Multi-shell tank

Abstract

To provide a flat-bottomed multiple shell tank for storing a low temperature liquefied gas that has improved cold insulation performance over a double shell tank, and has facilitated coupling of an inner tank and a tank foundation as compared to a triple shell tank.SOLUTION: A multiple shell tank includes: a tank foundation; an outer tank having an outer tank bottom plate disposed on the tank foundation and fixed to the tank foundation, a cylindrical outer tank side plate whose lower end part is fixed to the outer tank bottom plate, and an outer tank roof provided on an upper end part of the outer tank side plate; an inner tank having an inner tank bottom plate, a cylindrical inner tank side plate whose lower end part is fixed to the inner tank bottom plate, and an inner tank roof provided on an upper end part of the inner tank side plate, and arranged on the outer tank bottom plate inside the outer tank through an inner side bottom part cold insulation layer; and an intermediate tank having a cylindrical intermediate tank side plate arranged between the outer tank side plate and the inner tank side plate, whose lower end part is fixed to the outer tank bottom plate, and an intermediate tank roof arranged between the outer tank roof and the inner tank roof and provided on an upper end part of the intermediate tank side plate. A liquefied gas is stored in the inner tank.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a flat-bottom, multi-shell tank for storing cryogenic liquefied gas. [Background technology]

[0002] Conventionally, flat-bottom double-shell tanks and triple-shell tanks for storing low-temperature liquefied gas have been proposed. For example, Patent Document 1 discloses a flat-bottom triple-shell tank.

[0003] In the triple-shell tank disclosed in Patent Document 1, an outer tank is mounted on a concrete tank foundation, a perlite concrete base plate with a cooling effect is mounted on the bottom plate of the outer tank, an intermediate tank is mounted on this base plate, a level concrete layer is mounted on the bottom plate of the intermediate tank, and an inner tank is mounted on the level concrete layer. A mounting seat is provided between the bottom plate of the inner tank and the level concrete layer, slidably supporting the peripheral edge of the bottom plate of the inner tank. The outer peripheral edge of the mounting seat extends close to the inner wall of the intermediate tank and can abut from below against a locking piece provided on the inner wall of the intermediate tank. One end of a first anchor member is connected to the side plate of the inner tank, and the other end is connected to the mounting seat. One end of a second anchor member is connected to the side plate of the intermediate tank, and the other end extends into and is fixed to the tank foundation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 55-20937 Summary of the Invention [Problem to be solved by the invention]

[0005] In the triple-shell tank of Patent Document 1, an intermediate tank is provided inside an outer tank, and an inner tank is provided inside the intermediate tank. One end of a first anchor member is connected to a side plate of the inner tank, and the other end is connected to a mounting seat located between the bottom plate of the inner tank and the bottom plate of the intermediate tank. The mounting seat is frictionally engaged with the inner tank, but is not fixed to the inner or intermediate tanks, nor is it fixed to the tank foundation. While it is desirable for the anchor member to be fixed to the tank foundation, the triple-shell tank of Patent Document 1 has an intermediate tank and an outer tank between the inner tank and the tank foundation, making it difficult to connect the inner tank and the tank foundation with the anchor member while maintaining airtightness inside and outside the intermediate tank.

[0006] The present disclosure has been made in consideration of the above circumstances, and its purpose is to propose a structure for a flat-bottomed multi-shell tank for storing low-temperature liquefied gas, which has improved cold insulation properties compared to a double-shell tank, while making it easier to connect the inner tank to the tank foundation compared to a triple-shell tank. [Means for solving the problem]

[0007] This disclosure to Such multi-shell tanks are: Tank foundations and An outer tank bottom plate is placed on the tank foundation and fixed to the tank foundation, and a lower end of the outer tank bottom plate is and an outer tank roof provided on the upper end of the outer tank side plate. and an outer tank for an inner tank bottom plate; a cylindrical inner tank side plate extending in the vertical direction and having a lower end fixed to the inner tank bottom plate; The inner tank has an inner tank roof provided on the upper end of the inner tank side plate, and the outer tank bottom is provided inside the outer tank. an inner tank disposed on the plate via an inner bottom insulation layer; A cylindrical tank is disposed between the outer tank side plate and the inner tank side plate, and the lower end of the cylindrical tank is fixed to the outer tank bottom plate. An intermediate tank side plate and an upper end of the intermediate tank side plate disposed between the outer tank roof and the inner tank roof an intermediate tank having an intermediate tank roof provided in the portion; a first anchor strap that is passed between the inner tank side plate and the intermediate tank side plate and penetrates the outer tank bottom plate to connect the inner tank side plate and the tank foundation; a second anchor strap that is passed between the intermediate tank side plate and the outer tank side plate, penetrates the outer tank bottom plate, and connects the intermediate tank side plate and the tank foundation; Equipped with The inner tank is characterized in that liquefied gas is stored therein.

[0008] The multi-shell tank with the above-mentioned configuration has a triple-walled side panel and roof, which allows for improved cold insulation compared to conventional double-shell tanks. Furthermore, the multi-shell tank has a double-walled bottom panel, which makes construction easier and less costly than conventional triple-shell tanks.

[0009] Furthermore, in a multi-shell tank, the bottom plate of the outer tank also serves as the bottom plate of the intermediate and outer tanks, so the bottom plate of the outer tank, which is directly fixed to the tank foundation, is exposed between the inner and intermediate tanks, and between the intermediate and outer tanks. Therefore, it is possible to fix the inner tank to the tank foundation by utilizing the space between the inner and intermediate tanks, without passing through the space between the intermediate and outer tanks. As a result, the connection between the inner tank and the tank foundation is simpler than with conventional triple-shell tanks, making construction easier. [Effects of the Invention]

[0010] According to the present invention, a structure can be proposed for a flat-bottomed multi-shell tank for storing low-temperature liquefied gas, which has improved cold insulation properties compared to a double-shell tank, while making it easier to connect the inner tank to the tank foundation compared to a triple-shell tank. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing the overall configuration of a multi-shell tank according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing the overall configuration of a multi-shell tank 1 according to an embodiment of the present invention. The multi-shell tank 1 shown in Fig. 1 is a flat-bottom tank that is installed on the ground and has triple-shelled sides and a double-shelled bottom. The multi-shell tank 1 includes a concrete tank foundation 7, an outer tank 5 provided on the tank foundation 7, an inner tank 3 contained within the outer tank 5, and an intermediate tank 4 provided between the outer tank 5 and the inner tank 3. A concrete dike 6 is provided around the multi-shell tank 1.

[0013] The inner tank 3 is a container for storing low-temperature liquefied gas. Examples of low-temperature liquefied gas include liquid helium, liquid hydrogen, liquid nitrogen, LNG, and LPG. The inner tank 3 has a generally flat inner tank bottom plate 31, a cylindrical inner tank side plate 32 whose lower end is fixed to the inner tank bottom plate 31, and a hemispherical shell-shaped (dome-shaped) inner tank roof 33 attached to the upper end of the inner tank side plate 32.

[0014] The inner tank 3 is contained in the outer tank 5. The outer tank 5 has a generally flat outer tank bottom plate 51 installed on and fixed to the tank foundation 7, a cylindrical outer tank side plate 52 whose lower end is fixed to the outer tank bottom plate 51, and a hemispherical shell-shaped outer tank roof 53 installed on the upper end of the outer tank side plate 52. An inner bottom cold insulation layer 36 is interposed between the outer tank bottom plate 51 and the inner tank bottom plate 31.

[0015] The outer tank side plate 52 is connected to the tank foundation 7 by anchor bolts (not shown). Alternatively, the outer tank bottom plate 51 may be fixed to an anchor plate driven into the tank foundation 7.

[0016] The intermediate tank 4 has a cylindrical intermediate tank side plate 42 whose lower end is fixed to the outer tank bottom plate 51, and a hemispherical intermediate tank roof 43 attached to the upper end of the intermediate tank side plate 42. In other words, the outer tank bottom plate 51 serves as the bottom plate of both the intermediate tank 4 and the outer tank 5. The intermediate tank side plate 42 is provided between the inner tank side plate 32 and the outer tank side plate 52. The intermediate tank roof 43 is provided between the inner tank roof 33 and the outer tank roof 53. The inner tank roof 33 may be supported by being suspended from the intermediate tank roof 43.

[0017] A gap is provided between the inner tank side plate 32 and the intermediate tank side plate 42, and a gap is provided between the inner tank roof 33 and the intermediate tank roof 43. These gaps form a gap between the inner tank 3 and the intermediate tank 4 (hereinafter referred to as the "first gap 61"). A gap is provided between the intermediate tank side plate 42 and the outer tank side plate 52, and a gap is provided between the intermediate tank roof 43 and the outer tank roof 53. These gaps form a gap between the intermediate tank 4 and the outer tank 5 (hereinafter referred to as the "second gap 62"). The first gap 61 and the second gap 62 are filled with a heat insulating material 63. The heat insulating material 63 may be, for example, perlite, glass wool, or any other material that has been used as a heat insulating material in conventional multi-shell tanks.

[0018] A BOG pipe 22 opens at the top of the inner tank 3, and vaporized gas generated in the inner tank 3 is sent to the outside of the multi-shell tank 1 through the BOG pipe 22. This BOG pipe 22 penetrates the inner tank roof 33, the intermediate tank roof 43, and the outer tank roof 53. A discharge pipe (not shown) opens at the bottom of the inner tank 3, and liquefied gas in the inner tank 3 is sent to the outside through this discharge pipe. However, the discharge pipe may be configured to extend upward within the inner tank 3 and send liquefied gas to the outside through the top of the multi-shell tank 1.

[0019] The first space between the tanks 61 and the second space between the tanks 62 are separated by an airtight intermediate tank 4. The first space between the tanks 61 and the second space between the tanks 62 is filled with the same type of gas as the vaporized gas of the liquefied gas contained in the inner tank 3, or a gas with a low boiling point equivalent to that of the vaporized gas of the liquefied gas. To supply gas to the first space between the tanks 61, a communicating pipe 21 that communicates the upper part of the inner tank 3 with the first space between the tanks 61 is provided on the inner tank roof 33. However, the communicating pipe 21 may be omitted, and a branch pipe of the BOG piping 22 may be connected to the first space between the tanks 61, so that the vaporized gas discharged from the inner tank 3 through the BOG piping 22 may be introduced into the first space between the tanks 61.

[0020] The second tank space 62 is filled with an inert gas, which is supplied from an inert gas supply source 24 through an introduction pipe 23. This inert gas has a boiling point higher than that of the liquefied gas stored in the inner tank 3. Nitrogen is an example of such an inert gas.

[0021] The inner tank side plate 32 and the tank foundation 7 are connected by first anchor straps 9 that pass through the first tank gap 61. A large number of first anchor straps 9 are provided circumferentially around the inner tank side plate 32 at approximately equal intervals. The upper ends 9a of the first anchor straps 9 are connected to the outer wall of the inner tank side plate 32. The upper ends 9a of the first anchor straps 9 may be connected to the outer wall of the inner tank side plate 32 so that vertical displacement on the outer wall of the inner tank side plate 32 is permitted. The lower ends 9b of the first anchor straps 9 are connected by welding to an anchor box 71 that penetrates the outer tank bottom plate 51 and is fitted into the tank foundation 7.

[0022] The intermediate tank side plate 42 and the tank foundation 7 are connected by second anchor straps 10 that pass through the second tank gap 62. A large number of second anchor straps 10 are provided circumferentially around the intermediate tank side plate 42 at approximately equal intervals. The upper ends 10a of the second anchor straps 10 are joined to the outer wall of the intermediate tank side plate 42 by welding or other methods. The lower ends 10b of the second anchor straps 10 are joined by welding to an anchor box 72 that penetrates the outer tank bottom plate 51 and is embedded in the tank foundation 7. The first anchor straps 9 and second anchor straps 10 are strip-shaped members made of a material (e.g., SUS) that has low-temperature toughness. However, the first anchor straps 9 and second anchor straps 10 may also be shaft-shaped or linear members.

[0023] [Summary] As described above, the multi-shell tank 1 according to the present disclosure has the following features: Tank foundation 7 and an outer tank 5 having an outer tank bottom plate 51 placed on a tank foundation 7 and fixed to the tank foundation 7, a cylindrical outer tank side plate 52 having a lower end fixed to the outer tank bottom plate 51, and an outer tank roof 53 provided on the upper end of the outer tank side plate 52; an inner tank 3 having an inner tank bottom plate 31, a cylindrical inner tank side plate 32 whose lower end is fixed to the inner tank bottom plate 31, and an inner tank roof 33 provided on the upper end of the inner tank side plate 32, and disposed inside the outer tank 5 on the outer tank bottom plate 51 via an inner bottom cold insulation layer 36; an intermediate tank (4) having a cylindrical intermediate tank side plate (42) arranged between an outer tank side plate (52) and an inner tank side plate (32) and having a lower end fixed to an outer tank bottom plate (51); and an intermediate tank (4) having an intermediate tank roof (43) arranged between an outer tank roof (53) and an inner tank roof (33) and provided at an upper end of the intermediate tank side plate (42), The inner tank 3 contains liquefied gas.

[0024] The multi-shell tank 1 configured as described above has a triple-walled structure for the side panels and roof, thereby improving cold insulation compared to double-shelled tanks. Furthermore, the multi-shell tank 1 has a double-walled structure for the bottom panel, making construction easier and less costly than conventional triple-shelled tanks. Furthermore, in the multi-shelled tank 1, the outer tank bottom plate 51 also serves as the bottom plate for the intermediate tank 4 and the outer tank 5. Therefore, the outer tank bottom plate 51, which is directly fixed to the tank foundation 7, is exposed between the inner tank 3 and the intermediate tank 4 and between the intermediate tank 4 and the outer tank 5. In this multi-shelled tank 1, the inner tank 3 can be fixed to the tank foundation 7 using the first tank gap 61 between the inner tank 3 and the intermediate tank 4, without passing through the second tank gap 62 between the intermediate tank 4 and the outer tank 5. As a result, the connection between the inner tank 3 and the tank foundation 7 is simpler than in conventional triple-shelled tanks, making construction easier.

[0025] In addition, the multi-shell tank 1 according to the present disclosure further includes a first anchor strap 9 that is passed between the inner tank side plate 32 and the intermediate tank side plate 42, penetrates the outer tank bottom plate 51, and connects the inner tank side plate 32 and the tank foundation 7, and a second anchor strap 10 that is passed between the intermediate tank side plate 42 and the outer tank side plate 52, penetrates the outer tank bottom plate 51, and connects the intermediate tank side plate 42 and the tank foundation 7.

[0026] In the multi-shell tank 1 configured as described above, the first anchor straps 9 connecting the inner tank side plate 32 and the tank foundation 7 pass only through the first tank space 61, not through the second tank space 62. Therefore, there is no need to form an opening between the intermediate tank 4 and the outer tank 5 to pass the first anchor straps 9 through. Because there is no need to form such an opening, it is easier to connect the inner tank side plate 32 and the tank foundation 7 compared to conventional triple-shell tanks. Furthermore, the airtightness of the intermediate tank 4 is not reduced, and leakage of gas from the first tank space 61 to the second tank space 62 can be more strictly prevented.

[0027] Furthermore, in the multi-shell tank 1 according to the present disclosure, the first space between the inner tank 3 and the intermediate tank 4 is filled with a vaporized gas of the liquefied gas contained in the inner tank 3, and the second space between the intermediate tank 4 and the outer tank 5 is filled with a gas having a higher boiling point than the liquefied gas. Here, when the first space between the inner tank 3 and the intermediate tank 4 is communicated with the interior of the inner tank 3, the pressure difference between the inner tank 3 and the outer tank 5 can be reduced, and the stress applied to the first anchor strap 9 can be reduced.

[0028] The preferred embodiments of the present invention have been described above, but the present invention also includes modifications to the specific structure and / or function of the above embodiments without departing from the spirit of the present invention. The configuration of the above multi-shell tank 1 can be modified as follows.

[0029] For example, in the above embodiment, the inner tank side plate 32, the intermediate tank side plate 42, and the outer tank side plate 52 are cylindrical, but they are not limited to being cylindrical and may be substantially polygonal tubular.

[0030] For example, in the above embodiment, the liquid barrier 6 is provided around the multi-shell tank 1, but the liquid barrier 6 may be omitted.

[0031] For example, although the outer vessel 5 is made of a room temperature material in the above embodiment, it may be made of a low temperature material having a low embrittlement transition temperature. [Explanation of symbols]

[0032] 1: Multi-shell tank 3: Inner tank 4: Intermediate tank 5: Outer tank 7: Tank foundation 9: First anchor strap 10: Second anchor strap 31: Inner tank bottom plate 32: Inner tank side plate 33: Inner tank roof 36: Inner bottom cold insulation layer 42: Intermediate tank side plate 43: Intermediate tank roof 51: Outer tank bottom plate 52:Outer tank side plate 53: Outer tank roof 61: Between the 1st tanks 62: 2nd tank space

Claims

[Claim 1] Tank foundations and an outer tank having an outer tank bottom plate placed on the tank foundation and fixed to the tank foundation, a cylindrical outer tank side plate whose lower end is fixed to the outer tank bottom plate, and an outer tank roof provided on the upper end of the outer tank side plate; an inner tank having an inner tank bottom plate, a cylindrical inner tank side plate whose lower end is fixed to the inner tank bottom plate, and an inner tank roof provided on an upper end of the inner tank side plate, and the inner tank is disposed inside the outer tank on the outer tank bottom plate via an inner bottom cold insulation layer; an intermediate tank having a cylindrical intermediate tank side plate disposed between the outer tank side plate and the inner tank side plate and having a lower end portion fixed to the outer tank bottom plate, and an intermediate tank roof disposed between the outer tank roof and the inner tank roof and provided at an upper end portion of the intermediate tank side plate; a first anchor strap that is passed between the inner tank side plate and the intermediate tank side plate and penetrates the outer tank bottom plate to connect the inner tank side plate and the tank foundation; a second anchor strap that is passed between the intermediate tank side plate and the outer tank side plate and penetrates the outer tank bottom plate to connect the intermediate tank side plate and the tank foundation, The inner tank contains liquefied gas. Multi-hull tank.

Images