JP3811866B2 - Support device for liquefied gas tank - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a support device for a liquefied gas tank used in an LNG ship, an LPG ship, a liquid hydrogen transport ship, or the like.
[0002]
[Prior art]
For example, as shown schematically in FIG. 4, an LNG ship for transporting LNG as a low-temperature liquefied gas is provided with partition walls 3 in the hull 1 to form a plurality of (four in FIG. 4) holds 4. The self-standing rectangular liquefied gas tank 2 as a liquefied gas tank is accommodated in each of the holds 4.
[0003]
Conventionally, as shown in FIG. 5, a support device used for supporting the above-mentioned self-standing square liquefied gas tank 2 in the hold 3 of the hull 1 is a steel base disposed on the double bottom 5 of the hull 1. 7 and a plywood block 8 placed on the steel table 7 are used to support the self-supporting square liquefied gas tank 2, and further, In order to prevent displacement in the front-rear (stern) direction, the front and rear chock 9 that sandwiches the block 9 a provided on the upper surface of the liquefied gas tank 2 and the left and right that sandwich the block 10 a provided on the upper surface of the liquefied gas tank 2 The chock 10 is provided so as to project downward on the lower side of the upper deck of the hull 1, and the rising prevention chock 11 for preventing the vertical displacement of the self-supporting square liquefied gas tank 2 is provided as a self-supporting square liquefied gas tank. The upper surface corner portion of the are to be respectively installed.
[0004]
Taking the 135,000m ³ LNG ship (4TK) as an example, the weight of the self-supporting liquefied gas tank 2 with a full load of LNG is about 18000t / TK (tank), so it is given during vessel navigation. Assuming that the maximum gravity is 1.5 g, the apparent maximum weight of the self-standing liquefied gas tank 2 is
18000t × 1.5g = 27000t
As given. In the case of the tank support structure 6 as shown in FIG. 5, about 70 units are arranged for one self-standing square liquefied gas tank 2, so the average reaction force is
27000t / 70 units ≈ 380t / unit, but in consideration of variation in reaction force due to deformation of the double bottom 5, usually,
The design condition is 380 t / unit × 2.5 times = 950 t / unit.
[0005]
[Problems to be solved by the invention]
However, in the case of the above conventional liquefied gas tank support device, the self-supporting square liquefied gas tank 2 is supported on the double bottom 5 of the hull 1 via a large number of tank support structures 6. For the concentrated load from 6, a large amount of reinforcing material such as a stiffener must be used for the self-standing square liquefied gas tank 2 and the double bottom 5, and the structure of the self-standing square liquefied gas tank 2 and the double bottom 5 is complicated. Therefore, the processing man-hour for that purpose is increased, and even if a large amount of reinforcing material is used, it is impossible to make the deformation of the double bottom 5 zero. Since the reaction force distribution of the structure 6 changes significantly, a complicated strength calculation is required, and the increase in the number of reinforcements at the bottom of the free-standing square liquefied gas tank 2 causes the low-temperature liquefied gas received in the tank to flow Since the unloading time is increased and the self-supporting square liquefied gas tank 2 is supported by the bottom of the tank where heat is most easily transferred into the tank, the intrusion into the self-supporting square liquefied gas tank 2 is achieved. There is a problem that heat increases, liquefied gas as a cargo is easily vaporized, and the boil-off rate of the entire tank increases. In addition, when installing the self-standing square liquefied gas tank 2, it is essential to adjust the gap of each tank support structure 6, and a large amount of labor must be expended. Further, a large number of tank support structures arranged on the upper part of the double bottom 5. In addition to 6, a front and rear chock 9 and a left and right chock 10 for preventing the displacement of the free-standing square liquefied gas tank 2 due to the hull shaking are separately installed on the hull side, and an anti-lift chock 11 is provided above the free-standing square liquefied gas tank 2. There is also a problem that it must be installed separately.
[0006]
Therefore, the present invention is intended to provide a support device for a liquefied gas tank that can simplify the structure by eliminating the need to reinforce the bottom of the self-standing square liquefied gas tank and the double bottom of the hull.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a plurality of support brackets in the circumferential direction on the side outer wall at the position where the horizontal girder of the self-standing liquefied gas tank is installed. A plurality of support bases are arranged on the inner surface of the side wall of the hull close to the liquefied gas tank, corresponding to the plurality of support brackets arranged on the side outer wall of the self-standing square liquefied gas tank, with a required interval in the circumferential direction. mounted respectively so as to project inwardly spaced, on the respective support base via a heat insulating block mounted slidably to the supporting bracket in the horizontal direction, a support base provided on the side wall inner surface of the hull The side of the self-standing square liquefied gas tank is supported via the heat insulation block and the support bracket, and the self-standing square liquefied gas tank is supported and fixed in a state where it is lifted from the double bottom of the hull. .
[0008]
If the side of the self-supporting liquefied gas tank is supported by the support on the inner side wall of the hull at the horizontal girder, the self-supporting liquefied gas tank is supported in a state where it is lifted from the double bottom of the hull. As a result, it is possible to eliminate the need to reinforce the self-supporting square liquefied gas tank and the double bottom, and to prevent heat transfer from the tank bottom to the self-supporting square liquefied gas tank. Further, the heat intrusion into the tank can be minimized by interposing a heat insulating block between the support bracket and the support base.
[0009]
Further, the support base of the upper surface being each located on both sides of the vicinity of the central portion in the vicinity of and left and right side each central portion before and after the self Rectangular liquefied gas tank, the side stoppers so as to sandwich the insulation block on the support table Attached to both the front and rear chock and the left and right chock of the self-standing square liquefied gas tank, and the upper stopper for regulating the vertical movement of the self-standing square liquefied gas tank is attached to the upper surface of all or part of the support base In addition, when the self-standing square liquefied gas tank is also used as the anti-floating chock, there is no need to separately install a front / rear chock, a left / right chock, and an anti-floating chock above the self-standing square liquefied gas tank. it can.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
1 (a) to (b) to FIG. 3 (b) to (b) show an embodiment of a liquefied gas tank support device of the present invention, which is provided in a self-standing square liquefied gas tank 2 as a liquefied gas tank. A plurality of vertical plates 13 attached so as to protrude outward at the circumferentially required interval position at the position of the lowermost horizontal girder 12 of the horizontal girder 12 and the outer periphery of the self-standing square liquefied gas tank 2 are arranged above. A large number of support brackets 15 composed of a horizontal plate 14 fixed to the lower end of each vertical plate 13 are fixed, and the lower surface of each support bracket 15 is made of a material having high heat insulation properties such as a reinforced plywood. On the other hand, the above-mentioned numerous support blocks 18 are mounted on the inner surface of the side wall 16 of the hull, which is positioned so as to surround the free-standing square liquefied gas tank 2. A plurality of support bases 17 are installed corresponding to the brackets 15 so as to protrude inward in the circumferential direction at predetermined intervals, and the support brackets are provided on the support bases 17 via the heat insulating blocks 18. 15, and the side portion of the self-standing square liquefied gas tank 2 is supported on the support base 17 installed on the inner side surface of the side wall 16 of the hull through the heat insulating block 18 and the bracket 15.
[0012]
Further, as shown in FIGS. 3 (a) and 3 (b), near the central portions on both the front and rear sides of the self-standing square liquefied gas tank 2 supported on the support base 17 via the heat insulating block 18, and on both the left and right sides. A side stopper 19 is attached to the upper surface of the support base 17 positioned near each central portion so as to sandwich the heat insulating block 18, and a wedge liner 20 is sandwiched between the side stopper 19 and the heat insulating block 18, The side stopper 19 positioned at the front portion is also used as a front / rear chock for restricting only the movement of the self-standing square liquefied gas tank 2 in the front-rear direction. The left and right chocks that restrict only the movement of the liquefied gas tank 2 in the left-right direction are also used. Further, an upper stopper 21 bent in an inverted L shape is attached to the upper surface of all or a part of the support base 17 so that the upper side of the upper stopper 21 extends above the horizontal plate 14 of the bracket 15. Then, the bracket 15 is pushed by the upper stopper 21 to restrict the vertical movement of the self-standing square liquefied gas tank 2 so as to also serve as a floating prevention chock for the self-standing square liquefied gas tank 2.
[0013]
A bracket 15 is fixed to the position of the horizontal girder 12 at the bottom of the outer wall of the self-standing square liquefied gas tank 2, and the bracket is attached to the inner surface of the side wall 16 of the hull structure located near the self-standing square liquefied gas tank 2. A plurality of support bases 17 are installed so as to surround the self-supporting square liquefied gas tank 2 at a position corresponding to 15, and the bracket 15 is placed on the support base 17 via a heat insulating block 18, thereby When the side portion of the rectangular liquefied gas tank 2 is supported and fixed in a state where it is lifted from the double bottom 5, the self-standing square liquefied gas tank 2 is mainly subjected to a vertical shearing force on the side wall, and the side wall And the tank bottom is not directly subjected to internal or external pressure, so that it is not necessary to reinforce the bottom of the self-supporting liquefied gas tank 2 or the double bottom 5 of the hull 1. The heat insulation block 18 fixed to the bracket 15 and interposed between the bracket 15 and the support base 17 can be slid on the upper surface of the support base 17 so that, for example, the self-standing square liquefied gas tank 2 can be moved. In response to the shrinkage of the self-standing square liquefied gas tank 2 that occurs when the low-temperature liquefied gas is received, the heat insulating block 18 moves so as to slide on the support base 17 to absorb the shrinkage of the self-standing square liquefied gas tank 2. can do. At this time, since the movement of the heat insulating block 18 positioned at the center of each side surface of the self-standing square liquefied gas tank 2 is restricted by the side stopper 19, the tank 2 is not displaced as a whole. Further, since the tank bottom portion where heat is most easily transmitted into the self-standing square liquefied gas tank 2 is separated from the double bottom 5, heat transfer from the tank bottom portion can be prevented, and the bracket 15 and the support base 17 Since the heat insulating block 18 is interposed between the two, the heat intrusion into the self-standing square liquefied gas tank 2 can be minimized.
[0014]
Further, since the self-standing square liquefied gas tank 2 is lifted from the double bottom 5 so that there is no interference between the tank bottom and the double bottom of the hull, as shown by a two-dot chain line in FIG. The inclined structure 22 can also be applied to the bottom of the self-standing square liquefied gas tank 2, and the liquid collecting property in the tank can be easily improved.
[0015]
Further, when the upper stopper 21 is attached to all or a part of the support base 17 so as to also serve as an anti-floating chock, the front and rear chocks, the left and right chocks, and the anti-floating chocks are placed above the free-standing square liquefied gas tank 2 as in the prior art. And need not be installed separately.
[0016]
Taking the 135,000m ³ LNG ship (4TK) as an example in the above, the number of support bases 17 that support one self-supporting liquefied gas tank 2 is about 40, which is smaller than about 70 of the conventional tank support structure 6. However, since each support base 17 is fixed to the side wall 16 of the hull which has sufficient strength to support the self-supporting liquefied gas tank 2 and has the least deformation, the deformation The variation of the reaction force due to suffices to be estimated about 1.5 times, so the design conditions in this case are
27000 t / 40 units × 1.5 times≈1000 t / unit, which is equivalent to 950 t / unit of the conventional tank support structure 6. Further, when the present invention is used for the self-supporting liquefied gas tank 2 of the liquid hydrogen transport ship having a small cargo specific gravity, it is sufficient that the number of the support bases 17 is about 10 for one self-supporting liquefied gas tank 2. It can be applied very easily.
[0017]
The present invention is not limited only to the above-described embodiment. For example, the material of the heat insulating block 18 is rich in heat insulating properties and does not collapse even if the weight of the self-supporting liquefied gas tank 2 is supported. Of course, any other material than the reinforced plywood may be used, and other various modifications can be made without departing from the scope of the present invention.
[0018]
【The invention's effect】
As described above, according to the support device for a liquefied gas tank of the present invention, a plurality of support brackets are arranged in the circumferential direction on the side outer wall at the installation position of the horizontal girder of the self-standing square liquefied gas tank , A plurality of support bases are provided on the inner surface of the side wall of the hull adjacent to the self-supporting square liquefied gas tank so as to correspond to the plurality of support brackets disposed on the side outer walls of the self-supporting square liquefied gas tank. The support brackets are slidably mounted in the horizontal direction on the respective support bases via heat insulation blocks, and are mounted on the inner side surface of the hull side wall. a support table provided by supporting the side of the self Rectangular liquefied gas tank via a support bracket and insulation block, supporting and fixing of a state in which lift the free-standing square liquefied gas tank from double bottom hull Since you have a structure in which the so that, will be self Rectangular liquefied gas tank is supported and fixed in a state lifted from the double bottom of the hull, double bottom bottom and hull of self Rectangular liquefied gas tank It is possible to eliminate the need to attach a reinforcing material to the hull, and the double bottom of the hull can be designed optimally with its own strength, greatly reducing the design effort and improving workability. In addition, the structural reliability can be improved by simplifying the structure, and heat transfer from the bottom of the tank where heat is most easily transmitted into the self-standing square liquefied gas tank can be prevented. By interposing a heat insulation block between the bracket and the support base, it is possible to minimize the intrusion of heat into the self-standing square liquefied gas tank, and the boil-off level of the entire tank can be reduced. It is possible to lower the door. Further, since there is no interference with the hull at the bottom of the self-standing square liquefied gas tank, it is possible to adopt an inclined structure in consideration of the liquid collecting property of the low-temperature liquefied gas received in the tank. Furthermore, if a side stopper is attached to the upper surface of the support base and the front and rear chocks and left and right chocks of the self-standing square liquefied gas tank are combined, or an upper stopper is attached and the lift prevention chock is also used, Displacement of the self-standing square liquefied gas tank supported via the heat insulating block and the support bracket can be regulated by the side stopper and the upper stopper on the support base. The excellent effect of eliminating the need to install each chock separately.
[Brief description of the drawings]
FIG. 1 shows an outline of an embodiment of a support device for a liquefied gas tank according to the present invention, in which (A) is a cross-sectional view and (B) is an enlarged view of a portion A in (A).
FIG. 2 is a perspective view showing an embodiment of the present invention.
3A and 3B show a relationship between a bracket and a support base in the present invention, in which FIG. 3A is a schematic view corresponding to FIG. 1B, and FIG.
FIG. 4 is a schematic view showing an LNG ship for transporting LNG as a low-temperature liquefied gas.
FIG. 5 is a cross-sectional view showing a conventional liquefied gas tank support device.
[Explanation of symbols]
2 Self-supporting liquefied gas tank 12 Horizontal garter 15 Bracket 16 Hull side wall 17 Support base 18 Thermal insulation block 19 Side stopper 21 Upper stopper

Claims (2)

  A plurality of support brackets are disposed on the outer side wall of the horizontal girder liquefied gas tank at the position where the horizontal girder is installed. A plurality of support bases corresponding to the plurality of support brackets arranged on the side outer wall of the self-supporting square liquefied gas tank, respectively attached so as to protrude inward in the circumferential direction with a required interval, The support bracket is slidably mounted in a horizontal direction on each support base via a heat insulation block, and a self-standing square type is provided on the support base provided on the inner side surface of the hull side wall via the heat insulation block and the support bracket. An apparatus for supporting a liquefied gas tank, characterized in that the side portion of the liquefied gas tank is supported and fixed while the self-standing square liquefied gas tank is lifted from the double bottom of the hull. The support base of the upper surface being each located on both sides of the vicinity of the central portion in the vicinity of and left and right side each central portion before and after the self Rectangular liquefied gas tank, by attaching the side stoppers so as to sandwich the insulation block on the support table In addition, the front and rear chocks and the left and right chocks of the self-standing square liquefied gas tank are combined, and an upper stopper for regulating the vertical movement of the self-standing square liquefied gas tank is attached to the upper surface of all or part of the support base, 2. The support device for a liquefied gas tank according to claim 1, wherein the support device is also used as a floating prevention chock for the self-standing square liquefied gas tank.

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