Composite material pressure container inner container with reinforcing ribs and manufacturing method of composite material pressure container inner container

Abstract

The invention relates to the technical field of composite material pressure vessel forming, and discloses a composite material pressure vessel inner container with reinforcing ribs, which comprises a cylinder body, sealing heads are arranged on the two sides of the cylinder body, the cylinder body section is provided with a plurality of cylinder body reinforcing ribs which are arranged at equal intervals along the axial direction of the cylinder body; the invention further discloses a manufacturing method of the composite material pressure container inner container with the reinforcing ribs, and the manufacturing method comprises the following steps that S1, segmented molds are designed and manufactured, and the molds comprise the inner mold and the outer mold; and S2, carbon fiber prepreg is laid on the surface of the inner mold to form a carbon fiber cylinder body section. The structural strength and uniformity of the inner container are optimized through design of reinforcing ribs and filling of a circumferential fiber winding reinforcing layer, the thickness of the reinforcing ribs is calculated based on the difference value between the minimum thickness and the thickness of the end socket, in winding forming, a co-curing process is adopted to be matched with a high-precision mold, an inner mold is fused into the inner container to provide support, and meanwhile, the thickness of the reinforcing ribs is reduced. And the interface strength is optimized through inner mold supporting and a laminated gradient structure.

Description

Technical Field

[0001] The invention relates to the technical field of composite pressure vessel molding, in particular to a composite pressure vessel liner with reinforcing ribs and a manufacturing method thereof. Background Art

[0002] A pressure vessel is a device used to store and process gas or liquid. It can operate safely under conditions above atmospheric pressure and is widely used in industries such as petroleum, chemical, energy, and aerospace. In design and manufacturing, pressure vessels must meet strict standards and specifications to ensure their structural strength, safety, and durability under complex conditions such as high temperature and high pressure. With the continuous increase in industrial demand, pressure vessels are gradually developing in the direction of lightweight and high performance. This trend has prompted the application of new materials and manufacturing processes in the field of pressure vessels, among which fiber-reinforced composite materials have gradually become an important choice due to their excellent specific strength and specific stiffness.

[0003] Carbon fiber dry winding is a manufacturing process that directly winds dry carbon fiber bundles onto a mold or core material. Its characteristics are that no liquid resin is required, and the emission of volatiles is reduced during the winding process, which has environmental advantages. However, dry winding has high requirements for the control of fiber arrangement and number of layers. Improper operation may lead to insufficient fiber bonding strength or uneven structure, thus affecting the mechanical properties of the finished product. Therefore, this process needs to solve the problem of fiber bonding strength and structural uniformity in practical applications.

[0004] Carbon fiber wet winding is suitable for the manufacture of complex-shaped products by pre-impregnating the carbon fiber in liquid resin and then winding it onto a mold. Wet winding can ensure the initial bonding between fiber layers, but this process increases production time and is accompanied by environmental pollution during resin volatilization and curing. Wet winding requires high operating skills from technicians, and uneven resin impregnation may lead to a decrease in mechanical properties. These factors limit its application in the manufacture of high-performance pressure vessels.

[0005] Variable tension winding molding technology is a technology that optimizes the performance of fiber-reinforced composite materials in recent years. By dynamically adjusting the fiber tension and arrangement during the winding process, it can significantly improve the strength, stiffness and anisotropy of the composite material, while achieving lightweight design. However, this technology has extremely high requirements for tension control and liner pressure. Any inappropriateness may lead to uneven fiber laying, internal defects and decreased interlayer bonding strength, and ultimately make the mechanical properties of the finished product unable to meet the design requirements.

[0006] Based on the above shortcomings of the prior art, how to improve the fiber bonding strength, optimize the structural performance, and achieve approximate equal tension control in the manufacturing process of composite pressure vessels has become the research focus of the current technical field. To this end, the present invention proposes a composite pressure vessel liner with reinforcing ribs and a manufacturing method thereof. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a composite pressure vessel liner with reinforcing ribs and a method for manufacturing the same, which solves the problem of insufficient mechanical properties of the composite pressure vessel liner due to improper tension control, insufficient fiber bonding strength and uneven structure.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: A composite material pressure vessel liner with reinforcing ribs, comprising:

[0009] The barrel has heads on both sides, and the barrel section is provided with a plurality of barrel reinforcing ribs arranged at equal intervals along the axial direction of the barrel, and the gaps between the barrel reinforcing ribs are filled by a circumferential fiber winding reinforcement layer;

[0010] Bottle mouth, which is pre-buried and arranged at the end sections on both sides of the inner liner;

[0011] The outer winding layer covers the barrel section and the head surface.

[0012] Preferably, the bottle mouth is made of aluminum alloy, and the head, barrel, hoop fiber winding reinforcement layer and outer winding layer are all made of T400-12K carbon fiber.

[0013] Preferably, the thickness of the barrel reinforcement rib is the difference between the minimum thickness t of the barrel section and the thickness h of the head, and the minimum thickness t satisfies the following formula:

[0014]

[0015] Wherein, p is the internal pressure; R is the inner radius of the liner; E1 is the longitudinal tensile elastic modulus of the cylinder; E2 is the circumferential tensile elastic modulus of the cylinder;

[0016] The minimum thickness t of the barrel is the larger value between t1 and t2.

[0017] Preferably, the head is elliptical, and its thickness h satisfies the following formula:

[0018]

[0019] Where D is the inner diameter of the head; p is the internal pressure; E hd Design the radial tensile elastic modulus for the head.

[0020] A method for manufacturing a composite pressure vessel liner with reinforcing ribs comprises the following steps:

[0021] S1. Design and manufacture segmented molds, including inner molds and outer molds;

[0022] S2, laying carbon fiber prepreg on the surface of the inner mold to form a carbon fiber barrel section;

[0023] S3. Lay the cut barrel reinforcement ribs on the outer mold surface according to the designed thickness and position;

[0024] S4, laying the cut carbon fiber head prepreg on the specified position of the mold, and pre-embed the aluminum alloy bottle mouth;

[0025] S5, combining the inner and outer molds into one, placing them into a curing device and performing co-curing according to preset process parameters;

[0026] S6. A circumferential fiber winding reinforcement layer is filled between the cured barrel section and the reinforcing rib by adopting a circumferential winding process;

[0027] S7. After the reinforcement layer is filled, the outer carbon fiber outer winding layer is wound to form a complete structure.

[0028] Preferably, in step S2, the carbon fiber prepreg is filled with epoxy resin as a matrix.

[0029] Preferably, the step S5 specifically includes the following steps:

[0030] S5.1. Align and assemble the inner mold and the outer mold;

[0031] S5.2. Place the assembled mold into the curing equipment and process it according to the curing process parameters;

[0032] S5.3. After curing is completed, the temperature is slowly lowered to room temperature, and then the outer mold is removed;

[0033] S5.4. After the mold is disassembled, the cured carbon fiber composite inner mold is retained as part of the liner.

[0034] Preferably, the curing process parameters in step S5.2 are:

[0035] Curing temperature: from room temperature to 120°C-180°C at a heating rate of 1°C-2°C / min;

[0036] Constant temperature curing time: Maintain 2-6 hours in the target temperature range to complete the cross-linking reaction of the epoxy resin matrix;

[0037] Curing pressure: Apply a uniform pressure of 0.5-2MPa during the curing process.

[0038] The present invention provides a composite material pressure vessel liner with reinforcing ribs and a manufacturing method thereof. The liner has the following beneficial effects:

[0039] 1. The present invention significantly improves the compressive and impact resistance of the composite material liner by designing a plurality of reinforcing ribs along the axial direction of the carbon fiber barrel section and filling the reinforcing layer with circumferential fiber winding between the reinforcing ribs. The thickness of the reinforcing ribs is calculated based on the difference between the minimum thickness of the barrel and the thickness of the head, thereby ensuring the force uniformity of the barrel. During the curing process, the epoxy resin matrix forms an integral structure with the carbon fiber layer and the reinforcing ribs through a cross-linking reaction, thereby solving the problem of insufficient fiber bonding strength in the traditional production process and achieving the effect of uniform structure and significantly optimized mechanical properties of the composite material liner. Compared with the insufficient fiber bonding strength and structural unevenness caused by the complex process in the prior art, the present invention solves the problem of insufficient compressive and impact resistance of the liner through the innovative design of reinforcing ribs and circumferential fiber winding.

[0040] 2. In the winding process, the present invention controls the fiber tension to achieve approximately equal tension distribution by designing reinforcing ribs and circumferential fiber winding reinforcement layers, and combines the co-curing process. In the mold assembly process, through high-precision matching of internal and external molds, the internal mold not only serves as a supporting structure, but also directly integrates into the liner structure through curing, avoiding deformation, collapse or dimensional deviation caused by uneven tension during the molding process. In addition, the carbon fiber prepreg is compacted layer by layer during the paving process, combined with the uniform infiltration of the epoxy resin matrix, further ensuring that the liner structure has precise size and stability after curing, and achieving precise size control and shape stability during the winding process of the liner. Compared with the conventional winding molding process in the prior art, improper tension control often leads to deformation or dimensional deviation of the bottle. The present invention solves the problem of structural instability of the liner during the molding process by optimizing the tension distribution and mold design, ensuring the stability and reliability of product quality.

[0041] 3. The present invention utilizes the cured carbon fiber composite material inner mold as part of the liner to provide high-strength and high-rigidity support for the barrel and head section during the curing process. By applying uniform hot pressure in the curing equipment, it is ensured that the barrel section, reinforcing ribs and head have no collapse and stress concentration during the integration process. Furthermore, at the connection between the head and the barrel, the interface bonding strength is optimized through the laminated gradient structure design, the interface stress concentration phenomenon is reduced, and the fatigue performance and impact resistance of the liner are significantly improved, achieving the technical effect of avoiding the collapse of the liner, enhancing the fatigue resistance and improving the structural stability. Compared with the conventional winding molding process of the prior art, improper internal stamping often leads to the collapse of the liner, the decline of fatigue performance and poor bonding quality. The present invention solves the problems of liner collapse and performance degradation through the support of the cured inner mold and the gradient connection design, greatly improving the service life of the liner. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a cross-sectional view of the inner liner of the composite pressure vessel of the present invention;

[0043] Figure 2 A partial view of the inner liner of the composite pressure vessel of the present invention;

[0044] Figure 3 The present invention is a flow chart of the preparation method.

[0045] Among them, 1. Bottle mouth; 2. End cap; 3. Cylinder body; 4. Cylinder body reinforcement ribs; 5. Circumferential fiber winding reinforcement layer; 6. Outer winding layer. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Please see attached Figure 1 -Attached Figure 2 The embodiment of the present invention provides a composite pressure vessel liner with reinforcing ribs, comprising:

[0048] The barrel 3 is provided with heads 2 on both sides thereof, and the barrel 3 is provided with a plurality of barrel reinforcing ribs 4 arranged at equal intervals along the axial direction of the barrel, and the gaps between the barrel reinforcing ribs 4 are filled with a circumferential fiber winding reinforcement layer 5;

[0049] A bottle mouth 1, which is pre-buried and arranged in two sections of the end caps on both sides of the inner liner;

[0050] The outer winding layer 6 covers the barrel 3 sections and the surface of the head 2.

[0051] Specifically, the combination of the barrel 3 and the head 2 constitutes an integral pressure-bearing shell. Under high pressure, the barrel 3 mainly bears longitudinal and circumferential stresses, while the head 2, through its elliptical geometry, evenly disperses the internal pressure to avoid excessive local stress. In order to further optimize the mechanical properties of the connection area between the barrel 3 and the head 2 and enhance the stability of the overall structure, a layer-by-layer compaction method is adopted in the transition area, and a laminated gradient structure is achieved by controlling the changes in fiber direction and thickness. This structure gradually transitions the stiffness and strength of the connection, effectively reduces the interface stress concentration phenomenon, and significantly improves the fatigue performance and impact resistance of the connection.

[0052] The arrangement of the barrel reinforcement ribs 4 further improves the rigidity of the barrel 3. The thickness of the reinforcement ribs 4 is calculated to be the difference between the minimum barrel thickness t and the head thickness h. The circumferential fiber winding reinforcement layer 5 between the ribs plays a connecting and filling role, so that the barrel section forms a continuous mechanical support system, disperses the internal pressure, and improves the fatigue resistance.

[0053] The embedded bottle mouth 1 is set in the head 2 section, and forms an integrated structure with the liner through the co-curing process to ensure the sealing and strength of the interface area. The bottle mouth area also adopts the layer-by-layer paving and compaction process to optimize the combination quality of the fiber and the metal bottle mouth, reduce stress concentration, and improve the safety and reliability of the interface.

[0054] The outer winding layer 6 covers the entire surface of the inner liner, not only providing additional mechanical protection, but also strengthening the overall structure of the inner liner by continuous circumferential winding. Combined with the intercostal circumferential fiber winding reinforcement layer 5, the outer winding layer further disperses the internal and external stresses, improving the impact resistance and long-term stability of the inner liner.

[0055] The bottle mouth 1 is made of aluminum alloy material, and the head 2, the barrel 3, the circumferential fiber winding reinforcement layer 5 and the outer winding layer 6 are all made of T400-12K carbon fiber.

[0056] The thickness design of the barrel reinforcement rib 4 is centered on ensuring that the liner has excellent mechanical properties under high pressure. According to the formula calculation, the thickness of the reinforcement rib is equal to the difference between the minimum thickness t of the barrel section and the thickness h of the head, thus achieving structural rationality and strength balance between the barrel section and the head section.

[0057] The calculation of the minimum thickness t is based on the stress conditions of the inner shell section. Under high pressure, the shell section is subjected to longitudinal stress and hoop stress at the same time. The formulas are:

[0058]

[0059] Calculate the minimum wall thickness required for longitudinal and circumferential forces. Where:

[0060] t1 is the wall thickness required for longitudinal force, which is inversely proportional to the longitudinal tensile elastic modulus E1 of the barrel;

[0061] t2 is the wall thickness required for hoop force, which depends on the hoop tensile elastic modulus E2 of the barrel.

[0062] Finally, the larger value of the two is taken as the minimum thickness t of the barrel section to ensure that the mechanical properties of the material meet the design requirements of the pressure vessel.

[0063] The head 2 adopts an elliptical design, through the formula:

[0064]

[0065] Calculate its thickness h. The design radial tensile elastic modulus E of the head in the formula hd It determines the head's ability to resist deformation under high pressure. At the same time, the relationship between the inner diameter D and the internal pressure p reflects the head's ability to respond to the internal pressure.

[0066] By rationally designing the minimum thickness t of the barrel section and the thickness h of the head, the thickness of the reinforcing rib 4 is determined by the difference between t and h, so that the reinforcing rib not only provides structural support, but also avoids local collapse or deformation caused by insufficient thickness. Ultimately, the thickness design ensures the coordination of the barrel section and the head section in the stress environment, greatly improving the structural strength and durability of the liner.

[0067] Please see attached Figure 3 A method for manufacturing a composite pressure vessel liner with reinforcing ribs comprises the following steps:

[0068] S1. Design and manufacture segmented molds, including inner molds and outer molds;

[0069] S2, laying carbon fiber prepreg on the surface of the inner mold to form three sections of carbon fiber barrel;

[0070] S3, laying the cut barrel reinforcement ribs 4 on the outer mold surface according to the designed thickness and position;

[0071] S4, laying the cut carbon fiber head 2 prepreg on the specified position of the mold, and pre-embed the aluminum alloy bottle mouth 1;

[0072] S5, combining the inner and outer molds into one, placing them into a curing device and performing co-curing according to preset process parameters;

[0073] S6, filling the hoop fiber winding reinforcement layer 5 between the solidified barrel section 3 and the reinforcing rib 4 by hoop winding process;

[0074] S7. After the reinforcing layer is filled, the outer carbon fiber outer winding layer 6 is wound to form a complete structure.

[0075] In step S2, the carbon fiber prepreg is filled with epoxy resin as a matrix.

[0076] Step S5 specifically includes the following steps:

[0077] S5.1. Align and assemble the inner mold and the outer mold;

[0078] S5.2. Place the assembled mold into the curing equipment and process it according to the curing process parameters;

[0079] S5.3. After curing is completed, the temperature is slowly lowered to room temperature, and then the outer mold is removed;

[0080] S5.4. After the mold is disassembled, the cured carbon fiber composite inner mold is retained as part of the liner.

[0081] The curing process parameters in step S5.2 are:

[0082] Curing temperature: from room temperature to 120°C-180°C at a heating rate of 1°C-2°C / min;

[0083] Constant temperature curing time: Maintain 2-6 hours in the target temperature range to complete the cross-linking reaction of the epoxy resin matrix;

[0084] Curing pressure: Apply a uniform pressure of 0.5-2MPa during the curing process.

[0085] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composite pressure vessel liner with reinforcing ribs, characterized in that: include: The barrel (3) is provided with heads (2) on both sides thereof, the barrel (3) is provided with a plurality of barrel reinforcing ribs (4) arranged at equal intervals along the axial direction of the barrel, and the gaps between the barrel reinforcing ribs (4) are filled by a circumferential fiber winding reinforcement layer (5); A bottle mouth (1) is pre-buried in the end caps (2) on both sides of the inner liner; The outer winding layer (6) covers the barrel (3) section and the surface of the sealing head (2).

2. The composite pressure vessel liner with reinforcing ribs according to claim 1, characterized in that: The bottle mouth (1) is made of aluminum alloy material, and the sealing head (2), the barrel (3), the circumferential fiber winding reinforcement layer (5) and the outer winding layer (6) are all made of T400-12K carbon fiber.

3. The composite pressure vessel liner with reinforcing ribs according to claim 1, characterized in that: The thickness of the barrel reinforcement rib (4) is the difference between the minimum thickness t of the barrel (3) section and the thickness h of the end cap, and the minimum thickness t satisfies the following formula: Wherein, p is the internal pressure; R is the inner radius of the inner liner; E1 is the longitudinal tensile elastic modulus of the barrel (3); E2 is the circumferential tensile elastic modulus of the barrel (3); The minimum thickness t of the barrel (3) is the larger value between t1 and t2.

4. The composite pressure vessel liner with reinforcing ribs according to claim 1, characterized in that: The end cap (2) is elliptical, and its thickness h satisfies the following formula: Where D is the inner diameter of the head (2); p is the internal pressure; E hd The radial tensile elastic modulus is designed for the head (2).

5. A method for manufacturing a composite pressure vessel liner with reinforcing ribs, characterized in that: The following steps are involved: S1. Design and manufacture segmented molds, including inner molds and outer molds; S2, laying carbon fiber prepreg on the surface of the inner mold to form a carbon fiber barrel (3) section; S3, laying the cut barrel reinforcement ribs (4) on the outer mold surface according to the designed thickness and position; S4, laying the cut carbon fiber end cap (2) prepreg on the designated position of the mold, and pre-embed the aluminum alloy bottle mouth (1); S5, combining the inner and outer molds into one, placing them into a curing device for co-curing according to preset process parameters; S6, filling a hoop fiber winding reinforcement layer (5) between the solidified barrel (3) section and the reinforcing rib (4) by a hoop winding process; S7. After the reinforcing layer is filled, the outer carbon fiber outer winding layer (6) is wound to form a complete structure.

6. The method for manufacturing a composite material pressure vessel liner with reinforcing ribs according to claim 5, characterized in that: In the step S2, the carbon fiber prepreg is filled with epoxy resin as a matrix.

7. The method for manufacturing a composite material pressure vessel liner with reinforcing ribs according to claim 5, characterized in that: The step S5 specifically includes the following steps: S5.

1. Align and assemble the inner mold and the outer mold; S5.

2. Place the assembled mold into the curing equipment and process it according to the curing process parameters; S5.

3. After curing is completed, the temperature is slowly lowered to room temperature, and then the outer mold is removed; S5.

4. After the mold is disassembled, the cured carbon fiber composite inner mold is retained as part of the liner.

8. The method for manufacturing a composite pressure vessel liner with reinforcing ribs according to claim 5, characterized in that: The curing process parameters in step S5.2 are: Curing temperature: from room temperature to 120°C-180°C at a heating rate of 1°C-2°C / min; Constant temperature curing time: Maintain 2-6 hours in the target temperature range to complete the cross-linking reaction of the epoxy resin matrix; Curing pressure: Apply a uniform pressure of 0.5-2MPa during the curing process.

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