Hydrogen liquefaction and slurry hydrogen co-production system and method

Abstract

The invention belongs to the technical field of hydrogen liquefaction, and discloses a hydrogen liquefaction and slurry hydrogen co-production system and method.A hydrogen storage tank directly supplies materials for slurry hydrogen preparation, dependence of slurry hydrogen preparation on external liquid hydrogen raw materials is avoided, a raw material supply link is simplified, a vacuum device pumps cold hydrogen generated in slurry hydrogen preparation, and the hydrogen liquefaction and slurry hydrogen co-production system is suitable for industrial production. The hydrogen precooling heat exchanger is introduced to precool the hydrogen liquefaction raw material gas, so that cold energy which is directly discharged originally is efficiently recycled, partial external cold source requirements are replaced, the dependency degree of a hydrogen liquefaction system on an expansion machine and a liquid nitrogen cold source is reduced, hydrogen generated in the slurry hydrogen preparation process and the cold energy carried by the hydrogen are reduced, and the hydrogen liquefaction efficiency is improved. And the raw material hydrogen is recycled by the heat exchanger and is used for precooling the raw material hydrogen in the hydrogen liquefaction module, so that the hydrogen liquefaction rate is remarkably improved, the refrigeration energy consumption and raw material gas loss of the system are reduced, and gradient efficient utilization of energy is realized.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen liquefaction technology, specifically a hydrogen liquefaction and slurry hydrogen co-production system and method. Background Technology

[0002] Hydrogen energy, as a clean secondary energy source with great development potential, has been widely applied in key areas such as large-scale renewable energy consumption and storage, and aerospace propulsion. Among them, cryogenic liquid hydrogen, with its excellent energy density and storage and transportation characteristics, has become one of the important carriers for the large-scale application of hydrogen energy. In the field of energy storage, liquid hydrogen can realize long-term, cross-seasonal storage and flexible allocation of renewable energy, effectively improving the stability and economy of the energy system; in the aerospace field, liquid hydrogen, as a key component of high-performance propellants, provides extremely high specific impulse and propulsion performance for spacecraft such as launch vehicles.

[0003] Hydrogen liquefaction, a key technology for obtaining liquid hydrogen, requires the conversion of gaseous hydrogen into liquid through cryogenic processes. Existing processes generally rely on external cold sources to gradually cool hydrogen from room temperature, resulting in numerous system devices, high initial investment, and increased energy consumption due to the continuous demand for external cooling. This leads to existing hydrogen liquefaction systems generally suffering from high equipment redundancy, complex control, and low overall energy efficiency, thus limiting their economic competitiveness in large-scale continuous operation scenarios.

[0004] The production of plasma hydrogen generates a large amount of cold, low-temperature hydrogen gas. Currently, this cold energy is often not effectively recovered and is directly emitted, resulting in energy waste. Meanwhile, the raw materials required for plasma hydrogen production are the products of hydrogen liquefaction. Although plasma hydrogen shows promising applications in aerospace, scientific research, industry, and energy, hydrogen liquefaction and plasma hydrogen production remain disconnected within industrial systems. While there have been laboratory-scale attempts at plasma hydrogen production both domestically and internationally, these have failed to achieve process coupling with large-scale hydrogen liquefaction production lines. This means the cold energy generated during plasma hydrogen production cannot be used in the hydrogen liquefaction process, and the cooling capacity of the hydrogen liquefaction system cannot support plasma hydrogen production, creating a dilemma of redundant equipment and cumulative energy consumption.

[0005] Based on the aforementioned technological status, existing hydrogen liquefaction processes face issues such as equipment redundancy and high energy consumption, while independent slurry hydrogen preparation processes suffer from bottlenecks such as cold energy waste and raw material dependence. It is worth noting that the cold hydrogen emitted during slurry hydrogen preparation can provide a potential low-temperature cold source for the pre-cooling stage of hydrogen liquefaction. The two have a natural complementarity in terms of energy and material flow; that is, by actively extracting cold hydrogen using a vacuum device as a pre-cooling medium, dependence on expanders is reduced. Summary of the Invention

[0006] This invention provides a hydrogen liquefaction and slurry hydrogen co-production system and method, which solves the problems of equipment redundancy and high energy consumption in existing hydrogen liquefaction processes, while the independent slurry hydrogen production process has the problems of cold energy waste and raw material dependence.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A hydrogen liquefaction and slurry hydrogen co-production system includes a hydrogen production unit, a liquid hydrogen storage tank, and a slurry hydrogen preparation storage tank. The bottom of the liquid hydrogen storage tank is connected to the slurry hydrogen preparation storage tank. A hydrogen compressor is connected to the hydrogen production unit. A heat exchange unit and a heating channel on a hydrogen precooling heat exchanger are sequentially connected to the top outlets of the slurry hydrogen preparation storage tank and the liquid hydrogen storage tank. A vacuum device is connected to the heating channel of the hydrogen precooling heat exchanger connected to the slurry hydrogen preparation storage tank. The heating channel on the hydrogen precooling heat exchanger is connected to the inlet of the hydrogen compressor. The outlet of the hydrogen compressor is connected to the cooling channel of the hydrogen precooling heat exchanger. A liquid nitrogen pool, a positive and negative hydrogen converter, a cooling channel of the heat exchange unit, and a throttling valve are sequentially connected to the cooling channel of the hydrogen precooling heat exchanger. The throttling valve is connected to the inlet of the liquid hydrogen storage tank through a pipeline. A slurry hydrogen storage tank is connected to the bottom of the slurry hydrogen preparation storage tank.

[0008] Preferably, the liquid nitrogen pool has a built-in cooling channel immersed in liquid nitrogen, and the nitrogen heat exchanger is equipped with an independent heating channel and a cooling channel.

[0009] Preferably, the liquid nitrogen pool is connected to the heating channels of a hydrogen precooling heat exchanger and a nitrogen heat exchanger, respectively. The heating channels of the hydrogen precooling heat exchanger and the nitrogen heat exchanger are connected to the same nitrogen compressor. The nitrogen compressor is connected to the cooling channel of the nitrogen heat exchanger. The cooling channel of the nitrogen heat exchanger is connected to the inlet of a nitrogen throttle valve. The outlet of the nitrogen throttle valve is connected to the liquid nitrogen pool.

[0010] Preferably, the top of the slurry hydrogen preparation storage tank is provided with a vacuum port, and the bottom is provided with a slurry hydrogen outlet and a liquid hydrogen inlet. The slurry hydrogen outlet is connected to the inlet of the slurry hydrogen storage tank, and the liquid hydrogen inlet is connected to the liquid hydrogen outlet of the liquid hydrogen storage tank.

[0011] Preferably, the heat exchange unit includes a first low-temperature heat exchanger and a second low-temperature heat exchanger connected in sequence, and each of the first low-temperature heat exchanger and the second low-temperature heat exchanger is provided with one independent cooling channel and two heating channels.

[0012] Preferably, the heat exchange unit includes a first low-temperature heat exchanger, a second low-temperature heat exchanger, a third low-temperature heat exchanger, and a fourth low-temperature heat exchanger connected in sequence. Each of the first, second, third, and fourth low-temperature heat exchangers has one independent cooling channel and two heating channels. The cooling channel outlet of the first low-temperature heat exchanger is provided with a diversion structure, one channel is connected to a hydrogen expander, and the outlet of the hydrogen expander is connected to the heating channel between the third and fourth low-temperature heat exchangers. The other channel is connected to the cooling channel of the second low-temperature heat exchanger.

[0013] Preferably, the heat exchange unit includes a first low-temperature heat exchanger, a second low-temperature heat exchanger, a third low-temperature heat exchanger, and a fourth low-temperature heat exchanger connected in sequence. The first low-temperature heat exchanger, the second low-temperature heat exchanger, and the third low-temperature heat exchanger are each provided with one independent cooling channel and two heating channels. The fourth low-temperature heat exchanger is provided with one cooling channel and three heating channels. A helium refrigeration cycle system is connected to one of the heating channels of the fourth low-temperature heat exchanger.

[0014] Preferably, the helium refrigeration cycle system includes a helium expander, a first helium heat exchanger, a second helium heat exchanger, and a helium compressor. The helium expander is connected to the inlet of the heating channel of a fourth cryogenic heat exchanger. The outlet of the heating channel of the fourth cryogenic heat exchanger is connected to the inlet of the heating channel of the first helium heat exchanger. The outlet of the heating channel of the first helium heat exchanger is connected to the inlet of the heating channel of the second helium heat exchanger. The outlet of the heating channel of the second helium heat exchanger is connected to the inlet of the helium compressor. The outlet of the helium compressor is connected to the inlet of the cooling channel of the second helium heat exchanger. The outlet of the cooling channel of the second helium heat exchanger is connected to the inlet of the cooling channel of a liquid nitrogen pool. The outlet of the cooling channel of the liquid nitrogen pool is connected to the inlet of the cooling channel of the first helium heat exchanger. The outlet of the cooling channel of the first helium heat exchanger is connected to the inlet of the helium expander.

[0015] Preferably, the liquid hydrogen storage tank is connected to a liquid hydrogen storage and transportation module, and the slurry hydrogen storage tank is connected to a slurry hydrogen storage and transportation module.

[0016] A method for hydrogen liquefaction and slurry hydrogen co-production includes: Liquid hydrogen from the liquid hydrogen storage tank is transferred to the slurry hydrogen preparation tank through the bottom outlet. A vacuum device is activated to evacuate the slurry hydrogen preparation tank, reducing the pressure inside to below the triple point pressure of hydrogen. During the vacuuming process, the extracted low-temperature hydrogen passes through the heating channel of the heat exchange unit and the hydrogen pre-cooling heat exchanger. After merging with the hydrogen produced by the hydrogen production unit, it is compressed into high-pressure hydrogen by the hydrogen compressor. The high-pressure hydrogen first enters the cooling channel of the hydrogen pre-cooling heat exchanger, where heat exchange is performed through the heat exchange unit to pre-cool the high-pressure hydrogen in the cooling channel. The pre-cooled high-pressure hydrogen then enters… The cooling channel entering the liquid nitrogen pool completes secondary cooling, and then the cooling channel of the subsequent heat exchange unit undergoes heat exchange to further recover cold energy and cool the high-pressure hydrogen. The high-pressure hydrogen, after being cooled again, enters the throttling valve, and after throttling and depressurization, it is converted into liquid hydrogen. The liquid hydrogen is stored in the liquid hydrogen storage tank. The incompletely liquefied hydrogen, as well as the low-temperature hydrogen generated during the slurry hydrogen preparation process, enters the hydrogen pre-cooling heat exchanger and the heating channel of the heat exchange unit through the reflux device to participate in cold energy recovery, and finally flows into the inlet of the hydrogen compressor to participate in the compression and liquefaction process again.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a hydrogen liquefaction and slurry hydrogen co-production system, in which the liquid hydrogen storage tank directly supplies the slurry hydrogen preparation, avoiding the dependence of slurry hydrogen preparation on external liquid hydrogen raw materials, simplifying the raw material supply chain, and the vacuum device extracts the cold hydrogen gas generated in slurry hydrogen preparation and introduces it into the hydrogen precooling heat exchanger to precool the raw material gas for hydrogen liquefaction, efficiently recovering the cold energy that was originally directly emitted, replacing part of the external cold source requirement, reducing the dependence of the hydrogen liquefaction system on the expander and liquid nitrogen cold source. The hydrogen gas generated in the slurry hydrogen preparation process and the cold energy it carries are recovered by the heat exchanger and used to precool the raw material hydrogen in the hydrogen liquefaction module, thereby significantly improving the hydrogen liquefaction rate, reducing the system's cooling energy consumption and raw material gas loss, and realizing the efficient utilization of energy in a cascade manner.

[0018] Furthermore, compared to the traditional model where hydrogen liquefaction and slurry hydrogen production are operated separately and independently, which has inherent drawbacks such as complex system structure, high construction and operation costs, and large hydrogen consumption, this system only needs to rely on a single power input to simultaneously produce both liquid hydrogen and slurry hydrogen. It has particularly outstanding advantages in simplifying the process, controlling costs, reducing hydrogen consumption, and improving system efficiency, and its technical and economic benefits are significant.

[0019] Furthermore, the implementation path of the slurry hydrogen preparation function of this system is extremely convenient. It only requires adding a slurry hydrogen preparation subsystem to the existing mature hydrogen liquefaction process, without the need for complex modifications to the original core equipment, which greatly reduces the threshold and cost of technology upgrades. In addition, our team has built a low-temperature slurry preparation experimental device and completed a series of rigorous verifications. The experimental data fully confirms the scientific nature and feasibility of this technical route, providing solid and reliable technical support for the industrialization and large-scale promotion of the system.

[0020] Furthermore, the hydrogen production module adopts the proton exchange membrane electrolysis method, which has the core advantage of high current density operation, while also having the significant characteristics of low power consumption, high system integration, high gas purity, and easy realization of high-pressure hydrogen production. More importantly, it can operate stably within a wide range of operating parameters and can flexibly adapt to the fluctuations of renewable energy power generation, providing a solid guarantee for the green hydrogen supply of the system. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the expander liquefaction cycle-hydrogen liquefaction and slurry hydrogen co-production structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a hydrogen liquefaction and slurry hydrogen co-production system according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the pre-cooling throttling liquefaction cycle-hydrogen liquefaction and slurry hydrogen co-production system according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the helium expansion refrigeration hydrogen liquefaction cycle-hydrogen liquefaction and slurry hydrogen co-production system according to an embodiment of the present invention; Figure 5 The changes in slurry hydrogen density and its gain under different solid contents; Figure 6 The variation and gain of slurry hydrogen cooling capacity under different solid content; Figure 7 The variation and gain of daily hydrogen evaporation rate in slurry under different solid content; In the diagram, 1-hydrogen production unit; 2-hydrogen compressor; 3-vacuum device; 4-hydrogen precooling heat exchanger; 5-liquid nitrogen tank; 6-neo-parahydrogen converter; 701-first cryogenic heat exchanger; 702-second cryogenic heat exchanger; 703-third cryogenic heat exchanger; 704-fourth cryogenic heat exchanger; 8-throttle valve; 9-liquid hydrogen storage tank; 10-slurry hydrogen preparation storage tank; 11-slurry hydrogen storage tank; 12-nitrogen compressor; 13-nitrogen heat exchanger; 14-nitrogen throttle valve. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," and "set up" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components.

[0027] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] like Figure 1As shown, this invention provides a hydrogen liquefaction and slurry hydrogen co-production system, including a hydrogen production unit 1, a liquid hydrogen storage tank 9, and a slurry hydrogen preparation storage tank 10. The bottom of the liquid hydrogen storage tank 9 is connected to the slurry hydrogen preparation storage tank 10. A hydrogen compressor 2 is connected to the hydrogen production unit 1. The top outlet of the slurry hydrogen preparation storage tank 10 and the liquid hydrogen storage tank 9 are sequentially connected to a heat exchange unit and a heating channel on a hydrogen precooling heat exchanger 4. A vacuum device 3 is connected to the heating channel of the hydrogen precooling heat exchanger 4 connected to the slurry hydrogen preparation storage tank 10. The heating channel of the hydrogen precooling heat exchanger 4 is connected to the inlet of the hydrogen compressor 2. The outlet of the hydrogen compressor 2 is connected to the cooling channel of the hydrogen precooling heat exchanger 4. A liquid nitrogen pool 5, a neutral hydrogen converter 6, a cooling channel of the heat exchange unit, and a throttling valve 8 are sequentially connected to the cooling channel of the hydrogen precooling heat exchanger 4. The throttling valve is connected to the inlet of the liquid hydrogen storage tank 9 through a pipe. A slurry hydrogen storage tank 11 is connected to the bottom of the slurry hydrogen preparation storage tank 10.

[0029] The detailed design is as follows: like Figure 2 As shown, its specific structure includes the following core modules.

[0030] Hydrogen production module The hydrogen production module includes a hydrogen production device 1, whose core internal components include anode and cathode plates, anode and cathode gas diffusion layers, anode and cathode catalyst layers, an electrolyzer, and a proton exchange membrane. This module uses electrical energy as the external energy input and pure water as the working fluid.

[0031] During operation, external electrical energy is converted into direct current and introduced into the electrolytic cell via the anode and cathode plates. Inside the electrolytic cell, the proton exchange membrane drives a pure water electrolysis reaction, producing hydrogen and oxygen. The oxygen is simultaneously separated and discharged, while the hydrogen is collected via a dedicated pipeline. The produced hydrogen is then exported through an output pipeline and mixed with hydrogen evaporated from the liquid hydrogen storage and transportation equipment and excess hydrogen produced by the slurry hydrogen preparation equipment, ultimately being sent together to the hydrogen liquefaction module.

[0032] Hydrogen liquefaction module The hydrogen liquefaction module consists of a hydrogen compressor 2, a hydrogen precooling heat exchanger 4, a liquid nitrogen tank 5, a neutral hydrogen converter 6, a first low-temperature heat exchanger 701, a second low-temperature heat exchanger 702, a throttle valve 8, a nitrogen compressor 12, a nitrogen heat exchanger 13, and a nitrogen throttle valve 14.

[0033] Among them, the hydrogen precooling heat exchanger 4 is equipped with one independent cooling channel and three heating channels that can exchange heat; the first low temperature heat exchanger 701 and the second low temperature heat exchanger 702 are each equipped with one independent cooling channel and two heating channels that can exchange heat; the liquid nitrogen pool 5 has a built-in cooling channel immersed in liquid nitrogen; and the nitrogen heat exchanger 13 is equipped with one independent heating channel and one cooling channel that can exchange heat.

[0034] The connections between the various devices are divided into two parts: the hydrogen liquefaction pipeline and the liquid nitrogen circulation pipeline, as detailed below: Hydrogen liquefaction pipeline connection The inlet of hydrogen compressor 2 is connected to a manifold, receiving reflux hydrogen from the hydrogen production unit, liquid hydrogen storage and transportation module, and slurry hydrogen preparation module; its outlet is connected to the cooling channel inlet of hydrogen precooling heat exchanger 4. Of the three heating channels of hydrogen precooling heat exchanger 4, two channels have inlets connected to the outlet of the cooling channel of the first cryogenic heat exchanger 701, receiving cryogenic media from that heat exchanger; the inlet of the remaining heating channel is connected to the liquid nitrogen system, introducing cryogenic nitrogen as a cold source. The outlet of the cooling channel of hydrogen precooling heat exchanger 4 is connected to the cooling channel inlet of liquid nitrogen pool 5, and the outlet of the liquid nitrogen pool cooling channel is connected to the inlet of the ortho- and para-hydrogen converter 6; the outlet of the ortho- and para-hydrogen converter is connected to the cooling channel inlet of the first cryogenic heat exchanger 701, and the outlet of the cooling channel of this heat exchanger is connected to the cooling channel inlet of the second cryogenic heat exchanger 702. The heating channels of the first cryogenic heat exchanger 701 and the second cryogenic heat exchanger 702 are connected in series, with the outlet of the heating channel of the first cryogenic heat exchanger 701 connected to the inlet of the heating channel of the second cryogenic heat exchanger 702. The outlet of the cooling channel of the second cryogenic heat exchanger 702 is connected to the inlet of the throttle valve 8, and the outlet of the throttle valve is connected to the liquid hydrogen storage tank 9 of the liquid hydrogen storage and transportation system.

[0035] Liquid nitrogen circulation pipeline The nitrogen gas evaporated in the liquid nitrogen pool 5 is split into two streams by a distributor: one stream connects to the inlet of the heating channel of the hydrogen precooling heat exchanger 4, and the other stream connects to the inlet of the heating channel of the nitrogen heat exchanger 13. After heat exchange, the two streams of nitrogen gas merge at a junction and then connect to the inlet of the nitrogen compressor 12. The outlet of the nitrogen compressor 12 connects to the inlet of the cooling channel of the nitrogen heat exchanger 13. The outlet of the cooling channel of the heat exchanger is connected to the inlet of the nitrogen throttling valve 14, and the outlet of the nitrogen throttling valve 14 connects to the liquid inlet of the liquid nitrogen pool 5, forming a closed-loop liquid nitrogen circulation.

[0036] During operation, the combined hydrogen gas is compressed into high-pressure hydrogen by the hydrogen compressor 2 and first enters the cooling channel of the hydrogen precooling heat exchanger 4. Simultaneously, the return hydrogen and the low-temperature nitrogen from the liquid nitrogen system flow synchronously through the heating channel of the hydrogen precooling heat exchanger 4, achieving precooling of the high-pressure hydrogen in the cooling channel through heat exchange. The precooled high-pressure hydrogen enters the cooling channel of the liquid nitrogen pool 5 for secondary cooling, and then flows sequentially through the cooling channels of the first low-temperature heat exchanger 701 and the second low-temperature heat exchanger 702. The return hydrogen exchanges heat with it through the heating channels of the two-stage heat exchangers, further recovering cold energy and cooling the high-pressure hydrogen. After cooling, the high-pressure hydrogen enters the throttle valve 8, and after throttling and depressurization, it is converted into liquid hydrogen, which is stored in the liquid hydrogen storage tank 9. The incompletely liquefied hydrogen, as well as the low-temperature hydrogen generated during the slurry hydrogen preparation process, enter the heating channels of the hydrogen precooling heat exchanger 4, the first low-temperature heat exchanger 701 and the second low-temperature heat exchanger 702 in sequence through the reflux device to participate in the cold energy recovery, and finally flow into the inlet of the hydrogen compressor 2 to participate in the compression and liquefaction process again.

[0037] During the heat exchange process, some of the liquid nitrogen in the liquid nitrogen tank 5 evaporates into nitrogen gas. The evaporated nitrogen gas is divided into two streams by a distributor: one stream enters the heating channel of the hydrogen precooling heat exchanger 4 to provide a cold source for hydrogen precooling; the other stream enters the heating channel of the nitrogen heat exchanger 13 to prepare for subsequent nitrogen cooling. After the two streams of nitrogen gas complete the heat exchange, they converge and are pressurized into high-pressure nitrogen by the nitrogen compressor 12. Then, they enter the cooling channel of the nitrogen heat exchanger 13 for cooling. The cooled high-pressure nitrogen gas enters the nitrogen throttling valve 14, where it is throttled, depressurized, liquefied, and converted back into liquid nitrogen. Finally, it flows back into the liquid nitrogen tank 5, realizing the recycling of liquid nitrogen and ensuring a continuous supply of cold source for the system.

[0038] Hydrogen preparation unit The slurry hydrogen preparation unit consists of a vacuum device 3, a slurry hydrogen preparation storage tank 10, and supporting pipelines. The slurry hydrogen preparation storage tank 10 has a vacuum port at the top and a slurry hydrogen outlet and a liquid hydrogen inlet at the bottom. The slurry hydrogen outlet is connected to the inlet of the slurry hydrogen storage tank 11 of the slurry hydrogen storage and transportation module, while the liquid hydrogen inlet is connected to the liquid hydrogen outlet of the liquid hydrogen storage tank 9. The connection path of the vacuum port at the top of the tank is as follows: first, it is connected to the inlet of the heating channel of the second cryogenic heat exchanger 702; the outlet of the heating channel of this heat exchanger is connected to the inlet of the heating channel of the first cryogenic heat exchanger 701; the outlet of the heating channel of the first cryogenic heat exchanger 701 is then connected to the inlet of the heating channel of the hydrogen precooling heat exchanger 4; finally, the outlet of the heating channel of the hydrogen precooling heat exchanger 4 is connected to the inlet of the vacuum device 3, and the outlet of the vacuum pump is connected to the junction of the inlet of the hydrogen compressor 2.

[0039] During operation: Liquid hydrogen in liquid hydrogen storage tank 9 is transported to slurry hydrogen preparation storage tank 10 through the bottom outlet; vacuum device 3 is activated to evacuate the tank, reducing the pressure inside to below the hydrogen triple point pressure. The low-temperature hydrogen extracted during the vacuuming process flows sequentially through the heating channels of the second low-temperature heat exchanger 702, the first low-temperature heat exchanger 701, and the hydrogen pre-cooling heat exchanger 4, exchanging heat with the high-pressure hydrogen in the cooling channels of each heat exchanger. The low-temperature hydrogen releases cold energy as it heats up, which is efficiently recovered and used to assist the high-pressure hydrogen in the cooling channels in completing the cooling process. Once the liquid hydrogen in the tank reaches the hydrogen triple point condition, a solid hydrogen layer will naturally form on its surface; subsequently, the pressure inside the tank is adjusted to above the hydrogen triple point pressure, causing the portion of the solid hydrogen layer in contact with the inner wall of the tank to melt and sink. At this point, the agitator inside the tank is turned on, and the melted solid hydrogen particles are uniformly mixed with liquid hydrogen through mechanical stirring to form slurry hydrogen with the target solid-liquid ratio; the prepared slurry hydrogen is transported to slurry hydrogen storage tank 11 through the bottom outlet to complete the storage.

[0040] Liquid hydrogen and slurry hydrogen storage and transportation modules The liquid hydrogen and slurry hydrogen storage and transportation module adopts an integrated design, consisting of liquid hydrogen storage tank 9, slurry hydrogen storage tank 11, and supporting transfer equipment. Both types of storage tanks are equipped with independent inlets and outlets, which can realize cryogenic and sealed storage of liquid hydrogen and slurry hydrogen respectively, and can also be used to independently and safely transport the two types of products to downstream application terminals through supporting cryogenic tank trucks and other transfer equipment.

[0041] This module has the dual functions of "immediate production and storage, and immediate storage and transportation". It not only supports the simultaneous production and classified storage of liquid hydrogen and slurry hydrogen in the system, but also ensures the independence, reliability and operational flexibility of the two products in the storage and transportation process, thereby providing integrated storage and transportation support for diversified hydrogen energy application scenarios.

[0042] This invention provides a highly efficient hydrogen liquefaction and slurry hydrogen co-production system and method. This system achieves deep process coupling between the hydrogen liquefaction module and the slurry hydrogen preparation module. Utilizing a multi-channel heat exchanger and reflux pipeline, it fully reuses the low-temperature hydrogen energy extracted during the slurry hydrogen preparation process for the pre-cooling and deep cooling stages of the hydrogen liquefaction process, thus constructing a cold energy "production" system. The design utilizes an integrated closed-loop system. This design fundamentally solves the problem of cold energy waste in traditional separate processes, significantly reducing overall energy consumption. Especially in the hydrogen liquefaction stage, the energy reduction effect is particularly outstanding by using the cold energy of supercooled hydrogen generated during the slurry hydrogen preparation process for auxiliary cooling.

[0043] Meanwhile, the hydrogen circulates within a fully enclosed pipeline system, not only avoiding the risk of hydrogen leakage caused by material transfer in traditional separate processes and improving the inherent safety level of production, but also achieving efficient circulation and full utilization of hydrogen. The system also realizes integrated production across the entire process from hydrogen preparation and liquefaction to slurry hydrogen preparation. Through integrated equipment design, the system shares a single hydrogen compression and manifold device, and the slurry hydrogen preparation unit directly connects to the liquid hydrogen outlet of the hydrogen liquefaction module, eliminating the need for additional liquid hydrogen transfer and reprocessing equipment. Combined with the compact layout of the series-connected cryogenic heat exchanger, the number of equipment and floor space are significantly reduced, lowering infrastructure and equipment procurement costs, and making it more suitable for large-scale, intensive production needs.

[0044] Furthermore, the system can simultaneously produce both liquid hydrogen and slurry hydrogen without switching processes. By simply adjusting the pressure and stirring parameters during the slurry hydrogen preparation process, the solid-liquid fraction of the slurry hydrogen can be flexibly adjusted to precisely match the product requirements of different application scenarios. Compared to traditional separate processes that output only one product, this system significantly improves the market adaptability and application flexibility of the product.

[0045] The system design of this invention features flexible process adaptability, allowing for the selection of appropriate hydrogen liquefaction cycle configurations based on target production capacity. This system is not only suitable for laboratory and micro-scale slurry and liquid hydrogen production, but can also be configured with different configurations, such as expansion refrigeration cycles and helium expansion refrigeration cycles, to adapt to various production scenarios ranging from demonstration and verification to large-scale industrialization, thereby achieving economical and efficient operation across the entire scale.

[0046] like Figure 3 As shown, one embodiment of the present invention provides a hydrogen liquefaction and slurry hydrogen co-production system. A third low-temperature heat exchanger 703 and a fourth low-temperature heat exchanger 704 are added after the second low-temperature heat exchanger 702. Each of the two newly added heat exchangers is equipped with one independent and heat-exchangeable heating channel and two cooling channels, and the heating and cooling channels of both are connected to the corresponding channels of the second low-temperature heat exchanger 702. Simultaneously, a diversion structure is set at the outlet of the cooling channel of the first low-temperature heat exchanger 701: a portion of the hydrogen enters the inlet of a 15-hydrogen expander, and the expander outlet is connected between the third and fourth low-temperature heat exchangers 703 and 704; the other portion of the hydrogen continues to flow along the main liquefaction path, sequentially entering the cooling channels of the second, third, and fourth low-temperature heat exchangers 702, 703, and 704.

[0047] The actual working process of this embodiment is as follows: After passing through the first cryogenic heat exchanger 701, the high-pressure hydrogen gas is divided into two paths by a splitting structure: one path enters the 15-hydrogen expander for expansion and cooling, forming deeply cooled cryogenic hydrogen gas, and its outlet precisely connects with the return hydrogen inlet of the third cryogenic heat exchanger 703; the other path enters the cooling channels of the second, third, and fourth cryogenic heat exchangers 702, 703, and 704 sequentially along the main path, completing a staged deep cooling process. The cryogenic hydrogen gas generated during expansion flows counter-clockwise along the heating channel of the third cryogenic heat exchanger 703 → second cryogenic heat exchanger 702 → first cryogenic heat exchanger 701, engaging in multiple stages of heat exchange with the high-pressure hydrogen gas to be liquefied in each cooling channel. This significantly improves the utilization rate of cold energy and the efficiency of the refrigeration cycle, providing core support for large-scale hydrogen liquefaction.

[0048] This design achieves the dual advantages of cold energy synergistic reuse and dual-product co-production by strengthening the deep process coupling of hydrogen liquefaction and slurry hydrogen preparation. The newly added third cryogenic heat exchanger 703 and fourth cryogenic heat exchanger 704 are both specifically designed with reserved heating channels for the flow of cryogenic hydrogen from the slurry hydrogen preparation module. This allows for the efficient recovery of the cold energy carried by the cryogenic hydrogen during slurry hydrogen preparation and its feedback to the hydrogen liquefaction process, providing additional cold source support for the hydrogen to be liquefied. This coupling design not only significantly improves the hydrogen liquefaction rate, ensuring a more complete conversion of raw material hydrogen into liquid hydrogen, but also achieves synergistic linkage between hydrogen liquefaction and slurry hydrogen preparation. Based on this coupling architecture, the system can efficiently complete large-scale hydrogen liquefaction while simultaneously producing slurry hydrogen products without the need for additional independent preparation equipment. This simplifies the process flow, reduces equipment investment, expands product range, and achieves large-scale integrated co-production of liquid hydrogen and slurry hydrogen, significantly improving the system's technical and economic efficiency and market adaptability.

[0049] like Figure 4 As shown, an upgraded and optimized embodiment of the present invention is provided: a third low-temperature heat exchanger 703 and a fourth low-temperature heat exchanger 704 are added after the second low-temperature heat exchanger 702. The third low-temperature heat exchanger 703 is configured with one cooling channel and two heating channels, while the fourth low-temperature heat exchanger 704 is configured with one cooling channel and three heating channels. One heating channel of the fourth low-temperature heat exchanger 704 is connected to the newly added helium refrigeration cycle, and the remaining heating channels are connected to the corresponding channels of the third low-temperature heat exchanger 703.

[0050] This embodiment adds a complete helium refrigeration cycle system. The core components include a 15-helium expander, a 1601-first helium heat exchanger, a 1602-second helium heat exchanger, and a 17-helium compressor. The closed-loop connection path is as follows: Cryogenic liquid helium is first introduced into the heating channel inlet of the fourth cryogenic heat exchanger 704, and the outlet of this channel connects to the heating channel inlet of the 1601-first helium heat exchanger; the heating channel outlet of the 1601-first helium heat exchanger connects to the heating channel inlet of the 1602-second helium heat exchanger, and so on. The outlet of the heating channel of the helium-2 heat exchanger is connected to the inlet of the helium compressor 17; the outlet of the helium compressor 17 is connected to the inlet of the cooling channel of the second helium heat exchanger 1602, and the outlet of the cooling channel of the second helium heat exchanger is connected to the inlet of the cooling channel of the liquid nitrogen pool 5; the outlet of the cooling channel of the liquid nitrogen pool is connected to the inlet of the cooling channel of the first helium heat exchanger 1601, and the outlet of the cooling channel of the first helium heat exchanger 1601 is connected to the inlet of the helium expander 15. Finally, the outlet of the helium expander is connected to the corresponding inlet of the fourth cryogenic heat exchanger 704, forming a complete helium refrigeration closed loop.

[0051] The working process of this embodiment is as follows: After the helium refrigeration cycle starts, the helium gas in the cycle first passes through the 1601-first helium heat exchanger and the 1602-second helium heat exchanger to exchange heat with the high-pressure helium gas and cool down. The resulting low-temperature atmospheric pressure helium gas is then pressurized into high-pressure helium gas by the 17-helium compressor. Subsequently, the high-pressure helium gas enters the 1602-second helium heat exchanger and the liquid nitrogen pool 5 for pre-cooling, and then passes through the 1601-first helium heat exchanger for further deep cooling. The cooled high-pressure helium gas enters the 15-helium expander and is converted into low-temperature liquid helium through expansion. The low-temperature liquid helium is introduced into the heating channel of the fourth low-temperature heat exchanger 704 and exchanges heat efficiently with the hydrogen gas to be liquefied in the cooling channel, which can significantly reduce the temperature of the hydrogen gas and ultimately achieve 100% liquefaction of the raw material hydrogen. It can also produce high-purity supercooled liquid hydrogen, further improving the system's liquefaction efficiency and product quality.

[0052] The supercooled liquid hydrogen produced by the system can be directly used as the core raw material for slurry hydrogen production. The extremely low temperature of the supercooled liquid hydrogen significantly reduces the energy consumption required for additional refrigeration during slurry hydrogen production, while simultaneously improving the production efficiency of solid hydrogen, thus optimizing energy consumption and product quality from the source. Furthermore, the low-temperature hydrogen recirculated during the slurry-air energy storage process can participate in the refrigeration cycle through the reserved channel of the newly added heat exchanger, forming a synergistic and complementary relationship with helium refrigeration, further enhancing the system's refrigeration capacity and providing support for the efficient linkage between hydrogen liquefaction and slurry hydrogen production.

[0053] Figure 5 , Figure 6 and Figure 7The performance improvement of slurry hydrogen with different solid contents is visually demonstrated, specifically covering three core performance indicators: density and density gain, cooling capacity, and evaporation rate. When liquid hydrogen is supercooled to the triple point, the density of triple point liquid hydrogen can increase by 8.74%, and the density of solid hydrogen can increase by approximately 22.1% compared to conventional liquid hydrogen. Driven by this density improvement effect, the density of slurry hydrogen increases synchronously with the increase of solid content, with a density gain range of 10.1% to 16.4%. This significant density improvement characteristic has strong practical conversion value, especially in the large-scale storage and transportation of hydrogen energy, particularly in long-distance vehicle-mounted and tank container transportation, where it can effectively increase the hydrogen energy loading per unit transportation volume and reduce the number of transportation vehicles and equipment investment.

[0054] Apparent cooling capacity per unit volume is defined as the sensible heat absorbed by a unit volume of cryogenic propellant when heated from a supercooled state to its standard boiling point. As shown in the figure, liquid hydrogen achieves a significant increase in sensible cooling capacity per unit volume through supercooling alone, reaching 4.06 MJ / m³; while the increase is even more pronounced for solid hydrogen, reaching as high as 9.6 MJ / m³. Furthermore, slurry hydrogen with different solid contents also exhibits excellent sensible cooling performance, with the corresponding sensible cooling capacity per unit volume increasing in a gradient from 4.56 MJ / m³ to 7.23 MJ / m³. Simultaneously, its high cooling capacity and high heat capacity make slurry hydrogen a high-efficiency cooling medium in industrial applications, further expanding the application boundaries of hydrogen energy.

[0055] Liquid hydrogen suffers from significant evaporation losses, particularly in intermittent use scenarios and vehicle-mounted transportation environments, due to its large temperature difference with room temperature and low latent heat of vaporization. While liquid hydrogen is well-suited for large-scale energy storage needs, its liquefaction energy consumption still requires optimization. In contrast, slurry hydrogen has a significantly lower daily evaporation rate, substantially reducing hydrogen loss during storage and transportation. This not only maintains the advantages of high-density storage but also further improves the economics of storage and transportation. Test data using a 300m³ liquid hydrogen tanker as the research subject shows that the initial daily evaporation rate was 0.23%. After using supercooled liquid hydrogen, the daily evaporation rate decreased to 0.19%, a reduction of approximately 16%. If slurry hydrogen is further used, the daily evaporation rate can be reduced from 0.19% to 0.17%, a reduction of approximately 20% to 30%. This advantage stems from the low evaporation characteristics of solid hydrogen, which has a daily evaporation rate of approximately 0.15%, a reduction of 33% compared to conventional liquid hydrogen. The low evaporation rate of slurry hydrogen during transportation not only significantly improves the safety of cryogenic hydrogen transportation by eliminating the need for frequent pressure release from storage tanks to balance internal pressure, but also further reduces hydrogen loss, enhancing the economy and reliability of storage and transportation.

[0056] In summary: During system operation, the hydrogen production module, driven by external energy, produces hydrogen through proton exchange membrane electrolysis. The resulting hydrogen is transported to the hydrogen liquefaction module, where it undergoes multi-stage cooling and liquefaction before being split into two outputs: one enters the liquid hydrogen storage and transportation module for storage and transfer, while the other is sent as raw material to the slurry hydrogen preparation module. The key innovation of this invention lies in achieving deep process coupling between the slurry hydrogen preparation module and the hydrogen liquefaction module. Specifically, the low-temperature hydrogen and its contained cold energy generated during the slurry hydrogen preparation process are re-transported to the corresponding heat exchange nodes in the hydrogen liquefaction module through an integrated heat exchange and reflux design. This coupling mechanism makes the slurry hydrogen preparation module essentially an integrated supplementary cold source for the hydrogen liquefaction module, significantly improving the liquefaction efficiency of the hydrogen liquefaction process, reducing raw material hydrogen loss, and effectively reducing the overall system energy consumption through efficient cold energy recovery and utilization. Finally, the slurry hydrogen produced by the slurry hydrogen preparation module is transported to the slurry hydrogen storage and transportation module for storage and transfer.

[0057] This invention achieves the simultaneous production of liquid hydrogen and slurry hydrogen through the above-mentioned integrated co-production design. The system takes into account high energy efficiency, low loss and operational reliability, and is suitable for a variety of application scenarios, including aerospace propulsion, large-scale energy storage and industrial cold energy.

[0058] The components and design principles of this invention are described below: The hydrogen production module employs proton exchange membrane electrolysis: the electrolyzer contains a proton exchange membrane that electrolyzes water into hydrogen and oxygen, with the generated hydrogen collected through pipelines. The module is equipped with an intelligent control system that can adjust the electrolysis current and voltage in real time based on parameters such as renewable energy power generation, hydrogen storage container pressure, and electrical load, ensuring hydrogen production efficiency and system operational stability. This method features high current density operation while also offering advantages such as low power consumption, high system integration, high gas purity, and ease of achieving high-pressure hydrogen production.

[0059] The hydrogen liquefaction module consists of a refrigeration unit, a heat exchanger, and an expansion valve, and is compatible with three process schemes: "Linde-Hampson pre-cooling throttling liquefaction cycle," "hydrogen expander liquefaction cycle," and "helium expansion refrigeration hydrogen liquefaction cycle." The appropriate scheme can be flexibly selected based on different industrial application scenarios and construction costs. The slurry hydrogen preparation module consists of a vacuum device, a heat exchanger, and a slurry hydrogen preparation storage tank. It uses a "freeze-pressurize-melt method" to prepare slurry hydrogen. The specific process is as follows: the vacuum port of the storage tank, in conjunction with a heating auxiliary unit, evacuates the slurry hydrogen preparation area inside the tank, reducing the pressure in the area below the hydrogen triple point pressure. After liquid hydrogen is transferred to this area and reaches the triple point condition, a solid hydrogen layer naturally forms on the liquid surface. Subsequently, the pressure in the preparation area is rapidly increased to above the triple point pressure, causing the solid hydrogen layer to melt and sink in contact with the inner wall of the tank. Through the stirring components built into the split-tower storage tank, the melted solid hydrogen particles are mixed with liquid hydrogen to form slurry hydrogen with the target solid-liquid ratio, which is finally transported to the slurry hydrogen storage and transportation module through the discharge port at the bottom of the storage tank. The hydrogen liquefaction module and the slurry hydrogen preparation module are coupled through a dual-pathway system: on the one hand, the hydrogen liquefaction module supplies liquid hydrogen raw materials to the slurry hydrogen preparation module; on the other hand, the hydrogen extracted during the slurry hydrogen preparation process is recycled back to the hydrogen liquefaction module after undergoing cold energy exchange through a heat exchanger. This not only fully utilizes the cold energy and improves the hydrogen liquefaction rate, but also significantly reduces the energy consumption of the hydrogen liquefaction process. At the same time, the heat exchanger can also serve as a heating auxiliary unit to increase the inlet temperature of the vacuum device and ensure the stability of equipment operation.

[0060] Meanwhile, in order to reduce the cost of hydrogen liquefaction and reduce reliance on large hydrogen expanders, a vacuum decompression method is used to lower the temperature of liquid hydrogen, and cold hydrogen is extracted as a deep precooling working fluid. The reflux precooling flow rate is actively increased, thereby reducing the energy consumption of hydrogen liquefaction.

[0061] The system is divided into a liquid hydrogen storage and transportation module and a slurry hydrogen storage and transportation module, both equipped with dedicated cryogenic storage tanks and transfer equipment. The liquid hydrogen storage and transportation module stores and transfers a portion of the products from the hydrogen liquefaction module, while the slurry hydrogen storage and transportation module receives the finished products from the slurry hydrogen preparation module. The system can simultaneously produce both liquid hydrogen and slurry hydrogen without switching process flows. The solid-liquid fraction of the slurry hydrogen can be flexibly adjusted simply by regulating the pressure and stirring parameters during the slurry hydrogen preparation process, precisely matching the product requirements of different application scenarios. Compared to traditional separate processes that output only one product, this system significantly improves the market adaptability and application flexibility of the product.

[0062] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0063] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A hydrogen liquefaction and slurry hydrogen co-production system, characterized in that, The system includes a hydrogen production unit (1), a liquid hydrogen storage tank (9), and a slurry hydrogen preparation storage tank (10). The bottom of the liquid hydrogen storage tank (9) is connected to the slurry hydrogen preparation storage tank (10). A hydrogen compressor (2) is connected to the hydrogen production unit (1). The top outlets of the slurry hydrogen preparation storage tank (10) and the liquid hydrogen storage tank (9) are sequentially connected to a heat exchange unit and a heating channel on a hydrogen precooling heat exchanger (4). A vacuum device (3) is connected to the heating channel of the hydrogen precooling heat exchanger (4) connected to the slurry hydrogen preparation storage tank (10). The heating channel on the hydrogen precooling heat exchanger (4) is connected to the inlet of the hydrogen compressor (2), and the outlet of the hydrogen compressor (2) is connected to the cooling channel of the hydrogen precooling heat exchanger (4). The cooling channel of the hydrogen precooling heat exchanger (4) is connected in sequence to the liquid nitrogen pool (5), the positive and negative hydrogen converter (6), the cooling channel of the heat exchange unit, and the throttle valve (8). The throttle valve is connected to the inlet of the liquid hydrogen storage tank (9) through a pipe. The bottom of the slurry hydrogen preparation storage tank (10) is connected to the slurry hydrogen storage tank (11).

2. The hydrogen liquefaction and slurry hydrogen co-production system according to claim 1, characterized in that, The liquid nitrogen pool (5) has a built-in cooling channel immersed in liquid nitrogen, while the nitrogen heat exchanger (13) is equipped with an independent heating channel and a cooling channel.

3. The hydrogen liquefaction and slurry hydrogen co-production system according to claim 1, characterized in that, The liquid nitrogen pool (5) is connected to the heating channel of the hydrogen precooling heat exchanger (4) and the heating channel of the nitrogen heat exchanger (13). The heating channels of the hydrogen precooling heat exchanger (4) and the nitrogen heat exchanger (13) are connected to the same nitrogen compressor (12). The nitrogen compressor (12) is connected to the cooling channel of the nitrogen heat exchanger (13). The cooling channel of the nitrogen heat exchanger (13) is connected to the inlet of the nitrogen throttle valve (14). The outlet of the nitrogen throttle valve (14) is connected to the liquid nitrogen pool (5).

4. The hydrogen liquefaction and slurry hydrogen co-production system according to claim 1, characterized in that, The top of the slurry hydrogen preparation storage tank (10) is provided with a vacuum port, and the bottom is provided with a slurry hydrogen outlet and a liquid hydrogen inlet. The slurry hydrogen outlet is connected to the inlet of the slurry hydrogen storage tank (11), and the liquid hydrogen inlet is connected to the liquid hydrogen outlet of the liquid hydrogen storage tank (9).

5. The hydrogen liquefaction and slurry hydrogen co-production system according to claim 1, characterized in that, The heat exchange unit includes a first low-temperature heat exchanger (701) and a second low-temperature heat exchanger (702) connected in sequence. The first low-temperature heat exchanger (701) and the second low-temperature heat exchanger (702) are each provided with one independent cooling channel and two heating channels.

6. The hydrogen liquefaction and slurry hydrogen co-production system according to claim 1, characterized in that, The heat exchange unit includes a first low-temperature heat exchanger (701), a second low-temperature heat exchanger (702), a third low-temperature heat exchanger (703), and a fourth low-temperature heat exchanger (704) connected in sequence. Each of the first low-temperature heat exchanger (701), the second low-temperature heat exchanger (702), the third low-temperature heat exchanger (703), and the fourth low-temperature heat exchanger (704) is provided with one independent cooling channel and two heating channels. The cooling channel outlet of the first low-temperature heat exchanger (701) is provided with a diversion structure, one channel is connected to a hydrogen expander (15), and the outlet of the hydrogen expander (15) is connected to the heating channel between the third low-temperature heat exchanger (703) and the fourth low-temperature heat exchanger (704). The other channel is connected to the cooling channel of the second low-temperature heat exchanger (702).

7. The hydrogen liquefaction and slurry hydrogen co-production system according to claim 1, characterized in that, The heat exchange unit includes a first low-temperature heat exchanger (701), a second low-temperature heat exchanger (702), a third low-temperature heat exchanger (703), and a fourth low-temperature heat exchanger (704) connected in sequence. The first low-temperature heat exchanger (701), the second low-temperature heat exchanger (702), and the third low-temperature heat exchanger (703) are each provided with one independent cooling channel and two heating channels. The fourth low-temperature heat exchanger (704) is provided with one cooling channel and three heating channels. A helium refrigeration cycle system is connected to one of the heating channels of the fourth low-temperature heat exchanger (704).

8. A hydrogen liquefaction and slurry hydrogen co-production system according to claim 7, characterized in that, The helium refrigeration cycle system includes a helium expander (15), a first helium heat exchanger (1601), a second helium heat exchanger (1602), and a helium compressor (17). The helium expander (15) is connected to the inlet of the heating channel of a fourth cryogenic heat exchanger (704). The outlet of the heating channel of the fourth cryogenic heat exchanger (704) is connected to the inlet of the heating channel of the first helium heat exchanger (1601). The outlet of the heating channel of the first helium heat exchanger (1601) is connected to the inlet of the heating channel of the second helium heat exchanger (1602). The heating channel outlet of the second helium heat exchanger (1602) is connected to the inlet of the helium compressor (17), the outlet of the helium compressor (17) is connected to the cooling channel inlet of the second helium heat exchanger (1602), the cooling channel outlet of the second helium heat exchanger (1602) is connected to the cooling channel inlet of the liquid nitrogen pool (5), the cooling channel outlet of the liquid nitrogen pool (5) is connected to the cooling channel inlet of the first helium heat exchanger (1601), and the cooling channel outlet of the first helium heat exchanger (1601) is connected to the inlet of the helium expander (15).

9. A hydrogen liquefaction and slurry hydrogen co-production system according to claim 1, characterized in that, The liquid hydrogen storage tank (9) is connected to a liquid hydrogen storage and transportation module, and the slurry hydrogen storage tank (11) is connected to a slurry hydrogen storage and transportation module.

10. A method for hydrogen liquefaction and slurry hydrogen co-production, characterized in that, A hydrogen liquefaction and slurry hydrogen co-production system according to any one of claims 1-9 includes: Liquid hydrogen in liquid hydrogen storage tank (9) is transported to slurry hydrogen preparation storage tank (10) through bottom outlet. Vacuum device (3) is activated to perform vacuuming operation on slurry hydrogen preparation storage tank (10) to reduce the pressure inside the tank to below the triple point pressure of hydrogen. During the vacuuming process, the low-temperature hydrogen gas extracted passes through the heating channel of heat exchange unit and hydrogen precooling heat exchanger (4), and merges with the hydrogen generated by hydrogen production device (1). After being compressed into high-pressure hydrogen by hydrogen compressor (2), the high-pressure hydrogen gas first enters the cooling channel of hydrogen precooling heat exchanger (4). Heat exchange is carried out through heat exchange unit to achieve precooling of high-pressure hydrogen gas in cooling channel. After precooling High-pressure hydrogen enters the cooling channel of the liquid nitrogen pool (5) for secondary cooling, and then enters the cooling channel of the secondary heat exchange unit for heat exchange, further recovering cold energy and cooling the high-pressure hydrogen. After being cooled again, the high-pressure hydrogen enters the throttle valve (8), and after throttling and depressurization, it is converted into liquid hydrogen. The liquid hydrogen is stored in the liquid hydrogen storage tank (9). The hydrogen that is not completely liquefied, as well as the low-temperature hydrogen generated during the preparation of slurry hydrogen, enter the hydrogen precooling heat exchanger (4) and the heating channel of the heat exchange unit through the reflux device to participate in cold energy recovery, and finally flow into the inlet of the hydrogen compressor (2) to participate in the compression and liquefaction process again.

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