Liquefied gas fuel tank storage space transportation device

Abstract

To provide a fuel tank storage space transportation device that facilitates visual inspection of fuel tanks arranged below the upper deck of a liquefied gas fuel ship such as LNG, and that ensures a transportation route within the fuel tank compartment below the upper deck that allows easy access and transportation to the fuel tank.SOLUTION: A fuel tank storage space transportation device includes a suspended stage, a perimeter stage, and a bridge stage, connected by stairs and common landings that allow access between the stages.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a transportation device for fuel tank storage spaces, such as car carriers, that uses liquefied gas such as LNG (liquefied natural gas) as fuel. [Background technology]

[0002] The applicant of the present application has already proposed the disclosure of Patent Publication No. 6554126 (invention title: "Independent tank installation structure for LNG or other gas fuel on a car carrier") regarding the installation of fuel tanks on car carriers and the like that use LNG or other fuels. However, when it comes to independent gas fuel tanks such as LNG on car carriers, external inspections of the installed fuel tanks and prescribed maintenance work are required after installation, which makes access to and traffic to the fuel tanks essential. In addition, maintenance work such as visual inspection of this type of fuel tank for LNG or the like is described, for example, in the publication of JP-A-2023-518629. The disclosure of JP 2023-518629 A relates to an invention titled "Dual-Fuel Bulk Carrier," which is intended to "eliminate the drawbacks of the LNG fuel supply system being complex and difficult to layout, making it difficult to rationally arrange the LNG fuel tank on the main deck" (see paragraph 0006 of the specification of the same publication), and as one means of eliminating these drawbacks, the dual-fuel bulk carrier is configured such that "a maintenance work platform is arranged above the air dome above the LNG fuel tank" (see the description of claim 5 of the same publication, etc., and paragraph 0015 of the specification of the same publication).

[0003] However, the structure disclosed in JP 2023-518629 A has an LNG fuel tank located on the main deck (upper deck), not inside the hull, and the maintenance work platform is "used to place a crane for lifting the LNG transport pump installed inside the LNG fuel tank" (see paragraph 0016 of the specification of the same publication).

[0004] Figure 8 is a schematic diagram showing the left side structure of a dual-fuel bulk carrier according to a preferred embodiment of the disclosed invention, which is attached as Figure 2 in JP-A-2023-518629. In Figure 8, 101a and 101b are LNG fuel tanks, 102a and 102b are air domes, 112 is LNG fuel tank protective steel, 131 is a support structure, and 301 is an extension area (note that the applicant of the present application has changed the reference numerals to three digits in order to clarify that they are prior art. The reference numeral 301 is written as it is in the original specification).

[0005] For the visual inspection of fuel tanks such as LNG, the applicant company has previously used the hull structure itself of the car carrier as an inspection stage (corresponding to the above-mentioned "maintenance work platform"), which has caused inconvenience in accessing and traveling to the LNG fuel tank. In addition, by using the hull structure as a substitute, it is necessary to secure a work space when loading the LNG fuel tank, which means that the fuel storage space must be expanded toward the cargo loading space, resulting in a problem of reduced cargo capacity. Therefore, the present invention has devised a transportation device within a fuel tank compartment that facilitates visual inspection of the fuel tank and allows easy access and transportation to the LNG fuel tank for required maintenance work. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6554126 [Patent Document 2] Special Publication No. 2023-518629 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to provide a fuel tank storage space transportation device that facilitates visual inspection of fuel tanks located below the upper deck of a liquefied gas fuelled ship and ensures a transportation route within the fuel tank compartment below the upper deck that allows easy access to and transportation to the fuel tanks. [Means for solving the problem]

[0008] In order to solve the above problems, the invention according to claim 1 of the present application is characterized in that, in a fuel tank storage space transportation device, there is provided a hanging stage with a hanging structure on the ceiling of the fuel tank storage space located below the upper deck of a liquefied gas fuelled ship. The invention according to claim 2 of the present application is characterized in that in the fuel tank storage space transportation device according to claim 1, the suspension stage is a parallel suspension structure with a gap in the center of the extension direction that allows access to and transportation to the area (Tank Connection Space) surrounding each tank connection part and tank valve on the top of the fuel tanks arranged side by side in the longitudinal direction of the hull. The invention according to claim 3 of the present application is characterized in that the fuel tank storage space transportation device according to claim 1 has an outer peripheral stage which is welded in a cantilever manner to the front, rear, left and right side walls of the fuel tank storage space located below the upper deck of a liquefied gas fuelled ship. The invention according to claim 4 of the present application is characterized in that in the fuel tank storage space transportation device according to claim 3, the bottom of the outer circumferential stage is at the same height as the top of the fuel tank. Furthermore, the invention according to claim 5 of the present application is a fuel tank storage space transportation device according to claim 1, characterized in that it has a bridging stage that spans the front and rear of the fuel tank storage space located below the upper deck of the liquefied gas fuelled ship and bridges between the fuel tanks arranged side by side. The invention according to claim 6 of the present application is characterized in that in the LNG fuel tank storage space transportation device according to claim 5, the bridge stages connect each of the hull structures with a single bridge. Furthermore, the invention of claim 7 of the present application is characterized in that, in the LNG fuel tank storage space transportation device described in claim 6, there is a third bridge stage that is fixed to the hull structure by bolting on the stern side, and a first bridge stage that is placed on the bow side so that it can slide between the hull structure and the third bridge stage, with a sliding material made of a resin liner interposed therebetween. Furthermore, the invention according to claim 8 of the present application is an LNG fuel tank storage space transportation device according to any one of claims 1 to 7, characterized in that the fuel tank storage space transportation device has a suspension stage, a peripheral stage, and a bridge stage, and these stages are connected by stairs and a common landing that allow passage between them. [Effects of the Invention]

[0009] As configured as described above, the fuel tank storage space transportation device according to the present invention has the following advantages. (1) Since the outer periphery stage can be installed inside the fuel tank storage space after the fuel tank is loaded, there is no need to reserve space for the outer periphery stage in advance inside the fuel tank storage space, and therefore it is possible to maximize the expansion of the adjacent cargo loading section. (2) In addition, the installation of the outer stage can be carried out in a manner that also serves as the scaffolding when the hull blocks are installed, improving workability in this respect as well. After the fuel tanks are installed, the bridge stage will be installed inside the fuel tank storage space, and a hanging stage will be installed on the rear loading block, which will contribute to easing the process after the tanks are installed. (3) One side of the bridge is fixed and the other side is a sliding, non-fixed structure, which allows the structure to follow the deformation of the hull. (4) By using the device as a substitute for the hull structure, it is possible to avoid the need to secure a work space when loading the fuel tank, and it is possible to avoid the reduction in cargo loading capacity due to the expansion of the fuel storage space toward the cargo loading space. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a diagram showing an overall outline of a first embodiment of a fuel tank storage space transportation device according to the present invention. [Figure 2] FIG. 2 is a plan view showing an outline of the hanging stage 5 of the fuel tank storage space transportation device 1 according to the first embodiment. [Figure 3] FIG. 3 is a side view showing an outline of the hanging stage 5 of the fuel tank storage space transportation device 1 according to the first embodiment. [Figure 4] FIG. 4 is a schematic plan view showing the arrangement of the outer periphery stage 6 and the bridge stage 7 of the fuel tank storage space transportation device 1 according to the first embodiment. [Figure 5] FIG. 5 is a left side view showing an outline of the outer peripheral stage 6 on the left side of the hull of the fuel tank storage space transportation device 1 according to the first embodiment. [Figure 6] FIG. 6 is a right side view showing an outline of the outer peripheral stage 6 on the left side of the hull of the fuel tank storage space transportation device 1 according to the first embodiment. [Figure 7] FIG. 7 is a schematic side view of the bridge stage 7 of the fuel tank storage space transportation device 1 according to the first embodiment. [Figure 8] FIG. 8 is a schematic diagram showing the left side structure of a dual-fuel bulk carrier according to a preferred embodiment of the disclosed invention, which is attached as FIG. 2 in JP-T-2023-518629. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of a fuel tank storage space transportation device according to the present invention will be described in detail with reference to the accompanying drawings. [Example]

[0012] FIG. 1 is a diagram showing an overall outline of a first embodiment of a fuel tank storage space transportation device according to the present invention. In FIG. 1, reference numeral 1 denotes a fuel tank storage space access device according to the first embodiment, reference numeral 2 denotes a fuel tank storage space consisting of an enclosed compartment located below the upper deck of the hull, reference numeral 3 denotes independent fuel tanks arranged in parallel along the length of the hull, and reference numeral 4 denotes a Tank Connection Space, an area surrounding a tank connection part and tank valves attached to a fuel tank that houses pumps and instruments for filling LNG and using it as fuel, and is located above the tank, and is a part that particularly requires access and access for maintenance, etc.

[0013] To give an overview of the fuel tank storage space transportation device 1 according to this embodiment 1, as shown in FIG. 1, it is a fuel tank storage space transportation device consisting of a hanging stage 5, an outer periphery stage 6, and a bridge stage 7, and these hanging stage 5, outer periphery stage 6, and bridge stage 7 are configured to allow workers to move through by means of a number of different staircases or ladders provided on the bow and stern sides of the fuel tank storage space 2, as well as landings provided at each height position. The arrangement and configuration of each stage will be described in detail below.

[0014] (hanging stage) FIG. 2 is a plan view showing an outline of the hanging stage 5 of the fuel tank storage space transportation device 1 according to the first embodiment, and FIG. 3 is a side view of the same. 2 and 3, reference numeral 6 denotes the ceiling of the fuel tank storage space 2, 7 denotes a passageway, and 8 denotes an ascending staircase. As is clear from Fig. 2 and Fig. 3, the suspended stage 5 of the fuel tank storage space transportation device 1 according to this embodiment 1 is suspended from the ceiling 6 of the fuel tank storage space 2 above the fuel tank, and has a suspension bridge structure in which several pieces of general-purpose structural steel (SS steel), which are general-purpose materials, are welded to the framework of the ceiling 6 of the fuel tank storage space 2 at predetermined intervals, and a plurality of floor plates (not shown) of a predetermined width are laid on the upper bottom surface at right angles to the extension direction of the suspended stage 5 to secure a passageway for workers.

[0015] As shown in FIG. 3 , in order to facilitate access to and transportation to the tank connection space 4, which is located above the above-mentioned juxtaposed fuel tanks 3, 3 and surrounds the tanks, the hanging stage 5 of the fuel tank storage space transportation device 1 according to this embodiment 1 is close enough for workers to enter the tank connection space 4, 4 surrounding each tank connection and tank valve, and has a parallel hanging structure with a slight gap in the center of its extension direction. This allows for observation of the spaces between the LNG tanks 3, 3, and the hanging stage 5 has a shape and structure that extends to near the longitudinal centers of the fuel tanks arranged juxtaposed in the longitudinal direction of the hull. Note that handrails (not shown) or the like may be provided on the stainless steel material that is suspended and welded vertically from the ceiling 6 to ensure safety during passage.

[0016] In order for workers to reach the suspended stage 5 of the fuel tank storage space transportation device 1 according to this embodiment 1, as shown in Figures 2 and 3, a staircase 8 is installed from the bottom of the fuel tank storage space 2, consisting of a plurality of small steps or ladders and a common landing that allows access to the other stages 6 and 7, and workers use this staircase 8 to reach the target location requiring maintenance (the arrows in Figure 2 indicate the progress of the workers).

[0017] (Outer Stage 6) Fig. 4 is a schematic plan view showing the arrangement of the outer periphery stage 6 and the bridge stage 7 of the fuel tank storage space traffic device 1 according to the first embodiment, Fig. 5 is a right side view showing an outline of the outer periphery stage 6 on the left side of the hull of the fuel tank storage space traffic device 1 according to the first embodiment, and Fig. 6 is a left side view of the same. In Figs. 4 to 6, reference numeral 7a denotes the bow-side first bridge stage constituting the bridge stage 7, 7b denotes the subsequent second bridge stage, 7c denotes the stern-side third bridge stage, 9 denotes a pipe space arranged transversely of the hull above the tanks 3, 3 of the fuel tank storage space 2, 10a denotes the bow-side first pillar, 10b denotes the second pillar, 10c denotes the third pillar, 11a to 11c denote avoidance bridges for avoiding each pillar, and the remaining reference numerals denote the same members or parts as those shown in Figs. 1 to 3.

[0018] As shown in FIGS. 4 to 6, the outer periphery stage 6 of the fuel tank storage space transportation device 1 according to the first embodiment has cantilever-shaped connection pieces (not shown) attached to general structural steel (SS material) protruding into the left and right side surfaces and the front and rear side walls of the fuel tank storage space 2, and after the LNG fuel tanks 3, 3 are installed, a plurality of floor plates (not shown) are fastened with bolts between each of the connection pieces so that the outer periphery stage 6 is fixed in a cantilever state to the peripheral wall of the fuel tank storage space 2. As with the hanging stage 5 described above, the outer periphery stage 6 has a shape and structure in which a plurality of floor plates (not shown) of a predetermined width are laid horizontally on the upper surfaces of the cantilevers against the left and right and front and rear side surfaces of the fuel tank storage space 2 to ensure passageways for workers.

[0019] As shown in FIGS. 5 and 6, the bottom of the fuel tank 3 is set at a height position substantially equal to the height position of the upper portions of the fuel tanks 3, 3. The outer periphery stage 6 is configured so that maintenance workers can ascend and descend using the aforementioned ascending stairs 8 and circulate around the fuel tank storage space transportation device 1 which serves as a passageway.

[0020] Also, as shown in Figure 6, in order to avoid the pipe space 9 arranged from the center of the fuel tank storage space 2 in the transverse direction of the hull on the right side of the hull of the fuel tank storage space transportation device 1 according to this embodiment 1, the relevant part is configured with a lower shape or structure with both ends connected by stairs.

[0021] (Cross-linking stage 7) In the fuel tank storage space transportation device 1 according to the first embodiment, as shown in the schematic plan view of Figure 4, a bridge stage 7 consisting of three stages, a first bridge stage 7a, a second bridge stage 7b, and a third bridge stage 7c, is arranged between the fuel tanks 3, 3. The reason for dividing it into three is that the pillars are connected by bridges, so that no extra equipment needs to be attached, and the first bridge stage 7a to the third bridge stage 7c are at different height positions because the heights at the stern side are different to avoid contact with the heads of workers passing under the hanging stage. FIG. 7 is a schematic side view of the bridge stage 7 of the fuel tank storage space transportation device 1 according to the first embodiment.

[0022] In FIG. 7, reference numeral 12 denotes stairs leading to the bottom of the fuel tank storage space 2, and the other reference numerals denote the same members or parts as those shown in FIGS. As shown in Figure 7, the bridge stage 7 of the fuel tank storage space transportation device 1 according to the first embodiment is a structure supported by the hull structure at the front and rear ends of the fuel tank storage space 2. It is composed of first to third bridge stages 7a, 7b, and 7c extending from the bow side and spanning first to third pillars 10a, 10b, and 10c extending from the bow side between the fuel tanks 3, 3 arranged side by side between the fuel tanks 3, 3. A maintenance stage (passageway) is also provided in a location away from the hull structure, such as the peripheral wall of the fuel tank storage space 2, enabling maintenance of locations away from the hull structure. As shown in Figure 7, the bridge stages consisting of the first to third bridge stages are each connected to the hull structure by a single bridge ("support for claim 6"). The first bridge stage 7a and the second and third bridge stages 7b and 7c are different structures because the first bridge stage 7a also needs to serve as a structure for fixing the fuel tanks 3, 3 to the hull.

[0023] As shown in Figure 7, the bridge stages 7 of the fuel tank storage space transportation device 1 in this embodiment 1 are arranged so that the first bridge stage 7a on the bow side is at a height position near the top of the LNG fuel tanks 3,3, and the second bridge stage 7b and third bridge stage 7c are at a height position approximately three-quarters of the height from the top of the fuel tanks 3,3, which is slightly lower than the first bridge stage 7a.This is to avoid workers' heads coming into contact with the stage and ensure clearance, but the height positions are not limited to these.

[0024] Furthermore, as shown in FIG. 4, the bridge stage 7 of the fuel tank storage space 1 according to the first embodiment is provided with avoidance bridges 11a to 11c to avoid the first pillar 10a, the second pillar 10b, and the third pillar 10c, so that workers can move around the pillars 10a to 10c even if they are present. The bridge stage 7 of the fuel tank storage space transportation device 1 according to this embodiment 1 is constructed so that both ends are placed on the hull structure, but the stern side is fixed to the hull structure by bolting, and the bow side has a resin liner (ultra-high molecular weight polyethylene) interposed between it and the hull structure as a sliding material to take into account sliding caused by hull rocking.

[0025] (Improved workability) With the above-described configuration, the fuel tank storage space traffic device 1 according to the first embodiment has a structure consisting of three components, namely, the suspension stage 5, the outer periphery stage 6, and the bridge stage 7, for the purpose of daily inspection of the LNG fuel tanks 3, 3 installed under the upper deck, which makes it possible to improve construction efficiency in hull construction.

[0026] That is, since the suspension stage 5 is installed above the LNG fuel tanks 3, 3, it was previously necessary to install the suspension stage 5 after the LNG fuel tanks 3, 3 are loaded on board, or to attach the suspension stage 5 to the LNG fuel tanks 3, 3 in advance and then install it; however, by suspending it from the ceiling of the fuel tank storage space 2, it can be attached during the ceiling block process, which has a great advantage in that construction work can be shortened.

[0027] Regarding the outer perimeter stage 6, in order to make the cargo compartments located on the bow and sides of the fuel tank storage space 2 as large as possible, it is necessary to make the space 2 inside the ship as small as possible, and for this reason, in the fuel tank storage space traffic device 1 according to this embodiment 1, by arranging a maintenance passage (traffic device) around the fuel tanks 3, 3, it is possible to avoid enlarging the fuel tank storage space 2 itself, i.e., to avoid reducing the cargo compartments. Furthermore, normally, this type of outer perimeter stage cannot be installed until the LNG fuel tanks 3, 3 are installed, but in the fuel tank storage space traffic device 1 according to this embodiment 1, the above-mentioned corridor-type outer perimeter stage 6 is provided on the peripheral wall of the fuel tank storage space 2, and therefore it can also be used as a scaffold when installing the hull blocks, improving workability in this respect as well.

[0028] Furthermore, even when attaching the fuel tanks 3, 3 after they have been installed, mating pieces that ensure the width of the passage are welded to the peripheral wall of the fuel tank storage space 2 before the fuel tanks 3, 3 are installed, and after the tanks are installed, a floor plate of a specified width is fastened to the mounting pieces with bolts, which also means that the outer periphery stage 6 can be installed efficiently.

[0029] Furthermore, by bridging multiple bridge stages 7a to 7c between multiple pillars 10a to 10c arranged between side-by-side fuel tanks 3, 3, it is possible to provide a maintenance stage (passageway) even in places where the hull structure is separated.Furthermore, the bridge is a structure placed on top of the hull structure, with the stern side fixed with bolts and the bow side having a sliding, non-fixed structure with a resin liner (ultra-high molecular weight polyethylene) interposed as a sliding material, so it is possible to follow hull deformation and hull rolling. As such, it is broadly composed of three structures, and each of them can be said to have a shape or concept that takes construction into consideration. [Industrial Applicability]

[0030] The present invention is used in transportation devices for storing fuel tanks in spaces that use liquefied gas (such as LNG (liquefied natural gas)) as fuel, such as car carriers. [Explanation of symbols]

[0031] 1. Fuel tank storage space transportation device according to embodiment 1 2 Fuel tank storage space 3, 3 LNG fuel tanks 4, 4 Area surrounding tank connection and tank valve 5 Hanging stage 6. Outer Stage 7. Cross-linking stage 7a, 7b, 7c 1st to 3rd crosslinking stage 8. Staircase 9 Pipe Space 10a, 10b, 10c 1st to 3rd pillars 11a, 11b, 11c: Avoidance bridges 1-3 12. Lifting and lowering phases 101a, 101b LNG fuel tank 102a, 102b エアドーム 112 LNG fuel tank protective steel 131 Support Construction 301 Extended in the field

Claims

1. A fuel tank storage space transportation device comprising a suspended stage having a suspended structure attached to the ceiling of a fuel tank storage space located below the upper deck of a liquefied gas fuelled ship.

2. 2. The fuel tank storage space transportation device according to claim 1, wherein the suspension stage is a parallel suspension structure with a gap in the center of the extension direction, which allows access to and transportation to the area (Tank Connection Space) surrounding each tank connection section and tank valves on the upper part of the fuel tanks arranged side by side in the longitudinal direction of the hull.

3. 2. The fuel tank storage space transportation device according to claim 1, further comprising an outer peripheral stage welded in a cantilever manner to the front, rear, left and right side walls of the fuel tank storage space located below the upper deck of a liquefied gas fuelled ship.

4. 4. The fuel tank storage space transportation device according to claim 3, wherein the bottom of the outer peripheral stage is at the same height as the top of the fuel tank.

5. 2. A fuel tank storage space transportation device according to claim 1, further comprising a bridge stage that spans the front and rear of the fuel tank storage space located below the upper deck of a liquefied gas fuelled ship and bridges between the fuel tanks arranged side by side.

6. 6. The fuel tank storage space transportation device according to claim 5, wherein the bridge stages each connect the hull structural pipes with a single bridge.

7. A fuel tank storage space transportation device as described in claim 6, characterized in that it comprises a third bridge stage that is fixed to the hull structure by bolting at the stern side, and a first bridge stage that is slidably placed between the bow side and the hull structure with a resin liner sliding material interposed therebetween.

8. 8. The fuel tank storage space transportation device according to claim 1, wherein the fuel tank storage space transportation device has a suspended stage, a peripheral stage, and a bridge stage, and these stages are connected by stairs and a common landing that allow passage between them.

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