Buried CO2 pipeline leakage multi-physical field simulation device and method

Abstract

The invention discloses a buried CO2 pipeline leakage multi-physics field simulation device and method, the device comprises a soil environment simulation mechanism, a simulation pipeline, a multi-physics field monitoring mechanism, a CO2 supply mechanism, a pressure stabilizing mechanism, a rainfall simulation mechanism and an evaluation module, the simulation pipeline is buried in soil in a box body; the multi-physical field monitoring mechanism comprises a plurality of thermocouples, a moisture sensor, a carbon dioxide concentration sensor and a gas flow rate sensor which are uniformly buried in soil in the box body; the CO2 supply mechanism is used for conveying liquid CO2 to one end of the simulation pipeline; data such as soil temperature, moisture, carbon dioxide concentration and gas flow velocity are acquired in real time through the multi-physical field monitoring mechanism, and the data are analyzed by the evaluation module, so that the influence of rainfall and CO2 leakage on a soil layer and the relationship between the rainfall intensity and the CO2 leakage range and speed can be deeply studied; and a scientific basis is provided for accurately evaluating the leakage risk of the buried CO2 pipeline.

Description

Technical Field

[0001] The present invention relates to the field of pipeline leakage simulation and impact assessment, and in particular to a multi-physics field simulation device and method for buried CO2 pipeline leakage. Background Art

[0002] In the field of carbon capture and storage (CCS), the safety of buried CO2 pipelines is a crucial factor. With increasing global attention to environmental protection and climate change, CCS technology has become a key means of reducing greenhouse gas emissions and mitigating climate change. As key infrastructure in CCS systems, buried CO2 pipelines are responsible for transporting captured CO2 to underground storage sites. Their safety is not only directly related to the successful implementation of CCS projects but also has a profound impact on the stability of the surrounding environment and ecosystems. A leak would not only cause massive CO2 emissions, exacerbating the greenhouse effect, but could also cause severe damage to the soil, groundwater, and surrounding ecosystems. Therefore, in-depth research on buried CO2 pipeline leakage is crucial for ensuring the safe operation of CCS systems and protecting the environment.

[0003] Previous studies have often employed basic experimental setups and methods to investigate CO2 leakage. For example, simple pipeline models combined with a few sensors were used. Some focused solely on the impact of a single physical factor on pipeline leakage, such as considering only the diffusion of gas in air without considering the effect of soil on leakage. Others constructed simple laboratory simulations to observe the flow of CO2 in a small amount of medium within a confined space. However, this approach fails to reflect the actual conditions in complex geological environments. Others have used theoretical calculations and numerical simulations to predict the consequences of CO2 leakage. However, these calculations are often based on simplified assumptions and cannot accurately reflect the true multi-physics coupling effects. Furthermore, some experiments have isolated a single physical process, such as the effects of temperature changes or soil moisture, without comprehensively considering the interactions of multiple factors.

[0004] However, existing experimental devices and methods have significant drawbacks. Buried CO2 pipeline leakage presents a complex multi-physics coupling scenario, influenced by factors such as soil viscosity, the coke-soak effect, fluid flash evaporation, and rainfall. However, existing experimental devices and methods struggle to fully simulate these complex conditions and accurately capture the leakage characteristics and patterns of buried CO2 pipelines under various actual operating conditions. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above technical deficiencies and to provide a multi-physics field simulation device and method for buried CO2 pipeline leakage.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] The present invention provides a multi-physics field simulation device for buried CO2 pipeline leakage, comprising:

[0008] A soil environment simulation mechanism includes a box body, the upper end of which is open and is used to fill soil;

[0009] A simulated pipeline is buried in the soil in the box, a leakage hole is opened on the simulated pipeline, and an electromagnetic leakage valve is provided on the leakage hole;

[0010] a multi-physics field monitoring mechanism, comprising a plurality of thermocouples, moisture sensors, carbon dioxide concentration sensors, and gas flow rate sensors uniformly buried in the soil within the box, wherein the plurality of thermocouples are used to obtain the temperature field within the soil within the box, the plurality of moisture sensors are used to obtain the soil moisture content distribution within the box, the plurality of carbon dioxide concentration sensors are used to obtain the soil carbon dioxide content distribution within the box, and the plurality of gas flow rate sensors are used to obtain the gas flow rate content distribution within the soil within the box;

[0011] A CO2 supply mechanism, which is used to deliver liquid CO2 to one end of the simulation pipeline;

[0012] a pressure stabilizing mechanism, the pressure stabilizing mechanism being in communication with the other end of the simulation pipeline and being configured to maintain the pressure in the simulation pipeline and to collect liquid CO2 discharged from the simulation pipeline;

[0013] A rainfall simulation mechanism, which is used to spray rainwater above the box;

[0014] An evaluation module is communicatively connected to the electromagnetic leakage valve, the multi-physics field monitoring mechanism, the CO2 supply mechanism, and the rainfall simulation mechanism, and is used to evaluate the impact of CO2 pipeline leakage on the soil layer, the impact of simultaneous rainfall and CO2 leakage on the soil layer, and the impact of rainfall on the leakage range and leakage rate of the CO2 pipeline in the soil.

[0015] In some embodiments, a horizontally arranged perforated partition is formed in the box body, the upper part of the perforated partition is used to fill soil, and a drainage cavity is formed below the perforated partition. A drainage port connected to the drainage cavity is formed on the side wall of the box body, and a drainage valve is provided on the drainage port. The drainage valve is used to control the opening degree of the drainage port to simulate different soil drainage conditions.

[0016] In some embodiments, the CO2 supply mechanism includes a CO2 storage tank, a booster pump, an exhaust pipe and a preheater. The CO2 storage tank is used to store CO2 liquid, the inlet of the booster pump is connected to the outlet of the CO2 storage tank, and the outlet of the booster pump is connected to one end of the exhaust pipe. The preheater is used to heat the CO2 liquid in the exhaust pipe to the temperature required for the supercritical state.

[0017] In some embodiments, the CO2 supply mechanism further includes a CO2 pressure sensor and a CO2 flow meter, and the CO2 pressure sensor and the CO2 flow meter are both disposed in the exhaust pipe.

[0018] In some embodiments, the pressure stabilizing mechanism includes a back pressure valve and a recovery container. The back pressure valve is arranged at the other end of the simulation pipeline for adjusting the pressure in the simulation pipeline. The recovery container is connected to the outlet of the back pressure valve.

[0019] In some embodiments, the rainfall simulation mechanism includes a plurality of sprinkler heads, a water supply pipe, a water pump and a water tank. An array of the plurality of sprinkler heads is arranged above the tank. The inlet of the water pump is connected to the water tank. The outlet of the water pump is connected to the inlet of each sprinkler head via the water supply pipe. The evaluation module adjusts the spraying intensity and spraying time of the sprinkler head by controlling the working state of the water pump to simulate different rainfall intensities and rainfall durations.

[0020] In some embodiments, a water temperature regulator is provided in the water tank.

[0021] In some embodiments, the water supply line is provided with a control valve.

[0022] In some embodiments, two opposite side surfaces of the box body are provided with perforations, the simulated pipe passes through two of the perforations, and the simulated pipe is sealed and connected with the perforations at the contact points. There are multiple leakage holes and multiple electromagnetic leakage valves, and the orientations of the leakage holes are different. The electromagnetic valves are respectively installed on the corresponding leakage holes.

[0023] The present invention also provides a multi-physics field simulation method for buried CO2 pipeline leakage, which is suitable for the multi-physics field simulation device for buried CO2 pipeline leakage and includes the following steps:

[0024] S1. Bury the simulated pipeline in the soil inside the box, evenly bury the thermocouple, moisture sensor, carbon dioxide concentration sensor, and gas flow rate sensor in the soil inside the box, and establish communication connection with the evaluation module;

[0025] S2. The multi-physics field monitoring mechanism starts working. The thermocouple obtains the temperature field data in the soil inside the box, the moisture sensor obtains the soil moisture content distribution data, the carbon dioxide concentration sensor obtains the soil carbon dioxide content distribution data, and the gas flow rate sensor obtains the soil gas flow rate content distribution data. These data are then transmitted to the evaluation module.

[0026] In step S3, the CO2 supply mechanism starts to deliver liquid CO2 to one end of the simulation pipeline, so that the pipeline reaches a certain pressure. The pressure stabilizing mechanism maintains the pressure in the simulation pipeline and collects the liquid CO2 discharged from the simulation pipeline. The evaluation module controls the electromagnetic leakage valve to open, and the liquid CO2 leaks into the surrounding soil through the leakage hole. The multi-physics field monitoring mechanism continues to work. The thermocouple obtains the temperature field data in the soil inside the box, the moisture sensor obtains the soil moisture content distribution data, the carbon dioxide concentration sensor obtains the soil carbon dioxide content distribution data, and the gas flow rate sensor obtains the gas flow rate content distribution data in the soil. These data are then transmitted to the evaluation module. The evaluation module evaluates the impact of the CO2 pipeline leakage on the soil layer based on the collected data, and analyzes the changes in the temperature field and moisture content distribution in the soil before and after the leakage.

[0027] S4. During the CO2 leakage process, the evaluation module controls the rainfall simulation mechanism to spray rainwater above the box to simulate a rainfall scene; the multi-physics field monitoring mechanism continues to monitor the soil temperature, moisture, carbon dioxide concentration, gas flow rate and other data in real time, and the evaluation module analyzes the impact of the simultaneous effects of rainfall and CO2 leakage on the soil layer;

[0028] S5. The evaluation module controls the rainfall simulation mechanism to set different rainfall intensities and repeats the above-mentioned CO2 leakage and rainfall process. The evaluation module simulates the impact of rainfall on the leakage range and leakage rate of the CO2 pipeline in the soil based on the multi-physical field data collected under different rainfall intensities, and analyzes the relationship between rainfall intensity and leakage range and leakage rate.

[0029] Compared with the existing technology, the beneficial effects of the multi-physical field simulation device and method for buried CO2 pipeline leakage provided by the present invention are: through the coordinated work of the soil environment simulation mechanism, the simulation pipeline, the multi-physical field monitoring mechanism, the CO2 supply mechanism, the pressure stabilization mechanism, the rainfall simulation mechanism and the evaluation module, it can simulate the influence of various factors such as soil viscosity resistance, coke-soak effect, fluid flash evaporation, rainfall, etc. on the leakage of buried CO2 pipelines, and comprehensively cover the complex multi-physical field coupling conditions involved in the actual leakage process; through the multi-physical field monitoring mechanism, soil temperature, moisture, carbon dioxide concentration and gas flow rate data are obtained in real time, and the evaluation module analyzes these data, it can deeply study the influence of rainfall and CO2 leakage on the soil layer, as well as the relationship between rainfall intensity and CO2 leakage range and speed, providing a scientific basis for accurately assessing the risk of buried CO2 pipeline leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 1 is a schematic structural diagram of a multi-physics field simulation device for buried CO2 pipeline leakage provided by one embodiment of the present invention;

[0031] Figure 2 yes Figure 1 A partial enlarged view of the middle area A;

[0032] Figure 3 yes Figure 1 A partial enlarged view of the middle area B;

[0033] Figure 4 yes Figure 1 Schematic diagram of the structure of the CO2 supply mechanism;

[0034] Figure 5 yes Figure 1 A schematic diagram of the structure of the voltage stabilizing mechanism;

[0035] Explanation of the accompanying symbols: 1. Soil environment simulation mechanism; 11. Box body; 12. Perforated partition; 13. Drain chamber; 14. Drain outlet; 15. Drain valve; 2. Simulation pipeline; 21. Leakage hole; 22. Electromagnetic leakage valve; 3. Multi-physics field monitoring mechanism; 31. Thermocouple; 32. Moisture sensor; 33. Carbon dioxide concentration sensor; 34. Gas flow rate sensor; 4. CO2 supply mechanism; 41. CO2 storage tank; 42. Booster pump; 43. Discharge pipe; 44. Preheater; 45. CO2 pressure sensor; 46. CO2 flow meter; 5. Pressure stabilizing mechanism; 51. Back pressure valve; 52. Recovery container; 6. Rainfall simulation mechanism; 61. Sprinkler head; 62. Water supply pipeline; 63. Water pump; 64. Water tank; 65. Control valve; 66. Water temperature regulator. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. The described embodiments are only possible technical implementations of the present invention, but are not limited thereto. Those skilled in the art can fully combine the embodiments of the present invention, and other embodiments obtained without creative work are also within the scope of protection of the present invention.

[0037] This application mainly adopts an experimental device and method for simulating the multi-physical field of buried CO2 pipeline leakage, which achieves the effect of accurately simulating the multi-physical field coupling situation of buried CO2 pipeline leakage. The following is a further detailed description of this application.

[0038] Example 1

[0039] Please refer to Figure 1-Figure 5The buried CO2 pipeline leakage multi-physics field simulation device provided in the embodiment of the present application includes a soil environment simulation mechanism 1, a simulation pipeline 2, a multi-physics field monitoring mechanism 3, a CO2 supply mechanism 4, a pressure stabilizing mechanism 5, a rainfall simulation mechanism 6 and an evaluation module, wherein the soil environment simulation mechanism 1 is used to simulate the soil environment in which the buried CO2 pipeline is located, the simulation pipeline 2 is buried in the soil and is provided with a leakage hole 21 and an electromagnetic leakage valve 22, the multi-physics field monitoring mechanism 3 is used to monitor multi-physics field data such as the temperature field, moisture content distribution, carbon dioxide content distribution and gas flow rate content distribution in the soil, the CO2 supply mechanism 4 transports liquid CO2 to the simulation pipeline 2, the pressure stabilizing mechanism 5 maintains the pressure in the simulation pipeline 2 and collects the discharged liquid CO2, the rainfall simulation mechanism 6 simulates the rainfall scene, and the evaluation module analyzes and evaluates the data of each mechanism, thereby achieving the effect of comprehensively simulating the multi-physics field coupling of the buried CO2 pipeline leakage and accurately presenting its leakage characteristics and laws under various actual working conditions. This is because through the collaborative work of various institutions, the effects of various factors such as soil viscosity resistance, coke-soak effect, fluid flash evaporation, rainfall, etc. on the leakage of buried CO2 pipelines can be simulated, thereby obtaining experimental results that are closer to the actual situation.

[0040] For details, please refer to Figure 1-Figure 3 The soil environment simulation mechanism 1 includes a box body 11, the upper end of which is open for easy operation and observation. The box body 11 is generally made of high-strength metal materials, such as stainless steel. It is sturdy and durable, can withstand certain pressure and external impact, and ensure the stability of the experiment. A horizontally arranged perforated partition 12 is formed in the box body 11. The perforated partition 12 can be a porous plate made of metal with a moderate pore size, which can ensure smooth drainage and support the soil above. The upper part of the perforated partition 12 is used to fill the soil, and a drainage cavity 13 is formed below. A drainage port 14 connected to the drainage cavity 13 is provided on the side wall of the box body 11, and a drainage valve 15 is provided on the drainage port 14. The drainage valve 15 can be an electric ball valve, which is easy to control and can accurately control the opening degree of the drainage port 14 to simulate different soil drainage conditions. A manual gate valve can also be used, which is low in cost and suitable for situations where low control accuracy is required. In this embodiment, the housing 11 of the soil environment simulation mechanism 1 is constructed from high-strength metal materials, such as stainless steel, to withstand pressure and external impact, ensuring stability during the experiment. The design of the perforated partition 12, drainage chamber 13, and drain valve 15 effectively simulates various soil drainage conditions, providing a stable and adjustable soil environment for the experiment.

[0041] The simulated pipeline 2 is buried in the soil within the enclosure 11. It is typically constructed of the same or similar material as an actual buried CO2 pipeline, such as carbon steel, which offers excellent strength and corrosion resistance. Leak holes 21 are defined in the simulated pipeline 2. These holes can be round, square, or similar in shape. There are multiple leak holes 21 and electromagnetic leakage valves 22, each positioned differently. Each electromagnetic leakage valve 22 is installed on a corresponding leak hole 21. During simulations, selectively opening one or more electromagnetic leakage valves 22 can simulate pipeline leakage at different locations, providing flexibility and versatility for studying the impact of leaks at different locations on the surrounding soil. The electromagnetic leakage valves 22 can be normally closed. When leak simulation is required, the evaluation module controls their opening, allowing liquid CO2 to leak through the leak holes 21 into the surrounding soil. The enclosure 11 features perforations 23 on opposite sides of the enclosure. The simulated pipeline 2 passes through two of these perforations. The contact between the simulated pipeline 2 and the perforations 23 is sealed to prevent liquid CO2 from leaking outside the enclosure 11. The sealing material may be a rubber sealing ring, which has good elasticity and sealing performance.

[0042] Please refer to Figure 1-Figure 3 The multi-physics field monitoring mechanism 3 includes several thermocouples 31, a moisture sensor 32, a carbon dioxide concentration sensor 33, and a gas flow rate sensor 34 uniformly buried in the soil within the box 11. The thermocouple 31 can be a K-type thermocouple, which has a wide temperature measurement range and high accuracy, and can accurately obtain the temperature field in the soil within the box 11. A J-type thermocouple can also be selected, which is suitable for certain specific temperature measurement environments. The moisture sensor 32 can be a capacitive moisture sensor, which indirectly measures the soil moisture content by measuring the dielectric constant of the soil, with a fast response speed and accurate measurement. The carbon dioxide concentration sensor 33 can be an infrared absorption sensor, which uses the absorption characteristics of CO2 for infrared light of a specific wavelength to measure the CO2 concentration, with high sensitivity and good stability. The gas flow rate sensor 34 can be a thermal gas flow rate sensor, which determines the gas flow rate by measuring the cooling effect of gas flow on the hot wire, with a large measurement range and high accuracy. These sensors transmit the acquired data to the evaluation module for analysis and evaluation. In this embodiment, the multi-physical field monitoring mechanism 3 is equipped with a thermocouple 31, a moisture sensor 32, a carbon dioxide concentration sensor 33 and a gas flow rate sensor 34, which can comprehensively obtain multi-physical field data such as the temperature field, moisture content distribution, carbon dioxide content distribution and gas flow rate content distribution in the soil, providing rich and accurate data support for in-depth analysis of the impact of CO2 leakage on the soil and the surrounding environment.

[0043] Please refer to Figure 1 and Figure 4The CO2 supply mechanism 4 includes a CO2 storage tank 41, a booster pump 42, a discharge pipe 43, and a preheater 44. The CO2 storage tank 41 is used to store liquid CO2 and is generally constructed of high-strength steel with good pressure resistance. The inlet of the booster pump 42 is connected to the outlet of the CO2 storage tank 41. The booster pump 42 can be a centrifugal pump, which has a high flow rate and high head, capable of pressurizing the CO2 liquid and delivering it to the discharge pipe 43. A plunger pump can also be used, which offers high pressure and is suitable for applications with higher pressure requirements. The outlet of the booster pump 42 is connected to one end of the discharge pipe 43. The preheater 44 is used to heat the CO2 liquid in the discharge pipe 43 to the temperature required for supercritical state. The preheater 44 can be an electric preheater, which has a fast heating rate and precise temperature control. The CO2 supply mechanism 4 also includes a CO2 pressure sensor 45 and a CO2 flowmeter 46, both of which are located on the discharge pipe 43. The CO2 pressure sensor 45 may be a piezoelectric pressure sensor, which can monitor in real time the pressure change in the discharge pipe 43. The CO2 flowmeter 46 may be a vortex flowmeter, which has high measurement accuracy and strong reliability.

[0044] Please refer to Figure 1 and Figure 5 The pressure stabilizing mechanism 5 includes a back-pressure valve 51 and a recovery container 52. The back-pressure valve 51 is disposed at the other end of the simulation pipeline 2 and is used to regulate the pressure within the simulation pipeline 2. The back-pressure valve 51 may be a pilot-operated back-pressure valve that automatically adjusts its opening according to a set pressure value to ensure stable pressure within the simulation pipeline 2. The recovery container 52 is connected to the outlet of the back-pressure valve 51 and is used to collect liquid CO2 discharged from the simulation pipeline 2. The recovery container 52 may be a steel storage tank with good sealing and pressure resistance.

[0045] Please refer to Figure 1The rainfall simulation mechanism 6 includes a plurality of sprinkler heads 61, a water supply line 62, a water pump 63, and a water tank 64. The sprinkler heads 61 are arranged in an array above the housing 11. The sprinkler heads 61 can be rotating sprinkler heads, which can evenly spray rainwater on the soil surface above the housing 11. Fixed sprinkler heads can also be used, which have a simpler structure and lower cost. The inlet of the water pump 63 is connected to the water tank 64. The water pump 63 can be a centrifugal pump, which can transport water from the water tank 64 to the water supply line 62. The outlet of the water pump 63 is connected to the inlet of each sprinkler head 61 via the water supply line 62. The water supply line 62 is equipped with a control valve 65. The control valve 65 can be an electric regulating valve, which can precisely control the size and on / off of the water flow. The water tank 64 is equipped with a water temperature regulator 66, which can be an electric heating rod, which can adjust the temperature of the water in the water tank 64 to simulate rainfall scenarios of different temperatures. The evaluation module adjusts the spray intensity and duration of sprinkler head 61 by controlling the operating state of water pump 63 to simulate different rainfall intensities and durations. In this embodiment, the rainfall simulation mechanism 6, through water pump 63, sprinkler head 61, control valve 65, and water temperature regulator 66, can precisely adjust the spray intensity, spray duration, and water temperature to simulate rainfall scenarios of varying rainfall intensities and temperatures, achieving precise simulation and control of rainfall conditions.

[0046] The evaluation module is in communication with the electromagnetic leakage valve 22, the multi-physics field monitoring mechanism 3, the CO2 supply mechanism 4, and the rainfall simulation mechanism 6. It is used to evaluate the impact of CO2 pipeline leakage on the soil layer, the impact of rainfall and CO2 leakage on the soil layer, and the impact of rainfall on the scope and rate of CO2 pipeline leakage in the soil. The evaluation module can be a high-performance computer equipped with specialized data analysis software that processes and analyzes the data collected by the sensors to produce accurate evaluation results.

[0047] The working principle of this embodiment is as follows: Through the coordinated operation of various mechanisms, the simulation device comprehensively simulates the multiple factors affecting buried CO2 pipeline leakage, including soil viscosity resistance, the coke-soak effect, fluid flash evaporation, rainfall, and other multi-physics field coupling conditions. By accurately acquiring data such as the soil temperature field, moisture content distribution, carbon dioxide content distribution, and gas flow rate distribution, and conducting analysis and evaluation, it can more accurately present the leakage characteristics and patterns of buried CO2 pipelines under various actual operating conditions, providing a strong basis for safety assessment and risk prevention and control of buried CO2 pipelines. Compared with existing technologies, this overcomes the difficulty of fully simulating complex multi-physics field coupling conditions, thereby improving the accuracy and reliability of experiments.

[0048] Example 2

[0049] The multi-physics field simulation method for buried CO2 pipeline leakage provided in the embodiment of the present application includes the following steps:

[0050] S1, lay the soil in layers in the box 11. Each time a layer of soil is laid, a layer of sensors is installed until the soil laying height reaches the set value. Usually, the thickness of the soil layer covering the simulated pipe 2 is about 1 meter. The simulated pipe 2 is buried in the soil in the box 11, and the thermocouple 31, moisture sensor 32, carbon dioxide concentration sensor 33 and gas flow rate sensor 34 are evenly buried in the soil in the box 11, and a communication connection is established with the evaluation module. When burying the simulated pipe 2, it is necessary to ensure that it is in a horizontal state and is well sealed with the perforation 23 of the box 11. When burying the sensors, they should be evenly distributed according to the experimental requirements to ensure that the multi-physical field data of each position in the soil can be accurately obtained. The communication connection between the sensor and the evaluation module can be a wired connection, such as an Ethernet cable, whose data transmission is stable and reliable; it can also be a wireless connection, such as Bluetooth, which is easy to install and not restricted by wiring.

[0051] In step S2, the multi-physics field monitoring mechanism 3 begins operation. The thermocouple 31 acquires temperature field data within the soil within the housing 11, the moisture sensor 32 acquires soil moisture content distribution data, the carbon dioxide concentration sensor 33 acquires soil carbon dioxide content distribution data, and the gas flow rate sensor 34 acquires soil gas flow rate content distribution data. These data are then transmitted to the evaluation module. Each sensor collects data in real time according to its respective operating principle and transmits the data to the evaluation module via a communication line. Upon receiving the data, the evaluation module performs preliminary processing and storage to prepare for subsequent analysis.

[0052] S3, the CO2 supply mechanism 4 starts to transport liquid CO2 to one end of the simulated pipeline 2, so that the pipeline reaches a certain pressure. The pressure stabilizing mechanism 5 maintains the pressure in the simulated pipeline 2 and collects the liquid CO2 discharged from the simulated pipeline 2. The booster pump 42 in the CO2 supply mechanism 4 pressurizes the CO2 liquid in the CO2 storage tank 41 and transports it to the simulated pipeline 2 through the discharge pipe 43. The preheater 44 heats the CO2 liquid to the temperature required for the supercritical state to simulate the actual situation. The back pressure valve 51 in the pressure stabilizing mechanism 5 automatically adjusts the valve opening according to the set pressure value to maintain the pressure in the simulated pipeline 2 stable. Excess liquid CO2 is discharged into the recovery container 52 through the back pressure valve 51. The evaluation module controls the opening of electromagnetic leakage valve 22, allowing liquid CO2 to leak through leakage hole 21 into the surrounding soil. Multi-physics field monitoring mechanism 3 continues to operate, with thermocouple 31 acquiring soil temperature data within chamber 11, moisture sensor 32 acquiring soil moisture distribution data, CO2 concentration sensor 33 acquiring soil CO2 content distribution data, and gas flow rate sensor 34 acquiring soil gas flow rate and content distribution data. These data are then transmitted to the evaluation module, which then evaluates the impact of the CO2 pipeline leakage on the soil layer, analyzing changes in soil temperature and moisture distribution before and after the leakage. By comparing pre- and post-leakage data, the evaluation module analyzes temperature trends, determines whether the sudden temperature drop is due to the coke-soak effect and fluid flash evaporation, and determines the impact of this temperature change on soil porosity and CO2 mobility. Furthermore, it analyzes changes in moisture distribution to understand the impact of the liquid CO2 leakage on soil moisture.

[0053] S4, during the CO2 leakage process, the evaluation module controls the rainfall simulation mechanism 6 to spray rainwater above the box 11 to simulate a rainfall scene. The evaluation module controls the working state of the water pump 63 and adjusts the spraying intensity and spraying time of the sprinkler head 61 according to the experimental requirements. By adjusting the rotation speed of the water pump 63, the water flow rate is changed to achieve different spraying intensities; by controlling the on and off time of the water pump 63, different rainfall durations are simulated. The multi-physical field monitoring mechanism 3 continues to monitor the soil temperature, moisture, carbon dioxide concentration, gas flow rate and other data in real time, and the evaluation module analyzes the impact of rainfall and CO2 leakage on the soil layer. The evaluation module comprehensively analyzes the multi-physical field data before and after rainfall and during CO2 leakage to study the impact of rainfall on soil sealing and the impact of the interaction between rainfall and CO2 leakage on the diffusion of CO2 in the soil.

[0054] In step S5, the evaluation module controls the rainfall simulation mechanism 6 to set different rainfall intensities, repeating the aforementioned CO2 leakage and rainfall process. Based on the multi-physics field data collected at different rainfall intensities, the evaluation module simulates the impact of rainfall on the leakage range and rate of the CO2 pipeline in the soil, and analyzes the relationship between rainfall intensity, leakage range, and leakage rate. The evaluation module conducts multiple experiments at different rainfall intensities, recording the CO2 leakage range and rate in each experiment. The module then performs a statistical analysis on this data, plotting a relationship curve between rainfall intensity, leakage range, and leakage rate to identify patterns.

[0055] The implementation principle of this embodiment is as follows: This simulation method, through a rational arrangement of steps, comprehensively simulates the actual situation of buried CO2 pipeline leakage, taking into account the interaction of multiple factors. Real-time data acquisition by the multi-physics field monitoring mechanism 3 and analysis and evaluation by the evaluation module accurately study the impact of rainfall and CO2 leakage on the soil layer, as well as the relationship between rainfall intensity and the scope and rate of CO2 leakage. Compared with existing technologies, this method can more comprehensively and accurately simulate complex multi-physics field coupling situations, providing scientific methods and reliable data support for buried CO2 pipeline safety research, and facilitating the development of more effective safety measures and risk prevention and control strategies.

[0056] The beneficial effects of the technical solution provided by the present invention are as follows: through the coordinated work of the soil environment simulation mechanism 1, the simulation pipeline 2, the multi-physical field monitoring mechanism 3, the CO2 supply mechanism 4, the pressure stabilizing mechanism 5, the rainfall simulation mechanism 6 and the evaluation module, it is possible to simulate the influence of various factors such as soil viscosity resistance, the coke-soak effect, fluid flash evaporation, rainfall, etc. on the leakage of the buried CO2 pipeline, and comprehensively cover the complex multi-physical field coupling conditions involved in the actual leakage process; through the multi-physical field monitoring mechanism 3, data such as soil temperature, moisture, carbon dioxide concentration and gas flow rate are obtained in real time, and the evaluation module analyzes these data, which can deeply study the influence of rainfall and CO2 leakage on the soil layer, as well as the relationship between rainfall intensity and the range and speed of CO2 leakage, providing a scientific basis for accurately assessing the leakage risk of buried CO2 pipelines.

[0057] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A multi-physics field simulation device for buried CO2 pipeline leakage, characterized in that: include: A soil environment simulation mechanism includes a box body, the upper end of which is open and is used to fill soil; A simulated pipeline is buried in the soil in the box, a leakage hole is opened on the simulated pipeline, and an electromagnetic leakage valve is provided on the leakage hole; a multi-physics field monitoring mechanism, comprising a plurality of thermocouples, moisture sensors, carbon dioxide concentration sensors, and gas flow rate sensors uniformly buried in the soil within the box, wherein the plurality of thermocouples are used to obtain the temperature field within the soil within the box, the plurality of moisture sensors are used to obtain the soil moisture content distribution within the box, the plurality of carbon dioxide concentration sensors are used to obtain the soil carbon dioxide content distribution within the box, and the plurality of gas flow rate sensors are used to obtain the gas flow rate content distribution within the soil within the box; A CO2 supply mechanism, which is used to deliver liquid CO2 to one end of the simulation pipeline; a pressure stabilizing mechanism, the pressure stabilizing mechanism being in communication with the other end of the simulation pipeline and being configured to maintain the pressure in the simulation pipeline and to collect liquid CO2 discharged from the simulation pipeline; A rainfall simulation mechanism, which is used to spray rainwater above the box; An evaluation module is communicatively connected to the electromagnetic leakage valve, the multi-physics field monitoring mechanism, the CO2 supply mechanism, and the rainfall simulation mechanism, and is used to evaluate the impact of CO2 pipeline leakage on the soil layer, the impact of simultaneous rainfall and CO2 leakage on the soil layer, and the impact of rainfall on the leakage range and leakage rate of the CO2 pipeline in the soil.

2. The multi-physics field simulation device for buried CO2 pipeline leakage according to claim 1 is characterized in that: A horizontally arranged perforated partition is formed in the box body, the upper part of the perforated partition is used to fill soil, and a drainage cavity is formed below the perforated partition. A drainage port connected to the drainage cavity is opened on the side wall of the box body, and a drainage valve is provided on the drainage port. The drainage valve is used to control the opening degree of the drainage port to simulate different soil drainage conditions.

3. The multi-physics field simulation device for buried CO2 pipeline leakage according to claim 1 is characterized in that: The CO2 supply mechanism includes a CO2 storage tank, a booster pump, an exhaust pipe and a preheater. The CO2 storage tank is used to store CO2 liquid. The inlet of the booster pump is connected to the outlet of the CO2 storage tank. The outlet of the booster pump is connected to one end of the exhaust pipe. The preheater is used to heat the CO2 liquid in the exhaust pipe to the temperature required for the supercritical state.

4. The multi-physics field simulation device for buried CO2 pipeline leakage according to claim 3 is characterized in that: The CO2 supply mechanism further includes a CO2 pressure sensor and a CO2 flow meter, and the CO2 pressure sensor and the CO2 flow meter are both arranged on the discharge pipe.

5. The multi-physics field simulation device for buried CO2 pipeline leakage according to claim 1, characterized in that: The pressure stabilizing mechanism includes a back pressure valve and a recovery container. The back pressure valve is arranged at the other end of the simulation pipeline and is used to adjust the pressure in the simulation pipeline. The recovery container is connected to the outlet of the back pressure valve.

6. The multi-physics field simulation device for buried CO2 pipeline leakage according to claim 1, characterized in that: The rainfall simulation mechanism includes several sprinkler heads, a water supply pipeline, a water pump and a water tank. The several sprinkler heads are arranged in an array above the tank. The inlet of the water pump is connected to the water tank, and the outlet of the water pump is connected to the inlet of each sprinkler head via the water supply pipeline. The evaluation module adjusts the spraying intensity and spraying time of the sprinkler head by controlling the working state of the water pump to simulate different rainfall intensities and rainfall durations.

7. The multi-physics field simulation device for buried CO2 pipeline leakage according to claim 6, characterized in that: A water temperature regulator is arranged in the water tank.

8. The multi-physics field simulation device for buried CO2 pipeline leakage according to claim 6, characterized in that: The water supply pipeline is provided with a control valve.

9. The multi-physics field simulation device for buried CO2 pipeline leakage according to claim 1, characterized in that: The two sides of the box body are provided with perforations opposite to each other, and the simulated pipe passes through two of the perforations. The contact points between the simulated pipe and the perforations are sealed. There are multiple leakage holes and electromagnetic leakage valves, and the orientations of the leakage holes are different. The electromagnetic valves are respectively installed on the corresponding leakage holes.

10. A multi-physics field simulation method for buried CO2 pipeline leakage, characterized in that: The invention is adapted to the multi-physics field simulation device for buried CO2 pipeline leakage according to any one of claims 1 to 9, and comprises the following steps: S1. Bury the simulated pipeline in the soil inside the box, evenly bury the thermocouple, moisture sensor, carbon dioxide concentration sensor, and gas flow rate sensor in the soil inside the box, and establish communication connection with the evaluation module; S2. The multi-physics field monitoring mechanism starts working. The thermocouple obtains the temperature field data in the soil inside the box, the moisture sensor obtains the soil moisture content distribution data, the carbon dioxide concentration sensor obtains the soil carbon dioxide content distribution data, and the gas flow rate sensor obtains the soil gas flow rate content distribution data. These data are then transmitted to the evaluation module. In step S3, the CO2 supply mechanism starts to deliver liquid CO2 to one end of the simulation pipeline, so that the pipeline reaches a certain pressure. The pressure stabilizing mechanism maintains the pressure in the simulation pipeline and collects the liquid CO2 discharged from the simulation pipeline. The evaluation module controls the electromagnetic leakage valve to open, and the liquid CO2 leaks into the surrounding soil through the leakage hole. The multi-physics field monitoring mechanism continues to work. The thermocouple obtains the temperature field data in the soil inside the box, the moisture sensor obtains the soil moisture content distribution data, the carbon dioxide concentration sensor obtains the soil carbon dioxide content distribution data, and the gas flow rate sensor obtains the gas flow rate content distribution data in the soil. These data are then transmitted to the evaluation module. The evaluation module evaluates the impact of the CO2 pipeline leakage on the soil layer based on the collected data, and analyzes the changes in the temperature field and moisture content distribution in the soil before and after the leakage. S4. During the CO2 leakage process, the evaluation module controls the rainfall simulation mechanism to spray rainwater above the box to simulate a rainfall scene; the multi-physics field monitoring mechanism continues to monitor the soil temperature, moisture, carbon dioxide concentration, gas flow rate and other data in real time, and the evaluation module analyzes the impact of the simultaneous effects of rainfall and CO2 leakage on the soil layer; S5. The evaluation module controls the rainfall simulation mechanism to set different rainfall intensities and repeats the above-mentioned CO2 leakage and rainfall process. The evaluation module simulates the impact of rainfall on the leakage range and leakage rate of the CO2 pipeline in the soil based on the multi-physical field data collected under different rainfall intensities, and analyzes the relationship between rainfall intensity and leakage range and leakage rate.

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