Vacuum insulated liquerfied gas storage tank and ship comprising same

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 which surrounds the inner tank; a vacuum insulation part which is formed between the outer tank and the inner tank and is filled with an insulating material to block heat transfer; and a vacuum pipe which is disposed within the vacuum insulation part and has an intake port formed, wherein the intake port may have a plurality of intake ports formed along the lengthwise direction of the vacuum pipe.

Description

Vacuum-insulated liquefied gas storage tank and vessel containing the same

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

[0002] Typically, liquefied gas is transported in its gaseous state through onshore or offshore gas pipelines, or stored in storage tanks for transport. Cooling this liquefied gas to cryogenic temperatures significantly reduces its volume compared to its gaseous state, making it more efficient for storage and long-distance transportation.

[0003] If external heat is transferred to liquefied gas, the liquefied gas may vaporize, increasing the pressure within the storage tank or causing loss of liquefied gas. Therefore, to safely and efficiently store liquefied gas, the storage tank must be sufficiently rigid to withstand extremely low temperatures and possess high insulation to block external heat transfer.

[0004] In particular, liquefied hydrogen (LH2), which has recently been in the spotlight as an alternative energy source, has a low boiling point with a liquefaction temperature of approximately -253℃, which is lower than that of liquefied natural gas (LNG) (approximately -162℃), so it vaporizes very easily, and its boil-off rate (BOR) per volume is 10 times that of liquefied natural gas. Therefore, storage tanks for storing liquefied hydrogen require better insulation performance than storage tanks for storing liquefied natural gas.

[0005] Storage tanks can be equipped with vacuum insulation between the inner and outer tanks to enhance insulation. Vacuum-insulated storage tanks are the most commonly selected storage tanks. In particular, vacuum-insulated storage tanks are primarily used for small LNG storage tanks with a high surface area-to-volume ratio or for liquefied hydrogen storage tanks requiring a high level of insulation.

[0006] A vacuum insulated storage tank is composed of an inner tank for directly storing liquefied gas, an outer tank for vacuum insulation that completely surrounds the inner tank, a vacuum insulation portion formed between the inner tank and the outer tank, and a support structure connecting the inner tank and the outer tank for the purpose of maintaining the vacuum insulation portion and firmly supporting and fixing the inner tank to the outer tank.

[0007] The vacuum insulation part can be filled with powder-type insulation materials such as Expanded Perlite Power and Hollow Glass Microsphere, and the insulation performance of the vacuum insulation part can be improved through a process of creating a vacuum in the space between the insulation materials while the insulation material is filled.

[0008] However, when creating a vacuum between the insulation layers while the insulation is filled, exhaust may not proceed smoothly if the space is far from the vacuum pump that creates the vacuum. Therefore, the time and effort required to create a vacuum in the vacuum insulation may increase. As the storage tank size increases, the time and effort required to create a vacuum in the vacuum insulation may also increase.

[0009] Therefore, technological development is necessary to reduce the time and labor required to create a vacuum in the vacuum insulation section of a liquefied gas storage tank.

[0010] The present invention was created to solve the problems of the prior art as described above, and the purpose of the present invention is to reduce the time and man-hours required for the process of making the vacuum insulation part into a vacuum by providing a plurality of vacuum pipes in the vacuum insulation part of a liquefied gas storage tank.

[0011] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those of ordinary skill in the art from the description below.

[0012] A vacuum-insulated liquefied gas storage tank according to the present invention comprises: an inner tank in which liquefied gas is stored; an outer tank spaced apart from the inner tank and surrounding the inner tank; a vacuum insulation part 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 a vacuum pipe disposed within the vacuum insulation part and having a suction port formed on a side thereof; wherein a plurality of the suction ports may be formed along the length direction of the vacuum pipe.

[0013] Specifically, the vacuum pipe can suck gas between the insulating materials filled in the vacuum insulation section into the vacuum pipe through the suction port.

[0014] Specifically, it may further include a filter unit that covers the suction port and prevents the insulation from being discharged to the outside.

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

[0016] Specifically, the vacuum pipe can be fixed at a position spaced apart from the central welding line formed when the structure constituting the outer tank or the inner tank is welded.

[0017] Specifically, at least two of the above vacuum pipes may be provided in the vacuum insulation section.

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

[0019] Specifically, the vacuum pipe may further include a connecting member for fixing the vacuum pipe to the outer tank.

[0020] Specifically, the connecting portion may be installed spaced apart from the central welding line formed when the structure constituting the outer shell or the inner shell is welded.

[0021] Specifically, the present invention may further include a support structure provided between the inner and outer parts to secure the inner parts to the outer parts.

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

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

[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, and the vacuum insulation section is insulated by vacuum, so that heat transfer between the inside and 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 will be clearly understood by those skilled in the art from the description of the claims.

[0026] FIG. 1 is a front view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0027] FIG. 2(a), FIG. 2(b), and FIG. 2(c) are drawings showing two, three, and four vacuum pipes arranged horizontally, respectively, in a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0028] FIG. 3(a), FIG. 3(b), and FIG. 3(c) are drawings showing two, three, and four vacuum pipes arranged diagonally, respectively, in a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0029] FIG. 4(a), FIG. 4(b), and FIG. 4(c) are drawings showing two, three, and four vacuum pipes arranged vertically, respectively, in a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0030] FIG. 5 is a first plan view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0031] Figure 6 is a second plan view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0032] Figure 7 is a cross-sectional view of a vacuum pipe of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0033] Figure 8 is a cross-sectional view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0034] FIG. 9 is a drawing showing a vacuum pipe of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention being fixed to an outer tank.

[0035] FIG. 10 is a drawing showing a plurality of suction ports and filter sections formed in a vacuum pipe of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0036] Hereinafter, when a part is said to "include" a certain component, this means that it may include other components, rather than excluding other components, unless otherwise specifically stated.

[0037] Hereinafter, the present invention will be described in more detail to facilitate understanding of the present invention.

[0038] Hereinafter, a liquefied gas storage tank in which liquefied gas is stored may be installed on a ship, and the ship may be a liquefied gas carrier.

[0039] Hereinafter, liquefied gas may be liquefied natural gas, liquefied petroleum gas, ethane, ethanol, methanol, etc., and may refer to any substance that is transported in a liquid state by refrigeration but has a boiling point lower than room temperature and can evaporate into a gaseous state at room temperature. Liquefied gas may refer to liquefied natural gas or liquefied hydrogen (LH2), for example, and boil-off gas may refer to BOG (Boil Off Gas), which is naturally vaporized liquefied gas, etc. Liquefied gas may refer to a gaseous gas formed by forced vaporization of boil-off gas or liquid liquefied gas.

[0040] Hereinafter, the term "ship" is used to refer to all marine structures, including container ships, merchant ships, ships capable of producing natural gas at sea, and gas platforms and floating structures.

[0041] Hereinafter, the horizontal direction, diagonal direction and vertical direction mean the horizontal direction, diagonal direction and vertical direction, respectively, based on the bottom surface on which the liquefied gas storage tank (1) is placed, i.e., the bottom surface on which the outer tank is supported.

[0042] FIG. 1 is a front view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0043] Referring to FIG. 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 part (50), a pump pipe (60), a vacuum pump (70), and a dome (80).

[0044] A liquefied gas storage tank (1) can store liquefied gases such as liquefied hydrogen (LH2) and liquefied natural gas (LNG), and may include a configuration in which heat transfer with the outside is blocked to maintain the liquefied gas in an extremely low temperature state. The liquefied gas storage tank (1) may be a pressure tank manufactured to withstand pressure increase even when the internal pressure of the tank increases due to boil-off gas (BOG) generated when the liquefied gas stored inside the tank vaporizes.

[0045] The liquefied gas storage tank (1) may be a membrane type in which the tank is placed inside the ship, or an independent type in which the tank exists independently without being integrally formed with the hull. Specifically, the liquefied gas storage tank (1) may be a Moss type, a cylindrical type, a bi-lobe type, etc. The liquefied gas storage tank (1) is preferably a Moss type tank in which a spherical tank is installed on the upper part of the hull, and a plurality of Moss type liquefied gas storage tanks (1) may be placed along the longitudinal direction of the ship, and the upper part of the liquefied gas storage tank (1) may protrude toward the upper part of the ship. However, the present invention is not limited by the shape or type of the liquefied gas storage tank (1).

[0046] A liquefied gas storage tank (1) has a double structure in which an outer tank (10) surrounds an inner tank (20), and a support structure (30) is provided between the outer tank (10) and the inner tank (20) to separate the outer tank (10) and the inner tank (20) and to fix the inner tank (20) to the outer tank (10). In addition, a fixing structure (40) is provided on the outer tank (10) of the liquefied gas storage tank (1) to withstand the entire load of the liquefied gas storage tank (1) and to fix the liquefied gas storage tank (1) to an external structure such as a ship.

[0047] The outer tank (10) constitutes the exterior of the liquefied gas storage tank (1) and can withstand impact transmitted from the outside of the liquefied gas storage tank (1) and 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 to withstand stress or load transmitted from the inside and outside.

[0048] The inner tank (20) may be fixed to the outer tank (10) at a certain distance from the outer tank (10). The inner tank (20) has a space formed inside for storing liquefied gas. Since the inner tank (20) comes into direct contact with the liquefied gas, it may 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) may be manufactured from aluminum (Al), an aluminum alloy material, or stainless steel.

[0049] It is preferable that the outer tank (10) and the inner tank (20) have a spherical or cylindrical shape so that the stress or load generated by the liquefied gas stored inside the inner tank (20) is evenly distributed and transmitted to the liquefied gas storage tank (1).

[0050] A plurality of support structures (30) may be installed between the double structure of the outer tank (10) and the inner tank (20), and in particular, may be installed on the lower side of the liquid hydrogen storage tank (1) to support the bottom surface of the inner tank (20). The support structures (30) may fix the inner tank (20) to the outer tank (10). Since the support structures (30) are in contact with the inner tank (20), the temperature may drop to extremely low temperatures. Therefore, the support structures (30) may be made of a material that can withstand extremely low temperatures, such as wood, SUS, PTFE (polytetrafluoroethylene), or bakelite.

[0051] The support structure (30) can be formed of multiple layers, and can include a material with low thermal conductivity because it can serve as a medium for heat transfer between the outer shell (10) and the inner shell (20), and the support structure (30) can include an elastic material because cracks can occur or be damaged when the outer shell (10) and the inner shell (20) are deformed due to thermal shrinkage and thermal expansion.

[0052] The fixed structure (40) fixes the liquefied gas storage tank (1) to an external structure such as a ship and supports the outer tank (10) to support the entire load of the liquefied hydrogen storage tank (1). The fixed structure (40) may have a shape corresponding to the bottom surface of the outer tank (10) so that the liquefied gas storage tank (1) can be installed. For example, when the outer tank (10) has a circular bottom surface, the fixed structure (40) may have a concave shape capable of supporting the circular outer tank (10).

[0053] The fixed structure (40) may be manufactured from a steel material 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 manufactured from a metal material with excellent low-temperature properties to prepare for cases where the liquefied gas leaks, and the metal material with excellent low-temperature properties may be any one of stainless steel, aluminum, and an aluminum alloy.

[0054] A vacuum insulation part (50) may be provided between the outer tank (10) and the inner tank (20). The vacuum insulation part (50) may maintain a vacuum state. The vacuum insulation part (50) may block heat transfer by conduction or convection between the outer tank (10) and the inner tank (20).

[0055] A pump pipe (60) and a vacuum pump (70) for creating a vacuum state in the vacuum insulation section (50) may be provided at the bottom of the liquefied gas storage tank (1). One end of the pump pipe (60) may be connected to the vacuum insulation section (50), and the other end may be connected to the vacuum pump (70). When the vacuum pump (70) is operated, the gas contained in the vacuum insulation section (50) is exhausted to the outside, thereby creating a vacuum state in the vacuum insulation section (50).

[0056] Additionally, although not shown in the drawing, a monitoring means for checking the vacuum level of the vacuum insulation unit (50) may be provided.

[0057] The vacuum insulation unit (50) may be filled with an insulating material. The insulating material may be an organic insulating material such as polypropylene, polyurethane, polystyrene, polyethylene, or polyisocyanurate. In addition, the insulating material may be an inorganic insulating material such as an aerogel blanket, fumed silica, calcium silicate, mineral wool, glass wool, glass microfiber material, or perlite, and may be a hybrid material of an organic insulating material and an inorganic insulating material.

[0058] Preferably, the insulation material may be a powder-type insulation material such as perlite and glass bubbles as the core material, for example, Expanded Perlite Power, Hollow Glass Microsphere.

[0059] When the vacuum insulation part (50) is filled with insulation, the gases between the insulation materials are exhausted so that the vacuum insulation part (50) can be in a vacuum state. At this time, the vacuum level is about 10 -5 It can be up to 1 Torr.

[0060] An opening may be formed on the upper surface of the liquefied gas storage tank (1). The opening is connected to a dome (80), and the dome (80) can discharge the liquefied gas to the outside of the liquefied gas storage tank (1). Various pipes (not shown) may be provided in the dome (80), and the pipes may extend to the lower side of the liquefied gas storage tank (1), and the liquefied gas may be discharged to the outside along the pipes by a pump (not shown) provided in a submerged form in the inner tank. The insulation may be supplied to the vacuum insulation unit (50) through the dome (80).

[0061] If the liquefied gas storage tank (1) is large or the vacuum level is increased to enhance insulation performance, it takes longer to create a vacuum in the vacuum insulation section (50), and the man-hours required for this process also increase. Furthermore, if insulation material is filled to enhance the insulation performance of the vacuum insulation section (50), the effort required to create a vacuum in the vacuum insulation section (50) may also increase.

[0062] Therefore, the vacuum-insulated liquefied gas storage tank (1) of the present invention additionally includes a vacuum pipe (100), thereby minimizing the time and labor required to create a vacuum state in the vacuum insulation section (50). The vacuum pipe (100) will be described in detail below.

[0063] FIG. 2(a), FIG. 2(b), and FIG. 2(c) are drawings showing two, three, and four vacuum pipes arranged horizontally, respectively, in a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0064] FIG. 3(a), FIG. 3(b), and FIG. 3(c) are drawings showing two, three, and four vacuum pipes arranged diagonally, respectively, in a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0065] FIG. 4(a), FIG. 4(b), and FIG. 4(c) are drawings showing two, three, and four vacuum pipes arranged vertically, respectively, in a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0066] Descriptions that overlap with those in Fig. 1 are omitted below, and the added configurations are described in detail.

[0067] Referring to FIG. 2, the vacuum insulation section (50) of the liquefied gas storage tank (1) may include one or more vacuum pipes (100).

[0068] In Fig. 2, the vacuum pipe (100) appears to be straight, but the vacuum pipe (100) surrounds the inner chamber (20). Since the vacuum insulation portion (50) is filled with insulation, the vacuum pipe (100) may be buried in the insulation.

[0069] A suction port (110) and a plug (120) may be formed on the side of the vacuum pipe (100). The suction port (110) may be used as a passage through which gas between the insulating materials is sucked, and the plug (120) may be connected to a pump pipe (60) and a vacuum pump (70), and when the vacuum pump (70) is operated, the gas between the insulating materials may be sucked into the vacuum pipe (100) through the suction port (110) and discharged to the outside. During this process, the vacuum insulation part (50) may be in a vacuum state.

[0070] Referring to Fig. 2, at this time, one or more vacuum pipes (100) may be arranged, preferably two or more. Fig. 2(a) shows that two vacuum pipes (100) are arranged, Fig. 2(b) shows that three vacuum pipes (100) are arranged, and Fig. 2(c) shows that four vacuum pipes (100) are arranged. However, the present invention is not limited by the number of vacuum pipes (100) arranged.

[0071] The vacuum pipe (100) may be arranged in multiple locations on the vacuum insulation unit (50) so as to be widely distributed in the vacuum insulation unit (50). In addition, the suction ports (110) may be formed in multiple locations along the length of the vacuum pipe (100). Accordingly, points far from the suction ports (110) may not be created within the vacuum insulation unit (50). In addition, the suction ports (110) may be formed in various directions on the vacuum pipe (100), so that suction may occur at various locations surrounding the vacuum pipe (100).

[0072] In particular, the vacuum pipes (100) can be arranged at uniform intervals (characteristic length, lc). Accordingly, the exhaust efficiency through the vacuum pipes (100) can be increased.

[0073] Meanwhile, referring to Fig. 2(b), the outer tank (10) and the inner tank (20) may be joined by welding a hemispherical structure, in which case a central welding line (90) is formed at a midpoint between the heights of the outer tank (10) and the inner tank (20). If the vacuum pipe (100) is fixed to the outer tank (10) at the same position as the central welding line (90), the structural stability of the liquefied gas storage tank (1) and the fixing force of the vacuum pipe (100) may be reduced. Therefore, it is preferable that the vacuum pipes (100) be fixed spaced apart from each other so as not to overlap the central welding line (90).

[0074] Referring to FIG. 2, the vacuum pipe (100) can be arranged in a horizontal direction. Referring to FIG. 3, the vacuum pipe (100) can be arranged in a diagonal direction, and referring to FIG. 4, the vacuum pipe (100) can be arranged in a vertical direction.

[0075] When the vacuum pipe (100) is arranged diagonally or vertically as in FIG. 3 or 4, the plug (120) can be formed adjacent to the central welding line (90), and the plug (120) can be formed near the central welding line (90) (near the deck). The plug (120) can be formed within about 10 m in the vertical direction from the central welding line (90), and preferably within 2 m. Accordingly, the worker can easily connect the pump pipe (60) to the plug (120) without using any other tools. That is, when the vacuum pipe (100) is arranged diagonally or vertically, the worker can connect the pump pipe (60) to the vacuum pipe (100) near the deck, thereby improving the worker's work efficiency.

[0076] FIG. 5 is a first plan view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0077] FIG. 6 is a first and second plan view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0078] Figures 5 and 6 illustrate cross-sections of a liquefied gas storage tank (1) at different heights, respectively. 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) exhibit a circular shape. The circle may have a maximum diameter at the middle height of the liquefied gas storage tank (1). Figure 5 illustrates that the diameter of the cross-section is smaller than that of Figure 6, and Figure 5 illustrates a cross-section at a position further away from the center (middle height) of the liquefied gas storage tank (1) compared to Figure 6.

[0079] Referring to FIGS. 5 and 6, a vacuum pipe (100) may be provided in the vacuum insulation part (50) between the outer tank (10) and the inner tank (20). A plurality of vacuum pipes (100) may be provided. For example, a plurality of vacuum pipes (100) may be provided according to height as in FIGS. 5 and 6. Alternatively, a plurality of vacuum pipes (100) may be provided in the direction from the inner tank (20) to the outer tank (10) at the same height. However, the present invention is not limited thereto.

[0080] 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 provided in the height direction or in the direction from the inner tank (20) to the outer tank (10), it is preferable that the first vacuum pipe (100a) and the second vacuum pipe (100b) be installed at an appropriate distance to maintain a vacuum throughout the entire liquefied gas storage tank (1).

[0081] In addition, the first vacuum pipe (100a) and the second vacuum pipe (100b) may be spaced apart from the outer tank (10) or the inner tank (20) by the same distance within the vacuum insulation unit (50), and the distance at which the first vacuum pipe (100a) is spaced apart from the outer tank (10) and the distance at which the first vacuum pipe (100a) is spaced apart from the inner tank (20) may be the same or different, and similarly, the distance at which the second vacuum pipe (100b) is spaced apart from the outer tank (10) and the distance at which the second vacuum pipe (100b) is spaced apart from the inner tank (20) may be the same or different. That is, the first vacuum pipe (100a) and the second vacuum pipe (100b) may be arranged close to the outer tank (10) or close to the inner tank (20), respectively, within the vacuum insulation unit (50).

[0082] The first vacuum pipe (100a) may be provided with a first suction port (110a) and may be fixed to the outer tank (10) by a first connecting portion (11a). Similarly, the second vacuum pipe (100b) may be provided with a second suction port (110b) and may be fixed to the outer tank (10) by a second connecting portion (11b). The first vacuum pipe (100a) and the second vacuum pipe (100b) may be provided with plugs (120), and the pump pipe (60) may be connected to the plugs (120), and gas within the vacuum insulation unit (50) may be sucked in through the first suction port (110a) and the second suction port (110b).

[0083] Figure 7 is a cross-sectional view of a vacuum pipe of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0084] Referring to FIG. 7, the vacuum pipe (100) may include a suction port (110) formed on the side (in the width direction) and a filter portion (111) covering the suction port (110).

[0085] The vacuum pipe (100) is connected to the pump pipe (60) through the plug (120), and when the vacuum pump (70) is operated, gases inside the vacuum insulation part (50) can be sucked into the vacuum pipe (100) through the suction port (110) and exhausted to the outside.

[0086] At this time, since the vacuum insulation part (50) is filled with an insulating material such as powder, when the vacuum pump (70) is operated, the insulating material can be sucked into the suction port (110) and the insulating material can be delivered to the vacuum pump (70) along the vacuum pipe (100).

[0087] If the insulation is delivered to the vacuum pump (70) through the suction port (110), the vacuum performance of the vacuum pump (70) may be reduced and may cause fatal damage to the vacuum pump (70). Therefore, in order to prevent the insulation from flowing into the vacuum pump (70) while creating a vacuum state in the vacuum insulation unit (50) through the suction port (110), the suction port (110) may be covered with a filter unit (111).

[0088] The filter unit (111) has a porous structure such as a mesh, and the filter unit (111) can be arranged in multiple layers to enhance the insulation filtering effect. For example, the filter unit (111) can be in the form of a metal mesh or a filter made of pulp material laminated in multiple layers.

[0089] The holes formed in the filter unit (111) itself or the holes formed in the filter unit (111) when multiple filter units (111) are laminated may have a diameter smaller than the particle diameter of the insulating material to prevent the insulating material from flowing into the suction port (110). The filter unit (111) may be composed of various materials other than the above-mentioned materials and may be manufactured in various sizes or shapes, but the present invention is not limited thereto.

[0090] The filter unit (111) can cover only the area where the suction port (110) is formed, or can cover the area where the suction port (110) is formed while surrounding the entire vacuum pipe (100). However, the present invention is not limited thereto.

[0091] Figure 8 is a cross-sectional view of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0092] FIG. 9 is a drawing showing a vacuum pipe of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention being fixed to an outer tank.

[0093] Referring to FIGS. 8 and 9, the vacuum pipe (100) can be fixed to the outer tank (10) by a connecting portion (11). Since the connecting portion (11) is provided in the vacuum insulation portion (50), the connecting portion (11) can receive cold heat from the inner tank (20) and thus the temperature can drop. Therefore, the connecting portion (11) can be made of a material that can withstand low temperatures, such as wood, SUS, PTFE (polytetrafluoroethylene), or bakelite.

[0094] However, if the connecting part (11) is installed on the central welding line (90) of the outer tank, the structural stability of the liquefied gas storage tank (1) and the fixing force of the vacuum pipe (100) may be reduced. Therefore, it is preferable that the vacuum pipe (100) be installed spaced apart from each other so as not to overlap the central welding line (90).

[0095] In this way, the vacuum-insulated liquefied gas storage tank (1) according to the present invention can solve the problem of exhaust performance deteriorating as the distance from the suction port (110) increases by widely distributing the vacuum pipe (100) and the suction port (110) formed in the vacuum pipe (100) in the vacuum insulation section (50) to reduce the distance from the suction port (110) to each point of the vacuum insulation section (50).

[0096] In addition, the vacuum pipe (100) can be fixed to the outer tank (10) at a distance from the central welding line (90), thereby preventing the structural stability of the liquefied gas storage tank (1) and the fixing force of the vacuum pipe (100) from being reduced.

[0097] In addition, when the vacuum pipe (100) is arranged in a diagonal or vertical direction, the plug (120) of the vacuum pipe (100) can be positioned near the deck, making it easy for the worker to connect the pump pipe (60) to the plug (120).

[0098] FIG. 10 is a drawing showing a plurality of suction ports and filter sections formed in a vacuum pipe of a vacuum-insulated liquefied gas storage tank according to one embodiment of the present invention.

[0099] Referring to Fig. 10, a plurality of suction ports (110) may be formed along the length of a vacuum pipe (100). The vacuum pipe (100) is placed within a vacuum insulation member (50) and a plurality of suction ports (110) may be formed on the side.

[0100] The vacuum pipe (100) can suck gas into the interior between the insulation materials in multiple areas within the vacuum insulation section (50) through multiple suction ports (110). The vacuum pipe (100) can suck gas simultaneously from multiple areas within the vacuum insulation section (50) through multiple suction ports (110).

[0101] A plurality of filter sections (111) can be arranged in a plurality of suction ports (110).

[0102] The present invention is not limited to the embodiments described above, and may include a combination of the above embodiments or a combination of at least one of the above embodiments and a known technology as another embodiment.

[0103] Although the present invention has been described in detail through specific examples, this is intended to specifically explain the present invention, and the present invention is not limited thereto, and it will be apparent that modifications and improvements can be made by those skilled in the art within the technical spirit of the present invention.

[0104] All simple modifications or changes of the present invention fall within the scope of the present invention, and the specific protection scope of the present invention will be made clear by the appended claims.

[0105]

[0106] Description of the symbol

[0107] 1: Liquefied gas storage tank 10: Outer tank

[0108] 11: Connection

[0109] 20: inner 30: support structure

[0110] 40: Fixed structure 50: Vacuum insulation

[0111] 60: Pump piping 70: Vacuum pump

[0112] 80: Dome 90: Center weld line

[0113] 100: Vacuum pipe 110: Inlet

[0114] 111: Filter section 120: Plug

Claims

1. An inner tank in which liquefied gas is stored; An outer layer surrounding the inner layer and separated from the inner layer; A vacuum insulation part formed between the outer shell and the inner shell and filled with an insulating material to block heat transfer between the outer shell and the inner shell; and A vacuum pipe is disposed within the above vacuum insulation and has a suction port formed on the side; The above suction port is, A vacuum-insulated liquefied gas storage tank, a plurality of which are formed along the length of the above vacuum pipe.

2. In paragraph 1, The above vacuum pipe, A vacuum-insulated liquefied gas storage tank that sucks gas between the insulating materials filled in the vacuum insulation section into the vacuum pipe through the suction port.

3. In paragraph 2, A vacuum insulated liquefied gas storage tank further comprising a filter section that covers the suction port to prevent insulation from being discharged to the outside.

4. In paragraph 1, The above vacuum pipe, A vacuum-insulated liquefied gas storage tank fixed to the outer shell and surrounding the inner shell.

5. In paragraph 1, The above vacuum pipe, A vacuum-insulated liquefied gas storage tank, which is fixed at a position spaced from the central welding line formed by welding the structure forming the outer or inner tank.

6. In paragraph 1, The above vacuum pipe, A vacuum-insulated liquefied gas storage tank, wherein at least two of the above vacuum insulators are provided.

7. In paragraph 1, The above insulation material is, A vacuum insulated liquefied gas storage tank comprising at least one of polypropylene, polyurethane, polystyrene, polyethylene, polyisocyanurate, aerogel blanket, fumed silica, calcium silicate, mineral wool, glass wool, glass microfiber, perlite and glass bubbles.

8. In paragraph 1, A vacuum-insulated liquefied gas storage tank further comprising a connecting member for fixing the vacuum pipe to the outer tank.

9. In paragraph 8, The above connecting part, A vacuum-insulated liquefied gas storage tank installed spaced apart from the central welding line formed by welding the structures forming the outer or inner tank.

10. In paragraph 1, A vacuum-insulated liquefied gas storage tank further comprising a support structure provided between the inner tank and the outer tank to secure the inner tank to the outer tank.

11. In paragraph 1, A vacuum-insulated liquefied gas storage tank, which is a small LNG storage tank or liquefied hydrogen storage tank.

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

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