of the sloshing phenomenon through the arrangement of the second tanks 170 having low manufacturing cost and the movement of the fluid L between the second tanks 170 . For example, in one embodiment of the present invention, as the fluid L stored in the tank unit is consumed, the amount of the fluid L stored in the plurality of second tanks 170 is maintained above the set upper limit value or below the set lower limit value. make it Hereinafter, in the structure in which the above-described offshore structure 100 has a tank unit, the sloshing phenomenon is minimized through the arrangement of the second tanks 170 and the movement of the fluid L between the second tanks 170 . A method for storing the fluid will be described. In addition, the set upper limit value to be described below will be described as an example that the second tank 170 is 70% of the maximum amount of the fluid that can be stored. In addition, the set lower limit value described below will be described as an example that the second tank 170 is 10% of the maximum amount of fluid that can be stored. However, the present invention is not limited thereto, and the set upper limit value and the set lower limit value may be variously modified depending on whether sloshing occurs. In addition, the controller 190 may control opening/closing of the selected valves 183 and 184 among the plurality of valves 183 and 184 to perform the fluid storage method described below.

(preparatory stage)

9, in the preparation stage, tank 1 171, tank 2 172, tank 3 173, tank 4 174, tank 5 175, tank 6 ( 176), and the 7th tank 177 may be filled with the fluid L more than the set upper limit value. For example, in the preparation stage, tank 1 171 , tank 2 172 , tank 3 173 , tank 4 174 , tank 5 175 , tank 6 176 , and number 7 The tank 177 may be filled with the fluid L 100%.

(Step 1)

10, in the first step, tank 1 171, tank 2 172, tank 3 173, tank 4 174, tank 5 175, tank 6 (176), and the first tank 171, the second tank 172, the third tank 173 so that the amount of the fluid (L) stored in the seventh tank 177 is equal to or greater than the set upper limit value or the set upper limit value. ), the fourth tank 174 , the fifth tank 175 , the sixth tank 176 , and the fluid L stored in the seventh tank 177 is consumed. For example, tank 1 171 , tank 2 172 , tank 3 173 , tank 4 174 , tank 5 175 , tank 6 176 , and tank 7 177 . ) is consumed so that the amount of fluid (L) stored in it becomes 70%. Thereafter, the fluid (L) stored in the 6th tank 176 and the 7th tank 177 is transferred to the 1st tank 171 , the 2nd tank 172 , the 3rd tank 173 , and the 4th tank 174 . , delivered to the 5th tank 175. After the first step is performed, the amount of the fluid (L) stored in the first tank 171, the second tank 172, the third tank 173, the fourth tank 174 may be 100%, The amount of the fluid (L) stored in the fifth tank 175 may be 90%. In addition, the amount of the fluid (L) stored in the sixth tank 176 and the seventh tank 177 may be 0%.

That is, in the first step, the controller 190 consumes the fluid L stored in the plurality of second tanks 170 (eg, tanks 1 to 7), and thus the plurality of second tanks (170, for example, tanks 1 to 7) are consumed. When the amount of the fluid L stored in the 7th tank) reaches 70%, the second tank 170 (eg, the 6th tank and 7 Controlling the opening and closing of the valves 183 and 184 so that the fluid L stored in the tank) is transferred to the remaining second tanks 170 (eg, tanks 1 to 5) among the plurality of second tanks 170 . can do.

(Step 2)

As shown in FIG. 11 , in the second step, the fluid stored in the first tank 171 , the second tank 172 , the third tank 173 , the fourth tank 174 , and the fifth tank 175 . Tank 1 171, Tank 2 172, Tank 3 173, Tank 4 174, and Tank 5 so that the amount of (L) is equal to or greater than the set upper limit value or the set upper limit value The fluid (L) stored in (175) is consumed. For example, so that the amount of the fluid (L) stored in the first tank 171 , the second tank 172 , the third tank 173 , the fourth tank 174 , and the fifth tank 175 is 70% consume Thereafter, the fluid L stored in the No. 5 tank 176 is transferred to the No. 1 tank 171 , the No. 2 tank 172 , and the No. 3 tank 173 . After the second step is performed, the amount of the fluid (L) stored in the first tank 171 and the second tank 172 may be 100%, and the amount of the fluid (L) stored in the third tank 173 is The amount may be 80%, and the amount of the fluid L stored in the fourth tank 174 may be maintained at 70%. In addition, the amount of the fluid L stored in the fifth tank 175 , the sixth tank 176 , and the seventh tank 177 may be 0%.

That is, in the second step, the controller 190 controls the fluid L stored in the second tank 170 (eg, tanks 1 to 5) selected from among the plurality of second tanks 170 (eg, tanks 1 to 7). ) is consumed and the amount of fluid L stored in the selected second tank 170 (for example, tanks 1 to 5) reaches 70%, at least one of the selected second tanks (170, for example, tank 5) ) of the remaining second tanks 170 (eg, tanks 1 to 3) of the second tanks 170 (eg, tanks 1 to 5) in which the fluid (L) stored in the stored fluid (L) is selected. Opening and closing of the valves 183 and 184 may be controlled to be transmitted to at least one.

(Step 3)

12, in the third step, the amount of the fluid (L) stored in the first tank 171 , the second tank 172 , and the third tank 173 is a set upper limit value, or a set upper limit value The fluid L stored in the No. 1 tank 171 , the No. 2 tank 172 , and the No. 3 tank 173 is consumed so as to be abnormal. For example, the amount of the fluid (L) stored in the first tank 171 , the second tank 172 , and the third tank 173 is consumed so as to be 70%. Thereafter, the fluid L stored in the fourth tank 176 is transferred to the first tank 171 , the second tank 172 , and the third tank 173 . After the third step is performed, the amount of the fluid (L) stored in the first tank 171 and the second tank 172 may be 100%, and the amount of the fluid (L) stored in the third tank 173 is The amount may be 80%, and the amount of the fluid L stored in the 4th tank 174 , the 5th tank 175 , the 6th tank 176 and the 7th tank 177 may be 0% .

That is, in the third step, the controller 190 controls the fluid L stored in the second tank 170 (eg, tanks 1 to 3) selected from among the plurality of second tanks 170 (eg, tanks 1 to 7). ) is consumed, the remaining second tanks 170 (eg, tanks 4 to 7) remain so that the amount of fluid L stored in the selected second tank 170 (eg, tanks 1 to 3) is maintained at 70% or more of the valves 183 and 184 so that the fluid L is transferred from at least one of the second tanks (170, 4 tanks) to the selected second tank 170 (eg, tanks 1 to 3). Opening and closing can be controlled.

(Step 4)

As shown in FIG. 13, in the fourth step, tank 1 ( 171), and the fluid (L) stored in the second tank 172 is consumed. For example, the amount of the fluid (L) stored in the first tank 171 and the second tank 172 is consumed so that 70%. Thereafter, the fluid L stored in the third tank 176 is transferred to the first tank 171 and the second tank 172 . After the second step is performed, the amount of the fluid (L) stored in the first tank 171 and the second tank 172 may be 100%, and the amount of the fluid (L) stored in the third tank 173 is The amount may be 10%, and the amount of the fluid L stored in the fourth tank 174 , the fifth tank 175 , the sixth tank 176 and the seventh tank 177 may be 0%. .

That is, in the fourth step, the controller 190 controls the fluid (L) stored in the second tank 170 (eg, tank 1, tank 2) selected from among the plurality of second tanks 170 (eg, tanks 1 to 7). ) is consumed, the remaining second tanks 170 (eg, tanks 3 to 7) so that the amount of the fluid L stored in the selected second tank 170 (eg, tank 1, tank 2) is maintained at 70% or more of the valves 183 and 184 so that the fluid L is transferred from at least one of the second tanks 170, tank 3) to the selected second tank 170 (eg, tank 1, tank 2). Opening and closing can be controlled.

(Step 5)

As shown in FIG. 14, in the fifth step, tank 1 ( 171), and the fluid (L) stored in the second tank 172 is consumed. For example, the amount of the fluid (L) stored in the first tank 171 and the second tank 172 is consumed so that 70%. Thereafter, the fluid (L) stored in the second tank 172 is transferred to the first tank 171 , the third tank 173 , the fourth tank 174 , the fifth tank 175 , and the sixth tank 176 . forward to After the fifth step is performed, the amount of the fluid (L) stored in the first tank 171 may be 100%, and the amount of the fluid (L) stored in the second tank 172 to the sixth tank 176 is It may be 10%, the amount of the fluid (L) stored in the 7th tank 177 may be 0%.

That is, in the fifth step, the controller 190 controls the fluid L stored in the second tank 170 (eg, tank 1, tank 2) selected from among the plurality of second tanks 170 (eg, tanks 1 to 7). ) is consumed and the amount of fluid L stored in the selected second tank 170 (eg, tank 1, tank 2) reaches 70%, the selected second tank 170 (eg, tank 1, tank 2) ) of the fluid (L) stored in at least one (tank 2) is transferred to at least one of the remaining second tanks (170, tanks 3 to 7), and the remaining second tank (170, tank 3) to the 7th tank) may control the opening and closing of the valves 183 and 184 so that the amount of the fluid L stored in the tank is 10% or less.

(Step 6)

15, in the sixth step, the fluid (L) stored in the first tank 171 so that the amount of the fluid (L) stored in the first tank 171 is equal to or greater than the set upper limit value or the set upper limit value consumes For example, the amount of the fluid (L) stored in the first tank 171 is consumed so that 70%. Thereafter, the fluid (L) stored in the second tank 172 to the seventh tank 177 is continuously delivered to the first tank 171, so that the amount of the fluid (L) stored in the first tank 171 is 70 % should be maintained. Thereafter, when all of the fluid L is consumed in the second tank 172 to the seventh tank 177 , the second tank 172 to the sixth tank 176 with the fluid L stored in the first tank 171 . ) to pass After the sixth step is performed, the amount of the fluid (L) stored in the No. 1 tank 171 to the No. 6 tank 176 may be 10%, and the amount of the fluid L stored in the No. 7 tank 177 is It can be 0%.

That is, in the present invention, as the fluid stored in the tank unit is consumed, the amount of the fluid L stored in the second tank 170 is greater than or equal to a set upper limit value (eg, 70%) or a set lower limit value (eg, 10%). By maintaining the following, it is possible to minimize the occurrence of sloshing by the combination of the second tanks 170 in which the sloshing prevention member 165 is not installed. In addition, when excessive sloshing occurs in the second tank 170 as described above, the controller 190 controls the gas exhaust line (171a, 172a, 173a, 174a, 175a, 176a, 177a) rather than the gas exhaust line ( By controlling the tank unit to exhaust the boil-off gas in 160a) and use it as fuel required to operate the offshore structure 100, it is possible to suppress the occurrence of sloshing as much as possible.

The above detailed description is illustrative of the present invention. In addition, the above description shows and describes preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. That is, changes or modifications are possible within the scope of the concept of the invention disclosed herein, the scope equivalent to the written disclosure, and/or within the scope of skill or knowledge in the art. The written embodiment describes the best state for implementing the technical idea of the present invention, and various changes required in specific application fields and uses of the present invention are possible. Accordingly, the detailed description of the present invention is not intended to limit the present invention to the disclosed embodiments. Also, the appended claims should be construed to include other embodiments.

Offshore Structures: 100
Hull: 110
Turret Unit: 130
Line fixing member: 132
mooring line: 134
Propulsion Unit: 150
Turning center point: C
Tank units: 160, 170
1st tank: 160
1st storage space: 161
1st gas dome: 162
Anti-sloshing member: 165
bulkhead: 165a
Inlet: 165b
Exhaust passage: 165c
Gas exhaust line: 161a
2nd tank: 170
Tank 1 : 171
Tank #2: 172
Tank 3 : 173
Tank #4: 174
Tank #5: 175
Tank #6: 176
Tank 7 : 177
1st gas discharge line: 171a
Second gas discharge line: 172a
Third gas discharge line: 173a
4th gas discharge line: 174a
5th gas discharge line: 175a
6th gas discharge line: 176a
7th gas discharge line: 177a
1st fluid pipe: 181
Second fluid pipe: 182
1st valve : 183
2nd valve: 184
Controller: 190

Claims (5)

In the marine structure floating in seawater,
hull;
a tank unit installed on the hull and storing a fluid; and
A controller for controlling the tank unit,
The tank unit is
a first tank in which a sloshing prevention member is installed;
a plurality of second tanks having a structure different from that of the first tank;
a plurality of fluid pipes for moving the fluid between the plurality of second tanks;
a plurality of valves installed in each of the plurality of fluid pipes;
The controller is
Controlling the opening and closing of the selected valve among the plurality of valves so that the amount of the fluid stored in the plurality of second tanks is maintained above a set upper limit value or below a set lower limit value as the fluid stored in the tank unit is consumed offshore structures. According to claim 1,
The controller is
When the fluid stored in the plurality of second tanks is consumed and the amount of the fluid stored in the plurality of second tanks reaches the set upper limit value, the fluid stored in the second tank selected from among the plurality of second tanks An offshore structure for controlling the opening and closing of the valve so that the plurality of second tanks are transferred to the remaining second tank. According to claim 1,
The controller is
When the fluid stored in the second tank selected from among the plurality of second tanks is consumed and the amount of the fluid stored in the selected second tank reaches the set upper limit value, the fluid stored in at least one of the selected second tanks Offshore structure for controlling the opening and closing of the valve so that the fluid is delivered to the remaining second tank of the selected second tanks. According to claim 1,
The controller is
Even if the fluid stored in the second tank selected from among the plurality of second tanks is consumed, the amount of the fluid stored in the selected second tank maintains at least the set upper limit value in at least one of the remaining second tanks. An offshore structure for controlling opening and closing of the valve so that the fluid is transferred to the selected second tank. According to claim 1,
The controller is
When the fluid stored in the second tank selected from among the plurality of second tanks is consumed and the amount of the fluid stored in the selected second tank reaches the set upper limit value, the fluid stored in at least one of the selected second tanks is delivered to at least one of the remaining second tanks, and the remaining amount of the fluid stored in the second tank is below the set lower limit value.

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