Primary and secondary hydrogen continuous converter

Abstract

The present disclosure relates to a primary and secondary hydrogen continuous converter which can not only meet the requirements of the industry for the outlet hydrogen temperature and the secondary hydrogen concentration, but also has a more compact structure and a smaller volume, which is conducive to reducing the equipment cost.

Description

Technical Field

[0001] This disclosure relates to the field of n- and para-hydrogen conversion, and more specifically, to a n- and para-hydrogen continuous converter. Background Technology

[0002] The conversion of ortho- and para-hydrogen is a crucial step in hydrogen liquefaction. Hydrogen molecules exist in two spin isomers: ortho-hydrogen has two nuclei with the same spin direction, while para-hydrogen has two with opposite spin directions. Under standard conditions, hydrogen gas consists of 75% ortho-hydrogen and 25% para-hydrogen. At 20 K, the para-hydrogen concentration reaches 99.82%. Since the conversion of ortho-hydrogen to para-hydrogen releases 670 kJ / kg of heat, and the latent heat of hydrogen liquefaction is 452 kJ / kg, it can lead to the vaporization of liquid hydrogen. To extend the storage time of liquid hydrogen, the concentration of para-hydrogen in the liquid hydrogen produced by hydrogen liquefaction must be ≥95%. The spontaneous conversion rate of ortho- and para-hydrogen is relatively slow, so catalysts are used to accelerate the conversion process during hydrogen liquefaction. Depending on whether the hydrogen temperature drop and reaction occur simultaneously, there are two types of n- and para-hydrogen converters in hydrogen liquefaction. One type is where the n- and para-hydrogen converter is independent of the heat exchanger, with conversion mainly occurring under adiabatic conditions. This conversion method leads to an increase in hydrogen temperature, resulting in higher energy consumption for hydrogen liquefaction. The other type is where the n- and para-hydrogen converter is coupled with the heat exchanger, with conversion occurring in a continuous reaction mode. The heat of reaction can be promptly removed by the cooling medium, improving conversion efficiency and reducing energy consumption. Currently, continuous n- and para-hydrogen conversion is achieved by filling the n- and para-hydrogen catalyst into a plate-fin heat exchanger (CN114353563A). This type of continuous n- and para-hydrogen converter has a large volume and high pressure drop. Furthermore, as the scale of hydrogen liquefaction increases, problems such as uneven catalyst filling and easy clogging arise. CN116294715A adopts an integrated structure with a catalyst coating on the inner wall of the hot fluid channel. This structure can reduce the converter pressure drop and improve overall efficiency, but it still suffers from the problem of a large continuous n- and para-hydrogen converter, resulting in a large overall cold box volume and high overall equipment cost for hydrogen liquefaction. Therefore, this invention proposes a compact continuous conversion device for n- and para-hydrogen based on a microchannel structure, which can solve the problems of large pressure drop in n- and para-hydrogen converters and large size and high cost of hydrogen liquefaction devices. Summary of the Invention

[0003] The purpose of this disclosure is to provide a continuous converter for both positive and negative hydrogen, which not only meets the industrial requirements for outlet hydrogen temperature and negative hydrogen concentration, but also has a more compact structure and smaller size, which helps to reduce equipment costs.

[0004] To achieve the above objectives, this disclosure provides a continuous converter for n- and para-hydrogen, comprising a hot runner plate and a cold runner plate, which are alternately stacked. The upper surface of the hot runner plate includes a first region and a second region, which are alternately arranged along the direction of hot fluid flow. The first region has a plurality of parallel hot fluid microchannels extending along the direction of hot fluid flow. The second region extends perpendicular to the direction of hot fluid flow and has a n- and para-hydrogen catalyst. Along the direction perpendicular to the direction of hot fluid flow, the maximum size of the hot fluid microchannels is smaller than the maximum size of the second region.

[0005] Optionally, the maximum dimension of the heat fluid microchannel perpendicular to the heat fluid flow direction is 0.1~2mm, and the maximum dimension of the second region perpendicular to the heat fluid flow direction is 50~1000mm; Preferably, along the direction perpendicular to the flow of the hot fluid, the ratio of the maximum size of the hot fluid microchannel to the maximum size of the second region is 1:(100~800).

[0006] Optionally, the first region further has multiple partitions disposed between two adjacent hot fluid microchannels; more preferably, the second region does not have partitions. Optionally, the partition plate has a dimension of 0.1 to 2 mm perpendicular to the direction of hot fluid flow.

[0007] Optionally, the length of the thermal fluid microchannel along the thermal fluid flow direction is 2~20mm, preferably 3~8mm; the length of the second region along the thermal fluid flow direction is 2~30mm, preferably 3~8mm; Preferably, along the direction of hot fluid flow, the ratio of the length of the hot fluid microchannel to the length of the second region is 1:(1~4).

[0008] Optionally, the secondary hydrogen catalyst is applied to the second region by filling or coating. Optionally, when the positive and negative hydrogen catalyst is filled into the second region, a filter screen is also provided between the first region and the second region. The mesh size of the filter screen is 50~500μm, preferably 100~200μm.

[0009] Optionally, the particle diameter of the secondary hydrogen catalyst is 100-600 μm, preferably 200-300 μm; the filling thickness of the secondary hydrogen catalyst in the second region is 100-2000 μm, preferably 1000-2000 μm; and the coating thickness of the secondary hydrogen catalyst in the second region is 5-100 μm, preferably 5-10 μm. The intermediate hydrogen catalyst includes iron-based catalysts and / or nickel-based catalysts, wherein the iron-based catalyst includes one or more of hydrated iron oxide, ferric oxide, and iron tetroxide.

[0010] Optionally, the thermal fluid microchannel also has a secondary hydrogen catalyst, which is coated inside the thermal fluid microchannel by means of a coating, and the coating thickness of the secondary hydrogen catalyst inside the thermal fluid microchannel is 5~100μm.

[0011] Optionally, the cross-sectional shape of the thermal fluid microchannel includes one or more of the following: semicircle, ellipse, rectangle, and square; and the cross-sectional shape of the second region includes one or more of the following: semicircle, ellipse, rectangle, and square.

[0012] Optionally, the upper surface of the cold runner plate includes a cold fluid channel that extends along the direction of cold fluid flow. The maximum dimension of the cold fluid channel perpendicular to the direction of cold fluid flow is 0.1 to 2 mm. The cross-sectional shape of the cold fluid channel includes one or more of the following: semicircle, ellipse, rectangle, and square. Optionally, the direction of the cold fluid flow is perpendicular to the direction of the hot fluid flow.

[0013] Optionally, the continuous positive and negative hydrogen converter further includes a hot fluid inlet, a hot fluid distributor, a cold fluid distributor, a cold fluid inlet, a hot fluid collector, a hot fluid outlet, a side sealing plate, a cold fluid outlet, and a cold fluid collector. The hot fluid inlet is connected to the inlet of the hot runner plate via the hot fluid distributor, and the outlet of the hot runner plate is connected to the hot fluid outlet via the hot fluid collector. The cold fluid inlet is connected to the inlet of the cold runner plate via the cold fluid distributor, and the outlet of the cold runner plate is connected to the cold fluid outlet via the cold fluid collector. The side sealing plate is located on the upper and lower surfaces of the continuous positive and negative hydrogen converter, and is connected to the hot fluid distributor, cold fluid distributor, hot fluid collector and cold fluid collector around its perimeter, so that the continuous positive and negative hydrogen converter forms a closed structure.

[0014] Through the above technical solution, this disclosure provides a continuous converter for n- and para-hydrogen. The hot runner plate of this converter adopts a microchannel structure, with different regions having different dimensions perpendicular to the hot fluid flow direction. The larger second region contains a n- and para-hydrogen catalyst, allowing hydrogen to exchange heat with the cold fluid in the smaller hot fluid microchannel, and then contact the catalyst in the larger second region for n- and para-hydrogen conversion. Afterwards, driven by pressure difference, it flows out of the second region and re-enters the hot fluid microchannel for heat exchange, repeating this heat exchange-conversion-heat exchange process. Ultimately, the n- and para-hydrogen conversion process is segmented in different regions, approximating a continuous conversion process. The hot fluid microchannel of this disclosure has a large specific surface area, which is beneficial for improving heat exchange efficiency, reducing hydrogen liquefaction energy consumption, and improving n- and para-hydrogen conversion efficiency. Compared to conventional plate-fin n- and para-hydrogen converters, the n- and para-hydrogen continuous converter of this disclosure, when processing the same amount of hydrogen, not only meets industrial requirements for outlet hydrogen temperature and para-hydrogen concentration, but also has a more compact structure and smaller volume, which helps reduce equipment costs.

[0015] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a top view of the hot runner plate 3 used in Embodiment 1 of this disclosure; Figure 2 This is a top view of the hot runner plate 3 used in Embodiment 1 of this disclosure; Figure 3 This is a top view schematic diagram of the hot runner plate 3 used in one embodiment of this disclosure; Figure 4 This is a top view schematic diagram of the hot runner plate 3 used in one embodiment of this disclosure; Figure 5 This is a top view schematic diagram of the hot runner plate 3 used in one embodiment of this disclosure; Figure 6 This is a schematic diagram of the structure of the continuous positive and negative hydrogen converter used in Embodiment 1 of this disclosure; Figure 7 This is a schematic diagram of the plate-fin type positive and negative hydrogen converter used in Comparative Example 1 of this disclosure.

[0017] Explanation of reference numerals in the attached figures 1-Hot fluid inlet, 2-Hot fluid distributor, 3-Hot runner plate, 4-Cold runner plate, 5-Cold fluid distributor, 6-Cold fluid inlet, 7-Hot fluid collector, 8-Hot fluid outlet, 9-Side sealing plate, 10-Cold fluid outlet, 11-Cold fluid collector, 12-Baffle, 13-Hot fluid microchannel, 14-Second zone, 15-Filter screen, 16-Neo-parahydrogen catalyst. Detailed Implementation

[0018] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0019] This disclosure provides a continuous converter for n- and para-hydrogen, comprising a hot runner plate 3 and a cold runner plate 4, which are alternately stacked. The upper surface of the hot runner plate 3 includes a first region and a second region, which are alternately arranged along the direction of hot fluid flow. The first region has a plurality of parallel hot fluid microchannels extending along the direction of hot fluid flow. The second region extends perpendicular to the direction of hot fluid flow and has a n- and para-hydrogen catalyst. Along the direction perpendicular to the direction of hot fluid flow, the maximum size of the hot fluid microchannels is smaller than the maximum size of the second region.

[0020] The hot runner plate of the continuous n- and para-hydrogen converter disclosed herein employs a microchannel structure. Different regions have varying dimensions perpendicular to the hot fluid flow direction, with the larger second region containing a n- and para-hydrogen catalyst. This allows hydrogen to exchange heat with a cold fluid within the smaller hot fluid microchannel, then contact the catalyst in the larger second region for n- and para-hydrogen conversion. Subsequently, driven by a pressure difference, it flows out of the second region and re-enters the hot fluid microchannel for heat exchange, repeating this heat exchange-conversion-heat exchange process. Ultimately, the n- and para-hydrogen conversion process is segmented in different regions, approximating a continuous conversion process. The hot fluid microchannel of this disclosure has a large specific surface area, which is beneficial for improving heat exchange efficiency, reducing hydrogen liquefaction energy consumption, and increasing n- and para-hydrogen conversion efficiency. Compared to conventional plate-fin n- and para-hydrogen converters, the continuous n- and para-hydrogen converter of this disclosure, when processing the same amount of hydrogen, not only meets industrial requirements for outlet hydrogen temperature and para-hydrogen concentration, but also has a more compact structure and smaller volume, which helps reduce equipment costs.

[0021] "The maximum size of the thermal fluid microchannel along the direction perpendicular to the flow of the thermal fluid" refers to the maximum vertical distance between two opposite sides of the thermal fluid channel along the direction perpendicular to the flow of the thermal fluid. For example, for a semi-circular thermal fluid channel, the maximum size refers to the diameter of the semi-circle, and for a rectangular thermal fluid channel, the maximum size refers to the side length of the rectangle.

[0022] "The maximum size of the second region along the direction perpendicular to the flow of the hot fluid" refers to the maximum vertical distance between two opposite sides of the second region along the direction perpendicular to the flow of the hot fluid. For example, for a rectangular second region, the maximum size refers to the side length of the rectangle.

[0023] In one embodiment of this disclosure, the maximum dimension of the hot fluid microchannel perpendicular to the hot fluid flow direction is 0.1~2 mm, and the maximum dimension of the second region perpendicular to the hot fluid flow direction is 50~1000 mm. In a preferred embodiment, the ratio of the maximum dimension of the hot fluid microchannel to the maximum dimension of the second region perpendicular to the hot fluid flow direction is 1:(100~800), preferably 1:(500~800). In the above embodiments, by selecting hot fluid microchannels of the preferred size, the hot fluid microchannels can be arranged more compactly, which is beneficial for increasing the specific surface area of ​​the heat exchange between the hot and cold fluids and reducing the converter volume; using a second region of the preferred size is beneficial for ensuring sufficient contact between hydrogen and the secondary hydrogen catalyst in the second region, and improving the secondary hydrogen conversion efficiency.

[0024] In one embodiment of this disclosure, the first region further includes multiple baffles disposed between two adjacent hot fluid microchannels; more preferably, the second region does not have baffles; optionally, the dimensions of the baffles perpendicular to the hot fluid flow direction are 0.1~2 mm. In the above embodiments, hydrogen undergoes heat exchange and cooling within the parallel hot fluid microchannels, then enters the second region to converge and contact with the secondary hydrogen catalyst to achieve secondary hydrogen conversion.

[0025] In one embodiment of this disclosure, the length of the thermal fluid microchannel along the thermal fluid flow direction is 2-20 mm, preferably 3-8 mm; the length of the second region along the thermal fluid flow direction is 2-30 mm, preferably 3-8 mm; preferably, the ratio of the length of the thermal fluid microchannel to the length of the second region along the thermal fluid flow direction is 1:(1-4), more preferably 1:(1-2). In the above embodiment, selecting the preferred lengths of the thermal fluid microchannel and the second region is beneficial for achieving a balance between catalytic efficiency and flow pressure drop, achieving the highest catalytic efficiency while minimizing the thermal fluid flow pressure drop.

[0026] The disclosed n- and parahydrogen catalyst can be applied to the second region by filling or coating. In one embodiment, the n- and parahydrogen catalyst is applied to the second region by filling, and a filter screen 15 is provided between the first region and the second region to prevent the n- and parahydrogen catalyst from entering the hot fluid microchannel. The mesh size of the filter screen 15 is 50~500μm, preferably 100~200μm.

[0027] In another embodiment, the secondary hydrogen catalyst is loaded onto the inner surface of the second region as a coating, in which case the filter screen 15 may not be provided between the first and second regions. In a preferred embodiment, the secondary hydrogen catalyst can also be loaded onto the inner surface of the hot fluid microchannel as a coating, but the coating thickness of the secondary hydrogen catalyst in the hot fluid microchannel should not be too high, preferably 5~100μm, to avoid reducing the heat exchange efficiency of the hot and cold fluids.

[0028] In one embodiment of this disclosure, the particle diameter of the secondary hydrogen catalyst is 100-600 μm, preferably 200-300 μm; the filling thickness of the secondary hydrogen catalyst in the second region is 100-2000 μm, preferably 1000-2000 μm; and the coating thickness of the secondary hydrogen catalyst in the second region is 5-100 μm, preferably 5-10 μm.

[0029] In a specific embodiment, the intermediate hydrogen catalyst includes an iron-based catalyst and / or a nickel-based catalyst, wherein the iron-based catalyst includes one or more of hydrated iron oxide, ferric oxide, and iron tetroxide.

[0030] In one embodiment of this disclosure, the cross-sectional shape of the thermal fluid microchannel includes one or more of the following: semicircular, elliptical, rectangular, and square; and the cross-sectional shape of the second region includes one or more of the following: semicircular, elliptical, rectangular, and square. The cross-section of the thermal fluid microchannel refers to the cross-section perpendicular to the direction of thermal fluid flow, and the cross-section of the second region refers to the cross-section parallel to the direction of thermal fluid flow.

[0031] In the first embodiment, the cross-section of the heat fluid microchannel perpendicular to the heat fluid flow direction is semi-circular, and the cross-section of the second region parallel to the heat fluid flow direction is rectangular, such as... Figure 2 As shown; in the second embodiment, the cross-section of the heat fluid microchannel perpendicular to the heat fluid flow direction is rectangular, and the cross-section of the second region parallel to the heat fluid flow direction is semi-circular and rectangular, as shown. Figure 3 As shown; in the third embodiment, the cross-section of the thermal fluid microchannel perpendicular to the thermal fluid flow direction is rectangular, and the cross-section of the second region parallel to the thermal fluid flow direction is rectangular, as shown. Figure 4 As shown; in the fourth embodiment, the cross-section of the heat fluid microchannel perpendicular to the heat fluid flow direction is semi-circular, and the cross-section of the second region parallel to the heat fluid flow direction is semi-circular, as shown. Figure 5 As shown.

[0032] In one embodiment of this disclosure, the upper surface of the cold flow channel plate 4 includes a cold fluid channel extending along the cold fluid flow direction, and the maximum dimension of the cold fluid channel perpendicular to the cold fluid flow direction is 0.1~2mm. The smaller maximum dimension of the cold fluid channel perpendicular to the cold fluid flow direction in this disclosure is beneficial for increasing the specific surface area of ​​the cold fluid channel and improving the heat exchange efficiency of the hot and cold fluids.

[0033] In one embodiment, the cross-sectional shape of the cold fluid channel perpendicular to the cold fluid flow direction includes one or more of the following: semicircle, ellipse, rectangle, and square.

[0034] In one embodiment, the flow direction of the cold fluid is perpendicular to the flow direction of the hot fluid. In this disclosure, the flow directions of the cold and hot fluids are perpendicular to each other, which facilitates sufficient contact between the fluids and further improves heat exchange efficiency.

[0035] In one embodiment of this disclosure, the continuous positive and negative hydrogen converter further includes a hot fluid inlet 1, a hot fluid distributor 2, a cold fluid distributor 5, a cold fluid inlet 6, a hot fluid collector 7, a hot fluid outlet 8, a side sealing plate 9, a cold fluid outlet 10, and a cold fluid collector 11.

[0036] In a specific embodiment, the hot fluid inlet 1 is connected to the inlet of the hot runner plate 3 via the hot fluid distributor 2, the outlet of the hot runner plate 3 is connected to the hot fluid outlet 8 via the hot fluid collector 7, the cold fluid inlet 6 is connected to the inlet of the cold runner plate 4 via the cold fluid distributor 5, and the outlet of the cold runner plate 4 is connected to the cold fluid outlet 10 via the cold fluid collector 11.

[0037] In one embodiment, the side sealing plate 9 is located on the upper and lower surfaces of the continuous positive and negative hydrogen converter, and is connected to the hot fluid distributor 2, cold fluid distributor 5, hot fluid collector 7 and cold fluid collector 11 around its perimeter, so that the continuous positive and negative hydrogen converter forms a sealed structure.

[0038] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0039] In the embodiments and comparative examples disclosed herein, all raw materials used are commercially available materials.

[0040] Example 1 A continuous converter for positive and negative hydrogen, such as Figure 6 As shown, it includes a hot fluid inlet 1, a hot fluid distributor 2, a hot runner plate 3, a cold runner plate 4, a cold fluid distributor 5, a cold fluid inlet 6, a hot fluid collector 7, a hot fluid outlet 8, a side sealing plate 9, a cold fluid outlet 10, and a cold fluid collector 11. Hot fluid inlet 1 is connected to the raw material hydrogen source. Hot fluid inlet 1 is connected to the inlet of hot runner plate 3 via hot fluid distributor 2. The outlet of hot runner plate 3 is connected to hot fluid outlet 8 via hot fluid collector 7. Cold fluid inlet 6 is connected to the inlet of cold runner plate 4 via cold fluid distributor 5. The outlet of cold runner plate 4 is connected to cold fluid outlet 10 via cold fluid collector 11. Side sealing plate 9 is located on the upper and lower surfaces of the intermediate hydrogen continuous converter and is connected to hot fluid distributor 2, cold fluid distributor 5, hot fluid collector 7 and cold fluid collector 11 on all sides to form a closed structure for the intermediate hydrogen continuous converter.

[0041] The hot runner plate 3 and cold runner plate 4 are alternately stacked. The upper surface of the hot runner plate 3 includes a first region and a second region 14, which are arranged alternately along the direction of hot fluid flow. The first region has multiple parallel hot fluid microchannels 13 and multiple baffles 12. Each baffle 12 is disposed between two adjacent hot fluid microchannels 13. The hot fluid microchannels 13 extend along the direction of hot fluid flow, and their cross-sectional shape perpendicular to the direction of hot fluid flow is semi-circular. The second region 14 extends perpendicular to the direction of hot fluid flow, and does not have baffles. Its cross-sectional shape parallel to the direction of hot fluid flow is rectangular. A top view of the hot runner plate 3 is shown below. Figure 1 and 2 As shown.

[0042] The maximum dimension of the heat fluid microchannel 13 perpendicular to the heat fluid flow direction is 1.2 mm, and its length along the heat fluid flow direction is 3 mm. The maximum dimension of the second region 14 perpendicular to the heat fluid flow direction is 800 mm, and its length along the heat fluid flow direction is 3 mm. The ratio of the maximum dimension of the heat fluid microchannel to the maximum dimension of the second region perpendicular to the heat fluid flow direction is 1:666. The ratio of the length of the heat fluid microchannel to the length of the second region along the heat fluid flow direction is 1:1.

[0043] The inner surface of the hot fluid microchannel 13 does not have a secondary hydrogen catalyst, while the inner surface of the second region 14 is filled with a secondary hydrogen catalyst 16. The particle diameter of the secondary hydrogen catalyst 16 is 200 μm, and the filling thickness in the second region is 2000 μm. A filter screen 15 with a mesh size of 150 μm is also provided between the first and second regions to prevent the secondary hydrogen catalyst from entering the hot fluid microchannel.

[0044] The upper surface of the cold runner plate 4 includes a cold fluid channel that extends along the direction of cold fluid flow. The maximum dimension of the cold fluid channel perpendicular to the direction of cold fluid flow is 1.2 mm. The direction of cold fluid flow is perpendicular to the direction of hot fluid flow.

[0045] The feedstock hydrogen (flow rate of 0.697 kg / s, inlet temperature of -190°C) is introduced into the hot fluid microchannel 13 through the hot fluid inlet 1 for heat exchange. It then enters the second region 14 where it converges and contacts the neutral and secondary hydrogen catalyst to achieve neutral and secondary hydrogen conversion. Afterward, driven by pressure difference, it flows out of the second region 14 and is diverted back into the parallel hot fluid microchannel 13 for heat exchange. This heat exchange-conversion-heat exchange process is repeated until the final outlet hydrogen temperature is -227°C and the secondary hydrogen concentration is 80%, achieving complete conversion of neutral and secondary hydrogen. The total volume of this continuous neutral and secondary hydrogen converter is 0.23 m³. 3 .

[0046] Example 2 Similar to Example 1, the only difference is that the particle diameter of the secondary hydrogen catalyst 16 is 500 μm, and the total volume of the secondary hydrogen continuous converter required to achieve the same throughput and treatment effect as in Example 1 is 0.57 m³. 3 .

[0047] Example 3 Similar to Example 1, the only difference is that the maximum size of the hot fluid microchannel 13 perpendicular to the hot fluid flow direction is 3 mm, such that the ratio of the maximum size of the hot fluid microchannel to the maximum size of the second region perpendicular to the hot fluid flow direction is 1:266. When achieving the same throughput and processing effect as in Example 1, the total volume of the required continuous positive and negative hydrogen converter is 0.41 m³. 3 .

[0048] Example 4 Similar to Example 1, the only difference is that the length of the second region 14 along the direction of hot fluid flow is 10 mm, such that the ratio of the length of the hot fluid microchannel to the length of the second region along the direction of hot fluid flow is 1:3.3. When achieving the same processing capacity and effect as in Example 1, the total volume of the required continuous positive and negative hydrogen converter is 0.43 m³. 3 .

[0049] Comparative Example 1 A plate-fin type secondary hydrogen converter includes a hot-side fluid channel, a cold-side fluid channel, a partition plate, fins, and a secondary hydrogen catalyst filled in the hot-side fluid channel. The secondary hydrogen catalyst has a particle diameter of 400-600 μm, and its structure is as follows. Figure 7 As shown.

[0050] The feedstock hydrogen (flow rate of 0.697 kg / s, inlet temperature of -190°C) is fed into a plate-finned intermediate hydrogen converter for heat exchange and conversion. The final outlet hydrogen temperature is -227°C, and the intermediate hydrogen concentration is 80%. The total volume of the plate-finned intermediate hydrogen converter is 0.68 m³. 3 .

[0051] A comparison of the data from Examples 1-4 with Comparative Example 1 shows that Examples 1-4 utilize the continuous n- and para-hydrogen converter of this disclosure. The smaller dimensions of the hot and cold fluid channels perpendicular to the fluid flow direction enable rapid and efficient heat exchange, improving heat exchange efficiency and reducing hydrogen liquefaction energy consumption. Furthermore, the interconnected structure of the second region allows for sufficient contact between hydrogen and the n- and para-hydrogen catalyst, further enhancing n- and para-hydrogen conversion efficiency. This results in a smaller converter volume required to achieve the same processing capacity and effect, thus reducing equipment costs. In contrast, Comparative Example 1 did not use the converter of this disclosure, leading to lower heat exchange and n- and para-hydrogen conversion efficiencies, a larger converter volume, and higher equipment costs. Compared to the plate-fin n- and para-hydrogen converter of Comparative Example 1, the continuous n- and para-hydrogen converter of Example 1 of this disclosure has a 66.2% smaller volume, significantly reducing equipment costs.

[0052] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0053] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0054] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A primary-secondary hydrogen continuous converter characterized by, The continuous positive and negative hydrogen converter includes a hot runner plate and a cold runner plate, which are stacked alternately. The upper surface of the hot runner plate includes a first region and a second region, which are arranged alternately along the direction of hot fluid flow. The first region has a plurality of hot fluid microchannels arranged in parallel, which extend along the direction of hot fluid flow. The second region extends perpendicular to the direction of hot fluid flow and has a neutral hydrogen catalyst. Along the direction perpendicular to the flow of the hot fluid, the maximum size of the hot fluid microchannel is smaller than the maximum size of the second region.

2. The primary-secondary hydrogen continuous converter according to claim 1, characterized in that, The maximum dimension of the heat fluid microchannel perpendicular to the heat fluid flow direction is 0.1~2mm, and the maximum dimension of the second region perpendicular to the heat fluid flow direction is 50~1000mm; Preferably, along the direction perpendicular to the flow of the hot fluid, the ratio of the maximum size of the hot fluid microchannel to the maximum size of the second region is 1:(100~800).

3. The primary-secondary hydrogen continuous converter according to claim 1, characterized in that, The first region also has multiple partitions, which are disposed between two adjacent hot fluid microchannels; more preferably, the second region does not have partitions. Optionally, the partition plate has a dimension of 0.1 to 2 mm perpendicular to the direction of hot fluid flow.

4. The primary-secondary hydrogen continuous converter according to claim 1, characterized in that, The length of the thermal fluid microchannel along the thermal fluid flow direction is 2~20mm, preferably 3~8mm; the length of the second region along the thermal fluid flow direction is 2~30mm, preferably 3~8mm; Preferably, along the direction of hot fluid flow, the ratio of the length of the hot fluid microchannel to the length of the second region is 1:(1~4).

5. The primary-secondary hydrogen continuous converter according to claim 1, characterized in that, The positive and negative hydrogen catalyst is coated in the second region by filling or coating. Optionally, when the positive and negative hydrogen catalyst is filled into the second region, a filter screen is also provided between the first region and the second region. The mesh size of the filter screen is 50~500μm, preferably 100~200μm.

6. The primary-secondary hydrogen continuous converter according to claim 5, characterized in that, The particle diameter of the secondary hydrogen catalyst is 100~600μm, preferably 200~300μm; the filling thickness of the secondary hydrogen catalyst in the second region is 100~2000μm, preferably 1000~2000μm; the coating thickness of the secondary hydrogen catalyst in the second region is 5~100μm, preferably 5~10μm. The intermediate hydrogen catalyst includes iron-based catalysts and / or nickel-based catalysts, wherein the iron-based catalyst includes one or more of hydrated iron oxide, ferric oxide, and iron tetroxide.

7. The primary-secondary hydrogen continuous converter according to claim 1, characterized in that, The thermal fluid microchannel also has a secondary hydrogen catalyst, which is coated inside the thermal fluid microchannel by means of a coating. The coating thickness of the secondary hydrogen catalyst inside the thermal fluid microchannel is 5~100μm.

8. The continuous positive and negative hydrogen converter according to claim 1, characterized in that, The cross-sectional shape of the thermal fluid microchannel includes one or more of the following: semicircle, ellipse, rectangle, and square. The cross-sectional shape of the second region includes one or more of the following: semicircle, ellipse, rectangle, and square.

9. The continuous positive and negative hydrogen converter according to claim 1, characterized in that, The upper surface of the cold runner plate includes a cold fluid channel that extends along the direction of cold fluid flow. The maximum dimension of the cold fluid channel perpendicular to the direction of cold fluid flow is 0.1~2mm. The cross-sectional shape of the cold fluid channel includes one or more of the following: semicircle, ellipse, rectangle, and square. Optionally, the direction of the cold fluid flow is perpendicular to the direction of the hot fluid flow.

10. The continuous positive and negative hydrogen converter according to claim 1, characterized in that, The continuous converter for positive and negative hydrogen also includes a hot fluid inlet, a hot fluid distributor, a cold fluid distributor, a cold fluid inlet, a hot fluid collector, a hot fluid outlet, a side sealing plate, a cold fluid outlet, and a cold fluid collector. The hot fluid inlet is connected to the inlet of the hot runner plate via the hot fluid distributor, and the outlet of the hot runner plate is connected to the hot fluid outlet via the hot fluid collector. The cold fluid inlet is connected to the inlet of the cold runner plate via the cold fluid distributor, and the outlet of the cold runner plate is connected to the cold fluid outlet via the cold fluid collector. The side sealing plate is located on the upper and lower surfaces of the continuous positive and negative hydrogen converter, and is connected to the hot fluid distributor, cold fluid distributor, hot fluid collector and cold fluid collector around its perimeter, so that the continuous positive and negative hydrogen converter forms a closed structure.

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