JP5357466B2 - Liquefied gas carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquefied gas carrying vessel capable of reducing wind resistance on a front face of a house and/or a front face of a tank cover. <P>SOLUTION: The liquefied gas carrying vessel 1 is provided with: a plurality of spherical tanks 2 storing liquefied gas therein, disposed along the bow and stern direction, and fixed to a vessel body 5 through a skirt; and a plurality of tank covers 7 covering the upper half of the spherical tanks 2 and extending along the bow and stern direction as well as the width direction of the vessel. In order to prevent that a wind blowing from the bow side to the stern side along a upper surface of the tank cover 7 pushes directly against a front face 21 of a house 16, a wind direction changing device 15 changing the wind direction forward of the front face 21 of the house 16 is mounted on the upper surface of the tank cover 7. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a liquefied gas carrier, and more particularly to an LNG carrier that stores and transports natural gas (LNG) liquefied at low temperatures in a moss-type spherical tank.

As a liquefied gas carrier ship that stores and transports natural gas (LNG) liquefied at a low temperature in a moss type spherical tank, for example, one disclosed in Patent Document 1 is known.
JP 2005-521589 A

However, the liquefied gas carrier ship disclosed in Patent Document 1 is provided with one continuous tank cover that covers the upper half of a plurality of spherical tanks arranged along the stern direction. In order to satisfy the various conditions required by the rules, etc., the height of the bridge must be increased, and the wind flowing from the bow side toward the stern side along the upper surface of the tank cover There was a problem that the wind pressure resistance received by the front of the house increased directly.
Similarly, there is a problem in that the wind that flows from the front of the bow toward the front of the tank cover directly hits the front of the tank cover, increasing the wind pressure resistance received by the front of the tank cover.

  This invention is made | formed in view of said situation, and it aims at providing the liquefied gas carrier ship which can reduce the wind pressure resistance which the front surface of a house and / or the front surface of a tank cover receive.

The present invention employs the following means in order to solve the above problems.
The liquefied gas carrier ship according to the present invention stores a liquefied gas therein, and is arranged along the bow-stern direction and fixed to the hull via a skirt, and a top of these spherical tanks. A liquefied gas carrier ship that covers one half and includes one or a plurality of tank covers that extend along the fore and aft directions, from the bow side to the stern side along the upper surface of the tank cover. Wind direction changing means for changing the direction of the wind in front of the front of the house is provided on the upper surface of the tank cover so that the wind flowing toward the front does not directly hit the front of the house , The vertical height at the rear end of the wind direction changing means is 40% to 90% of the difference between the vertical distance from the ship bottom to the top surface of the house and the vertical distance from the ship bottom to the top surface of the tank cover. The wind direction changing means is set so that the horizontal distance from the rear end to the front surface of the house is within a range of 30% to 150% of the vertical distance from the bottom of the ship to the top surface of the tank cover. The inclination angle of the wind direction changing means is set within a range of 20 degrees to 60 degrees .
The upper surface of the tank cover is a surface including the top surface of the tank cover and an inclined surface inclined from the top surface toward the heel side.

  According to the liquefied gas carrier ship of the present invention, the direction of the wind flowing from the bow side toward the stern side along the upper surface of the tank cover is changed by the wind direction changing means in front of the house, for example, upward. Since the wind that flows from the bow side toward the stern side along the upper surface of the tank cover does not directly hit the front of the house, the wind pressure resistance received by the front of the house can be reduced. As a result, the wind pressure resistance received by the entire ship can be reduced.

  According to the liquefied gas carrier ship of the present invention, the direction of the wind that has flowed from the front of the bow toward the front surface of the tank cover by the wind direction changing means is changed from the front of the tank cover to the front, for example, upward. Since the wind directly hitting the front surface of the tank cover is reduced, the wind pressure resistance received by the front surface of the tank cover can be reduced, and as a result, the wind pressure resistance received by the entire ship can be reduced.

The liquefied gas carrier ship according to the present invention stores a liquefied gas therein, and is arranged along the bow-stern direction and fixed to the hull via a skirt, and a top of these spherical tanks. A liquefied gas carrier ship that covers one half and includes one or a plurality of tank covers that extend along the fore and aft directions, from the bow side to the stern side along the upper surface of the tank cover. First wind direction changing means for changing the direction of the wind in front of the front of the house is provided on the upper surface of the tank cover so that the wind flowing toward the front does not directly hit the front of the house. and has the height in the vertical direction at the rear end of the first wind direction changing means includes a vertical distance from the vessel bottom to the top surface of the house, the difference between the vertical distance from the ship bottom to a top surface of the tank cover The first wind direction changing means is set such that the horizontal distance from the rear end to the front surface of the house is 30% of the vertical distance from the ship bottom to the top surface of the tank cover. The inclination angle of the first wind direction changing means is set within a range of 20 degrees to 60 degrees, and from the front of the bow toward the front surface of the tank cover. wind flowed is, so as not exposed to direct to the front of the tank cover, the second wind direction changing means for changing the wind direction at the front than the front surface of the tank cover is provided on the fore deck The vertical height at the rear end of the second wind direction changing means is set within a range of 20% to 70% of the vertical distance from the upper deck to the top surface of the tank cover, and the second wind direction. The inclination angle of the changing means is It is set within a range in degrees 60 degrees.

According to the liquefied gas carrier ship of the present invention, the direction of the wind flowing from the bow side toward the stern side along the upper surface of the tank cover is changed upward in front of the house by the first wind direction changing means. Since the wind flowing from the bow side toward the stern side along the upper surface of the tank cover does not directly hit the front surface of the house, the wind pressure resistance received by the house can be reduced.
Further, the second wind direction changing means changes the direction of the wind flowing from the front of the bow toward the front surface of the tank cover to the upper side in front of the front surface of the tank cover, so that the wind directly hitting the front surface of the tank cover Therefore, the wind pressure resistance received by the front surface of the tank cover can be reduced.
As a result, the wind pressure resistance experienced by the entire ship can be reduced.

  The liquefied gas carrier according to the present invention has an effect that the wind pressure resistance received by the front surface of the house and / or the front surface of the tank cover can be reduced.

Hereinafter, a first embodiment of a liquefied gas carrier ship according to the present invention will be described with reference to FIGS. 1 to 5.
FIG. 1 is a diagram of a liquefied gas carrier according to the present embodiment, where (a) is a right side view, (b) is a plan view, FIG. 2 is a front view of the liquefied gas carrier according to the present embodiment, and FIG. FIG. 4A is a sectional view taken along the line II-II in FIG. 1A, FIG. 4 is a diagram of the liquefied gas carrier ship according to the present embodiment, and FIG. FIG. 5B is a cross-sectional view taken along the line BB in FIG. 1A, and FIG. 5 is a cross-sectional view taken along the line IV-IV in FIG.

As shown in FIG. 1 (a), FIG. 1 (b), and FIG. 4 (a), a liquefied gas carrier ship (in this embodiment, “LNG ship”) 1 according to this embodiment includes, for example, four aluminum Each of the aluminum spherical tanks 2 is liquefied gas (in this embodiment, liquefied at a low temperature), each of which is provided with a spherical tank (also referred to as a “moss type spherical tank”) 2 made of aluminum. Natural gas) can be stored.
Further, as shown in FIG. 3, each of these spherical tanks 2 is connected through a cylindrical skirt 3 whose upper end is fixed to the equator of the spherical tank 2 and whose lower end is fixed on the foundation deck 4. It is supported by the hull 5. That is, the weight of these spherical tanks 2 is received by the hull 5 through the skirt 3.

Further, as shown in FIGS. 1 (a), 1 (b), and 3, the upper half of these spherical tanks 2 is fixed on the upper deck 6 at its lower end, It is covered with one continuous tank cover 7 extending along the ship width direction. Further, no expansion joint is provided between the tank cover 7 and the upper deck 6, and the tank cover 7 has a rigid structure. That is, the tank cover 7, together with the hull 5, is a bending force generated by its own weight, cargo to be loaded, and wave force with respect to the longitudinal strength of the ship required by the rules of the classification society (head-to-tail direction (vertical direction)). And strength against shearing force).
In addition, the code | symbols 8 and 9 in FIG. 3 have each shown the vertical partition and the ship side outer plate.

As shown in FIG. 1 (a), FIG. 3, FIG. 4 (a), FIG. 4 (b), and FIG. 5, there are a plurality of boats at the bottom of the hull 5 along the fore and aft directions. (In the present embodiment, 17 ballast tanks 10) are provided.
Among these ballast tanks 10, the ballast tanks 10 other than the ballast tank 10 arranged at the position closest to the bow are arranged along the circumferential direction of the spherical tank 2 and surrounding the upper portion of the spherical tank 2. The upper part and the lower part arrange | positioned along the ship's side outer plate | board 9 and the ship bottom (boat bottom outer plate | board) 11 of the hull 5 in the bow-stern direction are provided.

  As shown in FIGS. 1A, 1B, and 2, the liquefied gas carrier 1 according to the present embodiment has a cover top FIN (hereinafter, “top fin”) on the upper surface of the tank cover 7. 15) is provided. The top fin (wind direction changing means: first wind direction changing means) 15 is configured to allow wind flowing from the bow side (right side in FIG. 1) to the stern side (right side in FIG. 1) along the upper surface of the tank cover 7. The wind flow direction is changed upward so as not to directly hit the front surface of the house (residential area) 16 (more specifically, the front surface of the bridge 17 provided on the upper portion of the house 16).

The vertical height c at the rear end of the top fin 15 is the vertical distance from the ship bottom 11 to the top surface 19 of the house 16 (more specifically, the bridge 17 provided on the upper portion of the house 16) (“the height of the bridge”). Also within the range of 40% to 90% of the difference between a and the vertical distance b from the bottom 11 of the tank cover 7 to the top surface 20 of the tank cover 7, and the conditions required by the rules of the classification society, etc. The height is set to meet.
Further, in the top fin 15, the horizontal distance d from the rear end (or upper end) to the front surface 21 of the house 16 is in the range of 30% to 150% of the vertical distance b from the ship bottom 11 to the top surface 20 of the tank cover 7. In addition, it is installed at a position that satisfies various requirements required by the rules of the classification society.
The inclination angle α of the top fin 15 is in the range of 20 degrees to 60 degrees (45 degrees in this embodiment, more preferably 30 degrees), and satisfies various conditions required by the rules of the classification society. The tilt angle is set.

Here, the effect by the top fin 15 mentioned above is demonstrated using FIG. 6 and FIG. FIG. 6 is a chart showing the results of a wind tunnel test carried out by fixing the inclination angle α of the top fin 15 to 45 degrees and changing the values of d / b and c / (ab). FIG. 7 is a graph of the results shown in FIG.
As shown in FIGS. 6 and 7, the top fin 15 indicates d / b = 0.00, c / (ab) = 0.00, and relative value = 1.00 in FIGS. 6 and 7. It can be seen that the drag (also referred to as “wind pressure resistance”) is less than that without the top fin 15. In particular, when d / b = 0.37 and c / (ab) = 0.90, it can be seen that the drag is reduced by 11% as compared with the case where the top fin 15 is not provided.

  According to the liquefied gas carrier 1 according to the present embodiment, the direction of the wind flowing from the bow side toward the stern side along the upper surface of the tank cover 7 is changed upward in front of the house 16 by the top fin 15. Since the wind flowing from the bow side toward the stern side along the upper surface of the tank cover 7 does not directly hit the front surface 21 of the house 16, the wind pressure resistance received by the front surface 21 of the house 16 is reduced. As a result, the wind pressure resistance experienced by the entire ship can be reduced.

  Also, one continuous tank cover 7 covering the upper half of the spherical tank 2 is rigidly coupled to the hull 5 and, together with the hull 5, ensures the vertical strength of the ship as required by the rules of the classification society. Therefore, the width of the hull 5 can be reduced by about 2% to 4% (preferably about 2%), the hull resistance and the hull weight can be reduced, and the navigation performance is improved. In addition, the total amount of material (for example, steel) constituting the hull 5 can be reduced, and the construction cost can be reduced.

  Furthermore, as shown in FIG. 4A, the upper part of the ballast tank 10 is arranged so as to extend along the circumferential direction of the spherical tank 2 and surround the upper part of the bottom of the spherical tank 2. The upper part can be used as a part of the skirt 3 that supports the spherical tank 2, the total amount of the material constituting the skirt 3 can be reduced, and the construction cost can be reduced.

A second embodiment of the liquefied gas carrier ship according to the present invention will be described with reference to FIGS. FIG. 8 is a right side view of the liquefied gas carrier ship according to this embodiment, and FIG. 9 is a front view of the liquefied gas carrier ship according to this embodiment.
As shown in FIGS. 8 and 9, the liquefied gas carrier ship 25 according to this embodiment differs from that of the first embodiment described above in that a bow cover 26 is provided instead of the top fin 15. . Since other components are the same as those of the first embodiment described above, description of these components is omitted here.

The bow cover (wind direction changing means: second wind direction changing means) 26 is configured to change the direction of the wind flowing from the front of the bow toward the front surface 27 of the tank cover 7 in front of the front surface 27 of the tank cover 7 and upward. In other words, the drag generated on the front surface 27 of the tank cover 7 (also referred to as “wind pressure resistance”) is reduced, and is substantially the width direction and the length direction of the bow deck (also referred to as “mooring machine deck”). It is provided so as to cover the whole.
The vertical height f at the rear end of the bow cover 26 is 20% to 70% of the vertical distance (also referred to as “tank cover height”) e from the upper deck 6 to the top surface 20 of the tank cover 7. % Is set within the range.
The inclination angle θ of the bow cover 26 (angle formed with the horizontal plane 28) is set within a range of 5 degrees to 60 degrees.

Here, the effect by the bow part cover 26 mentioned above is demonstrated using FIGS. 11-13. FIG. 11 shows a wind tunnel test conducted by fixing the value of e of the bow cover 26 (shown as “bow cover (shape 1)” in FIG. 11) and changing the values of θ and f / e. FIG. 12 and FIG. 13 (indicated by “shape 1” in FIGS. 12 and 13) are graphs showing the results shown in FIG.
As shown in FIGS. 11 to 13, by the bow cover 26, the bow cover 26 shown by θ = 0.00, f / e = 0.00, and drag relative value = 1.00 in FIGS. It can be seen that the drag (also referred to as “wind pressure resistance”) is reduced as compared with those not equipped with. In particular, when θ = 10.40 degrees and f / e = 0.492, it can be seen that the drag is reduced by 5% as compared with the case where the bow cover 26 is not provided.

According to the liquefied gas carrier ship 25 according to the present embodiment, the direction of the wind flowing from the front of the bow toward the front surface 27 of the tank cover 7 is higher than the front surface 27 of the tank cover 7 by the bow cover 26. Since the wind directly hitting the front surface 27 of the tank cover 7 is reduced, the wind pressure resistance received by the front surface 27 of the tank cover 7 can be reduced. As a result, the wind pressure resistance received by the entire ship is reduced. Can be reduced.
Other functions and effects are the same as those of the above-described first embodiment, and thus description thereof is omitted here.

A third embodiment of the liquefied gas carrier ship according to the present invention will be described with reference to FIG. FIG. 10 is a right side view of the liquefied gas carrier ship according to the present embodiment.
As shown in FIG. 10, the liquefied gas carrier ship 31 according to the present embodiment is different from that of the second embodiment described above in that a bow cover 32 is provided instead of the bow cover 26. Since other components are the same as those of the second embodiment described above, description of these components is omitted here.

  The bow cover (wind direction changing means: second wind direction changing means) 32, like the bow cover 26, determines the direction of the wind flowing from the front of the bow toward the front surface 27 of the tank cover 7. The mooring device (which is also referred to as “wind pressure resistance”) is changed in the front side of the tank cover 7 to reduce the drag generated at the front surface 27 of the tank cover 7 and its tip is installed on the bow deck ( The bow cover described above in that it is shifted to the stern side relative to the tip 33 so as to be located on the stern side relative to the front side 27 of the tank cover 7 so as to be located on the stern side relative to the stern side. 26.

Here, the effect by the bow part cover 32 mentioned above is demonstrated using FIGS. 11-13. 11 fixes the value of e of the bow cover 32 (shown in FIG. 11 as “the bow tank shape (shape 2)”), sets the value of θ to 30.77 degrees, and sets the value of f / e to FIG. 12 and FIG. 13 (shown as “shape 2” in FIGS. 12 and 13) are graphs of the results shown in FIG. 11 respectively. .
As shown in FIGS. 11 to 13, by the bow cover 32, the bow cover 32 shown by θ = 0.00, f / e = 0.00, and drag relative value = 1.00 in FIGS. It can be seen that the drag force (also referred to as “wind pressure resistance”) is reduced by 6% compared to those not equipped with.

According to the liquefied gas carrier ship 31 according to the present embodiment, the tip of the bow cover 32 is shifted to the stern side from the tip 33 so as to be located on the stern side with respect to the mooring device installed on the bow deck. Since the mooring device is installed on the exposure deck as before, the mooring work as usual can be performed.
Further, the direction of the wind flowing from the front of the bow toward the front surface 27 of the tank cover 7 is changed by the bow cover 32 toward the front and higher than the front surface 27 of the tank cover 7. Since the direct wind is reduced, the wind pressure resistance received by the front surface 27 of the tank cover 7 can be reduced. As a result, the wind pressure resistance received by the entire ship can be reduced.
Other functions and effects are the same as those of the above-described embodiment, and thus description thereof is omitted here.

A fourth embodiment of the liquefied gas carrier according to the present invention will be described with reference to FIGS. 14 and 15. FIG. 14 is a right side view of the liquefied gas carrier ship according to this embodiment, and FIG. 15 is a front view of the liquefied gas carrier ship according to this embodiment.
As shown in FIGS. 14 and 15, the liquefied gas carrier 41 according to the present embodiment is the same as that of the first embodiment described above in that the bow cover 26 described in the second embodiment is further provided. And different. Since other components are the same as those of the first embodiment described above, description of these components is omitted here.

According to the liquefied gas carrier 41 according to the present embodiment, the direction of the wind flowing from the bow side toward the stern side along the upper surface of the tank cover 7 is changed upward in front of the house 16 by the top fin 15. Since the wind flowing from the bow side toward the stern side along the upper surface of the tank cover 7 does not directly hit the front surface 21 of the house 16, the wind pressure resistance received by the front surface 21 of the house 16 is reduced. Can be reduced.
Further, the direction of the wind flowing from the front of the bow toward the front surface 27 of the tank cover 7 is changed by the bow cover 26 toward the front and above the front surface 27 of the tank cover 7. Since the direct wind is reduced, the wind pressure resistance received by the front surface 27 of the tank cover 7 can be reduced.
As a result, the wind pressure resistance experienced by the entire ship can be further reduced.

  In addition, this invention is not limited to embodiment mentioned above, For example, it can also implement combining 1st Embodiment and 3rd Embodiment, In the above-mentioned embodiment, the inner periphery of the skirt 3 can be carried out. And the inner peripheral surface of a wall portion (wall portion existing along the circumferential direction of the spherical tank 2) 12 (see FIG. 3) that configures (forms) the upper portion of the ballast tank 10; and The skirt 3 and the wall 12 can be modified and changed as necessary as long as they do not depart from the technical idea of the present invention, such as the same member.

  In the above-described embodiment, the upper half of the four spherical tanks 2 is covered with one continuous tank cover 7 extending along the bow-stern direction and the ship width direction. The present invention is not limited to such a configuration, and the present invention can be applied to a configuration having four tank covers corresponding to each spherical tank 2.

It is a figure of the liquefied gas carrier ship concerning 1st Embodiment of this invention, Comprising: (a) is a right view, (b) is a top view. It is a front view of the liquefied gas carrier ship concerning a 1st embodiment of the present invention. It is II-II arrow sectional drawing of Fig.1 (a). It is a figure of the liquefied gas carrier ship concerning 1st Embodiment of this invention, Comprising: (a) is AA arrow sectional drawing of Fig.1 (a), (b) is BB arrow of Fig.1 (a). FIG. It is IV-IV arrow directional cross-sectional view of Fig.1 (a). It is a table | surface which shows the result of the wind tunnel test conducted in order to demonstrate the effect by a top fin. FIG. 7 is a graph of the results shown in FIG. It is a right view of the liquefied gas carrier ship which concerns on 2nd Embodiment of this invention. It is a front view of the liquefied gas carrier ship concerning a 2nd embodiment of the present invention. It is a right view of the liquefied gas carrier ship which concerns on 3rd Embodiment of this invention. It is a graph which shows the result of the wind tunnel test conducted in order to demonstrate the effect by a bow part cover. FIG. 12 is a graph of the results shown in FIG. FIG. 12 is a graph of the results shown in FIG. It is a right view of the liquefied gas carrier ship which concerns on 4th Embodiment of this invention. It is a front view of the liquefied gas carrier ship concerning a 4th embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquefied gas carrier 2 Spherical tank 3 Skirt 5 Hull 7 Tank cover 15 Top fin (wind direction change means: 1st wind direction change means)
16 House 21 Front 25 Liquefied gas carrier 26 Bow cover (wind direction changing means: second wind direction changing means)
27 Front 31 Liquefied gas carrier 32 Bow cover (wind direction changing means: second wind direction changing means)
41 Liquefied gas carrier

Claims (2)

A plurality of spherical tanks that store liquefied gas inside and are arranged along the fore-and-aft direction and are fixed to the hull through skirts;
A liquefied gas carrier ship that covers the upper half of these spherical tanks and includes one or a plurality of tank covers that extend along the bow-stern direction and the ship width direction,
Wind direction changing means for changing the direction of the wind in front of the front of the house so that the wind flowing from the bow side toward the stern side along the upper surface of the tank cover does not directly hit the front of the house Is provided on the upper surface of the tank cover,
The vertical height at the rear end of the wind direction changing means is 40% to 90% of the difference between the vertical distance from the ship bottom to the top surface of the house and the vertical distance from the ship bottom to the top surface of the tank cover. Set within range,
The wind direction changing means is installed such that a horizontal distance from the rear end to the front surface of the house is within a range of 30% to 150% of a vertical distance from the ship bottom to the top surface of the tank cover.
The inclination angle of the wind direction changing means is set within a range of 20 degrees to 60 degrees. A plurality of spherical tanks that store liquefied gas inside and are arranged along the fore-and-aft direction and are fixed to the hull through skirts;
A liquefied gas carrier ship that covers the upper half of these spherical tanks and includes one or a plurality of tank covers that extend along the bow-stern direction and the ship width direction,
A first direction that changes the direction of the wind in front of the front of the house so that the wind flowing from the bow side toward the stern side along the upper surface of the tank cover does not directly hit the front of the house. A wind direction changing means is provided on the upper surface of the tank cover,
The vertical height at the rear end of the first wind direction changing means is 40% to the difference between the vertical distance from the ship bottom to the top surface of the house and the vertical distance from the ship bottom to the top surface of the tank cover. Set within the 90% range,
The first wind direction changing means is installed such that a horizontal distance from the rear end to the front surface of the house is within a range of 30% to 150% of a vertical distance from the ship bottom to the top surface of the tank cover,
The inclination angle of the first wind direction changing means is set within a range of 20 degrees to 60 degrees,
A second wind direction change that changes the direction of the wind in front of the front of the tank cover so that the wind that flows from the front of the bow toward the front of the tank cover does not directly hit the front of the tank cover Means are provided on the bow deck,
The vertical height at the rear end of the second wind direction changing means is set within a range of 20% to 70% of the vertical distance from the upper deck to the top surface of the tank cover,
The liquefied gas carrier ship, wherein the inclination angle of the second wind direction changing means is set within a range of 5 to 60 degrees.

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