Cryogenic fluid transport systems for ships

Abstract

A cryogenic fluid transport system for a ship is provided, which is capable of storing a large amount of cryogenic fluid and stably storing and transporting the fluid for a long period of time. [Solution] The cryogenic fluid transport system of the present invention includes a liquid phase cryogenic fluid storage section which is supplied with and stores liquid phase cryogenic fluid; a solidification section which solidifies a portion of the liquid phase cryogenic fluid stored in the liquid phase cryogenic fluid storage section to generate a slush cryogenic fluid in which liquid phase cryogenic fluid and solid phase cryogenic fluid are mixed; a re-liquefaction section which is supplied with a portion of the evaporated gas generated by evaporation of the liquid phase cryogenic fluid from the solidification section and re-liquefies the gas to generate a re-liquefied cryogenic fluid; and a power generation section which is supplied with the remainder of the evaporated gas generated by evaporation of the liquid phase cryogenic fluid from the solidification section to generate electricity and selectively supply the generated electricity to the re-liquefaction section, and the re-liquefied cryogenic fluid generated in the re-liquefaction section is supplied to the solidification section and mixed with the slush cryogenic fluid.

Description

Technical Field

[0001] The present invention relates to a cryogenic fluid transportation system for ships.

Background Art

[0002] Generally, in order to efficiently transport a large amount of a fluid that is in the gas phase at room temperature by storing it in a limited space, such as a cargo hold of a ship, it is necessary to increase the storage density of the fluid by changing the phase of the gas-phase fluid to a liquid-phase fluid to increase the density.

[0003] At this time, a method of lowering the temperature of a fluid that exists as a gas phase at room temperature to a cryogenic temperature that is relatively lower than room temperature and changing the phase of the gas-phase fluid to a cryogenic liquid-phase fluid (hereinafter referred to as "liquid-phase cryogenic fluid") is recognized as an appropriate method for the large-scale storage and transportation of cryogenic fluids.

[0004] On the other hand, the lower the boiling point of the liquid-phase cryogenic fluid stored in the cargo hold, the easier it is to further promote the evaporation of the liquid-phase cryogenic fluid. When the liquid-phase cryogenic fluid evaporates in this way, a gas-phase cryogenic fluid, such as boil-off gas (BOG), is generated. Such evaporation gas increases the pressure inside the cargo hold and reduces the safety of storing the liquid-phase cryogenic fluid. Conventionally, therefore, a heat insulation technology has been applied to the cargo hold, or a re-liquefaction technology for re-liquefying and treating the evaporation gas has been applied.

[0005] However, when a heat 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 because there is a limit to reducing the generation of evaporation gas generated inside the cargo hold.

[0006] In addition, when a re-liquefaction facility for evaporation gas is connected to the cargo hold, a large amount of energy is required for re-liquefying the evaporation gas, and there is a problem that the substantial storage capacity of the cargo hold is reduced by the re-liquefaction facility for evaporation gas in a ship with limited space.

[0007] Therefore, there is a need for a cryogenic fluid transport system on ships that can not only reduce the generation of evaporated gases and store large quantities of cryogenic fluids, but also stably store and transport cryogenic fluids for long periods of time. [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention was made to solve the above-mentioned conventional problems, and the object of the present invention is to provide a cryogenic fluid transport system for ships that can not only reduce the generation of evaporated gas and store large quantities of cryogenic fluid, but also stably store and transport cryogenic fluid for long periods of time. [Means for solving the problem]

[0009] The cryogenic fluid transport system for ships according to the present invention includes: a liquid-phase cryogenic fluid storage unit that is supplied with and stores a liquid-phase cryogenic fluid; a solidification unit connected to the liquid-phase cryogenic fluid storage unit that solidifies at least a portion of the liquid-phase cryogenic fluid stored in the liquid-phase cryogenic fluid storage unit to generate a slush cryogenic fluid in which the liquid-phase cryogenic fluid and the solid-phase cryogenic fluid are mixed; a reliquefaction unit connected to the solidification unit that is supplied with at least a portion of the evaporated gas generated by the evaporation of the liquid-phase cryogenic fluid from the solidification unit to reliquefy it and generate a reliquefied cryogenic fluid; and a power generation unit connected to the solidification unit that is supplied with the remaining evaporated gas generated by the evaporation of the liquid-phase cryogenic fluid from the solidification unit to generate electricity and selectively supplies the generated electricity to the reliquefaction unit, wherein the reliquefied cryogenic fluid generated by reliquefaction in the reliquefaction unit is supplied to the solidification unit and mixed with the slush cryogenic fluid.

[0010] Furthermore, the system may include a solidification promoting unit connected to the solidification unit, which applies energy to the solidification unit to promote the solidification of the re-liquefied cryogenic fluid mixed with the slush cryogenic fluid.

[0011] The system may further include a sensing unit connected to the liquid-phase cryogenic fluid storage unit, which generates a fluid signal for at least one of the liquid-phase cryogenic fluid, solid-phase cryogenic fluid, slush cryogenic fluid, and evaporated gas stored in the liquid-phase cryogenic fluid storage unit, and a control unit that controls at least one of the liquid-phase cryogenic fluid storage unit, solidification unit, reliquefaction unit, power generation unit, and solidification promotion unit based on the fluid signal generated by the sensing unit.

[0012] Furthermore, the liquid-phase cryogenic fluid storage section may include a cargo hold provided in the hull, which has a space for storing the liquid-phase cryogenic fluid and for solidifying the liquid-phase cryogenic fluid; a vacuum insulation layer provided outside the cargo hold; and an equilibrium water storage section provided outside the vacuum insulation layer.

[0013] Furthermore, the reliquefaction unit may include a first evaporative gas transfer line, one end of which is connected to the cargo hold; a reliquefaction device, connected to the other end of the first evaporative gas transfer line, which reliquefies the evaporative gas using a cooling medium; a reliquefaction cryogenic fluid transfer line, connecting the reliquefaction device and the cargo hold; a first evaporative gas transfer valve provided in the first evaporative gas transfer line; and a reliquefaction cryogenic fluid transfer valve provided in the reliquefaction cryogenic fluid transfer line.

[0014] Furthermore, the solidification unit may include a vacuum pump connected to the first evaporative gas transfer line to reduce the pressure inside the cargo hold.

[0015] Furthermore, the solidification unit may include a pressure regulating pump provided in the reliquefied cryogenic fluid transfer line, an injection device provided at the rear end of the pressure regulating pump and at least a portion of which is located inside the cargo hold, and a cold transfer line connecting the reliquefied device and the injection device, which transmits the coldness of the cooling medium of the reliquefied device to the injection device.

[0016] Furthermore, the solidification section may include an ultrasonic generator for solidification provided on at least one of the inner surfaces of the cargo hold.

[0017] Furthermore, the solidification promotion unit may include an ultrasonic generator for promoting solidification, which is provided on at least one of the inner surfaces of the cargo hold.

[0018] Furthermore, the liquid-phase cryogenic fluid storage unit may further include a liquid-phase cryogenic fluid transfer line 14 connected to the re-liquefied cryogenic fluid transfer line and supplying the liquid-phase cryogenic fluid to the cargo warehouse, and a liquid-phase cryogenic fluid transfer valve provided in the liquid-phase cryogenic fluid transfer line.

[0019] Furthermore, the power generation unit may include a second evaporative gas transfer line branching off from the first evaporative gas transfer line, a second evaporative gas transfer valve provided in the second evaporative gas transfer line, a power generation device connected to the second evaporative gas transfer line and generating electricity using the evaporative gas, and a power transfer line connected between the power generation device and the reliquefaction device and transferring at least a portion of the electricity generated by the power generation device to the reliquefaction device. [Effects of the Invention]

[0020] According to embodiments of the present invention, it is possible to reduce the generation of evaporated gases and store large quantities of cryogenic fluid, as well as to stably store and transport cryogenic fluid for long periods of time. [Brief explanation of the drawing]

[0021] [Figure 1] This is a block diagram showing a cryogenic fluid transport system for a ship in one embodiment of the present invention. [Figure 2] Figure 1 is a schematic process diagram illustrating the cryogenic fluid transport system of the ship. [Figure 3] Figure 1 is a control block diagram of the cryogenic fluid transport system of a ship. [Figure 4]It is a graph for explaining the phase change of the liquid-phase cryogenic substance performed in the solidification section in the cryogenic fluid transportation system of the ship in FIG. 1. [Figure 5] In another embodiment of the present invention, it is a block diagram showing a cryogenic fluid transportation system of a ship. [Figure 6] It is a process diagram schematically showing the cryogenic fluid transportation system of the ship in FIG. 5. [Figure 7] It is a control block diagram of the cryogenic fluid transportation system of the ship in FIG. 5. [Figure 8] In still another embodiment of the present invention, it is a block diagram showing a cryogenic fluid transportation system of a ship. [Figure 9] It is a process diagram schematically showing the cryogenic fluid transportation system of the ship in FIG. 8. [Figure 10] It is a control block diagram of the cryogenic fluid transportation system of the ship in FIG. 8.

Embodiments for Carrying Out the Invention

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

[0023] In the description of the present invention, when it is determined that the specific description of related known configurations or functions makes the gist of the present invention unclear, the detailed description thereof will be omitted.

[0024] Also, when a certain component is referred to as being "connected" to another component, it should be understood that it may be directly connected to the other component, but other components may exist in between.

[0025] The terms used in this specification are merely used for explaining specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly has a different meaning.

[0026] Furthermore, in this specification, expressions such as "one side," "the other side," "upper side," and "lower side" are explained based on the illustrations in the drawings, and it should be made clear in advance that they will be expressed differently if the orientation of the object changes. For similar reasons, some components in the attached drawings are exaggerated, omitted, or shown schematically, and the size of each component does not fully reflect the actual size.

[0027] Furthermore, while terms including ordinal numbers, such as "first," "second," etc., are used to describe various components, those components are not limited by such terms. These terms are used solely for the purpose of distinguishing one component from others.

[0028] As used herein, "includes" embodies a particular characteristic, domain, integer, stage, operation, element and / or component, and does not exclude the presence or addition of other particular characteristics, domains, integers, stages, operations, elements, components and / or groups.

[0029] The specific configuration of a cryogenic fluid transport system for a ship in one embodiment of the present invention will be described below with reference to the drawings.

[0030] Figure 1 is a block diagram showing a cryogenic fluid transport system for a ship in one embodiment of the present invention, Figure 2 is a schematic process diagram showing the cryogenic fluid transport system for the ship in Figure 1, and Figure 3 is a control block diagram of the cryogenic fluid transport system for the ship in Figure 1.

[0031] Referring to Figures 1-3, in one embodiment of the present invention, the cryogenic fluid transport system 1 for ships stores the cryogenic fluid in slush form, reducing the generation of boil-off gas (BOG). As a result, it is possible to store a large quantity of cryogenic fluid at a higher storage density than conventional systems, and to stably store and transport the cryogenic fluid for a long period of time.

[0032] For this purpose, in one embodiment of the present invention, the cryogenic fluid transport system 1 for a ship includes 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 sensing unit 60, and a control unit 70.

[0033] The liquid-phase cryogenic fluid storage unit 10 is capable of storing and supplying liquid-phase cryogenic fluid. To this end, the liquid-phase cryogenic fluid storage unit 10 includes a cargo hold 11, a vacuum insulation layer 12, an equilibrium water storage unit 13, a liquid-phase cryogenic fluid transfer line 14, and a liquid-phase cryogenic fluid transfer valve 15.

[0034] The cargo hold 11 is provided in the hull (not shown) and is a portion for storing a liquid-phase cryogenic fluid, and may include a space in which the liquid-phase cryogenic fluid can be solidified. For example, the liquid-phase cryogenic fluid is liquid hydrogen as one example. In this case, the liquid hydrogen is either liquid hydrogen supplied from an external source or liquid hydrogen produced by liquefying gaseous hydrogen supplied from an external source. However, this is merely an example and does not limit the concept of the present invention. For example, the liquid-phase cryogenic fluid includes at least one of liquid nitrogen, liquid oxygen, and natural gas.

[0035] The vacuum insulation layer 12 can block heat from entering the cargo hold 11 from the outside. For this purpose, the vacuum insulation layer 12 is provided on the outside of the cargo hold 11, and the equilibrium water storage section 13 is provided on the outside of the vacuum insulation layer 12.

[0036] In this configuration, the vacuum insulation layer 12 is provided with a predetermined thickness that can block heat from entering the cargo hold 11 from the outside. The thickness of such a vacuum insulation layer 12 is directly related to the external heat insulation rate, which is the rate at which external heat can be blocked. However, if the thickness of the vacuum insulation layer 12 is increased by considering only the external heat insulation rate, the external heat insulation rate improves, but there is a problem that the actual storage capacity of the cargo hold 11 decreases. On the other hand, if the thickness of the vacuum insulation layer 12 is made thin by considering only the storage capacity of the cargo hold 11, the storage capacity of the cargo hold 11 can be increased, but there is a problem that the external heat insulation rate decreases, and the generation of evaporated gases inside the cargo hold 11 increases. However, in this embodiment, as the heat entering the cargo hold 11 from the outside is absorbed by the heat of fusion generated in the solid phase section 20, the heat entering the cargo hold 11 from the outside can be effectively blocked even if the thickness of the vacuum insulation layer 12 is thinner than that of a conventional vacuum insulation layer. Consequently, since the vacuum insulation layer 12 has a reduced thickness compared to conventional designs, the storage capacity of the cargo warehouse 11 can be substantially increased even if the vacuum insulation layer 12 and the equilibrium water storage section 13 are sequentially installed on the outside of the cargo warehouse 11.

[0037] The liquid-phase cryogenic fluid transfer line 14 is a line that transfers the liquid-phase cryogenic fluid from the liquid-phase cryogenic fluid storage tank 2 to the cargo warehouse 11. One end of the liquid-phase cryogenic fluid transfer line 14 is connected to the liquid-phase cryogenic fluid storage tank 2, and the other end of the liquid-phase cryogenic fluid transfer line 14 is connected to the re-liquefied cryogenic fluid transfer line 33 of the re-liquefaction unit 30, which will be described later.

[0038] The liquid-phase cryogenic fluid transfer valve 15 is installed in the liquid-phase cryogenic fluid transfer line 14, and when it is opened or closed, it determines whether or not liquid-phase cryogenic fluid is supplied to the cargo hold 11. The liquid-phase cryogenic fluid transfer valve 15 is opened and closed by the control unit 70 based on the fluid signal from the sensing unit 60 transmitted to the control unit 70.

[0039] The solidification unit 20 can freeze and thaw the liquid-phase cryogenic fluid to produce a slush cryogenic fluid in which the liquid-phase cryogenic fluid and solid-phase cryogenic fluid are mixed. For this purpose, the solidification unit 20 is connected to the liquid-phase cryogenic fluid storage unit 10, and the liquid-phase cryogenic fluid is supplied from the liquid-phase cryogenic fluid storage unit 10.

[0040] Such a solidification unit 20 is connected to the first evaporated gas transfer line 31 of the reliquefaction unit 30, which will be described later, and includes a vacuum pump 21 that reduces the pressure inside the cargo hold 11. Such a vacuum pump 21 is driven when a liquid-phase cryogenic fluid is supplied inside the cargo hold 11. The vacuum pump 21 is turned on and off by the control unit 70 based on a fluid signal from the sensing unit 60 transmitted to the control unit 70.

[0041] At this time, when the vacuum pump 21 is driven while liquid-phase cryogenic fluid is supplied to the inside of the cargo hold 11, the inside of the cargo hold 11 is maintained in a vacuum state. For example, when the inside of the cargo hold 11 is depressurized by the vacuum pump 21 and becomes a vacuum state, the pressure of the liquid-phase cryogenic fluid stored inside the cargo hold 11 decreases, and the temperature of the liquid-phase cryogenic fluid decreases. In addition, when the liquid-phase cryogenic fluid is depressurized to near its triple point by the operation of the vacuum pump 21, the liquid-phase cryogenic fluid evaporates on its surface. The latent heat of vaporization generated at this time lowers the temperature of the liquid-phase cryogenic fluid, causing the solid-phase cryogenic fluid to crystallize on the surface of the liquid-phase cryogenic fluid.

[0042] On the other hand, Figure 4 shows a graph illustrating the phase change of the liquid-phase cryogenic substance that occurs in the solidification section 20.

[0043] Referring further to Figure 4, the liquid-gas coexistence line is a curve that slopes downward to the left and upward to the right. Therefore, as you move from the first point A on the liquid-gas coexistence line, i.e., the point with a first temperature T1 and a first pressure P1, past the second point B, i.e., the point with a second temperature T2 and a second pressure P2, to the third point C, i.e., the point with a third temperature T3 and a third pressure P3, the pressure of the liquid-phase cryogenic fluid decreases, and the temperature also decreases.

[0044] In particular, when the liquid-phase cryogenic fluid reaches the third point C, i.e., the triple point, it undergoes a phase change to a solid-phase cryogenic fluid. That is, even if 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 cannot deviate from the liquid-gas coexistence line. Therefore, even if the pressure in the cargo hold 11 containing the liquid-phase cryogenic fluid decreases due to the vacuum pump 21, and the temperature of the liquid-phase cryogenic fluid decreases, the liquid-phase cryogenic fluid and the gaseous cryogenic fluid will coexist inside the cargo hold 11 until the entire liquid-phase cryogenic fluid contained in the cargo hold 11 has been converted into a gaseous cryogenic fluid. In this state, when the temperature T3 of the liquid-phase cryogenic fluid reaches the triple point, as the liquid-phase cryogenic fluid changes into a solid-phase cryogenic fluid, a slush cryogenic fluid in which the liquid-phase cryogenic fluid and the solid-phase cryogenic fluid are mixed is generated inside the cargo hold 11.

[0045] The reliquefaction unit 30 can generate a reliquefied cryogenic fluid by receiving at least a portion of the evaporated gas generated by the evaporation of the liquid-phase cryogenic fluid from the solidification unit 20 and reliquefying it. For this purpose, the reliquefaction unit 30 is connected to the solidification unit 20.

[0046] Such a reliquefaction unit 30 includes a first evaporative gas transfer line 31, a reliquefaction device 32, a reliquefaction cryogenic fluid transfer line 33, a first evaporative gas transfer valve 34, and a reliquefaction cryogenic fluid transfer valve 35.

[0047] The first evaporative gas transfer line 31 is a line that transfers at least a portion of the evaporative gas generated inside the cargo warehouse 11 to the reliquefaction unit 32, and is connected between the cargo warehouse 11 and the reliquefaction unit 32.

[0048] The reliquefaction device 32 can liquefy the evaporated gas supplied from the first evaporated gas transfer line 31. At this time, the reliquefaction device 32 can liquefy the evaporated gas supplied from the first evaporated gas transfer line 31 using a cooling medium.

[0049] Such a reliquefaction device 32 is driven by electricity supplied from the power generator 43 of the power generation unit 40, which will be described later. When electricity is supplied to the reliquefaction device 32 from the power generator 43 of the power generation unit 40, which will be described later, the reliquefaction device 32 is driven and the evaporated gas is liquefied, thereby producing a reliquefied cryogenic fluid. At this time, the amount of evaporated gas supplied to the reliquefaction device 32 is significantly less than in the conventional method, so the reliquefaction device 32 is simplified compared to the conventional method, and the energy required to reliquefy the evaporated gas is also significantly reduced compared to the conventional method.

[0050] Meanwhile, the reliquefied cryogenic fluid generated via the reliquefaction unit 32 is supplied to the cargo warehouse 11 along a reliquefied cryogenic fluid transfer line 33 connected between the reliquefaction unit 32 and the cargo warehouse 11. The reliquefied cryogenic fluid supplied into the cargo warehouse 11 is mixed with the slush cryogenic fluid already generated in the cargo warehouse 11.

[0051] At this time, if reliquefied cryogenic fluid continues to be supplied via the reliquefied cryogenic fluid transfer line 33 while slush cryogenic fluid already generated inside the cargo hold 11 is stored, the proportion of reliquefied cryogenic fluid to slush cryogenic fluid inside the cargo hold 11 may increase. An increase in the proportion of reliquefied cryogenic fluid inside the cargo hold 11 may increase the amount of evaporated gas generated.

[0052] On the other hand, in order to prevent an increase in the amount of evaporated gas generated due to an increase in the proportion of reliquefied cryogenic fluid, the solidification ultrasonic generator 51 of the solidification promotion unit 50, which will be described later, is driven to promote the solidification of the reliquefied cryogenic fluid mixed with the slush cryogenic fluid. This prevents the proportion of cryogenic fluid to reliquefied slush cryogenic fluid from becoming excessively high inside the cargo hold 11. This will be described later.

[0053] The first evaporative gas transfer valve 34 is installed in the first evaporative gas transfer line 31. The first evaporative gas transfer valve 34 is opened or closed by the control unit 70 so that the evaporative gas generated in the cargo hold 11 is supplied to either the reliquefaction unit 32 or the power generator 43 of the power generation unit 40, which will be described later. The first evaporative gas transfer valve 34 is opened and closed by the control unit 70 based on the fluid signal from the sensing unit 60 transmitted to the control unit 70.

[0054] The reliquefied cryogenic fluid transfer valve 35 is installed in the reliquefied cryogenic fluid transfer line 33. At this time, the first evaporative gas transfer valve 34 is an on / off valve that is opened or closed by the control unit 70, so that the reliquefied cryogenic fluid from the reliquefaction device 32 is selectively supplied to the cargo hold 11. The reliquefied cryogenic fluid transfer valve 35 is opened and closed by the control unit 70 based on a fluid signal from the sensing unit 60 transmitted to the control unit 70.

[0055] The power generation unit 40 can generate electricity by receiving the remaining evaporated gas from the solidification unit 20, which is produced by the evaporation of the liquid-phase cryogenic fluid, and can selectively supply the generated electricity to the reliquefaction unit 30. For this purpose, the power production unit 40 may include a second evaporated gas transfer line 41, a second evaporated gas transfer valve 42, a power generation device 43, and a power transfer line 44.

[0056] The second evaporative gas transfer line 41 connects the cargo hold 11 and the power generation device 43, allowing the evaporative gas generated inside the cargo hold 11 to be transferred to the power generation device 43. This second evaporative gas transfer line 41 is branched from the first evaporative gas transfer line 31 and may be equipped with a second evaporative gas transfer valve 42. The second evaporative gas transfer valve 42 is opened and closed by the control unit 70 based on a fluid signal from the sensing unit 60 transmitted to the control unit 70.

[0057] The power generator 43 receives evaporated gas from the second evaporated gas transfer line 41 and can convert the supplied evaporated gas into electricity. For example, the power generator 43 can be equipped as a fuel cell. The electricity converted via the power generator 43 is supplied to the electricity demand destinations 3 on the ship via the power transfer lines 44 and 45, or to the reliquefaction unit 32.

[0058] The solidification acceleration unit 50 can accelerate the solidification of the reliquefied cryogenic fluid mixed with the slush cryogenic fluid by applying energy to the solidification unit 20. For this purpose, the solidification promotion unit 50 includes a solidification ultrasonic generator 51.

[0059] The solid-phase ultrasonic generator 51 can generate an ultrasonic signal. The frequency of the ultrasonic signal generated by the solid-phase ultrasonic generator 51 is adjusted by the control unit 70. At this time, the solid-phase ultrasonic generator 51 is installed on at least a portion of the inner surface of the cargo hold 11, for example, on the inner bottom surface of the cargo hold 11.

[0060] At this time, ultrasonic vibrations are generated according to the ultrasonic signal generated by the solid-phase ultrasonic generator 51. These generated ultrasonic vibrations are transmitted to the re-liquefied cryogenic fluid mixed with the slush cryogenic fluid stored in the cargo hold 11. When ultrasonic vibrations are transmitted to the re-liquefied cryogenic fluid mixed with the slush cryogenic fluid, the re-liquefied cryogenic fluid mixed with the slush cryogenic fluid is alternately depressurized and pressurized, causing a cavity phenomenon in which cavities repeatedly form and disappear in the re-liquefied cryogenic fluid mixed with the slush cryogenic fluid. This phenomenon promotes the solidification of the re-liquefied cryogenic fluid mixed with the slush cryogenic fluid.

[0061] On the other hand, in this embodiment, the case in which ultrasonic waves are used to pulverize the particles of the solid-phase cryogenic fluid contained in the slush cryogenic fluid was described as an example, but this is merely an example and does not limit the concept of the present invention.

[0062] The sensing unit 60 can generate a fluid signal for at least one of the liquid-phase cryogenic fluid, solid-phase cryogenic fluid, slush cryogenic fluid, and evaporated gas stored in the cargo hold 11. For this purpose, the sensing unit 60 is installed in the cargo hold 11, and the fluid signal generated by the sensing unit 60 is transmitted to the control unit 70, which uses it to control at least one of the liquid-phase cryogenic fluid storage unit 10, solidification unit 20, reliquefaction unit 30, power generation unit 40, and solidification acceleration unit 50.

[0063] The control unit 70 can control at least one of the following: 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 consist of, for example, a small built-in computer and may include a data processing unit consisting of a program, memory, and CPU. Here, the program includes an algorithm for controlling at least one of the fluid storage unit 10, solidification unit 20, reliquefaction unit 30, power generation unit 40, and solidification promotion unit 50 based on fluid signals transmitted from the sensing unit 60. Such a program is stored in the memory of a computer storage medium, such as a flexible disk, compact disk, hard disk, or MO (magneto-optical disk), and installed in the control unit 70.

[0065] In the cryogenic fluid transport system 1 of a ship having the above configuration, the liquid-phase cryogenic fluid solidifies in the solidification section 20, forming a slush cryogenic fluid in which the liquid-phase cryogenic fluid and solid-phase cryogenic fluid are mixed. Because the cryogenic fluid in this slush state can be made denser with solid particles, it has the effect of being able to store and transport large quantities of cryogenic fluid at a higher storage density than conventional systems.

[0066] Furthermore, heat entering the cargo hold 11 from the outside is absorbed by the heat of fusion generated in the solidification section 20, and as the solidification of the re-liquefied cryogenic fluid mixed with the slush cryogenic fluid is promoted via the solidification promotion section 50, the generation of evaporated gas in the cargo hold 11 is reduced. This has the effect of enabling stable long-term storage and transportation of cryogenic fluids compared to conventional methods.

[0067] Furthermore, since the amount of evaporated gas generated in the cargo hold 11 is reduced compared to conventional designs, the thickness of the vacuum insulation layer 12 of the cargo hold 11 can be significantly reduced. This simplifies the equipment for processing the evaporated gas compared to conventional designs, resulting in improved cost-effectiveness.

[0068] The following describes a cryogenic fluid transport system for ships in another embodiment of the present invention, with reference to Figures 5-7.

[0069] Figure 5 is a block diagram showing a cryogenic fluid transport system for a ship in another embodiment of the present invention, Figure 6 is a schematic process diagram showing the cryogenic fluid transport system for a ship in Figure 5, and Figure 7 is a control block diagram of the cryogenic fluid transport system for a ship in Figure 5.

[0070] Referring to Figures 5-7, in another embodiment of the present invention, the cryogenic fluid transport system 1' for a ship includes 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 sensing unit 60, and a control unit 70. However, the cryogenic fluid transport system 1' for a ship shown in Figures 5 and 6 is substantially the same as the cryogenic fluid transport system 1 for a ship described with reference to Figures 1-3, except for the solidification unit 20'. Therefore, the following description will focus on the solidification unit 20', which is the difference, and the same parts will be described using the above-mentioned embodiments and reference numerals.

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

[0072] The pressure regulating pump 22 can pressurize the liquid-phase cryogenic fluid to a predetermined pressure. The liquid-phase cryogenic fluid pressurized via the pressure regulating pump 22 is supercooled by the cold energy transmitted via the cold energy transfer line 24, and then supplied to the injection device 23.

[0073] The injection device 23 can inject a supercooled liquid-phase cryogenic fluid into the cargo hold 11. The supercooled liquid-phase cryogenic fluid supplied to the injection device 23 undergoes a phase change as it passes through the injection device 23.

[0074] In this case, the injection device 23 can be equipped with injection holes (not shown) of substantially the same size. As a result, the particle size of the supercooled liquid-phase cryogenic fluid that passes through the injection device 23 is also substantially the same. In this way, the supercooled liquid-phase cryogenic fluid injected through the injection device 23 is injected while having substantially the same particle size, which helps to facilitate the phase change of the supercooled liquid-phase cryogenic fluid that passes through the injection device 23.

[0075] On the other hand, when the phase change of the supercooled liquid-phase cryogenic fluid is easily performed by the injection device 23, at least a portion of the supercooled liquid-phase cryogenic fluid injected into the cargo hold 11 via the injection device 23 is vaporized and solidified. To explain this, first, the volume of the supercooled liquid-phase cryogenic fluid injected via the injection device 23 increases and the pressure decreases. Due to this decrease in pressure, the vaporization point of the supercooled liquid-phase cryogenic fluid injected via the injection device 23 is lowered, and the supercooled liquid-phase cryogenic fluid vaporizes. The latent heat of vaporization of the supercooled liquid-phase cryogenic fluid converted to a gaseous state removes the heat of fusion of the supercooled liquid-phase cryogenic fluid, and the solidified cryogenic fluid accumulates at the bottom of the cargo hold 11. This solidified cryogenic fluid can be mixed with the liquid-phase cryogenic fluid to form a slush cryogenic fluid.

[0076] The cold heat transfer line 24 can connect the reliquefaction unit 32 and the injection unit 23, and can supply the cooling medium used for reliquefaction of evaporated gas in the reliquefaction unit 32 to the injection unit 23. At this time, the cooling medium supplied to the injection unit 23 via the cold heat transfer line 24 can exchange heat with the liquid-phase cryogenic fluid supplied to the injection unit 23 via the liquid-phase cryogenic fluid transfer line 14. This heat exchange maximizes the Joule-Thomson cooling effect, and the liquid-phase cryogenic fluid is supercooled, so that the supercooled liquid-phase cryogenic fluid is injected through the injection unit 23.

[0077] The following describes a cryogenic fluid transport system for ships in the present invention and other embodiments, with reference to Figures 8-10.

[0078] Figure 8 is a block diagram showing a cryogenic fluid transport system for a ship in another embodiment of the present invention, Figure 9 is a schematic process diagram showing the cryogenic fluid transport system for a ship in Figure 8, and Figure 10 is a control block diagram of the cryogenic fluid transport system for a ship in Figure 8.

[0079] Referring to Figures 8-10, in yet another embodiment of the present invention, the cryogenic fluid transport system 1'' for ships includes a liquid-phase cryogenic fluid storage unit 10, a solidification unit 20'', a reliquefaction unit 30, a power generation unit 40, a sensing unit 60, and a control unit 70. However, the liquid-phase cryogenic fluid storage unit 10, reliquefaction unit 30, power generation unit 40, and control unit 70 of the cryogenic fluid transport system 1'' for ships shown in Figures 8-10 are substantially the same as the liquid-phase cryogenic fluid storage unit 10, reliquefaction unit 30, power generation unit 40, and control unit 70 of the cryogenic fluid transport system 1 for ships described with reference to Figures 1-3, or the liquid-phase cryogenic fluid storage unit 10, reliquefaction unit 30, power generation unit 40, and control unit 70 of the cryogenic fluid transport system 1' for ships described with reference to Figures 5-7. Therefore, the following description will focus on the solidification unit 20'', which is the difference, and the same parts will be described in the above-mentioned embodiments and refer to the corresponding reference numerals.

[0080] The solidification section 20'' includes a solidification ultrasonic generator 25 provided on at least one of the inner surfaces of the cargo hold 11. Here, the inner surfaces of the cargo hold 11 are at least one of the inner bottom surface, left side wall surface, right side wall surface, front side wall surface, and rear side wall surface. In this embodiment, the case in which the solidification ultrasonic generator 25 is provided on all of the inner surfaces of the cargo hold 11—the inner bottom surface, left side wall surface, right side wall surface, front side wall surface, and rear side wall surface—is described as an example, but this is merely an example and does not limit the concept of the present invention. The installation position and number of solidification ultrasonic generators 25 can be changed as needed.

[0081] At this time, the solid-phase ultrasonic generator 25 solidifies at least a portion of the liquid-phase cryogenic fluid supplied into the cargo hold 11, so that a slush cryogenic fluid in which the liquid-phase cryogenic fluid and the solid-phase cryogenic fluid are mixed is generated inside the cargo hold 11. In addition, the solid-phase ultrasonic generator 25 can solidify at least a portion of the re-liquefied cryogenic fluid supplied from the re-liquefaction unit 30 into the cargo hold 11 and the slush cryogenic fluid mixed with the re-liquefied cryogenic fluid.

[0082] For this purpose, the solid-phase ultrasonic generator 25 can generate an ultrasonic signal. The frequency of the ultrasonic signal generated by the solid-phase ultrasonic generator 25 is adjusted by the control unit 70. At this time, ultrasonic vibrations are generated according to the ultrasonic signal generated by the solid-phase ultrasonic generator 25. The ultrasonic vibrations thus generated are transmitted 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 vibrations are transmitted 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 is solidified while being alternately depressurized or pressurized.

[0083] Although embodiments of the present invention have been described above with specific examples, these are merely illustrative, and the present invention is not limited thereto, but should be interpreted as encompassing the broadest scope of the fundamental ideas disclosed herein. Those skilled in the art can combine or substitute the disclosed embodiments to carry out patterns of shapes not specified, and this also does not depart from the scope of the present invention. Furthermore, it is clear that those skilled in the art can easily modify or transform the embodiments disclosed herein, and such modifications or transformations also fall within the scope of the present invention. [Explanation of Symbols]

[0084] 1. Cryogenic fluid transport systems for ships 1' Cryogenic fluid transport systems for ships 1'' Cryogenic fluid transport systems for ships 2. Liquid-phase cryogenic fluid storage tank 3 Electricity demand destination 10 Liquid-phase cryogenic fluid storage section 11 Cargo hold 12 Vacuum insulation layer 13. Equilibrium Water Storage Unit 14. Liquid-phase cryogenic fluid transfer line 15. Liquid-phase cryogenic fluid transfer valve 20 Solid phase section 20' Solid phase section 20'' solid phase section 21 Vacuum pump 22 Pressure Regulating Pump 23 Injection device 24. Cold and heat transfer line 25. Ultrasonic generator for solid-phase formation 30 Reliquefaction section 31. First Evaporation Gas Transfer Line 32 Reliquefaction equipment 33 Reliquefied cryogenic fluid transfer line 34. First evaporative gas transfer valve 35 Reliquefied cryogenic fluid transfer valve 40 Power generation section 41. Second Evaporation Gas Transfer Line 42. Second evaporative gas transfer valve 43 Power generation equipment 44, 45 Power transfer lines 50 Solid phase promotion part 51. Ultrasonic generator for solid-phase formation 60 Sensing part 70 Control Unit

Claims

1. A liquid-phase cryogenic fluid storage unit, including a cargo hold for supplying and storing liquid-phase cryogenic fluid, A solidification unit connected to the liquid-phase cryogenic fluid storage unit, which solidifies at least a portion of the liquid-phase cryogenic fluid stored in the liquid-phase cryogenic fluid storage unit to generate a slush cryogenic fluid in which the liquid-phase cryogenic fluid and solid-phase cryogenic fluid are mixed, A reliquefaction unit is connected to the solidification unit and generates a reliquefied cryogenic fluid by receiving at least a portion of the evaporated gas generated by the evaporation of the liquid-phase cryogenic fluid from the solidification unit and reliquefying it. The system includes a power generation unit connected to the solidification unit, which is supplied with the remaining evaporated gas generated by the evaporation of the liquid-phase cryogenic fluid from the solidification unit to generate electricity, and which selectively supplies the generated electricity to the reliquefaction unit, The reliquefied cryogenic fluid produced by reliquefaction in the reliquefaction unit is supplied to the cargo hold and mixed with the slush cryogenic fluid. A cryogenic fluid transport system for a ship, further comprising a solidification promoting unit connected to the cargo hold, which induces a cavity phenomenon in the liquid-phase cryogenic fluid or the re-liquefied cryogenic fluid stored inside the cargo hold by applying energy to the cargo hold, thereby solidifying the re-liquefied cryogenic fluid.

2. A sensing unit connected to the liquid-phase cryogenic fluid storage unit, which generates a fluid signal for at least one of the liquid-phase cryogenic fluid, the solid-phase cryogenic fluid, the slush cryogenic fluid, and the evaporated gas stored in the liquid-phase cryogenic fluid storage unit, The cryogenic fluid transport system for a ship according to claim 1, further comprising a control unit that 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 promotion unit based on the fluid signal generated by the sensing unit.

3. The aforementioned liquid phase cryogenic fluid storage unit is A vacuum insulation layer is provided on the outside of the cargo hold, The cryogenic fluid transport system for a ship according to claim 1, further comprising an equilibrium water storage section provided on the outside of the vacuum insulation layer.

4. The aforementioned re-liquefaction unit is, A first evaporative gas transfer line, one end of which is connected to the cargo warehouse, A reliquefaction device connected to the other end of the first evaporative gas transfer line, which reliquefies the evaporative gas using a cooling medium, A reliquefied cryogenic fluid transfer line connecting the reliquefaction apparatus and the cargo warehouse, A first evaporation gas transfer valve provided in the first evaporation gas transfer line, A reliquefied cryogenic fluid transfer valve is provided in the aforementioned reliquefied cryogenic fluid transfer line, A cryogenic fluid transport system for a ship according to claim 1, characterized by including the following:

5. The solidified phase portion is, The cryogenic fluid transport system for a ship according to claim 4, characterized in that it includes a vacuum pump connected to the first evaporative gas transfer line for reducing the pressure inside the cargo hold.

6. The solidified phase portion is, A pressure regulating pump is provided in the aforementioned reliquefied cryogenic fluid transfer line, An injection device provided at the rear end of the pressure regulating pump and at least a portion of which is located inside the cargo hold, The cryogenic fluid transport system for a ship according to claim 4, further comprising a cold transfer line connecting the reliquefaction device and the injection device, which transmits the cold energy of the cooling medium of the reliquefaction device to the injection device.

7. The solidification promotion unit is, The cargo hold includes an ultrasonic generator for promoting solidification, which is provided on at least one of the inner surfaces of the cargo hold and selectively generates ultrasonic energy to be transmitted to the reliquefied cryogenic fluid stored in the cargo hold. The cryogenic fluid transport system for a ship according to claim 5 or 6, characterized in that the ultrasonic energy generated by the ultrasonic generator for promoting solidification induces a cavity phenomenon in the liquid-phase cryogenic fluid or the re-liquefied cryogenic fluid, thereby solidifying the re-liquefied cryogenic fluid.

8. A liquid-phase cryogenic fluid storage unit, including a cargo hold for supplying and storing liquid-phase cryogenic fluid, A solidification unit connected to the liquid-phase cryogenic fluid storage unit is provided, which solidifies at least a portion of the liquid-phase cryogenic fluid stored in the liquid-phase cryogenic fluid storage unit to generate a slush cryogenic fluid in which the liquid phase and solid phase are mixed. A reliquefaction unit is connected to the solidification unit and generates a reliquefied cryogenic fluid by receiving at least a portion of the evaporated gas generated by the evaporation of the liquid-phase cryogenic fluid from the solidification unit and reliquefying it. The system includes a power generation unit connected to the solidification unit, which is supplied with the remaining evaporated gas generated by the evaporation of the liquid-phase cryogenic fluid from the solidification unit to generate electricity, and which selectively supplies the generated electricity to the reliquefaction unit, The reliquefied cryogenic fluid produced by reliquefaction in the reliquefaction unit is supplied to the cargo hold and mixed with the slush cryogenic fluid. The solidification unit is provided on at least one of the inner surfaces of the cargo hold and includes a solidification ultrasonic generator that generates ultrasonic energy to be transmitted to the liquid-phase cryogenic fluid or the re-liquefied cryogenic fluid stored in the cargo hold. A cryogenic fluid transport system for ships, characterized in that ultrasonic energy generated by the ultrasonic generator for solidification induces a cavity phenomenon in the liquid-phase cryogenic fluid or the re-liquefied cryogenic fluid, thereby solidifying the liquid-phase cryogenic fluid or the re-liquefied cryogenic fluid.

9. The aforementioned re-liquefaction unit is, A first evaporative gas transfer line, one end of which is connected to the cargo warehouse, A reliquefaction device connected to the other end of the first evaporative gas transfer line, which reliquefies the evaporative gas using a cooling medium, A reliquefied cryogenic fluid transfer line connecting the reliquefaction apparatus and the cargo warehouse, A first evaporation gas transfer valve provided in the first evaporation gas transfer line, A reliquefied cryogenic fluid transfer valve is provided in the aforementioned reliquefied cryogenic fluid transfer line, A cryogenic fluid transport system for a ship according to claim 8, characterized by including the following:

10. The aforementioned liquid phase cryogenic fluid storage unit is A liquid-phase cryogenic fluid transfer line connected to the aforementioned re-liquefaction cryogenic fluid transfer line, which supplies the liquid-phase cryogenic fluid to the cargo warehouse, A cryogenic fluid transport system for a ship according to any one of claims 5, 6, and 9, further comprising a liquid-phase cryogenic fluid transfer valve provided in the liquid-phase cryogenic fluid transfer line.

11. The power generation unit is A second evaporation gas transfer line that branches off from the first evaporation gas transfer line, A second evaporation gas transfer valve provided in the second evaporation gas transfer line, A power generation device connected to the second evaporation gas transfer line and which generates electricity using the evaporation gas, The cryogenic fluid transport system for a ship according to claim 10, further comprising a power transfer line connected between the power generator and the reliquefaction device, which transfers at least a portion of the power generated by the power generator to the reliquefaction device.

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