Liquid hydrogen solidification device and method

Abstract

The application discloses a liquid hydrogen solid-void preparation and testing device and a method thereof, and can realize solid-void preparation process visualization and component measurement function under the condition of liquid hydrogen medium immersion, and strengthens the understanding of liquid hydrogen solid-void. The application sets a cold insulation container and a preparation container from top to bottom in the visual liquid hydrogen Dewar, greatly improves the heat insulation performance of the preparation container, and effectively avoids the influence of the conventional liquid hydrogen evacuation method on the solid-void form. Meanwhile, the application adjusts the oxygen and nitrogen concentration in the simulation gas, realizes solid-void preparation and testing under various initial conditions, and has the function diversification characteristic.

Description

Technical Field

[0001] This invention relates to the field of liquid hydrogen safety, and in particular to a liquid hydrogen solid-air preparation and testing apparatus and method. Background Technology

[0002] Liquid hydrogen boasts advantages such as high hydrogen storage density, high transportation efficiency, and low storage and transportation pressure, making it an ideal form for large-scale hydrogen energy storage and transportation. Early hydrogen liquefaction plants had low capacity, but with the implementation of hydrogen energy strategies, the hydrogen liquefaction industry has entered a phase of rapid development. Liquefied hydrogen sources contain trace amounts of oxygen (greater than 1×10⁻⁶). -8 When air diffuses into the hydrogen liquefaction and storage facilities, solid air is formed. When solid air accumulates to a certain proportion, there is a risk of explosion even under the stimulation of weak energy. Several solid air explosion accidents have already occurred.

[0003] Solid-air purging is a widespread problem in hydrogen energy utilization, requiring periodic reheating to eliminate safety hazards. However, currently, only relatively stringent national military or aerospace standards can be referenced. For example, the aerospace standard QJ 3271, "Safety Regulations for the Production of Liquid Hydrogen for Hydrogen-Oxygen Engine Testing," stipulates that liquid hydrogen containers should be heated and purged after three months of continuous production (mainly for liquid hydrogen receiving containers); the national military standard GJB-2645, "Requirements for Packaging, Storage, and Transportation of Liquid Hydrogen," stipulates that liquid hydrogen storage tanks should be periodically heated to remove accumulated solid volatile impurities. However, frequent reheating has drawbacks such as long processing time and significant cooling loss, hindering the large-scale promotion of liquid hydrogen. Due to the special properties of liquid hydrogen and the dangers of solid-air purging, most research institutions are not yet qualified to conduct liquid hydrogen solid-air experiments, and there is a limited amount of reference material available for such experiments. Summary of the Invention

[0004] The purpose of this invention is to provide a liquid hydrogen solid-space preparation and testing apparatus and method, which realizes the objectives of solid-space preparation, growth process visualization and solid-space component measurement in a real liquid hydrogen medium.

[0005] The present invention intends to achieve its objective by adopting the following technical solution:

[0006] In a first aspect, the present invention provides a liquid hydrogen solid-air preparation and testing apparatus, which includes a visualization liquid hydrogen Dewar, a simulated gas pipeline, an oxygen pipeline, a nitrogen pipeline, a helium pipeline, a metering pipeline, a first liquid hydrogen venting pipeline, a liquid hydrogen filling pipeline, a first filling branch, a second filling branch, and a second liquid hydrogen venting pipeline.

[0007] The wall of the visualization liquid hydrogen Dewar consists of an inner and outer wall, forming a double-layer vacuum insulation structure. The upper and lower parts of the inner cavity of the visualization liquid hydrogen Dewar are respectively equipped with a cold-insulating container and a preparation container. The preparation container is surrounded by a liquid hydrogen cold screen formed by a metal coil, with both the inlet and outlet of the metal coil located inside the cold-insulating container. A support is installed inside the preparation container, with a gradient magnetic field component mounted on its upper part. A heating module is located at the bottom of the preparation container to heat it and sublimate the solid-void deposited on the support. A visualization window is located on the wall of the visualization liquid hydrogen Dewar at the height of the simulated gas pipeline outlet, allowing observation of the solid-void formation process on the support and gradient magnetic field component.

[0008] The oxygen pipeline is connected in sequence to the high-pressure oxygen cylinder, the oxygen regulating valve, and the mixer; the nitrogen pipeline is connected in sequence to the high-pressure nitrogen cylinder, the nitrogen regulating valve, and the mixer; the simulated gas pipeline is connected in sequence to the mixer and the simulated gas regulating valve, then passes through the cold storage container and enters the preparation container. The simulated gas pipeline is located in the outer sleeve of the visualized liquid hydrogen Dewar cavity, and its outlet end extends out of the sleeve and is located directly above the support and the gradient magnetic field component.

[0009] After the helium pipeline is connected to the high-pressure helium cylinder and the helium regulating valve in sequence, it is divided into two branches. The end of the first helium branch is connected to the sleeve and used to introduce helium into the sleeve as a protective gas to prevent ice blockage inside the simulated gas pipeline. The second helium branch passes through the cold insulation container in a heat-exchangeable form and then connects to the preparation container. It is used to input helium into the preparation container as a pressurizing gas when the liquid hydrogen medium is emptied.

[0010] One end of the measuring pipeline is connected to the preparation container, and the other end passes through the cold storage container and is connected in sequence to the measuring control valve and the gas composition analysis device located outside the visualization liquid hydrogen Dewar. The sublimation gas of liquid hydrogen solid air enters the gas composition analysis device through the measuring pipeline.

[0011] One end of the first liquid hydrogen venting pipeline is connected to the cold storage container, and the other end extends out of the visible liquid hydrogen Dewar and is connected to the first liquid hydrogen venting valve, which is used to vent the hydrogen gas generated in the cold storage container.

[0012] The liquid hydrogen filling pipeline is connected to a liquid hydrogen tank at the front end and divided into a first filling branch and a second filling branch at the rear end. The first filling branch is connected to the first liquid hydrogen filling valve and the preparation container in sequence, and the second filling branch is connected to the second liquid hydrogen filling valve and the cold storage container in sequence. The two filling branches are used to fill the preparation container and the cold storage container with liquid hydrogen, respectively. The first filling branch outside the liquid hydrogen visualization dewar is connected to the second liquid hydrogen venting pipeline, which is equipped with a second liquid hydrogen venting valve to vent the liquid hydrogen inside the preparation container after the solid-air preparation is completed.

[0013] As a preferred embodiment of the first aspect, the visualization dewar has two visualization windows arranged at 180° opposite each other on the outer wall and at the same height as the gradient magnetic field component; the light source illuminates the gradient magnetic field component below the simulated gas pipeline through the visualization windows on both sides.

[0014] As a preferred embodiment of the first aspect above, the visualization window uses sapphire glass as an endoscope that is in direct contact with the liquid hydrogen medium and quartz glass as an exoscope.

[0015] As a preferred embodiment of the first aspect mentioned above, the second helium branch passing through the cold storage container adopts the form of a heat exchange coil.

[0016] As a preferred embodiment of the first aspect, the liquid hydrogen tank is refilled with liquid hydrogen through a self-pressurization method, and the liquid hydrogen refilling pipeline, the first refilling branch, and the second refilling branch all use vacuum insulated pipes.

[0017] As a preferred embodiment of the first aspect mentioned above, the metal coil is filled with a secondary positive hydrogen catalyst.

[0018] As a preferred embodiment of the first aspect mentioned above, it also includes a temperature controller, a controller, and a high-speed camera. The temperature controller, the controller, and the high-speed camera are respectively connected to the controller via signal lines. The heating module is connected to the temperature controller. The controller controls the power of the heating module through the temperature controller. The controller acquires image information of the solid-state growth process through the high-speed camera.

[0019] As a preferred embodiment of the first aspect above, the gas composition analysis device is a gas chromatograph used to measure oxygen and nitrogen distribution data in solid space.

[0020] As a preferred embodiment of the first aspect described above, the gradient magnetic field component (36) is a permanent magnet used to form a gradient magnetic field.

[0021] In a second aspect, the present invention provides a method for preparing and testing liquid hydrogen in solid air using any of the apparatus described in the first aspect above, comprising the following steps:

[0022] S1. Liquid Hydrogen Filling: Open the first liquid hydrogen vent valve, the measurement control valve, the first liquid hydrogen filling valve, and the second liquid hydrogen filling valve. The liquid hydrogen medium in the liquid hydrogen tank enters the preparation container and the cold storage container sequentially through the liquid hydrogen filling pipeline, the first filling branch, and the second filling branch. The hydrogen gas generated during the filling process of the cold storage container is discharged through the first liquid hydrogen vent pipeline, and the hydrogen gas generated during the filling process of the preparation container is discharged through the measurement pipeline. The liquid hydrogen in the cold storage container needs to be filled to exceed the inlet of the metal coil so that the liquid hydrogen in the cold storage container fills the metal coil and thus cools the preparation container. After the filling is completed, close the first liquid hydrogen filling valve and the second liquid hydrogen filling valve.

[0023] S2. Simulated gas delivery: Open the helium regulating valve to allow the helium medium in the high-pressure helium cylinder to enter the sleeve for cryogenic protection of the simulated gas, and then close the helium regulating valve; open the oxygen regulating valve and the nitrogen regulating valve to allow the gas in the high-pressure oxygen cylinder and the high-pressure nitrogen cylinder to enter the mixer in a preset ratio for thorough mixing, and then open the simulated gas regulating valve to allow the simulated gas to enter the preparation container in the visualized liquid hydrogen Dewar through the simulated gas pipeline.

[0024] S3. Solid preparation: While opening the simulated gas regulating valve, the controller, high-speed camera and light source are started. The simulated gas from the simulated gas pipeline forms a solid with a specific oxygen and nitrogen distribution under the action of the gradient magnetic field component in the preparation container, and is deposited on the support under the action of gravity. The high-speed camera collects image information of the solid growth process and stores it in the controller.

[0025] S4. Liquid Hydrogen Evaporation: After completing solid-air preparation and image information acquisition, close the oxygen regulating valve, nitrogen regulating valve, simulated gas regulating valve, and measurement control valve. Open the helium regulating valve and the second liquid hydrogen evaporation valve. Helium from the high-pressure helium cylinder enters the visualization liquid hydrogen Dewar through the helium pipeline. First, it fully exchanges heat with the liquid hydrogen medium inside the cold-insulating container, cooling the helium temperature from room temperature to the liquid hydrogen temperature range of 20K. Then, it enters the preparation container for pressurization. The liquid hydrogen soaked in solid-air in the preparation container is evaporated through the second liquid hydrogen evaporation pipeline. After the liquid hydrogen evaporation is completed, close the helium regulating valve and the second liquid hydrogen evaporation valve.

[0026] S5. Solid-air oxygen and nitrogen analysis: The pressure inside the preparation container is controlled below the triple point pressure of the oxygen and nitrogen medium. The power of the heating module is controlled by a temperature controller, and the temperature inside the preparation container begins to rise. The solid air on the support gradually sublimates. The measurement control valve is opened, and the sublimated solid air gas enters the gas chromatograph through the measurement pipeline to obtain real-time oxygen and nitrogen concentration data until all the solid air has sublimated. After the analysis is completed, the power to the heating module is cut off by the temperature controller, and the measurement control valve is closed. After the liquid hydrogen medium in the cold-insulating container has completely vaporized and emptied, the first liquid hydrogen venting valve is closed to complete the test.

[0027] The significant and beneficial technical effects of this invention compared to existing technologies are: it enables the visualization and component measurement of the solid-air preparation process under liquid hydrogen immersion conditions, enhancing the understanding of liquid hydrogen solid-air composition. The visualized liquid hydrogen Dewar features a top-to-bottom arrangement of a cooling container and a preparation container, significantly improving the insulation performance of the preparation container and effectively avoiding the influence of conventional liquid hydrogen venting methods on the solid-air morphology. By adjusting the oxygen and nitrogen concentrations in the simulated gas, solid-air preparation and testing under various initial conditions can be achieved, demonstrating its versatility.

[0028] The following will further explain the concept, specific structure and technical effects of the present invention with reference to the accompanying drawings, so as to fully understand the purpose, features and effects of the present invention. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a liquid hydrogen solid-air preparation and testing device according to the present invention.

[0030] The attached diagram is labeled as follows: Simulated gas line 1, Oxygen line 2, Nitrogen line 3, Mixer 4, Oxygen regulating valve 5, Nitrogen regulating valve 6, High-pressure oxygen cylinder 7, High-pressure nitrogen cylinder 8, Simulated gas regulating valve 9, Tubing 10, Helium line 11, Helium regulating valve 12, High-pressure helium cylinder 13, Measuring line 14, Measuring control valve 15, Gas chromatograph 16, First liquid hydrogen vent line 17, First liquid hydrogen vent valve 18, Liquid hydrogen filling line 19, First filling branch 20, ... 21. Second liquid hydrogen filling branch line; 22. Second liquid hydrogen venting line; 23. Liquid hydrogen tank; 24. First liquid hydrogen filling valve; 25. Second liquid hydrogen venting valve; 26. Second liquid hydrogen filling valve; 27. Signal line; 28. Temperature controller; 29. ​​Controller; 30. High-speed camera; 31. Dewar outer wall; 32. Visualization window; 33. Dewar inner wall; 34. Support; 35. Heating module; 36. Gradient magnetic field component; 37. Metal coil; 38. Preparation container; 39. Cold storage container; 40. Visualization liquid hydrogen Dewar; 41. Light source. Detailed Implementation

[0031] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. Technical features in the various embodiments of the present invention can be combined accordingly without mutual conflict.

[0032] In the description of this invention, it should be understood that when an element is considered to be "connected" to another element, it can be a direct connection to the other element or an indirect connection, i.e., there is an intermediate element. Conversely, when an element is said to be "directly" connected to another element, there is no intermediate element.

[0033] In the description of this invention, it should be understood that the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0034] See Figure 1In a preferred embodiment of the present invention, a liquid hydrogen solid-air preparation and testing apparatus is provided. The apparatus comprises a simulated gas pipeline 1, an oxygen pipeline 2, a nitrogen pipeline 3, a mixer 4, an oxygen regulating valve 5, a nitrogen regulating valve 6, a high-pressure oxygen cylinder 7, a high-pressure nitrogen cylinder 8, a simulated gas regulating valve 9, a sleeve 10, a helium pipeline 11, a helium regulating valve 12, a high-pressure helium cylinder 13, a measuring pipeline 14, a measuring control valve 15, a gas chromatograph 16, a first liquid hydrogen venting pipeline 17, a first liquid hydrogen venting valve 18, and liquid hydrogen... The apparatus comprises: a filling pipeline 19, a first filling branch 20, a second filling branch 21, a second liquid hydrogen venting pipeline 22, a liquid hydrogen tank 23, a first liquid hydrogen filling valve 24, a second liquid hydrogen venting valve 25, a second liquid hydrogen filling valve 26, a signal line 27, a temperature controller 28, a controller 29, a high-speed camera 30, the outer wall of the Dewar 31, a visualization window 32, the inner wall of the Dewar 33, a support 34, a heating module 35, a gradient magnetic field component 36, a metal coil 37, a preparation container 38, a cold storage container 39, a visualization liquid hydrogen Dewar 40, and a light source 41. The following is a detailed description of the interrelationships between the components of this apparatus.

[0035] The visualized liquid hydrogen Dewar 40 employs a double-layer vacuum insulation structure, consisting of an inner wall 33 and an outer wall 31, with a vacuum layer between them for efficient insulation. The visualized liquid hydrogen Dewar 40 is entirely sealed and insulated, with its top cover serving as the installation and passage point for various pipelines. From top to bottom, the inner cavity of the visualized liquid hydrogen Dewar 40 houses a cold insulation container 39 and a preparation container 38. The preparation container 38 is surrounded by a liquid hydrogen cold shield composed of metal coils 37. The metal coils 37 must cover the entire height of the preparation container 38 vertically and also cover its bottom to ensure effective insulation. The inlet and outlet of the metal coils 37 are located inside the cold insulation container 39. When liquid hydrogen is added to the cold insulation container 39 above the inlet height, it gradually enters the metal coils 37 until they are completely filled.

[0036] In an embodiment of the present invention, the interior of the metal coil 37 may also be partially filled with a secondary positive hydrogen catalyst to improve the thermal insulation performance of the preparation container.

[0037] The preparation container 38 has a support 34 located below the outlet of the simulated gas pipeline 1, and a gradient magnetic field component 36 and other devices for regulating the distribution of oxygen and nitrogen in the solidified air are installed on its upper part. A heating module 35 is located at the bottom of the preparation container 38 to heat the solidified air in the preparation container 38 during the component measurement stage, causing the solidified air deposited on the support 34 to sublimate. Furthermore, a visualization window 32 is located on the wall of the visualization liquid hydrogen Dewar 40 at the height of the outlet of the simulated gas pipeline 1, allowing for the acquisition of image information of the solidified air formation process on the gradient magnetic field component 36 from the outside.

[0038] In an embodiment of the invention, two visualization windows 32 are provided on the liquid hydrogen visualization Dewar 40, arranged 180° opposite each other on the outer wall and at the same height as the gradient magnetic field component 36. Light sources 41 can be installed at either of the visualization windows 32, and the light sources 41 illuminate the gradient magnetic field component 36 below the simulated gas pipeline 1 through the visualization windows 32. This opposing illumination method improves image clarity. The visualization window 21 preferably uses sapphire glass as the endoscope that directly contacts the liquid hydrogen medium and quartz glass as the exoscope.

[0039] The oxygen pipeline 2 is connected in sequence to the high-pressure oxygen cylinder 7, the oxygen regulating valve 5, and the mixer 4. The high-pressure oxygen in the high-pressure oxygen cylinder 7 can be injected into the mixer 4 through the oxygen pipeline 2. The oxygen regulating valve 5 can control the opening and closing of the oxygen pipeline 2 and the flow rate by adjusting the opening degree.

[0040] Nitrogen pipeline 3 is connected in sequence to high-pressure nitrogen cylinder 8, nitrogen regulating valve 6, and mixer 4. High-pressure oxygen in high-pressure nitrogen cylinder 8 can be injected into mixer 4 through nitrogen pipeline 3. Nitrogen regulating valve 6 can control the opening and closing and flow rate of nitrogen pipeline 3 by adjusting the opening degree.

[0041] Simulated gas pipeline 1 is sequentially connected to mixer 4, simulated gas regulating valve 9, passes through cold storage container 39, and enters preparation container 38. Oxygen and nitrogen in mixer 4 are thoroughly mixed to form simulated gas, which can be injected into preparation container 38 through simulated gas pipeline 1 to simulate solidification. Simulated gas regulating valve 9 can control the on / off state and flow rate of simulated gas pipeline 1 by adjusting its opening degree. The section of simulated gas pipeline 1 inside cold storage container 39 will have heat exchange contact with the interior of cold storage container 39. Since cold storage container 39 stores low-temperature liquid hydrogen, simulated gas may condense and cause ice blockage when passing through cold storage container 39. Therefore, a sleeve 10 needs to be installed on the simulated gas pipeline 1 outside the visualized liquid hydrogen Dewar 40 section. Helium is injected into the sleeve 10 as a protective gas to prevent direct heat exchange contact between simulated gas pipeline 1 and the liquid hydrogen inside cold storage container 39, thereby preventing simulated gas condensation and ice blockage. The outlet end of the simulated gas pipeline 1 extends out of the sleeve 10 and is located directly above the support 34 and the gradient magnetic field component 36. The simulated gas discharged from the outlet end will form solid space under the action of the gradient magnetic field and liquid hydrogen.

[0042] After the helium pipeline 11 is connected to the high-pressure helium cylinder 13 and the helium regulating valve 12 in sequence, it splits into two branches. The end of the first helium branch is connected to the sleeve 10 and used to introduce helium into the sleeve 10 as a protective gas to prevent ice blockage inside the simulated gas pipeline 1. The second helium branch passes through the cold insulation container 39 in a heat-exchangeable form and then connects to the preparation container 38. It is used to input helium into the preparation container 38 as a pressurizing gas when the liquid hydrogen medium is emptied.

[0043] In an embodiment of the present invention, the second helium branch in the cold storage container 39 may be in the form of a heat exchange coil to improve the heat exchange and cooling effect between helium and liquid hydrogen medium.

[0044] One end of the measuring pipeline 14 is connected to the preparation container 38, and the other end passes through the cold storage container 39 and is sequentially connected to the measuring control valve 15 located outside the visualization liquid hydrogen Dewar 40 and the gas composition analysis device. The sublimation gas of liquid hydrogen solid air enters the gas composition analysis device through the measuring pipeline 14. In an embodiment of the present invention, the gas composition analysis device can be implemented using a gas chromatograph 16. The sublimation gas of liquid hydrogen solid air enters the gas chromatograph 16 through the measuring pipeline 14 to measure the oxygen and nitrogen distribution data of the solid air.

[0045] One end of the first liquid hydrogen venting pipeline 17 is connected to the cold storage container 39, and the other end extends out of the visible liquid hydrogen Dewar 40 and is connected to the first liquid hydrogen venting valve 18, which is used to vent the hydrogen generated by the cold storage container 39.

[0046] The liquid hydrogen filling pipeline 19 is connected to the liquid hydrogen tank 23 at its front end and splits into a first filling branch 20 and a second filling branch 21 at its rear end. The first filling branch 20 is connected to the first liquid hydrogen filling valve 24 and the preparation container 38 in sequence, realizing the filling of liquid hydrogen into the preparation container 38. The second filling branch 21 is connected to the second liquid hydrogen filling valve 26 and the cold insulation container 39 in sequence, realizing the filling of liquid hydrogen into the cold insulation container 39. Thus, the two filling branches can respectively fill the preparation container 38 and the cold insulation container 39 with the first liquid hydrogen filling valve 24 and the second liquid hydrogen filling valve 26 open. The first filling branch 20 outside the visible liquid hydrogen Dewar 40 is connected to the second liquid hydrogen venting pipeline 22, which is equipped with a second liquid hydrogen venting valve 25. After the solid-air preparation is completed, the second liquid hydrogen venting valve 25 is opened to vent the liquid hydrogen inside the preparation container 38.

[0047] In embodiments of the present invention, the liquid hydrogen tank 23 can be used to fill the preparation container 38 and the cold storage container 39 with liquid hydrogen through self-pressurization or other means. In addition, in order to reduce heat exchange with the environment during the liquid hydrogen filling process, the liquid hydrogen filling pipeline 19, the first filling branch 20 and the second filling branch 21 are all made of vacuum insulated pipes to reduce the liquid hydrogen filling loss rate.

[0048] In addition, in order to achieve automatic control, the above-mentioned device in the embodiment of the present invention further includes a temperature controller 28, a controller 29 and a high-speed camera 30. The temperature controller 28, the controller 29 and the high-speed camera 30 are respectively connected to the controller 29 through a signal line 27. The heating module 35 is connected to the temperature controller 28. The controller 29 controls the power of the heating module 35 through the temperature controller 28. The controller 29 collects image information of the solid-state growth process through the high-speed camera 30.

[0049] Additionally, it should be noted that the high-pressure oxygen cylinder, high-pressure nitrogen cylinder, and high-pressure helium cylinder in this invention can be replaced by other forms of high-pressure gas sources.

[0050] Additionally, it should be noted that all electrical equipment in the liquid hydrogen solid-air preparation and testing apparatus of this invention must be explosion-proof. A nitrogen fire suppression system must be installed at the experimental site and linked to the hydrogen concentration monitoring host. Nitrogen should be used to dilute the hydrogen when necessary. Furthermore, before the experiment, it is best to replace all pipes and chambers inside the liquid hydrogen solid-air preparation and testing apparatus with helium or nitrogen to avoid residual air or other gases.

[0051] Furthermore, in another embodiment of the present invention, the above-described... Figure 1 The apparatus shown also provides a method for preparing and testing liquid hydrogen in solid air. The specific steps of this method are as follows (note that all valves in the apparatus are initially closed):

[0052] (1) Liquid hydrogen filling: Open the first liquid hydrogen vent valve 18, the measuring control valve 15, the first liquid hydrogen filling valve 24, and the second liquid hydrogen filling valve 26. The liquid hydrogen medium in the liquid hydrogen tank 23 enters the preparation container 38 and the cold storage container 39 sequentially through the liquid hydrogen filling pipeline 19, the first filling branch 20, and the second filling branch 21. The hydrogen gas generated during the filling process of the cold storage container 39 is discharged through the first liquid hydrogen vent pipeline 17, and the hydrogen gas generated during the filling process of the preparation container 38 is discharged through the measuring pipeline 14. The liquid hydrogen in the cold storage container 39 needs to be filled to the specified liquid level and then the filling should be stopped. The filling height needs to exceed the inlet of the metal coil 37 by a certain height so that the liquid hydrogen in the cold storage container 39 can enter and fill the metal coil 37 to cool the preparation container 38. At the same time, a reserve of liquid hydrogen vaporization capacity needs to be reserved. After the filling is completed, close the first liquid hydrogen filling valve 24 and the second liquid hydrogen filling valve 26.

[0053] (2) Simulated gas delivery: Open the helium regulating valve 12 to allow the helium medium in the high-pressure helium cylinder 13 to enter the sleeve 10 for cryogenic protection of the simulated gas, and then close the helium regulating valve 12. Then open the oxygen regulating valve 5 and the nitrogen regulating valve 6 to allow the gases in the high-pressure oxygen cylinder 7 and the high-pressure nitrogen cylinder 8 to enter the mixer 4 in the preset ratio required for the experiment for thorough mixing to form simulated gas. Then open the simulated gas regulating valve 9 to allow the simulated gas to enter the preparation container 38 in the visualized liquid hydrogen Dewar 40 through the simulated gas pipeline 1.

[0054] (3) Solid preparation: While opening the simulated gas regulating valve 9, start the controller 29, high-speed camera 30 and light source 41. The simulated gas from the simulated gas pipeline 1 forms a solid with a specific oxygen and nitrogen distribution under the action of the gradient magnetic field component 36 in the preparation container 38, and is deposited on the support 34 under the action of gravity. The high-speed camera 30 collects image information of the solid growth process and stores it in the controller 29.

[0055] (4) Liquid hydrogen venting: After completing solid-air preparation and image information acquisition, close oxygen regulating valve 5, nitrogen regulating valve 6, simulated gas regulating valve 9, and measurement control valve 15. Open helium regulating valve 12 and the second liquid hydrogen venting valve 25. Helium from high-pressure helium cylinder 13 enters the visualization liquid hydrogen Dewar 40 through helium pipeline 11. First, it fully exchanges heat with the liquid hydrogen medium inside the cold-insulating container 39, cooling the helium temperature from room temperature to the liquid hydrogen temperature range of 20K. Then, it enters the preparation container 38 for pressurization, and the liquid hydrogen soaked in the solid-air in preparation container 38 is vented through the second liquid hydrogen venting pipeline 22. Since the temperature of the cooled helium is much lower than the triple point temperature of oxygen and nitrogen, the solid-air state during the liquid hydrogen venting process will not be affected. After the liquid hydrogen venting is completed, close helium regulating valve 12 and the second liquid hydrogen venting valve 25.

[0056] (5) Solid-air oxygen and nitrogen analysis: The pressure inside the preparation container 38 is controlled below the triple point pressure of the oxygen and nitrogen medium. The power of the heating module 35 is controlled by the temperature controller 28, and the temperature inside the preparation container 38 begins to rise. The solid air on the support 34 gradually sublimates. The measurement control valve 15 is opened, and the sublimated solid air gas enters the gas chromatograph 16 through the measurement pipeline 14 to obtain real-time oxygen and nitrogen concentration data until all the solid air has sublimated. After the analysis is completed, the power supply to the heating module 35 is cut off by the temperature controller 28, and the measurement control valve 15 is closed. After the liquid hydrogen medium in the cold-keeping container 39 has completely vaporized and emptied, the first liquid hydrogen venting valve 18 is closed, the test is completed, and the experiment ends.

[0057] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A liquid hydrogen solidification and testing apparatus, comprising: The visualization liquid hydrogen Dewar (40), the simulation gas pipeline (1), the oxygen pipeline (2), the nitrogen pipeline (3), the helium pipeline (11), the measuring pipeline (14), the first liquid hydrogen evacuation pipeline (17), the liquid hydrogen filling pipeline (19), the first filling branch (20), the second filling branch (21) and the second liquid hydrogen evacuation pipeline (22) are included. The wall of the visualization liquid hydrogen Dewar (40) is composed of the Dewar inner wall (33) and the Dewar outer wall (31), which is a double-layer vacuum insulation structure; the upper and lower parts of the inner cavity of the visualization liquid hydrogen Dewar (40) are respectively provided with a cold insulation container (39) and a preparation container (38), the outside of the preparation container (38) is provided with a liquid hydrogen cold shield formed by a surrounding metal coil pipe (37), and the inlet and outlet of the metal coil pipe (37) are both arranged in the cold insulation container (39); the inside of the preparation container (38) is provided with a support (34), and the upper part of the support (34) is provided with a gradient magnetic field component (36); the outer bottom of the preparation container (38) is provided with a heating module (35) for heating the preparation container (38) to make the solid air deposited on the support (34) sublimate; the wall of the visualization liquid hydrogen Dewar (40) is provided with a visualization window (32) at the height of the outlet of the simulation gas pipeline (1) for observing the solid air formation process on the support (34) and the gradient magnetic field component (36); The oxygen pipeline (2) is sequentially connected with a high-pressure oxygen cylinder (7), an oxygen regulating valve (5) and a mixer (4), and the nitrogen pipeline (3) is sequentially connected with a high-pressure nitrogen cylinder (8), a nitrogen regulating valve (6) and the mixer (4); the simulation gas pipeline (1) is sequentially connected with the mixer (4) and a simulation gas regulating valve (9) and then passes through the cold insulation container (39) to be connected into the preparation container (38), and the part of the simulation gas pipeline (1) in the inner cavity of the visualization liquid hydrogen Dewar (40) is sleeved with a sleeve pipe (10), the outlet end of the simulation gas pipeline (1) extends out of the sleeve pipe (10) and is located directly above the support (34) and the gradient magnetic field component (36); the simulation gas from the simulation gas pipeline (1) forms solid air with a specific oxygen-nitrogen distribution under the action of the gradient magnetic field component (36) in the preparation container (38) and is deposited on the support (34) under the action of gravity; The helium pipeline (11) is sequentially connected with a high-pressure helium cylinder (13) and a helium regulating valve (12) and then is divided into two branches, the first helium branch is connected into the sleeve pipe (10) and is used for introducing helium into the sleeve pipe (10) as a protection gas to prevent ice blockage in the simulation gas pipeline (1), and the second helium branch passes through the cold insulation container (39) in a heat exchangeable form and then is connected into the preparation container (38) to input helium into the preparation container (38) as a pressurizing gas when the liquid hydrogen medium is evacuated; The measuring pipeline (14) is connected at one end with the preparation container (38) and at the other end with a measuring control valve (15) and a gas composition analysis device which are located outside the visualization liquid hydrogen Dewar (40) in sequence after passing through the cold insulation container (39), and the sublimation gas of the liquid hydrogen solid air enters the gas composition analysis device through the measuring pipeline (14); The first liquid hydrogen evacuation pipeline (17) has one end connected to the cold insulation container (39) and the other end extending out of the back of the visual liquid hydrogen Dewar (40) to be connected to the first liquid hydrogen evacuation valve (18), for evacuating hydrogen generated by the cold insulation container (39); The liquid hydrogen filling pipeline (19) has a front end connected to the liquid hydrogen tank (23) and a rear end divided into a first filling branch (20) and a second filling branch (21), wherein the first filling branch (20) is connected to the first liquid hydrogen filling valve (24) and the preparation container (38) in sequence, and the second filling branch (21) is connected to the second liquid hydrogen filling valve (26) and the cold insulation container (39) in sequence, and the two filling branches are respectively used for liquid hydrogen filling of the preparation container (38) and the cold insulation container (39); The first filling branch (20) outside the visual liquid hydrogen Dewar (40) is connected with the second liquid hydrogen evacuation pipeline (22), and the second liquid hydrogen evacuation valve (25) is installed thereon, for evacuating the liquid hydrogen in the preparation container (38) after the solid-void preparation is completed.

2. The apparatus of claim 1, wherein The visual window (32) provided on the visual liquid hydrogen Dewar (40) has two, which are arranged in opposition at 180° on the outer wall and are at the same height as the gradient magnetic field member (36); The light source (41) oppositely illuminates the gradient magnetic field member (36) below the simulation air pipe (1) through the two visual windows (32).

3. The apparatus of claim 1, wherein the apparatus is configured to produce a solid object from the liquid hydrogen. The visual window (32) uses sapphire glass as the endoscope directly contacting with the liquid hydrogen medium and uses quartz glass as the external view mirror.

4. The apparatus of claim 1, wherein the apparatus is configured to produce a solid object from the liquid hydrogen. The second helium branch passing through the cold insulation container (39) adopts a heat exchange coil form.

5. The apparatus of claim 1, wherein the apparatus is configured to produce a solid object from the liquid hydrogen. The liquid hydrogen tank (23) is filled with liquid hydrogen by a self-pressurizing method, and the liquid hydrogen filling pipeline (19), the first filling branch (20) and the second filling branch (21) all adopt vacuum insulation pipes.

6. The apparatus of claim 1, wherein the apparatus is configured to produce a solid object from the liquid hydrogen. The metal coil (37) is filled with para-hydrogen catalyst.

7. The apparatus of claim 1, wherein the apparatus is configured to produce a solid object from the liquid hydrogen. It also includes a temperature controller (28), a controller (29) and a high-speed camera (30), the temperature controller (28), the controller (29) and the high-speed camera (30) are connected to the controller (29) through signal lines (27), the heating module (35) is connected to the temperature controller (28), the power control of the heating module (35) is realized by the controller (29) through the temperature controller (28), and the image information acquisition of the solid-void growth process is realized by the controller (29) through the high-speed camera (30).

8. The apparatus of claim 1, wherein the apparatus is configured to produce a solid object from the liquid hydrogen. The gas composition analysis equipment is a gas chromatograph (16) for measuring oxygen and nitrogen distribution data of the solid-void.

9. The apparatus of claim 1, wherein the apparatus is configured to produce a solid object from the liquid hydrogen. The gradient magnetic field member (36) is a permanent magnet for forming a gradient magnetic field.

10. A method for producing and testing liquid hydrogen solidification using the apparatus according to any one of claims 1 to 9, characterized by, The method comprises the following steps: S1, liquid hydrogen filling: open the first liquid hydrogen evacuation valve (18), the measurement control valve (15), the first liquid hydrogen filling valve (24) and the second liquid hydrogen filling valve (26), the liquid hydrogen medium in the liquid hydrogen tank (23) enters the preparation container (38) and the cold container (39) through the liquid hydrogen filling pipeline (19), the first filling branch (20) and the second filling branch (21) in turn, the hydrogen gas generated in the cold container (39) filling process is discharged through the first liquid hydrogen evacuation pipeline (17), and the hydrogen gas generated in the preparation container (38) filling process is discharged through the measurement pipeline (14); the liquid hydrogen in the cold container (39) needs to be filled to more than the inlet of the metal coil (37), so that the liquid hydrogen in the cold container (39) fills the metal coil (37) and then cools the preparation container (38); after filling is completed, the first liquid hydrogen filling valve (24) and the second liquid hydrogen filling valve (26) are closed; S2, simulate gas delivery: open the helium regulating valve (12), so that the helium medium in the high-pressure helium cylinder (13) enters the sleeve (10) to protect the simulate gas at low temperature, then close the helium regulating valve (12); open the oxygen regulating valve (5) and the nitrogen regulating valve (6), so that the gas in the high-pressure oxygen cylinder (7) and the high-pressure nitrogen cylinder (8) enters the mixer (4) for sufficient mixing according to the preset ratio, then open the simulate gas regulating valve (9), so that the simulate gas enters the preparation container (38) in the visual liquid hydrogen dewar (40) through the simulate gas pipeline (1); S3, solid-void preparation: open the simulate gas regulating valve (9) at the same time, start the controller (29), the high-speed camera (30) and the light source (41), the simulate gas from the simulate gas pipeline (1) forms a solid-void with a specific oxygen-nitrogen distribution under the action of the gradient magnetic field component (36) in the preparation container (38), and deposits on the support (34) under the action of gravity, the high-speed camera (30) collects image information of the solid-void growth process and stores it in the controller (29); S4, liquid hydrogen evacuation: after the solid-void preparation and image information collection are completed, close the oxygen regulating valve (5), the nitrogen regulating valve (6), the simulate gas regulating valve (9) and the measurement control valve (15), open the helium regulating valve (12) and the second liquid hydrogen evacuation valve (25), the helium from the high-pressure helium cylinder (13) enters the visual liquid hydrogen dewar (40) through the helium pipeline (11), first exchanges heat with the liquid hydrogen medium in the cold container (39) to cool the helium temperature from room temperature to the liquid hydrogen temperature zone 20 K, then enters the preparation container (38) to pressurize, the liquid hydrogen soaked in the solid-void in the preparation container (38) is evacuated through the second liquid hydrogen evacuation pipeline (22), and the helium regulating valve (12) and the second liquid hydrogen evacuation valve (25) are closed after the liquid hydrogen evacuation is completed; S5, solid air oxygen nitrogen analysis: the pressure inside the preparation container (38) is controlled below the oxygen nitrogen medium three-phase point pressure, the power of the heating module (35) is controlled by the temperature controller (28), the inside of the preparation container (38) starts to heat up, the solid air on the support (34) gradually sublimates, the measuring control valve (15) is opened, the solid air sublimation gas enters the gas chromatograph (16) through the measuring pipeline (14), and real-time oxygen nitrogen concentration data is obtained until the whole solid air sublimates; after the analysis is completed, the power of the heating module (35) is cut off by the temperature controller (28), and the measuring control valve (15) is closed; after the liquid hydrogen medium in the cryogenic container (39) is completely vaporized and emptied, the first liquid hydrogen emptying valve (18) is closed, and the test is completed.

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