WO2019012709A1 - Deck-placed tank structure, ship, tank installation method, and inspection method - Google Patents

Abstract

A deck-placed tank structure (1A) comprises: a plurality of saddles (3); a lattice member (4); a plurality of support parts (5A); a tank (6A); an upper cover (22); and a plurality of lower covers (23). The plurality of saddles (3) are provided with spaces therebetween so as to protrude from a top deck of a ship. The lattice member (4) is supported from below by the plurality of saddles (3) and has a lattice shape in plan view. The plurality of support parts (5A) are arranged on an upper surface of the lattice member (4). The tank (6) is supported from below by the plurality of support parts (5A) and a liquefied gas is accommodated inside thereof. The upper cover (22) is supported by the lattice member and covers the sides and top of the tank. The plurality of lower covers (23) are attached so as to close lattice openings (4a) of the lattice member 4, thereby forming a closed space together with the upper cover (22).

Description

Deck set tank structure, ship, installation method and inspection method of tank

The present invention relates to a deck-placement tank structure, a ship, and a method of installing and checking a tank.
Priority is claimed on Japanese Patent Application No. 2017-136911, filed July 13, 2017, the content of which is incorporated herein by reference.

In ships, it is desirable to reduce the emission of air pollutants such as carbon dioxide and sulfur oxides. In order to suppress the discharge of such air pollutants, there is a method of using liquefied gas (LNG, LPG, etc.) as fuel.
Patent Literature 1 and Patent Literature 2 describe a ship in which a fuel tank of liquefied natural gas is installed on an upper deck. The tank structure described in Patent Document 1 supports the fuel tank from below by using a grid-like frame body which is disposed to be separated upward from the upper deck by a plurality of saddles.

JP, 2014-162430, A Japanese Patent Application Publication No. 2013-530865

In the tank structure of Patent Document 1, after the tank is installed in a lattice-like frame, tank covers are attached to the upper side, the front side, the rear side, the lower side and the both sides of the tank. Under the present circumstances, since the lower tank cover is installed between a tank and a grid | lattice-like frame, the subject that the workability at the time of attaching a lower tank cover is bad occurs.
In the case where an inspection or the like in the tank cover is performed after the tank cover is attached, for example, it is necessary to remove the lower tank cover. At that time, there is a problem that the workability is poor because the grid-like frame is installed as in the case of the attachment of the tank cover.

The present invention provides a deck-placement tank structure, a vessel, and a method of installing and checking a tank, which can improve the workability such as installation and inspection.

According to a first aspect of the present invention, a decking tank structure includes a plurality of saddles, a grid member, a plurality of supports, a tank, an upper cover, and a plurality of lower covers.
A plurality of saddles are spaced apart to project from the deck of the vessel. The grid material is supported from below by the plurality of saddles, and forms a grid in plan view. A plurality of supports are disposed on the top surface of the grid material. The tank is supported from below by a plurality of supports, and the liquefied gas is contained therein. The upper cover is supported by the grid material and covers the side and upper side of the tank. The plurality of lower covers form a closed space together with the upper cover by being attached so as to close the lattice-like opening of the lattice material.
With this configuration, for example, when constructing the tank structure, finally, the lower cover can close the lattice-like opening of the lattice material. When inspecting the tank structure, it is possible to inspect the inside of the cover through the grid opening by removing only the lower cover near the point to be inspected.
Therefore, since the lower cover can be easily attached and detached, the workability when attaching and detaching the cover can be improved.

According to a second aspect of the present invention, in the deck storage tank structure according to the first aspect, the lower cover attached so as to close the opening of the grid material and the grid material surrounding the opening are provided. , And may be provided with a recess that opens upward.
With such a configuration, the recess formed by the grid member and the lower cover can be used as a container for receiving the liquefied gas leaked from the tank. As a result, it is possible to suppress an increase in the number of parts as compared to the case where a container for receiving liquefied gas is separately provided.

According to a third aspect of the present invention, in the deck storage tank structure according to the first aspect, the heat insulating material covering the surface of the tank may be provided. At least one of the surface of the tank and the heat insulating material may include a groove for guiding the liquefied gas leaked from the tank to the recess.
By this configuration, even if the heat insulating material and the surface of the tank are in close contact with each other, the leaked liquefied gas can be guided to the recess by the groove.

According to the fourth aspect of the present invention, the support according to the first to third aspects may be provided with a heat insulating block and a height adjustment member. The heat protection block has a lower thermal conductivity than the tank and the grid material. The height adjustment member adjusts the height of the upper surface of the heat shield block.
As described above, when the support portion includes the heat insulating block and the height adjusting member, the height adjustment of the upper surface of the heat insulating block by the height adjusting member can be performed through the grid-like opening. Therefore, the clearance adjustment between the support portion and the tank can be easily performed.

According to a fifth aspect of the present invention, the tank according to any one of the first to fourth aspects has a shape of any one of a rectangular tank, a cylindrical tank, and a spherical tank, LNG or LPG may be accommodated as the liquefied gas.
With this configuration, after the tank is placed on the support portion and the upper cover is installed, the lower cover may be attached to and detached from the lattice-like opening. Therefore, while being able to install easily the square tank for LNG and LPG, a cylindrical tank, and a spherical tank, it can inspect easily.

According to a sixth aspect of the present invention, a ship is provided with the deck storage tank structure according to the first to fifth aspects.
By configuring in this manner, for example, a tank for containing liquefied gas can be easily installed on the upper deck located above the cargo space or the like. As a result, reduction in cargo space and living space can be suppressed.

According to the seventh aspect of the present invention, the method of installing a tank includes a supporting portion installing step, a tank installing step, an adjusting step, a closing step, a hull side saddle attaching step, a lattice material side saddle attaching step, including. A support part installation process installs a plurality of support parts on the upper surface of a lattice material which makes a lattice shape by plane view. In the tank installation step, a tank in which the liquefied gas is stored is installed on the support portion so as to be supported from below by the plurality of support portions. In the adjusting step, the clearance between the support portion and the tank is adjusted through the grid-like opening of the grid material. In the closing step, the lattice-like openings of the lattice material are sealed by the lower cover. In the hull-side saddle mounting process, a plurality of saddles supporting the grid material from below are mounted on the hull. The lattice material side saddle attachment process attaches the plurality of saddles to the lattice material.
In this way, after the clearance between the support portion and the tank is adjusted through the lattice openings of the lattice material, the lower cover can be attached to the lattice openings of the lattice material and sealed. Therefore, the burden on the operator who installs the tank can be reduced.

According to an eighth aspect of the present invention, in the tank installation method according to the seventh aspect, the tank installation method may be such that the grid material side saddle installation process is performed after the hull side saddle installation process. .
By doing so, for example, after performing the hull-side saddle mounting step, it is possible to perform the lattice material-side saddle mounting step, the support portion installation step, the tank installation step, the adjustment step, and the closing step on the ship.

According to a ninth aspect of the present invention, in the tank installation method according to the seventh aspect, the tank installation method may be such that the hull side saddle installation process is performed after the grid material side saddle installation process. .
In this way, the saddle attached to the lattice can be attached to the hull. Therefore, for example, since the lattice material side saddle attachment process can be performed outside the ship, it is possible to shorten the time for putting the ship in the dock when installing a tank on a ship or the like in service.

According to a tenth aspect of the present invention, in the tank installation method according to the eighth aspect, the tank installation method is such that the hull side saddle installation process is performed after at least the support installation process and the tank installation process. It is good.
By doing this, for example, while performing the support part installation process, the tank installation process, etc. in a factory etc., after performing the lattice material side saddle installation process, the assembled assembly is lifted with a crane or the like, The saddle can be fixed to the hull after it has been moved onto the deck of the ship. Therefore, when installing in the ship etc. which are in service, the period which docks a ship can be shortened further.

According to an eleventh aspect of the present invention, an inspection method includes a plurality of saddles, a lattice material, a plurality of supports, a tank, an upper cover, and a plurality of lower covers. It is an inspection method. A plurality of saddles are spaced apart to project from the deck of the vessel. The grid material is supported from below by the plurality of saddles, and forms a grid in plan view. A plurality of supports are disposed on the top surface of the grid material. The tank is supported from below by a plurality of supports, and the liquefied gas is contained therein. The upper cover is supported by the grid material and covers the side and upper side of the tank. The plurality of lower covers form a closed space together with the upper cover by being attached so as to close the lattice-like opening of the lattice material. The inspection method of the deck placement tank structure includes a lower cover removal process, an inspection process, and a reclose process. In the lower cover removing step, a part of the lower cover of the plurality of lower covers attached so as to close the lattice-like opening of the lattice material is removed from the lattice material. In the inspection process, the inside of the sealed space is inspected through the opening from which the lower cover is removed. In the reclosing step, the opening is sealed again by the lower cover removed in the lower cover removing step.
By doing this, it is possible to inspect the inside of the enclosed space by attaching / detaching only the lower cover of the necessary place from below the grid material. Therefore, the burden on the worker performing the inspection can be reduced.

According to the above-described deck-placement tank structure, the vessel, and the installation method and inspection method of the tank, it is possible to improve the workability such as installation and inspection.

It is a perspective view showing a schematic structure of a vessel in an embodiment of this invention. It is the perspective view which expanded tank structure 1A in the embodiment of this invention. It is a perspective view of a saddle, a lattice material, and a tank body. It is the perspective view which looked at the lattice material of the state supported by the said saddle from upper direction. It is the perspective view which looked at the tank structure in the embodiment of this invention from the lower part. It is a side view of the tank structure in an embodiment of this invention. It is a flowchart of the installation method of the tank structure in embodiment of this invention. It is explanatory drawing of the adjustment process in the installation method of the said tank structure. It is a flowchart of the inspection method in embodiment of this invention. It is a flowchart of the installation method of the tank structure in the 1st modification of embodiment of this invention. It is a flowchart of the installation method of the tank structure in the 2nd modification of embodiment of this invention. It is a perspective view of the tank main body in the 3rd modification of an embodiment of this invention.

Next, a deck-placement tank structure, a vessel, a method of installing and checking a tank according to an embodiment of the present invention will be described based on the drawings.
FIG. 1 is a perspective view showing a schematic configuration of a ship according to an embodiment of the present invention.
As shown in FIG. 1, the ship 2 of this embodiment is provided with a hull 8, an upper structure 9, and a tank structure (deck placement tank structure) 1A.

The ship 2 illustrated in this embodiment is a ship such as a tanker transporting oil. In the ship 2, an upper structure 9 and a tank structure 1 </ b> A are disposed on an upper deck (deck) 10 that is an exposed deck of the hull 8. The superstructure 9 has a living area and a bridge, and is disposed closer to the stern in the ship's forward direction than the cargo space for storing the oil, which is the cargo.

The tank structure 1A is disposed adjacent to the bow side of the upper structure 9. Two tank structures 1A in this embodiment are arranged side by side in the ship width direction. The upper surfaces of the tank structures 1A are disposed below the bridge in order to ensure visibility from the bridge of the upper structure 9.

FIG. 2 is an enlarged perspective view of a tank structure in the embodiment of the present invention. FIG. 3 is a perspective view of a saddle, a grid and a tank body. FIG. 4 is a perspective view of the grid member supported by the saddle as viewed from above.
As shown in FIGS. 2 to 4, the tank structure 1 </ b> A includes a saddle 3, a lattice member 4, a support 5 </ b> A, a tank body 6 </ b> A, and a tank cover 7.
The saddle 3 is provided to project upward from the upper deck 10. A plurality of saddles 3 are provided at intervals, respectively, and support the lattice material 4 from below. The saddle 3 illustrated in this embodiment has an X-shaped cross section. The lower end portion of the saddle 3 is fixed to, for example, a strength member (not shown) or the like that is attached to the lower surface of the upper deck 10 and extends in the ship width direction or the ship success direction. The saddle 3 in this embodiment has a length of about 2 m from the upper deck 10 to the upper end thereof.

As shown in FIG. 4, the lattice material 4 is formed in a lattice shape. The grid member 4 is supported from below by the plurality of saddles 3 described above. More specifically, the lattice material 4 is disposed in a posture parallel to the upper deck 10, and the upper end portion of the saddle 3 is fixed to the lower surface thereof. The grid material 4 in this embodiment is formed of, for example, an H-shaped steel or an I-shaped steel. The lattice material 4 includes an outer frame portion 15, a longitudinal beam portion 16, and a transverse beam portion 17.

The outer frame portion 15 forms a rectangular outer frame. The outer frame portion 15 in this embodiment is provided with a pair of longitudinal members 15a extending in the direction of the ship's success and a pair of transverse members 15b extending in the direction of the ship's width. The longitudinal beam portions 16 are formed to extend in the ship's forward direction, and a plurality of longitudinal beam portions 16 are provided inside the outer frame portion 15 at intervals in the ship width direction. The cross beam portion 17 is formed to extend in the width direction of the ship, and a plurality of cross beam portions 17 are provided inside the outer frame portion 15 at intervals in the direction of the ship. The longitudinal beam portion 16 and the transverse beam portion 17 intersect with each other on the inner side of the outer frame portion 15. In this embodiment, although the case where five vertical beam portions 16 and three horizontal beam portions 17 are provided is illustrated, the number of vertical beam portions 16 and horizontal beam portions 17 is not limited to the above number.

A plurality of support portions 5A are arranged on the upper surface 4u of the lattice material 4. The support portions 5A illustrated in this embodiment are disposed at the intersections of the longitudinal beam portions 16 and the transverse beam portions 17, respectively. The upper surfaces 5a of the plurality of support portions 5A are disposed to abut on the lower surface 6a (see FIG. 8) of the tank body 6A. The support 5 </ b> A includes a heat shield block 20. The heat shield block 20 is formed of a synthetic resin such as a phenol resin, or a material having a thermal conductivity lower than that of the tank body 6A and the grid member 4 such as wood. In this manner, the support portion 5A suppresses the heat conduction from the tank body 6A at extremely low temperature to the grid member 4 while supporting the tank body 6A from below.

The tank main body (tank) 6A accommodates, for example, liquefied natural gas (LNG), which is a fuel for a ship to travel therein. As shown in FIG. 3, the tank body 6A in this embodiment is a rectangular tank provided with a trunk top 21 for carrying a load of liquefied natural gas or the like in the upper center thereof. The tank body 6A is supported from below by the plurality of support portions 5A described above. The tank body 6A is formed of a metal such as an aluminum alloy which does not break brittlely against the cryogenic temperature of the liquefied natural gas. The tank main body 6A in this embodiment is covered with a heat insulating material 40 (see FIG. 8) such as polyurethane, except for a portion in contact with the support 5A described above.

FIG. 5 is a perspective view of the tank structure in the embodiment of the present invention as viewed from below.
As shown in FIGS. 2 and 5, the tank cover 7 is disposed so as to cover the above-described tank body 6A, and forms a sealed space around the tank body 6A. The tank cover 7 includes an upper cover 22 and a lower cover 23 (see FIG. 5).

The upper cover 22 is supported by the grid member 4 and covers the side and upper side of the tank body 6A. More specifically, the upper cover 22 includes an upper wall 22a and a side wall 22b. The upper wall portion 22a is formed in a rectangular plate shape covering the upper side of the tank main body 6A. The side wall portions 22 b are each formed in a tubular shape having a rectangular cross section extending downward from the four sides of the upper wall portion 22 a. In the upper cover 22 formed in this manner, the opening edge 22c facing downward is fixed to the outer frame portion 15 of the grid member 4 by welding or the like over the entire circumference.

A plurality of lower covers 23 are provided and attached so as to respectively close a plurality of grid-like openings 4 a (see FIG. 4) formed by the grid material 4. The plurality of lower covers 23 together with the upper cover 22 form a closed space isolated from the outside around the tank body 6A. More specifically, a closed space is formed by the lower cover 23, the upper cover 22 and the lattice material 4. The lower cover 23 illustrated in this embodiment is formed in a rectangular plate shape slightly larger than the opening 4a. For example, the entire periphery of each outer peripheral portion 23a of the plurality of lower covers 23 is fixed to the lower surface of the grid member 4 at the periphery of the opening 4a by welding or the like. In other words, the openings 4 a of the grid material 4 are respectively sealed from below by the lower cover 23.

The lower cover 23 closes the opening 4 a of the grid member 4 from the lower side to form a recess 50 (see FIG. 6) that opens upward together with the grid member 4 on the periphery of the lower cover 23. In FIG. 5, the case where the lower cover 23 which closes one opening 4a and the lower cover 23 which closes two openings 4a is illustrated. However, the configuration of the lower cover 23 is not limited to the above configuration. For example, one opening 4a may be closed by a plurality of lower covers 23, or three or more openings 4a may be closed by a single lower cover 23.

FIG. 6 is a side view of the tank structure in the embodiment of the present invention.
As shown in FIG. 6, in the tank structure 1A in this embodiment, the surface of the tank main body 6A is in close contact with the inner surface of the heat insulating material 40 covering the surface. At least one of the surface of the tank main body 6A and the inner surface of the heat insulating material 40 has a groove 41. The groove 41 guides the leaked liquefied natural gas, for example, when the liquefied natural gas gradually leaks from the tank body 6A. More specifically, the liquefied natural gas leaked from the tank main body 6A is guided to a predetermined recess 50A among the plurality of recesses 50 formed by the grid member 4 and the lower cover 23 described above.

Here, the groove portions 41 exemplified in this embodiment are formed in a lattice shape so as to extend vertically and horizontally, and are slightly inclined so that the liquefied natural gas can be moved by its own weight toward the predetermined concave portion 50A. It is formed. The predetermined concave portion 50A may be provided with a cover member formed of a material which is hard to break easily at low temperature. A part of the lattice material 4 forming the predetermined concave portion 50A or the lower cover 23 forming the predetermined concave portion 50A may be formed of a material which is less likely to be brittlely broken at a low temperature. Although the case where groove part 41 was formed in the shape of a lattice was illustrated, groove part 41 should just be a shape which can guide liquefied natural gas to predetermined crevice 50A, and is not restricted to the above-mentioned shape.

Next, a method of installing the above-described tank structure 1A will be described with reference to the drawings.
FIG. 7 is a flow chart of a method of installing a tank structure in an embodiment of the present invention. FIG. 8 is an explanatory view of the adjustment process in the method of installing the tank structure. In the description of the installation method of the tank structure 1A, a case where the installation work is mainly performed on the upper deck 10 will be described as an example.

As shown in FIG. 7, first, a hull-side saddle mounting step (step S01) is performed. In the hull-side saddle mounting process, a plurality of saddles 3 are installed at intervals so as to protrude from the upper deck 10 of the ship 2.

Next, a lattice material side saddle attaching process (step S02) is performed. In this grid material side saddle mounting process, the grid material 4 in a grid shape in plan view is mounted on the saddle 3 so as to be supported from below by a plurality of saddles 3 installed in the hull side saddle mounting process. At this time, for example, by welding or the like the entire circumference of the saddle 3, the saddle 3 is fixed so as not to be separated from the lattice material 4. Thereby, the lattice material 4 is installed in a posture to be disposed on a virtual plane parallel to the upper deck 10.

Thereafter, a support portion installation step (step S03) of installing the plurality of support portions 5A on the upper surface of the grid member 4 is performed. In this support portion installation step, the plurality of support portions 5A are respectively disposed in a predetermined arrangement spaced apart from each other in the ship success direction and the ship width direction so that the load of the tank body 6A is dispersed.

And a tank installation process (step S04) is performed. In the tank installation step, the tank body 6A is installed on the support 5A so as to be supported from below by the plurality of supports 5A. At this time, the tank body 6A is installed so that the heat shield block 20 of the support portion 5A abuts on the lower surface 6a of the tank body 6A. In the tank installation step in this embodiment, after the tank body 6A is installed, the heat insulating material 40 is attached to the tank body 6A. Further, the upper cover 22 is installed, and the opening edge 22c of the upper cover 22 and the outer frame portion 15 of the lattice material are fixed by welding or the like.

Next, the adjustment process (step S05) is performed. In this adjustment process, for example, the clearance between the support portion 5A and the tank main body 6A is adjusted through the lattice-shaped openings 4a of the lattice material 4. At this time, an operator performs adjustment work on a scaffold or the like assembled below the grid member 4. As shown in FIG. 8, a gap may be generated between the heat-insulation block 20 of the support portion 5A and the lower surface 6a of the tank body 6A only by installing the tank body 6A. Therefore, in this adjustment step, the height position of the heat insulating block 20 is adjusted such that all the heat insulating blocks 20 of the plurality of support portions 5A are in contact with the lower surface 6a of the tank body 6A. As the adjustment method in this adjustment step, the method shown in FIG. 8 can be exemplified. In the adjustment method shown in FIG. 8, a shim plate 53 having a thickness corresponding to the gap is inserted as a height adjustment member between the heat shield block 20 and the grid member 4 from the side on which the rib 52 is not disposed. The height position of the heat insulating block 20 is adjusted such that the upper surface of the heat insulating block 20 (in other words, the upper surface 5a of the support 5A) is in contact with the lower surface 6a of the tank body 6A.

Thereafter, the closing step (step S06) is performed. In this closing step, the grid-like openings 4 a of the grid material 4 are closed by the lower cover 23. More specifically, on a scaffold or the like assembled below the grid member 4, the worker blocks all of the plurality of openings 4 a from below with the plurality of lower covers 23. At this time, the entire periphery of the lower cover 23 is fixed to the grid member 4 by welding or the like so that the opening 4 a is sealed by the lower cover 23. Thus, a sealed space is formed between the tank cover 7 and the tank body 6A.
Then, the scaffolding assembled below the lattice material 4 is disassembled, and the installation work of the tank structure 1A is completed.

Next, a method of checking the tank structure 1A installed as described above will be described with reference to the drawings.
FIG. 9 is a flowchart of the inspection method in the embodiment of the present invention.
As shown in FIG. 9, first, the lower cover removing step (step S10) is performed. In the lower cover removing step, a part of the lower cover 23 among the plurality of lower covers 23 attached so as to close the grid-like opening 4 a of the grid 4 is removed from the grid 4. More specifically, the lower cover 23 closing the opening 4a near the inspection point is removed. Under the present circumstances, a scaffold etc. are assembled below the grating | lattice material 4, and the work which removes the lower cover 23 from the downward direction of the grating | lattice material 4 is performed.

Next, an inspection process (step S11) is performed. In this inspection process, the inside of the sealed space is inspected visually, for example, through the opening 4a from which the lower cover 23 is removed. At this time, a worker may enter the inside of the tank cover 7 through the opening 4a. In addition, if it is determined by inspection that repair or the like is necessary, repair work may be carried out as it is.

Thereafter, the re-closing step (step S12) is performed. In the reclosing step, the opening 4a from which the lower cover 23 has been removed in the lower cover removal step is again sealed by the lower cover 23. At this time, the lower cover 23 may be reused after being removed. For example, when the lower cover 23 is broken due to the removal, a new lower cover 23 may be used.
Then, the scaffold or the like assembled below the grid member 4 is disassembled to complete the inspection.

Therefore, according to the embodiment described above, for example, when constructing the tank structure 1A, the clearance adjustment between the support portion 5A and the tank main body 6A is performed through the lattice-shaped opening 4a, and finally the lattice material 4 is formed by the lower cover 23. The grid-like opening 4a can be closed. Furthermore, when inspecting the tank structure 1A, it is possible to inspect the inside of the tank cover 7 through the grid-like opening 4a by removing only the lower cover 23 near the location to be inspected. As a result, the workability of installation and inspection of the tank structure 1A can be improved, and the burden on the operator can be reduced.

Furthermore, the recess 50 formed by the grid member 4 and the lower cover 23 can be used as a container for receiving the liquefied natural gas leaked from the tank body 6A. As a result, it is possible to suppress an increase in the number of parts as compared to the case where a container for receiving liquefied natural gas is separately provided.

Furthermore, when performing the clearance adjustment operation, it can be performed from the lower side through the grid-like opening 4a. Furthermore, the clearance between the heat shield block 20 and the tank main body 6A can be easily confirmed visually or the like from the opening 4a.
And by adopting the above-mentioned tank structure 1A, a square tank for liquefied natural gas can be easily installed on the upper deck 10 or the like.

In the installation method of the tank structure of the embodiment described above, the case where the saddle installation step (step S01) and the grid material installation step (step S02) are performed first has been described. However, the timing at which the saddle 3 is attached to the lattice 4 is not limited to the timing in the above-described embodiment.

(First modification)
FIG. 10 is a flowchart of a method of installing the tank structure in the first modified example of the embodiment of the present invention. In the description of the first modified example, the same steps as those of the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted.
As shown in FIG. 10, in the installation method of the tank structure in the first modification, first, a support portion installation step (step S03), a tank installation step (step S04), an adjustment step (step S05), and a closing step ( Step S06) is performed.

Thereafter, a hull side saddle mounting process (step S01) is performed to attach the saddle 3 to the hull so that the saddle 3 protrudes from the upper deck. Subsequently, the grid material side saddle mounting step (step S02) of attaching the plurality of saddles 3 attached to the hull to the grid material 4 is performed so that the grid material 4 is supported from below by the plurality of saddles Finish installation of.
In this first modification, the case of performing the hull side saddle mounting step (step S01) and the lattice material side saddle mounting step (step S02) after the closing step (step S06) has been described, but the hull side saddle mounting step (step S06) The closing step (step S06) may be performed after step S01) and the grid material side saddle attaching step (step S02). Although the case where the hull side saddle attachment process (step S01) is performed after the support portion installation step (step S03), the tank installation step (step S04), etc. has been described, the hull side saddle attachment step (step S01) It may be performed in parallel with the installation step (step S03), the tank installation step (step S04), and the like.

(Second modification)
FIG. 11 is a flowchart of a method of installing a tank structure in a second modification of the embodiment of the present invention. In the description of the second modification, the same steps as those of the embodiment described above are denoted by the same reference numerals, and redundant description will be omitted.
As shown in FIG. 11, in the installation method of the tank structure in the second modification, first, the support portion installation step (step S03), the tank installation step (step S04), the adjustment step (step S05), and the closing step ( Step S06) is performed.

Thereafter, the grid material side saddle mounting step (step S02) for attaching the saddle 3 to the grid material 4 is performed so that the saddle 3 protrudes downward from the grid material 4. The lattice material side saddle attaching process (step S02) in the second modification may be any configuration as long as it is performed before the hull side saddle attaching process (step S01). For example, a support portion installation process (step S03), a tank It may be performed before the installation step (step S04) and the like, or may be performed in parallel with the support portion installation step (step S03), the tank installation step (step S04) and the like.

Then, while lifting up the assembly (not shown) to which the saddle 3 is attached by a crane (not shown) or the like, the saddle 3 is mounted on a strength member of the hull, such as aggregate provided on the lower surface side of the upper deck 10. And the ship-side saddle mounting step (step S01) for fixing the tank structure, and the installation of the tank structure is completed. At this time, the saddle 3 is fixed to the hull such as aggregate so that the grid member 4 is disposed apart from the upper deck 10.
In this second modification, the grid material side saddle mounting process (step S02) and the saddle hull side saddle mounting process (step S01) are performed after the closing process (step S06), but the grid material side saddle mounting is performed. The closing step (step S06) may be performed after the step (step S02) or the saddle hull side saddle attaching step (step S01).

(Third modification)
Next, a third modification of the embodiment of the present invention will be described based on the drawings. The third modification differs from the above embodiment in that the shape of the tank body is cylindrical. Therefore, in the third modified example, the same parts as those in the above-described embodiment will be described with the same reference numerals, and the redundant description will be omitted.
As shown in FIG. 12, a tank structure 1B in the third modification includes a saddle 3, a lattice member 4, a support portion 5B, a tank body (cylindrical tank) 6B, and a tank cover 7. . In addition, in FIG. 12, only the lower cover 23 is shown among the tank covers 7, and illustration of the upper cover 22 is abbreviate | omitted. The upper cover 22 may have the same shape as that of the above-described embodiment, or may have another shape according to the tank body 6B.

The saddle 3 is provided to project upward from the upper deck 10. A plurality of saddles 3 are provided at intervals, respectively, and support the lattice material 4 from below. The saddle 3 illustrated in the third modified example of this embodiment is formed to have an H-shaped cross section, and the lower end portion thereof is, for example, the ship width direction or the ship success direction attached to the lower surface of the upper deck 10. It is fixed to a strength member (not shown) etc. As in the embodiment described above, the saddle 3 in the third modification also has a length from the upper deck 10 to the upper end thereof of about 2 m.

The grid material 4 is formed in a grid shape as in the above-described embodiment. The grid member 4 is supported from below by the plurality of saddles 3 described above. The lattice material 4 includes an outer frame portion 15, a longitudinal beam portion 16, and a transverse beam portion 17.

The support 5 </ b> B is installed on the upper surface 17 u of the cross beam 17 of the lattice material 4. Two support portions 5B illustrated in the third modification are provided at intervals in the extending direction of the longitudinal beam portion 16. The plurality of support portions 5B include a support portion main body 5Ba and a contact portion 5Bb.
The support portion main body 5Ba extends upward from the upper surface 17u of the cross beam portion 17, and has a recess 60 corresponding to the shape of the tank main body 6B. The recess 60 in this third modification is formed in an arc shape having a radius of curvature slightly larger than the radius of the tank body 6B when viewed in the extending direction of the longitudinal beam portion 16.

The contact portion 5Bb is formed to abut on the tank body 6B. The contact portion 5Bb is formed in an arc shape along the recess 60 as viewed from the extending direction of the vertical beam portion 16, and is formed in a plate shape spreading on both sides in the thickness direction of the support portion main body 5Ba. Although not shown, the supporting portion 5B has a heat more than the tank main body 6B and the grid member 4 between the supporting portion main body 5Ba and the abutting portion 5Bb or between the abutting portion 5Bb and the tank main body 6B. A heat shield made of a low conductivity material is provided. Examples of the material having a thermal conductivity lower than that of the tank main body 6B and the lattice 4 may include synthetic resins such as phenol resin, and wood. In this manner, the support portion 5B suppresses the heat conduction from the tank body 6B at extremely low temperature to the grid member 4 while supporting the tank body 6B from below.

As in the first embodiment, the tank body (tank) 6B accommodates liquefied natural gas (LNG), which is a fuel for a ship to travel, in its inside. The tank body 6B in this embodiment is a cylindrical tank. The tank main body 6B has a spherical surface in which both ends in the direction of the axis O protrude outward. The tank body 6B is supported from below by the plurality of support portions 5B described above. The tank body 6B is formed of a metal such as an aluminum alloy which does not break brittlely at the cryogenic temperature of the liquefied natural gas, as in the embodiment described above. The tank main body 6B is covered with a heat insulating material 40 (see FIG. 8) such as polyurethane, except for a portion in contact with the support portion 5B described above. In addition, illustration of the trunk top 21 is abbreviate | omitted in FIG.

For example, while a gap is formed between the heat insulating material 40 (not shown) and the tank main body 6B, an axis O extending along the upper deck 10 (not shown), as shown in FIG. In the case of the cylindrical tank main body 6B having the above, the leaked liquefied gas moves downward along the outer peripheral surface of the tank main body 6B. Then, they gather at the straight lowermost part along the axis O. For example, by providing a pipe or the like (not shown) reaching a predetermined recessed portion 50A (see FIG. 6) in a part of the lowermost portion, the liquefied gas collected at the lowermost portion is guided to the predetermined recessed portion 50A. The liquefied gas can be stored in a predetermined recess 50A. By providing the pipe or the like in this manner, it is not necessary to incline the cylindrical tank 6A in order to collect the liquefied gas in one place.

(4th modification)
In the third modification, the case where the tank body 6B is a cylindrical tank has been described. However, in addition to the cylindrical type, for example, a spherical tank may be used.
Here, the “spherical tank” is not limited to a spherical shape, but has a shape in which the vicinity of the equatorial portion is formed in a cylindrical or truncated cone shape, or a shape including an elliptical curved surface or the like in at least a part of the cross section. It may be.

For example, if a gap is formed between the heat insulator 40 (not shown) and the spherical tank, the leaked liquefied gas travels along the outer surface of the spherical tank to the lowest point, for example, by its own weight. Fall down. That is, in the case of the spherical tank, if the above-described predetermined recess 50A (see FIG. 6) is disposed immediately below the lowest point, liquefied gas can be stored in the predetermined recess 50A.

(Other modifications)
The present invention is not limited to the configurations of the embodiment and the modifications described above, and design changes can be made without departing from the scope of the invention.
For example, in the embodiment described above, the case where the support portion 5A includes the shim plate 53 under the heat shield block 20 has been described. However, the shape of the support portion 5A may be any structure capable of suppressing heat transfer between the tank main body 6A and the lattice material 4 and capable of height adjustment, and is not limited to the shape of the embodiment described above.

In the embodiment described above, the case where the support portion 5A is disposed at the intersection of the longitudinal beam portion 16 and the transverse beam portion 17 is exemplified. However, the support portion 5A may be provided at a place other than where the longitudinal beam portion 16 and the transverse beam portion 17 intersect.

In the embodiment mentioned above, the case where fixation of lattice material 4 to saddle 3 and fixation of tank cover 7 to lattice material 4 were performed by welding was illustrated. However, these fixing methods are not limited to welding, and may be adhesion, for example.
In the embodiment described above, the case where the groove portion 41 is formed in at least one of the heat insulator 40 and the tank main body 6A has been described. However, the groove 41 may be provided as appropriate, and may be omitted. When the groove 41 is omitted as described above, for example, a gap may be provided between the heat insulating material 40 and the tank main body 6A.

In the embodiment described above, the case where the opening 4a of the lattice material 4 is closed from below by the lower cover 23 has been described. However, the configuration is not limited to this as long as the configuration can close the opening 4a. For example, the opening 4a of the grid member 4 may be closed from above.

In the above-described embodiment and the third and fourth modified examples, the case where the tank bodies 6A and 6B contain the LNG has been described. However, LPG etc. may be sufficient as the liquefied gas which tank main body 6A, 6B accommodates.
In the above-mentioned embodiment, the ship 2 illustrated the tanker which transports oil. However, it is not limited to this ship type. For example, other types of ships, such as a liquefied gas carrier vessel and a liquefied gas supply vessel, may be used.

The present invention can be applied to a deck-placement tank structure, a vessel, a method of installing and checking a tank, and a method of checking the same. According to the present invention, it is possible to improve the workability such as installation and inspection.

1A, 1B Tank Structure 2 Ship 3 Saddle 4 Grid Material 4a Opening 5A, 5B Support 6A, 6B Tank Body (Tank)
6a Lower surface 7 Tank cover 8 Hull 9 Upper structure 10 Upper deck 15 Outer frame 15a Vertical member 15b Horizontal member 16 Vertical beam 17 Horizontal beam 20 Heat shield block 20a Upper surface 21 Trunk top 22 Upper cover 22a Upper wall 22b Side wall 22c Opening Edge 23 Lower cover 40 Thermal insulation 41 Groove 50, 50A Recess 52 Rib 53 Shim plate 60 Recess

Claims (11)

1. A plurality of saddles spaced apart to project from the deck of the ship;
   A grid material supported from below by the plurality of saddles and forming a grid in plan view;
   A plurality of supports disposed on the top surface of the grid material;
   A tank supported from below by the plurality of supports and containing a liquefied gas therein;
   An upper cover supported by the grid member and covering the side and upper side of the tank;
   A plurality of lower covers which are attached to close the lattice openings of the lattice material to form a sealed space together with the upper cover;
   Deck placement tank structure with.
2. The deck placement tank structure according to claim 1, further comprising a recess formed by the lower cover attached so as to close the opening of the lattice material and the lattice material surrounding the opening and opening upward.
3. A heat insulator covering the surface of the tank;
   The deck placement tank structure according to claim 2, wherein at least one of the surface of the tank and the heat insulating material includes a groove for guiding the liquefied gas leaked from the tank to the recess.
4. The support portion is
   A heat shield block having a thermal conductivity lower than that of the tank and the grid material;
   A height adjustment member for adjusting the height of the upper surface of the heat shield block;
   The deck placement tank structure according to any one of claims 1 to 3, comprising:
5. The deck according to any one of claims 1 to 4, wherein the tank has a shape of any one of a rectangular tank, a cylindrical tank, and a spherical tank, and accommodates LNG or LPG as the liquefied gas. Place tank structure.
6. A vessel comprising the decking tank structure according to any one of claims 1 to 5.
7. A support portion installation step of installing a plurality of support portions on the upper surface of a lattice material having a lattice shape in plan view;
   Installing a tank in which liquefied gas is accommodated inside the support section so as to be supported from below by the plurality of support sections;
   An adjusting step of adjusting a clearance between the support portion and the tank through a grid-like opening of the grid material;
   Closing the grid-like opening of the grid material with a lower cover;
   A ship-side saddle mounting step of mounting a plurality of saddles supporting the grid material from below to the hull;
   A grid material side saddle mounting step of mounting the plurality of saddles to the grid material;
   How to install the tank, including
8. The tank installation method according to claim 7, wherein the grid material side saddle mounting step is performed after the hull side saddle mounting step.
9. The tank installation method according to claim 7, wherein the hull side saddle mounting step is performed after the grid material side saddle mounting step.
10. The tank installation method according to claim 9, wherein the hull-side saddle mounting step is performed after at least the support portion installation step and the tank installation step.
11. A plurality of saddles spaced apart to project from the deck of the ship;
    A grid material supported from below by the plurality of saddles and forming a grid in plan view;
    A plurality of supports disposed on the top surface of the grid material;
    A tank supported from below by the plurality of supports and containing a liquefied gas therein;
    An upper cover supported by the grid member and covering the side and upper side of the tank;
    A method of checking a deck placement tank structure, comprising: a plurality of lower covers which are attached so as to close a lattice-like opening of the lattice material to form a closed space together with the upper cover,
    A lower cover removing step of removing a part of the lower cover from the grid material among the plurality of lower covers attached to close the grid-like opening of the grid material;
    An inspection step of inspecting the inside of the sealed space through the opening from which the lower cover is removed;
    A reclosing step of resealing the opening by the lower cover removed in the lower cover removing step;
    Inspection method including.

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