WO2021111623A1 - Floating-type structure - Google Patents

Abstract

[Problem] To provide a floating-type structure that can be constructed at low cost and in a short delivery time. [Solution] A floating-type structure retrofitted to a liquefied-gas carrier ship provided with a hull part in which a membrane-type or self-supporting prismatic-type storage tank is mounted, the floating-type structure comprising the hull part, a projecting part which is fixed to the hull part and which projects to at least one side in the width direction of the hull part, and a gas-processing facility positioned in the projecting part, the projecting part and the gas-processing facility being portions that are added during the retrofitting.

Description

Floating structure

The present invention relates to a floating structure obtained by modifying an existing LNG carrier.

Conventionally, there is a floating structure equipped with an LNG tank for storing liquefied natural gas, as well as a natural gas processing facility for treating natural gas. As a method of constructing such a floating structure, it is conceivable to first construct a new structure, but in addition to the method of constructing a new structure, a method of using an existing LNG carrier or the like is also conceivable.

As a method of utilizing an existing LNG carrier, for example, a technique has been proposed in which an LNG tank is transferred from an aged LNG carrier and reused to construct a new floating structure (for example, a patent document). 1). This technology focuses on the property that even if the hull of an existing LNG carrier is aged, the liquefied natural gas stored inside is not corrosive and the LNG tank is not easily aged.

According to this technology, by reusing the LNG tank of an existing LNG carrier, it is not necessary to construct a new LNG tank, so that the construction process of a new floating structure can be significantly shortened and the cost can be reduced. It can be reduced.

Japanese Unexamined Patent Publication No. 2012-86768

However, when the LNG tank of an aged LNG carrier is transferred to construct a new floating structure as in the above-mentioned technology, it is necessary to newly construct the hull part of the floating structure. Therefore, even if the existing LNG tank is reused, the hull part requires the same construction process and cost as before, which is not sufficient for shortening the construction period and reducing the cost.

In this case, it is conceivable to use the existing LNG carrier as it is and convert it to a floating structure, but there is a problem that it is not possible to secure a space for mounting natural gas processing equipment.

An object of the present invention is to provide a floating structure that can be constructed at low cost and with a short delivery time.

The floating structure of the present invention
A floating structure modified from a liquefied gas carrier equipped with a hull equipped with a membrane-type or self-supporting square storage tank.
With the hull
An overhanging portion fixed to the hull portion and overhanging at least one side in the width direction of the hull portion,
It is provided with a gas treatment facility arranged in the overhanging portion.
In the floating structure of the present invention, the overhanging portion and the gas treatment facility are portions added at the time of remodeling.
In this way, the floating structure can be constructed at low cost and in a short delivery time by expanding the overhanging portion and the gas treatment facility by using the existing liquefied gas carrier as it is. Further, by providing the overhanging portion, it is possible to secure a sufficient space for arranging the gas treatment equipment.

Further, the floating structure of the present invention is
The gas treatment facility is composed of modules.
In this way, the gas treatment equipment can also be configured by modules.

Further, the floating structure of the present invention is
The module has a protrusion that projects onto the hull.
By projecting the module onto the hull in this way, the space on the hull can be effectively used.

Further, the floating structure of the present invention is
The hull part is the disembarkation part to which the overhanging part is fixed, and
It is provided with an upper hull portion that protrudes above the lower hull portion and constitutes the upper part of the storage tank.
The upper hull portion is provided with a hull inclined portion that inclines downward toward the lower hull portion at an end portion in the width direction of the upper hull portion.
The protruding portion protrudes toward the upper hull portion,
Below the protruding portion, a module inclined portion that inclines upward along the inclined portion of the hull is formed.
By forming the module inclined portion below the protruding portion in this way, the module can be projected along the hull inclined portion of the upper hull portion, and the space of the inclined portion of the upper hull portion is utilized without waste. be able to.

Further, the floating structure of the present invention is
It is provided with a plurality of columns to support the module.
All struts are arranged on the overhang.
That is, the module is placed on the strut at the overhang. Therefore, the overhanging portion can be designed in advance so as to have the strength to support the module, and the reinforcement work of the hull portion for supporting the module becomes unnecessary.

Further, the floating structure of the present invention is
It is provided with a plurality of columns to support the module.
Some of the stanchions are arranged on the hull and the remaining stanchions are arranged on the overhangs.
That is, according to the above configuration, the load of the module can be distributed to the hull portion and the overhanging portion, so that the module can be supported in a well-balanced and stable manner. Further, since a part of the weight of the module can be supported by the hull portion, the strength of the overhanging portion itself and the fixing strength to the hull portion can be reduced, and the construction cost of the overhanging portion can be reduced.

Further, the floating structure of the present invention is
The pillars on the hull side are arranged on the ship side outer plate constituting the hull side.
As a result, the load received by the support column is transmitted to the ship-side outer plate having a higher strength than the other parts, so that the support column can be firmly supported.

Further, the floating structure of the present invention is
The module is formed with the storage tank extending in the width direction of the hull portion.
As a result, the hollow on the storage tank can be effectively used.

Further, the floating structure of the present invention is
A floating structure modified from a liquefied gas carrier equipped with a hull equipped with a membrane-type or self-supporting square storage tank.
With the hull
Modules that make up the gas treatment equipment and
To be equipped.
In the floating structure of the present invention, the module is arranged on the storage tank in the width direction of the hull portion, supported by columns arranged on both sides of the storage tank.
This is the part where the module was added at the time of remodeling.
By installing the columns on the hull and arranging the modules on the columns in this way, the modules can be arranged by utilizing the space above the hull. Therefore, the cost and man-hours for remodeling the existing liquefied gas carrier can be significantly reduced.

According to the present invention, it is possible to provide a floating structure that can be constructed at low cost and with a short delivery time.

It is a schematic view which looked at the floating structure which concerns on embodiment from above. It is a schematic diagram which looked at the floating structure which concerns on embodiment from the front. It is a figure explaining the construction method of the floating structure which concerns on embodiment. It is a figure explaining the situation which the module is mounted on the extension part extended in the floating structure which concerns on embodiment. It is a schematic view which looked at the floating structure which concerns on other embodiment from the front. It is a schematic view which looked at the floating structure which concerns on other embodiment from the front. It is a schematic view which looked at the floating structure which concerns on other embodiment from the front.

Hereinafter, the floating structure according to the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of the floating structure 2 according to the embodiment viewed from above, and FIG. 2 is a schematic view of the floating structure 2 as viewed from the front (direction of arrow A shown in FIG. 1). As shown in FIGS. 1 and 2, the floating structure 2 is a unidirectionally long structure having a hull portion 4 as a main body, which is called a hull. The floating structure 2 according to the embodiment is a modified LNG carrier 26 (see FIG. 3) as an existing liquefied gas carrier.

The floating structure 2 is used as a marine plant. Such equipment includes FPSO (floating production storage and shipping equipment) that produces, stores, and ships oil and natural gas, and FSO (floating production storage and shipping equipment) that does not have production equipment and only stores and ships. ), FSU (floating production storage facility) that only stores. Further, as one of the FPSOs, FLNG (floating production liquefied natural gas production facility) specialized in the production, storage and shipping of liquefied natural gas (LNG) is known. In the embodiment of the present invention, the case where the floating structure 2 is FLNG will be described as an example. The floating structure 2 does not have a self-propelled function, and when it moves, it is towed by a power ship.

In the floating structure 2, the hull part 4 uses the hull part 4 of the existing LNG carrier 26 (see FIG. 3). The hull portion 4 is provided with a ballast tank 10 inside the hull side 8 and the bottom 9 which is a space for injecting seawater or the like in order to adjust the weight of the hull portion 4 and balance the hull portion 4. Further, the hull portion 4 is equipped with a storage tank 12 for storing liquefied natural gas.

Here, the type of the storage tank 12 is defined by "The International Code of the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code)" issued by the IMO (International Maritime Organization). Specific types are a spherical type called Moss type and a square type called Membrane type, which is integrated with the hull by attaching a thin film tank material inside the hull. , Various types are known, such as a self-supporting square type in which the hull and the square tank are separated and independent.

In the present embodiment, the membrane type storage tank 12 will be described as an example, but the storage tank 12 may be a self-supporting square type. In the present embodiment, the storage tank 12 having an octagonal cross section is illustrated, but the storage tank 12 may be non-spherical and is not limited to the octagonal shape.

The hull unit 4 includes a disembarkation unit 41 that accommodates the storage tank 12, and an upper hull unit 18 that projects above the disembarkation unit 41 and constitutes the upper part of the storage tank 12. Further, the disembarkation body portion 41 includes a ship side outer plate 40 forming an outer shell of the ship side 8 and a ship bottom outer plate 42 forming an outer shell of the ship bottom 9. The upper hull portion 18 includes hull inclined portions 18a that incline downward toward the lower hull portion 41 at both ends of the upper hull portion 18 in the width direction. That is, the peripheral edge of the upper hull portion 18 is inclined downward corresponding to the inclined portion of the upper end portion of the storage tank 12. The width direction of the upper hull portion 18 coincides with the width direction of the hull portion 4.

On both sides of the hull portion 4 in the width direction, called pontoon or sponson, etc., overhanging portions 14 projecting to the outside of the hull portion 4 are fixed. In the present embodiment, the overhanging portion 14 is fixed to the disembarking body portion 41. A waste oil tank, an additional ballast tank, and the like are provided inside the overhanging portion 14. Further, a space on the overhanging portion 14 where the module 16 described later is not arranged is used as a device storage place or the like.

Further, a gas treatment facility for treating gas is arranged on the overhanging portion 14. In the present embodiment, a natural gas processing facility is arranged on the overhanging portion 14 as a gas processing facility. Specifically, a module 16 used as a natural gas processing facility is arranged on the overhanging portion 14. The module 16 is a structure equipped with equipment and pipes for processing natural gas. After the module 16 is installed on the overhanging portion 14, the devices and pipes in the adjacent modules 16 are connected to each other as needed to form a natural gas processing facility.

Further, the module 16 is supported by a support column 17 called a stool arranged on the overhanging portion 14. The stanchion 17 includes a first stanchion 17a located on the hull 4 side in the width direction of the hull 4 and a second stanchion 17b located on the opposite side of the hull 4 side. Both the first support column 17a and the second support column 17b are lined up in a row at predetermined intervals along the longitudinal direction of the hull portion 4. In the present embodiment, the overhanging portion 14, the module 16 which is a natural gas processing facility, and the support columns 17 (first support column 17a, second support column 17b) are included in the extension portion described later.

Here, the module 16 has a protruding portion 16a protruding above the hull portion 4. Below the protruding portion 16a, a module inclined portion 16b that inclines upward toward the hull portion 4 side is formed. In the present embodiment, the protruding portion 16a protrudes toward the upper hull portion 18, and the module inclined portion 16b is inclined upward along the hull inclined portion 18a of the upper hull portion 18.

By projecting the module 16 toward the hull portion 4 in this way, the space on the hull portion 4 can be effectively used. Further, by forming the module inclined portion 16b below the module 16, the module 16 can be projected in accordance with the hull inclined portion 18a of the upper hull portion 18, and the hull inclined portion 18a of the upper hull portion 18 is inclined. Space can be used without waste.

In addition, on the floating structure 2, a residential area 20 equipped with a sailor's room, a kitchen, etc. is arranged.

Next, an example of the construction method of the floating structure 2 according to the embodiment will be described. First, the LNG carrier 26 equipped with the membrane type or self-supporting square type storage tank 12 is towed by a towing ship such as a tugboat and docked in the dock 24 as shown in FIG. 3A. Next, as shown in FIG. 3B, the seawater in the dock 24 is drained and the LNG carrier 26 is landed on the bottom of the culvert. Then, the overhanging portions 14 are carried into both sides of the hull portion 4 of the LNG carrier 26 in the width direction. Next, by welding the overhanging portion 14 to the hull portion 4, as shown in FIG. 3C, the overhanging portion 14 is added to the hull portion 4.

When the overhanging portion 14 is expanded, a support column 17 is arranged on the overhanging portion 14, and the module 16 is usually mounted on the overhanging portion 14 by a crane. As an alternative to the mounting method, as shown in FIG. 4A, a rail 29 for transferring the module 16 is provided on the support column 17. During this time, the module 16 is appropriately carried into the dock 24. The module 16 is transferred to a lift 30 located in the vicinity of the dock 24, and then the lift 30 rises to the same level as the rail 29, as shown in FIG. 4 (b).

Next, by moving the module 16 from the lift 30 to the rail 29, the module 16 is installed on the overhanging portion 14 as shown in FIG. 4 (c). Such a transfer process is called jack-up and skidding, and is sometimes adopted as one of the module mounting methods. As a result, the remodeling of the LNG carrier 26 is completed, and the floating structure 2 obtained by remodeling the LNG carrier 26 is completed. Next, the dock 24 is injected with water, the floating structure 2 is launched and docked, and is towed to the destination by a towing vessel. Natural gas processing takes place at this destination.

In the floating structure 2 constructed as described above, a known pretreatment for removing impurities from natural gas and a known liquefaction treatment for liquefying the pretreated natural gas are carried out in a natural gas processing facility.

According to the invention according to the present embodiment, the floating structure 2 can be constructed at low cost and in a short delivery time by expanding the overhanging portion 14, the module 16, etc. by using the existing LNG carrier as it is. it can. Further, by providing the overhanging portion 14, a sufficient space for arranging the module 16 can be secured.

Further, since all the columns 17 of the first support column 17a and the second support column 17b are arranged on the overhanging portion 14, the overhanging portion 14 should be designed in advance so as to have the strength to support the module 16. This eliminates the need for reinforcement work on the hull portion 4 to support the module 16. Further, even when reinforcement work on the hull portion 4 side of the overhanging portion 14 is required, the support column 17 (first support column 17a) does not get in the way. Therefore, the reinforcement work can be easily performed.

In the above-described embodiment, the case where both the first support column 17a and the second support column 17b are arranged on the overhanging portion 14 in the width direction of the hull portion 4 has been described as an example. As shown in the above, the first support column 17a may be arranged on the hull portion 4. That is, a part of the columns 17 may be arranged on the hull portion 4. As a result, the load of the module 16 can be distributed to the hull portion 4 and the overhanging portion 14, so that the module 16 can be supported in a well-balanced and stable manner. Further, since a part of the weight of the module 16 can be supported by the hull portion 4, the strength of the overhanging portion 14 itself and the fixing strength to the hull portion 4 can be reduced, and the construction cost of the overhanging portion 14 can be reduced. can do. Further, since the distance between the columns 17 in the width direction of the hull portion 4 is widened, the module 16 can be stably supported.

Further, in this case, the first support column 17a may be arranged on the ship side outer plate 40 constituting the ship side 8 of the hull portion 4. The ship side outer plate 40 has higher strength than the portion where the storage tank 12 is installed. Therefore, the load received by the first support column 17a is directly transmitted to the ship-side outer plate 40, and the first support column 17a can be firmly supported.

Further, in the above-described embodiment, as shown in FIG. 2, the modules 16 are arranged on the overhanging portions 14 on both sides of the hull portion 4 in the width direction. However, the module 16 may have the storage tank 12 formed over the width direction of the hull portion 4. For example, as shown in FIG. 6, each module 16 arranged in the overhanging portion 14 may be connected on the storage tank 12. As a result, the hollow on the storage tank 12 can also be effectively used.

Further, when the module 16 is arranged on the storage tank 12 in this way, as shown in FIG. 7, the columns 17 are arranged on both sides of the storage tank 12 in the width direction of the hull portion 4, and the overhanging portion is provided. It is not necessary to provide 14. In this case, the support column 17 is preferably installed on the ship side outer plate 40, and the module 16 is supported by the support column 17 arranged on both sides of the storage tank 12.

That is, when there is a small space in the hull portion 4 where the storage tank 12 is not arranged, by arranging the columns 17 directly on the hull portion 4 in this way, the module does not need to provide the overhanging portion 14. 16 arrangements are possible. Therefore, the module 16 can be installed by utilizing the space above the hull portion 4, and the cost and man-hours when remodeling the existing LNG carrier 26 can be significantly reduced.

Further, in the above-described embodiment, the case where the overhanging portions 14 are provided on both sides of the hull portion 4 is described as an example, but the overhanging portion 14 is only on one side of the hull portion 4. It may be provided in.

Further, in the above-described embodiment, the case where both the first support column 17a and the second support column 17b are lined up in a row at predetermined intervals along the longitudinal direction of the hull portion 4 is illustrated. It does not necessarily have to be arranged in this way. For example, the columns 17 may be arranged without distinction between the first column 17a and the second column 17b.

Further, in the above-described embodiment, the case where the module 16 is a natural gas processing facility is illustrated, but the module 16 may include a module 16 used in addition to the natural gas processing facility.

Further, in the above-described embodiment, the floating structure 2 having no self-propelled function has been described as an example, but the means of moving the floating structure 2 is not particularly limited, and the floating structure 2 is not particularly limited. The object 2 may have a self-propelled function.

Further, although not particularly mentioned in the above-described embodiment, the module 16 includes a high-temperature module in which a device for pretreating natural gas before liquefaction is installed and a low-temperature module in which a device for liquefying natural gas is installed. May be provided. In this case, the high temperature module may be arranged on one side in the width direction of the hull portion 4, and the low temperature module may be arranged on the other side. Further, two low temperature modules may be provided, and one system may be arranged on each side of the storage tank 12.

Further, although not particularly mentioned in the above-described embodiment, the module inclined portion 16b may be arranged along the hull inclined portion 18a, and may have a shape inclined as a whole due to a step, for example. Good. In short, the module inclined portion 16b may have a shape that can effectively utilize the dead space by arranging the module inclined portion 16b along the hull inclined portion 18a.

2 Floating structure 4 Hull part 8 Hull side 10 Ballast tank 12 Storage tank 14 Overhang part 16 Module 16a Protruding part 16b Module inclined part 17 Pillar 17a First pillar 17b Second pillar 18 Upper hull part 18a Hull inclined part 20 Living area 24 Dock 26 Carrier 28 Space 29 Rail 30 Lift 40 Ship side skin 41 Lower hull 42 Ship bottom skin

Claims (9)

A floating structure modified from a liquefied gas carrier equipped with a hull equipped with a membrane-type or self-supporting square storage tank.
With the hull
An overhanging portion fixed to the hull portion and overhanging at least one side in the width direction of the hull portion,
It is equipped with a gas treatment facility arranged in the overhanging portion.
A floating structure in which the overhanging portion and the gas treatment facility are added at the time of remodeling. The floating structure according to claim 1, wherein the gas treatment facility is composed of modules. The floating structure according to claim 2, wherein the module has a protruding portion protruding above the hull portion. The hull portion includes a disembarkation portion to which the overhanging portion is fixed and a hull portion.
It is provided with an upper hull portion that protrudes above the lower hull portion and constitutes the upper part of the storage tank.
The upper hull portion includes a hull inclined portion that inclines downward toward the lower hull portion at an end portion in the width direction of the upper hull portion.
The protruding portion protrudes toward the upper hull portion,
The floating structure according to claim 3, wherein a module inclined portion that inclines upward along the hull inclined portion is formed below the protruding portion. It is provided with a plurality of columns to support the module.
The floating structure according to any one of claims 2 to 4, wherein all the columns are arranged on the overhanging portion. It is provided with a plurality of columns to support the module.
The floating structure according to any one of claims 2 to 4, wherein a part of the columns is arranged on the hull portion and the remaining columns are arranged on the overhanging portion. The floating structure according to claim 6, wherein the support column on the hull portion is arranged on a ship side outer plate constituting the ship side of the hull portion. The floating structure according to any one of claims 2 to 7, wherein the module is formed with the storage tank extending in the width direction of the hull portion. A floating structure modified from a liquefied gas carrier equipped with a hull equipped with a membrane-type or self-supporting square storage tank.
With the hull
Modules that make up the gas treatment equipment and
With
The module is arranged on the storage tank in the width direction of the hull portion, supported by columns arranged on both sides of the storage tank.
Floating structure, which is the part where the module was added at the time of remodeling.

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