Staged cooling continuous ortho-parahydrogen conversion method and device

Abstract

The invention relates to the technical field of ortho-parahydrogen conversion, in particular to a staged cooling continuous ortho-parahydrogen conversion method and device. The method comprises the following steps: S1, heating and vacuumizing an ortho-parahydrogen conversion pipeline filled with a magnetic catalyst, so that the magnetic catalyst is heated and activated under a vacuum condition; s2, cooling the magnetic catalyst in the ortho-parahydrogen conversion pipeline; s3, after the hydrogen is cooled by liquid nitrogen and an adsorber, the hydrogen enters an ortho-parahydrogen conversion pipeline filled with a magnetic catalyst to be cooled, and continuous conversion from ortho-hydrogen to parahydrogen is completed under the action of the catalyst; s4, after the conversion temperature is stable, the hydrogen inlet speed is controlled, and parahydrogen discharged from a gas outlet of the ortho-parahydrogen conversion pipeline is collected. The purpose of prolonging the service life of the catalyst is achieved, and the heat load of the ultralow-temperature refrigeration pump can be reduced, so that the ortho-parahydrogen conversion time is shortened.

Description

Technical Field

[0001] This invention relates to the field of n-parahydrogen conversion technology, specifically to a staged cooling continuous n-parahydrogen conversion method and apparatus. Background Technology

[0002] With the increasing use of fossil fuels, environmental problems caused by greenhouse gas emissions have become a critical issue that urgently needs to be addressed. In recent years, hydrogen, as the most ideal clean energy source, has attracted much attention due to its advantages such as renewability and high energy density. Hydrogen is a colorless, odorless, flammable, and explosive gas, and the technologies for its production, purification, and use are constantly evolving. Currently, hydrogen is mostly stored as a high-pressure gas, which poses significant safety hazards. Hydrogen liquefaction technology can convert hydrogen into a liquid state, thereby changing the transportation and storage methods and making it more suitable for the development of hydrogen energy. Hydrogen molecules exist in two states: positive hydrogen and negative hydrogen, mainly distinguished by the different orientations of the nuclear spin of the hydrogen atom.

[0003] Hydrogen molecules, composed of two hydrogen atoms, exist in two forms: orthohydrogen and secondary hydrogen. The distinguishing feature between orthohydrogen and secondary hydrogen is the relative orientation of the spins of their individual atomic nuclei. The nuclear spins of the two atoms forming a hydrogen molecule can be in the same direction (parallel) or opposite directions (antipole). Hydrogen molecules with parallel nuclear spins are called orthohydrogen, possessing an odd number of rotational quantum numbers; hydrogen molecules with antiparallel nuclear spins are called secondary hydrogen, possessing an even number of rotational quantum numbers. While the two types of hydrogen molecules are chemically indistinguishable, they differ in some physical properties. During hydrogen liquefaction, orthohydrogen transforms into secondary hydrogen. This transformation occurs at low temperatures and is very slow; it is an exothermic process. The heat generated during this transformation can vaporize the already liquid hydrogen, increasing storage difficulties and safety risks.

[0004] In existing technologies, the secondary hydrogen content reaches 99.75% after conversion at 19K. This low-temperature conversion process requires high equipment cooling capacity, necessitating the maintenance of an ultra-low temperature environment. The conversion of n- and secondary hydrogen requires refrigeration equipment with high cooling power to handle the significant temperature difference in heat exchange. The temperature difference from room temperature to the optimal conversion temperature for n- and secondary hydrogen exceeds 270K. During the conversion of n- and secondary hydrogen, the ultra-low temperature refrigeration pump bears the dual heat load generated by hydrogen cooling and n- and secondary hydrogen conversion, prolonging the preparation time. During the preparation process, small amounts of impurity gases such as O2, H2O, and CO are present in the hydrogen. After prolonged use, these impurity gases adsorb onto the catalyst surface, leading to catalyst poisoning and deactivation, thus reducing the conversion efficiency of n- and secondary hydrogen. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a staged cooling continuous n- and para-hydrogen conversion method and apparatus to achieve a highly efficient continuous n- and para-hydrogen conversion process.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a staged cooling continuous positive and negative hydrogen conversion method, comprising the following steps:

[0008] Step S1: The adsorber containing the adsorbent and the positive and negative hydrogen conversion pipeline containing the magnetic catalyst are heated and evacuated to activate the adsorbent and magnetic catalyst under vacuum conditions.

[0009] Step S2: Cool the magnetic catalyst in the positive and negative hydrogen conversion pipeline;

[0010] Step S3: Perform preliminary cooling of the hydrogen gas;

[0011] Step S4: After being further cooled by liquid nitrogen and an adsorber, the hydrogen enters the positive and negative hydrogen conversion pipeline containing a magnetic catalyst for further cooling, and completes the continuous conversion of positive hydrogen to negative hydrogen under the action of the catalyst.

[0012] Step S5: After the conversion temperature stabilizes, control the hydrogen inlet speed and collect the secondary hydrogen gas released from the outlet of the positive and negative hydrogen conversion pipeline.

[0013] In step S1, the secondary hydrogen conversion pipeline is heated to desorb impurity molecules from the catalyst. Hydrogen gas is repeatedly introduced into the secondary hydrogen conversion pipeline and then evacuated to ensure that there is no impurity contamination during the subsequent secondary hydrogen conversion process.

[0014] In step S2, the magnetic catalyst in the intermediate hydrogen conversion pipeline is cooled as follows: the intermediate hydrogen conversion pipeline is placed in a vacuum chamber, and when the vacuum chamber is cooled to -20 to -80°C by an external circulating refrigeration pump, the cryogenic refrigeration pump is turned on to generate cryogenic temperature, so that the temperature of the magnetic catalyst in the intermediate hydrogen conversion pipeline drops to 20K to 30K.

[0015] The initial inlet pressure of hydrogen is controlled at half of the required pressure, and then the inlet pressure and flow rate are adjusted according to the temperature of the magnetic catalyst; the magnetic catalyst is kept in an operating temperature range below 30K.

[0016] Another aspect of the present invention provides a staged cooling continuous secondary hydrogen conversion device for implementing the method described above. The device includes a vacuum chamber and a secondary hydrogen conversion pipeline disposed in the vacuum chamber, an ultra-low temperature cold pump head, a metal cylinder and a liquid nitrogen tank. The ultra-low temperature cold pump head is disposed at the bottom of the vacuum chamber, the secondary hydrogen conversion pipeline is disposed at the top of the ultra-low temperature cold pump head, and the secondary hydrogen conversion pipeline contains a magnetic catalyst. The ultra-low temperature cold pump head is used to cool the magnetic catalyst in the secondary hydrogen conversion pipeline.

[0017] The liquid nitrogen tank is located at the top of the vacuum chamber, and the metal cylinder is located at the bottom of the liquid nitrogen tank. The metal cylinder covers the outside of the intermediate hydrogen conversion pipeline. The intermediate hydrogen conversion pipeline is connected to the hydrogen input pipeline that passes through the liquid nitrogen tank. The liquid nitrogen tank is used to cool the hydrogen in the hydrogen input pipeline.

[0018] An adsorber for removing impurities from hydrogen is provided between the liquid nitrogen tank and the metal cylinder. The adsorber contains adsorbent, and a heating wire for adsorbent desorption and regeneration is wound around the outside of the adsorber. The adsorber is cooled by the liquid nitrogen tank. After being cooled and purified twice by the adsorber, the hydrogen enters the anisotropic hydrogen conversion pipeline through the hydrogen input pipeline. The low-temperature hydrogen is cooled three times in the anisotropic hydrogen conversion pipeline.

[0019] The top of the cryogenic cold pump head is provided with a cylinder, and a temperature probe for detecting temperature changes is fixed on the cylinder; the secondary hydrogen conversion pipeline is wound around the cylinder, and a heating wire is wound around the outside of the secondary hydrogen conversion pipeline.

[0020] The positive and negative hydrogen conversion pipeline is made of copper; the cylinder is made of oxygen-free copper; the positive and negative hydrogen conversion pipeline is welded to the cylinder, and a flexible thermally conductive pad is placed between the contact surface of the cylinder and the cold head of the ultra-low temperature cold pump.

[0021] The vacuum chamber includes a vacuum chamber body and a vacuum chamber cover located on top of the vacuum chamber body. The liquid nitrogen tank is located on the vacuum chamber cover. Coolant pipelines are arranged on the side wall of the vacuum chamber body. The coolant pipelines are wrapped with multiple layers of heat insulation material. The coolant pipelines cool the vacuum chamber body through the coolant.

[0022] The inlet of the secondary hydrogen conversion pipeline is connected to the hydrogen input pipeline, and the hydrogen input pipeline is equipped with an inlet valve and a flow meter; the outlet of the secondary hydrogen conversion pipeline is connected to an aluminum gas cylinder, which collects and stores the secondary hydrogen released from the outlet or performs cryogenic liquefaction storage; the outlet of the secondary hydrogen conversion pipeline is equipped with an outlet valve and a pressure gauge.

[0023] The advantages and beneficial effects of the present invention are as follows: The present invention provides a staged cooling continuous n-parahydrogen conversion method. By using staged cooling, the impurity gas entering the n-parahydrogen conversion catalyst can be reduced to extend the catalyst's service life. At the same time, the thermal load of the cryogenic refrigeration pump can be reduced, thereby shortening the n-parahydrogen conversion time and realizing a continuous n-parahydrogen conversion process.

[0024] This invention provides a staged cooling continuous positive and negative hydrogen conversion device and method. It utilizes low temperature to extend catalyst life and achieves automation of the positive and negative hydrogen conversion process through flow control. It has the ability to continuously and rapidly produce negative hydrogen gas, and is highly safe and easy to operate. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a staged cooling continuous ortho-parahydrogen conversion device according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the ortho-parahydrogen conversion pipeline in an embodiment of the present invention.

[0027] In the diagram: 1. Vacuum chamber cover; 2. Hydrogen conversion pipeline; 201. Gas inlet; 202. Gas outlet; 3. Vacuum chamber; 4. Ultra-low temperature cold pump head; 5. Metal cylinder; 6. Liquid nitrogen tank. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] See Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a staged cooling continuous positive and negative hydrogen conversion method, characterized by comprising the following steps:

[0030] Step S1: The adsorber containing the adsorbent and the positive and negative hydrogen conversion pipeline 2 containing the magnetic catalyst are heated and evacuated to activate the adsorbent and magnetic catalyst under vacuum conditions.

[0031] Step S2: Cool the magnetic catalyst inside the secondary hydrogen conversion pipeline 2;

[0032] Step S3: Perform preliminary cooling of the hydrogen gas;

[0033] Step S4: After being cooled by liquid nitrogen and an adsorber, hydrogen enters the positive and negative hydrogen conversion pipeline 2 containing a magnetic catalyst for further cooling, and completes the continuous conversion of positive hydrogen to negative hydrogen under the action of the catalyst.

[0034] Step S5: After the conversion temperature stabilizes, control the hydrogen inlet speed and collect the secondary hydrogen gas released from the outlet of the secondary hydrogen conversion pipeline 2.

[0035] Specifically, in step S1, the magnetic catalyst is loaded into the secondary hydrogen conversion pipeline 2. The secondary hydrogen conversion pipeline 2 is heated to desorb impurity molecules from the catalyst, thereby activating the catalyst. Hydrogen gas is repeatedly introduced into the secondary hydrogen conversion pipeline 2 and then evacuated to ensure that there is no impurity contamination during the subsequent secondary hydrogen conversion process. After the excess hydrogen gas is evacuated, the valve is closed to maintain the vacuum state of the secondary hydrogen conversion pipeline 2.

[0036] Specifically, in step S2, the magnetic catalyst in the anthocyanin-hydrogen conversion pipeline 2 is cooled as follows: the anthocyanin-hydrogen conversion pipeline 2 is made of copper and is placed on the cryogenic cold pump head 4 inside the vacuum chamber. When the vacuum chamber is cooled to -20 to -80°C by an external circulating refrigeration pump, the cryogenic refrigeration pump is turned on to generate ultra-low temperatures, causing the temperature of the magnetic catalyst in the anthocyanin-hydrogen conversion pipeline 2 to drop to 20K to 30K. The hydrogen inlet valve is opened, and the hydrogen inlet pipe passes through the liquid nitrogen tank 6. The temperature of the hydrogen cooled by liquid nitrogen can reach 77K. The cryogenic hydrogen enters the anthocyanin-hydrogen conversion pipeline 2 for further cooling and anthocyanin-hydrogen conversion.

[0037] Specifically, the inlet pressure of hydrogen entering the secondary hydrogen conversion pipeline 2 needs to be controlled. There is a pressure difference between the hydrogen source and the secondary hydrogen conversion pipeline. The initial inlet pressure of hydrogen is controlled at half of the required pressure, and then the inlet pressure and flow rate are adjusted according to the temperature of the magnetic catalyst. After the hydrogen enters, the temperature reading of the temperature measuring system rises, and the temperature fluctuation should be kept below 10K as much as possible. The magnetic catalyst is kept in an operating temperature range below 30K, allowing for continuous hydrogen flow to complete the conversion of secondary hydrogen.

[0038] Once the outlet pressure reaches the required pressure, the inlet speed is controlled by a flow meter, and secondary hydrogen gas is released from the outlet. It is then collected and stored in aluminum cylinders or liquefied at low temperatures.

[0039] This invention provides a staged cooling continuous n-parahydrogen conversion method. By using staged cooling, the impurity gases entering the n-parahydrogen conversion catalyst can be reduced to extend the catalyst's service life. At the same time, the thermal load on the cryogenic refrigeration pump can be reduced, shortening the n-parahydrogen conversion time, thereby realizing a continuous n-parahydrogen conversion process.

[0040] Based on the above embodiments, another embodiment of the present invention provides a staged cooling continuous n-parahydrogen conversion device, which realizes the staged cooling continuous n-parahydrogen conversion method in the above embodiments.

[0041] See Figure 1 and Figure 2As shown, another embodiment of the present invention provides a staged cooling continuous n-parahydrogen conversion device, including a vacuum chamber and a n-parahydrogen conversion pipeline 2, an ultra-low temperature cold pump head 4, a metal cylinder 5, and a liquid nitrogen tank 6 disposed within the vacuum chamber. The ultra-low temperature cold pump head 4 is disposed at the bottom of the vacuum chamber, and the n-parahydrogen conversion pipeline 2 is disposed at the top of the ultra-low temperature cold pump head 4. The n-parahydrogen conversion pipeline 2 contains a magnetic catalyst, and the ultra-low temperature cold pump head 4 is used to cool the magnetic catalyst in the n-parahydrogen conversion pipeline 2. The liquid nitrogen tank 6 is disposed at the top of the vacuum chamber, and the metal cylinder 5 is disposed at the bottom of the liquid nitrogen tank 6, and the metal cylinder 5 covers the outside of the n-parahydrogen conversion pipeline 2. The n-parahydrogen conversion pipeline 2 is connected to a hydrogen input pipeline passing through the liquid nitrogen tank 6, and the liquid nitrogen tank 6 is used to cool the hydrogen in the hydrogen input pipeline.

[0042] Furthermore, an adsorber for removing impurities from hydrogen is provided between the liquid nitrogen tank 6 and the metal cylinder 5. The adsorber contains an adsorbent, and a heating wire for adsorbent desorption and regeneration is wound around the outside of the adsorber. The adsorber is cooled by the liquid nitrogen tank 6. After the hydrogen is cooled and purified twice by the adsorber, it enters the secondary hydrogen conversion pipeline 2 through the hydrogen input pipeline. The low-temperature hydrogen is cooled three times in the secondary hydrogen conversion pipeline 2.

[0043] In an embodiment of the present invention, the top of the cryogenic cold pump cold head 4 is provided with a cylinder, and the secondary hydrogen conversion pipeline 2 is wound around the cylinder and needs to be kept as tight as possible; in order to ensure uniform heat conduction, the copper pipe needs to be welded to the cylinder; a temperature measuring probe for detecting temperature changes is fixed on the cylinder.

[0044] Furthermore, the material of the intermediate hydrogen conversion pipeline 2 is copper; the material of the cylinder is oxygen-free copper; the intermediate hydrogen conversion pipeline 2 is loaded with a magnetic catalyst; this section of the intermediate hydrogen conversion pipeline is heated by a heating wire; at the same time, a small vacuum pump is used to evacuate the intermediate hydrogen conversion pipeline, so that the adsorbed molecules on the surface of the magnetic catalyst are desorbed, thereby activating the catalyst.

[0045] Furthermore, the heating wire wrapped around the adsorber can also be used for heating and desorbing impurities. Hydrogen gas can be repeatedly introduced into the hydrogen inlet pipeline and the anisotropic hydrogen conversion pipeline can be evacuated multiple times to heat and purge the catalyst to desorb impurity molecules, ensuring no impurity contamination during subsequent anisotropic hydrogen conversion processes. After evacuating excess hydrogen, the valve is closed to maintain a vacuum state in the anisotropic hydrogen conversion pipeline. The catalyst and adsorber can be evacuated in stages. After the entire anisotropic hydrogen conversion pipeline has cooled, the cylinder is placed on the cryogenic pump cold head 4. To ensure good contact between the cylinder and the cryogenic pump cold head 4, a flexible thermally conductive pad is placed between the contact surfaces to ensure that the cold pump can cool the loaded cylinder and the connected anisotropic hydrogen conversion pipeline 2 to the maximum extent. A temperature probe is fixed on the cylinder to detect temperature changes.

[0046] Furthermore, the hydrogen conversion pipeline 2 is welded to the cylinder, and a flexible thermally conductive pad is placed between the contact surface of the cylinder and the cryogenic cold pump head 4. The cryogenic cold pump head 4 is connected to the cryogenic refrigeration pump.

[0047] See Figure 1 As shown, in an embodiment of the present invention, the vacuum chamber includes a vacuum chamber body 3 and a vacuum chamber cover 1 disposed on the top of the vacuum chamber body 3, and a liquid nitrogen tank 6 is disposed on the vacuum chamber cover 1; coolant pipelines are arranged on the side wall of the vacuum chamber body 3, and the coolant pipelines are wrapped with multiple layers of heat insulation material, and the coolant pipelines cool the vacuum chamber body 3 through the coolant.

[0048] See Figure 2 As shown in the embodiment of the present invention, the inlet 201 of the secondary hydrogen conversion pipeline 2 is connected to the hydrogen input pipeline, and the hydrogen input pipeline is equipped with an inlet valve and a flow meter; the outlet 202 of the secondary hydrogen conversion pipeline 2 is connected to an aluminum gas cylinder, which collects and stores the secondary hydrogen released from the outlet 202 or performs cryogenic liquefaction storage; the outlet 202 of the secondary hydrogen conversion pipeline 2 is equipped with an outlet valve and a pressure gauge.

[0049] Furthermore, the staged cooling continuous ortho-parahydrogen conversion device provided by the present invention also includes a vacuum pump for evacuating the ortho-parahydrogen conversion pipeline 2, a vacuum pump for maintaining the vacuum in the vacuum chamber, and a circulating refrigeration pump for maintaining the low temperature of the outer wall of the vacuum chamber.

[0050] An embodiment of the present invention provides a staged cooling continuous positive and negative hydrogen conversion device, the working principle of which is as follows:

[0051] To lower the outer wall temperature of vacuum chamber 3, an external circulating refrigeration pump is used to cool the chamber, reducing the temperature to -20 to -80°C. This initially reduces the heat load on the cryogenic pump caused by external radiative heat exchange. An inlet pipe is installed through this area to achieve initial cooling and impurity removal of the hydrogen gas. While the outer wall of vacuum chamber 3 is being cooled, a small vacuum pump maintains a vacuum within the chamber. Liquid nitrogen tank 6 can be connected to Dewar flasks or other containers of varying volumes to increase the liquid nitrogen storage, depending on the volume of secondary hydrogen to be prepared. After the external temperature monitoring system is activated and the temperature stabilizes, the cryogenic refrigeration pump is turned on. The catalytic conversion system displays that the temperature of the secondary hydrogen conversion pipeline 2 begins to decrease, and the catalyst temperature can be observed through the temperature monitoring system.

[0052] The hydrogen input pipeline, which has been preliminarily cooled, passes through the liquid nitrogen tank 6. After liquid nitrogen is added to the liquid nitrogen tank 6, it can cool the hydrogen input pipeline and the hydrogen. The liquid nitrogen tank 6 is in contact with the adsorber, which can cool the temperature of the adsorber and the adsorbent. After the hydrogen is cooled and purified by the adsorber, it enters the positive and negative hydrogen conversion pipeline 2 through the gas inlet pipe.

[0053] When the temperature monitoring system indicates that the catalyst has reached the conversion temperature of 20-30K, the hydrogen inlet valve is opened, allowing low-temperature hydrogen to pass through the hydrogen input pipeline and the liquid nitrogen tank 6. After secondary liquid nitrogen cooling, the hydrogen temperature can reach 77K. The low-temperature hydrogen then enters the secondary hydrogen conversion pipeline 2, which contains the magnetic catalyst, for a third cooling process and undergoes secondary hydrogen conversion. Secondary hydrogen conversion is an exothermic process, and the temperature of the secondary hydrogen conversion pipeline 2 containing the magnetic catalyst will rise during the conversion. To ensure the purity of the secondary hydrogen, temperature fluctuations are generally controlled within 30K. Once the temperature inside the conversion unit is stably below 30K, the inlet flow rate can be increased. The inlet pressure and the temperature of the secondary hydrogen conversion pipeline 2 must be controlled when hydrogen enters the secondary hydrogen conversion unit. Since there is a pressure difference between the hydrogen source and the secondary hydrogen conversion pipeline, the inlet flow rate can be increased slowly according to the temperature.

[0054] Repeat the gas intake operation until the outlet pressure gauge reaches the operating pressure. Open the outlet valve to allow the intake pressure to be slightly higher than the outlet pressure. Control the intake speed using a flow meter to release the secondary hydrogen gas from the outlet. Collect and store the gas in an aluminum cylinder or perform cryogenic liquefaction storage. When stopping the device, close the inlet valve and open the outlet valve to slowly discharge the secondary hydrogen gas into the tailpipe. Turn off the cryogenic pump, the chamber vacuum pump, and the circulating refrigeration pump connected to the vacuum chamber. Allow the entire device to warm up naturally. Once the pressure in the secondary hydrogen conversion pipeline equals atmospheric pressure, close the outlet valve and turn on the vacuum pump to remove any remaining hydrogen gas from the secondary hydrogen conversion pipeline until the temperature of the secondary hydrogen conversion pipeline is the same as room temperature. Maintain a vacuum state in the secondary hydrogen conversion pipeline for future use.

[0055] Staged cooling is not limited to three steps; multiple stages can be added or removed depending on different conversion rates. The flow rate in the continuous conversion process is not limited and can be adjusted accordingly based on the cooling capacity.

[0056] The present invention provides a staged cooling continuous positive and negative hydrogen conversion method and apparatus, the purpose of which is to convert hydrogen into negative hydrogen after staged cooling, thereby ensuring conversion efficiency.

[0057] Specifically, impurities such as O2, H2O, and CO in hydrogen are removed by staged cooling (liquid nitrogen precooling + adsorber purification) to avoid catalyst poisoning; at the same time, surface adsorbates are thoroughly removed by heating and vacuuming and hydrogen purging during catalyst activation, further improving catalyst stability and significantly extending its service life.

[0058] Staged cooling gradually reduces hydrogen from room temperature to the conversion temperature (first cooled to -20℃ to -80℃ by the chamber, then cooled to 77K by liquid nitrogen, and finally cooled to 20K to 30K by the cryogenic refrigeration pump), significantly reducing the heat load of the cryogenic refrigeration pump (it does not need to directly handle the temperature difference heat exchange above 270K) and shortening the cooling time. Through the linkage control of flow meter and temperature monitoring, the inlet parameters can be dynamically adjusted according to the catalyst temperature to achieve continuous hydrogen supply and stable secondary hydrogen production, breaking through the limitations of traditional intermittent conversion.

[0059] By integrating temperature monitoring, flow regulation, and valve control into the control module, the conversion process can be automated, reducing manual intervention. The insulation and vacuum design of the vacuum chamber, the safe storage method of the aluminum gas cylinder, and the real-time monitoring of pressure and temperature significantly reduce safety risks such as hydrogen leakage and vaporization, and greatly improve the ease of operation and safety.

[0060] The number of cooling steps can be flexibly increased or decreased according to the actual conversion rate, and does not need to be fixed at 3 steps; the hydrogen flow rate can be dynamically adjusted according to the power of the refrigeration system, which is suitable for secondary hydrogen production needs of different scales.

[0061] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, extensions, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A continuous primary-secondary hydrogen conversion process with staged cooling, characterized in that, The method comprises the following steps: Step S1: heating and vacuumizing the adsorber loaded with adsorbent and the primary-secular hydrogen conversion pipeline (2) loaded with magnetic catalyst, and heating and activating the adsorbent and the magnetic catalyst under vacuum condition; Step S2: cooling the magnetic catalyst in the primary-secular hydrogen conversion pipeline (2); Step S3: preliminarily cooling the hydrogen; Step S4: cooling the hydrogen further by liquid nitrogen and the adsorber, and then cooling the hydrogen in the primary-secular hydrogen conversion pipeline (2) loaded with magnetic catalyst, and continuously converting the primary hydrogen into the secondary hydrogen under the action of the catalyst; Step S5: after the conversion temperature is stable, controlling the hydrogen inlet speed, and collecting the secondary hydrogen discharged from the outlet of the primary-secular hydrogen conversion pipeline (2).

2. The staged cooling continuous para-ortho hydrogen conversion process according to claim 1, characterized in that, In step S1, the primary-secular hydrogen conversion pipeline (2) is heated to desorb the impurity molecules from the catalyst, and the hydrogen is repeatedly introduced into the primary-secular hydrogen conversion pipeline (2) and evacuated to ensure that there is no impurity pollution in the subsequent primary-secular hydrogen conversion process.

3. The staged cooling continuous para-ortho hydrogen conversion process of claim 1, wherein, In step S2, the cooling treatment of the magnetic catalyst in the primary-secular hydrogen conversion pipeline (2) is as follows: the primary-secular hydrogen conversion pipeline (2) is placed in a vacuum chamber, the vacuum chamber is cooled to-20 to-80℃ by an external circulating refrigeration pump, the ultra-low temperature refrigeration pump is started to generate ultra-low temperature, and the temperature of the magnetic catalyst in the primary-secular hydrogen conversion pipeline (2) is reduced to 20K to 30K.

4. The staged cooling continuous para-ortho hydrogen conversion process of claim 1 wherein, The initial inlet pressure of the hydrogen is controlled at half of the required pressure, and then the inlet pressure and flow rate are adjusted according to the temperature of the magnetic catalyst; the working temperature of the magnetic catalyst is maintained below 30K.

5. A continuous primary-secondary hydrogen conversion apparatus for performing the method according to any one of claims 1 to 4, characterized in that The device comprises a vacuum chamber, a primary-secular hydrogen conversion pipeline (2), an ultra-low temperature cold pump cold head (4), a metal cylinder (5), and a liquid nitrogen tank (6) arranged in the vacuum chamber, wherein the ultra-low temperature cold pump cold head (4) is arranged at the bottom of the vacuum chamber, the primary-secular hydrogen conversion pipeline (2) is arranged at the top of the ultra-low temperature cold pump cold head (4), the primary-secular hydrogen conversion pipeline (2) is loaded with magnetic catalyst, and the ultra-low temperature cold pump cold head (4) is used for cooling the magnetic catalyst in the primary-secular hydrogen conversion pipeline (2); The liquid nitrogen tank (6) is arranged at the top of the vacuum chamber, the metal cylinder (5) is arranged at the bottom of the liquid nitrogen tank (6), and the metal cylinder (5) covers the outside of the primary-secular hydrogen conversion pipeline (2); the primary-secular hydrogen conversion pipeline (2) is connected with a hydrogen input pipeline passing through the liquid nitrogen tank (6), and the liquid nitrogen tank (6) is used for cooling the hydrogen in the hydrogen input pipeline.

6. The staged cooling continuous para-ortho hydrogen conversion apparatus of claim 5, wherein, An adsorber for removing impurities in the hydrogen is arranged between the liquid nitrogen tank (6) and the metal cylinder (5), an adsorbent is arranged in the adsorber, heating wires are wound on the outside of the adsorber for desorption and regeneration of the adsorbent; the adsorber is cooled by the liquid nitrogen tank (6), the hydrogen is purified by secondary cooling in the adsorber, and then the hydrogen enters the primary-secular hydrogen conversion pipeline (2) through the hydrogen input pipeline, and the low-temperature hydrogen is cooled for the third time in the primary-secular hydrogen conversion pipeline (2).

7. The staged cooling continuous para-ortho hydrogen conversion apparatus of claim 5, wherein, A cylinder is arranged at the top of the ultra-low temperature cold pump cold head (4), a temperature measuring probe for detecting temperature change is fixed on the cylinder, the primary-secular hydrogen conversion pipeline (2) is wound on the cylinder, and heating wires are wound on the outside of the primary-secular hydrogen conversion pipeline (2).

8. The staged cooling continuous para-ortho hydrogen conversion apparatus according to claim 7, wherein, The material of the primary and secondary hydrogen conversion pipeline (2) is copper; the material of the cylinder is oxygen-free copper; the primary and secondary hydrogen conversion pipeline (2) is welded with the cylinder, and a flexible heat-conducting gasket is arranged between the contact surface of the cylinder and the ultra-low-temperature cold pump cold head (4).

9. The staged cooling continuous para-ortho hydrogen conversion apparatus of claim 5, wherein, The vacuum chamber comprises a vacuum cavity (3) and a vacuum cavity upper cover (1) arranged on the top of the vacuum cavity (3), and the liquid nitrogen tank (6) is arranged on the vacuum cavity upper cover (1); a cooling liquid pipeline is arranged on the side wall of the vacuum cavity (3), the cooling liquid pipeline is wrapped with multilayer heat insulation materials, and the cooling liquid pipeline cools the vacuum cavity (3) through the cooling liquid.

10. The staged cooling continuous para-ortho hydrogen conversion apparatus of claim 5, wherein, The gas inlet (201) of the primary and secondary hydrogen conversion pipeline (2) is connected with the hydrogen input pipeline, the hydrogen input pipeline is provided with a gas inlet valve and a flowmeter; the gas outlet (202) of the primary and secondary hydrogen conversion pipeline (2) is connected with an aluminum cylinder, the aluminum cylinder collects and stores the secondary hydrogen gas released from the gas outlet (202) or performs low-temperature liquefaction storage; the gas outlet (202) of the primary and secondary hydrogen conversion pipeline (2) is provided with a gas outlet valve and a pressure gauge.

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