Technical Field
The present invention relates to a vertical type fuel tank and a support structure for installing the fuel tank in a vertically placed state in the hull of a ship, the fuel tank storing a fuel that is used by the ship to travel, the fuel tank being, for example, a cylindrical tank.
Background Art
Conventionally, for example, horizontal type cylindrical tanks to be loaded on a ship have been widely used, and their support structure and design technology have been established. Specifically, such a horizontal type cylindrical tank is securely and stably supported by a support structure that includes saddles that are provided at the front and rear of the tank.
Japanese Laid-Open Patent Application Publication No. 2003-240198 discloses one example of a support structure of such a horizontal type cylindrical tank.
Citation List
Patent Literature
PTL 1: Japanese Laid-Open Patent Application Publication No. 2003-240198
Summary of Invention
Technical Problem
However, the horizontal type cylindrical tank as described above requires an installation space that accommodates, at least, the length of the cylindrical tank. In order to effectively utilize the limited space of the hull, it is demanded to reduce the installation space of the horizontal type cylindrical tank.
Moreover, for example, assume a case where a fuel used by a ship to travel is stored in the above-described horizontal type cylindrical tank. In this case, in order to make the installation space for the installation of the fuel tank, for example, the space of a liquid cargo hold or a cargo hold for storing a liquid cargo or a cargo loaded in the hull is reduced. Therefore, there is a high demand for reducing the installation space for the installation of the fuel tank in the ship length direction.
Meanwhile, a space that is short in the ship length direction but deep in the vertical direction may be formed in the hull due to, for example, design reasons of the hull and the size and shape of the liquid cargo hold or the cargo hold for storing a liquid cargo or a cargo loaded in the hull. Such a space is required to be utilized effectively.
Examples of such a space include: a comparted area between the engine room and the liquid cargo hold or the cargo hold of the ship; and a comparted area below living quarters of the ship.
The present invention has been made in order to solve the above-described problems. An object of the present invention is to provide a vertical type fuel tank and a support structure that make it possible to reduce a fuel tank installation space in the ship length direction and effectively utilize the limited space of the hull.
Solution to Problem
In order to solve the above-described problems, the inventors of the present invention focused their attention on a vertically placed fuel tank and its support structure so as to efficiently place the fuel tank in a compartment that is formed deep in the vertical direction and efficiently arrange the hull compartments without reducing the cargo hold area of the hull.
A vertical type fuel tank support structure according to the present invention is a fuel tank support structure for installing a fuel tank in a hull, the fuel tank extending vertically and serving to store a fuel that is used by a ship to travel, the vertical type fuel tank support structure including: the fuel tank that is placed vertically; a lower support structure that supports a lower tank portion of the fuel tank; and an upper support structure that supports an upper tank portion of the fuel tank. The lower support structure is configured to support a load that is exerted on the fuel tank vertically and loads that are exerted on the fuel tank in a ship width direction and a ship length direction when the hull swings. The upper support structure is configured to support the loads that are exerted on the fuel tank in the ship width direction and the ship length direction when the hull swings.
The fuel tank, which is included in the vertical type fuel tank support structure according to the present invention, is capable of storing, for example, a propulsion engine fuel used for the traveling of the ship in which the fuel tank is provided. The fuel tank includes a cylindrical body portion, and the upper tank portion and the lower tank portion of the fuel tank are each formed to have a hemispherical shape.
In the vertical type fuel tank support structure according to the present invention, the lower support structure supporting the lower tank portion is disposed along an outer surface of the lower tank portion, and the lower support structure includes: first and second retaining portions that cross each other at a lowermost part of the lower tank portion; and a support base that supports the lower tank portion via the first and second retaining portions. The first retaining portion extends from the lowermost part of the lower tank portion to both sides in the ship width direction, and the second retaining portion extends from the lowermost part of the lower tank portion to both sides in the ship length direction.
In the vertical type fuel tank support structure according to the present invention, the upper support structure supporting the upper tank portion includes: a first member that is provided on the upper tank portion and that is in a shape of a rectangular parallelepiped; and a second member that sandwiches the first member. The first and second members are provided for the purpose of preventing swinging of the tank in front-rear and right-left directions.
The load that is vertically exerted on the vertically placed fuel tank and the loads that are exerted on the vertically placed fuel tank in the ship width direction and the ship length direction when the hull swings can be supported by the lower support structure and the upper support structure of the tank.
In the vertical type fuel tank support structure according to the present invention, in a case where a low-temperature liquefied gas (e.g., liquefied natural gas (LNG)) is stored in the tank, the first and second retaining portions of the lower support structure supporting the lower tank portion and the rectangular-parallelepiped-shaped first member provided on the upper tank portion may be each formed by a thermal insulating member.
Accordingly, external heat can be suppressed from entering the tank via the first and second retaining portions of the lower support structure supporting the lower tank portion or via the rectangular-parallelepiped-shaped member provided on the upper tank portion. This makes it possible to suppress the occurrence of boil-off from the low-temperature liquefied gas.
Advantageous Effects of Invention
According to the vertical type fuel tank and the support structure of the present invention, the fuel tank is supported in a vertically placed state. This makes it possible to reduce the installation space of the fuel tank in the ship length direction and effectively utilize the limited space of the hull.
Brief Description of Drawings
- Fig. 1 is a sectional side view of a vertical type fuel tank support structure according to the present invention.
- Fig. 2 is a front sectional view of the support structure shown in Fig. 1.
- Fig. 3 is a top plan view of a fuel tank shown in Fig. 1 (as seen from above).
- Fig. 4 is a bottom view of the fuel tank shown in Fig. 1 (as seen from below).
- Fig. 5 is a sectional view of a lower support structure shown in Fig. 1, the sectional view being taken along a line V-V of Fig. 1.
- Fig. 6 is a sectional view of the lower support structure shown in Fig. 2, the sectional view being taken along a line VI-VI of Fig. 2.
- Fig. 7 is a partially-enlarged front view of a portion B of an upper support structure shown in Fig. 1, and is a partially-enlarged front view of a portion B' of the upper support structure shown in Fig. 2.
Description of Embodiments
A vertical type fuel tank support structure 11 shown in Fig. 1 is a support structure for installing a fuel tank 13 in a vertically placed state in a ship 12, the fuel tank 13 serving to store a fuel that is used by the ship 12 to travel. The vertical type fuel tank 13 serves to store, for example, a propulsion engine fuel used for the traveling of the ship 12, in which the fuel tank 13 is installed.
The vertical type fuel tank support structure 11 shown in Fig. 1 includes the fuel tank 13, a lower support structure 14, and an upper support structure 15. The lower support structure 14 is provided on a flat 23. The upper support structure 15 is provided on a deck 32. The reference sign 36 in Fig. 1 indicates a bulkhead.
The fuel tank 13 is vertically installed by means of the fuel tank support structure 11. The stored fuel is a liquefied gaseous fuel containing, for example, liquefied natural gas (LNG).
As shown in Fig. 1 to Fig. 4, the fuel tank 13 includes a metal tank body 16. The tank body 16 is formed to have a vertical cylindrical shape, and includes a cylindrical body portion 16a. A hemispherical lower tank portion 16b is provided under the body portion 16a, and a hemispherical upper tank portion 16c is provided over the body portion 16a.
The tank body 16, which has a vertical cylindrical shape, is coated by thermal insulators 17 as shown in Fig. 1. The thermal insulators 17, which are in a large number, have thermal insulation capacity, and are mounted to the tank body 16.
The lower support structure 14 shown in Fig. 1 serves to support the lower tank portion 16b of the fuel tank 13, and is capable of supporting a load that is exerted on the fuel tank 13 vertically and loads that are exerted on the fuel tank 13 in the ship width direction and the ship length direction when the hull swings.
As shown in Fig. 4, Fig. 5, and Fig. 6, the lower support structure 14 is disposed along the outer surface of the lower tank portion 16b, and includes: first and second retaining portions 18 and 19, which cross perpendicularly to each other at the lowermost part of the lower tank portion 16b; and a support base 20, which supports the lower tank portion 16b via the first and second retaining portions 18 and 19.
As shown in Fig. 2, the first retaining portion 18 is configured to extend from the lowermost part of the lower tank portion 16b to both sides in the ship width direction in an arc-like manner. As shown in Fig. 1, the second retaining portion 19 is configured to extend from the lowermost part of the lower tank portion 16b to both sides in the ship length direction in an arc-like manner. The central angle θ of each of the first and second retaining portions 18 and 19 formed in the arc-like manner is, for example, 140° to 150°. It should be noted that the point O shown in Fig. 1 is the central point.
These first and second retaining portions 18 and 19 are highly rigid and have thermal insulation capacity. For example, the first and second retaining portions 18 and 19 are made of laminated phenolic resin. As shown in Fig. 4, the first and second retaining portions 18 and 19 are mounted to the outer surface of the lower tank portion 16b via first and second reinforcing plates 21 and 22 (wear plates). The first and second reinforcing plates 21 and 22 are fixed to the lower tank portion 16b.
It should be noted that the reference sign 29B in Fig. 5 indicates a second upper fixing portion. The second upper fixing portion 29B fixes the second retaining portion 19 on the second reinforcing plate 22. Similarly, the reference sign 29A in Fig. 6 indicates a first upper fixing portion. The first upper fixing portion 29A fixes the first retaining portion 18 on the first reinforcing plate 21.
As shown in Fig. 5 and Fig. 6, the support base 20 serves to support the lower tank portion 16b via the first and second retaining portions 18 and 19, and is fixedly installed on the flat 23 of the hull. The support base 20 includes two first and second upper plates 24 and 25, each of which is formed in an arc-like manner, such that the first and second upper plates 24 and 25 are in contact with the lower surfaces of the first and second retaining portions 18 and 19, respectively. These two first and second upper plates 24 and 25 are supported by first and second support plates 26 and 27, respectively. Each of the first and second support plates 26 and 27 is provided with a plurality of fall-preventing plates 28 for supporting each of the first and second support plates 26 and 27 so that the first and second support plates 26 and 27 will not fall. These first and second support plates 26 and 27 and the fall-preventing plates 28 are fixedly provided on the flat 23.
The upper support structure 15 shown in Fig. 7 includes: a first member 30, which is provided on the uppermost part of the upper tank portion 16c and which is in the shape of a rectangular parallelepiped; and a second member 31, which is provided on (the hull-side portion of) the deck 32 of the hull and which sandwiches the first member 30 in a surrounding manner.
It should be noted that the reference sign 34 in Fig. 7 indicates a third lower fixing portion. The third lower fixing portion 34 fixes the first member 30 on a third reinforcing plate 33 by sandwiching the first member 30 in a surrounding manner.
These first and second members 30 and 31 are highly rigid, and one of, or each of, the first and second members 30 and 31 has thermal insulation capacity. The first and second members 30 and 31 are made of, for example, laminated phenolic resin. As shown in Fig. 6, the first member 30 is mounted to the outer surface of the upper tank portion 16c via the third reinforcing plate 33 (wear plate).
The fuel tank 13 supported by the vertical type fuel tank support structure 11 shown in Fig. 1 is, for example, disposed in a vertically placed state in a comparted area between an engine room and a liquid cargo hold or a cargo hold of the ship, or disposed in a vertically placed state in a comparted area below living quarters of the ship.
Industrial Applicability
As described above, the vertical type fuel tank support structure and the vertical type fuel tank according to the present invention have an excellent advantage of making it possible to reduce the installation space of the fuel tank and effectively utilize the limited space of the hull. Thus, the present invention is suitably applicable to vertical type fuel tanks and support structures thereof.
Reference Signs List
- 11
- vertical type fuel tank support structure
- 12
- ship
- 13
- fuel tank
- 14
- lower support structure
- 15
- upper support structure
- 16
- tank body
- 16a
- body portion
- 16b
- lower tank portion
- 16c
- upper tank portion
- 17
- thermal insulator
- 18
- first retaining portion
- 19
- second retaining portion
- 20
- support base
- 21
- first reinforcing plate
- 22
- second reinforcing plate
- 23
- flat
- 24
- first upper plate
- 25
- second upper plate
- 26
- first support plate
- 27
- second support plate
- 28
- fall-preventing plate
- 29
- second upper fixing portion
- 30
- first member
- 31
- second member
- 32
- deck
- 33
- third reinforcing plate
- 34
- third lower fixing portion
- 36
- bulkhead