Method, system and equipment for predicting fire resistance of vehicle-mounted hydrogen storage cylinder and medium

Abstract

The invention provides a method, a system, equipment and a medium for predicting fire resistance of a vehicle-mounted hydrogen storage cylinder, and belongs to the technical field of hydrogen storage cylinder application. The method comprises the following steps: establishing a mechanical property degradation model of the carbon fiber epoxy resin-based composite material at a high temperature and a mechanical response finite element model of the vehicle-mounted hydrogen storage cylinder under a thermal-mechanical coupling effect; the mechanical property degradation model is applied to a mechanical response finite element model, finite element analysis is carried out in combination with a gas cylinder fire failure criterion to obtain a first change curve, and the first change curve represents the relation between the fire failure degree of the vehicle-mounted hydrogen storage cylinder and the gas pressure in the cylinder; acquiring a second change curve which represents the change rule of the gas pressure in the vehicle-mounted hydrogen storage cylinder along with the burning time; and performing combined analysis on the first change curve and the second change curve according to a gas cylinder burning failure criterion to obtain the bursting pressure and the fire-resistant time of the vehicle-mounted hydrogen storage cylinder under the burning condition. According to the method, the fire-resistant performance parameters of the vehicle-mounted hydrogen storage cylinder can be reliably predicted.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen storage cylinder applications, and in particular to a method, system, equipment and medium for predicting the fire resistance performance of vehicle-mounted hydrogen storage cylinders. Background Art

[0002] In the prior art, since most vehicle-mounted hydrogen storage cylinders are equipped with pressure relief devices, the high-pressure hydrogen stored in the vehicle-mounted hydrogen storage cylinders can be released in time when encountering a fire. Before the vehicle-mounted hydrogen storage cylinders are officially put into use, fire tests are usually carried out on the vehicle-mounted hydrogen storage cylinders and the pressure relief devices to complete the safety performance test. However, during this test, the situation where the pressure relief device cannot be opened in time is not taken into account, resulting in an unreliable evaluation of the fire resistance performance of the vehicle-mounted hydrogen storage cylinders. Summary of the invention

[0003] The main purpose of this application is to propose a method, system, equipment and medium for predicting the fire resistance performance of on-board hydrogen storage cylinders, which can perform finite element mechanical modeling analysis based on the structural material characteristics of the on-board hydrogen storage cylinders themselves, and at the same time combine the cylinder fire failure criteria for evaluation, so as to more reliably predict the fire resistance performance parameters of the on-board hydrogen storage cylinders.

[0004] To achieve the above object, one aspect of the present application provides a method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder, wherein the vehicle-mounted hydrogen storage cylinder comprises a composite material layer, and the composite material layer is made of a carbon fiber epoxy resin-based composite material. The method comprises:

[0005] Establishing a mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature and a finite element model of the mechanical response of the on-board hydrogen storage cylinder under thermal-mechanical coupling;

[0006] The mechanical property degradation model is applied to the mechanical response finite element model, and a finite element analysis is performed in combination with a preset gas cylinder fire failure criterion to obtain a first change curve, wherein the first change curve is used to characterize the relationship between the degree of fire failure of the vehicle-mounted hydrogen storage gas cylinder and the gas pressure in the cylinder;

[0007] Obtaining a second variation curve, where the second variation curve is used to characterize a variation law of the gas pressure in the vehicle-mounted hydrogen storage cylinder with the burning time;

[0008] According to the cylinder fire failure criterion, the first change curve and the second change curve are combined and analyzed to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire.

[0009] Furthermore, the mechanical property degradation model is obtained by:

[0010] Acquire multiple groups of first test data, wherein the multiple groups of first test data are collected when conducting a high temperature mechanical property test of the carbon fiber epoxy resin-based composite material, each group of the first test data includes a temperature value and a mechanical property parameter value of the carbon fiber epoxy resin-based composite material at the temperature value, and the mechanical property parameter value includes a tensile strength value;

[0011] Curve fitting is performed on the multiple groups of first test data to obtain the mechanical property degradation model, and the mechanical property degradation model is used to characterize the variation law of the mechanical property parameters of the carbon fiber epoxy resin-based composite material with temperature.

[0012] Furthermore, the mechanical response finite element model is obtained by:

[0013] Establishing a three-dimensional finite element model of the vehicle-mounted hydrogen storage cylinder;

[0014] Setting mechanical analysis conditions, boundary conditions and mechanical response analysis conditions of the three-dimensional finite element model to form the mechanical response finite element model;

[0015] Among them, the mechanical analysis conditions include the relationship between the stress and strain of the composite material layer and the relationship between the strain and displacement of the composite material layer; the boundary conditions include load constraints and displacement constraints acting on the three-dimensional finite element model, and the load constraints include the thermal load and internal pressure load of the on-board hydrogen storage cylinder at any fire time; the mechanical response analysis conditions include the load step and the solver type required when performing model finite element analysis.

[0016] Furthermore, the gas cylinder fire failure criterion records the failure conditions of the on-board hydrogen storage cylinder, and the failure conditions include: at the current fire time, the ratio between the current maximum stress of the composite material layer and the tensile strength of the composite material layer at the current temperature is greater than or equal to 1, and the ratio is the current fire failure degree value of the on-board hydrogen storage cylinder.

[0017] Furthermore, the mechanical property degradation model is applied to the mechanical response finite element model, and a finite element analysis is performed in combination with a preset gas cylinder fire failure criterion to obtain a first change curve, including:

[0018] Obtaining a plurality of heat loads and a plurality of internal pressure loads corresponding to the vehicle-mounted hydrogen storage cylinder at a plurality of different fire burning times;

[0019] For each of the fire time, the thermal load of the on-board hydrogen storage cylinder at the fire time is applied to the mechanical response finite element model for temperature update, and the mechanical property degradation model is used to solve the model to obtain the tensile strength of the composite material layer at the fire time; the thermal load and internal pressure load of the on-board hydrogen storage cylinder at the fire time are applied to the mechanical response finite element model for solution to obtain the maximum stress of the composite material layer at the fire time; according to the cylinder fire failure criterion and the tensile strength and maximum stress of the composite material layer at the fire time, the fire failure degree value of the on-board hydrogen storage cylinder at the fire time is determined; the internal pressure load of the on-board hydrogen storage cylinder at the fire time is used as the gas pressure in the cylinder, and the fire failure degree value of the on-board hydrogen storage cylinder at the fire time and the gas pressure in the cylinder are combined to form a set of second test data;

[0020] A plurality of groups of second test data corresponding to the vehicle-mounted hydrogen storage cylinder at the plurality of fire times are obtained to generate the first change curve.

[0021] Further, the second variation curve is obtained by:

[0022] Acquire multiple sets of third test data, wherein the multiple sets of third test data are collected by carrying out a real fire test or a numerical simulation test of the fire process of the vehicle-mounted hydrogen storage cylinder, and each set of the third test data includes the fire time and the gas pressure in the vehicle-mounted hydrogen storage cylinder at the fire time;

[0023] The second variation curve is generated according to the plurality of sets of third test data.

[0024] Furthermore, the first change curve and the second change curve are combined and analyzed according to the cylinder fire failure criterion to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions, including:

[0025] Filtering out the gas pressure in the bottle corresponding to the case where the fire failure degree value of the on-board hydrogen storage gas bottle is equal to 1 from the first variation curve, and using the filtered gas pressure in the bottle as the bursting pressure;

[0026] The first variation curve and the second variation curve are converted to obtain a third variation curve, wherein the third variation curve is used to characterize the variation law of the degree of fire failure of the vehicle-mounted hydrogen storage cylinder with the fire time;

[0027] The fire time corresponding to the case where the fire failure degree value of the vehicle-mounted hydrogen storage cylinder is equal to 1 is screened out from the third variation curve, and the screened fire time is used as the fire resistance time.

[0028] To achieve the above object, another aspect of the present application provides a fire resistance prediction system for a vehicle-mounted hydrogen storage cylinder, wherein the vehicle-mounted hydrogen storage cylinder comprises a composite material layer, wherein the composite material layer is made of a carbon fiber epoxy resin-based composite material, and the system comprises:

[0029] Establishing a module for establishing a mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature and a mechanical response finite element model of the on-board hydrogen storage cylinder under thermal-mechanical coupling;

[0030] A first analysis module is used to apply the mechanical property degradation model to the mechanical response finite element model, and to perform finite element analysis in combination with a preset gas cylinder fire failure criterion to obtain a first change curve, wherein the first change curve is used to characterize the relationship between the degree of fire failure of the vehicle-mounted hydrogen storage gas cylinder and the gas pressure in the cylinder;

[0031] An acquisition module, used for acquiring a second variation curve, where the second variation curve is used for representing a variation rule of the gas pressure in the vehicle-mounted hydrogen storage cylinder with the burning time;

[0032] The second analysis module is used to combine and analyze the first change curve and the second change curve according to the cylinder fire failure criterion to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions.

[0033] To achieve the above objective, another aspect of the present application provides an electronic device, the electronic device comprising a memory and a processor, the memory storing a computer program, and the processor implementing the above method when executing the computer program.

[0034] To achieve the above objective, another aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program implements the above method when executed by a processor.

[0035] The present application includes at least the following beneficial effects: taking into account the high-temperature mechanical property degradation characteristics of carbon fiber epoxy resin-based composite materials, and starting from the structural characteristics of the on-board hydrogen storage cylinder itself, finite element mechanical modeling analysis is performed under the action of thermal-mechanical coupling, and at the same time combined with the cylinder fire failure criteria for evaluation, the relevant fire resistance performance parameters of the on-board hydrogen storage cylinder itself can be more reliably predicted. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flow chart of a method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder provided in an embodiment of the present application;

[0037] Figure 2is a schematic diagram of a three-dimensional finite element model of a vehicle-mounted hydrogen storage cylinder provided in an embodiment of the present application;

[0038] Figure 3 It is a schematic diagram of a curve of a change between the degree of fire failure of a vehicle-mounted hydrogen storage cylinder and the gas pressure in the cylinder provided in an embodiment of the present application;

[0039] Figure 4 It is a schematic diagram of a curve of the gas pressure in a vehicle-mounted hydrogen storage cylinder changing with the burning time provided in an embodiment of the present application;

[0040] Figure 5 It is a schematic diagram of a curve showing the variation of the degree of fire failure of a vehicle-mounted hydrogen storage cylinder with the fire time provided in an embodiment of the present application;

[0041] Figure 6 It is a structural schematic diagram of a fire resistance performance prediction system for a vehicle-mounted hydrogen storage cylinder provided in an embodiment of the present application;

[0042] Figure 7 It is a schematic diagram of the hardware structure of the electronic device provided in the embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are only examples of systems and methods consistent with some aspects of the embodiments of the present application as detailed in the attached claims.

[0044] It is understood that the terms "first", "second", etc. used in this application can be used to describe various concepts in this article, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another concept. For example, without departing from the scope of the embodiment of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein can be interpreted as "at the time of" or "when" or "in response to determination".

[0045] The terms "at least one", "multiple", "each", "any", etc. used in this application, at least one includes one, two or more, multiple includes two or more, each refers to each of the corresponding multiple, and any refers to any one of the multiple.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0047] Hydrogen fuel cell vehicles are one of the core applications of the hydrogen energy industry. Currently, hydrogen fuel cell vehicles generally use on-board hydrogen storage cylinders made of carbon fiber epoxy resin-based composite materials to store high-pressure hydrogen. Since the nominal working pressure of on-board hydrogen storage cylinders for storing high-pressure hydrogen is as high as 70MPa, and carbon fiber epoxy resin-based composite materials are flammable, when a hydrogen fuel cell vehicle has an accident and causes a fire, if the high-pressure hydrogen stored in the on-board hydrogen storage cylinder cannot be released in time and an explosion occurs, the resulting explosion fireball, shock wave and fragments will pose a serious safety threat to the surrounding environment and pedestrians.

[0048] At present, regulations and standards require that a pressure relief device be installed on the vehicle-mounted hydrogen storage cylinder so that the high-pressure hydrogen stored in the vehicle-mounted hydrogen storage cylinder can be released in time in the event of a fire, thereby preventing the vehicle-mounted hydrogen storage cylinder from exploding. Before the vehicle-mounted hydrogen storage cylinder is officially put into use, it is usually required to conduct a fire test on the vehicle-mounted hydrogen storage cylinder and the pressure relief device together to verify the safety performance of the vehicle-mounted hydrogen storage cylinder and the pressure relief device in the event of a fire. Therefore, the main results obtained in the standard fire test include the opening time of the pressure relief device, and the increase of the hydrogen temperature and pressure in the vehicle-mounted hydrogen storage cylinder with the fire time when the pressure relief device can be opened. However, the standard fire test does not take into account the situation where the pressure relief device cannot be opened in time, which is a situation that is likely to occur in actual application scenarios. At this time, if the more reliable bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder itself cannot be obtained, it will affect the progress and safety of fire rescue.

[0049] In view of this, the embodiments of the present application provide a method, system, equipment and medium for predicting the fire resistance performance of on-board hydrogen storage cylinders. The scheme takes into account the high-temperature mechanical property degradation characteristics of carbon fiber epoxy resin-based composite materials, and performs finite element mechanical modeling analysis under thermal-mechanical coupling based on the structural characteristics of the on-board hydrogen storage cylinder itself. At the same time, combined with the cylinder fire failure criteria for evaluation, the relevant fire resistance performance parameters of the on-board hydrogen storage cylinder itself can be more reliably predicted.

[0050] The embodiment of the present application provides a method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder, which relates to the field of hydrogen storage cylinder application technology, and can be applied to a terminal, a server, or software running in a terminal or a server. In some embodiments, the terminal can be a smart phone, a tablet computer, a laptop computer, a desktop computer, a smart speaker, a smart watch, and a vehicle-mounted terminal, etc., but is not limited to this; the server side can be configured as an independent physical server, or a server cluster or distributed system composed of multiple physical servers, and can also be configured as a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network; the software can be an application that implements the above-mentioned method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder, etc., but is not limited to the above forms.

[0051] The present application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc. The present application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0052] Figure 1 This is an optional flow chart of a method for predicting the fire resistance of a vehicle-mounted hydrogen storage cylinder provided in an embodiment of the present application. First, it is explained that the vehicle-mounted hydrogen storage cylinder comprises a composite material layer, and the composite material layer is mainly made of a carbon fiber epoxy resin-based composite material. Figure 1 The method may include but is not limited to steps S101 to S104:

[0053] Step S101, establishing a mechanical property degradation model of carbon fiber epoxy resin-based composite materials at high temperatures and a mechanical response finite element model of a vehicle-mounted hydrogen storage cylinder under thermal-mechanical coupling;

[0054] Step S102: applying the mechanical property degradation model to the mechanical response finite element model, and performing finite element analysis in combination with a preset gas cylinder fire failure criterion to obtain a first variation curve, wherein the first variation curve is used to characterize the relationship between the degree of fire failure of the vehicle-mounted hydrogen storage gas cylinder and the gas pressure in the cylinder;

[0055] Step S103, obtaining a second variation curve, where the second variation curve is used to characterize the variation law of the gas pressure in the vehicle-mounted hydrogen storage cylinder with the burning time;

[0056] Step S104: According to the fire failure criterion of the gas cylinder, the first variation curve and the second variation curve are combined and analyzed to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage gas cylinder under fire.

[0057] Steps S101 to S104 shown in the embodiment of the present application, by performing finite element mechanical modeling analysis based on the structural material properties of the on-board hydrogen storage cylinder itself, and combining it with the cylinder fire failure criteria for evaluation, can more reliably predict the fire resistance performance parameters of the on-board hydrogen storage cylinder.

[0058] In step S101 of some embodiments, the mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature mainly characterizes the variation law of the mechanical property parameters of the carbon fiber epoxy resin-based composite material with temperature, which is obtained by the following method:

[0059] A plurality of groups of first test data are collected by conducting a high-temperature mechanical property test on the carbon fiber epoxy resin-based composite material in advance, each group of first test data includes a temperature value and a mechanical property parameter value of the carbon fiber epoxy resin-based composite material at the temperature value, and the mechanical property parameter value includes a tensile strength value and an elastic modulus, etc.; then, curve fitting is performed on the collected plurality of groups of first test data to obtain the mechanical property degradation model, and in the present application, a hyperbolic tangent function is preferably used to complete the curve fitting.

[0060] Among them, the high-temperature mechanical properties test principles of the carbon fiber epoxy resin-based composite material include the following: based on the thermogravimetric analysis test of the material, the thermal decomposition process of the material is determined through the thermal weight loss curve of the material at different heating rates; based on the derivative thermogravimetric curve of the material at different heating rates, the peak temperature is obtained to determine the temperature range of each decomposition stage; based on the non-isothermal derivative thermogravimetric curve and mechanism function of the carbon fiber epoxy resin-based composite material, the thermal decomposition kinetic parameters of the material are determined, and the kinetic parameters include activation energy and pre-exponential factor; prepare unidirectional carbon fiber epoxy resin-based composite laminates; use the ANSYS software thermal analysis module to calculate the heating time required for the unidirectional carbon fiber epoxy resin-based composite laminates to reach a stable thermal equilibrium state; determine the maximum tensile load of the carbon fiber epoxy resin-based composite material at different temperature points under a high temperature environment; calculate the tensile strength of the carbon fiber epoxy resin-based composite material in accordance with the standard GB / T 3354-2014 to obtain relevant test values.

[0061] In step S101 of some embodiments, the finite element model of the mechanical response of the vehicle-mounted hydrogen storage cylinder under the action of thermal-mechanical coupling is obtained in the following manner:

[0062] A three-dimensional finite element model of the vehicle-mounted hydrogen storage cylinder is established, and in this application, ANSYS Workbench software is preferably used to implement modeling and analysis, which is specifically manifested as: defining the structural unit type of the composite material layer and setting the geometric size parameters of the vehicle-mounted hydrogen storage cylinder (including the outer diameter of the bottle body and the thickness of the composite material layer), meshing the initially formed three-dimensional finite element model of the vehicle-mounted hydrogen storage cylinder, and refining some meshes of the head and the bottle mouth; in addition, considering that the vehicle-mounted hydrogen storage cylinder also includes an inner liner layer, which is mainly made of aluminum alloy material, the structural unit type of the inner liner layer can also be defined and the thickness of the inner liner layer can be set at the same time; then, the mechanical analysis conditions, boundary conditions and mechanical response analysis conditions of the three-dimensional finite element model of the vehicle-mounted hydrogen storage cylinder are set to form a mechanical response finite element model of the vehicle-mounted hydrogen storage cylinder under thermal-mechanical coupling.

[0063] The mechanical analysis conditions mainly include the relationship between the stress and strain of the composite material layer and the relationship between the strain and displacement of the composite material layer, which are specifically described as follows:

[0064] The linear elastic analysis method is used to clarify that the carbon fiber epoxy resin-based composite material is an anisotropic material. The composite material layer is a typical winding structure, generally composed of multiple composite material monolayers with different winding angles. The equilibrium equation of each composite material monolayer in the cylindrical coordinate system is:

[0065]

[0066] Where r is the radial direction of the cylindrical coordinate system, σ r is the radial stress of a single layer of the composite material, σ θ It is the hoop stress of a single layer of composite material, which can also be called transverse stress;

[0067] The relationship between stress and strain of each composite material layer can be expressed as:

[0068]

[0069]

[0070] In the formula, σ z is the axial stress of a single layer of the composite material, also known as the longitudinal stress, τ zθ is the shear stress of the composite material single layer, C is the stiffness matrix of the composite material single layer, ε z is the axial strain of the composite single layer, ε θ is the hoop strain of the composite material single layer, ε r is the radial strain of the composite single layer, γ zθ is the shear strain of the composite material single layer, η 1 is the first thermal expansion coefficient, which mainly characterizes the thermal expansion degree of the carbon fiber epoxy resin-based composite material along the fiber direction, η 2 is the second thermal expansion coefficient, which mainly characterizes the thermal expansion degree of the carbon fiber epoxy resin-based composite material in the direction perpendicular to the fiber, η 3 is the third thermal expansion coefficient, which mainly characterizes the thermal expansion degree of the carbon fiber epoxy resin-based composite material along the interlayer direction, η 6 is the fourth thermal expansion coefficient, which mainly characterizes the thermal expansion degree of the carbon fiber epoxy resin-based composite material in the plane formed by the fiber direction and the direction perpendicular to the fiber, ΔT is the manufacturing temperature difference of the carbon fiber epoxy resin-based composite material, S is the flexible matrix of the composite material single layer, E 1 is the longitudinal tensile strength of the carbon fiber epoxy resin matrix composite material, E 2 is the transverse tensile strength of the carbon fiber epoxy resin matrix composite material, ν 12 is the Poisson's ratio generated when the carbon fiber epoxy resin matrix composite material is stretched in the interlaminar direction, ν 23 is the Poisson's ratio generated when the fiber direction of the carbon fiber epoxy resin-based composite material is stretched;

[0071] The relationship between the strain and displacement of each composite material layer can be expressed as:

[0072]

[0073] In the formula, u ris the radial displacement of the composite material single layer, u z is the axial displacement of the composite material single layer, z is the axial direction of the cylindrical coordinate system, ε 0 is the average strain of the composite material single layer, u θ is the circumferential displacement of the composite material single layer, γ 0 is a preset constant.

[0074] In addition, the mechanical analysis conditions may also include a relationship between the stress and strain of the liner layer and a relationship between the strain and displacement of the liner layer, which are specifically described as follows:

[0075] The linear elastic analysis method is used to clarify that the aluminum alloy material is an isotropic material. The relationship between the stress and strain of the liner layer under internal pressure and thermal stress can be expressed as:

[0076]

[0077] In the formula, σ' z is the axial stress of the liner layer, σ' θ is the hoop stress of the liner layer, σ r ' is the radial stress of the liner layer, τ' zθ is the shear stress of the liner layer, a, b and c are stiffness coefficients, ε' z is the axial strain of the liner layer, ε' θ is the hoop strain of the liner layer, ε' r is the radial strain of the liner layer, γ' zθ is the shear strain of the liner layer, η 1 ', η' 2 , η 3 'And η' 6 are the thermal expansion coefficients of the aluminum alloy materials, and ΔT' is the manufacturing temperature difference of the aluminum alloy materials;

[0078] The relationship between the strain and displacement of the liner layer can be expressed as:

[0079]

[0080] In the formula, u' r is the radial displacement of the liner layer, B is the integral constant, ε' 0 is the equivalent strain.

[0081] Among them, the boundary conditions mainly include load constraints and displacement constraints acting on the three-dimensional finite element model of the vehicle-mounted hydrogen storage cylinder. The load constraints mainly include the thermal load and internal pressure load of the vehicle-mounted hydrogen storage cylinder at any fire time. The internal pressure load mainly acts on the inner wall surface of the vehicle-mounted hydrogen storage cylinder. It should be noted that in the finite element analysis process, the load constraints should be loaded first and then the displacement constraints.

[0082] Among them, the mechanical response analysis conditions include the load step and the solver type required when performing finite element analysis of the model, and the solver type preferably adopts an iterative solver; after setting the mechanical response analysis conditions, the mechanical response of the vehicle-mounted hydrogen storage cylinder under fire conditions can be solved by finite element analysis, including stress, strain, etc.

[0083] In step S102 of some embodiments, the gas cylinder fire failure criterion mainly records the failure condition of the vehicle-mounted hydrogen storage gas cylinder, and the failure condition includes: at the current fire time, the ratio between the current maximum stress of the composite material layer and the tensile strength of the composite material layer at the current temperature is greater than or equal to 1, and the ratio refers to the current fire failure degree value of the vehicle-mounted hydrogen storage gas cylinder.

[0084] It should be noted that the current maximum stress of the composite material layer includes the current maximum longitudinal stress, the current maximum transverse stress and the current maximum shear stress of the composite material layer, the tensile strength of the composite material layer at the current temperature includes the longitudinal strength, the transverse strength and the shear strength of the composite material layer at the current temperature, and the failure condition can be subdivided into a longitudinal failure condition, a transverse failure condition and a shear failure condition, which are specifically described as follows:

[0085] The longitudinal failure condition is: at the current burning time, the ratio between the current maximum longitudinal stress of the composite material layer and the longitudinal strength of the composite material layer at the current temperature is greater than or equal to 1, indicating that the on-board hydrogen storage cylinder has longitudinal failure;

[0086] The transverse failure condition is: at the current burning time, the ratio between the current maximum transverse stress of the composite material layer and the transverse strength of the composite material layer at the current temperature is greater than or equal to 1, indicating that the on-board hydrogen storage cylinder has transverse failure;

[0087] The shear failure condition is: at the current burning time, if the ratio between the current maximum shear stress of the composite material layer and the shear strength of the composite material layer at the current temperature is greater than or equal to 1, it means that the on-board hydrogen storage cylinder has shear failure.

[0088] Taking into account the winding manufacturing process, stress-strain distribution and actual failure conditions of the vehicle-mounted hydrogen storage cylinder, the lateral stress and shear stress of the composite material layer are very small. The vehicle-mounted hydrogen storage cylinder basically fails longitudinally in the event of a fire. Therefore, this application mainly focuses on the longitudinal failure condition.

[0089] In some embodiments, the above step S102 may include but is not limited to steps S201 to S203:

[0090] Step S201, obtaining a number of internal pressure loads and a number of thermal loads corresponding to the vehicle-mounted hydrogen storage cylinder at a number of different burning times, the number of thermal loads are different from each other, the thermal load refers to the thermal load on the inner and outer walls of the vehicle-mounted hydrogen storage cylinder, the number of burning times is gradually increasing, and the corresponding number of internal pressure loads is also gradually increasing.

[0091] Step S202: for each fire time, the thermal load of the vehicle-mounted hydrogen storage cylinder at the fire time is applied to the mechanical response finite element model for temperature update, and the mechanical property degradation model is used to solve the model to obtain the tensile strength of the composite material layer at the fire time; the thermal load and internal pressure load of the vehicle-mounted hydrogen storage cylinder at the fire time are applied to the mechanical response finite element model for solution to obtain the maximum stress of the composite material layer at the fire time; the fire failure degree value of the vehicle-mounted hydrogen storage cylinder at the fire time is calculated by combining the cylinder fire failure criterion and the maximum stress and tensile strength of the composite material layer at the fire time; the internal pressure load of the vehicle-mounted hydrogen storage cylinder at the fire time is defined as the gas pressure in the bottle, and the gas pressure in the bottle and the fire failure degree value of the vehicle-mounted hydrogen storage cylinder at the fire time are combined to form a set of second test data.

[0092] In this step, the thermal load of the vehicle-mounted hydrogen storage cylinder at the fire time is applied to the mechanical response finite element model for temperature update, which can be understood as: the thermal load of the vehicle-mounted hydrogen storage cylinder at the fire time is solved by the heat transfer equation to obtain the thermal distribution of the bottle body of the vehicle-mounted hydrogen storage cylinder, and the mechanical response finite element model updates the node temperature according to the thermal distribution of the bottle body of the vehicle-mounted hydrogen storage cylinder.

[0093] In this step, the internal pressure load of the vehicle-mounted hydrogen storage cylinder at the fire time is applied to the mechanical response finite element model for solution. This can be understood as: the internal pressure load of the vehicle-mounted hydrogen storage cylinder at the fire time is applied to the inner surface of the bottle body in the mechanical response finite element model, and after determining the appropriate load step, the stress distribution of the composite material layer at each load step is solved by finite element analysis.

[0094] It should be noted that, considering that with the increase of the burning time, the mechanical properties of the composite material layer continue to deteriorate, and the carrying capacity of the vehicle-mounted hydrogen storage cylinder also gradually decreases, in this step, the mechanical response of the vehicle-mounted hydrogen storage cylinder at different burning times is mainly solved along the time history and the data collection is completed.

[0095] Step S203, obtaining a plurality of groups of second test data corresponding to the vehicle-mounted hydrogen storage cylinder at the plurality of fire times obtained by solving the above step S202, and then generating the first change curve by directly connecting the data points.

[0096] It should be noted that the several groups of second test data should include the cases where the value of the degree of fire failure is less than 1 and the value of the degree of fire failure is greater than or equal to 1.

[0097] In step S103 of some embodiments, the second variation curve is obtained by:

[0098] Multiple groups of third test data are collected by conducting numerical simulation tests or actual fire tests on the vehicle-mounted hydrogen storage cylinder in advance, each group of third test data includes the fire time and the gas pressure in the vehicle-mounted hydrogen storage cylinder at the fire time, and then the second change curve is generated by directly connecting the data points.

[0099] In some embodiments, the above step S104 may include but is not limited to steps S301 to S303:

[0100] Step S301, selecting from the first variation curve the corresponding gas pressure in the vehicle-mounted hydrogen storage cylinder when the fire failure degree value is equal to 1, and then defining the selected gas pressure in the cylinder as the bursting pressure of the vehicle-mounted hydrogen storage cylinder in the case of fire;

[0101] Step S302: converting the first change curve and the second change curve to obtain a third change curve, wherein the third change curve mainly represents a change rule of the fire failure degree of the vehicle-mounted hydrogen storage cylinder with the fire time;

[0102] Step S303, filtering out from the third variation curve the fire time corresponding to the case where the fire failure degree value of the vehicle-mounted hydrogen storage cylinder is equal to 1, and then defining the filtered fire time as the fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire.

[0103] The method for predicting the fire resistance performance of the on-board hydrogen storage cylinder proposed in the embodiment of the present application takes into account the high-temperature mechanical property degradation characteristics of the carbon fiber epoxy resin-based composite material in order to be more in line with actual fire conditions, and conducts finite element mechanical modeling analysis under thermal-mechanical coupling based on the structural characteristics of the on-board hydrogen storage cylinder itself. At the same time, combined with the cylinder fire failure criterion for evaluation, the relevant fire resistance performance parameters of the on-board hydrogen storage cylinder itself can be more reliably predicted.

[0104] The following is a further description of the solution of the embodiment of the present application in conjunction with a specific application example, which mainly includes the following steps 1 to 7:

[0105] First of all, it is clear that the on-board hydrogen storage cylinder is a 70MPa aluminum alloy liner carbon fiber fully wrapped composite material hydrogen storage cylinder. The geometric size parameters of the on-board hydrogen storage cylinder are: the outer diameter of the bottle body is 310mm, the thickness of the composite material layer is 25mm, and the thickness of the aluminum alloy liner layer is 4.5mm.

[0106] Step 1, construct a mechanical property degradation model of carbon fiber epoxy resin based composite materials at high temperature;

[0107] Specifically, by conducting high-temperature mechanical properties tests on the carbon fiber epoxy resin-based composite material in advance to collect relevant data, a hyperbolic tangent function is used to complete curve fitting, and then the mechanical properties degradation model of the carbon fiber epoxy resin-based composite material at high temperature (20°C to 450°C) is obtained as follows:

[0108] P(T)=2019-180{1+tanh[0.01(T-112)]}-350{1+tanh[0.0167(T-339)]}

[0109] Wherein, T is temperature, P(T) is the longitudinal strength of the carbon fiber epoxy resin based composite material at temperature T, and the longitudinal strength of the carbon fiber epoxy resin based composite material at room temperature is 2019 MPa.

[0110] Step 2: construct a finite element model of the mechanical response of the on-board hydrogen storage cylinder under the action of thermal-mechanical coupling;

[0111] Specifically, ANSYS Workbench software was first used to construct a three-dimensional finite element model of the on-board hydrogen storage cylinder, and the structural unit types of the composite material layer and the aluminum alloy liner layer were defined respectively. The structural unit Sol id186 was used to mesh the three-dimensional finite element model of the on-board hydrogen storage cylinder, and the meshes of the head and the bottle mouth were refined. After mesh independence verification, the three-dimensional finite element model of the on-board hydrogen storage cylinder had a total of 71584 units and 314393 nodes, as shown in Figure 2. Figure 2As shown; then, the constitutive relationship of the carbon fiber epoxy resin-based composite material and the aluminum alloy material is constructed, and the mechanical analysis of the composite material layer and the aluminum alloy liner layer is performed; secondly, boundary conditions are applied to the three-dimensional finite element model of the on-board hydrogen storage cylinder, including: obtaining the thermal load of the on-board hydrogen storage cylinder at any fire time and applying it to the bottle body, obtaining the internal pressure load of the on-board hydrogen storage cylinder at the fire time and applying it to the inner wall of the bottle body, and applying an axial balance load to the annular surface of the bottle mouth, and applying axial displacement constraints and rotation constraints in three directions at the nodes at the apex of the tail of the bottle body. The rotation constraints in these three directions can be understood as axial rotation constraints, circumferential rotation constraints and radial rotation constraints; finally, the mechanical response analysis conditions of the three-dimensional finite element model of the on-board hydrogen storage cylinder are set, including the Iterative solver and its load step parameters to be applied.

[0112] Step 3: Apply the mechanical property degradation model to the mechanical response finite element model, and perform finite element analysis in combination with the preset gas cylinder fire failure criterion to obtain a curve of the change between the degree of fire failure of the on-board hydrogen storage cylinder and the gas pressure in the cylinder, such as Figure 3 shown.

[0113] Step 4: After collecting relevant data by conducting a numerical simulation test on the fire process of the on-board hydrogen storage cylinder in advance, the data points are connected to obtain a curve of the change of the gas pressure in the on-board hydrogen storage cylinder with the fire time, such as Figure 4 shown.

[0114] Step five, according to the fire failure criterion of the gas cylinder, data screening is performed on the curve between the fire failure degree of the vehicle-mounted hydrogen storage cylinder and the gas pressure in the cylinder, and the bursting pressure of the vehicle-mounted hydrogen storage cylinder in the case of fire is obtained to be 95.4MPa.

[0115] Step 6: Convert the curve of the change between the degree of fire failure of the vehicle-mounted hydrogen storage cylinder and the gas pressure in the cylinder and the curve of the change between the gas pressure in the cylinder and the fire time of the vehicle-mounted hydrogen storage cylinder to obtain the curve of the change between the degree of fire failure of the vehicle-mounted hydrogen storage cylinder and the fire time, such as Figure 5 shown.

[0116] Step seven, according to the fire failure criterion of the gas cylinder, data screening is performed on the curve of the fire failure degree of the vehicle-mounted hydrogen storage gas cylinder changing with the fire time, and the fire resistance time of the vehicle-mounted hydrogen storage gas cylinder under fire is obtained to be 844s.

[0117] See also Figure 6The embodiment of the present application also provides a structural schematic diagram of a vehicle-mounted hydrogen storage cylinder fire resistance performance prediction system, which can implement the above-mentioned vehicle-mounted hydrogen storage cylinder fire resistance performance prediction method. First of all, it is explained that the vehicle-mounted hydrogen storage cylinder includes a composite material layer, and the composite material layer is mainly made of carbon fiber epoxy resin-based composite material. The system includes:

[0118] Establishing module 401, for establishing a finite element model of the mechanical response of the vehicle-mounted hydrogen storage cylinder under the action of thermal-mechanical coupling and a mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature;

[0119] The first analysis module 402 is used to apply the mechanical performance degradation model to the mechanical response finite element model, and perform finite element analysis in combination with a preset gas cylinder fire failure criterion to obtain a first change curve, wherein the first change curve mainly represents the relationship between the degree of fire failure of the vehicle-mounted hydrogen storage gas cylinder and the gas pressure in the cylinder;

[0120] An acquisition module 403 is used to acquire a second variation curve, which mainly represents a variation rule of the gas pressure in the vehicle-mounted hydrogen storage cylinder with the burning time;

[0121] The second analysis module 404 is used to combine and analyze the first change curve and the second change curve according to the cylinder fire failure criterion to obtain the fire resistance time and bursting pressure of the vehicle-mounted hydrogen storage cylinder under fire.

[0122] It can be understood that the contents of the above method embodiments are all applicable to the present system embodiments, the functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0123] The embodiment of the present application also provides an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor implements the above-mentioned method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder when executing the computer program. The electronic device may include any intelligent terminal such as a tablet computer and a vehicle-mounted computer.

[0124] It can be understood that the contents of the above method embodiments are all applicable to the present device embodiments, the functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0125] See also Figure 7 , Figure 7 The hardware structure of an electronic device according to another embodiment is shown. The electronic device includes:

[0126] The processor 501 may be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application;

[0127] The memory 502 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 502 can store an operating system and other application programs. When the technical solution provided in the embodiment of the present application is implemented by software or firmware, the relevant program code is stored in the memory 502, and the processor 501 calls and executes the technical solution provided in the embodiment of the present application;

[0128] Input / output interface 503, used to implement information input and output;

[0129] Communication interface 504, used to realize communication interaction between the device and other devices, which can be realized through wired mode (such as USB, network cable, etc.) or wireless mode (such as mobile network, WI FI, Bluetooth, etc.);

[0130] A bus 505 that transmits information between the various components of the device (e.g., the processor 501, the memory 502, the input / output interface 503, and the communication interface 504);

[0131] The processor 501 , the memory 502 , the input / output interface 503 and the communication interface 504 are connected to each other in communication within the device via the bus 505 .

[0132] An embodiment of the present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned method for predicting the fire resistance performance of the on-board hydrogen storage cylinder is implemented.

[0133] It can be understood that the contents of the above method embodiments are all applicable to the present storage medium embodiments, the functions specifically implemented by the present storage medium embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0134] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0135] The embodiments described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0136] Those skilled in the art will appreciate that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0137] The system embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0138] Those skilled in the art will appreciate that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices may be implemented as software, firmware, hardware, or a suitable combination thereof.

[0139] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0140] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0141] In the several embodiments provided in the present application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are only schematic. For example, the division of the above units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of systems or units, which can be electrical, mechanical or other forms.

[0142] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0143] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0144] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including multiple instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, referred to as ROM), random access memory (Random Access Memory, referred to as RAM), disk or optical disk and other media that can store programs.

[0145] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. A method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder, wherein the vehicle-mounted hydrogen storage cylinder comprises a composite material layer, and the composite material layer is made of a carbon fiber epoxy resin-based composite material, characterized in that: The method comprises: Establishing a mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature and a finite element model of the mechanical response of the on-board hydrogen storage cylinder under thermal-mechanical coupling; The mechanical property degradation model is applied to the mechanical response finite element model, and a finite element analysis is performed in combination with a preset gas cylinder fire failure criterion to obtain a first change curve, wherein the first change curve is used to characterize the relationship between the degree of fire failure of the vehicle-mounted hydrogen storage gas cylinder and the gas pressure in the cylinder; Obtaining a second variation curve, where the second variation curve is used to characterize a variation law of the gas pressure in the vehicle-mounted hydrogen storage cylinder with the burning time; According to the cylinder fire failure criterion, the first change curve and the second change curve are combined and analyzed to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire.

2. The method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder according to claim 1, characterized in that: The mechanical property degradation model is obtained by: Acquire multiple groups of first test data, wherein the multiple groups of first test data are collected when conducting a high temperature mechanical property test of the carbon fiber epoxy resin-based composite material, each group of the first test data includes a temperature value and a mechanical property parameter value of the carbon fiber epoxy resin-based composite material at the temperature value, and the mechanical property parameter value includes a tensile strength value; Curve fitting is performed on the multiple groups of first test data to obtain the mechanical property degradation model, and the mechanical property degradation model is used to characterize the variation law of the mechanical property parameters of the carbon fiber epoxy resin-based composite material with temperature.

3. The method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder according to claim 1, characterized in that: The mechanical response finite element model is obtained in the following way: Establishing a three-dimensional finite element model of the vehicle-mounted hydrogen storage cylinder; Setting mechanical analysis conditions, boundary conditions and mechanical response analysis conditions of the three-dimensional finite element model to form the mechanical response finite element model; Among them, the mechanical analysis conditions include the relationship between the stress and strain of the composite material layer and the relationship between the strain and displacement of the composite material layer; the boundary conditions include load constraints and displacement constraints acting on the three-dimensional finite element model, and the load constraints include the thermal load and internal pressure load of the on-board hydrogen storage cylinder at any fire time; the mechanical response analysis conditions include the load step and the solver type required when performing model finite element analysis.

4. The method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder according to claim 1, characterized in that: The gas cylinder fire failure criterion records the failure conditions of the on-board hydrogen storage gas cylinder, and the failure conditions include: at the current fire time, the ratio between the current maximum stress of the composite material layer and the tensile strength of the composite material layer at the current temperature is greater than or equal to 1, and the ratio is the current fire failure degree value of the on-board hydrogen storage gas cylinder.

5. The method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder according to claim 4 is characterized in that: The mechanical property degradation model is applied to the mechanical response finite element model, and a finite element analysis is performed in combination with a preset gas cylinder fire failure criterion to obtain a first change curve, including: Obtaining a plurality of heat loads and a plurality of internal pressure loads corresponding to the vehicle-mounted hydrogen storage cylinder at a plurality of different fire burning times; For each of the fire time, the thermal load of the on-board hydrogen storage cylinder at the fire time is applied to the mechanical response finite element model for temperature update, and the mechanical property degradation model is used to solve the model to obtain the tensile strength of the composite material layer at the fire time; the thermal load and internal pressure load of the on-board hydrogen storage cylinder at the fire time are applied to the mechanical response finite element model for solution to obtain the maximum stress of the composite material layer at the fire time; according to the cylinder fire failure criterion and the tensile strength and maximum stress of the composite material layer at the fire time, the fire failure degree value of the on-board hydrogen storage cylinder at the fire time is determined; the internal pressure load of the on-board hydrogen storage cylinder at the fire time is used as the gas pressure in the cylinder, and the fire failure degree value of the on-board hydrogen storage cylinder at the fire time and the gas pressure in the cylinder are combined to form a set of second test data; A plurality of groups of second test data corresponding to the vehicle-mounted hydrogen storage cylinder at the plurality of fire times are obtained to generate the first variation curve.

6. The method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder according to claim 1, characterized in that: The second variation curve is obtained by: Acquire multiple sets of third test data, wherein the multiple sets of third test data are collected by carrying out a real fire test or a numerical simulation test of the fire process of the vehicle-mounted hydrogen storage cylinder, and each set of the third test data includes the fire time and the gas pressure in the vehicle-mounted hydrogen storage cylinder at the fire time; The second variation curve is generated according to the plurality of sets of third test data.

7. The method for predicting the fire resistance performance of a vehicle-mounted hydrogen storage cylinder according to claim 4, characterized in that: The first variation curve and the second variation curve are combined and analyzed according to the cylinder fire failure criterion to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions, including: Filtering out the gas pressure in the bottle corresponding to the case where the fire failure degree value of the on-board hydrogen storage gas bottle is equal to 1 from the first variation curve, and using the filtered gas pressure in the bottle as the bursting pressure; The first variation curve and the second variation curve are converted to obtain a third variation curve, wherein the third variation curve is used to characterize the variation law of the degree of fire failure of the vehicle-mounted hydrogen storage cylinder with the fire time; The fire time corresponding to the case where the fire failure degree value of the vehicle-mounted hydrogen storage cylinder is equal to 1 is screened out from the third variation curve, and the screened fire time is used as the fire resistance time.

8. A fire resistance prediction system for a vehicle-mounted hydrogen storage cylinder, wherein the vehicle-mounted hydrogen storage cylinder comprises a composite material layer, wherein the composite material layer is made of a carbon fiber epoxy resin-based composite material, characterized in that: The system comprises: Establishing a module for establishing a mechanical property degradation model of the carbon fiber epoxy resin-based composite material at high temperature and a mechanical response finite element model of the on-board hydrogen storage cylinder under thermal-mechanical coupling; A first analysis module is used to apply the mechanical property degradation model to the mechanical response finite element model, and to perform finite element analysis in combination with a preset gas cylinder fire failure criterion to obtain a first change curve, wherein the first change curve is used to characterize the relationship between the degree of fire failure of the vehicle-mounted hydrogen storage gas cylinder and the gas pressure in the cylinder; An acquisition module, used for acquiring a second variation curve, where the second variation curve is used for representing a variation rule of the gas pressure in the vehicle-mounted hydrogen storage cylinder with the burning time; The second analysis module is used to combine and analyze the first change curve and the second change curve according to the cylinder fire failure criterion to obtain the bursting pressure and fire resistance time of the vehicle-mounted hydrogen storage cylinder under fire conditions.

9. An electronic device, characterized in that: The electronic device comprises a memory and a processor, the memory stores a computer program, and the processor implements the method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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