Thin-wall metal inner container composite material ultrahigh pressure container and preparation method thereof

Abstract

The thin-wall metal inner container composite material ultrahigh pressure container comprises a metal inner container and a full-winding carbon fiber composite material layer arranged on the outer surface of the metal inner container. The metal inner container comprises a first straight cylinder section and connector parts arranged at the two ends of the first straight cylinder section, each connector part comprises a second straight cylinder section connected with the first straight cylinder section, and the second straight cylinder sections connect the connector connecting parts into a whole through the neck parts. The second straight cylinder section is connected with the neck part through a curved surface transition section, the curved surface transition section is of a variable-wall-thickness structure, and the thickness of the curved surface transition section is gradually increased in the direction from the second straight cylinder section to the neck part until the thickness of the neck part is equal; the whole connector part is dumbbell-shaped so as to meet the requirements that the connector part is installed on a system and bears unbalance loading of a cantilever. Through the structural design and control over all procedures, the whole container is light in weight, and meanwhile the container can be suitable for the ultra-high pressure working condition. The pressure resistance of the metal welded liner composite material pressure vessel is improved to the ultrahigh pressure level, the lightweight effect is remarkable, the production efficiency is high, and the advantage of low cost is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultra-high pressure containers, and in particular relates to an ultra-high pressure container with a thin-walled metal liner composite material and a preparation method thereof. Background Art

[0002] As a special equipment, composite high-pressure vessels are widely used in aerospace, energy, transportation, chemical industry and other fields. With the implementation of the national dual-carbon strategy, in order to reduce carbon emissions, various application fields have put forward higher requirements on the weight of storage media per unit weight of containers, and the application demand for high-performance, ultra-high pressure, lightweight and low-cost pressure vessels is becoming more and more intense. At present, composite pressure vessels are mainly made of steel or aluminum, which are welded or spun and then wrapped with composite materials. There are generally problems such as high product quality, low pressure resistance, high manufacturing cost, and no fastening assembly interface.

[0003] Generally speaking, the larger the diameter of a high-pressure container, the greater the gas volume, and the more convenient it is to charge and discharge the gas, but it also means that the gas cylinder is heavier, larger in size, and inconvenient to carry. Gas cylinders with smaller diameters are smaller in size and easier to carry, but the efficiency and convenience of charging and discharging gas are correspondingly reduced. In addition, as the field of use changes, composite high-pressure containers need to be assembled on other systems, and the installation site is subject to loads. Existing composite high-pressure containers cannot meet the needs of actual use.

[0004] CN202111113634.4 discloses a method for preparing a large-diameter metal welded liner composite material container, wherein a seamless austenitic stainless steel pipe is selected as a substrate to prepare a cylinder; an elliptical head is prepared by stamping or cold spinning an austenitic stainless steel plate, and a through hole is opened in the center of the elliptical head; a cap-shaped bottleneck joint is prepared by forging integral forming, and internal and external threads and sealing surfaces are processed on the cap-shaped bottleneck joint; the cylinder, the elliptical head and the cap-shaped bottleneck joint are welded to prepare a stainless steel welded liner, and the welding adopts single-sided welding and double-sided forming; a combined winding process of orthogonal winding and cross winding is adopted to wind carbon fiber on the outer surface of the stainless steel welded liner to obtain a carbon fiber winding pressure-bearing layer; glass fiber is wound on the outer surface of the carbon fiber winding pressure-bearing layer to obtain a glass fiber winding protective layer; drying and curing. However, the head is formed by spinning, and it is impossible to prepare a thin-walled metal liner, and the pressure resistance performance reaches the ultra-high pressure level while achieving lightweight.

[0005] CN202123134740.9 discloses a high-pressure stainless steel bottle carbon fiber fully wrapped gas cylinder liner, including an inner liner cylinder and at least one head, the head is welded to the end of the inner liner cylinder, the head includes a bottle shoulder, a bottle mouth and a serrated structure, and the serrated structure is arranged on the outer surface of the head. A serrated structure is provided on the outside of the head, and the bottle shoulder, bottle mouth and serrated structure of the head are integrated components, which enhances the tensile stress borne by the bottle mouth. The volume of the inner liner cylinder is 20 to 140L, the nominal outer diameter of the inner liner cylinder is Φ200 to 400mm, the length of the inner liner cylinder is not more than 3m, and the wall thickness of the inner liner cylinder is 3 to 8mm.

[0006] The above technologies are all aimed at solving the technical problems of low pressure resistance, high manufacturing cost, and no fastening assembly interface in the existing process technology for manufacturing composite pressure vessels with thin-walled metal liner, especially composite pressure vessels with metal welded liner; at the same time, the impact of assembly stress on the life of the pressure vessel is not considered. Therefore, in order to solve the above problems, it is very necessary to propose a method for preparing a thin-walled metal liner composite ultra-high pressure vessel. Summary of the invention

[0007] In view of the existing technology for designing and manufacturing large-caliber, thin-walled metal liner composite pressure vessels, there are technical problems such as low pressure resistance level and high manufacturing cost, and the relationship between caliber and assembly is fully considered. The present invention provides a thin-walled metal liner composite ultra-high pressure vessel and a preparation method thereof. The design and manufacture of thin-walled metal liner composite ultra-high pressure vessels are realized, meeting the requirements of lightweight, impact resistance, large caliber and low cost. In particular, the pressure resistance of the metal welded liner composite pressure vessel is improved to the ultra-high pressure level, with significant lightweight effect, high production efficiency and low cost advantage.

[0008] To achieve the above object, the present invention discloses the following technical solution: Disclosed is a thin-walled metal liner composite material ultra-high pressure container, comprising a metal liner and a fully wound carbon fiber composite material layer arranged on the outer surface of the metal liner; the metal liner comprises a straight cylinder section 1 and joint parts arranged at both ends of the straight cylinder section 1, the joint part comprises a straight cylinder section 2 connected to the straight cylinder section 1, and the straight cylinder section 2 connects the joint connection part into one body through a neck; the straight cylinder section 2 and the neck are connected through a curved transition section, the curved transition section is a variable wall thickness structure, and gradually becomes thicker from the straight cylinder section 2 to the neck until the neck becomes of uniform wall thickness; the entire joint part is dumbbell-shaped to meet the requirements of the joint part being installed on the system and bearing cantilever eccentric load.

[0009] The thin-walled metal liner composite material ultra-high pressure container of the present invention is designed in structure so that the connection between the joint part and the metal liner is provided with a curved surface connection part, and the inner and outer surfaces of the curved surface transition section are scientifically designed so that the installation reliability of the entire joint part is strong, and the thickness of the arc surface arm gradually decreases from the joint part to the straight tube section until it is connected with the straight tube section. This structural design can not only increase the caliber of the ultra-high pressure container, but also make it meet the requirements of static strength, swing fatigue strength, stability and deformation.

[0010] Furthermore, the outer wall of the joint connection part is circumferentially provided with a threaded portion for installation of the ultra-high pressure container. The thin-walled metal liner composite material ultra-high pressure container of the present invention breaks through the traditional ultra-high pressure container that only has an internal thread assembly structure at the inner end. The threaded portion is arranged on the outer wall of the joint part, which is more convenient to install and can be used in working conditions with a high pressure exceeding 100KPa, which can not only meet the large caliber requirements of the working conditions, but also will not damage the liner due to the high pressure.

[0011] Furthermore, the maximum wall thickness of the curved transition section is at least three times the wall thickness of the straight section. This design is an important setting to ensure the safety of the entire container.

[0012] Another object of the present invention is to disclose a method for preparing the above-mentioned thin-walled metal liner composite material ultra-high pressure container, comprising the following steps: S1. Determine the wall thickness and size of the blanking sheet: Determine the outer diameter D of the blank and the wall thickness H of the sheet according to the outer diameter d and wall thickness h of the straight section of the metal liner; S2. Cutting: Cut the plate with a wall thickness of H into rectangular plate size of L1×L2, where the width L1 of the cut plate satisfies: L1=3.14×(DH)+X, where the range of X is -0.1mm-4mm, and the length L2 is consistent with the length direction of the strip during rolling; S3. Preforming: Divide the blank sheet into equal parts in width L1, use a bending machine to symmetrically bend it along the length L2, and weld the longitudinal seam of the joint line; S4. Rolling the qualified tube blank into a seamless metal straight tube; S5. Processing of the joint: The thickness of the straight section 2 of the joint is determined according to the measured outer diameter and wall thickness of the straight section 1; S6. Welding: Butt the joints at both ends with the straight section of the metal liner, and weld the annular seam with argon arc welding, with the arc closing position covering the arc starting point by more than 10mm; S7. Fully wrap the carbon fiber composite layer on the outer surface of the metal liner, and wrap the impregnated carbon fiber in a circumferential direction around the circumferential weld on the metal liner for local reinforcement.

[0013] The preparation method of the thin-walled metal liner composite material ultra-high pressure container adopts argon arc welding to perform two weldings on the annular seam, which changes the previous head using spin forming. A thin-walled metal liner can be prepared to achieve lightweight while achieving ultra-high pressure grade pressure resistance.

[0014] The preparation method of the ultra-high pressure container made of a thin-walled metal liner composite material strictly and accurately controls each process, thereby achieving lightweighting of the entire container and being suitable for ultra-high pressure conditions.

[0015] Furthermore, the relationship between the outer diameter d of the straight section, the wall thickness h, the outer diameter D of the barrel blank and the wall thickness H is 4mm≤(Dd)≤10mm, 0<(Hh)≤3mm. This design can accurately cut materials, facilitate subsequent molding, and accurately achieve the target wall thickness of the inner liner barrel.

[0016] Furthermore, the wall thickness H of the plate is 3mm-6mm, and the material is industrial pure titanium plate.

[0017] Furthermore, the seamless metal straight tube in step S4 has an outer diameter roundness tolerance of ≤0.5mm, a wall thickness h of 1mm-3mm, and a wall thickness h tolerance of ±0.1mm.

[0018] Furthermore, in step S6, an arc-shaped welding protective cover is used for inflating protection around the annular seam, and the central angle of the arc protective cover is ≥300°. After the seam welding is completed, ventilation protection is continued for more than 1 minute. This prevents the welding material from contacting with oxygen in the air during the high-temperature melting process, thereby preventing the welding material from oxidizing and ensuring the quality of the welded joint. After welding, the heat-affected zone is small, the deformation of the welded joint is small, and the residual stress is also small. Further, after the circumferential seam welding is completed in step S6, the weld excess height is less than 0.5 mm. The excess height portion can increase the cross-sectional area of ​​the weld, thereby improving the strength and bearing capacity of the weld. ‌Reducing stress concentration‌: Appropriate excess height can disperse welding stress, reduce stress concentration, and improve the fatigue strength of the weld. ‌Protecting the weld‌: The excess height portion can protect the weld from erosion by the external environment and extend the service life of the weld.

[0019] Furthermore, in step S7, the width of the local reinforcement of the circumferentially wound impregnated carbon fiber is greater than 80 mm, and the thickness of the reinforcement is 0.2 mm to 0.6 mm. The local reinforcement improves its bearing capacity and reliability.

[0020] Furthermore, in step S7, except for the hoop winding for local reinforcement, the remaining carbon fiber composite material layers are alternately laid by hoop winding and spiral winding. Such winding can significantly improve the radial and axial compressive strength of the product, thereby meeting the working conditions of the product under ultra-high pressure.

[0021] Another object of the present invention is to disclose a thin-walled metal liner composite material ultra-high pressure container prepared by the above preparation method for use in devices in the fields of aerospace, energy, transportation, chemical industry, etc.

[0022] Compared with the prior art, the advantages of the present invention are: The thin-walled metal liner composite material ultra-high pressure container of the present invention is designed in structure so that the connection between the joint part and the metal liner is provided with a curved connection part, and the inner and outer surfaces of the curved transition section are scientifically designed so that the installation reliability of the entire joint part is strong and the strength requirements required for assembly on other systems are met. In addition, the curved transition section is a variable wall thickness structure, which gradually becomes thicker from the straight tube section 2 to the neck direction until the neck becomes a uniform wall thickness. This structural design is not only suitable for large-caliber high-pressure containers, but also can make it meet the requirements of static strength, swing fatigue strength, stability and deformation.

[0023] The method for preparing the ultra-high pressure container of the thin-walled metal liner composite material of the present invention can meet the requirements of lightweighting the entire container and be applicable to ultra-high pressure conditions through the control of each process. The pressure resistance of the metal welded liner composite material pressure container is improved to the ultra-high pressure level, the lightweight effect is significant, the production efficiency is high, and the low cost advantage is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the metal liner of the thin-walled metal liner composite material ultra-high pressure container of the present invention.

[0025] Figure 2 This is a schematic structural diagram of the thin-walled metal liner composite material ultra-high pressure container of the present invention.

[0026] Among them, 1-metal liner, 2-fully wrapped carbon fiber composite layer, 21-arc arm, 11-straight section one, 3-joint, 31-straight section two, 32-neck, 33-joint connection, 34-curved transition section, 35-threaded section. DETAILED DESCRIPTION

[0027] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] The following is combined with Figure 1 - Attachment Figure 2 , embodiments of the present invention are described in detail, but the present invention can be implemented in many different ways as defined and covered by the claims. Example 1

[0029] like Figure 1-Figure 2As shown, the thin-walled metal liner composite material ultra-high pressure container comprises a metal liner 1 and a fully wound carbon fiber composite material layer 2 arranged on the outer surface of the metal liner 1; the metal liner 1 comprises a straight section 11 and a joint part 3 arranged at both ends of the straight section 11, the joint part 3 comprises a straight section 2 31 connected to the straight section 11, and the straight section 2 31 connects the joint connection part 33 as a whole through the neck 32; the straight section 2 31 and the neck 32 are connected by a curved surface transition section 34, and the curved surface transition section 34 is a variable wall thickness structure, which gradually thickens from the straight section 2 31 to the neck 32 until the neck 32 becomes a uniform wall thickness; the entire joint part 3 is dumbbell-shaped to meet the requirements of the joint part 3 being installed on the system and bearing the cantilever eccentric load. The outer wall of the joint connection part 33 is circumferentially provided with a threaded part 35 for assembling the ultra-high pressure container.

[0030] The thin-walled metal liner composite material ultra-high pressure container is very different from the prior art. The neck 32 is larger than the straight tube section 11 in diameter, and the neck shrinkage is smaller during manufacturing.

[0031] The straight tube section 2 31 , the neck 32 , the straight tube section 1 11 , and the joint connection portion 33 are all cylindrical structures.

[0032] The fully wound carbon fiber composite layer 2 is coaxially arranged with the straight section 11 in the middle, and the two ends are provided with arc surface arms 21 concave from the outer edge inward, the inner surface of the arc surface arm 21 is close to the outer surface of the curved surface transition section 34, and the inner and outer surfaces of the curved surface transition section 34 are both within a circle with the diameter of the metal liner 1 as the diameter, and an ellipse with the liner diameter as the major axis and 1 / 2 of the liner diameter as the minor axis. From the metal liner 1 to the joint part 3, the thickness of the curved surface transition section gradually increases, and the maximum wall thickness of the curved surface transition section is at least 3 times the wall thickness of the straight section 1.

[0033] The thin-walled metal liner composite material ultra-high pressure container of this embodiment is designed in structure so that the connection between the metal joint and the metal liner 1 is provided with a curved connection part, and the inner and outer surfaces of the curved transition section are scientifically designed, so that the installation reliability of the entire joint part is strong and the strength requirements required for assembly on other systems are met. In addition, the thickness gradually increases from the straight section 11 to the joint part 3 until the neck 32 becomes the same wall thickness. This structural design can not only increase the caliber of the ultra-high pressure container, but also make it meet the requirements of static strength, swing fatigue strength, stability and deformation.

[0034] The manufacturing method comprises the following steps: S1. Determine the wall thickness and size of the blanking sheet: Determine the outer diameter D of the blank and the wall thickness H of the sheet according to the outer diameter d and wall thickness h of the straight section 11 of the metal liner 1; where 4mm≤Dd≤10mm, 0<Hh≤3mm. This design allows for precise blanking, facilitates subsequent forming, and can accurately achieve the target wall thickness of the liner cylinder.

[0035] S2. Cutting: Cut industrial pure titanium plates such as TA1, TA2, TA3, TA4 with a wall thickness of H (3mm-6mm) into rectangular plates of size L1×L2, where the width L1 of the cut plate satisfies: L1=3.14×(DH)+X, where the range of X is -0.1mm-4mm, and the length L2 is consistent with the length direction during the strip rolling process.

[0036] S3. Preforming: Divide the blank sheet equally in width L1, and use a bending machine to symmetrically bend it along the length L2. Use plasma arc welding to weld the longitudinal seam of the joint line. Before welding the longitudinal seam, use a stainless steel brush or polish the inner and outer surfaces within 30mm of the straight edge of the joint to a metallic luster, and use acetone or ethanol to clean the polished surface; after welding, check the appearance quality of the longitudinal seam, and perform radiographic inspection to obtain a tube blank with a roundness tolerance of ≤2.5mm.

[0037] S4. The qualified tube blanks are rolled by a five-roll rolling mill to obtain seamless metal straight tubes with outer diameter roundness tolerance ≤ 0.5mm, wall thickness (h) of 1mm-3mm, and wall thickness tolerance of ±0.1mm; S5. Processing of the joint: The thickness of the straight section 2 31 of the joint 3 is determined according to the measured outer diameter and wall thickness of the straight section 11; specifically, the titanium alloy forging is machined to obtain a metal joint, and the length of the straight edge section of the metal joint is ≥ 20 mm, so as to avoid stress concentration at the welding point, and when the high-pressure vessel is damaged, it can be cut and repaired here. The machining outer diameter and wall thickness of the straight edge section are precisely matched and determined according to the measured outer diameter and wall thickness of the metal straight tube in step S4, and the outer diameter tolerance of the metal straight tube is ±0.2 mm, and the wall thickness tolerance is ±0.05 mm.

[0038] S6. Butt the joints 3 at both ends with the straight section 11 of the metal liner 1. Before the circumferential seam welding, the inner and outer sides of the straight edge sections within 30mm of the metal joint and the metal straight tube welding place are polished to a metallic luster, and the polished surface is cleaned with acetone or ethanol; the circumferential seam is welded in two passes by argon arc welding, and the arc closing position covers the arc starting point by more than 10mm. The circumferential seam is inflated with an arc-shaped welding protective cover for protection. The central angle of the arc protective cover is ≥300°. After the circumferential seam welding is completed, the weld residual height is less than 0.5mm. After the seam welding is completed, ventilation protection is continued for more than 1 minute to prevent the welding material from contacting with oxygen in the air during the high-temperature melting process, thereby preventing the oxidation of the welding material and ensuring the quality of the welded joint; the heat-affected zone after welding is small, the deformation of the welded joint is small, and the residual stress is also small.

[0039] S7. Fully wrap the carbon fiber composite layer 2 on the outer surface of the metal liner 1, and wrap the impregnated carbon fiber in a circumferential direction with the circumferential weld on the metal liner 1 as the center for local reinforcement. The width of the local reinforcement of the circumferentially wound impregnated carbon fiber is greater than 80mm; the reinforcement thickness is 0.2mm-0.6mm; local reinforcement improves its bearing capacity and reliability. In addition to the circumferential winding of local reinforcement, the remaining carbon fiber composite layers are alternately laid by circumferential winding and spiral winding.

[0040] The present invention provides a curved connection part at the joint of the joint part and the metal liner through structural design, scientifically designs the inner and outer surfaces of the curved transition section, and makes the installation reliability of the entire joint part strong. The thickness of the metal liner is combined with the curved transition section through design and measurement. This structure can ensure that the wall thickness of the metal liner is relatively thin while meeting the use requirements such as strength. The thin-walled metal liner composite material ultra-high pressure container meets the requirements of lightweight, impact resistance, large diameter and low cost.

[0041] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A thin-walled metal liner composite material ultra-high pressure container, characterized in that: The invention comprises a metal liner (1) and a fully wound carbon fiber composite layer (2) arranged on the outer surface of the metal liner (1); the metal liner (1) comprises a straight section (11) and joints (3) arranged at both ends of the straight section (11); the joints (3) comprise a straight section (31) connected to the straight section (11); the straight section (31) connects the joint connection part (33) to form a whole through a neck (32); the straight section (31) and the neck (32) are connected through a curved transition section (34); the curved transition section (34) is a variable wall thickness structure, which gradually becomes thicker from the straight section (31) to the neck (32) until the neck (32) becomes of uniform wall thickness; the entire joint (3) is in a dumbbell shape to meet the requirements of the joint (3) being installed on the system and bearing the cantilever eccentric load.

2. The thin-walled metal liner composite material ultra-high pressure container according to claim 1, characterized in that: A threaded portion (35) is circumferentially provided on the outer wall of the joint connection portion (33) for assembling an ultra-high pressure container.

3. The thin-walled metal liner composite material ultra-high pressure container according to claim 1, characterized in that: The maximum wall thickness of the curved transition section (34) is at least three times the wall thickness of the straight tube section.

4. A method for preparing a thin-walled metal liner composite material ultra-high pressure container according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Determine the wall thickness and size of the blanking sheet: Determine the outer diameter D of the blank and the wall thickness H of the sheet according to the outer diameter d and the wall thickness h of the straight tube section (11) of the metal liner (1); S2. Cutting: Cut the plate with a wall thickness of H into rectangular plate size of L1×L2, where the width L1 of the cut plate satisfies: L1=3.14×(DH)+X, where the range of X is -0.1mm-4mm, and the length L2 is consistent with the length direction of the strip during rolling; S3. Preforming: Divide the blank sheet into equal parts in width L1, use a bending machine to symmetrically bend it along the length L2, and weld the longitudinal seam of the joint line; S4. Rolling the qualified tube blank into a seamless metal straight tube; S5. Processing of the joint portion: The thickness of the joint portion (3) of the straight tube section II (31) is determined according to the measured outer diameter and wall thickness of the straight tube section (11); S6. Welding: The joints (3) at both ends are butted against a straight section (11) of the metal liner (1), and the annular seam is welded by argon arc welding, with the arc closing position covering the arc starting point by more than 10 mm; S7. The carbon fiber composite layer (2) is fully wrapped around the outer surface of the metal liner (1), and the impregnated carbon fiber is wrapped around the circumferential weld on the metal liner (1) to perform local reinforcement.

5. The method for preparing a thin-walled metal liner composite material ultra-high pressure container according to claim 4, characterized in that: The relationship between the outer diameter d, wall thickness h of the straight tube section 1 (11), and the outer diameter D and wall thickness H of the tube blank is 4mm≤(Dd)≤10mm, 0<(Hh)≤3mm.

6. The method for preparing a thin-walled metal liner composite material ultra-high pressure container according to claim 4, characterized in that: The wall thickness H of the plate is 3mm-6mm, and the material is industrial pure titanium plate.

7. The method for preparing a thin-walled metal liner composite material ultra-high pressure container according to claim 4, characterized in that: The seamless metal straight tube in step S4 has an outer diameter roundness tolerance of ≤0.5mm, a wall thickness h of 1mm-3mm, and a wall thickness h tolerance of ±0.1mm.

8. The method for preparing a thin-walled metal liner composite material ultra-high pressure container according to claim 4, characterized in that: In step S6, an arc-shaped welding protective cover is used for inflating protection around the annular seam, the central angle of the arc protective cover is ≥300°, and ventilation protection is continued for more than 1 minute after the seam welding is completed.

9. The method for preparing a thin-walled metal liner composite material ultra-high pressure container according to claim 8, characterized in that: After the circumferential seam welding is completed in step S6, the weld excess height is less than 0.5 mm.

10. The method for preparing a thin-walled metal liner composite material ultra-high pressure container according to claim 9, characterized in that: In step S7, the width of the local reinforcement of the hoop-wound impregnated carbon fiber is greater than 80 mm; the reinforcement thickness is 0.2 mm-0.6 mm.

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