Liquefied gas storage tank and ship including the same

Abstract

A liquefied gas storage tank according to an embodiment of the present invention may include: a tank unit in which liquefied gas is stored; an inner tank unit disposed inside the tank unit and installed at a bottom portion of the tank unit; and a pump unit having an inlet pipe portion formed to pass through a lower wall portion of the inner tank unit and communicate with the inside of the inner tank unit, and the pump unit sucks the liquefied gas stored in the tank unit through the inlet pipe portion to supply the liquefied gas to the outside.

Description

Technical Field

[0001] The present invention relates to a liquefied gas storage tank and a ship having the liquefied gas storage tank. Background Art

[0002] Generally, petroleum resources used as transportation fuels for automobiles and ships and various fuels used at home and abroad are gradually being depleted, and due to rising oil prices, increasingly strict environmental regulations, etc., the amount of liquefied gas used as an alternative energy source is increasing.

[0003] For example, liquefied gases include liquefied natural gas (LNG), liquefied petroleum gas (LPG), etc. Since the volume of liquefied gas is greatly reduced compared to the gaseous state (for example, when LNG is liquefied, the volume of LNG can be reduced to 1 / 600, and when LPG is liquefied, the volume of LPG can be greatly reduced to 1 / 250), liquefied gas is convenient for storage and transportation in the liquefied state, but it is difficult to keep the temperature below the boiling point (for LNG, the boiling point is about -162 °C, and for LPG, the boiling point is about -50 °C).

[0004] To store such liquefied gas, a cryogenic liquefied gas storage tank that keeps the liquefied gas below the boiling point is required.

[0005] However, a liquefied gas storage tank is a structure for storing liquefied fuel used in transportation vehicles such as ships, and since the liquefied gas storage tank stores liquid therein, the liquefied gas storage tank may not always be flush with the water surface or the ground due to the movement of a floating structure such as a ship or a land transportation vehicle, resulting in the flow of liquid fuel.

[0006] In addition, as the liquid fuel is consumed, when the liquid level of the liquefied gas fuel inside the liquefied gas storage tank decreases and the above-mentioned liquefied gas storage tank tilts, there is a problem that the inlet pipe of the pump unit for supplying the liquefied gas fuel inside the liquefied gas storage tank to the outside is not immersed in the liquefied gas fuel but is exposed to the space of the liquefied gas storage tank.

[0007] Therefore, gas such as vaporized fuel gas is introduced through the inlet pipe, and thus the gas is introduced into the components of the engine to which the liquefied gas fuel is to be supplied, which causes a failure, and there is a problem that the engine system of the transportation vehicle needs to be stopped to prevent this situation.

[0008] Therefore, the capacity of the liquefied gas storage tank may not be utilized to the maximum extent, and there are limitations such as loss of driving distance and time due to frequent refueling, and since the liquefied gas fuel in the liquefied gas storage tank needs to be always filled to a certain depth or deeper, the weight of the transportation vehicle, such as a ship, increases, resulting in a decrease in fuel consumption efficiency.

[0009] In addition, when a part of the inlet pipe is not immersed in the liquefied gas fuel and is thus exposed to the space of the liquefied gas storage tank, since this part of the inlet pipe is exposed to a relatively high temperature area, there are problems such as the liquefied gas may be vaporized during transportation and transmitted to the outside of the engine even when the liquefied gas fuel is introduced into the inlet pipe.

[0010] Therefore, in order to solve or improve the above problems, it is necessary to study a liquefied gas storage tank and a ship having the liquefied gas storage tank. Summary of the Invention

[0011]

Technical Problem

[0012] The present invention provides the following liquefied gas storage tank and a ship having the liquefied gas storage tank: the liquefied gas storage tank can prevent the problem that the inlet pipe of the pump unit is not immersed in the liquefied gas fuel and is thus exposed to the space of the liquefied gas storage tank.

[0013] The present invention provides the following liquefied gas storage tank and a ship including the liquefied gas storage tank: the liquefied gas storage tank can prevent the problem that the inlet pipe of the pump unit is exposed to the relatively high temperature space filled with gas in the liquefied gas storage tank.

[0014]

Technical Solution

[0015] In one aspect of the present invention, a liquefied gas storage tank may include: a tank unit in which liquefied gas is stored; an inner tank unit disposed inside the tank unit and installed in the bottom portion of the tank unit; and a pump unit having an inlet pipe portion formed to pass through the lower wall portion of the inner tank unit and communicate with the inside of the inner tank unit, and the pump unit sucks the liquefied gas stored in the tank unit through the inlet pipe portion and supplies the liquefied gas to the outside.

[0016] The inner tank unit may be formed to be recessed downward from the bottom portion of the tank unit.

[0017] The inner tank unit may be arranged to surround the inlet pipe.

[0018] The inner tank unit may include a reflux prevention unit arranged such that the liquefied gas is introduced but not discharged.

[0019] The anti-backflow unit may include a first flip door which is provided in the inner tank unit and opens and closes only in one direction.

[0020] At least one first flip door may be provided on the upper wall portion or the side wall portion of the inner tank unit.

[0021] One end portion of the first flip door may be hinged to one side where the inner tank unit is open, and the other end portion of the first flip door may be provided to extend so as to be caught on the inner surface of the inner tank unit, and the first flip door may be moved into close contact with the inner tank unit by elastic force.

[0022] The anti-backflow unit may include a differential pressure pipe having a differential pressure inlet end portion and a differential pressure outlet end portion. The differential pressure inlet end portion extends to the outside of the inner tank unit, and the differential pressure outlet end portion extends into the inner tank unit and is provided at a height lower than that of the differential pressure inlet end portion.

[0023] The liquefied gas storage tank may further include: a cryogenic unit which is provided to be in contact with at least the inlet pipe, and in which liquefied gas is accommodated.

[0024] The cryogenic unit may include an insertion cylinder portion which is provided to pass through the inlet pipe so that the inside of the inner tank unit communicates with the inlet pipe, and the insertion cylinder portion is formed in a cylindrical shape in contact with the inlet pipe.

[0025] The insertion cylinder portion may include: an inner pipe portion in contact with the inlet pipe; and an outer portion which is spaced apart from the inner pipe portion at a predetermined interval to accommodate liquefied gas, and the outer portion has a lower end portion coupled to the inner pipe portion.

[0026] The insertion cylinder portion may have an open upper end portion.

[0027] The cryogenic unit may include a double-wall portion provided with a second flip door which communicates with the lower end portion of the insertion cylinder, extends to the lower wall portion of the inner tank unit or the lower wall portion and the side wall portion of the inner tank unit, and the second flip door may open and close only in one direction so as to introduce liquefied gas into the second flip door.

[0028] In another aspect of the present invention, a ship may include: a liquefied gas storage tank; and a hull which is provided with the liquefied gas storage tank and includes an engine unit for providing driving force.

[0029]

Advantageous Effects

[0030] The liquefied gas storage tank according to the present invention and a ship having the same can prevent the problem that the inlet pipe of the pump unit is not immersed in the liquefied gas fuel and thus is exposed to the space of the liquefied gas storage tank.

[0031] On the other hand, the liquefied gas storage tank according to the present invention and a ship having the same can prevent the problem that the inlet pipe of the pump unit is exposed to the relatively high-temperature space filled with gas in the liquefied gas storage tank.

[0032] Therefore, the following problems can be prevented: gas is introduced into the configuration of an engine or the like to which liquefied gas fuel is to be supplied, resulting in a failure, and the engine unit stops when the ship moves.

[0033] In addition, the capacity of the liquefied gas storage tank can be maximally utilized to increase the traveling distance, prevent time loss caused by frequent refueling, and improve the following problem: since the liquefied gas fuel in the liquefied gas storage tank needs to be always filled to a certain depth or deeper, the ship weight increases, thereby reducing the fuel consumption efficiency.

[0034] However, the various beneficial advantages and effects of the present invention are not limited to the above, and the various beneficial advantages and effects of the present invention can be more easily understood during the description of the exemplary embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A front view illustrating the liquefied gas storage tank of the present invention.

[0036] Figure 2 A front view illustrating the state in which the liquefied gas storage tank of the present invention is tilted.

[0037] Figure 3 A front view illustrating an embodiment in which the upper side portion of the tank unit in the liquefied gas storage tank of the present invention is connected to the supply pipe portion.

[0038] Figure 4 A front view illustrating the state in which the liquefied gas storage tank is tilted in an embodiment in which the supply pipe portion of the liquefied gas storage tank of the present invention is connected to the upper side portion of the tank unit.

[0039] Figure 5 A front view illustrating a part of the inner tank unit in the liquefied gas storage tank of the present invention.

[0040] Figure 6 A front view illustrating an embodiment in which a first flip door is provided on the upper wall portion of the inner tank unit in the liquefied gas storage tank of the present invention.

[0041] Figure 7Front view showing an embodiment in which a differential pressure pipe is provided in an inner tank unit of a liquefied gas storage tank according to the present invention.

[0042] Figure 8 Front view showing an embodiment in which a cryogenic unit is provided in a liquefied gas storage tank according to the present invention.

[0043] Figure 9 Front view showing an embodiment in which a cryogenic unit extends to a lower wall portion of a liquefied gas storage tank according to the present invention.

[0044] Figure 10 Front view showing an embodiment in which a cryogenic unit extends to a lower wall portion and a side portion of a liquefied gas storage tank according to the present invention.

[0045] Figure 11 Side view showing a liquefied gas storage tank according to the present invention and a ship having the liquefied gas storage tank. Detailed embodiments

[0046] Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings. However, the exemplary embodiments of the present invention can be modified in many other forms, and the scope of the present invention is not limited to the exemplary embodiments to be described below. Rather, these exemplary embodiments are provided so that the present invention will be fully described to those skilled in the art. In the drawings, for clarity, the shape, size, etc. of the components may be enlarged.

[0047] In addition, in this specification, unless the context clearly indicates otherwise, the singular form includes the plural form, and the same or similar reference numerals refer to the same or corresponding components throughout the specification.

[0048] The present invention relates to a liquefied gas storage tank 1 and a ship having the storage tank, wherein the inlet pipe 210 of the pump unit 200 is formed to pass through the lower wall portion 340 of the inner tank unit 300 and extend into the interior of the inner tank unit 300, and thus, the inlet pipe 210 is configured to be immersed in the liquefied gas L fuel located by gravity in the lower wall portion 340.

[0049] In addition, the inner tank unit 300 includes an anti-backflow unit 310 that surrounds the inlet pipe 210 of the pump unit 200 and is arranged such that the liquefied gas L is introduced but not discharged, thus preventing the problem that the inlet pipe 210 is not immersed in the liquefied gas L fuel and thus exposed to the space of the liquefied gas storage tank 1.

[0050] On the other hand, the liquefied gas storage tank 1 of the present invention and the ship having the storage tank include a cryogenic unit 400, so that the problem that the inlet pipe 210 is exposed to the relatively high-temperature space filled with gas in the liquefied gas storage tank 1 can be prevented.

[0051] Therefore, the problem of failure caused by gas being introduced into the configuration of an engine or the like to be supplied with the liquefied gas L fuel can be prevented, thereby preventing the problem that the engine unit 2a stops during the movement of the ship, and the capacity of the liquefied gas storage tank 1 can be maximally utilized, thereby increasing the traveling distance, preventing time loss caused by frequent refueling, and improving the reduction in fuel consumption efficiency due to the increase in the weight of the ship.

[0052] A detailed description will be made with reference to the accompanying drawings. Figure 1 is a front view illustrating the liquefied gas storage tank 1 of the present invention, and Figure 2 is a front view illustrating the state in which the liquefied gas storage tank 1 of the present invention is inclined.

[0053] That is, as Figure 1 and Figure 2 illustrated, a plurality of inlet pipes 210 may be provided, and the inlet pipes 210 may be formed to pass through the lower wall portion 340 of the inner tank unit 300.

[0054] Figure 3 is a front view illustrating an embodiment in which the upper side portion of the tank unit 100 in the liquefied gas storage tank 1 of the present invention is connected to the supply pipe portion 220, and Figure 4 is a front view illustrating the state in which the liquefied gas storage tank 1 of the present invention is inclined in an embodiment in which the supply pipe portion 220 of the liquefied gas storage tank 1 of the present invention is connected to the upper side portion of the tank unit 100.

[0055] That is, as Figure 3 and Figure 4 illustrated, one inlet pipe 210 is provided, and the inlet pipe 210 is formed to pass through the lower wall portion 340 of the inner tank unit 300, and the supply pipe portion 220 for transferring the liquefied gas L to the liquefied gas storage tank 1 may be formed to extend from the upper side portion.

[0056] In addition, Figure 5 is a front view illustrating a part of the inner tank unit 300 in the liquefied gas storage tank 1 of the present invention, and Figure 6 is a front view illustrating an embodiment in which a first flip door 311 is provided on the upper wall portion 320 of the inner tank unit 300 in the liquefied gas storage tank 1 of the present invention.

[0057] Refer to Figure 5, the liquefied gas storage tank 1 according to an embodiment of the present invention may include: a tank unit 100 in which liquefied gas L is stored; an inner tank unit 300 disposed inside the tank unit 100 and installed at a bottom portion of the tank unit 100; and a pump unit 200 having an inlet pipe 210 formed to pass through a lower wall portion 340 of the inner tank unit 300 and communicate with the inside of the inner tank unit 300, and the pump unit 200 sucks the liquefied gas L stored in the tank unit through the inlet pipe 210 and supplies the liquefied gas to the outside.

[0058] In this way, in the liquefied gas storage tank 1 of the present invention, the inlet pipe 210 of the pump unit 200 is formed to pass through the lower wall portion 340 of the inner tank unit 300 and communicate with the inside of the inner tank unit 300, so that the inlet pipe 210 can be configured not to be exposed to a high-temperature space outside the low-temperature liquefied gas L.

[0059] In other words, the low-temperature liquefied gas L gathers in the lower wall portion 340 by gravity. Thus, by connecting the inlet pipe 210 to the lower wall portion 340 where the low-temperature liquefied gas L is located, the inlet pipe 210 can be prevented from being exposed to a high-temperature space.

[0060] To this end, the inlet pipe 210 may be coupled to the lower wall portion 340 of the inner tank unit 300 and may be disposed at the same height as the lower wall portion 340. Alternatively, the inlet pipe 210 may be formed to extend into the inner tank unit 300 at a predetermined height.

[0061] Here, the inner tank unit 300 of the liquefied gas storage tank 1 according to an embodiment of the present invention may be formed to be recessed downward from a bottom portion of the tank unit 100.

[0062] According to this configuration, since the lower wall portion 340 of the inner tank unit 300 is formed at a height lower than the bottom portion of the tank unit 100, the liquefied gas L received in the tank unit 100 can converge to the lower wall portion 340 of the inner tank unit 300 at the lowest height.

[0063] In addition, the inner tank unit 300 of the liquefied gas storage tank 1 according to an embodiment of the present invention may be disposed to surround the periphery of the inlet pipe 210.

[0064] Here, the inner tank unit 300 of the liquefied gas storage tank according to an embodiment of the present invention may include a reflux prevention unit 310 configured such that the liquefied gas L is introduced but not discharged.

[0065] In this way, the liquefied gas storage tank 1 of the present invention is arranged to surround the peripheral edge of the inlet pipe 210 of the pump unit 200 and has liquefied gas L contained therein unidirectionally. Therefore, when the liquefied gas L fuel is used inside the tank unit 100, the water level of the liquefied gas L fuel drops, or when the liquefied gas storage tank 1 tilts due to the swaying of a ship or the like, even if the liquefied gas L fuel is offset to one side, the outer periphery of the inlet pipe 210 can be filled with the liquefied gas L fuel.

[0066] Therefore, problems of failure caused by gas being introduced into the configuration of an engine or the like to which the liquefied gas L fuel is to be supplied can be prevented, thereby preventing the problem of the engine unit 2a stopping during ship movement, and the capacity of the liquefied gas storage tank 1 can be utilized to the maximum extent, thereby increasing the traveling distance, preventing time loss caused by frequent refueling, and improving the reduction in fuel consumption efficiency due to the increase in the weight of the ship.

[0067] The tank unit 100 has a configuration capable of storing cryogenic liquefied gas L, such as liquefied natural gas (LNG) or liquefied petroleum gas (LPG), and this configuration can generally be provided by being coupled to the hull 2 of a ship or the like.

[0068] Here, when the liquefied gas L is stored, a heat insulating material can be coupled to the outer surface of the tank unit 100 to ensure heat insulation of the liquefied gas L.

[0069] In addition, the tank unit 100 can include a support member 110 provided therein for storing the internal high-pressure liquefied gas L, and the support member 110 can be arranged in an annular shape along the circumferential direction of the tank unit 100. For example, the support member 110 can be arranged in the form of a disk having a hole in the middle.

[0070] The pump unit 200 is used to transfer the liquefied gas L fuel inside the tank unit 100 to the outside.

[0071] However, in order for the pump unit 200 to transfer the liquefied gas L fuel to the outside, the inlet pipe 210 of the pump unit 200 needs to be immersed in the liquefied gas L. Conventionally, when a swaying phenomenon occurs, there is a problem that the inlet pipe 210 is not immersed in the liquefied gas L fuel and is thus exposed to the gas space of the liquefied gas storage tank 1 according to the present invention. By providing the inner tank unit 300, this problem can be improved.

[0072] In addition, the liquefied gas L is located in the lower wall portion 340 by gravity, and the inlet pipe 210 can be provided on the lower wall portion 340 to be more easily immersed in the liquefied gas L.

[0073] In addition, the pump unit 200 may further include a supply pipe portion 220 for supplying the liquefied gas L from the outside into the tank unit 100. The supply pipe portion 220 may be connected to the upper portion of the tank unit 100, or may be connected to the lower portion of the tank unit 100 in the same manner as the inlet pipe 210.

[0074] The inner tank unit 300 is used to fill the periphery of the inlet pipe 210 with the liquefied gas L fuel. For this purpose, the inner tank unit 300 is provided in the form of a container surrounding the periphery of the inlet pipe 210, and the inner tank unit 300 includes a backflow prevention unit 310 through which the liquefied gas L is introduced but not discharged.

[0075] As an example of the backflow prevention unit 310, a flip-type first flip door 311 that opens only in one direction may be provided.

[0076] That is, the backflow prevention unit 310 of the liquefied gas storage tank 1 according to an embodiment of the present invention is provided in the inner tank unit 300, but may include a first flip door 311 that is set to open and close only in one direction.

[0077] In other words, the first flip door 311 closes the open area of the inner tank unit 300, but the first flip door 311 may be configured to allow the liquefied gas L to flow and be opened in the inflow direction.

[0078] Specifically, in the first flip door 311 of the liquefied gas storage tank 1 according to an embodiment of the present invention, one end portion of the first flip door 311 may be hinged to one side of the opening of the inner tank unit 300, and the other end portion of the first flip door 311 may be provided to extend so as to be caught on the inner surface of the inner tank unit 300, and the first flip door 311 may move into close contact with the inner tank unit 300 by elastic force.

[0079] That is, when the first flip door 311 is pushed so that the liquefied gas L moves from the inside of the inner tank unit 300 to the outside, the first flip door 311 moves to close the open area of the inner tank unit 300 and is no longer actuated to open by pivoting outward. However, when the first flip door 311 is pushed into the inner tank unit 300 so that the liquefied gas L moves from the outside of the inner tank unit 300 to the inside, the first flip door 311 is actuated to open by pivoting.

[0080] In this case, a spring member or the like may be provided at one end portion of the first flip door 311 hinged to the inner tank unit 300, and the elastic force of the spring member or the like is applied to the outside.

[0081] Here, at least one first swing door 311 of the liquefied gas storage tank 1 according to an embodiment of the present invention may be provided on the upper wall portion 320 or the side wall portion 330 of the inner tank unit 300.

[0082] In other words, an opening for introducing the liquefied gas L into the inner tank unit 300 may be formed not only in the upper wall portion 320 of the inner tank unit 300 but also in the side wall portion 330 of the inner tank unit 300, and the number of openings may be odd or plural. As described above, the first swing door 311 may be installed in the opening formed in at least one of the upper wall portion 320 and the side wall portion 330 so that the liquefied gas L is only accommodated in the inner tank unit 300.

[0083] In addition, the inner tank unit 300 is configured to close the periphery of the inlet pipe 210 in a state where the first swing door 311 is closed. In this case, when the liquefied gas L inside the inner tank unit 300 is vaporized due to a temperature rise or the like, the liquefied gas is vaporized in the closed area and thus is not vaporized more than a certain amount. Therefore, the vaporization problem of the liquefied gas L can be improved.

[0084] In addition, the inner tank unit 300 of the liquefied gas storage tank 1 according to an embodiment of the present invention may share at least one side wall portion 330 with a support member provided in the tank unit 100.

[0085] Therefore, the problem of weight increase of the liquefied gas storage tank 1 due to the provision of the inner tank unit 300 can be improved.

[0086] In addition, since the inner tank unit 300 is integrally provided with the support member connected to the tank unit 100, the coupling force of the inner tank unit 300 can be further increased.

[0087] Here, the inner tank unit 300 of the liquefied gas storage tank 1 according to an embodiment of the present invention may be provided such that the side wall portion 330 connected between the support members extends upward from the upper wall portion 320.

[0088] That is, in addition to the side wall portion 330 replaced by the support member, the remaining side wall portion 330 is provided, and the remaining side wall portion 330 may be configured to include an extension portion extending further upward from the upper wall portion 320.

[0089] Therefore, even when the liquefied gas L inside the tank unit 100 flows due to swinging or the like, the periphery of the inner tank unit 300 serves as a wave baffle member so as not to be affected by the flow of the liquefied gas L.

[0090] Therefore, the liquefied gas L can be stably introduced into the inner tank unit 300.

[0091] Figure 7 The front view which illustrates the embodiment where the differential pressure pipe 314 is provided in the inner tank unit 300 of the liquefied gas storage tank 1 of the present invention. Refer to Figure 7 , according to an embodiment of the present invention, the anti-backflow unit 310 of the liquefied gas storage tank 1 may include a differential pressure pipe 314, and the differential pressure pipe 314 is provided with a differential pressure inlet end portion 314a extending to the outside of the inner tank unit 300 and a differential pressure outlet end portion 314b extending into the inner tank unit 300 and provided at a height lower than that of the differential pressure inlet end portion 314a.

[0092] In this way, since the anti-backflow unit 310 is provided with the differential pressure pipe 314, the liquefied gas L can be introduced into the inner tank unit 300 and will not be discharged.

[0093] That is to say, since the inner tank unit 300 is arranged to surround the periphery of the inlet pipe 210 and unidirectionally accommodate the liquefied gas L therein, even if the liquefied gas L fuel is offset to one side due to the inclination of the tank unit 100, the periphery of the inlet pipe 210 can be filled with the liquefied gas L fuel.

[0094] The differential pressure pipe 314 can move the liquefied gas L to the inner tank unit 300 through the differential pressure generated because the differential pressure outlet end portion 314b provided inside the inner tank unit 300 is lower than the differential pressure inlet end portion 314a provided outside the inner tank unit 300.

[0095] That is to say, regardless of the height of the central portion of the differential pressure pipe 314, and only the heights of the two end portions of the differential pressure pipe 314 determine the flow direction of the liquefied gas L. Since the differential pressure inlet end portion 314a is higher than the differential pressure outlet end portion 314b, the liquefied gas L flows from the differential pressure inlet end portion 314a to the differential pressure outlet end portion 314b.

[0096] In addition, the anti-backflow unit 310 of the liquefied gas storage tank 1 according to an embodiment of the present invention may include an extended inlet end portion and an extended pipe. The extended inlet end portion is arranged to face the outside of the inner tank unit 300 and is provided with a first flip door 311, and the extended pipe is provided with an extended outlet end portion extending into the inner tank unit 300.

[0097] That is to say, since the first flip door 311 is provided at the extended inlet end portion of the extended pipe, the extended pipe can be configured to allow the liquefied gas L to flow into the inner tank unit 300, but prevent the liquefied gas L from escaping to the outside of the inner tank unit 300.

[0098] In addition, since the extension pipe extends into the inner tank unit 300, the number of paths for the liquefied gas L contained in the inner tank unit 300 to move from the extension outlet end portion to the extension inlet end portion can be increased. Therefore, the problem that the liquefied gas L inside the inner tank unit 300 escapes to the outside through the first flip door 311 can be more effectively prevented.

[0099] Here, the extension pipe of the liquefied gas storage tank 1 according to an embodiment of the present invention can be formed in the form of a curved pipe, wherein the extension pipe is provided in the central portion below the extension inlet end portion and is provided higher than the extension outlet end portion.

[0100] That is, when the extension pipe has the form of a curved pipe rather than a straight pipe shape, since the movement path of the liquefied gas L can be further increased, the escape of the liquefied gas L can be more effectively prevented.

[0101] In addition, the anti-backflow unit 310 of the liquefied gas storage tank 1 according to an embodiment of the present invention may include an inclined pipe, which is provided on the side wall portion 330 of the inner tank unit 300 and is provided in the form of a fallopian tube communicating with the outside, and the inclined pipe has a first flip door 311 provided at its inner end portion.

[0102] That is, since the inclined pipe has a first flip door 311 provided at its extension inlet end portion, the inclined pipe can be configured to allow the liquefied gas L to flow into the inner tank unit 300 but prevent the liquefied gas L from escaping to the outside of the inner tank unit 300.

[0103] In addition, the inclined pipe is configured to have a width that increases as it approaches the outer end portion from the inner end portion. In this way, since the liquefied gas L contained in the inner tank unit 300 needs to pass through a relatively narrow area when escaping to the outside, the effect of preventing the liquefied gas L from escaping to the outside can be improved, and when the liquefied gas L is accommodated from the outside of the inner tank unit 300 into the inside of the inner tank unit 300, since the liquefied gas L only needs to pass through a relatively wide area, there is an effect of more easily accommodating the liquefied gas L.

[0104] Figure 8 The front view illustrates an embodiment in which the cryogenic unit 400 is provided in the liquefied gas storage tank 1 of the present invention. Figure 9 The front view illustrates an embodiment in which the cryogenic unit 400 extends to the lower wall portion 340 of the liquefied gas storage tank 1 of the present invention, and Figure 10 The front view illustrates an embodiment in which the cryogenic unit 400 extends to the lower wall portion 340 and the side wall portion 330 of the liquefied gas storage tank 1 of the present invention.

[0105] Referring to the accompanying drawings, the cryogenic unit 400 may be arranged to be in contact with at least the inlet pipe 210 of the liquefied gas storage tank 1 according to an embodiment of the present invention and to contain liquefied gas L therein.

[0106] That is, the liquefied gas storage tank 1 of the present invention may keep the inlet pipe 210 at a low temperature by including the cryogenic unit 400, and thus it is possible to prevent the problem that the liquefied gas L flowing through the inlet pipe 210 vaporizes due to a temperature rise.

[0107] In other words, even if the periphery of the inlet pipe 210 may be filled with liquefied gas L by the inner tank unit 300, when the liquefied gas L contained in the inner tank unit 300 is discharged to the outside through the inlet pipe 210, a relatively high-temperature gas region may be formed around the inlet pipe 210. In this case, since there may be a problem that the liquefied gas L flowing through the inlet pipe 210 vaporizes, the cryogenic unit 400 is provided.

[0108] Specifically, the cryogenic unit 400 of the liquefied gas storage tank 1 according to an embodiment of the present invention may include an insertion cylinder part 410 which is arranged such that the inlet pipe 210 passes through the insertion cylinder part 410, so that the interior of the inner tank unit 300 communicates with the inlet pipe 210 and is formed in a cylindrical shape in contact with the inlet pipe 210.

[0109] In other words, the cryogenic unit 400 includes the insertion cylinder part 410 which is in contact with the periphery of the inlet pipe 210 but contains relatively low-temperature liquefied gas L therein.

[0110] As an example, the liquefied gas L may be liquefied natural gas (LNG), liquefied propane gas (LPG), etc. Since for liquefied natural gas, the boiling point is about -162 °C, and for liquefied propane gas, the boiling point is about -50 °C, the temperature of the inlet pipe 210 may be kept at about -162 °C and about -50 °C, respectively.

[0111] To this end, the insertion cylinder part 410 may include an inner pipe part 411 and an outer part 412. The insertion cylinder part 410 of the liquefied gas storage tank 1 according to an embodiment of the present invention may include the inner pipe part 411 and the outer part 412, the inner pipe part 411 being in contact with the inlet pipe 210, and the outer part 412 being spaced apart from the inner pipe part 411 at a predetermined interval to contain liquefied gas L and having a lower end part connected to the inner pipe part 411.

[0112] Here, the inlet pipe 210 may be inserted into the inner pipe part 411 and be in contact with the inner pipe part 411, and a space may be formed between the inner pipe part 411 and the outer part 412 to contain liquefied gas L.

[0113] That is to say, the inner pipe portion 411 and the outer portion 412 have a double-pipe structure, and the lower end portion of the inner pipe portion 411 and the lower end portion of the outer portion 412 are coupled to each other to have a structure that can accommodate the liquefied gas L without leakage.

[0114] In addition, the insertion cylinder portion 410 of the liquefied gas storage tank 1 according to an embodiment of the present invention may be in a form with an open upper end portion.

[0115] In the case of this embodiment, the liquefied gas L can be accommodated without providing the first flip door 311 or the like in the upper end portion of the insertion cylinder portion 410.

[0116] However, when the first flip door 311 for allowing the liquefied gas L to move only in one direction is provided on the upper end portion of the insertion cylinder, the first flip door 311 can be provided.

[0117] The cryogenic unit 400 of the liquefied gas storage tank 1 according to an embodiment of the present invention may include a double-wall portion 420 provided with a second flip door 421 that communicates with the lower end portion of the insertion cylinder portion 410, extends to the lower wall portion 340 of the inner tank unit 300, or extends to the lower wall portion 340 and the side wall portion 330 of the inner tank unit 300, and the second flip door 421 opens and closes only in one direction so that the liquefied gas L is introduced into the second flip door 421.

[0118] In addition to forming the inlet pipe 210 in a cryogenic environment, the double-wall portion 420 also serves to form an outer portion of the inner tank unit 300 in a cryogenic environment.

[0119] Therefore, the problem that the liquefied gas L accommodated in the inner tank unit 300 is exposed to a high-temperature environment and vaporized can be improved.

[0120] In other words, the double-wall portion 420 may be provided in the lower wall portion 340 of the inner tank unit 300, and when viewed from a front cross-sectional view, the double-wall portion 420 may be formed in an "L" shape. For this, reference may be made to Figure 9 .

[0121] According to this situation, in addition to being able to handle the liquefied gas L so as to keep the inlet pipe 210 in a cryogenic environment through the insertion cylinder portion 410, the liquefied gas L can also be handled so as to keep the lower wall portion 340 of the inner tank unit 300 in a cryogenic environment.

[0122] In addition, the double-wall portion 420 may be provided in the lower wall portion 340 and the side wall portion 330 of the inner tank unit 300, and when viewed from the front cross-sectional view, the double-wall portion 420 may be formed in a "U" shape. For this purpose, reference may be made to Figure 10 .

[0123] According to this situation, in addition to being able to handle the liquefied gas L so as to keep the inlet pipe 210 in a low-temperature environment through the insertion cylinder portion 410, the liquefied gas L can also be handled so as to keep the lower wall portion 340 and the side wall portion 330 of the inner tank unit 300 in a low-temperature environment.

[0124] Here, in order to accommodate the liquefied gas L in the double-wall portion 420, the double-wall portion 420 may be a double plate in which a space is formed, and the double-wall portion 420 may communicate with the space between the outer portion 412 and the inner pipe portion 411 of the insertion cylinder portion 410.

[0125] In order to accommodate the liquefied gas L into the double-wall portion 420, a second flip door 421 is provided on the upper surface portion, and the second flip door 421 may be configured to accommodate the liquefied gas L into the double-wall portion 420 but prevent the liquefied gas L from moving to the outside.

[0126] Figure 11 is a side view showing the liquefied gas storage tank 1 of the present invention and a ship having the liquefied gas storage tank. Reference is made to Figure 11 , a ship according to another embodiment of the present invention may include a hull 2, the hull 2 including a liquefied gas storage tank 1 and an engine unit 2a, the engine unit 2a being provided with the liquefied gas storage tank 1 and providing driving force.

[0127] That is, by including the above-described liquefied gas storage tank 1 in the ship, the level of the liquefied gas L fuel decreases as the liquefied gas L fuel is used in the tank unit 100, or even if the liquefied gas L fuel is biased to one side due to the inclination of the liquefied gas storage tank 1 caused by the rocking of the ship, the liquefied gas L fuel can be used to fill the periphery of the inlet pipe 210.

[0128] In addition, by keeping the periphery of the inlet pipe 210 in a low-temperature environment, the liquefied gas L moving through the inlet pipe 210 can be prevented from vaporizing.

[0129] Therefore, problems of failure caused by gas being introduced into the configuration of an engine or the like to which liquefied gas L fuel is to be supplied can be prevented, thereby preventing the problem that the engine unit 2a stops during the movement of the ship, and the capacity of the liquefied gas storage tank 1 can be maximally utilized, thereby increasing the traveling distance, preventing time loss caused by frequent refueling, and improving the fuel consumption efficiency reduction caused by the increase in the weight of the ship.

[0130] Although the exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the scope of the invention as defined by the appended claims.

Claims

1. A liquefied gas storage tank, comprising: A tank unit in which liquefied gas is stored; An inner tank unit disposed inside the tank unit and mounted at the bottom portion of the tank unit; and A pump unit having an inlet pipe portion formed to pass through the lower wall portion of the inner tank unit and communicate with the interior of the inner tank unit, and the pump unit sucks the liquefied gas stored in the tank unit through the inlet pipe portion and supplies the liquefied gas to the outside, Wherein the inner tank unit is formed to be recessed downward from the bottom portion of the tank unit, and the lower wall portion of the inner tank unit is formed at a height lower than the bottom portion of the tank unit, Wherein the inner tank unit is provided in the form of a container surrounding the periphery of the inlet pipe and is used to fill the periphery of the inlet pipe with liquefied gas fuel, Wherein the inner tank unit includes a backflow prevention unit provided such that the liquefied gas is introduced but not discharged, Wherein the backflow prevention unit includes a first flip door provided in the inner tank unit and opening and closing only in one direction, The inner tank unit is configured to enclose the periphery of the inlet pipe in a state where the first flip door is closed.

2. The liquefied gas storage tank according to claim 1, wherein, At least one first flip door is provided on the upper wall portion or the side wall portion of the inner tank unit.

3. The liquefied gas storage tank according to claim 1, wherein, One end portion of the first flip door is hinged to one side of the opening of the inner tank unit, and the other end portion of the first flip door is provided to extend so as to be caught on the inner surface of the inner tank unit, and the first flip door moves into close contact with the inner tank unit by elastic force.

4. The liquefied gas storage tank according to claim 1, further comprising: A cryogenic unit provided to be in contact with at least the inlet pipe, and the liquefied gas is accommodated in the cryogenic unit.

5. The liquefied gas storage tank according to claim 4, wherein, The cryogenic unit includes an insertion cylinder portion provided to pass through the inlet pipe so that the interior of the inner tank unit communicates with the inlet pipe, and the insertion cylinder portion is formed in a cylindrical shape in contact with the inlet pipe.

6. The liquefied gas storage tank according to claim 5, wherein, The insertion cylinder portion includes: An inner pipe portion in contact with the inlet pipe; and An outer portion spaced apart from the inner pipe portion at a predetermined interval to accommodate the liquefied gas, and the outer portion has a lower end portion connected to the inner pipe portion.

7. The liquefied gas storage tank according to claim 5, wherein, The insertion cylinder portion has an open upper end portion.

8. The liquefied gas storage tank according to claim 5, wherein, The cryogenic unit includes a double wall portion provided with a second flip door that communicates with the lower end portion of the insertion cylinder, extends to the lower wall portion of the inner tank unit or the lower wall portion and the side wall portion of the inner tank unit, and the second flip door opens and closes only in one direction so that the liquefied gas is introduced into the second flip door.

9. A ship, comprising: The liquefied gas storage tank according to any one of claims 1 to 8; and a hull provided with a liquefied gas storage tank and including an engine unit that provides driving force.

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