V-shaped hydrogen storage bottle structure for aircraft

Abstract

The V-shaped hydrogen storage bottle structure comprises an inner-layer metal insert, an outer-layer metal coating layer, a first carbon fiber composite material layer and a second carbon fiber composite material layer, the first carbon fiber composite material layer and the second carbon fiber composite material layer are attached to each other, and the outer-layer metal coating layer comprises a first boss and a first circular ring column connected to the outer side of the first boss; the inner-layer metal insert comprises a second boss and a second circular ring column connected to the outer side of the second boss, and the bottle opening, the inner side of the first boss and the outer side of the first carbon fiber composite material layer and the inner side of the first carbon fiber composite material layer and the outer side of the second boss are attached to each other through thermal deformation compensation layers; the second carbon fiber composite material layer is attached to the inner side of the second boss, and the first cylindrical ring and the second cylindrical ring are connected with each other. Through the design that the carbon fiber layer is clamped by the inner aluminum alloy metal layer and the outer aluminum alloy metal layer, the thermal mismatch phenomenon between the carbon fiber coating layer and the aluminum alloy metal insert under the low-temperature and high-pressure low-temperature liquid hydrogen storage working condition is restrained.

Description

Technical Field

[0001] The present invention relates to the technical field of the design and manufacture of hydrogen storage pressure vessel equipment, and particularly relates to a V-type hydrogen storage bottle structure for an aircraft. Background Art

[0002] In the process of the development and utilization of hydrogen energy, there are mainly several links including production, storage and transportation, and use. One of the most important links is the storage and transportation of hydrogen energy, which will directly determine the use safety and utilization efficiency of hydrogen energy. At present, the storage and transportation technologies of hydrogen energy mainly include high-pressure gaseous hydrogen storage, cryogenic liquid hydrogen storage, metal hydride hydrogen storage, etc. Cryogenic liquid hydrogen storage has a large hydrogen storage density and a high energy density, and the hydrogen storage density can reach 70 kg / m 3 , and has broad application prospects. Among them, the demand of low-speed near-space aircraft for long endurance and large payloads makes the power supply scheme of "airborne liquid hydrogen + hydrogen fuel cell" an important research direction at present.

[0003] Among the various functional components of cryogenic liquid hydrogen storage, the hydrogen storage bottle is the main functional component. The performance of the hydrogen storage bottle is directly related to important indicators such as the hydrogen storage volume density, mass density, cycle service life and safety of cryogenic liquid hydrogen storage. According to the development history of the hydrogen storage bottle, the inner liner material and the winding structure, it can be divided into five categories. Among them, the all-carbon fiber-wrapped inner-linerless hydrogen storage bottle (V-type bottle) has the advantages of light weight and no inner liner defects, and is the focus of subsequent research.

[0004] In the prior art, the bottle body section of the V-type hydrogen storage bottle has no inner liner structure, and a metal frustum structure is still required at the bottle mouth for connection with external pipelines; at the same time, the bottle mouth of the hydrogen storage bottle is generally designed as an ellipsoidal or spherical shape. Therefore, the complex curved surface connection between the carbon fiber composite material and the metal material at the bottle mouth of the V-type hydrogen storage bottle has become a difficulty in the design and manufacture of the V-type hydrogen storage bottle. Further, the storage condition of cryogenic liquid hydrogen in the V-type hydrogen storage bottle is generally 20K and 2MPa. Due to the too large difference in the thermodynamic properties between the carbon fiber composite material and the metal material, and the thermal expansion coefficient of aluminum alloy is much larger than that of the carbon fiber composite material, the existing hydrogen storage bottle mouth structure is prone to excessive shear stress at the connection between the aluminum alloy and the carbon fiber composite material and even delamination phenomenon under low-temperature working conditions, that is, it is prone to low-temperature thermal mismatch problems. Therefore, designing a V-type hydrogen storage bottle mouth structure suitable for low-temperature and high-pressure working conditions and the ply structure of its bottle body is a key problem that urgently needs to be solved in the V-type hydrogen storage bottle structure design. Summary of the Invention

[0005] The purpose of the present invention is to provide a V-type hydrogen storage bottle structure for an aircraft that has reliable connection, simple processing technology, and is not prone to thermal mismatch problems under low-temperature and high-pressure working conditions in view of the defects of the prior art.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] A V-shaped hydrogen storage bottle structure for an aircraft, comprising a carbon fiber bottle body and a metal bottle mouth, characterized in that: the metal bottle mouth includes an inner metal insert and an outer metal coating layer, the carbon fiber bottle body includes a first carbon fiber composite layer and a second carbon fiber composite layer that are mutually attached, the outer metal coating layer includes a first boss and a first circular cylinder connected to the outside of the first boss, the inner metal insert includes a second boss and a second circular cylinder connected to the outside of the second boss, at the bottle mouth, between the inner side of the first boss and the outer side of the first carbon fiber composite layer, and between the inner side of the first carbon fiber composite layer and the outer side of the second boss, they are mutually attached through a thermal deformation compensation layer, the second carbon fiber composite layer is attached to the inner side of the second boss, the inner side of the first circular cylinder and the outer side of the second circular cylinder are connected to each other, and a through hole is provided in the center of the inner metal insert.

[0008] Further, the thermal deformation compensation layer includes a number of S-shaped aluminum alloy members, the S-shaped aluminum alloy members are connected end to end to form an interlocking structure, and the surface of the S-shaped aluminum alloy members is covered with a low-temperature resin adhesive.

[0009] Further, the low-temperature resin adhesive uses 7wt.% polyethylene glycol-modified polyurethane resin.

[0010] Further, a gas barrier resin layer is filled between the first carbon fiber composite layer and the second carbon fiber composite layer, the gas barrier resin layer uses epoxy resin mixed with polyethylene as raw materials, and is used to prevent the hydrogen stored in the bottle from leaking along the gap between the inner metal insert and the second carbon fiber composite layer.

[0011] Further, both the first boss and the second boss are ellipsoidal structures, the longitudinal cross-sectional shape of the first boss is an elliptical arc, the outer longitudinal cross-section of the second boss is an elliptical arc, and the inner side is a vertical line.

[0012] Further, a third circular cylinder is connected to the inner side of the second boss, and a carbon fiber layup mold auxiliary structure is connected to the third circular cylinder.

[0013] Further, the first circular cylinder and the second circular cylinder are connected by threads, and the third circular cylinder and the carbon fiber layup mold auxiliary structure are connected by threads.

[0014] Further, the first carbon fiber composite layer is prepared by a carbon fiber winding process, using T1100 carbon fiber as the fiber material and epoxy resin as the resin base for layup, with a total of 10 layers.

[0015] Furthermore, the second carbon fiber composite layer is prepared by a carbon fiber winding process. T1100 carbon fiber is used as the fiber material, and a mixture of epoxy resin and polyethylene is used as the resin base for laying up, with a total of 6 layers laid up.

[0016] Furthermore, the winding and laying angles of the first carbon fiber composite layer and the second carbon fiber composite layer are at an angle of ±45° with the horizontal direction.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. For the composite laminated structure of the bottle mouth, the connection between the carbon fiber and aluminum alloy at the bottle mouth is designed as an aluminum alloy - carbon fiber - aluminum alloy composite laminated structure. Through the design of clamping the carbon fiber layer by the inner and outer aluminum alloy layers, the thermal mismatch phenomenon between the carbon fiber coating layer and the aluminum alloy frustum under the low-temperature and high-pressure low-temperature liquid hydrogen storage condition is inhibited.

[0019] 2. In the two carbon fiber composite layers, for the inner second carbon fiber composite layer, T1100 carbon fiber is used as the fiber material, and a mixture of epoxy resin and polyethylene is used as the resin base for laying up. For the outer first carbon fiber composite layer, T1100 carbon fiber is used as the fiber material and epoxy resin is used as the resin base for laying up. The resin base of the mixture of epoxy resin and polyethylene can improve the gas barrier property against hydrogen. On the basis of ensuring the performance of the carbon fiber composite with the original epoxy resin as the resin base, the gas barrier property of the carbon fiber composite reinforcement layer against hydrogen is improved, enabling the single material layer of the carbon fiber composite to meet the requirements of the type V bottle for strength and gas barrier performance.

[0020] 3. The carbon fiber composite layer is connected to the inner metal insert and the outer metal coating layer by means of bonding. The bonding material used is 7wt.% polyethylene glycol modified polyurethane resin. The 7wt.% polyethylene glycol modified polyurethane resin has better tensile strength at low temperature (70K), which can improve the connection stability between different material layers of the type V hydrogen storage bottle mouth composite laminated structure at low temperature. Ensure the reliability of the type V hydrogen storage bottle mouth composite laminated structure under the low-temperature liquid hydrogen storage condition. At the same time, the 7wt.% polyethylene glycol modified polyurethane resin bonding layer acts as a sealant to prevent hydrogen from leaking between the carbon fiber composite layer and the inner metal insert and the outer metal coating layer, ensuring the airtightness of the whole gas cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a three-dimensional view of the structure of the type V hydrogen storage bottle according to the embodiment of the present invention;

[0022] Figure 2 is a longitudinal sectional view of the structure of the type V hydrogen storage bottle;

[0023] Figure 3 is Figure 2Partial enlarged view at location A in

[0024] Figure 4 Structural diagram of the inner metal insert

[0025] Figure 5 is Figure 4 Sectional view taken along line B - B of

[0026] Figure 6 Structural diagram of the outer metal cladding layer

[0027] Figure 7 is Figure 6 Sectional view taken along line C - C of

[0028] Figure 8 Structural diagram of a single S - shaped aluminum alloy component

[0029] Figure 9 Schematic diagram of the interlocking structure between S - shaped aluminum alloy components

[0030] Figure 10 Schematic diagram of the first carbon fiber composite layer

[0031] Figure 11 Schematic diagram of the fiber laying direction of the first carbon fiber composite layer

[0032] Figure 12 Schematic diagram of the second carbon fiber composite layer

[0033] Figure 13 Sectional view of the auxiliary structure of the carbon fiber laying mold

[0034] In the figure: 1 - the first carbon fiber composite layer, 2 - the second carbon fiber composite layer, 3 - the first boss, 4 - the first circular cylinder, 5 - the second boss, 6 - the second circular cylinder, 7 - the thermal deformation compensation layer, 8 - the through - hole, 9 - the S - shaped aluminum alloy component, 10 - the gas - barrier resin layer, 11 - the third circular cylinder, 12 - the auxiliary structure of the carbon fiber laying mold, 13 - the regular hexagonal column. Detailed implementation manners

[0035] To deepen the understanding of the present invention, the following will further elaborate on the present invention in conjunction with the accompanying drawings. This embodiment is only used to explain the present invention and does not limit the protection scope of the present invention.

[0036] A specific embodiment of a V - type hydrogen storage bottle structure for an aircraft, as shown in Figures 1-3As shown, it includes a carbon fiber bottle body and a metal bottle mouth. The metal bottle mouth is made of aluminum alloy and includes an inner metal insert and an outer metal coating layer. The carbon fiber bottle body includes a first carbon fiber composite layer 1 and a second carbon fiber composite layer 2 that are mutually adhered. The outer metal coating layer includes a first boss 3 and a first circular cylinder 4 connected to the outside of the first boss 3. The inner metal insert includes a second boss 5 and a second circular cylinder 6 connected to the outside of the second boss 5. As Figure 3 , at the bottle mouth, between the inner side of the first boss 3 and the outer side of the first carbon fiber composite layer 1, and between the inner side of the first carbon fiber composite layer 1 and the outer side of the second boss 5, they are mutually adhered through a thermal deformation compensation layer 7. The second carbon fiber composite layer 2 is adhered to the inner side of the second boss 5. The inner side of the first circular cylinder 4 and the outer side of the second circular cylinder 6 are mutually connected. A through hole 8 is provided at the center of the inner metal insert.

[0037] As Figure 4 , 5 shown, the inner metal insert is an ellipsoidal second boss 5 with a second circular cylinder 6 and a third circular cylinder 11 connected to the left end and the right end respectively. Among them, the inner diameter of the second circular cylinder 6 is 18mm, the outer diameter is 36mm, and the length is 35mm; the inner diameter of the third circular cylinder 11 is 18mm, the outer diameter is 30mm, and the length is 25mm; the left side of the second boss 5 is an elliptical wall surface, and its cross-section is a 1 / 4 ellipse with a major axis of 84mm and a minor axis of 42mm. The right side of the second boss 5 is designed as a vertical wall surface, and the thinnest part of the wall thickness of the second boss 5 is 4mm. An M18×2.0 internal thread is designed on the inner side of the second circular cylinder 6 for connecting with an external joint connected to a pipeline, so as to form a gas passage with the pipeline outside the gas cylinder and connect the gas inside and outside the gas cylinder. An M36×4 external thread is designed on the outside of the second circular cylinder 6 for connecting with the outer metal coating layer. An M30×3.5 external thread is designed on the outside of the third circular cylinder 11 for connecting with the carbon fiber layup mold auxiliary structure 12.

[0038] As Figure 6 , 7 shown, the outer metal coating layer is designed as an ellipsoidal first boss 3 with a first circular cylinder 4 connected to the left end. A regular hexagonal cylinder 13 is sleeved on the outside of the first circular cylinder 4. Among them, the inner diameter of the first circular cylinder 4 is 36mm, the outer diameter is 42mm, and the length is 21mm; the side length of the regular hexagonal cylinder 13 is 30mm, and the length is 11mm. The first boss 3 is an ellipsoidal wall surface structure, and its right cross-section is a 1 / 4 ellipse with a major axis of 128mm and a minor axis of 64mm. The wall thickness of the first boss 3 is 4mm. An M36×4 internal thread is designed on the inner side of the first circular cylinder 4 for connecting with the external thread on the outside of the second circular cylinder 4. The inner wall surface of the first boss 3 is designed as an elliptical wall surface with the same radian as the outer side surface of the first carbon fiber composite layer 1, which is convenient for connecting with the first carbon fiber composite layer 1.

[0039] Both the inner metal insert and the outer metal cladding layer are made of 6061-T6 aluminum alloy and prepared by one-piece machining, thus simplifying the processing steps, optimizing the coaxiality error caused by separate processing, and eliminating the problem of gas cylinder neck failure caused by welding.

[0040] The 6061-T6 aluminum alloy material has good hydrogen permeation prevention performance and fatigue resistance, which can avoid hydrogen leakage at the neck of the type V hydrogen storage cylinder and improve the service life of the type V hydrogen storage cylinder.

[0041] The thermal deformation compensation layer 7 includes a number of S-shaped aluminum alloy members 9, as Figure 8 、 9 shown. The S-shaped aluminum alloy members 9 are connected end to end to form an interlocking structure. The S-shaped aluminum alloy members 9 are prepared by one-piece machining using 6061-T6 aluminum alloy, and both their inner and outer side surfaces have the same curvature as the fitting structure, facilitating connection with the structure to be fitted. This interlocking structure has a gap in the circumferential direction. When the aluminum alloy material at the neck contracts and deforms at low temperature, the gap between the two S-shaped aluminum alloy members 9 in the circumferential direction decreases without direct extrusion, reducing the stress caused by low-temperature deformation of the aluminum alloy.

[0042] Both sides of the S-shaped aluminum alloy member 9 are covered with a low-temperature resin adhesive for bonding and fitting between the first boss 3 and the first carbon fiber composite layer 1, and between the first carbon fiber composite layer 1 and the second boss 5. The low-temperature resin adhesive uses 7wt.% polyethylene glycol-modified polyurethane resin to improve the shear strength of the bonding surface under low-temperature and high-pressure working conditions and ensure the connection reliability of the joint. The 7wt.% polyethylene glycol-modified polyurethane resin has better tensile strength at low temperature (70K), which can improve the connection stability between different material layers of the type V hydrogen storage cylinder neck composite laminated structure at low temperature. Ensure the reliability of the type V hydrogen storage cylinder neck composite laminated structure under low-temperature liquid hydrogen storage conditions. At the same time, as a sealant, it prevents hydrogen from leaking between the first carbon fiber composite layer 1 and the first boss 3 and the second boss 5, ensuring the airtightness of the entire gas cylinder.

[0043] A gas barrier resin layer 10 is filled between the first carbon fiber composite layer 1 and the second carbon fiber composite layer 2. The gas barrier resin layer 10 uses epoxy resin mixed with polyethylene as the resin material to prevent the stored hydrogen from leaking along the gap between the second boss 5 and the second carbon fiber composite layer 2.

[0044] As Figure 10 、 11As shown in the figure, the first carbon fiber composite layer 1 is prepared by using the carbon fiber winding process. T1100 carbon fiber is used as the fiber material, and epoxy resin is used as the resin matrix for laying up, with a total of 10 layers laid up. The specific method is to wind the pre-impregnated fiber yarns onto the surface of the second boss 5 at a laying-up angle alternating at +45° or -45° with the horizontal direction for 10 layers, and then complete the laying-up preparation through curing in a curing furnace. The first carbon fiber composite layer 1 uses T1100 carbon fiber as the fiber material and epoxy resin as the resin matrix for laying up. Compared with the commonly used T300 and T700 carbon fiber materials at present, the T1100 carbon fiber material has better tensile strength. Under the same design strength requirements, it can reduce the number of laying-up layers and the laying-up thickness, realizing high-precision laying-up preparation and lightweight requirements.

[0045] As Figure 12 shown in the figure, the second carbon fiber composite layer 2 is prepared by using the carbon fiber winding process. T1100 carbon fiber is used as the fiber material, and epoxy resin mixed with polyethylene is used as the resin matrix for laying up, with a total of 6 layers laid up. The specific method is to wind the pre-impregnated fiber yarns onto the surface of the carbon fiber laying-up mold at a laying-up angle alternating at +45° or -45° with the horizontal direction for 6 layers, and then complete the laying-up preparation through curing in a curing furnace. The second carbon fiber composite layer 2 uses T1100 carbon fiber as the fiber material and epoxy resin mixed with polyethylene as the resin matrix for laying up. The resin matrix of epoxy resin mixed with polyethylene can improve the gas barrier property against hydrogen. On the basis of ensuring the performance of the carbon fiber composite with the original epoxy resin as the resin matrix, it improves the gas barrier property of the second carbon fiber composite layer 2 against hydrogen, enabling the single material layer of the carbon fiber composite to meet the requirements of the strength and gas barrier performance of the type-V hydrogen storage cylinder.

[0046] The first carbon fiber composite layer 1 and the second carbon fiber composite layer 2 are designed to have the same thickness in the radial direction, which is convenient for subsequent laying-up preparation.

[0047] As Figure 13 shown in the figure, the carbon fiber laying-up mold auxiliary structure 12 is a circular ring structure. It is designed with an internal thread of M30×3.5 on the inner side for connecting with the third circular column 11. When preparing the type-V hydrogen storage cylinder, the laying-up mold of the second carbon fiber composite layer 2 is prepared by using a soluble material on the carbon fiber laying-up mold auxiliary structure 12, and then the carbon fiber laying-up mold auxiliary structure 12 is combined with the third circular column 11 to complete the subsequent processing. By separating the carbon fiber laying-up mold from the inner metal insert, the damage to the inner metal insert during the preparation of the carbon fiber laying-up mold is reduced. At the same time, through the design of the third circular column 11, the connection strength between the carbon fiber laying-up mold auxiliary structure 12 and the carbon fiber laying-up mold is improved.

[0048] The carbon fiber composite material layer is prepared by laying with the dry winding process. Dry winding is to directly wind the pre-impregnated fiber yarns or tapes on the surface of the mandrel, or wind the fibers softened to the viscous flow state by heating on the surface of the mandrel on the winding machine. Since the pre-impregnated yarns or tapes are professionally produced, strict control of the resin content (which can be accurate to within 2%) and the amount of pre-impregnated yarn can be ensured. Therefore, the dry winding forming process can accurately control the quality of the products. The biggest feature of the dry winding process is that the winding equipment is clean, the processing environment is hygienic, the quality of the wound products is stable, the winding speed can reach 100m - 200m / min, and the production efficiency is high. It is suitable for the preparation of the carbon fiber composite material layer in the composite laminated structure of the V-type hydrogen storage bottle mouth.

[0049] The above specific implementation manners are only for explaining the technical concept and structural features of the present invention, aiming to enable those skilled in the art to implement it accordingly. However, the above content does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A V-type hydrogen storage bottle structure for aircraft, comprising a carbon fiber bottle body and a metal bottle mouth, characterized in that: The metal bottle mouth comprises an inner metal insert and an outer metal coating layer; the carbon fiber bottle body comprises a first carbon fiber composite material layer (1) and a second carbon fiber composite material layer (2) bonded to each other; the outer metal coating layer comprises a first boss (3) and a first circular column (4) connected to the outer side of the first boss (3); the inner metal insert comprises a second boss (5) and a second circular column (6) connected to the outer side of the second boss (5); at the bottle mouth, the inner side of the first boss (3) and the outer side of the first carbon fiber composite material layer (1) and the inner side of the first carbon fiber composite material layer (1) and the outer side of the second boss (5) are bonded to each other via a thermal deformation compensation layer (7); the second carbon fiber composite material layer (2) is bonded to the inner side of the second boss (5); the inner side of the first cylindrical ring (4) and the outer side of the second cylindrical ring (6) are connected to each other; and a through hole (8) is provided at the center of the inner metal insert.

2. A V-type hydrogen storage bottle structure for aircraft according to claim 1, characterized in that: The thermal deformation compensation layer (7) comprises a plurality of S-shaped aluminum alloy components (9), wherein the S-shaped aluminum alloy components (9) are connected end to end to form an interlocking structure, and the surfaces of the S-shaped aluminum alloy components (9) are covered with low-temperature resin glue.

3. A V-type hydrogen storage bottle structure for aircraft according to claim 2, characterized in that: The low temperature resin glue adopts 7wt.% polyethylene glycol modified polyurethane resin.

4. A V-type hydrogen storage bottle structure for aircraft according to claim 1, characterized in that: A gas barrier resin layer (10) is filled between the first carbon fiber composite material layer (1) and the second carbon fiber composite material layer (2); the gas barrier resin layer (10) uses epoxy resin mixed with polyethylene as a raw material and is used to prevent the hydrogen stored in the bottle from leaking along the gap between the inner metal insert and the second carbon fiber composite material layer (2).

5. The V-type hydrogen storage bottle structure for aircraft according to claim 1, characterized in that: The first boss (3) and the second boss (5) are both ellipsoidal structures. The longitudinal section of the first boss (3) is an elliptical arc, and the outer longitudinal section of the second boss (5) is an elliptical arc, and the inner side is a vertical line.

6. The V-type hydrogen storage bottle structure for aircraft according to claim 1, characterized in that: A third circular column (11) is connected to the inner side of the second boss (5), and a carbon fiber layup mold auxiliary structure (12) is connected to the third circular column (11).

7. A V-type hydrogen storage bottle structure for aircraft according to claim 6, characterized in that: The first cylindrical ring (4) and the second cylindrical ring (6) are threadedly connected, and the third cylindrical column (11) and the carbon fiber layup mold auxiliary structure (12) are threadedly connected.

8. The V-type hydrogen storage bottle structure for aircraft according to claim 1, characterized in that: The first carbon fiber composite material layer (1) is prepared by a carbon fiber winding process, using T1100 carbon fiber as the fiber material and epoxy resin as the resin base for laying, with a total of 10 layers laid.

9. The V-type hydrogen storage bottle structure for aircraft according to claim 1, characterized in that: The second carbon fiber composite material layer (2) is prepared by a carbon fiber winding process, using T1100 carbon fiber as the fiber material and epoxy resin mixed with polyethylene as the resin base for lamination, with a total of 6 layers.

10. A V-type hydrogen storage bottle structure for aircraft according to claim 8 or 9, characterized in that: The winding and laying angles of the first carbon fiber composite material layer (1) and the second carbon fiber composite material layer (2) are ±45° with respect to the horizontal direction.

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