Main cryogenic heat exchanger for coal-based liquid hydrogen, onshore coal-to-hydrogen production, storage and transportation system and method

Abstract

This invention belongs to the field of onshore coal gasification hydrogen production, storage, and transportation technology. It proposes a main cryogenic heat exchanger for coal-based liquid hydrogen, an onshore coal-based hydrogen production, storage, and transportation system, and a method. The refrigerant shell-side inlet is connected to the inner cavity of the shell via a distributor. A first inlet and a second inlet are provided on the side wall of the shell near the refrigerant shell-side outlet. A first outlet and a second outlet are provided on the side wall of the shell near the refrigerant shell-side inlet. The first and second inlets, as well as the first and second outlets, are connected by spiral tubes. During the pre-cooling stage, the first and second inlets are respectively the refrigerant pipe-side inlet and the coal-based hydrogen inlet. While the coal-based hydrogen in the spiral tube exchanges heat with the refrigerant in the shell's inner cavity, the refrigerant in the other spiral tube exchanges heat with the refrigerant in the shell's inner cavity, maximizing the utilization of the cold energy in the refrigerant.

Description

Technical Field

[0001] This invention belongs to the field of onshore coal gasification hydrogen production, storage and transportation technology, and particularly relates to a coal-based liquid hydrogen main cryogenic heat exchanger, an onshore coal hydrogen production, storage and transportation system and method. Background Technology

[0002] With the development of coal gasification hydrogen production technology, hydrogen can be produced by using groundwater and coal, and then delivered to the hydrogen energy market through hydrogen liquefaction and separation technology, providing a feasible approach for the low-carbon and clean development of coal.

[0003] The inventors discovered that there is currently a lack of efficient liquefaction, storage, and transportation processes and methods for onshore coal-based hydrogen. In particular, the main cryogenic heat exchanger used for coal-based liquid hydrogen in the pre-cooling and cryogenic stages has poor compactness, resulting in a large amount of cold energy being wasted after refrigerant cooling, which affects the overall heat exchange efficiency of the heat exchanger. Furthermore, existing technologies increase the length of the pipes inside the heat exchanger to ensure the overall heat exchange efficiency. However, the increased pipe length leads to an excessively large size of the entire heat exchanger, increasing the footprint of the entire hydrogen production, storage, and transportation system and raising costs. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a primary cryogenic heat exchanger for coal-based liquid hydrogen, an onshore coal-based hydrogen production and storage system and method, which maximizes the utilization of refrigerant cold energy, avoids the waste of a large amount of cold energy after refrigeration, and improves the heat exchange effect without increasing the volume of the heat exchanger.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a primary cryogenic heat exchanger for coal-based liquid hydrogen, employing the following technical solution:

[0006] A coal-based liquid hydrogen main cryogenic heat exchanger includes a shell, with a refrigerant shell-side inlet and a refrigerant shell-side outlet respectively provided at both ends of the shell, and the refrigerant shell-side inlet is connected to the shell through a distributor;

[0007] The housing has a first inlet and a second inlet on the side wall near the refrigerant shell outlet; the housing has a first outlet and a second outlet on the side wall near the refrigerant shell inlet; the first inlet and the second inlet, as well as the first outlet and the second outlet, are respectively connected by spiral tubes.

[0008] During the precooling stage, the first inlet and the second inlet are respectively the refrigerant pipe side inlet and the coal-based hydrogen inlet, and the refrigerant in the spiral tube exchanges heat with the refrigerant sprayed by the distributor; during the cryogenic stage, the first inlet and the second inlet are respectively the positive hydrogen-rich inlet and the negative hydrogen-rich inlet.

[0009] Furthermore, during the precooling stage, a precooled secondary hydrogen conversion catalyst is installed inside the spiral tube between the second inlet and the second outlet.

[0010] Furthermore, in the cryogenic stage, a cryogenic catalyst for enriching intermediate hydrogen is installed in the spiral tube between the first inlet and the first outlet, and a cryogenic catalyst for enriching positive hydrogen is installed in the spiral tube between the second inlet and the second outlet.

[0011] Furthermore, a central column is provided inside the housing, and two helical tubes are arranged around the central column.

[0012] Furthermore, during the pre-cooling stage, the first outlet is connected to a separator; the separator includes a first separator connected to the first outlet and a second separator connected to the first separator.

[0013] Furthermore, the refrigerant includes methane, ethane, propane, butane, ethylene, propylene, nitrogen, and hydrogen.

[0014] Furthermore, in the cryogenic stage, the first outlet is connected to a first liquid hydrogen storage tank, and the second outlet is connected to a second liquid hydrogen storage tank.

[0015] To achieve the above objectives, in a second aspect, the present invention also provides a method for using a primary cryogenic heat exchanger for coal-based liquid hydrogen, employing the following technical solution:

[0016] A method of using a primary cryogenic heat exchanger for coal-based liquid hydrogen, comprising the primary cryogenic heat exchanger for coal-based liquid hydrogen as described in the first aspect, including:

[0017] During the precooling stage, the first inlet and the second inlet are respectively the refrigerant pipe side inlet and the coal-based hydrogen inlet, and the coal-based hydrogen and refrigerant in the spiral tube exchange heat with the refrigerant sprayed by the distributor; during the deep cooling stage, the first inlet and the second inlet are respectively the secondary hydrogen-rich inlet and the primary hydrogen-rich inlet, and the secondary hydrogen-rich and primary hydrogen-rich in the spiral tube exchange heat with the refrigerant in the shell cavity.

[0018] To achieve the above objectives, in a third aspect, the present invention also provides an onshore coal gasification hydrogen production, storage, and transportation system, which adopts the following technical solution:

[0019] An onshore coal gasification hydrogen production, storage and transportation system includes an interconnected onshore coal gasification system, a pre-cooling liquefaction and secondary hydrogen conversion system, and a cryogenic liquefaction and secondary hydrogen conversion system; the heat exchangers in the pre-cooling liquefaction and secondary hydrogen conversion system and the cryogenic liquefaction and secondary hydrogen conversion system adopt the main cryogenic heat exchanger for coal-based liquid hydrogen as described in the first aspect.

[0020] To achieve the above objectives, in a fourth aspect, the present invention also provides a method for producing hydrogen from onshore coal gasification, employing the following technical solution:

[0021] A method for onshore coal gasification to produce hydrogen, stored, and transported, characterized in that it uses an onshore coal gasification to produce hydrogen, stored, and transported system as described in the third aspect, comprising:

[0022] Coal-based hydrogen is obtained through the onshore coal gasification system, and carbon dioxide is extracted. The obtained coal-based hydrogen is then passed through the pre-cooling liquefaction and intermediate hydrogen conversion system to obtain positive hydrogen-rich and intermediate hydrogen-rich hydrogen, and carbon dioxide, liquid carbon monoxide and liquid nitrogen are extracted. The positive hydrogen-rich and intermediate hydrogen-rich hydrogen are then passed through the cryogenic liquefaction and intermediate hydrogen conversion system to obtain liquid hydrogen.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. In this invention, the refrigerant shell-side inlet is connected to the inner cavity of the shell via a distributor; a first inlet and a second inlet are provided on the side wall of the shell near the refrigerant shell-side outlet; a first outlet and a second outlet are provided on the side wall of the shell near the refrigerant shell-side inlet; the first inlet and the second inlet, as well as the first outlet and the second outlet, are respectively connected by spiral tubes; during the pre-cooling stage, the first inlet and the second inlet are respectively the refrigerant tube-side inlet and the coal-based hydrogen inlet. While the coal-based hydrogen in the spiral tube exchanges heat with the refrigerant in the inner cavity of the shell, the refrigerant in the other spiral tube exchanges heat with the refrigerant in the inner cavity of the shell, thereby maximizing the utilization of cold energy in the refrigerant and avoiding the problem of a large amount of cold energy being wasted after cooling. The refrigerant in the spiral tube absorbs cold energy and then undergoes throttling and cooling, improving the cooling effect.

[0025] 2. In this invention, the method of producing hydrogen through coal gasification can significantly reduce carbon emissions and pollutant generation from coal. Furthermore, combining this with hydrogen liquefaction technology greatly improves the efficiency of hydrogen storage and transportation. The hydrogen liquefaction process employs a coupled technology of hydrogen cooling, secondary hydrogen conversion, and CO2-CO-N2 liquefaction separation. During the cooling and liquefaction of the raw hydrogen, the catalytic conversion of secondary hydrogen and the liquefaction separation of impurities such as CO2-CO-N2 are achieved. The liquid hydrogen uses a complex mixed non-azeotropic refrigerant composed of multiple gases such as methane, ethane, propane, butane, ethylene, propylene, hydrogen, helium, and neon. This complex mixed non-azeotropic refrigerant has high refrigeration efficiency. Secondary hydrogen is converted and separated simultaneously; the lower the secondary hydrogen content, the faster the conversion rate and the higher the conversion efficiency under the same conditions. Simultaneously, reducing the amount of secondary hydrogen conversion catalyst in secondary hydrogen-rich pipelines significantly improves transportation efficiency and reduces pressure drop losses. Coal-based liquid hydrogen coiled tube heat exchangers offer advantages such as high heat transfer coefficients, low refrigerant charge, and compact structure. The relatively low temperature during hydrogen liquefaction further amplifies the self-compensating advantage of thermal expansion / contraction of the coiled tubes in liquid hydrogen coiled tube heat exchangers. Considering the complex flow, heat, and mass transfer coupling processes on both the tube and shell sides of the coiled tube heat exchanger, and leveraging the hydrogen conversion heat to reduce the formation of solid impurities like carbon dioxide and suppress tube blockage, enhanced heat transfer measures for coiled tube heat exchangers in practical onshore coal-to-hydrogen production, storage, and transportation processes are proposed. Attached Figure Description

[0026] The accompanying drawings, which form part of this embodiment, are used to provide a further understanding of this embodiment. The illustrative embodiments and their descriptions are used to explain this embodiment and do not constitute an improper limitation of this embodiment.

[0027] Figure 1 This is the main cryogenic heat exchanger for precooling coal-based liquid hydrogen in Embodiment 1 of the present invention;

[0028] Figure 2 This is the main cryogenic heat exchanger for cryogenic coal-based liquid hydrogen in Embodiment 1 of the present invention;

[0029] Figure 3 This is a flowchart of the onshore coal gasification to hydrogen production, liquefaction, storage and transportation process of Embodiment 3 of the present invention;

[0030] The components include: 1. Shell-side inlet for pre-cooling refrigerant; 2. Shell of the main cryogenic heat exchanger for pre-cooling coal-based liquid hydrogen; 3. Distributor of the main cryogenic heat exchanger for pre-cooling coal-based liquid hydrogen; 4. Pipe-side outlet for refrigerant; 5. Spiral tube for pre-cooling refrigerant; 6. Spiral tube for coal-based hydrogen; 7. Outlet for coal-based hydrogen; 8. Pipe-side inlet for refrigerant; 9. Catalyst for pre-cooling neutral hydrogen conversion; 10. Pre-cooling central column; 11. Inlet for coal-based hydrogen; 12. Shell-side outlet for refrigerant; 13. Separator; 1301. First separator; 1302. Second separator; 14. 15. Shell-side inlet of cryogenic refrigerant; 16. Shell of main cryogenic coal-based liquid hydrogen heat exchanger; 17. Hydrogen-rich spiral tube; 18. Cryogenic central column; 19. Hydrogen-rich spiral tube; 20. First hydrogen outlet; 21. First liquid hydrogen storage tank; 22. Second hydrogen outlet; 23. Second liquid hydrogen storage tank; 24. Hydrogen-rich inlet; 25. Catalyst for cryogenic rich positive hydrogen; 26. Hydrogen-rich positive hydrogen inlet; 27. Catalyst for cryogenic rich secondary hydrogen; 28. Shell-side outlet of cryogenic refrigerant; 29. ​​Distributor of main cryogenic heat exchanger for cryogenic coal-based liquid hydrogen. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0033] Example 1:

[0034] Traditional coal-based liquid hydrogen uses a primary cryogenic heat exchanger where the refrigerant only cools the material. A large amount of cold energy is wasted after the refrigerant cools, affecting the overall heat exchange efficiency. Furthermore, existing technologies increase the length of the pipes inside the heat exchanger to ensure the overall heat exchange efficiency. However, this increased pipe length leads to an excessively large heat exchanger size, increasing the footprint of the entire hydrogen production, storage, and transportation system and raising costs.

[0035] In response to the above problems, such as Figure 1 and Figure 2 As shown, this embodiment provides a main cryogenic heat exchanger for coal-based liquid hydrogen, including a shell, with a refrigerant shell-side inlet and a refrigerant shell-side outlet respectively provided at both ends of the shell, and the refrigerant shell-side inlet being connected to the shell through a distributor;

[0036] The housing has a first inlet and a second inlet on the side wall near the refrigerant shell outlet; the housing has a first outlet and a second outlet on the side wall near the refrigerant shell inlet; the first inlet and the second inlet, as well as the first outlet and the second outlet, are respectively connected by spiral tubes.

[0037] During the precooling stage, the first inlet and the second inlet are respectively the refrigerant pipe side inlet and the coal-based hydrogen inlet, and the refrigerant in the spiral tube exchanges heat with the refrigerant sprayed by the distributor; during the cryogenic stage, the first inlet and the second inlet are respectively the positive hydrogen-rich inlet and the negative hydrogen-rich inlet.

[0038] Specifically, during the precooling stage, the first inlet and the second inlet are the refrigerant pipe side inlet and the coal-based hydrogen inlet, respectively. While the coal-based hydrogen in the spiral tube exchanges heat with the refrigerant in the shell cavity, the refrigerant in the other spiral tube exchanges heat with the refrigerant in the shell cavity. This maximizes the utilization of the cold energy in the refrigerant and avoids the problem of a large amount of cold energy being wasted after cooling. The refrigerant in the spiral tube absorbs cold energy and then undergoes throttling and cooling, improving the cooling effect. At the same time, the spiral tube not only reduces the requirement for the shell length but also further improves the heat exchange effect. Combined with the improvement of cold energy utilization, the heat exchange effect is improved without increasing the volume of the heat exchanger.

[0039] During the precooling stage, a precooling secondary hydrogen conversion catalyst is installed in the spiral tube between the second inlet and the second outlet. A separator is connected to the first outlet.

[0040] Specifically, such as Figure 1 As shown, the main cryogenic heat exchanger for coal-based liquid hydrogen is a pre-cooled main cryogenic heat exchanger for coal-based liquid hydrogen. The first inlet is the refrigerant pipe-side inlet 8, the second inlet is the coal-based hydrogen inlet 11, the first outlet is the refrigerant pipe-side outlet 4, and the second outlet is the coal-based hydrogen outlet 7. The refrigerant shell-side inlet is the pre-cooled refrigerant shell-side inlet 1, and the refrigerant shell-side outlet is the pre-cooled refrigerant shell-side outlet 12. The central column is the pre-cooled central column 10, and the shell is the shell 2 of the pre-cooled main cryogenic heat exchanger for coal-based liquid hydrogen. The refrigerant can be a pre-cooled complex mixed non-azeotropic refrigerant, which may include various gases such as methane, ethane, propane, butane, ethylene, propylene, nitrogen, and hydrogen.

[0041] The refrigerant enters the main cryogenic heat exchanger for pre-cooling coal-based liquid hydrogen through the refrigerant pipe-side inlet 8, absorbing cold energy. After heat exchange, the refrigerant passes through the refrigerant pipe-side outlet 4, where it is throttled and cooled by a throttling valve. Then, it enters the inner cavity of the shell 2 of the main cryogenic heat exchanger for pre-cooling coal-based liquid hydrogen through the shell-side inlet 1 and the distributor 3, releasing cold energy and flowing out from the refrigerant shell-side outlet 12. The pre-cooling refrigerant spiral tube 5 and the coal-based hydrogen spiral tube 6 are wound around the pre-cooling central column 10. The raw coal-based hydrogen enters the main cryogenic heat exchanger for pre-cooling coal-based liquid hydrogen through the coal-based hydrogen inlet 11. The coal-based hydrogen spiral tube 6 is filled with a pre-cooling positive and negative hydrogen conversion catalyst 9. After heat exchange and positive and negative hydrogen conversion, the raw hydrogen flows out from the coal-based hydrogen outlet 7 and enters the separator 13. The separator 13 is a liquid impurity and positive and negative hydrogen separator, achieving the separation of positive hydrogen, negative hydrogen, and liquid impurities.

[0042] Understandably, in this embodiment, the precooling catalyst is a positive and negative hydrogen conversion catalyst; the separator 13 includes a first separator 1301 for separating impurities and a second separator 1302 for obtaining positive and negative hydrogen richness, the second separator 1302 being a positive and negative hydrogen separator; the positive and negative hydrogen conversion catalyst, the first separator 1301 and the second separator 1302 can all be implemented using existing technology, and will not be described in detail here; the distributor 3 of the precooled coal-based liquid hydrogen main low-temperature heat exchanger can be a nozzle, which can distribute the material into the inner cavity of the precooled coal-based liquid hydrogen main low-temperature heat exchanger shell 2, and exchange heat with the spiral tube.

[0043] In the cryogenic stage, a cryogenic catalyst for enriching secondary hydrogen is installed in the spiral tube between the first inlet and the first outlet, and a cryogenic catalyst for enriching positive hydrogen is installed in the spiral tube between the second inlet and the second outlet. The first outlet is connected to a first liquid hydrogen storage tank, and the second outlet is connected to a second liquid hydrogen storage tank.

[0044] Specifically, such as Figure 2 As shown, the main cryogenic heat exchanger for coal-based liquid hydrogen is a cryogenic main cryogenic heat exchanger for coal-based liquid hydrogen. The first inlet is a hydrogen-rich intermediate inlet 23, the second inlet is a hydrogen-rich positive inlet 25, the first outlet is a second hydrogen outlet 21, and the second outlet is a first hydrogen outlet 19. The refrigerant shell-side inlet is a cryogenic refrigerant shell-side inlet 14, and the refrigerant shell-side outlet is a cryogenic refrigerant shell-side outlet 27. The shell is the shell 15 of the cryogenic main cryogenic heat exchanger for coal-based liquid hydrogen. The central column is a cryogenic central column 17. The refrigerant can be a cryogenic complex mixed non-azeotropic refrigerant, which may include hydrogen, helium, neon, and other gases. The distributor is the distributor 28 of the cryogenic main cryogenic heat exchanger for coal-based liquid hydrogen.

[0045] The refrigerant can enter the inner cavity of the main cryogenic heat exchanger shell 15 of the cryogenic coal-based liquid hydrogen main cryogenic heat exchanger through the cryogenic refrigerant shell-side inlet 14, passing through the distributor 28. After heat exchange, it releases cooling capacity and flows out from the cryogenic refrigerant shell-side outlet 27. A positive hydrogen-rich spiral tube 16 and a secondary hydrogen-rich spiral tube 18 are wound around the cryogenic central column 17. The positive hydrogen-rich spiral tube 16 is filled with a positive hydrogen-rich catalyst 24, and the secondary hydrogen-rich spiral tube 18 is filled with a cryogenic secondary hydrogen-rich catalyst 26. The secondary hydrogen and positive hydrogen enter the cryogenic coal-based liquid hydrogen main cryogenic heat exchanger through the secondary hydrogen inlet 23 and the positive hydrogen inlet 25, respectively. After heat exchange and conversion of the positive and secondary hydrogens, the raw material hydrogen enters the first liquid hydrogen storage tank 20 and the second liquid hydrogen storage tank 22 through the first hydrogen outlet 19 and the second hydrogen outlet 21, respectively.

[0046] It is understandable that both the cryogenic catalyst for enriched secondary hydrogen and the cryogenic catalyst for enriched primary hydrogen are secondary hydrogen conversion catalysts. Existing catalysts can be used for secondary hydrogen conversion, which will not be detailed here. The difference is that when the secondary hydrogen conversion catalyst is used as a cryogenic catalyst for enriched secondary hydrogen, its distribution density in the spiral tube is lower than that in the other two cases.

[0047] In this embodiment, the refrigerant may optionally include methane, ethane, propane, butane, ethylene, propylene, nitrogen, and hydrogen. The spiral tube may be a corrugated tube. The corrugated tube increases the flow area of ​​the material within the spiral tube and causes fluctuations in the material flow, resulting in alternating internal and external material exchange in the radial direction, thus improving heat exchange efficiency. For example, when the temperature of the material near the spiral tube wall decreases after absorbing cold energy, its ability to absorb cold energy decreases. At this time, the fluctuations in the material cause the material near the spiral tube wall to alternate with the material in the middle of the spiral tube. The material in the middle, with a higher temperature, approaches the spiral tube wall to absorb cold energy, thereby ensuring the effectiveness of cold energy absorption and improving heat exchange efficiency.

[0048] Example 2:

[0049] This embodiment provides a method for using a primary cryogenic heat exchanger for coal-based liquid hydrogen, which uses the primary cryogenic heat exchanger for coal-based liquid hydrogen as described in Embodiment 1, including:

[0050] During the precooling stage, the first inlet and the second inlet are respectively the refrigerant pipe side inlet and the coal-based hydrogen inlet, and the coal-based hydrogen and refrigerant in the spiral tube exchange heat with the refrigerant sprayed by the distributor; during the deep cooling stage, the first inlet and the second inlet are respectively the secondary hydrogen-rich inlet and the primary hydrogen-rich inlet, and the secondary hydrogen-rich and primary hydrogen-rich in the spiral tube exchange heat with the refrigerant in the shell cavity.

[0051] Example 3:

[0052] like Figure 3As shown, this embodiment provides an onshore coal gasification hydrogen production, storage and transportation system, including an onshore coal gasification system, a pre-cooling liquefaction and secondary hydrogen conversion system and a cryogenic liquefaction and secondary hydrogen conversion system connected to each other; the heat exchangers in the pre-cooling liquefaction and secondary hydrogen conversion system and the cryogenic liquefaction and secondary hydrogen conversion system adopt the main low-temperature heat exchanger for coal-based liquid hydrogen as described in Embodiment 1.

[0053] Coal-based hydrogen is generated through onshore coal gasification technology. After pre-cooling, the main low-temperature heat exchanger for coal-based liquid hydrogen separates carbon dioxide, carbon monoxide, and nitrogen. The cooled coal-based hydrogen is then separated into secondary hydrogen-rich and primary hydrogen-rich hydrogen, which are then converted into secondary and primary hydrogen through the main low-temperature heat exchanger for cryogenic coal-based liquid hydrogen, and finally liquefied into liquid hydrogen.

[0054] It is understandable that, apart from the heat exchanger, all other equipment in the onshore coal gasification system, precooling liquefaction and secondary hydrogen conversion system, and cryogenic liquefaction and secondary hydrogen conversion system can be implemented using existing equipment, which will not be described in detail here.

[0055] Example 4:

[0056] This embodiment provides a method for producing hydrogen from onshore coal gasification, using the onshore coal gasification hydrogen production and storage system described in Embodiment 3, including:

[0057] Coal-based hydrogen is obtained through the onshore coal gasification system, and carbon dioxide is extracted. The obtained coal-based hydrogen is then passed through the pre-cooling liquefaction and intermediate hydrogen conversion system to obtain positive hydrogen-rich and intermediate hydrogen-rich hydrogen, and carbon dioxide, liquid carbon monoxide and liquid nitrogen are extracted. The positive hydrogen-rich and intermediate hydrogen-rich hydrogen are then passed through the cryogenic liquefaction and intermediate hydrogen conversion system to obtain liquid hydrogen.

[0058] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A primary cryogenic heat exchanger for coal-based liquid hydrogen, characterized in that, The device includes a housing, with a refrigerant housing-side inlet and a refrigerant housing-side outlet at each end. The refrigerant housing-side inlet is connected to the housing via a distributor. The housing has a first inlet and a second inlet on the side wall near the refrigerant shell outlet; the housing has a first outlet and a second outlet on the side wall near the refrigerant shell inlet. The first inlet and the first outlet, as well as the second inlet and the second outlet, are respectively connected by spiral tubes; In the precooling stage, the first inlet and the second inlet are respectively the refrigerant pipe-side inlet and the coal-based hydrogen inlet. The refrigerant in the spiral tube exchanges heat with the refrigerant sprayed by the distributor. The first outlet is connected to a separator, which includes a first separator connected to the first outlet and a second separator connected to the first separator. In the cryogenic stage, the first inlet and the second inlet are respectively the secondary hydrogen-rich inlet and the positive hydrogen-rich inlet. A catalyst for cryogenic secondary hydrogen enrichment is installed in the spiral tube between the first inlet and the first outlet, and a catalyst for cryogenic positive hydrogen enrichment is installed in the spiral tube between the second inlet and the second outlet.

2. The main cryogenic heat exchanger for coal-based liquid hydrogen as described in claim 1, characterized in that, During the precooling stage, a precooling secondary hydrogen conversion catalyst is installed in the spiral tube between the second inlet and the second outlet.

3. The main cryogenic heat exchanger for coal-based liquid hydrogen as described in claim 1, characterized in that, A central column is provided inside the housing, and two spiral tubes are arranged around the central column.

4. The main cryogenic heat exchanger for coal-based liquid hydrogen as described in claim 1, characterized in that, The refrigerant includes methane, ethane, propane, butane, ethylene, propylene, nitrogen, and hydrogen.

5. The main cryogenic heat exchanger for coal-based liquid hydrogen as described in claim 1, characterized in that, During the cryogenic stage, the first outlet is connected to a first liquid hydrogen storage tank, and the second outlet is connected to a second liquid hydrogen storage tank.

6. A method of using a primary cryogenic heat exchanger for coal-based liquid hydrogen, characterized in that, The main cryogenic heat exchanger for coal-based liquid hydrogen as described in any one of claims 1-5 is used, comprising: During the precooling stage, the first inlet and the second inlet are respectively the refrigerant pipe side inlet and the coal-based hydrogen inlet, and the coal-based hydrogen and refrigerant in the spiral tube exchange heat with the refrigerant sprayed by the distributor; during the deep cooling stage, the first inlet and the second inlet are respectively the secondary hydrogen-rich inlet and the primary hydrogen-rich inlet, and the secondary hydrogen-rich and primary hydrogen-rich in the spiral tube exchange heat with the refrigerant in the shell cavity.

7. An onshore coal gasification hydrogen production, storage, and transportation system, characterized in that, It includes an interconnected onshore coal gasification system, a precooling liquefaction and secondary hydrogen conversion system, and a cryogenic liquefaction and secondary hydrogen conversion system; the heat exchangers in the precooling liquefaction and secondary hydrogen conversion system and the cryogenic liquefaction and secondary hydrogen conversion system adopt the main cryogenic heat exchanger for coal-based liquid hydrogen as described in any one of claims 1-5.

8. A method for producing hydrogen from onshore coal gasification, characterized in that, The onshore coal gasification hydrogen production, storage, and transportation system as described in claim 7 is used, comprising: Coal-based hydrogen is obtained through the onshore coal gasification system, and carbon dioxide is extracted. The obtained coal-based hydrogen is then passed through the pre-cooling liquefaction and intermediate hydrogen conversion system to obtain positive hydrogen-rich and intermediate hydrogen-rich hydrogen, and carbon dioxide, liquid carbon monoxide and liquid nitrogen are extracted. The positive hydrogen-rich and intermediate hydrogen-rich hydrogen are then passed through the cryogenic liquefaction and intermediate hydrogen conversion system to obtain liquid hydrogen.

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