A deep sea corrosion environment simulation and monitoring device with multivariable coupling control

Abstract

The application belongs to the field of deep-sea corrosion experiment equipment, and particularly relates to a deep-sea corrosion environment simulation and monitoring device with multivariate coupling control, which comprises an environment control unit, wherein a seawater environment cabin is internally vertically provided with a test sample, the two ends of the test sample are penetrated through and extended to the outside of the seawater environment cabin; a pressure control system and a temperature control system are connected to the seawater environment cabin through sealing flanges and are respectively used for simulating deep-sea hydrostatic pressure and low-temperature environment; a mechanical loading system is used for bearing the seawater environment cabin and clamping the two ends of the test sample through a sample clamping system to apply multiaxial dynamic mechanical load; a gas regulation unit is used for controlling the dissolved oxygen concentration in the seawater environment cabin; and a multi-source monitoring module is used for collecting detection data and analyzing to obtain the corrosion rate of the test sample. The application breaks through the limitation of single-variable control of traditional devices and provides a high-fidelity experiment platform for deep-sea material corrosion mechanism research and equipment life evaluation.

Description

Technical Field

[0001] This invention belongs to the field of deep-sea corrosion experimental equipment, specifically a deep-sea corrosion environment simulation and monitoring device with multivariable coupling control. Background Technology

[0002] With the increasing global demand for marine resources, deep-sea resource development has become an important research direction in the field of marine engineering. Deep-sea areas are rich in oil and gas resources, mineral resources, and biological resources, possessing enormous economic potential. However, the extreme characteristics of the deep-sea environment, such as high hydrostatic pressure, low temperature, low dissolved oxygen, high salinity, and complex microbial ecosystems, make material corrosion increasingly severe. Deep-sea corrosion not only affects the long-term stability and safety of marine engineering structures but also significantly increases maintenance and replacement costs, and may even pose potential hazards to the marine ecosystem. Therefore, studying and simulating material corrosion behavior under deep-sea corrosion environments has become a key research topic in the current technological field.

[0003] Existing corrosion research equipment often focuses on testing single environmental factors, such as simulating high salinity or low temperature environments using laboratory devices. However, the applicability of these devices to the multivariate coupled deep-sea environment is extremely limited, making it difficult to fully reproduce the complex corrosion conditions in actual deep-sea conditions. For example, existing high-pressure chambers typically only simulate high hydrostatic pressure, lacking effective control over dissolved oxygen variations and microbial corrosion behavior. Dissolved oxygen is a crucial participant in corrosion electrochemical reactions, and its concentration changes significantly affect the oxidation rate and corrosion morphology of materials. Furthermore, microbial corrosion in the deep sea is a significant factor in material corrosion, involving microorganisms influencing chemical reactions on the material surface through metabolic activities, further exacerbating corrosion damage.

[0004] Microbial corrosion is particularly complex in deep-sea environments. Due to the diversity of deep-sea microorganisms and their specific living conditions, these microorganisms accelerate localized corrosion of materials by secreting metabolic products such as sulfides and organic acids. Existing laboratory equipment cannot accurately simulate the dynamic processes in the complex deep-sea microbial ecosystem, especially the real-time monitoring of the interaction between microbial activity and corrosion reactions. In actual deep-sea environments, materials not only suffer from electrochemical corrosion but also experience various forms of corrosion due to microbial involvement, such as sulfide corrosion induced by sulfur-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB). These complex microbial-material interactions often lead to the formation of localized corrosion pits and cracks, significantly shortening the service life of materials.

[0005] Furthermore, traditional corrosion monitoring technologies have limitations in deep-sea environments. Most current corrosion monitoring techniques rely on static experiments and single-parameter measurements, lacking real-time tracking and dynamic analysis of the corrosion process. For example, while electrochemical corrosion monitoring can measure parameters such as corrosion current and corrosion potential, it typically only reflects the corrosion state at a specific moment and cannot continuously reflect the changing trends of the corrosion process. On the other hand, research on microbial corrosion relies on sample analysis in the later stages of the experiment. Information on the interaction between microorganisms and materials after corrosion is usually obtained through chemical detection or microscopic analysis. Such post-detection is not only time-consuming but also fails to reflect real-time corrosion dynamics.

[0006] Based on the above problems, existing deep-sea corrosion simulation devices cannot simultaneously simulate the coupled effects of multiple variables, and lack real-time, comprehensive monitoring methods for corrosion behavior. Therefore, designing a corrosion device capable of comprehensively simulating various deep-sea environmental factors and performing real-time monitoring and dynamic analysis of material corrosion processes under such extreme conditions has become a key technological requirement in deep-sea corrosion research.

[0007] Most existing research is limited to laboratory simulations of single environmental factors, making it difficult to realistically reproduce the multivariate coupling effects in deep-sea environments. Practical problems in marine engineering involve the combined effects of multiple corrosion factors, such as temperature, hydrostatic pressure, dissolved oxygen, and microorganisms, all simultaneously influencing the corrosion process on material surfaces. Due to the complex and variable interactions between these factors, experiments with a single factor cannot reveal the true corrosion mechanisms of materials in deep-sea environments. Therefore, there is an urgent need for a device capable of multivariate coordinated control, accurately simulating key environmental parameters such as temperature, pressure, dissolved oxygen, salinity, and microorganisms, and providing real-time, dynamic corrosion monitoring to meet the needs of assessing the corrosion resistance of deep-sea materials.

[0008] Therefore, the complexity and diversity of corrosion behavior in the deep-sea environment compels researchers to seek more comprehensive and sophisticated corrosion simulation and monitoring devices to accurately predict the service life of materials and provide a scientific basis for the design, selection and maintenance of deep-sea engineering materials. Summary of the Invention

[0009] The purpose of this invention is to provide a deep-sea corrosion environment simulation and monitoring device with multivariable coupled control. It addresses the problems of single environmental parameter control and insufficient monitoring dimensions in existing deep-sea corrosion simulation devices. By integrating modules such as environmental control, mechanical loading, and multimodal monitoring, it achieves high-precision simulation and real-time dynamic analysis of complex deep-sea corrosion environments.

[0010] The technical solution adopted by the present invention to achieve the above objectives is: a deep-sea corrosion environment simulation and monitoring device with multivariable coupling control, comprising: a pressure-resistant and stable structure and an environmental control unit, a mechanical loading system, a gas control unit, and a multi-source monitoring module disposed on the pressure-resistant and stable structure;

[0011] An environmental control unit includes: a seawater environment chamber, in which a test sample is vertically installed, with both ends of the test sample penetrating and extending to the outside of the seawater environment chamber; a pressure control system and a temperature control system connected to the seawater environment chamber via sealing flanges, which are used to simulate deep-sea hydrostatic pressure and low-temperature environment, respectively.

[0012] The mechanical loading system is coaxially mounted on the central axis of the compressive stability structure to support the seawater environment chamber and to clamp the two ends of the test sample through the sample clamping system to apply multiaxial dynamic mechanical loads.

[0013] The gas control unit is connected to the seawater environment chamber and is used to control the dissolved oxygen concentration in the seawater environment chamber;

[0014] The multi-source monitoring module is used to collect detection data from the environmental control unit, mechanical loading system, and gas control unit, and analyze the data to obtain the corrosion rate of the test sample.

[0015] The pressure-resistant and stabilizing structure includes: a device stabilizing frame, a device counterweight base, an upper stabilizing baffle, and a placement plate;

[0016] The device's stabilizing frame includes multiple columns, which together with the base plate and the upper stabilizing baffle form a cubic frame.

[0017] A counterweight base is provided on the base plate, and the device stabilizing frame and the counterweight base form a rigid support system to prevent the frame from swaying.

[0018] A placement plate is horizontally positioned in the middle of the device's stabilizing frame; the mechanical loading system is symmetrically arranged on the placement plate and the upper baffle.

[0019] A seawater environment chamber is provided between the upper baffle and the placement plate, and is clamped by a mechanical loading system.

[0020] The mechanical loading system includes: a sample clamping system and a load loading system;

[0021] The load loading system consists of a pair, which are symmetrically rotated on the upper stabilizing baffle and the placement plate, respectively, to apply multi-axis dynamic mechanical loads to the test sample fixed on the sample clamping system.

[0022] The load loading system includes a multi-axis servo loading mechanism in three orthogonal directions. The servo loading mechanism is connected to the drive motor via a synchronous belt. It applies a maximum tensile / compressive alternating load of 500kN, with a loading frequency range of 0.001-10Hz, and provides real-time feedback of the stress-strain curve to the multi-source monitoring module.

[0023] The sample clamping system is located on the upper and lower sides of the seawater environment chamber and is connected to the corresponding load loading system to clamp the two ends of the test sample.

[0024] The gas control unit includes: a nitrogen storage tank, a hydrogen storage tank, and a gas control system connected to both.

[0025] The nitrogen storage tank and the hydrogen storage tank are respectively connected to the seawater environment chamber via pipelines and a gas control system.

[0026] The gas control system includes: a mass flow controller and a dissolved oxygen probe;

[0027] The dissolved oxygen probe is installed inside the seawater environment chamber to monitor the dissolved oxygen concentration inside the chamber in real time.

[0028] The mass flow controller is used to monitor the dissolved oxygen concentration in the seawater environment chamber based on the dissolved oxygen probe. It controls the flow rate of the nitrogen and hydrogen mixture through a PID algorithm to keep the dissolved oxygen concentration in the seawater within the range of 0.01-8 mg / L, with a resolution of 0.001 mg / L.

[0029] The multi-source monitoring module includes: an electrochemical corrosion testing system, a microbial sensor, and a data collection system;

[0030] The electrochemical corrosion testing system includes: a reference electrode and a counter electrode installed in a seawater environment chamber; a dynamic potential scanning module to collect time-series corrosion current I(t) in real time at a scanning rate of 0.1mV / s-100mV / s; and an impedance spectroscopy analysis module to obtain time-series impedance spectra Z(ω) in the frequency range of 10μHz-1MHz.

[0031] The microbial sensor is vertically inserted into the seawater environment chamber, with the detection surface facing the test sample; the microbial sensor is a functionalized nanoelectrode array, and the electrode surface is covered with a sulfur ion selective membrane and a pH sensitive membrane.

[0032] The microbial sensor is used to dynamically detect the time-series concentration S(t) of metabolites at a sampling frequency of 1 Hz; the detection limit is 1 × 10⁻⁶. -9 mol / L, response time <10s, simultaneous monitoring of H2S and HS - H +Concentration changes;

[0033] The data collection system is connected to the electrochemical corrosion testing system and the microbial sensor respectively, and is used to synchronously integrate electrochemical and microbial monitoring data. It also has a built-in multi-physics coupling analysis algorithm, which establishes a correlation model between electrochemical corrosion rate, microbial metabolic activity and mechanical load parameters, and outputs a corrosion damage evolution trend prediction curve in real time.

[0034] The pressure control system adopts a multi-stage hydraulic compensation device, and the pressure control accuracy is ≤ ±0.5%.

[0035] The temperature control system includes a refrigeration module and a temperature controller, with a temperature control range of -2℃ to 30℃ and a temperature fluctuation of ≤±0.1℃.

[0036] The seawater environment cabin is equipped with multiple visual observation windows;

[0037] The visualization observation window uses a sapphire lens, and a long working distance microscope objective is integrated on the surface of the visualization observation window. Together with a high-speed camera group, it can realize in-situ observation of surface morphology with a resolution of 50nm. The spatial overlap between the observation area and the electrochemical test area is >95%.

[0038] The inner wall of the seawater environment chamber is provided with a porous microbial carrier layer, which is inoculated with at least two deep-sea corrosion microorganisms selected from sulfate-reducing bacteria, iron-oxidizing bacteria, and acid-producing bacteria. The microbial density is controllable within a range of 10. 3 -10 9 CFU / cm 2 .

[0039] A method for operating a deep-sea corrosion environment simulation and monitoring device with multivariable coupled control includes the following steps:

[0040] 1) Set the target pressure value P and temperature value T through the pressure control system and temperature control system, and send them to the data collection system;

[0041] 2) The mixing ratio of nitrogen and hydrogen is adjusted through the gas control system to achieve the set value C of dissolved oxygen concentration, and the data is then sent to the data collection system.

[0042] 3) The load loading system is activated to apply multiaxial composite stress σ to the test sample and the data is sent to the data collection system;

[0043] 4) Simultaneously activate the electrochemical corrosion testing system and the microbial sensor to collect the corrosion current I(t), impedance spectrum Z(ω), and metabolite concentration S(t) in real time and send them to the data collection system;

[0044] 5) The data collection system analyzes the data acquired in real time and outputs a prediction curve of the corrosion damage evolution trend in real time;

[0045] 6) Based on the real-time prediction curve, if the corrosion rate exceeds the threshold, an alarm will be triggered and the load will be automatically reduced or environmental parameters will be adjusted.

[0046] The data collection system analyzes the data acquired in real time, namely:

[0047] The quantitative relationship between corrosion rate v and P, T, C, and σ is established as follows:

[0048] v = k·P α ·T β ·C γ ·σ δ

[0049] Where k is the material property coefficient, and α, β, γ, and δ are environmental coupling factors;

[0050] The instantaneous corrosion rate v(t) is inverted by the corrosion current I(t) of the time series, and the dynamic characteristics of the corrosion interface and the evolution law of the film are analyzed by combining the impedance spectrum Z(ω). At the same time, the synergistic effect of microbial metabolic activity on the corrosion process is evaluated by the concentration of metabolites S(t).

[0051] By inputting the above parameters into the corrosion damage evolution model, the environmental coupling factors α, β, γ, δ and material property coefficient k of the dynamic quantitative relationship are used to output the corrosion damage evolution trend prediction curve, thereby realizing multi-dimensional coupled modeling and trend prediction of corrosion dynamics.

[0052] The present invention has the following beneficial effects and advantages:

[0053] 1. The significant advantage of this invention lies in its high integration and multi-dimensional monitoring capabilities. The device of this invention seamlessly integrates environmental control, mechanical loading and monitoring functions through modular design, solving the parameter mismatch problem caused by the decentralized operation of traditional equipment.

[0054] 2. This invention is based on the synergistic monitoring of an electrochemical corrosion testing system and a microbial sensor, which can simultaneously capture the electrochemical corrosion rate of materials, microbial metabolic activity and the evolution of corrosion products, providing key data support for revealing the deep-sea microbial-stress synergistic corrosion mechanism.

[0055] 3. The gas control unit of this invention, through the precise ratio of nitrogen and hydrogen, can simulate the dissolved oxygen gradient environment in different deep-sea areas, expanding the applicable scenarios of the device. This device can be widely used in the corrosion resistance assessment of marine engineering materials (such as titanium alloys, stainless steel, and coating materials), the life prediction of deep-sea equipment, and the development of anti-corrosion technologies, providing scientific basis and technical support for major projects such as deep-sea resource development and subsea pipeline laying.

[0056] 4. By simulating the extreme environment of the real deep sea, this invention significantly improves the reliability and engineering guidance value of material corrosion testing, and has important prospects for scientific research and industrial application. Attached Figure Description

[0057] Figure 1 A schematic diagram of the deep-sea corrosion environment simulation and monitoring device of the present invention;

[0058] Among them, 1 is the device stabilizing frame, 2 is the device counterweight base, 3 is the upper stabilizing baffle, 4 is the load loading system, 5 is the sample clamping system, 6 is the seawater environment chamber, 7 is the test sample, 8 is the pressure control system, 9 is the temperature control system, 10 is the nitrogen storage tank, 11 is the hydrogen storage tank, 12 is the gas control system, 13 is the reference electrode, 14 is the counter electrode, 15 is the microbial sensor, 16 is the electrochemical corrosion testing system, 17 is the data collection system, and 18 is the corrosive microorganism. Detailed Implementation

[0059] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0060] like Figure 1 The diagram shown is a structural schematic of the deep-sea corrosion environment simulation and monitoring device of the present invention. The present invention can simultaneously control multiple key environmental variables, such as temperature, hydrostatic pressure, dissolved oxygen, external load and microbial concentration, to conduct corrosion research and monitoring of materials in deep-sea environments, and is widely used in marine engineering, deep-sea resource development and other fields.

[0061] Specifically, a deep-sea corrosion environment simulation and monitoring device with multivariable coupled control includes: a pressure-resistant and stable structure and an environmental control unit, a mechanical loading system, a gas control unit, and a multi-source monitoring module installed on the pressure-resistant and stable structure;

[0062] An environmental control unit includes: a seawater environment chamber 6, in which a test sample 7 is vertically arranged, with both ends of the test sample 7 penetrating and extending to the outside of the seawater environment chamber 6; a pressure control system 8 and a temperature control system 9 connected to the seawater environment chamber 6 via sealing flanges, which are used to simulate deep-sea hydrostatic pressure and low-temperature environment, respectively.

[0063] The mechanical loading system is coaxially mounted on the central axis of the pressure-resistant and stable structure to support the seawater environment chamber 6 and to clamp the two ends of the test sample 7 through the sample clamping system 5 to apply multiaxial dynamic mechanical loads.

[0064] The gas control unit is connected to the seawater environment chamber 6 and is used to control the dissolved oxygen concentration in the seawater environment chamber 6.

[0065] The multi-source monitoring module is used to collect detection data from the environmental control unit, the mechanical loading system, and the gas control unit, and analyze the data to obtain the corrosion rate of the test sample 7.

[0066] The pressure-resistant and stable structure includes: a device stabilizing frame 1, a device counterweight base 2, an upper stabilizing baffle 3, and a placement plate;

[0067] The device stabilizing frame 1 includes multiple columns, which together with the base plate and the upper stabilizing baffle 3 form a cubic frame;

[0068] A counterweight base 2 is provided on the base plate, and the device stabilizing frame 1 and the counterweight base 2 form a rigid support system to prevent the frame from swaying.

[0069] A placement plate is horizontally positioned in the middle of the device's stabilizing frame 1; the mechanical loading system is symmetrically arranged on the placement plate and the upper baffle 3.

[0070] A seawater environment chamber 6 is provided between the upper baffle 3 and the placement plate, and is clamped by a mechanical loading system.

[0071] The mechanical loading system includes: a sample clamping system 5 and a load loading system 4;

[0072] There is a pair of load loading systems 4, which are symmetrically rotated on the upper stabilizing baffle 3 and the placement plate, respectively, so as to apply multi-axis dynamic mechanical loads to the test sample 7 fixed on the sample clamping system 5.

[0073] The load loading system 4 includes a multi-axis servo loading mechanism in three orthogonal directions. The servo loading mechanism is connected to the drive motor via a synchronous belt. It applies a maximum tensile / compressive alternating load of 500kN, with a loading frequency range of 0.001-10Hz, and provides real-time feedback of the stress-strain curve to the multi-source monitoring module.

[0074] The sample clamping system 5 is located on the upper and lower sides of the seawater environment chamber 6, and is connected to the corresponding load loading system 4 to clamp the two ends of the test sample 7.

[0075] The gas control unit includes: a nitrogen storage tank 10, a hydrogen storage tank 11, and a gas control system 12 connected to both.

[0076] Nitrogen storage tank 10 and hydrogen storage tank 11 are respectively connected to the seawater environment chamber 6 via pipelines and gas control system 12;

[0077] The gas control system 12 includes: a mass flow controller and a dissolved oxygen probe;

[0078] The dissolved oxygen probe is installed inside the seawater environment chamber 6 to monitor the dissolved oxygen concentration inside the seawater environment chamber 6 in real time.

[0079] The mass flow controller is used to monitor the dissolved oxygen concentration in the seawater environment chamber 6 based on the dissolved oxygen probe. It controls the flow rate of the nitrogen and hydrogen mixture through a PID algorithm to keep the dissolved oxygen concentration in the seawater within the range of 0.01-8 mg / L, with a resolution of 0.001 mg / L.

[0080] The multi-source monitoring module includes: an electrochemical corrosion testing system 16, a microbial sensor 15, and a data collection system 17;

[0081] The electrochemical corrosion testing system 16 includes a reference electrode 13 and a counter electrode 14 installed in the seawater environment chamber 6. The system acquires the time-series corrosion current I(t) in real time at a scanning rate of 0.1mV / s-100mV / s through a dynamic potential scanning module, and obtains the time-series impedance spectrum Z(ω) in the frequency range of 10μHz-1MHz through an impedance spectroscopy analysis module.

[0082] The microbial sensor 15 is vertically inserted into the seawater environment chamber 6, with its detection surface facing the test sample 7; the microbial sensor 15 is a functionalized nanoelectrode array, and the electrode surface is covered with a sulfur ion selective membrane and a pH sensitive membrane.

[0083] Microbial sensor 15 is used for dynamic detection of time-series metabolite concentration S(t) at a sampling frequency of 1 Hz; the detection limit is 1 × 10⁻⁶. -9 mol / L, response time <10s, simultaneous monitoring of H2S and HS - H + Concentration changes;

[0084] The data collection system 17 is connected to the electrochemical corrosion testing system 16 and the microbial sensor 15 respectively, for synchronous integration of electrochemical and microbial monitoring data; and has a built-in multi-physics field coupling analysis algorithm, which establishes a correlation model between electrochemical corrosion rate, microbial metabolic activity and mechanical load parameters, and outputs a corrosion damage evolution trend prediction curve in real time.

[0085] The pressure control system 8 adopts a multi-stage hydraulic compensation device, and the pressure control accuracy is ≤ ±0.5%.

[0086] The temperature control system 9 includes a refrigeration module and a temperature controller, with a temperature control range of -2℃ to 30℃ and a temperature fluctuation of ≤±0.1℃.

[0087] The marine environment cabin 6 is equipped with multiple visualization observation windows;

[0088] The visualization observation window uses a sapphire lens, and a long working distance microscope objective is integrated on the surface of the visualization observation window. Together with a high-speed camera group, it can realize in-situ observation of surface morphology with a resolution of 50nm. The spatial overlap between the observation area and the electrochemical test area is >95%.

[0089] The inner wall of the seawater environment chamber 6 is equipped with a porous microbial carrier layer, which is inoculated with at least two deep-sea corrosion microorganisms 18 from sulfate-reducing bacteria, iron-oxidizing bacteria, and acid-producing bacteria. The microbial community density is controllable within a range of 10. 3 -10 9 CFU / cm 2 .

[0090] A method for operating a deep-sea corrosion environment simulation and monitoring device with multivariable coupled control includes the following steps:

[0091] 1) Set the target pressure value P and temperature value T through the pressure control system 8 and temperature control system 9, and send them to the data collection system 17;

[0092] 2) The mixing ratio of nitrogen and hydrogen is adjusted by the gas control system 12 to make the dissolved oxygen concentration reach the set value C, and then sent to the data collection system 17.

[0093] 3) The load loading system 4 is activated to apply a multiaxial composite stress σ to the test sample 7 and the stress is transmitted to the data collection system 17;

[0094] 4) Simultaneously activate the electrochemical corrosion testing system 16 and the microbial sensor 15 to collect the corrosion current I(t), impedance spectrum Z(ω) and metabolite concentration S(t) in real time and send them to the data collection system 17.

[0095] 5) The data collection system 17 analyzes the data acquired in real time and outputs a corrosion damage evolution trend prediction curve in real time;

[0096] The data collection system 17 analyzes the data acquired in real time, namely:

[0097] The quantitative relationship between corrosion rate v and P, T, C, and σ is established as follows:

[0098] v = k·P α ·T β ·C γ ·σ δ

[0099] Where k is the material property coefficient, and α, β, γ, and δ are environmental coupling factors;

[0100] The instantaneous corrosion rate v(t) is inverted by the corrosion current I(t) of the time series, and the dynamic characteristics of the corrosion interface and the evolution law of the film are analyzed by combining the impedance spectrum Z(ω). At the same time, the synergistic effect of microbial metabolic activity on the corrosion process is evaluated by the concentration of metabolites S(t).

[0101] By inputting the above parameters into the corrosion damage evolution model, the environmental coupling factors α, β, γ, δ and material property coefficient k of the dynamic quantitative relationship are used to output the corrosion damage evolution trend prediction curve, thereby realizing multi-dimensional coupled modeling and trend prediction of corrosion dynamics.

[0102] 6) Based on the real-time prediction curve, if the corrosion rate exceeds the threshold, an alarm will be triggered and the load will be automatically reduced or environmental parameters will be adjusted.

[0103] Example 1:

[0104] In this embodiment, the core of the device includes an environmental control unit (seawater environment chamber 6, pressure control system 8, temperature control system 9), a mechanical loading system (load loading system 4, sample clamping system 5), a gas control unit (nitrogen storage system 10, hydrogen storage system 11, gas control system 12), and a multi-source monitoring module (electrochemical corrosion testing system 16, high-sensitivity microbial sensor 15, data collection system 17). A pressure-resistant structure is constructed using a stable frame 1 and a counterweight base 2, combined with an upper baffle 3 to enhance overall stability, ensuring safe operation of the device under high pressure, low temperature, and low oxygen conditions. This device can precisely control the hydrostatic pressure, temperature, dissolved oxygen concentration, and types and quantities of microorganisms in the deep-sea environment, while simultaneously applying composite loads such as tension and compression to comprehensively simulate the material service conditions under extreme deep-sea conditions.

[0105] In this embodiment, the seawater environment chamber 6 houses corrosive microorganisms 18. A pressure control system 8 adjusts the hydrostatic pressure to a deep-sea equivalent value, a temperature control system 9 maintains a low-temperature environment, and a gas control system 12, in conjunction with nitrogen and hydrogen storage tanks 10 and 11, regulates dissolved oxygen concentration to create a low-oxygen or anaerobic corrosive medium. A sample clamping system 5 holds the tensile test sample 7, and a load loading system 4 applies dynamic stress through a multi-axis mechanical loading device to simulate the mechanical-chemical coupling damage of deep-sea equipment. In the monitoring module, an electrochemical reference electrode 13 and a counter electrode 14, combined with an electrochemical corrosion testing system 16, collect parameters such as polarization curves and impedance spectra of the material surface in real time. A high-sensitivity microbial sensor 15 dynamically detects changes in the concentration of metabolic products (such as sulfide and hydrogen ions), and a data collection system 17 simultaneously integrates electrochemical and microbial data.

[0106] Specifically, the target pressure value P and temperature value T are set through the pressure control system 8 and temperature control system 9; the mixing ratio of nitrogen and hydrogen is adjusted through the gas control system 12 to make the dissolved oxygen concentration reach the set value C; the load loading system 4 is activated to apply multiaxial composite stress σ to the test sample 7; the electrochemical corrosion testing system 16 and microbial sensor 15 are activated simultaneously to collect the corrosion current I(t), impedance spectrum Z(ω) and metabolite concentration S(t) of the time series; through the multivariate regression analysis module of the data collection system 17, a quantitative relationship between corrosion rate v and P, T, C and σ is established: v=k·P^α·T^β·C^γ·σ^δ, where k is the material characteristic coefficient, and α, β, γ and δ are environmental coupling factors.

[0107] Among them, the data collection system 17 has a built-in multiphysics coupling analysis algorithm, which establishes a correlation model between electrochemical corrosion rate, microbial metabolic activity and mechanical load parameters, and outputs a prediction curve of corrosion damage evolution trend in real time.

[0108] Furthermore, the marine environment chamber 6 is equipped with a visualization observation window, which, combined with microscopic imaging technology, enables real-time tracking of the corrosion morphology of material surfaces. Through multi-system collaboration, this invention overcomes the limitations of traditional devices that rely on single-variable control, achieving multi-variable coupled regulation of temperature, pressure, dissolved oxygen, microorganisms, and mechanical loads, providing a high-fidelity experimental platform for in-situ research on the corrosion behavior of deep-sea materials.

[0109] In summary, in conjunction with the embodiments of the present invention, the present invention breaks through the limitations of single-variable control in traditional devices and provides a high-fidelity experimental platform for the study of deep-sea material corrosion mechanisms and equipment life assessment.

[0110] Those skilled in the art will understand that the above description is merely a preferred embodiment of the present invention, and the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. This is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0111] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. A deep-sea corrosion environment simulation and monitoring device with multivariable coupled control, characterized in that, include: The pressure-resistant and stabilizing structure, and the environmental control unit, mechanical loading system, gas control unit, and multi-source monitoring module installed on the pressure-resistant and stabilizing structure; The pressure-resistant and stabilizing structure includes: a device stabilizing frame (1), a device counterweight base (2), an upper stabilizing baffle (3), and a placement plate; The device stabilizing frame (1) includes multiple columns, which together with the base plate and the upper stabilizing baffle (3) form a cubic frame; A counterweight base (2) is provided on the base plate. The device stabilizing frame (1) and the counterweight base (2) form a rigid support system to prevent the frame from shaking. A placement plate is horizontally positioned in the middle of the device's stabilizing frame (1); the mechanical loading system is symmetrically positioned on the placement plate and the upper baffle (3); A seawater environment chamber (6) is provided between the upper baffle (3) and the placement plate, and is clamped by a mechanical loading system; The environmental control unit includes: a seawater environment chamber (6), in which a test sample (7) is vertically arranged, with both ends of the test sample (7) penetrating and extending to the outside of the seawater environment chamber (6); a pressure control system (8) and a temperature control system (9) connected to the seawater environment chamber (6) via a sealing flange, which are used to simulate deep-sea hydrostatic pressure and low-temperature environment, respectively. The mechanical loading system is coaxially mounted on the central axis of the pressure-resistant and stable structure to support the seawater environment chamber (6) and to clamp the two ends of the test sample (7) through the sample clamping system (5) to apply multiaxial dynamic mechanical loads. The mechanical loading system includes: a sample clamping system (5) and a load loading system (4). The load loading system (4) has a pair, which are symmetrically rotated on the upper stabilizing baffle (3) and the placement plate, respectively, so as to apply multi-axis dynamic mechanical load to the test sample (7) fixed on the sample clamping system (5); The load loading system (4) includes a multi-axis servo loading mechanism in three orthogonal directions. The servo loading mechanism is connected to the drive motor via a synchronous belt. It applies a maximum tensile / compressive alternating load of 500kN, with a loading frequency range of 0.001-10Hz, and provides real-time feedback of the stress-strain curve to the multi-source monitoring module. The sample clamping system (5) is located on the upper and lower sides of the seawater environment chamber (6) and is connected to the corresponding load loading system (4) to clamp the two ends of the test sample (7). The gas control unit is connected to the seawater environment chamber (6) and is used to control the dissolved oxygen concentration in the seawater environment chamber (6); The multi-source monitoring module is used to collect detection data from the environmental control unit, the mechanical loading system and the gas control unit, and analyze the data to obtain the corrosion rate of the test sample (7). The multi-source monitoring module includes: an electrochemical corrosion testing system (16), a microbial sensor (15), and a data collection system (17). The electrochemical corrosion testing system (16) includes a reference electrode (13) and a counter electrode (14) installed in the seawater environment chamber (6). The system acquires the time-series corrosion current I(t) in real time at a scanning rate of 0.1mV / s-100mV / s through a dynamic potential scanning module, and acquires the time-series impedance spectrum Z(ω) in the frequency range of 10μHz-1MHz through an impedance spectrum analysis module. The microbial sensor (15) is vertically inserted into the seawater environment chamber (6), with the detection surface facing the test sample (7); the microbial sensor (15) is a functionalized nanoelectrode array, and the electrode surface is covered with a sulfur ion selective membrane and a pH sensitive membrane. The microbial sensor (15) is used to dynamically detect the concentration S(t) of time-series metabolites at a sampling frequency of 1 Hz; the detection limit is 1 × 10⁻ 9 mol / L, response time <10s, and simultaneous monitoring of H2S, HS⁻, and H⁺ concentration changes; The data collection system (17) is connected to the electrochemical corrosion testing system (16) and the microbial sensor (15) respectively, for synchronous integration of electrochemical and microbial monitoring data; and has a built-in multi-physics field coupling analysis algorithm, which outputs the corrosion damage evolution trend prediction curve in real time by establishing a correlation model between electrochemical corrosion rate, microbial metabolic activity and mechanical load parameters.

2. The deep-sea corrosion environment simulation and monitoring device with multivariable coupled control according to claim 1, characterized in that, The gas control unit includes: a nitrogen storage tank (10), a hydrogen storage tank (11), and a gas control system (12) connected to both. The nitrogen storage tank (10) and hydrogen storage tank (11) are respectively connected to the seawater environment chamber (6) through pipelines via the gas control system (12); The gas control system (12) includes: a mass flow controller and a dissolved oxygen probe; The dissolved oxygen probe is installed inside the seawater environment chamber (6) to monitor the dissolved oxygen concentration inside the seawater environment chamber (6) in real time. The mass flow controller is used to monitor the dissolved oxygen concentration in the seawater environment chamber (6) based on the dissolved oxygen probe. It controls the flow rate of the mixed gas of nitrogen and hydrogen through the PID algorithm so that the dissolved oxygen concentration in the seawater is controlled within the range of 0.01-8 mg / L with a resolution of 0.001 mg / L.

3. The deep-sea corrosion environment simulation and monitoring device with multivariable coupled control according to claim 1, characterized in that, The pressure control system (8) adopts a multi-stage hydraulic compensation device, and the pressure control accuracy is ≤ ±0.5%; The temperature control system (9) includes a refrigeration module and a temperature controller, with a temperature control range of -2℃ to 30℃ and a temperature fluctuation of ≤±0.1℃.

4. The deep-sea corrosion environment simulation and monitoring device with multivariable coupled control according to claim 1, characterized in that, The seawater environment cabin (6) is equipped with multiple visualization observation windows; The visualization observation window uses a sapphire lens, and a long working distance microscope objective is integrated on the surface of the visualization observation window. Together with a high-speed camera group, it can realize in-situ observation of surface morphology at a resolution of 50nm. The spatial overlap between the observation area and the electrochemical test area is >95%. The inner wall of the seawater environment chamber (6) is provided with a porous microbial carrier layer, which is inoculated with at least two deep-sea corrosion microorganisms (18) among sulfate-reducing bacteria, iron-oxidizing bacteria and acid-producing bacteria. The microbial density is controllable within the range of 10³-10⁻⁶. 9 CFU / cm².

5. The operation method of the deep-sea corrosion environment simulation and monitoring device with multivariable coupled control according to any one of claims 1 to 4, characterized in that, Includes the following steps: 1) Set the target pressure value P and temperature value T through the pressure control system (8) and temperature control system (9) and send them to the data collection system (17). 2) The mixing ratio of nitrogen and hydrogen is adjusted by the gas control system (12) so that the dissolved oxygen concentration reaches the set value C and is sent to the data collection system (17). 3) Start the load loading system (4) to apply multiaxial composite stress σ to the test sample (7) and send it to the data collection system (17). 4) Simultaneously activate the electrochemical corrosion testing system (16) and the microbial sensor (15) to collect the corrosion current I(t), impedance spectrum Z(ω) and metabolite concentration S(t) of the time series in real time, and send them to the data collection system (17). 5) The data collection system (17) analyzes the data acquired in real time and outputs the corrosion damage evolution trend prediction curve in real time; 6) Based on the real-time prediction curve, if the corrosion rate exceeds the threshold, an alarm will be triggered and the load will be automatically reduced or environmental parameters will be adjusted.

6. The operation method of the deep-sea corrosion environment simulation and monitoring device with multivariable coupling control according to claim 5, characterized in that, The data collection system (17) analyzes the data acquired in real time, namely: The quantitative relationship between corrosion rate v and P, T, C, and σ is established as follows: v=k·P α ·T β ·C γ ·σ δ Where k is the material property coefficient, and α, β, γ, and δ are environmental coupling factors; The instantaneous corrosion rate v(t) is inverted by the corrosion current I(t) of the time series, and the dynamic characteristics of the corrosion interface and the evolution law of the film are analyzed by combining the impedance spectrum Z(ω). At the same time, the synergistic effect of microbial metabolic activity on the corrosion process is evaluated by the concentration of metabolites S(t). By inputting the above parameters into the corrosion damage evolution model, the environmental coupling factors α, β, γ, δ and material property coefficient k of the dynamic quantitative relationship are used to output the corrosion damage evolution trend prediction curve, thereby realizing multi-dimensional coupled modeling and trend prediction of corrosion dynamics.

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