A hydrogen storage pressure vessel and a method of manufacturing the same

Abstract

The application discloses a hydrogen storage pressure container and a manufacturing method thereof, and belongs to the technical field of pressure containers. The pressure container comprises an inner liner, valve seats and an outer shell. The inner liner is a cavity structure with two open ends and is used for containing hydrogen. Two valve seats are respectively installed in the openings at the two ends of the inner liner and are integrally formed with the inner liner, and the valve seats are used for connecting external gas charging connectors. The outer shell covers the outer surface of the inner liner and comprises an inner layer and an outer layer. The inner layer is formed by layer-by-layer laying and pasting of one-way carbon fiber prepreg and covers the outer surface of the inner liner. The outer layer is formed by layer-by-layer laying and pasting of glass cloth prepreg and covers the outer surface of the inner layer. The manufacturing method of the pressure container replaces the winding process with a laying and pasting process, vacuum is drawn during the laying and pasting process and solidification, and solidification forming is achieved under the conditions of low temperature and high pressure in a hot pressing tank, so that the problems of great manufacturing difficulty, long production cycle, high porosity and insufficient compactness of carbon fiber composite materials in the existing pressure container manufacturing process adopting the winding process are solved.

Description

Technical Field

[0001] This invention belongs to the field of pressure vessel technology, specifically relating to a hydrogen storage pressure vessel and its manufacturing method. Background Technology

[0002] In recent years, hydrogen production and storage equipment has made significant progress. Hydrogen storage equipment generally uses plastic as the inner lining and wraps several layers of carbon fiber composite material around its outer surface for reinforcement, making it not only strong but also lightweight.

[0003] In the prior art, Chinese invention patent CN110822280A discloses a pressure vessel and its manufacturing method. This method prevents the reinforcing fibers from sliding on the outer circumferential surface of the dome by flexibly spirally winding reinforcing fibers around the pressure vessel body, thus reducing the manufacturing cost of the pressure vessel. Chinese invention patent CN115230194A also discloses a pressure vessel and its manufacturing method. This method avoids slippage of the carbon fiber composite material during winding by preparing metal bosses on the inner lining and machining concave-convex patterns on the outer surface of the bosses.

[0004] Both patents offer solutions to the problem of carbon fiber composite material slippage during the winding of carbon fiber filaments (or fiber bundles) onto the outer surface of the liner, solving the challenge of accurately winding carbon fiber composite material in the required posture and position. However, certain drawbacks remain: 1. When spirally winding reinforcing fibers onto a thin-shell plastic liner, excessive pressure cannot be applied. This can lead to fiber slippage and deformation of the thin-shell plastic liner, resulting in instability or buckling failure, significantly reducing cyclic fatigue performance and severely impacting the container's safe lifespan. 2. The preparation methods in both patents cannot completely eliminate air bubbles and moisture in the fiber filaments, resulting in high porosity and a high product defect rate. 3. Pressure vessels experience uniform pressure in all directions and uniform force per unit area, simultaneously bearing radial and axial forces. While winding the fiber filaments at a specific angle solves the winding problem, it does not conform to the optimal stress principle, affecting product lifespan. 4. Although the process of winding carbon fiber composite material offers the advantage of continuous fiber filaments, the winding process is difficult and has a long production cycle.

[0005] In the prior art, Chinese invention patent CN112166282 A discloses a composite material pressure vessel with a reinforced liner and its manufacturing method. This method involves arranging a wrapped fabric in a mold cavity and applying pressure by blowing pressurized fluid (e.g., air) into the liner, causing the liner wall to bulge and pressing the fabric against the inner wall of the mold cavity. This patent increases the adhesion between the liner and the reinforcing layer by arranging the wrapped fabric in the mold cavity and blowing pressurized fluid (e.g., air) into the liner to apply pressure, thus preventing liner deformation. However, while this method solves the problem of liner deformation, it requires an additional mold during manufacturing and necessitates controlling the fit between the mold's internal shape and the outer surface of the liner with the reinforcing fibers. Therefore, this method results in high production costs and significant processing difficulties. Summary of the Invention

[0006] Technical problem to be solved: In order to avoid the shortcomings of the prior art, the present invention provides a hydrogen storage pressure vessel and its manufacturing method. The existing reinforcing fiber is replaced with fiber prepreg, and the traditional winding process is replaced with a laying process. At the same time, the fiber prepreg is vacuumed during the laying process and cured under low temperature and high pressure conditions. This solves the problems of high manufacturing difficulty, long production cycle, high porosity and insufficient density in carbon fiber composite materials that exist in the manufacturing of existing pressure vessels using the winding process.

[0007] The technical solution of the present invention is: a hydrogen storage pressure vessel, comprising: an inner liner, valve seats, and an outer shell; the inner liner is a cavity structure with openings at both ends for containing hydrogen gas; two valve seats are respectively installed in the openings at both ends of the inner liner and integrally formed with the inner liner, and the valve seats are used to connect to an external gas filling connector; the outer shell covers the outer surface of the inner liner, and the outer shell includes an inner layer and an outer layer; the inner layer is made of unidirectional carbon fiber prepreg laid layer by layer, and the unidirectional carbon fiber prepreg of adjacent layers has different laying directions, and the inner layer covers the outer surface of the inner liner; the outer layer is made of glass cloth prepreg laid layer by layer, and the outer layer covers the outer surface of the inner layer.

[0008] A further technical solution of the present invention is: the unidirectional carbon fiber prepreg of the inner layer is laid in the following directions: 0°, 90°, +45°, and -45°. The unidirectional carbon fiber prepreg in the same layer is laid in the same direction. Different directions are laid in different directions layer by layer. The thickness of the inner layer is determined according to the volume of the hydrogen storage pressure vessel, the pressure to be withstood, and the material properties of the unidirectional carbon fiber prepreg.

[0009] A further technical solution of the present invention is: the laying direction of the outer layer of glass cloth prepreg is ±45°, the laying direction of the glass cloth prepreg in the same layer is the same, and different directions are laid in a cross pattern layer by layer, for a total of 5-10 layers.

[0010] A further technical solution of the present invention is: the inner liner has a cylindrical shell structure in the middle and hemispherical shell structures at both ends symmetrically arranged relative to the middle column, and the openings at both ends of the inner liner are located at the center of the hemispherical shells at both ends.

[0011] A further technical solution of the present invention is: the lining material is a thermosetting resin, and the lining is formed by rotational molding or injection molding. The thermosetting resin includes, but is not limited to, polyamide resin, polyolefin resin, polycarbonate resin, and polystyrene resin.

[0012] A further technical solution of the present invention is: the valve seat is a stepped rotating body, and a through hole is provided at its axial center position for gas to enter and exit; the through hole of the valve seat is provided with an internal thread for threaded connection with an external gas filling connector; the outer diameter of the valve seat is provided with multiple annular grooves, and multiple axial inner grooves are evenly distributed around the outer diameter of the valve seat.

[0013] A further technical solution of the present invention is that the valve seat material is brass or stainless steel.

[0014] A method for manufacturing a hydrogen storage pressure vessel includes the following steps:

[0015] Step 1: Lining Design;

[0016] The outer dimensions and wall thickness of the liner are determined according to the gas storage requirements, and a suitable liner material for rotational molding or injection molding is selected; the liner material includes, but is not limited to, polyamide resin, polyolefin resin, polycarbonate resin, and polystyrene resin.

[0017] Step 2: Design and manufacture of the inner lining molding mold;

[0018] Based on the dimensions of the inner lining structure, design the inner lining rotational molding mold. When designing the molding mold, the process allowance of the inner lining and the valve seat installation and positioning point should be designed.

[0019] Step 3: Lining molding;

[0020] The lining rotational molding mold is fixed on the shuttle machine. The valve seats are fixed at the valve seat mounting positions at both ends of the mold. The lining material is poured into the mold, the mold is closed, and the lining is formed according to the rotational molding process; thus, an lining with machining allowance is obtained.

[0021] Step 4: Install the outer casing;

[0022] The process allowance at both ends of the supporting liner is used to clean the surface of the liner before placing it in the cleanroom to lay the outer shell. Laying the outer shell involves first laying the inner layer, then laying the outer layer. The process for laying the inner layer is as follows: unidirectional carbon fiber prepreg is laid on the outer surface of the liner, with the same laying direction within each layer. Each layer is laid at 0°, 90°, +45°, and -45° intervals. After every 3-5 layers, a vacuum bag is placed over the inner layer, and a vacuum is applied to ensure tightness until the inner layer thickness meets the design requirements. The process for laying the outer layer is as follows: glass cloth prepreg is laid on the outer surface of the inner layer, with the same laying direction within each layer. Each layer is laid at ±45° intervals until the outer layer thickness meets the design requirements. This results in the liner and outer shell assembly.

[0023] Step 5: Curing; Wrap the inner liner and outer shell assembly in a vacuum bag and place it in an oven or autoclave. Vacuum the vacuum bag and heat it to 60°C according to the molding process for curing.

[0024] Step 6: Remove process allowance; cut off the process allowance to obtain the hydrogen storage pressure vessel.

[0025] A further technical solution of the present invention is: when the curing in step 5 is carried out in a hot autoclave, the pressure of the hot autoclave is set to 3 to 6 atmospheres.

[0026] A further technical solution of the present invention is: the vacuum bag structure matches the inner liner, the two ends of the vacuum bag are sealed at the process allowance at both ends of the inner liner, and an air extraction nozzle is provided in the middle of the vacuum bag to draw a vacuum.

[0027] Beneficial effects

[0028] The beneficial effects of the present invention are as follows: The present invention provides a hydrogen storage pressure vessel and its manufacturing method, which replaces the winding process with a laying process, shortens the manufacturing cycle, reduces the manufacturing difficulty, and avoids lining deformation; at the same time, the laying process conforms to the principle of optimal stress distribution, ensuring uniform stress distribution on the lining, and improving product quality and service life.

[0029] By increasing the process allowance during the manufacturing of hydrogen storage pressure vessels, the present invention facilitates vacuum bag sealing. By using vacuum bags during the manufacturing process, vacuuming is carried out during the laying process and during curing, so that the fiber prepreg is applied to the outer surface of the inner lining, eliminating air bubbles and moisture in the carbon fiber composite material and reducing the porosity of the outer shell.

[0030] By using an autoclave for curing and molding, combined with the design of openings at both ends of the liner, and setting the pressure inside the autoclave to 3 to 6 atmospheres, gas can smoothly enter the liner cavity during curing and balance the pressure on the outer shell surface. Under the action of internal and external pressure, not only is the liner firmly bonded to the outer shell, but the molding under low temperature and high pressure conditions can also fully utilize the mechanical properties of carbon fiber composite materials, thereby improving product quality and durability. Attached Figure Description

[0031] Figure 1 This is a cross-sectional view of the hydrogen storage pressure vessel structure of the present invention;

[0032] Figure 2 This is a cross-sectional view of the inner lining structure of the present invention with machining allowance;

[0033] Figure 3 for Figure 2 Enlarged view of section H in the middle;

[0034] Figure 4 This is an isometric view of the valve seat structure of the present invention;

[0035] Figure 5 This is a schematic diagram of the stress state of the hydrogen storage pressure vessel of the present invention during the curing process in a thermostatic tank.

[0036] Explanation of reference numerals in the attached drawings: 1. Liner, 2. Outer shell, 3. Valve seat, 4. Process allowance, 5. Vacuum nozzle, 6. Vacuum bag. Detailed Implementation

[0037] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0038] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] See Figure 1-5 The hydrogen storage pressure vessel of the present invention includes an inner liner 1, an outer shell 2, and a valve seat 3.

[0040] The inner liner 1 is made of thermosetting resin and is formed by rotational molding or injection molding. The middle portion of the inner liner 1 is a cylindrical shell structure, with hemispherical shell structures symmetrically arranged at both ends relative to the central column. These hemispherical shells face each other towards the central column, together forming an inner cavity to contain hydrogen gas. Openings are provided at both ends of the inner liner 1, located at the center of the hemispherical shells, for injecting hydrogen gas. Two valve seats 3 are provided, respectively installed in the openings at both ends of the inner liner 1, and integrally formed with the inner liner 1 using rotational molding or injection molding. The material of the inner liner 1 is required to prevent hydrogen permeation and have good thermal conductivity, suitable for rotational molding or injection molding. Therefore, thermosetting materials such as polyamide resin, polyolefin resin, polycarbonate resin, and polystyrene resin are selected for the inner liner 1, with appropriate thermal conductive agents added to increase thermal conductivity.

[0041] The valve seat 3 is a stepped shaft-shaped rotating body with a through hole at its axial center for gas inlet and outlet. The through hole of the valve seat 3 has an internal thread for threaded connection to the external gas filling connector during use of the hydrogen storage pressure vessel. The valve seat 3 is made of brass or stainless steel to ensure the strength and durability required for connection to external connectors. To ensure the reliability of the connection between the valve seat 3 and the inner liner 1, so that the valve seat 3 can withstand axial force without dislodging during subsequent use, and to prevent the valve seat 3 from rotating relative to the inner liner 1, such as... Figure 4 As shown, an annular groove is provided at the junction of the two stepped shafts on the valve seat 3. In this embodiment, a total of two annular grooves are provided, and multiple axially arranged inner grooves are evenly distributed around the outer diameter of the two stepped shafts on the valve seat 3. Through the stepped structure of the valve seat 3, combined with the design of the annular groove and inner grooves, the reliability of the fit between the valve seat 3 and the inner liner 1 is ensured after the valve seat 3 and the inner liner 1 are integrally formed by rotational molding.

[0042] The outer shell 2 covers the outer surface of the inner liner 1. The outer shell 2 includes an inner layer and an outer layer. The inner layer is a fiber-reinforced layer used to withstand the pressure of the hydrogen storage tank, and it is directly laid on the outer surface of the inner liner 1. The outer layer is a protective layer made of glass cloth prepreg, and it is laid on the outer surface of the inner layer. The inner layer uses T700 unidirectional carbon fiber prepreg, laid in a cross pattern at 0°, 90°, +45°, and -45°, with the unidirectional carbon fiber prepreg laid in the same direction within the same layer. The outer layer's glass cloth prepreg is laid in a cross pattern at ±45°. 0 The fiberglass prepreg is laid in a cross-hatching pattern, with each layer in a different direction. Within the same layer, the fiberglass prepreg is laid in the same direction. The outer layer covers the outer surface of the inner layer, protecting it. The thickness of the inner layer is determined based on the volume of the hydrogen storage pressure vessel, the required pressure, and the material properties of the unidirectional carbon fiber prepreg. Preferably, the inner unidirectional carbon fiber prepreg thickness is 10–15 mm, the outer fiberglass prepreg thickness is 1–3 mm, and 5–10 layers are laid.

[0043] The manufacturing steps of the hydrogen storage pressure vessel are as follows:

[0044] Step 1: Lining 1 Design;

[0045] The external dimensions of the liner 1 are determined according to the hydrogen storage requirements; the wall thickness needs to effectively prevent hydrogen permeation and has a certain rigidity, preferably designed to be 3-8mm; a suitable material for the liner 1 is selected for rotational molding or injection molding; the liner 1 is used to seal hydrogen and reduce various chemical corrosions, and its material is selected from thermosetting resins such as polyamide resin, polyolefin resin, polycarbonate resin, and polystyrene resin, with the addition of appropriate thermal conductive agents to improve thermal conductivity.

[0046] Step 2: Design and manufacture of the molding die for liner 1;

[0047] Based on the structural dimensions of the inner liner 1, a rotational molding mold for the inner liner is designed. The mold design must include the process allowance 4 for the inner liner 1 and the mounting and positioning points for the valve seat 3. The process allowance 4 is located at both ends of the inner liner 1 and on the outside of the valve seat 3. The process allowance 4 is a cylindrical structure with its central hole coaxial with the inner hole of the valve seat 3 and having the same diameter. The process allowance 4 is an auxiliary part used in the intermediate manufacturing process to support the inner liner 1 when laying the outer shell 2, and also to attach the vacuum bag 6 when vacuuming the outer shell 2. The process allowance 4 is removed after curing.

[0048] Step 3: Liner 1 is formed;

[0049] The rotomolding mold for the inner lining is fixed on the shuttle machine. The valve seats 3 are fixed at the mounting and positioning points at both ends of the mold. The material of the inner lining 1 is poured into the mold, the mold is closed, and the rotomolding process is followed. The machining allowance 4 is manufactured along with the inner lining 1. After the inner lining 1 is rotomolded, the inner lining 1 with the machining allowance 4 is obtained. At the same time, the valve seat 3 is also integrally formed at the opening of the inner lining 1.

[0050] Step 4: Laying the outer shell 2;

[0051] The process allowance 4 at both ends of the supporting liner 1 is used to clean the surface of the liner 1 before placing the liner 1 into the cleanroom to lay the outer shell 2. Laying the outer shell 2 includes first laying the fiber-reinforced inner layer and then laying the protective outer layer.

[0052] The process for laying the inner layer is as follows: Unidirectional carbon ribbon prepreg is laid on the outer surface of the inner liner 1. During laying, the laying direction within the same layer is the same, with each layer laid at alternating angles of 0°, 90°, +45°, and -45°. After every 3-5 layers, a vacuum bag 6 is placed over the inner layer, and a vacuum is drawn once to ensure the tightness of the laying. This process continues until the inner layer thickness meets the design requirements. The preferred thickness of the unidirectional carbon ribbon prepreg is 10-15 mm. The vacuum bag 6 has a structure that matches the inner liner. The two ends of the vacuum bag 6 are sealed with the outer diameter of the inner liner 1 using a process allowance of 4. A vacuum nozzle 5 is installed in the middle of the vacuum bag 6, through which a vacuum is drawn. The vacuum nozzle 5 and the vacuum bag 6 are industry-standard products.

[0053] The process for laying the outer layer is as follows: Prepreg of fiberglass cloth is laid on the outer surface of the inner layer. During laying, the laying direction within the same layer is the same, and each layer is laid at ±45° intervals until the thickness of the outer layer meets the design requirements. Preferably, the thickness of the outer fiberglass prepreg is 1–3 mm. After the outer layer is laid, the inner liner 1 and outer shell 2 are obtained as a combined assembly.

[0054] Step 5: Curing; Wrap the inner liner 1 and outer shell 2 assembly in a vacuum bag 6 and place it in an oven or autoclave. Connect an external vacuum pump to the suction nozzle 5 to evacuate the vacuum bag 6. Heat to 60°C for curing according to the molding process. Curing is preferably carried out in an autoclave, set to 3-6 atmospheres. Figure 5 As shown, because the inner liner 1 has open ends, gas can smoothly enter the cavity of the inner liner 1 in the autoclave, balancing the pressure on the surface of the outer shell 2. Under the action of internal and external pressure P, the inner liner 1 and the outer shell 2 are reliably bonded. The outer shell 2 is cured at low temperature and high pressure, fully utilizing the mechanical properties of the composite material. To achieve better curing results, the curing method in step 5 can be used for pre-curing every 20 to 30 layers of the inner layer.

[0055] Step 6: Remove process allowance 4; cut off process allowance 4 to obtain hydrogen storage pressure vessel. Specific Implementation Example 1:

[0057] The manufacturing steps of a hydrogen storage pressure vessel are as follows:

[0058] Step 1: Lining 1 Design;

[0059] The outer dimensions of the liner 1 are determined based on the hydrogen storage requirements. The wall thickness is designed to be 3mm. The liner material is high-density polystyrene resin, and the rotational molding process is adopted. An appropriate thermal conductive agent is added during the molding process.

[0060] Step 2: Design and manufacture of the molding die for liner 1;

[0061] Based on the structural dimensions of the inner liner 1, a rotational molding die for the inner liner is designed. The design of the molding die takes into account the process allowance 4 of the inner liner 1 and the installation and positioning requirements of the valve seat 3. Cast aluminum is selected as the material for the rotational molding die, which has low production cost and good heat conduction. The rotational molding die has a uniform wall thickness, resulting in a uniform wall thickness of the molded inner liner 1. The rough surface of the die ensures a stronger bond between the inner liner 1 and the outer shell 2.

[0062] Step 3: Liner 1 is formed;

[0063] The rotomolding mold for the inner lining is fixed on the shuttle machine. A valve seat 3, made of stainless steel, is fixed to the mold. Polystyrene resin (the material for the inner lining 1) is poured into the mold, the mold is closed, and the rotomolding process is followed. To ensure the reliable connection between the inner lining 1 and the valve seat 3, amplifiers are installed at both ends of the mold during molding. The rotomolding process is a mature existing technology and will not be described in detail here. The machining allowance 4 is manufactured along with the inner lining 1. After the inner lining 1 is rotomolded, an inner lining 1 with the machining allowance 4 is obtained, and the valve seat 3 is also integrally molded at the opening of the inner lining 1.

[0064] Step 4: Laying the outer shell 2;

[0065] The process allowance 4 at both ends of the supporting liner 1 is used to clean the surface of the liner 1 before placing the liner 1 into the cleanroom to lay the outer shell 2. Laying the outer shell 2 includes first laying the fiber-reinforced inner layer and then laying the protective outer layer.

[0066] The process for laying the inner layer is as follows: T700 unidirectional carbon ribbon prepreg is laid on the outer surface of the inner lining 1. The laying direction is the same within the same layer. Each layer is laid at 0°, 90°, +45° and -45°. After every 3 layers, a vacuum bag 6 is placed outside the inner layer and vacuum is applied once to ensure the tightness of the laying, until the thickness of the inner layer is 10mm.

[0067] The process for laying the outer layer is as follows: Prepreg of fiberglass cloth is laid on the outer surface of the inner layer. During laying, the laying direction within the same layer is the same, and each layer is laid at ±45° intervals until the outer layer thickness meets the design requirements. The preferred thickness of the outer fiberglass prepreg is 1mm. After the outer layer is laid, the inner liner 1 and outer shell 2 assembly are obtained. The inner layer is pre-cured once using the curing method described in step 5 every 20 layers.

[0068] Step 5: Curing; Wrap the inner liner 1 and outer shell 2 assembly in a vacuum bag 6 and place it in an autoclave. Connect an external vacuum pump to the vacuum nozzle 5 and evacuate the vacuum bag 6. Heat to 60℃ for curing according to the molding process. Set the autoclave to 5 atmospheres during curing.

[0069] Step 6: Remove process allowance 4; cut off process allowance 4 to obtain hydrogen storage pressure vessel. Specific Implementation Example 2:

[0071] The manufacturing steps of a hydrogen storage pressure vessel are as follows:

[0072] Step 1: Lining 1 Design;

[0073] The outer dimensions of the liner 1 are determined based on the hydrogen storage requirements. The wall thickness is designed to be 8mm. The liner material is polyamide resin, and the rotational molding process is adopted. An appropriate thermal conductive agent is added during the molding process.

[0074] Step 2: Design and manufacture of the molding die for liner 1;

[0075] Based on the structural dimensions of the inner liner 1, a rotational molding die for the inner liner is designed. The design of the molding die takes into account the process allowance 4 of the inner liner 1 and the installation and positioning requirements of the valve seat 3. Cast aluminum is selected as the material for the rotational molding die, which has low production cost and good heat conduction. The rotational molding die has a uniform wall thickness, resulting in a uniform wall thickness of the molded inner liner 1. The rough surface of the die ensures a stronger bond between the inner liner 1 and the outer shell 2.

[0076] Step 3: Liner 1 is formed;

[0077] The rotomolding mold for the inner lining is fixed on the shuttle machine. Valve seat 3, made of brass, is fixed to the mold. Polyamide resin (the material for the inner lining 1) is poured into the mold, the mold is closed, and the rotomolding process is followed. To ensure the reliable connection between the inner lining 1 and the valve seat 3, amplifiers are installed at both ends of the mold during molding. The rotomolding process is a mature existing technology and will not be described in detail here. The machining allowance 4 is manufactured along with the inner lining 1. After the inner lining 1 is rotomolded, the inner lining 1 with the machining allowance 4 is obtained, and the valve seat 3 is also integrally molded at the opening of the inner lining 1.

[0078] Step 4: Laying the outer shell 2;

[0079] The process allowance 4 at both ends of the supporting liner 1 is used to clean the surface of the liner 1 before placing the liner 1 into the cleanroom to lay the outer shell 2. Laying the outer shell 2 includes first laying the fiber-reinforced inner layer and then laying the protective outer layer.

[0080] The process for laying the inner layer is as follows: T700 unidirectional carbon ribbon prepreg is laid on the outer surface of the inner lining 1. The laying direction is the same within the same layer. Each layer is laid in a 0°, 90°, +45°, -45° alternating pattern. After every 5 layers, a vacuum bag 6 is placed outside the inner layer and vacuumed once to ensure the tightness of the laying, until the thickness of the inner layer is 15mm.

[0081] The process for laying the outer layer is as follows: Prepreg of fiberglass cloth is laid on the outer surface of the inner layer. During laying, the laying direction within the same layer is the same, and each layer is laid at ±45° intervals until the outer layer thickness meets the design requirements. The preferred thickness of the outer fiberglass prepreg is 3mm. After the outer layer is laid, the inner liner 1 and outer shell 2 assembly are obtained. The inner layer is pre-cured once every 30 layers using the curing method described in step 5.

[0082] Step 5: Curing; Wrap the inner liner 1 and outer shell 2 assembly in a vacuum bag 6 and place it in an autoclave. Connect an external vacuum pump to the vacuum nozzle 5 and evacuate the vacuum bag 6. Heat to 60℃ for curing according to the molding process. Set the autoclave to 6 atmospheres during curing.

[0083] Step 6: Remove process allowance 4; cut off process allowance 4 to obtain hydrogen storage pressure vessel.

[0084] The hydrogen storage pressure vessel structure and manufacturing method of this invention replace the winding process with a lay-up process, shortening the manufacturing cycle, reducing manufacturing difficulty, and preventing deformation of the inner liner 1. By increasing the process allowance 4, the vacuum bag 6 is easily sealed. The vacuuming process allows the fiber prepreg to be applied to the outer surface of the inner liner, eliminating air bubbles and moisture in the composite material and reducing porosity. The autoclave curing process not only ensures a strong bond between the inner liner 1 and the outer shell 2, but also fully utilizes the mechanical properties of the composite material under low temperature and high pressure conditions, improving product quality and durability. The manufacturing method of this invention is simple, low-cost, improves quality and durability, reduces product defect rates, and increases production efficiency.

[0085] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A method for manufacturing a hydrogen storage pressure vessel, characterized in that: The hydrogen storage pressure vessel includes an inner liner (1), an outer shell (2), and valve seats (3); the inner liner (1) is a cavity structure with openings at both ends, used to contain hydrogen; the two valve seats (3) are respectively installed in the openings at both ends of the inner liner (1) and are integrally formed with the inner liner (1), and the valve seats (3) are used to connect to external gas filling connectors; the outer shell (2) covers the outer surface of the inner liner (1), and the outer shell (2) includes an inner layer and an outer layer; the inner layer is made of unidirectional carbon fiber prepreg laid layer by layer, and the unidirectional carbon fiber prepreg of adjacent layers has different laying directions, and the inner layer covers the outer surface of the inner liner (1); the outer layer is made of glass cloth prepreg laid layer by layer, and the outer layer covers the outer surface of the inner layer; The manufacturing steps of a hydrogen storage pressure vessel are as follows: Step 1: Lining (1) Design; The outer dimensions and wall thickness of the liner (1) are determined according to the gas storage requirements, and a suitable material for the liner (1) is selected for rotational molding or injection molding; the material of the liner (1) includes one of polyamide resin, polyolefin resin, polycarbonate resin, and polystyrene resin. Step 2: Design and manufacture of the molding die for the inner lining (1); Based on the structural dimensions of the liner (1), design the liner rotation molding mold. When designing the molding mold, the process allowance (4) of the liner (1) and the installation and positioning of the valve seat (3) should be designed. Step 3: Lining (1) molding; Fix the inner lining rotation molding mold on the shuttle machine, fix the valve seat (3) at the installation and positioning position of the valve seat (3) at both ends of the mold, pour the material of the inner lining (1) into the mold, close the mold, and form according to the rotation molding process; A liner (1) with a process allowance (4) is obtained. Step 4: Laying the outer shell (2); The process allowance (4) at both ends of the supporting liner (1) is used to clean the surface of the liner (1), and then the liner (1) is placed in the clean room to lay the outer shell (2); the laying of the outer shell (2) includes laying the inner layer first and then laying the outer layer; the process of laying the inner layer is as follows: lay unidirectional carbon fiber prepreg on the outer surface of the liner (1), and the laying direction of the same layer is the same, and each layer is laid according to 0 ° 90 ° The process involves alternating between +45° and -45°. After every 3-5 layers, a vacuum bag (6) is placed over the inner layer, and a vacuum is applied once to ensure the tightness of the layering until the thickness of the inner layer meets the design requirements. The process for laying the outer layer is as follows: glass cloth prepreg is laid on the outer surface of the inner layer. The laying direction within the same layer is the same, and each layer is laid according to ±45°. ° The process is repeated until the outer layer thickness meets the design requirements, resulting in a combination of inner lining (1) and outer shell (2). Step 5: Curing; Wrap the lining (1) and outer shell (2) assembly in a vacuum bag (6) and place it in an oven or autoclave. Vacuum the vacuum bag (6) and heat it to 60°C in sequence according to the molding process to cure. Step 6: Remove process allowance (4); Remove the process allowance (4) to obtain a hydrogen storage pressure vessel.

2. The method for manufacturing a hydrogen storage pressure vessel according to claim 1, characterized in that: The inner layer of unidirectional carbon fiber prepreg is laid in directions including 0°, 90°, +45°, and -45°. The unidirectional carbon fiber prepreg in the same layer is laid in the same direction, and different directions are laid in a cross pattern layer by layer. The thickness of the inner layer is determined based on the volume of the hydrogen storage pressure vessel, the pressure to be withstood, and the material properties of the unidirectional carbon fiber prepreg.

3. The method for manufacturing a hydrogen storage pressure vessel according to claim 1, characterized in that: The outer layer of glass cloth prepreg is laid in a ±45° direction. The glass cloth prepreg in the same layer is laid in the same direction, and different directions are laid in a cross pattern layer by layer, for a total of 5-10 layers.

4. The method for manufacturing a hydrogen storage pressure vessel according to claim 1, characterized in that: The inner liner (1) has a cylindrical shell structure in the middle and hemispherical shell structures at both ends that are symmetrically arranged relative to the middle column. The openings at both ends of the inner liner (1) are located at the center of the hemispherical shells at both ends.

5. The method for manufacturing a hydrogen storage pressure vessel according to claim 1, characterized in that: The material of the liner (1) is a thermosetting resin, and the liner (1) is formed by rotational molding or injection molding; the thermosetting resin includes one of polyamide resin, polyolefin resin, polycarbonate resin and polystyrene resin.

6. A method for manufacturing a hydrogen storage pressure vessel according to claim 1, characterized in that: The valve seat (3) is a stepped rotating body with a through hole at its axial center for gas inlet and outlet; the through hole of the valve seat (3) is provided with an internal thread for threaded connection with an external gas filling connector; the outer diameter of the valve seat (3) is provided with multiple annular grooves, and multiple axial inner grooves are evenly distributed around the outer diameter of the valve seat (3).

7. A method for manufacturing a hydrogen storage pressure vessel according to claim 1, characterized in that: The valve seat (3) is made of brass or stainless steel.

8. A method for manufacturing a hydrogen storage pressure vessel according to claim 1, characterized in that: When the curing in step 5 is carried out in an autoclave, the autoclave is set to 3 to 6 atmospheres.

9. A method for manufacturing a hydrogen storage pressure vessel according to claim 1, characterized in that: The vacuum bag (6) has a structure and size that matches the inner liner (1). The two ends of the vacuum bag (6) are sealed at the process allowance (4) at both ends of the inner liner (1). The vacuum bag (6) has a suction nozzle (5) in the middle, and a vacuum is drawn from the suction nozzle (5).

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