Vacuum-insulated liquefied gas storage tanks and ships containing them

Abstract

The present invention relates to a vacuum-insulated liquefied gas storage tank, comprising an inner tank in which liquefied gas is stored, an outer tank surrounding the inner tank, a vacuum insulation section formed between the outer tank and the inner tank and filled with an insulating material to block heat transfer, and vacuum piping disposed within the vacuum insulation section and having suction ports formed therein. Multiple suction ports can be formed along the longitudinal direction of the vacuum piping.

Description

Technical Field

[0001] The present invention relates to a vacuum-insulated liquefied gas storage tank and a ship including the same.

Background Art

[0002] Generally, liquefied gas is transported in a gaseous state through onshore or offshore gas pipelines, or stored and transported in a liquefied gas state using a storage tank. When such liquefied gas is cooled to an extremely low temperature, its volume is significantly reduced compared to when it is in a gaseous state, thus enhancing the efficiency of storage and long-distance transportation.

[0003] When external heat is transferred to the liquefied gas, the liquefied gas may vaporize, causing the pressure inside the storage tank to rise or resulting in a loss of the liquefied gas. Therefore, in order to safely and efficiently store liquefied gas, the storage tank needs to have sufficient rigidity against extremely low temperatures and high heat insulation performance so that heat transfer from the outside is blocked.

[0004] In particular, recently, liquefied hydrogen (LH2), which has been in the spotlight as an alternative energy source, has a liquefaction temperature of about -253°C, which is lower than the liquefaction temperature (about -162°C) of liquefied natural gas (LNG), a typical liquefied gas. Due to its low boiling point characteristics, it vaporizes very easily, and the boil-off rate (BOR) per unit volume can reach 10 times that of liquefied natural gas. Therefore, the storage tank for storing liquefied hydrogen is required to have better heat insulation performance than the storage tank for storing liquefied natural gas.

[0005] In order to enhance the heat insulation performance, a vacuum insulation section can be provided between the inner tank and the outer tank of the storage tank, and a vacuum-insulated storage tank is mainly selected as the storage tank. In particular, vacuum-insulated storage tanks are mainly applied to small LNG storage tanks with a high ratio of surface area to volume or liquefied hydrogen storage tanks that require a high level of heat insulation.

[0006] A vacuum-insulated storage tank consists of an inner tank for directly filling with liquefied gas, an outer tank that completely encloses the inner tank and is subjected to vacuum insulation, a vacuum insulation section formed between the inner and outer tanks, and a support structure that connects the inner and outer tanks to maintain the vacuum insulation section and to firmly support and fix the inner tank to the outer tank.

[0007] The vacuum-insulated section may be filled with powdery insulating material such as Expanded Perlite Power or Hollow Glass Microsphere, and the insulation performance of the vacuum-insulated section can be improved by creating a vacuum in the space between the insulating materials while the section is filled with insulating material.

[0008] However, when creating a vacuum in the space between the insulation materials while the tank is filled with insulation, exhaust may not occur smoothly in areas far from the vacuum pump. Therefore, the time and labor required to create a vacuum in the insulated section may increase. The larger the size of the storage tank, the more time and labor required to create a vacuum in the insulated section may increase.

[0009] Therefore, there is a need for technological development to reduce the time and effort required to create a vacuum in the vacuum-insulated section of a liquefied gas storage tank. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] This invention was derived to solve the problems of the prior art described above, and aims to reduce the time and man-hours required in the process of creating a vacuum in the vacuum insulation section of a liquefied gas storage tank by providing multiple vacuum pipes in the vacuum insulation section.

[0011] The problems that the present invention addresses are not limited to those mentioned above, and any other problems not mentioned can be clearly understood by a person of ordinary skill from the following description. [Means for solving the problem]

[0012] The vacuum-insulated liquefied gas storage tank according to the present invention includes an inner tank formed to store liquefied gas inside, an outer tank spaced apart from the inner tank and surrounding the inner tank, a vacuum insulation section formed between the outer tank and the inner tank and filled with an insulating material to block heat transfer between the outer tank and the inner tank, and vacuum piping disposed within the vacuum insulation section and having suction ports on its sides, wherein a plurality of suction ports can be formed along the longitudinal direction of the vacuum piping.

[0013] Specifically, the vacuum piping can draw gas between the insulating materials filling the vacuum insulation section into the vacuum piping through the suction port.

[0014] Specifically, it may further include a filter section that covers the intake port to prevent the heat insulating material from being discharged to the outside.

[0015] Specifically, the vacuum piping can be fixed to the outer tank and surround the inner tank.

[0016] Specifically, the vacuum piping can be fixed at a position spaced apart from the central weld line formed by welding the structures constituting the outer tank or the inner tank.

[0017] Specifically, the vacuum piping may be provided in at least two sections within the vacuum insulation section.

[0018] Specifically, the thermal insulation material may include one or more of the following: polypropylene, polyurethane, polystyrene, polyethylene, polyisocyanurate, aerogel blanket, fumed silica, calcium silicate, mineral wool, glass wool, glass microfiber, perlite, and glass bubbles.

[0019] Specifically, the system may further include a connecting portion for fixing the vacuum piping to the outer tank.

[0020] Specifically, the connecting portion can be installed at a distance from the central weld line formed by welding the structures constituting the outer tank or the inner tank.

[0021] Specifically, a support structure can be further included, which is provided between the inner tank and the outer tank and fixes the inner tank to the outer tank.

[0022] Specifically, it may be a small LNG storage tank or a liquefied hydrogen storage tank.

[0023] The present invention can include the vacuum-insulated liquefied gas storage tank.

Advantages of the Invention

[0024] The vacuum-insulated liquefied gas storage tank according to the present invention is composed of a triple structure of an inner tank, an outer tank, and a vacuum insulation section. Since the vacuum insulation section is insulated by a vacuum, heat transfer occurring between the inside and the outside of the storage tank can be limited to a minimum.

[0025] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those with ordinary knowledge from the description of the claims.

Brief Description of the Drawings

[0026] [Figure 1] It is a front view of a vacuum-insulated liquefied gas storage tank according to an embodiment of the present invention. [Figure 2] (a), (b), and (c) are diagrams showing that two, three, and four vacuum pipes are respectively arranged horizontally in a vacuum-insulated liquefied gas storage tank according to an embodiment of the present invention. [Figure 3] (a), (b), and (c) are diagrams showing that two, three, and four vacuum pipes are respectively arranged diagonally in a vacuum-insulated liquefied gas storage tank according to an embodiment of the present invention. [Figure 4](a), (b), and (c) are diagrams showing that two, three, and four vacuum pipes are arranged vertically in a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention. [Figure 5] This is a first plan view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention. [Figure 6] This is a second plan view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention. [Figure 7] This is a cross-sectional view of the vacuum piping of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention. [Figure 8] This is a cross-sectional view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention. [Figure 9] This figure shows that the vacuum piping of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention is fixed to the outer tank. [Figure 10] This figure shows multiple suction ports and filter sections formed in the vacuum piping of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention. [Modes for carrying out the invention]

[0027] In the following, when a part is described as "containing" a certain component, unless otherwise specified, this means that it may include other components, rather than excluding them.

[0028] The present invention will be described in more detail below to facilitate understanding of it.

[0029] Hereinafter, the liquefied gas storage tanks in which liquefied gas is stored may be installed on a ship, and the ship may be a liquefied gas carrier.

[0030] Hereinafter, "liquefied gas" may refer to liquefied natural gas, liquefied petroleum gas, ethane, ethanol, methanol, etc., and can mean any substance that is transported in a liquid state by cooling, has a boiling point lower than room temperature, and can evaporate into a gaseous state at room temperature. For example, "liquefied gas" may refer to liquefied natural gas or liquefied hydrogen (LH2), and "evaporated gas" may refer to BOG (Boil Off Gas), such as liquefied gas that has spontaneously vaporized. "Liquefied gas" can also refer to evaporated gas or gas in the gas phase formed by the forced vaporization of liquid-phase liquefied gas.

[0031] In the following, the term "vessel" encompasses not only container ships, merchant vessels, and ships capable of producing natural gas at sea, but also all offshore structures, including gas platforms and floating objects.

[0032] Hereinafter, the horizontal, diagonal, and vertical directions refer to the horizontal, diagonal, and vertical directions, respectively, with respect to the bottom surface on which the liquefied gas storage tank 1 is located, that is, the bottom surface on which the outer tank is supported.

[0033] Figure 1 is a front view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0034] Referring to Figure 1, a vacuum-insulated liquefied gas storage tank 1 according to one embodiment of the present invention may include an outer tank 10, an inner tank 20, a support structure 30, a fixed structure 40, a vacuum insulation section 50, pump piping 60, a vacuum pump 70, and a dome 80.

[0035] The liquefied gas storage tank 1 can store liquefied gases such as liquefied hydrogen (LH2) and liquefied natural gas (LNG), and may include a configuration that isolates it from heat transfer to the outside in order to maintain the liquefied gas in an extremely low temperature state. The liquefied gas storage tank 1 is a pressure tank and may be a tank manufactured to withstand the increase in pressure even if the internal pressure of the tank increases due to the evaporation gas (BOG: Boil-Off Gas) generated when the liquefied gas stored inside the tank vaporizes.

[0036] The liquefied gas storage tank 1 may be a membrane type, where the tank is located inside the ship, or an independent type, where it exists independently and is not integrated with the hull. Specifically, the liquefied gas storage tank 1 may be a Moss type, cylindrical type, or bi-lobe type tank. Preferably, the liquefied gas storage tank 1 is a Moss type tank, where a spherical tank is installed at the upper end of the hull. Multiple Moss type liquefied gas storage tanks 1 can be arranged along the longitudinal direction of the ship, and the upper ends of the liquefied gas storage tanks 1 can protrude from the top of the ship. However, the present invention is not limited by the form or type of the liquefied gas storage tank 1.

[0037] The liquefied gas storage tank 1 has a double-walled structure in which an outer tank 10 surrounds an inner tank 20. Between the outer tank 10 and the inner tank 20, there is a support structure 30 for separating the outer tank 10 and the inner tank 20 and fixing the inner tank 20 to the outer tank 10. In addition, the outer tank 10 of the liquefied gas storage tank 1 is equipped with a fixing structure 40 that can withstand the entire load of the liquefied gas storage tank 1 and fix the liquefied gas storage tank 1 to an external structure such as a ship.

[0038] The outer tank 10 constitutes the exterior of the liquefied gas storage tank 1, withstands shocks transmitted from outside the liquefied gas storage tank 1, and can share the pressure generated by the liquefied gas stored in the inner tank 20 with the inner tank 20. The outer tank 10 is preferably made of steel in order to withstand stresses or loads transmitted from both the inside and outside.

[0039] The inner tank 20 can be fixed to the outer tank 10 at a predetermined distance from the outer tank 10. The inner tank 20 has a space formed inside for storing liquefied gas. Since the inner tank 20 is in direct contact with the liquefied gas, it can be manufactured from a metal with excellent low-temperature properties that can withstand the extremely low temperatures of the liquefied gas. Preferably, the inner tank 20 can be manufactured from aluminum (Al), aluminum alloy material, or stainless steel material.

[0040] The outer tank 10 and the inner tank 20 are preferably spherical or cylindrical in shape so that the stress or load generated by the liquefied gas stored inside the inner tank 20 is uniformly distributed and transmitted to the liquefied gas storage tank 1.

[0041] Multiple support structures 30 can be installed between the double-walled outer tank 10 and inner tank 20, and in particular, they can be installed on the underside of the liquefied hydrogen storage tank 1 to support the bottom surface of the inner tank 20. The support structures 30 can fix the inner tank 20 to the outer tank 10. Since the support structures 30 are in contact with the inner tank 20, their temperature may drop to extremely low temperatures. Therefore, the support structures 30 can be manufactured from materials that can withstand extremely low temperatures, such as wood, stainless steel (SUS), PTFE (polytetrafluoroethylene), or bakelite.

[0042] The support structure 30 can be formed from multiple layers and can act as a medium for heat transfer between the outer tank 10 and the inner tank 20, so it can contain materials with low thermal conductivity. The support structure 30 can also contain elastic materials, as it may crack or break when the outer tank 10 and the inner tank 20 deform due to thermal contraction and thermal expansion.

[0043] The fixed structure 40 supports the entire load of the liquefied hydrogen storage tank 1 by fixing the liquefied gas storage tank 1 to an external structure such as a ship and supporting the outer tank 10. The fixed structure 40 can have a shape that corresponds to the bottom surface of the outer tank 10 so that the liquefied gas storage tank 1 can be placed on it. For example, if the bottom surface of the outer tank 10 is circular, the fixed structure 40 can have a concave shape that can support the circular outer tank 10.

[0044] The fixed structure 40 can be made of steel to withstand the load of the liquefied gas storage tank 1, but the present invention is not limited thereto. The fixed structure 40 is preferably made of a metal material with excellent low-temperature properties in case of liquefied gas leakage, and the metal material with excellent low-temperature properties may be any one of stainless steel, aluminum, or aluminum alloy.

[0045] A vacuum insulation section 50 may be provided between the outer tank 10 and the inner tank 20. The vacuum insulation section 50 can maintain a vacuum state. The vacuum insulation section 50 can block heat transfer between the outer tank 10 and the inner tank 20 by conduction or convection.

[0046] At the bottom of the liquefied gas storage tank 1, pump piping 60 and a vacuum pump 70 can be provided to create a vacuum in the vacuum insulation section 50. One end of the pump piping 60 can be connected to the vacuum insulation section 50, and the other end can be connected to the vacuum pump 70. When the vacuum pump 70 is in operation, the gas contained in the vacuum insulation section 50 is exhausted to the outside, and the vacuum insulation section 50 can be created into a vacuum.

[0047] Furthermore, although not shown in the drawings, monitoring means for checking the vacuum level of the vacuum insulation section 50 may be provided.

[0048] The vacuum insulation section 50 can be filled with an insulating material. The insulating material may be an organic insulating material such as polypropylene, polyurethane, polystyrene, polyethylene, or polyisocyanurate. Alternatively, it may be an inorganic insulating material such as aerogel blanket, fumed silica, calcium silicate, mineral wool, glass wool, glass microfiber material, or perlite, or a hybrid material of organic and inorganic insulating materials.

[0049] Preferably, the insulation material may be a powdered insulation material such as perlite and glass bubbles, for example, Expanded Perlite Power or Hollow Glass Microsphere.

[0050] With the vacuum insulation section 50 filled with insulation material, the gas between the insulation materials can be evacuated, and the vacuum insulation section 50 can be made into a vacuum. Here, the degree of vacuum is approximately 10 -5 It can become ~1 Torr.

[0051] An opening can be formed on the upper surface of the liquefied gas storage tank 1. The opening is connected to a dome 80, which can discharge liquefied gas to the outside of the liquefied gas storage tank 1. Various types of piping (not shown) can be provided in the dome 80, and the piping extends to the bottom of the liquefied gas storage tank 1 and is submerged in the inner tank, where a pump (not shown) can discharge the liquefied gas to the outside along the piping. Insulation material can be supplied to the vacuum insulation section 50 via the dome 80.

[0052] If the liquefied gas storage tank 1 is large, or if the vacuum level is further increased to improve insulation performance, it will take longer to create a vacuum in the vacuum insulation section 50, and the labor involved in this process will also increase. Furthermore, if insulation material is filled in the vacuum insulation section 50 to improve its insulation performance, the effort required to create a vacuum in the vacuum insulation section 50 may become even greater.

[0053] Therefore, the vacuum-insulated liquefied gas storage tank 1 of the present invention further includes vacuum piping 100, which minimizes the time and effort required to bring the vacuum insulation section 50 into a vacuum state. The vacuum piping 100 will be described in detail below.

[0054] Figures 2(a), 2(b), and 2(c) show two, three, and four vacuum pipes, respectively, arranged horizontally in a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0055] Figures 3(a), 3(b), and 3(c) show that two, three, and four vacuum pipes, respectively, are arranged diagonally in a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0056] Figures 4(a), 4(b), and 4(c) show two, three, and four vacuum pipes, respectively, arranged vertically in a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0057] Descriptions that overlap with Figure 1 will be omitted below, and the added configurations will be described in detail.

[0058] Referring to Figure 2, the vacuum insulation section 50 of the liquefied gas storage tank 1 may include one or more vacuum pipes 100.

[0059] In Figure 2, the vacuum piping 100 appears to be straight, but it surrounds the inner tank 20. Since the vacuum insulation section 50 is filled with insulation material, the vacuum piping 100 may be embedded in the insulation material.

[0060] A suction port 110 and a plug 120 can be formed on the side of the vacuum piping 100. The suction port 110 can be used as a passage for gas to be drawn in between the insulating materials, and the plug 120 can be connected to the pump piping 60 and the vacuum pump 70. When the vacuum pump 70 is in operation, the gas between the insulating materials can be drawn into the vacuum piping 100 through the suction port 110 and discharged to the outside. In this process, the vacuum insulation section 50 can be brought into a vacuum state.

[0061] Referring to Figure 2, one or more, preferably two or more, vacuum pipes 100 can be arranged here. Figure 2(a) shows two vacuum pipes 100 arranged, Figure 2(b) shows three vacuum pipes 100 arranged, and Figure 2(c) shows four vacuum pipes 100 arranged. However, the present invention is not limited by the number of vacuum pipes 100 arranged.

[0062] Numerous vacuum pipes 100 can be arranged in the vacuum insulation section 50 and widely distributed within it. Furthermore, numerous suction ports 110 can be formed along the longitudinal direction of the vacuum pipes 100. This ensures that no points far from the suction ports 110 occur within the vacuum insulation section 50. Additionally, the suction ports 110 can be formed in various directions along the vacuum pipes 100, allowing suction to occur at various locations surrounding the vacuum pipes 100.

[0063] In particular, the vacuum piping 100 can be arranged at uniform intervals (characteristic length, lc). This allows for increased exhaust efficiency through the vacuum piping 100.

[0064] On the other hand, referring to Figure 2(b), the outer tank 10 and the inner tank 20 may be joined by welding hemispherical structures together. In this case, a central weld line 90 can be formed at the midpoint between the heights of the outer tank 10 and the inner tank 20, but it is not necessarily limited to this. For example, the central weld line 90 can extend in various directions. If the vacuum piping 100 is fixed to the outer tank 10 at the same position as the central weld line 90, the structural stability of the liquefied gas storage tank 1 and the fixing force of the vacuum piping 100 may decrease. Therefore, it is preferable that the vacuum piping 100 be fixed at a distance from each other so as not to overlap with the central weld line 90.

[0065] Referring to Figure 2, the vacuum piping 100 can be arranged horizontally. Referring to Figure 3, the vacuum piping 100 can be arranged diagonally, and referring to Figure 4, the vacuum piping 100 can be arranged vertically.

[0066] As shown in Figure 3 or Figure 4, when the vacuum piping 100 is arranged diagonally or vertically, the plug 120 can be formed adjacent to the central weld line 90, or near the central weld line 90 (near the deck). The plug 120 can be formed within approximately 10 m vertically from the central weld line 90, preferably within 2 m. This allows the worker to easily connect the pump piping 60 to the plug 120 without using other tools. In other words, when the vacuum piping 100 is arranged diagonally or vertically, the worker can connect the pump piping 60 to the vacuum piping 100 near the deck, thereby increasing the worker's work efficiency.

[0067] Figure 5 is a first plan view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0068] Figure 6 is a second plan view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0069] Figures 5 and 6 show cross-sections of the liquefied gas storage tank 1 at different heights. Since the outer tank 10 and the inner tank 20 each have a spherical shape, the cross-sections of the outer tank 10 and the inner tank 20 are circular in shape. The circle can have its maximum diameter at the middle height of the liquefied gas storage tank 1. Figure 5 shows that the diameter of the cross-section is smaller than the diameter of the cross-section in Figure 6, and Figure 5 shows a cross-section at a position further away from the center (middle height) of the liquefied gas storage tank 1 compared to Figure 6.

[0070] Referring to Figures 5 and 6, a vacuum piping 100 can be provided in the vacuum insulation section 50 between the outer tank 10 and the inner tank 20. Multiple vacuum pipes 100 can be provided; for example, multiple vacuum pipes 100 may be provided according to height as shown in Figures 5 and 6, or alternatively, multiple vacuum pipes 100 may be provided at the same height from the inner tank 20 towards the outer tank 10. However, the present invention is not limited thereto.

[0071] The first vacuum pipe 100a can surround the inner tank 20, and the second vacuum pipe 100b can surround the inner tank 20. When the first vacuum pipe 100a and the second vacuum pipe 100b are installed in the height direction or from the inner tank 20 to the outer tank 10 direction, it is preferable that the first vacuum pipe 100a and the second vacuum pipe 100b are installed at an appropriate distance from each other in order to create a vacuum over the entire liquefied gas storage tank 1.

[0072] Furthermore, the first vacuum pipe 100a and the second vacuum pipe 100b can be spaced the same distance from each other within the vacuum insulation section 50, and the distance from the outer tank 10 to the first vacuum pipe 100a and the distance from the inner tank 20 to the first vacuum pipe 100a may be the same or different from each other. Similarly, the distance from the outer tank 10 to the second vacuum pipe 100b and the distance from the inner tank 20 to the second vacuum pipe 100b may be the same or different from each other. In other words, the first vacuum pipe 100a and the second vacuum pipe 100b can be positioned close to the outer tank 10 or close to the inner tank 20, respectively, within the vacuum insulation section 50.

[0073] The first vacuum pipe 100a may be equipped with a first suction port 110a and can be fixed to the outer tank 10 by a first connecting portion 11a. Similarly, the second vacuum pipe 100b may be equipped with a second suction port 110b and can be fixed to the outer tank 10 by a second connecting portion 11b. The first vacuum pipe 100a and the second vacuum pipe 100b are equipped with plugs 120, and pump piping 60 is connected to the plugs 120, allowing gas from inside the vacuum insulation section 50 to be drawn in through the first suction port 110a and the second suction port 110b.

[0074] Figure 7 is a cross-sectional view of the vacuum piping of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0075] Referring to Figure 7, the vacuum piping 100 may include a suction port 110 formed on its side (width direction) and a filter section 111 that covers the suction port 110.

[0076] The vacuum piping 100 is connected to the pump piping 60 via the plug 120, and when the vacuum pump 70 is operating, the internal gas of the vacuum insulation section 50 can be drawn into the vacuum piping 100 via the suction port 110 and exhausted to the outside.

[0077] Here, since the vacuum insulation section 50 is filled with an insulating material such as powder, when the vacuum pump 70 is in operation, the insulating material can be drawn into the suction port 110 and transmitted to the vacuum pump 70 along the vacuum piping 100.

[0078] If the insulation material is transmitted to the vacuum pump 70 through the suction port 110, the vacuum performance of the vacuum pump 70 will decrease, potentially causing fatal damage to the vacuum pump 70. Therefore, to prevent the insulation material from flowing into the vacuum pump 70 while the vacuum insulation section 50 is under vacuum through the suction port 110, the suction port 110 can be covered with a filter section 111.

[0079] The filter section 111 has a porous structure such as a mesh, and the filter section 111 can be arranged in multiple layers to enhance the filtering effect of the heat insulating material. For example, the filter section 111 may be in the form of multiple layers of mesh made of metal or filters made of pulp material stacked on top of each other.

[0080] The holes formed in the filter section 111 itself, or the holes formed in the filter section 111 while multiple layers of the filter section 111 are stacked, may have a diameter smaller than the particle size of the insulating material in order to prevent the insulating material from flowing into the intake port 110. The filter section 111 can be made of various materials other than the aforementioned material and can be manufactured in various sizes or forms, but the present invention is not limited thereto.

[0081] The filter section 111 can cover only the area where the suction port 110 is formed, and can cover the area where the suction port 110 is formed while enclosing the entire vacuum piping 100. However, the present invention is not limited thereto.

[0082] Figure 8 is a cross-sectional view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0083] Figure 9 shows that the vacuum piping of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention is fixed to the outer tank.

[0084] Referring to Figures 8 and 9, the vacuum piping 100 can be fixed to the outer tank 10 by the connecting portion 11. Since the connecting portion 11 is provided in the vacuum insulation portion 50, the connecting portion 11 can receive cold and heat transfer from the inner tank 20 and its temperature can decrease. Therefore, the connecting portion 11 is made of a material that can withstand low temperatures and can be manufactured from wood, SUS, PTFE (polytetrafluoroethylene), or bakelite.

[0085] However, if the connecting section 11 is installed on the central weld line 90 of the outer tank, the structural stability of the liquefied gas storage tank 1 and the fixing force of the vacuum piping 100 may decrease. For this reason, it is preferable that the vacuum piping 100 be installed spaced apart from each other so as not to overlap with the central weld line 90.

[0086] Thus, the vacuum-insulated liquefied gas storage tank 1 according to the present invention solves the problem that exhaust performance deteriorates the further away from the suction port 110 is, by widely distributing the vacuum piping 100 and the suction ports 110 formed in the vacuum piping 100 in the vacuum insulation section 50 and reducing the distance from the suction ports 110 to each point in the vacuum insulation section 50.

[0087] Furthermore, by ensuring that the vacuum piping 100 is fixed to the outer tank 10 at a distance from the central weld line 90, it is possible to prevent a decrease in the structural stability of the liquefied gas storage tank 1 and the fixing force of the vacuum piping 100.

[0088] Furthermore, when the vacuum piping 100 is arranged diagonally or vertically, the plug 120 of the vacuum piping 100 is positioned near the deck, making it easier for the operator to connect the pump piping 60 to the plug 120.

[0089] Figure 10 shows a plurality of suction ports and filter sections formed in the vacuum piping of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0090] Referring to Figure 10, multiple suction ports 110 can be formed along the longitudinal direction of the vacuum piping 100. The vacuum piping 100 is placed inside the vacuum insulation section 50, and multiple suction ports 110 can be formed on its side.

[0091] The vacuum piping 100 can draw gas into the interior from between the insulating materials in multiple regions within the vacuum insulation section 50 via multiple suction ports 110. The vacuum piping 100 can simultaneously draw gas into multiple regions within the vacuum insulation section 50 via multiple suction ports 110.

[0092] Multiple filter units 111 can be arranged in multiple suction ports 110.

[0093] The present invention is not limited to the embodiments described above, and it goes without saying that other embodiments may include combinations of the embodiments or combinations of at least one of the embodiments with known technologies.

[0094] Although the present invention has been described in detail above with reference to specific embodiments, this is for the purpose of specifically illustrating the present invention, and it goes without saying that the present invention is not limited thereto, and that modifications and improvements can be made within the technical concept of the present invention by those with ordinary skill in the art.

[0095] Any simple modification or alteration of the present invention falls within the scope of the present invention, and the specific scope of protection of the present invention is clarified by the appended claims. [Explanation of Symbols]

[0096] 1. Liquefied gas storage tank 10 Outer tank 11 Connecting part 20 Inner tank 30 Support structure 40 Fixed structure 50 Vacuum insulation section 60 Pump Piping 70 Vacuum pump 80 Domes 90 Central weld line 100 Vacuum piping 110 Inlet 111 Filter section 120 plug

Claims

1. An inner tank formed to store liquefied gas inside, An outer tank that surrounds the inner tank and is separated from it, A vacuum insulation section is formed between the outer tank and the inner tank, and is filled with insulating material to block heat transfer between the outer tank and the inner tank. The vacuum piping is disposed within the vacuum insulation section and has a suction port formed on its side, The aforementioned suction port is A vacuum-insulated liquefied gas storage tank, of which multiple tanks are formed along the longitudinal direction of the vacuum piping.

2. The aforementioned vacuum piping is The vacuum-insulated liquefied gas storage tank according to claim 1, wherein the gas between the insulating materials filling the vacuum insulation section is drawn into the vacuum piping via the suction port.

3. The vacuum-insulated liquefied gas storage tank according to claim 2, further comprising a filter section that covers the intake port to prevent the insulating material from being discharged to the outside.

4. The aforementioned vacuum piping is A vacuum-insulated liquefied gas storage tank according to claim 1, fixed to the outer tank and surrounding the inner tank.

5. The aforementioned vacuum piping is The vacuum-insulated liquefied gas storage tank according to claim 1, wherein the structure constituting the outer tank or the inner tank is fixed at a position spaced apart from the central weld line formed by welding.

6. The aforementioned vacuum piping is The vacuum-insulated liquefied gas storage tank according to claim 1, wherein at least two or more vacuum insulation sections are provided.

7. The aforementioned insulating material is A vacuum-insulated liquefied gas storage tank according to claim 1, comprising one or more of the following: polypropylene, polyurethane, polystyrene, polyethylene, polyisocyanurate, aerogel blanket, fumed silica, calcium silicate, mineral wool, glass wool, glass microfiber, perlite, and glass bubbles.

8. The vacuum-insulated liquefied gas storage tank according to claim 1, further comprising a connecting portion for fixing the vacuum piping to the outer tank.

9. The aforementioned connecting portion is The vacuum-insulated liquefied gas storage tank according to claim 8, which is installed at a distance from the central weld line formed by welding the structures constituting the outer tank or the inner tank.

10. The vacuum-insulated liquefied gas storage tank according to claim 1, further comprising a support structure provided between the inner tank and the outer tank for fixing the inner tank to the outer tank.

11. A vacuum-insulated liquefied gas storage tank according to claim 1, which is a small LNG storage tank or a liquefied hydrogen storage tank.

12. A ship comprising the vacuum-insulated liquefied gas storage tank according to any one of claims 1 to 11.

Images