JP2019014440A - Ship - Google Patents

Abstract

To provide a ship which reduces a gap between a tank cover and a cargo tank while providing a passage part and a lifting part to increase the capacity of the cargo tank.SOLUTION: A ship 10 includes: a hull 11; a cargo tank 20 having an upper non-spherical shape part 23 in which a radial dimension gradually reduces upward; a tank cover 30 having a standing part 31 and an upper cover part 34; a passage part 40 which is provided at an upper part of the standing part 31 and extends in a circumferential direction of the standing part 31 along a cargo tank 20 side inner peripheral surface 31g; a hatch 41 provided at the upper part of the standing part 31 and allowing communication between an inner peripheral surface 31g side and an outer peripheral surface 31f side of the standing part 31; and a lifting part 42 which is provided on an outer peripheral surface 31f opposite to the cargo tank 20 side in the standing part 31 and may move up or down between an upper deck 12 and the hatch 41.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a ship.

  A ship that transports liquefied gas such as LNG (Liquefied Natural Gas) has a cargo tank that stores the liquefied gas. The cargo tank is generally arranged in a cargo loading section (cargo hold) on the bow side of the superstructure. The cargo tank is provided with its upper portion protruding upward from the upper deck provided in the cargo loading section.

  In order to protect the cargo tank, such a ship is provided with a tank cover that covers a portion of the cargo tank that protrudes above the upper deck.

A gap is provided between the cargo tank and the tank cover so that an operator can enter in order to perform installation work and maintenance work.
For example, as disclosed in Patent Document 1, in order for an operator to enter an internal gap from the outside of the tank cover, the tank cover is provided with an entrance such as a manhole. Also, inside the tank cover, there are provided a passage part for workers who enter the tank cover from the doorway to move in the horizontal direction inside the tank cover, and a lifting part such as a trap for moving up and down. It has been.

JP-A-8-99690

By the way, in order to secure the capacity of the cargo tank as much as possible, it is desirable to make the gap between the cargo tank and the tank cover as small as possible. However, if a passage part or an elevating part is provided in the gap between the tank cover and the cargo tank, it is difficult to reduce the gap between the cargo tank and the tank cover.
The present invention has been made in view of the above circumstances, and provides a ship capable of reducing a gap between a tank cover and a cargo tank and increasing a capacity of the cargo tank while providing a passage portion and an elevating portion. For the purpose.

The present invention employs the following means in order to solve the above problems.
According to the first aspect of the present invention, a ship includes a hull and an upper diameter-reduced portion that is provided so that an upper portion projects from the upper deck of the hull, and whose diameter is gradually reduced from below to above. A tank, a tank that covers the cargo tank from the outside in the radial direction, has a cylindrical rising portion that extends in the vertical direction, and a tank that is provided on the rising portion and covers the upper portion of the cargo tank from above. A cover, a passage provided in an upper part of the rising part, extending in a circumferential direction of the rising part along an inner surface near the cargo tank, and provided in an upper part of the rising part, A communication portion that communicates the inner surface side and the outer surface side, and an outer surface that is opposite to the cargo tank at the rising portion, and that rises between the upper deck and the communication portion. It comprises a lifting unit can, for.

  By providing the passage portion above the rising portion and providing the lifting portion on the outer surface of the rising portion, a space for providing the passage portion and the lifting portion is provided between the tank cover and the cargo tank at the lower portion of the rising portion. There is no need to secure it. Therefore, it is possible to install the passage portion and the lifting portion while reducing the gap between the tank cover and the cargo tank, and to increase the diameter of the cargo tank.

According to the second aspect of the present invention, the passage portion according to the first aspect may be provided on the radially outer side of the upper reduced diameter portion above the maximum diameter portion of the cargo tank in the vertical direction. Good.
Since the cargo tank has the upper diameter-reduced portion, the radial gap between the rising portion of the tank cover and the upper diameter-reduced portion of the cargo tank increases from the lower side to the upper side. Therefore, a passage portion is provided on the outer side in the radial direction of the upper reduced diameter portion in a portion where the radial gap between the rising portion of the tank cover and the upper reduced diameter portion of the cargo tank is larger than the maximum diameter portion of the cargo tank. Thus, the passage portion can be installed without interfering with the cargo tank.

According to the third aspect of the present invention, the passage portion according to the second aspect has a larger width dimension in the radial direction of the tank cover than a gap between the tank cover and the cargo tank at the maximum diameter portion. It may be.
Thus, by providing the passage portion above the maximum diameter portion of the cargo tank, the width dimension of the passage portion can be made larger than the gap below the passage portion, and the mobility of the worker is improved.

According to the fourth aspect of the present invention, the ship according to any one of the first to third aspects is formed below the passage part, and the inner surface side of the rising part with respect to the communication part And an inner step part that can be raised and lowered between the inner step part and the passage part.
By comprising in this way, when an operator enters / exits in a tank cover, it can reach a channel | path part via a raising / lowering part, an inner side step part, and an inner raising / lowering part. Since the passage portion is positioned above the inner step portion, the width dimension of the passage portion can be increased with respect to the inner step portion. Therefore, the mobility of workers can be improved.

  According to the ship described above, the gap between the tank cover and the cargo tank can be reduced and the capacity of the cargo tank can be increased while providing the passage portion and the elevating portion.

It is a side view which shows the whole structure of the ship in embodiment of this invention. It is a top view which shows the whole structure of the said ship. It is the half sectional view which looked at the cargo tank and tank cover provided in the above-mentioned ship from the bow tail direction. It is the semi-sectional view which looked at the cargo tank and tank cover of the ship in the modification of the said embodiment from the bow tail direction.

Hereinafter, a ship according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing the overall configuration of a ship according to an embodiment of the present invention. FIG. 2 is a plan view showing the overall configuration of the ship.
As shown in FIGS. 1 and 2, the ship 10 of this embodiment carries liquefied gas such as liquefied natural gas (LNG) as a cargo. The ship 10 includes at least a hull 11, an upper deck 12, an upper structure 17, a cargo tank 20, and a tank cover 30.

  The hull 11 has a pair of anchor sides 14. The hull 11 is provided with a cargo loading section (hold) 15 between a pair of anchor sides 14 on the bow 11c side with respect to the upper structure 17 having a residential area.

  The upper deck 12 is an all deck that is exposed to the outside, and is provided so as to cover the cargo loading section 15. The above-described upper structure 17 is formed on the upper deck 12 on the stern 11d side of the cargo loading section 15.

  The cargo tank 20 is made of, for example, an aluminum alloy, and accommodates liquefied gas to be transported therein. A plurality of cargo tanks 20 are arranged in the cargo loading section 15 side by side in the fore / aft direction Da connecting the bow 11c side and the stern 11d side of the hull 11. Each cargo tank 20 is provided with an upper portion 20 a protruding upward from the upper deck 12 of the hull 11.

FIG. 3 is a half cross-sectional view of the cargo tank and the tank cover provided on the ship as seen from the stern direction.
As shown in FIG. 3, each cargo tank 20 includes a lower hemispherical portion 21, a cylindrical portion (maximum diameter portion) 22, and an upper non-spherical shape portion (upper reduced diameter portion) 23. .

The lower hemispherical portion 21 has a true spherical shape with a certain radius of curvature at the lower portion of the cargo tank 20.
The cylindrical portion 22 is formed at an intermediate portion in the vertical direction Dv of the cargo tank 20 and extends upward from the upper end of the lower hemispherical portion 21. The cylindrical portion 22 has a cylindrical shape having a constant inner diameter. The cylindrical portion 22 forms the maximum diameter portion of the cargo tank 20 in the vertical direction Dv.
Here, the cylindrical portion 22 can also have a truncated cone shape in which the inner diameter gradually increases or decreases from the bottom to the top.

The upper non-spherical portion 23 is formed on the cylindrical portion 22, in other words, the upper portion 20 a of the cargo tank 20. The diameter of the upper non-spherical shape portion 23 is gradually reduced from the bottom to the top.
In this embodiment, the upper non-spherical shape portion 23 is formed so that the radius of curvature gradually increases from the bottom to the top. That is, the upper non-spherical shape portion 23 is formed below the first curved portion 23a having the curvature radius R1, and formed above the first curved portion 23a, and has a curvature radius R2 larger than the curvature radius R1. And a second curved portion 23b having The cargo tank 20 is not limited to the shape shown above. In the cargo tank 20, the upper non-spherical shape portion 23 may be a perfect sphere or may be a sphere shape that does not have the cylindrical portion 22.

  Here, a heat insulating material (not shown) that suppresses heat input from the outside is provided on the outer surface of the cargo tank 20 described above.

  A dome top 25 that protrudes upward is formed on the top 20 t of the cargo tank 20. An upper portion of the dome top 25 is integrally provided with a flange portion 26 that extends outward in the radial direction.

  The tank cover 30 is provided on the upper deck 12 of the hull 11 so as to cover the upper portion 20a of the cargo tank 20 from above. The tank cover 30 includes a rising portion 31 and an upper cover portion 34.

  The rising portion 31 is formed so as to rise upward from the upper deck 12. The rising portion 31 is formed in a cylindrical shape having a constant inner diameter in the vertical direction Dv. The rising portion 31 is formed so as to surround the entire circumference of the cargo tank 20 from the outside in the radial direction with a space on the outside in the radial direction of the cargo tank 20 in plan view (see FIG. 2). The upper end 31 t of the rising portion 31 is disposed above the upper end 22 t of the cylindrical portion 22.

  The upper cover part 34 is provided on the rising part 31 and covers the upper part 20a of the cargo tank 20 from above. The upper cover portion 34 includes a top surface portion 32 and a true spherical shape portion 33.

The top surface portion 32 is disposed above so as to face the top portion 20t of the cargo tank 20. The top surface portion 32 has a planar shape located in the horizontal plane.
An opening 32 h is formed at the center of the top surface 32. The dome top 25 formed at the top 20t of the cargo tank 20 protrudes upward through the opening 32h. The eaves part 26 is provided at an interval above the top surface part 32. The flange 26 has an outer diameter larger than the inner diameter of the opening 32h.

  The true spherical shape portion 33 is formed so as to connect the rising portion 31 and the top surface portion 32. The true spherical shape portion 33 is formed with a constant radius of curvature R4.

  A plurality of reinforcing members 35 are provided on the outer peripheral surface (outer surface) 31f of the rising portion 31 of the tank cover 30 opposite to the cargo tank 20 side with an interval in the vertical direction Dv. Each reinforcing member 35 has an L-shaped section or a T-shaped section, extends in the horizontal direction, and is continuous in the circumferential direction of the tank cover 30.

  The ship 10 described above further includes a passage portion 40, a hatch (communication portion) 41, an elevating portion 42, an inner step portion 45, and an inner elevating portion 46 in each tank cover 30.

  The passage portion 40 is provided along the inner peripheral surface (inner surface) 31 g on the side close to the cargo tank 20 in the upper portion of the rising portion 31. The passage portion 40 is formed continuously in the circumferential direction of the rising portion 31. The passage portion 40 includes a floor portion 40a and a handrail portion 40b. The floor portion 40 a has an outer peripheral end joined to the rising portion 31. The floor 40a is located in a horizontal plane so that an operator can walk on the upper surface. The handrail portion 40b is formed to extend upward from the inner peripheral end portion of the floor portion 40a.

  Further, the passage portion 40 is disposed on the outer side in the radial direction of the upper non-spherical shape portion 23 above the cylindrical portion 22 of the cargo tank 20 in the vertical direction. The passage portion 40 is formed such that the width dimension W2 in the radial direction of the tank cover 30 is larger than the width dimension W1 of the gap 100S between the tank cover 30 and the cargo tank 20 in the cylindrical portion 22.

  The hatch 41 is provided on the upper portion of the rising portion 31 and communicates the inner peripheral surface 31g side and the outer peripheral surface 31f side of the rising portion 31 with each other. The hatch 41 can be opened and closed by a door (not shown). The hatch 41 is formed below the floor portion 40 a of the passage portion 40, and an operator can go in and out of the tank cover 30 through the hatch 41.

  An outer step portion 44 is provided on the outer side in the radial direction of the rising portion 31 with respect to the hatch 41. The outer step portion 44 is joined to the outer peripheral surface 31f on the opposite side of the rising portion 31 from the cargo tank 20 side.

  The elevating part 42 is provided on the outer peripheral surface 31 f of the rising part 31. The elevating part 42 extends in the vertical direction so as to connect between the upper deck 12 and the outer step part 44 provided on the outer side in the radial direction of the hatch 41. The elevating unit 42 includes a ladder, stairs, and the like that can be raised and lowered by an operator.

  The inner step portion 45 is provided below the passage portion 40 on the inner peripheral surface 31 g side of the rising portion 31. The inner step portion 45 is disposed on the inner peripheral surface 31 g side of the rising portion 31 with respect to the hatch 41. Here, the width dimension W3 of the inner step portion 45 is smaller than the width dimension W2 of the passage portion 40.

  The inner elevating unit 46 includes a ladder, a staircase, and the like provided between the inner step unit 45 and the passage unit 40. The inner elevating unit 46 is provided so that an operator can move up and down between the inner step unit 45 and the passage unit 40.

  In order for the worker to reach the passage portion 40 in the tank cover 30, first, the worker climbs the lifting / lowering portion 42 from the upper deck 12, and enters the tank cover 30 from the outer step portion 44 via the hatch 41. Move to the inner step portion 45 of. Further, in the tank cover 30, the worker ascends the inner elevating unit 46 from the inner step unit 45 and thereby reaches the passage unit 40.

  Therefore, according to the ship 10 of the above-described embodiment, the tank cover is provided at the lower portion of the rising portion 31 by providing the passage portion 40 on the upper portion of the rising portion 31 and providing the elevating portion 42 on the outer peripheral surface 31f of the rising portion 31. It is not necessary to secure a space for providing the passage portion 40 and the elevating portion 42 in the gap 100S between the tank 30 and the cargo tank 20. As a result, the passage portion 40 and the elevating portion 42 can be installed while reducing the gap 100S between the tank cover 30 and the cargo tank 20. As a result, the diameter of the cargo tank 20 can be increased and the capacity of the cargo tank 20 can be increased.

Further, the passage portion 40 is provided on the radially outer side of the upper non-spherical shape portion 23 above the cylindrical portion 22 of the cargo tank 20 in the vertical direction. According to such a configuration, since the cargo tank 20 has the upper non-spherical shape portion 23, the rising portion 31 of the tank cover 30 and the upper non-true sphere of the cargo tank 20 from the lower side to the upper side. A gap in the radial direction with the shape portion 23 is increased. Accordingly, the passage portion 40 is provided without interfering with the cargo tank 20 by providing the passage portion 40 on the radially outer side of the upper non-spherical shape portion 23 above the cylindrical portion 22 of the cargo tank 20. can do.
Furthermore, the passage portion 40 can have a width dimension W2 in the radial direction of the tank cover 30 larger than the width dimension W1 of the gap 100S between the tank cover 30 and the cargo tank 20 in the cylindrical portion 22. Thereby, the mobility of the worker in the passage portion 40 is increased.

  Further, an inner step portion 45 is provided below the passage portion 40. The width dimension of the passage portion 40 can be increased with respect to the inner step portion 45 provided in a portion where the gap between the tank cover 30 and the cargo tank 20 is smaller than that of the passage portion 40. Thereby, the mobility of an operator can be improved.

(Modification of the embodiment)
In the said embodiment, although the inner side step part 45 and the inner side raising / lowering part 46 were provided, it is not restricted to this structure.
FIG. 4 is a half cross-sectional view of the cargo tank and the tank cover of the ship according to a modification of the above embodiment as viewed from the bow-stern direction.
As shown in FIG. 4, each tank cover 30 in this modification includes a passage portion 40, a hatch (communication portion) 41B, and an elevating portion 42B.

  The passage portion 40 is provided along the inner peripheral surface 31 g on the cargo tank 20 side in the upper portion of the rising portion 31. The passage portion 40 is formed continuously in the circumferential direction of the rising portion 31.

  The hatch 41 </ b> B is provided on the upper portion of the rising portion 31. The hatch 41B is formed above the floor portion 40a of the passage portion 40, and an operator can enter and leave the tank cover 30 through the hatch 41B. An outer step portion 44B is provided on the radially outer side of the rising portion 31 with respect to the hatch 41B.

  The elevating part 42B is provided on the outer peripheral surface 31f on the opposite side of the rising part 31 from the cargo tank 20 side. The elevating part 42 is provided so as to connect between the upper deck 12 and an outer step part 44B provided on the radially outer side of the hatch 41B. The raising / lowering part 42B consists of a ladder, stairs, etc. which an operator can raise / lower.

  In the modification of the embodiment described above, in order for the worker to reach the passage portion 40 in the tank cover 30, first, the worker climbs the elevating unit 42 </ b> B from the upper deck 12. Then, the worker reaches the passage portion 40 by moving from the outer step portion 44B into the tank cover 30 through the hatch 41B.

Therefore, according to this modification, in particular, since the inner elevating part 46 is not provided in the tank cover 30, it is possible to simplify the route for the worker to reach the passage part 40.
(Other variations)
The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention. That is, the specific shapes, configurations, and the like given in the embodiment are merely examples, and can be changed as appropriate.
For example, the shape of the upper cover portion 34 is not limited to the shapes of the above-described embodiments and modifications.

10 Ship 11 Hull 11c Bow 11d Stern 12 Upper deck 14 Side 15 Cargo loading compartment 17 Upper structure 20 Cargo tank 20a Upper 20t Top 21 Lower hemispherical part 22 Cylindrical part (maximum diameter part)
22t upper end 23 upper non-spherical part (upper diameter reduced part)
23a 1st bending part 23b 2nd bending part 25 Dome top 26 Gutter part 30 Tank cover 31 Standing part 31f Outer peripheral surface (outer surface)
31g Inner peripheral surface (inner surface)
31t Upper end 32 Top surface part 32h Opening part 33 True spherical part 34 Upper cover part 35 Reinforcing member 40 Passage part 40a Floor part 40b Handrail part 41, 41B Hatch (communication part)
42, 42B Lifting part 44, 44B Outer step part 45 Inner step part 46 Inner lifting part 100S Gap Da Stern direction Dv Vertical direction W1 Width dimension W2 Width dimension W3 Width dimension

Claims (4)

The hull,
A cargo tank provided with an upper portion protruding from the upper deck of the hull, and having an upper diameter-reduced portion whose diameter is gradually reduced from below to above;
A tank cover that covers the cargo tank from the outside in the radial direction and has a cylindrical rising portion that extends in the vertical direction, and an upper cover portion that is provided on the rising portion and covers the upper portion of the cargo tank from above.
A passage portion provided at an upper portion of the rising portion and extending in the circumferential direction of the rising portion along an inner surface on a side close to the cargo tank;
A communication portion provided on an upper portion of the rising portion to communicate the inner surface side and the outer surface side of the rising portion;
An elevating part provided on the outer surface opposite to the cargo tank in the rising part, and capable of raising and lowering between the upper deck and the communication part,
Ship equipped with.   2. The ship according to claim 1, wherein the passage portion is provided on a radially outer side of the upper reduced diameter portion above the maximum diameter portion of the cargo tank in the vertical direction.   The ship according to claim 2, wherein the passage portion has a width dimension in a radial direction of the tank cover larger than a gap between the tank cover and the cargo tank in the maximum diameter portion. An inner step portion that is formed below the passage portion and communicates with the communication portion on the inner surface side of the rising portion;
An inner lifting part that can be raised and lowered between the inner step part and the passage part;
A ship according to any one of claims 1 to 3.

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