Hydrogen storage bottle and method of making same

Abstract

The application provides a hydrogen storage bottle and a preparation method thereof. The hydrogen storage bottle relates to the technical field of gas storage devices, and comprises an inner container and a plurality of winding layer groups which are compounded on the peripheral surface of the inner container. The plurality of winding layer groups comprise an inner layer annular winding layer group, an intermediate winding layer group and an outer layer spiral winding layer group which are arranged in sequence from inside to outside along the radial direction of the inner container. The intermediate winding layer group comprises an intermediate spiral winding layer group and an intermediate annular winding layer group which are arranged in sequence from inside to outside along the radial direction of the inner container. The intermediate spiral winding layer group comprises winding layers with a plurality of winding angles, and the winding angles of the winding layers in the intermediate spiral winding layer group decrease in sequence from inside to outside along the radial direction of the inner container. The hydrogen storage bottle has fewer transition layers in the preparation process, can reduce the overall weight of the hydrogen storage bottle, reduce the material consumption of the hydrogen storage bottle, and reduce the manufacturing cost of the hydrogen storage bottle.

Description

Technical Field

[0001] This invention relates to the field of gas storage devices, and particularly to a hydrogen storage cylinder. Furthermore, this invention also relates to a method for preparing the hydrogen storage cylinder. Background Technology

[0002] Hydrogen storage cylinders are generally classified into four types: all-metal cylinders (Type I), metal-lined fiber-wound cylinders (Type II), metal-lined fiber-wound cylinders (Type III), and non-metal-lined fiber-wound cylinders (Type IV).

[0003] Type I and Type II gas cylinders are relatively heavy, making it difficult to meet the requirements for hydrogen storage density per unit mass. Compared to Type III gas cylinders, Type IV gas cylinders are generally manufactured using a non-metallic inner liner such as plastic with carbon fiber winding, resulting in lighter weight, lower cost, and higher hydrogen storage density per unit mass. This makes them easier to market and gives them broader application prospects.

[0004] In existing technologies, to improve the quality of Type IV gas cylinders, the carbon fiber wound pads on the inner liner typically have multiple layers and various winding angles (the angle between the carbon fiber yarn and the cylinder axis), forming an interlacing relationship between the multiple winding layers. Generally, winding layers approaching 90° are called circumferential winding layers, while others are called helical winding layers, and multiple turns of carbon fiber on the same winding layer have the same winding angle.

[0005] In existing Type IV gas cylinders, a transition layer is generally required during the transition of carbon fiber from a circumferential winding layer to a helical winding layer. However, existing gas cylinders have a large number of transition layers, which increases the amount of carbon fiber used, resulting in an unnecessary increase in the weight and cost of the gas cylinder.

[0006] In addition, a large number of transition layers is not conducive to the winding process. Slippage is likely to occur during the transition, which often leads to a reduction in winding speed to avoid slippage. This increases the difficulty of the process, has a certain impact on product quality, and also reduces the winding speed, which in turn affects the processing cost. Summary of the Invention

[0007] In view of this, the present invention aims to provide a hydrogen storage cylinder that can improve the quality of the hydrogen storage cylinder, reduce its weight and manufacturing cost.

[0008] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0009] A hydrogen storage cylinder includes an inner liner and multiple sets of winding layers composited on the outer circumferential surface of the inner liner;

[0010] Each group of winding layers includes multiple winding layers arranged sequentially from the inside to the outside along the radial direction of the inner liner. The multiple groups of winding layers include an inner circumferential winding layer group, an intermediate winding layer group, and an outer spiral winding layer group arranged sequentially from the inside to the outside along the radial direction of the inner liner.

[0011] The intermediate winding layer group includes an intermediate spiral winding layer group and an intermediate circumferential winding layer group arranged sequentially from the inside to the outside along the radial direction of the inner liner;

[0012] The intermediate spiral winding layer group includes winding layers with multiple winding angles, and the winding angles of the winding layers in the intermediate spiral winding layer group decrease sequentially from the inside to the outside along the radial direction of the inner liner.

[0013] Furthermore, each of the aforementioned winding layers is made of carbon fiber composite material, and / or;

[0014] The intermediate winding layer group consists of multiple groups, which are arranged sequentially along the radial direction of the inner liner.

[0015] Furthermore, the winding angle of each winding layer in the inner circumferential winding layer group and the intermediate circumferential winding layer group is between 88° and 90°;

[0016] Along the radial direction of the inner liner from the inside out, the maximum winding angle α of each winding layer in the first group of intermediate spiral winding layers is calculated according to the following formula:

[0017] α = arcsin(r1 / R);

[0018] The winding angle β of the next winding layer in the intermediate spiral winding layer group of the first group is calculated according to the following formula:

[0019] β=arcsin{ [r1-(nb / 2) ] / R};

[0020] The minimum winding angle γ of each winding layer in the first group of intermediate spiral winding layers is calculated according to the following formula:

[0021] γ = arcsin(r0 / R);

[0022] The winding angle of each winding layer in the outer spiral winding layer group is γ;

[0023] The maximum winding angle of the winding layer in each subsequent intermediate spiral winding layer group is between 30° and 60°, and the remaining winding angles of the winding layer in each subsequent intermediate spiral winding layer group are at least one of α, β and γ;

[0024] In the formula above, r1 is the flange radius of the valve seat of the hydrogen storage cylinder, R is the radius of the inner liner; r0 is the radius of the polar hole of the inner liner, n is the number of times the winding angle of the winding layer changes, and b is the bandwidth of the raw material for preparing the winding layer.

[0025] Furthermore, the inner circumferential winding layer group extends from the body of the hydrogen storage bottle toward the end cap by 1 to 2 bandwidths in the axial direction of the inner liner at both the winding start position and the winding end position.

[0026] In each of the intermediate spiral winding layer groups, the winding layer at the later winding angle is reduced by 1 to 2 bandwidths towards the center at both the winding start and winding end positions in the inner liner axial direction compared to the winding layer at the previous winding angle;

[0027] The intermediate circumferential winding layer group in the first subsequent group is 1 to 2 bandwidths shorter than the inner circumferential winding layer group in terms of the winding start and winding end positions in the axial direction of the inner liner. The intermediate circumferential winding layer group in the second subsequent group is 1 to 2 bandwidths shorter than the intermediate circumferential winding layer group in the first subsequent group in terms of the winding start and winding end positions in the axial direction of the inner liner.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] The hydrogen storage cylinder of this invention comprises a middle spiral winding layer group with winding layers of various winding angles. The winding angles of the winding layers in the middle spiral winding layer group decrease sequentially from the inside to the outside along the radial direction of the inner liner. This reduces the amount of transition layer between the circumferential and spiral winding layers, thereby reducing the amount of carbon fiber used and lowering the weight and cost of the hydrogen storage cylinder. Simultaneously, the risk of yarn slippage during the switching between the circumferential and spiral winding layers is reduced, lowering the process difficulty, improving product quality, and accelerating the winding speed, further reducing the manufacturing cost of the hydrogen storage cylinder.

[0030] Furthermore, the raw materials for each winding layer are made of carbon fiber composite materials. This structure has the advantages of high strength and lightweight, which helps ensure the sealing performance and safety of the hydrogen storage cylinder. Limiting the intermediate winding layer group to multiple sets further improves the strength and stability of the hydrogen storage cylinder, meeting the requirements of high-pressure hydrogen storage.

[0031] Furthermore, by defining the winding angle of each winding layer and calculating it using formulas, a tighter interwoven structure is formed between the winding layers, which effectively improves the load-bearing capacity of the hydrogen storage cylinder in all directions. Specifically, the helical winding layer with the largest winding angle significantly increases the axial load-bearing capacity of the hydrogen storage cylinder. The winding angles of subsequent helical winding layers vary sequentially, adjusting with the increase in winding layers and the change in bandwidth to achieve a more uniform stress distribution. The combination of helical and circumferential winding layers improves the overall strength and stability of the hydrogen storage cylinder, while also effectively reducing the amount of transition layer required and its associated benefits.

[0032] Furthermore, the starting and ending points of the axial winding of the inner liner extend the bandwidth from the cylinder body towards the end cap. This design helps ensure that the circumferential winding layer can fully cover the cylinder body and parts of the end cap, thus improving the circumferential load-bearing capacity of the hydrogen storage cylinder. Subsequent winding layers reduce the bandwidth towards the center. This design helps achieve a gradual transition of the helical winding layer in the axial direction, avoiding stress concentration and improving the overall strength and stability of the hydrogen storage cylinder.

[0033] Another object of the present invention is to provide a method for preparing a hydrogen storage cylinder, the method comprising:

[0034] Surface treatment of the inner liner of the hydrogen storage cylinder;

[0035] Multiple layers of the winding layer are laminated onto the outer circumferential surface of the inner liner to form a hydrogen storage bottle as described above.

[0036] Furthermore, the surface treatment of the inner liner of the hydrogen storage cylinder includes sequentially cleaning and plasma treatment of the inner liner.

[0037] Furthermore, when the dyn value of the plasma-treated inner liner surface is between 55 dyn / cm and 75 dyn / cm, the multiple sets of winding layers are then bonded to the outer circumferential surface of the inner liner.

[0038] Furthermore, the composite winding layers on the outer circumferential surface of the inner liner are applied using a wet winding process;

[0039] After the multi-layer winding layer is laminated on the outer circumferential surface of the inner liner, the preparation method of the hydrogen storage bottle further includes: performing pre-curing treatment, curing treatment and cooling treatment on the hydrogen storage bottle in sequence, while keeping the hydrogen storage bottle rotating.

[0040] Furthermore, the temperature of the pre-curing treatment is between 40℃ and 85℃, the heating rate is between 0.5℃ / min and 3℃ / min, and the treatment time is between 1 h and 2 h.

[0041] The curing temperature is between 100℃ and 130℃, the heating rate is between 0.5℃ / min and 3℃ / min, and the treatment time is between 6 h and 8 h.

[0042] The furnace opening temperature for the cooling process is ≤50℃, and the cooling rate is ≤5℃ / min.

[0043] Furthermore, when the winding layer is first laminated onto the inner liner, the inflation pressure in the inner liner is between 0.5 bar and 1 bar.

[0044] During the process of compounding the inner liner with the winding layer, as the number of winding layers increases, the inflation pressure in the inner liner increases by 0.1 bar to 0.5 bar for every 2 to 4 additional winding layers.

[0045] The method for preparing the hydrogen storage bottle described in this invention has the same beneficial effects as the aforementioned hydrogen storage bottle compared to the prior art. In addition, the surface treatment of the inner liner before laminating the multi-layer winding layer on the outer circumference of the inner liner can ensure a good bond between the inner liner and the multi-layer winding layer, thereby improving the corrosion resistance and service life of the inner liner.

[0046] Furthermore, the surface treatment of the inner liner of the hydrogen storage cylinder includes sequential cleaning and plasma treatment. Cleaning removes oil, dust, oxides, and other impurities from the inner liner surface, preventing them from affecting the effectiveness of subsequent processing steps and improving the overall performance of the hydrogen storage cylinder. Plasma treatment modifies the inner liner surface to improve its wettability and adhesion. The combined use of cleaning and plasma treatment provides a good foundation for the subsequent winding layer lamination, thus significantly improving the quality of the hydrogen storage cylinder. Limiting the dyne value of the inner liner surface enhances the bonding force between the subsequent winding layer and the inner liner, thereby improving the overall performance of the hydrogen storage cylinder.

[0047] In addition, after the winding layer is completed, the hydrogen storage cylinder undergoes pre-curing, curing, and cooling treatments. Pre-curing helps stabilize the structure of the winding layer, effectively expelling air trapped during winding and reducing potential deformation or cracking during subsequent curing. The curing process is crucial for forming a strong bond between the winding layer and the inner liner, ensuring uniform resin curing throughout the winding. The cooling process primarily controls the cooling rate of the hydrogen storage cylinder to prevent stress and cracking caused by rapid cooling. Maintaining rotation of the hydrogen storage cylinder during pre-curing, curing, and cooling ensures uniform resin distribution within the winding layer, avoiding uneven curing in certain areas and thus improving the quality of the hydrogen storage cylinder.

[0048] Furthermore, by precisely controlling parameters such as the temperature, heating rate, processing time, and rotation of the hydrogen storage cylinder during pre-curing, curing, and cooling processes, high-quality, high-performance hydrogen storage cylinders can be manufactured to meet the application needs of hydrogen fuel cell vehicles and other fields.

[0049] By precisely controlling the inflation pressure and timing of the inner liner, it can be ensured that the winding layer adheres tightly to the inner liner, thereby improving the overall strength and stability of the hydrogen storage cylinder. Attached Figure Description

[0050] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0051] Figure 1 This is a schematic diagram illustrating a portion of the multiple winding layers in the hydrogen storage cylinder described in an embodiment of the present invention;

[0052] Figure 2 is Figure 1 Enlarged view of part A in the image;

[0053] Figure 3 for Figure 1 Enlarged view of part B in the image.

[0054] Explanation of reference numerals in the attached figures:

[0055] 1. Inner liner; 2. Winding layer;

[0056] 101. Cylinder body; 102. End cap; 103. Valve seat;

[0057] 201. Inner circumferential winding layer group; 202. Middle spiral winding layer group; 203. Middle circumferential winding layer group; 204. Outer spiral winding layer group. Detailed Implementation

[0058] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0059] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0060] This embodiment relates to a hydrogen storage cylinder, which, through reasonable winding layer design and process control, can be manufactured into a hydrogen storage cylinder with high strength, lightweight and good stability, providing strong support for the widespread application of hydrogen fuel cell vehicles.

[0061] Based on the above design concept, an exemplary structure of the hydrogen storage cylinder in this embodiment is as follows: Figure 1 and Figure 2As shown, in terms of overall structure, the hydrogen storage cylinder of this embodiment mainly includes an inner liner 1 and multiple winding layers 2 composite on the outer circumferential surface of the inner liner 1.

[0062] Each winding layer 2 includes multiple winding layers 2 arranged sequentially from the inside to the outside along the radial direction of the inner liner 1. The multiple winding layers 2 include an inner circumferential winding layer group 201, an intermediate winding layer group, and an outer spiral winding layer group 204 arranged sequentially from the inside to the outside along the radial direction of the inner liner 1. The intermediate winding layer group includes an intermediate spiral winding layer group 202 and an intermediate circumferential winding layer group 203 arranged sequentially from the inside to the outside along the radial direction of the inner liner 1.

[0063] Specifically, the intermediate spiral winding layer group 202 includes winding layers 2 with multiple winding angles, and the winding angles of each winding layer 2 in the intermediate spiral winding layer group 202 decrease sequentially from the inside to the outside along the radial direction of the inner liner 1.

[0064] In this embodiment of the hydrogen storage bottle, the intermediate spiral winding layer group 202 includes winding layers 2 with multiple winding angles, and the winding angles of each winding layer 2 in the intermediate spiral winding layer group 202 decrease sequentially from the inside to the outside along the radial direction of the inner liner 1. This reduces the amount of transition layer between the circumferential winding layer 2 and the spiral winding layer 2, thereby reducing the amount of carbon fiber used and lowering the weight and cost of the hydrogen storage bottle. At the same time, the risk of yarn slippage during the switching between the circumferential winding layer 2 and the spiral winding layer 2 is reduced, which reduces the process difficulty, improves product quality, and speeds up the winding process, further reducing the manufacturing cost of the hydrogen storage bottle.

[0065] Structurally, the hydrogen storage cylinder mainly comprises an inner liner 1, an intermediate layer covering the inner liner 1, and a protective layer. The intermediate layer is typically made of carbon fiber composite material, while the protective layer is typically made of glass fiber composite material. Although the protective layer is not mentioned in this embodiment regarding the hydrogen storage cylinder and its preparation method, it is understood that a protective layer is generally coated on the outer circumference of the hydrogen storage cylinder. The specific raw materials and coating method of the protective layer can be found in existing descriptions.

[0066] In a preferred embodiment, each winding layer 2 is made of carbon fiber composite material, which includes carbon fibers and a resin layer covering the outer periphery of the carbon fibers. This structure has the advantages of high strength and lightweight, which helps to ensure the sealing performance and safety of the hydrogen storage cylinder.

[0067] To improve the load-bearing capacity of the hydrogen storage cylinder, multiple intermediate winding layers are arranged sequentially along the radial direction of the inner liner 1. By limiting the intermediate winding layers to multiple sets, the strength and stability of the hydrogen storage cylinder can be further improved to meet the requirements of high-pressure hydrogen storage.

[0068] In the embodiments described below, the intermediate winding layer group is illustrated using three groups as an example. Figures 1 to 3 In this diagram, two intermediate winding layers are used as an example. It should be understood that, depending on the performance requirements of the hydrogen storage cylinder, the number of intermediate winding layers can be other than three, such as one, two, or four. When a thicker winding layer 2 is required for the hydrogen storage cylinder, the number of intermediate winding layers can be increased to meet the manufacturing requirements.

[0069] In a preferred embodiment, the number of winding layers 2 in the inner circumferential winding layer group 201 is between 2 and 8 layers, such as 2, 4, 6, or 8 layers; the number of winding layers 2 in the middle spiral winding layer group 202 for each winding angle is between 2 and 4 layers, such as 2 or 4 layers; the number of winding layers 2 in the middle circumferential winding layer group 203 is between 2 and 10 layers, such as 2, 4, 6, 8, or 10 layers; and the number of winding layers 2 in the outer spiral winding layer group 204 is between 2 and 4 layers, such as 2 or 4 layers.

[0070] It should be noted that in this embodiment, the number of winding layers 2 at the same angle is preferably even. It should be understood that it is also feasible for the number of winding layers 2 at the same angle to be odd. However, it is beneficial to improve the performance of the final hydrogen storage bottle when the number of winding layers 2 at the same angle is even.

[0071] In addition, the winding angle of the winding layer 2 in the intermediate spiral winding layer group 202 decreases sequentially. Specifically, as in this embodiment, the winding angle of every two winding layers 2 is the same, and the winding angle changes every two winding layers. Alternatively, the winding angle of every four winding layers 2 is the same, and the winding angle changes every four winding layers. Or, the winding angle of every one winding layer 2 is the same, and the winding angle changes every one winding layer. Alternatively, the winding angle of the winding layer 2 can be decreased irregularly.

[0072] To better understand this embodiment, the classification of winding angles will be explained first. Generally, the winding angle of the circumferential winding layer 2 is between 88° and 90°. When the winding angle of the helical winding layer 2 is not more than 30°, it is called a low-angle winding layer. When the winding angle of the helical winding layer 2 is greater than 30° but not more than 60°, it is called a high-angle winding layer.

[0073] In the following formula, r1 is the flange radius of the valve seat 103 of the hydrogen storage cylinder, R is the radius of the inner liner 1, r0 is the radius of the polar hole of the inner liner 1, n is the number of times the winding angle of the winding layer 2 changes, specifically, the number of times the winding angle changes in the intermediate spiral winding layer group 202, and b is the bandwidth of the raw material for preparing the winding layer 2.

[0074] It should be noted that the flange radius refers to the radius of the largest circle in the valve seat 103, which is usually matched with the inner liner 1, while the polar hole radius refers to the radius of the smallest circle that intersects the winding layer 2 when a cross section is taken perpendicular to the axis of the hydrogen storage bottle.

[0075] In a preferred embodiment, the winding angle of each winding layer 2 in the inner circumferential winding layer group 201 and the middle circumferential winding layer group 203 is between 88° and 90°. This circumferential winding method is mainly for cylindrical structures and can effectively eliminate the circumferential stress generated by the internal pressure of the hydrogen storage bottle, thereby enhancing the circumferential load-bearing capacity of the hydrogen storage bottle.

[0076] In a preferred embodiment, the maximum winding angle α of each winding layer 2 in the first group of intermediate spiral winding layer group 202 along the radial direction of the inner liner 1 from the inside out is calculated according to the following formula: α=arcsin(r1 / R), which can better increase the axial load-bearing capacity of the hydrogen storage cylinder.

[0077] The winding angle β of the next winding layer 2 in the first group of intermediate helical winding layers 202 is calculated according to the following formula: β=arcsin{ [r1-(nb / 2) ] / R}. This setting ensures that the winding angle of the subsequent helical winding layers 2 changes sequentially, adjusting with the increase of winding layers 2 and the change of bandwidth to achieve a more uniform stress distribution.

[0078] The minimum winding angle γ of each winding layer 2 in the first group of intermediate spiral winding layer group 202 is calculated according to the following formula: γ=arcsin(r0 / R), and the winding angle of each winding layer 2 in the outer spiral winding layer group 204 is γ, which is also conducive to improving the load-bearing capacity of the hydrogen storage cylinder.

[0079] The maximum winding angle of the winding layer 2 in each subsequent intermediate spiral winding layer group 202 is between 30° and 60°, such as 30°, 40°, 50°, 60°, etc. Furthermore, the remaining winding angles of the winding layer 2 in each subsequent intermediate spiral winding layer group 202 are at least one of α, β, and γ. The more types of winding angles the winding layer 2 in each subsequent intermediate spiral winding layer group 202 has, the better it is for improving the performance of the hydrogen storage cylinder. In the above structure, the winding angle of each winding layer 2 is limited, and the winding angle of each winding layer 2 is calculated using a formula, resulting in a tighter interwoven structure between the winding layers 2, which can better improve the load-bearing capacity of the hydrogen storage cylinder in all directions. In addition, the combination of the spiral winding layer 2 and the circumferential winding layer 2 is beneficial for improving the overall strength and stability of the hydrogen storage cylinder, while also effectively reducing the amount of transition layer used and the resulting benefits.

[0080] To better understand this embodiment, the bandwidth will be explained first. The bandwidth refers to the width of the wound carbon fiber composite material.

[0081] Reference Figure 1 and Figure 2 As shown, in a preferred embodiment, the inner circumferential winding layer group 201 extends from the cylinder body 101 of the hydrogen storage bottle to the end cap 102 at both the starting and ending positions of the winding in the axial direction of the inner liner 1 by 1 to 2 bandwidths, such as 1, 1.2, 1.5, 1.7, or 2. This can better reinforce the connection between the cylinder body 101 and the end cap 102, which is beneficial to improving the structural strength of the hydrogen storage bottle.

[0082] In each intermediate spiral winding layer group 202, the winding layer 2 at the next winding angle is reduced by 1 to 2 bandwidths towards the center at both the starting and ending positions of the winding layer 2 at the previous winding angle in the axial direction of the inner liner 1. For example, it can be 1, 1.3, 1.5, 1.7, or 2 bandwidths. Subsequently, the first intermediate circumferential winding layer group 203 is reduced by 1 to 2 bandwidths towards the center at both the starting and ending positions of the winding layer 201 in the axial direction of the inner liner 1. For example, it can be 1, 1.3, 1.5, 1.8, or 2 bandwidths.

[0083] In addition, the starting and ending positions of the subsequent intermediate circumferential winding layer group 203 in the axial direction of the inner liner 1 are reduced by 1 to 2 bandwidths compared to the previous intermediate circumferential winding layer group 203. For example, it can be 1, 1.2, 1.5, 1.8, or 2 bandwidths.

[0084] In this embodiment, the starting and ending positions of the axial winding of the inner liner 1 extend the bandwidth from the cylinder body 101 of the hydrogen storage cylinder towards the end cap 102. This design helps ensure that the circumferential winding layer 2 can fully cover the cylinder body 101 and a portion of the end cap 102 of the inner liner 1, thereby improving the circumferential load-bearing capacity of the hydrogen storage cylinder. The subsequent winding layer 2 reduces its bandwidth towards the center. This design helps achieve a gradual transition of the helical winding layer 2 in the axial direction, avoiding stress concentration and improving the overall strength and stability of the hydrogen storage cylinder.

[0085] It should be noted that, as Figure 3 As shown, the winding start position and winding end position of each winding layer 2 in the inner circumferential winding layer group 201 and the middle circumferential winding layer group 202 can be determined as described above.

[0086] The starting and ending positions of each winding layer 2 in the intermediate spiral winding layer group 202 and the outer spiral winding layer group 204 can be referenced for example. Figure 3 As shown in the structure, these winding layers 2 need to cover the entire end cap 102, and the winding start and end positions of most of the winding layers 2 extend to the valve seat 103.

[0087] It should be noted that, in the preferred embodiment, the starting and ending positions of each winding layer 2 in the intermediate spiral winding layer group 202 and the outer spiral winding layer group 204 need to be adjusted according to the winding angle. The larger the winding angle, the closer the starting and ending positions are to the cylinder body 101, which helps to ensure the performance of the hydrogen storage cylinder. For details, please refer to the prior art.

[0088] This embodiment also relates to a method for preparing the hydrogen storage bottle as described above. The method includes: surface treatment of the inner liner 1 of the hydrogen storage bottle, and then laminating multiple sets of winding layers 2 onto the outer circumferential surface of the inner liner 1 to form the hydrogen storage bottle as described above. It should be noted that in this method, the number of winding layers 2, the winding angle, and the arrangement are all as described above, and will not be detailed here.

[0089] It should also be noted that before the multi-layer winding layer 2 is laminated on the outer circumference of the inner liner 1, the surface of the inner liner 1 is treated to ensure a good bond between the inner liner 1 and the multi-layer winding layer 2, thereby improving the corrosion resistance and service life of the inner liner 1.

[0090] To further improve the quality of the hydrogen storage cylinder, as a preferred embodiment, the inner liner 1 of the hydrogen storage cylinder undergoes surface treatment, including sequential cleaning and plasma treatment. Cleaning removes oil, dust, oxides, and other impurities from the surface of the inner liner 1, preventing them from affecting the effectiveness of subsequent processing steps and improving the overall performance of the hydrogen storage cylinder. Plasma treatment modifies the surface of the inner liner 1 to improve its wettability and adhesion. The combined cleaning and plasma treatment provides a good foundation for the subsequent lamination of the winding layer 2, thereby significantly improving the quality of the hydrogen storage cylinder.

[0091] In a further preferred embodiment, when the dyne value of the plasma-treated inner liner 1 surface is between 55 dyn / cm and 75 dyn / cm, multiple sets of winding layers 2 are then laminated onto the outer circumferential surface of the inner liner 1. By limiting the dyne value of the inner liner 1 surface, the bonding force between the subsequent winding layers 2 and the inner liner 1 can be improved, thereby enhancing the overall performance of the hydrogen storage cylinder.

[0092] After plasma treatment, the surface dyne value is tested using a dyne pen. If no line shrinkage occurs within 3 seconds when drawing a straight line with the dyne pen, it indicates that the dyne value indicated by that dyne pen has been reached. A larger dyne pen can then be used for further testing until shrinkage occurs within 3 seconds.

[0093] As a preferred embodiment, the composite of multiple winding layers 2 on the outer circumferential surface of the inner liner 1 is performed using a wet winding process. The wet winding process involves laying continuous, untwisted carbon fiber tape impregnated or pre-impregnated with resin onto the inner liner 1, which is made of plastic material, at different winding angles. The resin is preferably a thermosetting resin. It should be understood that, in addition to this, the composite of multiple winding layers 2 on the outer circumferential surface of the inner liner 1 can also be performed using a dry winding process; specific process parameters can be found in existing technologies.

[0094] After the inner liner 1 is laminated with multiple layers of winding 2 on its outer circumference using a wet winding process, the preparation method of the hydrogen storage bottle further includes: performing pre-curing treatment, curing treatment and cooling treatment on the hydrogen storage bottle in sequence, and keeping the hydrogen storage bottle rotating during the pre-curing treatment, curing treatment and cooling treatment.

[0095] The pre-curing process helps stabilize the structure of the winding layer 2, effectively removing air trapped during the winding process and reducing potential deformation or cracking during subsequent curing. The curing process is crucial for forming a strong bond between the winding layer 2 and the inner liner 1, ensuring uniform resin curing throughout the winding layer 2. The cooling process primarily controls the cooling rate of the hydrogen storage cylinder to prevent stress and cracking caused by rapid cooling. Maintaining rotation of the hydrogen storage cylinder during the pre-curing, curing, and cooling processes ensures uniform resin distribution within the winding layer 2, avoiding uneven curing in certain areas and thus improving the quality of the hydrogen storage cylinder.

[0096] As described above, by precisely controlling parameters such as the temperature, heating rate, processing time, and rotation of the hydrogen storage cylinder during pre-curing, curing, and cooling processes, high-quality, high-performance hydrogen storage cylinders can be manufactured, thus better meeting the application needs of hydrogen energy vehicles and other fields.

[0097] After multiple winding layers 2 are laminated on the outer circumferential surface of the inner liner 1 using a wet winding process, the preparation method of the hydrogen storage bottle also includes: performing pre-curing treatment, curing treatment and cooling treatment on the hydrogen storage bottle in sequence, and keeping the hydrogen storage bottle rotating during the pre-curing treatment, curing treatment and cooling treatment.

[0098] In a preferred embodiment, the pre-curing temperature is between 40℃ and 85℃, such as 40℃, 50℃, 60℃, 70℃, or 85℃, the heating rate is between 0.5℃ / min and 3℃ / min, such as 0.5℃ / min, 1℃ / min, 2℃ / min, or 3℃ / min, and the treatment time is between 1 h and 2 h, such as 1 h, 1.3 h, 1.7 h, or 2 h.

[0099] In the above method, the pre-curing temperature is between 40℃ and 85℃. This temperature range is chosen to allow the resin to begin softening and partially curing, thereby stabilizing the structure of the winding layer 2. Too low a temperature may result in incomplete resin curing, while too high a temperature may trigger unnecessary chemical reactions or cause over-curing. A heating rate controlled between 0.5℃ / min and 3℃ / min helps the resin to distribute evenly in the winding layer 2 and reduces thermal stress caused by rapid temperature changes. A treatment time between 1 hour and 2 hours ensures that the resin forms a stable structure in the winding layer 2 and also effectively removes trapped air.

[0100] In a preferred embodiment, the curing temperature is between 100℃ and 130℃, such as 100℃, 110℃, 120℃, or 130℃; the heating rate is between 0.5℃ / min and 3℃ / min, such as 0.5℃ / min, 1℃ / min, 2℃ / min, or 3℃ / min; and the treatment time is between 6 h and 8 h, such as 6 h, 6.5 h, 7 h, 7.5 h, or 8 h.

[0101] In the above method, the curing temperature is between 100℃ and 130℃. This temperature range is chosen to ensure complete resin curing, thereby forming a strong bonding interface. The curing temperature can be optimized according to the type of resin and the structure of the winding layer 2. The heating rate is also controlled between 0.5℃ / min and 3℃ / min. Similar to the pre-curing treatment, a slower heating rate helps reduce thermal stress and ensures uniform curing of the resin in the winding layer 2. The treatment time is between 6h and 8h. A longer treatment time ensures complete resin curing, thereby improving the overall strength and stability of the hydrogen storage cylinder.

[0102] In a preferred embodiment, the furnace start-up temperature for the cooling process is ≤50°C, and the cooling rate is ≤5°C / min. The limited start-up temperature is intended to avoid thermal stress or deformation caused by excessively high temperatures during the cooling process. The limited cooling rate of ≤5°C / min helps reduce thermal stress and ensures that the hydrogen storage cylinder maintains a stable shape and dimensions during cooling.

[0103] Since the inflation pressure of the inner liner 1 is an important parameter, affecting the composite effect of the winding layer 2 and the final performance of the hydrogen storage tank, as a preferred embodiment, when starting to composite the winding layer 2 on the inner liner 1, the inflation pressure in the inner liner 1 is between 0.5 bar and 1 bar. This pressure range is chosen to ensure that the inner liner 1 maintains a stable shape and size during the winding process, avoiding collapse or deformation of the inner liner 1 due to excessively low pressure, and excessive expansion or rupture due to excessively high pressure.

[0104] In a preferred embodiment, during the process of composite winding layer 2 on inner liner 1, as the thickness of winding layer 2 increases, the inflation pressure in inner liner 1 increases by 0.1 bar to 0.5 bar for every 2 to 4 additional winding layers 2, such as 0.1 bar, 0.2 bar, 0.3 bar, 0.4 bar, or 0.5 bar.

[0105] It should be noted that during the entire process of hydrogen storage bottle curing, the inner liner 1 needs to be inflated to prevent axial deformation of the inner liner 1 during the curing process. Preferably, the inflation pressure during the hydrogen storage bottle curing process should be consistent with the pressure of the inner liner 1 after the hydrogen storage bottle is wrapped.

[0106] This pressure adjustment method allows for precise control of the inflation pressure and timing of the inner liner 1, ensuring that the winding layer 2 adheres tightly to the inner liner 1, forming a robust bonding interface. As the number of winding layers 2 increases, the outer diameter of the inner liner 1 gradually increases. If the inflation pressure remains constant, the gap between the winding layer 2 and the inner liner 1 may widen, affecting the overall strength and stability of the hydrogen storage cylinder. Therefore, by gradually increasing the inflation pressure, it is ensured that the winding layer 2 always adheres tightly to the inner liner 1, thereby improving the quality and performance of the hydrogen storage cylinder, specifically enhancing its overall strength and stability.

[0107] Finally, it should be noted that during the winding process of each winding layer 2 onto the inner liner 1, the inner circumferential winding layer group 201 is wound first. After completing the circumferential winding layer group 2, one or more intermediate circumferential winding layer groups 203 and intermediate spiral winding layer groups 202 are wound. Among them, the winding layer 2 at each winding angle in the intermediate spiral winding layer group 202 consists of 2 layers. The purpose of the spiral winding layer 2 at the first winding angle is to enhance the connection between the valve seat 103 and the inner liner 1. The winding angle is calculated according to the formula above.

[0108] It should be noted that in the intermediate spiral winding layer group 202, each time the winding angle of the winding layer 2 changes, the starting and ending positions of the winding layer 2 along the axial direction of the hydrogen storage bottle are reduced by half a bandwidth towards the center until the minimum winding angle is reached.

[0109] After completing the first set of intermediate spiral winding layers 202, the next set of intermediate winding layers or outer spiral winding layers 204 is wound. Each winding angle consists of two winding layers 2, and the winding angle of the winding layer 2 in the intermediate spiral winding layer set 202 is at least two. If necessary, two high-angle winding layers can be added at the beginning of the intermediate spiral winding layer set 202. The starting and ending positions of the low-angle winding layers along the axial direction of the hydrogen storage cylinder are reduced by half a bandwidth towards the middle. The two winding layers 2 in the outermost spiral winding layer set 204 are low-angle winding layers.

[0110] This multi-angle winding method allows the winding layers 2 to interweave with each other, which can improve the strength of the fibers, effectively improve the stress structure of the hydrogen storage cylinder, reduce the use of transition layers, and reduce the weight of the hydrogen storage cylinder.

[0111] For example: the inner liner 1 of the prepared hydrogen storage cylinder has a radius R of 160 mm, the flange radius r1 of the valve seat 103 is 60 mm, the pole hole radius r0 is 30 mm, the length L of the cylinder body 101 along the axial direction of the hydrogen storage cylinder is 600 mm, and the width b of the carbon fiber composite material is 20 mm.

[0112] Assuming a total of 40 winding layers are required, including 16 circumferential layers and 24 helical layers, the specific winding method is as follows:

[0113] The winding angle of each winding layer 2 in the inner circumferential winding layer group 201 is 89°, and there are 8 winding layers.

[0114] In the first group of intermediate spiral winding layers 202:

[0115] The maximum winding angle is 22°, which can be obtained using the formula arcsin(r1 / R)=arcsin(60 / 160).

[0116] The winding angle of the next winding layer 2 is 18°.

[0117] It can be obtained using the formula arcsin{ [r1-(nb / 2) ] / R}=arcsin{ [60-(1×20 / 2)] / 160}.

[0118] The winding angle of the next winding layer 2 is 14°.

[0119] It can be obtained using the formula arcsin{ [r1-(nb / 2) ] / R}=arcsin{ [60-(2×20 / 2)] / 160}.

[0120] The winding angle of the next winding layer 2 is, that is, the minimum winding angle is 10°.

[0121] It can be obtained using the formula arcsin{ [r1- nb / 2) ] / R}=arcsin{ [60-(3×20 / 2)] / 160}.

[0122] Two layers are wrapped at each winding angle, for a total of eight layers;

[0123] In the first group of intermediate circumferential winding layers 203, the winding angle of each winding layer 2 is 89°, and there are 4 winding layers.

[0124] The winding angles of each winding layer 2 in the second group of intermediate spiral winding layers 202 are as follows: 48° (usually greater than 30° but not exceeding 60°, depending on the size of the inner liner 1), 18°, 14°, 10° (calculated according to the formula), with 2 layers wound at each winding angle, for a total of 8 layers.

[0125] In the second group of intermediate circumferential winding layers 203, the winding angle of each winding layer 2 is 89°, and there are 2 winding layers.

[0126] The winding angles of each winding layer 2 in the third group of intermediate spiral winding layer group 202 are as follows: 55° (usually greater than 30° but not exceeding 60°, depending on the size of the inner liner 1), 22°, and 18°. Two layers are wound at each winding angle, for a total of 6 layers.

[0127] In the third group of intermediate circumferential winding layers 203, the winding angle of each winding layer 2 is 89°, and there are 2 winding layers.

[0128] The winding angle of each winding layer 2 in the outer spiral winding layer group 204 is 10°, which is obtained according to the formula arcsin(r0 / R), and there are a total of 2 layers.

[0129] The following example illustrates the preparation of hydrogen storage cylinders using a wet winding process.

[0130] First, prepare the finished inner liner to be wound, carbon fiber, epoxy resin, glass fiber, and other tooling.

[0131] The finished inner liner 1 (referring to the combination of plastic inner liner 1 and valve seat 103) to be wound is first cleaned with anhydrous ethanol and left to air dry for 3 min to 5 min. In this embodiment, it is left to air dry for 3 min. After the anhydrous ethanol has completely evaporated, plasma treatment is performed using a plasma spray gun.

[0132] During plasma treatment, the finished inner liner 1 should be placed on a stand and fixed. The equipment should be turned on, allowing the inner liner 1 to rotate uniformly around its own axis. The plasma spray gun for surface treatment should be 2-3 cm away from the surface of the inner liner 1, moving uniformly from one end of the inner liner 1 to the other at a speed of approximately 2.5 cm / s, and then returning along the same path. This back-and-forth treatment is repeated on each inner liner 1 until the dyne value of the inner liner 1 surface meets the requirements as described above. It should be noted that the specific number of treatments depends on the diameter of the inner liner 1 and the specific dyne value; the more treatments, the higher the dyne value. Typically, for inner liner 1 diameters ≤ 400 mm, two back-and-forth treatments are sufficient to meet the requirements.

[0133] The aforementioned epoxy resin adhesive can be prepared using existing technology. It is typically made by mixing epoxy resin and a curing agent. Generally, the epoxy resin and curing agent are added in the order of addition to the adhesive in a mixer, and stirred at a constant speed and direction. Stirring can be stopped when the adhesive has a uniform color. The ratio of epoxy resin to curing agent can be flexibly determined based on the type, environmental conditions, and compatibility with carbon fiber. It should be noted that since epoxy resin and curing agents are generally sold as a set by various manufacturers, when using epoxy resin, the matching curing agent from that manufacturer should be purchased. In this embodiment, for example, the product manufactured by Daosheng Tianhe Materials Technology (Shanghai) Co., Ltd. can be used.

[0134] Preferably, the mass ratio of epoxy resin to curing agent is 6:5 to 16:13, such as 120:100 to 80:65. Using this mass ratio of epoxy resin and curing agent, the bonded and cured carbon fiber exhibits optimal fiber strength. In this embodiment, the mass ratio of epoxy resin to curing agent is 6:5.

[0135] Preferably, after mixing the epoxy resin and curing agent to form a liquid adhesive, it can be placed in an oven at 40℃~65℃ for at least 1 hour. This step allows the epoxy resin and curing agent to further fuse, making the adhesive molecules relatively active, which is more conducive to the adhesion of the adhesive to the carbon fiber. In this embodiment, it was placed in an oven at 40℃ for 1 hour.

[0136] Carbon fiber yarn is arranged on a winding device, ensuring the yarns do not cross, forming an orderly yarn from one side to the other. The prepared adhesive solution is then poured into the impregnation tank. Preferably, the tank temperature is between 25°C and 40°C, and the gap between the roller and the doctor blade is between 0.15 mm and 0.3 mm. In this embodiment, the tank temperature is 25°C, and the gap between the roller and the doctor blade is 0.15 mm.

[0137] Next, each layer 2 is wound onto the inner liner 1. At the start of winding, the tension regulator applies tension to the carbon fiber tape. Depending on the number of strands used, the tension applied to a single strand of the first layer should be flexibly determined. Preferably, the total tension of the carbon fiber tape should be between 300 N and 450 N. During the winding process, the tension applied to the carbon fiber tape should decrease layer by layer. Depending on the size of the hydrogen storage tank and the total thickness of the winding layer 2, optionally, the tension can be stabilized after the winding layer 2 reaches a certain thickness (this needs to be determined by actual measurement of deformation) and no further reduction in tension is required.

[0138] When applying tension, the inner liner 1 needs to be inflated to prevent it from deforming due to excessive tension. The inflation pressure of the inner liner 1 should be flexibly determined depending on the total tension of the carbon fiber yarn. The inflation pressure should be 0.5 bar at the beginning of winding. During the winding process, as the thickness of the winding layer 2 increases, the inflation pressure increases by 0.1 bar after every two winding layers 2.

[0139] Because a significant amount of air is introduced during the winding process, this embodiment employs a pre-curing process at a lower temperature to fully expel air from the resin. The pre-curing stage is performed at 40°C. It should be noted that the resin does not react during the pre-curing stage; therefore, to improve production efficiency and reduce costs, the preheating rate is 3°C / min, and the preheating holding time is 1 hour.

[0140] During the curing stage, the curing temperature is 100℃, the heating rate is 3℃ / min, and the holding time is 6h.

[0141] During the cooling process, in order to prevent product deformation and residual stress caused by rapid temperature changes, the cooling rate should not be too fast and the furnace opening temperature should not be too high. In this embodiment, the cooling rate is 5℃ / min and the furnace opening temperature is 50℃.

[0142] Throughout the curing process of the hydrogen storage bottle, it needs to be rotated to ensure uniform resin flow. The rotation speed should not be too fast to avoid the resin being splashed out. For example, the rotation speed of the inner liner 1 can be between 5 r / min and 25 r / min. In this embodiment, the rotation speed of the inner liner 1 is 5 r / min.

[0143] The hydrogen storage cylinders prepared using the above methods can solve the problems existing in the wet winding process of the prior art, and improve production efficiency and quality stability.

[0144] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hydrogen storage cylinder, characterized in that: It includes an inner liner (1) and multiple sets of winding layers (2) composited on the outer circumferential surface of the inner liner (1); Each group of winding layers (2) includes multiple winding layers (2) arranged sequentially from the inside to the outside along the radial direction of the inner liner (1). The multiple groups of winding layers (2) include an inner circumferential winding layer group (201), an intermediate winding layer group, and an outer spiral winding layer group (204) arranged sequentially from the inside to the outside along the radial direction of the inner liner (1). The intermediate winding layer group includes an intermediate spiral winding layer group (202) and an intermediate circumferential winding layer group (203) arranged in sequence from the inside to the outside along the radial direction of the inner liner (1). The intermediate spiral winding layer group (202) includes winding layers (2) with multiple winding angles, and the winding angles of the winding layers (2) in the intermediate spiral winding layer group (202) decrease sequentially from the inside to the outside along the radial direction of the inner liner (1). The winding angle of each winding layer (2) in the inner circumferential winding layer group (201) and the intermediate circumferential winding layer group (203) is between 88° and 90°; Along the radial direction of the inner liner (1) from the inside out, the maximum winding angle α of the winding layer (2) in the first group of intermediate spiral winding layer groups (202) is calculated according to the following formula: α = arcsin(r1 / R); The winding angle β of the next winding layer (2) in the intermediate spiral winding layer group (202) of the first group is calculated according to the following formula: β=arcsin{ [r1-(nb / 2) ] / R}; The minimum winding angle γ of the winding layer (2) in the intermediate spiral winding layer group (202) of the first group is calculated according to the following formula: γ = arcsin(r0 / R); The winding angle of each winding layer (2) in the outer spiral winding layer group (204) is γ; The maximum winding angle of the winding layer (2) in each subsequent intermediate spiral winding layer group (202) is between 30° and 60°, and the remaining winding angles of the winding layer (2) in each subsequent intermediate spiral winding layer group (202) are at least one of α, β and γ; In the above formula, r1 is the flange radius of the valve seat (103) in the hydrogen storage bottle, R is the radius of the inner liner (1); r0 is the radius of the polar hole of the inner liner (1), n ​​is the number of times the winding angle of the winding layer (2) changes, and b is the bandwidth of the raw material for preparing the winding layer (2).

2. The hydrogen storage cylinder according to claim 1, characterized in that: Each of the aforementioned winding layers (2) is made of carbon fiber composite material; and / or, The intermediate winding layer group consists of multiple groups, and the multiple groups of intermediate winding layer groups are arranged sequentially along the radial direction of the inner liner (1).

3. The hydrogen storage cylinder according to any one of claims 1-2, characterized in that: The inner circumferential winding layer group (201) extends from the cylinder body (101) of the hydrogen storage bottle to the end cap (102) at both the starting and ending positions of the winding in the axial direction of the inner liner (1); In each of the intermediate spiral winding layer groups (202), the winding layer (2) of the later winding angle is reduced by 1 to 2 bandwidths towards the center at both the winding start position and the winding end position in the axial direction of the inner liner (1) compared to the winding layer (2) of the previous winding angle; The intermediate circumferential winding layer group (203) of the first group is 1 to 2 bandwidths shorter than the inner circumferential winding layer group (201) in the axial direction of the inner liner (1) at both the winding start position and the winding end position. The intermediate circumferential winding layer group (203) of the second group is 1 to 2 bandwidths shorter than the intermediate circumferential winding layer group (203) of the first group in the axial direction of the inner liner (1) at both the winding start position and the winding end position.

4. A method for preparing a hydrogen storage cylinder, characterized in that, The method includes: The inner liner (1) of the hydrogen storage cylinder is surface treated; A multi-layer winding layer (2) is laminated on the outer circumferential surface of the inner liner (1) to form a hydrogen storage bottle according to any one of claims 1-3.

5. The method for preparing a hydrogen storage cylinder according to claim 4, characterized in that: The surface treatment of the inner liner (1) of the hydrogen storage cylinder includes cleaning and plasma treatment of the inner liner (1) in sequence.

6. The method for preparing a hydrogen storage cylinder according to claim 5, characterized in that: When the dyn value of the plasma-treated inner liner (1) is between 55 dyn / cm and 75 dyn / cm, multiple sets of winding layers (2) are composited on the outer circumferential surface of the inner liner (1).

7. The method for preparing a hydrogen storage cylinder according to claim 4, characterized in that: The composite multiple winding layers (2) on the outer circumferential surface of the inner liner (1) are carried out by wet winding process; After the multilayer winding layer (2) is laminated on the outer circumferential surface of the inner liner (1), the preparation method of the hydrogen storage bottle further includes: performing pre-curing treatment, curing treatment and cooling treatment on the hydrogen storage bottle in sequence, while keeping the hydrogen storage bottle rotating.

8. The method for preparing a hydrogen storage cylinder according to claim 7, characterized in that: The pre-curing treatment temperature is between 40℃ and 85℃, the heating rate is between 0.5℃ / min and 3℃ / min, and the treatment time is between 1 h and 2 h. The curing temperature is between 100℃ and 130℃, the heating rate is between 0.5℃ / min and 3℃ / min, and the treatment time is between 6 h and 8 h. The furnace opening temperature for the cooling process is ≤50℃, and the cooling rate is ≤5℃ / min.

9. The method for preparing a hydrogen storage bottle according to claim 7, characterized in that: When the winding layer (2) is first applied to the inner liner (1), the inflation pressure in the inner liner (1) is between 0.5 bar and 1 bar. During the process of bonding the winding layer (2) onto the inner liner (1), as the number of winding layers (2) increases, the inflation pressure in the inner liner (1) increases by 0.1 bar to 0.5 bar for every 2 to 4 additional winding layers (2).

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