CN110612250A

CN110612250A - Storage tank structure placed on deck, ship, installation method and inspection method of storage tank

Info

Publication number: CN110612250A
Application number: CN201780090524.6A
Authority: CN
Inventors: 渡部亨尚; 大塚浩友; 宫崎智
Original assignee: Mitsubishi Shipbuilding Corp
Current assignee: Mitsubishi Shipbuilding Corp; Mitsubishi Shipbuilding Co Ltd
Priority date: 2017-07-13
Filing date: 2017-10-17
Publication date: 2019-12-24
Anticipated expiration: 2037-10-17
Also published as: WO2019012709A1; JP6609828B2; JP2019018638A; CN110612250B; KR102246400B1; KR20190132680A

Abstract

The invention provides a storage tank structure (1A) placed on a deck, which is provided with a plurality of saddles (3), a grid material (4), a plurality of support parts (5A), a storage tank (6A), an upper cover (22), and a plurality of lower covers (23). The saddles (3) are provided at intervals so as to protrude from the deck of the ship. The grid material (4) is supported from below by a plurality of saddles (3) and has a grid shape in a plan view. The plurality of support portions (5A) are arranged on the upper surface of the grid material (4). The tank (6) is supported from below by a plurality of support sections (5A), and contains liquefied gas therein. An upper cover (22) is supported by the grid material and covers the sides and the top of the storage tank. The plurality of lower covers (23) are attached so as to close the grid-like openings (4a) of the grid material (4), thereby forming a sealed space together with the upper cover (22).

Description

Storage tank structure placed on deck, ship, installation method and inspection method of storage tank

Technical Field

The invention relates to a storage tank structure arranged on a deck, a ship, an installation method of the storage tank and an inspection method of the storage tank.

The present application claims priority based on japanese patent application No. 2017-136911, filed in japan on 13/7/2017, and the contents thereof are incorporated herein by reference.

Background

In ships, it is desired to suppress the discharge of air pollutants such as carbon dioxide and sulfur oxides. In order to suppress the discharge of such air pollutants, liquefied gases (LNG, LPG, etc.) are used as fuel.

Patent documents 1 and 2 describe ships having a fuel tank for liquefied natural gas provided on an upper deck. The tank structure described in patent document 1 supports a fuel tank from below using a grid-like frame body, and the frame body is arranged so as to be separated from an upper deck upward by a plurality of saddles.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open No. 2014-162430

Patent document 2: japanese Kohyo publication No. 2013-530865

Disclosure of Invention

Technical problem to be solved by the invention

In the tank structure of patent document 1, after the tank is provided in the lattice-like frame body, tank covers are attached to the upper side, front side, rear side, lower side, and both sides of the tank. In this case, since the lower tank cover is provided between the tank and the grid-like frame body, there is a problem that the operability is poor when the lower tank cover is attached.

In the case where inspection or the like of the inside of the tank cover is performed after the tank cover is attached, for example, an operation of detaching the lower tank cover is required. In this case, similarly to the attachment of the tank cover, there is a problem that the workability is poor because the lattice-shaped frame is provided.

The invention provides a storage tank structure placed on a deck, a ship, a method for installing the storage tank and a method for inspecting the storage tank, which can improve the operability of installation, inspection and the like.

Means for solving the technical problem

According to a first aspect of the present invention, a tank structure placed on a deck includes a plurality of saddles, a grid member, a plurality of support portions, a tank, an upper cover, and a plurality of lower covers.

The plurality of saddles are provided at intervals so as to protrude from the deck of the ship. The grid material is supported from below by a plurality of saddles and has a grid-like shape in a plan view. The plurality of support portions are disposed on an upper surface of the grid material. The tank is supported from below by a plurality of support portions, and contains liquefied gas therein. An upper cover is supported by the grid material and covers the sides and the top of the storage tank. The plurality of lower covers are attached so as to close the grid-like openings of the grid material, thereby forming a sealed space together with the upper cover.

By so constituting, for example, when constructing the tank structure, the grid-like openings of the grid material can be finally blocked by the lower cover. When the tank structure is inspected, only the lower cover near the portion to be inspected is removed, and the interior of the cover can be detected through the grid-like opening.

Therefore, the lower cover can be easily attached and detached, and the operability in attaching and detaching the cover can be improved.

According to a second aspect of the present invention, the tank structure on deck according to the first aspect may include a recess that is formed by the lower cover attached so as to close an opening of the grid member and the grid member surrounding the opening and that opens upward.

With this configuration, the recessed portion formed by the grid member and the lower cover can be used as a container for receiving the liquefied gas leaking from the tank. As a result, the number of parts can be suppressed from increasing as compared with a case where a container for receiving liquefied gas is separately provided.

According to a third aspect of the present invention, in the tank structure on deck according to the first aspect, a heat insulating material may be provided to cover a surface of the tank. At least one of the surface of the tank and the heat insulating material may include a groove portion that guides the liquefied gas leaked from the tank to the recessed portion.

With this configuration, even when the heat insulator and the surface of the tank are in close contact with each other, the leaked liquefied gas can be guided to the recessed portion through the groove portion.

According to a fourth aspect of the present invention, the support portion according to the first to third aspects may include a heat-proof block and a height adjustment member. The thermal conductivity of the thermal block is lower than that of the storage tank and the grid material. The height adjustment component adjusts the height of the upper surface of the heat-proof block.

In this way, when the support portion includes the heat shielding block and the height adjustment member, the height of the upper surface of the heat shielding block can be adjusted by the height adjustment member through the grid-shaped opening. Therefore, the gap between the support portion and the tank can be easily adjusted.

According to a fifth aspect of the present invention, the tank according to any one of the first to fourth aspects has any one shape of a square tank, a cylindrical tank, and a spherical tank, and LNG or LPG can be contained as the liquefied gas.

With this configuration, the tank is supported by the support portion, and after the upper cover is provided, the lower cover may be attached to and detached from the grille-like opening. Therefore, the square tank, the cylindrical tank, and the spherical tank for LNG and LPG can be easily installed, and inspection can be easily performed.

According to a sixth aspect of the present invention, a ship includes the tank structure on deck according to the first to fifth aspects.

With this configuration, for example, a tank for containing liquefied gas can be easily installed on an upper deck located above a cargo space or the like. As a result, the reduction of the cargo space and the living space can be suppressed.

According to a seventh aspect of the present invention, a method of installing a storage tank includes a support portion installing step, a storage tank installing step, an adjusting step, a closing step, a hull side saddle installing step, and a grid material side saddle installing step. In the support portion setting step, a plurality of support portions are provided on the upper surface of the grid material having a grid shape in plan view. In the tank installation step, a tank containing liquefied gas therein is installed on the support portions so as to be supported from below by the plurality of support portions. In the adjusting step, a gap between the support portion and the tank is adjusted by the grid-shaped openings of the grid member. In the closing process, the grid-like openings of the grid material are sealed by a lower cover. In the hull-side saddle mounting step, a plurality of saddles for supporting the grid material from below are mounted on the hull. In the grating material side saddle mounting step, the plurality of saddles are mounted to the grating material.

Thus, after the gap between the support portion and the tank is adjusted by the grid-shaped opening of the grid material, the lower cover can be attached to and sealed against the grid-shaped opening of the grid material. Therefore, the burden on the worker who installs the tank can be reduced.

According to an eighth aspect of the present invention, in the tank mounting method according to the seventh aspect, the step of mounting the grid material side saddle may be performed after the step of mounting the hull side saddle.

Thus, for example, after the hull side saddle mounting step, the grating material side saddle mounting step, the support portion setting step, the storage tank setting step, the adjusting step, and the closing step can be performed on the ship.

According to a ninth aspect of the present invention, in the tank mounting method according to the seventh aspect, the hull-side saddle mounting step may be performed after the grating-material saddle mounting step.

Thus, the saddle attached to the grating material can be attached to the hull. Therefore, for example, the step of attaching the saddle to the side of the grating material can be performed at a position other than on the ship, and thus, when the tank is attached to a ship or the like that is taking a voyage, the time required for the ship to enter the dock can be shortened.

According to a tenth aspect of the present invention, in the tank mounting method according to the eighth aspect, the hull-side saddle mounting step may be performed at least after the support portion setting step and the tank setting step.

Thus, for example, after the support portion installation step, the storage tank installation step, and the like are performed in a factory or the like, and the lattice material side saddle installation step is performed, the assembled assembly is lifted by a crane or the like and moved to the deck of the ship, and then the saddle can be fixed to the hull. Therefore, when the ship is installed in a ship or the like that is starting a ship, the time for the ship to enter the dock can be further shortened.

According to an eleventh aspect of the present invention, a method of inspecting a tank structure placed on a deck, the tank structure including a plurality of saddles, a grid material, a plurality of support portions, a tank, an upper cover, and a plurality of lower covers. The plurality of saddles are provided at intervals so as to protrude from the deck of the ship. The grid material is supported from below by a plurality of saddles and has a grid-like shape in a plan view. The plurality of support portions are disposed on an upper surface of the grid material. The tank is supported from below by a plurality of support portions, and contains liquefied gas therein. An upper cover is supported by the grid material and covers the sides and the top of the storage tank. The plurality of lower covers are attached so as to close the grid-like openings of the grid material, thereby forming a sealed space together with the upper cover. The method for inspecting the storage tank structure on the deck comprises a lower cover disassembling process, an inspection process and a reclosing process. In the lower cover removing step, a part of the lower covers are removed from the grid material among the plurality of lower covers attached so as to close the grid-shaped openings of the grid material. In the inspection process, the inside of the sealed space is inspected through the opening where the lower cover is detached. In the reclosing process, the opening is resealed by the lower cover removed in the lower cover removing process.

Thus, only the lower cover at a desired position is attached and detached from the lower side of the grid material, and the inside of the sealed space can be inspected. Therefore, the burden on the worker who performs the inspection can be reduced.

Effects of the invention

According to the above-described tank structure placed on the deck, the ship, the method for installing the tank, and the method for inspecting the tank, the operability of installation, inspection, and the like can be improved.

Drawings

Fig. 1 is a perspective view showing a schematic structure of a ship according to an embodiment of the present invention.

Fig. 2 is an enlarged perspective view of the tank structure 1A in the embodiment of the present invention.

FIG. 3 is a perspective view of the saddle, the grid material, and the tank body.

Fig. 4 is a perspective view of the lattice material supported by the saddle as viewed from above.

Fig. 5 is a perspective view of the tank structure in the embodiment of the present invention as viewed from below.

Fig. 6 is a side view of a tank structure in an embodiment of the invention.

Fig. 7 is a flowchart of a method of installing a tank structure in an embodiment of the invention.

Fig. 8 is an explanatory diagram of an adjustment process in the tank structure mounting method.

Fig. 9 is a flow chart of a verification method in an embodiment of the invention.

Fig. 10 is a flowchart of a method of mounting the tank structure in the first modification of the embodiment of the present invention.

Fig. 11 is a flowchart of a method of mounting the tank structure in the second modification of the embodiment of the present invention.

Fig. 12 is a perspective view of a tank main body in a third modification of the embodiment of the present invention.

Detailed Description

Next, a tank structure placed on a deck, a ship, a tank installation method, and a tank inspection method according to embodiments of the present invention will be described with reference to the drawings.

As shown in fig. 1, a ship 2 of this embodiment includes a hull 8, an upper structure 9, and a tank structure (tank structure placed on a deck) 1A.

The ship 2 exemplified in this embodiment is a ship such as an oil tanker that carries oil. The ship 2 is provided with an upper structure 9 and a tank structure 1A on an upper deck (deck) 10 as an exposed deck of the hull 8. The superstructure 9 has a residential area and a bridge, and is disposed on the side of the stern in the fore-aft direction of the ship than a cargo space in which oil as cargo is stored.

The tank structure 1A is disposed adjacent to the bow side of the superstructure 9. The tank structure 1A in this embodiment is arranged in 2 in the ship width direction. These tank structures 1A are arranged with their upper surfaces below the bridge to ensure a view of the bridge from the superstructure 9.

Fig. 2 is a perspective view of an enlarged structure of the tank in the embodiment of the present invention. FIG. 3 is a perspective view of the saddle, the grid material, and the tank body. Fig. 4 is a perspective view of the lattice material supported by the saddle as viewed from above.

As shown in fig. 2 to 4, the tank structure 1A includes a saddle 3, a grid member 4, a support portion 5A, a tank main body 6A, and a tank cover 7.

The saddle 3 is provided so as to protrude upward from the upper deck 10. The saddles 3 are provided in plurality at intervals, respectively, and support the grid material 4 from below. The saddle 3 illustrated in this embodiment has an X-shaped cross section. The lower end of the saddle 3 is fixed to, for example, a strength member (not shown) attached to the lower surface of the upper deck 10 and extending in the ship width direction or the ship fore-aft direction. The length of the saddle 3 in this embodiment from the upper deck 10 to the upper end thereof is about 2 m.

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

The outer frame portion 15 forms a rectangular outer frame. The outer frame portion 15 in this embodiment includes a pair of longitudinal members 15a extending in the fore-aft direction and a pair of lateral members 15b extending in the width direction. The side member portion 16 is formed to extend in the bow-stern direction, and a plurality of side member portions are provided at intervals in the ship width direction inside the outer frame portion 15. The beam portion 17 is formed to extend in the ship width direction, and a plurality of beams are provided at intervals in the ship fore-aft direction inside the outer frame portion 15. The beam portion 16 and the beam portion 17 intersect each other inside the outer frame portion 15. In this embodiment, the case where 3 side members 16 and 5 cross members 17 are provided is exemplified, but the number of the side members 16 and the cross members 17 is not limited to the above number.

A plurality of support portions 5A are disposed on the upper surface 4u of the grid member 4. The support portions 5A illustrated in this embodiment are disposed at the intersections of the side member portions 16 and the cross member portions 17. The upper surfaces 5A of the plurality of support portions 5A are arranged so as to abut against the lower surface 6A (see fig. 8) of the tank main body 6A. The support portion 5A is provided with a heat-proof block 20. The heat-proof block 20 is formed of a synthetic resin such as phenol resin or a material such as wood having a lower thermal conductivity than the tank main body 6A and the grid material 4. In this way, the support portion 5A supports the tank main body 6A from below, and suppresses heat conduction from the tank main body 6A at an extremely low temperature to the grid member 4.

The tank main body (tank) 6A contains, for example, Liquefied Natural Gas (LNG) as fuel for ship navigation in its interior. As shown in fig. 3, the tank body 6A in this embodiment is a square tank provided with a surrounding roof (trunk top)21 at the center of the upper portion thereof for loading and unloading the liquefied natural gas. The tank main body 6A is supported from below by the plurality of support portions 5A. The tank main body 6A is made of a metal such as an aluminum alloy that does not cause brittle fracture at an ultra-low 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 urethane around the portion, etc., which is in contact with the support portion 5A.

As shown in fig. 2 and 5, the tank cover 7 is disposed so as to cover the tank main body 6A, and forms a sealed space around the tank main 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 main body 6A. More specifically, the upper cover 22 includes an upper wall portion 22a and a side wall portion 22 b. 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 portion 22b is formed in a tubular shape having a rectangular cross section and extending downward from each of the four sides of the upper wall portion 22 a. The opening edge 22c of the upper cover 22 formed in this manner is fixed to the outer frame portion 15 of the grid member 4 by welding or the like over the entire circumference.

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

The lower cover 23 closes the opening 4a of the grid material 4 from below, thereby forming a recess 50 (see fig. 6) that opens upward together with the grid material 4 on the peripheral edge of the lower cover 23. Fig. 5 illustrates a case where the lower cover 23 that closes one opening 4a and the lower cover 23 that closes 2 openings 4a are provided. However, the structure of the lower cover 23 is not limited to the above structure. For example, one opening 4a may be closed by a plurality of lower covers 23, or 3 or more openings 4a may be closed by one lower cover 23.

Fig. 6 is a side view of a tank structure in an embodiment of the invention.

As shown in fig. 6, in the tank structure 1A according to this embodiment, the surface of the tank main body 6A is in close contact with the inner surface of the heat insulator 40 covering the surface. At least one of the surface of the tank main body 6A and the inner surface of the heat insulator 40 includes a groove 41. For example, when the liquefied natural gas gradually leaks from the tank main body 6A, the groove portion 41 guides the leaked liquefied natural gas. More specifically, the liquefied natural gas leaked from the tank main body 6A is guided to the predetermined recess 50A among the plurality of recesses 50 formed by the grid member 4 and the lower cover 23.

Here, the groove portion 41 exemplified in this embodiment is formed in a grid shape so as to extend in the vertical direction and the horizontal direction, and is formed to be slightly inclined so that the liquefied natural gas can move toward the predetermined concave portion 50A by its own weight. The predetermined recess 50A may be provided with a cover member made of a material that is not easily fragile at low temperatures on the inner side thereof. A part of the grid material 4 forming the predetermined recess 50A or the lower cover 23 forming the predetermined recess 50A may be formed of a material that is not easily broken at low temperature. Although the groove 41 is formed in a lattice shape, the groove 41 is not limited to the above shape as long as it can guide the liquefied natural gas to the predetermined recess 50A.

Next, a method of mounting the tank structure 1A will be described with reference to the drawings.

Fig. 7 is a flowchart of a method of installing a tank structure in an embodiment of the invention. Fig. 8 is an explanatory diagram of an adjustment process in the tank structure mounting method. In the description of the installation method of the tank structure 1A, a case where the installation work is performed on the upper deck 10 will be mainly described as an example.

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

Next, a grating material side saddle mounting process is performed (step S02). In this step of attaching the grid material side saddles, the grid material 4 having a grid shape in a plan view is attached to the saddles 3 so as to be supported from below by the saddles 3 provided in the step of attaching the hull side saddles. At this time, the saddle 3 is fixed so as not to be deviated from the grid material 4 by, for example, welding the entire periphery of the saddle 3. Thereby, the grid member 4 is disposed in a posture of being arranged on an imaginary plane parallel to the upper deck 10.

Then, a support portion setting step of setting the plurality of support portions 5A on the upper surface of the grid member 4 is performed (step S03). In the support portion setting step, the plurality of support portions 5A are set to a predetermined arrangement, that is, are spaced apart in the fore-aft direction and the width direction of the ship so as to disperse the load of the tank main body 6A.

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

Next, an adjustment process is performed (step S05). In this adjustment step, for example, the gap between the support portion 5A and the tank main body 6A is adjusted by the grid-like openings 4a of the grid member 4. At this time, the worker performs the adjustment work on a scaffold or the like assembled below the grid member 4. As shown in fig. 8, if only the tank main body 6A is provided, a gap may be formed between the heat shielding block 20 of the support portion 5A and the lower surface 6A of the tank main body 6A. Therefore, in this adjustment step, the height position of the heat prevention block 20 is adjusted so that all the heat prevention blocks 20 of the plurality of support portions 5A contact the lower surface 6A of the tank main body 6A. As an adjusting method in this adjusting step, a method shown in fig. 8 can be exemplified. The adjustment method shown in fig. 8 is as follows: a spacer plate 53 having a thickness corresponding to the gap is inserted between the heat shielding block 20 and the grid member 4 from the side where the reinforcing rib member 52 is not arranged, as a height adjustment member, and the height position of the heat shielding block 20 is adjusted so that the upper surface of the heat shielding block 20 (in other words, the upper surface 5A of the support portion 5A) contacts the lower surface 6A of the tank main body 6A.

Then, a sealing process is performed (step S06). In this closing step, the lower cover 23 closes the grid-like openings 4a of the grid member 4. More specifically, the operator closes all of the plurality of openings 4a from below by the plurality of lower covers 23 on a scaffold or the like assembled below the grid member 4. 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 4a is sealed by the lower cover 23. Thereby, a sealed space is formed between the tank cover 7 and the tank main body 6A.

Then, the scaffold and the like assembled below the grating material 4 are disassembled to end the installation work of the tank structure 1A.

Next, a method of inspecting the tank structure 1A arranged as described above will be described with reference to the drawings.

As shown in fig. 9, first, the lower cover removing step is performed (step S10). In the lower cover removing step, a part of the lower covers 23 of the plurality of lower covers 23 attached so as to close the grid-like openings 4a of the grid member 4 is removed from the grid member 4. More specifically, the lower cover 23 that closes the opening 4a close to the inspection site is removed. At this time, a scaffold or the like is assembled below the grid member 4, and the lower cover 23 is detached from below the grid member 4.

Subsequently, a checking process is performed (step S11). In this inspection step, the inside of the sealed space is inspected by visual observation or the like, for example, through the opening 4a of the detached lower cover 23. At this time, the operator can enter the inside of the tank cover 7 through the opening 4 a. In addition, when it is determined by the inspection that repair or the like is necessary, the repair work can be directly performed.

Then, a resealing process is performed (step S12). In this reclosing process, the opening 4a of the lower cover 23 removed in the lower cover removing process is sealed again by the lower cover 23. At this time, the detached lower cover 23 can be reused, and for example, when the lower cover 23 is broken by detachment, a new lower cover 23 can be used.

Then, the scaffold and the like assembled under the grid material 4 are disassembled to complete the inspection.

Thus, according to the above embodiment, for example, when the tank structure 1A is constructed, the gap between the support portion 5A and the tank main body 6A is adjusted by the lattice-shaped opening 4a, and finally the lattice-shaped opening 4a of the lattice material 4 can be closed by the lower cover 23. In the inspection of the tank structure 1A, only the lower cover 23 near the site to be inspected is removed, and the inside of the tank cover 7 can be inspected through the grille-like opening 4 a. As a result, the operability of the installation, inspection, and the like of the tank structure 1A is improved, and the burden on the operator can be reduced.

Further, 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 main body 6A. As a result, the increase in the number of parts can be suppressed as compared with the case where a tank for receiving liquefied natural gas is separately provided.

In addition, when the gap adjustment work is performed, the gap adjustment work can be performed through the grid-like openings 4a from below. Further, the gap between the heat shielding block 20 and the tank main body 6A can be easily confirmed from the opening 4a by visual observation or the like.

Further, by adopting the tank structure 1A, the liquefied natural gas square tank can be easily installed on the upper deck 10 and the like.

In the method of attaching the tank structure according to the above embodiment, the case where the saddle installation step (step S01) and the grating material installation step (step S02) are first performed will be described. However, the timing of attaching the saddle 3 to the grid material 4 is not limited to the timing of the above embodiment.

(first modification)

Fig. 10 is a flowchart of a method of mounting the tank structure in the first modification of the embodiment of the present invention. In the description of the first modification, the same steps as those of the above embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.

As shown in fig. 10, in the tank structure mounting method according to the first modification, first, the support portion setting step (step S03), the tank setting step (step S04), the adjusting step (step S05), and the closing step (step S06) are performed.

Next, a hull-side saddle attaching step (step S01) is performed in which the saddle 3 is attached to the hull so that the saddle 3 protrudes from the upper deck. Next, a lattice material side saddle mounting step of mounting the plurality of saddles 3 mounted to the hull to the lattice material 4 so that the lattice material 4 is supported from below by the plurality of saddles 3 is performed (step S02), and the mounting of the tank structure is completed.

In the first modification, the case where the hull-side saddle mounting step (step S01) and the grating-material-side saddle mounting step (step S02) are performed after the sealing step (step S06) has been described, but the sealing step (step S06) may be performed after the hull-side saddle mounting step (step S01) and the grating-material-side saddle mounting step (step S02). The case where the hull-side saddle attaching step (step S01) is performed after the support portion setting step (step S03), the tank setting step (step S04), and the like is described, but the hull-side saddle attaching step (step S01) may be performed together with the support portion setting step (step S03) or the tank setting step (step S04).

(second modification)

Fig. 11 is a flowchart of a method of mounting the tank structure in the second modification of the embodiment of the present invention. In the description of the second modification, the same steps as those of the above embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.

As shown in fig. 11, in the mounting method of the tank structure according to the second modification, first, the support portion setting step (step S03), the tank setting step (step S04), the adjusting step (step S05), and the closing step (step S06) are performed.

Next, a grating material side saddle mounting step (step S02) is performed in which the saddle 3 is mounted to the grating material 4 so that the saddle 3 protrudes downward from the grating material 4. The grille-material-side saddle mounting step (step S02) in the second modification may be performed before the hull-side saddle mounting step (step S01), and may be performed before the support-portion setting step (step S03), the tank setting step (step S04), or together with the support-portion setting step (step S03), the tank setting step (step S04), for example.

Then, a hull-side saddle attaching step (step S01) of fixing the saddle 3 to a hull strength member such as a frame member provided on the lower surface side of the upper deck 10 while lifting the assembly (not shown) to which the saddle 3 is attached by a crane (not shown) or the like is performed, and the attachment of the tank structure is completed. At this time, the saddle 3 is fixed to the hull such as a frame member so that the lattice member 4 is spaced apart from the upper deck 10.

In the second modification, the case where the grating material side saddle mounting step (step S02) or the hull side saddle mounting step (step S01) is performed after the sealing step (step S06) is described, but the sealing step (step S06) may be performed after the grating material side saddle mounting step (step S02) or the hull side saddle mounting step (step S01).

(third modification)

Next, a third modification of the embodiment of the present invention will be described with reference to the drawings. This third modification is different from the above-described embodiment in that the tank body has a cylindrical shape. Therefore, in this third modification, the same portions as those of the above-described embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.

As shown in fig. 12, the tank structure 1B in the third modification includes a saddle 3, a grid member 4, a support portion 5B, a tank main body (cylindrical tank) 6B, and a tank cover 7. In fig. 12, only the lower cover 23 is shown in the tank cover 7, and the upper cover 22 is not shown. The upper cover 22 may have the same shape as that of the above-described embodiment, or may have another shape corresponding to the tank main body 6B.

The saddle 3 is provided so as to protrude upward from the upper deck 10. The saddles 3 are provided in plurality at intervals, respectively, and support the grid material 4 from below. The saddle 3 exemplified in the third modification of the present embodiment has an H-shaped cross section, and the lower end portion thereof is fixed to, for example, a strength member (not shown) or the like extending in the ship width direction or the ship fore-aft direction attached to the lower surface of the upper deck 10. Similarly to the above embodiment, 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.

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

The support portion 5B is provided on the upper surface 17u of the beam portion 17 of the grid material 4. The support portions 5B illustrated in the third modification example are provided two at an interval in the direction in which the side member portions 16 extend. These support portions 5B include support portion main bodies 5Ba and contact portions 5 Bb.

The support portion main body 5Ba has a recess 60, and the recess 60 extends upward from the upper surface 17u of the beam portion 17 and corresponds to the shape of the tank main body 6B. The concave portion 60 in the third modification is formed in an arc shape having a curvature radius slightly larger than the radius of the tank main body 6B when viewed from the direction in which the side member portion 16 extends.

The abutment portion 5Bb is formed to abut against the tank main body 6B. The abutting portion 5Bb is formed in an arc shape along the concave portion 60 and in a plate shape spreading to both sides in the thickness direction of the support portion main body 5Ba when viewed from the direction in which the side member portion 16 extends. Although not shown, a heat dissipating material having a lower thermal conductivity than the tank main body 6B and the grid material 4 is provided in the support portion 5B between the support portion main body 5Ba and the abutment portion 5Bb or between the abutment portion 5Bb and the tank main body 6B. Examples of the material having lower thermal conductivity than the tank main body 6B and the grid material 4 include synthetic resin such as phenol resin, wood, and the like. In this way, the support portion 5B supports the tank main body 6B from below, and suppresses heat conduction from the tank main body 6B at an extremely low temperature to the grid member 4.

The tank main body (tank) 6B accommodates therein Liquefied Natural Gas (LNG) as a fuel for the voyage of the ship, as in the first embodiment. The tank main body 6B in this embodiment is a cylindrical tank. The tank main body 6B is a spherical surface whose both end portions in the axis O direction protrude outward. The tank main body 6B is supported from below by the plurality of support portions 5B. As in the above embodiment, the tank main body 6B is made of a metal such as an aluminum alloy that is not brittle at an extremely low temperature of the liquefied natural gas. The tank main body 6B is covered with a heat insulator 40 (see fig. 8) such as urethane, except for a portion in contact with the support portion 5B. In fig. 12, illustration of the shroud top plate 21 is omitted.

For example, when a gap is formed between the insulating material 40 (not shown) and the tank main body 6B, and the tank main body 6B is a cylindrical tank main body 6B having an axis O extending along the upper deck 10 (not shown), as shown in fig. 12, the leaked liquefied gas moves downward along the outer peripheral surface of the tank main body 6B. Then, the light is concentrated on the straight bottom along the axis O. For example, by providing a pipe or the like (not shown) reaching a predetermined concave portion 50A (see fig. 6) in a local portion of the bottommost portion, the liquefied gas collected in the bottommost portion is guided to the predetermined concave portion 50A, and the liquefied gas can be stored in the predetermined concave portion 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 at one location.

(fourth modification)

In the third modification, the case where the tank main body 6B is a cylindrical tank is described. However, other than the cylindrical type, for example, a spherical tank or the like may be used.

Here, the "spherical tank" is not limited to a regular sphere, and may be a cylindrical or truncated cone shape in the vicinity of the equator thereof, or a shape including an elliptic curved surface at least in part in the cross section thereof.

For example, when a gap is formed between the heat insulating material 40 (not shown) and the spherical tank, the leaked liquefied gas moves to the lowest point along the outer surface of the spherical tank and drops due to its own weight. That is, in the case of a spherical tank, if the predetermined concave portion 50A (see fig. 6) is disposed just below the lowest point, liquefied gas can be stored in the predetermined concave portion 50A.

(other modification example)

The present invention is not limited to the configurations of the above-described embodiments and modifications, and the design thereof may be modified without departing from the spirit and scope of the invention.

For example, in the above embodiment, the case where the support portion 5A includes the shim plate 53 below the heat shielding block 20 is described. However, the shape of the support portion 5A is not limited to the shape of the above-described embodiment, and may be any structure as long as the height can be adjusted while suppressing heat transfer between the tank main body 6A and the grid member 4.

In the above embodiment, the support portion 5A is shown as an example in a case where it is arranged at a portion where the side member portion 16 and the cross member portion 17 intersect. However, the support portion 5A may be provided in a place other than the portion where the beam portion 16 and the beam portion 17 intersect.

In the above embodiment, the case where the grid member 4 is fixed to the saddle 3 or the tank cover 7 is fixed to the grid member 4 by welding is exemplified. However, these fixing methods are not limited to welding, and may be, for example, bonding or the like.

In the above embodiment, the case where the groove portion 41 is formed in at least one of the heat insulator 40 and the tank main body 6A is described. However, the groove 41 may be provided as appropriate or omitted. In the case where the groove 41 is omitted in this manner, for example, a gap may be provided between the heat insulator 40 and the tank main body 6A.

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

In the above-described embodiment, third modification, and fourth modification, the case where the tank main bodies 6A and 6B contain LNG is described. However, the liquefied gas contained in the tank bodies 6A, 6B may be LPG or the like.

In the above embodiment, a tanker for transporting oil from the ship 2 is exemplified. However, the present invention is not limited to this type of ship. For example, the liquefied gas carrier or liquefied gas supply vessel may be another type of vessel.

Industrial applicability

The present invention can be applied to a storage tank structure placed on a deck, a ship, a method for installing a storage tank, and a method for inspecting a storage tank. According to the present invention, operability such as installation and inspection can be improved.

Description of the symbols

1A, 1B-tank structure, 2-vessel, 3-saddle, 4-grid material, 4 a-opening, 5A, 5B-bearing, 6A, 6B-tank body (tank), 6A-lower surface, 7-tank cover, 8-hull, 9-superstructure, 10-upper deck, 15-outer frame, 15A-longitudinal material, 15B-transverse material, 16-stringer, 17-crossbeam, 20-heat proof block, 20A-upper surface, 21-coaming top plate, 22-upper cover, 22 a-upper wall, 22B-side wall, 22 c-opening edge, 23-lower cover, 40-tank insulation material, 41-trough, 50A-recess, 52-reinforcing material, 53-pad, 60-recess.

Claims

1. A tank structure placed on a deck, comprising:

a plurality of saddles provided at intervals so as to protrude from a deck of a ship;

a lattice material supported from below by the plurality of saddles and having a lattice shape in a plan view;

a plurality of support portions arranged on an upper surface of the grid material;

a tank which is supported from below by the plurality of support portions and contains liquefied gas therein;

an upper cover supported by the grid material and covering the side and upper part of the storage tank; and

and a plurality of lower covers attached to the grid-like openings of the grid material so as to close the openings, thereby forming a sealed space together with the upper covers.

2. The above-placed-on-deck tank structure according to claim 1, comprising:

and a recess formed by the lower cover mounted to close the opening of the grid material and the grid material surrounding the opening and opened upward.

3. The above-placed storage tank structure according to claim 2, comprising:

a thermal insulation material covering a surface of the storage tank,

at least one of the surface of the tank and the heat insulating material is provided with a groove portion for guiding the liquefied gas leaked from the tank to the recessed portion.

4. Deck-placed tank structure according to any one of claims 1 to 3,

the support portion includes:

a heat shielding block having a lower thermal conductivity than the storage tank and the grid material;

and a height adjusting member for adjusting the height of the upper surface of the heat-proof block.

5. Deck-placed tank structure according to any one of claims 1 to 4,

the tank has any one shape of a square tank, a cylindrical tank, and a spherical tank, and stores LNG or LPG as the liquefied gas.

6. A ship provided with a tank structure according to any one of claims 1 to 5 placed on deck.

7. A method of installing a storage tank, comprising:

a support portion setting step of setting a plurality of support portions on an upper surface of a grid material having a grid shape in a plan view;

a tank installation step of installing a tank containing liquefied gas therein on the support portions so as to be supported from below by the plurality of support portions;

an adjustment step of adjusting a gap between the support portion and the tank through a grid-shaped opening of the grid material;

a sealing step of sealing the grid-like openings of the grid material with a lower cover;

a hull-side saddle mounting step of mounting a plurality of saddles supporting the grid material from below on a hull; and

and a step of mounting a saddle on the side of the grid material, wherein the plurality of saddles are mounted on the grid material.

8. The method of installing a storage tank of claim 7,

after the hull side saddle mounting step, the lattice material side saddle mounting step is performed.

9. The method of installing a storage tank of claim 7,

and a hull side saddle mounting step of performing the hull side saddle mounting step after the grating material side saddle mounting step.

10. The method of installing a storage tank of claim 9,

the hull side saddle mounting step is performed at least after the support portion setting step and the tank setting step.

11. An inspection method for an on-deck tank structure, the on-deck tank structure comprising:

a plurality of lower covers installed in a manner of blocking the grid-shaped openings of the grid material, thereby forming a sealed space together with the upper cover, the inspection method comprising:

a lower cover removing step of removing a part of the lower cover from the grid member, among the plurality of lower covers attached so as to close the grid-like openings of the grid member;

a checking step of checking the inside of the sealed space by detaching the opening of the lower cover; and

a reclosing step of resealing the opening with the lower cover removed in the lower cover removing step.