Liquefaction device and liquefaction method

Abstract

To improve liquefaction efficiency of raw material gas.SOLUTION: A liquefaction device comprises: a raw material pipe through which raw material gas flows; a magnetic body connected to the raw material pipe, capable of adsorbing the raw material gas supplied from the raw material pipe, and whose temperature decreases when the application of a magnetic field is stopped; and a magnet for applying the magnetic field to the magnetic body. The magnet stops the application of the magnetic field to the magnetic body while the magnetic body adsorbs the raw material gas, and thereby the magnetic body cools the adsorbed raw material gas.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a liquefaction device and a liquefaction method. [Background technology]

[0002] There are known techniques for liquefying and storing raw material gases such as hydrogen gas. For example, Non-Patent Document 1 describes that raw material hydrogen gas is liquefied by cooling it with liquid nitrogen and expanding it with a Joule-Thomson valve. [Prior art documents] [Patent documents]

[0003] [Non-Patent Document 1] Seiji Yamashita et al., "Development of Hydrogen Liquefaction Storage System," Journal of Japan Society of Energy and Resources, Vol. 37, No. 4 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the liquefaction of gas using a Joule-Thomson valve utilizes the principle of isenthalpic expansion, there is a risk of low liquefaction efficiency. Therefore, there is a demand for improving the liquefaction efficiency of the raw gas.

[0005] An object of the present disclosure is to provide a liquefaction apparatus and a liquefaction method capable of improving the efficiency of liquefying a raw material gas. [Means for solving the problem]

[0006] The liquefaction apparatus according to the present disclosure comprises a raw material pipe through which a raw material gas flows, a magnetic body connected to the raw material pipe and capable of adsorbing the raw material gas supplied from the raw material pipe, the temperature of which decreases when application of a magnetic field is stopped, and a magnet that applies a magnetic field to the magnetic body, wherein the magnet stops applying the magnetic field to the magnetic body while the magnetic body has adsorbed the raw material gas, thereby causing the magnetic body to cool the adsorbed raw material gas.

[0007] The liquefaction method according to the present disclosure includes a step of adsorbing a source gas to a magnetic material capable of adsorbing the source gas and whose temperature decreases when application of a magnetic field is stopped, and a step of cooling the adsorbed source gas by the magnetic material by stopping application of a magnetic field to the magnetic material while the magnetic material has adsorbed the source gas. Effect of the Invention

[0008] According to the present disclosure, the efficiency of liquefying a raw material gas can be improved. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a liquefaction device according to the present embodiment. [Diagram 2] FIG. 2 is a flow chart illustrating the method for liquefying a raw material gas. [Diagram 3] FIG. 3 is a schematic diagram illustrating the adsorption of the source gas. [Figure 4] FIG. 4 is a schematic diagram illustrating cooling of the adsorbed source gas. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the present disclosure is not limited to these embodiments, and when there are multiple embodiments, the present disclosure also includes combinations of the embodiments.

[0011] (liquefier) FIG. 1 is a schematic diagram of a liquefaction apparatus according to this embodiment. The liquefaction apparatus 1 according to this embodiment is an apparatus for liquefying a raw material gas HG. Hereinafter, the liquefied raw material gas HG will be referred to as liquid HL. The raw material gas HG may be any substance, such as hydrogen, oxygen, or natural gas, but in this embodiment, hydrogen is used as the raw material gas HG. Therefore, the liquid HL in this embodiment is liquid hydrogen. In addition, the raw material gas HG and the liquid HL may be used for any purpose, such as rocket fuel.

[0012] As shown in FIG. 1, the liquefaction apparatus 1 has a raw material piping 10, a raw material supply section 12, a liquid storage section 14, nitrogen pipes 20, 22, a nitrogen supply section 24, a refrigerant piping 30, a refrigerant compression section 32, a refrigerant cooling section 34, refrigerant expansion sections 36, 38, a raw material cooling section 40, a raw material storage section 50, a magnetic refrigeration section 60, a magnetic material cooling section 70, a raw material expansion section 80, and a control device 100.

[0013] The control device 100 is a controller that controls each mechanism of the liquefaction apparatus 1. The control device 100 controls each mechanism of the liquefaction apparatus 1, whereby the raw material gas HG is liquefied by the liquefaction apparatus 1 to produce a liquid HL. The control device 100 may be, for example, a computer having an arithmetic circuit such as a CPU (Central Processing Unit), a memory, and the like. The control contents of the control device 100 will be described later.

[0014] (Liquefaction line) The raw material pipe 10, the raw material supply unit 12, the liquid storage unit 14, the raw material cooling unit 40, the raw material storage unit 50, the magnetic refrigeration unit 60, and the raw material expansion unit 80 constitute a liquefaction line that liquefies the raw material gas HG. The raw material pipe 10 is a pipe through which the raw material gas HG and the liquid HL pass. The raw material supply unit 12 is a mechanism that is connected to the raw material pipe 10 and supplies the raw material gas HG to the raw material pipe 10. The raw material supply unit 12 may be, for example, a container in which the raw material gas HG is stored. The liquid storage unit 14 is a mechanism that is connected to the raw material pipe 10 and supplies the liquid HL liquefied in the raw material pipe 10. The liquid storage unit 14 may be, for example, a container in which the liquid HL is stored. In the example of this embodiment, one end of the raw material pipe 10 is connected to the raw material supply unit 12, and the other end of the raw material pipe 10 is connected to the liquid storage unit 14. Hereinafter, the direction from the raw material supply unit 12 toward the liquid reservoir 14 in the raw material piping 10, that is, the direction in which the raw material gas HG and the liquid HL flow in the raw material piping 10, is referred to as the raw material flow direction DH.

[0015] The raw material cooling section 40, the raw material storage section 50, the magnetic refrigeration section 60, and the raw material expansion section 80 will be described later.

[0016] (Nitrogen line) The nitrogen pipes 20, 22 and the nitrogen supply unit 24 constitute a nitrogen line that conducts nitrogen for cooling the raw material gas HG. The nitrogen pipe 20 is a pipe through which liquid nitrogen NL passes. The nitrogen supply unit 24 is a mechanism that is connected to the nitrogen pipe 20 and supplies liquid nitrogen NL to the nitrogen pipe 20. The nitrogen supply unit 24 may be, for example, a container in which liquid nitrogen NL is stored. In this embodiment, one end of the nitrogen pipe 20 is connected to the nitrogen supply unit 24, and the other end of the nitrogen pipe 20 is connected to a third raw material cooling unit 44 described later. The third raw material cooling unit 44 is supplied with liquid nitrogen NL from the nitrogen pipe 20.

[0017] The nitrogen pipe 22 is a pipe through which nitrogen gas NG, which is vaporized liquid nitrogen NL, passes. The nitrogen pipe 22 is connected to the third raw material cooling section 44. That is, at least a part of the liquid nitrogen NL is vaporized in the third raw material cooling section 44 to become nitrogen gas NG, and the nitrogen gas NG is introduced into the nitrogen pipe 22.

[0018] In this embodiment, the raw material gas HG is cooled by the liquid nitrogen NL and nitrogen gas NG flowing through the nitrogen line, but the nitrogen line is not an essential component. That is, cooling of the raw material gas HG by the liquid nitrogen NL and nitrogen gas NG is not essential. The raw material gas HG may be cooled by at least the refrigerant C described below.

[0019] (Refrigerant line) The refrigerant pipe 30, the refrigerant compression section 32, the refrigerant cooling section 34, and the refrigerant expansion sections 36 and 38 constitute a refrigerant line that conducts a refrigerant C for cooling the raw material gas HG. The refrigerant C may be any substance capable of cooling the raw material gas HG, but is hydrogen in this embodiment.

[0020] The refrigerant piping 30 is a pipe through which the refrigerant C passes. The refrigerant compression section 32 is connected to the refrigerant piping 30. The refrigerant compression section 32 increases the temperature of the refrigerant C by compressing the refrigerant C. More specifically, the refrigerant compression section 32 compresses the refrigerant C after cooling the raw material gas HG (the refrigerant C after heat exchange in the raw material cooling section 40 described below). The refrigerant compression section 32 may be any mechanism capable of compressing the refrigerant C, but in this embodiment, a compression turbine that compresses the refrigerant C is used.

[0021] The refrigerant pipe 30 is a loop-shaped pipe in which the refrigerant C circulates inside the refrigerant pipe 30. That is, one end of the refrigerant pipe 30 is connected to the outlet 32A of the refrigerant compression section 32, and the other end is connected to the inlet 32B of the refrigerant compression section 32. The outlet 32A is the outlet from which the refrigerant C compressed in the refrigerant compression section 32 is discharged, and the inlet 32B is the inlet through which the refrigerant C is introduced into the refrigerant compression section 32. Hereinafter, the direction from the outlet 32A to the inlet 32B inside the refrigerant pipe 30, that is, the direction in which the refrigerant C flows inside the refrigerant pipe 30, is referred to as the refrigerant flow direction DC. That is, it can be said that the start point of the refrigerant flow direction DC is the outlet 32A, and the end point of the refrigerant flow direction DC is the inlet 32B.

[0022] The refrigerant cooling unit 34 is a heat exchanger that cools the refrigerant C flowing through the refrigerant pipe 30. The refrigerant cooling unit 34 is provided at a position on the refrigerant flow direction DC side (downstream side of the flow of the refrigerant C) of the refrigerant compression unit 32 and in contact with the refrigerant pipe 30. Thus, the refrigerant cooling unit 34 cools the refrigerant C flowing through the refrigerant pipe 30 after being compressed by the refrigerant compression unit 32. Note that the contact here is not limited to direct contact, but also includes contact via other members (solid, liquid, or gas), and the same applies hereinafter. That is, for example, the refrigerant cooling unit 34 may be in direct contact with the refrigerant pipe 30 at a position on the refrigerant flow direction DC side of the refrigerant compression unit 32, or may be in contact via other members (solid, liquid, or gas).

[0023] The refrigerant cooling unit 34 may use any method for cooling the refrigerant C. For example, the refrigerant cooling unit 34 may have a cooling liquid piping through which a cooling liquid (e.g., water) flows and a member in contact with the cooling liquid piping and the refrigerant piping 30, and may cool the refrigerant C by exchanging heat between the cooling liquid flowing through the cooling liquid piping and the refrigerant C flowing through the refrigerant piping 30.

[0024] The refrigerant expansion section 36 is connected to the refrigerant pipe 30 on the side in the refrigerant flow direction DC of the refrigerant compression section 32, and in this embodiment, on the side in the refrigerant flow direction DC of the refrigerant cooling section 34. The refrigerant expansion section 36 expands the refrigerant C flowing through the refrigerant pipe 30, thereby cooling the refrigerant C. The refrigerant compression section 32 may be any mechanism capable of expanding the refrigerant C, and may use, for example, a two-phase expansion turbine or a Joule-Thomson valve, but in this embodiment, a Joule-Thomson valve is used.

[0025] The refrigerant expansion section 36 is connected in series to the refrigerant pipe 30. That is, an inlet (an inlet into which the refrigerant C is introduced) of the refrigerant expansion section 36 is connected to the refrigerant flow direction DC side of the position where the refrigerant compression section 32 (refrigerant cooling section 34) of the refrigerant pipe 30 is provided. And, an outlet (an outlet from which the refrigerant C is discharged) of the refrigerant expansion section 36 is connected to the opposite side in the refrigerant flow direction DC (upstream side) of the position where the refrigerant compression section 32 of the refrigerant pipe 30 is provided.

[0026] The refrigerant expansion section 38 is connected to the refrigerant pipe 30 on the side in the refrigerant flow direction DC of the refrigerant compression section 32, and in this embodiment, on the side in the refrigerant flow direction DC of the refrigerant cooling section 34. The refrigerant expansion section 38 expands the refrigerant C flowing through the refrigerant pipe 30, thereby cooling the refrigerant C. The refrigerant expansion section 38 may be any mechanism capable of expanding the refrigerant C, and may use, for example, a two-phase expansion turbine or a Joule-Thomson valve, but in this embodiment, a two-phase expansion turbine is used.

[0027] The refrigerant expansion section 38 is connected in parallel (branched) to the refrigerant piping 30. The inlet of the refrigerant expansion section 38 (the inlet into which the refrigerant C is introduced) is connected to a location between the position where the refrigerant cooling section 34 of the refrigerant piping 30 is provided and the position where the refrigerant expansion section 36 is provided in the refrigerant flow direction DC (more specifically, a location between the second feedstock cooling section 42 and the fourth feedstock cooling section 46 described later). The outlet of the refrigerant expansion section 38 (the outlet from which the refrigerant C is discharged) is connected to a location between the position where the refrigerant expansion section 36 of the refrigerant piping 30 is provided and the position where the refrigerant compression section 32 is provided in the refrigerant flow direction DC (more specifically, a location between the fourth feedstock cooling section 46 and the second feedstock cooling section 42 described later).

[0028] (raw material cooling section) The raw material cooling section 40 is a mechanism for cooling the raw material gas HG flowing through the raw material piping 10 by the refrigerant C. Any method for cooling the raw material gas HG by the raw material cooling section 40 may be used, but in this embodiment, the raw material gas HG is cooled by exchanging heat between the refrigerant C flowing through the refrigerant piping 30 and the raw material gas HG flowing through the raw material piping 10. That is, the raw material cooling section 40 in this embodiment is a heat exchanger.

[0029] The number of raw material cooling sections (heat exchangers) included in raw material cooling section 40 may be arbitrary, but in this embodiment, raw material cooling section 40 is provided with a first raw material cooling section 41, a second raw material cooling section 42, a third raw material cooling section 44, and a fourth raw material cooling section 46. Each raw material cooling section will be described below.

[0030] (1st raw material cooling section) First raw material cooling section 41 is provided at a position closer to the raw material flow direction DH (downstream of the flow of raw material gas HG) than raw material supply section 12 and in contact with raw material piping 10. First raw material cooling section 41 is also provided at a position in contact with nitrogen piping 22. First raw material cooling section 41 cools the raw material gas HG by exchanging heat between the raw material gas HG flowing through raw material piping 10 and the nitrogen gas NG flowing through nitrogen piping 22.

[0031] The first raw material cooling section 41 preferably cools the raw material gas HG to a temperature of, for example, −50° C. to −100° C. or lower.

[0032] (Second raw material cooling section) The second raw material cooling section 42 is provided at a position closer to the raw material flow direction DH than the raw material supply section 12 and in contact with the raw material piping 10. The second raw material cooling section 42 is also provided at a position in contact with the refrigerant piping 30. The second raw material cooling section 42 cools the raw material gas HG by exchanging heat between the raw material gas HG flowing through the raw material piping 10 and the refrigerant C flowing through the refrigerant piping 30.

[0033] More specifically, in this embodiment, second feedstock cooling section 42 is provided on the side of first feedstock cooling section 41 in the feedstock flow direction DH. Moreover, second feedstock cooling section 42 is provided at a location on refrigerant piping 30, in terms of refrigerant flow direction DC, between the position where fourth feedstock cooling section 46 is provided and the position where refrigerant compression section 32 is provided. Therefore, second feedstock cooling section 42 further cools the feedstock gas HG, which has been cooled in first feedstock cooling section 41, by refrigerant C flowing through refrigerant piping 30 from fourth feedstock cooling section 46 in the refrigerant flow direction DC.

[0034] In this embodiment, second raw material cooling section 42 is provided in refrigerant flow direction DC, at a location on refrigerant piping 30 between the position where refrigerant cooling section 34 is provided and the position where fourth raw material cooling section 46 is provided. Therefore, second raw material cooling section 42 also cools refrigerant C that has been cooled in refrigerant cooling section 34, by refrigerant C flowing through refrigerant piping 30 from fourth raw material cooling section 46 in refrigerant flow direction DC.

[0035] The second raw material cooling section 42 preferably cools the raw material gas HG to a temperature of, for example, −100° C. to −150° C. or lower.

[0036] (3rd raw material cooling section) Third raw material cooling section 44 is connected to nitrogen piping 20 and stores liquid nitrogen NL supplied from nitrogen piping 20. A portion of raw material piping 10 on the raw material flow direction DH side of second raw material cooling section 42 passes through third raw material cooling section 44. Third raw material cooling section 44 exchanges heat between the stored liquid nitrogen NL and raw material gas HG passing through raw material piping 10 in third raw material cooling section 44, thereby further cooling the raw material gas HG after being cooled in second raw material cooling section 42 with liquid nitrogen NL. The liquid nitrogen NL, whose temperature has been increased by the heat exchange, is vaporized and discharged to nitrogen piping 22 as nitrogen gas NG.

[0037] In this embodiment, in the third feedstock cooling section 44, the feedstock pipe 10 is connected to an ortho-para conversion catalyst 44A. The ortho-para conversion catalyst 44A is a catalyst that promotes the conversion of ortho-hydrogen to para-hydrogen (ortho-para conversion). The ortho-hydrogen contained in the feedstock gas HG passing through the feedstock pipe 10 in the third feedstock cooling section 44 is converted to para-hydrogen by contacting with the ortho-para conversion catalyst 44A. In addition, the feedstock gas HG generates heat during ortho-para conversion, but the temperature rise can be suppressed by cooling it with liquid nitrogen NL.

[0038] The third raw material cooling section 44 preferably cools the raw material gas HG to a temperature of, for example, −180° C. or lower.

[0039] (4th raw material cooling section) Fourth raw material cooling section 46 is provided at a position closer to raw material flow direction DH than raw material supply section 12 and in contact with raw material piping 10. Fourth raw material cooling section 46 is also provided at a position in contact with refrigerant piping 30. Fourth raw material cooling section 46 cools raw material gas HG by exchanging heat between raw material gas HG flowing through raw material piping 10 and refrigerant C flowing through refrigerant piping 30.

[0040] More specifically, in this embodiment, fourth feedstock cooling section 46 is provided on the feedstock flow direction DH side of third feedstock cooling section 44. Moreover, fourth feedstock cooling section 46 is provided at a location in refrigerant flow direction DC, between the position of refrigerant expansion section 36 and the position of second feedstock cooling section 42, of refrigerant pipe 30. Therefore, fourth feedstock cooling section 46 further cools the feedstock gas HG after being cooled in third feedstock cooling section 44, by refrigerant C flowing through refrigerant pipe 30 from refrigerant expansion section 36 in refrigerant flow direction DC.

[0041] In this embodiment, fourth raw material cooling section 46 is provided in a location on refrigerant pipe 30 in refrigerant flow direction DC between the position where second raw material cooling section 42 is provided and the position where refrigerant expansion section 36 is provided. Therefore, fourth raw material cooling section 46 also cools refrigerant C after heat exchange in second raw material cooling section 42 by refrigerant C flowing through refrigerant pipe 30 from refrigerant expansion section 36 in refrigerant flow direction DC.

[0042] In this embodiment, the raw material piping 10 is connected to the ortho-para conversion catalyst 46A even at the position where it contacts the fourth raw material cooling section 46. The ortho-para conversion catalyst 46A is a catalyst that promotes the conversion of ortho-hydrogen to para-hydrogen (ortho-para conversion). The ortho-hydrogen contained in the raw material gas HG passing through the raw material piping 10 is converted to para-hydrogen by contacting the ortho-para conversion catalyst 46A. In addition, the raw material gas HG generates heat during ortho-para conversion, but by being cooled by the fourth raw material cooling section 46, the temperature rise can be suppressed.

[0043] The fourth raw material cooling section 46 preferably cools the raw material gas HG to a temperature of, for example, −240° C. or higher and −220° C. or lower.

[0044] The raw material cooling unit 40 is not an essential component, and it is not essential that the raw material gas HG be cooled by the refrigerant C. The raw material gas HG may be cooled by at least the magnetic refrigeration unit 60.

[0045] (Raw material storage section) The raw material storage section 50 is connected to the raw material piping 10 on the side of the raw material flow direction DH of the raw material cooling section 40, and in this embodiment, on the side of the fourth raw material cooling section 46 in the raw material flow direction DH. The raw material storage section 50 is a container that temporarily stores the raw material gas HG after it has been cooled in the raw material cooling section 40. The raw material piping 10 is also provided with a raw material outlet section 50A for discharging the raw material gas HG stored in the raw material storage section 50 to the side of the raw material piping 10 in the raw material flow direction DH. The raw material outlet section 50A may be, for example, an on-off valve.

[0046] However, the raw material storage section 50 and the raw material discharge section 50A are not essential components. That is, for example, the raw material gas HG after being cooled in the raw material cooling section 40 may be supplied directly to the downstream magnetic refrigeration section 60 without being stored in the raw material storage section 50.

[0047] (Magnetic Refrigeration Unit) The magnetic refrigeration unit 60 is provided in the raw material piping 10 on the side in the raw material flow direction DH of the raw material cooling unit 40, and in this embodiment on the side in the raw material flow direction DH of the raw material storage unit 50 and the raw material discharge unit 50A. The magnetic refrigeration unit 60 cools the raw material gas HG by a magnetic refrigeration method.

[0048] The magnetic refrigeration unit 60 has a magnetic body 62 and a magnet 64. The magnetic body 62 is provided in the raw material piping 10 on the raw material flow direction DH side of the raw material cooling unit 40 (in this embodiment, the raw material storage unit 50 and the raw material discharge unit 50A).

[0049] The magnetic body 62 is a member capable of absorbing the source gas HG, and whose temperature drops when the application of the magnetic field is stopped. The magnetic body 62 absorbs the source gas HG by being cooled (the temperature drops), and is cooled (the temperature drops) by releasing the source gas HG. Furthermore, the temperature of the magnetic body 62 rises when the magnetic flux density (the degree of application of the magnetic field) increases, and drops when the magnetic flux density drops.

[0050] The material of the magnetic body 62 may be any material capable of adsorbing the source gas HG and capable of decreasing in temperature when the magnetic flux density (degree of application of a magnetic field) decreases. For example, a porous metal complex (MOF) may be used as a material capable of adsorbing the source gas HG, and may be, for example, copper benzene-1,3,5-tricarboxylate (Cu-BTC). In addition, a material capable of decreasing in temperature when the magnetic flux density decreases may be, for example, a gadolinium compound. The magnetic body 62 may be made of a hybrid material that combines a material capable of adsorbing the source gas HG and a material capable of decreasing in temperature when the magnetic flux density decreases, or may be made of a single material capable of adsorbing the source gas HG and capable of decreasing in temperature when the magnetic flux density decreases.

[0051] Moreover, the magnetic body 62 is preferably capable of promoting the conversion of ortho-hydrogen contained in the raw gas HG to para-hydrogen. That is, the magnetic body 62 preferably has a function of adsorbing the raw gas and a magnetic refrigeration function of decreasing the temperature when the magnetic flux density decreases, as well as a function of an ortho-para conversion catalyst. The material of the magnetic body 62 may be any material capable of adsorbing the raw gas, decreasing the temperature when the magnetic flux density decreases, and capable of promoting the conversion of ortho-hydrogen to para-hydrogen. For example, an MOF having a kagome lattice is an example of a material capable of promoting the conversion of ortho-hydrogen to para-hydrogen. For example, by using Cu ions and an isophthalic acid derivative, an MOF having a kagome lattice can be synthesized. The magnetic body 62 may be composed of a hybrid material that combines a member capable of adsorbing the raw gas HG, a member whose temperature decreases when the magnetic flux density decreases, and a member capable of promoting the conversion of ortho-hydrogen to para-hydrogen, or may be composed of a single material capable of adsorbing the raw gas HG, decreasing the temperature when the magnetic flux density decreases, and capable of promoting the conversion of ortho-hydrogen to para-hydrogen.

[0052] When the magnetic body 62 has a function of an ortho-para conversion catalyst, an ortho-para conversion catalyst does not need to be provided in the raw material cooling section 40. In other words, the liquefaction apparatus 1 only needs to be provided with at least one ortho-para conversion catalyst in the liquefaction line, and furthermore, it does not need to be provided with an ortho-para conversion catalyst.

[0053] The magnet 64 is a member that applies a magnetic field to the magnetic body 62. The magnet 64 is a magnet that generates a magnetic field, and may be an electromagnet or a permanent magnet. In the example of FIG. 1, the magnet 64 is a ring-shaped electromagnet, and is disposed so as to surround the magnetic body 62.

[0054] The method of cooling the raw material gas HG by the magnetic refrigeration unit 60 will be described in detail later.

[0055] (Magnetic material cooling section) The magnetic body cooling unit 70 is a mechanism for cooling the magnetic body 62 by the refrigerant C. The magnetic body cooling unit 70 cools the magnetic body 62 by exchanging heat between the refrigerant C flowing through the refrigerant pipe 30 and the magnetic body 62.

[0056] The magnetic material cooling section 70 is provided at a position in contact with the magnetic material 62. The magnetic material cooling section 70 is also provided at a location in the refrigerant flow direction DC, between the position where the refrigerant expansion section 36 is provided and the position where the fourth raw material cooling section 46 is provided, of the refrigerant pipe 30. Therefore, the magnetic material cooling section 70 cools the magnetic material 62 by the refrigerant C flowing through the refrigerant pipe 30 from the refrigerant expansion section 36 in the refrigerant flow direction DC.

[0057] In this way, the magnetic material cooling section 70 cools the magnetic material 62 by the refrigerant C cooled in the refrigerant expansion section 36. Therefore, the magnetic material 62 can be cooled by the refrigerant C that is at the lowest temperature in the refrigerant line. In this embodiment, the raw material gas HG is pre-cooled in the raw material cooling section 40 by the refrigerant C after cooling the magnetic material 62. More specifically, the refrigerant C after cooling the magnetic material 62 flows in the refrigerant line in the order of the fourth raw material cooling section 46 and the second raw material cooling section 42. Therefore, the temperature of the refrigerant C decreases in the order of the second raw material cooling section 42, the fourth raw material cooling section 46, and the magnetic material cooling section 70. Therefore, the raw material gas HG and the magnetic material 62 can be efficiently cooled by the refrigerant C.

[0058] (Raw material expansion part) The raw material expansion section 80 is connected to the raw material piping 10 on the raw material flow direction DH side of the magnetic refrigeration section 60. The raw material expansion section 80 expands the raw material gas HG that has been cooled in the magnetic refrigeration section 60 but remains unliquefied, thereby cooling the raw material gas HG and generating liquid HL. The liquid HL generated by the raw material expansion section 80 is introduced from the raw material piping 10 into the liquid storage section 14 and is stored in the liquid storage section 14. The raw material expansion section 80 may be any mechanism capable of expanding the raw material gas HG, such as a two-phase expansion turbine or a Joule-Thomson valve, but in this embodiment, a two-phase expansion turbine is used.

[0059] The position of the raw material expansion section 80 is not limited to being located on the side closer to the raw material flow direction DH than the magnetic refrigeration section 60, and may be located on the opposite side of the magnetic refrigeration section 60 from the raw material flow direction DH (between the raw material cooling section 40 and the magnetic refrigeration section 60). In this case, the raw material expansion section 80 may expand and cool the raw material gas HG cooled in the raw material cooling section 40, and the magnetic refrigeration section 60 may cool and liquefy the raw material gas HG that remains unliquefied after being cooled in the raw material expansion section 80. The raw material expansion section 80 may be located both on the side closer to the raw material flow direction DH than the magnetic refrigeration section 60 and on the opposite side of the magnetic refrigeration section 60 from the raw material flow direction DH.

[0060] However, the raw material expansion section 80 is not an essential component. For example, the liquefaction apparatus 1 may not have the raw material expansion section 48, and may liquefy the raw material gas HG only by the magnetic refrigeration section 60.

[0061] (Liquefaction method) The flow of the method for liquefying the raw material gas HG using the above-described liquefaction apparatus 1 will be described with reference to a flowchart. Fig. 2 is a flowchart for explaining the method for liquefying the raw material gas.

[0062] (Cooling by raw material cooling section) As shown in FIG. 2, in this method, the raw material cooling section 40 cools the raw material gas HG with the refrigerant C (step S10). In this step, the controller 100 causes the raw material supply section 12 to supply the raw material gas HG into the raw material pipe 10. In this case, for example, the controller 100 may control the valve of the raw material supply section 12 to supply the raw material gas HG from the raw material supply section 12. In addition, the controller 100 causes the nitrogen supply section 24 to supply liquid nitrogen NL into the nitrogen pipe 20. In this case, for example, the controller 100 may control the valve of the nitrogen supply section 24 to supply liquid nitrogen NL from the nitrogen supply section 24. In addition, the controller 100 operates the refrigerant compression section 32, the refrigerant cooling section 34, and the refrigerant expansion sections 36 and 38 to circulate the refrigerant C in the refrigerant pipe 30. As a result, the raw material gas HG flows in the raw material pipe 10 along the raw material flow direction DH while being cooled by the raw material cooling section 40. Specifically, the raw material gas HG is cooled in the first raw material cooling section 41 by the nitrogen gas NG flowing through the nitrogen piping 22. Then, the raw material gas HG cooled in the first raw material cooling section 41 is further cooled in the second raw material cooling section 42 by the refrigerant C flowing through the refrigerant piping 30. Then, the raw material gas HG cooled in the second raw material cooling section 42 is cooled by the liquid nitrogen NL while being ortho-para converted in the third raw material cooling section 44. Then, the raw material gas HG cooled in the third raw material cooling section 44 is cooled in the fourth raw material cooling section 46 by the refrigerant C flowing through the refrigerant piping 30 while being ortho-para converted. The raw material gas HG cooled in the fourth raw material cooling section 46 is stored in the raw material storage section 50.

[0063] (adsorption of raw gas) Next, in this method, the magnetic body 62 is cooled while a magnetic field is applied to the magnetic body 62, and the raw material gas HG cooled in the raw material cooling unit 40 is adsorbed to the magnetic body 62 (step S12). Hereinafter, a method for adsorbing the raw material gas HG to the magnetic body 62 will be described with reference to Fig. 3. Fig. 3 is a schematic diagram for explaining the adsorption of the raw material gas.

[0064] When the raw material gas HG is adsorbed to the magnetic body 62, as shown in step S12A of FIG. 3, a magnetic field is applied from the magnet 64 to the magnetic body 62 while the supply of the raw material gas HG to the magnetic body 62 is stopped. For example, the control device 100 controls the raw material outlet 50A (for example, closes a valve) to stop the supply of the raw material gas HG stored in the raw material storage 50 to the magnetic body 62. Then, the control device 100 applies a magnetic field from the magnet 64 to the magnetic body 62 while the supply of the raw material gas HG to the magnetic body 62 is stopped. The magnetic body 62 is heated by the application of the magnetic field, and the temperature increases. Note that a method of applying a magnetic field from the magnet 64 to the magnetic body 62 may be arbitrary, and a voltage may be applied to the magnet 64, which is an electromagnet, or the distance between the magnet 64, which is a permanent magnet, and the magnetic body 62 may be reduced.

[0065] In step S12A, while a magnetic field is being applied to the magnetic body 62, the magnetic body cooling unit 70 exchanges heat between the refrigerant C flowing through the refrigerant pipe 30 and the magnetic body 62. This cools (discharges heat) the magnetic body 62 that has been heated by the application of the magnetic field.

[0066] 3, the raw material gas HG is supplied to the cooled magnetic body 62 while the magnetic field is applied thereto, so that the raw material gas HG is adsorbed by the magnetic body 62. For example, the control device 100 controls the raw material outlet unit 50A (for example, by opening a valve) to supply the raw material gas HG stored in the raw material storage unit 50 to the magnetic body 62. The magnetic body 62 adsorbs the raw material gas HG because it is cooled by the magnetic body cooling unit 70. Note that the magnetic body cooling unit 70 cools the magnetic body 62 even while the magnetic body 62 is adsorbing the raw material gas HG, i.e., while the raw material gas HG is being supplied to the magnetic body 62. This makes it possible to suppress a temperature rise in the magnetic body 62 due to the adsorption of the raw material gas HG.

[0067] The amount of the raw material gas HG adsorbed to the magnetic body 62 in the state where the magnetic field is applied may be arbitrary. For example, the control device 100 may supply the raw material gas HG from the raw material storage unit 50 to the magnetic body 62 until the internal pressure of the raw material storage unit 50 (the pressure of the raw material gas HG stored in the raw material storage unit 50) drops by about 0.3 MPa or more and 0.8 MPa or less (preferably 0.5 MPa). That is, for example, when the internal pressure of the raw material storage unit 50 before the supply of the raw material gas HG is 1 MPa, the raw material gas HG may be supplied from the raw material storage unit 50 to the magnetic body 62 until the internal pressure of the raw material storage unit 50 becomes 0.5 MPa.

[0068] (Cooling of raw gas) Once the source gas HG has been adsorbed to the magnetic body 62, as shown in Fig. 2, the application of the magnetic field to the magnetic body 62 is stopped, and the source gas HG adsorbed by the magnetic body 62 is further cooled (step S14). A method for cooling the adsorbed source gas HG will be described below with reference to Fig. 4. Fig. 4 is a schematic diagram for explaining the cooling of the adsorbed source gas.

[0069] 4, once the raw material gas HG is adsorbed to the magnetic body 62 with the magnetic field applied thereto, the application of the magnetic field to the magnetic body 62 is stopped. For example, the control device 100 controls the magnet 64 to stop the application of the magnetic field from the magnet 64 to the magnetic body 62. Note that any method may be used to stop the application of the magnetic field to the magnetic body 62, and the application of a voltage to the magnet 64, which is an electromagnet, may be stopped, or the distance between the magnet 64, which is a permanent magnet, and the magnetic body 62 may be increased.

[0070] In this embodiment, it is preferable to stop applying the magnetic field to the magnetic body 62 while the raw material gas HG is being supplied from the raw material reservoir 50 to the magnetic body 62. By removing the magnetic field, the temperature of the magnetic body 62 decreases, and the magnetic body 62 can further adsorb the raw material gas HG.

[0071] The amount of the raw material gas HG adsorbed to the magnetic body 62 when the application of the magnetic field is stopped may be arbitrary. For example, the control device 100 may supply the raw material gas HG from the raw material storage unit 50 to the magnetic body 62 until the internal pressure of the raw material storage unit 50 (the pressure of the raw material gas HG stored in the raw material storage unit 50) drops by about 0.1 MPa or more and 0.5 MPa or less (preferably 0.3 MPa). That is, for example, when the internal pressure of the raw material storage unit 50 before the application of the magnetic field is stopped is 0.5 MPa, the raw material gas HG may be supplied from the raw material storage unit 50 to the magnetic body 62 until the internal pressure of the raw material storage unit 50 becomes 0.2 MPa.

[0072] 4, the supply of the raw material gas HG to the magnetic body 62 with the magnetic field applied thereto is stopped. For example, the control device 100 controls the raw material outlet 50A (for example, closes a valve) to stop the supply of the raw material gas HG stored in the raw material storage unit 50 to the magnetic body 62. Since the application of the magnetic field has been stopped, the temperature of the magnetic body 62 decreases, and the adsorbed raw material gas HG is cooled. Note that the magnetic body 62 preferably cools the raw material gas HG to a temperature of, for example, −250° C. or lower.

[0073] The raw material gas HG cooled by the magnetic body 62 is discharged from the magnetic body 62 in the raw material flow direction DH. The magnetic body 62 is further cooled by the discharge of the raw material gas HG.

[0074] A plurality of magnetic refrigeration units 60 may be provided. In this case, for example, each magnetic refrigeration unit 60 may be connected in parallel to the raw material pipe 10. This allows each magnetic refrigeration unit 60 (magnetic body 62) to alternately adsorb the raw material gas HG and cool the raw material gas HG, and allows the raw material gas HG to be continuously cooled.

[0075] The raw material gas HG released from the magnetic body 62 is supplied to the raw material expansion section 80 and expanded by the raw material expansion section 80. The raw material gas HG expanded in the raw material expansion section 80 is further cooled and liquefied, and is introduced into the liquid storage section 14 as the liquid HL and stored in the liquid storage section 14.

[0076] The magnetic refrigeration unit 60 (magnetic body 62) may cool the raw gas HG to a degree that the raw gas HG is not liquefied, may cool the raw gas HG to a degree that at least a portion of the raw gas HG is liquefied, or may cool the raw gas HG to a degree that all of the raw gas HG is liquefied. When the magnetic body 62 liquefies all of the raw gas HG, the raw material expansion unit 80 need not be provided.

[0077] In this manner, in this embodiment, the raw gas HG is adsorbed to the magnetic body 62, and the application of a magnetic field to the magnetic body 62 that has adsorbed the raw gas HG is stopped to cool the magnetic body 62, thereby cooling the adsorbed raw gas HG. According to this embodiment, the liquefaction efficiency of the raw gas HG can be improved by using magnetic refrigeration. Furthermore, in this embodiment, the adsorbed raw gas HG is released from the magnetic body 62. In the process of releasing the raw gas HG, the magnetic body 62 is further cooled, so that the raw gas HG can be more suitably cooled. Furthermore, in this embodiment, the raw gas HG that has been pre-cooled with the refrigerant C is cooled in the magnetic refrigeration section 60 and expanded in the raw material expansion section 48. In this manner, the raw gas HG is cooled in two steps, expansion and magnetic refrigeration, so that the liquefaction efficiency can be more suitably improved. Furthermore, in this embodiment, the magnetic body 62 of the magnetic refrigeration section 60 is cooled by the refrigerant C used for pre-cooling the raw gas HG. Therefore, it is also possible to efficiently perform the refrigeration cycle of the magnetic body 62 and the pre-cooling of the raw gas HG.

[0078] (effect) As described above, the liquefaction apparatus 1 according to the first embodiment of the present disclosure includes the raw material pipe 10 through which the raw material gas HG flows, the magnetic body 62 that is connected to the raw material pipe 10 and capable of adsorbing the raw material gas HG supplied from the raw material pipe 10 and whose temperature drops when application of the magnetic field is stopped, and the magnet 64 that applies a magnetic field to the magnetic body 62. When the magnet 64 stops applying the magnetic field to the magnetic body 62 while the magnetic body 62 is in a state in which the magnetic body 62 has adsorbed the raw material gas HG, the magnetic body 62 cools the adsorbed raw material gas HG. According to the present disclosure, the liquefaction efficiency of the raw material gas HG can be improved by using magnetic refrigeration.

[0079] The liquefaction device 1 according to the second embodiment of the present disclosure is the liquefaction device according to the first embodiment, further including a magnetic body cooling unit 70 for cooling the magnetic body 62, and the magnetic body cooling unit 70 cools the magnetic body 62 in a state where a magnetic field is applied from the magnet 64 to the magnetic body 62, thereby causing the magnetic body 62 to adsorb the source gas HG. According to the present disclosure, the source gas HG is adsorbed to the magnetic body 62 by discharging heat from the magnetic body 62 to which the magnetic field is applied, and the source gas HG is released from the magnetic body 62 in a state where the application of the magnetic field is stopped. This allows the adsorption of the source gas HG and the cooling of the source gas HG to be performed suitably, and improves the efficiency of liquefying the source gas HG.

[0080] The liquefaction apparatus 1 according to a third aspect of the present disclosure is the liquefaction apparatus according to the first or second aspect, and further includes a raw material expansion section 80 that is provided at least either upstream or downstream of the magnetic body 62 in the flow of the raw material gas HG (raw material flow direction DH) in the raw material piping 10, and expands the raw material gas HG to liquefy it. In this way, by cooling the raw material gas HG in a two-stage process of expansion and magnetic refrigeration, the liquefaction efficiency can be more suitably improved.

[0081] The liquefaction apparatus 1 according to a fourth aspect of the present disclosure is the liquefaction apparatus according to the third aspect, and uses a two-phase expansion turbine or a Joule-Thomson valve as the raw material expansion section 80. According to the present disclosure, the raw material gas HG can be appropriately expanded, and the liquefaction efficiency can be more suitably improved.

[0082] The liquefaction apparatus 1 according to a fifth aspect of the present disclosure is the liquefaction apparatus according to any one of the first to fourth aspects, and further includes a raw material cooling section 40 that is provided upstream of the magnetic body 62 in the flow of the raw material gas HG in the raw material piping 10 and cools the raw material gas HG with a refrigerant C. According to the present disclosure, the raw material gas HG pre-cooled with the refrigerant C is cooled by the magnetic body 62, and therefore the liquefaction efficiency can be more suitably improved.

[0083] A liquefaction apparatus 1 according to a sixth aspect of the present disclosure is the liquefaction apparatus according to any one of the first to fifth aspects, in which the raw material gas HG is hydrogen gas. According to the present disclosure, hydrogen can be appropriately liquefied.

[0084] The liquefaction apparatus 1 according to a seventh aspect of the present disclosure is the liquefaction apparatus according to the sixth aspect, in which the magnetic body 62 can promote the conversion of ortho-hydrogen contained in the raw material gas HG to para-hydrogen. By providing the magnetic body 62 with a function of an ortho-para conversion catalyst, hydrogen can be more appropriately liquefied.

[0085] A liquefaction method according to an eighth aspect of the present disclosure includes a step of adsorbing the source gas HG to a magnetic body 62 that is capable of adsorbing the source gas HG and whose temperature drops when application of a magnetic field is stopped, and a step of cooling the adsorbed source gas HG by the magnetic body 62 by stopping application of the magnetic field to the magnetic body 62 in a state in which the magnetic body 62 has adsorbed the source gas HG. According to the present disclosure, the liquefaction efficiency of the source gas HG can be improved.

[0086] A liquefaction method according to a ninth aspect of the present disclosure is the liquefaction method according to the eighth aspect, and in the step of adsorbing the source gas HG, the magnetic body 62 is cooled while a magnetic field is applied to the magnetic body 62, thereby adsorbing the source gas HG to the magnetic body 62. This makes it possible to suitably adsorb the source gas HG and cool the source gas HG, thereby improving the efficiency of liquefying the source gas HG.

[0087] Although the embodiment of the present disclosure has been described above, the embodiment is not limited by the contents of this embodiment. In addition, the above-mentioned components include those that a person skilled in the art can easily imagine, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-mentioned components can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the gist of the above-mentioned embodiment. [Explanation of symbols]

[0088] 1 Liquefier 10 Raw material piping 12 Raw material supply department 14 Liquid storage section 20, 22 Nitrogen piping 24 Nitrogen supply unit 30 Refrigerant piping 32 Refrigerant compression section 34 Refrigerant cooling section 36, 38 Refrigerant expansion section 40 Raw material cooling section 50 Raw material storage section 60 Magnetic Refrigeration Unit 62 Magnetic material 64 Magnet 70 Magnetic cooling section 80 Raw material expansion section HG raw gas HL liquid

Claims

1. A raw material pipe through which a raw material gas flows; a magnetic body connected to the source gas pipe, capable of adsorbing the source gas supplied from the source gas pipe, and having a temperature that decreases when application of a magnetic field is stopped; A magnet that applies a magnetic field to the magnetic body; having the magnet stops applying a magnetic field to the magnetic body in a state in which the magnetic body adsorbs the source gas, thereby causing the magnetic body to cool the adsorbed source gas. Liquefaction equipment.

2. Further comprising a magnetic body cooling unit that cools the magnetic body, The liquefaction apparatus according to claim 1 , wherein the magnetic body cooling unit adsorbs the source gas to the magnetic body by cooling the magnetic body while a magnetic field is applied from the magnet to the magnetic body.

3. The liquefaction apparatus according to claim 1 or 2, further comprising a raw material expansion section provided at least on the upstream side or downstream side of the magnetic body in the flow of the raw material gas in the raw material piping, which expands the raw material gas and liquefies the raw material gas.

4. The liquefaction apparatus according to claim 3 , wherein the feed expansion section is a two-phase expansion turbine or a Joule-Thomson valve.

5. 3. The liquefaction apparatus according to claim 1, further comprising a raw material cooling section provided upstream of the magnetic body in a flow of the raw material gas in the raw material piping, for cooling the raw material gas with a refrigerant.

6. 3. The liquefaction apparatus according to claim 1, wherein the raw material gas is hydrogen gas.

7. The liquefaction apparatus according to claim 6 , wherein the magnetic material is capable of promoting conversion of ortho-hydrogen contained in the feed gas into para-hydrogen.

8. a step of adsorbing the source gas to a magnetic material capable of adsorbing the source gas and whose temperature decreases when application of a magnetic field is stopped; stopping application of a magnetic field to the magnetic body while the magnetic body is adsorbing the source gas, thereby cooling the adsorbed source gas by the magnetic body; A liquefaction method comprising:

9. 9. The liquefaction method according to claim 8, wherein in the step of adsorbing the source gas, the magnetic body is cooled in a state in which a magnetic field is applied to the magnetic body, thereby adsorbing the source gas to the magnetic body.

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