JP2012086768A - Method for manufacturing floating type structure equipped with liquefied natural gas tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a floating type structure capable of preventing an LNG tank from being brought into contact with sea water when manufacturing the floating type structure by recycling the LNG tank of an LNG carrier.SOLUTION: The method includes a step of removing a liquefied natural gas tank 11 from a hull 10 of an LNG carrier by using a crane 61, and a step of mounting the liquefied natural gas tank on a hull 20 different from the hull 10 by using the crane 61. The method prevents the liquefied natural gas tank from being brought into contact with sea water since the crane is used for removing and mounting the liquefied natural gas tank.

Description

  The present invention relates to a method for manufacturing a floating structure by reusing a liquefied natural gas tank (LNG tank) of a liquefied natural gas carrier (LNG ship).

  In the case of a low temperature liquefied gas carrier, even if the hull is aging due to long-term use, the low temperature liquefied gas tank is in an inert atmosphere, so it is hardly aged and can be reused.

  Patent document 1 is disclosing the hull new replacement construction method of a low temperature liquefied gas carrier ship in connection with reuse of a low temperature liquefied gas tank. In this new hull replacement method, the old hull is used to unify the reusable low-temperature liquefied gas tank, its upper deck, and the horizontal bulkhead located between adjacent tanks from the old hull for transporting low-temperature liquefied gas. Cut and remove at least the upper wing tank. After that, the old hull is submerged and the tank and upper deck etc. are floated on the ocean in an integrated state, and this is guided onto the double bottom of the semi-submersible or submerged new hull and mounted on the new hull.

  Patent document 2 is disclosing the method of manufacturing an offshore stockpile tank using the hull of a surplus tanker or a surplus bulk carrier, and the low temperature liquefied gas tank of an aging low temperature liquefied gas carrier ship. In this manufacturing method, a tank insertion opening is formed in the bow of the surplus hull as a surplus tanker or surplus bulk carrier hull, the transverse bulkhead of the surplus hull is appropriately cut out, and the bottom surface of the tank placement planned location in the surplus hull Forming a secondary barrier having a concrete wall and a heat insulating material. After the cryogenic liquefied gas tank taken out from the aging cryogenic liquefied gas carrier is floating on the sea, it is inserted into the surplus hull from the tank insertion opening and placed on the secondary barrier, and then the tank insertion opening is sealed and surplus The hull has a floating structure.

JP 59-184083 A JP 59-184084 A

  An object of the present invention is to provide a method for manufacturing a floating structure that prevents the LNG tank from coming into contact with seawater when the LNG tank of the LNG ship is reused to manufacture the floating structure.

  The means for solving the problem will be described below using the numbers used in the (DETAILED DESCRIPTION). These numbers are added to clarify the correspondence between the description of (Claims) and (Mode for Carrying Out the Invention). However, these numbers should not be used to interpret the technical scope of the invention described in (Claims).

  The method for manufacturing a floating structure according to the present invention includes the step of removing the liquefied natural gas tank (11, 11A, 11B) from the first hull (10) of the first liquefied natural gas carrier using the first crane (61, 71). And mounting the liquefied natural gas tank on a hull (20, 30) different from the first hull using a second crane (61, 71) as the same or different crane from the first crane. .

  Since the crane is used to remove and mount the liquefied natural gas tank, the liquefied natural gas is prevented from coming into contact with seawater.

  The step of removing the liquefied natural gas tank and the step of mounting the liquefied natural gas tank on the hull different from the first hull are arranged in a state in which the first hull and the hull are arranged in the building dock (60). Execute.

  The method of manufacturing a floating structure includes the step of removing the liquefied natural gas tank from the first hull and the step of mounting the liquefied natural gas tank on the hull different from the first hull. The method further includes the step of transporting the gas tank by sea.

  At least one of the first crane or the second crane is a crane (71) of a crane ship (70).

  The method for manufacturing a floating structure further includes a step of removing a residential area (13) or a cargo handling facility (12) from the first liquefied natural gas carrier ship, and a step of mounting the residential area or the cargo handling equipment on the hull. It has.

  In the method for manufacturing a floating structure, the hull is a bulk carrier hull (20). The method for manufacturing a floating structure includes a step of forming an opening (22) in the upper deck (21) of the hull of the bulk carrier, and a tank support (25 in the cargo hold (23) of the hull of the bulk carrier. 26). The steps of mounting the liquefied natural gas tank on the hull different from the first hull include placing the liquefied natural gas tank into the cargo hold through the opening, and placing the liquefied natural gas tank on the tank support. Is provided.

  The manufacturing method of the floating structure is a liquefied natural gas production / storage plant (31) for generating and storing liquefied natural gas from natural gas mined from a gas field, or a re-gasification for regasifying the stored liquefied natural gas. The method further includes the step of mounting the gasification plant (31) on the hull.

  The method for manufacturing a floating structure includes a step of fixing the first hull and the second hull (10) of the second liquefied gas carrier in parallel and generating liquefied natural gas from natural gas mined from a gas field A step of mounting the liquefied natural gas generation / storage plant (41) to be stored or the regasification plant (41) for regasifying the stored liquefied natural gas on the first hull or the second hull. It has.

  ADVANTAGE OF THE INVENTION According to this invention, when manufacturing a floating structure by reusing the LNG tank of an LNG ship, the manufacturing method of the floating structure which prevents an LNG tank from contacting seawater is provided.

FIG. 1 is a conceptual diagram of a method for manufacturing a floating structure according to the first embodiment of the present invention. FIG. 2 is a conceptual diagram of a process of removing the LNG tank from the hull of an existing LNG ship in the method for manufacturing a floating structure according to the second embodiment of the present invention. FIG. 3A is a conceptual diagram of a process of mounting an LNG tank on the hull of a newly built LNG ship in the method for manufacturing a floating structure according to the second embodiment. FIG. 3B is a conceptual diagram of a modified example of the process of mounting the LNG tank on the hull of a new LNG ship in the method for manufacturing a floating structure according to the second embodiment. FIG. 3C is a conceptual diagram of another modified example of the process of mounting the LNG tank on the hull of a new LNG ship in the method for manufacturing a floating structure according to the second embodiment. FIG. 4A is a cross-sectional view of a hull before remodeling of an existing bulk carrier in which an LNG tank is to be mounted in the method for manufacturing a floating structure according to the third embodiment of the present invention. FIG. 4B is a cross-sectional view of an existing bulk carrier hull modified to mount an independent spherical tank. FIG. 4C is a cross-sectional view of the hull of an existing bulk carrier equipped with an independent spherical tank. FIG. 4D is a cross-sectional view of an existing bulk carrier hull modified to mount an independent square tank. FIG. 4E is a cross-sectional view of an existing bulk carrier hull equipped with an independent square tank. FIG. 5 is a conceptual diagram of a method for manufacturing a floating structure according to the fourth embodiment of the present invention. FIG. 6 is a plan view of a floating facility manufactured in the method for manufacturing a floating structure according to the fifth embodiment of the present invention.

  With reference to an accompanying drawing, the form for carrying out the manufacturing method of the floating type structure by the present invention is explained below. Here, the floating structure means a structure that floats on the sea including an LNG tank, such as an LNG ship, a floating production storage and loading facility (FPSO), and a floating storage regasification unit (FSRU).

(First embodiment)
With reference to FIG. 1, the manufacturing method of the floating structure based on the 1st Embodiment of this invention is demonstrated. In this embodiment, an LNG ship is manufactured as a floating structure.

  First, the hull 10 of the existing LNG ship and the hull 20 of the new LNG ship are arranged in parallel in the construction dock 60. An LNG tank 11, a cargo handling facility 12, and a residential area 13 are mounted on the hull 10 of an existing LNG ship. The LNG tank 11 is a tank for storing liquefied natural gas (LNG), and has a sealing function, a pressure resistance function, a weight support function, and a heat insulation function. The LNG 11 tank is, for example, an independent spherical tank or an independent square tank. The cargo handling facility 12 is used for cargo handling of LNG. The cargo handling facility 12 may include a loading arm. The residential area 13 includes, for example, a bridge. Here, the hull 10 of the existing LNG ship has aged hull structure due to long-term use, but the LNG tank 11 is hardly aged because it was in an inert atmosphere. The hull 20 of the new LNG ship is a newly manufactured hull.

  As a method of arranging the hull 10 of the existing LNG ship and the hull 20 of the new LNG ship in parallel in the construction dock 60, the hull 10 of the existing LNG ship is drawn into the construction dock 60 and the construction dock 60 is drained. The hull 20 of the new LNG ship may be built next to the hull 10, and the hull 20 of the new LNG ship after launch and the hull 10 of the existing LNG ship are drawn into the construction dock 60 to drain the construction dock 60. May be.

  Thereafter, the LNG tank 11 is removed from the hull 10 of the existing LNG ship using the crane 61 provided on land, and the LNG tank 11 is mounted on the hull 20 of the newly built LNG ship.

  Further, when the cargo handling equipment 12 and the residential area 13 are not deteriorated, the cargo handling equipment 12 and the residential area 13 are removed from the hull 10 of the existing LNG ship using the crane 61 and mounted on the hull 20 of the newly built LNG ship. In addition, when constructing the existing LNG ship, if the residential area 13 is made into a floating structure so that distortion is not transmitted from the hull 10 to the residential area 13, the residential area 13 is prevented from being aged.

  According to this embodiment, since the LNG tank 11, the cargo handling facility 12, and the residential area 13 are reused, the construction process of the new LNG ship is shortened, resources are effectively used, and the construction energy of the new LNG ship is reduced. The In particular, since the LNG tank 11 takes time to manufacture, reusing the LNG tank 11 significantly shortens the construction process of a new LNG ship. Further, when the LNG tank 11 is made of an aluminum alloy, a lot of electric power is required for the production of the LNG tank 11, so that the construction energy of the new LNG ship can be greatly reduced by reusing the LNG tank 11.

  According to the present embodiment, the LNG tank 11 is removed from the hull 10 of the existing LNG ship using the crane 61 and mounted on the hull 20 of the new LNG ship, so that the LNG tank 11 is prevented from coming into contact with seawater.

  According to this embodiment, since the existing LNG ship is dismantled in the construction dock 60, environmental pollution at the time of dismantling is prevented.

  In the present embodiment, the removal of the existing LNG ship and the construction of the new LNG ship are performed in the construction dock 60 in parallel. Therefore, compared with the case where the removal of the existing LNG ship and the construction of the new LNG ship are performed at different docks, the total cost of the removal of the existing LNG ship and the construction cost of the new LNG ship is suppressed.

(Second Embodiment)
A method for manufacturing a floating structure according to the second embodiment of the present invention will be described with reference to FIGS. 2 and 3A.

  With reference to FIG. 2, the process of removing the LNG tank 11 from the hull 10 of the existing LNG ship in the manufacturing method of the floating structure according to the present embodiment will be described. Using the crane 71 of the crane ship 70, the LNG tank 11 is removed from the hull 10 of the existing LNG ship moored on the quay 65 and placed on the barge 75. Therefore, when there is no land crane near the quay 65, or even when there is a land crane near the quay 65, the height of the crane is insufficient to remove the LNG tank 11 from the hull 10 and place it on the barge 75. Even in this case, it is possible to remove the LNG tank 11 from the hull 10 of the existing LNG ship and place it on the barge 75.

  With reference to FIG. 3A, the process of mounting the LNG tank 11 in the hull 20 of a new LNG ship in the method for manufacturing a floating structure according to the present embodiment will be described. The barge 75 is used to transport the LNG tank 11 to the quay 66 near the dock 60 by sea. Using the crane 61, the LNG tank 11 is lifted from the barge 75 and mounted on the hull 20 of a newly built LNG ship arranged in the construction dock 60.

  According to this embodiment, since the LNG tank 11 removed from the hull 10 of the existing LNG ship is transported by sea, the LNG removed from the hull 10 of the existing LNG ship without drawing the hull 10 of the existing LNG ship into the construction dock 60. The tank 11 can be mounted on the hull 20 of a newly built LNG ship. Since the hull 10 of the existing LNG ship is not drawn into the building dock 60, there is little risk of process disruption of the building dock 60.

  With reference to FIG. 3B, the modification of the process of mounting the LNG tank 11 in the hull 20 of a newly built LNG ship is demonstrated. In the modified example, the LNG tank 11 is lifted from the barge 75 using the crane 71 of the crane ship 70 and mounted on the hull 20 of a new LNG ship arranged in the construction dock 60. In the modified example, when there is no land crane near the building dock 60 and the quay 66, or even when there is a land crane near the building dock 60 and the quay 66, the height of the crane moves the LNG tank 11 from the barge 75. It is suitable for a case where it is insufficient to be lifted and mounted on the hull 20 of a new LNG ship. Note that, using a crane ship different from the crane ship 70, the LNG tank 11 may be lifted from the barge 75 and mounted on the hull 20 of a new LNG ship disposed in the construction dock 60.

  With reference to FIG. 3C, another modified example of the process of mounting the LNG tank 11 on the hull 20 of the new LNG ship will be described. Using the barge 75, the LNG tank 11 is transported by sea to the vicinity of the hull 20 of a newly-built LNG ship moored on the rigged quay wall 67. In another modification, the crane 71 of the crane ship 70 is used to lift the LNG tank 11 from the barge 75 and mount it on the hull 20 of a new LNG ship moored on the quay quay 67. Alternatively, the LNG tank 11 may be lifted from the barge 75 and mounted on the hull 20 of a newly built LNG ship moored on the outfitting quay 67 using a crane ship other than the crane ship 70.

  In the second embodiment, the modification of the second embodiment, and the other modification of the second embodiment described above, a marine transportation means other than the barge 75 may be used. Further, similarly to the case of the LNG tank 11, the cargo handling equipment 12 and the residential area 13 may be transported by sea.

(Third embodiment)
The method for manufacturing a floating structure according to the third embodiment of the present invention, except that the hull of an existing ship having a large space in the cargo portion such as an existing bulk carrier is used as the hull 20 of a new LNG ship. This is the same as in the first and second embodiments. A process of mounting the LNG tank 11 according to the present embodiment on the hull 20 of the new LNG ship will be described by taking as an example the case where an existing bulk carrier hull is used as the hull 20 of the new LNG ship.

  First, the process of mounting the LNG tank 11 as an independent circular tank on the hull 20 of a new LNG ship as a hull of an existing bulk carrier will be described with reference to FIGS. Hereinafter, the hull 20 of the new LNG ship as the hull of the existing bulk carrier is referred to as the existing bulk carrier hull 20, and the LNG tank 11 as the independent circular tank is referred to as the LNG tank 11A.

  Referring to FIG. 4A, an existing bulk carrier hull 20 includes an upper deck 21, a cargo hold 23, and a double bottom 24 that forms the floor of the cargo hold 23.

  With reference to FIG. 4B, an opening 22 is formed in the upper deck 21, and a tank support 25 is provided in the cargo hold 23. The tank support part 25 is a skirt, for example. Here, the tank support 25 is installed on the double bottom 24. It is preferable to reinforce the portion where the tank support 25 of the double bottom 24 is installed.

  Referring to FIG. 4C, the LNG tank 11A is put into the cargo hold 23 through the opening 22, and the LNG tank 11A is placed on the tank support 25. The tank support portion 25 supports the equator portion of the LNG tank 11A.

  Next, the process of mounting the LNG tank 11 as an independent square tank on the hull 20 of the existing bulk carrier will be described with reference to FIGS. 4D and 4E. Hereinafter, the LNG tank 11 as an independent square tank is referred to as an LNG tank 11B.

  Referring to FIG. 4D, an opening 22 is formed in the upper deck 21, and a tank support 26 is provided in the cargo hold 23. Here, the tank support 26 is installed on the double bottom 24. It is preferable to reinforce the portion where the tank support 26 of the double bottom 24 is installed.

  Referring to FIG. 4E, the LNG tank 11B is put into the cargo hold 23 through the opening 22, and the LNG tank 11B is placed on the tank support 26. The tank support portion 26 supports the bottom surface of the LNG tank 11B.

  According to the present embodiment, when the demand for a bulk carrier is low and the demand for an LNG ship is high, a new LNG ship is created by using an unnecessary bulk carrier hull and an LNG tank of an LNG ship whose ship hull structure is aged. It can be constructed in a short period of time and at a low cost.

(Fourth embodiment)
With reference to FIG. 5, the manufacturing method of the floating structure based on the 4th Embodiment of this invention is demonstrated. In the present embodiment, floating facilities such as FPSO and FSRU are manufactured as floating structures.

  First, the hull 10 of the existing LNG ship and the hull 30 of the new floating body facility are arranged in parallel in the construction dock 60. The method of arranging the hull 10 of the existing LNG ship and the hull 30 of the newly built floating equipment in parallel in the construction dock 60 is to arrange the hull 10 of the existing LNG ship and the hull 20 of the new LNG ship in parallel in the construction dock 60. This is the same as the method of arranging them side by side.

  Thereafter, the crane 61 is used to remove the LNG tank 11 from the hull 10 of the existing LNG ship and mount it on the hull 30 of the new floating body facility. You may remove the cargo handling equipment 12 and the residential area 13 from the hull 10 of the existing LNG ship using the crane 61, and you may mount in the hull 30 of a new floating body equipment. Furthermore, the additional equipment 31 is mounted on the hull 30 of the new floating body equipment. The additional equipment 31 is, for example, a liquefied natural gas generation / storage plant that generates and stores LNG from natural gas extracted from a gas field, or a regasification plant that regasifies the stored LNG.

  According to this embodiment, the same effect as the first embodiment can be obtained.

  The second embodiment, the modification of the second embodiment, and another modification of the second embodiment may be applied to the manufacture of a new floating body facility.

(Fifth embodiment)
With reference to FIG. 6, the manufacturing method of the floating body structure which concerns on the 5th Embodiment of this invention is demonstrated. In the present embodiment, the new floating equipment 40 such as FPSO and FSRU is manufactured as a floating structure.

  The new floating body equipment 40 is manufactured using the hulls 10 of the two existing LNG ships from which the LNG tank 11 is removed in any of the above-described embodiments. In the hull 10 of the existing LNG ship, a portion where the LNG tank 11, the cargo handling equipment 12, and the residential area 13 are removed is indicated by a broken line. In one hull 10, the LNG tank 11, the cargo handling equipment 12, and the residential area 13 are left without being removed. In the other hull 10, the LNG tank 11 and the cargo handling facility 12 are left without being removed. In the method for manufacturing a floating structure according to the present embodiment, the hulls 10 of two existing LNG ships are aligned and fixed in parallel. That is, the hulls 10 are fixed so that the starboard of one hull 10 is adjacent to the portside of the other hull 10. Furthermore, the additional equipment 41 is mounted on the hull 10. The additional equipment 41 is, for example, a liquefied natural gas generation / storage plant that generates and stores LNG from natural gas extracted from a gas field, or a regasification plant that regasifies the stored LNG.

  According to this embodiment, since the hull 10 of the existing LNG ship after removing the LNG tank 11 is used for manufacturing the new floating body equipment 40 without being dismantled, the dismantling work is minimized.

  The present invention has been described above with reference to the embodiment, but the present invention is not limited to the above embodiment. Various modifications can be made to the above embodiment, and the above embodiments can be combined. For example, the crane 61 is used to remove the LNG tank 11 from the hull 10 of the existing LNG ship moored on the quay 66 and mount it on the hull 20 of the new LNG ship or the hull 30 of the new floating structure installed in the construction dock 60. May be.

DESCRIPTION OF SYMBOLS 10 ... Hull 11 (11A, 11B) of existing LNG ship ... LNG tank 12 ... Cargo handling facility 13 ... Residential area 20 ... Hull 21 of newly built LNG ship ... Upper deck 22 ... Opening 23 ... Cargo hold 24 ... Double bottom 25 26 ... Tank support section 30 ... New floating body equipment hull 31 ... Additional equipment 40 ... New floating body equipment 41 ... Additional equipment 60 ... Construction dock 61 ... Crane 65, 66 ... Quay 67 ... Outfitting quay 70 ... Crane ship 71 ... Crane 75 ... Barge

Claims (8)

Removing the liquefied natural gas tank from the first hull of the first liquefied natural gas carrier using the first crane;
Mounting the liquefied natural gas tank on a hull different from the first hull using a second crane that is the same as or different from the first crane. A method for manufacturing a floating structure. The step of removing the liquefied natural gas tank and the step of mounting the liquefied natural gas tank on the hull different from the first hull are executed in a state where the first hull and the hull are arranged side by side in a building dock. Item 2. A method for producing a floating structure according to Item 1. Further comprising the step of transporting the liquefied natural gas tank by sea between the step of removing the liquefied natural gas tank from the first hull and the step of mounting the liquefied natural gas tank on the hull different from the first hull. The method for manufacturing a floating structure according to claim 1. The method for manufacturing a floating structure according to claim 1 or 3, wherein at least one of the first crane and the second crane is a crane of a crane ship. Removing a residential area or cargo handling equipment from the first liquefied natural gas carrier;
The method for manufacturing a floating structure according to any one of claims 1 to 4, further comprising a step of mounting the residential area or the cargo handling facility on the hull. The hull is a bulk carrier hull,
Forming an opening in the upper deck of the bulk carrier hull;
Providing a tank support in a cargo hold of the bulk carrier hull,
The step of mounting the liquefied natural gas tank on the hull different from the first hull includes:
Putting the liquefied natural gas tank into the cargo hold through the opening;
The method for producing a floating structure according to claim 1, further comprising a step of placing the liquefied natural gas tank on the tank support portion. A step of mounting a liquefied natural gas generation / storage plant for generating and storing liquefied natural gas from natural gas mined from a gas field or a regasification plant for regasifying the stored liquefied natural gas on the hull; A method for producing a floating structure according to any one of claims 1 to 5. Fixing the first hull and the second hull of the second liquefied gas carrier in parallel and fixing;
A liquefied natural gas generation / storage plant that generates and stores liquefied natural gas from natural gas mined from a gas field, or a regasification plant that regasifies the stored liquefied natural gas is the first hull or the second The method for producing a floating structure according to claim 1, further comprising a step of mounting on a hull.

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