Hydrogen liquefaction system using ammonia pre-cooling method

Abstract

A hydrogen liquefaction system using an ammonia pre-cooling method according to the present invention comprises: a hydrogen liquefaction facility which liquefies hydrogen; an ammonia supply line which supplies ammonia (NH3) in a liquid state from an ammonia supply source; a hydrogen supply line which supplies hydrogen to the hydrogen liquefaction facility; a refrigerant supply line which supplies refrigerant to the hydrogen liquefaction facility; and a heat exchange unit which is formed so that the ammonia supply line, the hydrogen supply line, and the refrigerant supply line pass through, and lowers the temperature of the hydrogen and the refrigerant through the coldness of the ammonia.

Description

Hydrogen liquefaction system using ammonia precooling

[0001] The present invention relates to a hydrogen liquefaction system, and more particularly, to a hydrogen liquefaction system capable of efficiently liquefying hydrogen using an ammonia pre-cooling method.

[0002] Recently, ammonia storage and transport has emerged as a representative method for large-scale green hydrogen storage and transport.

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

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

[0005] In order to obtain hydrogen from ammonia, a reforming process must be performed, and since this reforming process is usually performed at high temperatures, ammonia stored in a low-temperature tank must be heated, which requires a lot of energy.

[0006] Furthermore, when liquefying hydrogen produced through the ammonia reforming process for storage and transport, the resulting hydrogen must be cooled to a low temperature. In particular, because the hydrogen liquefaction process uses a large amount of refrigerant, a significant amount of cooling energy is required not only for the hydrogen but also for the refrigerant itself.

[0007] To explain in more detail, theoretically, 17 kg of ammonia must be decomposed to obtain 3 kg of hydrogen, and this conversion reaction is endothermic (ΔH=2.7 MJ / kg of Ammonia), so a large amount of energy is required.

[0008] Additionally, a lot of energy is required to separate the generated hydrogen, and in particular, additional energy is required in the process of pressurizing the hydrogen itself and the process of pressurizing the refrigerant to liquefy the hydrogen at a liquefaction temperature of -253℃.

[0009] Even a simple calculation like the above shows that more than 10 times as much ammonia is needed for the total amount of hydrogen to be produced and liquefied.

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

[0011] Therefore, a method to solve these problems is required.

[0012] The present invention is an invention devised to solve the problems of the above-described prior art, and has the purpose of minimizing energy consumption in the entire process of extracting, storing, and liquefying hydrogen through ammonia for transport.

[0013] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

[0014] The hydrogen liquefaction system using the ammonia pre-cooling method of the present invention for achieving the above-described purpose includes a hydrogen liquefaction facility 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 facility, a refrigerant supply line for supplying refrigerant to the hydrogen liquefaction facility, and a heat exchange unit formed so that the ammonia supply line, the hydrogen supply line, and the refrigerant supply line pass therethrough, and lowering the temperatures of the hydrogen and the refrigerant through the cold heat of the ammonia.

[0015] At this time, the heat exchange unit may include a first heat exchange unit that exchanges heat between the hydrogen supply line and the ammonia supply line and a second heat exchange unit that exchanges heat between the refrigerant supply line and the ammonia supply line. In this case, the ammonia supply line may be formed to branch and individually pass through the first heat exchange unit and the second heat exchange unit.

[0016] And the refrigerant supply lines may be provided in multiple numbers to allow different refrigerants to flow, and in this case, the second heat exchange units may be arranged in multiple numbers to correspond to each of the multiple refrigerant supply lines.

[0017] In addition, the above heat exchange unit may be formed in a submerged form to utilize the cold heat according to the latent heat of evaporation of ammonia and to recover the evaporated ammonia.

[0018] And the heat exchange units may be configured in series in a plurality of units, and the hydrogen supply line and the refrigerant supply line may be formed to pass through the plurality of heat exchange units.

[0019] Additionally, the ammonia supply line may be branched and formed to individually pass through a plurality of the heat exchange units.

[0020] Meanwhile, the above heat exchange unit can 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] At this time, hydrogen extracted through the ammonia reformer can 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 hydrogen supplied through the hydrogen supply line.

[0024] Additionally, the present invention may further include a fuel supply unit for supplying fuel to the ammonia reformer.

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

[0026] In addition, the present invention may further include an ammonia bypass line that directly introduces a portion of the ammonia supplied through the ammonia supply line to the fuel supply unit.

[0027] The present invention may further include a compression power providing unit that receives fuel from the fuel supply unit and uses it for a compression process of hydrogen supplied to the hydrogen supply line and a compression process of refrigerant supplied to the refrigerant supply line.

[0028] In addition, the present invention may further include a carbon dioxide supply line that captures carbon dioxide generated in the carbon dioxide liquefaction facility, the hydrogen liquefaction facility, and the ammonia reformer and supplies it to the carbon dioxide liquefaction facility, and is formed to pass through the heat exchange unit so that the temperature of the carbon dioxide is lowered through the cooling heat of the ammonia.

[0029] In such a case, the present invention may further include a refrigerant auxiliary supply line that supplies refrigerant to the carbon dioxide liquefaction facility, but is formed to pass through the heat exchange unit so that the temperature of the refrigerant is lowered through the cooling heat of the ammonia.

[0030] Meanwhile, the present invention further includes a refrigerant recovery line for recovering refrigerant that has passed through the heat exchange unit and the hydrogen liquefaction facility through the refrigerant supply line, so that the refrigerant supply line and the refrigerant recovery line can form a refrigerant cycle in which the refrigerant circulates.

[0031] At this time, multiple refrigerant cycles may be provided.

[0032] In addition, the refrigerant cycle may include at least one of an expansion valve assembly and an expander that cools the refrigerant by reducing its pressure.

[0033] And the hydrogen liquefaction facility may include a heat exchange type liquefaction unit that is formed so that the hydrogen supply unit and the refrigerant cycle pass through it, and lowers the temperature of the hydrogen through the cooling heat of the refrigerant.

[0034] A plurality of heat exchange type liquefaction units of this type may be provided.

[0035] In addition, the refrigerant supply line and the refrigerant recovery line are formed to perform heat exchange through the heat exchange type liquefaction unit, so that the temperature of the refrigerant flowing through the refrigerant supply line can be lowered through the cooling heat of the refrigerant flowing through the refrigerant recovery line.

[0036] In addition, the present invention may further include a hydrogen recovery line that recovers unliquefied hydrogen from the hydrogen liquefaction facility and supplies it to the hydrogen supply line.

[0037] The hydrogen liquefaction system using the ammonia pre-cooling method of the present invention for solving the above-mentioned problem has the advantage of being able to greatly increase energy efficiency by minimizing the energy used for liquefying ultra-low temperature hydrogen by utilizing the cold heat of ammonia liquefied at a low temperature through the storage and transportation process in the pre-cooling process of hydrogen and refrigerant for hydrogen liquefaction.

[0038] In addition, the present invention can minimize carbon emissions and maximize energy eco-friendliness in the hydrogen production process by simultaneously reducing energy costs throughout the entire process and increasing production volume.

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

[0040] FIG. 1 is a drawing showing a hydrogen liquefaction system according to a first embodiment of the present invention.

[0041] Figure 2 is a drawing showing a hydrogen liquefaction system according to a second embodiment of the present invention.

[0042] Figure 3 is a drawing showing a hydrogen liquefaction system according to a third embodiment of the present invention.

[0043] Figure 4 is a drawing showing a hydrogen liquefaction system according to a fourth embodiment of the present invention.

[0044] FIG. 5 is a drawing showing a hydrogen liquefaction system according to a fifth embodiment of the present invention.

[0045] Figure 6 is a drawing showing a hydrogen liquefaction system according to a sixth embodiment of the present invention.

[0046] Figure 7 is a drawing showing a hydrogen liquefaction system according to the seventh embodiment of the present invention.

[0047] Figure 8 is a drawing showing a hydrogen liquefaction system according to the eighth embodiment of the present invention.

[0048] Figure 9 is a drawing showing a hydrogen liquefaction system according to the ninth embodiment of the present invention.

[0049] FIG. 10 is a drawing showing a hydrogen liquefaction system according to the tenth embodiment of the present invention.

[0050] FIG. 11 is a drawing showing a hydrogen liquefaction system according to the 11th embodiment of the present invention.

[0051] FIG. 12 is a drawing showing a hydrogen liquefaction system according to the 12th embodiment of the present invention.

[0052] Figure 13 is a drawing showing a hydrogen liquefaction system according to the 13th embodiment of the present invention.

[0053] FIG. 14 is a drawing showing a hydrogen liquefaction system according to the 14th embodiment of the present invention.

[0054] FIG. 15 is a drawing showing a hydrogen liquefaction system according to the 15th embodiment of the present invention.

[0055] In this specification, when it is said that a component (or region, layer, portion, etc.) is “on,” “connected to,” or “coupled to” another component, it means that it can be directly disposed / connected / coupled to the other component, or a third component may be disposed between them.

[0056] Identical drawing numbers indicate identical components. Furthermore, in the drawings, the thicknesses, proportions, and dimensions of components are exaggerated for the purpose of effectively illustrating the technical content.

[0057] “And / or” includes any combination of one or more of the associated constructs that can be defined.

[0058] While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a "second component," and similarly, a second component may also be referred to as a "first component." Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0059] Additionally, terms such as "below," "lower," "above," and "upper" are used to describe the relationships between components depicted in the drawings. These terms are relative concepts and are described based on the directions indicated in the drawings.

[0060] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. Furthermore, terms defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the relevant technical context, and unless interpreted in an idealized or overly formal sense, they are explicitly defined herein.

[0061] Terms such as "include" or "have" should be understood to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0062] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0063] FIG. 1 is a drawing showing a hydrogen liquefaction system according to a first embodiment of the present invention.

[0064] As illustrated in FIG. 1, a hydrogen liquefaction system according to a first embodiment of the present invention includes 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).

[0065] The hydrogen liquefaction facility (200) is provided to liquefy gaseous hydrogen, and this hydrogen liquefaction process can be achieved through heat exchange between hydrogen and a refrigerant supplied through a refrigerant supply line (30). This will be described in more detail in other embodiments described later.

[0066] The ammonia supply line (10) supplies liquid ammonia (NH3) from an ammonia supply source.

[0067] In this embodiment, the ammonia supply line (10) flows liquid ammonia from the ammonia supply tank, but is extended in a path passing through the heat exchange unit (100).

[0068] The hydrogen supply line (20) supplies hydrogen from a hydrogen supply source to a hydrogen liquefaction facility (200) and extends along a path passing through a heat exchange unit (100).

[0069] At this time, the hydrogen supply source may be a hydrogen supply tank that stores hydrogen, or it may be a method of supplying hydrogen extracted by reforming ammonia. Details regarding this will be described in the other embodiments described below.

[0070] The refrigerant supply line (30) is provided to supply refrigerant to the hydrogen liquefaction facility (200).

[0071] And the refrigerant supplied to the refrigerant supply line (30) may be a single component refrigerant, but may also be a mixed refrigerant of multiple components. For example, the refrigerant may be a single component or mixed component of helium (He), hydrogen (H2), neon (Ne), nitrogen (N2), ammonia (NH3), propane (C3H8, ethylene (C2H4), and methane (CH4).

[0072] In addition, a plurality of refrigerant supply lines (30) may be provided (1, 2...n) to allow different refrigerants to flow, and each refrigerant supply line (30) extends along a path passing through a heat exchange unit (100).

[0073] The heat exchange unit (100) is formed so that the ammonia supply line (10), the hydrogen supply line (20), and the refrigerant supply line (30) pass through it, respectively, and lowers the temperature of the hydrogen and the refrigerant through the cold heat of the ammonia supplied to the ammonia supply line (10).

[0074] The heat exchange unit (100) can be implemented in various forms, but the heat exchange unit (100) of this embodiment uses a plate fin heat exchanger, which is a multi-flow heat exchanger.

[0075] 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 a heat exchange unit (100).

[0076] In addition, since the present invention can relatively reduce the energy required for vaporizing and heating ammonia through a heat exchange process, it can reduce the energy used, thereby increasing energy efficiency, lowering energy costs, and simultaneously increasing production volume.

[0077] 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.

[0078] Hereinafter, various embodiments implemented by the present invention will be described. In each embodiment described below, redundant descriptions of components provided in the same manner as in the first embodiment described above will be omitted.

[0079] Figure 2 is a drawing showing a hydrogen liquefaction system according to a second embodiment of the present invention.

[0080] The second embodiment of the present invention illustrated in FIG. 2 includes 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 (100a, 100b) like the first embodiment described above.

[0081] However, this embodiment has the characteristic that a plurality of heat exchange units (100a, 100b) are provided, and the plurality of heat exchange units (100a, 100b) are provided in an independent form.

[0082] Specifically, the present embodiment includes a first heat exchange unit (100a) for heat exchange between a hydrogen supply line (20) and an ammonia supply line (10), and a second heat exchange unit (100b) for heat exchange between a refrigerant supply line (30) and an ammonia supply line (10).

[0083] And the ammonia supply line (10) is provided in a branched form, and is formed to individually pass through the first heat exchange unit (100a) and the second heat exchange unit (100b).

[0084] At this time, in this embodiment, since a plurality of refrigerant supply lines (30) are provided to allow different refrigerants to flow, a plurality of second heat exchange units (100b) can be arranged to correspond to each of the plurality of refrigerant supply lines (30).

[0085] Figure 3 is a drawing showing a hydrogen liquefaction system according to a third embodiment of the present invention.

[0086] The third embodiment of the present invention illustrated in FIG. 3 also includes 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) like the first embodiment described above.

[0087] And this embodiment has the characteristic that the heat exchange unit (100) is formed in a submerged form to utilize the cold heat according to the latent heat of evaporation of ammonia and to recover the evaporated ammonia.

[0088] This method is applicable because the ammonia supplied through the ammonia supply line (10) is in a liquid state.

[0089] This method has a limitation in that it cannot fully utilize the cold heat of ammonia up to room temperature, but it has the advantage of being able to apply a simple structure of the heat exchange unit (100) and easy to control the temperature.

[0090] Figure 4 is a drawing showing a hydrogen liquefaction system according to a fourth embodiment of the present invention.

[0091] The fourth embodiment of the present invention illustrated in FIG. 4 has the characteristic that, like the third embodiment described above, the heat exchange unit (100a, 100b) is formed in a submerged manner, and further, a plurality of heat exchange units (100a, 100b) are configured in series.

[0092] Additionally, in this embodiment, the hydrogen supply line (20) and the refrigerant supply line (30) are each formed to sequentially pass through a plurality of heat exchange units (100a, 100b).

[0093] And the ammonia supply line (10) is provided in a branched form, so that each branched ammonia supply line (10) passes through a plurality of heat exchange units (100a, 100b) individually.

[0094] This method has the advantage of reducing the additional power required for pressurization in the process of additionally pressurizing ammonia to utilize the recovered ammonia after using the cold heat of ammonia in the heat exchange unit (100a, 100b).

[0095] In addition, in this embodiment, the heat exchange unit (100a) disposed on the upstream side 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) disposed on the downstream side.

[0096] FIG. 5 is a drawing showing a hydrogen liquefaction system according to a fifth embodiment of the present invention.

[0097] The fifth embodiment of the present invention illustrated in FIG. 5 is formed to have the same overall configuration and arrangement as the first embodiment described above.

[0098] However, in the case of this embodiment, the difference 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.

[0099] Figure 6 is a drawing showing a hydrogen liquefaction system according to a sixth embodiment of the present invention.

[0100] The sixth embodiment of the present invention illustrated in FIG. 6 is formed to have the same overall configuration and arrangement as the first embodiment described above.

[0101] And the present embodiment further includes an ammonia reformer (300) that extracts hydrogen from ammonia supplied from an ammonia supply line (10).

[0102] Additionally, in the present embodiment, hydrogen extracted through the ammonia reformer (300) can be supplied to the hydrogen supply line (20), and hydrogen supplied to the hydrogen supply line (20) can be compressed by a compressor during the flow process.

[0103] Figure 7 is a drawing showing a hydrogen liquefaction system according to the seventh embodiment of the present invention.

[0104] The seventh embodiment of the present invention illustrated in FIG. 7 includes an ammonia reformer (300) that extracts hydrogen from ammonia supplied from an ammonia supply line (10), as in the sixth embodiment described above.

[0105] And the present embodiment has the feature of further including a fuel supply unit (310), an ammonia bypass line (11), and a compression power providing unit (320).

[0106] The fuel supply unit (310) supplies fuel to the ammonia reformer (300), or supplies ammonia to a separate power generation facility or other facility that uses ammonia. At this time, the fuel supplied by the fuel supply unit (310) is not limited to a specific type of fuel, but in the present embodiment, it is assumed to be ammonia.

[0107] In addition, the fuel supply unit (310) can be configured to recover and reuse the ammonia remaining in the ammonia reformer (300).

[0108] The ammonia bypass line (11) serves to directly introduce a portion of the ammonia supplied through the ammonia supply line (10) to the fuel supply unit (310).

[0109] Therefore, ammonia supplied through the ammonia supply line (10) can be supplied to the ammonia reformer (300) or bypassed and introduced to the fuel supply unit (310).

[0110] The compression power supply unit (320) is provided to receive fuel from the fuel supply unit (310) and supply fuel for the compression process of hydrogen supplied to the hydrogen supply line (20) and the compression process of refrigerant supplied to the refrigerant supply line (30).

[0111] That is, in this embodiment, ammonia partially recovered from the fuel supply unit (310) and provided to the compression power providing unit (320) can be used as fuel for a compressor that compresses hydrogen and a compressor that compresses refrigerant by the compression power providing unit (320).

[0112] Figure 8 is a drawing showing a hydrogen liquefaction system according to the eighth embodiment of the present invention.

[0113] The eighth embodiment of the present invention illustrated in FIG. 8 includes an ammonia reformer (300) that extracts hydrogen from ammonia supplied from an ammonia supply line (10), as in the sixth embodiment described above.

[0114] And this embodiment has the feature of further including a separator (330) that separates and recovers ammonia mixed with hydrogen supplied to the hydrogen supply line (20).

[0115] That is, in the present embodiment, when some ammonia is not completely converted in the process of converting ammonia into hydrogen in the ammonia reformer (300), it is allowed to flow together with hydrogen into the hydrogen supply line (20), and ammonia can be separated separately through the separator (330) in the process of cooling the hydrogen in the heat exchanger (100).

[0116] At this time, the separation method performed by the separator (330) can be applied in various ways, such as simple gas-liquid separation or distillation.

[0117] Figure 9 is a drawing showing a hydrogen liquefaction system according to the ninth embodiment of the present invention.

[0118] The ninth embodiment of the present invention illustrated in FIG. 9 includes 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) like the first embodiment described above.

[0119] And in the case of this embodiment, a refrigerant recovery line (40) for recovering refrigerant that has passed through the heat exchange unit (100) and the hydrogen liquefaction facility (200) through the refrigerant supply line (30) is further included, and thus the refrigerant supply line (30) and the refrigerant recovery line (40) form a refrigerant cycle (C1, C2) in which the refrigerant is circulated.

[0120] A plurality of such refrigerant cycles (C1, C2) may be provided, and in the present embodiment, it is exemplified as including a first refrigerant cycle (C1) and a second refrigerant cycle (C2).

[0121] At this time, each refrigerant cycle (C1, C2) can select refrigerant components according to the corresponding temperature, or use refrigerants by mixing them.

[0122] For example, in the present 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.

[0123] Meanwhile, the hydrogen liquefaction facility (200) may include a heat exchange type liquefaction unit (210a, 210b, 210c) that is formed so that a hydrogen supply unit (20) and a refrigerant cycle (C1, C2) pass through it, and lowers the temperature of hydrogen through the cold heat of the refrigerant.

[0124] A plurality of heat exchange type liquefaction units may be provided, and in the case of this embodiment, a first heat exchange type liquefaction unit (210a), a second heat exchange type liquefaction unit (210b), and a third heat exchange type liquefaction unit (210c) are exemplified as being arranged in series.

[0125] In the present embodiment, the first refrigerant cycle (C1) forms a circulation path by passing through the first heat exchange type liquefaction unit (210a), the second heat exchange type liquefaction unit (210b), and the third heat exchange type liquefaction unit (210c), and the second refrigerant cycle (C2) is arranged to circulate through the circulation path only by passing through the first heat exchange type liquefaction unit (210a) and the second heat exchange type liquefaction unit (210b).

[0126] Accordingly, the first refrigerant cycle (C1) can perform hydrogen liquefaction and auxiliary cooling functions, and the second refrigerant cycle (C2) can perform hydrogen cooling functions.

[0127] However, the number and arrangement of heat exchange liquefaction units (210a, 210b, 210c) are not limited by this embodiment and can be modified into various forms.

[0128] In addition, in the present embodiment, the refrigerant cycles (C1, C2) may each include an expansion valve assembly (220) that cools the refrigerant by reducing its pressure. For example, a JT (Joule-Thomson) valve may be applied as the expansion valve assembly (220).

[0129] FIG. 10 is a drawing showing a hydrogen liquefaction system according to the tenth embodiment of the present invention.

[0130] The tenth embodiment of the present invention illustrated in FIG. 10 includes a first refrigerant cycle (C1) and a second refrigerant cycle (C2) composed of a refrigerant supply line (30) and a refrigerant recovery line (40), as in the ninth embodiment described above.

[0131] However, this embodiment has a feature in that the first refrigerant cycle (C1) includes an expander (230) in place of the expansion valve assembly (220). The expander (230) also performs the function of cooling the refrigerant by reducing its pressure.

[0132] In this way, 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).

[0133] FIG. 11 is a drawing showing a hydrogen liquefaction system according to the 11th embodiment of the present invention.

[0134] The eleventh embodiment of the present invention illustrated in FIG. 11 includes a first refrigerant cycle (C1) and a second refrigerant cycle (C2) composed of a refrigerant supply line (30) and a refrigerant recovery line (40), as in the ninth embodiment described above.

[0135] In addition to the components of the ninth embodiment, this embodiment has a form in which an ammonia reformer (300) for extracting hydrogen from ammonia supplied from an ammonia supply line (10) is additionally applied, as in the sixth embodiment described above.

[0136] FIG. 12 is a drawing showing a hydrogen liquefaction system according to the 12th embodiment of the present invention.

[0137] The twelfth embodiment of the present invention illustrated in FIG. 12 is formed to have the same overall components as the eleventh embodiment described above.

[0138] However, this embodiment has the feature of further including a hydrogen recovery line (50) that recovers unliquefied hydrogen from a hydrogen liquefaction facility (200) and supplies it to a hydrogen supply line (20), and accordingly, this embodiment can further increase the liquefaction rate of hydrogen.

[0139] In addition, in this embodiment, the hydrogen recovery line (50) is formed to pass through the third heat exchange type liquefaction unit (210c) of the hydrogen liquefaction facility (200). Therefore, in this embodiment, the cold heat of the hydrogen flowing through the hydrogen recovery line (50) can be utilized for the liquefaction of the hydrogen supplied to the hydrogen supply line (20).

[0140] Figure 13 is a drawing showing a hydrogen liquefaction system according to the 13th embodiment of the present invention.

[0141] The 13th embodiment of the present invention illustrated in FIG. 13 is formed to have the same overall components as the 12th embodiment described above.

[0142] And in the 12th embodiment described above, the refrigerant recovery line (40) of the first refrigerant cycle (C1) does not perform heat exchange in the heat exchange unit (100) and the first heat exchange type liquefaction unit (210a) of the hydrogen liquefaction facility (200), and also, the refrigerant recovery line (40) of the second refrigerant cycle (C2) does not perform heat exchange in the heat exchange unit (100).

[0143] On the other hand, in the case of the present embodiment, the refrigerant recovery line (40) of the first refrigerant cycle (C1) is formed to perform heat exchange in the heat exchange unit (100) and the first heat exchange type liquefaction unit (210a) of the hydrogen liquefaction facility (200), and the refrigerant recovery line (40) of the second refrigerant cycle (C2) is formed to perform heat exchange in the heat exchange unit (100).

[0144] That is, the present embodiment is implemented to enable additional cold heat recovery from the refrigerant recovery line (40).

[0145] FIG. 14 is a drawing showing a hydrogen liquefaction system according to the 14th embodiment of the present invention.

[0146] The 14th embodiment of the present invention illustrated in FIG. 14 is formed to have the same overall components as the 13th embodiment described above.

[0147] In addition to the components of the 13th embodiment, this embodiment has a form in which an ammonia reformer (300), a fuel supply unit (310), an ammonia bypass line (11), and a compression power providing unit (320) are additionally applied, as in the 7th embodiment described above.

[0148] FIG. 15 is a drawing showing a hydrogen liquefaction system according to the 15th embodiment of the present invention.

[0149] The fifteenth embodiment of the present invention illustrated in FIG. 15 is formed to have the same overall components as the first embodiment described above, and is characterized by further including a carbon dioxide liquefaction facility (400), a carbon dioxide supply line (60), and a refrigerant auxiliary supply line (70).

[0150] The carbon dioxide liquefaction facility (400) is provided to liquefy carbon dioxide in a gaseous state.

[0151] And the carbon dioxide supply line (60) is formed to pass through a heat exchange unit, thereby allowing the temperature of carbon dioxide to drop through the cooling heat of ammonia.

[0152] At this time, the carbon dioxide supplied by the carbon dioxide supply line (60) may be carbon dioxide generated in the hydrogen liquefaction facility (200) and the ammonia reformer (300) shown in other embodiments.

[0153] The refrigerant auxiliary supply line (70) supplies refrigerant to the carbon dioxide liquefaction facility (400), and is formed to pass through the heat exchange unit (100) so that the temperature of the refrigerant is lowered through the cooling heat of ammonia.

[0154] That is, in this embodiment, the cold heat of liquid ammonia can be utilized in the pre-cooling process for liquefying hydrogen and carbon dioxide through the heat exchange unit (100).

[0155] As described above, preferred embodiments of the present invention have been described. It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms, in addition to the embodiments described above, without departing from the spirit or scope thereof. Therefore, the above-described embodiments should be considered illustrative rather than restrictive, and accordingly, the present invention is not limited to the above description, but may be modified within the scope of the appended claims and their equivalents.

[0156] [Explanation of symbols]

[0157] 10: Ammonia supply line

[0158] 11: Ammonia bypass line

[0159] 20: Hydrogen supply line

[0160] 30: Refrigerant supply line

[0161] 40: Refrigerant recovery line

[0162] 50: Hydrogen recovery line

[0163] 60: Carbon dioxide supply line

[0164] 70: Refrigerant auxiliary supply line

[0165] 100: Heat exchange unit

[0166] 200: Hydrogen liquefaction facility

[0167] 210a: First heat exchanger liquefaction unit

[0168] 210b: Second heat exchanger liquefaction unit

[0169] 210c: Third heat exchanger liquefaction unit

[0170] 220: Expansion valve assembly

[0171] 230: Expander

[0172] 300: Ammonia reformer

[0173] 310: Fuel supply unit

[0174] 320: Compression power supply unit

[0175] 330: Separator

[0176] 400: Carbon dioxide liquefaction facility

Claims

1. Hydrogen liquefaction facility that liquefies hydrogen; An ammonia supply line that supplies liquid ammonia (NH3) from an ammonia source; A hydrogen supply line for supplying hydrogen to the hydrogen liquefaction facility; A refrigerant supply line for supplying refrigerant to the hydrogen liquefaction facility; 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 lowers the temperature of the hydrogen and the refrigerant through the cold heat of the ammonia; including, Hydrogen liquefaction system using ammonia pre-cooling method.

2. In paragraph 1, The above heat exchange unit, A first heat exchange unit for heat exchange between the hydrogen supply line and the ammonia supply line; and A second heat exchange unit that exchanges heat between the refrigerant supply line and the ammonia supply line; Includes, The above ammonia supply line is branched and formed to pass through the first heat exchange unit and the second heat exchange unit individually. Hydrogen liquefaction system using ammonia pre-cooling method.

3. In paragraph 2, The above refrigerant supply line is provided in multiple numbers to allow different refrigerants to flow, The second heat exchange unit is arranged in multiple numbers to correspond to each of the plurality of refrigerant supply lines. Hydrogen liquefaction system using ammonia pre-cooling method.

4. In paragraph 1, The above heat exchange unit is formed in a submerged manner to utilize the cold heat according to the latent heat of vaporization of ammonia and to recover the evaporated ammonia. Hydrogen liquefaction system using ammonia pre-cooling method.

5. In paragraph 4, The above heat exchange units are configured in series in multiple numbers, and the hydrogen supply line and the refrigerant supply line are formed to pass through the multiple heat exchange units. Hydrogen liquefaction system using ammonia pre-cooling method.

6. In paragraph 5, The above ammonia supply line is branched and formed to individually pass through a plurality of the above heat exchange units. Hydrogen liquefaction system using ammonia pre-cooling method.

7. In paragraph 1, The above heat exchange unit is formed in the form of a plate fin heat exchanger or a spiral wound heat exchanger. Hydrogen liquefaction system using ammonia pre-cooling method.

8. In paragraph 1, Further comprising an ammonia reformer for extracting hydrogen from ammonia supplied from the ammonia supply line. Hydrogen liquefaction system using ammonia pre-cooling method.

9. In paragraph 8, The hydrogen extracted through the ammonia reformer is supplied to the hydrogen supply line. Hydrogen liquefaction system using ammonia pre-cooling method.

10. In paragraph 9, Further comprising a separator for separating and recovering ammonia mixed with hydrogen supplied through the hydrogen supply line. Hydrogen liquefaction system using ammonia pre-cooling method.

11. In paragraph 8, Further comprising a fuel supply unit for supplying fuel to the ammonia reformer, Hydrogen liquefaction system using ammonia pre-cooling method.

12. In paragraph 11, The fuel supplied by the above fuel supply unit is ammonia, The above fuel supply unit is configured to recover and reuse the ammonia remaining in the ammonia reformer. Hydrogen liquefaction system using ammonia pre-cooling method.

13. In paragraph 12, Further comprising an ammonia bypass line for directly introducing a portion of the ammonia supplied through the ammonia supply line to the fuel supply unit side. Hydrogen liquefaction system using ammonia pre-cooling method.

14. In paragraph 11, Further comprising a compression power providing unit that receives fuel from the fuel supply unit and uses it for the compression process of hydrogen supplied to the hydrogen supply line and the compression process of refrigerant supplied to the refrigerant supply line. Hydrogen liquefaction system using ammonia pre-cooling method.

15. In paragraph 8, Carbon dioxide liquefaction facility; and A carbon dioxide supply line that captures carbon dioxide generated from the hydrogen liquefaction facility and the ammonia reformer and supplies it to the carbon dioxide liquefaction facility, and is formed to pass through the heat exchange unit so that the temperature of the carbon dioxide is lowered through the cold heat of the ammonia; including more, Hydrogen liquefaction system using ammonia pre-cooling method.

16. In paragraph 15, A refrigerant auxiliary supply line is further included, which supplies refrigerant to the carbon dioxide liquefaction facility, and is formed to pass through the heat exchange unit so that the temperature of the refrigerant is lowered through the cold heat of the ammonia. Hydrogen liquefaction system using ammonia pre-cooling method.

17. In paragraph 1, Further including a refrigerant recovery line for recovering refrigerant that has passed through the heat exchange unit and the hydrogen liquefaction facility through the refrigerant supply line. The above refrigerant supply line and the above refrigerant recovery line form a refrigerant cycle in which the refrigerant circulates. Hydrogen liquefaction system using ammonia pre-cooling method.

18. In paragraph 17, The above refrigerant cycle is provided in multiple numbers, Hydrogen liquefaction system using ammonia pre-cooling method.

19. In paragraph 17, The above refrigerant cycle includes at least one of an expansion valve assembly and an expander that cools the refrigerant by reducing its pressure. Hydrogen liquefaction system using ammonia pre-cooling method.

20. In paragraph 17, The above hydrogen liquefaction facility includes a heat exchange type liquefaction unit formed so that the hydrogen supply unit and the refrigerant cycle pass through it, and lowers the temperature of the hydrogen through the cooling heat of the refrigerant. Hydrogen liquefaction system using ammonia pre-cooling method.

21. In paragraph 20, The above heat exchange type liquefaction unit is provided in multiple units. Hydrogen liquefaction system using ammonia pre-cooling method.

22. In paragraph 20, The above refrigerant supply line and the above refrigerant recovery line are formed to perform heat exchange through the heat exchange type liquefaction unit, thereby lowering the temperature of the refrigerant flowing into the refrigerant supply line through the cold heat of the refrigerant flowing into the refrigerant recovery line. Hydrogen liquefaction system using ammonia pre-cooling method.

23. In paragraph 1, Further comprising a hydrogen recovery line for recovering unliquefied hydrogen from the hydrogen liquefaction facility and supplying it to the hydrogen supply line. Hydrogen liquefaction system using ammonia pre-cooling method.

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