A method of wrapping a liquid hydrogen tank

Abstract

The application discloses a winding and assembling method for a liquid hydrogen storage tank, which comprises the following steps: fixing an inner container on a rotatable winding tool, rotating at a constant speed to layer by layer wind a plurality of layers of heat insulation materials and simultaneously stitch; after winding, hoisting the inner container, installing movable wheels on a load bearing support at the bottom of the inner container; laying a guide rail inside an outer shell, and horizontally hoisting the inner container to the starting end of the guide rail; sliding the movable wheels along the guide rail to horizontally move the inner container into the outer shell, and alternately switching hoisting points to remove the movable wheels in sections; supporting the inner container by the load bearing support to adjust the concentricity of the inner container and the outer shell; after fixing the inner container, sealing both ends of the outer shell and performing air tightness detection; introducing dry nitrogen into the inner container to replace moisture and air; after replacement, vacuumizing to a set vacuum degree, and completing assembly. The method realizes lossless winding and assembly of the plurality of layers of heat insulation materials, solves the manufacturing problem of the large capacity storage tank, reduces welding seam and material exposure time, and improves the quality and production efficiency of the storage tank.

Description

Technical Field

[0001] This invention pertains to the field of liquid hydrogen storage tank manufacturing technology, and specifically relates to a method for winding and assembling a liquid hydrogen storage tank. Background Technology

[0002] In the field of cryogenic storage and transportation, high-vacuum multilayer insulation technology is widely used in the insulation systems of liquid hydrogen storage tanks due to its excellent thermal insulation performance. Multilayer insulation materials are usually composed of aluminum foil and glass fiber paper. The aluminum foil effectively blocks radiative heat transfer due to its low emissivity, while the glass fiber paper uses its porous structure to suppress convection and conduction heat transfer. The synergistic effect of the two can improve the insulation performance to several times that of traditional insulation materials, meeting the stringent cryogenic storage requirements of liquid hydrogen (boiling point -252.8℃).

[0003] However, existing manufacturing processes face significant challenges in the production of large-capacity storage tanks. In the winding process, the manufacturing of small-capacity storage tanks often relies on specialized rotary winding fixtures, which can achieve precise tension control and uniform laying. However, due to the excessive size of large-capacity storage tanks, small fixtures are difficult to adapt. Customizing large-scale specialized equipment not only has a long development cycle, but also presents a contradiction between the high purchase and maintenance costs and the low frequency of use in non-mass production models, making it unaffordable for most companies. Regarding the assembly process, while conventional overhead crane assembly is simple to operate, it requires insulation materials with high damage resistance. The easily wrinkled nature of aluminum foil and the brittle nature of fiberglass paper make them highly susceptible to damage during lifting friction and collisions, compromising the integrity of the insulation layer. The segmented assembly method, which disassembles the outer shell into multiple sections and assembles the insulation layer separately, reduces the difficulty of a single operation. However, the added welding process not only prolongs the production cycle but also significantly increases the exposure time of the multi-layer insulation material to air. This leads to the adsorption of large amounts of moisture and impurities from the environment, causing a decrease in subsequent vacuum replacement efficiency and an exponential increase in vacuuming difficulty, severely impacting the vacuum life and insulation performance of the storage tank. Therefore, these technical bottlenecks restrict the large-scale production and application of large-volume, high-vacuum, multi-layered insulated liquid hydrogen storage tanks. Summary of the Invention

[0004] The purpose of this invention is to provide a method for winding and assembling liquid hydrogen storage tanks. This invention enables non-destructive winding and assembly of multi-layer insulation materials, solving the manufacturing challenges of large-volume storage tanks, reducing weld seam and material exposure time, and replacing traditional drying ovens with nitrogen purging, thereby improving storage tank quality and production efficiency.

[0005] The technical solution of the present invention: a method for winding and assembling a liquid hydrogen storage tank, comprising the following steps:

[0006] Step 1: In a clean environment, fix the inner container to a rotatable winding fixture, drive the inner container to rotate at a uniform speed, wind multiple layers of insulation material and sew them together simultaneously.

[0007] Step 2, after winding is completed, hoist the inner container and install the moving wheels on the load-bearing support at the bottom of the inner container;

[0008] Step 3, lay the guide rail inside the shell, and hoist the inner container horizontally to the starting end of the guide rail;

[0009] Step 4, slide the moving wheels along the guide rail to move the inner container horizontally into the shell, and alternately switch the hoisting points during the moving process to remove the moving wheels in sections;

[0010] Step 5, support the inner container by the load-bearing support, and adjust the concentricity of the inner container and the shell by the radial positioning tool;

[0011] Step 6, after the inner container is fixed, seal the two ends of the shell and conduct the air tightness test;

[0012] Step 7, introduce dry nitrogen into the inner container, and heat the outer surface of the shell to make the nitrogen in the interlayer circulate to replace moisture and air;

[0013] Step 8, after the replacement is completed, vacuumize to the set vacuum degree to complete the manufacturing and assembly of the liquid hydrogen storage tank.

[0014] The winding and assembling method of the liquid hydrogen storage tank, in step 1, the humidity of the clean environment is controlled below 50%; the heat insulation material is a combination of aluminum foil and glass fiber paper.

[0015] The winding and assembling method of the liquid hydrogen storage tank, the winding tool includes a winding drum, a standard roller frame, a permanent connection tool and an intermediate lifting lug; wherein the standard roller frame is symmetrically arranged below the two ends of the inner container to support the inner container, the winding drum is arranged in parallel on one side of the inner container and maintains a preset distance with the inner container, and the permanent connection tool is fixed to the end of the inner container and forms a transmission connection with the winding drum; the intermediate lifting lug is arranged at the connection position of the head and the cylinder body at the two ends of the inner container, and the hoisting axis of the intermediate lifting lug is parallel to the axis of the inner container.

[0016] The winding and assembling method of the liquid hydrogen storage tank, in step 2, the assembling lifting lug is used for hoisting, and the assembling lifting lug is symmetrically arranged at the middle position of the outer surface of the inner container.

[0017] The winding and assembling method of the liquid hydrogen storage tank, in step 3, the guide rail is laid along the axial direction of the shell, a limiting block is arranged on the guide rail, and a support plate is arranged on one side of the guide rail.

[0018] The winding and assembling method of the liquid hydrogen storage tank, in step 4, the alternately switched hoisting points use the intermediate lifting lug; when the inner container is moved into the shell and the intermediate lifting lug passes out of the shell port, the intermediate lifting lug is used as the stress point for subsequent hoisting and removal of the moving wheels.

[0019] In the winding and sleeving method of the liquid hydrogen storage tank, the load-bearing supports are arranged on the inner bottom of the shell and symmetrically distributed along the axial direction of the shell, and the top of the load-bearing supports is matched with the supporting part of the outer surface of the inner container; the load-bearing supports bear the weight of the inner container after the removal of the moving wheels and the guide rails, and realize the front and rear positioning and stable support of the inner container.

[0020] In the winding and sleeving method of the liquid hydrogen storage tank, the radial positioning tool is arranged on the inner wall of the shell; the outer surface of the inner container is provided with a radial supporting point; when positioning, the radial positioning tool and the radial supporting point are in contact to form rigid limiting to ensure the coaxiality of the inner container and the shell.

[0021] In the winding and sleeving method of the liquid hydrogen storage tank, in step 6, flanges are used for sealing the two ends of the shell, metal winding gaskets are arranged on the sealing surfaces of the flanges, and the helium mass spectrometry leak detection method is used for the air tightness detection.

[0022] In the winding and sleeving method of the liquid hydrogen storage tank, in step 7, dry circulating nitrogen is introduced into the inner container, and the temperature of the nitrogen is set to be higher than 120 DEG C.

[0023] Compared with the prior art, the present application realizes the lossless winding of the heat insulation material of the storage tank with different volumes through the lossless rapid winding process of the multi-layer heat insulation material, avoids the aluminum foil wrinkles and the glass fiber paper breakage, guarantees the heat preservation performance, and does not need to purchase expensive large special equipment, but only needs to modify the existing equipment, thereby reducing the equipment investment cost. Through the lossless horizontal assembly process, the present application realizes the rapid lossless sleeving of the vertical and horizontal storage tanks with different sizes, greatly shortens the sleeving time, reduces the total number of welding seams of the shell, shortens the exposure time of the heat insulation material, reduces the welding risk and water vapor impurity adsorption, guarantees the vacuum performance. Through the nitrogen replacement process, the present application replaces the traditional drying room, breaks through the size limitation, avoids the damage of the heat insulation material in the transfer process, eliminates the high-temperature safety hazard and the secondary moisture absorption problem, ensures the long-lasting dry effect, and improves the manufacturing quality and production efficiency of the liquid hydrogen storage tank. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structure schematic diagram of the lossless rapid winding tool;

[0025] Figure 2 It is an enlarged structure schematic diagram of the lossless rapid winding tool;

[0026] Figure 3 It is a sleeving hoisting point schematic diagram;

[0027] Figure 4 It is a sleeving tool position schematic diagram;

[0028] Figure 5 It is a track schematic diagram;

[0029] Figure 6 is a schematic diagram of the moving of the wrapping tool set;

[0030] Figure 7 is a schematic diagram of the enlarged structure of the wrapping tool set;

[0031] Figure 8 is a schematic diagram of the radial positioning tool;

[0032] Figure 9 is a schematic diagram of the nitrogen replacement

[0033] Reference signs

[0034] 1, winding drum; 2, inner container; 3, standard roller frame; 4, permanent connection tool; 5, intermediate lifting lug; 6, wrapping lifting lug; 7, load-bearing support; 8, moving wheel; 9, guide rail; 10, limiting block; 11, support plate; 12, radial support point; 13, radial positioning tool; 14, external heating device; 15, nitrogen storage tank; 16, circulating fan; 17, electric heater. DETAILED DESCRIPTION

[0035] The application will be further described below in conjunction with the drawings and examples, but it is not limited to the basis of the application.

[0036] Example 1: A wrapping tool set method for a liquid hydrogen storage tank, comprising the following steps:

[0037] Step 1: In a clean environment, fix the inner container 2 on the rotatable wrapping tool, drive the inner container 2 to rotate at a constant speed, wrap multiple layers of heat insulation material and simultaneously sew;

[0038] In this step, as Figures 1-3As shown, the winding tool includes a winding roller 1, a standard roller frame 3, a permanent connection tool 4 and an intermediate lifting lug 5; wherein the standard roller frame 3 is symmetrically arranged below both ends of the inner container 2 to support the inner container 2, the winding roller 1 is arranged in parallel with the inner container 2 on one side of the inner container 2 and maintains a preset interval (such as 50-100 mm, which can be adjusted according to the thickness of the heat insulation material) with the inner container 2, the permanent connection tool 4 is fixed to the end of the inner container 2 and forms a transmission connection with the winding roller 1, and the intermediate lifting lug 5 is arranged at the connection position between the head and the cylinder of the inner container 2 at both ends, and the lifting axis of the intermediate lifting lug 5 is parallel to the axis of the inner container 2. After the inner container 2 is combined with the winding tool, the inner container 2 is slowly rotated, and the outer surface of the inner container 2 is completely cleaned of grease, impurities and moisture, then the humidity is ensured to be below 50% in a clean environment, the multi-layer heat insulation material for winding is prepared, and the heat insulation material is a combination of aluminum foil and glass fiber paper. Then the inner container 2 is slowly rotated, the heat insulation material is wound layer by layer, and the heat insulation material is stitched layer by layer to ensure uniform distribution of the heat insulation material. In this embodiment, the overlap width of each layer of aluminum foil and glass fiber paper is 50-80 mm, the stitching line is made of glass fiber line, and the stitching interval is 150-200 mm.

[0039] This step is a kind of lossless and fast winding process, which has the advantages of breaking the limitation of conventional process mainly suitable for small volume containers, and can be wound by this process whether it is a small or large container. And without purchasing new, expensive large special equipment, by modifying or adjusting the existing relatively simple equipment in the factory, the manufacturing needs of the new process can be met, which significantly reduces the initial investment threshold. The core of this step process is that the size of the key components can be adjusted, which is crucial for winding large volume containers. By accurately adjusting the key size, the winding process can be optimized, effectively dispersing and reducing the stress of the local area of the container during winding, ultimately ensuring that the local stress of the container after winding and during use does not exceed the material allowable limit, protecting the structural integrity of the container, avoiding premature failure or body damage due to excessive local stress, which is the core contribution of the process in safety.

[0040] Step 2, after winding is completed, remove the bolts between the winding roller 1 and the intermediate lifting lug 5, and use the set lifting lug 6 to lift the inner container 2, as shown in Figure 3 As shown, the set lifting lug 6 is symmetrically arranged at the middle position of the outer surface of the inner container 2, a standard lifting ring nut is installed, the entire inner container 2 is lifted by two cranes, and a plurality of movable wheels 8 are installed on the load-bearing support 7 at the bottom of the inner container 2, as shown in Figure 4 .

[0041] Step 3, lay the guide rail 9 inside the shell, and horizontally lift the inner container 2 to the starting end of the guide rail 9; as shown in Figures 5-7As shown in the figure, the guide rail 9 is laid along the direction of the shell axis, and a limiting block 10 is arranged on the guide rail 9. A support plate 11 is arranged on one side of the guide rail 9, and the support plate 11 is used for mounting the guide rail 9 and the shell. The distance between the top surface of the guide rail 9 and the inner wall of the bottom of the shell is 200-300 mm.

[0042] Step 4, hoist the inner container 2 for packaging, slowly move the inner container 2, so that the first group of moving wheels 8 contact the guide rail 9, then pause the movement, remove the connection between the ring nut of the hoisting ring closest to the shell and the packaging lifting lug 6, and move the first vehicle away. Then, the front traction and the slow movement of the second vehicle slowly package, when the middle lifting lug 5 is pulled out of the shell and the rear moving wheels 8 contact the guide rail 9, the first vehicle is re-hoisted on the middle lifting lug 5; remove the connection between the ring nut of the hoisting ring of the second vehicle and the packaging lifting lug 6, and move the second vehicle to the rear end and re-hoist it on the middle lifting lug 5. Slowly move the inner container 2 to adjust to the appropriate position, slightly lift the inner container 2 to facilitate the removal of the moving wheels 8; after the moving wheels 8 are removed, the guide rail 9 is removed by using a forklift.

[0043] Step 5, slowly adjust the position of the inner container 2, support the inner container 2 by using the load-bearing support 7, and adjust the concentricity of the inner container 2 and the shell by using the radial positioning tool 13; as shown in the figure, Figure 6 and Figure 7 As shown in the figure, the load-bearing support 7 is arranged on the inner bottom of the shell and is symmetrically distributed along the direction of the shell axis. The top of the load-bearing support 7 is adapted to the support part of the outer surface of the inner container. After the moving wheels and the guide rail are removed, the load-bearing support 7 bears the weight of the inner container, realizes the front and rear positioning of the inner container, and stably supports the inner container. As shown in the figure, Figure 8 The radial positioning tool 13 is arranged on the inner wall of the shell. The outer surface of the inner container 2 is provided with a radial support point 12. When positioning, the radial positioning tool 13 and the radial support point 12 are in contact to form a rigid limit, which ensures the coaxiality of the inner container 2 and the shell, and the error is not more than 0.5 mm.

[0044] Step 6, after all the positioning is completed, the load-bearing support 7 supports the inner container, the radial positioning tool 13 is removed, and the two ends of the shell are sealed and subjected to air tightness detection. In this step, the flange connection is used for sealing the two ends of the shell, the metal winding gasket is arranged on the sealing surface of the flange, and the helium mass spectrometry leak detection method is used for air tightness detection.

[0045] Step 7, the inner container 2 is supplied with dry and clean circulating nitrogen, which is used for heating the inner container 2. Dry and clean nitrogen is supplied into the interlayer, which is used for replacing the moisture and air in the interlayer. The external heating device 14 is wound on the outer surface of the shell, which is used for heating the shell. The inner and outer surfaces jointly act on the nitrogen in the interlayer, and the temperature of the nitrogen is required to be above 120℃, and the nitrogen is replaced for multiple times. In this step, as shown in the figure, Figure 9As shown, the device circulating nitrogen nitrogen storage tank 15, circulating fan 16 and electric heater 17, nitrogen storage tank 15 provides nitrogen source, through circulating fan 16 and electric heater 17 form 120 ℃ above the nitrogen gas flow circulation. The external heating device 14 of the outer surface of the shell is a winding type electric heating belt, which is controlled by an electric control cabinet. The winding density of the electric heating belt is 5-8 turns per meter of shell length, and the adhesion to the outer surface of the shell is not less than 90%.

[0046] Step 8, after displacement, vacuum to the set vacuum degree, complete the manufacture and assembly of liquid hydrogen tank.

[0047] In this embodiment, steps 2-6 are a non-destructive horizontal assembly process for a liquid hydrogen tank. Through carefully designed steps and tooling, the sleeve is realized by using guide rail 9, which is extremely efficient and only takes about 1 hour. This process is accurate and reliable, and can ensure zero damage to the multi-layer insulation material, especially solving the problem of horizontal container sleeve. This process has wide application range, and is suitable for vertical, horizontal and different size containers; for large containers, the shell can be segmented, thereby significantly reducing the number of total assembly welds, shortening the welding and sealing processing time, and reducing the risk of damage to the insulation material. Because the exposure time of the insulation material is reduced, the insulation performance is maximized, and the efficiency, non-destructiveness, applicability and protection of the insulation performance are all more advantageous than traditional lifting.

[0048] In this embodiment, step 7 is a nitrogen displacement process. The core purpose of this process is to replace the traditional oven by completely eliminating the moisture in the multi-layer insulation material and the interlayer to ensure and improve the vacuum insulation performance. Compared with the traditional oven, it has the following advantages: no need to build a special oven, saving cost and space, and not limited by the size of the container, with wide applicability; can be operated in situ at the manufacturing or assembly station, avoiding damage to the multi-layer insulation material caused by transferring the container; usually only need to heat the nitrogen during operation, the equipment does not need to be moved and additional operation, the temperature is safe and controllable; by continuously introducing dry and high-temperature nitrogen to exhaust the moisture, it can efficiently dehumidify, and after displacement, it can quickly connect to the subsequent sealing process, greatly reducing the time of the insulation material exposed to humid air, effectively preventing secondary moisture absorption, ensuring the dry effect is lasting, and the process integration is more optimal.

[0049] Embodiment 2: According to the step process of embodiment 1, the manufacturing and assembly of a 50m³ horizontal liquid hydrogen tank is taken as an example, and the specific steps are as follows:

[0050] Step 1: Non-destructive winding of the inner container insulation material;

[0051] Environmental preparation: operation in a clean workshop, control the environmental humidity to 45% (≤50%) by the dehumidification system, and keep the temperature at 20-25℃ to avoid moisture absorption of the insulation material.

[0052] Tool installation: Place the inner container 2 (cylinder length 8 m, diameter 2.5 m) on both ends of the symmetrically arranged standard roller frame 3, the roller frame spacing is 6 m, and ensure that the inner container is horizontally supported; Weld the intermediate lifting lug 5 (a total of 2 groups, symmetrically distributed) at the connection part of the head and the cylinder at one end of the inner container 2, and the lug axis is parallel to the axis of the inner container; Connect the end of the inner container 2 with the winding drum 1 through the permanent connection tool 4, and the winding drum 1 is arranged on one side of the inner container with a distance of 80 mm from the outer surface of the inner container, forming a transmission cooperation.

[0053] Winding operation: A combination of aluminum foil (thickness 0.05 mm) and glass fiber paper (thickness 0.1 mm) is used as a thermal insulation material, and "aluminum foil + glass fiber paper" is used as a layer, a total of 30 layers are wound; Start the winding drum 1, drive the inner container 2 to rotate at a constant speed of 5 r / min, and layer by layer winding the thermal insulation material, each layer overlaps by 60 mm (overlaps in the direction of rotation), while stitching with glass fiber wire (diameter 0.5 mm), the stitching interval is 180 mm, to ensure that there is no wrinkle and no damage between the layers.

[0054] Step 2: Inner container hoisting and mobile wheel installation;

[0055] Hoisting preparation: Remove the connection between the winding drum 1 and the inner container, symmetrically weld 2 sets of fitted lifting lugs 6 (spacing 4 m) on the middle of the outer surface of the inner container, and install M30 standard lifting ring nuts.

[0056] Hoisting and wheel installation: Use two 50t cranes to hoist the inner container horizontally through the fitted lifting lugs 6 (hoisting height 1.2 m); Under the 4 groups of load-bearing supports 7 (symmetrically distributed along the axis) at the bottom of the inner container, install 1 group of mobile wheels 8 (load-bearing 10 t / group) with brakes, and ensure that the wheel spacing matches the subsequent guide rail.

[0057] Step 3: Shell guide rail laying and inner container positioning;

[0058] Guide rail installation: Lay 2 parallel guide rails 9 (material Q345B, cross-sectional size 100 mm x 100 mm) inside the shell (length 9 m, diameter 2.8 m) along the axis direction, the guide rail spacing is 1.5 m; Set a limiting block 10 (height 50 mm) every 2 m on the guide rail to prevent the wheel from slipping off; The guide rail is fixed to the inner wall of the shell through the support plate 11 (thickness 10 mm), ensuring that the top surface of the guide rail is 250 mm away from the bottom of the shell.

[0059] Inner container positioning: Move the inner container horizontally to the starting end of the guide rail through the crane, align the mobile wheels 8 with the guide rail, and slowly lower it onto the guide rail, and then release the crane hoisting.

[0060] Step 4: Inner container horizontally moves into the shell and wheel removal;

[0061] Segmented moving in: the front part is pulled by a traction device (pulling force 5t), while the rear part is pushed by a crane to assist, so that the inner container moves into the shell along the guide rail at a speed of 0.5m / min; when the front end intermediate lifting lug 5 is pulled out of the shell port (exposed length 300mm), the movement is paused, the front crane is lifted through the intermediate lifting lug 5, the lifting ring nut of the sleeved lifting lug 6 is removed, and the rear crane is moved away; continue to move the inner container, when the rear end intermediate lifting lug 5 is pulled out of the shell, the rear end intermediate lifting lug 5 is lifted by the rear crane, the front crane is removed, and the lifting point is alternately switched until the inner container is completely moved into the shell.

[0062] Wheel and guide rail removal: fine-tune the crane to lift the inner container by 50mm, and sequentially remove the 4 groups of moving wheels 8; use a forklift to pull out the guide rail 9 from the shell, and complete the track removal.

[0063] Step 5: Inner container positioning and concentricity adjustment;

[0064] Load support: slowly lower the inner container so that the 4 groups of load supports 7 fall on the support seats inside the shell, achieving front and rear positioning (axial deviation ≤2mm).

[0065] Radial positioning: 8 groups of radial positioning tools 13 (uniformly distributed along the circumference) are welded on the inner wall of the shell, which are in contact with the radial support points 12 (corresponding position welded boss) on the outer surface of the inner container; by adjusting the tightening bolts of the positioning tools (precision 0.02mm), the concentricity of the inner container and the shell is controlled within 0.3mm (detected by laser centering instrument), and after completion, the positioning tools are locked.

[0066] Step 6: Shell sealing and air tightness detection;

[0067] Sealing operation: low-temperature resistant metal winding gaskets (material 316L, suitable temperature -269℃) are installed between the flanges (diameter 2.8m) at both ends of the shell and the inner container head, and are fastened with M48 bolts, with a bolt pre-tightening force of 500N m.

[0068] Air tightness detection: a helium mass spectrometer leak detector is used to fill 0.2MPa helium gas into the interlayer between the shell and the inner container, detect the leakage rate, and ensure that the leakage rate is ≤5×10 -10 Pa m³ / s, and after passing, the gas is released.

[0069] Step 7: Nitrogen replacement and interlayer drying;

[0070] Equipment connection: dry nitrogen gas (dew point ≤-40℃) is introduced into the inner container, and a circulation is formed through a nitrogen gas storage tank 15→ circulating fan 16→ electric heater 17 (heated to 130℃), with a flow rate of 20m³ / h;

[0071] The electric heating belt (power 2kW / m) is wound on the outer surface of the shell, 6 turns per meter of shell are wound, the adhesion degree is 95%, and the temperature is kept above 120 DEG C through the electric control cabinet.

[0072] Substitution operation: nitrogen is continuously introduced for 3 hours, nitrogen in the interlayer is circulated, moisture and air are replaced (the dew point instrument is used to detect the gas at the outlet of the interlayer, and when the dew point is less than or equal to -60 DEG C, the operation is stopped).

[0073] Step 8: vacuumizing and assembling are completed;

[0074] The nitrogen valve is closed, the interlayer is vacuumized through the vacuum unit (limit vacuum 1x10 -5 Pa), the vacuum degree is stopped when reaching 5x10 -4 Pa, the pressure is kept for 24 hours, the vacuum degree decreases by less than or equal to 1x10 -4 Pa, and the manufacturing and assembling of the liquid hydrogen storage tank are completed.

[0075] In summary, the present application realizes the lossless winding of the heat insulation material of the storage tank with different volumes through the lossless and rapid winding process of the multilayer heat insulation material, avoids the aluminum foil wrinkle and the glass fiber paper breakage, guarantees the heat preservation performance, and does not need to purchase expensive large special equipment, but only needs to realize through the modification of the existing equipment, so that the equipment investment cost is reduced. Through the lossless horizontal assembly process, the vertical and horizontal, different size storage tanks are quickly and losslessly sleeved, the sleeving time is greatly shortened, the total number of welding seams of the shell is reduced, the exposure time of the heat insulation material is shortened, the welding risk and water vapor impurity adsorption are reduced, and the vacuum performance is guaranteed. Through the nitrogen replacement process, the traditional drying room is replaced, the size limit is broken, the damage of the heat insulation material in the transfer process is avoided, the high-temperature safety hidden danger and the secondary moisture absorption problem are eliminated, the dry effect is ensured to be durable, and the manufacturing quality and production efficiency of the liquid hydrogen storage tank are improved as a whole.

Claims

1. A method of wrapping a liquid hydrogen tank, characterized by, The method comprises the following steps: Step 1, in a clean environment, fix the inner container on a rotatable winding tool, drive the inner container to rotate at a constant speed, wind multiple layers of thermal insulation material and simultaneously stitch; the winding tool comprises a winding roller, a standard roller frame, a permanent connection tool and an intermediate lifting lug; wherein the standard roller frame is symmetrically arranged below the two ends of the inner container to support the inner container, the winding roller is arranged in parallel with the inner container on one side and maintains a preset distance with the inner container, and the permanent connection tool is fixed to the end of the inner container and forms a transmission connection with the winding roller; the intermediate lifting lug is arranged at the connection position of the head and the cylinder of the inner container at both ends, and the lifting axis of the intermediate lifting lug is parallel to the axis of the inner container; Step 2, after winding, remove the bolts between the winding roller and the intermediate lifting lug, use the sleeved lifting lug to hoist the inner container, and install the moving wheels on the load-bearing support at the bottom of the inner container; Step 3, lay the guide rail inside the shell, and horizontally hoist the inner container to the starting end of the guide rail; Step 4, slide the moving wheels along the guide rail to horizontally move the inner container into the shell, and alternately switch the hoisting points during the moving process to remove the moving wheels in sections; Step 5, support the inner container by the load-bearing support, and adjust the concentricity of the inner container and the shell by the radial positioning tool; Step 6, after fixing the inner container, seal the two ends of the shell and conduct the air tightness test; Step 7, introduce dry nitrogen into the inner container, and heat the outer surface of the shell to make the nitrogen in the interlayer circulate to replace moisture and air; Step 8, after the replacement is completed, vacuumize to a set vacuum degree to complete the manufacturing and assembly of the liquid hydrogen storage tank.

2. The method of claim 1, wherein the method further comprises: In step 1, the humidity of the clean environment is controlled below 50%; the thermal insulation material is a combination of aluminum foil and glass fiber paper.

3. The method of claim 1, wherein the method further comprises: In step 2, the sleeved lifting lug is symmetrically arranged at the middle position of the outer surface of the inner container.

4. The method of claim 1, wherein the method further comprises: In step 3, the guide rail is laid along the axis direction of the shell, a limiting block is arranged on the guide rail, and a support plate is arranged on one side of the guide rail.

5. The method of claim 1, wherein the method further comprises: In step 4, the alternately switched hoisting points use the intermediate lifting lug; when the intermediate lifting lug is pulled out from the port of the shell after the inner container is moved into the shell, the intermediate lifting lug is used as the stress point for subsequent hoisting and removal of the moving wheels.

6. The method of claim 1, wherein the method further comprises: In step 5, the load-bearing support is arranged at the bottom inside the shell and is symmetrically distributed along the axis direction of the shell, and the top thereof is matched with the support position on the outer surface of the inner container; after the moving wheels and the guide rail are removed, the load-bearing support bears the weight of the inner container to realize the front and rear positioning and stable support of the inner container.

7. The method of claim 1, wherein the method further comprises: In step 5, the radial positioning tool is arranged on the inner wall of the shell; the outer surface of the inner container is provided with a radial support point; during positioning, the radial positioning tool and the radial support point are in contact to form rigid limiting to ensure the coaxiality of the inner container and the shell.

8. The method of claim 1, wherein the method further comprises: In step 6, the flange connection is used for sealing the two ends of the shell, the metal winding gasket is arranged on the sealing surface of the flange, and the helium mass spectrometry leak detection method is used for the air tightness test.

9. The method of claim 1, wherein the method further comprises: In step 7, the dry circulating nitrogen introduced into the inner container has a temperature of above 120℃.

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