Gas pipe network combined use evaluation method and device, storage medium and electronic equipment

Abstract

The invention discloses a gas pipe network combined use evaluation method and device, a storage medium and electronic equipment, and the method comprises the steps: S01, carrying out the pre-evaluation of a high-risk pipe section; s02, evaluating the applicability of the material; s03, carrying out residual strength evaluation and standard exceeding defect safety evaluation; s04, safety evaluation of the buried steel pipeline under bad conditions; s05, residual life prediction; and S06, assembling an old gas pipe network combination use evaluation report. According to the method, the evaluation method is divided into specific parts for evaluation and final integration, the influence of various factors is comprehensively considered, the use of the old gas pipe network is comprehensively judged, and the accuracy degree of use evaluation is improved.

Description

Technical Field

[0001] The present invention relates to a pressure pipeline fitness for use evaluation technology, and in particular to a gas pipeline network fitness for use evaluation method, device, storage medium and electronic equipment. Background Art

[0002] At present, natural gas is still one of the important fuels in my country. After being mined, it needs to be transported to thousands of households through a complex gas pipeline network. Every pipeline along the way is crucial. However, the gas pipeline network in most areas has been in operation for more than 20 years. These old pipelines are not only the "life network" of the city but also the "safety network" to protect people's lives. Therefore, conducting an evaluation of the suitability of old gas pipeline networks is of great significance to ensure the stable operation of urban gas transmission and distribution systems and eliminate gas safety hazards.

[0003] However, most of the existing evaluations on the fitness for use of gas pipeline networks are based on a certain traditional method, only considering a single defect or evaluating the gas pipeline network under specific working conditions. These traditional evaluation methods often cannot meet the applicability evaluation of pipeline networks in densely populated urban areas with relatively complex geographical and climatic conditions, and the evaluation results often cannot accurately reflect the actual situation; there are problems such as incomplete pre-assessment of high-risk pipeline sections, inaccurate life prediction, and inability to fully evaluate whether the pipeline system is suitable for use. Summary of the invention

[0004] The main purpose of the present invention is to provide a method, device, storage medium and electronic equipment for evaluating the fitness for use of a gas pipeline network. By coupling the stress analysis of the pipe system and the erosion inside the pipe, high-risk pipe sections are determined and pre-evaluated, providing the location of the pipe sections that should be focused on and evaluated and more comprehensive data support for the prediction of the remaining service life of the pipeline. From the pipe system to the inside of the pipe, from material performance testing to defect strength assessment, the gas pipeline network is evaluated in sections, and opinions are given based on the results of each section to make the fitness for use evaluation more accurate.

[0005] According to one aspect of the present invention, a method for evaluating the suitability of a gas pipeline network for use is provided, comprising:

[0006] S01: Pre-assessment of high-risk pipe sections. Perform software simulation calculations on the pipe network, determine high-risk pipe sections based on data results, and conduct pre-assessment to provide the locations of pipe sections that should be focused on inspection and assessment for subsequent evaluation. This includes pipe system stress simulation calculations and scour flow field simulation inside the pipes.

[0007] S02: Material applicability evaluation: prepare samples from the rich area of ​​the pipe base material to test various material properties to determine whether they meet the applicable standards; the material applicability evaluation includes mechanical property testing and metallographic structure analysis, and the mechanical property testing includes tensile property analysis and hardness testing;

[0008] S03: Residual strength assessment and safety assessment of excessive defects, determine the number and location of pipeline excavation points, conduct non-destructive testing on them, determine the defect type, and carry out residual strength assessment and safety assessment of excessive defects in turn;

[0009] S04: Safety assessment of buried steel pipelines under adverse conditions, analyzing and determining the types of adverse working conditions that may exist in the environment where the pipeline is located, and assessing the limit state;

[0010] S05: Remaining life prediction: Select appropriate methods to predict the remaining life of pipelines based on the proportion of straight pipe sections, elbows and tees;

[0011] S06: Compile an evaluation report on the fitness for use of old gas pipeline networks. Based on the evaluation results of the above parts and the measured data of the pipelines, conduct a comprehensive evaluation of the fitness for use of the pipelines and put forward suggestions for maintenance, replacement and rectification.

[0012] Furthermore, the stress simulation calculation of the piping system in step S01 should be modeled using stress analysis software, and the model nodes need to be set and basic data input during the process, wherein the basic data is obtained from actual measurement or experiment;

[0013] Considering the surface conditions, measured burial depth, laying environment, etc. of the pipeline, soil models with different physical properties are created. The model parameters consider soil type, friction coefficient, density and soil internal friction angle to determine the load combination.

[0014] According to the actual direction of the pipeline, the structural parameters of the pipeline units such as elbows, expansion joints, and tees are set in the stress analysis software. Then, according to the load conditions, spring boundaries, force boundaries, and displacement boundary conditions are added to the model to generate the support of the pipeline in the buried state. The construction of the stress analysis model is completed;

[0015] After the modeling is completed, run the model to check for errors. If there are no errors, set the static load and buried soil support according to the model parameters mentioned above; then perform the pipe system stress analysis, during which the software automatically calculates according to the set parameter nodes; the results are the stress data under four conditions: operating state OPE, associated continuous condition ALT-SUS, continuous load condition and primary stress SUS, expansion condition and secondary stress EXP. Analyze the maximum primary stress under the SUS condition and the maximum secondary stress under the EXP condition, and identify the area where the maximum stress of the pipeline is located as a high-risk pipe section;

[0016] Based on the high-risk pipe sections determined by the above stress analysis, flow field analysis software is used to model the pipe erosion and corrosion calculations, including:

[0017] Establish a geometric model and perform finite element processing. Combined with the basic data of the pipeline, first use 3D software to build a model. Import the built software model into the spatial analysis module for model preprocessing, and set the inlet and outlet and wall surfaces. After the preprocessing is completed, enter the grid module to divide the grid, and use grid encryption processing for the elbow to obtain more accurate simulation data. In order to obtain the flow state of the fluid near the wall, set an expansion layer near the wall, and the layer height is obtained by matching the turbulence model with the numerical calculation in the Y direction. After the setting is completed, the grid can be generated.

[0018] Set the physical property parameters, enable multi-component transport in the flow field analysis software, and enter the natural gas components and their corresponding mass fractions; the gravel that causes pipeline erosion and corrosion is simulated using the discrete phase DPM model, set to be injected from the surface, and consider the effect of gravity on the gravel; the natural gas density, viscosity, gas flow rate, particle density, particle diameter and particle mass flow rate should also be set;

[0019] Determine the boundary conditions, select the appropriate turbulence model, and set the model inlet, outlet and wall; the wall setting includes the tangential and normal discrete terms DPM reflection coefficient, the impact angle function, diameter function and velocity exponential function in the erosion model;

[0020] After the above model is constructed and related parameters are set, the calculation method and control method are selected, the residual is set, the monitoring curve is added, the model is initialized, the corrosion rate cloud map, the particle deposition cloud map and the particle trajectory map are created, and finally, a suitable number of iteration steps is given, the calculation is run and the data results can be displayed after convergence; the data results and cloud map phenomena are analyzed to determine whether the corrosion rate is within the standard range.

[0021] Furthermore, the preparation of pipeline test samples in step S02 includes tensile specimens and metallographic specimens. The tensile specimens are prepared by wire cutting at different areas of the upper and lower surfaces of the pipeline; the metallographic specimens are prepared by taking metallographic specimens from the upper and lower surfaces of the pipeline.

[0022] Furthermore, the defect types in step S03 include volume defects and wall thickness reduction, specifically:

[0023] The volume defect uses the first level to evaluate the residual strength of the pipeline, requiring that the operating pressure of the pipeline shall not exceed the maximum allowable working pressure, which is:

[0024] P=K·P F

[0025] Where, P is the maximum allowable working pressure of the pipeline, in megapascals (MPa); K is the design factor, which is selected based on the type of medium in the pipeline, the regional level where the defect is located, etc.

[0026] Failure pressure of pipeline PF , calculated by the following formula:

[0027]

[0028] Where P F —Failure pressure of defective pipeline, in megapascals (MPa); D—pipeline diameter, in millimeters (mm); t—pipeline wall thickness, in millimeters (mm); d—corrosion defect depth, in millimeters (mm);

[0029] Flow stress σ flow , determined by the following formula:

[0030]

[0031] In the formula, —Minimum yield strength of the material, in megapascals (MPa);

[0032] M—Folias expansion coefficient, determined by the following formula:

[0033]

[0034] Where, L is the defect length, in millimeters (mm);

[0035] Compare the maximum allowable working pressure of the pipe section and the maximum working pressure inside the pipe according to the calculation results to determine whether the pipeline meets the requirements for safe operation according to the operating pressure;

[0036] The thinning of the tube wall can be determined by instrument detection and theoretical calculation verification. The theoretical calculation formula is as follows:

[0037] T sd =T s +C

[0038]

[0039] C=C1+C2

[0040] Where, T sd —Pipeline wall thickness, in millimeters (mm); T s —Calculated thickness of straight pipe, in millimeters (mm); P—design pressure, in megapascals (MPa); D0—outer diameter of pipe, in millimeters (mm); — allowable stress of the material at the design temperature, in megapascals (MPa); E j —welding joint coefficient; C—the sum of thickness additions, in millimeters (mm); C1—thickness reduction additions, in millimeters (mm); C2—corrosion or abrasion additions, in millimeters (mm); Y—correction coefficient;

[0041] The pipe wall thickness T is obtained by calculation sd In addition to theoretical calculations, the wall thickness of the pipeline was measured to obtain actual wall surface data; the wall thickness obtained by theoretical calculation was compared with the actual average wall thickness measured to determine whether the wall surface was significantly thinned.

[0042] Furthermore, the pipeline safety assessment under adverse conditions in step S04 is divided into safety assessment of determining the adverse condition type and pipeline limit state;

[0043] Adverse working conditions include mining subsidence, frozen soil, lateral landslide, fault, occupation and flood. The terrain, landform and geological data along the pipeline are collected and analyzed to determine which type of adverse working condition the pipeline section belongs to and whether there is an extreme state.

[0044] The pipeline limit states include fracture, buckling and ovality. The possible limit states are determined through field investigation and excavation inspection. After determination, calculation and judgment can be carried out step by step, specifically:

[0045] Pipeline rupture is caused by tensile strain reaching or exceeding the limit value. The minimum strength requirement that tensile strain should meet is:

[0046]

[0047] In the formula, ε tf —Uniaxial tensile strain in longitudinal or circumferential direction; φ εt — tensile strain resistance factor; —Tensile limit strain of pipe wall or welded parts;

[0048] Lower than the minimum strength ε that the required longitudinal / circumferential uniaxial tensile strain should meet tf No breakage will occur in the case of

[0049] When the pipeline is subjected to compressive load or severe bending, compressive stress and strain will be generated in the pipeline section. The minimum strength requirement that the longitudinal compressive strain should meet is:

[0050]

[0051] In the formula, ε cf —Uniaxial compressive strain in longitudinal or circumferential direction; φ εc —compression strain resistance factor; —Axial or circumferential compressive limit strain can be obtained by the following formula:

[0052]

[0053] Where, t is the pipe wall thickness, in millimeters (mm); D is the pipe outer diameter, in millimeters (mm); P i—maximum design internal pressure, in megapascals (MPa); P e —minimum external hydrostatic pressure, in megapascals (MPa); E s =207GPa; E y —Minimum yield strength, in megapascals (MPa); based on the axial or hoop compressive limit strain The minimum strength ε that the longitudinal / circumferential compressive strain should satisfy can be calculated cf , below the minimum strength, the pipe will not buckle.

[0054] Furthermore, the remaining life prediction in step S05 includes two prediction calculation methods: uniform corrosion and local corrosion life prediction of straight pipe sections, and uniform corrosion and local corrosion life prediction of pipe components such as elbows and tees;

[0055] For uniform corrosion and local corrosion of straight pipe sections, the wall thickness method is used to predict the remaining life. The calculation method is shown in the following formula:

[0056]

[0057] In the formula, R L —remaining life, in years (a); t mm —The measured average wall thickness of the pipeline, in millimeters (mm); t min —Minimum required wall thickness of the pipe, in millimeters (mm); R t —Residual wall thickness ratio, obtained by residual strength evaluation; RSF a —Allowable residual strength factor, refer to the specification for value; when the straight pipe section is uniformly corroded, R t By RSF a Instead, only uniform corrosion is considered in the straight pipe section of the tested pipeline; C rate —The expected corrosion rate in millimeters per year (mm / a) can be determined by the following formula:

[0058]

[0059] Where, I is the current intensity in amperes (A); A is the anode surface area in square centimeters (cm 2 ); T—test time, in minutes (d); ρ—metal density, in cubic centimeters per gram (g / cm 3 ).

[0060] According to another aspect of the present invention, an evaluation device is provided, characterized in that it includes an electronic universal testing machine for tensile property testing, a Vickers hardness tester for hardness testing, and a thermal field emission scanning electron microscope for metallographic structure analysis.

[0061] According to another aspect of the present invention, an electronic device is provided, including a processor, a storage device and a program running on a computer, wherein the processor is responsible for implementing the steps of the gas network suitability for use evaluation method when executing the program.

[0062] Advantages of the present invention:

[0063] The present invention proposes a method, device, storage medium and electronic equipment for evaluating the suitability of a gas pipeline network, including: pre-evaluation of high-risk pipe sections, coupling pipe system stress and internal erosion to determine high-risk pipe sections and analyze them; judging whether the applicable standards are met based on material applicability evaluation; judging whether the pipeline meets the strength requirements for suitability for use based on residual strength evaluation and safety assessment of excessive defects; determining the type of adverse working conditions based on safety assessment analysis of buried steel pipelines under adverse conditions, and evaluating the limit state; accurately calculating the remaining service life of the pipeline based on residual life prediction; the present invention splits the evaluation method into specific parts, evaluates them separately, and finally integrates them, comprehensively considers the influence of multiple factors, comprehensively judges the suitability of old gas pipeline networks for use, and improves the accuracy of use evaluation.

[0064] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0066] Figure 1 It is a flow chart of the gas pipe network suitability for use evaluation method of the present invention;

[0067] Figure 2 It is a schematic diagram of a standard length sample of a material prepared in a method for evaluating the use of a gas pipe network of the present invention;

[0068] Figure 3 It is a schematic diagram of the pipe wall thickness measurement points in the gas pipe network suitability for use evaluation method of the present invention;

[0069] Figure 4 is a schematic block diagram of an evaluation device of the present invention;

[0070] Figure 5 is a schematic structural block diagram of an electronic device of the present invention;

[0071] Figure 6 This is a schematic diagram of the actual engineering pipeline direction in an embodiment of the present invention;

[0072] Figure 7 2 is a diagram showing the results of a tensile test in an embodiment of the present invention. DETAILED DESCRIPTION

[0073] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0074] Example 1

[0075] In engineering examples, fitness for use evaluation is mostly based on a traditional method, only considering a single defect or evaluating the gas pipeline network under specific working conditions. It is often not applicable to pipelines in densely populated urban areas with relatively complex geographical and climatic conditions, and the evaluation results often cannot accurately reflect the actual situation. In order to make up for the shortcomings of the above methods and solve a series of related problems, the present invention aims to provide a method, device, storage medium and electronic equipment for fitness for use evaluation of gas pipeline networks, which determines high-risk pipe sections and conducts preliminary evaluation by coupling pipe system stress analysis and pipe erosion, provides the location of pipe sections that should be focused on detection and evaluation and more comprehensive data support for the prediction of the remaining service life of the pipeline, and makes the fitness for use evaluation more accurate.

[0076] The embodiments of the gas pipeline network suitable for use evaluation method, device, storage medium and electronic equipment proposed in the present invention are described in combination with actual engineering cases. The engineering project case parameters are as follows:

[0077] The total length of a city's gas pipeline network is 30 km, of which the northwest branch pipeline was completed on October 25, 1992 and put into use on November 1, 1992. The total length of the pipeline is 0.646 km, the pipeline specification is φ219×6, the pipeline operating pressure is 0.3Mpa, the design temperature is 20℃, the pipeline grade is GB1-V, the pipeline material is Q235-A, the buried anti-corrosion and thermal insulation asphalt is 10mm, the actual service life is 31 years, and the pipeline direction diagram is shown in Figure 6 .

[0078] See also Figure 1 , a gas pipeline network suitable for use evaluation method, device, storage medium and electronic equipment, specifically comprising the following steps:

[0079] S01: Pre-evaluation of high-risk pipeline sections, conduct software simulation calculations on pipelines, determine high-risk pipeline sections based on data results and conduct pre-evaluation at the same time, and provide the locations of pipeline sections that should be focused on inspection and evaluation for subsequent evaluation. This includes simulation calculations of pipeline stress and simulation of scour flow fields inside the pipe.

[0080] S02: Material applicability evaluation: Prepare samples from the rich area of ​​the pipe base material to test various material properties to determine whether they meet the applicable standards. The material applicability evaluation includes mechanical property testing and metallographic structure analysis, of which the former includes tensile property analysis and hardness testing.

[0081] S03: Residual strength assessment and safety assessment of defects exceeding the standard, determine the number and location of pipeline excavation points, conduct non-destructive testing on them, determine the defect type, and carry out residual strength assessment and safety assessment of defects exceeding the standard in turn.

[0082] S04: Safety assessment of buried steel pipelines under adverse conditions, analyze and determine the types of adverse working conditions that may exist in the environment where the pipeline is located, and assess the limit state.

[0083] S05: Remaining life prediction: Select appropriate method to predict the remaining life of pipeline based on the proportion of straight pipe sections, elbows and tees.

[0084] S06: Compile an evaluation report on the fitness for use of old gas pipeline networks. Based on the evaluation results of the above parts and combined with the measured data of the pipelines, conduct a comprehensive evaluation of the fitness for use of the pipelines and put forward suggestions for maintenance, replacement and rectification.

[0085] The stress simulation calculation of the pipe system in step S01 should be modeled using stress analysis software. During the process, the model nodes need to be set and basic data input, where the basic data is obtained from actual measurements or experiments. In the stress analysis software, the measured pipeline is divided into units, and each unit is connected at the node. Usually, the adjacent node numbers are taken at intervals of 5 to 10. However, for the convenience of analysis, this method selects 1 node at intervals, and divides the evaluated pipeline into 92 nodes. After determining the node, the corresponding pipeline data such as temperature, pressure, and pipe length are input. There is no Q235 in the material library, but the characteristics of Q235-A material such as allowable stress are basically consistent with it, which does not affect the calculation, so the latter is selected. After selecting the material, the corresponding allowable stress, linear expansion coefficient, etc. will be automatically entered.

[0086] Considering the surface conditions, measured burial depth, laying environment, etc. of the pipeline, soil models with different physical properties are created. The model parameters consider soil type, friction coefficient, density and soil internal friction angle to determine the load combination. The soil parameter model is shown in Table 1.

[0087] Table 1 Soil performance parameters

[0088]

[0089]

[0090] Since the assessed pipeline is a buried pipeline, the impact of pipeline load was comprehensively considered, and based on the actual situation, it was finally determined to consider a combination of four situations: the internal pressure of the transported natural gas, the dead weight of the steel pipe and its accessories, the gravity of the transported natural gas, and the horizontal and vertical earth pressures.

[0091] According to the actual direction of the pipeline, the structural parameters of the pipe units such as elbows, expansion joints, and tees are set in the stress analysis software to establish a preliminary model. Then, according to the load conditions, spring boundaries, force boundaries, and displacement boundary conditions are added to the model to generate the support of the pipeline in the buried state. The evaluated pipeline is a buried pipe, and the required pipeline support can be simulated and generated by inputting soil, burial depth and other data. The data is shown in Table 2 below:

[0092] Table 2 Soil parameter data

[0093]

[0094] After starting the operation, the model can be viewed in the 3D animation interface. At this point, the stress analysis model is built.

[0095] After the modeling is completed, run the model error check. If there are no errors, set the static load and buried soil support according to the model parameters mentioned above. Then, the pipe system stress analysis can be carried out. The process software automatically calculates according to the set parameter nodes. The results are stress data under four conditions: OPE (operating state), ALT-SUS (associated continuous working condition), SUS (continuous load working condition, check primary stress), and EXP (expansion working condition, check secondary stress). The maximum primary stress under the SUS working condition and the maximum secondary stress under the EXP working condition are analyzed to determine that the area with the maximum stress of the pipeline is a high-risk pipe section. The data results are shown in Tables 3 and 4:

[0096] Table 3 Primary stress (SUS) verification data

[0097]

[0098] Table 4 Secondary stress (EXP) verification data

[0099]

[0100] From the data results shown in Table 3 and Table 4, it can be concluded that the primary stress and secondary stress checks of the pipeline have passed. The maximum primary stress point is at Node = 53, and the maximum primary stress σ max1 =38068.1KPa; the maximum secondary stress point is at Node=77, the maximum secondary stress σ max2=3021.6KPa. Under the SUS and EXP conditions, the pipeline will undergo a certain degree of flexural deformation. Since the soil parameters are added to simulate the generation of buried supports, flexure only occurs at the elbows. The results show that the maximum primary stress is located at the second elbow of the Π-type bend, and the maximum secondary stress is located at the last elbow of the pipeline. To ensure accurate assessment, the high-risk pipe sections finally determined are the Π-type bend (max1 pipe section) and the last elbow (max2 pipe section).

[0101] Based on the above stress analysis, the high-risk pipe sections are modeled using flow field analysis software to calculate the erosion and corrosion in the pipe. This includes:

[0102] (1) Establish a geometric model and perform finite element processing. Combined with the basic data of the pipeline, modeling is first performed using 3D software. The built model is imported into the spatial analysis module for model preprocessing, and the inlet and outlet and wall surfaces are set. After the preprocessing is completed, enter the grid module to divide the grid, and mesh encryption is performed on the elbow to obtain more accurate simulation data; in order to obtain the flow state of the fluid near the wall, an expansion layer is set near the wall, and the layer height is obtained by matching the turbulence model with the numerical calculation in the Y direction. After the setting is completed, the grid can be generated. The max1 pipe is 22m long, and the total number of grid cells is about 202,000; the max2 pipe is 2m long, and the total number of grid cells is about 11,000.

[0103] (2) Set physical property parameters. Enable multi-component transport in the flow field analysis software and enter the components of natural gas and their corresponding mass fractions. The components and mass fractions are shown in Table 5 below:

[0104] Table 5 Composition of natural gas transported by a city’s gas pipeline network

[0105]

[0106]

[0107] The gravel that causes pipeline erosion and corrosion is simulated using the discrete phase (DPM) model, set to be injected from the surface, considering the effect of gravity on the gravel, given 9.81m / s in the negative Y direction, and given an initial velocity in the X direction of gas movement. In addition, the natural gas density, viscosity, gas flow rate, particle density, particle diameter and particle mass flow rate should also be set. The specific simulation key parameters are shown in Table 6 below:

[0108] Table 6 Key parameters of model simulation

[0109]

[0110] (3) Determine the boundary conditions. Select a suitable turbulence model and set the model inlet, outlet and wall. After comparing the applicability, the standard k-ε model that is more consistent with the fluid properties in the pipeline being evaluated is selected, and the turbulence intensity is set to 5%. The inlet of the model is set to the velocity inlet type. In order to further restore the flow in the pipe, the outlet is set to the pressure type, and the pressure is set to the pipeline operating pressure of 0.3Mpa. The wall settings include the tangential and normal phase discrete terms (DPM) reflection coefficients, the impact angle function in the erosion model, the diameter function and the velocity exponent function. Among them, the diameter function is set to 1.8×10 -9 , the velocity exponential function is set to 2.6, and the impact angle function is set as shown in Table 7:

[0111] Table 7 Impact angle linear piecewise function values

[0112]

[0113] In the discrete reflection coefficient, the normal reflection coefficient ε N and the tangential reflection coefficient ε T Please set according to Table 8:

[0114] Table 8 DPM reflection coefficient setting table

[0115]

[0116]

[0117] After the above model construction and related parameter setting are completed, the calculation method is selected as Simple, and the convergence residual is set to 10 -5 , the control method keeps the default calculation model. In addition, two monitoring curves are set for monitoring the operation process, one is the mass flow rate curve for judging convergence, and the other is the unit area corrosion rate curve. After setting, the model is initialized. Create corrosion rate cloud map, particle deposition cloud map and particle trajectory map. Finally, give 150 iteration steps, run the calculation, and wait for convergence to display the data results. The erosion data results of max1 and max2 pipe sections are shown in Table 9.

[0118] Table 9 Pipeline erosion calculation results

[0119]

[0120] Analyze the data results and cloud map phenomena, and judge whether the pipeline meets the use standards based on the pipeline erosion situation and corrosion rate.

[0121] The corrosion cloud map can intuitively show the erosion and corrosion of the pipe section. The erosion of the max1 pipe section is concentrated on the outer wall of the first elbow of the Π-shaped bend, and the erosion of the max2 pipe section is concentrated on the outer bend center curved surface. At the same time, the erosion area of ​​the curved surface of the elbow first increases and then decreases. Because the sand-containing fluid flows along the straight pipe section in the X direction before the elbow, it has a large kinetic energy. When the fluid enters the elbow, the flow direction suddenly changes, and a large centrifugal force is generated to cause the particles to collide with the outer wall surface, forming an elliptical erosion area on the wall surface. At this time, the erosion rate rises sharply, and the particles rebound after hitting the wall surface, which hinders the erosion of subsequent particles on the wall surface. The erosion rate gradually decreases, resulting in the most serious erosion on the outer side of the elbow, forming a conical erosion area. The max1 pipe section has less deposition in the first and fourth elbows, and slightly more deposition in the third elbow, and is mainly concentrated in the second elbow. Because the fluid flows at a high speed when passing through the first elbow, after colliding with the wall at the elbow, the particles continue to move upward. When flowing through the second elbow, the particle movement trajectory is uneven and the speed slows down. Most of them collide with the upper wall in the Y direction to cause deposition. When flowing through the third elbow, they adhere to the wall in the X direction and deposit. The particle deposition of the max2 pipe section is mainly on the outer wall of the outlet. Because the pipeline length is short, the fluid collides and deposits on the outer wall of the elbow when it flows through the elbow, causing the particle movement direction to change and contact with the inner wall, which eventually leads to the particle deposition on the outer wall of the outlet.

[0122] The pipeline corrosion rate smooth curve and rate node distribution divide the pipeline into three areas according to the wall nodes: transition zone, first collision zone, and second collision zone. The corrosion rate of the max1 pipeline in the transition zone shows an upward trend, the rate in the first collision zone fluctuates greatly and the maximum corrosion rate appears, and the rate in the second collision zone gradually decreases. It can be seen that the erosion is mainly concentrated on the wall of the first collision zone, and its node corresponds to the outer wall of the first elbow. The max2 rate curve rises in both the transition zone and the first collision zone, and the rate decreases in the second collision zone after reaching the maximum value. It can be seen that corrosion is mainly concentrated on the walls of the first and second collision zones.

[0123] Through the above analysis of erosion results, combined with the calculation data and compared with the national standard requirements, it is determined that the evaluated pipeline meets the standards for use in terms of erosion corrosion.

[0124] The preparation of pipeline test samples in step S02 includes tensile and metallographic samples. The former uses a wire cutting method to take a standard length sample from three different areas on the upper and lower surfaces of the pipeline. The prepared samples are shown in Figure 2 ; The latter takes two metallographic samples from the upper and lower surfaces of the pipe.

[0125] In the tensile performance test in step S02, the upper surface of the sample is recorded as S1, S2, S3, and the lower surface is recorded as X1, X2, X3. The tensile test is carried out using a Japanese Shimadzu AGS-X electronic universal testing machine. The sample after the tensile test is shown in the figure. Figure 7, draw the test stress-strain curve, and the test results of mechanical properties of upper and lower surface specimens are shown in Tables 10 and 11.

[0126] Table 10 Mechanical properties test results of upper surface samples

[0127]

[0128] Table 11 Mechanical properties test results of lower surface samples

[0129]

[0130]

[0131] According to the above sample test results, the relevant mechanical properties of the pipeline, such as tensile strength, elongation after fracture and yield strength, basically meet the specified standards, and the sample strength meets the use requirements; the hardness test uses the American Buehler VH1102 Vickers hardness tester to randomly select 10 points on the sample surface. The test data results are shown in Table 12, and the average hardness value is measured to be 145.26HV.

[0132] Table 12 Hardness test data

[0133]

[0134] From the hardness test results, we can see that the hardness of the pipe samples basically meets the standard requirements; the metallographic structure analysis uses the American FEIQuantaFEG-450 thermal field emission scanning electron microscope to analyze whether the microstructure performance of the samples meets the specified requirements. The equipment is used to observe the metallographic structure of the pipe sample surface, and it can be seen that the sample structure distribution is uneven, the grains are small, the body is concentrated in some areas, there are no obvious defects on the surface, and the material metallographic structure meets the specified requirements.

[0135] The defect types in step S03 consider volume defects and wall thickness reduction. Specifically:

[0136] (1) Volume defect The residual strength of the pipeline is evaluated using the first level, requiring that the operating pressure of the pipeline shall not exceed the maximum allowable working pressure. The maximum allowable working pressure is:

[0137] P=K·P F ,

[0138] Where, P is the maximum allowable working pressure of the pipeline, in megapascals (MPa); K is the design coefficient, which is selected based on the type of medium in the pipeline, the regional level where the defect is located, etc.

[0139] Failure pressure of pipeline P F , calculated by the following formula:

[0140]

[0141] Where P F —Failure pressure of defective pipeline, in megapascals (MPa); D—pipeline diameter, in millimeters (mm); t—pipeline wall thickness, in millimeters (mm); d—corrosion defect depth, in millimeters (mm).

[0142] Flow stress σ flow , determined by the following formula:

[0143]

[0144] In the formula, —Minimum yield strength of the material, in megapascals (MPa).

[0145] M—Folias expansion coefficient, determined by the following formula:

[0146]

[0147] Where, L is the defect length, in millimeters (mm).

[0148] According to the calculation results, the maximum allowable working pressure of the pipe section and the maximum working pressure inside the pipe are compared to determine whether the pipeline meets the requirements for safe operation according to the operating pressure. The results are shown in Table 13.

[0149] Table 13 Pipeline residual evaluation calculation data

[0150]

[0151] The maximum allowable working pressure of the pipe section is P2.893MPa, and the maximum working pressure inside the pipe is P sj It is only 0.3MPa, the working pressure is much lower than the failure pressure, and the pipeline meets the requirements for safe operation according to the operating pressure.

[0152] (2) Whether the tube wall is thinned can be determined by instrument detection and theoretical calculation verification. The theoretical calculation formula is as follows:

[0153] T sd =T s +C,

[0154]

[0155] C=C1+C2,

[0156] Where, T sd —Pipeline wall thickness, in millimeters (mm); T s —Calculated thickness of straight pipe, in millimeters (mm); P—design pressure, in megapascals (MPa); D0—outer diameter of pipe, in millimeters (mm); — allowable stress of the material at the design temperature, in megapascals (MPa); E j —Welding joint coefficient; C—the sum of thickness additions, in millimeters (mm); C1—thickness reduction additions, in millimeters (mm); C2—corrosion or abrasion additions, in millimeters (mm), generally 1.5mm; Y—correction coefficient.

[0157] The pipe wall thickness T is obtained by calculation sd =5.645. In addition to theoretical calculation, the wall thickness of the pipeline needs to be measured. When the straight pipe, elbow pipe and tee are excavated, the thickness measurement points are selected. Figure 3 The 4 values ​​shown are measured at a distance of 100 mm from the flange. The measured data of the wall are shown in Table 14.

[0158] Table 14 Evaluation of pipe wall thickness measurement data

[0159]

[0160] Comparing the wall thickness obtained by theoretical calculation with the actual average wall thickness measured, the wall thickness obtained by theoretical calculation is 5.645mm, and the actual average wall thickness of the pipeline measured by pipeline wall thickness measurement is 5.655mm. Within the allowable error range, it can be considered that there is no obvious wall thinning in the pipeline.

[0161] The pipeline safety assessment under adverse conditions in step S04 is divided into determining the adverse condition type and the safety assessment of the pipeline limit state.

[0162] Types of adverse working conditions include mining subsidence, frozen soil, lateral landslides, faults, occupation and floods. Collect and analyze the terrain, landform and geological data along the pipeline to determine which type of adverse working condition the pipeline section belongs to and whether there is a limit state. See Table 15 for specific working conditions.

[0163] Table 15 The most common load conditions, deformation conditions and limit states of buried pipelines under adverse conditions

[0164]

[0165] Through field investigation, it was found that the working geographical environment of the tested pipeline was not particularly harsh and the possibility of reaching the limit state was small. However, in order to ensure the comprehensiveness of the pipeline safety assessment, the fracture and buckling limit states were analyzed.

[0166] The limit states of pipelines include fracture, buckling and ovality. The possible limit states are determined through field investigation and excavation inspection, and calculations can be made step by step after they are determined. Specifically:

[0167] (1) Pipeline rupture may be caused by tensile strain reaching or exceeding the limit value. Therefore, the minimum strength requirement that tensile strain should meet is:

[0168]

[0169] In the formula, ε tf —Uniaxial tensile strain in longitudinal or circumferential direction; φ εt — tensile strain resistance factor; —The tensile limit strain of the pipe wall or welded parts.

[0170] Lower than the minimum strength ε that the required longitudinal / circumferential uniaxial tensile strain should meet tf No breakage will occur.

[0171] See Table 16 for specific calculation data:

[0172] Table 16 Pipeline rupture limit state strain data

[0173]

[0174] According to the calculation results in Table 16, the minimum strength ε that the longitudinal / circumferential uniaxial tensile strain of the pipeline should meet is tf =0.00525, that is, when the value is less than this, the pipeline will not break.

[0175] (2) When the pipeline is subjected to compressive load or severe bending, compressive stress and strain will be generated in the pipeline cross section. The minimum strength requirement that the longitudinal compressive strain should meet is:

[0176]

[0177] In the formula, ε cf —Uniaxial compressive strain in longitudinal or circumferential direction; φ εc —compression strain resistance factor; —Axial or circumferential compressive limit strain can be obtained by the following formula:

[0178]

[0179] Where, t is the pipe wall thickness, in millimeters (mm); D is the pipe outer diameter, in millimeters (mm); P i —maximum design internal pressure, in megapascals (MPa); P e —minimum external hydrostatic pressure, in megapascals (MPa); E s =207GPa; E y —Minimum yield strength, in megapascals (MPa).

[0180] The axial or circumferential compressive limit strain can be obtained by the above formula: The specific data results are shown in Table 17.

[0181] Table 17 Calculation data of axial or circumferential compression limit strain

[0182]

[0183] According to the data in Table 17, the relevant strain data of the pipeline under the buckling limit state can be obtained, see Table 18.

[0184] Table 18 Strain data of pipeline under buckling limit state

[0185]

[0186]

[0187] According to the calculation results in Table 18, the minimum strength ε that the longitudinal / circumferential compressive strain of the pipeline should meet cf =1.6879, that is, when the strength is lower than the minimum strength, the pipeline will not buckle and deform, and can operate in a safe state.

[0188] The remaining life prediction in step S05 includes two calculation methods: uniform corrosion and local corrosion life prediction of straight pipe sections and uniform corrosion and local corrosion life prediction of pipe components such as elbows and tees. The entire pipeline under evaluation is mainly straight pipe sections. The corrosion rate at the elbow is calculated to be relatively low in the previous part, so the straight pipe section is selected for the remaining life calculation.

[0189] For uniform corrosion and local corrosion of straight pipe sections, the wall thickness method is used to predict the remaining life. The calculation method is shown in the following formula:

[0190]

[0191] In the formula, R L —remaining life, in years (a); t mm —The measured average wall thickness of the pipeline, in millimeters (mm); t min —Minimum required wall thickness of the pipe, in millimeters (mm); R t —Residual wall thickness ratio, obtained by residual strength evaluation. RSF a —Allowable residual strength factor, according to the specification, is 0.9; when the straight pipe section is uniformly corroded, R t By RSF a Instead, only uniform corrosion is considered in the straight pipe section of the tested pipeline. rate —The expected corrosion rate in millimeters per year (mm / a) can be determined by the following formula:

[0192]

[0193] Where, I is the current intensity in amperes (A); A is the anode surface area in square centimeters (cm 2); T—test time, in minutes (d); ρ—metal density, in cubic centimeters per gram (g / cm 3 ); through the detection of soil resistivity, pipeline natural corrosion potential, redox potential, soil pH value, soil water content, soil salt content, soil Cl content and soil texture, it is concluded that the soil corrosion level is intermediate, that is, there is slight corrosion. Using the above formula, C rate =0.11mm / a.

[0194] Lifetime prediction can be performed through the calculation method mentioned in step S05 and actual detection data.

[0195] See Table 19 for detailed calculation data:

[0196] Table 19 Pipeline Remaining Life Calculation Data Table

[0197]

[0198] Combined with the evaluation results of the above steps, a suitable use evaluation report can be compiled through step S06 to provide data theoretical support and guarantee for the monitoring, rectification, maintenance and replacement of old gas pipeline networks.

[0199] Example 2

[0200] This embodiment provides an evaluation device, the structural diagram of which is shown in Figure 4 , specifically including an electronic universal testing machine Y1 for tensile properties testing in mechanical properties testing; a Vickers hardness tester Y2 for hardness testing; and a thermal field emission scanning electron microscope Y3 for metallographic structure analysis.

[0201] This embodiment provides an electronic device, the structural diagram of which is shown in FIG. Figure 5 , specifically including a processor Z1, a storage Z2, a communication interface Z3 and a communication bus Z4. The processor Z1, the storage Z2 and the communication interface Z3 complete mutual signal transmission through the communication bus Z4, and the processor is responsible for executing the instructions of the gas pipeline network suitable for use evaluation method as described in Example 1. The processor Z1 in some embodiments can be a central processing unit (CPU), a controller, a microprocessor or other data processing chip, which is used to run the program code stored in the memory Z2 or process data, such as running stress analysis software and flow field analysis software.

[0202] This embodiment provides a computer-readable storage medium for storing a computer program. When the program in Example 1 is executed by a processor, the gas pipeline network suitability for use evaluation method in Example 1 is implemented. The readable storage medium includes a flash memory, a hard disk, a multimedia card, a card-type memory (such as an SD memory), a magnetic disk, an optical disk, etc. In some embodiments, the memory Z2 may be an internal storage unit of an electronic device, such as a hard disk of the electronic device. In other embodiments, the memory Z2 may also be an external storage device of an electronic device, such as a plug-in hard disk equipped on the electronic device, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. Furthermore, the memory Z2 may also include both an internal storage unit and an external storage device of the electronic device. The memory Z2 can be used not only to store application software and various types of data of the electronic device, but also to temporarily store data that has been output or is to be output.

[0203] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for evaluating the suitability of a gas pipeline network for use, characterized in that: include: S01: Pre-assessment of high-risk pipeline sections: software simulation calculations are performed on the pipeline network to determine high-risk pipeline sections based on data results. Pre-assessment is also performed to provide the locations of pipeline sections that should be focused on inspection and assessment for subsequent evaluation. Including pipe system stress simulation calculation and pipe scouring flow field simulation; S02: Material applicability evaluation: prepare samples from the rich area of ​​the pipe base material to test various material properties to determine whether they meet the applicable standards; the material applicability evaluation includes mechanical property testing and metallographic structure analysis, and the mechanical property testing includes tensile property analysis and hardness testing; S03: Residual strength assessment and safety assessment of excessive defects, determine the number and location of pipeline excavation points, conduct non-destructive testing on them, determine the defect type, and carry out residual strength assessment and safety assessment of excessive defects in turn; S04: Safety assessment of buried steel pipelines under adverse conditions, analyzing and determining the types of adverse working conditions that may exist in the environment where the pipeline is located, and assessing the limit state; S05: Remaining life prediction: Select appropriate methods to predict the remaining life of pipelines based on the proportion of straight pipe sections, elbows and tees; S06: Compile an evaluation report on the fitness for use of old gas pipeline networks. Based on the evaluation results of the above parts and comprehensive pipeline measured data, conduct a comprehensive evaluation of the fitness for use of the pipelines and put forward suggestions for maintenance, replacement and rectification.

2. The method for evaluating the suitability of a gas pipeline network for use according to claim 1, characterized in that: In the step S01, the stress simulation calculation of the piping system should be modeled using stress analysis software, and the model nodes need to be set and basic data input during the process, wherein the basic data is obtained from actual measurement or experiment; Considering the surface conditions, measured burial depth, laying environment, etc. of the pipeline, soil models with different physical properties are created. The model parameters consider soil type, friction coefficient, density and soil internal friction angle to determine the load combination. According to the actual direction of the pipeline, the structural parameters of the pipeline units such as elbows, expansion joints, and tees are set in the stress analysis software. Then, according to the load conditions, spring boundaries, force boundaries, and displacement boundary conditions are added to the model to generate the support of the pipeline in the buried state. The construction of the stress analysis model is completed; After modeling is completed, run the model to check for errors. If no errors are found, set the static load and buried soil support according to the model parameters mentioned above; Then the pipe system stress analysis was carried out, during which the software automatically calculated according to the set parameter nodes; the stress data under four working conditions were obtained, namely, the operating state OPE, the associated continuous working condition ALT-SUS, the continuous load working condition and the primary stress SUS, the expansion working condition and the secondary stress EXP. The maximum primary stress under the SUS working condition and the maximum secondary stress under the EXP working condition were analyzed, and the area with the maximum stress of the pipeline was identified as the high-risk pipe section; Based on the high-risk pipe sections determined by the above stress analysis, flow field analysis software is used to model the pipe erosion and corrosion calculations, including: Establish a geometric model and perform finite element processing. Combined with the basic data of the pipeline, first use 3D software to build a model. Import the built software model into the spatial analysis module for model preprocessing, and set the inlet and outlet and wall surfaces. After the preprocessing is completed, enter the grid module to divide the grid, and use grid encryption processing for the elbow to obtain more accurate simulation data. In order to obtain the flow state of the fluid near the wall, set an expansion layer near the wall, and the layer height is obtained by matching the turbulence model with the numerical calculation in the Y direction. After the setting is completed, the grid can be generated. Set the physical property parameters, enable multi-component transport in the flow field analysis software, and enter the natural gas components and their corresponding mass fractions; the gravel that causes pipeline erosion and corrosion is simulated using the discrete phase DPM model, set to be injected from the surface, and consider the effect of gravity on the gravel; the natural gas density, viscosity, gas flow rate, particle density, particle diameter and particle mass flow rate should also be set; Determine the boundary conditions, select the appropriate turbulence model, and set the model inlet, outlet and wall; the wall setting includes the tangential and normal discrete terms DPM reflection coefficient, the impact angle function, diameter function and velocity exponential function in the erosion model; After the above model is constructed and related parameters are set, the calculation method and control method are selected, the residual is set, the monitoring curve is added, the model is initialized, the corrosion rate cloud map, the particle deposition cloud map and the particle trajectory map are created, and finally, a suitable number of iteration steps is given, the calculation is run and the data results can be displayed after convergence; the data results and cloud map phenomena are analyzed to determine whether the corrosion rate is within the standard range.

3. The method for evaluating the suitability of a gas pipeline network for use according to claim 1, characterized in that: In step S02, the preparation of pipeline test samples includes tensile specimens and metallographic specimens. The tensile specimens are prepared by wire cutting at different areas of the upper and lower surfaces of the pipeline; the metallographic specimens are prepared at the upper and lower surfaces of the pipeline.

4. The method for evaluating the suitability of a gas pipeline network for use according to claim 1, characterized in that: The defect types in step S03 include volume defects and wall thickness reduction, specifically: The volume defect uses the first level to evaluate the residual strength of the pipeline, requiring that the operating pressure of the pipeline shall not exceed the maximum allowable working pressure, which is: P=K·P F Where, P is the maximum allowable working pressure of the pipeline, in megapascals (MPa); K is the design factor, which is selected based on the type of medium in the pipeline, the regional level where the defect is located, etc. Failure pressure of pipeline P F , calculated by the following formula: Where P F —Failure pressure of defective pipeline, in megapascals (MPa); D—pipeline diameter, in millimeters (mm); t—pipeline wall thickness, in millimeters (mm); d—corrosion defect depth, in millimeters (mm); Flow stress σ flow , determined by the following formula: In the formula, —Minimum yield strength of the material, in megapascals (MPa); M—Folias expansion coefficient, determined by the following formula: Where, L is the defect length, in millimeters (mm); Compare the maximum allowable working pressure of the pipe section and the maximum working pressure inside the pipe according to the calculation results to determine whether the pipeline meets the requirements for safe operation according to the operating pressure; The thinning of the pipe wall can be determined by instrument detection and theoretical calculation verification. The theoretical calculation formula is as follows: T sd =T s +C C=C1+C2 Where, T sd —Pipeline wall thickness, in millimeters (mm); T s —Calculated thickness of straight pipe, in millimeters (mm); P—design pressure, in megapascals (MPa); D0—outer diameter of pipe, in millimeters (mm); — allowable stress of the material at the design temperature, in megapascals (MPa); E j —welding joint coefficient; C—the sum of thickness additions, in millimeters (mm); C1—thickness reduction additions, in millimeters (mm); C2—corrosion or abrasion additions, in millimeters (mm); Y—correction coefficient; The pipe wall thickness T is obtained by calculation sd In addition to theoretical calculations, the wall thickness of the pipeline was measured to obtain actual wall surface data; the wall thickness obtained by theoretical calculation was compared with the actual average wall thickness measured to determine whether the wall surface was significantly thinned.

5. The method for evaluating the suitability of a gas pipeline network for use according to claim 1, characterized in that: The pipeline safety assessment under adverse conditions in step S04 is divided into determining the adverse condition type and the safety assessment of the pipeline limit state; Adverse working conditions include mining subsidence, frozen soil, lateral landslide, fault, occupation and flood. The terrain, landform and geological data along the pipeline are collected and analyzed to determine which type of adverse working condition the pipeline section belongs to and whether there is an extreme state. The pipeline limit states include fracture, buckling and ovality. The possible limit states are determined through field investigation and excavation inspection. After determination, calculation and judgment can be carried out step by step, specifically: Pipeline rupture is caused by tensile strain reaching or exceeding the limit value. The minimum strength requirement that tensile strain should meet is: In the formula, ε tf —Uniaxial tensile strain in longitudinal or circumferential direction; φ εt — tensile strain resistance factor; —Tensile limit strain of pipe wall or welded parts; Lower than the minimum strength ε that the required longitudinal / circumferential uniaxial tensile strain should meet tf No breakage will occur in the case of When the pipeline is subjected to compressive load or severe bending, compressive stress and strain will be generated in the pipeline section. The minimum strength requirement that the longitudinal compressive strain should meet is: In the formula, ε cf —Uniaxial compressive strain in longitudinal or circumferential direction; φ εc —compression strain resistance factor; —Axial or circumferential compressive limit strain can be obtained by the following formula: Where, t is the pipe wall thickness, in millimeters (mm); D is the pipe outer diameter, in millimeters (mm); P i —maximum design internal pressure, in megapascals (MPa); P e —minimum external hydrostatic pressure, in megapascals (MPa); E s =207GPa; E y —Minimum yield strength, in megapascals (MPa); based on the axial or hoop compressive limit strain The minimum strength ε that the longitudinal / circumferential compressive strain should satisfy can be calculated cf , below the minimum strength, the pipe will not buckle.

6. The method for evaluating the suitability of a gas pipeline network for use according to claim 1, characterized in that: The remaining life prediction in step S05 includes two prediction calculation methods: uniform corrosion and local corrosion life prediction of straight pipe sections, and uniform corrosion and local corrosion life prediction of pipe components such as elbows and tees; For uniform corrosion and local corrosion of straight pipe sections, the wall thickness method is used to predict the remaining life. The calculation method is shown in the following formula: In the formula, R L —remaining life, in years (a); t mm —The measured average wall thickness of the pipeline, in millimeters (mm); t min —Minimum required wall thickness of the pipe, in millimeters (mm); R t —Residual wall thickness ratio, obtained by residual strength evaluation; RSF a —Allowable residual strength factor, refer to the specification for value; when the straight pipe section is uniformly corroded, R t By RSF a Instead, only uniform corrosion is considered in the straight pipe section of the tested pipeline; C rate —The expected corrosion rate in millimeters per year (mm / a) can be determined by the following formula: Where, I is the current intensity in amperes (A); A is the anode surface area in square centimeters (cm 2 ); T—test time, in minutes (d); ρ—metal density, in cubic centimeters per gram (g / cm 3 ).

7. An evaluation device, characterized in that: It includes an electronic universal testing machine for tensile properties testing, a Vickers hardness tester for hardness testing, and a thermal field emission scanning electron microscope for metallographic structure analysis.

8. An electronic device, characterized in that: It comprises a processor, a storage and a program running on a computer, wherein the processor is responsible for implementing the steps of the gas pipeline network suitability for use evaluation method according to any one of claims 1 to 6 when executing the program.

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