A design method for a type IV large-volume hydrogen storage bottle

Abstract

The present invention relates to the technical field of hydrogen storage cylinders, and discloses a design method for a type IV large-volume hydrogen storage cylinder, comprising the following steps: determining the service parameters and structural parameters of the hydrogen storage cylinder; designing the structure of the composite winding layer of the hydrogen storage cylinder to obtain N laying schemes of the composite winding layer; for the winding layer formed by each laying scheme, analyzing the mechanical response of the winding layer under three key working conditions of rated working pressure, water pressure test pressure and minimum bursting pressure, and obtaining the dangerous parts of the winding layer under different working conditions; analyzing and evaluating the dangerous parts based on the maximum stress failure criterion, and selecting the optimal laying scheme of the winding layer based on the evaluation results; constructing a theoretical model of the inflation of the hydrogen storage cylinder; applying the model to simulate the transient inflation process of the hydrogen storage cylinder to obtain the temperature rise evolution law of the hydrogen storage cylinder; and formulating a temperature control strategy based on this. The present invention is suitable for the design of hydrogen storage cylinders for long-tube trailers, and takes into account the temperature rise evolution law during the filling process, and has the advantages of safety and reliability.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen storage cylinders, and in particular to a design method for a type IV large-volume hydrogen storage cylinder. Background Art

[0002] So far, many scholars have studied the filling process of hydrogen storage cylinders, especially small-volume on-board hydrogen storage cylinders, and have obtained a large amount of valuable experimental data and research results. However, there are still many shortcomings, such as the lack of research on the design of large-volume composite hydrogen storage cylinders, such as hydrogen storage cylinders for long-tube trailers. The difference in the temperature rise law of large-volume composite hydrogen storage cylinders and small-volume composite hydrogen storage cylinders during the filling process due to different factors is still unclear. And there is currently no research on the impact of the cylinder incident configuration, such as the structural parameters of the intake pipe, on the temperature rise during the filling process of the hydrogen storage cylinder.

[0003] In view of this, it is urgent to propose a safe and reliable design method for large-volume, high-pressure composite hydrogen storage cylinders based on the research results and the actual filling process. Summary of the invention

[0004] The purpose of the present invention is to propose a safe and reliable design method for a large-volume IV type hydrogen storage bottle based on research results and actual filling technology.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A method for designing a type IV large-volume hydrogen storage bottle comprises the following steps:

[0007] S10. Determine the service parameters and structural parameters of the hydrogen storage cylinder. The service parameters include at least the rated working pressure, water pressure test pressure and minimum bursting pressure; the structural parameters include at least the volume of the hydrogen storage cylinder, the radius of the barrel section and the length corresponding to the short semi-axis of the head;

[0008] S11. Design of the composite winding layer structure of the hydrogen storage cylinder to obtain N laying schemes of the composite winding layer, each laying scheme at least includes determining the winding layer material, winding layer direction, winding layer number and laying method;

[0009] S12. For each winding layer formed by the laying scheme, the mechanical response of the winding layer under the three key working conditions of rated working pressure, water pressure test pressure and minimum bursting pressure is analyzed by using the mechanical response analysis tool to obtain the dangerous parts of the winding layer under different working conditions; the dangerous parts are analyzed and evaluated based on the maximum stress failure criterion, and the optimal laying scheme of the winding layer is selected based on the evaluation results;

[0010] S13. Construct a theoretical model for filling a hydrogen storage cylinder;

[0011] S14. Apply the inflation theoretical model to simulate the transient inflation process of the hydrogen storage cylinder and obtain the temperature rise evolution law of the hydrogen storage cylinder;

[0012] S15. Develop a temperature control strategy based on the temperature evolution law of the hydrogen storage cylinder.

[0013] As a possible implementation method, S11 specifically includes:

[0014] S110. Determine the basic assumptions for the design of the composite wrapping layer, which include: the load caused by the internal pressure of the hydrogen storage cylinder is entirely borne by the tensile stress of the composite wrapping layer; the strength of the composite wrapping layer is entirely borne by the tensile strength of the fiber; the composite wrapping layer is continuously wrapped around the inner liner and is evenly and symmetrically distributed; the hydrogen storage cylinder is regarded as a thin-walled container, and the bending stress is not considered when laying the composite wrapping layer; the winding method is spiral winding and plane winding;

[0015] S111. Select composite materials based on service parameters;

[0016] S112. Calculate the thickness of a single layer of the composite winding layer;

[0017] S113. Determine the winding mode including helical winding and toroidal winding;

[0018] S114. Based on the grid theory, mechanical analysis is performed on the cylinder section and the head section respectively, and the winding angle of the winding layer is obtained based on engineering experience, and the total thickness of the spiral winding layer and the total thickness of the circumferential winding layer are further determined based on the winding angle;

[0019] S115. The number of spiral winding layers is calculated based on the total thickness of the spiral winding layer and the thickness of a single layer; the number of hoop winding layers is calculated based on the total thickness of the hoop winding layer and the thickness of a single layer;

[0020] S116. Formulate a preliminary laying method for the winding layer, and further determine at least three laying methods for the winding layer based on the actual winding process.

[0021] As a possible implementation manner, S115 specifically includes the following sub-steps:

[0022] S1150. Substitute the thickness of the single layer of the winding layer into the formula of the longitudinal pressure that each winding layer can bear and the formula of the circumferential pressure that each winding layer can bear to obtain the longitudinal bearing pressure and circumferential bearing pressure that a single layer of the winding layer can bear at different winding angles;

[0023] S1151. Superimpose the longitudinal bearing pressures of each layer to obtain the longitudinal total bearing capacity, and superimpose the circumferential bearing pressures of each layer to obtain the circumferential total bearing capacity, and determine whether both the longitudinal total bearing capacity and the circumferential total bearing capacity meet the minimum bursting pressure. If so, jump to S1152; otherwise, adjust the number of spiral winding layers and / or the number of circumferential winding layers until the superimposed longitudinal and circumferential total bearing capacities meet the minimum bursting pressure, and then jump to S1152;

[0024] S1152. Determine a winding layer laying plan, and formulate N winding layer laying plans by alternating laying or layered laying; each laying plan includes a winding layer direction, a corresponding number of winding layers, and a laying order.

[0025] As a possible implementation method, three winding layer laying schemes are formulated. The first winding layer laying scheme is 90° is circumferential laying, 10°, 17°, 25°, 37°, 40°, 45° are spiral laying; the subscript is the number of laying layers;

[0026] The second winding layer laying scheme is Among them, 90° is circumferential laying, 10°, 17°, 25°, 37°, 40°, 45° are spiral laying; the subscript is the number of laying layers;

[0027] The third winding layer laying scheme is Among them, 90° is circumferential laying, ±10°, ±17°, ±25°, ±37°, ±40° and ±45° are spiral laying, and the number of spiral laying layers are 7, 7, 7, 7, 5 and 5 respectively; For circumferential laying, the number of laying layers is twice the number of corresponding spiral laying layers.

[0028] As a possible implementation method, ESACOMP software is used to execute S12, which specifically includes the following steps:

[0029] S120. Construct a three-dimensional model of the inner liner of the hydrogen storage cylinder;

[0030] S121. Configuring the resin matrix material and the carbon fiber material in the composite material layer, and setting the volume content of the carbon fiber material;

[0031] S122. Lay the layers according to the laid plan for each winding layer;

[0032] S123. Setting boundary conditions, including setting the degree of freedom at one end to 0 and not constraining the degree of freedom at the other end; applying internal pressure load; the internal pressure load is one of the rated working pressure, water pressure test pressure or minimum bursting pressure;

[0033] S124. Constructing a winding layer failure criterion, wherein the winding layer failure criterion is a maximum stress failure criterion;

[0034] S125. Obtain the total displacement cloud map, X-direction displacement cloud map, Y-direction displacement cloud map, and Z-direction displacement cloud map of the barrel section under the internal pressure load for each winding layer laying scheme;

[0035] S126. Determine the direction and distribution of the maximum displacement of the barrel section by analyzing the above displacement cloud diagrams;

[0036] S127. Select the maximum displacement unit in the direction of the maximum displacement, the maximum displacement unit is the dangerous position of the winding layer;

[0037] S128. Obtaining a stress diagram of the carbon fiber material layer in each winding layer where the displacement maximum value unit is located;

[0038] S129. The evaluation result is obtained based on the stress diagram. The evaluation result is quantified by 1 / RF_FPF. When the value of 1 / RF_FPF is greater than 1, it means that the bearing capacity of the winding layer cannot withstand the internal pressure load, causing fiber damage, that is, failure.

[0039] As a possible implementation method, S14 specifically includes the following steps:

[0040] S140. Determine the influencing factors of the temperature rise evolution of the hydrogen storage cylinder, the influencing factors at least including the filling rate, ambient temperature, initial pressure and inlet structure;

[0041] S141. The control variable method is used to analyze the evolution law of temperature rise of hydrogen storage cylinders under various influencing factors.

[0042] As a possible implementation method, analyzing the effect of filling rate on the temperature rise evolution of hydrogen storage cylinders specifically includes the following steps:

[0043] The minimum hydrogen filling time is determined based on the filling rate index, the water volume of the hydrogen storage cylinder, the real-time density of hydrogen in the hydrogen storage cylinder at the reference temperature, and the maximum peak speed of hydrogen filling;

[0044] Determine N1 filling rate calculation case conditions, each of which includes filling time, filling rate, ambient temperature, initial temperature, initial pressure and target pressure; the filling time is greater than the minimum filling time; the ambient temperature, initial temperature, initial pressure and target pressure are quantitative; determine the filling rate under each filling rate calculation case condition based on the target pressure, initial pressure and filling time;

[0045] Apply the inflation theoretical model, specifically including: configuring the operating parameters of the numerical simulation of hydrogen storage cylinder filling; the operating parameters at least include the gravity direction, ambient temperature, selected turbulence model, inlet boundary conditions, step size, hydrogen inflow direction, fluid medium, solver settings, inlet pressure and residual curve accuracy;

[0046] Numerical simulation of the winding layer under the filling rate example condition is performed to obtain the temperature peak of the winding layer under each filling rate example condition.

[0047] As a possible implementation method, analyzing the effect of initial pressure on the temperature rise of hydrogen storage cylinders specifically includes the following steps:

[0048] Determine N2 initial pressure calculation case conditions, each of which includes filling time, filling rate, ambient temperature, initial temperature, initial pressure and target pressure; the filling time is greater than the minimum filling time; the filling rate, ambient temperature, initial temperature and target pressure are quantitative; determine the initial pressure under each initial pressure calculation case condition based on the target pressure, filling rate and filling time;

[0049] Apply the inflation theory model to simulate the winding layer value under the initial pressure case condition and obtain the peak temperature of the winding layer under each initial pressure case condition; or,

[0050] The analysis of the effect of ambient temperature on the temperature rise of hydrogen storage cylinders specifically includes the following steps:

[0051] Determine N3 ambient temperature calculation conditions, each of which includes filling time, filling rate, ambient temperature, initial temperature, initial pressure and target pressure; the filling time is greater than the minimum filling time; the filling rate, initial pressure, initial temperature and target pressure are quantitative; the ambient temperature is a variable;

[0052] The inflation theory model is applied to simulate the winding layer values ​​under the ambient temperature case conditions, and the peak temperature of the winding layer under each ambient temperature case condition is obtained.

[0053] As a possible implementation method, analyzing the effect of the air inlet structure on the temperature rise evolution of the hydrogen storage cylinder specifically includes the following steps:

[0054] Determine N4 intake port structure calculation example working conditions, each of which includes the intake pipe inner diameter, intake pipe penetration length and intake pipe wall thickness; wherein the intake pipe wall thickness is quantitative; one intake pipe inner diameter corresponds to multiple intake pipe penetration lengths; the arrays of multiple intake pipe penetration lengths corresponding to different intake pipe inner diameters are the same; the filling time, filling rate, ambient temperature, initial temperature, initial pressure and target pressure are quantitative;

[0055] The inflation theory model is applied to simulate the winding layer values ​​under the air inlet structure example working condition, and the temperature peak value of the winding layer under each air inlet structure example working condition is obtained.

[0056] As a possible implementation method, a temperature control strategy is formulated based on the temperature evolution law of the hydrogen storage cylinder, including:

[0057] The filling rate, ambient temperature, initial pressure and air inlet structure are determined based on the principle of minimizing the temperature peak.

[0058] Compared with the prior art, the beneficial effects of the present invention are:

[0059] 1. The design method of type IV large-volume hydrogen storage bottle provided by the present invention proposes three winding layer laying schemes based on the service parameters and structural parameters of the hydrogen storage bottle, and uses ESACOMP software to analyze the mechanical response of the winding layer under three key working conditions: rated working pressure, water pressure test pressure and minimum bursting pressure, to obtain the optimal laying scheme of the winding layer.

[0060] 2. The design method of type IV large-volume hydrogen storage bottles provided by the present invention conducts a thermodynamic analysis of the filling process for large-capacity composite hydrogen storage cylinders for 70MPa long-tube trailers, and establishes a numerical simulation model of heat transfer flow and real gas effects that is suitable for large capacity and takes buoyancy effects into consideration, to ensure the safety and reliability of the design method.

[0061] 3. The design method of type IV large-volume hydrogen storage bottles provided by the present invention determines the influencing factors of the temperature rise evolution of the hydrogen storage bottle, adopts the control variable method to analyze the temperature rise evolution law of the hydrogen storage bottle under various influencing factors, and formulates a temperature control strategy based on the temperature evolution law of the hydrogen storage bottle to ensure reliable design and safe use. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0063] Figure 1 A flow chart of a method for designing a type IV large-volume hydrogen storage bottle provided in an embodiment of the present invention;

[0064] Figure 2 A stress diagram of spirally wound microelement in the Z-axis direction in the design method of a type IV large-volume hydrogen storage bottle provided in an embodiment of the present invention;

[0065] Figure 3 A microelement stress diagram of spiral winding in the θ-axis direction in the design method of a type IV large-volume hydrogen storage bottle provided in an embodiment of the present invention;

[0066] Figure 4A graph showing the maximum temperature variation trend of the gas in the hydrogen storage bottle during the filling process after a temperature control strategy is adopted in the design method for a Type IV large-volume hydrogen storage bottle provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0067] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0068] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0069] In the present invention, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. The following at least one item (items) or similar expressions thereof refer to any combination of these items, including any combination of single items (items) or plural items (items). For example, at least one item (items) of a, b or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0070] There are many deficiencies in the existing research on the filling process of hydrogen storage cylinders, such as the lack of research on the design of large-volume composite hydrogen storage cylinders, such as hydrogen storage cylinders for long-tube trailers. It is not clear whether different factors affect the temperature rise of large-volume composite hydrogen storage cylinders and small-volume composite hydrogen storage cylinders during the filling process. And there is currently no research on the impact of the cylinder incident configuration, such as the structural parameters of the intake pipe, on the temperature rise of the hydrogen storage cylinder filling process.

[0071] In view of this, the present invention proposes to provide a design method for a type IV large-volume hydrogen storage bottle, see Figure 1 , including the following steps:

[0072] S10. Determine the service parameters and structural parameters of the hydrogen storage cylinder. The service parameters include at least the rated working pressure, water pressure test pressure and minimum bursting pressure; the structural parameters include at least the volume of the hydrogen storage cylinder, the radius of the barrel section and the length corresponding to the short semi-axis of the head;

[0073] As an example, combined with the relevant regulations of hydrogen storage cylinders, the service parameters and structural parameters of hydrogen storage cylinders are determined as follows: hydrogen storage cylinder volume: 1750L; rated working pressure: 70MPa; water pressure test pressure: 105MPa; minimum bursting pressure: 157.5Mpa; barrel section radius: 338mm; corresponding length of the short semi-axis of the head: 145.7mm.

[0074] S11. Design of the composite winding layer structure of the hydrogen storage cylinder to obtain N laying schemes of the composite winding layer, each laying scheme at least includes determining the winding layer material, winding layer direction, winding layer number and laying method;

[0075] As a possible implementation method, S11 specifically includes:

[0076] S110. Determine the basic assumptions for the design of the composite wrapping layer, which include: the load caused by the internal pressure of the hydrogen storage cylinder is entirely borne by the tensile stress of the composite wrapping layer; the strength of the composite wrapping layer is entirely borne by the tensile strength of the fiber; the composite wrapping layer is continuously wrapped around the inner liner and is evenly and symmetrically distributed; the hydrogen storage cylinder is regarded as a thin-walled container, and the bending stress is not considered when laying the composite wrapping layer; the winding method is spiral winding and plane winding;

[0077] S111. Select composite materials based on service parameters;

[0078] As an example, the T700S-24K fiber material produced by Japan's Toray Corporation is selected. The tensile modulus of T700S-24K is 230 GPa and the tensile strength is 4900 MPa, both of which meet the requirements of high tensile strength and moderate tensile modulus.

[0079] S112. Calculate the thickness of a single layer of the composite winding layer;

[0080] As an example, the single-layer yarn width of the T700S-24K composite winding layer is measured on an actual winding machine and is 5 mm / strand. The single-layer thickness of the carbon fiber is L d It can be determined by the following formula:

[0081]

[0082] Where, L d is the thickness of a single carbon fiber layer, in mm; ρ t is the carbon fiber density, in g / m, the carbon fiber linear density of T700S-24K is 1.65g / m; ρx is the carbon fiber volume density, in g / cm 3 The carbon fiber density of T700S-24K is 1.80g / cm 3 ; Solving, the thickness of the carbon fiber single layer L d It is 0.183mm.

[0083] S113. Determine the winding mode including helical winding and toroidal winding;

[0084] S114. Based on the grid theory, mechanical analysis is performed on the cylinder section and the head section respectively, and the winding angle of the winding layer is obtained based on engineering experience, and the total thickness of the spiral winding layer and the total thickness of the circumferential winding layer are further determined based on the winding angle;

[0085] As an example, in the cylinder section of the hydrogen storage cylinder, take a microelement of unit length in the radial and circumferential directions. According to Newton's third law, the axial internal force and axial external force on the cylinder are equal, as shown in the following formula:

[0086]

[0087] Where, D is the outer diameter of the inner shell of the hydrogen storage cylinder, in mm; D i is the inner diameter of the hydrogen storage cylinder, in mm; p is the internal pressure of the cylinder, in MPa; N Z is the axial membrane internal force at the microelement, in N.

[0088] Since the thickness of the carbon fiber winding layer is much smaller than the diameter of the cylinder, the thickness of the carbon fiber winding layer can be ignored, that is, D = D i , we can get:

[0089]

[0090] Where r is the radius of the cylinder L1 section, in mm; p is the internal pressure of the cylinder, in MPa;

[0091] Select a micro-element of a circular ring of unit length in the cylinder. According to Newton's third law, the external force in the horizontal direction of the micro-element is equal to the internal force in the vertical section, as shown in the following formula:

[0092]

[0093] Where α is the winding angle of the helical winding, in degrees.

[0094] See also Figures 2 to 3 When the carbon fiber is wound onto the bottle, the spiral part of the fiber layer is affected by tension in the Z-axis and θ-axis directions, and the annular part of the fiber layer is affected by tension in the θ-axis direction. According to Newton's third law, the fiber tension in the Z-axis direction is as follows:

[0095] T Z =N Z =tσsin 2 α

[0096] The fiber tension in the θ-axis direction is expressed as follows:

[0097] T θ =N θ =(1+tσ)cos 2 α

[0098] Then, the stress spiral winding of the fiber layer is:

[0099]

[0100] Where, t α Represents the total thickness of the spiral carbon fiber winding layer, in mm. ∈ represents the allowable stress of resin-fiber, in MPa; α represents the spiral winding angle, in degrees.

[0101] The stress of the fiber layer is circumferentially wound as follows:

[0102]

[0103] Where, t β Represents the total thickness of the circumferential carbon fiber winding layer, in m. ∈ represents the allowable stress of resin-fiber, in MPa; α represents the spiral winding angle, in degrees.

[0104] In the hydrogen storage cylinder head section, the first principal curvature radius of the head And the second principal radius of curvature Rθ is shown as follows:

[0105]

[0106] In the formula, r is the shape of the head surface, which is determined by the meridian equation r(z); With R θ The relationship is shown in the following formula:

[0107]

[0108] Where N θ is the annular internal force of the membrane unit, in N; is the radial internal force of the membrane unit, in N. The radial internal force can be obtained through the overall equilibrium condition of the head, as described in the following formula:

[0109]

[0110] Substitution We can get:

[0111]

[0112] In the formula, t f is the thickness of the composite material winding layer, in mm; With N θ The equilibrium condition is described as follows:

[0113]

[0114] The membrane element ring is forced inward N θ , radial internal force of membrane element The first principal curvature radius R of the head θ , The second principal radius of curvature of the head Substituting the equilibrium conditions into the equation, we get:

[0115]

[0116] In summary, the fiber stress σ of the composite material layer in the head section can be obtained f satisfy:

[0117]

[0118] In the formula, σ f is the fiber stress of the composite material layer, in N. Considering the actual winding process, the winding angle of the head section satisfies the following formula:

[0119]

[0120] The fiber stress of the winding layer of the head section is:

[0121]

[0122] In the formula, σ f is the fiber stress of the winding layer of the head section, in N; the equilibrium equation is combined with the winding angle of the head section and the fiber stress of the winding layer of the head section to obtain:

[0123]

[0124] In the formula, t fa is the thickness of the winding layer of the hydrogen storage head section, in mm; t is the thickness of the winding layer at any point of the hydrogen storage head section, in mm.

[0125] S115. The number of spiral winding layers is calculated based on the total thickness of the spiral winding layer and the thickness of a single layer; the number of hoop winding layers is calculated based on the total thickness of the hoop winding layer and the thickness of a single layer;

[0126] As an example, the following winding angle scheme is adopted: the radius corresponding to the end hole of the head section is +10° to the radius of the barrel, so the winding angle According to the total thickness of the spiral winding layer in S114 t α and the total thickness of the hoop winding layer t β According to the expression, the thickness of the spiral winding layer is determined to be 6.648 mm, and the number of winding layers is 72; the thickness of the annular winding layer is determined to be 14.98 mm, and the number of winding layers is 82.

[0127] As a possible implementation manner, S115 specifically includes the following sub-steps:

[0128] S1150. Substitute the thickness of the single layer of the winding layer into the formula of the longitudinal pressure that each winding layer can bear and the formula of the circumferential pressure that each winding layer can bear to obtain the longitudinal bearing pressure and circumferential bearing pressure that a single layer of the winding layer can bear at different winding angles;

[0129] As an example, the longitudinal pressure formula is:

[0130]

[0131] The formula for hoop pressure is:

[0132]

[0133] In the formula, α i is the winding angle of a single-layer composite material winding layer, in degrees; p αi is the longitudinal pressure that each single-layer board can bear, in MPa: p θi It is the annular pressure that each single layer of plate can bear, in MPa.

[0134] S1151. Superimpose the longitudinal bearing pressures of each layer to obtain the longitudinal total bearing capacity, and superimpose the circumferential bearing pressures of each layer to obtain the circumferential total bearing capacity, and determine whether both the longitudinal total bearing capacity and the circumferential total bearing capacity meet the minimum bursting pressure. If so, jump to S1152; otherwise, adjust the number of spiral winding layers and / or the number of circumferential winding layers until the superimposed longitudinal and circumferential total bearing capacities meet the minimum bursting pressure, and then jump to S1152;

[0135] As an example, the total longitudinal bearing capacity formula is:

[0136] p α =∑p αi ·n i

[0137] The formula for the total hoop bearing capacity is:

[0138] p θ =∑p θi ·ni

[0139] Where n i is α i Angle composite winding layer number; p α is the total longitudinal bearing capacity, in MPa; p θ is the total circumferential bearing capacity, in MPa.

[0140] S1152. Determine a winding layer laying plan, and formulate N winding layer laying plans by alternating laying or layered laying; each laying plan includes a winding layer direction, a corresponding number of winding layers, and a laying order.

[0141] As a possible implementation method, three winding layer laying schemes are formulated. The first winding layer laying scheme is 90° is circumferential laying, 10°, 17°, 25°, 37°, 40°, 45° are spiral laying; the subscript is the number of laying layers;

[0142] The second winding layer laying scheme is Among them, 90° is circumferential laying, 10°, 17°, 25°, 37°, 40°, 45° are spiral laying; the subscript is the number of laying layers;

[0143] The third winding layer laying scheme is Among them, 90° is circumferential laying, ±10°, ±17°, ±25°, ±37°, ±40° and ±45° are spiral laying, and the number of spiral laying layers are 7, 7, 7, 7, 5 and 5 respectively; For circumferential laying, the number of laying layers is twice the number of corresponding spiral laying layers.

[0144] S116. Formulate a preliminary laying method for the winding layer, and further determine at least three laying methods for the winding layer based on the actual winding process.

[0145] S12. For each winding layer formed by the laying scheme, the mechanical response of the winding layer under the three key working conditions of rated working pressure, water pressure test pressure and minimum bursting pressure is analyzed by using a mechanical response analysis tool to obtain the dangerous parts of the winding layer under different working conditions; the dangerous parts are analyzed and evaluated based on the maximum stress failure criterion, and the optimal laying scheme of the winding layer is selected based on the evaluation results;

[0146] As a possible implementation method, ESACOMP software is used to execute S12, which specifically includes the following steps:

[0147] S120. Construct a three-dimensional model of the inner liner of the hydrogen storage cylinder;

[0148] S121. Configuring the resin matrix material and the carbon fiber material in the composite material layer, and setting the volume content of the carbon fiber material;

[0149] S122. Lay the layers according to the laid plan for each winding layer;

[0150] S123. Setting boundary conditions, including setting the degree of freedom at one end to 0 and not constraining the degree of freedom at the other end; applying internal pressure load; the internal pressure load is one of the rated working pressure, water pressure test pressure or minimum bursting pressure;

[0151] S124. Constructing a winding layer failure criterion, wherein the winding layer failure criterion is preferably a maximum stress failure criterion, and may be a maximum strain failure criterion, a Zeicher failure criterion, or a Hoffman failure criterion;

[0152] As an example, the maximum stress failure criterion is used to judge whether the composite winding layer has failed, that is, to compare the stress in each fiber direction in the composite winding layer with the maximum strength corresponding to that direction. The fiber failure of the composite layer is shown as follows:

[0153]

[0154] The failure of the resin matrix is ​​shown as follows:

[0155]

[0156] Shear failure is expressed as follows:

[0157]

[0158] Where X and Y are:

[0159]

[0160] The maximum strain failure criterion is used to judge whether the composite winding layer has failed. That is, the strain in each fiber direction in the composite winding layer is compared with the maximum strength corresponding to that direction. The fiber failure of the composite layer is shown as follows:

[0161]

[0162] The failure of the resin matrix is ​​shown as follows:

[0163]

[0164] Shear failure is expressed as follows:

[0165]

[0166] in:

[0167]

[0168] The judgment expression is as follows:

[0169]

[0170] The Caixier failure criterion obtains a second-order approximate model by further increasing the order of the stresses in all directions. This failure criterion has only one variable that characterizes the failure. The criterion of this failure criterion under plane stress state is as follows:

[0171]

[0172] The Hoffman failure criterion considers the tensile strength and compressive strength in the same direction. The criterion of this failure criterion under plane stress state is as follows:

[0173]

[0174] S125. Obtain the total displacement cloud map, X-direction displacement cloud map, Y-direction displacement cloud map, and Z-direction displacement cloud map of the barrel section under the internal pressure load for each winding layer laying scheme;

[0175] S126. Determine the direction and distribution of the maximum displacement of the barrel section by analyzing the above displacement cloud diagrams;

[0176] S127. Select the maximum displacement unit in the direction of the maximum displacement, the maximum displacement unit is the dangerous position of the winding layer;

[0177] S128. Obtaining a stress diagram of the carbon fiber material layer in each winding layer where the displacement maximum value unit is located;

[0178] S129. The evaluation result is obtained based on the stress diagram. The evaluation result is quantified by 1 / RF_FPF. When the value of 1 / RF_FPF is greater than 1, it means that the bearing capacity of the winding layer cannot withstand the internal pressure load, causing fiber damage, that is, failure.

[0179] Based on the service parameters and structural parameters of the hydrogen storage cylinder, the present invention proposes three winding layer laying schemes, and uses ESACOMP software to analyze the mechanical response of the winding layer under three key working conditions: rated working pressure, water pressure test pressure and minimum bursting pressure, to obtain the optimal laying scheme of the winding layer.

[0180] S13. Construct a theoretical model for filling a hydrogen storage cylinder;

[0181] S14. Apply the inflation theoretical model to simulate the transient inflation process of the hydrogen storage cylinder and obtain the temperature rise evolution law of the hydrogen storage cylinder;

[0182] As a possible implementation method, S14 specifically includes the following steps:

[0183] S140. Determine the influencing factors of the temperature rise evolution of the hydrogen storage cylinder, the influencing factors at least including the filling rate, ambient temperature, initial pressure and inlet structure;

[0184] S141. The control variable method is used to analyze the evolution law of temperature rise of hydrogen storage cylinders under various influencing factors.

[0185] The design method of type IV large-volume hydrogen storage bottles provided by the present invention determines the influencing factors of the temperature rise evolution of the hydrogen storage bottle, adopts the control variable method to analyze the temperature rise evolution law of the hydrogen storage bottle under various influencing factors, and formulates a temperature control strategy based on the temperature evolution law of the hydrogen storage bottle to ensure reliable design and safe use.

[0186] The design method for type IV large-volume hydrogen storage bottles provided in the present invention conducts a thermodynamic analysis of the filling process for large-capacity composite hydrogen storage cylinders for 70MPa long-tube trailers, and establishes a numerical simulation model of heat transfer flow and real gas effects that is suitable for large capacity and takes buoyancy effects into consideration, thereby ensuring the safety and reliability of the design method.

[0187] S15. Develop a temperature control strategy based on the temperature evolution law of the hydrogen storage cylinder.

[0188] As a possible implementation method, analyzing the effect of filling rate on the temperature rise evolution of hydrogen storage cylinders specifically includes the following steps:

[0189] The minimum hydrogen filling time is determined based on the filling rate index, the water volume of the hydrogen storage cylinder, the real-time density of hydrogen in the hydrogen storage cylinder at the reference temperature, and the maximum peak speed of hydrogen filling;

[0190] As an example, the minimum hydrogen filling time is determined by the hydrogen filling rate SOC (State of Charge), and the hydrogen storage tank is not in an underfilled / overfilled state when the filling is completed. That is, the filling rate SOC should be within a reasonable range of 90% to 100%, and the SOC expression is as follows:

[0191]

[0192] In the formula, K soc Indicates the filling rate index; ρ(P, T) indicates the real-time density of hydrogen in the hydrogen storage cylinder at the end of filling, in g / L; ρ(NWP, 288.15K) indicates the real-time density of hydrogen in the hydrogen storage cylinder at the reference temperature of 288.15K (15°C), in g / L. When the filling rate index satisfies 90% ≤ K soc When ≤100%, the filling quality meets the following conditions:

[0193]

[0194] In the formula, V represents the water volume of the hydrogen storage tank, in L, Mpeak Represents the maximum peak speed of hydrogen filling, in g / s.

[0195] Determine N1 filling rate calculation case conditions, each of which includes filling time, filling rate, ambient temperature, initial temperature, initial pressure and target pressure; the filling time is greater than the minimum filling time; the ambient temperature, initial temperature, initial pressure and target pressure are quantitative; determine the filling rate under each filling rate calculation case condition based on the target pressure, initial pressure and filling time;

[0196] Apply the inflation theoretical model, specifically including: configuring the operating parameters of the numerical simulation of hydrogen storage cylinder filling; the operating parameters at least include the gravity direction, ambient temperature, selected turbulence model, inlet boundary conditions, step size, hydrogen inflow direction, fluid medium, solver settings, inlet pressure and residual curve accuracy;

[0197] Numerical simulation of the winding layer under the filling rate example condition is performed to obtain the temperature peak of the winding layer under each filling rate example condition.

[0198] As a possible implementation method, analyzing the effect of initial pressure on the temperature rise of hydrogen storage cylinders specifically includes the following steps:

[0199] Determine N2 initial pressure calculation case conditions, each of which includes filling time, filling rate, ambient temperature, initial temperature, initial pressure and target pressure; the filling time is greater than the minimum filling time; the filling rate, ambient temperature, initial temperature and target pressure are quantitative; determine the initial pressure under each initial pressure calculation case condition based on the target pressure, filling rate and filling time;

[0200] Apply the inflation theory model to simulate the winding layer value under the initial pressure case condition and obtain the peak temperature of the winding layer under each initial pressure case condition; or,

[0201] The analysis of the effect of ambient temperature on the temperature rise of hydrogen storage cylinders specifically includes the following steps:

[0202] Determine N3 ambient temperature calculation conditions, each of which includes filling time, filling rate, ambient temperature, initial temperature, initial pressure and target pressure; the filling time is greater than the minimum filling time; the filling rate, initial pressure, initial temperature and target pressure are quantitative; the ambient temperature is a variable;

[0203] The inflation theory model is applied to simulate the winding layer values ​​under the ambient temperature case conditions, and the peak temperature of the winding layer under each ambient temperature case condition is obtained.

[0204] As a possible implementation method, analyzing the effect of the air inlet structure on the temperature rise evolution of the hydrogen storage cylinder specifically includes the following steps:

[0205] Determine N4 intake port structure calculation example working conditions, each of which includes the intake pipe inner diameter, intake pipe penetration length and intake pipe wall thickness; wherein the intake pipe wall thickness is quantitative; one intake pipe inner diameter corresponds to multiple intake pipe penetration lengths; the arrays of multiple intake pipe penetration lengths corresponding to different intake pipe inner diameters are the same; the filling time, filling rate, ambient temperature, initial temperature, initial pressure and target pressure are quantitative;

[0206] The inflation theory model is applied to simulate the winding layer values ​​under the air inlet structure example working condition, and the temperature peak value of the winding layer under each air inlet structure example working condition is obtained.

[0207] As a possible implementation method, a temperature control strategy is formulated based on the temperature evolution law of the hydrogen storage cylinder, including:

[0208] The filling rate, ambient temperature, initial pressure and air inlet structure are determined based on the principle of minimizing the temperature peak.

[0209] As an example, during the filling process, the filling rate is controlled to use a relatively low filling rate in the first half of the filling process. After the gas cylinder is filled with gas, the filling rate is increased to ensure that the maximum temperature of the gas in the cylinder is reduced to a safe threshold as much as possible. The temperature control strategy is formulated as follows:

[0210] In the initial rapid pressure increase stage (2-18MPa), the filling rate is 0.034MPa / s, and in the slow pressure increase stage (18-70MPa), the filling rate is 0.054MPa / s. The total filling time is 1440s, and the hydrogen to be filled is pre-cooled at -40℃.

[0211] In a possible implementation, the maximum temperature change trend of the gas in the hydrogen storage cylinder during the filling process under the above temperature control strategy is as follows: Figure 4 As shown, the maximum temperature of the gas in the bottle dropped from 416K to 389K. It can be seen that after adopting the temperature control strategy, the maximum temperature of the gas in the bottle dropped significantly.

[0212] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the drawings, etc. In the specification, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the specification. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0213] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention and are deemed to have covered any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the technical solutions recorded in the embodiments of the present invention, the present invention is also intended to include these modifications and variations.

Claims

1. A method for designing a type IV large-volume hydrogen storage bottle, characterized in that: The steps include: S10. Determine the service parameters and structural parameters of the hydrogen storage cylinder, wherein the service parameters include at least the rated working pressure, the water pressure test pressure and the minimum burst pressure; the structural parameters include at least the volume of the hydrogen storage cylinder, the radius of the barrel section and the length corresponding to the short semi-axis of the head; S11. Design of the composite winding layer structure of the hydrogen storage cylinder to obtain N laying schemes of the composite winding layer, each of which at least includes determining the winding layer material, winding layer direction, winding layer number and laying method; S12. For each winding layer formed by the laying scheme, the mechanical response of the winding layer under three key working conditions, namely the rated working pressure, the water pressure test pressure and the minimum bursting pressure, is analyzed by using a mechanical response analysis tool to obtain the dangerous parts of the winding layer under different working conditions; the dangerous parts are analyzed and evaluated based on the maximum stress failure criterion, and the optimal laying scheme of the winding layer is selected based on the evaluation results; S12 is executed by using ESACOMP software, and S12 specifically includes the following steps: S120. Constructing a three-dimensional model of the inner liner of a hydrogen storage cylinder; S121. Configuring a resin matrix material and a carbon fiber material in a composite material layer, and setting a volume content of the carbon fiber material; S122. Lay the layers according to the laid plan for each winding layer; S123. Set boundary conditions, including setting the degrees of freedom at one end to 0 and unconstraining the degrees of freedom at the other end; apply internal pressure load; The internal pressure load is one of the rated working pressure, the water pressure test pressure or the minimum bursting pressure; S124. Constructing a winding layer failure criterion, wherein the winding layer failure criterion is a maximum stress failure criterion; S125. Obtain the total displacement cloud map, X-direction displacement cloud map, Y-direction displacement cloud map, and Z-direction displacement cloud map of the barrel segment under the internal pressure load for each of the winding layer laying schemes; S126. Determine the direction and distribution of the maximum displacement of the barrel section by analyzing the above displacement cloud diagrams; S127. Selecting the maximum displacement unit in the direction of the maximum displacement, the maximum displacement unit is the dangerous position of the winding layer; S128. Obtaining a stress diagram of the carbon fiber material layer in each winding layer where the maximum displacement unit is located; S129. Obtaining an evaluation result based on the stress diagram, wherein the evaluation result is quantified by 1 / RF_FPF. When the value of 1 / RF_FPF is greater than 1, it indicates that the bearing capacity of the winding layer cannot bear the internal pressure load, resulting in fiber damage, that is, failure occurs; S13. Construct a theoretical model for filling a hydrogen storage cylinder; S14. Apply the inflation theoretical model to simulate the transient inflation process of the hydrogen storage cylinder to obtain the temperature rise evolution law of the hydrogen storage cylinder; specifically, the steps include: S140. Determine the influencing factors of the temperature rise evolution of the hydrogen storage cylinder, the influencing factors including at least the filling rate, the ambient temperature, the initial pressure and the inlet structure; S141. The control variable method is used to analyze the temperature rise evolution law of the hydrogen storage cylinder under various influencing factors; the analysis of the effect of filling rate on the temperature rise evolution law of the hydrogen storage cylinder specifically includes the following steps: The minimum hydrogen filling time is determined based on the filling rate index, the water volume of the hydrogen storage cylinder, the real-time density of hydrogen in the hydrogen storage cylinder at the reference temperature, and the maximum peak speed of hydrogen filling; Determine N1 filling rate calculation example conditions, each of which includes a filling time, a filling rate, an ambient temperature, an initial temperature, an initial pressure, and a target pressure; the filling time is greater than a minimum filling time; the ambient temperature, the initial temperature, the initial pressure, and the target pressure are quantitative; determine the filling rate under each filling rate calculation example condition based on the target pressure, the initial pressure, and the filling time; Applying the inflation theoretical model specifically includes: configuring the operating parameters of the numerical simulation of hydrogen storage cylinder filling; the operating parameters at least include the gravity direction, ambient temperature, selected turbulence model, inlet boundary conditions, step size, hydrogen inflow direction, fluid medium, solver settings, inlet pressure and residual curve accuracy; Numerical simulation of the winding layer under the filling rate case condition, and obtaining the temperature peak of the winding layer under each filling rate case condition; S15. Develop a temperature control strategy based on the temperature rise evolution law of the hydrogen storage cylinder.

2. The method for designing a type IV large-volume hydrogen storage bottle according to claim 1, characterized in that: The S11 specifically includes: S110. Determine the basic assumptions for the design of the composite wrapping layer, including: the load caused by the internal pressure of the hydrogen storage cylinder is entirely borne by the tensile stress of the composite wrapping layer; the strength of the composite wrapping layer is entirely borne by the tensile strength of the fiber; the composite wrapping layer is continuously wrapped around the inner liner and is evenly and symmetrically distributed; the hydrogen storage cylinder is regarded as a thin-walled container, and the bending stress is not considered when laying the composite wrapping layer; the winding method is spiral winding and plane winding; S111. Selecting a composite material based on the service parameters; S112. Calculate the thickness of a single layer of the composite winding layer; S113. Determine winding methods including helical winding and toroidal winding; S114. Based on the grid theory, mechanical analysis is performed on the cylinder section and the head section respectively, and the winding angle of the winding layer is obtained based on engineering experience, and the total thickness of the spiral winding layer and the total thickness of the circumferential winding layer are further determined based on the winding angle; S115. The number of spirally wound layers is calculated based on the total thickness of the spirally wound layer and the thickness of the single layer; the number of hoop-wound layers is calculated based on the total thickness of the hoop-wound layer and the thickness of the single layer; S116. Develop a preliminary laying method for the winding layer, and further determine at least three laying methods for the winding layer based on the actual winding process.

3. The method for designing a type IV large-volume hydrogen storage bottle according to claim 2, characterized in that: The S115 specifically includes the following sub-steps: S1150. Substituting the thickness of the single layer of the winding layer into the longitudinal pressure formula that each winding layer can bear and the hoop pressure formula that each winding layer can bear, obtain the longitudinal bearing pressure and hoop bearing pressure that the single layer of winding layer can bear at different winding angles; S1151. Superimpose the longitudinal bearing pressures of each layer to obtain the longitudinal total bearing capacity, and superimpose the circumferential bearing pressures of each layer to obtain the circumferential total bearing capacity, and determine whether both the longitudinal total bearing capacity and the circumferential total bearing capacity meet the minimum bursting pressure. If so, jump to S1152; otherwise, adjust the number of spiral winding layers and / or the number of circumferential winding layers until the superimposed longitudinal and circumferential total bearing capacities meet the minimum bursting pressure, and then jump to S1152; S1152. Determine a winding layer laying scheme, and formulate N winding layer laying schemes by alternating laying or layered laying; each of the laying schemes includes a winding layer direction, a corresponding number of winding layers, and a laying order.

4. The method for designing a type IV large-volume hydrogen storage bottle according to claim 3, characterized in that: Three winding layer laying plans are formulated. The first winding layer laying plan is ; 90° is circumferential laying, 10°, 17°, 25°, 37°, 40°, 45° are spiral laying; the subscript is the number of laying layers; The second winding layer laying scheme is ; Among them, 90° is circumferential laying, 10°, 17°, 25°, 37°, 40°, 45° are spiral laying; the subscript is the number of laying layers; The third winding layer laying scheme is , where 90° is circumferential laying, , , , , It is spiral laid, and the number of spiral laying layers are 7, 7, 7, 7, 5 and 5 respectively; For circumferential laying, the number of laying layers is twice the number of corresponding spiral laying layers.

5. The method for designing a type IV large-volume hydrogen storage bottle according to claim 1, characterized in that: The analysis of the effect of initial pressure on the temperature rise of hydrogen storage cylinders specifically includes the following steps: Determine N2 initial pressure calculation example conditions, each of which includes a filling time, a filling rate, an ambient temperature, an initial temperature, an initial pressure, and a target pressure; the filling time is greater than a minimum filling time; the filling rate, the ambient temperature, the initial temperature, and the target pressure are quantitative; determine the initial pressure under each initial pressure calculation example condition based on the target pressure, the filling rate, and the filling time; Apply the inflation theory model to simulate the winding layer value under the initial pressure case condition and obtain the peak temperature of the winding layer under each initial pressure case condition; or, The analysis of the effect of ambient temperature on the temperature rise of hydrogen storage cylinders specifically includes the following steps: Determine N3 ambient temperature calculation example conditions, each of which includes a filling time, a filling rate, an ambient temperature, an initial temperature, an initial pressure, and a target pressure; the filling time is greater than a minimum filling time; the filling rate, the initial pressure, the initial temperature, and the target pressure are quantitative; and the ambient temperature is a variable; The inflation theory model is applied to simulate the winding layer values ​​under the ambient temperature case conditions, and the peak temperature of the winding layer under each ambient temperature case condition is obtained.

6. The method for designing a type IV large-volume hydrogen storage bottle according to claim 1, characterized in that: The analysis of the effect of the air inlet structure on the temperature rise evolution of the hydrogen storage cylinder includes the following steps: Determine N4 intake port structure calculation example working conditions, each of which includes the intake pipe inner diameter, intake pipe penetration length and intake pipe wall thickness; wherein the intake pipe wall thickness is quantitative; one intake pipe inner diameter corresponds to multiple intake pipe penetration lengths; the arrays of multiple intake pipe penetration lengths corresponding to different intake pipe inner diameters are the same; the filling time, filling rate, ambient temperature, initial temperature, initial pressure and target pressure are quantitative; The inflation theory model is applied to simulate the winding layer values ​​under the air inlet structure example working condition, and the temperature peak value of the winding layer under each air inlet structure example working condition is obtained.

7. The method for designing a type IV large-volume hydrogen storage bottle according to claim 1, characterized in that: The temperature control strategy is formulated based on the temperature rise evolution law of the hydrogen storage cylinder, including: The filling rate, ambient temperature, initial pressure and air inlet structure are determined based on the principle of minimizing the temperature peak.

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