Multi-hulled tank

Abstract

This multi-hulled tank comprises: a first tank; a second tank surrounding the first tank; a heat insulating layer disposed between the first tank and the second tank and covering the outer wall of the first tank; and a first piping that is for air supply or expulsion, has a first opening disposed between the tanks in a first inter-tank region between the first tank and the heat insulating layer, passes between the tanks, and extends to outside of the tank.

Description

Multi-shell tank

[0001] The present disclosure relates to the construction of a multi-shell tank for containing cryogenic liquefied gas.

[0002] For example, in a tank for storing a low-temperature liquefied gas such as liquid hydrogen, a thermal barrier with high thermal insulation performance is required to prevent the liquefied gas from evaporating inside the tank due to the large temperature difference between the liquefied gas and the outside. Therefore, a multi-shell tank is known as a tank for storing a liquefied gas, which includes an inner tank for storing the liquefied gas and an outer tank surrounding the inner tank, with a thermal barrier provided between the inner and outer tanks. For example, Patent Document 1 discloses this type of multi-shell tank.

[0003] The multi-shell tank disclosed in Patent Document 1 includes an inner tank for storing liquefied gas, an outer tank for accommodating the inner tank, and a thermal barrier layer made of insulating material disposed in the region between the inner and outer tanks.

[0004] International Publication No. 2020 / 202578

[0005] In some multi-shell tanks, the space between the inner and outer tanks is filled with the same gas as the vaporized gas of the liquefied gas contained in the inner tank, or with an inert gas. In such multi-shell tanks, when filling, replacing, cooling, and heating the space between the inner and outer tanks, an intake and exhaust process is performed in which the gas present between the inner and outer tanks is forcibly exhausted and new gas is introduced. Between the inner and outer tanks, insulating materials, support materials, reinforcing members, etc., which form a thermal barrier, are arranged, and there are areas where the gas flow is difficult. During the intake and exhaust process between the inner and outer tanks, the gas flow is likely to be stagnant in the areas where the gas flow is difficult between the inner and outer tanks, which may reduce the efficiency of the intake and exhaust process.

[0006] The present disclosure has been made in consideration of the above circumstances, and its purpose is to provide a technology for improving the efficiency of air intake and exhaust processing between tanks in a multi-shell tank including a first tank, a second tank surrounding the first tank, and a thermal barrier layer disposed between the first tank and the second tank and covering the first tank.

[0007] In order to solve the above problems, a multi-shell tank according to one embodiment of the present disclosure comprises: a first tank; a second tank surrounding the first tank; a thermal insulation layer disposed between the first tank and the second tank and covering the outer wall of the first tank; and a first pipe for air supply or exhaust that has a first opening disposed in a first inter-tank region between the first tank and the thermal insulation layer between the tanks and extends to the outside through the space between the tanks.

[0008] According to the present disclosure, a technology can be provided that improves the efficiency of air intake and exhaust processing between tanks in a multi-shell tank that includes a first tank, a second tank surrounding the first tank, and a thermal insulation layer disposed between the first and second tanks and covering the first tank.

[0009] Fig. 1 is a vertical cross-sectional view showing a schematic configuration of a multi-shell tank according to one embodiment of the present disclosure. Fig. 2 is an enlarged view of a tip portion of a first pipe. Fig. 3 is a diagram showing an example configuration of a first pipe and a second pipe having a shared portion. Fig. 4 is a diagram showing an example configuration of a first pipe having a plurality of first openings arranged in an annular shape. Fig. 5 is a diagram showing an example configuration of a first pipe having first openings both above and below a first tank.

[0010] Next, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a multi-shell tank 1 according to one embodiment of the present disclosure. The multi-shell tank 1 shown in FIG. 1 is a tank that stores a low-temperature liquefied gas L. Examples of the liquefied gas L include liquefied hydrogen and liquefied natural gas. The multi-shell tank 1 may be mounted on a floating structure such as a ship or an offshore structure, or may be installed at a land base. Furthermore, the multi-shell tank 1 may be a cargo tank that stores liquefied gas L as cargo, or a fuel tank that stores liquefied gas L as fuel.

[0011] The multi-shell tank 1 is a double-shell tank including a first tank 21 that contains liquefied gas L and a second tank 22 that surrounds the first tank 21. The first tank 21 and the second tank 22 are spaced apart in the radial direction of the multi-shell tank 1. However, the multi-shell tank 1 according to the present disclosure is not limited to a double-shell tank, and may have three or more shells (i.e., tanks) with an additional tank outside the second tank 22. By interpreting the relationship between the first tank 21 and the second tank 22 of the present disclosure as the relationship between two tanks adjacent to each other inside and outside, the present disclosure can be applied to a multi-shell tank with three or more shells.

[0012] A thermal barrier layer 24 is disposed between the first tank 21 and the second tank 22 in the space 23 between the first tank 21 and the second tank 22. The thermal barrier layer 24 covers the outer wall of the first tank 21 in the space 23 between the tanks, and suppresses heat input to the first tank 21. The thermal barrier layer 24 is formed, for example, from a heat insulating panel.

[0013] The multi-shell tank 1 is supported on a tank foundation 10 via supports 71 and 72. The tank foundation 10 is, for example, the hull of a floating structure such as a ship or an offshore structure, or the concrete foundation of a land base. The supports 71 and 72 are cylindrical bodies extending substantially vertically and mainly include a first skirt 71 that supports the first tank 21 and a second skirt 72 that supports the second tank 22. The first skirt 71 is surrounded by the second skirt 72. The upper end of the second skirt 72 is joined to the second tank 22, and the lower end of the second skirt 72 is fixed to the tank foundation 10. The upper end of the first skirt 71 is joined to the first tank 21 at the inter-tank space 23. The first skirt 71 passes through the inter-tank space 23, and the lower end of the first skirt 71 is fixed to the tank foundation 10. At the intersection of the first tank 21 and the first skirt 71, there is a narrow portion where the gas flow is stagnated in the space sandwiched between the first tank 21 and the first skirt 71. Furthermore, at the intersection of the thermal insulation layer 24 covering the first tank 21 and the first skirt 71, there is a narrow portion where the gas flow is stagnated in the space surrounded by the thermal insulation layer 24 and the first skirt 71.

[0014] Here, the area between the first tank 21 and the thermal insulation layer 24 is referred to as the "first inter-tank region 25," and the area between the thermal insulation layer 24 and the second tank 22 is referred to as the "second inter-tank region 26." That is, the inter-tank region 23 includes the first inter-tank region 25 surrounding the first tank 21 and the second inter-tank region 26 surrounding the first inter-tank region 25. The first inter-tank region 25 and the second inter-tank region 26 may be connected spaces or may be independent spaces. The first inter-tank region 25 may be formed in a gap between the outer wall of the first tank 21 and the thermal insulation layer 24, or may be formed by a gap or pore formed in the surface of the thermal insulation layer 24 facing the outer wall of the first tank 21. Furthermore, as shown in FIG. 2 , if a recess 25a is formed in the surface of the thermal insulation layer 24 that is recessed from the outer wall of the first tank 21 more than other portions, the space within this recess 25a is also included in the first inter-tank region 25.

[0015] Returning to FIG. 1 , each of the first inter-tank region 25 and the second inter-tank region 26 of the inter-tank 23 is filled with an inter-tank gas G. The inter-tank gas G is the same type of gas as the vaporized gas of the liquefied gas L, or an inert gas. For example, when the liquefied gas L is liquid hydrogen, hydrogen gas is used as the inter-tank gas G. Furthermore, for example, when the liquefied gas L is liquefied natural gas, nitrogen gas is used as the inter-tank gas G.

[0016] The multi-shell tank 1 includes a first pipe 3 and a second pipe 4 for supplying air to the spaces between the tanks 23 and exhausting air from the spaces between the tanks 23. The first pipe 3 and the second pipe 4 may be widely used for supplying and exhausting processes involving exhausting air from and supplying air to the spaces between the tanks 23, such as filling the spaces between the tanks 23 with inter-tank gas G, gas replacement, cooling, and heating.

[0017] The first piping 3 has a first opening 31 that opens into the first inter-tank region 25. The first piping 3 is mainly used for supplying air to and / or exhausting air from the first inter-tank region 25. In the example shown in Fig. 1 , one system of first piping 3 is used for both supplying air and exhausting air, but it is also possible to provide a first piping 3 for an air supply system that has the first opening 31 as an air supply port, and a first piping 3 for an exhaust system that has the first opening 31 as an exhaust port.

[0018] The first pipe 3 penetrates the second tank 22 and passes through the second inter-tank region 26 of the inter-tank region 23, and the first opening 31 provided at the tip portion 3a is located within the first inter-tank region 25.

[0019] Fig. 2 is an enlarged view of the tip portion 3a of the first pipe 3. As shown in Fig. 2, the tip portion 3a of the first pipe 3 is provided with a first opening 31 that opens into the first inter-tank region 25. The tip portion 3a of the first pipe 3 is supported on the first tank 21 by a first support member 36 fixed to the first tank 21. The middle portion 3b of the first pipe 3 is disposed along the inner wall of the second tank 22 in the second inter-tank region 26, and is supported on the second tank 22 by a second support member 37 fixed to the second tank 22.

[0020] The first pipe 3 has an expandable section 38 between the tip section 3a supported by the first support member 36 and the middle section 3b supported by the second support member 37. The expandable section 38 is formed, for example, by a flexible hose. When the first tank 21 contains liquefied gas L, the relative positions of the tip section 3a supported by the first tank 21 and the middle section 3b supported by the first tank 21 change due to the cold heat of the liquefied gas L. The change in the relative positions of the tip section 3a and the middle section 3b of the first pipe 3 is absorbed by the expansion or contraction of the expandable section 38, thereby reducing stress generated in the first pipe 3, stress generated at the joint between the first support member 36 and the first tank 21, and stress generated at the joint between the second support member 37 and the second tank 22.

[0021] Returning to Fig. 1 , the second piping 4 has a second opening 41 that opens into the second inter-tank region 26. The second piping 4 is mainly used for supplying and exhausting air to and from the second inter-tank region 26. In the multi-shell tank 1 illustrated in Fig. 1 , the second piping 4 is used for both supplying and exhausting air, but the tank may also be provided with a second piping 4 for an air supply system having the second opening 41 as an air supply port, and a second piping 4 for an exhaust system having the second opening 41 as an exhaust port.

[0022] The second pipe 4 penetrates the second tank 22 and passes through the second inter-tank region 26 of the inter-tank space 23, with a second opening 41 provided at its tip located within the second inter-tank region 26. The first pipe 3 and the second pipe 4 are independent pipes in the inter-tank space 23 of the multi-shell tank 1. However, the first pipe 3 and the second pipe 4 may share a portion of the pipe. FIG. 3 is a diagram showing an example of the configuration of the first pipe 3 and the second pipe 4 having a shared portion. The multi-shell tank 1 illustrated in FIG. 3 includes a common pipe 30 that penetrates the second tank 22 and passes through the second inter-tank region 26 of the inter-tank space 23, a first branch pipe 35 connected to the common pipe 30 and having a first opening 31 at its tip, and a second branch pipe 45 connected to the common pipe 30 and having a second opening 41 at its tip. Here, the combination of the common pipe 30 and the first branch pipe 35 functions as the first pipe 3, and the combination of the common pipe 30 and the second branch pipe 45 functions as the second pipe 4.

[0023] Returning to Figure 1, the first pipe 3 has at least one first opening 31 that opens in a height range where the first tank 21 and the second tank 22 overlap in the vertical direction. Furthermore, the second pipe 4 has at least one second opening 41 that opens in a height range where the first tank 21 and the second tank 22 overlap in the vertical direction. In the space between the tanks 23, particularly in the height range where the first tank 21 and the second tank 22 overlap in the vertical direction, the insulating material, supporting material, reinforcing members, etc. that make up the thermal barrier layer 24 are concentrated, and there are areas where gas flow is difficult. It is preferable that the openings 31, 41 are located in such areas where gas flow is difficult.

[0024] For example, the first piping 3 preferably has at least one first opening 31 arranged in a narrow portion sandwiched between the first tank 21 and the first skirt 71 at the intersection of the first tank 21 and the first skirt 71. For example, the second piping 4 preferably has a second opening 41 arranged in a narrow portion sandwiched between the thermal insulation layer 24 and the first skirt 71 at the intersection of the thermal insulation layer 24 and the first skirt 71. As described above, gas flow is more likely to be impeded in narrow portions than in other portions, but supplying and / or exhausting air through the openings 31, 41 arranged in the narrow portions promotes the flow of gas in the narrow portions, improving the efficiency of supply and exhaust processing.

[0025] The first pipe 3 and the second pipe 4 converge at a junction 50 located in an exposed location outside the multi-shell tank 1. An air supply system or an exhaust system is connected to the junction 50 via a filter 34. The filter 34 collects dust from the gas flowing through the first pipe 3 and the second pipe 4. The air supply system is provided with an air supply blower and gas sources such as a cooling gas source, a heating gas source, a replacement gas source, or an inter-chamber gas source. The exhaust system is provided with, for example, an exhaust blower, a release tower that releases inter-chamber gas G to the atmosphere outside the multi-shell tank 1 (i.e., the exposed location), and fuel-using equipment that uses the inter-chamber gas G as fuel. The junction 50 is connected to either the air supply system or the exhaust system, but the connected system may be switchable by a selector valve.

[0026] The first pipe 3 and the second pipe 4 join at the junction 50, so that gas supply and / or exhaust between the inter-tank regions 23 can be performed using a single system, reducing the number of filters 34 and blowers required. Furthermore, the first pipe 3 and the second pipe 4 are connected at the junction 50, so that the pressure in the first inter-tank region 25 and the second inter-tank region 26 is equalized, preventing the thermal barrier layer 24 from lifting or being damaged. However, the first pipe 3 and the second pipe 4 may each be equipped with a filter 34 and a blower. In this case, the temperature, pressure, or supply amount of gas supplied to the first inter-tank region 25 and the second inter-tank region 26 can be independently adjusted, and the amount of gas discharged from the first inter-tank region 25 and the second inter-tank region 26 can be independently adjusted.

[0027] Valves for operating the first pipe 3 and the second pipe 4, such as flow path switching valves and flow rate adjustment valves, may be concentrated at the confluence 50 of the first pipe 3 and the second pipe 4. This allows an operator to operate the valves of the first pipe 3 and the second pipe 4 in a concentrated manner.

[0028] The first pipe 3 and the second pipe 4 have sampling devices 51 at exposed locations outside the multi-shell tank 1. The sampling device 51, for example, samples the gas discharged from the inter-tank 23 or the gas supplied to the inter-tank 23 and detects the concentration of the gas. The sampling device 51 may be disposed at the junction 50 of the first pipe 3 and the second pipe 4. By providing the sampling devices 51 on the first pipe 3 and the second pipe 4 in this manner, the concentration of the gas supplied to the inter-tank 23 or the gas exhausted from the inter-tank 23 can be detected, and the supply flow rate or exhaust flow rate can be adjusted.

[0029] 1 has a first opening 31 disposed at the bottom and in each narrow portion of the inter-tank region 23, but preferably, the first piping 3 has a plurality of first openings 31. More preferably, the plurality of first openings 31 are dispersedly disposed on a substantially horizontal circumference surrounding the first tank 21 in the first inter-tank region 25. The gas supplied from the plurality of first openings 31 arranged in an annular pattern is dispersed substantially uniformly in the first inter-tank region 25.

[0030] Fig. 4 is a diagram showing an example of the configuration of a first pipe 3 having a plurality of first openings 31 arranged in an annular shape. The first pipe 3 shown in Fig. 4 includes a ring-shaped header pipe 32 and a plurality of nozzles 33 connected to the header pipe 32 and having the first openings 31 at their tips. Furthermore, combinations of the header pipe 32 and the plurality of nozzles 33 may be provided in multiple stages in the vertical direction.

[0031] Similarly to the first pipe 3, the second pipe 4 may have a plurality of second openings 41, and the plurality of second openings 41 may be distributed and arranged on a substantially horizontal circumference surrounding the first tank 21 in the second inter-tank region 26. However, the configuration of the first pipe 3 having a plurality of first openings 31 and the configuration of the second pipe 4 having a plurality of second openings 41 are not limited to the example shown in FIG.

[0032] FIG. 5 is a diagram showing an example of the configuration of the first piping 3 having first openings 31 both above and below the first tank 21. The first piping 3 shown in FIG. 5 includes a lower first piping 3B having a first opening 31 disposed in the first inter-tank region 25 below the first tank 21, and an upper first piping 3U having a first opening 31 disposed in the first inter-tank region 25 above the first tank 21. The lower first piping 3B and the upper first piping 3U may be used simultaneously as air supply pipes. The lower first piping 3B and the upper first piping 3U may also be used simultaneously as exhaust pipes. Alternatively, one of the lower first piping 3B and the upper first piping 3U may be used as an air supply pipe and the other as an exhaust pipe. The first piping 3 used as an exhaust pipe is connected to an exhaust system outside the multi-shell tank 1. The first piping 3 used as an air supply pipe is connected to an air supply system outside the multi-shell tank 1. By switching between the supply and exhaust of the lower first piping 3B and the upper first piping 3U depending on the purpose of the supply and exhaust treatment between the tanks 23 and the characteristics of the gas, efficient supply and exhaust treatment can be achieved.

[0033] Similarly to the first piping 3, the second piping 4 includes a lower second piping 4B having a second opening 41 disposed in the second inter-tank region 26 below the first tank 21, and an upper second piping 4U having a second opening 41 disposed in the second inter-tank region 26 above the first tank 21. The lower second piping 4B and the upper second piping 4U may be used simultaneously as an air supply pipe. The lower second piping 4B and the upper second piping 4U may be used simultaneously as an exhaust pipe. Alternatively, one of the lower second piping 4B and the upper second piping 4U may be used as an air supply pipe and the other as an exhaust pipe.

[0034] [Summary] The multi-shell tank 1 according to the present disclosure comprises: a first tank 21; a second tank 22 surrounding the first tank 21; a thermal insulation layer 24 disposed between the first tank 21 and the second tank 22 in a space 23 between the first tank 21 and the second tank 22 and covering the outer wall of the first tank 21; and a first piping 3 for air supply or exhaust that has a first opening 31 disposed in a first inter-tank region 25 between the first tank 21 and the thermal insulation layer 24 in the space between the tanks 23 and extends to the outside through the space between the tanks 23.

[0035] In the multi-shell tank 1 having the above-described configuration, the first piping 3 can be used to perform at least one of air supply and exhaust in the first inter-tank region 25. By actively supplying and exhausting air in the first inter-tank region 25 between the first tank 21 and the thermal insulation layer 24 in this manner, the air supply and exhaust process in the inter-tank region 23 can be made more efficient.

[0036] The multi-shell tank 1 according to the second item of the present disclosure is the multi-shell tank 1 according to the first item, further comprising a support 71 joined to the outer wall of the first tank 21 between the tanks 23, and the first opening 31 is located in the narrow section between the first tank 21 and the support 71.

[0037] The gas flow tends to be stagnant in the narrow portion between the first tank 21 and the support 71, but the gas flow is promoted by arranging the first opening 31 in this narrow portion. As a result, the intake and exhaust process between the tanks 23 can be made more efficient.

[0038] The multi-shell tank 1 according to the third item of the present disclosure is the multi-shell tank 1 according to the first or second item, wherein the first piping 3 has a plurality of first openings 31 arranged in a circumferentially dispersed manner around the first tank 21.

[0039] By distributing the plurality of first openings 31 , the flow of supply air or exhaust air around the first tank 21 can be made uniform.

[0040] The multi-shell tank 1 according to the fourth item of the present disclosure is the multi-shell tank 1 according to any one of the first to third items, in which the tip portion 3a including the first opening 31 of the first piping 3 is supported by a first support member 36 fixed to the outer wall of the first tank 21.

[0041] In this manner, the tip portion 3a of the first pipe 3 is supported on the outer wall of the first tank 21, thereby suppressing changes in the relative positions of the first tank 21 and the first opening 31 when the first tank 21 thermally shrinks.

[0042] The multi-shell tank 1 according to the fifth aspect of the present disclosure is the multi-shell tank 1 according to the fourth aspect, wherein the first piping 3 has an expansion / contraction section 38 between the tanks 23 .

[0043] As a result, when a relative displacement occurs between the tip portion 3a supported by the first tank 21 and other portions of the first piping 3 due to the difference in the amount of thermal contraction between the first tank 21 and the second tank 22, the expansion and contraction of the expansion section 38 reduces the stress generated in the first piping 3.

[0044] The multi-shell tank 1 according to the sixth item of the present disclosure is the multi-shell tank 1 according to any one of the first to fifth items, in which the first piping 3 is supported by a second support member 37 fixed to the inner wall of the second tank 22.

[0045] In this way, the first pipe 3 is laid between the tanks 23 by utilizing the inner wall of the second tank 22, which has less thermal shrinkage than the first tank 21, and the first pipe 3 is stably supported.

[0046] The multi-shell tank 1 according to the seventh item of the present disclosure is the multi-shell tank 1 according to any one of the first to sixth items, wherein the first piping 3 has a plurality of first openings 31, and the plurality of first openings 31 include a first opening 31 arranged above the first tank 21 and a first opening 31 arranged below the first tank 21.

[0047] By using one of the first openings 31 arranged above the first tank 21 and the other of the first openings 31 arranged below the first tank 21 as an air supply port and the other as an exhaust port, it is possible to efficiently perform air supply and exhaust treatment between the tanks 23. Furthermore, if the first openings 31 arranged above the first tank 21 and the first openings 31 arranged below the first tank 21 are each able to switch between air supply and exhaust depending on the type of gas supplied to or exhausted from the tanks 23, it is possible to perform more efficient air supply and exhaust treatment.

[0048] The multi-shell tank 1 according to the eighth item of the present disclosure is the multi-shell tank 1 according to any one of the first to seventh items, further comprising a second opening 41 disposed in the second inter-tank region 26 between the thermal insulation layer 24 and the second tank 22 between the tanks 23, and a second piping 4 for air supply or exhaust extending to the outside through the tanks 23.

[0049] By supplying and / or exhausting air in each of the first inter-tank region 25 and the second inter-tank region 26 of the inter-tank region 23, the air supply and exhaust process in the inter-tank region 23 can be performed efficiently.

[0050] The multi-shell tank 1 according to the ninth item of the present disclosure is the multi-shell tank 1 according to the eighth item, wherein the first pipe 3 and the second pipe 4 have a junction 50 arranged externally.

[0051] In this manner, the first pipe 3 and the second pipe 4 are connected at the junction 50, which allows the pressure in the first inter-tank region 25 and the second inter-tank region 26 to be equalized. Furthermore, the first pipe 3 and the second pipe 4 are connected at the junction 50, which allows the supply and / or exhaust of gas between the tanks 23 to be performed using a single system.

[0052] The foregoing discussion of the present disclosure has been presented for purposes of illustration and description and is not intended to limit the present disclosure to the form disclosed herein. For example, in the foregoing detailed description, various features of the present disclosure are grouped together in a single embodiment for the purpose of streamlining the disclosure, but some of the features may also be combined. Furthermore, the features included in the present disclosure may be combined into alternative embodiments, configurations, or aspects other than those discussed above.

Claims

1. A first tank; a second tank surrounding the first tank; a thermal barrier layer disposed between the first tank and the second tank and covering an outer wall of the first tank; a first pipe for supplying or exhausting air, the first pipe having a first opening disposed in a first inter-tank region between the first tank and the thermal insulation layer and extending to the outside through the tank; Multi-hull tank.

2. A support is further provided between the tanks and connected to an outer wall of the first tank, The first opening is disposed in a narrow portion between the first tank and the support.

2. The multi-shell tank of claim 1.

3. The first pipe has a plurality of the first openings arranged in a circumferential direction around the first tank.

3. A multi-shell tank according to claim 1 or 2.

4. a tip portion of the first pipe including the first opening portion is supported by a first support member fixed to an outer wall of the first tank; 3. A multi-shell tank according to claim 1 or 2.

5. The first piping has an expansion and contraction portion between the tanks.

5. The multi-shell tank according to claim 4.

6. The first piping is supported by a second support member fixed to an inner wall of the second tank.

3. A multi-shell tank according to claim 1 or 2.

7. the first piping has a plurality of the first openings, and the plurality of the first openings include the first opening disposed above the first tank and the first opening disposed below the first tank.

3. A multi-shell tank according to claim 1 or 2.

8. The apparatus further includes a second piping for supplying or exhausting air, the second piping having a second opening disposed in a second inter-tank region between the thermal insulation layer and the second tank and extending to the outside through the tank.

3. A multi-shell tank according to claim 1 or 2.

9. The first pipe and the second pipe have a junction portion disposed on the outside.

9. The multi-shell tank of claim 8.