Pressure vessel and method of manufacturing the same

Abstract

A pressure vessel includes: a liner comprising a cylindrical portion and side portions disposed at both ends of the cylindrical portion; and carbon fiber layers comprising a first annular layer surrounding a portion of the outer peripheral surface of the cylindrical portion and second annular layers surrounding other portions of the outer peripheral surface of the cylindrical portion, each of the second annular layers having a thickness different from that of the first annular layer.

Description

[0001] Citations of relevant applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0165541, filed with the Korean Intellectual Property Office on December 1, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to pressure vessels and methods for manufacturing the same. Background Technology

[0004] Hydrogen vehicles are constructed to generate their own electricity through a chemical reaction between hydrogen and oxygen and to drive an electric motor. More specifically, a hydrogen vehicle includes: 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 generated water; 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 force.

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

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

[0007] However, if the amount of carbon fiber composite material used to form the carbon fiber layer of the pressure vessel is reduced (e.g., if the thickness of the carbon fiber layer is reduced), it becomes difficult to ensure sufficient structural rigidity of the pressure vessel (specifically, structural rigidity to resist circumferential stresses applied to the cylindrical portion of the pressure vessel in the circumferential direction), and stability and reliability deteriorate.

[0008] Therefore, various studies have been conducted recently to ensure structural rigidity and minimize the use of carbon fiber composites, but the results are still insufficient. Thus, there is a need to develop technologies to ensure structural rigidity and minimize the use of carbon fiber composites. Summary of the Invention

[0009] This disclosure relates to pressure vessels and methods for manufacturing the same. Specific embodiments relate to a pressure vessel having ensured structural rigidity and improved stability and reliability, and a method for manufacturing the pressure vessel.

[0010] The embodiments disclosed herein can ensure the structural rigidity of the pressure vessel and minimize the amount of carbon fiber composite material used.

[0011] The embodiments disclosed herein can reduce weight and manufacturing costs.

[0012] The embodiments disclosed herein can simplify the manufacturing process and improve manufacturing efficiency.

[0013] The objectives achieved through exemplary embodiments are not limited to those described above, but also include objectives or effects that can be identified from the schemes or exemplary embodiments described below.

[0014] An exemplary embodiment of the present invention provides a pressure vessel comprising a liner and a carbon fiber layer. The liner includes a cylindrical portion and side portions disposed at both ends of the cylindrical portion, each side portion having a dome shape. The carbon fiber layer includes a first annular layer configured to surround a portion of the outer peripheral surface of the cylindrical portion and a second annular layer configured to surround the remaining portion of the outer peripheral surface of the cylindrical portion, each second annular layer having a thickness different from that of the first annular layer.

[0015] This is to ensure the structural rigidity of the pressure vessel and to minimize the amount of carbon fiber composite material used.

[0016] In other words, carbon fiber composites are lightweight and possess excellent strength and elasticity, but they are expensive. Therefore, it is necessary to minimize the use of carbon fiber composites in order to reduce the cost required for manufacturing pressure vessels.

[0017] However, if the amount of carbon fiber composite material used to form the carbon fiber layer of the pressure vessel is reduced (e.g., if the thickness of the carbon fiber layer is reduced), it becomes difficult to ensure sufficient structural rigidity of the pressure vessel (specifically, structural rigidity to resist circumferential stresses applied to the cylindrical portion of the pressure vessel in the circumferential direction), and stability and reliability deteriorate.

[0018] Conversely, according to an exemplary embodiment of this disclosure, by configuring the carbon fiber layers using a first annular layer and a second annular layer with different thicknesses, the advantageous effects of ensuring the structural rigidity of the pressure vessel and reducing the amount of carbon fiber composite material used can be obtained.

[0019] First, according to an exemplary embodiment of this disclosure, by configuring the carbon fiber layers using a first annular layer and a second annular layer with different thicknesses, it is possible to achieve the effect of ensuring sufficient structural rigidity (which resists circumferential stress applied to the cylindrical portion of the pressure vessel in the circumferential direction) and reducing the amount of carbon fiber composite material used.

[0020] According to an exemplary embodiment of this disclosure, the first annular layer may be configured to have a first thickness, and the second annular layer may be configured to have a second thickness less than the first thickness.

[0021] Specifically, the second thickness of the second annular layer can be half or less of the first thickness.

[0022] According to an exemplary embodiment of this 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.

[0023] Specifically, the center of the first annular layer may correspond to the center of the cylindrical portion, and 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.

[0024] This is derived from the fact that the circumferential stress applied to the central region of the cylindrical portion (the section forming the first annular layer) is the highest, and the circumferential stress applied to the two edge regions of the cylindrical portion (the sections forming the second annular layer) gradually decreases as the distance from the side portion decreases.

[0025] In the exemplary embodiment of this disclosure as described above, the thickness of the first annular layer formed in the section where relatively high circumferential stress is applied (in the central region of the circumferential stress concentration of the cylindrical portion) is large, while the thickness of the second annular layer formed in the section where relatively low circumferential stress is applied (in the edge region of the cylindrical portion) is small. Therefore, sufficient structural rigidity to resist the circumferential stress applied to the cylindrical portion can be ensured, and the amount of carbon fiber composite material used to form the second annular layer can be reduced to achieve the reduction in the thickness of the second annular layer. Thus, the advantageous effects of reducing the weight of the pressure vessel and lowering manufacturing costs can be obtained.

[0026] The structure of the first and second annular layers can be modified in various ways according to the required conditions and design specifications.

[0027] According to an exemplary embodiment of this disclosure, the first annular layer may include an inner annular layer configured to surround the outer peripheral surface of the cylindrical portion and an outer annular layer configured to surround the outer surface of the inner annular layer.

[0028] According to an exemplary embodiment of the present disclosure, the second annular layer may include a first winding layer wound around the outer peripheral surface of the cylindrical portion and a second winding layer wound around the outer peripheral surface of the cylindrical portion to define the same layer as the first winding layer.

[0029] According to an exemplary embodiment of this disclosure, the first annular layer can be provided by winding a carbon fiber composite material at a first winding angle, and the second annular layer can be provided by winding a carbon fiber composite material at a second winding angle different from the first winding angle.

[0030] Specifically, the second winding angle can be defined as an angle smaller than the first winding angle. For example, the first winding angle can be between 89° and 91°, and the second winding angle can be greater than 85° and less than 89°.

[0031] As described above, since the second winding angle is smaller than the first winding angle, a predetermined space (the section of the unwound carbon fiber composite material) between adjacent first winding layers can be ensured during the first winding process (first winding process), and during the second winding process (second winding process), the second winding layer is wound in the space between adjacent first winding layers, so that the first winding layer and the second winding layer can be in close contact with each other and are arranged alternately in the longitudinal direction of the cylindrical portion when defining the same layer.

[0032] According to another exemplary embodiment of this disclosure, the first winding layer and the second winding layer may be arranged to be spaced apart from each other in the longitudinal direction of the cylindrical portion.

[0033] According to an exemplary embodiment of the present disclosure, a pressure vessel may include a 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.

[0034] Another exemplary embodiment of this disclosure provides a method for manufacturing a pressure vessel, the method comprising: a preparation step of providing a liner including a cylindrical portion and side portions disposed at both ends of the cylindrical portion and each having a dome shape; 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 other portions surrounding the outer peripheral surface of the cylindrical portion, each second annular layer having a smaller thickness than the first annular layer.

[0035] According to an exemplary embodiment of the present disclosure, in the first annular layer forming step, the first annular layer may be configured to surround the central region of the cylindrical portion, and in the second annular layer forming step, the 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.

[0036] Specifically, the center of the first annular layer may correspond to the center of the cylindrical portion, and 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.

[0037] According to an exemplary embodiment of the present disclosure, a first annular layer can be provided by winding a carbon fiber composite material at a first winding angle in a first annular layer forming step, and a second annular layer can be provided by winding a carbon fiber composite material at a second winding angle smaller than the first winding angle in a second annular layer forming step.

[0038] According to an exemplary embodiment of the present disclosure, the first annular layer forming step may include: an inner annular layer forming step, forming an inner annular layer around the outer peripheral surface of the cylindrical portion, and an outer annular layer forming step, forming an outer annular layer around the outer surface of the inner annular layer; and the second annular layer forming step may include: a first winding layer forming step, winding a first winding layer around the outer peripheral surface of the cylindrical portion, and a second winding layer forming step, winding a second winding layer around the outer peripheral surface of the cylindrical portion to define a layer identical to the first winding layer, wherein the inner annular layer and the first winding layer may be formed first, and then the outer annular layer and the second winding layer may be formed.

[0039] According to an exemplary embodiment of the present disclosure, a method of manufacturing a pressure vessel may include a spiral layer forming step, forming a 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. Attached Figure Description

[0040] Figure 1 This is a block diagram illustrating a method for manufacturing a pressure vessel according to an exemplary embodiment of the present disclosure.

[0041] Figure 2 This is a block diagram illustrating a first annular layer forming step and a second annular layer forming step in a method for manufacturing a pressure vessel according to an exemplary embodiment of the present disclosure.

[0042] Figure 3 This is a top plan view illustrating the inner annular layer and the first winding layer of a pressure vessel according to an exemplary embodiment of the present disclosure.

[0043] Figure 4 This is a cross-sectional view illustrating the inner annular layer and the first winding layer of a pressure vessel according to an exemplary embodiment of the present disclosure.

[0044] Figure 5 This is a top plan view illustrating the outer annular layer and the second winding layer of a pressure vessel according to an exemplary embodiment of the present disclosure.

[0045] Figure 6 This is a cross-sectional view illustrating the outer annular layer and the second winding layer of a pressure vessel according to an exemplary embodiment of the present disclosure.

[0046] Figure 7 This is a view used to illustrate the spiral layers of a pressure vessel according to an exemplary embodiment of the present disclosure.

[0047] Figure 8 This is a view used to illustrate the circumferential stress applied to a cylindrical portion of a pressure vessel according to an exemplary embodiment of the present disclosure.

[0048] Figures 9 to 12 This is a view illustrating an improved example of a first annular layer forming step and a second annular layer forming step in a method for manufacturing a pressure vessel according to an exemplary embodiment of the present disclosure.

[0049] Figures 13 to 16 This is a view used to illustrate an example of a carbon fiber layer stack in a pressure vessel according to an exemplary embodiment of the present disclosure.

[0050] Figures 17 to 20 This is a view illustrating another example of a carbon fiber layer stack in a pressure vessel according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0051] Various embodiments of this disclosure will be described in detail below with reference to the accompanying drawings.

[0052] However, the spirit of this disclosure is not limited to the exemplary 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 exemplary embodiments may be selectively combined and substituted.

[0053] Furthermore, unless otherwise specifically and explicitly defined and stated, the terms (including technical and scientific terms) used in the exemplary embodiments of this disclosure are to be interpreted as having a meaning that would be commonly 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) can be interpreted in light of the contextual meaning of related technologies.

[0054] Furthermore, the terminology used in the exemplary embodiments of this disclosure is for illustrative purposes and not for limiting the scope of this disclosure.

[0055] Unless otherwise specified in the context of this specification, the singular form may also include the plural form. The description of "at least one (or one or more) of A, B, and C" as used herein may include one or more combinations that can be obtained by combining A, B, and C.

[0056] Additionally, terms such as first, second, A, B, (a), and (b) may be used to describe constituent elements of exemplary embodiments of this disclosure.

[0057] These terms are used only for the purpose of distinguishing one component from another, and the nature, sequence, or order of the components are not limited by these terms.

[0058] 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 through another component in between.

[0059] Furthermore, the statement that "one component is formed or arranged 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 additional components are formed or arranged between the two components. Additionally, the statement that "upward or downward" can include both downward and upward directions based on a single component.

[0060] refer to Figures 1 to 12 A method for manufacturing a pressure vessel according to an exemplary embodiment of the present disclosure includes: a preparation step S10, providing a liner 100, the liner including a cylindrical portion 110 and side portions 120, the side portions being disposed at both ends of the cylindrical portion 110 and each having a dome shape; a first annular layer forming step S20, 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 S30, forming a second annular layer 400, the second annular layer surrounding other portions of the outer peripheral surface of the cylindrical portion 110 and each having a smaller thickness than the first annular layer 300.

[0061] For reference, the pressure vessel 10 according to an exemplary embodiment of the present disclosure can be used to store high-pressure fluids (liquid or gas), and the present disclosure is not limited or restricted by the type and properties of the fluid stored in the pressure vessel 10.

[0062] In the following description, the construction of the pressure vessel 10 according to an exemplary embodiment of the present disclosure as a hydrogen tank used in a hydrogen storage system for a hydrogen vehicle will be described as an example.

[0063] Step 1:

[0064] First, a liner 100 including a columnar portion 110 and a side portion 120 is provided (step S10).

[0065] In preparation step S10, a liner 100 is provided, in which a dome-shaped side portion 120 is integrally formed at both ends of the columnar portion 110.

[0066] The liner 100 has a hollow structure with a storage space inside, and high-pressure compressed hydrogen can be stored in the storage space.

[0067] The material of the liner 100 can be varied according to the required conditions and design specifications, and this disclosure is not limited to or restricted by the material of the liner 100. Specifically, the liner 100 can be made of non-metallic materials, such as high-density plastics with excellent resilience and excellent fatigue resistance.

[0068] More specifically, the liner 100 includes a cylindrical portion 110 having a hollow cylindrical shape and dome-shaped side portions 120 integrally formed at both ends of the cylindrical portion 110.

[0069] Step 2:

[0070] Next, the first annular layer 300 is formed as part of the outer peripheral surface of the cylindrical portion 110 (step S20).

[0071] In the first annular layer forming step (step S20), the first annular layer 300 can be formed by winding a carbon fiber composite material (which is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.) onto the outer surface (outer peripheral surface) of the columnar portion 110 using a typical winding device.

[0072] For reference, in an exemplary embodiment of this disclosure, the first annular layer 300 may be defined as a layer for resisting stresses (e.g., maximum circumferential stress) applied primarily in the circumferential direction among the types of stresses applied to the cylindrical portion 110 (ensuring structural rigidity).

[0073] For example, a first annular layer 300 can 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) θ1 relative to the axis of the cylindrical portion 110 at a winding angle of 89° to 91°.

[0074] For example, carbon fiber composite material can be wound onto the outer surface of the cylindrical portion 110 using a winding jig (not shown). The winding angle of the carbon fiber composite material relative to the cylindrical portion 110 can be changed by adjusting the angle (or orientation) of the winding jig relative to the cylindrical portion 110.

[0075] Specifically, in the first annular layer forming step (step S20), the first annular layer 300 can be formed to have a first thickness that can resist the maximum circumferential stress applied to the cylindrical portion 110. The first thickness of the first annular layer 300 can be varied according to the required conditions and design specifications (e.g., the structure and dimensions of the pressure vessel).

[0076] Step 3:

[0077] Next, the second annular layer 400 is formed as the other portion surrounding the outer peripheral surface of the cylindrical portion 110 (step S30).

[0078] In the second annular layer forming step S30, the second annular layer 400 can be formed by winding a carbon fiber composite material (which is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.) onto the outer surface (outer peripheral surface) of the columnar portion 110 using a typical winding device.

[0079] For reference, in an exemplary embodiment of this disclosure, the second annular layer 400 may be defined as a layer for resisting stresses (circumferential stresses) of the type of stresses applied to the columnar portion 110 that are primarily applied in the circumferential direction (ensuring structural rigidity).

[0080] For example, a second annular layer 400 can be formed by winding carbon fiber composite material onto the outer surface of the cylindrical portion 110 at a winding angle (second winding angle) θ2 of 85° to 89° relative to the axis of the cylindrical portion 110.

[0081] Specifically, in the second annular layer forming step S30, the second annular layer 400 can be formed to have a second thickness that is less than the first thickness of the first annular layer 300. More specifically, the second thickness of the second annular layer 400 can be defined as half or less of the first thickness (the thickness of the first annular layer).

[0082] According to an exemplary embodiment of the present disclosure, in the first annular layer forming step (step S20), the first annular layer 300 is configured to surround the central region of the cylindrical portion 110, and in the second annular layer forming step (step S30), the second annular layer 400 is configured to surround the two edge regions of the cylindrical portion 110, and the first annular layer 300 is located between the second annular layers.

[0083] 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.

[0084] 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 is a problem of increased use of carbon fiber composite material and deterioration of the hydrogen weight efficiency (wt%) of the pressure vessel. 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.

[0085] 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.

[0086] [Equation 1]

[0087] L1 = L / 2

[0088] (In this case, L is the length of the cylindrical portion 110.)

[0089] In addition, the length L2 of the second annular layer 400 is defined by the following equation 2.

[0090] [Equation 2]

[0091] L2 = L / 4

[0092] (In this case, L is the length of the cylindrical portion 110.)

[0093] This is derived from the fact that the circumferential stress applied to the central region of the cylindrical portion 110 (the section forming the first annular layer) is the highest, and the circumferential stress applied to the two edge regions of the cylindrical portion 110 (the sections forming the second annular layer) gradually decreases as the distance from the side portion 120 decreases.

[0094] The stress (circumferential stress) applied to the cylindrical portion 110 is not uniform across the entire section of the cylindrical portion 110.

[0095] That is, reference Figure 8 It can be determined that the stress (circumferential stress) applied to the cylindrical portion 110 is higher in the central region of the cylindrical portion 110 (the region at a distance of 0.00 to 0.50 meters from the center C of the cylindrical portion), and the stress (circumferential stress) applied to the cylindrical portion 110 gradually decreases in the edge region of the cylindrical portion 110 (the region at a distance of 0.50 to 1.00 meters from the center of the cylindrical portion) as the distance from the side portion 120 decreases.

[0096] 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 to 0.50 meters 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 to 1.00 meters from the center of the cylindrical portion).

[0097] In the exemplary embodiment of this disclosure as described above, the first annular layer 300 formed in the section where relatively high circumferential stress is applied (in the central region of the circumferential stress concentration of the cylindrical portion) has a large thickness, while the second annular layer 400 formed in the section where relatively low circumferential stress is applied (in the edge region of the cylindrical portion) has a small thickness. Therefore, sufficient structural rigidity to resist the circumferential stress applied to the cylindrical portion 110 can be ensured, and the amount of carbon fiber composite material used to form the second annular layer 400 can be reduced, achieving the desired reduction in the thickness of the second annular layer 400. Thus, the advantageous effects of reducing the weight of the pressure vessel 10 and lowering manufacturing costs can be achieved.

[0098] For reference, in the exemplary embodiments of this disclosure, various changes may be made to the order and method of forming the first annular layer 300 and the second annular layer 400 according to the required conditions and design specifications, and this disclosure is not limited or restricted to the order and method of forming the first annular layer 300 and the second annular layer 400.

[0099] 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.

[0100] As another example, the first annular layer 300 and the second annular layer 400 can be formed continuously through a single winding process. For example, a portion of the second annular layer 400 can be formed continuously during the first winding process while a portion of the first annular layer 300 is being formed, and another portion of the second annular layer 400 can be formed continuously during the second winding process while another portion of the first annular layer 300 is being formed.

[0101] refer to Figure 2 According to an exemplary embodiment of this disclosure, the first annular layer forming step S20 may include an inner annular layer forming step S22 of forming an inner annular layer 310 surrounding the outer peripheral surface of the cylindrical portion 110, and an outer annular layer forming step S24 of forming an outer annular layer 320 surrounding the outer surface of the inner annular layer 310. Additionally, the second annular layer forming step S30 may include a first winding layer forming step S32 of winding a first winding layer 410 around the outer peripheral surface of the cylindrical portion 110, and a second winding layer forming step S34 of winding a second winding layer 420 around the outer peripheral surface of the cylindrical portion 110 to define a layer identical to the first winding layer 410.

[0102] Specifically, an inner annular layer 310 and a first winding layer 410 can be formed first, and then an outer annular layer 320 and a second winding layer 420 can be formed.

[0103] More specifically, see reference Figure 3 and Figure 4 In the first winding process (one winding process), the inner annular layer 310 may be formed in the central region of the cylindrical portion 110, and the first winding layer 410 may be formed in the two edge regions of the cylindrical portion 110.

[0104] In this case, the inner annular layer 310 can form part of the first annular layer 300, and the first winding layer 410 can form part of the second annular layer 400.

[0105] Next, refer to Figure 5 and Figure 6 In the second winding process (secondary winding process), the outer annular layer 320 can be formed to surround the outer surface of the inner annular layer 310, and the second winding layer 420 can be formed to define the same layer as the first winding layer 410.

[0106] The outer annular layer 320 and the inner annular layer 310 together can form the first annular layer 300, and the second winding layer 420 and the first winding layer 410 together can form the second annular layer 400.

[0107] Specifically, the outer annular layer 320 and the inner annular layer 310 constituting the first annular layer 300 can be formed by winding the carbon fiber composite material at a first winding angle θ1, and the first winding layer 410 and the second winding layer 420 constituting the second annular layer 400 can be formed by winding the carbon fiber composite material at a second winding angle θ2 different from the first winding angle θ1.

[0108] For example, the second winding angle θ2 is defined as an angle smaller than the first winding angle θ1. For example, the first winding angle θ1 is 89° to 91°, and the second winding angle θ2 is greater than 85° and less than 89°.

[0109] As described above, since the second winding angle θ2 is smaller than the first winding angle θ1, a predetermined space (the section of unwound carbon fiber composite material) between adjacent first winding layers 410 can be ensured during the first winding process (first winding process), and during the second winding process (second winding process), the second winding layer 420 is wound in the space between adjacent first winding layers 410, so that the first winding layer 410 and the second winding layer 420 can be in close contact with each other and are alternately arranged in the longitudinal direction of the columnar portion 110 when defining the same layer.

[0110] In the exemplary embodiments of the present disclosure described and illustrated above, an example has been described of forming a first annular layer 300 having a two-layer structure comprising two annular layers (e.g., an inner annular layer and an outer annular layer) in the inner annular layer forming step (step S22). However, according to another exemplary embodiment of the present disclosure, the first annular layer can be formed by stacking three or more annular layers.

[0111] In the exemplary embodiments of the present disclosure described and illustrated above, examples have been described of the first winding layer 410 and the second winding layer 420 being in close contact with each other to define the same layer. However, according to another exemplary embodiment of the present disclosure, the first winding layer and the second winding layer may be arranged to be spaced apart from each other in the longitudinal direction of the cylindrical portion.

[0112] For example, refer to Figures 9 to 12 By changing the second winding angle, the size of the space formed between adjacent first winding layers 410 can be adjusted (e.g., the size of the space can be increased). The first winding layer 410 and the second winding layer 420 can be spaced apart from each other and arranged alternately in the longitudinal direction of the cylindrical portion 110 when defining the same layer.

[0113] Step 4:

[0114] refer to Figure 1 and Figure 7 According to an exemplary embodiment of the present disclosure, a method for manufacturing a pressure vessel may include a spiral layer forming step S40 of forming a spiral layer 500 surrounding the outer surface of a first annular layer 300, the outer surface of a second annular layer 400, and the outer surface of a side portion 120.

[0115] In the spiral layer forming step S40, the spiral layer 500 can be formed by winding a carbon fiber composite material (which is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.) 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 typical winding device.

[0116] For reference, in an exemplary embodiment of this disclosure, the spiral layer 500 may be defined as a layer for resisting stresses and torsion (ensuring structural rigidity) primarily applied in the longitudinal direction among the types of stresses applied to the columnar portion 110.

[0117] For example, the helical layer 500 can be formed by winding the 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 limited or restricted by the winding pattern of the carbon fiber composite material used to form the helical layer 500 (e.g., clockwise winding, counterclockwise winding, oblique winding, etc.).

[0118] In the following, a pressure vessel 10 manufactured by a method of manufacturing a pressure vessel according to an exemplary embodiment of the present disclosure will be described.

[0119] refer to Figure 7 According to an exemplary embodiment of the present disclosure, a pressure vessel 10 includes: a liner 100, the liner including a cylindrical portion 110 and side portions 120, the side portions being disposed at both ends of the cylindrical portion 110 and each having a dome shape; and a carbon fiber layer 200, the carbon fiber layer including a first annular layer 300, the first annular layer being disposed around a portion of the outer peripheral surface of the cylindrical portion 110; and a second annular layer 400, the second annular layer being disposed around the other portion of the outer peripheral surface of the cylindrical portion 110 and each having a thickness different from the thickness of the first annular layer 300.

[0120] The liner 100 includes a cylindrical portion 110 having a hollow cylindrical shape and dome-shaped side portions 120 integrally formed at both ends of the cylindrical portion 110.

[0121] The liner 100 has a hollow structure with a storage space inside, and high-pressure compressed hydrogen can be stored in the storage space.

[0122] The material of the liner 100 can be varied according to the required conditions and design specifications, and this disclosure is not limited to or restricted by the material of the liner 100. Specifically, the liner 100 can be made of non-metallic materials, such as high-density plastics with excellent resilience and excellent fatigue resistance.

[0123] The first annular layer 300 is configured as part of the outer peripheral surface surrounding the cylindrical portion 110.

[0124] For reference, in an exemplary embodiment of this disclosure, the first annular layer 300 may be defined as a layer for resisting stresses (e.g., maximum circumferential stress) applied primarily in the circumferential direction among the types of stresses applied to the cylindrical portion 110 (ensuring structural rigidity).

[0125] The first annular layer 300 can be formed by winding a carbon fiber composite material (made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.) onto the outer surface (outer peripheral surface) of the cylindrical portion 110 using a typical winding device.

[0126] For example, a first annular layer 300 can 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.

[0127] Specifically, the first annular layer 300 can be formed to have a first thickness that can resist the maximum circumferential stress applied to the cylindrical portion 110. The first thickness of the first annular layer 300 can be varied according to the required conditions and design specifications (e.g., the structure and dimensions of the pressure vessel 10).

[0128] The second annular layer 400 is configured to surround the other parts of the outer periphery of the cylindrical portion 110.

[0129] For reference, in an exemplary embodiment of this disclosure, the second annular layer 400 may be defined as a layer for resisting stresses (circumferential stresses) of the type of stresses applied to the columnar portion 110 that are primarily applied in the circumferential direction (ensuring structural rigidity).

[0130] The second annular layer 400 can be formed by winding a carbon fiber composite material (made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.) onto the outer surface (outer peripheral surface) of the cylindrical portion 110 using a typical winding device.

[0131] For example, a 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 (second winding angle) of 85° to 89° relative to the axis of the cylindrical portion 110.

[0132] Specifically, the second annular layer 400 may be formed to have a second thickness that is less than the first thickness of the first annular layer 300. More specifically, the second thickness of the second annular layer 400 may be defined as half or less of the first thickness (the thickness of the first annular layer).

[0133] According to an exemplary 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 located between the second annular layers.

[0134] 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.

[0135] 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.

[0136] [Equation 1]

[0137] L1 = L / 2

[0138] (In this case, L is the length of the cylindrical portion 110.)

[0139] In addition, the length L2 of the second annular layer 400 is defined by the following equation 2.

[0140] [Equation 2]

[0141] L2 = L / 4

[0142] (In this case, L is the length of the cylindrical portion 110.)

[0143] This is derived from the fact that the circumferential stress applied to the central region of the cylindrical portion 110 (the section forming the first annular layer) is the highest, and the circumferential stress applied to the two edge regions of the cylindrical portion 110 (the sections forming the second annular layer 400) gradually decreases as the distance from the side portion 120 decreases.

[0144] The stress (circumferential stress) applied to the cylindrical portion 110 is not uniform across the entire section of the cylindrical portion 110.

[0145] That is, reference Figure 8 It can be determined that the stress (circumferential stress) applied to the cylindrical portion 110 is higher in the central region of the cylindrical portion 110 (the region at a distance of 0.00 to 0.50 meters from the center of the cylindrical portion), and the stress (circumferential stress) applied to the cylindrical portion 110 gradually decreases in the edge region of the cylindrical portion 110 (the region at a distance of 0.50 to 1.00 meters from the center of the cylindrical portion) as the distance from the side portion 120 decreases.

[0146] 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 to 0.50 meters 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 to 1.00 meters from the center of the cylindrical portion).

[0147] In the exemplary embodiment of this disclosure as described above, the first annular layer 300 formed in the section where relatively high circumferential stress is applied (in the central region of the circumferential stress concentration of the cylindrical portion) has a large thickness, while the second annular layer 400 formed in the section where relatively low circumferential stress is applied (in the edge region of the cylindrical portion) has a small thickness. Therefore, sufficient structural rigidity to resist the circumferential stress applied to the cylindrical portion 110 can be ensured, and the amount of carbon fiber composite material used to form the second annular layer 400 can be reduced, achieving the desired reduction in the thickness of the second annular layer 400. Thus, the advantageous effects of reducing the weight of the pressure vessel 10 and lowering manufacturing costs can be achieved.

[0148] For reference, in exemplary embodiments of this disclosure, various changes may be made to the order and method of forming the first annular layer 300 and the second annular layer 400 according to desired conditions and design specifications, and this disclosure is not limited or restricted to the order and method of forming the first annular layer 300 and the second annular layer 400.

[0149] For example, the first annular layer 300 may include an inner annular layer 310 configured to surround the outer peripheral surface of the cylindrical portion 110 and an outer annular layer 320 configured to surround the outer surface of the inner annular layer 310. The second annular layer 400 may include a first winding layer 410 wound around the outer peripheral surface of the cylindrical portion 110 and a second winding layer 420 wound around the outer peripheral surface of the cylindrical portion 110 to define the same layer as the first winding layer 410.

[0150] For example, the inner annular layer 310 and the first winding layer 410 may be formed first on the outer surface of the cylindrical portion 110. In this case, the inner annular layer 310 may form part of the first annular layer 300, and the first winding layer 410 may form part of the second annular layer 400.

[0151] Subsequently, an outer annular layer 320 may be formed on the outer surface of the inner annular layer 310, and a second winding layer 420 may be formed on the outer surface of the cylindrical portion 110 (e.g., in the space between the first winding layers 410). The outer annular layer 320 together with the inner annular layer 310 may form a first annular layer 300, and the second winding layer 420 together with the first winding layer 410 may form a second annular layer 400.

[0152] Specifically, the outer annular layer 320 and the inner annular layer 310 constituting the first annular layer 300 can be formed by winding the carbon fiber composite material at a first winding angle θ1, and the first winding layer 410 and the second winding layer 420 constituting the second annular layer 400 can be formed by winding the carbon fiber composite material at a second winding angle θ2 different from the first winding angle.

[0153] For example, the second winding angle θ2 is defined as an angle smaller than the first winding angle θ1. For example, the first winding angle θ1 is 89° to 91°, and the second winding angle θ2 is greater than 85° and less than 89°.

[0154] As described above, since the second winding angle θ2 is smaller than the first winding angle θ1, a predetermined space (the section of the unwound carbon fiber composite material) between adjacent first winding layers 410 can be ensured during the first winding process (first winding process), and during the second winding process (second winding process), the second winding layer 420 is wound in the space between adjacent first winding layers 410, so that the first winding layer 410 and the second winding layer 420 can be in close contact with each other and are arranged alternately in the longitudinal direction of the columnar portion 110 when defining the same layer.

[0155] In the exemplary embodiments of the present disclosure described and illustrated above, examples have been described of the first winding layer 410 and the second winding layer 420 being in close contact with each other to define the same layer. However, according to another exemplary embodiment of the present disclosure, the first winding layer and the second winding layer may be arranged to be spaced apart from each other in the longitudinal direction of the cylindrical portion.

[0156] For example, refer to Figures 9 to 12 By changing the second winding angle, the size of the space formed between adjacent first winding layers 410 can be adjusted (e.g., the size of the space can be increased). The first winding layer 410 and the second winding layer 420 can be spaced apart from each other and arranged alternately in the longitudinal direction of the cylindrical portion 110 when defining the same layer.

[0157] According to an exemplary embodiment of the present invention, the pressure vessel 10 may include a spiral layer 500, which surrounds 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.

[0158] For reference, in an exemplary embodiment of this disclosure, the spiral layer 500 may be defined as a layer for resisting stresses and torsion (ensuring structural rigidity) primarily applied in the longitudinal direction among the types of stresses applied to the columnar portion 110.

[0159] The spiral layer 500 can be formed by winding a carbon fiber composite material (which is made by impregnating carbon fibers with epoxy resin, thermosetting resin, etc.) onto 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 typical winding device.

[0160] For example, a spiral layer 500 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.

[0161] Meanwhile, the carbon fiber layer 200 (first annular layer, second annular layer and spiral layer) wrapped around the outer surface of the liner 100 can be cured by a subsequent heat treatment process.

[0162] In the exemplary embodiments of the present disclosure described and illustrated above, examples of pressure vessels comprising a single carbon fiber layer including a first annular layer, a second annular layer, and a helical layer have been described. However, according to another exemplary embodiment of the present disclosure, a pressure vessel may comprise multiple carbon fiber layers.

[0163] For example, refer to Figure 13 The pressure vessel 10 includes a liner 100 and a carbon fiber layer 200. The liner includes a cylindrical portion 110 and dome-shaped side portions 120, with the side portions located at both ends of the cylindrical portion 110. The carbon fiber layer includes: a first annular layer 300 configured to surround a portion of the outer peripheral surface of the cylindrical portion 110; a second annular layer 400 configured to surround the remaining portion of the outer peripheral surface of the cylindrical portion 110 and having a thickness different from that of the first annular layer 300; and a spiral layer 500 configured to surround 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 portions 120. Furthermore, multiple carbon fiber layers 200 can be stacked (in the radial direction of the liner).

[0164] The number of stacked carbon fiber layers 200 can be varied according to the required conditions and design specifications, and this disclosure is not limited or restricted by the number of stacked carbon fiber layers 200.

[0165] In the following description, an example of three carbon fiber layers 200 stacked on the outer surface of the liner 100 will be described. According to another exemplary embodiment of this disclosure, two carbon fiber layers may be stacked on the outer surface of the liner, or four or more carbon fiber layers may be stacked on the outer surface of the liner.

[0166] For reference, in the exemplary embodiments of the present disclosure described and illustrated above, an example of forming a second annular layer through two winding processes has been described. However, according to another exemplary embodiment of the present disclosure, the second annular layer can be formed through a single winding process.

[0167] That is, reference Figure 14 According to an exemplary embodiment of the present disclosure, in the first winding process (one winding process), an inner annular layer 310 (a part of the first annular layer) may be formed in the central region of the cylindrical portion 110, and a second annular layer 400 (e.g., a structure including both the first winding layer and the second winding layer) may be formed in the two edge regions of the cylindrical portion 110.

[0168] Next, refer to Figure 15 In the second winding process (secondary winding process), the outer annular layer 320 (another part of the first annular layer) can be formed in the central region of the columnar portion 110.

[0169] Subsequently, as Figure 16 As shown, in the third winding process (third winding process), the spiral layer 500 can be formed on 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.

[0170] In the manner described above, by repeating the execution Figures 14 to 16 The first winding process, the second winding process and the third winding process shown can be used to stack multiple carbon fiber layers 200 on the outer surface of the liner 100.

[0171] Furthermore, in the exemplary embodiments described and illustrated above, an example of forming an inner annular layer and a second annular layer followed by forming an outer annular layer has been described. However, according to another exemplary embodiment of this disclosure, it is possible to first form only the inner annular layer, and then form the outer annular layer and the second annular layer.

[0172] That is, reference Figure 17 According to an exemplary embodiment of the present disclosure, in the first winding process (one winding process), the inner annular layer 310 (a part of the first annular layer) may first be formed in the central region of the columnar portion 110.

[0173] Next, refer to Figure 18 In the second winding process (secondary winding process), the outer annular layer 320 (another part of the first annular layer) may be formed in the central region of the cylindrical portion 110, and the second annular layer 400 (e.g., a structure including both the first winding layer and the second winding layer) may be formed in the two edge regions of the cylindrical portion 110.

[0174] Subsequently, as Figure 19 As shown, in the third winding process (third winding process), the spiral layer 500 can be formed on 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.

[0175] In this manner as described above, such as Figure 20 As shown, multiple carbon fiber layers 200, including a first annular layer 300', a second annular layer 400, and a spiral layer 500, can be repeatedly processed. Figures 17 to 19 The first winding process, the second winding process and the third winding process shown in the figure are stacked on the outer surface of the liner 100.

[0176] According to the exemplary embodiments of this disclosure as described above, advantageous effects can be obtained in ensuring structural rigidity and improving stability and reliability.

[0177] Specifically, according to exemplary embodiments of this disclosure, the advantageous effects of ensuring the structural rigidity of the pressure vessel and minimizing the amount of carbon fiber composite material used can be obtained.

[0178] Furthermore, according to exemplary embodiments of this disclosure, the advantageous effects of reducing the weight of the pressure vessel and lowering manufacturing costs can be achieved.

[0179] Furthermore, according to the exemplary embodiments of this disclosure, the beneficial effects of simplifying the manufacturing process and improving manufacturing efficiency can be obtained.

[0180] While exemplary embodiments have been described above, they are merely illustrative and not intended to limit this disclosure. Those skilled in the art will understand that various modifications and changes not described above can be made to these exemplary embodiments without departing from their inherent characteristics. For example, the individual components specifically described in the exemplary embodiments can be modified and then performed. Furthermore, it should be understood that differences related to modifications and substitutions are included within the scope of this disclosure as defined by the appended claims.

Claims

1. A pressure vessel, comprising: The lining includes a cylindrical portion and side portions disposed at both ends of the cylindrical portion, each of the side portions having a dome shape; as well as The carbon fiber layer includes: a first annular layer surrounding a portion of the outer peripheral surface of the cylindrical portion; and a second annular layer surrounding the remaining portion of the outer peripheral surface of the cylindrical portion, each of the second annular layers having a thickness less than that of the first annular layer; the second annular layer includes a first edge annular layer and a second edge annular layer, the first edge annular layer surrounding a first edge region of the outer peripheral surface of the cylindrical portion; and the second edge annular layer surrounding a second edge region of the outer peripheral surface of the cylindrical portion. Each of the first and second edge annular layers comprises: a first winding layer wound around the outer peripheral surface of the cylindrical portion, the first winding layer having the thickness of each of the first and second edge annular layers; and a second winding layer wound around the outer peripheral surface of the cylindrical portion, the second winding layer having the thickness of each of the first and second edge annular layers. 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 layers. The second annular layer occupies the entire area between the first annular layer and the side portion, and the second annular layer has a constant thickness overall in both edge regions.

2. The pressure vessel according to claim 1, wherein, The first annular layer has a first thickness, each of the second annular layers has a second thickness, and wherein the second thickness is half or less of the first thickness.

3. The pressure vessel according to claim 1, wherein, The center of the first annular layer corresponds to the center of the cylindrical portion, and the length of the first annular layer is 40% to 60% of the length of the cylindrical portion.

4. The pressure vessel according to claim 1, wherein, The length of each of the second annular layers is 20% to 30% of the length of the cylindrical portion.

5. The pressure vessel according to claim 1, wherein, The first annular layer is provided by winding the carbon fiber composite material at a first winding angle, and the second annular layer is provided by winding the carbon fiber composite material at a second winding angle different from the first winding angle.

6. The pressure vessel according to claim 5, wherein, The second winding angle is an angle smaller than the first winding angle.

7. The pressure vessel according to claim 6, wherein, The first winding angle is between 89° and 91°, and the second winding angle is greater than 85° and less than 89°.

8. The pressure vessel according to claim 1, wherein, The carbon fiber layer includes a 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.

9. The pressure vessel according to claim 1, wherein, The first annular layer includes: An inner annular layer, the inner annular layer surrounding the outer peripheral surface of the cylindrical portion; and An outer annular layer surrounds the outer surface of the inner annular layer.

10. The pressure vessel according to claim 1, in, The second annular layer includes: A first winding layer is wound around the outer peripheral surface of the cylindrical portion; and A second winding layer is wound around the outer peripheral surface of the cylindrical portion to define the same layer as the first winding layer.

11. The pressure vessel according to claim 10, wherein, The first winding layer and the second winding layer are arranged alternately in the longitudinal direction of the cylindrical portion.

12. The pressure vessel according to claim 11, wherein, The first winding layer and the second winding layer are spaced apart from each other in the longitudinal direction of the cylindrical portion.

13. A method for manufacturing a pressure vessel, the method comprising: The liner includes a cylindrical portion and side portions disposed at both ends of the cylindrical portion, each side portion having a dome shape; A first annular layer is formed, the first annular layer surrounding a portion of the outer peripheral surface of the cylindrical portion, wherein forming the first annular layer includes forming an inner annular layer surrounding the outer peripheral surface of the cylindrical portion and forming an outer annular layer surrounding the outer surface of the inner annular layer; and A second annular layer is formed, the second annular layer surrounding other portions of the outer peripheral surface of the cylindrical portion, each of the second annular layers having a smaller thickness than the first annular layer, wherein forming the second annular layer includes: winding a first winding layer around the outer peripheral surface of the cylindrical portion; and winding a second winding layer around the outer peripheral surface of the cylindrical portion to define a layer identical to the first winding layer, and wherein the inner annular layer and the first winding layer are formed first, and then the outer annular layer and the second winding layer are formed, 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 layers. Wherein, the second annular layer occupies the entire area between the first annular layer and the side portion, and The second annular layer has a constant thickness in both edge regions.

14. The method according to claim 13, 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 the second annular layer is 20% to 30% of the length of the cylindrical portion.

15. The method according to claim 13, wherein, Forming the first annular layer includes winding a carbon fiber composite material at a first winding angle; and Forming the second annular layer involves winding a carbon fiber composite material at a second winding angle that is smaller than the first winding angle.

16. The method of claim 13, further comprising: A spiral layer is formed, which 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.

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