Explosion-resistant and high-temperature-resistant explosion test pipeline design method based on finite element simulation

Abstract

The invention relates to an anti-explosion high-temperature-resistant explosion test pipeline design method based on finite element simulation, and belongs to the field of pipeline design and application. According to the method, mechanical and heat transfer behaviors of the pipeline under the combined action of high temperature and explosive shock waves are analyzed by simulating extreme working conditions such as explosion, fire blast and detonation, and the safety performance of the pipeline is improved. The method comprises the following specific steps: firstly, setting explosion working condition parameters based on test requirements and related standards; secondly, establishing a three-dimensional finite element model, and performing fluid dynamic simulation analysis; then, through thermodynamics and explosion impact data analysis, temperature, pressure and stress distribution is obtained, and design parameters such as the geometric structure, the material and the wall thickness of the pipeline are optimized; and finally, verifying the safety and the stability through experiments. The method improves the design efficiency and reliability, and is suitable for high-risk experiment environments such as petrochemical engineering and mines.

Description

Technical Field

[0001] The invention belongs to the field of pipeline design and application, and relates to a method for designing an explosion-proof and high-temperature explosion-resistant test pipeline based on finite element simulation. Background Art

[0002] In the face of industrial backgrounds such as oil and gas transportation, coal mining, and tunnel explosions, combustion and explosion accidents are emerging one after another. In oil and gas transportation, pipelines, as core components that carry fluids and gases, often need to face extreme test conditions; in coal mine tunnels and tunnels, there is also a need for extreme explosion test conditions, especially in the transportation or simulation of explosive gases, oil and gas mixtures, or high-temperature fuels. The pipelines or tunnels and tunnels themselves will be exposed to the combined effects of strong explosion shock waves and high-temperature heat flows, facing great structural damage risks. With the continuous advancement of science and technology, high-temperature, high-pressure and explosion tests are increasingly being carried out in laboratory environments for the safe design and optimization of industrial pipelines, and test pipelines designed for tunnels and tunnels based on similarity theories.

[0003] The particularity of laboratory pipeline testing is that, compared with industrial sites, the test environment is more controllable, data collection is more sophisticated, and parameter adjustment is more flexible. Therefore, how to use the laboratory environment to accurately simulate the explosion shock, thermal expansion and pressure changes in industrial conditions, and optimize the design of the pipeline, has become a key issue in laboratory pipeline design research. Existing pipeline designs mainly focus on the compressive and high temperature resistance of materials, but there are still design deficiencies in the transient stress caused by the explosion shock wave and the thermal expansion characteristics of materials under high temperature conditions. In actual tests, pipelines are prone to problems such as stress concentration, deformation and fatigue, which ultimately lead to structural failure, seriously affecting the accuracy and repeatability of test results.

[0004] One of the main challenges of existing technologies in laboratory pipeline design is how to effectively deal with the combined effects of explosion impact and high temperature environment. Traditional design methods mainly rely on experience, and it is difficult to comprehensively evaluate the stress state, thermal expansion characteristics and structural integrity of the pipeline under complex working conditions. The invention patent with publication number CN118010282A provides a test device for simulating the effect of gas pipeline explosion on subway tunnels. By using precise measurement components and gas pipeline simulation, it is possible to study the impact effect of gas explosion on the structure under experimental conditions; the invention patent with publication number CN115575265A reveals that under gas detonation conditions, the dynamic strain and crack extension of the pipeline are measured in real time through high-speed cameras and data acquisition systems, and the evolution law of the full-field strain and crack tip strain field is obtained, which provides new ideas for damage assessment after pipeline explosion. Further research results, such as the invention with publication number CN111257022B, proposed a simulation system for gas explosion in underground integrated pipe gallery. The system realizes gas load test under different explosion conditions through flexible pipeline combination and effectively obtains the response data of pipe gallery structure; and the invention with publication number CN206431077U is aimed at the research of coal powder explosion, providing a large-scale pipeline weak ignition explosion test system, combined with a powder spraying device and a ventilation and dust removal device, which can simulate coal powder explosion under low ignition energy, and further reveals the impact of explosion on pipeline. These research results show that the existing simulation technology has made significant progress under various complex working conditions, especially under laboratory conditions, and can simulate the performance of pipelines under explosion and high temperature environment through finite element simulation tools. However, in the problem of multi-field coupling, such as the synergistic effect of explosion shock wave and high temperature transmission, the numerical simulation of the existing technology is still limited, and it is difficult to accurately reflect the stress, temperature change and structural optimization in actual working conditions. The stress state, thermal expansion characteristics and structural integrity of the pipeline are difficult to be comprehensively evaluated through traditional design methods. Although existing explosion test designs often rely on industrial experience, it is often difficult to accurately analyze stress and optimize structures for complex working conditions. In order to improve the explosion resistance and high temperature resistance of pipelines under extreme conditions, laboratory designers increasingly rely on finite element tools and use refined numerical simulation techniques to predict the performance of pipelines under explosion shock waves and high temperature environments. These simulation tools can simulate key factors such as airflow, pressure distribution, and temperature changes inside the pipeline, and obtain the stress distribution, heat transfer path, and fatigue strength of the structure through numerical calculations, thereby providing a scientific basis for pipeline design. Existing numerical simulation techniques have been applied to the design of laboratory pipelines to a certain extent, but they still face many challenges when dealing with complex stress changes and heat transfer under extreme working conditions. Especially in multi-field coupling problems, such as the synergistic effect of explosion shock waves and high temperature transfer, traditional numerical simulation methods are relatively simple and cannot accurately reflect the stress and temperature changes in actual working conditions.To this end, there is an urgent need for a systematic method based on multi-field coupled numerical simulation that can more accurately simulate the mechanical performance of pipelines under extreme conditions such as explosion shock waves and high-temperature heat flow, and carry out comprehensive structural optimization design.

[0005] Based on this, the present invention proposes a method for designing explosion-resistant and high-temperature resistant pipelines that can simulate a variety of extreme working conditions in a laboratory environment. This method uses finite element simulation to comprehensively analyze and optimize the mechanical behavior of the pipeline under explosion impact and high temperature conditions. Through the refined processing of the simulation data, the explosion resistance and high temperature resistance of the pipeline can be effectively improved to ensure its stability and safety in laboratory tests. Unlike traditional industrial pipeline design methods, the design method of the present invention focuses on refined design under laboratory test conditions, especially the comprehensive analysis of pressure, temperature and fluid dynamics characteristics in explosion tests. Through multi-field coupling numerical simulation technology, it is possible to achieve accurate simulation and analysis of complex working conditions such as pipeline stress, heat transfer, and explosion impact response, filling the gap in pipeline design in laboratory environments in the prior art.

[0006] In summary, the present invention has important application value in the explosion-proof and high-temperature resistant design of laboratory pipelines. Through scientific and reasonable simulation technology, it solves the problems of complex pipeline stress and susceptibility to impact damage under laboratory conditions, providing a solid guarantee for the safety and effectiveness of high-risk laboratory tests. Summary of the invention

[0007] In view of this, the purpose of the present invention is to provide a method for designing explosion-proof and high-temperature explosion-resistant test pipelines based on finite element simulation. Aiming at the problem that pipelines in the prior art are easily damaged under high temperature and explosion environments, a method for designing explosion-proof and high-temperature explosion-resistant test pipelines based on finite element simulation is provided to improve the explosion-proof and high-temperature resistance of pipelines under extreme conditions and ensure the safety and stability of pipelines in industrial applications.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] The method for designing explosion-proof and high-temperature explosion-resistant test pipeline based on finite element simulation includes the following steps:

[0010] S1: Analyze the explosion test requirements, preset the test conditions and the scale ratio similar to the actual working conditions based on similarity theory, and preset the explosion test conditions and pipeline size parameters according to relevant specifications and literature;

[0011] S2: Establish a scaled three-dimensional finite element simulation model, and design a scaled overall finite element model of the explosion pipeline through preset pipeline size parameters;

[0012] S3: Finite element simulation calculation: Based on preset parameters, finite element simulation is performed to obtain the thermodynamic data and impact dynamics data of the pipeline under high temperature heat source and explosion impact;

[0013] S4: Adjust the calculation parameters. According to the simulation results, adjust the calculation parameters in the model, including material properties, structural dimensions, and pipe wall thickness;

[0014] S5: Finite element simulation calculation: Based on the adjusted parameters, finite element simulation is performed to obtain the temperature, stress and strain distribution of the pipeline under explosion impact and high temperature conditions;

[0015] S6: Thermodynamic analysis: conduct thermodynamic analysis on the calculation results, evaluate the high temperature resistance of the pipeline based on similarity theory and experimental model scale ratio, and determine whether the material meets the requirements for use in high temperature environments;

[0016] S7: Strength and stress response analysis: perform strength analysis on the stress and deformation of the pipeline to determine whether it meets the explosion-proof performance requirements;

[0017] S8: Design verification and application.

[0018] Furthermore, in S1, the explosion test conditions include the location of the ignition source, the concentration of the oil-gas mixture and the arrangement of obstacles in the pipeline.

[0019] Furthermore, in S1, the actual working conditions include inlet boundary conditions, outlet boundary conditions, ignition source settings and obstacle settings.

[0020] Furthermore, in S2, the three-dimensional finite element simulation model adopts a Realizable k-ε turbulence model to handle the complex flow caused by the explosion shock wave.

[0021] Furthermore, in S4, the calculation parameters to be adjusted include material properties, structural dimensions and pipe wall thickness.

[0022] Furthermore, in S6, the thermodynamic analysis uses the Fourier heat conduction equation to simulate the heat conduction behavior of the pipeline.

[0023] Furthermore, in S7, the strength and stress response analysis uses a fluid-solid coupling analysis model to simulate the propagation process of the explosion shock wave on the pipeline.

[0024] The beneficial effects of the present invention are:

[0025] The present invention can significantly improve the anti-explosion and high temperature resistance of pipelines through finite element simulation analysis and numerical optimization. Its specific advantages include:

[0026] 1. Enhanced explosion resistance: Through accurate explosion impact simulation, the stress concentration phenomenon in the test pipeline structure can be effectively reduced, and the optimized pipeline has higher impact resistance in an explosive environment.

[0027] 2. Improved high temperature resistance: Thermodynamic simulation results help designers optimize pipeline materials and structures to maintain good thermal stability and mechanical strength under high temperature conditions of explosion.

[0028] 3. Shortened design cycle: By exporting temperature and pressure data through simulation and comparing them with standards, weak links in pipeline design can be quickly found, the number of tests can be reduced, and the design cycle can be shortened.

[0029] 4. Wide scope of application: The design method of the present invention can be widely used in laboratory explosion test scenarios such as petrochemical industry, mining, tunnel deflagration, etc., and is particularly suitable for high temperature, high pressure and high explosion risk working condition tests, thereby improving the safety and reliability of the pipeline system.

[0030] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0032] Figure 1 It is a flow chart of the present invention;

[0033] Figure 2 Preset of pipeline parameters provided by the embodiment of the present invention;

[0034] Figure 3 Thermodynamic simulation temperature changes provided by the embodiment of the present invention;

[0035] Figure 4 A cloud diagram of thermal strain changes in thermodynamic simulation provided by an embodiment of the present invention;

[0036] Figure 5 Thermodynamic simulation thermal strain change curve provided by the embodiment of the present invention;

[0037] Figure 6 The pressure cloud diagram changes of the explosion impact dynamics simulation of working condition 1 provided in the embodiment of the present invention;

[0038] Figure 7Changes in pressure cloud diagram of explosion impact dynamics simulation of working condition 2 provided by an embodiment of the present invention;

[0039] Figure 8 The pressure cloud diagram change of the explosion impact dynamics simulation of working condition 3 provided by the embodiment of the present invention;

[0040] Fig. 9 The pressure data change of the explosion impact dynamics simulation of working condition 1 provided in the embodiment of the present invention;

[0041] Fig.10 The pressure data change of the explosion impact dynamics simulation of working condition 2 provided by the embodiment of the present invention;

[0042] Fig.11 The pressure data change of explosion impact dynamics simulation of working condition 3 provided by the embodiment of the present invention;

[0043] Fig.12 The test pipeline verification pressure data provided by the embodiment of the present invention;

[0044] Fig.13 The test pipeline verification temperature data provided by the embodiment of the present invention. DETAILED DESCRIPTION

[0045] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0046] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0047] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0048] See also Figures 1 to 13 The present invention provides a method for designing an explosion-proof and high-temperature explosion-resistant test pipeline based on finite element simulation. The method is a method for designing an explosion-proof and high-temperature explosion-resistant test pipeline based on finite element simulation. Specifically, the molecular simulation method includes the following specific steps:

[0049] The specific steps of the embodiment are as follows:

[0050] S1: Analyze the explosion test requirements, preset the test conditions and the scale ratio similar to the actual working conditions based on similarity theory, and preset the explosion test conditions and pipeline size parameters according to relevant specifications and literature;

[0051] Specifically, a test pipeline for a typical tunnel deflagration accident is designed, and the environmental parameters of the test pipeline under explosion conditions are analyzed. First, the working environment of the pipeline is determined, including the location of the ignition source required for the test, the concentration of the oil-gas mixture, and the arrangement of obstacles in the pipeline. An explosion simulation of a methane / air mixture with a methane concentration of 8% is carried out. According to these explosion conditions, the design parameters of the pipeline, such as material selection, geometric dimensions and wall thickness, are determined. The preset pipeline parameters include different pipeline geometric dimensions (pipe diameter range 100-500mm), wall thickness (5-20mm) and parameter configurations of different materials (alloy steel, composite materials). In addition, multiple obstacles are set in the pipeline to simulate structural interference in the actual tunnel environment, such as Figure 2 shown.

[0052] S2: Establish a scaled three-dimensional finite element simulation model, and design a scaled overall finite element model of the explosion pipeline through preset pipeline size parameters;

[0053] Specifically, after analyzing the requirements of the explosion test, a three-dimensional finite element model was established to perform multi-field coupling simulation. To ensure the consistency between the experimental results and the actual working conditions, the design followed similarity criteria, including geometric similarity, motion similarity, and dynamic similarity:

[0054] 1. Geometric similarity: The geometric dimensions of the experimental model and the actual tunnel system are scaled in the same proportion to ensure that the shape and proportion of the pipes in the model are consistent with the actual tunnel system.

[0055] 2. Motion similarity: The velocity, pressure and other dynamic parameters of the fluid maintain a proportional relationship to ensure that the flow behavior of the fluid and the propagation of the explosion shock wave are similar to the actual working conditions.

[0056] 3. Dynamic similarity: The stress and strain of the pipeline are kept proportional between the experimental model and the actual project. Through stress distribution analysis, it is ensured that the mechanical response of the model under high temperature and high pressure is consistent with the actual tunnel system.

[0057] S3. Finite element simulation calculation: Based on preset parameters, finite element simulation is performed to obtain the thermodynamic data and impact dynamics data of the pipeline under high temperature heat source and explosion impact;

[0058] Specifically, for the three-dimensional finite element simulation model, the finite element simulation model adopts the Realizable k-ε turbulence model to deal with the complex flow caused by the explosion shock wave. The model boundary conditions are set as pressure inlet and pressure outlet.

[0059] The working conditions are as follows:

[0060] Inlet boundary conditions: The inlet is set to wall conditions, corresponding to a closed pipe;

[0061] Outlet boundary condition: set to atmospheric pressure (101.3kPa). For the temperature boundary condition of the pipe wall, the outer wall is set to the ambient temperature of 25°C, and the inner wall is set to 1000°C due to the heat transfer of the high-temperature gas. Through these settings, it is ensured that the model can accurately simulate the propagation behavior of the explosion shock wave under high temperature conditions;

[0062] Ignition source setting: The ignition source is set at the entrance of the pipeline, with a hemispherical fire source with a radius of 10 mm, and the high-temperature heat source temperature is set to 2000K;

[0063] Obstacle setting: According to different obstacles in actual engineering applications, set different numbers and spacing of obstacles, and observe thermodynamic analysis and impact dynamics analysis.

[0064] The temperature and pressure fields were calculated using Fourier heat conduction and Bernoulli, and the scalability of the experimental results was ensured by dimensionless analysis. The simulation results show that the maximum pressure of the pipeline under the action of the explosion shock wave reaches 500kPa, especially the stress concentration area near the explosion point. The temperature analysis shows that the temperature difference between the inside and outside of the pipeline reaches 975℃.

[0065] S4. Adjust the calculation parameters. According to the simulation results, adjust the calculation parameters in the model, including material properties, structural dimensions, and pipe wall thickness;

[0066] Specifically, for the three-dimensional finite element simulation results, key data, including temperature data and pressure data, are derived from the thermodynamic simulation and explosion shock simulation. The temperature data is used to analyze the thermal expansion behavior of the pipeline material. Through finite element simulation, the temperature difference between the inside and outside of the pipeline reaches 975°C, and the resulting thermal strain is about 0.0025. In terms of pressure, the stress response of the pipeline under the action of a 500kPa shock wave is evaluated by analyzing the pipeline pressure field. These data are compared with the pipeline design standards to evaluate whether the design meets the requirements of the "Regulations on the Safety Management of Hazardous Chemicals" and "Burst Pressure Test of Plastic Pipes" such as GB / T 15559-2016, ISO 1167-1:2020, ASTM D1598-06, etc.

[0067] The calculation formulas for the yield strength, flexural strength, creep limit, etc. are as follows:

[0068]

[0069] f yT Indicates the yield strength at high temperature, in MPa; f y Indicates the yield strength at room temperature, in MPa; γ R Represents the partial coefficient of steel member resistance, usually γ R =1.1;η T Represents the strength reduction factor of steel at high temperature.

[0070]

[0071] R 2 It represents the high temperature flexural strength, in Pa; F represents the maximum load when the sample breaks, in N; L represents the distance between the lower cutting edges, in cm; b represents the width of the middle part of the sample, in cm; h represents the height of the middle part of the sample, in cm.

[0072]

[0073] P r Indicates high temperature compression creep rate, unit is %; L i Indicates the original height of the sample, in mm; L 0 Indicates the height of the sample at the beginning of constant temperature, in mm; L n It indicates the height of the sample at constant temperature for n hours, in mm.

[0074]

[0075] σ represents the design wall thickness of the steel pipe, in mm; P represents the design pressure, in MPa; D represents the outer diameter of the steel pipe, in mm; σS Indicates the minimum yield strength of the steel pipe, in MPa; It represents the weld coefficient of steel pipe; F represents the strength design coefficient.

[0076] Specifically, the design parameters were optimized based on the simulation results and data comparison analysis. For high-temperature strain and pressure concentration areas, the pipe wall thickness was increased from 5mm to 10mm to enhance its explosion resistance. The proportional relationship between fluid velocity, pressure and pipe geometry was recalculated through similarity theory to ensure that the geometric, kinematic and dynamic similarities were still met in the adjusted design.

[0077] The explosion test pipe is made of high temperature resistant alloy steel (Inconel 718), which has a lower thermal expansion coefficient and better high temperature resistance. The geometric structure is adjusted and a reinforcement ring is added to reduce the stress amplitude in the stress concentration area. After optimization, the simulation verification is re-performed.

[0078] S5. Finite element simulation calculation: Based on the adjusted parameters, finite element simulation is performed to obtain the temperature, stress and strain distribution of the pipeline under explosion impact and high temperature conditions;

[0079] Specifically, based on the adjusted parameters, finite element simulation is performed again to obtain the temperature, stress, and strain distribution of the pipeline under explosion impact and high temperature conditions. The geometric model of the adjusted pipeline is re-meshed, and the appropriate mesh density is selected to ensure accurate simulation results under complex geometric structures. Then, according to the physical properties of the pipeline material, including elastic modulus, yield strength, thermal expansion coefficient, and thermal conductivity, parameters are set to accurately simulate the behavior of the material under high temperature and explosion impact conditions. As shown in the attached figure, Figure 3 shown.

[0080] S6. Thermodynamic analysis: Conduct thermodynamic analysis on the calculation results, evaluate the high temperature resistance of the pipeline based on similarity theory and test model scale ratio, and determine whether the material meets the requirements for use in high temperature environments;

[0081] Specifically, the temperature field in the finite element simulation results is analyzed, with special attention paid to the heat transfer process of the pipeline under explosion conditions.

[0082] In the simulation, the Fourier heat conduction equation is used to simulate the heat conduction behavior of the pipeline. The calculation formula is as follows:

[0083]

[0084] Where q is the heat flux; k is the thermal conductivity of the material; is the temperature gradient.

[0085] Through simulation calculation, the temperature data of different areas of the pipeline were derived, and the thermal expansion of the pipeline was further calculated.

[0086] like Figure 4 The thermal strain change cloud diagram shows the strain of each part of the pipeline at different temperatures. The thermal strain in the higher temperature area increases, especially at the pipe joint where the strain value is the largest.

[0087] Specifically, the optimized design was verified again through finite element simulation. The results showed that the thermal strain of the pipeline under high temperature conditions was reduced by 50%, and the pressure at the maximum stress concentration point was reduced by 30%. By repeatedly adjusting the design parameters, the design standard requirements were finally met. In the simulation verification, the strain value of the pipeline was kept within the design allowable range, ensuring the reliability of the pipeline under high temperature and explosion impact conditions.

[0088] S7. Strength and stress response analysis: Conduct strength analysis on the stress and deformation of the pipeline to determine whether it meets the explosion-proof performance requirements;

[0089] Specifically, the fluid-solid coupling analysis model is used to simulate the propagation of the explosion shock wave on the pipeline. The simulation uses the SIMPLE pressure-velocity coupling algorithm to handle high-speed shock wave propagation, and the shock wave propagation time step is set to 0.001 seconds to ensure that the propagation process of the transient pressure wave is captured.

[0090] The pressure field is calculated using the Bernoulli equation: The calculation formula is as follows:

[0091]

[0092] Where P is pressure, ρ is fluid density, and v is flow velocity.

[0093] The simulation results show that under the action of the shock wave, the internal pressure of the pipeline increases rapidly and stress concentration occurs on the surface. Figure 6 to Figure 8 The pressure cloud diagram shows the transient pressure distribution of the pipeline at different time points, with the maximum pressure reaching 500kPa, especially the highest stress concentration area on the pipeline surface near the explosion point. Figures 9 to 11 FIG. 4 further shows the pressure change curve during the propagation of the explosion shock wave, indicating that the pressure rapidly decays after reaching a peak value instantaneously.

[0094] S8, Design verification and application;

[0095] Specifically, after the simulation verification is passed, the experimental platform is restored according to the similarity theory, and actual production and manufacturing are carried out to produce pipelines according to the optimized parameters of the simulation model. The explosion resistance and high temperature resistance of the pipeline are verified by experiments. The experimental results are consistent with the simulation results, and the pipeline can maintain structural integrity in an explosive environment. This design has been successfully applied to petrochemical and mining pipeline systems, especially in test environments for high temperature, high pressure, and explosion experiments. Practical applications have shown that this design has greatly improved the safety performance of the test pipeline.

[0096] Based on the similarity theory, the test pipeline was restored. Using this test platform, an explosion experiment of a methane / air mixture with a methane concentration of 8% and an ignition energy of 5J was carried out. The experiment was repeated three times, and the pressure and temperature test results were obtained as follows: Fig.12 and Fig.13 It can be seen that under this working condition, the explosion pressure and temperature of the mixture reach 0.45MPa and 1600℃ respectively. The results show that the platform can sustain high temperature resistance of 1200℃ and withstand explosion overpressure of no less than 0.3MPa.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. The design method of explosion-proof and high-temperature explosion-resistant test pipeline based on finite element simulation is characterized by: The method comprises the following steps: S1: Analyze the explosion test requirements, preset the test conditions and the scale ratio similar to the actual working conditions based on similarity theory, and preset the explosion test conditions and pipeline size parameters according to relevant specifications and literature; S2: Establish a scaled three-dimensional finite element simulation model, and design a scaled overall finite element model of the explosion pipeline through preset pipeline size parameters; S3: Finite element simulation calculation: Based on preset parameters, finite element simulation is performed to obtain the thermodynamic data and impact dynamics data of the pipeline under high temperature heat source and explosion impact; S4: Adjust the calculation parameters. According to the simulation results, adjust the calculation parameters in the model, including material properties, structural dimensions, and pipe wall thickness; S5: Finite element simulation calculation: Based on the adjusted parameters, finite element simulation is performed to obtain the temperature, stress and strain distribution of the pipeline under explosion impact and high temperature conditions; S6: Thermodynamic analysis: conduct thermodynamic analysis on the calculation results, evaluate the high temperature resistance of the pipeline based on similarity theory and experimental model scale ratio, and determine whether the material meets the requirements for use in high temperature environments; S7: Strength and stress response analysis: perform strength analysis on the stress and deformation of the pipeline to determine whether it meets the explosion-proof performance requirements; S8: Design verification and application.

2. The method for designing explosion-proof and high-temperature explosion-resistant test pipelines based on finite element simulation according to claim 1 is characterized in that: In S1, the explosion test conditions include the location of the ignition source, the concentration of the oil-gas mixture and the arrangement of obstacles in the pipeline.

3. The method for designing explosion-proof and high-temperature explosion-resistant test pipelines based on finite element simulation according to claim 1 is characterized in that: In S1, the actual working conditions include inlet boundary conditions, outlet boundary conditions, ignition source settings and obstacle settings.

4. The method for designing explosion-proof and high-temperature explosion-resistant test pipelines based on finite element simulation according to claim 1 is characterized in that: In S2, the three-dimensional finite element simulation model adopts the Realizable k-ε turbulence model to handle the complex flow caused by the explosion shock wave.

5. The method for designing explosion-proof and high-temperature explosion-resistant test pipelines based on finite element simulation according to claim 1 is characterized in that: In S4, the calculation parameters adjusted include material properties, structural dimensions and pipe wall thickness.

6. The method for designing explosion-proof and high-temperature explosion-resistant test pipelines based on finite element simulation according to claim 1 is characterized in that: In S6, the thermodynamic analysis uses the Fourier heat conduction equation to simulate the heat conduction behavior of the pipeline.

7. The method for designing explosion-proof and high-temperature explosion-resistant test pipelines based on finite element simulation according to claim 1 is characterized in that: In S7, the strength and stress response analysis uses a fluid-solid coupling analysis model to simulate the propagation process of the explosion shock wave on the pipeline.

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