Liquid hydrogen cylinder and manufacturing method

Abstract

The invention discloses a liquid hydrogen cylinder and a manufacturing method, and relates to the technical field of liquid hydrogen storage, the liquid hydrogen cylinder comprises an outer container, an inner container arranged in the outer container, an inner heat insulation layer wrapping the outer wall of the inner container in the circumferential direction, an outer heat insulation layer wrapping the outer wall of the inner heat insulation layer, and a cold shield coil pipe arranged between the outer heat insulation layer and the inner heat insulation layer; the outer wall of the cold shield coil pipe is sleeved with a heat insulation sleeve, the inner heat insulation layer and the outer heat insulation layer cover the front end socket and the rear end socket of the inner container, the inner heat insulation layer and the outer heat insulation layer can remarkably reduce external heat entering the inner container through solid conduction, and the heat insulation sleeve arranged on the cold shield coil pipe in a sleeving mode further blocks a heat transfer path. The heat insulation effect of liquid hydrogen in the inner container can be effectively guaranteed only by using the cold screen coil pipe to improve the heat insulation performance of the container, the structure of the device can be greatly simplified, the inner heat insulation layer and the outer heat insulation layer cover the front end socket and the rear end socket of the inner container, heat insulation layer gaps caused by curved surface deformation of the end sockets can be eliminated, and the heat insulation effect is further guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid hydrogen storage, and particularly relates to a liquid hydrogen cylinder and a manufacturing method thereof. Background Art

[0002] The boiling point of liquid hydrogen is -253°C and its latent heat of vaporization is small. Therefore, even a very small amount of heat leakage will cause the medium to evaporate, so it is required that the container has very good heat insulation performance. High-vacuum multi-screen heat insulation is a heat insulation method that combines a reflective screen and a vapor-cooling screen. The metal screen (vapor-cooling screen) is connected to the vapor of the cryogenic fluid. The temperature of the metal screen decreases due to heat exchange with the gas, thereby suppressing the radiant heat flux. This heat insulation method can significantly improve the heat insulation performance of the container. However, it is necessary to insulate the inner container through the vapor-cooling screen structure. However, the vapor-cooling screen is suspended between the inner container and the outer shell, and the support structure for the vapor-cooling screen needs to be considered separately. The support structure should keep the vapor-cooling screen suspended at both normal temperature and low temperature, without squeezing the inner multi-layer heat insulation structure on the inner side, and there should be no rigid connection parts with the liquid hydrogen inner container, nor is it allowed to be in direct contact with the liquid hydrogen inner container. Moreover, the rigidity of the vapor-cooling screen should also be able to bear the deformation of the coil structure and the support structure under alternating temperature loads. Therefore, setting up the vapor-cooling screen will increase the risk of the gas cylinder under vibration conditions and shorten the equipment life. Moreover, the vapor-cooling screen is relatively heavy, and the setting of the vapor-cooling screen will increase the weight of the gas cylinder, which is not conducive to reducing energy consumption and saving costs.

[0003] Therefore, it is necessary to develop and design a liquid hydrogen cylinder and a manufacturing method thereof. Removing the vapor-cooling screen structure and only using the cold screen coil to improve the heat insulation performance of the container is a technical problem that needs to be solved urgently by those skilled in the art at present. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a liquid hydrogen cylinder and a manufacturing method thereof, which remove the vapor-cooling screen structure and can improve the heat insulation performance of the container only by using a cold screen coil.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A liquid hydrogen cylinder includes an outer cylinder, an inner cylinder disposed inside the outer cylinder, an inner heat insulation layer wrapped around the outer circumference of the outer wall of the inner cylinder, an outer heat insulation layer wrapped on the outer wall of the inner heat insulation layer, and a cold screen coil disposed between the outer heat insulation layer and the inner heat insulation layer. An insulation sleeve is sleeved on the outer wall of the cold screen coil, and both the inner heat insulation layer and the outer heat insulation layer cover the front and rear end heads of the inner cylinder.

[0007] Preferably, the cold screen coil includes an inlet pipe, a coil, and an exhaust pipe that are sequentially connected. The inlet pipe is connected to the end of the inner cylinder, and the exhaust pipe is used to be connected to a hydrogen utilization device.

[0008] Preferably, both the intake pipe and the exhaust pipe are arranged near the front head or the rear head of the inner container.

[0009] Preferably, the coil pipes are spirally and evenly wound around the inner heat insulation layer at intervals, and the distance between the pipe bodies of adjacent coil pipes is equal to twice the thickness of the heat insulation sleeve.

[0010] Preferably, fixing parts for fixing the intake pipe and the exhaust pipe are arranged on the inner container.

[0011] Preferably, the intake pipe is provided with an external thread, and the connection end of the inner container and the intake pipe is provided with an internal thread matching the external thread.

[0012] Preferably, the coil pipe is an austenitic stainless steel pipe, the diameter of the coil pipe is less than or equal to 10 mm, the wall thickness of the coil pipe is greater than or equal to 1.5 mm, the roundness tolerance of the coil pipe is ±2 mm, and the ferrite content of the coil pipe is less than or equal to 3%.

[0013] Preferably, a vacuum layer is formed between the inner wall of the outer container and the outer wall of the inner container.

[0014] Preferably, the inner heat insulation layer, the outer heat insulation layer and the heat insulation sleeve are fixed by binding with fiberglass ropes.

[0015] The present invention also discloses a manufacturing method of a liquid hydrogen cylinder, which is applied to the liquid hydrogen cylinder described above, and includes the following steps:

[0016] After the inner container is manufactured, the inner heat insulation layer is used to cover the inner container. When pipelines protrude or other components appear, the inner heat insulation layer is perforated. The inner heat insulation layer is fixed with fiberglass ropes, and stainless steel wires are longitudinally wound around the bottle body wrapped with the inner heat insulation layer at equal intervals;

[0017] The coil pipes are surrounded by the heat insulation sleeve. The heat insulation sleeve is made into an intestinal shape, and is sleeved from the front end of the intake pipe of the coil pipe and ends at the rear end of the outlet pipe, and is tied in sections with fiberglass ropes;

[0018] The coil pipes with the heat insulation sleeve fixed are wound around the inner container;

[0019] The intake pipe and the exhaust pipe are respectively connected to the coil pipes;

[0020] The outer heat insulation layer is wrapped around the circumferential direction of the coil pipes surrounded by the heat insulation sleeve to cover the front and rear heads of the coil pipes and the inner container, and is fixed with fiberglass ropes;

[0021] The outer container is closed, and the space between the outer container and the inner container is evacuated.

[0022] The present invention has achieved the following technical effects compared with the prior art:

[0023] By sequentially arranging an inner heat insulation layer, a cold shield coil, and an outer heat insulation layer on the outer side of the inner container, and sleeving a heat insulation sleeve on the outer wall of the cold shield coil, the inner heat insulation layer and the outer heat insulation layer can significantly reduce the external heat from entering the inner container through solid conduction. The heat insulation sleeve sleeved on the cold shield coil further blocks the heat transfer path, forming a gradient temperature distribution, reducing the overall heat flux density. Without setting up a vapor cooling shield structure, only using the cold shield coil to improve the heat insulation performance of the container can effectively ensure the heat insulation effect on the liquid hydrogen in the inner container, which can greatly simplify the structure of the device. Moreover, both the inner heat insulation layer and the outer heat insulation layer cover the front and rear heads of the inner container, which can eliminate the heat insulation layer gap caused by the deformation of the head surface and block the solid heat conduction path formed by the direct contact of the metal shell, further ensuring the heat insulation effect. Brief Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0025] Attached Figure 1 is a schematic diagram of the overall structure of the liquid hydrogen cylinder after removing the heat insulation layer disclosed in the present invention;

[0026] Attached Figure 2 is a schematic diagram of the overall structure of the liquid hydrogen cylinder after covering the heat insulation layer disclosed in the present invention

[0027] Among them, 1, exhaust pipe; 2, inner container; 3, fixing member; 4, inlet pipe; 5, coil; 6, inner heat insulation layer; 7, outer heat insulation layer; 8, heat insulation sleeve; 9, fiberglass rope; 10, outer container. Detailed Embodiments

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] In the description of the invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0030] The purpose of the present invention is to provide a liquid hydrogen cylinder and a manufacturing method thereof, which removes the vapor cooling screen structure and can improve the insulation performance of the container only by using a cold screen coil.

[0031] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Reference Figure 1 and Figure 2 As shown in and, the liquid hydrogen cylinder disclosed in the embodiment of the present invention at least includes an outer cylinder 10. An inner cylinder 2 is arranged inside the outer cylinder 10. An inner insulation layer 6 is wrapped around the outer wall of the inner cylinder 2 in the circumferential direction. An outer insulation layer 7 is wrapped on the outer wall of the inner insulation layer 6. A cold screen coil is arranged between the inner insulation layer 6 and the outer insulation layer 7. An insulation sleeve 8 is sleeved on the outer wall of the cold screen coil. Both the inner insulation layer 6 and the outer insulation layer 7 cover the front and rear end heads of the inner cylinder 2. By sequentially arranging the inner insulation layer 6, the cold screen coil and the outer insulation layer 7 outside the inner cylinder 2, and sleeving the insulation sleeve 8 on the outer wall of the cold screen coil, the inner insulation layer 6 and the outer insulation layer 7 can significantly reduce the external heat from entering the inner cylinder 2 through solid conduction. The insulation sleeve 8 sleeved on the cold screen coil further blocks the heat transfer path, forms a gradient temperature distribution, reduces the overall heat flux density, and there is no need to set a vapor cooling screen structure. Only using the cold screen coil to improve the insulation performance of the container can effectively ensure the insulation effect on the liquid hydrogen in the inner cylinder 2, which can greatly simplify the structure of the device. Moreover, both the inner insulation layer 6 and the outer insulation layer 7 cover the front and rear end heads of the inner cylinder 2, which can eliminate the insulation layer gap caused by the deformation of the end head curved surface and block the solid heat conduction path formed by the direct contact of the metal shell, further ensuring the insulation effect.

[0033] It should be noted that the inner insulation layer 6, the outer insulation layer 7 and the insulation sleeve 8 can be insulation quilts, or multi-layer aluminum foils or carbon fiber composite materials with low thermal conductivity.

[0034] Reference Figure 1 and Figure 2, in one embodiment, the cold screen coil includes an intake pipe 4, a coil 5, and an exhaust pipe 1 that are connected in sequence. The intake pipe 4 is connected to the end of the inner tank 2, specifically arranged at a position of the inner tank 2 close to the front head. The exhaust pipe 1 is used to communicate with a hydrogen utilization device. Since the temperatures of different parts of the liquid hydrogen cylinder are inconsistent, a "stratification" phenomenon will occur in the inner tank 2. That is, due to the convection effect, the liquid hydrogen with a higher temperature is concentrated in the upper part of the storage tank, and the liquid hydrogen with a lower temperature sinks to the lower part. As a result, the vapor pressure in the upper part of the inner tank 2 increases, while there is almost no change in the lower part, leading to uneven pressure on the inner tank 2. Therefore, during storage, it is necessary to discharge the gaseous hydrogen in the upper part to ensure safety. So, by connecting the intake pipe 4 to the inner tank 2, the relatively warm hydrogen can be led out of the inner tank 2 through the coil 5, which not only avoids excessive vapor pressure in the upper part of the inner tank 2 causing uneven stress on the cylinder body but also reduces the temperature difference between the upper and lower parts of the inner tank 2, preventing a large amount of vapor from being generated inside the gas cylinder. Connecting the exhaust pipe 1 to the hydrogen utilization device can maximize the utilization of liquid hydrogen.

[0035] Reference Figure 1 and Figure 2 , as a preferred method, both the intake pipe 4 and the exhaust pipe 1 are arranged close to the front head or the rear head of the inner tank 2. That is, the intake pipe 4 and the exhaust pipe 1 are arranged on the same side, which can ensure that the flow path of the cryogenic medium (such as liquid hydrogen) in the coil 5 is symmetrical, avoiding local temperature gradients caused by the temperature difference between the intake pipe 4 and the exhaust pipe 1, thereby reducing the risk of stress fatigue of the pipeline material due to thermal expansion and contraction. Moreover, arranging the intake pipe 4 and the exhaust pipe 1 on the same side can also facilitate the installation of subsequent valves.

[0036] Reference Figure 1 and Figure 2 , in one embodiment, the coil 5 is spirally and evenly wound around the inner insulation layer 6 at intervals. The distance between the pipe bodies of adjacent coils 5 is equal to twice the thickness of the insulation sleeve 8. That is, after the coil 5 sleeved with the insulation sleeve 8 is wound, there is no gap between the insulation sleeves 8 of adjacent coil pipe bodies, which can further ensure the insulation effect.

[0037] Reference Figure 1 and Figure 2 , as a preferred method, fixing parts 3 for fixing the intake pipe 4 and the exhaust pipe 1 are provided on the inner tank 2, which can facilitate the installation of the intake pipe 4 and the exhaust pipe 1 and prevent the intake pipe 4 and the exhaust pipe 1 from shifting.

[0038] Reference Figure 1 and Figure 2 , as a preferred method, the intake pipe 4 is provided with an external thread, and the connection end of the inner tank 2 and the intake pipe 4 is provided with an internal thread that matches the external thread, which can facilitate the fixation of the intake pipe 4 and the inner tank 2.

[0039] It should be noted that the connection end of the intake pipe 4 and the inner tank 2 can also be welded.

[0040] Reference Figure 1 and Figure 2 , as an implementation method, the coil pipe 5 is an austenitic stainless steel pipe, the diameter of the coil pipe 5 is less than or equal to 10 mm, the wall thickness of the coil pipe 5 is greater than or equal to 1.5 mm, the roundness tolerance of the coil pipe 5 is ±2 mm, and the ferrite content of the coil pipe 5 is less than or equal to 3%. This can not only reduce the bending and assembly difficulty, but also effectively resist the phenomenon of hydrogen embrittlement.

[0041] It should be noted that the material of the coil pipe 5 needs to be inspected and qualified, without defects such as deformation and cracks. Except for the U-shaped pipe at the connection of the two coil pipes 5 (that is, when the coil pipe 5 winds from the front head of the inner tank 2 to the rear head, there will be a bend at the bend, and the U-shaped pipe is used to connect another section of the coil pipe 5 at the bend, and then winds back to the front head) and the connections of the coil pipe 5 with the intake pipe 4 and the exhaust pipe 1 can be welded, welding is not allowed at other positions.

[0042] The coil pipe 5 needs to be degreased and defatted. The inlet and outlet ends of the coil pipe 5 are welded or a ferrule external thread joint is used to connect with the intake pipe 4 and the exhaust pipe 1.

[0043] Reference Figure 1 and Figure 2 , as an implementation method, the space formed between the inner wall of the outer tank 10 and the outer wall of the inner tank 2 is evacuated. The vacuum environment eliminates the collision heat transfer between gas molecules, making solid heat conduction the main heat transfer method, and further improving the heat insulation effect.

[0044] Reference Figure 1 and Figure 2 , as an implementation method, the inner heat insulation layer 6, the outer heat insulation layer 7 and the heat insulation sleeve 8 are tied and fixed by a glass fiber rope 9. By using the glass fiber rope 9 to bundle and fix the multi-layer heat insulation structure in different regions, the fitting degree of each layer can be accurately controlled.

[0045] The present invention also discloses a manufacturing method of a liquid hydrogen cylinder, which is applied to the liquid hydrogen cylinder described above, and includes the following steps:

[0046] After the inner tank 2 is manufactured, a ferrule internal thread joint is welded or installed at the connections of the intake pipe 4, the exhaust pipe 1 and the coil pipe 5, and the intake pipe 4 and the exhaust pipe 1 are fixed on the front head of the inner tank 2 by a fixing member 3; the inner heat insulation layer 6 is used to cover the inner tank 2, and when there are pipelines extending out or other components, the inner heat insulation layer 6 is perforated, the inner heat insulation layer 6 is fixed by a glass fiber rope 9, and three stainless steel wires are longitudinally wound around the bottle body wrapped with the inner heat insulation layer 6 at equal intervals. Through the stainless steel wires wound on the inner heat insulation layer 6, a wire loop can be formed for subsequent fixing of the coil pipe 5, and the joint position is processed to avoid the stainless steel wires scratching the inner heat insulation layer 6;

[0047] The coiled pipe 5 is surrounded by a heat-insulating sleeve 8. The heat-insulating sleeve 8 is made into an intestinal shape and is sleeved from the front end of the intake pipe 4 of the coiled pipe 5 and ends at the rear end of the exhaust pipe. It is bundled in sections with a fiberglass rope 9.

[0048] The coiled pipe 5 with the heat-insulating sleeve 8 fixed is surrounded on the inner tank 2. During the winding process, it is necessary to ensure that the inner heat-insulating layer 6 is not damaged. After being sleeved, the coiled pipe 5 is fixed to the wire ring formed by stainless steel wires on the inner tank 2 with stainless steel wires. The joint position is well-treated to avoid both the forward and backward sliding of the coiled pipe 5 and the scratching of the inner heat-insulating layer 6 by the stainless steel wires.

[0049] Connect the intake pipe 4 and the exhaust pipe 1 to the coiled pipe 5 respectively.

[0050] An outer heat-insulating layer 7 is wrapped around the circumference of the coiled pipe 5 with the heat-insulating sleeve 8, covering the front and rear end caps of the coiled pipe 5 and the inner tank 2, and is fixed with a fiberglass rope 9. When encountering pipelines extending out or other components, the outer heat-insulating layer is perforated to further ensure the heat-insulating performance of the inner tank 2 and at the same time ensure that the coiled pipe 5 does not shift forward and backward.

[0051] Close the outer tank 10 and evacuate the space between the inner wall of the outer tank 10 and the outer wall of the inner tank 2.

[0052] It should be noted that for those skilled in the art, obviously, the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A liquid hydrogen cylinder, characterized in that, It includes an outer container, an inner container disposed within the outer container, an inner heat insulation layer wrapped around the outer circumference of the outer wall of the inner container, an outer heat insulation layer wrapped around the outer wall of the inner heat insulation layer, and a cold shield coil disposed between the outer heat insulation layer and the inner heat insulation layer. An insulation sleeve is sleeved on the outer wall of the cold shield coil, and both the inner heat insulation layer and the outer heat insulation layer cover the front and rear end heads of the inner container.

2. The liquid hydrogen cylinder according to claim 1, wherein The cold shield coil includes an intake pipe, a coil pipe, and an exhaust pipe that are sequentially connected. The intake pipe is connected to the end of the inner container, and the exhaust pipe is used to be connected to a hydrogen utilization device.

3. The liquid hydrogen cylinder according to claim 2, characterized in that, Both the intake pipe and the exhaust pipe are disposed near the front end head or the rear end head of the inner container.

4. The liquid hydrogen cylinder according to claim 2, wherein, The coil pipe is spirally and evenly spaced around the inner heat insulation layer, and the distance between the pipe bodies of adjacent coil pipes is equal to twice the thickness of the insulation sleeve.

5. The liquid hydrogen cylinder according to claim 3, wherein, Fixing members for fixing the intake pipe and the exhaust pipe are provided on the inner container.

6. The liquid hydrogen cylinder according to claim 3, wherein, The intake pipe is provided with an external thread, and the connection end of the inner container and the intake pipe is provided with an internal thread that mates with the external thread.

7. The liquid hydrogen cylinder according to claim 1, characterized in that, The coil pipe is an austenitic stainless steel pipe, the diameter of the coil pipe is less than or equal to 10 mm, the wall thickness of the coil pipe is greater than or equal to 1.5 mm, the roundness tolerance of the coil pipe is ±2 mm, and the ferrite content of the coil pipe is less than or equal to 3%.

8. The liquid hydrogen cylinder according to claim 1, wherein A vacuum layer is formed between the inner wall of the outer container and the outer wall of the inner container.

9. The liquid hydrogen cylinder according to claim 1, characterized in that, The inner heat insulation layer, the outer heat insulation layer, and the insulation sleeve are fixed by binding with fiberglass ropes.

10. A manufacturing method of a liquid hydrogen cylinder, characterized in that, When applied to the liquid hydrogen cylinder according to any one of claims 1 to 9, it includes the following steps: After the inner container is manufactured, the inner heat insulation layer is used to wrap the inner container. When there are pipelines extending out or other components, the inner heat insulation layer is perforated. The inner heat insulation layer is fixed with fiberglass ropes, and stainless steel wires are longitudinally wound around the bottle body with the inner heat insulation layer wrapped at equal intervals. The coil pipe is surrounded by the insulation sleeve. The insulation sleeve is made into an intestinal shape, inserted from the front end of the intake pipe of the coil pipe, and terminated at the rear end of the outlet pipe, and is tied in sections with fiberglass ropes. The coil pipe with the insulation sleeve fixed is wound around the inner container. The intake pipe and the exhaust pipe are respectively connected to the coil pipe. The outer heat insulation layer is wrapped around the circumference of the coil pipe with the insulation sleeve, covering the coil pipe and the front and rear end heads of the inner container, and fixed with fiberglass ropes. The outer container is closed, and the space between the outer container and the inner container is evacuated.

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