JP3206626B2 - Thermal insulation structure of liquid hydrogen transport tanker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating and cooling structure for a liquid hydrogen transport tanker.

[0002]

2. Description of the Related Art Hydrogen has been attracting attention as a non-polluting clean energy.
Liquid hydrogen transport tankers are needed to produce hydrogen in energy-rich countries and transport it to countries that consume large amounts of energy. As a transport tanker for cryogenic fluid, an LNG ship has been widely known. As shown in FIG. 4, the heat insulating and cooling structure of such an LNG ship has a thickness of about 300 mm.
A heat insulating block 4 of plastic foam (polyurethane foam) having a length of 700 mm and a length and width of 700 mm was screwed with a stud bolt 5 attached in advance by welding and attached to the tank 2. Further, necessary gaps are provided between the heat insulating blocks 4 in order to absorb contraction and expansion due to a temperature difference, and a flexible heat insulating material 7 is filled therebetween. 4A is a schematic diagram of a liquid hydrogen transport tanker, FIG. 4B is an enlarged view of a portion A in FIG. 4A, and FIG.
FIG. 1B is a plan view of FIG. 1B, 1 is an adiabatic cold storage tank, 3 is a support member, and 6 is a fixing jig.

[0003]

However, since hydrogen has a low specific gravity and liquid hydrogen easily evaporates, in order to store and transport it at a very low temperature, it is necessary to enhance the adiabatic cooling performance far more than conventional LNG carriers. There was a problem. That is, since liquid hydrogen has a very low temperature (−252 ° C.) and a very small specific gravity (0.07 and ６ of LNG),
Evaporation is very easy compared to LNG, and there is a problem that the amount of evaporation becomes unnecessarily large with the same heat input. Therefore, LN
In order to suppress the evaporation rate to the same level as that of the Vessel G, when the same plastic foam as that of the LNG carrier is used for heat insulation, there is a problem that the thickness of the necessary heat insulating material is about 3000 times, which is about ten times as thick. In addition, because of the extremely low temperature (−252 ° C.), the plastic foam itself may be deteriorated by the extremely low temperature in the conventional structure.

Further, unlike a storage tank on land, a marine tank needs to absorb displacement due to hull movement.
When the thickness of the heat insulating material is as large as 3 m due to the above-described structure, there is a problem that even a structure that absorbs contraction / expansion due to a temperature difference becomes complicated, and the tank size increases by 6 m on both sides, and the hull size increases. .

The present invention has been made to solve such a problem. That is, an object of the present invention is to provide an adiabatic cooling structure of a liquid hydrogen transport tanker that has a significantly higher adiabatic cooling performance than a conventional plastic foam, and can absorb displacement due to shrinkage / expansion due to temperature difference and hull movement. Is to do.

[0006]

According to the present invention, a plurality of stud bolts are attached to an outer wall of a tank containing liquid hydrogen at a distance from each other and extend vertically outward to the outer wall. And a plurality of laminated rectangular plastic foams which are attached to the outer wall by a fixing jig screwed thereto and whose outer edges are adjacent to each other with a predetermined gap therebetween, and sandwiched between the laminated plastic foams, A plurality of vacuum insulation blocks of vacuum, and a flexible insulation material filled in the gaps of the plastic foam,
And a heat insulating and cooling structure for a liquid hydrogen transport tanker.

Further, according to the present invention, a plurality of stud bolts which are attached to an outer wall of a tank containing liquid hydrogen at a distance from each other and extend outwardly perpendicular to the outer wall; A plurality of rectangular plastic foams attached to the outer wall by a fixing jig to be combined and adjacent to each other with a predetermined gap at an outer edge thereof, and a plurality of vacuum insulation blocks sealed inside the plastic foam and having a vacuum inside, And a flexible heat insulating material filled in the gaps of the plastic foam.

Further, according to the present invention, a plurality of vacuum adiabatic units whose outer edges are attached to the outer wall of a tank containing liquid hydrogen with a predetermined gap therebetween and are laminated with a predetermined gap therebetween are provided. A heat insulating and cooling structure for a liquid hydrogen transport tanker, comprising: a block; and a flexible heat insulating material filled in the gap of the vacuum heat insulating block. According to a preferred embodiment of the present invention, each of the vacuum insulation blocks has a plurality of brim-like joining members projecting outward from an outer edge thereof, and the joining members are formed on an outer wall of a tank or an adjacent vacuum insulation block. It is joined to the joining member.

[0009]

According to the structure of the present invention, by combining and laminating a plastic foam with a vacuum heat insulating block having a thermal conductivity one order of magnitude smaller than that of a plastic foam, the heat insulation and cooling performance is significantly higher than that of a conventional plastic foam. Can be increased. In addition, the outer edges of the rectangular plastic foam and the vacuum insulation block are adjacent to each other with a predetermined gap therebetween so that shrinkage due to a temperature difference can be prevented.
The displacement caused by the expansion and the hull motion can be absorbed.
In addition, the heat insulation from the gap can be prevented by the flexible heat insulating material filled in the gap.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Conventional insulation (plastic foam) and 1
A vacuum insulation structure with a small thermal conductivity is used.However, it is considered that it is extremely difficult to maintain the degree of vacuum and the strength of a large marine tank in consideration of hull motion, etc. And the following structure.

[0011] A vacuum insulation block (panel) and a conventional plastic foam are combined to form a laminated structure. Thus, the thickness of the heat insulating layer is approximately equal to that of the conventional (LNG ship) (about twice as large as that of the conventional (LNG ship)). In addition, the size and mounting of the vacuum insulation block are configured to be able to absorb the temperature difference and the displacement due to the hull motion.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings, common parts are denoted by the same reference numerals. FIG. 1 is a view showing a first embodiment of a heat insulating and cooling structure of a liquid hydrogen transport tanker according to the present invention, wherein (A) is a cross-sectional view similar to FIG. 4 (B), and (B) is a plan view thereof. is there. In this figure, a heat insulating and cooling structure 10 of the present invention is attached to an outer wall of a tank 2 containing liquid hydrogen at a distance from each other, and a plurality of stud bolts 5 extending outwardly perpendicular to the outer wall; A plurality of laminated rectangular plastic foams 12 attached to the outer wall by bolts 5 and fixing jigs 6 screwed thereto and having their outer edges adjacent to each other with a predetermined gap therebetween; And a plurality of vacuum heat insulating blocks 11 having a vacuum inside, and flexible heat insulating materials 7 and 13 filled in gaps of the plastic foam 12.

As shown in FIG. 1, a vacuum heat insulating block 11 is sandwiched between plastic foams 12 laminated in two stages and screwed in a conventional manner. The size of the vacuum insulation block 11 is about half that of the plastic foam 12, and the whole is tightened and fixed while holding down the fixing jig 6 without making a hole for the stud bolt 5. The reason why a hole is not formed in the vacuum insulation block 11 is to maintain the degree of vacuum while avoiding processing or the like that causes damage to the vacuum insulation block 11 as much as possible. The vacuum insulation block 11 is a thin metal container, and the inside is evacuated. The outer shape of the vacuum heat insulating block 11 is preferably a rectangular plate, has a thin supporting member between the upper and lower surfaces, and can withstand external pressure. In addition, in order to absorb the difference in the degree of contraction and expansion due to the difference in the material, a necessary gap is opened between the plastic foam 12 and the vacuum heat insulating block 11, and the flexible heat insulating material 13 is formed.
Fill. Although the position where the vacuum block is sandwiched is the center in FIG. 1, it may be sandwiched near the inside or near the outside. When sandwiched inward, the insulation performance is the best, and when sandwiched outside, the security checkability is excellent.

FIG. 2 is a view showing a second embodiment of the heat insulating and cooling structure of the liquid hydrogen transport tanker according to the present invention. FIG. 2 (A) is a sectional view similar to FIG. 4 (B), and FIG. It is a top view. In this figure, the heat insulating and cooling structure 10 of the present invention
A plurality of stud bolts 5 are attached to the outer wall of the tank 2 containing liquid hydrogen at an interval from each other and extend vertically outward to the outer wall, and the stud bolt 5 and a fixing jig 6 screwed to the outer wall are used for the outer wall. And a plurality of rectangular plastic foams 12 whose outer edges are adjacent to each other with a predetermined gap therebetween, a plurality of vacuum insulation blocks 11 sealed inside the plastic foam 12 and having a vacuum inside, and the plastic foam 12 And flexible insulating materials 7 and 14 filled in the gaps.

The heat insulating and cooling structure member shown in FIG. 2 is formed by enclosing the vacuum heat insulating block 11 in advance and foaming when the plastic foam 12 is mixed with a foaming material and manufactured. Since the plastic foam 12 and the vacuum heat insulating block 11 are integrated, a layer is provided outside the vacuum heat insulating block 11 with a flexible heat insulating material 14 in order to absorb a difference in shrinkage and expansion due to a difference in material when entering the inside. It is better to form it. Foaming / molding may be performed in a factory or on site.

FIG. 3 is a sectional view similar to FIG. 4B showing a third embodiment of the heat insulating and cooling structure of the liquid hydrogen transport tanker of the present invention. In this figure, the adiabatic cooling structure of the present invention has an outer wall attached to the outer wall of a tank 2 containing liquid hydrogen with a predetermined gap therebetween, and has a vacuum inside when laminated with a predetermined gap therebetween. The vacuum insulation block includes a plurality of vacuum insulation blocks 11 and a flexible insulation material 7 filled in the gaps of the vacuum insulation blocks. Each of the vacuum insulation blocks 11 has a plurality of brim-like joining members 16 projecting outward from the outer edge thereof, and the joining members 16 are joined to the outer wall 2 of the tank or the joining members 16 of the adjacent vacuum insulation block 11. ing.

That is, the vacuum heat insulating block 11 of FIG. 3 is laminated in several stages to form a necessary heat insulating layer. A gap capable of absorbing contraction and expansion due to a temperature difference is provided between the layers, and a flexible heat insulating material 7 such as glass wool is filled. In assembly
The required number of brick-shaped vacuum insulation blocks 11 are stacked. The attachment to the wall surface and the mutual attachment are performed by, for example, welding, brazing, bonding, or the like, by combining the brim-like joining members 16 provided at the corners of the respective blocks 11. The joining member 16 is a plate-like member that is sufficiently smaller than the vacuum heat insulating block 11, and is made of a metal having a low thermal conductivity. The interior is preferably hollow and evacuated, but may be solid. The joining member 16 is slightly larger than the block surface so as to form a gap, and the gap is filled with a flexible heat insulating material 7 to absorb the displacement.

The thermal conductivity of the conventional plastic foam and the vacuum insulation block is approximately the same as the plastic foam:
About 0.02 kcal / mhr ° C, vacuum insulation block: about 0.002 kcal / mhr ° C (1/10 of plastic foam). Therefore, assuming that the thickness of the heat insulating layer in the case of the conventional LNG ship is, for example, 300 mm, the specific gravity of hydrogen is 1/6 of LNG, the temperature difference is -162 ° C for the LNG temperature, and the temperature of liquid hydrogen is -252 ° C. 90 ° C difference,
The temperature difference from the outside air temperature design condition of 45 ° C is 297 ° C for LNG and about 1.5 times that of LNG for 297 ° C for liquid hydrogen.
The required thermal insulation layer thickness of both is about 10 times that of the LNG carrier.

On the other hand, when the heat insulating layer is formed in combination with the vacuum heat insulating block, the following required heat insulating layer thickness is obtained (theoretical value). In case of plastic foam only, plastic foam is 3000mm, vacuum insulation block is 0mm, plastic foam (1/2) +
In the case of a vacuum insulation block (1/2), the plastic foam is 1500 mm, the vacuum insulation block is 150 mm,
In the case of plastic foam (1/5) + vacuum insulation block (4/5), the plastic foam is 600m
m, when the vacuum insulation block is 240 mm and only the vacuum insulation block is used, the plastic foam is 0 mm and the vacuum insulation block is 300 mm.

Therefore, by the above combination,
It is possible to reduce the thickness of the heat insulating layer.
Fig. 3 shows the case of the above case (dimensions do not always match). Further, as in the conventional case, the gap between the heat insulating blocks is opened and the flexible heat insulating material 7 is filled, so that the temperature difference and the displacement due to the hull movement can be absorbed. Further, the vacuum insulation block 11
Is the innermost (tank side), the cryogenic temperature is the same as the conventional (L
(NG or higher), the outside can be kept as it is in the prior art. Further, since it is possible to block the transmission of heat due to radiation, it is most effective in heat transfer when the inside is inside.

With the above-described heat insulating and cooling structure of the liquid hydrogen transport tanker of the present invention, the heat insulating effect can be enhanced and the heat insulating thickness can be made the same as the conventional heat insulating thickness. This also gives
By improving the heat insulation effect, the amount of liquid hydrogen evaporating can be reduced, and since the heat insulation layer can be made the same thickness as the conventional one, the installation of the heat insulating material becomes the same as the conventional one, and it can be easily installed.
It is possible to obtain effects such as an unnecessary increase in the size of the hull and a reduction in the amount of heat insulating material.

The vacuum panel is placed inside (tank side: LH
2), the outside can be kept at a low temperature equivalent to that of a conventional LNG ship, and the heat insulation structure (material, method) on the outside can be made the same as the conventional one. That is, according to the configuration of the present invention, by combining and laminating a vacuum heat insulating block and a plastic foam whose thermal conductivity is one order of magnitude smaller than that of a plastic foam, the heat insulating and cooling performance is significantly improved as compared with the conventional plastic foam. be able to. Further, by making the outer edges of the rectangular plastic foam and the vacuum heat insulating block adjacent to each other with a predetermined gap therebetween, the contraction / expansion due to the temperature difference and the displacement due to the hull motion can be absorbed. In addition, the heat insulation from the gap can be prevented by the flexible heat insulating material filled in the gap.

[0023]

Accordingly, the adiabatic cooling structure of the liquid hydrogen transport tanker of the present invention has a much higher adiabatic cooling performance than conventional plastic foams, and has a reduced amount of shrinkage / expansion due to a temperature difference and displacement due to hull movement. It has an excellent effect that can be absorbed.

[Brief description of the drawings]

FIG. 1 is a view showing a first embodiment of an adiabatic cooling structure of a liquid hydrogen transport tanker of the present invention.

FIG. 2 is a view showing a second embodiment of the heat insulating and cooling structure of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the heat insulating and cooling structure of the present invention.

FIG. 4 is a view showing a heat insulating and cooling structure of a conventional liquid hydrogen transport tanker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat insulation cold storage tank 2 Tank 3 Support member 4 Heat insulation block 5 Stud bolt 6 Fixing jig 7 Heat insulation material 10 Heat insulation cold insulation structure 11 Vacuum heat insulation block 12 Plastic foam 13 Heat insulation material 14 Heat insulation material 16 Collar connection member

Continuation of the front page (72) Inventor Takao Omori 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Pref. Ishikawajima-Harima Heavy Industries, Ltd. Technical Research Institute (56) References JP-A-4-194497 (JP, A) JP-A Sho 53-166673 (JP, A) JP-A-50-96962 (JP, A) JP-A-56-127167 (JP, A) JP-A-53-128058 (JP, A) JP-A-4-258598 (JP, A A) Fully open 1986-97193 (JP, U) Fully open 56-131095 (JP, U) Fully open 1988-46787 (JP, U) Fully open 1988-JP (JP, U) Fully open 1988 -1558695 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B65D 88/00-90/06 F17C 1/00-13/12

Claims (4)

(57) [Claims] 1. A plurality of stud bolts attached to an outer wall of a tank containing liquid hydrogen at a distance from each other and extending vertically outward to the outer wall, and a fixing jig screwed to the stud bolts. A plurality of stacked rectangular plastic foams attached to the outer wall and adjacent to each other with a predetermined gap at the outer edge, and a plurality of vacuum insulation blocks sandwiched between the stacked plastic foams and having a vacuum inside, A heat insulating and cooling structure for a liquid hydrogen transport tanker, comprising: a flexible heat insulating material filled in gaps of the plastic foam. 2. A plurality of stud bolts attached to an outer wall of a tank containing liquid hydrogen at an interval from each other and extending outwardly perpendicular to the outer wall, and a fixing jig screwed to the stud bolts. A plurality of rectangular plastic foams attached to the outer wall and adjacent to each other with a predetermined gap at the outer edges, and sealed inside the plastic foam,
A heat insulating and cooling structure for a liquid hydrogen transport tanker, comprising: a plurality of vacuum heat insulating blocks having a vacuum inside; and a flexible heat insulating material filled in a gap between the plastic foams. 3. A plurality of vacuum insulation blocks whose outer edges are attached to an outer wall of a tank containing liquid hydrogen with a predetermined gap therebetween and are laminated with a predetermined gap therebetween, and wherein And a flexible heat insulating material filled in the gap of the heat insulating block. 4. The vacuum insulation block each has a plurality of brim-like joining members projecting outward from an outer edge thereof, and the joining members are joined to an outer wall of a tank or a joining member of an adjacent vacuum insulation block. The adiabatic cooling structure of the liquid hydrogen transport tanker according to claim 3, wherein: