A system for hydrogen liquefaction using an ammonia pre-cooling method

Abstract

The system for hydrogen liquefaction using an ammonia pre-cooling method according to the present invention includes a hydrogen liquefaction apparatus for liquefying hydrogen, an ammonia supply line for supplying liquid ammonia (NH3) from an ammonia supply source, a hydrogen supply line for supplying hydrogen to the hydrogen liquefaction apparatus, a refrigerant supply line for supplying a refrigerant to the hydrogen liquefaction apparatus, and a heat exchange unit formed so that the ammonia supply line, the hydrogen supply line, and the refrigerant supply line pass through it, and which lowers the temperatures of hydrogen and refrigerant through the cold energy of ammonia. [Representative Diagram] Figure 1

Description

Technical Field

[0001] The present invention relates to a system for hydrogen liquefaction, and more particularly, to a system for hydrogen liquefaction that can efficiently liquefy hydrogen by using an ammonia precooling method.

Background Art

[0002] Recently, ammonia storage and transportation methods have attracted attention as representative methods for storing and transporting large-scale green hydrogen.

[0003] However, ammonia is a toxic substance and requires additional safety devices and is difficult to handle. Therefore, in order to use such technology in small-scale facilities such as homes and mobility rather than large-scale energy-consuming facilities such as power plants and ships, it is necessary to convert ammonia into liquid hydrogen.

[0004] Generally, large-scale transportation and storage devices for liquid ammonia for the hydrogen industry are often atmospheric pressure low-temperature tanks (at atmospheric pressure or slightly higher pressure), and the atmospheric pressure equilibrium state ammonia liquid is at -33.3°C.

[0005] In order to obtain hydrogen from ammonia, a reforming process must be performed. Since such a reforming process is usually performed at high temperature, the ammonia stored in the low-temperature tank must be heated, so a lot of energy is required.

[0006] Also, when liquefying the hydrogen generated by the ammonia reforming process for storage and transportation, it is necessary to further lower the temperature of the generated hydrogen to a lower temperature. In particular, since a large amount of refrigerant is used in the hydrogen liquefaction process, a lot of cold heat is required not only in the process of cooling the hydrogen but also in the process of cooling the refrigerant.

[0007] To explain in more detail, theoretically, 3 kg of hydrogen can only be obtained by decomposing 17 kg of ammonia, and since such a conversion reaction is an endothermic reaction (ΔH = 2.7 MJ / kg of ammonia), a large amount of energy is required.

[0008] Furthermore, a significant amount of energy is required to separate the generated hydrogen, and in particular, liquefying hydrogen at a liquefaction temperature of -253°C requires even more energy in processes such as pressurizing the hydrogen itself and pressurizing the refrigerant.

[0009] Even with such simple calculations, it's clear that more than 10 times the amount of ammonia is needed for the total amount of hydrogen produced and liquefied.

[0010] In other words, the entire process of extracting, storing, and transporting hydrogen through ammonia has the overall problem of consuming enormous amounts of energy.

[0011] Therefore, methods are needed to solve these problems. [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] The present invention was devised to solve the problems of the prior art described above, and aims to minimize energy consumption throughout the entire process of extracting hydrogen through ammonia and liquefying it for storage and transport.

[0013] The problems addressed by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0014] A system for hydrogen liquefaction utilizing the ammonia pre-cooling method of the present invention to achieve the above objectives includes a hydrogen liquefaction unit for liquefying hydrogen, an ammonia supply line for supplying liquid ammonia (NH3) from an ammonia source, a hydrogen supply line for supplying hydrogen to the hydrogen liquefaction unit, a refrigerant supply line for supplying a refrigerant to the hydrogen liquefaction unit, and a heat exchange unit formed so that the ammonia supply line, the hydrogen supply line, and the refrigerant supply line pass through it, and for lowering the temperatures of hydrogen and refrigerant through the cold of ammonia.

[0015] Here, the heat exchange unit may include a first heat exchange unit that performs heat exchange between the hydrogen supply line and the ammonia supply line and a second heat exchange unit that performs heat exchange between the refrigerant supply line and the ammonia supply line, in which case the ammonia supply line may be branched and configured to pass through the first heat exchange unit and the second heat exchange unit individually.

[0016] Furthermore, the refrigerant supply line may include a plurality of refrigerant supply lines that flow different refrigerants from each other, and in such a case, the second heat exchange unit may include a plurality of second heat exchange units corresponding to each of the plurality of refrigerant supply lines.

[0017] Furthermore, the heat exchange unit may be formed in an immersion type to utilize the cooling effect of the latent heat of vaporization of ammonia and to recover the evaporated ammonia.

[0018] Furthermore, the heat exchange units may be configured such that a plurality of them are arranged in series, and the hydrogen supply line and the refrigerant supply line may be formed to pass through the plurality of heat exchange units.

[0019] Furthermore, the ammonia supply line may be branched and configured to pass through multiple heat exchange units individually.

[0020] On the one hand, the heat exchange unit may be formed in the form of a plate fin heat exchanger or a spiral wound heat exchanger.

[0021] And the present invention may further include an ammonia reformer that extracts hydrogen from ammonia supplied from the ammonia supply line.

[0022] Here, the hydrogen extracted through the ammonia reformer may be supplied to the hydrogen supply line.

[0023] In addition, the present invention may further include a separator that separates and recovers ammonia mixed with the hydrogen supplied to the hydrogen supply line.

[0024] Also, the present invention may further include a fuel supply unit that supplies fuel to the ammonia reformer.

[0025] Here, the fuel supplied by the fuel supply unit is ammonia, and the fuel supply unit may be formed to recover and reuse the ammonia remaining in the ammonia reformer.

[0026] At the same time, the present invention may further include an ammonia bypass line that directly allows a part of the ammonia supplied to the ammonia supply line to flow into the side of the fuel supply unit.

[0027] And the present invention may further include a compression power providing unit that is used in the compression process of the hydrogen supplied to the hydrogen supply line and the compression process of the refrigerant supplied to the refrigerant supply line after being supplied with fuel from the fuel supply unit.

[0028] In addition, the present invention may further include a carbon dioxide supply line configured to collect carbon dioxide generated in the carbon dioxide liquefaction facility, the hydrogen liquefaction facility, and the ammonia reformer and supply it to the carbon dioxide liquefaction facility, and configured to pass through the heat exchange unit so that the temperature of carbon dioxide drops through the cold heat of ammonia.

[0029] In such a case, the present invention may further include a refrigerant auxiliary supply line configured to supply a refrigerant to the side of the carbon dioxide liquefaction facility and configured to pass through the heat exchange unit so that the temperature of the refrigerant drops through the cold heat of ammonia.

[0030] On the other hand, the present invention may further include a refrigerant recovery line configured to recover the refrigerant passing through the heat exchange unit and the hydrogen liquefaction facility through the refrigerant supply line, and the refrigerant supply line and the refrigerant recovery line may form a refrigerant cycle in which the refrigerant is circulated.

[0031] Here, the refrigerant cycle may include a plurality of refrigerant cycles.

[0032] Note that the refrigerant cycle may include at least one or more of an expansion valve assembly and an expander that depressurize and cool the refrigerant.

[0033] And the hydrogen liquefaction facility may include a heat exchange type liquefaction unit configured to pass through the hydrogen supply unit and the refrigerant cycle and configured to lower the temperature of the hydrogen through the cold heat of the refrigerant.

[0034] Such a heat exchange type liquefaction unit may include a plurality of heat exchange type liquefaction units.

[0035] Also, the refrigerant supply line and the refrigerant recovery line may be configured to perform heat exchange through the heat exchange type liquefaction unit, and the temperature of the refrigerant flowing through the refrigerant supply line may be lowered through the cold heat of the refrigerant flowing through the refrigerant recovery line.

[0036] Furthermore, the present invention may further include a hydrogen recovery line that recovers unliquefied hydrogen in the hydrogen liquefaction facility and supplies it to the hydrogen supply line. [Effects of the Invention]

[0037] The hydrogen liquefaction system using the ammonia pre-cooling method of the present invention, which solves the above-mentioned problems, has the advantage of minimizing the energy used for liquefying cryogenic hydrogen and greatly increasing energy efficiency by utilizing the cold energy of ammonia liquefied at a low temperature during the storage and transportation process in the pre-cooling process of hydrogen and refrigerant for hydrogen liquefaction.

[0038] Furthermore, this invention makes it possible to lower energy costs throughout the entire process while simultaneously increasing production volume, thereby minimizing carbon emissions and maximizing the environmental friendliness of energy in the hydrogen production process.

[0039] The effects of the present invention are not limited to those mentioned above, and any other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. [Brief explanation of the drawing]

[0040] [Figure 1] This is a drawing showing a hydrogen liquefaction system according to the first embodiment of the present invention. [Figure 2] This is a drawing showing a hydrogen liquefaction system according to a second embodiment of the present invention. [Figure 3] This is a drawing showing a hydrogen liquefaction system according to a third embodiment of the present invention. [Figure 4] This is a drawing showing a hydrogen liquefaction system according to a fourth embodiment of the present invention. [Figure 5] This is a drawing showing a hydrogen liquefaction system according to a fifth embodiment of the present invention. [Figure 6] This is a drawing showing a hydrogen liquefaction system according to the sixth embodiment of the present invention. [Figure 7]This is a drawing showing a hydrogen liquefaction system according to the seventh embodiment of the present invention. [Figure 8] This is a drawing showing a hydrogen liquefaction system according to the eighth embodiment of the present invention. [Figure 9] This is a drawing showing a hydrogen liquefaction system according to the ninth embodiment of the present invention. [Figure 10] This is a drawing showing a hydrogen liquefaction system according to the tenth embodiment of the present invention. [Figure 11] This is a drawing showing a hydrogen liquefaction system according to the 11th embodiment of the present invention. [Figure 12] This is a drawing showing a hydrogen liquefaction system according to the twelfth embodiment of the present invention. [Figure 13] This is a drawing showing a hydrogen liquefaction system according to the thirteenth embodiment of the present invention. [Figure 14] This is a drawing showing a hydrogen liquefaction system according to the 14th embodiment of the present invention. [Figure 15] This is a drawing showing a hydrogen liquefaction system according to the 15th embodiment of the present invention. [Modes for carrying out the invention]

[0041] In this specification, when a component (or region, layer, part, etc.) is referred to as "on top of," "connected to," or "joined" another component, it means that it can be directly placed on / connected to / joined to the other component, or that a third component can be placed between them.

[0042] The same drawing reference numerals refer to the same component. Furthermore, in drawings, the thickness, proportions, and dimensions of components are exaggerated for the sake of effective explanation of the technical content.

[0043] "and / or" includes all possible combinations of one or more related configurations.

[0044] Terms such as "first," "second," etc., may be used to describe various components, but such components should not be limited by such terms. The terms are used solely for the purpose of distinguishing one component from another. For example, without departing the scope of the invention, the first component may be called the second component, and similarly, the second component may be called the first component. A singular expression includes plural expressions unless otherwise intended to be clearly different in context.

[0045] Furthermore, terms such as "down," "on the lower side," "up," and "on the upper side" are used to describe the relationships between components illustrated in the drawings. These terms are relative concepts and are described in relation to the direction shown in the drawings.

[0046] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as those generally understood by those skilled in the art in which the present invention pertains. Furthermore, terms identical to those defined in commonly used dictionaries must be interpreted as having a meaning consistent with that in the context of the relevant art, and unless interpreted in an ideal or highly formal sense, they are explicitly defined herein.

[0047] Terms such as “includes” or “possesses” are intended to indicate the existence of features, figures, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood not to preemptively exclude the existence or possibility of adding one or more other features, figures, steps, actions, components, parts, or combinations thereof.

[0048] Embodiments of the present invention will be described in detail below with reference to the drawings.

[0049] Figure 1 is a diagram showing a hydrogen liquefaction system according to the first embodiment of the present invention.

[0050] As shown in Figure 1, the hydrogen liquefaction system according to the first embodiment of the present invention includes a hydrogen liquefaction equipment 200, an ammonia supply line 10, a hydrogen supply line 20, a refrigerant supply line 30, and a heat exchange unit 100.

[0051] The hydrogen liquefaction equipment 200 is provided for liquefying hydrogen in a gaseous state, and this hydrogen liquefaction process can be carried out through heat exchange between the refrigerant supplied through the refrigerant supply line 30 and the hydrogen. This will be described in more detail in the section on other embodiments described later.

[0052] The ammonia supply line 10 supplies liquid ammonia (NH3) from an ammonia supply source.

[0053] In this embodiment, the ammonia supply line 10 extends through a path that flows liquid ammonia from the ammonia supply tank and passes through the heat exchange unit 100.

[0054] The hydrogen supply line 20 supplies hydrogen from the hydrogen source to the hydrogen liquefaction equipment 200 and extends through a path that passes through the heat exchange unit 100.

[0055] Here, the hydrogen supply source may be a system that supplies hydrogen from a hydrogen supply tank in which hydrogen is stored, or it may be a system that supplies hydrogen extracted by reforming ammonia. Matters related to this will be explained in the section on other embodiments described later.

[0056] The refrigerant supply line 30 is provided to supply refrigerant to the hydrogen liquefaction equipment 200.

[0057] Furthermore, the refrigerant supplied to the refrigerant supply line 30 may be a single-component refrigerant or a mixed refrigerant containing multiple components. For example, the refrigerant may be a single component or a mixture of helium (He), hydrogen (H2), neon (Ne), nitrogen (N2), ammonia (NH3), propane (C3H8), ethylene (C2H4), or methane (CH4).

[0058] Furthermore, the refrigerant supply line 30 may be provided in multiple units (1, 2...n) to flow different refrigerants from each other, and each refrigerant supply line 30 is extended to a path that passes through the heat exchange unit 100.

[0059] The heat exchange unit 100 is configured such that an ammonia supply line 10, a hydrogen supply line 20, and a refrigerant supply line 30 pass through it, and the temperature of the hydrogen and refrigerant is lowered through the cold energy of the ammonia supplied to the ammonia supply line 10.

[0060] The heat exchange unit 100 can be realized in various forms, but in this embodiment, the heat exchange unit 100 is a plate fin heat exchanger, which is a multi-flow heat exchanger.

[0061] Since the latent heat of vaporization of ammonia is 326 kcal / kg even at atmospheric pressure, making it an excellent cooling source, the present invention can reduce a large amount of energy by using ammonia as a pre-cooling source for hydrogen liquefaction through the heat exchange unit 100 in this way.

[0062] Furthermore, since the present invention can relatively reduce the energy required for vaporizing and heating ammonia that must be used throughout the heat exchange process, it is possible to reduce the energy used, improve energy efficiency, lower the energy cost, and increase production volume at the same time.

[0063] In other words, the present invention has the advantage of maximizing environmental friendliness from the perspective of green hydrogen energy that can reduce carbon emissions.

[0064] In the following sections, various embodiments realized by the present invention will be described. Here, in each of the embodiments described below, redundant explanations of components that are the same as those provided in the first embodiment described above will be omitted.

[0065] Figure 2 is a diagram showing a hydrogen liquefaction system according to a second embodiment of the present invention.

[0066] The second embodiment of the present invention, shown in Figure 2, includes a hydrogen liquefaction equipment 200, an ammonia supply line 10, a hydrogen supply line 20, a refrigerant supply line 30, and heat exchange units 100a and 100b, as described in the first embodiment.

[0067] However, this embodiment is characterized in that it is equipped with multiple heat exchange units 100a and 100b, and that each of the multiple heat exchange units 100a and 100b is equipped in a form that is independent of the others.

[0068] Specifically, this embodiment includes a first heat exchange unit 100a that exchanges heat between a hydrogen supply line 20 and an ammonia supply line 10, and a second heat exchange unit 100b that exchanges heat between a refrigerant supply line 30 and an ammonia supply line 10.

[0069] The ammonia supply line 10 is provided in a branched configuration, each branched to pass through the first heat exchange unit 100a and the second heat exchange unit 100b individually.

[0070] In this embodiment, since there are multiple refrigerant supply lines 30 that flow different refrigerants to each other, multiple second heat exchange units 100b can be arranged so that each corresponds to one of the multiple refrigerant supply lines 30.

[0071] Figure 3 is a diagram showing a hydrogen liquefaction system according to a third embodiment of the present invention.

[0072] The third embodiment of the present invention, shown in Figure 3, also includes a hydrogen liquefaction equipment 200, an ammonia supply line 10, a hydrogen supply line 20, a refrigerant supply line 30, and a heat exchange unit 100, similar to the first embodiment described above.

[0073] Furthermore, this embodiment is characterized in that the heat exchange unit 100 is formed in an immersion type, utilizing the cooling effect of the latent heat of vaporization of ammonia and recovering the evaporated ammonia.

[0074] This method is applicable because the ammonia supplied through the ammonia supply line 10 is in a liquid state.

[0075] Although this method has the limitation that it cannot fully utilize the cold energy of ammonia down to room temperature, it has the advantage of being able to simply apply the structure of the heat exchange unit 100 and being easy to control the temperature.

[0076] Figure 4 is a diagram showing a hydrogen liquefaction system according to a fourth embodiment of the present invention.

[0077] The fourth embodiment of the present invention, shown in Figure 4, is characterized in that, as in the third embodiment described above, the heat exchange units 100a and 100b are formed in an immersion type, and a plurality of heat exchange units 100a and 100b are arranged in series.

[0078] Furthermore, in this embodiment, the hydrogen supply line 20 and the refrigerant supply line 30 are configured to pass sequentially through a plurality of heat exchange units 100a and 100b, respectively.

[0079] The ammonia supply line 10 is provided in a branched configuration, and each of the branched ammonia supply lines 10 is configured to pass through a plurality of heat exchange units 100a and 100b individually.

[0080] This method has the advantage of reducing the additional power required for pressurization during the process of using the cold energy of ammonia in the heat exchange units 100a and 100b and then further pressurizing the recovered ammonia for utilization.

[0081] In this embodiment, the heat exchange unit 100a located upstream of the hydrogen supply line 20 and the refrigerant supply line 30 can be operated to have a relatively higher pressure than the heat exchange unit 100b located downstream.

[0082] Figure 5 is a diagram showing a hydrogen liquefaction system according to a fifth embodiment of the present invention.

[0083] The fifth embodiment of the present invention, shown in Figure 5, is formed to have the same overall configuration and arrangement as the first embodiment described above.

[0084] However, the difference in this embodiment from the first embodiment is that the heat exchange unit 100 is formed in the form of a spiral-wound heat exchanger, which is a multi-flow heat exchanger.

[0085] Figure 6 is a diagram showing a hydrogen liquefaction system according to the sixth embodiment of the present invention.

[0086] The sixth embodiment of the present invention, shown in Figure 6, is formed to have the same overall configuration and arrangement as the first embodiment described above.

[0087] Furthermore, this embodiment further includes an ammonia reformer 300 that extracts hydrogen from ammonia supplied from an ammonia supply line 10.

[0088] Furthermore, in this embodiment, the hydrogen extracted via the ammonia reformer 300 can be supplied to the hydrogen supply line 20, and the hydrogen supplied to the hydrogen supply line 20 can be compressed by a compressor during the flow process.

[0089] Figure 7 is a diagram showing a hydrogen liquefaction system according to the seventh embodiment of the present invention.

[0090] The seventh embodiment of the present invention, shown in Figure 7, includes an ammonia reformer 300 that extracts hydrogen from ammonia supplied from the ammonia supply line 10, as described in the sixth embodiment above.

[0091] Furthermore, this embodiment is characterized by further including a fuel supply unit 310, an ammonia bypass line 11, and a compression power supply unit 320.

[0092] The fuel supply unit 310 is responsible for supplying fuel to the ammonia reformer 300 or supplying ammonia to other equipment that uses ammonia, such as a power generation facility. Here, the fuel supplied by the fuel supply unit 310 is not limited to a specific type of fuel, but in this embodiment, it is ammonia.

[0093] Furthermore, this allows the fuel supply unit 310 to be configured to recover and reuse the ammonia remaining in the ammonia reformer 300. The ammonia bypass line 11 serves to divert a portion of the ammonia supplied to the ammonia supply line 10 directly to the fuel supply unit 310.

[0094] Therefore, the ammonia supplied to the ammonia supply line 10 can be supplied to the ammonia reformer 300 or bypassed and flow into the fuel supply unit 310.

[0095] The compression power supply unit 320 is equipped to supply fuel to the compression process of hydrogen supplied from the fuel supply unit 310 to the hydrogen supply line 20, and to the compression process of refrigerant supplied to the refrigerant supply line 30.

[0096] In other words, in this embodiment, the ammonia that is partially recovered by the fuel supply unit 310 and provided to the compression power supply unit 320 can be used as fuel for the compressor that compresses hydrogen and the compressor that compresses refrigerant by the compression power supply unit 320.

[0097] Figure 8 is a diagram showing a hydrogen liquefaction system according to the eighth embodiment of the present invention.

[0098] The eighth embodiment of the present invention, shown in Figure 8, includes an ammonia reformer 300 that extracts hydrogen from ammonia supplied from the ammonia supply line 10, as described in the sixth embodiment above.

[0099] Furthermore, this embodiment is characterized by further including a separator 330 for separating and recovering ammonia that is mixed with hydrogen supplied to the hydrogen supply line 20.

[0100] In other words, in this embodiment, if some ammonia is not completely converted during the process of converting ammonia to hydrogen in the ammonia reformer 300, this ammonia can be flowed into the hydrogen supply line 20 together with the hydrogen, and the ammonia can be separated separately via the separator 330 during the process of the hydrogen cooling in the heat exchanger 100.

[0101] Here, the separation method performed by the separator 330 can be any of the following methods: simple gas-liquid separation or distillation.

[0102] Figure 9 is a diagram showing a hydrogen liquefaction system according to the ninth embodiment of the present invention.

[0103] The ninth embodiment of the present invention, shown in Figure 9, includes, as in the first embodiment described above, a hydrogen liquefaction facility 200, an ammonia supply line 10, a hydrogen supply line 20, a refrigerant supply line 30, and a heat exchange unit 100.

[0104] Furthermore, in this embodiment, a refrigerant recovery line 40 is included that recovers the refrigerant that has passed through the heat exchange unit 100 and the hydrogen liquefaction equipment 200 via the refrigerant supply line 30. Thus, the refrigerant supply line 30 and the refrigerant recovery line 40 form refrigerant cycles C1 and C2 in which the refrigerant is circulated.

[0105] Multiple such refrigerant cycles C1 and C2 may be provided, and in this embodiment, it is exemplified that a first refrigerant cycle C1 and a second refrigerant cycle C2 are included.

[0106] Here, each refrigerant cycle C1 and C2 can be configured to use either a selection of refrigerant components or a mixture of refrigerants, depending on the temperature.

[0107] For example, in this embodiment, the first refrigerant cycle C1 may be a single or mixture of helium, hydrogen, neon, and nitrogen, and the second refrigerant cycle C2 may be a single or mixture of ammonia, propane, ethylene, methane, and nitrogen.

[0108] On the other hand, the hydrogen liquefaction equipment 200 may include heat exchange liquefaction units 210a, 210b, and 210c that are configured to pass through the hydrogen supply unit 20 and refrigerant cycles C1 and C2, and that lower the temperature of hydrogen through the cold energy of the refrigerant.

[0109] Such a heat exchange liquefaction unit may include a plurality of heat exchange liquefaction units. In this embodiment, a first heat exchange liquefaction unit 210a, a second heat exchange liquefaction unit 210b, and a third heat exchange liquefaction unit 210c are arranged in series.

[0110] In this embodiment, the first refrigerant cycle C1 forms a circulation path by passing through the first heat exchange liquefaction unit 210a, the second heat exchange liquefaction unit 210b, and the third heat exchange liquefaction unit 210c, while the second refrigerant cycle C2 is configured to circulate through the circulation path by passing through only the first heat exchange liquefaction unit 210a and the second heat exchange liquefaction unit 210b.

[0111] As a result, the first refrigerant cycle C1 can perform hydrogen liquefaction and auxiliary cooling functions, and the second refrigerant cycle C2 can perform hydrogen cooling functions.

[0112] However, the number and arrangement of the heat exchange liquefaction units 210a, 210b, and 210c are not limited by this embodiment and can be modified into various configurations.

[0113] In this embodiment, refrigerant cycles C1 and C2 may each include an expansion valve assembly 220 that reduces the pressure of the refrigerant for cooling. For example, a JT (Joule-Thomson) valve can be used as the expansion valve assembly 220.

[0114] Figure 10 is a diagram showing a hydrogen liquefaction system according to the tenth embodiment of the present invention.

[0115] The tenth embodiment of the present invention, shown in Figure 10, includes a first refrigerant cycle C1 and a second refrigerant cycle C2, which are composed of a refrigerant supply line 30 and a refrigerant recovery line 40, as described in the ninth embodiment above.

[0116] However, this embodiment is characterized in that the first refrigerant cycle C1 includes an expander 230 instead of an expansion valve assembly 220. The expander 230 also plays a role in reducing the pressure of the refrigerant and cooling it.

[0117] Thus, at least one of the expansion valve assembly 220 and the expander 230 can be selectively applied to the first refrigerant cycle C1 and the second refrigerant cycle C2.

[0118] Figure 11 is a diagram showing a hydrogen liquefaction system according to the 11th embodiment of the present invention.

[0119] The 11th embodiment of the present invention, shown in Figure 11, includes a first refrigerant cycle C1 and a second refrigerant cycle C2, which consist of a refrigerant supply line 30 and a refrigerant recovery line 40, as described in the 9th embodiment above.

[0120] Furthermore, this embodiment has a configuration in which, in addition to the components of the ninth embodiment, an ammonia reformer 300 that extracts hydrogen from ammonia supplied from the ammonia supply line 10, as described in the sixth embodiment above, is added.

[0121] Figure 12 is a diagram showing a hydrogen liquefaction system according to the twelfth embodiment of the present invention.

[0122] The twelfth embodiment of the present invention, shown in Figure 12, is formed to have the same overall components as the eleventh embodiment described above.

[0123] However, this embodiment is characterized by further including a hydrogen recovery line 50 that recovers unliquefied hydrogen in the hydrogen liquefaction equipment 200 and supplies it to the hydrogen supply line 20, thereby enabling this embodiment to further increase the hydrogen liquefaction rate.

[0124] Furthermore, in this embodiment, the hydrogen recovery line 50 is configured to pass through the third heat exchange liquefaction unit 210c of the hydrogen liquefaction equipment 200. Therefore, in this embodiment, the cold energy of the hydrogen flowing through the hydrogen recovery line 50 can be utilized for liquefaction of the hydrogen supplied to the hydrogen supply line 20.

[0125] Figure 13 is a diagram showing a hydrogen liquefaction system according to the thirteenth embodiment of the present invention.

[0126] The thirteenth embodiment of the present invention, shown in Figure 13, is formed to have the same overall components as the twelfth embodiment described above.

[0127] Furthermore, the twelfth embodiment described above illustrates that in the first refrigerant cycle C1, the refrigerant recovery line 40 does not perform heat exchange with the heat exchange unit 100 and the first heat exchange type liquefaction unit 210a of the hydrogen liquefaction equipment 200, and in the second refrigerant cycle C2, the refrigerant recovery line 40 does not perform heat exchange with the heat exchange unit 100.

[0128] On the other hand, in this embodiment, the refrigerant recovery line 40 of the first refrigerant cycle C1 is configured to perform heat exchange with the heat exchange unit 100 and the first heat exchange type liquefaction unit 210a of the hydrogen liquefaction equipment 200, and the refrigerant recovery line 40 of the second refrigerant cycle C2 is configured to perform heat exchange with the heat exchange unit 100.

[0129] In other words, this embodiment is implemented in such a way that additional cold energy can be recovered from the refrigerant recovery line 40.

[0130] Figure 14 is a diagram showing a hydrogen liquefaction system according to the 14th embodiment of the present invention.

[0131] The 14th embodiment of the present invention, shown in Figure 14, is formed to have the same overall components as the 13th embodiment described above.

[0132] Furthermore, this embodiment has a configuration in which, in addition to the components of the 13th embodiment described above, an ammonia reformer 300, a fuel supply unit 310, an ammonia bypass line 11, and a compression power supply unit 320 are additionally applied, as in the 7th embodiment described above.

[0133] Figure 15 is a diagram showing a hydrogen liquefaction system according to the 15th embodiment of the present invention.

[0134] The 15th embodiment of the present invention, shown in Figure 15, is formed to have the same components as the first embodiment described above, and is further characterized by including a carbon dioxide liquefaction unit 400, a carbon dioxide supply line 60, and a refrigerant auxiliary supply line 70.

[0135] The carbon dioxide liquefaction equipment 400 is installed to liquefy carbon dioxide in a gaseous state.

[0136] Furthermore, the carbon dioxide supply line 60 is configured to pass through a heat exchange unit, thereby allowing the temperature of the carbon dioxide to be lowered through the cold energy of ammonia.

[0137] Here, the carbon dioxide supplied by the carbon dioxide supply line 60 may be carbon dioxide generated in the hydrogen liquefaction equipment 200 and the ammonia reformer 300 shown in other embodiments.

[0138] The refrigerant auxiliary supply line 70 is configured to supply refrigerant to the carbon dioxide liquefaction equipment 400 and to pass through the heat exchange unit 100 so that the temperature of the refrigerant is lowered through the cold energy of ammonia.

[0139] In other words, this embodiment allows the cold energy of liquid ammonia to be utilized in the pre-cooling process for liquefaction of hydrogen and carbon dioxide through the heat exchange unit 100.

[0140] Having considered preferred embodiments of the present invention as described above, it is obvious to those ordinary skill in the art that the present invention can be embodied in other specific forms without departing from its spirit or scope, in addition to the embodiments described herein. Therefore, the embodiments described above should be considered illustrative rather than restrictive, and the present invention is not limited to the above description, but may be modified within the scope of the appended claims and their equivalent scope. [Explanation of symbols]

[0141] 10: Ammonia supply line 11: Ammonia bypass line 20: Hydrogen supply line 30: Refrigerant supply line 40: Refrigerant recovery line 50: Hydrogen recovery line 60: Carbon dioxide supply line 70: Refrigerant auxiliary supply line 100: Heat exchange unit 200: Hydrogen liquefaction equipment 210a: First heat exchange liquefaction unit 210b: Second heat exchange liquefaction unit 210c: Third heat exchange liquefaction unit 220: Expansion valve assembly 230: Expander 300: Ammonia reformer 310: Fuel supply unit 320: Compressed Power Supply Unit 330: Separator 400: Carbon dioxide liquefaction equipment

Claims

1. A system for hydrogen liquefaction that utilizes an ammonia pre-cooling method, the system is A hydrogen liquefaction facility that liquefies hydrogen, Ammonia (NH) in liquid form from an ammonia source 3 an ammonia supply line that supplies ) and A hydrogen supply line that supplies hydrogen to the hydrogen liquefaction facility, A refrigerant supply line that supplies refrigerant to the hydrogen liquefaction equipment, and A heat exchange unit is formed such that the ammonia supply line, the hydrogen supply line, and the refrigerant supply line pass through it, and which lowers the temperature of hydrogen and refrigerant through the cold energy of ammonia, including, system.

2. The heat exchange unit is A first heat exchange unit that performs heat exchange between the hydrogen supply line and the ammonia supply line, and A second heat exchange unit that performs heat exchange between the refrigerant supply line and the ammonia supply line, Includes, The system according to claim 1, wherein the ammonia supply line is branched and configured to pass through the first heat exchange unit and the second heat exchange unit individually.

3. The refrigerant supply line includes a plurality of refrigerant supply lines that allow different refrigerants to flow through them. The system according to claim 2, wherein the second heat exchange unit includes a plurality of second heat exchange units, each corresponding to a plurality of refrigerant supply lines.

4. The system according to claim 1, wherein the heat exchange unit is formed in an immersion manner and is configured to utilize the cooling effect of the latent heat of vaporization of ammonia and to recover the evaporated ammonia.

5. The system according to claim 4, wherein the heat exchange units are configured to be arranged in series, and the hydrogen supply line and the refrigerant supply line are formed to pass through the multiple heat exchange units.

6. The system according to claim 5, wherein the ammonia supply line is branched and configured to pass through a plurality of heat exchange units individually.

7. The system according to claim 1, wherein the heat exchange unit is formed in the form of a plate fin heat exchanger or a spiral wound heat exchanger.

8. The system according to claim 1, further comprising an ammonia reformer for extracting hydrogen from ammonia supplied from the ammonia supply line.

9. The system according to claim 8, wherein the hydrogen extracted via the ammonia reformer is supplied to the hydrogen supply line.

10. The system according to claim 9, further comprising a separator for separating and recovering ammonia mixed with hydrogen supplied to the hydrogen supply line.

11. The system according to claim 8, further comprising a fuel supply unit for supplying fuel to the ammonia reformer.

12. The fuel supplied by the aforementioned fuel supply unit is ammonia. The system according to claim 11, wherein the fuel supply unit is configured to recover and reuse ammonia remaining in the ammonia reformer.

13. The system according to claim 12, further comprising an ammonia bypass line that directs a portion of the ammonia supplied to the ammonia supply line directly into the fuel supply unit.

14. The system according to claim 11, further comprising a compression power supply unit for use in the compression process of hydrogen supplied from the fuel supply unit to the hydrogen supply line and the compression process of refrigerant supplied to the refrigerant supply line.

15. Carbon dioxide liquefaction equipment, and, A carbon dioxide supply line is formed to collect carbon dioxide generated in the hydrogen liquefaction equipment and the ammonia reformer and supply it to the carbon dioxide liquefaction equipment, and to pass through the heat exchange unit so that the temperature of the carbon dioxide decreases through the cold energy of the ammonia, The system according to claim 8, further comprising:

16. The system according to claim 15, further comprising a refrigerant auxiliary supply line that supplies a refrigerant to the carbon dioxide liquefaction equipment and is formed to pass through the heat exchange unit so that the temperature of the refrigerant decreases through the cold energy of the ammonia.

17. The system further includes a refrigerant recovery line that recovers the refrigerant that has passed through the heat exchange unit and the hydrogen liquefaction equipment via the refrigerant supply line, The system according to claim 1, wherein the refrigerant supply line and the refrigerant recovery line form a refrigerant cycle in which the refrigerant is circulated.

18. The system according to claim 17, wherein the refrigerant cycle comprises a plurality of refrigerant cycles.

19. The system according to claim 17, wherein the refrigerant cycle includes at least one of an expansion valve assembly and an expander for reducing the pressure of the refrigerant and cooling it.

20. The system according to claim 17, wherein the hydrogen liquefaction equipment is configured such that the hydrogen supply line and the refrigerant cycle pass through it, and includes a heat exchange liquefaction unit that lowers the temperature of the hydrogen through the cold energy of the refrigerant.

21. The system according to claim 20, wherein the heat exchange liquefaction unit includes a plurality of heat exchange liquefaction units.

22. The system according to claim 20, wherein the refrigerant supply line and the refrigerant recovery line are configured to perform heat exchange through the heat exchange liquefaction unit, thereby lowering the temperature of the refrigerant flowing through the refrigerant supply line through the cold energy of the refrigerant flowing through the refrigerant recovery line.

23. The system according to claim 1, further comprising a hydrogen recovery line for recovering unliquefied hydrogen in the hydrogen liquefaction facility and supplying it to the hydrogen supply line.

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