JP7074276B2 - Ship - Google Patents

Description

The present invention relates to a ship provided with a tank for storing liquefied gas.

Vessels that carry liquefied gas, such as LNG (liquefied natural gas) vessels and LPG (liquefied petroleum gas) vessels, are equipped with tanks that store liquefied gas by cold insulation, pressurization, or both methods. Further, from the viewpoint of reducing environmental pollution, the number of liquefied gas fuel vessels that use liquefied gas as fuel is increasing, and this liquefied gas fuel vessel is equipped with a liquefied gas fuel tank.

In order to store liquefied gas, it is necessary to maintain the inside of the tank at a low temperature and high pressure to the extent that the gas liquefies, and the gas itself is a combustible substance. Therefore, the inside of the tank is a section that requires a special explosion-proof structure called a Class 0 hazardous area. The liquefied gas fuel tank mounted on the ship is equipped with measures such as pressure resistance, thermal expansion and contraction, and heat insulation in order to meet the requirements as a Class 0 dangerous place. In addition, a section where tanks with a structure independent of the hull are arranged, such as a stand-alone tank, is called a tank room, and this tank room becomes a type 1 dangerous place that does not require a strict explosion-proof structure as much as a type 0 dangerous place. The equipment that can be installed is limited to those equipped with a predetermined explosion-proof structure. Therefore, depending on the capacity of the tank and the type of ship, if the proportion of the Class 0 Dangerous Area or Class 1 Dangerous Area section (hereinafter referred to as the Dangerous Zone here) becomes large in the ship, it will be necessary equipment for the navigation of the ship. In addition, there may be a shortage of non-dangerous areas (hereinafter referred to as safety areas) in which equipment that is difficult to install in the 0-type dangerous area or the 1-type dangerous area is installed.

On the other hand, Patent Document 1 is not a liquefied gas fuel ship or a liquefied gas carrier, but is located at a position in contact with a partition partitioning a side oil tank and a center oil tank of a tanker ship, or outside the side oil tank in the width direction. A structure with an oil tank (dangerous area) and a separate safety zone (non-dangerous area) is described.
In this structure, an emergency fire extinguishing pump is installed in the safety zone, and the safety zone is communicated with the upper deck to allow workers to enter and exit (access) the safety zone.

On the other hand, since the structure described in Patent Document 1 is a structure in which the side oil tank and the center oil tank are integrated with the hull, it is directly applied to the structure in which the stand-alone tank is provided in the tank chamber partitioned by the horizontal bulkhead. Can not.
Further, in the case of a ship having a sonar on the bottom of the bow, it is conceivable to install the sonar in a safety zone provided inside a ballast tank or the like on the bow side of the bow side of the tank room, but in recent years, propulsion performance has been improved. Since the bow of a ship tends to become thinner and the flat part of the bottom of the ship tends to recede toward the stern for the purpose of improving fuel efficiency by improving it, a measuring instrument such as a sonar is installed in the safety section of the bow depending on the hull type. There is a problem that it is difficult to secure a safe area with a flat bottom that is necessary for this. In the structure described in Patent Document 1, a safety zone is secured on the outside in the width direction of the side oil tank, and this problem cannot be dealt with.

Japanese Unexamined Patent Publication No. 2013-1358

An object of the present invention is to secure a safety compartment directly above the flat portion of the bottom of the ship on the bow side even if the bow is formed thin to improve propulsion performance in a ship equipped with a tank for storing liquefied gas. It is the provision of vessels that can be used.

In order to solve the above problems, the ship of the present invention has a stand-alone tank in which the shape of the bow side portion is formed into a convex shape with a space on the bottom side, which is a type 1 danger for storing liquefied gas. It is a ship provided in the tank room, which is the place, and the bow side of the tank room provided closest to the bow side of the cargo compartment, via the horizontal partition wall at the tip of the bow side, to the bow side of the tank room. A safety compartment is provided, and a safety compartment is provided so as to project from the horizontal partition wall at the bow end of the tank chamber to the space on the bottom side of the stand-alone tank, and the safety compartment is on the bow side. An opening provided in the horizontal partition wall at the most advanced portion communicates with the bow-side safety section, and is characterized in that the safety section is formed together with the bow-side safety section .

In this configuration, in the tank chamber provided with the stand-alone tank, a safety compartment is provided in the space portion on the bottom side of the bow side portion of the stand-alone tank.
In particular, in a stand-alone tank for relatively high pressure such as LPG and LNG (for example, the design pressure is about 10 Bar), the type C is composed of a cylindrical part and convex parts (hemisphere etc.) at both ends thereof and can be increased in pressure. Tanks are often used, and a space is created on the bottom side of a stand-alone tank of this shape. Alternatively, since the type B independent spherical tank (moss spherical tank) for LNG is also spherical, a space portion is generated on the bottom side of the ship. Therefore, it is possible to secure a safety compartment for non-hazardous places without reducing the volume of the stand-alone tank.

According to the present invention, in a ship equipped with a tank for storing liquefied gas, even if the bow portion is formed thin to improve propulsion performance, the safety of a non-hazardous place directly above the flat portion of the bottom of the ship on the bow side. It is possible to provide a ship that can secure a compartment.

It is a side view which shows the ship which concerns on this embodiment. It is a top view which shows the ship which concerns on this embodiment. It is an enlarged view near the safety compartment of FIG. 1. It is sectional drawing which shows the ship which concerns on this embodiment, (a) is the sectional drawing of AA of FIG.

Hereinafter, the configuration of the ship according to the embodiment suitable for the present invention will be described in detail with reference to FIGS. 1 to 4.
Here, as a ship, a liquefied gas carrier that stores and transports liquefied gas in a stand-alone tank is exemplified.

As shown in FIGS. 1 and 2, the ship 1 includes a hull 3, a stand-alone tank 2, and a safety compartment 4.
The hull 3 is a structure that becomes the hull of the ship 1, and is configured to surround the inside of the ship with a ship bottom 5a, a side wall 5b, and an exposed deck 5c. The hull structure is not particularly limited. It may be a single hull or a double hull.
In FIG. 1, the hull 3 is divided into four sections, an engine section 6, a cargo section 7, a bow side safety section 9, and a bow section 11, and each section is arranged in this order toward the bow side in the captain's direction. Has been done.

The engine section 6 is a section in which a main engine, which is a heat engine for propelling the ship 1, and a boiler, a pump, and the like, which are other engines required for navigation of the ship 1, are arranged. In a liquefied gas carrier such as ship 1, the engine compartment 6 is arranged at the rearmost end on the stern side as shown in FIG.

The cargo compartment 7 is a compartment for loading the cargo carried by the ship 1. Here, it is a section in which a stand-alone tank 2 for storing liquefied gas as cargo is arranged. In FIG. 1, the cargo compartment 7 is arranged near the center in the direction of the captain. The rear end of the cargo compartment 7 in the captain direction is separated from the engine compartment 6 by a horizontal bulkhead 13 orthogonal to the captain direction. Further, when the upper end of the stand-alone tank 2 is higher than the exposed deck 5c as shown in FIG. 1, an upper structure 17 covering the upper part of the stand-alone tank 2 is provided above the exposed deck 5c of the cargo compartment 7. May be done. Further, in FIG. 1, four independent tanks 2 are arranged in series in the captain direction in the cargo compartment 7, and the horizontal bulkheads 13a, 13b, 13c for the tank chamber compartment arranged in series in the captain direction are the cargo compartments 7. Is separated into tank chambers (cargo hold) 7a to 7d. One stand-alone tank 2 is mounted in each of the tank chambers 7a to 7d.
Since the stand-alone tank 2 stores liquefied gas, the inside thereof is a section requiring a special explosion-proof structure called a Class 0 hazardous area. Since the cargo compartment 7 is a compartment adjacent to the stand-alone tank 2, it is a type 1 hazardous area that does not require as strict explosion-proof structure as the type 0 hazardous area, and the equipment that can be installed is restricted to those equipped with a predetermined explosion-proof structure. To.

The bow-side safety section 9 is a section provided on the bow side of the cargo section 7. The rear end of the bow-side safety compartment 9 in the captain direction is separated from the cargo compartment 7 by a horizontal bulkhead 15. Therefore, unlike the cargo compartment 7, the equipment that can be mounted on the bow side safety compartment 9 is a safety compartment that is not restricted to those equipped with an explosion-proof structure. The equipment mounted on the bow-side safety compartment 9 is not particularly limited, and examples thereof include a ballast tank.

The bow section 11 is a section at the bow end in the captain direction, and the rear end in the captain direction is separated from the bow side safety section 9 by the bow bulkhead 21. The bow compartment 11 is provided with, for example, a drainage facility and a facility for accommodating anchors.

The lengths of the engine compartment 6, the cargo compartment 7, the bow side safety compartment 9, and the bow compartment 11 in the captain direction are not particularly limited. It may be appropriately set according to the size of the equipment required for the navigation of the ship 1 and the capacity of the liquefied gas to be mounted.

The stand-alone tank 2 is a pressure vessel that stores liquefied gas by cold insulation, pressurization, or both methods. The liquefied gas here means a substance that is a gas at normal temperature and pressure and is liquefied by cooling or pressurizing. Specific examples of the liquefied gas include, but are not limited to, liquefied combustible gas such as LNG and LPG.

The stand-alone tank 2 is a pressure vessel having a structure independent of the hull 3. The independent structure referred to here means a structure in which the stand-alone tank 2 itself maintains the pressure for confining the liquefied gas inside and holds the weight of the liquefied gas. Therefore, a structure that uses a part of the hull 3 as a pressure vessel, such as a membrane structure, is not included.

The stand-alone tank 2 can be maintained at the temperature and pressure required to maintain the liquefied gas in a liquefied state, and has a structure as long as it has measures such as pressure resistance, thermal expansion and contraction, and heat insulation as a Class 0 dangerous place. Is not particularly limited.
However, as shown in FIGS. 1, 3, and 4 (a), the stand-alone tank 2 has a convex shape in which the shape of the bow side portion 2a is on the bottom side and a space portion 8 is formed between the bow side portion 2a and the bottom 5a in the captain direction. It needs to be formed into a shape. This is because the safety compartment 4 is arranged in the space 8.
On the other hand, the stand-alone tank 2 for relatively high pressure such as LPG and LNG (for example, the design pressure is about 10 Bar = 1 MPa) is composed of a cylindrical portion and convex portions such as hemispheres at both ends thereof, and can be increased in pressure. Type C tanks are often used, and a space 8 is formed on the bottom side of the stand-alone tank 2 having this shape. Alternatively, since the type B independent spherical tank (moss spherical tank) for LNG is also spherical, a space portion is generated on the bottom side of the ship.
The specific shape of the bow side portion 2a is not particularly limited as long as it has a convex shape in which the space portion 8 is formed between the ship bottom 5a and the ship bottom 5a.

The safety compartment 4 is an area partitioned for installing predetermined equipment, and as shown in FIGS. 1 and 3, the cross bulkhead 15 on the bow side of the tank chamber 7d is located on the bottom side of the stand-alone tank 2. It is a section protruding from the space portion 8. As shown in FIG. 3, the safety compartment 4 is separated from the tank chamber 7d by the safety compartment partition wall 4a, and unlike the tank chamber 7d, the equipment that can be mounted is not limited to the one provided with the explosion-proof structure.

In this way, in the tank chamber 7d provided with the stand-alone tank 2, the volume of the stand-alone tank 2 is provided by providing the safety compartment 4 in the space 8 on the bottom side of the bow side portion 2a of the stand-alone tank 2. It is possible to secure the safety compartment 4 of the non-hazardous place specification without reducing the number.

The type of predetermined equipment to be installed in the safety compartment 4 is not particularly limited, but equipment that needs to be installed on the bow side and is not explosion-proof so that it can be installed in the tank room 7d, which is a type 1 dangerous place, is installed. It is preferable to install it.
Examples of such equipment include sensors such as sonar. The sonar here means a facility that obtains information on an object in the water or the bottom of the water or information on the speed of a ship by using sound waves propagating in the water.

Sonar is a device used to detect underwater terrain and underwater navigation objects, but it is not usually designed to be explosion-proof so that it can be placed in a type 1 dangerous place such as the tank chamber 7d where the stand-alone tank 2 is placed. Therefore, by providing sonar in the safety compartment 4 which is a non-dangerous place, it is not necessary to use special sonar corresponding to the explosion-proof specification.
The type of sonar installed in the safety compartment 4 is not particularly limited as long as the information necessary for the navigation of the ship 1 can be obtained. It may be an active sonar such as a Doppler sonar or an echo sounder, or it may be a passive sonar.

The position of the safety compartment 4 in the height direction is not particularly limited as long as it protrudes from the horizontal partition wall 15 to the space 8 on the bottom side of the stand-alone tank 2, but is in contact with the floor of the bottom 5a or the tank room 7d. It is preferable that it is provided.
By providing the safety compartment 4 in contact with the floor surface of the ship bottom 5a or the tank room 7d, it is preferable to provide the device on the ship and near the water, such as a sonar that exposes a part of the device on the ship bottom 5a. It will be convenient to place.

The positions of the safety compartment 4 in the captain direction and the ship width direction are not particularly limited as long as they are positions protruding from the lateral bulkhead 15 to the space 8 on the bottom side of the stand-alone tank 2. However, the position in the captain direction is preferably a position protruding into the space 8 on the bottom side of the tank chamber 7d provided closest to the bow side of the cargo compartment 7. Further, the position in the ship width direction is preferably provided at a position including the central portion in the ship width direction. The reason is as follows.

Generally, a ship measuring device such as a sonar is preferably provided on the bow side in order to avoid the influence of the propeller and to detect the underwater topography and the underwater navigation object in front of the navigation direction. Further, since one device usually covers both the starboard side, the port side, and the lower side, it is preferable to provide the device on a flat bottom 5a near the center in the width direction of the ship.
By providing the safety compartment 4 on the bow side in this way, the sonar can be provided at a position closer to the bow side. Further, since the safety compartment 4 is provided at a position including the central portion in the width direction of the ship, it can be a more preferable place for the arrangement of equipment such as sonar.

Further, since the safety compartment 4 is provided in the tank chamber 7d provided closest to the bow side, the safety compartment 4 is arranged behind the bow side safety compartment 9, and the bow portion is used to improve the propulsion performance. It can also be used for ships with thinning.
For example, as shown in FIGS. 4A and 4B, comparing the widths W1 and W2 in the width direction of the flat portion of the stern end and the bottom 5a of the bow end in the bow side safety zone 9. The closer to the bow, the smaller the width. In particular, when the bow of a ship is thinned for the purpose of improving fuel efficiency by improving propulsion performance, this tendency becomes remarkable because the flat portion of the bottom 5a recedes toward the stern side. Further, since the width of the bow section 11 in the width direction is smaller than that of the bow side safety section 9, it is difficult to place the equipment on the bottom surface. Therefore, depending on the ship type, the bow side safety section 9 is the only non-dangerous area section where equipment that needs to be installed on the bow side and equipment that is difficult to install in the Class 0 dangerous area or Class 1 dangerous area section is installed. Then there may be a shortage.
Even in such a case, by providing the safety compartment 4, the safety compartment on the bow side can be enlarged, and the shortage of equipment installation locations can be solved.

The shape and dimensions of the safety compartment 4 are not particularly limited as long as there is a space in which desired equipment can be installed. For example, the length L of the safety compartment 4 shown in FIG. 3 in the captain direction and the height H1 of the safety compartment 4 shown in FIG. 4A do not come into contact with the bow side portion 2a of the stand-alone tank 2 and also. It is sufficient as long as it does not interfere with maintenance and inspection. The width W0 of the safety compartment 4 in the width direction of the ship shown in FIG. 4A does not come into contact with the support structure for supporting the tank provided in the tank chamber 7d, and does not interfere with maintenance and inspection. It may be within the range.
Further, in FIGS. 1, 3, and 4, the outer shape of the safety compartment 4 is a cube in which the safety compartment bulkhead 4a is arranged vertically and horizontally with respect to the ship bottom 5a, but it does not have to be a cube. ..

As shown in FIG. 3, it is preferable that the ship 1 is provided with an opening 4b for a worker to enter the safety compartment 4 for operation, maintenance and inspection of the equipment installed in the safety compartment 4. If the opening 4b is provided at a position accessible from the tank room 7d, which is a type 1 dangerous place, an airlock space (airtight space) and ventilation equipment are required to make the safety section room 4 a safe section, so that it is safe. It is preferable to install it in a position that is directly accessible from the compartment.
Specifically, as shown in FIG. 3, the opening 4b of the safety compartment 4 is formed in the horizontal bulkhead 15 on the bow side of the tank chamber 7d so as to communicate the tank chamber 7d and the bow side safety compartment 9. preferable.

With this configuration, a worker can easily enter the safety compartment 4 provided so as to easily project into the tank chamber 7d from the bow-side safety compartment 9 on the bow side of the tank chamber 7d. Further, by communicating the bow side safety section 9 and the safety section room 4 with the opening 4b, the safety section room 4 can be made into a safe place that does not require special additional equipment.

The specific structure of the opening 4b is not particularly limited as long as the structure allows the worker to access the safety compartment 4. Further, a hatch that is closed except when a worker enters or leaves the safety compartment 4 may be provided in the opening 4b so that the safety compartment 4 can be closed.
The above is the description of the configuration of the ship 1 according to the present embodiment.

As described above, the ship 1 of the present embodiment has a tank chamber 7d provided with a convex independent tank 2 having a space 8 on the bottom side of the bow side portion 2a, and a bow side safety provided via a horizontal partition wall 15. A compartment 9 and a safety compartment 4 projecting from the lateral partition 15 to the space 8 are provided.
Therefore, the safety compartment 4 of the non-hazardous place specification can be secured without reducing the volume of the stand-alone tank 2.
Therefore, in a ship 1 equipped with a stand-alone tank 2 for storing liquefied gas, even if the bow is formed thin to improve propulsion performance, a non-hazardous place is located directly above the flat portion of the bottom 5a on the bow side. The safety compartment 4 can be secured.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the configuration of the embodiments. It is natural for a person skilled in the art to come up with various modifications and improvements within the scope of the technical idea of the present invention, and these are also included in the present invention.
For example, in the present embodiment, the present invention has been described by taking as an example a liquefied gas carrier that stores and transports liquefied gas in a stand-alone tank 2, but the application of the present invention is not limited to the liquefied gas carrier. The present invention can be applied to a ship such as a liquefied gas fuel ship as long as the ship has a structure for storing the liquefied gas in the stand-alone tank 2.

1 Ship 2 Stand-alone tank 2a Bow side part 3 Hull 4 Safety compartment 4a Safety compartment partition 4b Opening 5a Ship bottom 5b Side wall 5c Exposed deck 6 Engine compartment 7 Cargo compartment 7a, 7b, 7c, 7d Tank chamber 8 Space 9 Ship Side safety compartment 11 Bow compartment 13,15 Horizontal partition 13a, 13b, 13c Horizontal partition for tank room compartment 17 Superstructure 21 Bow partition

Claims (4)

A ship equipped with a stand-alone tank in which the shape of the bow side part is formed into a convex shape with a space on the bottom side in the tank room, which is a type 1 dangerous place for storing liquefied gas.
A safety compartment on the bow side is provided on the bow side of the tank chamber via the horizontal bulkhead at the tip of the bow side of the tank chamber provided closest to the bow side of the cargo compartment .
A safety compartment is provided so as to project from the horizontal bulkhead at the bow end of the tank chamber to the space on the bottom side of the stand-alone tank .
The safety compartment is
A ship characterized in that it communicates with the bow side safety zone through an opening provided in the horizontal bulkhead at the most advanced portion on the bow side, and forms a safety zone together with the bow side safety section . The ship according to claim 1, wherein sonar is arranged in the safety compartment. The ship according to claim 1 or 2, wherein the safety compartment is provided in contact with the bottom of the ship or the floor of the tank room. 13. The ship according to any one of the items.

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