Low-temperature high-pressure double-layer hydrogen storage bottle and forming method thereof

Abstract

The low-temperature and high-pressure double-layer hydrogen storage bottle comprises an inner container, a bottle opening pipe is arranged at one end of the inner container in the axial direction of the hydrogen storage bottle, and an inner valve seat is arranged at the other end of the inner container; the heat insulation layer is arranged on the outer wall of the inner container; the outer container is provided with a through hole, the outer wall face of the bottle opening pipe is fixedly connected with the through hole, the outer container is provided with an outer valve seat corresponding to the inner valve seat, the outer container is formed in a segmented mode in the axial direction, and a vacuum layer is formed between the inner container and the outer container; one end of the connecting rod is connected with the inner valve seat, the other end of the connecting rod is connected with the outer valve seat, and the relative positions of the inner container and the outer container in the radial direction of the hydrogen storage bottle are fixed; the inner supporting frame is located in the vacuum layer, one axial end of the inner supporting frame is fixedly connected with the bottle opening pipe, the other axial end of the inner supporting frame is provided with a connecting ring, and the connecting ring is located on the periphery of the connecting rod and fixedly connected with the inner wall face of the outer container; the inner valve seat and the connecting ring are elastically connected in the axial direction through the elastic piece, so that the stress condition of the outer container in the low-temperature material adding and discharging process of the hydrogen storage bottle is improved, and the functional stability and safety of the double-layer hydrogen storage bottle are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of hydrogen storage container technology, and in particular to a low-temperature, high-pressure double-walled hydrogen storage bottle and its molding method. Background Technology

[0002] Low-temperature high-pressure hydrogen storage refers to the storage of hydrogen in a supercritical state at low temperatures (20°C) using insulated and pressure-resistant gas cylinders. This technology operates under a combination of 50K and high-pressure (35MPa) conditions. Compared to current high-pressure gaseous hydrogen storage, which typically operates at 70MPa, this technology achieves higher hydrogen storage density at lower pressures, thereby improving the system's hydrogen mass ratio. Compared to cryogenic liquid hydrogen storage, it offers better resistance to thermal disturbances and a longer "dormant" time, reducing hydrogen volatilization and extending storage time. Because it is designed to handle both high-pressure and cryogenic conditions, cryogenic high-pressure hydrogen storage also offers better safety than either method.

[0003] The aforementioned hydrogen storage method typically employs a double-walled hydrogen storage cylinder consisting of an inner liner and an outer liner. The inner liner serves as the low-temperature storage area, and to prevent temperature rise due to heat transfer, a vacuum insulation layer is installed between the inner and outer liner. Simultaneously, the outer liner also serves to fix and support the inner liner.

[0004] The inner liner needs to be resistant to high pressure and prevent hydrogen permeation. Its exterior is reinforced with carbon fiber winding, making it impossible to fix it to the surface using traditional methods such as welding or riveting. Typically, a valve seat is pre-embedded in the inner liner, connecting it to the outer liner. However, during the addition and discharging of cryogenic materials, the inner liner undergoes dimensional changes due to temperature variations, causing stress changes between the inner and outer liners. This can easily lead to connection failure, thus affecting the function and safety of the double-walled hydrogen storage cylinder. Summary of the Invention

[0005] In response to the shortcomings of the existing production technology, the applicant provides a low-temperature, high-pressure double-walled hydrogen storage cylinder and its molding method, thereby improving the stress on the outer liner of the hydrogen storage cylinder during the addition and discharge of low-temperature materials, and ensuring the functional stability and safety of the double-walled hydrogen storage cylinder.

[0006] The technical solution adopted in this invention is as follows: A low-temperature, high-pressure double-walled hydrogen storage cylinder, comprising: The inner liner has a bottle mouth tube at one end along the axial direction of the hydrogen storage bottle and an inner valve seat at the other end. An insulation layer is provided on the outer wall of the inner liner; The outer liner has a perforation, the outer wall of the bottle mouth tube is fixedly connected to the perforation, the outer liner has an outer valve seat corresponding to the inner valve seat, the outer liner is segmented along the axial direction, and a vacuum layer is formed between the inner liner and the outer liner; A connecting rod, one end of which is connected to the inner valve seat and the other end of which is connected to the outer valve seat, fixes the relative positions of the inner liner and the outer liner along the radial direction of the hydrogen storage bottle; An internal support frame, located within the vacuum layer, is fixedly connected to the bottle neck tube at one end along the axial direction, and a connecting ring is provided at the other end along the axial direction. The connecting ring is sleeved on the outer periphery of the connecting rod and fixedly connected to the inner wall surface of the outer liner. An elastic element elastically connects the inner valve seat and the connecting ring along the axial direction.

[0007] As a further improvement to the above technical solution: The internal support frame includes: The connecting ring; A retaining ring is coaxially arranged and fixedly connected to the bottle neck tube; Multiple bow-shaped ribs are evenly distributed around the bottle mouth tube. The bow-shaped ribs are in contact with the inner wall of the outer liner along the edge line of an axial section of the outer liner. One end of the bow-shaped rib is connected to a fixing ring, and the other end is connected to a connecting ring. Multiple annular ribs are spaced apart along the axial direction. Each annular rib contacts the inner wall of the outer liner along the circumferential line of the radial section of the outer liner. Each annular rib is connected to multiple bow-shaped ribs.

[0008] The internal support frame further includes multiple sets of radial buffer supports arranged along the axial direction, each set of radial buffer supports comprising: A circumferential structural component is coaxially arranged with the inner liner and fixedly connected to the outer wall surface of the inner liner; Multiple connecting pieces are evenly distributed around the outer periphery of the inner liner. The ends of the connecting pieces are connected to the circumferential structural members. The connecting pieces extend radially from the inner liner toward the outer liner. Multiple airfoil blades are provided, with two airfoil blades corresponding to one connecting piece. Each airfoil blade includes a sheet-like body, one end of which is a first overlapping part, and the other end of which is a second overlapping part. Among them, two airfoil plates are provided corresponding to a connecting piece. The second overlapping part of one airfoil plate is fixedly connected to a ring rib, and the second overlapping part of the other airfoil plate is fixedly connected to another ring rib. The first overlapping parts of both airfoil plates are fixedly connected to the plate-shaped body, so that the two corresponding airfoil plates are symmetrical about the connecting piece and are set at an angle.

[0009] The second overlapping part has a circumferential dimension along the outer periphery of the inner liner that is 3-5 times that of the first overlapping part, and the middle part of the sheet-like body is provided with a hollow hole with the same shape as the sheet-like body.

[0010] The elastic element is a compression spring, and the elastic element is sleeved outside the connecting rod; The inner valve seat includes a connecting pipe fixed to the inner liner. The inner wall of the connecting pipe is slidably connected to the connecting rod. The other end of the connecting rod is inserted into the outer valve seat. The outer circumferential surface of the connecting rod is connected to the inner hole of the connecting ring. One end of the elastic element is connected to the end of the connecting pipe, and the other end of the elastic element is connected to the end of the connecting ring.

[0011] The inner liner includes a shell molded from polytetrafluoroethylene, and a first bearing layer is provided on the outside of the shell. The first bearing layer is formed by winding carbon fiber composite material on the outer wall of the shell. The inner valve seat includes a first embedded part, which is fixed inside the housing. The first embedded part is provided with the connecting pipe, which is located outside the housing.

[0012] The outer valve seat includes a protrusion, and the connecting rod is provided with a slot for insertion into the protrusion.

[0013] The outer liner is made of high-density nylon or high-density polyethylene. The outer valve seat includes a second embedded part that is fixedly connected to the outer liner. A protrusion is fixed on the second embedded part. The protrusion is located on the inner side of the outer liner. The outer liner is provided with a second bearing layer formed by wrapping or laying composite material.

[0014] A method for forming a low-temperature, high-pressure double-walled hydrogen storage cylinder includes the following steps: Step 1: Fix the fixing ring to the bottle mouth tube at one end of the inner liner along the axial direction, slide the connecting rod to the inner valve seat at the other end of the inner liner along the axial direction, and fit an elastic element and a connecting ring on the outside of the connecting rod. The elastic element is a compression spring, and the elastic element is compressed to a fixed position. Step 2: Connect the fixing ring and the connecting ring with multiple bow-shaped ribs, and connect the bow-shaped ribs with multiple annular ribs located on the radial outer periphery of the inner liner to form a mesh frame located on the outside of the inner liner; Step 3: After releasing the compression of the elastic element, one end of the elastic element contacts the inner valve seat and the other end contacts the connecting ring, thus elastically connecting the inner valve seat and the connecting ring along the axial direction. Step 4: Place the first shell segment, formed by injection molding, onto the mesh frame, ensuring the bottle neck is positioned within the perforation on the first shell segment. Then, place the second shell segment, also formed by injection molding, onto the mesh frame. The outer valve seat on the second shell segment is inserted into the connecting rod, and the connecting ring contacts the second shell segment. The inner walls of both the first and second shell segments are in contact with the mesh frame via the mesh lines. After the first and second shell segments are joined together, an outer liner is formed. The outer liner and the connecting ring limit the end of the elastic element facing the outer liner. Simultaneously, the outer valve seat supports the inner liner radially along the inner liner via the connecting rod.

[0015] As a further improvement to the above technical solution: Before step two, attach circumferential structural components to the outside of the inner liner. There are multiple circumferential structural components distributed along the axial direction of the inner liner. The circumferential structural components are provided with multiple connecting pieces evenly distributed around the outer periphery of the inner liner. The connecting pieces extend along the radial side of the inner liner. Then, install two airfoil-shaped pieces on one connecting piece. The two corresponding airfoil-shaped pieces are symmetrical about the connecting piece and set at an angle. Then, lay an insulation layer on the outer wall of the inner liner. The thickness of the insulation layer is less than or equal to the radial dimension of the connecting piece along the inner liner. After the circumferential structural components, connecting pieces, and airfoil are assembled with the inner liner, before step four, the end of the airfoil facing the outer liner is the second overlap. The second overlap is connected to the corresponding annular rib, and the airfoil undergoes relative elastic deformation.

[0016] The beneficial effects of this invention are as follows: This invention features a compact and reasonable structure and is easy to operate. By fixing one end of the inner liner and the outer liner axially, and using a connecting rod to radially limit the other end, a connecting ring is set on the internal support frame that is fixedly connected to both the inner and outer liners, corresponding to the connecting rod. An elastic element is set between the inner valve seat of the inner liner and the connecting ring, thereby achieving axial elastic limiting of the inner liner at the connecting rod. This improves the stress on the outer liner during the addition and discharge of cryogenic materials from the hydrogen storage cylinder, ensuring the functional stability and safety of the double-layer hydrogen storage cylinder.

[0017] Furthermore, the present invention also has the following advantages: (1) By setting one end of the connecting rod to slide with the connecting pipe of the inner valve seat and the other end to fix the connecting ring, the connecting ring is positioned after the connecting rod and the connecting pipe are inserted, which facilitates the assembly of the internal support frame.

[0018] (2) Multiple arched ribs and ring ribs form a mesh frame located outside the inner liner. The inner liner is connected to the mesh frame through the two ends of the axial direction. The outer periphery of the mesh frame matches the inner wall of the outer liner and contacts the mesh line. On the basis of minimizing the contact surface of the support structure between the inner and outer liners to reduce heat transfer, the radial pressure of the inner liner on the outer liner is evenly distributed through the mesh frame. It also facilitates the setting of an external support structure for supporting the hydrogen storage bottle on the outer wall of the outer liner. At the same time, the internal support frame plays the role of supporting the outer liner from the inside, reducing the molding requirements of the outer liner.

[0019] (3) By setting a connecting piece extending radially from the inner liner to the outer liner side on the circumferential structural component of the inner liner connection, and setting two symmetrical wing-shaped pieces on one connecting piece, a buffer support assembly is formed along the radial direction of the inner liner. The inner liner is connected to the mesh frame structure through the buffer support assembly, which further enhances the strength of the internal support frame and further disperses the force applied by the inner liner to the outer liner along the axial direction of the inner liner, thereby reducing the strength design requirements of the outer liner of the low temperature and high pressure double-layer hydrogen storage cylinder.

[0020] (4) The width of the second overlap is greater than that of the first overlap, making the sheet body a trapezoidal structure and the perforated hole a trapezoidal structure in the same direction. This reduces the heat transfer of the airfoil and, combined with the perforated hole, gives the airfoil elastic deformation capability. When the airfoil is installed on the internal support frame, the airfoil has a certain elastic deformation margin after being connected to the connecting piece and the annular rib. This allows the circumferential structural component to move along the hydrogen storage cylinder axis with the inner liner when the inner liner changes size due to temperature changes, without affecting the support effect. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention (cross-sectional view, excluding the insulation layer).

[0022] Figure 2 This is a partially enlarged view of one end of the hydrogen storage bottle of the present invention.

[0023] Figure 3 for Figure 2 An exploded view from a specific perspective.

[0024] Figure 4 This is a schematic diagram (axonometric sectional view) of the outer liner of the present invention.

[0025] Figure 5 This is a schematic diagram of the internal support frame of the present invention.

[0026] Figure 6 This is a schematic diagram (sectional view) of the internal support frame of the present invention.

[0027] Figure 7 This is a schematic diagram of the structure of the connecting piece and the airfoil of the present invention.

[0028] Figure 8 This is a schematic diagram of the installation structure of the connecting piece and the airfoil piece of the present invention.

[0029] Figure 9 This is a schematic diagram of the structure of the inner liner, insulation layer, vacuum layer and outer liner of the present invention.

[0030] Figure 10 This is a schematic diagram of the hydrogen storage cylinder assembly process of the present invention.

[0031] in: 1. Inner liner; 101. Shell; 102. First bearing layer; 11. Bottle neck tube; 12. Inner valve seat; 1201. First embedded part; 1202. Connecting pipe; 2. Insulation layer; 201. Composite film; 202. Multilayer thermal insulation material; 3. Outer shell; 301. First shell section; 302. Second shell section; 31. Perforation; 32. Outer valve seat; 3201. Second embedded part; 3202. Protrusion; 4. Vacuum layer; 5. Internal support frame; 51. Fixing ring; 52. Radial buffer support; 521. Circumferential structural component; 522. Airfoil; 5221. First overlapping part; 5222. Hole; 5223. Sheet-shaped body; 5224. Second overlapping part; 523. Connecting piece; 53. Arch-shaped reinforcement; 54. Circular reinforcement; 55. Connecting ring; 6. Connecting rod; 61. Slot; 7. Elastic element; 8. Second load-bearing layer; 9. External support structure. Detailed Implementation

[0032] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0033] Example 1: like Figures 1-4 As shown, the low-temperature high-pressure double-layer hydrogen storage cylinder of this embodiment includes an inner liner 1, an insulation layer 2, an outer liner 3, a connecting rod 6, an internal support frame 5, and an elastic element 7.

[0034] The inner liner 1 has a bottle mouth tube 11 at one end along the axial direction of the hydrogen storage bottle and an inner valve seat 12 at the other end. Insulation layer 2 is provided on the outer wall of inner liner 1; The outer liner 3 has a perforation 31. The outer wall of the bottle mouth tube 11 is fixedly connected to the perforation 31. The outer liner 3 has an outer valve seat 32 corresponding to the inner valve seat 12. The outer liner 3 is segmented along the axial direction. A vacuum layer 4 is formed between the inner liner 1 and the outer liner 3. The connecting rod 6 is connected at one end to the inner valve seat 12 and at the other end to the outer valve seat 32, fixing the relative positions of the inner liner 1 and the outer liner 3 along the radial direction of the hydrogen storage bottle. The internal support frame 5 is located inside the vacuum layer 4. One end of it is fixedly connected to the bottle mouth tube 11 along the axial direction, and the other end of it is provided with a connecting ring 55. The connecting ring 55 is sleeved on the outer periphery of the connecting rod 6 and fixedly connected to the inner wall surface of the outer liner 3. The elastic element 7 elastically connects the inner valve seat 12 and the connecting ring 55 along the axial direction.

[0035] Specifically, such as Figure 1 The arrow indicates the axial direction of the hydrogen storage bottle. All the above-mentioned axial directions refer to the axial direction of the hydrogen storage bottle. The bottle mouth tube 11 passes through the inner cavity of the inner liner 1 and is used for the entry and exit of cryogenic materials. The fixed connection between the outer wall of the bottle mouth tube 11 and the perforation 31 is the existing technology and will not be described in detail here. The connection between the outer valve seat 32, the inner valve seat 12 and the connecting rod 6 can be a sliding connection with a plug-in type along the axial direction of the hydrogen storage bottle.

[0036] In this embodiment, the hydrogen storage cylinder is typically placed horizontally, such as... Figure 1As shown, the outer liner 3 is supported by the outer support structure 9. The outer liner 3 supports the inner liner 1 radially from both ends of the inner liner 1 along the hydrogen storage bottle via the connecting rod 6 and the bottle mouth tube 11. The connecting ring 55 on the internal support frame 5 is set corresponding to the connecting rod 6. The connecting ring 55 is fixed to the bottle mouth tube 11 of the inner liner 1 via the internal support frame 5 and connected to the outer liner 3. This fixes the position of the elastic element 7 facing the outer liner 3 and elastically supports the end of the inner liner 1 along the axial direction through the elastic element 7. This allows the position of the end of the inner liner 1 to change with the thermal expansion and contraction of the inner liner 1 while being fixed axially and radially by the outer liner 3, avoiding axial tension and pressure from the inner liner 1 on the outer liner 3, and thus preventing damage at the connection between the end of the outer liner 3 and the inner liner 1.

[0037] By fixing one end of the inner liner 1 and the outer liner 3 axially, and using a connecting rod 6 to radially limit the other end, a connecting ring 55 is set on the internal support frame 5, which is fixedly connected to both the inner liner 1 and the outer liner 3, corresponding to the connecting rod 6. An elastic element 7 is set between the inner valve seat 12 of the inner liner 1 and the connecting ring 55, so as to achieve axial elastic limiting of the inner liner 1 at the connecting rod 6, improve the stress condition of the outer liner 3 during the addition and discharge of low-temperature materials in the hydrogen storage cylinder, and ensure the functional stability and safety of the double-layer hydrogen storage cylinder.

[0038] In this embodiment, as Figure 2 , Figure 3 As shown, the elastic element 7 is a compression spring, which is sleeved on the outside of the connecting rod 6; the inner valve seat 12 includes a connecting pipe 1202 fixed on the inner liner 1, the inner wall of the connecting pipe 1202 is slidably connected to the connecting rod 6, the other end of the connecting rod 6 is inserted into the outer valve seat 32, the outer circumferential surface of the connecting rod 6 is connected to the inner hole of the connecting ring 55, one end of the elastic element 7 is connected to the end of the connecting pipe 1202, and the other end of the elastic element 7 is connected to the end of the connecting ring 55.

[0039] Specifically, the cross-section of the part of the connecting rod 6 corresponding to the compression spring is circular, and the cross-sectional shape of the sliding insertion part of the connecting rod 6 and the connecting pipe 1202 can be circular or polygonal, preferably polygonal. The insertion between the connecting rod 6 and the outer valve seat 32 is also a polygonal structure insertion, thereby restricting the relative torsion between the inner liner 1 and the outer liner 3. The connection between the outer circumference of the connecting rod 6 and the inner hole of the connecting ring 55 can be a fixed connection.

[0040] By setting one end of the connecting rod 6 to the connecting pipe 1202 of the inner valve seat 12 in a sliding connection and the other end to the connecting ring 55 in a fixed connection, the connecting ring 55 is positioned after the connecting rod 6 is inserted into the connecting pipe 1202, which facilitates the assembly of the internal support frame 5.

[0041] like Figure 9As shown, the inner liner 1 includes a shell 101 injection molded from polytetrafluoroethylene, and a first bearing layer 102 is provided on the outside of the shell 101. The first bearing layer 102 is formed by winding carbon fiber composite material on the outer wall of the shell 101. The inner valve seat 12 includes a first embedded part 1201, which is fixed inside the housing 101. A connecting pipe 1202 is provided on the first embedded part 1201, and the connecting pipe 1202 is located outside the housing 101.

[0042] Specifically, the bottle neck tube 11 is also connected to the shell 101 by pre-embedding. Both the bottle neck tube 11 and the inner valve seat 12 are made of metal. 6061 aluminum with good resistance to hydrogen embrittlement can be selected. In order to ensure the strict sealing requirements at the bottle neck of the metal components and the non-metallic material inner liner 1, the surface of the metal insert needs to be specially treated. Considering that the selected material must be able to withstand low temperature, resist hydrogen corrosion, prevent hydrogen leakage, and resist fatigue under long-term and cyclic loads, the selected polytetrafluoroethylene (PTFE) material is lighter and has better fatigue resistance than metal materials. Due to the high viscosity of PTFE, the shell 101 is formed by a special high temperature and high pressure injection molding process with additives. After the two halves are injection molded separately along the axial direction, the two halves are welded into a whole by laser welding technology to form a complete shell 101.

[0043] Specifically, the functions of the first load-bearing layer 102 are: (i) to bear all the pressure load; (ii) to protect the plastic shell 101; (iii) to reduce the input of external heat; and (iv) to provide a supporting surface for the laying of insulation materials. The first load-bearing layer 102 is usually formed by winding carbon fiber composite material on the outer wall of the shell 101 using a wet winding method. This process is existing technology and will not be described in detail here. After the winding is completed, the structure is placed in a curing oven for curing. Since the inner liner 1 needs to work under high pressure, high-strength medium-modulus carbon fiber (such as the commonly used T700 or T800 series) is selected to reduce the weight of the system. To improve manufacturing efficiency, large-tow carbon fiber (such as 36K or 48K yarn) can be considered.

[0044] The thickness of the polytetrafluoroethylene (PTFE) shell 101 can be as thin as possible while ensuring hydrogen impermeability and preventing instability caused by thermal stress due to large temperature differences, thus reducing the weight of the shell 101. Its load-bearing capacity is minimal; the pressure load is primarily borne by the carbon fiber composite material wound around the shell 101. The inner liner 1 is manufactured using a PTFE injection-molded shell 101 and a carbon fiber composite material-molded first load-bearing layer 102, resulting in a lightweight hydrogen storage cylinder.

[0045] like Figure 9 As shown, the insulation layer 2 includes a composite film 201 laid on the outer surface of the inner liner 1 and a multilayer thermal insulation material 202 located outside the composite film 201.

[0046] One embodiment of the forming of the composite film 201 is as follows: Some spatial network structures are fixed on the outer surface of the first bearing layer 102 (carbon fiber composite material) of the inner liner 1. Hollow glass microspheres (HGMs) are laid on the outer surface of the composite material winding layer. Then, a polyester film (Mylar) is used to cover the surface of the hollow glass microsphere (HGMs) layer. HGMs is short for Hollow Glass Microspheres, which refers to lightweight hollow microspheres used to prepare composite aerogels or heat insulation layers. The polyester film Mylar is a polyester film brand under DuPont. It is made of PET material and has excellent heat resistance, high surface flatness, strong light transmittance and good mechanical flexibility.

[0047] One embodiment of molding multilayer thermal insulation material 202 is as follows: Lightweight multilayer anti-radiation insulation material (MLI) is laid on a polyester film, and a separator is placed between the layers. MLI stands for Vacuum Multilayer Insulation, which is used for efficient heat insulation, especially in liquid hydrogen storage systems. By using vacuum interlayers and reflective materials, heat conduction is reduced to maintain a low-temperature environment.

[0048] The molding technology of insulation layer 2 is existing technology and will not be described in detail here.

[0049] like Figures 2-3 As shown, the outer valve seat 32 includes a protrusion 3202, and the connecting rod 6 is provided with a slot 61 that is inserted into the protrusion 3202.

[0050] Specifically, the connecting rod 6 is tubular and made of polytetrafluoroethylene (PTFE). The inner valve seat 12 and outer valve seat 32 are both made of metal. The protrusion 3202 engages with the slot 61 to position and install the outer liner 3. When the outer liner 3 at the outer valve seat 32 abuts against the connecting ring 55, the protrusion 3202 engages with the slot 61 to fix the connecting ring 55 to the inner wall of the outer liner 3. Both the protrusion 3202 and the slot 61 have polygonal cross-sections. The connecting rod 6 is made of a non-metallic material to reduce heat transfer between the inner liner 1 and the outer liner 3.

[0051] like Figures 2-3 , Figure 9 As shown, the outer liner 3 is made of high-density nylon or high-density polyethylene. The outer valve seat 32 includes a second embedded part 3201 that is fixedly connected to the outer liner 3. A protrusion 3202 is fixed on the second embedded part 3201. The protrusion 3202 is located on the inner side of the outer liner 3. The outer liner 3 is provided with a second bearing layer 8 formed by wrapping or laying composite materials.

[0052] Specifically, the outer shell 3 is formed by injection molding. The outer shell 3 is formed into a first shell section 301 and a second shell section 302. The perforation 31 is located at the center of the end cap of the first shell section 301, and the outer valve seat 32 is located at the center of the end cap of the second shell section 302.

[0053] During the molding of a low-temperature, high-pressure double-walled hydrogen storage cylinder, the inner liner 1 (including the bottle mouth tube 11 and the inner valve seat 12) and the first shell section 301 and the second shell section 302 (including the outer valve seat 32) of the outer liner 3 are molded according to specific design requirements. The structural components required for the internal support frame 5 can be molded using composite materials with low thermal conductivity (such as carbon fiber composite materials), and the internal support frame 5 can be assembled by bonding or other methods.

[0054] When assembling a cryogenic, high-pressure double-walled hydrogen storage cylinder: First, a connecting rod 6 is installed on the inner valve seat 12. An elastic element 7 and a connecting ring 55 are sleeved on the outside of the connecting rod 6, and the inner support frame 5 is fixedly connected to the inner liner 1. During this process, the elastic element 7 needs to be compressed to a fixed position so that the length of the elastic element 7 meets the requirement that after the inner support frame 5 is installed, the elastic element 7 does not contact the connecting ring 55 and the inner valve seat 12 at the same time. Then, after releasing the compression of the elastic element 7 to fix its posture, one end of the elastic element 7 contacts the inner valve seat 12 and the other end contacts the connecting ring 55, so that the inner valve seat 12 and the connecting ring 55 are elastically connected along the axial direction. Then, after the insulation layer 2 is formed on the inner liner 1, as follows: Figure 10 As shown, the first shell section 301 is fitted over the inner liner 1, so that the bottle mouth tube 11 is located in the perforation 31 on the first shell section 301. The second shell section 302 is fitted over the inner liner 1 from the other end, so that the outer valve seat 32 is inserted into the connecting rod 6, and the connecting ring 55 is in contact with the second shell section 302. Then, after the first shell section 301 and the second shell section 302 are docked, they are connected by laser welding to form the outer liner 3. The outer liner 3 and the connecting ring 55 limit the end of the elastic element 7 facing the outer liner 3. At the same time, the outer valve seat 32 supports the inner liner 1 radially along the inner liner 1 through the connecting rod 6, and seals the outer liner 3 with the bottle mouth tube 11, forming a sealed vacuum layer 4 between the inner liner 1 and the outer liner 3. Finally, a second load-bearing layer 8 is formed by winding a composite material around the outer liner 3. The composite material can be carbon fiber composite material. This step is existing technology and will not be described in detail here.

[0055] In this embodiment, after the cryogenic medium is injected into the inner liner 1 of the cryogenic double-layer hydrogen storage cylinder, the length of the elastic element 7 increases slightly, and the connecting rod 6 slides relative to the connecting pipe 1202. When the temperature of the inner liner 1 returns to normal, the position change of the connecting rod 6 and the direction of elastic deformation are opposite.

[0056] Example 2: like Figure 5As shown, based on Embodiment 1, the internal support frame 5 of the low-temperature high-pressure double-layer hydrogen storage cylinder in this embodiment includes a connecting ring 55, a fixing ring 51, multiple arc-shaped ribs 53 and multiple annular ribs 54.

[0057] The retaining ring 51 is coaxially arranged and fixedly connected to the bottle neck tube 11; Multiple bow-shaped ribs 53 are evenly distributed around the bottle mouth tube 11. The bow-shaped ribs 53 are in contact with the inner wall of the outer liner 3 along the edge line of an axial section of the outer liner 3. One end of the bow-shaped rib 53 is connected to the fixing ring 51, and the other end is connected to the connecting ring 55. Multiple annular ribs 54 are spaced apart along the axial direction of the hydrogen storage bottle. Each annular rib 54 contacts the inner wall of the outer liner 3 along the circumferential line of the radial section of the outer liner 3. Each annular rib 54 is connected to multiple bow-shaped ribs 53.

[0058] Specifically, the connecting ring 55 and the fixing ring 51 are molded from a composite material with low thermal conductivity (carbon fiber composite material) and can be connected to the bow-shaped rib 53 by adhesive bonding; multiple bow-shaped ribs 53 and annular ribs 54 are molded from carbon fiber composite material, and the intersection of the bow-shaped ribs 53 and annular ribs 54 is cross-shaped. The bow-shaped ribs 53 are segmented or the annular ribs 54 are segmented. The bow-shaped ribs 53 and annular ribs 54 at the segmented points are assembled into a mesh frame by adhesive bonding and mechanical connection (such as bolts or pins); the cross-sectional shape of the multiple bow-shaped ribs 53 and annular ribs 54 is uniformly circular, which facilitates molding and achieves line contact with the outer liner 3, reducing heat transfer.

[0059] Multiple arched ribs 53 and annular ribs 54 form a mesh frame located outside the inner liner 1. The inner liner 1 is connected to the mesh frame through its axial ends. The outer periphery of the mesh frame matches the inner wall of the outer liner 3 and contacts the mesh line. Based on minimizing the contact surface of the support structure between the inner liner 1 and the outer liner 3 to reduce heat transfer, the radial pressure of the inner liner 1 on the outer liner 3 is evenly distributed through the mesh frame. It also facilitates the setting of the outer support structure 9 for supporting the hydrogen storage bottle on the outer wall of the outer liner 3. At the same time, the internal support frame 5 plays the role of supporting the outer liner 3 from the inside, reducing the molding requirements of the outer liner 3.

[0060] Because of the internal support frame 5 that provides all-round support to the outer liner 3, most of the external pressure is borne by the internal support frame 5. The composite material of the formed second load-bearing layer 8 can be made of glass fiber. Compared with carbon fiber, glass fiber has better abrasion resistance and is cheaper. Flame retardants should be added to the resin used to prepare the glass fiber composite material to improve the flame retardancy of the second load-bearing layer 8.

[0061] Example 3: like Figures 5-8As shown, based on Embodiment 2, the internal support frame 5 of the low-temperature high-pressure double-layer hydrogen storage cylinder in this embodiment also includes multiple sets of radial buffer supports 52 arranged along the axial direction. Each set of radial buffer supports 52 includes a circumferential structural member 521, multiple connecting pieces 523 and multiple airfoil pieces 522.

[0062] The circumferential structural component 521 is coaxially arranged with the inner liner 1 and is fixedly connected to the outer wall surface of the inner liner 1; Multiple connecting pieces 523 are evenly distributed around the outer periphery of the inner liner 1. The ends of the connecting pieces 523 are connected to the circumferential structural members 521. The connecting pieces 523 extend radially from the inner liner 1 toward the outer liner 3. Multiple airfoil blades 522, with two airfoil blades 522 corresponding to a connecting piece 523. Each airfoil blade 522 includes a sheet-like body 5223, one end of which is a first overlapping portion 5221, and the other end of which is a second overlapping portion 5224. Among them, two airfoil plates 522 are provided corresponding to a connecting piece 523. The second overlapping part 5224 of one airfoil plate 522 is fixedly connected to a ring rib 54, and the second overlapping part 5224 of the other airfoil plate 522 is fixedly connected to another ring rib 54. The first overlapping part 5221 of both airfoil plates 522 is fixedly connected to the plate-shaped body 5223, so that the two corresponding airfoil plates 522 are symmetrical about the connecting piece 523 and are arranged at an angle.

[0063] Specifically, the first overlapping portions 5221 of the airfoil 522 connected to the same connecting piece 523 are located on both sides of the connecting piece 523; the number of radial buffer supports 52 is at least two sets, corresponding to the cylindrical part of the inner liner 1; one connecting piece 523 and two airfoil 522 form a buffer support assembly in the angular direction, and multiple buffer support assemblies are evenly distributed around the axis of the hydrogen storage cylinder, such as... Figure 5 As shown, each set of radial buffer brackets 52 includes four buffer support components, one arranged in every ninety degrees; the circumferential structural member 521, the connecting piece 523, and the airfoil 522 are all molded from a low thermal conductivity composite material (carbon fiber composite material); the connection section between the second overlap 5224 and the annular rib 54 has a bending structure adapted to the shape of the annular rib 54, and the connection end between the first overlap 5221 and the connecting piece 523 is bent, increasing the connection strength through surface contact; the connection is achieved by using adhesive to connect the circumferential structural member 521 to the inner liner 1 and the connecting piece 523 to the circumferential structural member 521, and by using adhesive combined with mechanical connections (such as bolts or pins) to install the airfoil 522.

[0064] By setting a connecting piece 523 extending radially from the inner liner 1 to the outer liner 3 on the circumferential structural member 521 connected to the inner liner 1, and setting two symmetrical wing-shaped pieces 522 on one connecting piece 523, a buffer support assembly is formed radially from the inner liner 1. The inner liner 1 is connected to the mesh frame structure through the buffer support assembly, which further enhances the strength of the internal support frame 5 and further disperses the force applied by the inner liner 1 to the outer liner 3 along the axial direction of the inner liner 1, thereby reducing the strength design requirements of the outer liner 3 of the low-temperature high-pressure double-layer hydrogen storage cylinder.

[0065] The vacuum layer 4 includes an insulation layer 2 and an internal support frame 5. When the outer wall of the inner liner 1 is provided with a circumferential structural member 521 and a connecting piece 523, the circumferential structural member 521 is covered when the insulation layer 2 is laid. The dimension of the connecting piece 523 along the radial direction of the inner liner 1 is greater than the thickness of the insulation layer 2.

[0066] Furthermore, such as Figure 7 , Figure 8 As shown, the second overlapping part 5224 has a circumferential dimension along the outer periphery of the inner liner 1 that is 3-5 times that of the first overlapping part 5221, and the middle part of the sheet-like body 5223 is provided with a hollow hole 5222 with the same shape as the sheet-like body 5223.

[0067] Specifically, the sheet-like body 5223 has a trapezoidal structure, specifically an isosceles trapezoidal structure.

[0068] The width of the second overlapping portion 5224 is greater than that of the first overlapping portion 5221, making the sheet-like body 5223 a trapezoidal structure. The perforated holes 5222 are also trapezoidal structures in the same direction. This reduces heat transfer to the airfoil 522, and combined with the perforated holes 5222, gives the airfoil 522 elastic deformation capability. When assembling the internal support frame 5 and installing the airfoil 522, it ensures that the airfoil 522 has a certain elastic deformation allowance after being connected to the connecting piece 523 and the annular rib 54. Figure 6 In this process, the airfoil 522 is bent in the direction of the arrow, so that when the inner liner 1 changes size due to temperature changes, the circumferential structural member 521 moves along the axial direction of the hydrogen storage bottle along with the inner liner 1 without affecting the support effect.

[0069] Specifically, the angle between the two corresponding airfoil blades 522 can be selected from 90° to 120°, which achieves the support effect while increasing the distance between adjacent annular ribs 54.

[0070] In this embodiment, after the cryogenic medium is injected into the inner liner 1 of the cryogenic double-layer hydrogen storage cylinder, the length of the elastic element 7 increases slightly, the connecting rod 6 slides relative to the connecting pipe 1202, and the airfoil 522 undergoes slight elastic deformation to adapt to the change in the axial length of the inner liner 1. When the temperature of the inner liner 1 returns to normal, the position change of the connecting rod 6 is opposite to the direction of the elastic deformation.

[0071] The overall design of the internal support frame 5 in this embodiment adopts the principle of minimizing the contact surface, aiming to minimize it while meeting the requirements of strength and rigidity.

[0072] The internal support frame 5 has multiple functions: (i) Together with the outer liner 3 and the second load-bearing layer 8, it provides support for the weight of the inner liner 1; (ii) Provide support for the outer shell 3 and the second load-bearing layer 8 to improve the shell instability threshold under external air pressure; (iii) It is connected to the inner liner 1 in the axial and circumferential directions, providing multi-directional elastic support.

[0073] Example 4: The molding method of the low-temperature high-pressure double-layer hydrogen storage bottle in this embodiment, wherein the low-temperature high-pressure double-layer hydrogen storage bottle is any of the hydrogen storage bottles in the above embodiments, includes the following steps: Step 1: Fix the fixing ring 51 to the bottle mouth tube 11 at one axial end of the inner liner 1, slide the connecting rod 6 to the inner valve seat 12 at the other axial end of the inner liner 1 along the axial direction, and fit the elastic element 7 and the connecting ring 55 on the outside of the connecting rod 6. The elastic element 7 is a compression spring, and the elastic element 7 is compressed to a fixed position. Specifically, the connecting ring 55 is slidably connected to the connecting rod 6, and the connecting rod 6 can be fixed to the connecting ring 55 by the connector to prevent it from falling off during the installation process; the fixed posture means that the length of the elastic element 7 meets the following condition: after the mesh frame is formed, the elastic element 7 does not contact the connecting ring 55 and the inner valve seat 12 at the same time.

[0074] Step 2: Use multiple bow-shaped ribs 53 to connect the fixing ring 51 and the connecting ring 55, and use multiple annular ribs 54 located on the radial outer periphery of the inner liner 1 to connect the bow-shaped ribs 53, forming a mesh frame located outside the inner liner 1. Specifically, after the insulation layer 2 on the outer wall of the inner liner 1 is laid, step two is then performed.

[0075] The aforementioned fixing ring 51, bow-shaped rib 53, and annular rib 54 are molded using composite materials with low thermal conductivity (such as carbon fiber composite materials) (vacuum induction, RTM, or autoclave technology can also be used). The connection can be made by structural adhesive bonding and mechanical connection (such as bolts or pins). The fixing ring 51 and the bottle mouth tube 11 are bonded with structural adhesive.

[0076] Step 3: After releasing the compression of the elastic element 7, one end of the elastic element 7 contacts the inner valve seat 12 and the other end contacts the connecting ring 55, so that the inner valve seat 12 and the connecting ring 55 are elastically connected along the axial direction. In the above process, the inner liner 1, which is fixedly supported, is used as a fixed reference for assembling other components.

[0077] Step 4, as follows Figure 10As shown, the first shell segment 301, formed by injection molding, is fitted onto the mesh frame, with the bottle neck tube 11 positioned in the perforation 31 on the first shell segment 301. The second shell segment 302, formed by injection molding, is fitted onto the mesh frame. The outer valve seat 32 on the second shell segment 302 is inserted into the connecting rod 6, and the connecting ring 55 contacts the second shell segment 302. The inner wall surfaces of both the first shell segment 301 and the second shell segment 302 are in contact with the mesh frame via mesh lines. After the first shell segment 301 and the second shell segment 302 are joined together, they form the outer liner 3. The outer liner 3 and the connecting ring 55 limit the end of the elastic element 7 facing the outer liner 3. At the same time, the outer valve seat 32 supports the inner liner 1 radially along the inner liner 1 via the connecting rod 6.

[0078] The distance between the inner valve seat 12 and the connecting ring 55 after the hydrogen storage bottle is formed allows the connecting rod 6 to have space to move relative to the inner valve seat 12 between the inner valve seat 12 and the outer valve seat 32, leaving space for the inner liner 1 to deform in both directions along the axis, adapting to working conditions that are higher or lower than the forming temperature.

[0079] Specifically, after the first shell section 301 and the second shell section 302 are joined together, they are connected by laser welding to form the outer liner 3, which seals the outer liner 3 with the bottle mouth tube 11, forming a sealed vacuum layer 4 between the inner liner 1 and the outer liner 3; after step four is completed, step five is carried out, in which a second load-bearing layer 8 is formed by winding a composite material around the outer liner 3, and the composite material is glass fiber composite material.

[0080] The internal support frame 5, which forms a mesh frame structure on the outside of the inner liner 1, allows for the installation of the connecting ring 55, which provides elastic positioning at the end of the inner liner 1. At the same time, the internal support frame 5 contacts the inner wall of the inner liner 1 in a mesh pattern, dispersing the radial pressure of the inner liner 1 on the outer liner 3 evenly through the mesh frame. This serves as a support structure for the installation of the outer liner 3, assists the outer liner 3 in bearing external pressure, improves the structural strength of the outer liner 3, and comprehensively enhances the service life of the outer liner 3.

[0081] Example 5: The molding method of the low-temperature high-pressure double-walled hydrogen storage cylinder in this embodiment differs from that in Embodiment 4 in that, before step two, a circumferential structural member 521 is attached to the outside of the inner liner 1. Multiple circumferential structural members 521 are distributed along the axial direction of the inner liner 1. Each circumferential structural member 521 has multiple connecting pieces 523 evenly distributed circumferentially around the outer periphery of the inner liner 1. The connecting pieces 523 extend radially outward from the inner liner 1 towards the outer liner 3. Then, two wing-shaped pieces 522 are installed on one connecting piece 523. The two corresponding wing-shaped pieces 522 are symmetrical about the connecting piece 523 and arranged at an included angle. Finally, a heat insulation layer 2 is laid on the outer wall of the inner liner 1. The thickness of the heat insulation layer 2 is less than or equal to the radial dimension of the connecting piece 523 along the inner liner 1. Figure 10 As shown; After the circumferential structural component 521, connecting piece 523, and airfoil 522 are assembled with the inner liner 1, before step four, the end of the airfoil 522 facing the outer liner 3 is the second overlapping portion 5224. The second overlapping portion 5224 is connected to the corresponding annular rib 54, causing the airfoil 522 to undergo relative elastic deformation, such as... Figure 6 As shown, the airfoil 522 is bent in the direction of the arrow.

[0082] Specifically, after the airfoil 522 is connected to the annular rib 54, it provides radial support to the inner liner 1 from both sides of the connecting piece 523. The airfoil 522 has a trapezoidal structure, and the size of the connection between the airfoil 522 and the connecting piece 523 and the width of the connecting piece 523 are minimized to reduce heat transfer.

[0083] The circumferential structural component 521 and the airfoil 522 are made of low thermal conductivity composite material (such as carbon fiber composite material) by compression molding (vacuum introduction, RTM or autoclave technology can also be used). The circumferential structural component 521 is connected to the inner liner 1 and the connecting piece 523 is connected to the circumferential structural component 521 by adhesive. The airfoil 522 is installed by adhesive combined with mechanical connection (such as bolts or pins).

[0084] An elastic airfoil 522 is installed between the internal support frame 5 and the inner liner 1. The herringbone layout structure supports the inner liner 1 and strengthens the mesh frame. During installation, the airfoil 522 undergoes relative elastic deformation. When the length of the inner liner 1 changes due to temperature, the airfoil 522 can adaptably undergo bidirectional elastic deformation to ensure the support effect of the internal support frame 5.

[0085] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A low-temperature, high-pressure double-walled hydrogen storage cylinder, characterized in that: include: The inner liner (1) has a bottle mouth tube (11) at one end along the axial direction of the hydrogen storage bottle and an inner valve seat (12) at the other end. Insulation layer (2) is provided on the outer wall of the inner liner (1); The outer liner (3) has a perforation (31) and the outer wall of the bottle mouth tube (11) is fixedly connected to the perforation (31). The outer liner (3) has an outer valve seat (32) corresponding to the inner valve seat (12). The outer liner (3) is segmented along the axial direction. A vacuum layer (4) is formed between the inner liner (1) and the outer liner (3). The connecting rod (6) is connected at one end to the inner valve seat (12) and at the other end to the outer valve seat (32), thereby fixing the relative positions of the inner liner (1) and the outer liner (3) along the radial direction of the hydrogen storage bottle; An internal support frame (5) is located inside the vacuum layer (4). One end of the frame is fixedly connected to the bottle mouth tube (11) along the axial direction, and the other end of the frame is provided with a connecting ring (55). The connecting ring (55) is sleeved on the outer periphery of the connecting rod (6) and fixedly connected to the inner wall surface of the outer liner (3). The elastic element (7) elastically connects the inner valve seat (12) and the connecting ring (55) along the axial direction.

2. The low-temperature, high-pressure double-walled hydrogen storage cylinder as described in claim 1, characterized in that: The internal support frame (5) includes: The connecting ring (55); A fixing ring (51) is coaxially arranged and fixedly connected to the bottle mouth tube (11); Multiple bow-shaped ribs (53) are evenly distributed around the bottle mouth tube (11). The bow-shaped ribs (53) are in contact with the inner wall of the outer liner (3) along the edge line of an axial section of the outer liner (3). One end of the bow-shaped ribs (53) is connected to a fixing ring (51), and the other end is connected to a connecting ring (55). Multiple annular ribs (54) are spaced apart along the axial direction. Each annular rib (54) contacts the inner wall of the outer liner (3) along the circumferential line of the radial section of the outer liner (3). Each annular rib (54) is connected to multiple bow-shaped ribs (53).

3. The low-temperature, high-pressure double-walled hydrogen storage cylinder as described in claim 2, characterized in that: The internal support frame (5) further includes multiple sets of radial buffer supports (52) arranged along the axial direction, each set of radial buffer supports (52) including: A circumferential structural component (521) is coaxially arranged with the inner liner (1) and fixedly connected to the outer wall surface of the inner liner (1); Multiple connecting pieces (523) are evenly distributed around the outer periphery of the inner liner (1), and the ends of the connecting pieces (523) are connected to the circumferential structural member (521). The connecting pieces (523) extend radially from the inner liner (1) toward the outer liner (3). Multiple airfoil blades (522), two airfoil blades (522) are provided with a connecting piece (523) corresponding to one airfoil blade (522), each airfoil blade (522) includes a sheet-like body (5223), one end of the sheet-like body (5223) is a first overlapping part (5221), and the other end of the sheet-like body (5223) is a second overlapping part (5224). Among them, two airfoil plates (522) are provided corresponding to a connecting piece (523). The second overlapping part (5224) of one airfoil plate (522) is fixedly connected to a ring rib (54), and the second overlapping part (5224) of the other airfoil plate (522) is fixedly connected to another ring rib (54). The first overlapping part (5221) of both airfoil plates (522) is fixedly connected to the plate-shaped body (5223), so that the two corresponding airfoil plates (522) are symmetrical about the connecting piece (523) and are arranged at an angle.

4. The low-temperature, high-pressure double-walled hydrogen storage cylinder as described in claim 3, characterized in that: The second overlapping part (5224) has a circumferential dimension along the outer periphery of the inner liner (1) that is 3-5 times that of the first overlapping part (5221), and the middle part of the sheet-like body (5223) is provided with a hollow hole (5222) that is consistent with the shape of the sheet-like body (5223).

5. The low-temperature, high-pressure double-walled hydrogen storage cylinder as described in claim 1, characterized in that: The elastic element (7) is a compression spring, and the elastic element (7) is sleeved on the outside of the connecting rod (6); The inner valve seat (12) includes a connecting pipe (1202) fixed on the inner liner (1). The inner wall of the connecting pipe (1202) is slidably connected to the connecting rod (6). The other end of the connecting rod (6) is inserted into the outer valve seat (32). The outer circumferential surface of the connecting rod (6) is connected to the inner hole of the connecting ring (55). One end of the elastic element (7) is connected to the end of the connecting pipe (1202), and the other end of the elastic element (7) is connected to the end of the connecting ring (55).

6. The low-temperature, high-pressure double-walled hydrogen storage cylinder as described in claim 5, characterized in that: The inner liner (1) includes a shell (101) injection molded from polytetrafluoroethylene, and a first bearing layer (102) is provided on the outside of the shell (101). The first bearing layer (102) is formed by winding carbon fiber composite material on the outer wall of the shell (101). The inner valve seat (12) includes a first embedded part (1201), which is fixed inside the housing (101). The first embedded part (1201) is provided with the connecting pipe (1202), which is located outside the housing (101).

7. The low-temperature, high-pressure double-walled hydrogen storage cylinder as described in claim 5, characterized in that: The outer valve seat (32) includes a protrusion (3202), and the connecting rod (6) is provided with a slot (61) for inserting into the protrusion (3202).

8. The low-temperature, high-pressure double-walled hydrogen storage cylinder as described in claim 7, characterized in that: The outer liner (3) is made of high-density nylon or high-density polyethylene. The outer valve seat (32) includes a second embedded part (3201) fixedly connected to the outer liner (3). A protrusion (3202) is fixed on the second embedded part (3201). The protrusion (3202) is located on the inner side of the outer liner (3). The outer liner (3) is provided with a second bearing layer (8) formed by wrapping or laying composite materials.

9. A method for forming a low-temperature, high-pressure double-walled hydrogen storage cylinder, characterized in that: Includes the following steps: Step 1: Fix the fixing ring (51) to the bottle mouth tube (11) at one end of the axial direction of the inner liner (1), slide the connecting rod (6) to the inner valve seat (12) at the other end of the axial direction of the inner liner (1) along the axial direction, and fit an elastic element (7) and a connecting ring (55) on the outside of the connecting rod (6). The elastic element (7) is a compression spring, and the elastic element (7) is compressed to a fixed position. Step 2: Use multiple bow-shaped ribs (53) to connect the fixing ring (51) and the connecting ring (55), and use multiple annular ribs (54) located on the radial outer periphery of the inner liner (1) to connect the bow-shaped ribs (53) to form a mesh frame located outside the inner liner (1); Step 3: After releasing the compression of the elastic element (7) to fix its posture, one end of the elastic element (7) contacts the inner valve seat (12) and the other end contacts the connecting ring (55), so that the inner valve seat (12) and the connecting ring (55) are elastically connected along the axial direction. Step 4: Place the first shell segment (301) formed by injection molding onto the mesh frame, and position the bottle neck tube (11) in the perforation (31) on the first shell segment (301). Place the second shell segment (302) formed by injection molding onto the mesh frame. Insert the outer valve seat (32) on the second shell segment (302) into the connecting rod (6). Contact the connecting ring (55) with the second shell segment (302). The inner wall surfaces of the first shell segment (301) and the second shell segment (302) are in contact with the mesh frame as mesh lines. After the first shell segment (301) and the second shell segment (302) are connected, an outer liner (3) is formed. The outer liner (3) and the connecting ring (55) limit the end of the elastic element (7) facing the outer liner (3). At the same time, the outer valve seat (32) supports the inner liner (1) radially along the inner liner (1) through the connecting rod (6).

10. The molding method of the low-temperature high-pressure double-walled hydrogen storage cylinder as described in claim 9, characterized in that: Before step two, a circumferential structural component (521) is pasted on the outside of the inner liner (1). There are multiple circumferential structural components (521) distributed along the axial direction of the inner liner (1). Multiple connecting pieces (523) are provided on the circumferential structural component (521) and are evenly distributed along the outer periphery of the inner liner (1). The connecting pieces (523) extend along the radial side of the inner liner (1) to the outer liner (3). Then, two airfoil pieces (522) are installed on one connecting piece (523). The two corresponding airfoil pieces (522) are symmetrical about the connecting piece (523) and set at an angle. Then, an insulation layer (2) is laid on the outer wall of the inner liner (1). The thickness of the insulation layer (2) is less than or equal to the radial dimension of the connecting piece (523) along the inner liner (1). After the circumferential structural component (521), connecting piece (523) and airfoil (522) are assembled with the inner liner (1), before step four, the end of the airfoil (522) facing the outer liner (3) is the second overlapping part (5224). The second overlapping part (5224) is connected to the corresponding annular rib (54), and the airfoil (522) undergoes relative elastic deformation.

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