Cryogenic fluid transport system of ship

Abstract

The present invention relates to a transportation system for a cryogenic fluid in a ship. The transportation system for a cryogenic fluid in a ship according to an embodiment of the present invention includes: a liquid phase cryogenic fluid storage unit receiving and storing a liquid phase cryogenic fluid; a solidification unit connected to the liquid phase cryogenic fluid storage unit and solidifying at least a part of the liquid phase cryogenic fluid stored in the liquid phase cryogenic fluid storage unit to generate a slush cryogenic fluid in which liquid phase cryogenic fluid and solid phase cryogenic fluid are mixed; a reliquefaction unit connected to the solidification unit and generating a reliquefied cryogenic fluid by receiving and reliquefying at least a part of boil-off gas (BOG) generated by the evaporation of the liquid phase cryogenic fluid in the solidification unit; and a power generation unit connected to the solidification unit receiving the remainder of the BOG generated by the evaporation of the liquid phase cryogenic fluid in the solidification unit to generate power, and selectively supplying the generated power to the reliquefaction unit, wherein the reliquefied cryogenic fluid generated by being reliquefied in the reliquefaction unit is supplied to the solidification unit and is mixed with the slush cryogenic fluid.

Description

[Technical Field]

[0001] The present invention relates to a transportation system for a cryogenic fluid in a ship.[Background Art]

[0002] In general, in order to store and efficiently transport a large amount of a gas phase fluid at room temperature in a limited space, for example, in a cargo hold of a ship, it is necessary to increase a storage density of the fluid by phase changing the gas phase fluid into a liquid phase fluid to increase the density of the fluid.

[0003] In this case, a method of lowering a temperature of a fluid existing in the gas phase at room temperature to a cryogenic temperature that is relatively lower than room temperature and phase changing the gas phase fluid into a cryogenic liquid phase fluid (hereinafter referred to as "liquid phase cryogenic fluid") is recognized as a suitable method for storing and transporting cryogenic fluid in a large amount.

[0004] Meanwhile, the lower the boiling point of liquid phase cryogenic fluid stored in the cargo hold, the more easily evaporation of liquid phase cryogenic fluid may be accelerated. When the liquid phase cryogenic fluid evaporates in this way, a gas phase cryogenic fluid, such as boil-off gas (BOG), is generated. Since the BOG increases a pressure inside the cargo hold and reduces the storage safety of the liquid phase cryogenic fluid, insulation technology was applied to the cargo hold in the related art, or reliquefaction technology was applied to reliquefy and process the BOG.

[0005] However, when an insulation layer is provided in the cargo hold, there is a problem that it is difficult to store and transport the liquid phase cryogenic fluid for a long period of time because there is a limit in reducing the generation of the BOG generated inside the cargo hold.

[0006] In addition, when connecting a boil-off gas reliquefaction facility to the cargo hold, there is a problem that a lot of energy is required to reliquefy the BOG, and the actual storage capacity of the cargo hold is reduced by the boil-off gas reliquefaction facility in a ship with limited space.

[0007] Therefore, there is a need for a ship's transportation system for the cryogenic fluid capable of not only reducing the generation of the BOG to store a large amount of cryogenic fluid, but also stably storing and transporting the cryogenic fluid for a long period of time[Disclosure][Technical Problem

[0008] Embodiments of the present invention have been devised to solve the above-described phase conventional problems, and are directed to providing a transportation system for a cryogenic fluid in ship capable of not only reducing the generation of boil-off gas (BOG) to store a large amount of cryogenic fluid, but also stably storing and transporting the cryogenic fluid for a long period of time.[Technical Solution]

[0009] According to one aspect of the present invention, the transportation system for cryogenic fluid in a ship may include a liquid phase cryogenic fluid storage unit for supplying and storing a liquid phase cryogenic fluid; a solidification unit connected to the liquid phase cryogenic fluid storage unit and solidifying at least a part of the liquid phase cryogenic fluid stored in the liquid phase cryogenic fluid storage unit to generate a slush cryogenic fluid in which a liquid phase cryogenic fluid and a solid phase cryogenic fluid are mixed; a reliquefaction unit connected to the solidification acceleration unit and generating reliquefied cryogenic fluid by receiving and reliquefying at least a part of boil-off gas (BOG) generated by evaporation of the liquid phase cryogenic fluid in the solidification unit; and a power generation unit connected to the solidification unit, receiving the remainder of the BOG generated by the evaporation of the liquid phase cryogenic fluid in the solidification unit to generate power, and selectively supplying the generated power to the reliquefaction unit, wherein the reliquefied cryogenic fluid generated by being reliquefied in the reliquefaction unit may be supplied to solidification unit and be mixed with the slush cryogenic fluid.

[0010] In addition, the transportation system for a cryogenic fluid in a ship may further include a solidification acceleration unit connected to the solidification unit and accelerating the solidification of the reliquefied cryogenic fluid mixed with the slush cryogenic fluid by applying energy to the solidification unit.

[0011] In addition, the transportation system for a cryogenic fluid in a ship may further include: a detection unit which is connected to the liquid phase cryogenic fluid storage unit and generating a fluid signal for at least one of the liquid phase cryogenic fluid stored in the liquid phase cryogenic fluid storage unit, the solid phase cryogenic fluid, the slush cryogenic fluid, and the BOG; and a control unit controlling at least one of the liquid phase cryogenic fluid storage unit, the solidification unit, the reliquefaction unit, the power generation unit, and the solidification acceleration unit on the basis of the fluid signal generated in the detection unit.

[0012] In addition, the liquid phase cryogenic fluid storage unit may include: a cargo hold provided in a hull, storing the liquid phase cryogenic fluid, and having a space in which the solidification of the liquid phase cryogenic fluid may be performed; a vacuum insulation layer provided outside the cargo hold; and a balance water storage part provided outside the vacuum insulation layer.

[0013] In addition, the reliquefaction unit may include: a first boil-off gas transfer line of which one end portion is connected to the cargo hold; a reliquefaction device connected to the other end portion of the first boil-off gas transfer line and reliquefying the BOG by using a cooling medium; a reliquefaction cryogenic fluid transfer line connecting the reliquefaction device and the cargo hold; a first boil-off gas transfer valve provided on the first boil-off gas transfer line; and a reliquefaction cryogenic fluid transfer valve provided in the reliquefaction cryogenic fluid transfer line.

[0014] In addition, the solidification unit may include a vacuum pump which is connected to the first boil-off gas transfer line and reduces a pressure inside the cargo hold.

[0015] In addition, the solidification unit may include: a pressure regulating pump provided on the reliquefaction cryogenic fluid transfer line; an injection device provided at a rear end of the pressure regulating pump and at least a part of which is disposed on the inside of the cargo hold; and a cold heat transfer line which connects the reliquefaction device and the injection device, and transfers cooling heat of the cooling medium of the reliquefaction device to the injection device.

[0016] In addition, the solidification unit may include an ultrasonic generation device for solidification which is provided on at least one of the inner surfaces of the cargo hold.

[0017] In addition, the solidification acceleration unit may include an ultrasonic generation device for accelerating solidification which is provided on at least one of the inner surfaces of the cargo hold.

[0018] In addition, the liquid phase cryogenic fluid storage unit may further include: a liquid phase cryogenic fluid transfer line connected to the reliquefaction cryogenic fluid transfer line; and supplying the liquid phase cryogenic fluid to the cargo hold; and a liquid phase cryogenic fluid transfer valve provided on the liquid phase cryogenic fluid transfer line.

[0019] In addition, the power generation unit may include a second boil-off gas transfer line branched off from the first boil-off gas transfer line; a second boil-off gas transfer valve provided on the second boil-off gas transfer line; a power generation device connected to the second boil-off gas transfer line and producing power by using the BOG; and a power transfer line connecting the power generation device and the reliquefaction device and transferring at least a part of the power produced in the power generation device to the reliquefaction device.[Advantageous Effects]

[0020] According to embodiments of the present invention, there is an effect that not only a large amount of cryogenic fluid can be stored by reducing the generation of boil-off gas (BOG), but also the cryogenic fluid can be stably stored and transported for a long period of time.[Description of Drawings]

[0021] FIG. 1 is a block diagram illustrating a transportation system for a cryogenic fluid in a ship according to one embodiment of the present invention. FIG. 2 is a process diagram schematically illustrating the transportation system for a cryogenic fluid in a ship of FIG. 1. FIG. 3 is a control block diagram of the transportation system for a cryogenic fluid in a ship of FIG. 1. FIG. 4 is a graph for describing the phase change of a liquid phase cryogenic material performed in a solidification unit in the transportation system for a cryogenic fluid in a ship of FIG. 1. FIG. 5 is a block diagram illustrating a transportation system for a cryogenic fluid in a ship according to another embodiment of the present invention. FIG. 6 is a process diagram schematically illustrating the transportation system for a cryogenic fluid in a ship of FIG. 5. FIG. 7 is a control block diagram of the transportation system for a cryogenic fluid in a ship of FIG. 5. FIG. 8 is a block diagram illustrating a transportation system for a cryogenic fluid in a ship according to still another embodiment of the present invention. FIG. 9 is a process diagram schematically illustrating the transportation system for a cryogenic fluid in a ship of FIG. 8. FIG. 10 is a control block diagram of the transportation system for a cryogenic fluid in a ship of FIG. 8. [Modes of the Invention]

[0022] Hereinafter, specific embodiments for implementing the spirit of the present invention will be described in detail with reference to the drawings.

[0023] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

[0024] In addition, it should be understood that when a component is referred to as being "connected" to another component, it may be directly connected to that another component while other components may be present therebetween.

[0025] The terms used herein are for describing particular embodiments only and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0026] In addition, it is to be noted in advance that expressions such as one side, the other side, an upper side, a lower side, etc. in this specification are described based on the illustration in the drawing, and may be expressed differently if the direction of the object is changed. For the same reason, some components in the accompanying drawings are exaggerated, omitted, or schematically illustrated, and the size of each component does not fully match the actual size thereof.

[0027] In addition, terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by such terms. These terms are only used to distinguish one component from another component.

[0028] The term "comprising" as used in the specification specifies particular characteristics, regions, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of other particular characteristics, regions, integers, steps, operations, elements, components, and / or groups thereof.

[0029] Hereinafter, a specific configuration of a transportation system for a cryogenic fluid in a ship according to one embodiment of the present invention will be described with reference to the drawings.

[0030] FIG. 1 is a block diagram illustrating a transportation system for a cryogenic fluid in a ship according to one embodiment of the present invention, FIG. 2 is a process diagram schematically illustrating the transportation system for a cryogenic fluid in a ship of FIG. 1, and FIG. 3 is a control block diagram of the transportation system for a cryogenic fluid in a ship of FIG. 1.

[0031] Referring to FIGS. 1 to 3, the transportation system for a cryogenic fluid in a ship 1 according to one embodiment of the present invention stores a cryogenic fluid in a slush form and reduces the generation of boil-off gas (BOG), thereby not only storing a large amount of cryogenic fluid at a higher storage density compared to the related art, but also stably storing and transporting a large amount of cryogenic fluid for a long period of time.

[0032] To this end, the transportation system for a cryogenic fluid in a ship 1 according to one embodiment of the present invention may include a liquid phase cryogenic fluid storage unit 10, a solidification unit 20, a reliquefaction unit 30, a power generation unit 40, a solidification acceleration unit 50, a detection unit 60, and a control unit 70.

[0033] The liquid phase cryogenic fluid storage unit 10 may store and supply a liquid phase cryogenic fluid. To this end, the liquid phase cryogenic fluid storage unit 10 may include a cargo hold 11, a vacuum insulation layer 12, a balance water storage part 13, a liquid phase cryogenic fluid transfer line 14, and a liquid phase cryogenic fluid transfer valve 15.

[0034] The cargo hold 11 is a part provided in a hull (not shown) for storing the liquid phase cryogenic fluid, and may include a space in which solidification of the liquid phase cryogenic fluid may be performed. For example, liquid phase cryogenic fluid may be liquid hydrogen as an example. In this case, the liquid hydrogen may be liquid hydrogen supplied from the outside, or liquid hydrogen generated by being liquefied from gaseous hydrogen supplied from the outside. However, it is only an example and the spirit of the present invention is not limited thereto. For example, the liquid phase cryogenic fluid may contain at least one of liquid nitrogen, liquid oxygen, and natural gas.

[0035] The vacuum insulation layer 12 may block heat from penetrating from the outside of the cargo hold 11 into the inside of the cargo hold 11. To this end, the vacuum insulation layer 12 may be provided outside the cargo hold 11, and the balance water storage part 13 may be provided outside the vacuum insulation layer 12.

[0036] In this case, the vacuum insulation layer 12 may be provided with a predetermined thickness capable of blocking heat from penetrating from the outside of the cargo hold 11 into the inside of the cargo hold 11. The thickness of the vacuum insulation layer 12 may be directly related to an external heat blocking rate which may block external heat. However, when the thickness of the vacuum insulation layer 12 is formed to be thicker in consideration of only the external heat blocking rate, the external heat blocking rate is improved but there is a problem that an actual storage capacity of the cargo hold 11 is reduced. On the other hand, when the thickness of the vacuum insulation layer 12 is formed thinner in consideration of only the storage capacity of the cargo hold 11, the storage capacity of the cargo hold 11 may be increased, but there is a problem that the external heat blocking rate is lowered and thus the generation of the BOG increases inside the cargo hold 11. However, in the present embodiment, since the heat penetrating from the outside of the cargo hold 11 into the inside of the cargo hold 11 is absorbed by heat of fusion generated in the solidification unit 20, even when the thickness of the vacuum insulation layer 12 is provided in a thinner thickness than that of the conventional vacuum insulation layer, the heat penetrating from the outside of the cargo hold 11 into the inside of the cargo hold 11 may be effectively blocked. Accordingly, since the vacuum insulation layer 12 has a reduced thickness compared to the related art, even when the vacuum insulation layer 12 and the balance water storage part 13 are sequentially provided outside the cargo hold 11, the storage capacity of the cargo hold 11 may be substantially increased.

[0037] The liquid phase cryogenic fluid transfer line 14 is a line which transfers a liquid phase cryogenic fluid of a liquid phase cryogenic fluid storage tank 2 to the cargo hold 11, one end portion of the liquid phase cryogenic fluid transfer line 14 may be connected to the liquid phase cryogenic fluid storage tank 2, and the other end portion of the liquid phase cryogenic fluid transfer line 14 may be connected to a reliquefaction cryogenic fluid transfer line 33 of the reliquefaction unit 30 to be described later.

[0038] As the liquid phase cryogenic fluid 15 is provided on the liquid phase cryogenic fluid transfer line 14 to be opened or closed, it may be determined whether liquid phase cryogenic fluid is supplied to the cargo hold 11. The liquid phase cryogenic fluid transfer valve 15 may be opened and closed by the control unit 70 on the basis of a fluid signal of the detection unit 60 transmitted to the control unit 70.

[0039] The solidification unit 20 may freeze and fuse liquid phase cryogenic fluid to generate a slush cryogenic fluid in which the liquid phase cryogenic fluid and a solid phase cryogenic fluid are mixed. To this end, the solidification unit 20 may be connected to the liquid phase cryogenic fluid storage unit 10 to receive the liquid phase cryogenic fluid from the fluid liquid phase cryogenic fluid storage unit 10.

[0040] The solidification unit 20 may include a vacuum pump 21 which is connected to a first boil-off gas transfer line 31 of the reliquefaction unit 30 to be described later and reduces a pressure inside the cargo hold 11. The vacuum pump 21 may be driven while the liquid phase cryogenic fluid is supplied to the inside of the cargo hold 11. The vacuum pump 21 may be turned on and off by the control unit 70 on the basis of the fluid signal of the detection unit 60 transmitted to the control unit 70.

[0041] In this case, when the vacuum pump 21 is driven while the liquid cryogenic fluid is supplied to the inside of the cargo hold 11, the inside of the cargo hold 11 may be maintained in a vacuum state. For example, when the pressure inside the cargo hold 11 is reduced by the vacuum pump 21 to be a vacuum state, the pressure of the liquid phase cryogenic fluid stored inside the cargo hold 11 may be lowered, and a temperature of the liquid phase cryogenic fluid may be lowered. In addition, when the pressure of the liquid phase cryogenic fluid is reduced to near a triple point by the driving of the vacuum pump 21, the liquid phase cryogenic fluid may evaporate from a surface of the liquid phase cryogenic fluid. The temperature of the liquid phase cryogenic fluid is lowered through latent heat of vaporization generated at this time, and thus the solid phase cryogenic fluid may be crystallized on the surface of the liquid phase cryogenic fluid.

[0042] Meanwhile, FIG. 4 illustrates a graph for describing a phase change of a liquid cryogenic material performed in the solidification unit 20.

[0043] Referring further to FIG. 4, since a liquid-gas coexistence line is a left downward-right upward curve, as it goes from a first point A, that is, a point having a first temperature T1 and a first pressure P1, through a second point B, that is, a point having a second temperature T2 and a second pressure P2, to a third point C, that is, the point having a third temperature T3 and a third pressure P3 on the liquid-gas coexistence line, the pressure of the liquid phase cryogenic fluid decreases and the temperature thereof also decreases.

[0044] In particular, when the liquid phase cryogenic fluid reaches the third point C, that is, the triple point, the liquid phase cryogenic fluid may be phase-changed into the solid phase cryogenic fluid. In other words, even when the liquid phase cryogenic fluid supplied from the liquid phase cryogenic fluid storage unit 10 to the solidification unit 20 evaporates, the liquid phase cryogenic fluid may not deviate from the liquid-gas coexistence line. Therefore, even when the pressure of the cargo hold 11 containing the liquid phase cryogenic fluid by the vacuum pump 21 is lowered and the temperature of the liquid phase cryogenic fluid is reduced, the liquid phase cryogenic fluid and gas phase cryogenic fluid coexist inside the cargo hold 11 until the entire liquid phase cryogenic fluid contained in the cargo hold 11 is changed into a gas phase cryogenic fluid. When the temperature T3 of the liquid phase cryogenic fluid reaches the triple point in this state, as the liquid phase cryogenic fluid is changed into the solid phase cryogenic fluid, the slush cryogenic fluid in which the liquid phase cryogenic fluid and the solid phase cryogenic fluid are mixed may be generated inside the cargo hold 11.

[0045] The reliquefaction unit 30 may generate a reliquefied cryogenic fluid by receiving and reliquefying at least a part of the BOG generated by evaporation of the liquid phase cryogenic fluid from the solidification unit 20. To this end, the reliquefaction unit 30 may be connected to the solidification unit 20.

[0046] The reliquefaction unit 30 may include a first boil-off gas transfer line 31, a reliquefaction device 32, a reliquefaction cryogenic fluid transfer line 33, a first boil-off gas transfer valve 34, and a reliquefaction cryogenic fluid transfer valve 35.

[0047] The first boil-off gas transfer line 31 is a line which transfers at least a part of the BOG generated inside the cargo hold 11 to the reliquefaction device 32, and may connect the cargo hold 11 and the reliquefaction device 32.

[0048] The reliquefaction device 32 may liquefy the BOG supplied from the first boil-off gas transfer line 31. In this case, the reliquefaction device 32 may liquefy the BOG supplied from the first boil-off gas transfer line 31 by using a cooling medium.

[0049] The reliquefaction device 32 may be driven by power supplied from a power generation device 43 of the power generation unit 40 to be described later. When the power is supplied from the power generation device 43 of the power generation unit 40 to the reliquefaction device 32 to be described later, the reliquefaction device 32 is driven and the BOG is liquefied, thereby generating the reliquefied cryogenic fluid. In this case, since the amount of the BOG supplied to the reliquefaction device 32 is significantly less compared to the related art, the reliquefaction device 32 may be simplified compared to the related art, and energy required to reliquefy the BOG may also be significantly reduced compared to the related art.

[0050] Meanwhile, the reliquefied cryogenic fluid generated through the reliquefaction device 32 may be supplied to the cargo hold 11 along the reliquefaction cryogenic fluid transfer line 33 which connects the reliquefaction device 32 and the cargo hold 11. The reliquefied cryogenic fluid supplied to the inside of the cargo hold 11 may be mixed with the slush cryogenic fluid already generated in the cargo hold 11.

[0051] In this case, when the reliquefied cryogenic fluid is continuously supplied through the reliquefaction cryogenic fluid transfer line 33 in a state in which the pre-generated slush cryogenic fluid is stored inside the cargo hold 11, a ratio of the reliquefied cryogenic fluid may increase than that of the slush cryogenic fluid inside the cargo hold 11. The increase of the ratio of the reliquefied cryogenic fluid inside the cargo hold 11 may increase the amount of BOG generated.

[0052] Meanwhile, in order to prevent the increase in the amount of BOG generated due to the increase in the ratio of reliquefied cryogenic fluid, an ultrasonic generation device for solidification 51 of the solidification acceleration unit 50 to be described later may be driven to accelerate the solidification of the reliquefied cryogenic fluid mixed with the slush cryogenic fluid. Accordingly, it is possible to prevent the ratio of cryogenic fluid to the reliquefied slush cryogenic fluid from becoming excessively high inside the cargo hold 11. This will be explained later.

[0053] A first boil-off gas transfer valve 34 may be provided on the first boil-off gas transfer line 31. The first boil-off gas transfer valve 34 may be opened or closed by the control of the control unit 70 so that the BOG generated in the cargo hold 11 may be supplied to any one of the reliquefaction device 32 and the power generation device 43 of the power generation unit 40 to be described later. The first boil-off gas transfer valve 34 may be opened and closed by the control unit 70 on the basis of the fluid signal of the detection unit 60 transmitted to the control unit 70.

[0054] The reliquefaction cryogenic fluid transfer valve 35 may be provided on the reliquefaction cryogenic fluid transfer line 33. In this case, the first boil-off gas transfer valve 34 is an opening and closing valve which is opened or closed by the control of the control unit 70 and allows the reliquefied cryogenic fluid of the reliquefaction device 32 to be selectively supplied to the cargo hold 11. The reliquefaction cryogenic fluid transfer valve 35 may be opened and closed by the control unit 70 on the basis of the fluid signal of the detection unit 60 transmitted to the control unit 70.

[0055] The power generation unit 40 may generate power by receiving the remainder of the BOG generated by the evaporation of the liquid phase cryogenic fluid in the solidification unit 20, and may selectively supply the generated power to the reliquefaction unit 30. To this end, the power generation unit 40 may include a second boil-off gas transfer line, a second boil-off gas transfer valve 42, a power generation device 43, and a power transfer line 44.

[0056] The second boil-off gas transfer line may connect the cargo hold 11 and the power generation device 43 to transfer the BOG generated inside the cargo hold 11 to the power generation device 43. The second boil-off gas transfer line 41 may be branched off from the first boil-off gas transfer line 31, and the second boil-off gas transfer valve 42 may be provided on the second boil-off gas transfer line 42. The second boil-off gas transfer valve 42 may be opened and closed by the control unit 70 on the basis of the fluid signal of the detection unit 60 transmitted to the control unit 70.

[0057] The power generation device 43 may receive the BOG from the second boil-off gas transfer line 41 and convert the supplied BOG into power. For example, the power generation device 43 may be provided as a fuel cell. The power converted through the power generation device 43 may be supplied to a power consumer 3 in the ship through power transfer lines 44, 45 or to the reliquefaction device 32.

[0058] The solidification acceleration unit 50 may accelerate the solidification of the reliquefied cryogenic fluid mixed with the slush cryogenic fluid by applying energy to the solidification unit 20. To this end, the solidification acceleration unit 50 may include the ultrasonic generation device for solidification 51.

[0059] The ultrasonic generation device for solidification 51 may generate an ultrasonic signal. A frequency of the ultrasonic signal generated from the ultrasonic generation device for solidification 51 may be controlled by the control unit 70. In this case, the ultrasonic generation device for solidification 51 may be provided on at least a part of an inner surface of the cargo hold 11, for example, on an inner bottom surface of the cargo hold 11.

[0060] In this case, ultrasonic vibration may be generated according to the ultrasonic signal generated in the ultrasonic generation device for solidification 51. The ultrasonic vibration generated in this way may be transferred to the reliquefied cryogenic fluid mixed with the slush cryogenic fluid stored in the cargo hold 11. When the ultrasonic vibration is transferred to the reliquefied cryogenic fluid mixed with the slush cryogenic fluid, as the reliquefied cryogenic fluid mixed with the slush cryogenic fluid is alternately depressurized or pressurized, a cavitation phenomenon in which the cavities repeatedly appear and disappear may occur in the reliquefied cryogenic fluid mixed with the slush cryogenic fluid. This phenomenon may accelerate the solidification of the reliquefied cryogenic fluid mixed with slush cryogenic fluid.

[0061] Meanwhile, in the embodiment, an example has been described in which energy for pulverizing the particles of the solid phase cryogenic fluid included in the slush cryogenic fluid is ultrasonic, but it is merely an example and the spirit of the present invention is not limited thereto.

[0062] The detection unit 60 may generate a fluid signal for at least one of the liquid phase cryogenic fluid, the solid cryogenic fluid, the slush cryogenic fluid, and the BOG stored in the cargo hold 11. In this case, the detection unit 60 may be provided in the cargo hold 11, and the fluid signal generated from the detection unit 60 may be transferred to the control unit 70 so that the control unit 70 may be utilized to control at least one of the liquid phase cryogenic fluid storage unit 10, the solidification unit 20, the reliquefaction unit 30, the power generation unit 40, and the solidification acceleration unit 50.

[0063] The control unit 70 may control at least one of the liquid phase cryogenic fluid storage unit 10, the solidification unit 20, the reliquefaction unit 30, the power generation unit 40, and the solidification acceleration unit 50.

[0064] In this case, the control unit 70 may be configured, for example, a small, embedded computer and may be provided with a data processing unit including a program, a memory, and a CPU. Here, the program may include an algorithm for controlling at least one of the fluid storage unit 10, the solidification unit 20, the reliquefaction unit 30, the power generation unit 40, and the solidification acceleration unit 50 based on the fluid signal transferred from the detection unit 60. In addition, the program may be stored in the memory of a computer memory medium such as a flexible disk, a compact disk, a hard disk, a MO (magneto-optical disk), etc. and may be installed in the control unit 70.

[0065] The transportation system for a cryogenic fluid in a ship 1 having the aforementioned configuration has an effect of storing and transporting a large amount of cryogenic fluid with a higher density than the related art because the liquid phase cryogenic fluid is solidified in the solidification unit 20 to form slush cryogenic fluid in which the liquid phase cryogenic fluid and the solid phase cryogenic fluid are mixed, and the slush-state cryogenic fluid formed in this way may be densified by solid particles.

[0066] In addition, as heat penetrating from the outside to the inside of the cargo hold 11 is absorbed by heat of fusion generated in the solidification unit 20 and the solidification of the reliquefied cryogenic fluid mixed with the slush cryogenic fluid is accelerated through the solidification acceleration unit 50, the generation of the BOG in the cargo hold 11 may be reduced. Accordingly, there is an effect that it is possible to stably store and transport the cryogenic fluid for a long period of time compared to the related art.

[0067] In addition, since the amount of the BOG generated in the cargo hold 11 is reduced compared to the related art, the thickness of the vacuum insulation layer 12 of the cargo hold 11 may be significantly reduced and an equipment for processing the BOG may be simplified compared to the related art, and thus there is an effect of ensuring economic efficiency.

[0068] Hereinafter, a transportation system for a cryogenic fluid in a ship according to another embodiment of the present invention will be described with reference to FIGS. 5 to 7.

[0069] FIG. 5 is a block diagram illustrating a transportation system for a cryogenic fluid in a ship according to another embodiment of the present invention, FIG. 6 is a process diagram schematically illustrating the transportation system for a cryogenic fluid in a ship of FIG. 5, and FIG. 7 is a control block diagram of the transportation system for a cryogenic fluid in a ship of FIG. 5.

[0070] Referring to FIGS. 5 to 7, a transportation system for a cryogenic fluid in a ship 1' according to another embodiment of the present invention may include a liquid phase cryogenic fluid storage unit 10, a solidification unit 20', a reliquefaction unit 30, a power generation unit 40, a solidification acceleration unit 50, a detection unit 60, and a control unit 70. However, since the transportation system for a cryogenic fluid in a ship illustrated in FIGS. 5 and 6 is substantially the same as the transportation system for a cryogenic fluid in a ship described with reference to FIGS. 1 to 3, except for the solidification unit 20', hereinafter, the description will focus on the solidification unit 20' corresponding to a difference, and the same matters will be cited by the description and the reference numerals of the aforementioned embodiments.

[0071] The solidification unit 20' may include a pressure regulating pump 22 which is provided in the reliquefaction cryogenic fluid transfer line 33, an injection device 23 which is provided at a rear end of the pressure regulating pump 22 and of which at least a part is disposed inside the cargo hold 11, and a cold heat transfer line 24 which connects the reliquefaction device 32 and the injection device 23 and transfers cold heat of a cooling medium of the reliquefaction device 32 to the injection device 23.

[0072] The pressure regulating pump 22 may pressurize the liquid phase cryogenic fluid at a predetermined pressure. The liquid phase cryogenic fluid pressurized through the pressure regulating pump 22 may be supercooled by the cold heat transferred through the cold heat transfer line 24 and then supplied to the injection device 23.

[0073] The injection device 23 may inject the supercooled liquid phase cryogenic fluid into the cargo hold 11. The liquid phase cryogenic fluid supplied to the injection device 23 may be phase-changed while passing through the injection device 23.

[0074] In this case, the injection device 23 may be provided with an injection hole (not shown) of substantially the same size. Accordingly, a particle size of the supercooled liquid phase cryogenic fluid which passed through the injection device 23 may also be substantially the same. In this way, as the supercooled liquid phase cryogenic fluid injected through the injection device 23 is injected while having substantially the same particle size, it is possible to assist so as to easily perform a phase change of the supercooled liquid phase cryogenic fluid passed through the injection device 23.

[0075] Meanwhile, when the phase change of the liquid phase cryogenic fluid of the supercooled state is easily performed by the injection device 23 in this way, at least a part of the supercooled liquid phase cryogenic fluid injected into the cargo hold 11 through the injection device 23 may be vaporized and solidified. To describe this, first, the supercooled liquid phase cryogenic fluid injected through the injection device 23 increases in volume and decreases in pressure. A vaporization point of the supercooled liquid phase cryogenic fluid injected through the injection device 23 is lowered due to the decrease in pressure, so that the supercooled liquid phase cryogenic fluid vaporizes. By the latent heat of vaporization of the supercooled liquid phase cryogenic fluid converted to a gas state, the heat of fusion of the supercooled liquid phase cryogenic fluid is removed, and the solidified cryogenic fluid is accumulated at a bottom of the cargo hold 11. The solidified cryogenic fluid may be mixed with the liquid phase cryogenic fluid to form the slush cryogenic fluid.

[0076] The cold heat transfer line 24 may connect the reliquefaction device 32 and the injection device 23 and supply the cooling medium used for reliquefaction of the BOG in the reliquefaction device 32 to the injection device 23. In this case, the cooling medium supplied to the injection device 23 through the cold heat transfer line 24 may exchange heat with the liquid phase cryogenic fluid supplied to the injection device 23 through the liquid phase cryogenic fluid transfer line 14, and the Joule-Thomson cooling effect is maximized by such heat exchange, the liquid phase cryogenic fluid is supercooled, so that the supercooled liquid phase cryogenic fluid may be injected through the injection device 23.

[0077] Hereinafter, a transportation system for a cryogenic fluid in a ship according to still another embodiment of the present invention will be described with reference to FIGS. 8 to 10.

[0078] FIG. 8 is a block diagram illustrating a transportation system for a cryogenic fluid in a ship according to still another embodiment of the present invention, FIG. 9 is a process diagram schematically illustrating the transportation system for a cryogenic fluid in a ship of FIG. 8, and FIG. 10 is a control block diagram of the transportation system for a cryogenic fluid in a ship of FIG. 8.

[0079] Referring to FIGS. 8 to 10, the transportation system for a cryogenic fluid in a ship 1" according to still another embodiment of the present invention may include a liquid phase cryogenic fluid storage unit 10, a solidification unit 20", a reliquefaction unit 30, a power generation unit 40, a detection unit 60, and a control unit 70. However, since the liquid phase cryogenic fluid storage unit 10, the reliquefaction unit 30, the power generation unit 40, and the control unit 70 of the transportation system for a cryogenic fluid in a ship 1" illustrated in FIGS. 8 to 10 are substantially the same as the liquid phase cryogenic fluid storage unit 10, the reliquefaction unit 30, the power generation unit 40, and the control unit 70 of the transportation system for a cryogenic fluid in a ship 1 illustrated in FIGS. 1 to 3 or the liquid phase cryogenic fluid storage unit 10, the reliquefaction unit 30, the power generation unit 40, and the control unit 70 of the transportation system for a cryogenic fluid in a ship 1' illustrated in FIGS. 5 to 7, hereinafter, the description will focus on the solidification unit 20", corresponding to a difference, and the same matters will be cited by the description and the reference numerals of the above-described embodiment.

[0080] The solidification unit 20" may include an ultrasonic generation device for solidification 25 provided in at least one of inner surfaces of the cargo hold 11. Here, the inner surface of the cargo hold 11 may be at least one of an inner bottom surface, a left side wall surface, a right side wall surface, a front side wall surface, and a rear side wall surface. In the embodiment, an example is described in which the ultrasonic generation device for solidification 25 is installed on all of the inner bottom surface, the left side wall surface, the right side wall surface, the front side wall surface, and the rear side wall surface of the inner surface of the cargo hold 11, but it is merely an example, and the spirit of the present invention is not limited thereto. An installation location, a number of installations, etc. of the ultrasonic generation device for solidification 25 may be appropriately changed as necessary.

[0081] In this case, the ultrasonic generation device for solidification 25 solidifies at least a part of the liquid phase cryogenic fluid supplied to the inside of the cargo hold 11 so that the slush cryogenic fluid in which the liquid phase cryogenic fluid and the solid phase cryogenic fluid are mixed may be generated inside the cargo hold 11. In addition, the ultrasonic generation device for solidification 25 may solidify at least a part of the reliquefied cryogenic fluid supplied from the reliquefaction unit 30 to the inside of the cargo hold 11 and the slush cryogenic fluid mixed with the reliquefied cryogenic fluid.

[0082] To this end, the ultrasonic generation device for solidification 25 may generate an ultrasonic signal. A frequency of the ultrasonic signal generated from the ultrasonic generation device for solidification 25 may be controlled by the control unit 70. In this case, ultrasonic vibration may be generated according to the ultrasonic signal generated in the ultrasonic generation device for solidification 25. The ultrasonic vibration generated in this way may be transferred to at least one of the liquid phase cryogenic fluid, the reliquefied cryogenic fluid, and the slush cryogenic fluid mixed with the reliquefied cryogenic fluid stored in the cargo hold 11. When the ultrasonic vibration is transferred to at least one of the liquid phase cryogenic fluid, the reliquefied cryogenic fluid, and the slush cryogenic fluid mixed with the reliquefied cryogenic fluid, at least one of the liquid phase cryogenic fluid, the reliquefied cryogenic fluid, and the slush cryogenic fluid mixed with the reliquefied cryogenic fluid may be solidified while alternately pressurized or depressurized.

[0083] Although the embodiments of the present invention have been described as specific embodiments, they are merely examples, and the present invention is not limited thereto, but should be interpreted to have the broadest scope in accordance with the basic idea disclosed in this specification. Those skilled in the art may combine / substitute the disclosed embodiments to implement patterns of shapes not specified, but this also does not depart from the scope of the present invention. In addition, those skilled in the art may easily change or modify the disclosed embodiments on the basis of this specification, and it is clear that such changes or modifications also fall within the scope of the present invention.

Claims

1. A transportation system for a cryogenic fluid in a ship comprising: a liquid phase cryogenic fluid storage unit including a cargo hold for receiving and storing a liquid phase cryogenic fluid; a solidification unit connected to the liquid phase cryogenic fluid storage unit and solidifying at least a part of the liquid phase cryogenic fluid stored in the liquid phase cryogenic fluid storage unit to generate a slush cryogenic fluid in which a liquid phase and a solid phase are mixed; a reliquefaction unit which is connected to the solidification unit and generating a reliquefied cryogenic fluid by receiving and reliquefying at least a part of boil-off gas (BOG) generated by evaporation of the liquid phase cryogenic fluid in the solidification unit; and a power generation unit connected to the solidification unit, receiving the remainder of the BOG generated by the evaporation of the liquid phase cryogenic fluid in the solidification unit to generate power, and selectively supplying the generated power to the reliquefaction unit, wherein the reliquefied cryogenic fluid generated by being reliquefied in the reliquefaction unit is supplied to the cargo hold and is mixed with the slush cryogenic fluid, and the transportation system for a cryogenic fluid in a ship further comprising a solidification acceleration unit connected to the cargo hold and solidifying the reliquefied cryogenic fluid by applying energy to the inside of the cargo hold to induce a cavitation phenomenon in the reliquefied cryogenic fluid stored inside the cargo hold.

2. The transportation system for a cryogenic fluid in a ship of claim 1, further comprising: a detection unit connected to the liquid phase cryogenic fluid storage unit and generating a fluid signal for at least one of the liquid phase cryogenic fluid stored in the liquid phase cryogenic fluid storage unit, the solid phase cryogenic fluid, the slush cryogenic fluid, and the BOG; and a control unit which controls at least one of the liquid phase cryogenic fluid storage unit, the solidification unit, the reliquefaction unit, the power generation unit, and the solidification acceleration unit on the basis of the fluid signal generated from the detection unit.

3. The transportation system for a cryogenic fluid in a ship of claim 1, wherein the liquid phase cryogenic fluid storage unit further includes: a vacuum insulation layer provided outside the cargo hold; and a balance water storage part provided outside the vacuum insulation layer.

4. The transportation system for a cryogenic fluid in a ship of claim 1, wherein the reliquefaction unit includes: a first boil-off gas transfer line of which one end portion is connected to the cargo hold; a reliquefaction device connected to the other end portion of the first boil-off gas transfer line and reliquefying the BOG by using a cooling medium; a reliquefaction cryogenic fluid transfer line connecting the reliquefaction device and the cargo hold; a first boil-off gas transfer valve provided on the first boil-off gas transfer line; and a reliquefaction cryogenic fluid transfer valve provided on the reliquefaction cryogenic fluid transfer line.

5. The transportation system for a cryogenic fluid in a ship of claim 4, wherein the solidification unit includes a vacuum pump which is connected to the first boil-off gas transfer line and reduces a pressure inside the cargo hold.

6. The transportation system for a cryogenic fluid in a ship of claim 4, wherein the solidification unit includes: a pressure regulating pump provided on the reliquefaction cryogenic fluid transfer line; an injection device provided at a rear end of the pressure regulating pump and at least a part of which is disposed on the inside of the cargo hold; and a cold heat transfer line which connects the reliquefaction device and the injection device and transfers cooling heat of the cooling medium of the reliquefaction device to the injection device.

7. The transportation system for a cryogenic fluid in a ship of claim 5 or 6, wherein the solidification acceleration unit includes: an ultrasonic generation device for accelerating solidification which is provided on at least one of inner surfaces of the cargo hold and selectively generates ultrasonic energy for transferring to the reliquefied cryogenic fluid stored in the cargo hold, and the ultrasonic energy generated in the ultrasonic generation device for accelerating solidification solidifies the reliquefied cryogenic fluid by inducing cavitation phenomenon in the reliquefied cryogenic fluid.

8. A transportation system for a cryogenic fluid in a ship comprising: a liquid phase cryogenic fluid storage unit including a cargo hold which receives and stores liquid phase cryogenic fluid; a solidification unit connected to the liquid phase cryogenic fluid storage unit and solidifying at least a part of the liquid phase cryogenic fluid stored in the liquid phase cryogenic fluid storage unit to generate a slush cryogenic fluid in which a liquid phase and a solid phase are mixed; a reliquefaction unit which is connected to the solidification unit 20 and generating a reliquefied cryogenic fluid by receiving and reliquefying at least a part of the BOG generated by evaporation of the liquid phase cryogenic fluid in the solidification unit; and a power generation unit connected to the solidification unit receiving the remainder of the BOG generated by the evaporation of the liquid phase cryogenic fluid in the solidification unit to generate power, and selectively supplying the generated power to the reliquefaction unit, wherein the reliquefied cryogenic fluid generated by being reliquefied in the reliquefaction unit is supplied to the cargo hold and is mixed with the slush cryogenic fluid, the solidification unit includes an ultrasonic generation device for solidification which is provided on at least one of the inner surfaces of the cargo hold and selectively generates ultrasonic energy for transferring to the liquid phase cryogenic fluid or the reliquefied cryogenic fluid stored in the cargo hold, and the ultrasonic energy generated in the ultrasonic generation device for solidification solidifies the liquid cryogenic fluid or the reliquefied cryogenic fluid by inducing a cavitation phenomenon in the liquid phase cryogenic fluid or the reliquefied cryogenic fluid.

9. The transportation system for a cryogenic fluid in a ship of any one of claims 5, 6, and 8, wherein the liquid phase cryogenic fluid storage unit further includes: a liquid phase cryogenic fluid connected to a reliquefaction cryogenic fluid transfer line and supplying the liquid phase cryogenic fluid to the cargo hold; and a liquid phase cryogenic fluid transfer valve provided on the liquid phase cryogenic fluid transfer line.

10. The transportation system for a cryogenic fluid in a ship of claim 9, wherein the power generation unit includes: a second boil-off gas transfer line which is branched off from a first boil-off gas transfer line; a second boil-off gas transfer valve provided on the second boil-off gas transfer line; a power generation device connected to the second boil-off gas transfer line and producing power by using the BOG; and a power transfer line connecting the power generation device and a reliquefaction device and transferring at least a part of the power produced in the power generation device to the reliquefaction device.

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