Orthohydrogen and parahydrogen converter

Abstract

The invention provides an ortho-parahydrogen converter and particularly relates to the technical field of hydrogen liquefaction, the ortho-parahydrogen converter comprises a conversion assembly and a cooling assembly, the conversion assembly comprises an impeller and a catalyst connected with the impeller, and the catalyst comprises a first heat exchange assembly arranged on the outer side and a first flow channel arranged on the inner side of the first heat exchange assembly; the first heat exchange assembly is filled with a catalyst; the cooling assembly is arranged on the outer side of the conversion assembly and comprises a plurality of second flow channels, the second flow channels communicate with the first flow channels, and cooling gas sequentially passes through the second flow channels, the impeller and the first flow channels, drives the impeller and the catalytic converter to rotate and exchanges heat with the catalytic converter, so that hydrogen is in uniform contact with the catalytic converter and is cooled when passing through the catalytic converter; cooling airflow is used for driving the catalyst to rotate, so that hydrogen is in uniform contact with the catalyst, the concentration gradient difference of reactants on the surface of the catalyst can be effectively avoided, sufficient contact time of the hydrogen and the catalyst is guaranteed, and the conversion efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen liquefaction, in particular to a normal-para hydrogen converter. Background Art

[0002] Hydrogen molecules have two spin isomers, orthohydrogen and parahydrogen. At room temperature, hydrogen is composed of approximately 75% orthohydrogen and 25% parahydrogen. When the temperature drops, orthohydrogen will spontaneously convert to parahydrogen and release heat. Qualified liquid hydrogen products require a parahydrogen content (volume fraction) ≥ 95%. After hydrogen is liquefied, if the orthohydrogen content is high, the heat spontaneously converted from orthohydrogen and parahydrogen is greater than the latent heat of vaporization of liquid hydrogen, which will cause the liquid hydrogen to evaporate and increase the pressure in the storage tank, posing a major challenge to liquid hydrogen storage.

[0003] Existing para-hydrogen converters usually use a fixed bed to complete the conversion. However, since the hydrogen flow rate in certain areas is too fast, the contact time with the catalyst is short. This will reduce the conversion efficiency of hydrogen during para-hydrogen conversion, and may cause the para-hydrogen content (volume fraction) of the liquid hydrogen to fail to meet the requirements. Summary of the Invention

[0004] In order to solve the problem that the parahydrogen content in liquid hydrogen does not meet the standard due to the reduction of the ortho-parahydrogen conversion efficiency, the present invention proposes an ortho-parahydrogen converter.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention proposes a normal-parahydrogen converter comprising a conversion component and a cooling component, wherein:

[0007] The conversion assembly includes an impeller and a catalyst connected to the impeller, the catalyst includes a first heat exchange assembly arranged on the outside and a first flow channel arranged on the inside of the first heat exchange assembly, and the first heat exchange assembly is filled with a catalyst;

[0008] The cooling assembly is arranged outside the conversion assembly and includes multiple second flow channels, which are connected to the first flow channels. The cooling gas passes through the second flow channels, the impeller and the first flow channels in sequence, driving the impeller and the catalyst to rotate and exchange heat with the catalyst, so that the hydrogen is in uniform contact with the catalyst when passing through the catalyst, thereby achieving conversion of orthohydrogen to parahydrogen while cooling.

[0009] Furthermore, the conversion component also includes a rotating shaft, and the impeller is arranged on the rear side of the rotating shaft and is fixedly connected to the catalyst through the rotating shaft.

[0010] Furthermore, the conversion component also includes a cylinder, the first heat exchange component includes a first heat exchange plate fin arranged on the inner side of the cylinder, the outer side of the cylinder is fixedly connected to the cooling component, the rotating shaft is rotatably arranged in the cylinder, the first heat exchange plate fin is rotatably connected to the inner side of the cylinder, and the inner side of the first heat exchange plate fin is fixedly connected to the rotating shaft through a plurality of straight plates.

[0011] Furthermore, the first heat exchange plate fins divide the space inside the cylinder into a plurality of through grooves, and the catalyst is filled into each of the through grooves.

[0012] Furthermore, the plurality of straight plates separate the first flow channel from the rotating shaft to the space between the inner side of the cylinder and the rotating shaft.

[0013] Furthermore, the cooling assembly includes an outer shell and a second heat exchange plate fin disposed inside the outer shell. The cylinder is located inside the outer shell, and the second heat exchange plate fin connects the outer shell and the outer side of the cylinder.

[0014] Furthermore, the second heat exchange plate fins separate the space between the shell and the cylinder into a plurality of second flow channels.

[0015] Furthermore, the catalyst is α-Fe2O3.

[0016] Beneficial effects of the present invention:

[0017] (1) The para-hydrogen converter proposed in the present invention utilizes a cooling airflow to drive the catalyst to rotate, disrupting the areas of different hydrogen concentrations on the catalyst surface, so that hydrogen contacts the catalyst uniformly at all angles and directions, effectively avoiding concentration gradient differences of reactants on the catalyst surface, ensuring sufficient contact time between hydrogen and the catalyst, and improving conversion efficiency.

[0018] (2) The ortho-parahydrogen converter proposed in the present invention utilizes an impeller to drive the catalyst and the catalyst inside to rotate relative to the cylinder. During the rotation process, the temperature distribution on the catalyst surface is more uniform, avoiding the phenomenon of local overheating affecting the activity of the catalyst. The heat can be taken out in time to ensure the efficient reaction. At the same time, it can also reduce the adhesion of impurities to a certain extent, keep the active sites of the catalyst exposed, and extend the service life of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a front structural diagram of the normal-parahydrogen converter of the present invention;

[0020] Figure 2 is a side cross-sectional view of the normal-parahydrogen converter of the present invention;

[0021] In the figure: cylinder 1, first heat exchange plate fin 2, catalyst 3, straight plate 4, rotating shaft 5, first flow channel 6, second flow channel 7, second heat exchange plate fin 8, housing 9, impeller 10;

[0022] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0023] In order to more clearly and completely illustrate the technical solution of the present invention, the present invention will be further described below with reference to the accompanying drawings.

[0024] Please refer to Figure 1-Figure 2 The present invention proposes a normal-parahydrogen converter comprising a conversion component and a cooling component, wherein:

[0025] The conversion assembly includes an impeller 10 and a catalyst connected to the impeller 10. The catalyst includes a first heat exchange assembly arranged on the outside and a first flow channel 6 arranged on the inside of the first heat exchange assembly. The first heat exchange assembly is filled with a catalyst 3.

[0026] The cooling assembly is arranged on the outside of the conversion assembly. The cooling assembly includes multiple second flow channels 7. The second flow channels 7 are connected to the first flow channels 6. The cooling gas passes through the second flow channels 7, the impeller 10 and the first flow channels 6 in sequence and drives the impeller 10 and the catalyst to rotate and exchange heat with the catalyst, so that the hydrogen is in uniform contact with the catalyst when passing through the catalyst, and the conversion of orthohydrogen to parahydrogen is achieved while cooling.

[0027] In a specific embodiment, the high-speed cooling gas flows through the second flow channel 7 to initially cool the hydrogen in the catalyst. The impact force generated then acts on the blades of the impeller 10, driving the impeller 10 and the catalyst to rotate. The gas then enters the first flow channel 6 to further cool the hydrogen in the catalyst. The hydrogen is cooled by the rotating catalyst and uniformly contacts the catalyst 3, completing the conversion of hydrogen to ortho-para-hydrogen.

[0028] In traditional fixed-bed catalytic converters, the flow direction and distribution of hydrogen are relatively fixed, which can easily lead to excessively fast or slow hydrogen flow rates in certain areas, resulting in uneven concentrations of reactants on the surface of catalyst 3 and forming concentration gradient differences. The present invention utilizes cooling airflow to drive the catalyst to rotate. The rotation can disrupt the local high-concentration or low-concentration areas of hydrogen formed on the surface of catalyst 3. Areas originally in different positions and with different hydrogen concentrations constantly change positions, which enables hydrogen to contact catalyst 3 from all angles and directions, avoiding the situation where hydrogen is only concentrated in certain specific areas to contact the catalyst, making the distribution of hydrogen on the surface of catalyst 3 more uniform, effectively avoiding concentration gradient differences of reactants on the surface of catalyst 3, ensuring sufficient contact time between hydrogen and catalyst 3, and improving conversion efficiency.

[0029] In one embodiment, the contact time of hydrogen is related to the flow rate and the filling length of the catalyst 3 and can be selected according to actual conditions.

[0030] Furthermore, the conversion assembly further includes a rotating shaft 5 , and the impeller 10 is arranged on the rear side of the rotating shaft 5 and is fixedly connected to the catalyst through the rotating shaft 5 .

[0031] In a specific embodiment, the cooling airflow passes through the impeller 10 and drives the impeller 10 to rotate, and the rotating shaft 5 connected to the impeller 10 and the catalyst also rotate, so that the normal-parahydrogen conversion efficiency is increased from the conventional 70% to 90% of the new converter. In actual situations, other driving mechanisms can also be used to replace the rotating shaft 5. When the impeller rotates and drives the catalyst to rotate through the driving mechanism, it can further increase the rotation speed of the catalyst.

[0032] In one embodiment, since the ortho-parahydrogen conversion reaction is a chemical reaction that generates heat, the present application utilizes an impeller 10 to drive the catalyst and the catalyst 3 inside to rotate. During the rotation process, the temperature distribution on the surface of the catalyst 3 is more uniform, avoiding the phenomenon of local overheating affecting the activity of the catalyst 3, and being able to bring out the heat in time to ensure the efficient reaction; finally, it can also reduce the adhesion of impurities to a certain extent, keep the active sites of the catalyst 3 exposed, and extend the service life of the catalyst 3.

[0033] Furthermore, the conversion component also includes a cylinder 1, the first heat exchange component includes a first heat exchange plate fin 2 arranged in the cylinder 1, the outer side of the cylinder 1 is fixedly connected to the cooling component, the rotating shaft 5 can be rotatably arranged in the cylinder 1, the first heat exchange plate fin 2 is rotatably connected to the inner side of the cylinder 1, and the inner side of the first heat exchange plate fin 2 is connected to the rotating shaft 5 through multiple straight plates.

[0034] In a specific embodiment, the first heat exchange plate fin 2 can improve the heat exchange effect of hydrogen. The first heat exchange plate fin 2 is arranged in the cylinder 1, and the inner side of the cylinder 1 is connected to the rotating shaft 5 through the straight plate 4. When the impeller 10 rotates, the first heat exchange plate fin 2 will be driven to rotate in the cylinder 1 through the rotating shaft 5.

[0035] Furthermore, the first heat exchange plate fins 2 separate the space inside the cylinder 1 into a plurality of through grooves, and the catalyst 3 is filled into each through groove.

[0036] In a specific embodiment, the first heat exchange plate fin 2 is a circumferential plate fin, which is arranged in the cylinder 1, and the space inside the cylinder 1 is divided into a plurality of through grooves of the same size. A catalyst 3 is arranged in the through groove. The hydrogen passes through the through groove and contacts the catalyst 3 while exchanging heat and cooling with the first heat exchange plate fin 2, thereby completing the conversion of normal hydrogen to para-hydrogen. During the filling process of the catalyst 3, the bottom of the through groove is sealed with a filter to prevent the catalyst 3 from leaking, and then the catalyst 3 particles are slowly poured in until the through groove is filled, and finally a layer of filter is covered on the top of the through groove to confine the catalyst 3 in the through groove. The filling volume of the catalyst 3 generally accounts for more than 75% of the volume of the through groove.

[0037] Furthermore, the plurality of straight plates 4 separate the space between the rotating shaft 5 and the inner side of the cylinder 1 and the rotating shaft 5 into a first flow channel 6 .

[0038] In a specific embodiment, multiple straight plates 4 connect the outer wall of the rotating shaft 5 and the inner side of the cylinder 1. When the cooling gas passes through the first flow channel 6, it will exchange heat with the cylinder 1 and the first heat exchange plate fin 2. The first flow channel 6 can further improve the heat exchange efficiency.

[0039] Furthermore, the cooling assembly includes a shell 9 and a second heat exchange plate fin 8 arranged inside the shell 9 , the cylinder 1 is located inside the shell 9 , and the second heat exchange plate fin 8 connects the shell 9 and the outside of the cylinder 1 .

[0040] In a specific embodiment, the shell 9 is a square or circular structure coaxial with the cylinder 1, the cylinder 1 is arranged at the center of the shell 9, and the top and bottom of the shell 9 are provided with second heat exchange plate fins 8. The second heat exchange plate fins 8 are used to perform preliminary heat exchange with the hydrogen introduced into the catalyst, and preliminary heat exchange and cooling are performed with the hydrogen.

[0041] Furthermore, the second heat exchange plate fins 8 separate the space between the shell 9 and the cylinder 1 into a plurality of second flow channels 7 .

[0042] In a specific embodiment, when the cooling gas flows in the second flow channel 7, it can effectively exchange heat with the external environment, ensuring that it maintains a stable low-temperature state when entering the impeller 10 and the first flow channel 6. The second heat exchange plate fin 8 separates multiple second flow channels 7, and the cooling gas is evenly distributed in the flow channel, which can provide stable power for the subsequent driving of the impeller 10.

[0043] Furthermore, the catalyst 3 uses α-Fe2O3.

[0044] In a specific embodiment, α-Fe2O3 is one of the more preferred materials with a higher conversion rate. Other materials can also be selected in actual selection. The particle size of the catalyst 3 is generally around 500 microns, and particles of other sizes can also be selected according to actual conditions.

[0045] In summary, in specific implementation, the cooling gas passes through the second flow channel 7, the impeller 10 and the first flow channel 6 in sequence, and the hydrogen directly passes through the through groove of the catalyst. The cooling gas exchanges heat with the hydrogen in the second flow channel 7 and the first flow channel 6, and drives the catalyst to rotate when passing through the impeller 10. The hydrogen passes through the catalyst and contacts the rotating catalyst 3 uniformly. The cooling gas absorbs the heat generated by the reaction and cools the hydrogen to complete the conversion of normal and para-hydrogen.

[0046] Of course, the present invention may have many other implementations. Based on this implementation, other implementations obtained by ordinary technicians in this field without any creative work are all within the scope of protection of the present invention.

Claims

1. A para-hydrogen converter, characterized in that: It includes a conversion component and a cooling component, wherein: The conversion assembly includes an impeller and a catalyst connected to the impeller, the catalyst includes a first heat exchange assembly arranged on the outside and a first flow channel arranged on the inside of the first heat exchange assembly, and the first heat exchange assembly is filled with a catalyst; The cooling assembly is arranged outside the conversion assembly and includes multiple second flow channels, which are connected to the first flow channels. The cooling gas passes through the second flow channels, the impeller and the first flow channels in sequence, driving the impeller and the catalyst to rotate and exchange heat with the catalyst, so that the hydrogen is in uniform contact with the catalyst when passing through the catalyst, thereby achieving conversion of orthohydrogen to parahydrogen while cooling.

2. The normal-parahydrogen converter according to claim 1, characterized in that The conversion component further includes a rotating shaft, and the impeller is arranged on the rear side of the rotating shaft and is fixedly connected to the catalyst through the rotating shaft.

3. The normal-parahydrogen converter according to claim 2, characterized in that The conversion component also includes a cylinder, and the first heat exchange component includes a first heat exchange plate fin arranged on the inner side of the cylinder. The outer side of the cylinder is fixedly connected to the cooling component. The rotating shaft is rotatably arranged in the cylinder, and the first heat exchange plate fin is rotatably connected to the inner side of the cylinder. The inner side of the first heat exchange plate fin is fixedly connected to the rotating shaft through a plurality of straight plates.

4. The normal-parahydrogen converter according to claim 3, characterized in that The first heat exchange plate fins divide the space inside the cylinder into a plurality of through slots, and catalyst is filled into each of the through slots.

5. The normal-parahydrogen converter according to claim 3, characterized in that The plurality of straight plates separate the first flow channel from the rotating shaft to the space between the inner side of the cylinder and the rotating shaft.

6. The normal-parahydrogen converter according to claim 3, characterized in that The cooling assembly includes an outer shell and a second heat exchange plate fin disposed inside the outer shell. The cylinder is located inside the outer shell, and the second heat exchange plate fin connects the outer shell and the outer side of the cylinder.

7. The normal-parahydrogen converter according to claim 5, characterized in that The second heat exchange plate fins separate the space between the shell and the cylinder into a plurality of second flow channels.

8. The normal-parahydrogen converter according to claim 1, characterized in that The catalyst is α-Fe2O3.

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