Pressure vessel and method of manufacturing the same

Abstract

The present disclosure relates to a pressure vessel including a liner including a cylindrical portion and dome-shaped side portions at both ends of the cylindrical portion, and a carbon fiber layer including a first annular layer surrounding a part of an outer peripheral surface of the cylindrical portion and second annular layers surrounding the remaining part of the outer peripheral surface of the cylindrical portion, a thickness of each of the second annular layers gradually decreasing in a direction from the cylindrical portion to a corresponding one of the side portions, and a method of manufacturing the same.

Description

[0001] Cross-citation of related applications

[0002] This application claims the benefit of Korean Patent Application No. 10-2020-0165630, filed on December 1, 2020, which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to a pressure vessel and a method for manufacturing the same. Background Technology

[0004] Hydrogen vehicles are configured to generate their own electricity through a chemical reaction between hydrogen and oxygen and to travel by the operation of an electric motor. More specifically, hydrogen vehicles include: a hydrogen tank (H2 tank) configured to store hydrogen (H2); a fuel cell stack configured to generate electricity through a redox reaction between hydrogen and oxygen (O2); various types of devices configured to discharge the water produced; a battery configured to store the electricity generated by the fuel cell stack; a controller configured to convert and control the generated electricity; and an electric motor configured to generate driving power.

[0005] Type 4 pressure vessels can be used as hydrogen tanks for hydrogen vehicles. A Type 4 pressure vessel includes a bushing (e.g., a bushing made of a non-metallic material) and a carbon fiber layer formed by winding a carbon fiber composite material around the outer surface of the bushing.

[0006] At the same time, carbon fiber composites are lightweight and have excellent strength and elasticity, but they are very expensive (for example, about 20 times or more more expensive than the same weight of commonly used carbon steel). Therefore, in order to reduce the manufacturing cost of pressure vessels, it is necessary to minimize the amount of carbon fiber composites used.

[0007] However, if the amount of carbon fiber composite material used to form the carbon fiber layer of the pressure vessel is reduced by a predetermined amount or more (e.g., if the thickness of the carbon fiber layer is reduced), there is a problem that it is difficult to ensure that the structural stiffness of the pressure vessel (especially the structural stiffness to resist the circumferential stress applied to the cylindrical part of the pressure vessel in the circumferential direction) is sufficient, as well as the stability and reliability deteriorate.

[0008] Therefore, in recent years, various studies have been conducted to ensure structural stiffness and minimize the use of carbon fiber composites, but the results are still insufficient. Therefore, there is a need to develop a technology to ensure structural stiffness and minimize the use of carbon fiber composites. Summary of the Invention

[0009] This disclosure relates to a pressure vessel and a method for manufacturing the same. Specific embodiments relate to a pressure vessel that ensures improved structural rigidity, stability, and reliability, as well as a method for manufacturing the pressure vessel.

[0010] Embodiments of this disclosure provide a pressure vessel that ensures improved structural rigidity, stability, and reliability, as well as a method for manufacturing the pressure vessel.

[0011] The embodiments disclosed herein can ensure the structural stiffness of the pressure vessel and minimize the amount of carbon fiber composite material used.

[0012] The embodiments disclosed herein can improve the efficiency of pressure vessels, reduce the weight of pressure vessels, and lower manufacturing costs.

[0013] The embodiments disclosed herein can simplify the manufacturing process and improve manufacturing efficiency.

[0014] The objectives achieved by the embodiments are not limited to those described above, and also include objectives or effects that can be found in the solutions or embodiments described below.

[0015] In one embodiment, this disclosure provides a pressure vessel comprising: a bushing including a cylindrical portion and dome-shaped side portions disposed at both ends of the cylindrical portion; and a carbon fiber layer including a first annular layer and a second annular layer, the first annular layer being configured to surround a portion of the outer peripheral surface of the cylindrical portion, the second annular layer being configured to surround the remaining portion of the outer peripheral surface of the cylindrical portion, and the thickness of each second annular layer gradually decreasing in the direction from the cylindrical portion to the side portions.

[0016] This is to ensure the structural stiffness of the pressure vessel and minimize the amount of carbon fiber composite material used.

[0017] In other words, carbon fiber composites are lightweight, have excellent strength and elasticity, but are expensive. Therefore, in order to reduce the manufacturing cost of pressure vessels, it is necessary to minimize the amount of carbon fiber composites used.

[0018] However, if the amount of carbon fiber composite material used to form the carbon fiber layer of the pressure vessel is reduced by a predetermined amount or more (e.g., if the thickness of the carbon fiber layer is reduced), there is a problem that it is difficult to ensure that the structural stiffness of the pressure vessel (in particular, the structural stiffness to resist the circumferential stress applied to the cylindrical portion of the pressure vessel in the circumferential direction) is sufficient and that the stability and reliability deteriorate.

[0019] Conversely, according to embodiments of this disclosure, since the thickness of the second annular layer constituting the carbon fiber layer gradually decreases, the advantageous effects of ensuring the structural stiffness of the pressure vessel and reducing the amount of carbon fiber composite material used can be achieved.

[0020] First, according to embodiments of the present disclosure, carbon fiber layers are configured by using a first annular layer and a second annular layer, with the thickness of each second annular layer gradually decreasing in the direction from the cylindrical portion to the side portion. Therefore, the advantageous effect of ensuring sufficient structural stiffness and reducing the amount of carbon fiber composite material used can be obtained, wherein the structural stiffness resists circumferential stress applied to the cylindrical portion of the pressure vessel in the circumferential direction.

[0021] According to embodiments of the present disclosure, a pressure vessel may include a first helical layer configured to surround the outer surface of a bushing.

[0022] Specifically, the thickness of the first helical layer can be set to be equal to or less than 5% of the total thickness of the carbon fiber layers to ensure the structural stiffness achieved by the first helical layer and to minimize the increase in the thickness and weight of the pressure vessel.

[0023] According to embodiments of the present disclosure, a first annular layer may be configured to surround the central region of the cylindrical portion, and a second annular layer may be configured to surround the two edge regions of the cylindrical portion, with the first annular layer located between the second annular layers.

[0024] Specifically, the center of the first annular layer may correspond to the center of the cylindrical portion, the length of the first annular layer may be 40% to 60% of the length of the cylindrical portion, and the length of the second annular layer may be 20% to 30% of the length of the cylindrical portion.

[0025] More specifically, the thickness of the second annular layer can decrease linearly in the direction from the cylindrical portion to the side portion.

[0026] According to an embodiment of this disclosure, the second annular layer is configured to have a right-angled triangular cross-section, the height of which corresponds to the thickness of the first annular layer, and the angle between the hypotenuse and the base of the right-angled triangular cross-section satisfies the following equation 3:

[0027] [Equation 3]

[0028] tanθ = H / L²,

[0029] Where H is the height of the right-angled triangular cross section, and L2 is the length of the base of the second annular layer corresponding to the right-angled triangular cross section.

[0030] This is because the circumferential stress applied to the central region of the cylindrical portion (where the first annular layer is formed) is the greatest, while the circumferential stress applied to the two edge regions of the cylindrical portion (where the second annular layer is formed) gradually decreases as the distance from the side portion decreases.

[0031] In the embodiments of this disclosure as described above, the thickness of the first annular layer formed in the section where relatively high circumferential stress is applied (the central region of the cylindrical portion where circumferential stress is concentrated) is large, while the thickness of the second annular layer formed in the section where relatively low circumferential stress is applied (the edge region of the cylindrical portion) gradually decreases with decreasing distance from the side portion. Therefore, sufficient structural stiffness can be ensured to resist the circumferential stress applied to the cylindrical portion, and the reduction in the thickness of the second annular layer allows for a reduction in the amount of carbon fiber composite material used to form the second annular layer. Thus, the advantageous effects of reducing the weight of the pressure vessel and lowering manufacturing costs can be achieved.

[0032] Furthermore, according to embodiments of this disclosure, the thickness of the first annular layer formed in the section where relatively high circumferential stress is applied is large, while the thickness of the second annular layer formed in the section where relatively low circumferential stress is applied gradually decreases with decreasing distance from the side portion, thereby reducing the stress difference applied to the cylindrical portion (making the stress more uniform). Therefore, the advantageous effect of reducing the stress applied to the vulnerable sections (e.g., the central region) of the cylindrical portion and further improving the safety margin can be obtained.

[0033] According to embodiments of the present disclosure, a pressure vessel may include a second spiral layer, the second spiral layer being configured to surround the outer surface of a first annular layer, the outer surface of the second annular layer, and the outer surface of a side portion.

[0034] According to embodiments of the present disclosure, the pressure vessel may include a third annular layer formed to cover the outer surface of the second spiral layer.

[0035] Specifically, the third annular layer can be configured to have a second thickness that is less than the first thickness of the first annular layer.

[0036] For example, the thickness of the first annular layer can be set to be equal to or greater than 90% of a preset reference annular layer thickness.

[0037] As another example, the thickness of the third annular layer can be set to be less than 10% of the preset reference annular layer thickness.

[0038] In another embodiment, this disclosure provides a method for manufacturing a pressure vessel, the method comprising: a step of providing a bushing preparation step, wherein the bushing includes a cylindrical portion and dome-shaped side portions disposed at both ends of the cylindrical portion; a first annular layer forming step of forming a first annular layer surrounding a portion of the outer peripheral surface of the cylindrical portion; and a second annular layer forming step of forming a second annular layer surrounding other portions of the outer peripheral surface of the cylindrical portion, wherein the thickness of each second annular layer gradually decreases in the direction from the cylindrical portion to the side portions.

[0039] According to an embodiment of the present disclosure, in the first annular layer forming step, a first annular layer may be provided around the central region of the cylindrical portion, and in the second annular layer forming step, a second annular layer may be provided around the two edge regions of the cylindrical portion, with the first annular layer located between the second annular layers.

[0040] Specifically, the center of the first annular layer may correspond to the center of the cylindrical portion, the length of the first annular layer may be 40% to 60% of the length of the cylindrical portion, and the length of the second annular layer may be 20% to 30% of the length of the cylindrical portion.

[0041] More specifically, the second annular layer is configured to have a right-angled triangular cross-section, the height H of which corresponds to the thickness of the first annular layer, and the angle θ between the hypotenuse and the base of the right-angled triangular cross-section satisfies the following equation 3:

[0042] [Equation 3]

[0043] tanθ = H / L²,

[0044] Where H is the height of the right-angled triangular cross section, and L2 is the length of the base of the second annular layer corresponding to the right-angled triangular cross section.

[0045] According to embodiments of the present disclosure, a method of manufacturing a pressure vessel may include a first spiral layer forming step, which forms a first spiral layer around the outer surface of a bushing, wherein a first annular layer and a second annular layer are disposed on the outer surface of the first spiral layer.

[0046] According to embodiments of the present disclosure, a method for manufacturing a pressure vessel may include a second spiral layer forming step, which forms a second spiral layer surrounding the outer surface of a first annular layer, the outer surface of a second annular layer, and the outer surface of a side portion.

[0047] According to embodiments of the present disclosure, a method for manufacturing a pressure vessel may include a third annular layer forming step, which forms a third annular layer covering the outer surface of a second spiral layer.

[0048] Specifically, the thickness of the third annular layer can be set to be smaller than that of the first annular layer, the thickness of the first annular layer can be set to be equal to or greater than 90% of the preset reference annular layer thickness, and the thickness of the third annular layer can be set to be less than 10% of the preset reference annular layer thickness.

[0049] According to the embodiments of this disclosure as described above, advantageous effects can be obtained in ensuring structural stiffness and improving stability and reliability.

[0050] Specifically, according to embodiments of this disclosure, the advantageous effects of ensuring the structural stiffness of the pressure vessel and minimizing the use of carbon fiber composite materials can be achieved.

[0051] Furthermore, according to embodiments of this disclosure, beneficial effects such as improved pressure vessel efficiency, reduced pressure vessel weight, and lower manufacturing costs can be achieved.

[0052] Furthermore, according to the embodiments of this disclosure, the beneficial effects of simplifying the manufacturing process and improving manufacturing efficiency can be obtained. Attached Figure Description

[0053] Figure 1 This is a flowchart illustrating a method for manufacturing a pressure vessel according to embodiments of the present disclosure.

[0054] Figure 2 This is a top plan view illustrating the first and second annular layers in relation to a method of manufacturing a pressure vessel according to embodiments of the present disclosure.

[0055] Figure 3 This is a cross-sectional view of the first and second annular layers in relation to a method of manufacturing a pressure vessel according to an embodiment of the present disclosure.

[0056] Figure 4 This is a cross-sectional view illustrating the second spiral layer and the third annular layer in relation to a method of manufacturing a pressure vessel according to an embodiment of the present disclosure.

[0057] Figure 5 This is a cross-sectional view of the first spiral layer used to illustrate a method of manufacturing a pressure vessel according to an embodiment of the present disclosure.

[0058] Figure 6 This is a view illustrating the steps of forming a first annular layer and a second annular layer in a method for manufacturing a pressure vessel according to embodiments of the present disclosure.

[0059] Figure 7 This is a view used to illustrate the stress applied to the cylindrical portion of a pressure vessel according to an embodiment of the present disclosure.

[0060] Figure 8 This is a view used to illustrate the efficiency of a pressure vessel according to an embodiment of the present disclosure.

[0061] Figure 9 This is a view used to illustrate an example of carbon fiber layers stacked on a pressure vessel according to an embodiment of the present disclosure.

[0062] The components in the attached figures are indicated by the following reference numerals:

[0063] 10: Pressure Vessel

[0064] 100: Bushing

[0065] 110: Columnar section

[0066] 120: Side view

[0067] 200: Carbon fiber layer

[0068] 300: First annular layer

[0069] 400: Second annular layer

[0070] 500: Third ring layer

[0071] 600: First spiral layer

[0072] 700: Second spiral layer Detailed Implementation

[0073] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0074] However, the spirit of this disclosure is not limited to the embodiments described herein, but can be implemented in various different forms. Within the scope of the spirit of this disclosure, one or more components in the embodiments can be selectively combined and substituted.

[0075] Furthermore, unless otherwise specifically and explicitly defined and stated, the terms (including technical and scientific terms) used in the embodiments of this disclosure are to be interpreted in a meaning generally understood by one of ordinary skill in the art to which this disclosure pertains. The meaning of commonly used terms (such as terms defined in dictionaries) may be interpreted with reference to the contextual meaning of related technologies.

[0076] Furthermore, the terminology used in the embodiments of this disclosure is for the purpose of explaining the embodiments and not for limiting this disclosure.

[0077] Unless otherwise specifically indicated in the context of this specification, the singular form may also include the plural form. The description herein of "at least one (or one or more) of A, B, and C" may include all combinations that can be formed by one or more of A, B, and C.

[0078] In addition, terms such as “first”, “second”, “A”, “B”, “(a)” and “(b)” can be used to describe the constituent elements of embodiments of this disclosure.

[0079] These terms are used only for the purpose of distinguishing one component from another, and the nature, order, or sequence of the components are not limited by these terms.

[0080] Furthermore, when a component is described as being “connected,” “coupled,” or “attached” to another component, a component may be directly connected, coupled, or attached to another component, or may be connected, coupled, or attached to another component in the case where other components are inserted into one component and another component.

[0081] Furthermore, the statement "one component is formed or placed above or below another component" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, the expression "above or below" can include meanings based on the downward and upward directions of a component.

[0082] Reference Figures 1 to 8 A method for manufacturing a pressure vessel according to an embodiment of the present disclosure includes: a preparation step S10, providing a bushing 100 including a cylindrical portion 110 and a plurality of side portions 120 disposed at both ends of the cylindrical portion 110 and each being dome-shaped; a first annular layer forming step S30, forming a first annular layer 300 surrounding a portion of the outer peripheral surface of the cylindrical portion 110; and a second annular layer forming step S40, forming a second annular layer 400 surrounding other portions of the outer peripheral surface of the cylindrical portion 110, wherein the thickness of each second annular layer gradually decreases in the direction from the cylindrical portion 110 to the side portions 120.

[0083] For reference, the pressure vessel 10 according to embodiments of the present disclosure can be used to store high-pressure fluids (liquid or gas), and the present disclosure is not constrained or limited by the type and properties of the fluid stored in the pressure vessel 10.

[0084] The following configuration will be described as an example, in which the pressure vessel 10 according to an embodiment of the present disclosure is used as a hydrogen tank for a hydrogen storage system applied to a hydrogen vehicle.

[0085] Step 1 :

[0086] First, a bushing 100 including a columnar portion 110 and a side portion 120 is provided (S10).

[0087] In preparation step S10, bushings 100 are provided that integrally form dome-shaped side portions 120 at both ends of the cylindrical portion 110.

[0088] The bushing 100 has a hollow structure with a storage space in which high-pressure compressed hydrogen can be stored.

[0089] An inlet (not shown) can be formed at one end of the bushing 100 to introduce hydrogen, and an outlet (not shown) can be formed at the other end of the bushing 100 to discharge hydrogen.

[0090] The material of bushing 100 can be varied according to required conditions and design specifications, and this disclosure is not constrained or limited by the material of bushing 100. Specifically, bushing 100 can be made of a non-metallic material (e.g., high-density plastic) with excellent resilience and excellent fatigue resistance.

[0091] More specifically, the bushing 100 includes a cylindrical portion 110 and a dome-shaped side portion 120, wherein the cylindrical portion has a hollow cylindrical shape, and the side portion is integrally formed at both ends of the cylindrical portion 110.

[0092] Step 2:

[0093] According to embodiments of the present disclosure, a method of manufacturing a pressure vessel may include a first spiral layer forming step S20, which forms a first spiral layer 600 surrounding the outer surface of a bushing 100.

[0094] In the first spiral layer forming step S20, the first spiral layer 600 can be formed by using a common winding device to wind the carbon fiber composite material around the outer surface of the bushing 100 (the outer surface of the cylindrical portion and the outer surface of the side portion), which is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.

[0095] For reference, in embodiments of this disclosure, the first helical layer 600 may be defined as a layer configured to enhance structural stiffness to resist torsional and stress applied primarily in the longitudinal direction (the longitudinal direction of the cylindrical portion) of the stresses applied to the bushing. The first helical layer 600 may be configured to cooperate with the second helical layer 700, which will be described below, to resist torsional and stress applied in the longitudinal direction of the bushing 100.

[0096] For example, the first helical layer 600 can be formed by winding a carbon fiber composite material around the outer surface of the cylindrical portion 110 at a winding angle of 45° to 88° relative to the axis of the cylindrical portion 110, and this disclosure is not constrained or limited by the winding angle and winding pattern (e.g., clockwise winding, counterclockwise winding, oblique winding, etc.) of the carbon fiber composite material used to form the first helical layer 600.

[0097] Specifically, the thickness TH1 of the first spiral layer 600 can be equal to or less than 5% of the total thickness WT of the carbon fiber layer 200, in order to ensure the structural stiffness achieved by the first spiral layer 600 and to minimize the increase in thickness and weight of the pressure vessel 10.

[0098] In this case, the total thickness WT of the carbon fiber layer 200 can be understood as the maximum thickness of the carbon fiber layer 200 in the radial direction of the cylindrical portion 110.

[0099] For example, assuming the total thickness WT of the layers constituting the carbon fiber layer 200 (e.g., the first helical layer, the first annular layer, the second helical layer, and the third annular layer) is 20 mm, the thickness TH of the first helical layer 600 can be formed to be 1 mm or less.

[0100] Step 3:

[0101] Next, a first annular layer 300 (S30) is formed around a portion of the outer peripheral surface of the cylindrical portion 110.

[0102] In the first annular layer forming step S30, the first annular layer 300 can be formed by winding a carbon fiber composite material around the outer surface (outer peripheral surface) of the cylindrical portion 110 using a commonly used winding device. The carbon fiber composite material is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.

[0103] For example, when the first spiral layer 600 is disposed on the outer surface of the bushing 100, the first annular layer 300 may be formed on the outer surface of the first spiral layer 600 to surround a portion of the outer peripheral surface of the cylindrical portion 110. According to another embodiment of the present disclosure, in the absence of a separate first spiral layer on the outer surface of the bushing, the first annular layer may be formed directly on the outer surface of the bushing.

[0104] For reference, in embodiments of this disclosure, the first annular layer 300 may be defined as a layer that is used to (ensure structural stiffness) resist the main circumferential stress (e.g., maximum circumferential stress) applied to the columnar portion 110.

[0105] For example, the first annular layer 300 can be formed by winding a carbon fiber composite material around the outer surface of the cylindrical portion 110 (the outer surface of the first spiral layer) at a winding angle of 89° to 91° relative to the axis of the cylindrical portion 110. According to another embodiment of the present disclosure, the first annular layer can be formed by winding a carbon fiber composite material at a winding angle of 85° to 89° relative to the axis of the cylindrical portion.

[0106] For example, carbon fiber composites can be wound using a winding clamp 20 (see...) Figure 6 The winding is applied around the outer surface of the cylindrical portion 110. This can be achieved by adjusting the winding clamp 20 (see...). Figure 6 The angle (or posture) relative to the cylindrical portion 110 is used to change the winding angle of the carbon fiber composite material relative to the cylindrical portion 110.

[0107] Specifically, in the first annular layer forming step S30, the first thickness T1 of the first annular layer 300 can be formed to resist the maximum circumferential stress applied to the cylindrical portion 110. The first thickness T1 of the first annular layer 300 can be varied according to required conditions and design specifications (e.g., the structure and dimensions of the pressure vessel).

[0108] Step 4:

[0109] Next, a second annular layer 400 (S40) is formed around the other parts of the outer peripheral surface of the cylindrical portion 110.

[0110] In the second annular layer forming step S40, the second annular layer 400 can be formed by winding the carbon fiber composite material around the outer surface (outer peripheral surface) of the cylindrical portion 110 using a commonly used winding device. The carbon fiber composite material is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.

[0111] For reference, in embodiments of this disclosure, the second annular layer 400 may be defined as a layer that is used to (ensure structural stiffness) resist the main circumferential stress (circumferential stress) applied to the columnar portion 110.

[0112] For example, the second annular layer 400 can be formed by winding a carbon fiber composite material around the outer surface of the cylindrical portion 110 at a winding angle of 89° to 91° relative to the axis of the cylindrical portion 110. According to another embodiment of the present disclosure, the second annular layer can be formed by winding a carbon fiber composite material at a winding angle of 85° to 89° relative to the axis of the cylindrical portion.

[0113] Specifically, in the second annular layer forming step S40, the thickness of the second annular layer 400 is formed to gradually decrease in the direction from the cylindrical portion 110 to the side portion 120. More specifically, the thickness of the second annular layer 400 may decrease linearly in the direction from the cylindrical portion 110 to the side portion 120.

[0114] According to an embodiment of the present disclosure, in the first annular layer forming step S30, the first annular layer 300 may be configured to surround the central region of the cylindrical portion 110, and in the second annular layer forming step S40, the second annular layer 400 may be configured to surround the two edge regions of the cylindrical portion 110, wherein the first annular layer 300 is located between these second annular layers.

[0115] Specifically, the center of the first annular layer 300 corresponds to the center C of the cylindrical portion, the length of the first annular layer 300 is 40% to 60% of the length L of the cylindrical portion 110, and the length of the second annular layer 400 is 20% to 30% of the length L of the cylindrical portion 110.

[0116] That is, if the length of the first annular layer 300 is less than 40% of the length L of the cylindrical portion 110, there is a problem of reduced burst strength of the pressure vessel. If the length of the first annular layer 300 is greater than 70% of the length L of the cylindrical portion 110, there are problems of increased usage of carbon fiber composite material and deterioration of the hydrogen weight efficiency (wt.%) of the pressure vessel 10. Therefore, the length of the first annular layer 300 can be 40% to 60% of the length L of the cylindrical portion 110, and the length of the second annular layer 400 can be 20% to 30% of the length L of the cylindrical portion 110.

[0117] According to another embodiment of the present disclosure, the total length (L2 + L1 + L2) of the first annular layer and the second annular layer can be less than the total length L of the cylindrical portion (L2 + L1 + L2 < L). Alternatively, the total length (L2 + L1 + L2) of the first annular layer and the second annular layer can be greater than the total length L of the cylindrical portion (L2 + L1 + L2 > L). Specifically, the total length (L2 + L1 + L2) of the first annular layer and the second annular layer can be ±10% of the total length L of the cylindrical portion (for example, 90% of the length L or 110% of the length L).

[0118] More specifically, the center of the first annular layer 300 corresponds to the center C of the cylindrical portion 110, and the length L1 of the first annular layer 300 is defined by Equation 1 below:

[0119] [Equation 1]

[0120] L1 = L / 2,

[0121] where L is the length of the cylindrical portion 110.

[0122] In addition, the length L2 of the second annular layer 400 is defined by Equation 2 below:

[0123] [Equation 2]

[0124] L2 = L / 4,

[0125] where L is the length of the cylindrical portion 110.

[0126] According to an embodiment of this disclosure, the second annular layer 400 is configured to have a right-angled triangular cross-section, the height H of which corresponds to the thickness of the first annular layer 300, and the angle θ between the hypotenuse HL and the base of the right-angled triangular cross-section can satisfy the following equation 3:

[0127] [Equation 3]

[0128] tanθ = H / L²,

[0129] Where H is the height of the right-angled triangular cross section, and L2 is the length of the base of the second annular layer corresponding to the right-angled triangular cross section.

[0130] This is because the circumferential stress applied to the central region of the cylindrical portion 110 (where the first annular layer is formed) is the greatest, while the circumferential stress applied to the two edge regions of the cylindrical portion 110 (where the second annular layer is formed) gradually decreases as the distance from the side portion 120 decreases.

[0131] The stress (circumferential stress) applied to the cylindrical portion 110 is not uniform across the entire section of the cylindrical portion 110.

[0132] That is, refer to Figure 7 It can be determined that the stress (circumferential stress) applied to the cylindrical portion 110 is high in the central region (the region at a distance of 0.00 m to 0.50 m from the center C of the cylindrical portion), and the stress (circumferential stress) applied to the cylindrical portion 110 gradually decreases as the distance from the side portion 120 decreases in the edge region (the region at a distance of 0.50 m to 1.00 m from the center of the cylindrical portion).

[0133] Specifically, it can be determined that the stress (maximum circumferential stress) is concentrated in the central region of the cylindrical portion 110 (the region at a distance of 0.00 m to 0.50 m from the center of the cylindrical portion), and the stress (circumferential stress) decreases rapidly in the edge region of the cylindrical portion 110 (the region at a distance of 0.50 m to 1.00 m from the center of the cylindrical portion).

[0134] In the embodiments of this disclosure as described above, the thickness of the first annular layer 300 formed in the section where relatively high circumferential stress is applied (the central region of the cylindrical portion where circumferential stress is concentrated) is large, while the thickness of the second annular layer 400 formed in the section where relatively low circumferential stress is applied (the edge region of the cylindrical portion) gradually decreases with decreasing distance from the side portion 120. Therefore, sufficient structural stiffness can be ensured to resist the circumferential stress applied to the cylindrical portion 110, and in terms of the reduced thickness of the second annular layer 400, the amount of carbon fiber composite material used to form the second annular layer 400 can be reduced. Thus, the advantageous effects of reducing the weight of the pressure vessel 10 and lowering manufacturing costs can be achieved.

[0135] Furthermore, according to embodiments of this disclosure, the thickness of the first annular layer 300 formed in the section where relatively high circumferential stress is applied is large, while the thickness of the second annular layer 400 formed in the section where relatively low circumferential stress is applied gradually decreases as the distance from the side portion 120 decreases, thereby reducing the stress difference applied to the cylindrical portion 110 (making the stress more uniform). Therefore, the advantageous effect of reducing the stress applied to the vulnerable sections (e.g., the central region) of the cylindrical portion 110 and further improving the safety margin can be obtained.

[0136] As described above, because the stress applied to the cylindrical portion 110 is made more uniform (the difference is reduced) as a whole, a favorable effect of increasing the efficiency (normalized efficiency) of the pressure vessel 10 by about 18% can be obtained compared with the prior art pressure vessel (in which annular and spiral layers of constant thickness are stacked as a whole). Figure 8 As shown.

[0137] For reference, in the embodiments shown and described above in this disclosure, an example has been described in which the thickness of the second annular layer 400 decreases linearly in the direction from the cylindrical portion 110 to the side portion 120. However, according to another embodiment of this disclosure, the thickness of the second annular layer may decrease non-linearly in the direction from the cylindrical portion to the side portion. For example, the upper surface of the second annular layer (corresponding to the hypotenuse of a right triangle) may be curved.

[0138] In the embodiments of this disclosure, the order and method of forming the first annular layer 300 and the second annular layer 400 may be varied according to desired conditions and design specifications, and this disclosure is not constrained or limited by the order and method of forming the first annular layer 300 and the second annular layer 400.

[0139] For example, the first annular layer 300 and the second annular layer 400 can be formed by separate winding processes. For example, the first annular layer 300 can be formed first, and then the second annular layer 400 can be formed. Alternatively, the second annular layer 400 can be formed first, and then the first annular layer 300 can be formed.

[0140] As another example, the first annular layer 300 and the second annular layer 400 can be formed continuously using the same winding process. More specifically, refer to... Figure 6 As the winding jig 20 moves linearly along the longitudinal direction of the bushing 100 (the longitudinal direction of the cylindrical portion), the carbon fiber composite material is wound around the outer peripheral surface of the cylindrical portion in a manner that continuously forms a first winding layer (first layer) comprising a portion of a first annular layer 300 and a portion of a second annular layer 400. Then, a second winding layer (second layer) is stacked on the outer surface of the first winding layer, the second winding layer (in the longitudinal direction of the cylindrical portion) being shorter than the length of the first winding layer. In this way, N winding layers with lengths gradually decreasing outward in the radial direction of the cylindrical portion are stacked (the Nth layer is stacked on the outermost peripheral surface of the cylindrical portion), thereby forming the first annular layer 300 and the second annular layer 400.

[0141] Step 5:

[0142] Reference Figure 4 According to embodiments of the present disclosure, a method for manufacturing a pressure vessel may include a second spiral layer forming step S50, which forms a second spiral layer 700 surrounding the outer surface of the first annular layer 300, the outer surface of the second annular layer 400, and the outer surface of the side portion 120.

[0143] In the second spiral layer forming step S50, the second spiral layer 700 can be formed by winding the carbon fiber composite material around the outer surface of the first annular layer 300, the outer surface of the second annular layer 400 and the outer surface of the side portion 120 using a common winding device. The carbon fiber composite material is made by impregnating carbon fibers with epoxy resin, thermosetting resin or the like.

[0144] For reference, in embodiments of this disclosure, the second spiral layer 700 may be defined as a layer configured to ensure structural stiffness to resist torsion and stress, primarily in the longitudinal direction, in the stresses applied to the columnar portion 110.

[0145] For example, the second helical layer 700 can be formed by winding a carbon fiber composite material around the outer surface of the cylindrical portion 110 at a winding angle of 45° to 88° relative to the axis of the cylindrical portion 110, and this disclosure is not constrained or limited by the winding pattern (e.g., clockwise winding, counterclockwise winding, oblique winding, etc.) of the carbon fiber composite material used to form the second helical layer 700.

[0146] Step 6:

[0147] Reference Figure 5 According to embodiments of the present disclosure, a method for manufacturing a pressure vessel may include a third annular layer forming step S60, wherein the third annular layer 500 formed in the third annular layer forming step covers the outer surface of the second spiral layer 700.

[0148] In this case, the configuration in which the third annular layer 500 is formed to cover the outer surface of the second spiral layer 700 can include two configurations: a configuration in which the length of the third annular layer 500 (in the longitudinal direction of the cylindrical portion) corresponds to the length of the first annular layer 300, and a configuration in which the length of the third annular layer 500 is longer than the first annular layer 300. Hereinafter, such a configuration will be described as an example: in this configuration, the length of the third annular layer 500 is longer than the first annular layer 300, and the third annular layer 500 is formed to cover the entire area of ​​the first annular layer 300 and partially cover a portion of the area of ​​the second annular layer 400.

[0149] In the third annular layer forming step S60, the third annular layer 500 can be formed by winding the carbon fiber composite material around the outer surface (outer peripheral surface) of the second spiral layer 700 using a commonly used winding device. The carbon fiber composite material is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.

[0150] For reference, in embodiments of this disclosure, the third annular layer 500 may be defined as a layer configured to enhance structural stiffness to resist stresses applied primarily in the circumferential direction to the columnar portion 110.

[0151] For example, the third annular layer 500 can be formed by winding a carbon fiber composite material around the outer surface of the second helical layer 700 at a winding angle of 89° to 91° relative to the axis of the cylindrical portion 110. According to another embodiment of the present disclosure, the third annular layer can be formed by winding a carbon fiber composite material at a winding angle of 85° to 89° relative to the axis of the cylindrical portion.

[0152] For example, carbon fiber composites can be wound using a winding clamp 20 (see...) Figure 6The winding is wrapped around the outer surface of the cylindrical portion 110. This can be achieved by adjusting the winding clamp 20 (see...). Figure 6 The angle (or posture) relative to the cylindrical portion 110 is used to change the winding angle of the carbon fiber composite material relative to the cylindrical portion 110.

[0153] According to an embodiment of the present disclosure, in the third annular layer forming step S60, the second thickness T2 of the third annular layer 500 can be set to be less than the first thickness T1 of the first annular layer 300.

[0154] For example, the thickness of the first annular layer 300 can be set to be equal to or greater than 90% of a preset reference annular layer thickness.

[0155] As another example, the thickness of the third annular layer 500 can be set to be less than 10% of the preset reference annular layer thickness.

[0156] In this case, the reference annular layer thickness can be defined as the thickness of the entire annular layer (the thickness of the first annular layer + the thickness of the third annular layer), and the thickness of the entire annular layer is defined in the radial direction of the cylindrical portion 110 and is set to resist the maximum circumferential stress applied to the bushing 100 (e.g., based on the circumferential stress that would damage the pressure vessel).

[0157] For example, assuming the thickness of the reference annular layer is 10 mm, the thickness of the first annular layer 300 can be formed to be 9 mm or greater, and the thickness of the third annular layer 500 can be formed to be less than 1 mm.

[0158] The following describes a pressure vessel 10 manufactured by a method for manufacturing a pressure vessel according to an embodiment of the present disclosure.

[0159] refer to Figure 5 According to an embodiment of the present disclosure, the pressure vessel 10 includes: a bushing 100 including a cylindrical portion 110 and dome-shaped side portions 120 disposed at both ends of the cylindrical portion 110; and a carbon fiber layer 200 including a first annular layer 300 and a second annular layer 400, wherein the first annular layer is configured to surround a portion of the outer peripheral surface of the cylindrical portion 110, the second annular layer is configured to surround the remaining portion of the outer peripheral surface of the cylindrical portion 110, and the thickness of each second annular layer gradually decreases in the direction from the cylindrical portion 110 to the side portion 120.

[0160] The bushing 100 includes a cylindrical portion 110 having a hollow cylindrical shape and a dome-shaped side portion 120 integrally formed at both ends of the cylindrical portion 110.

[0161] The bushing 100 has a hollow structure with a storage space in which high-pressure compressed hydrogen can be stored.

[0162] An inlet (not shown) can be formed at one end of the bushing 100 to introduce hydrogen, and an outlet (not shown) can be formed at the other end of the bushing 100 to discharge hydrogen.

[0163] The material of bushing 100 can be varied according to required conditions and design specifications, and this disclosure is not constrained or limited by the material of bushing 100. Specifically, bushing 100 can be made of a non-metallic material (e.g., high-density plastic) with excellent resilience and excellent fatigue resistance.

[0164] According to embodiments of the present disclosure, the pressure vessel 10 may include a first spiral layer 600 configured to surround the outer surface of the bushing 100.

[0165] For reference, in embodiments of this disclosure, the first helical layer 600 may be defined as a layer configured to enhance structural stiffness to resist torsional and stress applied primarily in the longitudinal direction (the longitudinal direction of the cylindrical portion) of the stresses applied to the bushing. The first helical layer 600 may be configured to cooperate with the second helical layer 700, which will be described below, to resist torsional and stress applied in the longitudinal direction of the bushing 100.

[0166] The first spiral layer 600 can be formed by winding a carbon fiber composite material around the outer surface of the bushing 100 (the outer surface of the cylindrical portion and the outer surface of the side portion) using a common winding device. The carbon fiber composite material is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.

[0167] For example, the first helical layer 600 may be formed by winding a carbon fiber composite material around the outer surface of the cylindrical portion 110 at a winding angle of 45° to 88° relative to the axis of the cylindrical portion 110, and this disclosure is not constrained or limited by the winding angle and winding pattern (e.g., clockwise winding, counterclockwise winding, oblique winding, etc.) of the carbon fiber composite material used to form the first helical layer 600.

[0168] Specifically, the thickness TH of the first helical layer 600 can be equal to or less than 5% of the total thickness of the carbon fiber layer 200 to ensure the structural stiffness achieved by the first helical layer 600 and to minimize the increase in thickness and weight of the pressure vessel 10.

[0169] In this case, the total thickness WT of the carbon fiber layer 200 can be understood as the maximum thickness of the carbon fiber layer 200 in the radial direction of the cylindrical portion 110.

[0170] For example, assuming the total thickness WT of the layers constituting the carbon fiber layer 200 (e.g., the first helical layer, the first annular layer, the second helical layer, and the third annular layer) is 20 mm, the thickness TH of the first helical layer 600 can be formed to be 1 mm or less.

[0171] The first annular layer 300 is configured as part of the outer peripheral surface of the cylindrical portion 110.

[0172] For reference, in embodiments of this disclosure, the first annular layer 300 may be defined as a layer that is used to (ensure structural stiffness) resist the main circumferential stress (e.g., maximum circumferential stress) applied to the columnar portion 110.

[0173] For example, if a first spiral layer 600 is provided on the outer surface of the bushing 100, a first annular layer 300 may be formed on the outer surface of the first spiral layer 600 to surround a portion of the outer peripheral surface of the cylindrical portion 110.

[0174] The first annular layer 300 can be formed by winding a carbon fiber composite material around the outer surface (outer peripheral surface) of the cylindrical portion 110 using a commonly used winding device. The carbon fiber composite material is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.

[0175] For example, the first annular layer 300 may be formed by winding a carbon fiber composite material around the outer surface of the cylindrical portion 110 at a winding angle (first winding angle) of 89° to 91° relative to the axis of the cylindrical portion 110. According to another embodiment of the present disclosure, the first annular layer may be formed by winding a carbon fiber composite material at a winding angle of 85° to 89° relative to the axis of the cylindrical portion.

[0176] Specifically, the first thickness T1 of the first annular layer 300 can be configured to resist the maximum circumferential stress applied to the cylindrical portion 110. The first thickness T1 of the first annular layer 300 can be varied according to required conditions and design specifications (e.g., the structure and dimensions of the pressure vessel).

[0177] The second annular layer 400 is configured to surround the other portions of the outer peripheral surface of the cylindrical portion 110.

[0178] For reference, in embodiments of this disclosure, the second annular layer 400 may be defined as a layer that is used to (ensure structural stiffness) resist the main circumferential stress (circumferential stress) applied to the columnar portion 110.

[0179] The second annular layer 400 can be formed by winding a carbon fiber composite material around the outer surface (outer peripheral surface) of the cylindrical portion 110 using a commonly used winding device. The carbon fiber composite material is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.

[0180] For example, the second annular layer 400 may be formed by winding a carbon fiber composite material around the outer surface of the cylindrical portion 110 at a winding angle (second winding angle) of 89° to 91° relative to the axis of the cylindrical portion 110. According to another embodiment of the present disclosure, the second annular layer may be formed by winding a carbon fiber composite material at a winding angle of 85° to 89° relative to the axis of the cylindrical portion.

[0181] Specifically, the thickness of the second annular layer 400 is formed to gradually decrease in the direction from the cylindrical portion 110 to the side portion 120. More specifically, the thickness of the second annular layer 400 may decrease linearly in the direction from the cylindrical portion 110 to the side portion 120.

[0182] According to an embodiment of the present disclosure, a first annular layer 300 is configured to surround the central region of the cylindrical portion 110, and a second annular layer 400 is configured to surround the two edge regions of the cylindrical portion 110, with the first annular layer 300 situated between these second annular layers.

[0183] Specifically, the center of the first annular layer 300 corresponds to the center C of the cylindrical portion, the length of the first annular layer 300 is 40% to 60% of the length L of the cylindrical portion 110, and the length of the second annular layer 400 is 20% to 30% of the length L of the cylindrical portion 110.

[0184] More specifically, the center of the first annular layer 300 corresponds to the center C of the cylindrical portion 110, and the length L1 of the first annular layer 300 is defined by the following Equation 1:

[0185] [Equation 1]

[0186] L1 = L / 2,

[0187] Where L is the length of the cylindrical portion 110.

[0188] Furthermore, the length L2 of the second annular layer 400 is defined by the following equation 2:

[0189] [Equation 2]

[0190] L2 = L / 4,

[0191] Where L is the length of the cylindrical portion 110.

[0192] According to an embodiment of this disclosure, the second annular layer 400 is configured to have a right-angled triangular cross-section, the height H of which corresponds to the thickness of the first annular layer 300, and the angle θ between the hypotenuse HL and the base of the right-angled triangular cross-section can satisfy the following equation 3:

[0193] [Equation 3]

[0194] tanθ = H / L²,

[0195] Where H is the height of the right-angled triangular cross section, and L2 is the length of the base of the second annular layer corresponding to the right-angled triangular cross section.

[0196] This is because the circumferential stress applied to the central region of the cylindrical portion 110 (where the first annular layer is formed) is the greatest, while the circumferential stress applied to the two edge regions of the cylindrical portion 110 (where the second annular layer 400 is formed) gradually decreases as the distance from the side portion 120 decreases.

[0197] The stress (circumferential stress) applied to the cylindrical portion 110 is not uniform across the entire section of the cylindrical portion 110.

[0198] That is, refer to Figure 7 It can be determined that the stress (circumferential stress) applied to the cylindrical portion 110 is high in the central region (the region at a distance of 0.00 m to 0.50 m from the center C of the cylindrical portion), and the stress (circumferential stress) applied to the cylindrical portion 110 gradually decreases as the distance from the side portion 120 decreases in the edge region (the region at a distance of 0.50 m to 1.00 m from the center of the cylindrical portion).

[0199] Specifically, it can be determined that the stress (maximum circumferential stress) is concentrated in the central region of the cylindrical portion 110 (the region at a distance of 0.00 m to 0.50 m from the center of the cylindrical portion), and the stress (circumferential stress) decreases rapidly in the edge region of the cylindrical portion 110 (the region at a distance of 0.50 m to 1.00 m from the center of the cylindrical portion).

[0200] In the embodiments of this disclosure as described above, the thickness of the first annular layer 300 formed in the section where relatively high circumferential stress is applied (the central region of the cylindrical portion where circumferential stress is concentrated) is large, while the thickness of the second annular layer 400 formed in the section where relatively low circumferential stress is applied (the edge region of the cylindrical portion) gradually decreases with decreasing distance from the side portion 120. Therefore, sufficient structural stiffness can be ensured to resist the circumferential stress applied to the cylindrical portion 110, and in terms of the reduced thickness of the second annular layer 400, the amount of carbon fiber composite material used to form the second annular layer 400 can be reduced. Thus, the advantageous effects of reducing the weight of the pressure vessel 10 and lowering manufacturing costs can be achieved.

[0201] Furthermore, according to embodiments of this disclosure, the thickness of the first annular layer 300 formed in the section where relatively high circumferential stress is applied is relatively large, while the thickness of the second annular layer 400 formed in the section where relatively low circumferential stress is applied gradually decreases as the distance from the side portion 120 decreases, thereby reducing the stress difference applied to the cylindrical portion 110 (making the stress more uniform). Therefore, the advantageous effects of reducing the stress applied to the vulnerable sections (e.g., the central region) of the cylindrical portion 110 and further improving the safety margin can be obtained.

[0202] As described above, because the stress applied to the cylindrical portion 110 is made more uniform (the difference is reduced) as a whole, a favorable effect of increasing the efficiency (normalized efficiency) of the pressure vessel 10 by about 18% can be obtained compared with the prior art pressure vessel (in which annular and spiral layers of constant thickness are stacked as a whole). Figure 8 As shown.

[0203] For reference, in the embodiments of this disclosure, the formation order and method of the first annular layer 300 and the second annular layer 400 may be varied according to the required conditions and design specifications, and this disclosure is not constrained or limited by the formation order and method of the first annular layer 300 and the second annular layer 400.

[0204] For example, the first annular layer 300 and the second annular layer 400 can be formed continuously by the same winding process. More specifically, refer to... Figure 6As the winding jig 20 moves linearly in the longitudinal direction (longitudinal direction of the cylindrical portion) of the bushing 100, the carbon fiber composite material is wound around the outer peripheral surface of the cylindrical portion in a manner that continuously forms a first winding layer (first layer) comprising a portion of a first annular layer 300 and a portion of a second annular layer 400. Then, a second winding layer (second layer) is stacked on the outer surface of the first winding layer, the second winding layer (in the longitudinal direction of the cylindrical portion) being shorter than the first winding layer. In this way, N winding layers with lengths gradually decreasing outward in the radial direction of the cylindrical portion are stacked (the Nth layer is stacked on the outermost peripheral surface of the cylindrical portion), thereby forming the first annular layer 300 and the second annular layer 400.

[0205] According to embodiments of the present disclosure, the pressure vessel 10 may include a second spiral layer 700, which is formed around the outer surface of the first annular layer 300, the outer surface of the second annular layer 400, and the outer surface of the side portion 120 (or the outer surface of the first spiral layer).

[0206] For reference, in embodiments of this disclosure, the second spiral layer 700 may be defined as a layer configured to ensure structural stiffness to resist torsion and stress, primarily in the longitudinal direction, in the stresses applied to the columnar portion 110.

[0207] The second spiral layer 700 can be formed by winding a carbon fiber composite material around the outer surface of the first annular layer 300, the outer surface of the second annular layer 400, and the outer surface of the side portion 120 (or the outer surface of the first spiral layer) using a common winding device. The carbon fiber composite material is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.

[0208] For example, the second spiral layer 700 may be formed by winding a carbon fiber composite material around the outer surface of the cylindrical portion 110 at a winding angle of 45° to 88° relative to the axis of the cylindrical portion 110.

[0209] According to embodiments of the present disclosure, the pressure vessel 10 may include a third annular layer 500 formed to cover the outer surface of the second spiral layer 700.

[0210] For example, the length of the third annular layer 500 is formed to be longer than that of the first annular layer 300, and the third annular layer 500 is formed to cover the entire area of ​​the first annular layer 300 and partially cover a portion of the second annular layer 400. According to another embodiment of the present disclosure, the length of the third annular layer may be formed to correspond to the length of the first annular layer (in the longitudinal direction of the cylindrical portion).

[0211] For reference, in embodiments of this disclosure, the third annular layer 500 may be defined as a layer configured to enhance structural stiffness to resist stresses applied primarily in the circumferential direction to the columnar portion 110.

[0212] The third annular layer 500 can be formed by winding a carbon fiber composite material around the outer surface (outer peripheral surface) of the second spiral layer 700 using a common winding device. The carbon fiber composite material is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.

[0213] For example, the third annular layer 500 may be formed by winding a carbon fiber composite material around the outer surface of the second spiral layer 700 at a winding angle of 89° to 91° relative to the axis of the cylindrical portion 110. According to another embodiment of the present disclosure, the third annular layer may be formed by winding a carbon fiber composite material at a winding angle of 85° to 89° relative to the axis of the cylindrical portion.

[0214] Specifically, the second thickness T2 of the third annular layer 500 can be set to be less than the first thickness T1 of the first annular layer 300.

[0215] For example, the thickness of the first annular layer 300 can be set to be equal to or greater than 90% of a preset reference annular layer thickness.

[0216] As another example, the thickness of the third annular layer 500 can be set to be less than 10% of the preset reference annular layer thickness.

[0217] In this case, the reference annular layer thickness can be defined as the thickness of the entire annular layer (the thickness of the first annular layer + the thickness of the third annular layer), which is defined in the radial direction of the cylindrical portion 110 and is set to resist the maximum circumferential stress applied to the bushing 100 (e.g., based on the circumferential stress that would damage the pressure vessel).

[0218] For example, assuming the reference annular layer thickness is 10 mm, the thickness of the first annular layer 300 can be formed to be 9 mm or greater, and the thickness of the third annular layer 500 can be formed to be less than 1 mm.

[0219] Meanwhile, the carbon fiber layer 200 (e.g., the first helical layer, the first annular layer, the second annular layer, and the second helical layer) wrapped around the outer surface of the bushing 100 can be cured by a subsequent heat treatment process.

[0220] In the embodiments described and illustrated above in this disclosure, examples comprising a single carbon fiber layer have been described, the single carbon fiber layer comprising a first annular layer, a second annular layer, and a second helical layer. However, according to another embodiment of this disclosure, the pressure vessel may comprise multiple carbon fiber layers.

[0221] For example, refer to Figure 9 The pressure vessel 10 may include: a bushing 100, the bushing including a cylindrical portion 110 and dome-shaped side portions 120 disposed at both ends of the cylindrical portion 110; and carbon fiber layers 200, 200', and 200" which include: first annular layers 300, 300', and 300" configured to surround a portion of the outer peripheral surface of the cylindrical portion 110; and second annular layers 400, 400', and 400" configured to surround the outer peripheral surface of the cylindrical portion 110. Other portions, and the thickness of each second annular layer gradually decreases in the direction from the cylindrical portion 110 to the side portion 120; and the second spiral layers 700, 700' and 700" are configured to surround the outer surfaces of the first annular layers 300, 300' and 300" and the outer surfaces of the second annular layers 400, 400' and 400" and the side portion 120, wherein the plurality of carbon fiber layers 200, 200' and 200" may be stacked (in the radial direction of the bushing).

[0222] The number of stacked carbon fiber layers 200, 200' and 200" can be varied according to required conditions and design specifications, and this disclosure is not constrained or limited by the number of stacked carbon fiber layers 200, 200' and 200".

[0223] The following describes an example of stacking three carbon fiber layers 200, 200', 200'' on the outer surface of the bushing 100. According to another embodiment of this disclosure, two carbon fiber layers may be stacked on the outer surface of the bushing, or four or more carbon fiber layers may be stacked on the outer surface of the bushing.

[0224] Furthermore, according to another embodiment of this disclosure, even when multiple carbon fiber layers 200, 200', and 200" are stacked, each of the carbon fiber layers 200, 200', and 200" may also include a first helical layer 600 (see [link to original text]). Figure 5 ) and the third annular layer 500 (see Figure 5 In other words, multiple carbon fiber layers, including a first annular layer, a second annular layer, a third annular layer, a first helical layer, and a second helical layer, can be stacked.

[0225] Specifically, the total lengths LA1, LA2, and LA3 of the first annular layers 300, 300', and 300" and the second annular layers 400, 400', and 400" that constitute carbon fiber layers 200, 200', and 200" respectively can gradually decrease outward in the radial direction of the bushing 100 (LA1>LA2>LA3).

[0226] That is, the first annular layer 300 and the second annular layer 400 (which constitute carbon fiber layer 200 formed by the first winding process (primary winding process)) can have a first length LA1, the first annular layer 300' and the second annular layer 400' (which constitute carbon fiber layer 200' formed by the subsequent second winding process (secondary winding process)) can have a second length LA2 that is less than the first length LA1, and the first annular layer 300" and the second annular layer 400" (which constitute carbon fiber layer 200" formed by the final third winding process (tertiary winding process)) can have a third length LA3 that is less than the second length LA2.

[0227] As described above, since the total lengths LA1, LA2, and LA3 of the first annular layers 300, 300', and 300" and the second annular layers 400, 400', and 400" constituting the carbon fiber layers 200, 200', and 200" gradually decrease outward in the radial direction of the bushing 100 (LA1>LA2>LA3), sufficient structural stiffness can be ensured to resist circumferential stress in sections where relatively high circumferential stress is applied, and the amount of carbon fiber composite material used can be reduced in sections where relatively low circumferential stress is applied. Therefore, the advantageous effect of improving the hydrogen weight efficiency (wt.%) of the pressure vessel 10 can be obtained.

[0228] According to another embodiment of this disclosure, a plurality of carbon fiber layers, including a first annular layer and a second annular layer, may be stacked in the radial direction of the bushing, and the total lengths of the first annular layer and the second annular layer constituting the carbon fiber layers may be equal to each other (e.g., LA1 = LA2 = LA3).

[0229] While embodiments have been described above, these embodiments are illustrative only and are not intended to limit the scope of this disclosure. Those skilled in the art will understand that various modifications and changes not described above can be made to these embodiments without departing from their essential characteristics. For example, individual components specifically described in the embodiments can be modified before operation. Furthermore, differences related to modifications and changes should be interpreted as being included within the scope of this disclosure as defined by the appended claims.

Claims

1. A pressure vessel, comprising: The bushing includes a cylindrical portion and dome-shaped side portions located at both ends of the cylindrical portion; as well as Carbon fiber layer, including: A first annular layer surrounds a portion of the outer peripheral surface of the cylindrical portion; The second annular layer surrounds the remaining portion of the outer peripheral surface of the cylindrical portion, and the thickness of each of the second annular layers gradually decreases in the direction from the cylindrical portion to a corresponding side portion of the side portion; and The second spiral layer surrounds the outer surface of the first annular layer, the outer surface of the second annular layer, and the outer surface of the side portion; The carbon fiber layer includes a first helical layer surrounding the outer surface of the bushing, and the first annular layer and the second annular layer are formed on the outer surface of the first helical layer; The carbon fiber layer includes a third annular layer that covers the outer surface of the second spiral layer. The length of the third annular layer is longer than that of the first annular layer, and the third annular layer covers the entire area of ​​the first annular layer and partially covers a portion of the second annular layer.

2. The pressure vessel according to claim 1, wherein, The first annular layer surrounds the central region of the cylindrical portion, and the second annular layer surrounds the two edge regions of the cylindrical portion, with the first annular layer located between the second annular layer.

3. The pressure vessel according to claim 2, wherein, The center of the first annular layer corresponds to the center of the cylindrical portion, the length of the first annular layer is 40% to 60% of the length of the cylindrical portion, and the length of each of the second annular layers is 20% to 30% of the length of the cylindrical portion.

4. The pressure vessel according to claim 3, wherein, The thickness of each of the second annular layers decreases linearly in the direction from the cylindrical portion to a corresponding side portion of the side portion.

5. The pressure vessel according to claim 4, wherein, Each of the second annular layers is configured to have a right-angled triangular cross-section, the height H of which corresponds to the thickness of the first annular layer, and the angle θ between the hypotenuse and the base of the right-angled triangular cross-section satisfies tanθ = H / L2, where H is the height of the right-angled triangular cross-section and L2 is the length of the base of the corresponding second annular layer corresponding to the right-angled triangular cross-section.

6. The pressure vessel according to claim 1, wherein, The thickness of the first spiral layer is equal to or less than 5% of the total thickness of the carbon fiber layers.

7. The pressure vessel according to claim 1, wherein, The thickness of the third annular layer is smaller than that of the first annular layer.

8. The pressure vessel according to claim 1, wherein, The thickness of the first annular layer is equal to or greater than 90% of the preset reference annular layer thickness.

9. The pressure vessel according to claim 1, wherein, The thickness of the third annular layer is less than 10% of the preset reference annular layer thickness.

10. A method for manufacturing a pressure vessel, the method comprising: A bushing is provided, the bushing including a cylindrical portion and dome-shaped side portions disposed at both ends of the cylindrical portion; A first annular layer is formed, the first annular layer surrounding a portion of the outer peripheral surface of the cylindrical portion; as well as A second annular layer is formed, which surrounds the remaining portion of the outer peripheral surface of the cylindrical portion, and the thickness of each second annular layer gradually decreases in the direction from the cylindrical portion to the corresponding side portion; The method further includes forming a first spiral layer surrounding the outer surface of the bushing, wherein the first annular layer and the second annular layer are disposed on the outer surface of the first spiral layer; The method further includes forming a second spiral layer, the second spiral layer surrounding the outer surface of the first annular layer, the outer surface of the second annular layer, and the outer surface of the side portion; The method further includes forming a third annular layer that covers the outer surface of the second spiral layer, the third annular layer being longer than the first annular layer, and the third annular layer being formed to cover the entire area of ​​the first annular layer and partially cover a portion of the second annular layer.

11. The method of claim 10, wherein: The first annular layer surrounds the central region of the cylindrical portion; and The second annular layer surrounds the two edge regions of the cylindrical portion, and the first annular layer is located between the second annular layer.

12. The method according to claim 11, wherein, The center of the first annular layer corresponds to the center of the cylindrical portion, the length of the first annular layer is 40% to 60% of the length of the cylindrical portion, and the length of each second annular layer in the second annular layer is 20% to 30% of the length of the cylindrical portion.

13. The method according to claim 12, wherein, Each of the second annular layers has a right-angled triangular cross-section, the height H of which corresponds to the thickness of the first annular layer, and the angle θ between the hypotenuse and the base of the right-angled triangular cross-section satisfies tan θ = H / L2, where H is the height of the right-angled triangular cross-section and L2 is the length of the base of the corresponding second annular layer corresponding to the right-angled triangular cross-section.

14. The method of claim 10, further comprising forming a second spiral layer surrounding the outer surface of the first annular layer, the outer surface of the second annular layer, and the outer surface of the side portion.

15. The method of claim 14, further comprising forming a third annular layer covering the outer surface of the second spiral layer.

16. The method according to claim 15, wherein, The thickness of the third annular layer is less than that of the first annular layer, the thickness of the first annular layer is equal to or greater than 90% of the thickness of a preset reference annular layer, and the thickness of the third annular layer is less than 10% of the thickness of the preset reference annular layer.

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