Method and System for Determining the Filling Pressure of Type IV Vehicle-Mounted Hydrogen Storage Cylinders

Abstract

This invention discloses a method and system for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder, relating to the field of engineering manufacturing technology. The method includes: performing buckling analysis on a three-dimensional finite element model of the cylinder liner to obtain the critical buckling load; calculating the winding tension of each layer of winding fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the fiber winding angle, total thickness of circumferential fibers, total thickness of helical fibers, thickness of a single circumferential winding layer, and thickness of a single helical winding layer; obtaining the remaining tension of the winding fibers when they are wound onto the cylinder liner based on the winding tension; obtaining the external pressure exerted by each layer of winding fibers on the cylinder liner based on the remaining tension and winding tension of each layer of winding fibers; determining the total external pressure value of the winding layers on the cylinder liner based on the external pressure exerted by all layers of winding fibers on the cylinder liner; and determining the filling pressure range based on the total external pressure value of the winding layers on the liner and the critical buckling load. This invention can improve the accuracy of the filling pressure.

Description

Technical Field

[0001] This invention relates to the field of engineering manufacturing technology, and in particular to a method and system for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder. Background Technology

[0002] Type IV vehicle-mounted hydrogen storage cylinders use engineering plastics as the inner liner, which has low rigidity and is more prone to buckling instability. Specifically, during fiber winding in manufacturing, the winding layer exerts radial outward pressure on the inner liner, leading to buckling instability. Currently, a common manufacturing method is to inflate the cylinder liner with gas during fiber winding to prevent buckling instability.

[0003] However, there is currently no specific method for determining the inflation pressure during the fiber winding process of Type IV vehicle-mounted hydrogen storage cylinders. Existing technology obtains the lower limit of the range by the difference between the external pressure applied to the liner by the first fiber layer and the critical load, and the upper limit of the range by the difference between the external pressure applied to the liner by the fiber layer and the critical load after the winding is stable. However, during the winding process, the tension of the outer winding layer on the inner winding layer is weakened. When the weakening effect of the outer winding layer reaches a certain level, the inner winding layer will loosen and lose its pressure on the liner. Furthermore, existing technology ignores the remaining tension of some inner winding layers. When the inner winding layer is wound with two layers of winding, existing technology assumes that the inner winding layer loses its pressure on the liner. However, in actual engineering manufacturing, the inflation pressure changes continuously during each layer winding, making the inflation pressure determined by existing technology inaccurate. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder, which can improve the accuracy of the filling pressure.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A method for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder includes:

[0007] Based on the finite element method, a three-dimensional finite element model of the cylinder lining of a Type IV vehicle-mounted hydrogen storage cylinder was constructed.

[0008] Buckling analysis was performed on the three-dimensional finite element model of the gas cylinder liner to obtain the critical buckling load;

[0009] The fiber winding angle, total thickness of circumferential fibers, total thickness of spiral fibers, thickness of circumferential winding single layer, and thickness of spiral winding single layer of the fiber wound on the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder are calculated based on the winding radius of the fiber wound on the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the expected burst pressure of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the fiber wound on the composite layer, the circumferential fiber failure stress of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral fiber failure stress of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the number of carbon fiber strands of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn in the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral bandwidth of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the circumferential bandwidth of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder.

[0010] The winding tension of each layer of fibers on the Type IV vehicle-mounted hydrogen storage cylinder is calculated based on the fiber winding angle, total thickness of circumferential fibers, total thickness of helical fibers, thickness of a single circumferential winding layer, and thickness of a single helical winding layer; the winding tension is either helical winding tension or circumferential winding tension.

[0011] For any layer of wound fiber, the remaining tension of the wound fiber when it is wound onto the wound fiber is obtained based on the winding tension of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder;

[0012] The external pressure exerted by each layer of winding fiber on the cylinder liner is obtained based on the remaining tension of each layer of winding fiber and the winding tension of each layer of winding fiber.

[0013] The total external pressure value of the winding layer on the liner is determined based on the external pressure exerted by all layers of winding fibers on the cylinder liner;

[0014] The filling pressure range of the Type IV vehicle-mounted hydrogen storage cylinder is determined based on the total external pressure of the winding layer on the liner and the critical buckling load.

[0015] Optionally, the calculation of the fiber winding angle, total circumferential fiber thickness, total spiral fiber thickness, circumferential winding single-layer thickness, and spiral winding single-layer thickness of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder based on the winding radius of the fiber at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the expected burst pressure of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the wound fiber in the composite layer on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential fiber failure stress of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral fiber failure stress of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the number of carbon fiber strands of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn in the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral bandwidth of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, and the circumferential bandwidth of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder specifically includes:

[0016] The fiber winding angle of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder is obtained based on the winding radius of the fiber at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder and the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder.

[0017] The total thickness of the circumferential fibers on the Type IV vehicle-mounted hydrogen storage cylinder is obtained based on the expected burst pressure of the cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the composite layer volume occupied by the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential fiber failure stress of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, and the fiber winding angle of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder.

[0018] The total thickness of the spiral fibers on the Type IV vehicle-mounted hydrogen storage cylinder is obtained based on the expected burst pressure of the cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the composite layer volume occupied by the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral fiber failure stress of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, and the fiber winding angle of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder.

[0019] The thickness of the circumferential winding single layer of the fiber on the Type IV vehicle-mounted hydrogen storage cylinder is obtained based on the number of carbon fiber strands wound on the fiber, the cross-sectional area of ​​each yarn in the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral width of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder in the volume of the composite layer.

[0020] The thickness of the spiral-wound single layer of the fiber on the Type IV vehicle-mounted hydrogen storage cylinder is obtained based on the number of carbon fiber strands wound on the fiber, the cross-sectional area of ​​each yarn in the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential bandwidth of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder in the volume of the composite layer.

[0021] Optionally, obtaining the remaining tension of the winding fiber when it is wound onto the winding fiber based on the winding tension of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder specifically includes:

[0022] According to the formula The remaining tension of the winding fiber when it is wound around the winding fiber is calculated, where σ(x) represents the remaining tension of the winding fiber when it is wound around the winding fiber, T(x) represents the winding tension of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, x represents the ratio of the radius of the winding fiber to the outer diameter of the inner liner when it is wound around the winding fiber, m represents the ratio of the outer diameter of the cylinder to the outer diameter of the inner liner when it is wound around the winding fiber, σ(a) represents the remaining tension of the outer fiber, a represents the integral term with respect to x and m, and H represents the structural influence factor.

[0023] Optionally, determining the filling pressure range of the Type IV vehicle-mounted hydrogen storage cylinder based on the total external pressure value of the winding layer on the liner and the critical buckling load specifically includes:

[0024] According to the formula P≥P c ≥PP cr Determine the filling pressure range for Type IV vehicle-mounted hydrogen storage cylinders, where P represents the total external pressure of the winding layer on the liner. c P indicates the filling pressure of the Type IV vehicle-mounted hydrogen storage cylinder. cr This indicates the critical buckling load.

[0025] A Type IV vehicle-mounted hydrogen storage cylinder filling pressure determination system includes:

[0026] The model building module is used to build a three-dimensional finite element model of the cylinder liner of the Type IV vehicle-mounted hydrogen storage cylinder based on the finite element method.

[0027] The buckling analysis module is used to perform buckling analysis on the three-dimensional finite element model of the gas cylinder liner to obtain the critical buckling load.

[0028] The parameter calculation module is used to calculate the fiber winding angle, total thickness of circumferential fibers, total thickness of spiral fibers, thickness of circumferential winding single layer, and thickness of spiral winding single layer of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder based on the winding radius of the fiber at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the expected burst pressure of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the winding fiber in the composite layer on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential fiber failure stress of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral fiber failure stress of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the number of carbon fiber strands of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn in the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral bandwidth of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, and the circumferential bandwidth of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder.

[0029] The winding tension calculation module is used to calculate the winding tension of each layer of winding fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the fiber winding angle, total thickness of circumferential fibers, total thickness of helical fibers, thickness of a single layer of circumferential winding, and thickness of a single layer of helical winding; the winding tension is helical winding tension or circumferential winding tension;

[0030] The residual tension calculation module is used to calculate the residual tension of the winding fiber when it is wound onto the winding fiber, based on the winding tension of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, for any layer of winding fiber.

[0031] The external pressure calculation module is used to calculate the external pressure exerted by each layer of winding fiber on the gas cylinder liner based on the remaining tension of each layer of winding fiber and the winding tension of each layer of winding fiber.

[0032] The total external pressure calculation module is used to determine the total external pressure value of the winding layer on the cylinder liner based on the external pressure exerted by all layers of winding fibers on the cylinder liner.

[0033] The pressure range determination module is used to determine the filling pressure range of the Type IV vehicle-mounted hydrogen storage cylinder based on the total external pressure value of the winding layer on the liner and the critical buckling load.

[0034] Optionally, the parameter calculation module specifically includes:

[0035] The fiber winding angle calculation unit is used to obtain the fiber winding angle of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder based on the winding radius of the fiber at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder and the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder.

[0036] The total thickness calculation unit for circumferential fibers is used to calculate the total thickness of circumferential fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the expected burst pressure of the cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the composite layer of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential fiber failure stress of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, and the fiber winding angle of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder.

[0037] The total thickness calculation unit for spiral fibers is used to calculate the total thickness of spiral fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the expected burst pressure of the cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the composite layer wound with fibers on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral fiber failure stress of the spiral fibers wound with fibers on the Type IV vehicle-mounted hydrogen storage cylinder, and the fiber winding angle of the spiral fibers wound with fibers on the Type IV vehicle-mounted hydrogen storage cylinder.

[0038] The circumferential winding single-layer thickness calculation unit is used to calculate the circumferential winding single-layer thickness of the fiber on the Type IV vehicle-mounted hydrogen storage cylinder based on the number of carbon fiber strands of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral bandwidth of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder to the volume of the composite layer.

[0039] The spiral winding single-layer thickness calculation unit is used to calculate the spiral winding single-layer thickness of the fiber on the Type IV vehicle-mounted hydrogen storage cylinder based on the number of carbon fiber strands of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn in the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential bandwidth of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder in the volume of the composite layer.

[0040] Optionally, the residual tension calculation module specifically includes:

[0041] The residual tension calculation unit is used to calculate the residual tension according to the formula. The remaining tension of the winding fiber when it is wound around the winding fiber is calculated, where σ(x) represents the remaining tension of the winding fiber when it is wound around the winding fiber, T(x) represents the winding tension of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, x represents the ratio of the radius of the winding fiber to the outer diameter of the inner liner when it is wound around the winding fiber, m represents the ratio of the outer diameter of the cylinder to the outer diameter of the inner liner when it is wound around the winding fiber, σ(a) represents the remaining tension of the outer fiber, a represents the integral term with respect to x and m, and H represents the structural influence factor.

[0042] Optionally, the pressure range determination module specifically includes:

[0043] Pressure range determination unit, used to determine the pressure range based on the formula P≥P c ≥PP cr Determine the filling pressure range for Type IV vehicle-mounted hydrogen storage cylinders, where P represents the total external pressure of the winding layer on the liner. c P indicates the filling pressure of the Type IV vehicle-mounted hydrogen storage cylinder. cr This indicates the critical buckling load.

[0044] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: The present invention performs buckling analysis on a three-dimensional finite element model of the gas cylinder liner to obtain the critical buckling load; calculates the winding tension of each layer of winding fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the fiber winding angle, total thickness of circumferential fibers, total thickness of helical fibers, thickness of a single layer of circumferential winding, and thickness of a single layer of helical winding; obtains the residual tension of the winding fibers when winding to the winding fibers based on the winding tension; obtains the external pressure exerted by each layer of winding fibers on the gas cylinder liner based on the residual tension of each layer of winding fibers and the winding tension of each layer of winding fibers; determines the total external pressure value of the winding layers on the liner based on the external pressure exerted by all layers of winding fibers on the gas cylinder liner; and determines the inflation pressure range based on the total external pressure value of the winding layers on the liner and the critical buckling load, which can determine the selection range of the inflation pressure for each winding, improving the accuracy of the inflation pressure. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 A schematic diagram illustrating a method for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder according to an embodiment of the present invention;

[0047] Figure 2 This is a flowchart illustrating a method for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder, as provided in an embodiment of the present invention. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a method for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder, including:

[0051] Step 101: Based on the finite element method, construct a three-dimensional finite element model of the cylinder lining of the Type IV vehicle-mounted hydrogen storage cylinder.

[0052] Step 102: Perform buckling analysis on the three-dimensional finite element model of the gas cylinder liner to obtain the critical buckling load P. cr .

[0053] Step 103: Based on the winding radius of the fiber at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the expected burst pressure of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the winding fiber on the composite layer, the circumferential fiber failure stress of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the helical fiber failure stress of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the number of carbon fiber strands of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn in the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the helical bandwidth of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, and the circumferential bandwidth of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, calculate the fiber winding angle, total circumferential fiber thickness, total helical fiber thickness, circumferential winding single layer thickness, and helical winding single layer thickness of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder.

[0054] Step 104: Calculate the winding tension of each layer of winding fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the fiber winding angle, total thickness of circumferential fibers, total thickness of helical fibers, thickness of a single layer of circumferential winding, and thickness of a single layer of helical winding; the winding tension is helical winding tension or circumferential winding tension.

[0055] Step 105: For any layer of wound fiber, obtain the remaining tension of the wound fiber when it is wound onto the wound fiber based on the winding tension of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder.

[0056] Step 106: Obtain the external pressure exerted by each layer of winding fiber on the gas cylinder liner based on the remaining tension of each layer of winding fiber and the winding tension of each layer of winding fiber.

[0057] Step 107: Determine the total external pressure value of the winding layer on the liner based on the external pressure exerted by all layers of winding fibers on the cylinder liner.

[0058] Step 108: Determine the filling pressure range of the Type IV vehicle-mounted hydrogen storage cylinder based on the total external pressure value of the winding layer on the liner and the critical buckling load.

[0059] In practical applications, step 103 specifically includes:

[0060] Step 301: Based on the winding radius r of the fiber at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder cThe fiber winding angle θ of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder is obtained by combining the outer diameter R of the cylinder with the outer diameter R of the cylinder.

[0061] Step 301 specifically involves applying the formula θ = arcsin(r) c / R)(1) is obtained.

[0062] Step 302: Based on the expected value P of the burst pressure of the Type IV vehicle-mounted hydrogen storage cylinder. bo The outer diameter R of the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the composite layer volume v of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder. f The circumferential fiber failure stress σ of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder fθ The total circumferential fiber thickness t on the Type IV vehicle-mounted hydrogen storage cylinder is obtained by calculating the fiber winding angle θ of the fibers wound on the cylinder. Gθ .

[0063] Step 302 specifically involves following the formula get.

[0064] Step 303: Based on the expected value P of the burst pressure of the Type IV vehicle-mounted hydrogen storage cylinder. bo The outer diameter R of the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the composite layer volume v of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder. f The failure stress σ of the spiral fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder fα The total thickness t of the spiral fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder is obtained by the fiber winding angle θ of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder. Gα .

[0065] Step 303 specifically involves: according to the formula get.

[0066] Step 304: Based on the number of carbon fiber strands N of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area A' of each strand of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the spiral width b of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder... θw The thickness t of the circumferentially wound single layer of fibers on the Type IV vehicle-mounted hydrogen storage cylinder is obtained by calculating the percentage of the composite layer volume of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder. θ .

[0067] Step 304 specifically involves following the formula

[0068] Step 305: Based on the number of carbon fiber strands wound on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn in the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, and the circumferential bandwidth b of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder... αw The thickness t of the spiral wound single layer of the fiber on the Type IV vehicle-mounted hydrogen storage cylinder is obtained by calculating the percentage of the fiber volume in the composite layer. α .

[0069] Step 305 specifically involves following the formula. get.

[0070] In practical applications, steps 301 to 303 are determined based on existing grid theory analysis.

[0071] In practical applications, step 104 specifically involves:

[0072] When calculating the circumferential winding tension, the circumferential winding tension regime is as follows:

[0073]

[0074] Formula 2

[0075] Equations (6) and (7) are applicable to the cases where the innermost layer is helical winding and the innermost layer is circumferential winding, respectively. Where t o Where is the thickness of the gas cylinder liner, j is the current layer number of the wound fiber, and T is the thickness of the inner liner. θj E represents the winding tension of the j-th layer of wound fiber. G E O The elastic modulus of the fiber and the lining, respectively, T nθ Let T be the circumferential winding tension of the outermost layer, and the same applies to the helical winding tension; let T be the circumferential winding tension of the outermost layer in the helical winding tension. nθ =σ Gi t θ ,in In the formula, μ o The inner bladder Poisson's ratio, σ Gi For optimal fiber prestress, σ G For fiber design strength, σ e For the elastic limit of the lining, σ p It is the critical compressive strength for instability.

[0076] The spiral winding tension regime is as follows:

[0077]

[0078]

[0079] Equations (10) and (11) are applicable to the cases where the innermost layer is helical winding and the innermost layer is circumferential winding, respectively, where T αi Let be the winding tension of the i-th layer.

[0080] In practical applications, an analytical model of a fiber-wound hydrogen storage cylinder is constructed based on elasticity mechanics. This model is used to determine the pressure exerted by the outer winding layer on each layer during winding. Step 105 specifically includes:

[0081] According to the formula Calculate the remaining tension of the winding fiber when it is wound around the winding fiber, where σ(x) represents the remaining tension of the winding fiber when it is wound around the winding fiber, T(x) represents the winding tension of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder obtained by formulas (6)(7)(10)(11), x represents the ratio of the radius of the winding fiber to the outer diameter of the inner liner when it is wound around the winding fiber, m represents the ratio of the outer diameter of the cylinder to the outer diameter of the inner liner when it is wound around the winding fiber, σ(a) represents the remaining tension of the outer fiber, a represents the integral term with respect to x and m, and H represents the structural influence factor.

[0082] Where, m=(R o +h) / R o x = r / R o , In the formula, μ O With μ G R represents the Poisson's ratio of the lining and the fiber layer, respectively. i R o Here, R represents the inner and outer diameters of the inner liner, r represents the outer diameter of the winding layer, h represents the total thickness of the current winding layer, m represents the ratio of the outer diameter of the cylinder after winding to the outer diameter of the inner liner, x represents the ratio of the radius of the current calculated layer to the outer diameter of the inner liner, and H, γ, and η are all influencing factors related to structural and material parameters. For example, assuming that 3 fiber layers are currently wound, the outer diameter of the inner liner is R... o The thickness is 10mm, and the thickness of each layer is 1mm. When calculating the second fiber layer, x = 12 / 10 and m = (10+3) / 10.

[0083] In practical applications, step 106 specifically includes:

[0084] The external pressure exerted by each winding layer on the cylinder liner is obtained from the relationship between winding tension and radial external pressure:

[0085]

[0086] In the formula, T is the equivalent calculated tension of the winding layer, the weakened inner winding layer is the remaining tension calculated by formula (12), and the unweakened outermost winding layer is the initial tension calculated by formulas (6)(7)(10)(11). For circumferential winding with a winding angle of 90°, it can be directly obtained by... The winding angle θ for spiral winding is obtained by equation (1).

[0087] Each time the winding process is completed, the internal winding tension changes. For example, when winding to the second layer, the first layer is weakened by the second layer. The initial tension is obtained through equations (6), (7), (10), and (11), and the remaining tension is obtained through equation (12). Finally, the external pressure of the first layer on the inner liner is obtained through equation (13). The pressure of the second layer is calculated directly using equation (13) based on the initial tension obtained through equations (6), (7), (10), and (11). The choice of equations (6), (7), (10), and (11) depends on the winding method, such as whether the innermost layer is spiral or circumferential, and whether the calculation layer is spiral or circumferential. When winding to the third layer, the remaining tension of the second layer is calculated first. The remaining tension of the second layer is the same as above. The first layer is weakened by the coupling effect of the second and third layers. The calculation method is the same as above, but the weakening effect of the second layer on it needs to be calculated using its remaining tension.

[0088] Step 107 specifically includes: according to the formula calculate

[0089] In the formula, P is the total external pressure of the winding layer on the liner, p hi With p li These represent the circumferential winding pressure and the helical winding pressure of the i-th layer, respectively. hi With p li All of these are external pressures exerted on the cylinder liner by the wound fibers. For example, if the innermost layer is circumferentially wound, followed by alternating winding, the winding pattern is: circumferential, spiral, circumferential, spiral... The external pressure of each layer can be obtained from equation (13). The calculated external pressure of the first layer is p. h1 The calculated external pressure of the second layer is p. l1 And so on.

[0090] In practical applications, the difference between the total external pressure and the critical buckling load of the cylinder liner is the minimum inflation pressure required to prevent instability: P c ≥PP cr According to the grid theory, to ensure its overall performance, the inflation pressure should be less than the external pressure of the fiber winding: P ≥ P c To prevent outward deformation, step 108 specifically includes:

[0091] According to the formula P≥P c ≥PPcr Determine the filling pressure range for Type IV vehicle-mounted hydrogen storage cylinders, where P represents the total external pressure of the winding layer on the liner. c P indicates the filling pressure of the Type IV vehicle-mounted hydrogen storage cylinder. cr This indicates the critical buckling load.

[0092] In accordance with the above method, this invention also provides a Type IV vehicle-mounted hydrogen storage cylinder filling pressure determination system, comprising:

[0093] The model building module is used to build a three-dimensional finite element model of the cylinder liner of the Type IV vehicle-mounted hydrogen storage cylinder based on the finite element method.

[0094] The buckling analysis module is used to perform buckling analysis on the three-dimensional finite element model of the gas cylinder liner to obtain the critical buckling load.

[0095] The parameter calculation module is used to calculate the fiber winding angle, total thickness of circumferential fibers, total thickness of spiral fibers, thickness of circumferential winding single layer, and thickness of spiral winding single layer of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder based on the winding radius of the fiber at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the expected burst pressure of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the winding fiber in the composite layer on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential fiber failure stress of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral fiber failure stress of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the number of carbon fiber strands of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn in the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral bandwidth of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, and the circumferential bandwidth of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder.

[0096] The winding tension calculation module is used to calculate the winding tension of each layer of winding fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the fiber winding angle, total thickness of circumferential fibers, total thickness of helical fibers, thickness of a single layer of circumferential winding, and thickness of a single layer of helical winding; the winding tension is helical winding tension or circumferential winding tension;

[0097] The residual tension calculation module is used to calculate the residual tension of the winding fiber when it is wound onto the winding fiber, based on the winding tension of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, for any layer of winding fiber.

[0098] The external pressure calculation module is used to calculate the external pressure exerted by each layer of winding fiber on the gas cylinder liner based on the remaining tension of each layer of winding fiber and the winding tension of each layer of winding fiber.

[0099] The total external pressure calculation module is used to determine the total external pressure value of the winding layer on the cylinder liner based on the external pressure exerted by all layers of winding fibers on the cylinder liner.

[0100] The pressure range determination module is used to determine the filling pressure range of the Type IV vehicle-mounted hydrogen storage cylinder based on the total external pressure value of the winding layer on the liner and the critical buckling load.

[0101] In practical applications, the parameter calculation module specifically includes:

[0102] The fiber winding angle calculation unit is used to obtain the fiber winding angle of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder based on the winding radius of the fiber at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder and the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder.

[0103] The total thickness calculation unit for circumferential fibers is used to calculate the total thickness of circumferential fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the expected burst pressure of the cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the composite layer of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential fiber failure stress of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, and the fiber winding angle of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder.

[0104] The total thickness calculation unit for spiral fibers is used to calculate the total thickness of spiral fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the expected burst pressure of the cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the composite layer wound with fibers on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral fiber failure stress of the spiral fibers wound with fibers on the Type IV vehicle-mounted hydrogen storage cylinder, and the fiber winding angle of the spiral fibers wound with fibers on the Type IV vehicle-mounted hydrogen storage cylinder.

[0105] The circumferential winding single-layer thickness calculation unit is used to calculate the circumferential winding single-layer thickness of the fiber on the Type IV vehicle-mounted hydrogen storage cylinder based on the number of carbon fiber strands of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral bandwidth of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder to the volume of the composite layer.

[0106] The spiral winding single-layer thickness calculation unit is used to calculate the spiral winding single-layer thickness of the fiber on the Type IV vehicle-mounted hydrogen storage cylinder based on the number of carbon fiber strands of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn in the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential bandwidth of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder in the volume of the composite layer.

[0107] In practical applications, the residual tension calculation module specifically includes:

[0108] The residual tension calculation unit is used to calculate the residual tension according to the formula. The remaining tension of the winding fiber when it is wound around the winding fiber is calculated, where σ(x) represents the remaining tension of the winding fiber when it is wound around the winding fiber, T(x) represents the winding tension of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, x represents the ratio of the radius of the winding fiber to the outer diameter of the inner liner when it is wound around the winding fiber, m represents the ratio of the outer diameter of the cylinder to the outer diameter of the inner liner when it is wound around the winding fiber, σ(a) represents the remaining tension of the outer fiber, a represents the integral term with respect to x and m, and H represents the structural influence factor.

[0109] In practical applications, the pressure range determination module specifically includes:

[0110] Pressure range determination unit, used to determine the pressure range based on the formula P≥P c ≥PP cr Determine the filling pressure range for Type IV vehicle-mounted hydrogen storage cylinders, where P represents the total external pressure of the winding layer on the liner. c P indicates the filling pressure of the Type IV vehicle-mounted hydrogen storage cylinder. cr This indicates the critical buckling load.

[0111] The present invention proposes a method for determining the inflation pressure during the fiber winding process of a Type IV vehicle-mounted hydrogen storage cylinder. This method can provide guidance for the selection of inflation pressure in engineering manufacturing, and can obtain the range of inflation pressure selection for each fiber winding. This effectively prevents the cylinder liner from buckling and becoming unstable due to insufficient inflation pressure, and the overall performance of the cylinder from declining due to excessive inflation pressure, thereby improving the quality, grade and yield of the cylinder.

[0112] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0113] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder, characterized in that, include: Based on the finite element method, a three-dimensional finite element model of the cylinder lining of a Type IV vehicle-mounted hydrogen storage cylinder was constructed. Buckling analysis was performed on the three-dimensional finite element model of the gas cylinder liner to obtain the critical buckling load; Based on the following factors: the winding radius of the fiber at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the expected burst pressure of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the wound fiber in the composite layer of the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential fiber failure stress of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the helical fiber failure stress of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the number of carbon fiber strands of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, and the cross-sectional area of ​​each yarn in the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder. The calculation of the fiber winding angle, total thickness of circumferential fibers, total thickness of spiral fibers, thickness of single layer of circumferential winding, and thickness of single layer of spiral winding of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder is specifically included, based on the winding radius of the fibers at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder and the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder. The total thickness of the circumferential fibers on the Type IV vehicle-mounted hydrogen storage cylinder is obtained based on the expected burst pressure of the cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the composite layer volume occupied by the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential fiber failure stress of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, and the fiber winding angle of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder. The total thickness of the spiral fibers on the Type IV vehicle-mounted hydrogen storage cylinder is obtained based on the expected burst pressure of the cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the composite layer volume occupied by the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral fiber failure stress of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, and the fiber winding angle of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder. The thickness of the circumferential winding single layer of the fiber on the Type IV vehicle-mounted hydrogen storage cylinder is obtained based on the number of carbon fiber strands wound on the fiber, the cross-sectional area of ​​each yarn in the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral width of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder in the volume of the composite layer. The thickness of the spiral-wound single layer of the fiber on the Type IV vehicle-mounted hydrogen storage cylinder is obtained based on the number of carbon fiber strands wound on the fiber, the cross-sectional area of ​​each yarn in the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential bandwidth of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder in the volume of the composite layer. The winding tension of each layer of fibers on the Type IV vehicle-mounted hydrogen storage cylinder is calculated based on the fiber winding angle, total thickness of circumferential fibers, total thickness of helical fibers, thickness of a single circumferential winding layer, and thickness of a single helical winding layer; the winding tension is either helical winding tension or circumferential winding tension. For any layer of wound fiber, the remaining tension of the wound fiber when it is wound onto the wound fiber is obtained based on the winding tension of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder; The external pressure exerted by each layer of winding fiber on the cylinder liner is obtained based on the remaining tension of each layer of winding fiber and the winding tension of each layer of winding fiber. The total external pressure value of the winding layer on the liner is determined based on the external pressure exerted by all layers of winding fibers on the cylinder liner; The filling pressure range of the Type IV vehicle-mounted hydrogen storage cylinder is determined based on the total external pressure of the winding layer on the liner and the critical buckling load.

2. The method for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder according to claim 1, characterized in that, The step of obtaining the remaining tension of the winding fiber when it is wound onto the winding fiber based on the winding tension of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder specifically includes: According to the formula Calculate the remaining tension of the winding fiber when it is wound around the winding fiber, where σ(x) represents the remaining tension of the winding fiber when it is wound around the winding fiber, T(x) represents the winding tension of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, x represents the ratio of the radius of the winding fiber to the outer diameter of the inner liner when it is wound around the winding fiber, m represents the ratio of the outer diameter of the cylinder to the outer diameter of the inner liner when it is wound around the winding fiber, σ(a) represents the remaining tension of the outer fiber, da represents the integral term with respect to x and m, and H represents the structural influence factor.

3. The method for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder according to claim 1, characterized in that, The determination of the filling pressure range of the Type IV vehicle-mounted hydrogen storage cylinder based on the total external pressure value of the winding layer on the liner and the critical buckling load specifically includes: According to the formula The filling pressure range of the Type IV vehicle-mounted hydrogen storage cylinder was determined, among which, This indicates the total external pressure exerted by the winding layer on the liner. This indicates the filling pressure of the Type IV vehicle-mounted hydrogen storage cylinder. This indicates the critical buckling load.

4. A system for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder, characterized in that, include: The model building module is used to build a three-dimensional finite element model of the cylinder liner of the Type IV vehicle-mounted hydrogen storage cylinder based on the finite element method. The buckling analysis module is used to perform buckling analysis on the three-dimensional finite element model of the gas cylinder liner to obtain the critical buckling load. The parameter calculation module is used to calculate the fiber winding angle, total circumferential fiber thickness, total spiral fiber thickness, circumferential winding single-layer thickness, and spiral winding single-layer thickness of the fibers wound on the Type IV vehicle-mounted hydrogen storage cylinder based on the winding radius of the fiber at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the expected burst pressure of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the wound fiber in the composite layer on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential fiber failure stress of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral fiber failure stress of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the number of carbon fiber strands of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn in the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral bandwidth of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder, and the circumferential bandwidth of the wound fiber on the Type IV vehicle-mounted hydrogen storage cylinder. Specifically, it includes: The fiber winding angle calculation unit is used to obtain the fiber winding angle of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder based on the winding radius of the fiber at the valve seat end of the Type IV vehicle-mounted hydrogen storage cylinder and the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder. The total thickness calculation unit for circumferential fibers is used to calculate the total thickness of circumferential fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the expected burst pressure of the cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the composite layer of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential fiber failure stress of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder, and the fiber winding angle of the wound fibers on the Type IV vehicle-mounted hydrogen storage cylinder. The total thickness calculation unit for spiral fibers is used to calculate the total thickness of spiral fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the expected burst pressure of the cylinder, the outer diameter of the Type IV vehicle-mounted hydrogen storage cylinder, the percentage of the volume of the composite layer wound with fibers on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral fiber failure stress of the spiral fibers wound with fibers on the Type IV vehicle-mounted hydrogen storage cylinder, and the fiber winding angle of the spiral fibers wound with fibers on the Type IV vehicle-mounted hydrogen storage cylinder. The circumferential winding single-layer thickness calculation unit is used to calculate the circumferential winding single-layer thickness of the fiber on the Type IV vehicle-mounted hydrogen storage cylinder based on the number of carbon fiber strands of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the spiral bandwidth of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder to the volume of the composite layer. The spiral winding single-layer thickness calculation unit is used to calculate the spiral winding single-layer thickness of the fiber on the Type IV vehicle-mounted hydrogen storage cylinder based on the number of carbon fiber strands of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the cross-sectional area of ​​each yarn of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, the circumferential bandwidth of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder, and the percentage of the fiber wound on the Type IV vehicle-mounted hydrogen storage cylinder to the volume of the composite layer. The winding tension calculation module is used to calculate the winding tension of each layer of winding fibers on the Type IV vehicle-mounted hydrogen storage cylinder based on the fiber winding angle, total thickness of circumferential fibers, total thickness of helical fibers, thickness of a single layer of circumferential winding, and thickness of a single layer of helical winding; the winding tension is helical winding tension or circumferential winding tension; The residual tension calculation module is used to calculate the residual tension of the winding fiber when it is wound onto the winding fiber, based on the winding tension of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, for any layer of winding fiber. The external pressure calculation module is used to calculate the external pressure exerted by each layer of winding fiber on the gas cylinder liner based on the remaining tension of each layer of winding fiber and the winding tension of each layer of winding fiber. The total external pressure calculation module is used to determine the total external pressure value of the winding layer on the cylinder liner based on the external pressure exerted by all layers of winding fibers on the cylinder liner. The pressure range determination module is used to determine the filling pressure range of the Type IV vehicle-mounted hydrogen storage cylinder based on the total external pressure value of the winding layer on the liner and the critical buckling load.

5. The system for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder according to claim 4, characterized in that, The residual tension calculation module specifically includes: The residual tension calculation unit is used to calculate the residual tension according to the formula. Calculate the remaining tension of the winding fiber when it is wound around the winding fiber, where σ(x) represents the remaining tension of the winding fiber when it is wound around the winding fiber, T(x) represents the winding tension of the winding fiber on the Type IV vehicle-mounted hydrogen storage cylinder, x represents the ratio of the radius of the winding fiber to the outer diameter of the inner liner when it is wound around the winding fiber, m represents the ratio of the outer diameter of the cylinder to the outer diameter of the inner liner when it is wound around the winding fiber, σ(a) represents the remaining tension of the outer fiber, da represents the integral term with respect to x and m, and H represents the structural influence factor.

6. The system for determining the filling pressure of a Type IV vehicle-mounted hydrogen storage cylinder according to claim 4, characterized in that, The pressure range determination module specifically includes: Pressure range determination unit, used to determine pressure range according to formula The filling pressure range of the Type IV vehicle-mounted hydrogen storage cylinder was determined, among which, This indicates the total external pressure exerted by the winding layer on the liner. This indicates the filling pressure of the Type IV vehicle-mounted hydrogen storage cylinder. This indicates the critical buckling load.

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