Ships equipped with liquefied gas tanks

Abstract

A ship according to one embodiment of the present disclosure comprises a liquefied gas tank for storing liquefied gas, a vent mast for discharging combustible gas generated by vaporization of liquefied gas in the liquefied gas tank, a lifeboat located outdoors, an evacuation exit leading to an outdoor space, an evacuation area connecting the lifeboat and the evacuation exit, and shielding equipment separating the discharge outlet of the vent mast from the lifeboat and the evacuation area.

Description

Technical Field

[0001] The present disclosure relates to a ship equipped with a liquefied gas tank.

Background Art

[0002] Large ships are equipped with lifeboats for crew members to escape from the hull in case of a maritime disaster such as a fire. This also applies to ships equipped with liquefied gas tanks (see, for example, Patent Document 1 below).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] [Figure 1] Figure 1 is a side view of a vessel according to the first embodiment. [Figure 2] Figure 2 is a plan view of the vessel according to the first embodiment. [Figure 3] Figure 3 is a side view of the vessel according to the second embodiment. [Figure 4] Figure 4 is a plan view of the vessel according to the second embodiment. [Figure 5] Figure 5 is a side view of the vessel according to the third embodiment. [Figure 6] Figure 6 is a plan view of the vessel according to the third embodiment. [Modes for carrying out the invention]

[0008] (First Embodiment) First, the vessel 100 according to the first embodiment will be described. Figure 1 is a side view of the vessel 100 according to the first embodiment. The right side of Figure 1 is the front of the vessel 100, and will be simply referred to as "front" below. The left side of Figure 1 is the rear of the vessel 100, and will be simply referred to as "rear" below. Furthermore, the longitudinal direction of the vessel 100 will be simply referred to as "longitudinal direction". Figure 2 is a top view of the vessel 100 according to the first embodiment. The vertical direction of Figure 2 is the width direction of the vessel 100, and will be simply referred to as "ship width direction" below.

[0009] The vessel 100 according to the first embodiment is a liquefied gas carrier for transporting liquefied gas. As shown in Figure 1, the vessel 100 includes a cargo area 10, a vent mast 20, a non-cargo area 30, a building 40, lifeboats 50, an escape exit 60, an evacuation area 70, and shielding equipment 80. These components will be described in order below.

[0010] The cargo area 10 is an area for storing liquefied gas. Liquefied gases include, for example, liquefied hydrogen, liquefied natural gas (LNG), and liquefied petroleum gas (LPG). In this embodiment, the cargo area 10 is located in the center of the ship 100 in the longitudinal direction. Multiple liquefied gas tanks 11 for storing liquefied gas are arranged in the longitudinal direction within the cargo area 10. The number, arrangement, and shape of the liquefied gas tanks 11 are not limited.

[0011] The vent mast 20 is equipment that discharges flammable gas generated when liquefied gas in the liquefied gas tank 11 vaporizes. In this embodiment, the vent mast 20 has an outlet 21 at its top, from which the flammable gas is discharged. When the flammable gas is discharged from the outlet 21, static electricity, lightning, etc., can act as an ignition source, potentially causing the flammable gas to ignite. In addition to the flammable gas discharged from the outlet 21 of the vent mast 20, fires can also occur from liquefied gas leaking from the liquefied gas piping. In this embodiment, the vent masts 20 are arranged to correspond to each liquefied gas tank 11. However, the number of vent masts 20 and their arrangement within the cargo area 10 are not limited.

[0012] The non-cargo area 30 is an area located forward, aft, or both of the cargo area 10. In this embodiment, the non-cargo area 30 includes a bow area 31 located forward of the cargo area 10 and a stern area 32 located aft of the cargo area 10.

[0013] The building 40 is a facility located at least partly on the upper deck 42 of the hull 41. In this embodiment, the building 40 includes living quarters where the crew works and lives, and is located in the stern area 32. The ends of the building 40 in the width direction are located inward in the width direction compared to the corresponding parts of the ship's sides 83 (the width direction edges of the hull 41).

[0014] The lifeboats 50 are equipment for crew members to escape from the hull 41. The lifeboats 50 are, for example, lifeboats or life rafts. In this embodiment, the lifeboats 50 are located in the stern area 32, on both sides of the ship's width direction from the building 40. In this embodiment, the lifeboats 50 are located on the upper deck 42, but they may also be located above the upper deck 42, for example, by being suspended.

[0015] The evacuation exit 60 is an exit for exiting the non-cargo area 30 to the outside. In this embodiment, the evacuation exit 60 is provided on both sides of the building 40 in the ship's width direction and connects to the outside of the stern area 32. The evacuation exit 60 does not have to be provided in the building 40; for example, it may be provided on the upper deck 42 of the non-cargo area 30.

[0016] The evacuation area 70 is the area connecting the lifeboat 50 and the evacuation exit 60. In Figure 2, the area indicated by the shaded lines is the evacuation area 70. In this embodiment, the evacuation area 70 is the area that directly connects the lifeboat 50 and the evacuation exit 60. However, if there is an obstacle between the lifeboat 50 and the evacuation exit 60, the evacuation area 70 is the area that connects the lifeboat 50 and the evacuation exit 60 while avoiding that obstacle. In other words, the evacuation area 70 is the area that crew members who have exited the evacuation exit 60 normally pass through when heading towards the lifeboat 50. Note that the evacuation area 70 includes not only a planar area but also three-dimensional areas such as exposed staircases.

[0017] The shielding device 80 is a device that protects the lifeboat 50 and the evacuation area 70 from heat and flames caused by a fire. The shielding device 80 includes a shielding plate 81. The shielding plate 81 is located at the boundary between the cargo area 10 and the stern area 32, and is a member that separates at least the discharge port 21 of the vent mast 20 from the lifeboat 50 and the evacuation area 70. The shielding plate 81 of the present embodiment is located on both sides in the ship width direction of the building 40 and extends from the building 40 to the ship's side 83. In this case, part or all of the shielding plate 81 may be located behind the front surface of the building 40. Further, each shielding plate 81 may be divided into a plurality in the ship width direction. Also, the shielding plate 81 may be located in front of the building 40. Further, the shielding plate 81 may extend from the ship's side 83 on one side in the ship width direction to the ship's side 83 on the other side in the ship width direction. Note that part or all of the shielding plate 81 may be located in a portion other than the boundary between the cargo area 10 and the non-cargo area 30.

[0018] As described above, since the shielding plate 81 is located between the cargo area 10 (the discharge port 21 of the vent mast 20) and the lifeboat 50 and the evacuation area 70, and separates at least the discharge port 21 of the vent mast 20 from the lifeboat 50 and the evacuation area 70, when a fire occurs in the cargo area 10 where the scale is likely to be large, particularly when the combustible gas discharged from the discharge port 21 of the vent mast 20 is ignited or when the combustible gas ignites, the lifeboat 50 and the evacuation area 70 can be protected from the flames and heat generated. Therefore, when a fire occurs, the crew can safely reach the lifeboat 50 from the evacuation exit 60.

[0019] The shielding plate 81 of this embodiment is flat and perpendicular to the front-rear direction. However, the shielding plate 81 may be bent or curved. For example, the shielding plate 81 may be composed of a vertical portion corresponding to a wall and a horizontal portion corresponding to a roof and may be bent in an L shape. In this case, the horizontal portion also functions as a rain shield. Note that the shielding plate 81 may be connected or supported by surrounding structures such as the building 40. Further, the shielding plate 81 may not be perpendicular to the front-rear direction. For example, each shielding plate 81 may be inclined such that the portion on the ship's side 83 is located rearward of the portion on the center side in the ship width direction. Also, each shielding plate 81 may be inclined such that the upper portion is located rearward of the lower portion. By inclining the shielding plate 81 in this way, the air resistance received by the shielding plate 81 during the navigation of the ship 100 can be suppressed.

[0020] Furthermore, the shielding plate 81 of this embodiment has a shape and size such that the lifeboat 50 and the evacuation area 70 are dead zones when viewed from the discharge port 21 of each vent mast 20. In FIG. 1, the straight dashed line extending from the discharge port 21 of the vent mast 20 is a line that extends from the discharge port 21 of the vent mast 20 closest to the shielding plate 81 and passes through the upper end of the shielding plate 81. That is, the portion below this dashed line is a dead zone when viewed from the discharge port 21 of the vent mast 20. By forming the shielding plate 81 as described above, even if the shielding plate 81 is ignited by the combustible gas discharged from the discharge port 21 of the vent mast 20 or the combustible gas ignites, the shielding plate 81 can protect the lifeboat 50 and the evacuation area 70 from the flames and heat generated near the discharge port 21.

[0021] Furthermore, the shielding equipment 80 of this embodiment includes a water injection nozzle 82 that sprays water onto the shielding plate 81. The water injection nozzle 82 of this embodiment is located in the area opposite to the stern area 32 (i.e., the cargo area 10) with the shielding plate 81 in between, and sprays water onto the surface of the shielding plate 81 facing the cargo area 10. By spraying water onto the shielding plate 81 in this way, the shielding plate 81 can withstand the heat from the fire for a certain period of time, and the rise in temperature of the shielding plate 81 can be suppressed, thereby protecting the lifeboats 50 and the evacuation area 70 from the heat from the fire for a certain period of time. The water injection nozzle 82 and the piping that supplies water to the water injection nozzle 82 may be fixed to the shielding plate 81, or they may be fixed to a different part from the shielding plate 81. The water injection nozzle 82 only needs to be able to spray water onto the shielding plate 81 and may be located away from the shielding plate 81.

[0022] Alternatively, the shielding equipment 80 may include water injection nozzles 82, and the shielding plate 81 may be an A-60 class partition. Here, an "A-60 class partition" is a partition defined in SOLAS (International Convention for the Safety of Life at Sea). Specifically, an A-60 class partition is a partition that is heat-insulated with non-combustible material so that for 60 minutes after the start of a fire, the average temperature on the side not exposed to fire does not rise by more than 140 degrees Celsius above the initial temperature, and the temperature at any point, including joints, does not rise by more than 180 degrees Celsius above the initial temperature. However, the shielding equipment 80 may include water injection nozzles 82, and the shielding plate 81 may be an A-60 class partition. With this configuration, the temperature rise of the shielding plate 81 can be further suppressed.

[0023] In this embodiment, the shielding equipment 80 includes a shielding plate 81, but a water curtain may be included instead of the shielding plate 81. Even in this case, the shielding equipment 80 can protect the lifeboats 50 and the evacuation area 70 from flames and heat generated at the outlet 21 of the vent mast 20.

[0024] (Second Embodiment) Next, the vessel 200 according to the second embodiment will be described. In the following, the differences between the vessel 200 according to the second embodiment and the vessel 100 according to the first embodiment will be mainly described, and redundant explanations will be omitted. Figure 3 is a plan view of the vessel 200 according to the second embodiment. Figure 4 is a side view of the vessel 200 according to the second embodiment.

[0025] As shown in Figures 3 and 4, in the vessel 200 according to the second embodiment, the building 40, lifeboats 50, escape exits 60, and escape areas 70 are located not only in the stern area 32 but also in the bow area 31, and the shielding equipment 80 is located not only on the stern area 32 side but also on the bow area 31 side.

[0026] In this embodiment, the building 40 located in the bow area 31 includes the living quarters, and the building 40 located in the stern area 32 includes the engine room. Furthermore, the building 40 located in the bow area 31 has both ends in the width direction located near the ship's sides 83, and the outer part in the width direction is lower than the central part in the width direction. In other words, the building 40 located in the bow area 31 has a stepped structure. To put it another way, the building 40 located in the bow area 31 has a wider width in the width direction at the lower part and a narrower width at the upper part. In addition, the upper surface of the outer part in the width direction of this building 40 is located above the upper deck 42, and the lifeboats 50 and the evacuation area 70 are located on this upper surface.

[0027] In this embodiment, the shielding plate 81 is located on the outer side in the width direction of the building 40 located in the bow area 31, separating the discharge port 21 of the vent mast 20 from the lifeboats 50 and the evacuation area 70. Furthermore, the shielding plate 81 located on the bow area 31 side has a shape and size that creates a blind spot for the lifeboats 50 and the evacuation area 70 when viewed from the discharge port 21 of each vent mast 20. Therefore, in particular, it can protect the lifeboats 50 and the evacuation area 70 located in the bow area 31 from flames and heat generated when flammable gas discharged from the discharge port 21 of the vent mast 20 ignites or when flammable gas ignites.

[0028] In the first embodiment, the lifeboats 50 and other equipment are located only on the stern area 32 side, while in the second embodiment, the lifeboats 50 and other equipment are located on both the bow area 31 side and the stern area 32 side. However, the lifeboats 50 and other equipment may be located only on the bow area 31 side. Furthermore, the shape of the building 40 located in the bow area 31 and the position of the lifeboats 50 in the bow area 31 are not limited to those described above.

[0029] (Third embodiment) Next, the vessel 300 according to the third embodiment will be described. Figure 5 is a plan view of the vessel 300 according to the third embodiment. Figure 6 is a side view of the vessel 300 according to the third embodiment. The vessel 300 according to the third embodiment differs from the vessels 100 and 200 according to the first and second embodiments in that it is a liquefied gas fuel vessel rather than a liquefied gas carrier. In other words, although the vessel 300 according to this embodiment is also equipped with a liquefied gas tank 11, this liquefied gas tank 11 stores liquefied gas used exclusively as fuel.

[0030] However, the vessel 300 according to this embodiment has similar components to the vessels 100 and 200 according to the first and second embodiments, although the arrangement and other aspects differ. In Figures 5 and 6, the same reference numerals are used for components that are the same as or correspond to the components shown in Figures 1 to 4. Below, the components of the vessel 300 according to this embodiment will be described, focusing on the differences from the components of the vessels 100 and 200 according to the first and second embodiments.

[0031] In this embodiment, the building 40 is located in the stern portion of the hull 41. However, the building 40 may be located in a portion of the hull 41 other than the stern portion. Liquefied gas tanks 11 are located on both sides of the building 40 in the width direction of the ship. In this embodiment, the liquefied gas tanks 11 are located on the upper deck 42. However, the number and location of the liquefied gas tanks 11 are not particularly limited, and for example, the liquefied gas tanks 11 may be located below the upper deck 42, that is, inside the hull 41. Vent masts 20 are located on both liquefied gas tanks 11, extending upward from both liquefied gas tanks 11. An outlet 21 is located at the top of the vent mast 20, and the flammable gas generated when the liquefied gas in the liquefied gas tanks 11 vaporizes is discharged from the outlet 21. The number and location of the vent masts 20 are not limited.

[0032] The lifeboats 50 are located at the rear of the building 40 and are held on a support platform 90 located above the upper deck 42. However, the number and location of the lifeboats 50 are not limited. The support platform 90 and the upper deck 42 are connected by an exposed staircase 91. Evacuation exits 60 are located on both sides of the building 40 in the width direction. The evacuation exits 60 lead to the outside of the hull 41. In this embodiment, the evacuation area 70 is the area shown by the diagonal lines in Figure 6.

[0033] The shielding equipment 80 of this embodiment also includes a shielding plate 81. However, the shielding plate 81 is positioned to surround the liquefied gas tank 11 from the front, rear, and inward in the width direction of the ship. If the liquefied gas tank 11 is located below the upper deck 42, the shielding plate 81 is positioned to surround the vent mast 20. The shielding plate 81 of this embodiment also has a shape and size that creates a blind spot for the lifeboats 50 and the evacuation area 70 when viewed from the discharge port 21 of each vent mast 20. Therefore, even if the flammable gas discharged from the discharge port 21 of the vent mast 20 ignites or the flammable gas ignites, the shielding plate 81 can protect the lifeboats 50 and the evacuation area 70 from flames and heat generated near the discharge port 21.

[0034] Furthermore, the shielding equipment 80 of this embodiment also includes a water injection nozzle 82 for spraying water onto the shielding plate 81. However, instead of including the water injection nozzle 82, the shielding equipment 80 may use an A-60 class partition for the shielding plate 81. Alternatively, the shielding equipment 80 may include the water injection nozzle 82 and use an A-60 class partition for the shielding plate 81. With these configurations, the temperature rise of the shielding plate 81 can be suppressed.

[0035] The embodiments described above are merely illustrative examples, and the individual components are not limited to the shape, number, position, size, etc., shown in the embodiments.

[0036] <Summary> The first item disclosed herein is a vessel comprising: a liquefied gas tank for storing liquefied gas; a vent mast for discharging flammable gas generated when the liquefied gas in the liquefied gas tank vaporizes; a lifeboat located outdoors; an escape exit leading to the outdoors; an evacuation area connecting the lifeboat and the escape exit; and a shielding device separating the outlet of the vent mast from the lifeboat and the evacuation area.

[0037] This configuration protects lifeboats and evacuation areas from flames and heat generated when liquefied gas fires, which tend to escalate, occur, particularly when flammable gases discharged from the vent mast outlet ignite or spontaneously combust. This allows crew members to safely reach lifeboats in the event of a fire.

[0038] The second item disclosed herein is the vessel described in the first item, wherein the shielding equipment has a shape and size such that the lifeboats and the evacuation area are in a blind spot when viewed from the outlet of the vent mast.

[0039] With this configuration, even if the flammable gas discharged from the vent mast outlet ignites or the flammable gas itself ignites, the lifeboats and evacuation areas can be protected from flames and heat generated near the outlet.

[0040] A third item disclosed herein is the vessel described in the first or second item, wherein the shielding equipment includes a shielding plate located between the vent mast outlet and the lifeboat and the evacuation area.

[0041] With this configuration, the shielding equipment can separate the vent mast outlet from the lifeboats and evacuation area with a simple structure.

[0042] The fourth item disclosed herein is the vessel according to the third item, further comprising a building located at least in part on the upper deck, wherein the shielding plate is located between the building and the side of the vessel.

[0043] This configuration allows for a shorter length of the shielding plate in the beam direction compared to a case where the shielding plate extends from one side of the ship's hull in the beam direction to the other side of the ship's hull in the beam direction.

[0044] A fifth item disclosed herein is the vessel described in the third or fourth item, wherein the shielding equipment further includes water injection nozzles for spraying water onto the shielding plate.

[0045] With this configuration, the shielding plate can withstand the heat from a fire for a certain period of time.

[0046] The sixth item disclosed herein is a vessel described in any one of items 3 to 5, wherein the shielding plate is an A-60 class partition.

[0047] With this configuration, the shielding plate can withstand the heat from a fire for a certain period of time.

[0048] The seventh item disclosed herein is a vessel according to any one of the third to sixth items, wherein the shielding plate is inclined such that the side portion of the vessel is located aft of the center portion in the width direction of the vessel.

[0049] This configuration makes it possible to reduce the air resistance experienced by the shielding plate when the ship is in motion. [Explanation of symbols]

[0050] 11. Liquefied gas tank 20 Vent Mast 21 Outlet 40 buildings 50 lifeboats 60 Evacuation exit 70 Evacuation Area 80 Shielding equipment 81 Shielding plate 82 Water spray nozzles 83 Ship side 100 ships 200 ships 300 ships

Claims

1. A liquefied gas tank for storing liquefied gas, A vent mast for discharging flammable gas generated when the liquefied gas in the liquefied gas tank vaporizes, Lifeboats located outdoors, An emergency exit leading to the outdoors, An evacuation area connecting the lifeboat and the evacuation exit, Equipped with shielding equipment, The shielding equipment is a vessel that separates the discharge port of the vent mast, which is located above the shielding equipment, from the lifeboat and the evacuation area.

2. The vessel according to claim 1, wherein the shielding equipment has a shape and size such that the lifeboat and the evacuation area are in a blind spot when viewed from the outlet of the vent mast.

3. The vessel according to claim 1, wherein the shielding equipment includes a shielding plate located between the outlet of the vent mast and the lifeboat and the evacuation area.

4. It also includes buildings, at least part of which are located on the upper deck. The vessel according to claim 3, wherein the shielding plate is located between the building and the side of the vessel.

5. The vessel according to claim 3, wherein the shielding equipment further includes a water injection nozzle for spraying water onto the shielding plate.

6. The vessel according to claim 3 or 5, wherein the shielding plate is an A-60 class partition.

7. The vessel according to claim 3, wherein the shielding plate is inclined such that the portion on the side of the vessel is located aft of the portion on the center side in the width direction of the vessel.

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