JP2720322B2 - Heat insulation structure for cryogenic tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquefied petroleum gas (LP)
G), liquefied natural gas (LNG), liquefied hydrogen (LH ₂ ),
Liquid nitrogen (LN _2), liquid oxygen (LO _2), relates primarily insulation structure of a cryogenic tank for storing the cryogenic substance, such as liquefied helium (LH _e). Cryogenic tanks targeted by the present invention are those that have a curvature, such as spherical or cylindrical, but not only those that are installed on the ground, for example, those that are mounted on ships, and that contain cryogenic substances. Including pipes to be transported.

[0002]

2. Description of the Related Art In this kind of cryogenic tank, it is necessary to cover the surface thereof with a heat insulating layer in order to prevent heat from entering the tank from outside air. Conventionally, this heat insulating layer has been disclosed in Japanese Patent Publication No. 54-1948 and Japanese Utility Model Publication No. 59-7676.
There is one described in Japanese Patent Publication No. In any case, a net-like reinforcing material is interposed between the inner heat-insulating layer portion and the outer heat-insulating layer portion made of synthetic resin foam such as hard polyurethane or phenol resin,
The synthetic resin has a self-adhesive action at the time of foaming or a structure integrated by bonding with an adhesive. The reinforcing material is interposed mainly to prevent low-temperature cracking of the outer heat-insulating layer, but the reinforcing material can be omitted. The tank body is made of stainless steel or aluminum alloy, and the heat-insulating layer that covers the outer peripheral surface of the tank body is provided by a large number of supports (such as stud bolts) that are planted at intervals on the peripheral surface of the tank body. It is supported, especially in the case of a spherical tank, etc., which prevents the heat insulating layer from falling in the lower half of the tank.
These supports are usually made of stainless steel or aluminum alloy which is the same material as the tank.

[0003] The heat insulating layer is made of a synthetic resin foam such as hard urethane or phenol resin molded in advance, has a net-like reinforcing material interposed therebetween, and has an aluminum surface layer (also referred to as an aluminum surface sheet material). A structure in which fixed heat insulation panels with a convex cross section are attached adjacent to each other on the surface of the tank body, and joints between the protrusions of the heat insulation panels are filled with at least one of synthetic resin material or foamed and connected. It is a target.

Conventionally, the surface of a heat insulating panel has a thickness of 0.3 m.
m (300 μm) of aluminum sheet. This is to prevent mechanical damage such as when an object hits. Further, when the heat insulating panel is mounted on the surface of the tank body via the support, a gap (joint) is generated between the protrusions of the adjacent heat insulating panels, and the joint is filled or foamed at least with a synthetic resin material on site. One of the buried to go. Although the joint resin foam 29 is also covered with the aluminum sheet 31 for connection,
This sheet thickness is around 0.25mm (250μm),
As shown in FIG. 6, a butyl rubber sheet 30 having a thickness of about 1 mm is stuck on the synthetic resin foam 29 and the outer edge of the aluminum sheet 26 of the heat insulation panel 25 around the butyl rubber sheet 30. The intermediate portion is floated from the joints (synthetic resin foam 29 and butyl rubber sheet 30) and is adhered only to the outer edge of the aluminum sheet 26 of the heat insulating panel 25, and is further stopped with rivets 32 at a constant interval. .

[0005]

However, the above-mentioned conventional heat-insulating structure or panel has room for improvement in the following points. That is, for example, when LNG is stored in an aluminum alloy tank, if the outside air temperature is set to 30 ° C., the heat shrinkage of the tank body is about 0.4%.
In the case of 0 m, it contracts about 80 mm in the radial direction. On the other hand, the heat insulation panel 25 on the surface of the tank body 21 has the aluminum sheet 26 on the surface disposed at the room temperature side, and does not thermally contract itself and has high rigidity.
Since compression deformation hardly occurs, as shown in FIG. 7, it deforms in a wave shape and projects to the joint side, and the synthetic resin foam 29 of the joint is formed.
Will be compressed and absorbed. Therefore, when the size of the heat insulation panel 25 is, for example, 1 m × 1 m (thickness is, for example, 200 mm), it is necessary to take at least 100 mm in the width of the joint. It takes time and effort to fill and foam the synthetic resin material 29 to be performed, and in order to ensure the same quality as the heat insulation panel 25 manufactured in advance in the factory, it requires a high level of technical skill in construction and the corresponding cost Goes up.
In addition, when filling and foaming, a holding jig is used to prevent it from protruding from the joint frame and foaming, and to suppress foaming (pressure), but this holding jig also becomes large, Since the workability is deteriorated, the overall workability is reduced. In the case of the above size, the joint width is set to 100 mm.
If it is narrower than this, it may exceed the compression elastic limit of the synthetic resin foam at the joint, so that it cannot be narrowed down below the design.

When the connecting aluminum sheet at the joint portion is attached across the outer edge portion of the aluminum sheet of the heat insulating panel, riveting is performed because the adhesive strength of a butyl rubber sheet or the like is not enough. Assuming that the pitch is 100 mm, in the case of a spherical tank having a radius of 20 m, it is necessary to perform a riveting operation of more than about 200,000 pieces per tank, and the labor required for this operation is enormous, and the rivet cost is also large. In addition, if the rivet is improperly set, a gap is formed, and there is a possibility that moisture may enter from the gap.

In order to attach the heat insulating panel to the surface of the tank body, the panel is fastened and supported via a washer by a number of stud bolts (supports) erected on the surface of the tank body, and the stud bolts are jointed. Are arranged along the center line. For example, as shown in FIG. 7, when stud bolts 24 are arranged at regular intervals in the horizontal joints of the tank body 21, the B crossing the vertical joints
The stud bolt 24 at the position has a low degree of restraint as a peripheral structural element, and the tensile load acting on the stud bolt 24 and the like when the tank body 21 thermally contracts is small. On the other hand, stud bolts 2 at positions A and C sandwiched between heat insulating panels 25
No. 4, the degree of freedom is limited only in one direction, so that the degree of restraint is large, and the tensile load applied when the tank body 21 thermally contracts is very large, about 10 times as large as the stud bolt 24 at the B position. There is. For this reason, it is necessary to reduce the pitch, and the number of stud bolts 24 increases.
To give a specific example, in the case of the conventional heat insulation structure, the radius is 11 m.
In an aluminum alloy LNG spherical tank, the stud bolt pitch must be 50 cm,
At this time, the total number of bolts is about 3,400 per tank. Thus, if the number of stud bolts is large,
When installing the heat insulation panel, it takes time and effort to tighten the nut with a washer, and the amount of heat that enters through the stud bolt increases, so that the heat insulation performance also decreases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has an object to reduce the width of joints between protrusions of a heat insulating panel mounted on the surface of a tank main body so as to fill and foam a synthetic resin material on site. The number of supports can be reduced by eliminating the need for riveting, reducing the labor and cost required for riveting, and by equalizing the load applied to supports such as stud bolts. It is an object of the present invention to provide a heat insulating structure and a heat insulating panel for a cryogenic tank, which can greatly reduce construction costs and improve workability and heat insulating performance.

[0009]

In order to achieve the above-mentioned object, the heat insulating structure of the present invention comprises: 1) a synthetic resin foam such as a hard urethane or phenol resin molded in advance and having an aluminum surface sheet material. Heat-insulating panels of a fixed cross-section with convex cross-sections are arranged adjacent to each other on the surface of the tank body, attached by supports implanted in the tank body, and made of synthetic resin material at joints between the protrusions of the heat-insulating panel. In a heat insulating structure for a cryogenic tank connected by performing at least one of filling or foaming, 2) the aluminum surface sheet material has a two-layer structure in which a synthetic resin layer is laminated on the surface of an aluminum foil, and 3) the joint and Tsu span on synthetic resin foam and the aluminum surface sheet material on the periphery thereof, a of the aluminum surface sheet material having the same configuration
The luminium connection sheet material is entirely adhered via the adhesive sheet material .

[0010] As described in claim 2, 1 ') a net-like reinforcing material may be interposed in the middle of the synthetic resin foam.

As described in claim 3, 4) the synthetic resin layers on the surface of the aluminum surface sheet material and the surface of the aluminum connection sheet material are each formed of a polyethylene terephthalate film, and 5) the thickness of the aluminum foil. Is preferably 20 to 100 μm, and the thickness of the polyethylene terephthalate layer is preferably 50 to 500 μm. In particular, it is more preferable that the thickness of the aluminum foil is 25 μm and the thickness of the polyethylene terephthalate layer is 100 μm.

According to a fourth aspect of the present invention, 6) a nonwoven fabric is preferably laminated on the inner surface of the aluminum foil of the aluminum surface sheet material.

[0013]

[0014]

[0015]

According to the heat-insulating structure of the present invention having the above-described structure, the aluminum foil on the surface of the heat-insulating panel is very thin compared to the aluminum sheet of the conventional heat-insulating panel, so that it has low rigidity and is flexible. When storing cryogenic substances such as LNG, the tank body shrinks,
When each heat-insulating panel is forcibly pulled toward the center of the tank body via a support such as a stud bolt, each heat-insulating panel is substantially uniformly compressed and deformed over the entire in-plane direction. Thus, unlike the related art, the compression deformation does not concentrate on the synthetic resin foam at the joint portion, so that the width of the joint can be arbitrarily selected without being restricted in terms of strength. In other words, the joint width may be set to the minimum necessary for construction for connecting the heat insulating panels, so that the joint width can be considerably reduced as compared with the conventional heat insulating structure. As a result, the amount of filling (injection) of the synthetic resin material to be filled and foamed at the joints is considerably reduced, so that workability is remarkably improved. In addition, as the joint width is reduced, the volume of the synthetic resin foam to be filled and foamed at the site is greatly reduced. Is improved.

Furthermore, since the compression deformation is not concentrated on the joints, the deformation of the joints is reduced, and the aluminum connecting sheet material covering the joints is made of aluminum foil similarly to the surface sheet material of the heat insulating panel. Because of this, since the rigidity is low and the flexibility is high, there is no need to float at joints as in the related art, and the entire surface can be adhered via the adhesive sheet material, thereby improving workability. Further, by integrally bonding the aluminum connecting sheet material and the pressure-sensitive adhesive sheet material integrally, the invasion of moisture is reliably prevented, and a sufficient moisture-proof function is exhibited. Furthermore, since the aluminum connection sheet material is firmly adhered to the entire surface, riveting is not required at all unlike the conventional art, and the labor and cost spent for the work are completely eliminated. On the other hand, the main part of the aluminum surface sheet material and aluminum connection sheet material was made thin by using aluminum foil, but a synthetic resin layer having a considerably thicker thickness was laminated on the surface by coating or laminating. Even if an external impact is applied, the synthetic resin layer on the surface prevents mechanical damage, and the surface sheet material or the connecting sheet material absorbs the impact integrally with the lower synthetic resin foam.

In the heat insulating structure according to the second aspect, the mesh-like reinforcing material interposed therebetween prevents the outer heat insulating layer from being cracked at low temperature.

According to the third aspect of the present invention, since the synthetic resin layer on the surface is made of a polyethylene terephthalate film, it is excellent in the effect of preventing mechanical damage against impact and the like. The thickness of the aluminum foil is 2
The reason why the thickness is set to 0 μm or more is that if it is thinner than that, there is a risk that the moisture-proof property may not be maintained. If the thickness is less than 100 μm, the rigidity is increased and the heat-insulating panel is evenly deformed. This is because there is a risk of disappearing. The reason why the thickness of the polyethylene terephthalate layer is set to 50 to 500 μm is that when the thickness is 50 μm or less, the mechanical damage preventing action is not sufficiently exhibited, and when the thickness is 500 μm or more, the rigidity is increased and the flexibility of the surface sheet material is impaired. This is because there is a danger of being caught.

In the heat insulating structure according to the fourth aspect, the nonwoven fabric laminated on the inner surface of the aluminum foil plays a role of enhancing the adhesion to the underlying synthetic resin foam, thereby increasing the reliability of the heat insulating structure.

[0020]

[0021]

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the heat insulating structure for a cryogenic tank according to the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a cryogenic tank provided with a heat-insulating structure of the present embodiment, FIG. 2 is a plan view showing an enlarged part of a heat-insulating layer on the tank, and FIG. 2 is a sectional view taken along the line AA, FIG. 3B is a sectional view taken along the line BB in FIG. 2, and FIG.
3 is a partially enlarged cross-sectional view of FIG. FIG. 5 is a perspective view showing an embodiment of the heat insulating panel.

As shown in FIG. 1, the tank main body 1 has a spherical shape with a radius of 11 m in this embodiment and has a curvature, and is formed of an aluminum alloy in this embodiment. The heat insulating layer 2 covering the outer peripheral surface of the tank body 1 has a two-layer laminated structure of an inner (tank side) heat insulating layer 2a and an outer heat insulating layer 2b.
A structure in which a net-like reinforcing material 3 is interposed between 2b and a self-adhesive action at the time of foaming when synthetic resins forming a heat-insulating layer are foamed with each other or by bonding with an adhesive to be integrated. The heat-insulating layer 2 has a large number of heat-insulating panels 5 (FIG. 5) adjoining each other on the outer peripheral surface of the tank body 1 and is easy to install when the heat-insulating panels 5 are installed on the outer peripheral surface of the tank body 1. , Arranged so that they are offset from each other in the parallel direction (staggered arrangement)
Then, it is configured by fixing with a stud bolt 4 as a support tool.

As shown in FIG. 5, the heat insulating panel 5 has a fixed shape (in this example, long side 1.2 m × short side 0.9 m (× thickness: 200 m).
mm, this thickness can be increased or decreased according to the required heat insulation performance. )), The inner heat-insulating layer 2a
Between the lower heat-insulating member 5a (100 mm thick) constituting the outer heat-insulating layer 2b and the convex upper heat-insulating member 5b (100 mm thick) constituting the outer heat-insulating layer 2b. It has a structure in which a wire mesh 5c is integrally provided.
The lower heat-insulating member 5a is selected from a hard urethane resin foam, a phenol resin foam, or the like reinforced with glass fiber, natural fiber, chemical fiber, or the like. In this example, the lower heat insulation member 5a is made of a phenol resin foam. The upper heat-insulating member 5b is selected from a hard urethane resin foam, a phenol resin foam, a styrene resin foam, and the like. In this example, the upper heat insulation member 5b is made of a hard urethane resin foam.

The surface of the heat insulating panel 5 is covered with an aluminum surface sheet material 6. This surface sheet material 6
As shown in FIG. 4, a 25 μm-thick aluminum foil (aluminum foil) 6a is mainly used, and a 100 μm-thick polyethylene terephthalate (PET) film 6b is laminated on the surface of the aluminum foil 6a. The aluminum foil 6a is integrally laminated, and a nonwoven fabric 6c having a thickness of about 100 μm is integrally laminated on the back surface (inner surface) of the aluminum foil 6a. In this example, the thickness of the aluminum foil 6a is 25
Although the thickness is set to μm, the reason is that if the thickness is 25 μm, the moisture-proof property is secured, and it is desirable to make the thickness as thin as possible in order to obtain flexibility. However, since the PET film 6b is further laminated on the upper layer, the moisture resistance of the PET film 6b can be expected, so that the thickness of the aluminum foil 6a is at least 20 μm.
m. On the other hand, if the thickness of the aluminum foil 6a is too large, the rigidity is increased and the heat shrinkage forced deformation of the entire surface of the heat insulating structure may not be performed uniformly. Therefore, it is necessary to set the thickness to 100 μm or less.

As shown in FIGS. 2 and 3, on the outer peripheral surface of the tank body 1, aluminum alloy stud bolts 4 are planted by welding or the like at regular intervals (in this example, 2 / m ² ). The end of the stud bolt 4 penetrates the connecting portion 3 b of the reinforcing member 3 laid over the mesh reinforcing member 5 c of the heat insulating panel 5. It holds the connecting portion 3b. There is a joint (gap) between the upper heat-insulating members 5b of the adjacent heat-insulating panels 5, and at least one of filling or foaming of the joint with at least one of the same type of synthetic resin material as the upper heat-insulating member 5b is performed. Thus, the joint is filled with the synthetic resin foam 9.

On the surface of the synthetic resin foam 9, FIG.
As shown in FIG. 2, double-sided butyl rubber sheets 10 having a thickness of, for example, 500 μm are adhered continuously (without floating) from the outer edge of the aluminum surface sheet material 6 of the heat insulating panels 5 on both sides. And the aluminum connection sheet material 11 is stuck or adhered on the rubber sheet 10 over the entire surface. This aluminum connecting sheet material 11 has a thickness of 2
The aluminum foil (aluminum foil) 11a of 5 μm is mainly used, and the surface of the aluminum foil 11a is
Polyethylene terephthalate (PE) about 50 μm thick
T) It has a structure in which the films 11b are integrally laminated by laminating or coating. The reason why the thickness of the PET film 11b is set to 50 μm is to reduce the thickness in consideration of workability such as sticking on a curved surface such as a spherical surface.

Considering that the outer peripheral surface of the tank body 1 was covered with the heat insulating layer 2 having the above configuration, the stud bolts 4 were planted at a pitch of 60 cm along the center line of the joint in the lateral direction. Joint width (normal temperature side) is 70m in horizontal (latitude) direction
m and 30 mm in the longitudinal (meridian) direction.

The following requirements were satisfied as a result of an overall simulation and an experiment simulating a state in which LNG was injected and stored in the tank provided with the heat insulating structure of the above embodiment.

[0031] Moistureproofing Prevention of mechanical damage (when an operator got on the tank,
Followability of the heat-insulating layer 2 to the heat shrinkage of the tank body 1 (dropping of the heat-insulating panel 5, peeling of the aluminum surface sheet material 6 of the heat-insulating panel 5, and of the aluminum connection sheet material 11 on the synthetic resin foam 9 at the joint) On the other hand, the tank provided with the heat insulating structure of the above example exhibited the following excellent effects.

A) The number of stud bolts 4 was about 2900 per tank, which was reduced by 500 compared to a conventional tank (radius 11 m) having a heat-insulating structure. This allows
The work of attaching the heat insulation panel 5 was facilitated, and the work time was shortened. At this time, the maximum tensile load acting on the stud bolt 4 (per one bolt) is reduced by about 30%, although the number of stud bolts is reduced and the maximum tensile load is originally increased. Was. This reduces the stress generated inside the synthetic resin foam 9 and the upper heat-insulating member 5b near the stud bolt or washer, and improves the reliability of the strength of the portion.

B) The joint has a cross-sectional volume of about 40% in the vertical direction (vertical joint) and the horizontal direction (horizontal joint) as compared with the conventional art.
In each case, it was reduced to about 80%. Since the total extension length of the joints is about 3000 m per tank, the effect of labor saving and material cost reduction of the filling and foaming work of the synthetic resin material at the joints is extremely high.

C) Conventionally, the number of rivets used in a tank (radius of 11 m) was about 60,000 per tank, and the workability for riveting was not required, thereby greatly improving workability.

Although the embodiment of the heat insulating structure for a cryogenic tank according to the present invention has been described above, the heat insulating structure according to the present invention can be implemented as follows.

1) The shape of the tank is not limited to a spherical shape, but may be, for example, a cylindrical shape. In addition to the tank, the present invention can be applied to a heat insulating structure such as a pipe for transporting a cryogenic substance.

2) The synthetic resin layer on the surface of the aluminum foils 6a and 11a is not limited to a polyester film such as a PET film, as long as it is soft and rich in flexibility and can prevent mechanical damage. Absent.

3) Primarily targeting cryogenic substances,
It can also be applied as a heat insulating structure when storing extremely high temperature substances.

4) In many cases, it is desirable to interpose a reinforcing material from the viewpoint of securing the strength of the entire heat insulation structure, but it can be omitted.

[0040]

As is apparent from the above description,
The heat insulating structure for a cryogenic tank according to the present invention has the following excellent effects.

(1) Compared to the conventional structure in which thermal expansion and contraction deformation caused by storing a cryogenic substance in a tank is intensively absorbed by joints, the heat insulating layer covering the outer surface of the tank body is substantially uniform. Therefore, unlike the conventional heat insulating layer structure, the thermal load acting on each support is reduced. Therefore, the material cost and the construction cost can be reduced by reducing the number of supports, and the amount of heat transfer entering through the supports is also reduced, so that the heat insulation performance is improved.

(2) Since the width of the joint can be greatly reduced,
The amount of filling (injection) of the synthetic resin material to be filled and foamed at the joint is reduced, and workability is remarkably improved. Further, as the joint width is reduced, the ratio of the filler or the synthetic resin foam in the joint is reduced as compared with the conventional art, so that the reliability of the entire heat insulation system is improved.

(3) The workability is improved because the aluminum connecting sheet material covering the joint does not need to be floated above the joint as in the prior art, and can be adhered to the entire surface via the adhesive sheet material. I do. In addition, by completely bonding, the invasion of moisture is reliably prevented, and a sufficient moisture-proof function is exhibited. Furthermore, since the aluminum connection sheet material is firmly adhered by the complete bonding, riveting is not required at all unlike the related art, and the labor and cost spent for the work are completely eliminated.

(4) The heat-insulating structure according to the third aspect is excellent in mechanical damage-inhibiting action against external impacts, etc., has sufficient moisture-proofing properties, is highly flexible, and has good thermal deformation. It is performed almost evenly, and the effect of preventing mechanical damage is sufficiently exhibited.

Further, since the synthetic resin layer on the surface of the aluminum surface sheet material and the surface of the aluminum connecting sheet material prevents the rust of the aluminum foil and becomes transparent, the original gloss and luster of the aluminum foil are kept as they are. Appears to be aesthetically pleasing and contributes to increasing the value of the product.

(5) In the heat insulating structure according to the fourth aspect, the nonwoven fabric laminated on the inner surface of the aluminum foil ensures the adhesiveness with the underlying synthetic resin foam.
No peeling occurs.

[0047]

[0048]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing an entire cryogenic tank provided with a heat insulating structure according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view showing a part of a heat insulating layer on the cryogenic tank of FIG. 1;

3A is a sectional view taken along line AA of FIG. 2, and FIG. 3B is a sectional view taken along line BB of FIG.

FIG. 4 is a partially enlarged sectional view of FIG. 3 (b).

FIG. 5 is used in the heat insulation structure of the cryogenic tank of the present invention.
Is a perspective view showing an example of that insulation panel.

6 is a cross-sectional view of a joint portion of a heat insulating structure of a conventional general cryogenic tank, and corresponds to FIG.

7A and 7B are a plan view showing a joint and its surroundings of a heat insulating structure of a conventional general cryogenic tank, and a sectional view taken along line aa and line bb of the plan view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tank main body 2 Heat insulation layer 3 Reinforcement 4 Stud bolt (support) 5 Heat insulation panel 5c Mesh reinforcement 6 Aluminum surface sheet material 6a / 11a Aluminum foil (aluminum foil) 6b / 11b Polyethylene terephthalate film 6c Nonwoven fabric 7 Washer 8 Nut 10 Butyl rubber sheet 11 Aluminum connection sheet material

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Keiji Miyashita 3-1-1 Higashi Kawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries, Ltd. Kobe Plant (72) Inventor Yukio Hosomi 1 Kyomachibori, Nishi-ku, Osaka-shi, Osaka No.8-5, Meisei Kogyo Co., Ltd. (72) Inventor Yasuhiro Okamoto 1-8-5, Kyomachibori, Nishi-ku, Osaka City, Osaka (56) Meisei Kogyo Co., Ltd. (56) References JP-A-4-258598 (JP, A) Japanese Patent Application Laid-Open No. Sho 51-129915 (JP, A) Japanese Utility Model Application Sho 59-43798 (JP, U)

Claims (4)

(57) [Claims] 1. A heat insulating panel made of a preformed synthetic resin foam such as rigid urethane or phenolic resin and having a convex cross section having an aluminum surface sheet material, which is adjacent to each other on the surface of the tank body. The heat insulation structure for a cryogenic tank is arranged and attached by a support tool implanted in the tank body, and at least one of a synthetic resin material is filled or foamed and connected to a joint between protrusions of the heat insulation panel. the aluminum surface sheet material, and a two-layer structure in which a synthetic resin layer laminated on the surface of the aluminum foil, extend over the aluminum surface sheet on the synthetic on resin foam and its periphery of the joint I, said aluminum topsheet Aluminum connection sheet material of the same configuration as the material
A heat insulating structure for a cryogenic tank, wherein the heat insulating structure is entirely adhered through an adhesive sheet material . 2. The heat insulating structure for a cryogenic tank according to claim 1, wherein a net-like reinforcing material is interposed between the synthetic resin foams. 3. The synthetic resin layers on the surface of the aluminum surface sheet material and the surface of the aluminum connection sheet material are each formed of a polyethylene terephthalate film, the aluminum foil has a thickness of 20 to 100 μm, and the polyethylene terephthalate layer has a thickness of 20 to 100 μm. 50 ~
3. The heat insulating structure for a cryogenic tank according to claim 1, wherein the heat insulating structure is 500 μm. 4. The heat insulating structure for a cryogenic tank according to claim 1, wherein a nonwoven fabric is laminated on the inner surface of the aluminum foil of the aluminum surface sheet material.