Liquid-proof bank and method for remolding liquid-proof bank

Abstract

To provide a liquid-proof bank and a method for remodeling the liquid-proof bank, capable of significantly reducing an environmental load, a construction cost, a construction period and the like when compared with the conventional method when a liquefied gas storage facility is newly built.SOLUTION: A liquid-proof bank 3 of a liquefied gas storage facility 100 in which at least an existing inner tank 2 is removed and reused has: a wall part 31 erected from a foundation slab 4; an existing outer tank side plate 12 placed on an inner surface of the wall part 31; and a cold-resistant relaxation material 5 provided on an inner surface of the existing outer tank side plate 12.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a liquid retaining dike in a liquefied gas storage facility and a method for modifying the liquid retaining dike.

Background Art

[0002] Conventionally, when constructing a new liquefied gas storage facility, if there is an existing liquefied gas storage facility at the construction site, the existing liquefied gas storage facility is disassembled and removed, and after clearing the site, a new liquefied gas storage facility is constructed.

[0003] On the other hand, Patent Document 1 discloses an invention that attempts to reuse an existing liquefied gas storage facility by improving its heat insulation performance in order to store liquefied gas at a lower temperature than the liquefied gas stored in the existing liquefied gas storage facility, thereby reducing the cost and time required for the construction of the storage facility.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above-mentioned conventional construction of a new liquefied gas storage facility, since it is necessary to disassemble and remove the existing liquefied gas storage facility, it takes time and cost. In addition, since it is a scrap & build method, the environmental impact is large. In addition, there are cases where the construction vibration generated during the disassembly work is transmitted to surrounding structures through the ground, affecting the operation of other existing facilities.

[0006] In the invention disclosed in Patent Document 1, the environmental impact and costs are reduced by reusing existing liquefied gas storage facilities. However, the invention focuses on the primary container (the container used during normal operation) and enables reuse, rather than the secondary container (the container used when the primary container breaks and leaks liquid).

[0007] Therefore, in view of the above problems and the like, the invention of the present application aims to provide a dike and a method for modifying the dike that can significantly reduce the environmental impact, construction costs, construction period, etc. compared to the prior art when constructing a new liquefied gas storage facility.

Means for Solving the Problems

[0008] The invention according to (1) is a dike for a liquefied gas storage facility in which at least an existing inner tank is removed and reused, comprising a wall portion erected from a base plate, an existing outer tank side plate placed on the inner surface of the wall portion, and a heat resistance relaxation material provided on the inner surface of the existing outer tank side plate.

[0009] The invention according to (2) is the dike according to (1) above, wherein a coating material capable of suppressing deterioration of the heat resistance relaxation material is provided on the inner surface of the heat resistance relaxation material.

[0010] The invention according to (3) is a method for modifying a dike of a liquefied gas storage facility in which at least an existing inner tank is removed and reused, comprising cutting off an existing outer tank roof from the upper part of a wall portion erected from a base plate, placing an existing outer tank side plate on the inner surface of the wall portion, and placing or re-constructing a heat resistance relaxation material provided on the inner surface of the existing outer tank side plate.

[0011] The invention according to (4) is the method for modifying a dike according to (3) above, wherein the inner surface of the heat resistance relaxation material is coated with a coating material capable of suppressing deterioration of the heat resistance relaxation material.

Advantages of the Invention

[0012] According to the present invention, an existing outer tank roof is removed, and an existing outer tank side plate is placed on the inner surface of the wall portion, and a heat transfer resistance relaxation material is provided on the inner surface of the existing outer tank side plate, so that it can be reused as a dike for a liquefied gas storage facility.

[0013] As a result, it is possible to save the labor of removing the dike and constructing a new dike, and it is possible to significantly reduce the environmental load, construction cost, construction period, etc. compared with the prior art.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0015] Hereinafter, each embodiment of the dike of the present invention and the method for modifying the dike will be described with reference to the drawings.

[0016] (First Embodiment) FIG. 1 shows an example of a schematic cross-sectional view of an existing liquefied gas storage facility 100. The liquid retaining dike 3 of the liquefied gas storage facility 100 on which the present invention is premised has a wall portion 31 erected from a base slab 4. Inside the wall portion 31, there is an existing outer tank 1 disposed on the outer tank bottom plate 13, and further inside the existing outer tank 1, an inner tank bottom plate 21 and an existing inner tank 2 are disposed on the existing bottom insulation material 22.

[0017] Also, the liquefied gas to be stored is at a low temperature, and in the case of liquefied natural gas, it can reach -164°C. In response to this, a heat transfer resistance mitigation material 5 is provided on the inner surface of the existing outer tank side plate 12 of the existing outer tank 1 so that the concrete of the liquid retaining dike 3 is not exposed to a rapid temperature change due to leakage of the liquefied gas.

[0018] And in order to effectively reuse the above-described existing liquefied gas storage facility 100, as a first step, as shown in FIG. 2, the existing outer tank 1, the existing inner tank 2, etc. are removed.

[0019] That is, in the liquid retaining dike 3, from the upper part of the wall portion 31 erected from the base slab 4, the existing outer tank roof 11 is cut off, and the existing outer tank side plate 12 is left on the inner surface of the wall portion 31.

[0020] At this time, the heat transfer resistance mitigation material 5 provided on the inner surface of the existing outer tank side plate 12 is also left. However, if the existing heat transfer resistance mitigation material 5 is damaged or deteriorated, or even if the state of the existing heat transfer resistance mitigation material 5 is sound, for the purpose of improving performance, etc., as shown in FIG. 3, as a second step, it is re-constructed with the same material or a different material.

[0021] Subsequently, as shown in FIG. 4, as a third step, the inner surface of the heat transfer resistance mitigation material 5 is coated with a coating material 6 capable of suppressing deterioration of the heat transfer resistance mitigation material 5.

[0022] That is, when there is a risk that the heat and cold resistance relaxation material 5 may deteriorate due to environmental conditions such as ultraviolet rays and rainwater (water addition), deterioration prevention measures are taken by placing protective concrete or attaching steel plates on the surface of the heat and cold resistance relaxation material 5. Thereby, the deterioration of the heat and cold resistance relaxation material 5 can be effectively prevented.

[0023] As shown in FIG. 4, a newly installed outer tank 1A, a newly installed inner tank 2A, a newly installed bottom cold insulation material 22A, and a newly installed inner tank bottom plate 21A are constructed. The outer tank bottom plate 13 may be reused from the existing outer tank bottom plate 13 or newly installed. Further, when the base plate 4 of the liquid retaining dike 3 and the base plate under the outer tank bottom plate 13 are separated, as a fourth step, a leakage penetration countermeasure part 7 is constructed.

[0024] This is to prevent the leaked liquid from penetrating into the ground due to the liquid leakage of the liquefied gas, and various known methods can be applied. Of course, the construction of the leakage penetration countermeasure part 7 in the fourth step as described above is not essential and may be carried out as necessary. That is, for the purpose of preventing the outflow of the leaked liquid outside the dike, as shown in FIG. 5, the base plate 4 and the existing outer tank bottom plate 13 corresponding to the construction part of the leakage penetration countermeasure part 7 in FIG. 4 may be left without being demolished.

[0025] By the method of modifying the liquid retaining dike 3 as described above, it becomes possible to reuse a part of the existing liquefied gas storage facility 100. Therefore, compared with newly constructing the liquefied gas storage facility 100, it is possible to significantly reduce the construction cost and greatly shorten the construction period.

[0026] Furthermore, the construction of the liquid retaining dike 3 has been difficult to ensure safety due to overlapping work with mechanical-related construction. However, since the civil engineering related to the construction of the liquid retaining dike 3 can be significantly reduced, it is possible to improve the safety during the construction period.

[0027] (Alternative Embodiment) Next, an alternative embodiment of the present invention will be described with reference to the drawings. Note that the description of the configuration common to the first embodiment described above will be omitted.

[0028] In the first embodiment described above, an example was shown in which the liquid retaining dike integrated type liquefied gas storage facility 100, where the liquid retaining dike and the outer tank are integrated, is constructed as a liquid retaining dike separated type as shown in FIG. 4. However, the present invention is not necessarily limited to such a form, and as shown in FIG. 6, it is also possible to construct the liquefied gas storage facility 100 of the liquid retaining dike integrated type again.

[0029] Specifically, as shown in FIG. 6, the newly installed outer tank roof 11A is connected to the existing outer tank side plate 12 without covering the heat resistance relaxation material 5 with the covering material 6 in the third step described above. Even in such an alternative embodiment, it is possible to significantly reduce the construction cost and greatly shorten the construction period.

[0030] In addition, the liquid retaining dike and the method for modifying the liquid retaining dike of the present invention can be applied to various liquefied gas storage facilities. For example, in addition to the liquefied natural gas described above, it can be applied to liquefied gas storage facilities such as liquefied hydrogen (LH2) reaching -253 °C, liquefied ammonia (LNH3), and methylcyclohexane (MCH).

[0031] Also, the liquid retaining dike of the present invention is not particularly limited as long as it is made of concrete, such as cast-in-place or precast. Furthermore, regarding the heat resistance relaxation material 5, various heat insulating materials can be applied in addition to rigid polyurethane foam.

[0032] Also, in the above-described embodiments, as shown in FIGS. 4 to 6, it is composed of the newly installed outer tank 1A, the newly installed inner tank 2A, the newly installed bottom heat insulating material 22A, the newly installed inner tank bottom plate 21A, the outer tank bottom plate 13, etc. However, the illustrated configurations in each figure are described schematically as an example, and various dimensions, shapes, cross-sectional configurations, materials, etc. can be applied.

[0033] Also, the scope of the present invention is defined by the claims rather than the descriptions of the above embodiments, and further includes all changes within the meaning and scope equivalent to the claims. In addition, the specific materials, dimensional shapes, etc. described in the above embodiments can be changed within the scope of solving the problems of the present invention.

Explanation of Reference Numerals

[0034] 1 Existing outer tank 11 Existing outer tank roof 11A Newly installed outer tank roof 12 Existing outer tank side plate 13 Outer tank bottom plate 2 Existing inner tank 2A Newly installed inner tank 21 Inner tank bottom plate 21A Newly installed inner tank bottom plate 22 Existing bottom insulation material 22A Newly installed bottom insulation material 3 Liquid retaining dike 31 Wall portion 4 Foundation slab 5 Heat transfer resistance mitigation material 6 Coating material 7 Liquid leakage penetration countermeasure portion 100 Liquefied gas storage facility

Claims

1. A liquid retaining dike for a liquefied gas storage facility in which at least an existing inner tank is removed and reused, comprising: a wall portion erected from a base plate; an existing outer tank side plate placed on the inner surface of the wall portion; and a heat resistance relaxation material provided on the inner surface of the existing outer tank side plate. The liquid retaining dike is characterized by the above.

2. A coating material capable of suppressing deterioration of the heat resistance relaxation material is provided on the inner surface of the heat resistance relaxation material. The liquid retaining dike according to Claim 1.

3. A method for modifying a liquid retaining dike of a liquefied gas storage facility in which at least an existing inner tank is removed and reused, comprising: cutting off an existing outer tank roof from the upper part of a wall portion erected from a base plate, placing an existing outer tank side plate on the inner surface of the wall portion, placing or reconstructing a heat resistance relaxation material provided on the inner surface of the existing outer tank side plate. The method for modifying a liquid retaining dike is characterized by the above.

4. The inner surface of the heat resistance relaxation material is coated with a coating material capable of suppressing deterioration of the heat resistance relaxation material. The method for modifying a liquid retaining dike according to Claim 3.

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