Hydrogen diffusion behavior analysis method and system for composite hydrogen delivery pipeline

Abstract

The application provides a hydrogen diffusion behavior analysis method and system for a composite hydrogen pipeline, and belongs to the technical field of hydrogen energy storage and transportation. In view of the problem that the prior art is difficult to simultaneously analyze the diffusion differences of different material layers, the interlayer interface influence and the cross-layer migration process, a multilayer structure analysis model containing each material layer and an interlayer interface region is constructed; the hydrogen diffusion coefficients of the single-layer materials corresponding to each material layer are extracted; the cross-layer diffusion process of hydrogen molecules is tracked, and the interface equivalent diffusion coefficient of the interlayer interface region is calculated; the hydrogen diffusion coefficients of the single-layer materials and the interface equivalent diffusion coefficient are taken as diffusion units arranged in series, and the thicknesses are combined to perform series resistance superposition calculation, so that the overall diffusion coefficient of the composite pipeline is obtained. The application can comprehensively characterize the overall hydrogen diffusion behavior and hydrogen blocking performance, and provides a basis for material selection and structure optimization of the composite pipeline.

Description

Technical Field

[0001] This invention relates to the intersection of computer simulation and materials analysis, and in particular to a method and system for analyzing hydrogen diffusion behavior in composite hydrogen transport pipelines. Background Technology

[0002] With the advancement of hydrogen energy storage and transportation technology, pipelines, as a crucial infrastructure for hydrogen transport, have received continuous attention for their barrier performance and operational safety. Due to the small size of hydrogen molecules, they readily dissolve, diffuse, and permeate within pipeline materials under the influence of factors such as temperature, pressure, and concentration differences. To improve the adaptability of pipelines to hydrogen media, existing technologies often employ composite hydrogen transport pipelines composed of two or more layers of different materials. This leverages the synergistic effect of multiple layers, including an inner lining, barrier layer, reinforcement layer, and outer protective layer, to improve overall hydrogen barrier performance. In studies targeting hydrogen diffusion behavior, existing approaches typically rely on single-material diffusion theory or experimental testing methods. These methods construct microscopic systems composed of hydrogen molecules and a single target material, using molecular dynamics simulations to calculate the mean square displacement of hydrogen molecules within the material to extract its diffusion coefficient.

[0003] However, when dealing with multilayer composite structures, existing solutions usually require treating different material layers separately, or directly simplifying the multilayer structure into an equivalent homogeneous single structure. The overall diffusion capacity is obtained through macroscopic equivalent experiments (such as permeation experiments or adsorption-desorption experiments), which cannot continuously and dynamically describe the multilayer material and the complex interface transitions between its layers.

[0004] Therefore, there is an urgent need for a method and system for analyzing hydrogen diffusion behavior in composite hydrogen transport pipelines to solve the problems existing in the current technology. Summary of the Invention

[0005] This invention provides a method and system for analyzing the hydrogen diffusion behavior of composite hydrogen transport pipelines. It addresses the problems of existing solutions, which are mainly based on single material analysis or macroscopic overall equivalent characterization, making it difficult to continuously reveal the cross-layer continuous diffusion process of hydrogen molecules from one layer of material across the interface and into another layer of material, and failing to accurately quantify the specific impact of the interlayer interface region on the overall hydrogen diffusion trend and hydrogen barrier performance of the pipeline.

[0006] The core technology of this invention is to treat each material layer in the wall thickness direction of the multi-layer composite pipeline and the interlayer interface region as independent continuous series diffusion units. By combining molecular dynamics and Monte Carlo random sampling, the hydrogen diffusion coefficient of a single layer material and the equivalent diffusion coefficient of the interface in the direction perpendicular to the interface are extracted respectively. Based on the thickness and diffusion coefficient of each diffusion unit, the series resistance is superimposed to obtain the overall hydrogen diffusion behavior analysis results of the composite hydrogen transport pipeline.

[0007] In a first aspect, the present invention provides a method for analyzing the hydrogen diffusion behavior of a composite hydrogen transport pipeline, the method comprising the following steps:

[0008] A multi-layer structural analysis model of a composite hydrogen transport pipeline is constructed. The multi-layer structural analysis model includes at least two material layers arranged sequentially along the pipeline wall thickness direction and the interlayer interface region between adjacent material layers. For each material layer in the multilayer structure analysis model, a corresponding diffusion analysis model is established to simulate the movement process of hydrogen molecules. Based on the statistical characteristics of the evolution of the microscopic movement position of hydrogen molecules over time, the hydrogen diffusion coefficient of each material layer is extracted. For each interlayer interface region, the continuous motion trajectory of hydrogen molecules migrating from one side of the material layer to the interlayer interface region and entering the other side of the material layer is tracked. Based on the statistical characteristics of the position change of hydrogen molecules in the interlayer interface region along the direction perpendicular to the interface over time, the equivalent diffusion coefficient of each interlayer interface region is calculated. The hydrogen diffusion coefficient of each single-layer material and the equivalent diffusion coefficient of each interface are taken as diffusion units arranged continuously along the pipe wall thickness direction. The overall diffusion coefficient of the composite hydrogen transport pipeline is obtained by superimposing series resistances by combining the thickness of each material layer and the equivalent thickness of the interface region between each layer.

[0009] Furthermore, when constructing the multilayer structure analysis model, the model parameters set include: the material type, arrangement order and thickness of each material layer, the interaction parameters between hydrogen molecules and material molecules in each material layer, the binding energy and defect distribution characteristics of the interlayer interface, and at least one operating condition factor among temperature, pressure and concentration difference.

[0010] Furthermore, the step of extracting the hydrogen diffusion coefficient of each material layer specifically includes: Under the temperature and pressure conditions of the target working condition, the molecular dynamics method is used to simulate the motion process of hydrogen molecules in the corresponding material layer to obtain the position coordinate information of hydrogen molecules changing with time, and the micro-mean square displacement of hydrogen molecules in the corresponding material layer is calculated based on the position coordinate information. The curve of the micro-mean square displacement changing with time is fitted within the linear diffusion range. The rate of change of the micro-mean square displacement with time is obtained using the Einstein diffusion relation. Based on the rate of change, the hydrogen diffusion coefficient of the corresponding single-layer material is calculated.

[0011] Furthermore, the steps for calculating the equivalent diffusion coefficient of each interlayer interface region specifically include: Molecular dynamics was used to simulate the motion of hydrogen molecules in the region near the interface. The position coordinates of hydrogen molecules over time were recorded. The continuous motion process of hydrogen molecules migrating from one side of the material layer to the interface, staying near the interface, and crossing the interface into the adjacent material layer was analyzed. The micro-mean square displacement of hydrogen molecules in the interlayer interface region along the direction perpendicular to the interface was obtained. The rate of change of the interface micro-mean square displacement with time is obtained by using one-dimensional diffusion statistics, and the interface equivalent diffusion coefficient of the corresponding interlayer interface region is calculated based on the rate of change.

[0012] Furthermore, tracking the translayer diffusion process of hydrogen molecules also includes: The number of hydrogen molecules that successfully cross the corresponding interlayer interface and the number of hydrogen molecules that enter the corresponding interlayer interface region are statistically analyzed through molecular simulation within a set time. The cross-interface migration probability of the corresponding interlayer interface is determined by using the ratio of the number of hydrogen molecules that successfully cross to the number of hydrogen molecules that enter. Based on cross-interface migration probability, the Monte Carlo random sampling method is used to simulate the random walk process of hydrogen molecules in a multilayer structure in order to obtain the statistical law of cross-layer random propagation of hydrogen molecules.

[0013] Furthermore, the step of calculating the overall diffusion coefficient of the composite hydrogen transport pipeline by superimposing series resistances specifically includes: The overall diffusion coefficient of the composite hydrogen transport pipeline is obtained by dividing the total thickness of the composite hydrogen transport pipeline along the hydrogen diffusion direction by the weighted sum of the reciprocal distribution values ​​of each diffusion unit. The weighted sum of the reciprocal distribution values ​​is composed of the sum of the ratios of the thickness of each material layer to the hydrogen diffusion coefficient of the corresponding single-layer material, and the sum of the ratios of the equivalent thickness of each interlayer interface region to the corresponding equivalent diffusion coefficient of the interface. The total thickness is obtained by adding the sum of the thicknesses of each material layer to the sum of the equivalent thicknesses of the interface regions between each layer.

[0014] Furthermore, after calculating the overall diffusion coefficient of the composite hydrogen transport pipeline, the following is also included: Based on the set operating conditions, the overall diffusion coefficient is multiplied by the hydrogen concentration gradient along the pipe wall thickness direction according to Fick's diffusion law, and the hydrogen diffusion flux along the composite hydrogen transport pipeline wall thickness direction is calculated. The operating conditions include at least one or more of the following: temperature conditions, pressure conditions, and the concentration difference of hydrogen inside and outside the pipeline.

[0015] Secondly, the present invention provides a device for analyzing the hydrogen diffusion behavior of a composite hydrogen transport pipeline, comprising: The model building module is used to build a multi-layer structure analysis model of the composite hydrogen transport pipeline. The multi-layer structure analysis model includes at least two material layers arranged sequentially along the pipeline wall thickness direction and the interlayer interface region between adjacent material layers. The first parameter extraction module is used to establish a corresponding diffusion analysis model for each material layer in the multilayer structure analysis model, simulate the movement process of hydrogen molecules, and extract the hydrogen diffusion coefficient of each material layer based on the statistical characteristics of the evolution of the microscopic movement position of hydrogen molecules over time. The second parameter extraction module is used to track the cross-layer diffusion process of hydrogen molecules from one side of the material layer to the interlayer interface region and into the other side of the material layer for each interlayer interface region. Based on the statistical characteristics of the position change of hydrogen molecules in the interlayer interface region along the direction perpendicular to the interface over time, the equivalent diffusion coefficient of each interlayer interface region is calculated. The overall parameter integration module is used to treat the hydrogen diffusion coefficient of each single-layer material and the equivalent diffusion coefficient of each interface as diffusion units arranged continuously along the pipe wall thickness direction. Combined with the thickness of each material layer and the equivalent thickness of the interface region between each layer, the module performs series resistance superposition calculation to obtain the overall diffusion coefficient of the composite hydrogen transport pipeline.

[0016] Thirdly, the present invention provides an electronic device including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to execute the above-described method for analyzing the hydrogen diffusion behavior of a composite hydrogen transport pipeline.

[0017] Fourthly, the present invention provides a readable storage medium storing a computer program, the computer program including program code for controlling a process to execute the process, the process including the hydrogen diffusion behavior analysis method for the composite hydrogen transport pipeline described above.

[0018] The main contributions and innovations of this invention are as follows: 1. This invention overcomes the limitation of existing technologies that simplify composite pipelines into homogeneous single structures by constructing a multi-layer structural analysis model that includes each material layer and the interlayer interface region between adjacent material layers. It integrates diffusion within a single layer, diffusion in the interface region, and continuous cross-layer movement into the same analysis framework, thereby achieving a systematic and multi-scale analysis of the hydrogen diffusion law of composite structures.

[0019] 2. This invention establishes separate cross-layer diffusion analysis objects for each interlayer interface region. By capturing the positional statistical characteristics of hydrogen molecules along the direction perpendicular to the interface, the equivalent diffusion coefficient of the interface is calculated. Furthermore, the cross-interface migration probability is introduced in conjunction with Monte Carlo random sampling to simulate the cross-layer random walk process. This can accurately characterize the accumulation effect or resistance abrupt change at the interlayer interface, greatly improving the accuracy of characterizing the micro-diffusion mechanism of multilayer composite pipeline structures.

[0020] 3. This invention uses the hydrogen diffusion coefficient of each single-layer material and the equivalent diffusion coefficient of each interface as diffusion units arranged continuously along the pipe wall thickness direction. Combined with the material layer thickness and the equivalent interface thickness, the series resistance superposition calculation is performed. This can establish a rigorous mathematical mapping between microscopic molecular simulation data and macroscopic engineering evaluation indicators, thereby enabling accurate and quantitative determination of the overall diffusion coefficient and diffusion flux of the composite pipeline under different working conditions.

[0021] 4. By repeatedly extracting diffusion unit parameters and performing overall tandem calculations under different temperature, pressure, or concentration difference operating conditions, this invention can quantitatively predict the impact of different service environments on the overall diffusion trend and hydrogen barrier performance of composite hydrogen transport pipelines. This provides scientific, efficient, and reliable data support for the material combination screening, multi-layer structure optimization design, and long-term safe service evaluation of composite hydrogen transport pipelines.

[0022] Details of one or more embodiments of the present invention are set forth in the following drawings and description, so that other features, objects and advantages of the invention will be more readily understood. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a flowchart of a method for analyzing the hydrogen diffusion behavior of a composite hydrogen transport pipeline according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the multilayer structure model of the composite hydrogen transport pipeline and the influence mechanism of diffusion behavior according to an embodiment of the present invention; Figure 3 This is a hydrogen diffusion diagram of the interface region in a multi-layered pipe structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram comparing and verifying the analysis results of hydrogen diffusion behavior according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0024] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with one or more embodiments of this specification. Rather, they are merely examples of apparatuses and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

[0025] It should be noted that the steps of the corresponding methods are not necessarily performed in the order shown and described in this specification in other embodiments. In some other embodiments, the methods may include more or fewer steps than described in this specification. Furthermore, a single step described in this specification may be broken down into multiple steps in other embodiments; and multiple steps described in this specification may be combined into a single step in other embodiments.

[0026] The present invention provides a method for analyzing the hydrogen diffusion behavior of composite hydrogen transport pipelines, which is applicable to composite hydrogen transport pipeline structures composed of two or more layers of different materials. It can perform multi-scale quantitative analysis of the diffusion of hydrogen molecules within each single layer of material and the cross-layer diffusion process from one layer of material through the interlayer interface region and into another layer of material.

[0027] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and through specific implementation steps and embodiments.

[0028] Example 1 like Figure 1 As shown in the figure, the method for analyzing hydrogen diffusion behavior in a composite hydrogen transport pipeline provided in this embodiment specifically includes the following steps: Step 1: Construct a multi-layer structural analysis model of the composite hydrogen transport pipeline and determine the analysis parameters.

[0029] Based on the actual hierarchical structure of the composite hydrogen transport pipeline, the material type, arrangement order, thickness, inner and outer diameters of each material layer, and the interface correspondence between adjacent material layers are determined. For example... Figure 2 As shown in this embodiment, the multi-layer structure of the composite hydrogen transport pipeline includes four material layers from the inside out: an inner lining layer, a barrier layer, a reinforcement layer, and an outer protective layer, with corresponding interlayer interface regions formed between adjacent material layers.

[0030] When constructing a multi-layer structure analysis model, the model parameters set include the following four categories: The first category consists of the basic structural parameters of each material layer, including the material type, arrangement order, and thickness of each layer. The material type is determined based on the actual structure of the composite hydrogen transport pipeline. For example, the inner lining layer can be made of polymer materials (such as high-density polyethylene, XRT70, etc.), the barrier layer can be made of metal materials (such as aluminum foil) or dense polymer materials (such as ethylene-vinyl alcohol copolymer), the reinforcement layer can be made of fiber-reinforced composite materials (such as polyester, glass fiber reinforced resin, etc.), and the outer protective layer can be made of polymer materials or metal alloy materials with corrosion resistance and aging resistance.

[0031] The second category consists of interaction parameters between hydrogen molecules and material molecules in each material layer, including van der Waals forces and local interaction strengths between hydrogen molecules and material molecules in each layer, which are quantified by setting intermolecular potential energy functions.

[0032] The third category is the bonding energy and defect distribution characteristics of interlayer interfaces. The bonding energy of interlayer interfaces reflects the tightness of the interface bonding between adjacent material layers. The defect distribution characteristics include the distribution of defects such as pores and cracks that may exist at the interface. By introducing an interface potential energy correction term and a defect distribution function, the accumulation effect of hydrogen molecules and the abrupt change in diffusion resistance at the interface can be characterized.

[0033] The fourth category includes at least one of the following operating conditions: temperature, pressure, and concentration gradient. Temperature affects the intensity of thermal motion and diffusion capacity of hydrogen molecules in the material layer and interface region; pressure affects the dissolution state of hydrogen in the pipeline and the rate at which it enters the material layer or interface region; concentration gradient affects the migration of hydrogen from the high concentration side to the low concentration side along the pipeline wall thickness. These operating conditions collectively determine the diffusion behavior of hydrogen in the composite hydrogen transport pipeline.

[0034] Step 2: Extract the hydrogen diffusion coefficient of each single-layer material.

[0035] Since the different material layers in the multi-layered structure of the composite hydrogen transport pipeline have different constraints on hydrogen molecules, local microenvironments, and interaction characteristics, it is necessary to establish a corresponding diffusion analysis model for each material layer.

[0036] In practice, representative local regions of the target material layer are extracted from the multilayer structure analysis model constructed in step one, and a diffusion analysis model incorporating this material layer and hydrogen molecules is built. Under the target operating conditions of temperature and pressure, molecular dynamics (MD) is used to simulate the motion of hydrogen molecules within the target material layer. The specific operation is as follows: In a preferred embodiment, when using molecular dynamics simulation, the Polymer Consistent Force Field (PCFF) is selected as the potential function for intermolecular interactions. First, the constructed diffusion analysis model is geometrically optimized using the Forcite module, with an iteration step count of 500 steps and an energy convergence tolerance of 0.001 kcal / mol. After geometric optimization, annealing is performed to eliminate unreasonable configurations and local stresses in the model. Subsequently, a 1 ns NPT ensemble simulation is conducted under target conditions (e.g., temperature 298 K, pressure 0.1 MPa), using an Andersen thermostat and a simulation step size of 1.0 fs to ensure the system reaches equilibrium under the target temperature and pressure conditions. After the NPT ensemble simulation, a 3 ns NVT ensemble simulation is performed to obtain the motion trajectory data of hydrogen molecules in the material layer for full diffusion, recording the position coordinates of hydrogen molecules over time.

[0037] After obtaining the trajectory data of hydrogen molecules, the mean square displacement of hydrogen molecules in the target material layer is calculated. Specifically, let the first... i The number of hydrogen molecules participating in the statistics in each material layer is , No. k The position vector of each hydrogen molecule at the initial moment is: At any moment t The position vector is Then the first i Mean square displacement of hydrogen molecules in each material layer It can be represented as:

[0038] in, Indicates the first k A hydrogen molecule in time t The vector of position change within, Indicates the first i Hydrogen molecules in each material layer in time t The mean square displacement within the target material layer is an important physical quantity characterizing the diffusion behavior of hydrogen molecules and can be used to reflect the degree of diffusion of hydrogen molecules in the target material layer.

[0039] Based on the curve of the mean square displacement of hydrogen molecules over time, a linear diffusion interval is selected for fitting. The rate of change of the microscopic mean square displacement over time (i.e., the slope of the mean square displacement curve in the linear interval) is obtained using the Einstein diffusion relation. Based on the rate of change, the first... i Hydrogen diffusion coefficient of a single layer of material The calculation formula is as follows:

[0040] in, For the first i Hydrogen molecules in each material layer in time t The mean square displacement within the layer. In this way, the independent hydrogen diffusion coefficients D1, D2, ..., D of each monolayer material can be obtained. i ,…,D m .

[0041] By calculating the diffusion coefficients of different material layers separately, the influence of each layer on the diffusion behavior of hydrogen molecules can be distinguished, avoiding the problem of inaccurate diffusion capacity characterization caused by equating the composite structure to a single homogeneous material. The obtained diffusion coefficients of each layer not only reflect the diffusion differences between different material layers in the composite hydrogen transport pipeline, but also serve as the basic input parameters for subsequent hydrogen molecule cross-layer trajectory tracking, calculation of equivalent diffusion coefficients in interlayer interface regions, and analysis of overall hydrogen diffusion behavior.

[0042] Step 3: For each interlayer interface region, track the cross-layer diffusion process of hydrogen molecules and calculate the equivalent diffusion coefficient of the interface.

[0043] like Figure 3 As shown, when hydrogen molecules diffuse from the inside to the outside of a multilayer structure, they not only move within a single layer of material but also undergo interfacial transitions and cross-interfacial diffusion between adjacent material layers. This step selects two adjacent material layers and their interlayer interface region as the object of cross-layer diffusion analysis. Under the target operating conditions of temperature, pressure, and concentration difference, molecular dynamics is used to simulate the motion of hydrogen molecules in the region near the interface. The position coordinates of hydrogen molecules over time are recorded, and the continuous motion process of hydrogen molecules migrating from one side of the material layer to the interface, lingering near the interface, and crossing the interface into adjacent material layers is dynamically analyzed. Thus, the microscopic mean square displacement of hydrogen molecules in the interlayer interface region along the direction perpendicular to the interface (i.e., along the pipe wall thickness direction) is obtained.

[0044] Based on the statistical relationship between the interface's micro-mean square displacement perpendicular to the interface direction and diffusion time, the rate of change of the interface's micro-mean square displacement with time is calculated using a one-dimensional diffusion statistical relationship. Based on this rate of change, the first... j The equivalent diffusion coefficient of the interface region between layers The calculation formula is as follows:

[0045] in, For the first j The mean square displacement of hydrogen molecules along the direction perpendicular to the interface within each interlayer interface region. t For the diffusion time, denoted as . In this formula, since only the projected displacement along a one-dimensional direction perpendicular to the interface is extracted and counted, the scaling constant is 1 / 2.

[0046] Furthermore, the number of hydrogen molecules that successfully crossed the corresponding interlayer interface within a set time period was statistically analyzed using molecular simulations. The number of hydrogen molecules entering the region Determine the first j Cross-interface migration probability between layers :

[0047] Based on the above probabilities, the Monte Carlo (MC) random sampling method is used to simulate the random walk process of hydrogen molecules in a multilayer structure model, thereby obtaining the statistical law of cross-layer random propagation of hydrogen molecules under the influence of interlayer interfaces, and providing probabilistic constraints for macroscopic integration.

[0048] In implementing the Monte Carlo random sampling method, hydrogen molecules are treated as randomly walking particles, and a time step is set. Based on the hydrogen diffusion coefficient of each monolayer material Determine the maximum single-step transition size of the particle within the corresponding material layer; within each time step, when the particle moves to the [missing information]... j When determining the boundary of an interlayer interface, the computer generates a uniformly distributed random number in the interval [0,1]. r and the random number r With cross-interface migration probability Perform size comparison: like If so, it is determined that the particle has successfully crossed the interface and entered the next material layer in the current time step; like If the particle fails to pass through, it will either remain at the original position on the interface or bounce back at the current time step.

[0049] By tracking the positional iteration process of a large number of particles, the statistical regularity of the overall diffusion behavior can be obtained.

[0050] Step 4: Calculate the overall diffusion coefficient by superimposing the series resistances, and analyze the hydrogen diffusion behavior of the composite hydrogen transport pipeline.

[0051] Since the composite hydrogen transport pipeline is composed of multiple material layers and interlayer interfaces sequentially distributed along the wall thickness, this step treats the hydrogen diffusion coefficient of each single-layer material and the equivalent diffusion coefficient of the interface as diffusion units arranged continuously along the pipeline wall thickness. The overall diffusion coefficient is obtained by dividing the total thickness L of the composite hydrogen transport pipeline along the hydrogen diffusion direction by the weighted sum of the reciprocals of the distribution values ​​of each diffusion unit. :

[0052] in, m The total number of material layers. kThis represents the total number of interlayer interface regions. For the first i The thickness of each material layer For the first i The hydrogen diffusion coefficient of a single-layer material. For the first j The equivalent thickness of the interlayer interface region For the first j The equivalent diffusion coefficient of the interlayer interface region. When quantitatively determining the microscopic range, the material density distribution curve along the pipe wall thickness direction of the multilayer structure analysis model is extracted. The average density of the bulk phase inside adjacent material layers is extracted as the reference density. Continuous intervals in the density distribution curve where the value deviates from the reference density on either side by more than a set threshold (e.g., 5%) are intercepted as the interlayer interface region. The physical distance corresponding to this continuous interval is the equivalent thickness. .

[0053] The total thickness L satisfies the following geometric additive relationship:

[0054] After calculating the overall diffusion coefficient Deq of the composite hydrogen transport pipeline, and further considering the set operating conditions, the overall diffusion coefficient is multiplied by the hydrogen concentration gradient along the pipeline wall thickness direction based on Fick's Law to calculate the hydrogen diffusion flux along the composite hydrogen transport pipeline wall thickness direction. J :

[0055] in, C Hydrogen concentration, x These are the spatial coordinates along the pipe wall thickness direction. This represents the hydrogen concentration gradient along the wall thickness. Operating conditions include at least one or more of the following: temperature, pressure, and hydrogen concentration difference between the inside and outside of the pipeline. By changing operating parameters such as temperature, pressure, or concentration difference, and repeating the calculations in steps two through four above, the changing trends of the overall diffusion coefficient and diffusion flux under different operating conditions can be output. This allows for a quantitative characterization of the overall hydrogen diffusion trend, diffusion characteristics, and hydrogen barrier performance of the composite hydrogen transport pipeline under different service environments.

[0056] like Figure 4 As shown, to ensure the accuracy of the analytical method, the calculated overall diffusion coefficient... and hydrogen diffusion flux JSubsequently, to further verify the accuracy of the analytical results, the values ​​calculated by this method can be compared with reference values ​​obtained from corresponding experimental test results (such as hydrogen permeation experiments, adsorption-desorption experiments, or electrochemical hydrogen permeation test results known in the art), or reference values ​​obtained from independent molecular simulation results (such as finite element simulations or independent molecular dynamics simulations). The relative errors are calculated separately. and :

[0057]

[0058] in, The reference global diffusion coefficient is obtained from experimental testing or independent simulation. This refers to the reference diffusion flux obtained from experimental testing or independent simulation. When both errors are no greater than 10%, the analysis results are deemed to meet the accuracy requirements under the target operating conditions, and the results can be directly used for material selection, multi-layer composite structure design optimization, and engineering evaluation of hydrogen barrier performance in composite hydrogen transport pipelines.

[0059] To facilitate understanding, this embodiment provides a set of specific numerical calculation procedures to illustrate the calculation process for series resistance superposition. The composite hydrogen transport pipeline comprises three material layers: an inner lining layer, a barrier layer, and a reinforcement layer (i.e.,...). m =3), and contains two inter-layer interface areas (i.e. k =2).

[0060] Under the given operating conditions, the parameters for each layer and interface are extracted as follows: Inner lining thickness L1 = 2.0 × 10 -3 m, the hydrogen diffusion coefficient of the monolayer material D1 = 2.35 × 10 -11 m² / s; Barrier layer thickness L2 = 5.0 × 10 -4 m, the hydrogen diffusion coefficient of the monolayer material D2 = 1.48 × 10 -13 m² / s; Reinforcing layer thickness L3 = 3.0 × 10 -3 m, the hydrogen diffusion coefficient of the monolayer material D3 = 5.21 × 10 -12 m² / s; The equivalent thickness of the interface region between the first and second layers is δ1 = δ2 = 5.0 × 10⁻⁶. -5 m, whose interface equivalent diffusion coefficients are respectively =1.85×10 -14 m² / s and =2.54×10 -14 m² / s.

[0061] Substitute into the formula to calculate the total thickness L of the composite pipe:

[0062] The overall diffusion coefficient of the composite pipeline is obtained by superimposing series resistances. :

[0063] Assume the hydrogen concentration difference between the inside and outside of the composite hydrogen transport pipeline is 10 mol / m 3 At this point, the concentration gradient can be simplified to: Substitute into the formula of Fick's diffusion law to calculate the macroscopic hydrogen diffusion flux. J :

[0064] By verifying that the above results are within the required error range, the influence weights of the resistance contributed by the single-layer material and the resistance contributed by the interlayer interface on the overall hydrogen barrier performance were quantitatively separated, providing direct data support for the structural optimization of hydrogen pipelines.

[0065] It should be noted that, in other embodiments, the process of extracting the hydrogen diffusion coefficient of each material layer in step two can also use the experimentally measured diffusion coefficient as the input parameter for the diffusion coefficient of each material layer, replacing the process of extracting the diffusion coefficient using molecular dynamics. In step three, the part using the Monte Carlo method to statistically analyze the hydrogen molecule migration process across layers can also be partially replaced by the finite element method, finite difference method, or finite volume method. Furthermore, different potential functions or different interface defect models can be used to correct the diffusion coefficient.

[0066] Example 2 Based on the same concept, this invention also proposes a device for analyzing the hydrogen diffusion behavior of a composite hydrogen transport pipeline, comprising: The model building module is used to build a multi-layer structure analysis model of the composite hydrogen transport pipeline. The multi-layer structure analysis model includes at least two material layers arranged sequentially along the pipeline wall thickness direction and the interlayer interface region between adjacent material layers. The first parameter extraction module is used to establish a corresponding diffusion analysis model for each material layer in the multilayer structure analysis model, simulate the movement process of hydrogen molecules, and extract the hydrogen diffusion coefficient of each material layer based on the statistical characteristics of the evolution of the microscopic movement position of hydrogen molecules over time. The second parameter extraction module is used to track the cross-layer diffusion process of hydrogen molecules from one side of the material layer to the interlayer interface region and into the other side of the material layer for each interlayer interface region. Based on the statistical characteristics of the position change of hydrogen molecules in the interlayer interface region along the direction perpendicular to the interface over time, the equivalent diffusion coefficient of each interlayer interface region is calculated. The overall parameter integration module is used to treat the hydrogen diffusion coefficient of each single-layer material and the equivalent diffusion coefficient of each interface as diffusion units arranged continuously along the pipe wall thickness direction. Combined with the thickness of each material layer and the equivalent thickness of the interface region between each layer, the module performs series resistance superposition calculation to obtain the overall diffusion coefficient of the composite hydrogen transport pipeline.

[0067] Example 3 This embodiment also provides an electronic device, see reference. Figure 5 It includes a memory 404 and a processor 402, wherein the memory 404 stores a computer program and the processor 402 is configured to run the computer program to perform the steps in any of the above method embodiments.

[0068] Specifically, the processor 402 may include a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of the present invention.

[0069] Memory 404 may include a mass storage device for data or instructions. For example, and not limitingly, memory 404 may include a hard disk drive (HDD), a floppy disk drive, a solid-state drive (SSD), flash memory, an optical disk drive, a magneto-optical disk drive, magnetic tape, or a Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 404 may include removable or non-removable (or fixed) media. Where appropriate, memory 404 may be internal or external to a data processing device. In a particular embodiment, memory 404 is non-volatile memory. In a particular embodiment, memory 404 includes read-only memory (ROM) and random access memory (RAM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable read-only memory (PROM), an erasable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), an electrically alterable read-only memory (EAROM), or flash memory, or a combination of two or more of these. Where appropriate, the RAM can be Static Random-Access Memory (SRAM) or Dynamic Random-Access Memory (DRAM). DRAM can be Fast Page Mode Dynamic Random Access Memory (FPMDRAM), Extended Data Out Dynamic Random Access Memory (EDODRAM), Synchronous Dynamic Random-Access Memory (SDRAM), etc.

[0070] The memory 404 can be used to store or cache various data files that need to be processed and / or communicated, as well as possible computer program instructions executed by the processor 402.

[0071] The processor 402 reads and executes computer program instructions stored in the memory 404 to implement any of the hydrogen diffusion behavior analysis methods for composite hydrogen transport pipelines in the above embodiments.

[0072] Optionally, the electronic device may further include a transmission device 406 and an input / output device 408, wherein the transmission device 406 is connected to the processor 402, and the input / output device 408 is connected to the processor 402.

[0073] The transmission device 406 can be used to receive or send data via a network. Specific examples of the network described above may include wired or wireless networks provided by the communication provider of the electronic device. In one example, the transmission device includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 406 may be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0074] Input / output device 408 is used for inputting or outputting information. It can be a speaker, microphone, monitor, or keyboard.

[0075] Example 4 This embodiment also provides a readable storage medium storing a computer program, the computer program including program code for controlling a process to execute the process, the process including the hydrogen diffusion behavior analysis method for a composite hydrogen transport pipeline according to Embodiment 1.

[0076] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated here.

[0077] Generally, various embodiments can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects of the invention can be implemented in hardware, while others can be implemented by firmware or software executed by a controller, microprocessor, or other computing device, but the invention is not limited thereto. Although various aspects of the invention may be shown and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, by way of non-limiting example, these blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0078] Embodiments of the present invention can be implemented by computer software, which may be executable by a data processor of a mobile device, such as a processor entity, or by hardware, or by a combination of software and hardware. Computer software or programs (also referred to as program products) including software routines, applets, and / or macros can be stored in any device-readable data storage medium, and they include program instructions for performing specific tasks. The computer program product may include one or more computer-executable components configured to perform the embodiments when the program is run. The one or more computer-executable components may be at least one piece of software code or a portion thereof. Additionally, it should be noted in this respect that, as Figure 1 Any box in the logical flow can represent a program step, or interconnected logic circuits, boxes and functions, or a combination of program steps and logic circuits, boxes and functions. Software can be stored on physical media such as memory chips or blocks of storage implemented within a processor, magnetic media such as hard disks or floppy disks, and optical media such as DVDs and their data variants, CDs, etc. The physical medium is a non-transient medium.

[0079] Those skilled in the art should understand that the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] The above embodiments are merely illustrative of several implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. A method for analyzing the hydrogen diffusion behavior of a composite hydrogen transport pipeline, characterized in that, Includes the following steps: A multi-layer structural analysis model for a composite hydrogen transport pipeline is constructed. The multi-layer structural analysis model includes at least two material layers arranged sequentially along the pipeline wall thickness direction and the interlayer interface region between adjacent material layers. For each material layer in the multilayer structure analysis model, a corresponding diffusion analysis model is established. Molecular dynamics is used to simulate the motion of hydrogen molecules to obtain the position coordinate information of hydrogen molecules changing with time. Based on the position coordinate information, the microscopic mean square displacement of hydrogen molecules in the corresponding material layer is calculated, and the hydrogen diffusion coefficient of each material layer is extracted. For each of the interlayer interface regions, molecular dynamics is used to simulate and track the continuous motion trajectory of hydrogen molecules migrating from one side of the material layer to the interlayer interface region and entering the other side of the material layer. Based on the micro-mean square displacement of the interface where the position of hydrogen molecules in the interlayer interface region changes along the direction perpendicular to the interface over time, the equivalent diffusion coefficient of each of the interlayer interface regions is calculated. The hydrogen diffusion coefficient of each single-layer material and the equivalent diffusion coefficient of each interface are taken as diffusion units arranged continuously along the pipe wall thickness direction. The overall diffusion coefficient of the composite hydrogen transport pipeline is obtained by superimposing series resistances by combining the thickness of each material layer and the equivalent thickness of each interlayer interface region. The equivalent thickness of the interlayer interface region is determined in the following way: Extract the material density distribution curve along the pipe wall thickness direction of the multilayer structure analysis model, take the average density of the bulk phase inside the material layers on both sides as the reference density, and determine the continuous interval in the material density distribution curve where the value deviates from the reference density on either side by more than a set threshold as the interlayer interface region. The distance corresponding to this continuous interval is the equivalent thickness of the interlayer interface region.

2. The method for analyzing hydrogen diffusion behavior in a composite hydrogen transport pipeline as described in claim 1, characterized in that, When constructing the multi-layer structure analysis model, the model parameters set include: The material type, arrangement order and thickness of each material layer, the interaction parameters between hydrogen molecules and material molecules in each material layer, the binding energy and defect distribution characteristics of the interlayer interface, and at least one of the operating conditions factors of temperature, pressure and concentration difference.

3. The method for analyzing hydrogen diffusion behavior in a composite hydrogen transport pipeline as described in claim 1, characterized in that, The step of extracting the hydrogen diffusion coefficient of each of the aforementioned material layers specifically includes: Under the temperature and pressure conditions of the target working condition, the molecular dynamics method is used to simulate the motion process of hydrogen molecules in the corresponding material layer to obtain the position coordinate information of hydrogen molecules changing with time, and the micro-mean square displacement of hydrogen molecules in the corresponding material layer is calculated based on the position coordinate information. The curve of the micro-mean square displacement changing with time is fitted within the linear diffusion range. The rate of change of the micro-mean square displacement with time is obtained using the Einstein diffusion relation. Based on the rate of change, the hydrogen diffusion coefficient of the corresponding single-layer material is calculated.

4. The method for analyzing hydrogen diffusion behavior in a composite hydrogen transport pipeline as described in claim 1, characterized in that, The steps for calculating the equivalent diffusion coefficient of each of the interlayer interface regions specifically include: Molecular dynamics was used to simulate the motion of hydrogen molecules in the region near the interface. The position coordinates of hydrogen molecules over time were recorded. The continuous motion process of hydrogen molecules migrating from one side of the material layer to the interface, staying near the interface, and crossing the interface into the adjacent material layer was analyzed. The micro-mean square displacement of hydrogen molecules in the interlayer interface region along the direction perpendicular to the interface was obtained. The rate of change of the micro-mean square displacement of the interface with time is obtained by using the one-dimensional diffusion statistics relationship, and the equivalent diffusion coefficient of the interface in the corresponding interlayer interface region is calculated based on the rate of change.

5. The method for analyzing hydrogen diffusion behavior in a composite hydrogen transport pipeline as described in claim 1, characterized in that, Tracking the translayer diffusion process of hydrogen molecules also includes: The number of hydrogen molecules that successfully cross the corresponding interlayer interface and the number of hydrogen molecules that enter the corresponding interlayer interface region are statistically analyzed through molecular simulation within a set time. The cross-interface migration probability of the corresponding interlayer interface is determined by using the ratio of the number of hydrogen molecules that successfully cross to the number of hydrogen molecules that enter. Based on the cross-interface migration probability, the Monte Carlo random sampling method is used to simulate the random walk process of hydrogen molecules in a multilayer structure in order to obtain the statistical law of cross-layer random propagation of hydrogen molecules.

6. The method for analyzing hydrogen diffusion behavior in a composite hydrogen transport pipeline as described in claim 1, characterized in that, The step of calculating the overall diffusion coefficient of the composite hydrogen transport pipeline by superimposing the series resistances specifically includes: The overall diffusion coefficient of the composite hydrogen transport pipeline is obtained by dividing the total thickness of the composite hydrogen transport pipeline along the hydrogen diffusion direction by the weighted sum of the reciprocal distribution values ​​of each diffusion unit. The weighted sum of the reciprocal allocation values ​​is composed of the sum of the ratios of the thickness of each material layer to the hydrogen diffusion coefficient of the corresponding single-layer material, and the sum of the ratios of the equivalent thickness of each interlayer interface region to the corresponding equivalent interface diffusion coefficient. The total thickness is obtained by adding the sum of the thicknesses of each of the material layers to the sum of the equivalent thicknesses of each of the interlayer interface regions.

7. The method for analyzing hydrogen diffusion behavior in a composite hydrogen transport pipeline as described in claim 1, characterized in that, After calculating the overall diffusion coefficient of the composite hydrogen transport pipeline, the following steps are also included: Based on the set operating conditions, the overall diffusion coefficient is multiplied by the hydrogen concentration gradient along the pipe wall thickness direction according to Fick's diffusion law, and the hydrogen diffusion flux along the composite hydrogen transport pipe wall thickness direction is calculated. The operating conditions include at least one or more of the following: temperature conditions, pressure conditions, and the concentration difference of hydrogen inside and outside the pipeline.

8. An apparatus for implementing the method for analyzing the hydrogen diffusion behavior of a composite hydrogen transport pipeline according to any one of claims 1 to 7, characterized in that, include: The model building module is used to build a multi-layer structure analysis model of the composite hydrogen transport pipeline. The multi-layer structure analysis model includes at least two material layers arranged sequentially along the pipeline wall thickness direction and the interlayer interface region between adjacent material layers. The first parameter extraction module is used to establish a corresponding diffusion analysis model for each material layer in the multilayer structure analysis model, use molecular dynamics to simulate the motion process of hydrogen molecules to obtain the position coordinate information of hydrogen molecules changing with time, calculate the micro-mean square displacement of hydrogen molecules in the corresponding material layer based on the position coordinate information, and extract the single-layer material hydrogen diffusion coefficient corresponding to each material layer. The second parameter extraction module is used to simulate and track the cross-layer diffusion process of hydrogen molecules from one side of the material layer to the interlayer interface region and into the other side of the material layer using molecular dynamics. Based on the micro-mean square displacement of the interface where the position of hydrogen molecules in the interlayer interface region changes along the direction perpendicular to the interface over time, the equivalent diffusion coefficient of the interface corresponding to each interlayer interface region is calculated. The overall parameter integration module is used to take the hydrogen diffusion coefficient of each single-layer material and the equivalent diffusion coefficient of each interface as diffusion units arranged continuously along the pipe wall thickness direction, and to perform series resistance superposition calculation by combining the thickness of each material layer and the equivalent thickness of each interlayer interface region to obtain the overall diffusion coefficient of the composite hydrogen transport pipeline.

9. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to run the computer program to perform the method for analyzing the hydrogen diffusion behavior of a composite hydrogen transport pipeline as described in any one of claims 1 to 7.

10. A readable storage medium, characterized in that, The readable storage medium stores a computer program that, when executed by a processor, implements the method for analyzing hydrogen diffusion behavior in composite hydrogen transport pipelines as described in any one of claims 1 to 7.

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