Three-layer shell tank

Abstract

The three-shell tank has: an outer tank; an intermediate tank disposed within the outer tank; an inner tank disposed within the intermediate tank for storing liquefied gas; and piping connecting the outer tank, the intermediate tank, and the inner tank. The piping is connected to the outer tank via a first telescopic pipe, and to one of the inner tank and the intermediate tank via a second telescopic pipe, and is connected to the other of the inner tank and the intermediate tank.

Description

Technical Field

[0001] This disclosure relates to a three-shell tank for storing cryogenic liquefied gas, and more particularly to a support structure for a nozzle penetrating the three shells. Background Technology

[0002] Previously, double-shell tanks for storing cryogenic liquefied gas were known. Typically, a double-shell tank has a double shell consisting of an inner tank and an outer tank, and insulating material filling the space between the inner and outer tanks. The double-shell tank is equipped with piping for discharging the cryogenic liquid contained in the inner tank to the outside of the tank. Such piping connects both the inner and outer tanks.

[0003] In a double-shell tank, when cryogenic liquefied gas is contained in the inner tank, the inner tank contracts due to temperature changes, causing relative displacement between the inner and outer tanks. Since liquids and / or gases are contained in each tank, airtightness between each tank and the piping is required. However, if the piping is directly connected to both the inner and outer tanks to ensure airtightness, excessive stress will be generated at the joints due to the relative displacement between the inner and outer tanks. Therefore, Patent Documents 1 and 2 propose a support structure for the piping of a double-shell tank.

[0004] In the cryogenic tank (double-shell tank) of Patent Document 1, a nozzle for liquid injection and discharge penetrates the top of the inner tank and the outer tank. The nozzle is suspended and supported by the top of the outer tank and is airtightly connected to the top of the inner tank via a bellows.

[0005] In the cryogenic tank (double-shell tank) of Patent Document 2, the liquid discharge nozzle penetrates the top of the inner tank and the outer tank. The outer cylinder of the nozzle is connected to the part of the inner tank top with lower rigidity than the other parts. The outer cylinder is connected to the outer tank top via a bellows and is placed on a support platform provided on the bottom plate of the inner tank.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 58-17296

[0009] Patent Document 2: Japanese Utility Model Application Publication No. 58-14594 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] Furthermore, triple-shell tanks are known to have an intermediate tank further provided between the inner and outer tanks of a double-shell tank. In a triple-shell tank, when the inner tank contains cryogenic liquefied gas, the distance between the inner, intermediate, and outer tanks changes due to thermal contraction. Since the temperatures of each tank are different, the degree of change in the distance between them also varies. Patent Documents 1 and 2 only disclose the piping support structure of a double-shell tank consisting of an inner and outer tank. Moreover, Patent Documents 1 and 2 do not disclose the relationship between the intermediate tank and the piping, therefore the piping support structure disclosed in these documents cannot be applied to triple-shell tanks.

[0012] This disclosure was made in view of the above circumstances, and proposes a support structure for piping that runs through the three shells in a three-shell tank having an inner tank, an intermediate tank and an outer tank.

[0013] Methods for solving problems

[0014] One aspect of the three-shell tank disclosed herein is characterized in that the three-shell tank comprises: an outer tank; an intermediate tank disposed within the outer tank; an inner tank disposed within the intermediate tank for storing liquefied gas; and a piping that extends through the outer tank, the intermediate tank, and the inner tank, the piping being connected to the outer tank via a first telescopic pipe, the piping being connected to one of the inner tank and the intermediate tank via a second telescopic pipe, the piping being engaged with the other of the inner tank and the intermediate tank, or the piping being inserted through and through the other of the inner tank and the intermediate tank.

[0015] Furthermore, another aspect of the three-shell tank disclosed herein is characterized in that the three-shell tank has: an outer tank; a middle tank disposed within the outer tank; an inner tank disposed within the middle tank, having an inner tank through insertion hole for storing liquefied gas; and a pipe that penetrates the outer tank, the middle tank, and the inner tank, the pipe being connected to the outer tank via a first telescopic pipe, the pipe being engaged with the middle tank, the pipe being inserted into the inner tank through insertion hole with a gap, and the interior of the inner tank being connected to the gap between the inner tank and the middle tank through the gap between the inner tank through insertion hole and the pipe.

[0016] According to the three-shell tank with the above structure, when the distance between the inner, middle, and outer tanks changes due to thermal contraction caused by the storage of cryogenic liquefied gas in the inner tank, the change in distance between the tanks is absorbed by the expansion and contraction of the expansion and contraction pipes, thus reducing the stress generated at the joints between each tank and the piping. Therefore, the piping support structure of the three-shell tank with the above structure can be said to be a suitable structure for supporting piping that runs through the three shells in a three-shell tank consisting of an inner tank, a middle tank, and an outer tank.

[0017] Invention Effects

[0018] According to this disclosure, it is possible to propose a support structure for piping that runs through the three shells of a three-shell tank having an inner tank, an intermediate tank, and an outer tank. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view showing the overall structure of a three-shell tank according to an embodiment of the present disclosure.

[0020] Figure 2 This is a diagram illustrating the support structure of the piping in Example 1.

[0021] Figure 3 This is a diagram illustrating the support structure of the piping in a variation of Example 1 of Example 1.

[0022] Figure 4 This is a diagram illustrating the support structure of the piping in variation 2 of example 1.

[0023] Figure 5 This is a diagram illustrating the support structure of the piping in variation 3 of example 1.

[0024] Figure 6 This is a diagram illustrating the support structure of the piping in Example 2.

[0025] Figure 7 This is a diagram illustrating the support structure of the piping in Example 3.

[0026] Figure 8 This is a diagram illustrating the support structure of the piping in variation 1 of example 3.

[0027] Figure 9 This is a diagram illustrating the support structure of the piping in variation 2 of example 3. Detailed Implementation

[0028] The embodiments of this disclosure will be described with reference to the accompanying drawings. Figure 1 This is a cross-sectional view showing the overall structure of the three-shell tank 1 according to an embodiment of the present disclosure.

[0029] Figure 1 The three-shell tank 1 shown is a flat-bottomed, ground-mounted three-shell tank. The three-shell tank 1 has a concrete tank foundation 7, an outer groove 5 set on the tank foundation 7, an intermediate groove 4 enclosing the outer groove 5, and an inner groove 3 enclosing the intermediate groove 4. The outer groove 5, the intermediate groove 4, and the inner groove 3 form a three-shell structure.

[0030] The inner tank 3 is a container for storing cryogenic liquefied gases. Examples of cryogenic liquefied gases include liquid helium, liquid hydrogen, liquid nitrogen, LNG, and LPG. The inner tank 3 has a generally flat inner tank bottom plate 31, cylindrical inner tank side plates 32 rising from the inner tank bottom plate 31, and an inner tank top 33 disposed on the upper part of the inner tank side plates 32. The inner tank side plates 32 and the tank foundation 7 can be connected, for example, by mooring components such as multiple anchor straps arranged at approximately equal intervals around the inner tank 3.

[0031] The intermediate trough 4 surrounds the inner trough 3. The intermediate trough 4 has a generally flat intermediate trough bottom plate 41, cylindrical intermediate trough side plates 42 rising from the intermediate trough bottom plate 41, and an intermediate trough top 43 disposed on the upper part of the intermediate trough side plates 42. A leveling concrete layer 35 and an inner bottom insulation layer 36 are sandwiched between the intermediate trough bottom plate 41 and the inner trough bottom plate 31. In addition, the intermediate trough top 43 can also support the inner trough top 33. That is, the inner trough top 33 can also be a suspended ceiling. The intermediate trough side plates 42 and the tank foundation 7 can be connected, for example, by mooring components such as multiple anchoring straps arranged at approximately equal intervals around the intermediate trough 4.

[0032] The outer trough 5 surrounds the intermediate trough 4. The outer trough 5 has a generally flat outer trough bottom plate 51 set on the tank foundation 7, a cylindrical outer trough side plate 52 rising from the outer trough bottom plate 51, and an outer trough top 53 set on the upper part of the outer trough side plate 52. A leveling concrete layer 45 and an outer bottom insulation layer 46 are sandwiched between the outer trough bottom plate 51 and the intermediate trough bottom plate 41. The outer trough side plate 52 can be connected to the tank foundation 7, for example, by means of anchor bolts or other connecting components. Alternatively, the outer trough bottom plate 51 can be connected to the tank foundation 7, for example, by means of anchor plates or other connecting components cast into the tank foundation 7.

[0033] A gap is formed between the outer wall of the inner tank 3 and the inner wall of the intermediate tank 4, forming a first tank space 91. A gap is formed between the outer wall of the intermediate tank 4 and the inner wall of the outer tank 5, forming a second tank space 92. The first tank space 91 and the second tank space 92 are filled with heat-insulating material 93. The heat-insulating material 93 can be, for example, perlite, glass wool, or other materials used as heat-insulating materials in existing double-shell tanks.

[0034] A BOG (Bottle-Off Gas) pipe 22 is provided at the top 33 of the inner tank. This BOG pipe 22 transports the vaporized gas generated within the inner tank 3 to the outside of the triple-shell tank 1. An outlet pipe 25 is provided at the bottom of the inner tank 3. This outlet pipe 25 transports the liquefied gas from the inner tank 3 to the outside. However, the outlet pipe 25 can also be configured to extend upwards within the inner tank 3 and transport the liquefied gas to the outside through the upper part of the triple-shell tank 1. A connecting pipe 21 is provided at the top 33 of the inner tank 3, connecting the upper part of the inner tank 3 to the first inter-tank 91. The vaporized gas of the liquefied gas generated in the inner tank 3 flows into the first inter-tank 91 through this connecting pipe 21. Thus, the first inter-tank 91 is filled with the vaporized gas of the liquefied gas. However, a low-boiling-point gas equivalent to the vaporized gas of liquefied gas can also be introduced into the first tank 91 from the outside of the three-shell tank 1, or the vaporized gas of liquefied gas can be introduced into the first tank 91 by connecting a branch pipe of the BOG pipe 22 to the first tank 91.

[0035] The airtightness of the intermediate tank 4, which separates the first tank 91 and the second tank 92, allows the two tanks to be separated as a space. Inert gas is supplied from the inert gas supply source 24 to the second tank 92 through the inlet pipe 23, filling it with inert gas. This inert gas is a gas with a boiling point higher than that of the liquefied gas stored in the inner tank 3. Nitrogen can be cited as an example of such an inert gas.

[0036] [Pipe support structure]

[0037] In the three-shell tank 1 with the above-described structure, the BOG pipe 22 and the discharge pipe 25 are pipes that connect the interior of the inner tank 3 to the outside by penetrating the three-shell structure consisting of the inner tank 3, the intermediate tank 4, and the outer tank 5. Hereinafter, the support structures S1 to S3 of the first to third examples of pipes P penetrating the three-shell structure, represented by the BOG pipe 22 and the discharge pipe 25, will be described. Furthermore, the support structures S1 to S3 of pipe P are not limited to those applied to the BOG pipe 22 and the discharge pipe 25, but can be applied to all pipes penetrating the three-shell structure. Additionally, the pipe P described below is a vacuum double-layered pipe consisting of a main pipe and an outer pipe, but pipes P using support structures S1 to S3 are not limited to vacuum double-layered pipes.

[0038] [S1 support structure for pipe P in Example 1]

[0039] Figure 2 This is a diagram illustrating the support structure S1 of the pipe P in Example 1. Furthermore, in Figure 2 The image shows an enlarged view of the inner groove 3, the intermediate groove 4, and the through section of the outer groove 5 of the piping P.

[0040] exist Figure 2In the support structure S1 of the pipe P shown, pipe P is joined to the inner groove 3, pipe P is connected to the intermediate groove 4 via the second telescopic pipe 62, and pipe P is connected to the outer groove 5 via the first telescopic pipe 61. Alternatively, pipe P may be inserted through the inner groove 3 without joining it. In this specification, "joint" means a mechanical or metallurgical connection between pipe P and the groove (inner groove 3, intermediate groove 4, or outer groove 5) without the telescopic pipe. Furthermore, in this specification, "connection" means pipe P is connected to the groove (inner groove 3, intermediate groove 4, or outer groove 5), and "connected via telescopic pipe" means connected by placing the telescopic pipe between the two.

[0041] The inner groove 3 is provided with an inner groove through insertion hole 34 for pipe P, into which pipe P is inserted. The opening edge of the inner groove through insertion hole 34 is welded to the outer casing of pipe P to ensure airtightness. This welded part can be regarded as a substantial joint 73 between the inner groove 3 and the pipe P.

[0042] The intermediate groove 4 is provided with an intermediate groove through insertion hole 44 for pipe P, which is inserted through the intermediate groove through insertion hole 44. A second telescopic tube 62 is joined to the opening edge of the intermediate groove through insertion hole 44. The second telescopic tube 62 is a cylindrical component protruding outward from the intermediate groove 4 (i.e., the side where the outer groove 5 is located), and pipe P is inserted into the second telescopic tube 62. The space between the outer circumferential surface of pipe P and the inner circumferential surface of the second telescopic tube 62 is filled with fibrous thermal insulation material 69 such as glass wool.

[0043] The base end of the second telescopic pipe 62 is joined to the intermediate groove 4, and the front end of the second telescopic pipe 62 is joined to the piping P. The joints between the second telescopic pipe 62 and the intermediate groove 4, as well as the joints between the second telescopic pipe 62 and the piping P, can be welded in a manner that ensures airtightness. The joint between the front end of the second telescopic pipe 62 and the piping P can be considered as a substantial joint 65 between the intermediate groove 4 and the piping P.

[0044] The second telescopic tube 62 has a telescopic portion 64 in at least a portion. The telescopic portion 64 can be implemented, for example, by means of a corrugated or corrugated pipe provided in the middle portion of the second telescopic tube 62. With the aid of this telescopic portion 64, the front end of the second telescopic tube 62 is allowed to be displaced relative to the base end in both the radial and axial directions of the second telescopic tube 62. In other words, the joint portion 65 is allowed to be displaced relative to the main body of the intermediate groove 4.

[0045] The outer groove 5 is provided with an outer groove through insertion hole 54 for pipe P, which is inserted through the outer groove through insertion hole 54. A first telescopic tube 61 is joined to the opening edge of the outer groove through insertion hole 54. The first telescopic tube 61 is a cylindrical component protruding outward from the outer groove 5, and pipe P is inserted into the first telescopic tube 61. A fibrous heat insulation material 70, such as glass wool, is filled between the outer peripheral surface of pipe P and the inner peripheral surface of the first telescopic tube 61.

[0046] The base end of the first telescopic pipe 61 is joined to the outer groove 5, and the front end of the first telescopic pipe 61 is joined to the piping P. The joints between the first telescopic pipe 61 and the outer groove 5, and between the first telescopic pipe 61 and the piping P, can be welded in a manner that ensures airtightness. The joint between the front end of the first telescopic pipe 61 and the piping P can be regarded as a substantial joint 66 between the outer groove 5 and the piping P.

[0047] The first telescopic tube 61 has a telescopic portion 63 in at least a portion. The telescopic portion 63 can be implemented, for example, by means of a corrugated or corrugated pipe provided in the middle portion of the first telescopic tube 61. With the aid of this telescopic portion 63, the front end of the first telescopic tube 61 is allowed to be displaced in both the radial and axial directions relative to the base end of the first telescopic tube 61. In other words, the joint portion 66 is allowed to be displaced relative to the main body of the outer groove 5.

[0048] In the three-layer shell tank 1 equipped with the aforementioned support structure S1, when cryogenic liquefied gas is contained in the inner tank 3, the inter-tank distance of the first inter-tank 91 (i.e., the interval between the inner tank 3 and the intermediate tank 4) and the inter-tank distance of the second inter-tank 92 (i.e., the interval between the intermediate tank 4 and the outer tank 5) change, based on the inner tank 3 being unloaded. Even so, the change in the inter-tank distance of the first inter-tank 91 and the inter-tank distance of the second inter-tank 92 can be absorbed by the expansion and contraction of the telescopic pipes 61 and 62, thereby reducing the stress generated at the joint 73 between the inner tank 3 and the pipe P, the joint 65 between the intermediate tank 4 and the pipe P, and the joint 66 between the outer tank 5 and the pipe P.

[0049] like Figure 3 As shown, when granular insulation material 93 is filled between the inner groove 3 and the intermediate groove 4, in the support structure S1 of the piping P in the first example described above, a particle barrier 67 may also be provided around the second telescopic pipe 62 provided in the intermediate groove 4. The particle barrier 67 is disposed in the second groove 92 to prevent granular insulation material from flowing into the vicinity of the second telescopic pipe 62.

[0050] exist Figure 3In the example shown, the particle barrier 67 is a cylindrical component surrounding the second telescopic tube 62. The particle barrier 67 is made of, for example, polyurethane foam. One end of the particle barrier 67 is bonded to the surface of the intermediate groove 4. There may be a space between the particle barrier 67 and the second telescopic tube 62, but it is preferably filled with a fibrous insulating material 72 such as glass wool.

[0051] Furthermore, the particle barrier 67 only needs to prevent granular insulation material from entering the area around the second expansion tube 62, and is not limited to... Figure 3 In this manner, for example, the particle barrier 67 could be a cylindrical component surrounding the second telescopic pipe 62, with its two ends not engaging with either the piping P or the intermediate groove 4. Furthermore, for example, it could also be as follows: Figure 4 As shown, the particle barrier 67 is a cylindrical component surrounding the second expansion pipe 62 and is connected to the piping P. In this case, there may be a space between the particle barrier 67 and the second expansion pipe 62, but it is preferably filled with a fibrous insulating material 72 such as glass wool.

[0052] In the support structure S1 of the piping P in the first example above, the second telescopic pipe 62 protrudes outward from the intermediate groove 4, but the second telescopic pipe 62 can also protrude inward from the intermediate groove 4. In this case, as... Figure 5 As shown, the second telescopic pipe 62 is a cylindrical component existing in the first slot 91 and surrounding the piping P. The base end of the second telescopic pipe 62 is joined to the intermediate slot 4, and the front end of the second telescopic pipe 62 is joined to the piping P. Thus, when the second telescopic pipe 62 protrudes inward from the intermediate slot 4, in order to prevent the granular insulation material filled in the first slot 91 from flowing into the vicinity of the second telescopic pipe 62, it is also preferable to provide a particle-proof dam 67 around the second telescopic pipe 62 in the same manner as described above.

[0053] [S2 support structure for pipe P in Example 2]

[0054] Figure 6 This diagram illustrates the support structure S2 of pipe P in example 2. Furthermore, in Figure 6 The image shows an enlarged view of the inner groove 3, the intermediate groove 4, and the through section of the outer groove 5 of the piping P.

[0055] exist Figure 6 In the support structure S2 of the pipe P shown, the pipe P is connected to the intermediate groove 4, the pipe P is connected to the inner groove 3 via the second telescopic pipe 68, and the pipe P is connected to the outer groove 5 via the first telescopic pipe 61. The connection structure between the outer groove 5 and the pipe P via the first telescopic pipe 61 is substantially the same as the connection structure shown in the support structure S1 of the pipe P in the first example, so detailed description is omitted.

[0056] The intermediate groove 4 is provided with an intermediate groove through insertion hole 44 for pipe P, into which pipe P is inserted. The opening edge of the intermediate groove through insertion hole 44 is welded to pipe P in a manner to ensure airtightness. More specifically, the opening edge of the intermediate groove through insertion hole 44 is welded to the outer casing of pipe P in a manner to ensure airtightness. This welded part can be regarded as a substantial joint 65 between the intermediate groove 4 and pipe P. However, if airtightness is not required for the intermediate groove 4, pipe P may be inserted into the intermediate groove through insertion hole 44, but the two may not be joined.

[0057] The inner groove 3 is provided with an inner groove through insertion hole 34 for pipe P, which is inserted through into the inner groove through insertion hole 34. A second telescopic tube 68 is joined to the opening edge of the inner groove through insertion hole 34. The second telescopic tube 68 is a cylindrical component protruding inward from the inner groove 3 (i.e., the inner side of the groove), and pipe P is inserted into the second telescopic tube 68. A fibrous heat insulation material 75, such as glass wool, is filled between the outer peripheral surface of pipe P and the inner peripheral surface of the second telescopic tube 68.

[0058] The base end of the second telescopic pipe 68 is joined to the inner groove 3, and the front end of the second telescopic pipe 68 is joined to the piping P. The joints between the second telescopic pipe 68 and the inner groove 3, as well as the joints between the telescopic pipe 68 and the piping P, can be welded in a manner that ensures airtightness. The joint between the front end of the telescopic pipe 68 and the piping P can be considered as a substantial joint 73 between the inner groove 3 and the piping P.

[0059] The second telescopic tube 68 has a telescopic portion 74 in at least a portion. The telescopic portion 74 can be implemented, for example, by means of a corrugated or corrugated pipe provided in the middle portion of the second telescopic tube 68. With the aid of this telescopic portion 74, the front end of the second telescopic tube 68 is allowed to be displaced relative to the base end in both the radial and axial directions of the second telescopic tube 68. In other words, the joint portion 73 is allowed to be displaced relative to the main body of the inner groove 3.

[0060] In the three-layer shell tank 1 equipped with the aforementioned support structure S2, when cryogenic liquefied gas is contained in the inner tank 3, the inter-tank distances of the first tank 91 and the second tank 92 change, taking the inner tank 3 as an empty tank as a reference. Here, even if the inter-tank distances of the first tank 91 and the second tank 92 change, this change can be absorbed by the expansion and contraction of the telescopic pipes 68 and 62, thereby reducing the stress generated at the joint 73 between the inner tank 3 and the pipe P, the joint 65 between the intermediate tank 4 and the pipe P, and the joint 66 between the outer tank 5 and the pipe P.

[0061] In the support structure S2 of the piping P in the second example above, the second telescopic pipe 68 protrudes inward from the inner groove 3, so even if the first groove 91 is narrow, the second telescopic pipe 68 can be installed in the inner groove 3. However, the telescopic pipe 68 can also protrude outward from the inner groove 3 and be disposed in the first groove 91.

[0062] [S3, the support structure of pipe P in Example 3]

[0063] Figure 7 This diagram illustrates the support structure S3 for pipe P in example 3. Furthermore, in Figure 7 The image shows an enlarged view of the through section of the inner groove 3, intermediate groove 4, and outer groove 5 of the piping P. The support structure S3 of the piping P in the third example is particularly suitable for piping that penetrates the top of the groove of the three-shell tank 1 (e.g., BOG piping 22).

[0064] exist Figure 7 In the support structure S3 of the pipe P shown, the pipe P is connected to the intermediate groove 4, and the pipe P is connected to the outer groove 5 via the first telescopic pipe 61. The pipe P is not connected to the inner groove 3. The connection structure between the outer groove 5 and the pipe P via the first telescopic pipe 61 is substantially the same as the connection structure shown in the support structure S1 of the pipe P in the first example, so detailed description is omitted. Furthermore, the connection structure between the intermediate groove 4 and the pipe P is substantially the same as the connection structure shown in the support structure S2 of the pipe P in the second example, so detailed description is omitted.

[0065] The inner groove 3 is provided with an inner groove through insertion hole 34 for pipe P, and pipe P is inserted into the inner groove through insertion hole 34 with a gap. Through the gap between the opening edge of the inner groove through insertion hole 34 and pipe P, the inner groove 3 is connected to the first groove 91 of the inner groove 3 and the intermediate groove 4, and the evaporated gas in the inner groove 3 flows into the first groove 91. Therefore, when using the support structure S3 for pipe P, the connecting pipe 21 can be omitted.

[0066] Preferably, a non-flowing insulating material 93, such as fibrous, panel-shaped, or block-shaped insulating material, is provided around the inner groove through-hole 34 to prevent the insulating material 93 from entering the inner groove 3 through the inner groove through-hole 34. However, the gap between the inner groove through-hole 34 and the pipe P can also be physically isolated from the first groove 91, so that the insulating material 93, dust, etc., will not enter the inner groove 3 through the gap between the inner groove through-hole 34 and the pipe P. For example, as... Figure 8As shown, the cylindrical body 81 is inserted into the inner groove through insertion hole 34 in a substantially concentric shape with the pipe P, and the outer wall of the cylindrical body 81 is fixed to the edge of the inner groove through insertion hole 34. The cylindrical body 81 protrudes from both the wall of the inner groove 3 into the first groove 91 and into the inner groove 3. In the first groove 91, a flange-shaped cover plate 83 protruding radially from the outer wall of the pipe P is fixed to the pipe P. The cover plate 83 covers the gap between the end of the cylindrical body 81 and the pipe P, and is positioned away from the cylindrical body 81 to avoid interference with the cylindrical body 81. The outer edge of the cover plate 83 is connected to the upper end of the cylindrical body 81 through a filter 82. The gap between the cover plate 83 and the cylindrical body 81 is sealed by the filter 82 in a ventilated manner. When the inner groove 3 contracts, the gap between the cylinder 81 fixed to the inner groove 3 and the cover plate 83 increases, but the filter 82, made of a stretchable and deformable material or having a stretching range, deforms in response to changes in the gap size. The filter 82 is preferably made of a thermally or chemically stable material, such as glass cloth. Furthermore, in Figure 8 In the example shown, the cover plate 83 and the filter 82 are disposed within the first slot 91, but they can also be disposed as shown in the example. Figure 9 As shown, the cover plate 83 and the filter 82 are disposed in the inner tank 3. In this case, a cover plate 83 protruding radially from the outer wall of the pipe P is fixed on the pipe P in the inner tank 3, and the outer edge of the cover plate 83 is connected to the lower end of the cylinder 81 through the filter 82.

[0067] In the three-layer shell tank 1 equipped with the aforementioned support structure S3, when cryogenic liquefied gas is contained in the inner tank 3, the inter-tank distances of the first tank 91 and the second tank 92 change, taking the inner tank 3 as an empty tank as a reference. Here, even if the inter-tank distance of the second tank 92 changes, this change can be absorbed by the expansion and contraction of the first telescopic pipe 61, reducing the stress generated at the joint 65 between the intermediate tank 4 and the piping P and at the joint 66 between the outer tank 5 and the piping P. Furthermore, since the piping P is not connected to the inner tank 3, even if the inter-tank distance of the first tank 91 changes, the stress generated at the joint 65 between the intermediate tank 4 and the piping P and at the joint 66 between the outer tank 5 and the piping P will also be reduced. Moreover, the connecting pipe 21 can be omitted.

[0068] 〔Summarize〕

[0069] As explained above, the three-shell tank 1 of this embodiment, which has the support structures S1 and S2 of the piping P in Examples 1 and 2, is characterized in that the three-shell tank 1 has: an outer tank 5; an intermediate tank 4 disposed within the outer tank 5; an inner tank 3 disposed within the intermediate tank 4, which stores liquefied gas inside; and a piping P that passes through the outer tank 5, the intermediate tank 4, and the inner tank 3. The piping P is connected to the outer tank 5 via a first telescopic pipe 61, and to one of the inner tank 3 and the intermediate tank 4 via a second telescopic pipe 62 / 68. The piping P is engaged with the other of the inner tank 3 and the intermediate tank 4 (or, the piping P is inserted through the other of the inner tank 3 and the intermediate tank 4).

[0070] According to the three-layer shell tank 1 with the above structure, when the distance between the inner tank 3, the intermediate tank 4, and the outer tank 5 changes due to thermal contraction of the tanks caused by the storage of cryogenic liquefied gas in the inner tank 3, the change in the distance between the tanks is absorbed by the expansion and contraction of the expansion and contraction pipes 61, 62, and 68, thereby reducing the stress generated at the joints 73, 65, and 66 between each tank and the piping P. Therefore, the support structures S1 and S2 of the three-layer shell tank 1 with the above structure are suitable for supporting the piping P that penetrates the three layers of the shell in the three-layer shell tank 1, which has a three-layer shell composed of an inner tank 3, an intermediate tank 4, and an outer tank 5.

[0071] In the three-layer shell tank 1 with the support structure S1 for the piping P of the first example, the intermediate groove 4 has an intermediate groove through insertion hole 44 for the piping P to be inserted through. The base end of the second telescopic tube 62 is joined to the intermediate groove 4 and the front end of the second telescopic tube 62 is joined to the piping P in such a way that it protrudes outward from the edge of the intermediate groove through insertion hole 44. In this three-layer shell tank 1 with the support structure S1 for the piping P, the second telescopic tube 62 is disposed in the second groove 92. Therefore, compared with the case where the second telescopic tube 62 is disposed in the inner groove 3 or the first groove 91, the construction is easier and the degree of cold and heat resistance of the second telescopic tube 62 can be less.

[0072] In the three-layer shell tank 1 with the support structure S1 of the piping P in the first example, granular insulation material may be filled in the space 92 between the intermediate groove 4 and the second groove of the outer groove 5, and a particle barrier 67 may be arranged around the second telescopic pipe 62 to prevent the granular insulation material from moving around the second telescopic pipe 62. Alternatively, fibrous insulation material 72 may be filled in the radial gap of the piping P between the particle barrier 67 and the piping P. Furthermore, the particle barrier 67 may be a cylindrical component surrounding the second telescopic pipe 62, with its first end connected to the intermediate groove 4 and its second end connected to the piping P.

[0073] Furthermore, in the three-layer shell tank 1 equipped with the support structure S1 for the piping P in the first example, the intermediate groove 4 has an intermediate groove through insertion hole 44 for the piping P to be inserted through. The base end of the second telescopic tube 62 is joined to the intermediate groove 4 and the front end of the second telescopic tube 62 is joined to the piping P by protruding inward from the edge of the intermediate groove through insertion hole 44. In this three-layer shell tank 1 equipped with the support structure S1 for the piping P, granular heat insulation material is filled in the first groove 91 between the inner groove 3 and the intermediate groove 4, and a particle barrier 67 is arranged around the second telescopic tube 62 to prevent the granular heat insulation material from moving around the second telescopic tube 62. Here, it is also possible that fibrous heat insulation material 72 is filled in the radial gap of the piping P between the particle barrier 67 and the piping P. Alternatively, the particle barrier 67 may be a cylindrical component surrounding the second telescopic pipe 62, with the first end of the cylindrical component engaging with the intermediate groove 4 and the second end of the cylindrical component engaging with the piping P.

[0074] When a particle barrier 67 is provided around the second telescopic tube 62 as described above, it can prevent granular heat insulation material from blocking or pressing against the telescopic part 64 of the second telescopic tube 62, and does not hinder the telescopic expansion and shear deformation of the second telescopic tube 62.

[0075] Furthermore, in the three-layer shell tank 1 equipped with the support structure S2 for the piping P of the second example, the inner groove 3 has an inner groove through insertion hole 34 for the piping P to be inserted through. The base end of the second telescopic tube 68 is joined to the inner groove 3 and the front end of the second telescopic tube 68 is joined to the piping P in such a way that it protrudes inward from the edge of the inner groove through insertion hole 34. In this three-layer shell tank 1 equipped with the support structure S2 for the piping P of the second example, the second telescopic tube 68 protrudes inward from the inner groove 3, so there are fewer constraints on the installation space for the second telescopic tube 68, and the degree of freedom in design and construction is high.

[0076] Furthermore, the three-shell tank 1 of this embodiment, which has the support structure S3 of the piping P in the third example, is characterized in that the three-shell tank 1 has: an outer groove 5; an intermediate groove 4 disposed in the outer groove 5; an inner groove 3 disposed in the intermediate groove 4, having an inner groove through insertion hole 34, and storing liquefied gas inside; and a piping P that passes through the outer groove 5, the intermediate groove 4 and the inner groove 3. The piping P is connected to the outer groove 5 via a first telescopic pipe 61, and the piping P is engaged with the intermediate groove 4. The piping P is inserted into the inner groove through insertion hole 34 with a gap, and the interior of the inner groove 3, the first groove gap 91 of the inner groove 3 and the intermediate groove 4 are connected through the gap between the inner groove through insertion hole 34 and the piping P.

[0077] According to the three-layer shell tank 1 with the above structure, when the distance between the inner tank 3, the intermediate tank 4, and the outer tank 5 changes due to thermal contraction caused by the storage of cryogenic liquefied gas in the inner tank 3, the change in the distance between the tanks is absorbed by the expansion and contraction of the first telescopic pipe 61, and the stress generated at the joints 65 and 66 between the intermediate tank 4 and the outer tank 5 and the piping P is reduced. Therefore, the support structure S3 for the piping P in the three-layer shell tank 1 with the above structure is suitable for supporting the piping P that penetrates through the three layers of the shell in the three-layer shell tank 1, which has an inner tank 3, an intermediate tank 4, and an outer tank 5. Furthermore, the inner tank 3 and the first tank 91 are connected by an inner tank through-hole 34 into which the piping P is inserted with a gap, thus the connecting pipe 21 can be omitted.

[0078] Alternatively, the three-layer shell tank 1 with the support structure S3 of the piping P in the third example described above may also include: a cylindrical body 81, which is fixed to the edge of the inner groove through insertion hole 34, and the piping P is inserted into the cylindrical body 81 with a gap; a flange-shaped cover plate 83, which is disposed away from the cylindrical body 81 in the first groove 91 or the inner groove 3 and protrudes from the outer wall of the piping P in the radial direction; and a retractable filter 82, which can ventilately seal the gap between the cylindrical body 81 and the cover plate 83.

[0079] The three-layer shell tank 1 with the above structure allows gas to pass between the inner tank through insertion hole 34 and the piping P, while preventing the passage of solids such as insulation material and dust. Therefore, gas in the inner tank 3 can move to the first compartment 91 through the inner tank through insertion hole 34, thus eliminating the need for an additional connecting pipe 21. Furthermore, it prevents the gas flow exiting from the inner tank 3 through the inner tank through insertion hole 34 to the first compartment 91 from directly colliding with the intermediate tank 4.

[0080] The preferred embodiments of this disclosure have been described above, but variations in the specific construction and / or function of the above embodiments without departing from the spirit of this disclosure may also be included in this disclosure. For example, the above structure can be modified as follows.

[0081] For example, in the above embodiment, the inner groove 3, the middle groove 4 and the outer groove 5 are cylindrical flat-bottomed cans, but are not limited to cylindrical, and can also be approximately polygonal cylindrical flat-bottomed cans.

[0082] For example, in the above embodiment, the connecting pipe 21 can be omitted. In other words, the inner groove 3, the intermediate groove 4, and the outer groove 5 can each be airtight.

[0083] For example, in the above embodiment, the triple-shell tank 1 is located on land, but the support structure S1 to S3 of the piping P of the triple-shell tank 1 can also be applied to triple-shell tanks mounted on ships.

[0084] Label Explanation

[0085] 1: Three-layer shell tank; 3: Inner tank; 4: Middle tank; 5: Outer tank; 22: BOG piping; 25: Discharge piping; 34: Inner tank through insertion hole; 44: Middle tank through insertion hole; 54: Outer tank through insertion hole; 61: First expansion pipe; 62: Second expansion pipe; 67: Particle barrier; 68: Second expansion pipe; 69, 70, 72, 75: Fibrous insulation material; 65, 66, 73: Joint; 91, 92: Between tanks; 93: Insulation material; P: Piping; S1~S3: Support structure.

Claims

1. A three-layer shell tank, comprising: Outer groove; An intermediate groove, which is disposed within the outer groove; An inner tank, which is disposed within the intermediate tank, stores liquefied gas inside; as well as Piping that runs through the outer groove, the intermediate groove, and the inner groove. The piping is connected to the outer tank via a first telescopic pipe, and the piping is connected to one of the inner tank and the intermediate tank via a second telescopic pipe. The piping is also connected to the other of the inner tank and the intermediate tank. The stress at the joint between the piping and the outer groove is reduced by the expansion and contraction of the first telescopic pipe, and the stress at the joint between the piping and the inner groove or the intermediate groove is reduced by the expansion and contraction of the second telescopic pipe.

2. The three-layer shell tank according to claim 1, wherein, The intermediate groove has a through insertion hole for the pipe to be inserted through, so that the base end of the second telescopic pipe is engaged with the intermediate groove and the front end of the second telescopic pipe is engaged with the pipe in such a way that it protrudes outward from the edge of the through insertion hole.

3. The three-layer shell tank according to claim 2, wherein, Granular heat-insulating material is filled between the intermediate groove and the outer groove, and a particle-proof dike is arranged around the second telescopic tube to prevent the granular heat-insulating material from moving around the second telescopic tube.

4. The three-layer shell tank according to claim 3, wherein, The radial gap between the particle barrier and the piping is filled with fibrous thermal insulation material.

5. The three-layer shell tank according to claim 3 or 4, wherein, The particle barrier is a cylindrical component that surrounds the second telescopic pipe. The first end of the cylindrical component is engaged with the intermediate groove, or the second end of the cylindrical component is engaged with the piping.

6. The three-layer shell tank according to claim 1, wherein, The intermediate groove has a through insertion hole for the pipe to be inserted through, so that the base end of the second telescopic tube is engaged with the intermediate groove and the front end of the second telescopic tube is engaged with the pipe in such a way that it protrudes inward from the edge of the through insertion hole.

7. The three-layer shell tank according to claim 6, wherein, Granular heat-insulating material is filled between the inner groove and the intermediate groove, and a particle-proof dike is arranged around the second telescopic tube to prevent the granular heat-insulating material from moving around the second telescopic tube.

8. The three-layer shell tank according to claim 7, wherein, The radial gap between the particle barrier and the piping is filled with fibrous thermal insulation material.

9. The three-shell tank according to claim 7 or 8, wherein, The particle barrier is a cylindrical component that surrounds the second telescopic pipe. The first end of the cylindrical component is engaged with the intermediate groove, or the second end of the cylindrical component is engaged with the piping.

10. The three-layer shell tank according to claim 1, wherein, The inner groove has a through insertion hole for the pipe to be inserted through, so that the base end of the second telescopic tube is engaged with the inner groove and the front end of the second telescopic tube is engaged with the pipe in such a way that it protrudes inward from the edge of the through insertion hole.

11. A three-layer shell tank, comprising: Outer groove; An intermediate groove, which is disposed within the outer groove; The inner tank, which is disposed within the intermediate tank, has an inner tank through insertion hole and stores liquefied gas inside; as well as Piping that runs through the outer groove, the intermediate groove, and the inner groove. The piping is connected to the outer groove via a first telescopic pipe. The piping is joined to the intermediate groove. The piping is inserted into the through insertion hole of the inner groove with a gap. The interior of the inner groove is connected to the grooves of the inner groove and the intermediate groove through the gap between the through insertion hole of the inner groove and the piping. The stress at the joint between the piping and the outer groove is reduced by the expansion and contraction of the first telescopic tube.

12. The three-layer shell tank according to claim 11, wherein, The three-layer shell tank also has: A cylindrical body, which is fixed to the edge of the inner groove through insertion hole, and the piping is inserted into the cylindrical body with a gap between them; A flange-shaped cover plate, disposed away from the cylinder in the first groove or the inner groove, protruding radially from the outer wall of the piping; and A retractable filter that can airtightly seal the gap between the cylinder and the cover plate.

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