Complex steam environment metal corrosion dynamic simulation system and monitoring system

Abstract

The invention discloses a complex steam environment metal corrosion dynamic simulation system and monitoring system, and relates to the technical field of power plant boiler tubes, the complex steam environment metal corrosion dynamic simulation system comprises a steam generation unit, a pressure regulation and control unit and a simulation generator; the steam generation unit generates high-temperature and high-pressure steam, the pressure and the flow speed of the high-temperature and high-pressure steam are adjusted through the pressure regulation and control unit, then the high-temperature and high-pressure steam is conveyed to the simulation generator, and dynamic simulation of oxidation and stripping behaviors of metal materials is conducted in the high-temperature and high-pressure environment. Through the design of double parallel steam generators, continuous supply of high-temperature and high-pressure steam is ensured; the pressure regulation and control unit realizes accurate regulation of steam flow velocity and pressure and simulates complex working conditions of a power plant boiler; the simulation generator is combined with tube furnace heating and high-temperature steam introduction to integrally simulate oxidation and peeling behaviors, a monitoring system is integrated, data is collected in real time through an oxidation film thickness and stress sensor, support is provided in combination with an analysis module, and a foundation is laid for optimizing material selection and anti-corrosion measures.

Description

Technical Field

[0001] The invention relates to the technical field of power plant boiler tubes, in particular to a dynamic simulation system and a monitoring system for metal corrosion in a complex steam environment. Background Art

[0002] With the rapid development of modern industry, the problem of metal corrosion in high-temperature, high-pressure, and complex steam environments has received increasing attention, especially in the fields of electricity, petrochemicals, and nuclear energy. The corrosion behavior of metal materials in high-temperature, high-pressure steam environments directly affects the safety, reliability, and service life of equipment. For example, in thermal power plants, boiler pipes are exposed to high-temperature, high-pressure water vapor for long periods of time, and an oxide film forms on their surface. This oxide film may also flake off, leading to serious accidents such as pipe leakage or even pipe bursts. Therefore, studying the corrosion behavior of metal materials in high-temperature, high-pressure, and complex steam environments is of great significance for improving the safety and extending the service life of equipment.

[0003] However, traditional devices cannot achieve long-term continuous gas supply, and experiments are easily interrupted due to adding water or restarting the steam generator; the adjustment range of steam flow rate and pressure is narrow, making it difficult to simulate complex working conditions; and there is a lack of dynamic high-temperature and high-pressure steam introduction function, which cannot truly restore the actual operating environment; and existing devices mostly focus on static oxidation behavior research, lacking real-time monitoring and analysis of oxide film thickness and stress distribution.

[0004] Based on the above problems, we proposed a dynamic simulation system and monitoring system for metal corrosion in complex steam environment. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is: how to realize the dynamic simulation of the oxidation and spalling behavior of metal materials in a high-temperature, high-pressure and complex steam environment, and overcome the problems of insufficient gas supply continuity, limited steam flow rate and pressure regulation capabilities in the existing technology.

[0006] The above technical problems are solved by the following technical solutions: The present invention proposes a dynamic simulation system for metal corrosion in a complex steam environment, which includes a steam generating unit, a pressure control unit and a simulation generator; the steam generating unit generates high-temperature and high-pressure steam and after adjusting the pressure and flow rate through the pressure control unit, it is transported to the simulation generator to dynamically simulate the oxidation and spalling behavior of metal materials in a high-temperature and high-pressure environment.

[0007] In a preferred embodiment of the complex steam environment metal corrosion dynamic simulation system of the present invention: the steam generation unit includes a deoxygenated water storage tank and two or more steam generators connected in parallel.

[0008] In a preferred embodiment of the complex steam environment metal corrosion dynamic simulation system of the present invention: the water outlet of the deoxygenation water storage tank is connected to the water inlet of each steam generator through a water supply pipe.

[0009] In a preferred embodiment of the complex steam environment metal corrosion dynamic simulation system of the present invention: the steam generating unit further includes a gas flow meter, and the water outlet of the steam generator is connected to the water inlet of the gas flow meter through a first steam pipe.

[0010] In a preferred embodiment of the complex steam environment metal corrosion dynamic simulation system of the present invention: the pressure control unit includes a gas booster pump, and a second steam pipe is provided between the inlet of the gas booster pump and the water outlet of the gas flow meter.

[0011] In a preferred embodiment of the complex steam environment metal corrosion dynamic simulation system of the present invention: a valve is provided on the outer wall of the second steam pipe, and the pressure control unit further includes an air compressor.

[0012] In a preferred embodiment of the complex steam environment metal corrosion dynamic simulation system of the present invention: the air compressor and the gas booster pump are connected via a driving air pipeline.

[0013] In a preferred embodiment of the complex steam environment metal corrosion dynamic simulation system of the present invention: the water outlet of the gas booster pump is connected to the simulation generator through a third steam pipe.

[0014] The present invention also proposes a monitoring system, which includes an acquisition module, a data processing module, a control unit and a display and analysis module; the acquisition module is responsible for acquiring data from the simulation generator in real time, the data processing module analyzes and preprocesses the acquired data, the control unit generates control instructions based on the processed data and coordinates the system operation, and the display and analysis module visualizes the results and provides in-depth analysis.

[0015] In a preferred embodiment of the monitoring system of the present invention: the acquisition module includes an oxide film thickness sensor and a stress sensor provided on the simulation generator.

[0016] The beneficial effects of the present invention are as follows: the dual-parallel steam generator design ensures a continuous supply of high-temperature, high-pressure steam, avoiding experimental interruptions and improving experimental stability; the pressure control unit achieves precise regulation of steam flow rate and pressure, simulating the complex operating conditions of power plant boilers and providing realistic experimental conditions; the deoxygenated water reservoir and flow meter cooperate to regulate the dissolved oxygen content in real time, providing a basis for studying the effect of oxygen content on oxide film growth. The simulation generator combines tubular furnace heating with high-temperature steam flow to simulate oxidation and spalling behavior, realistically reproducing the metal corrosion process. The integrated monitoring system collects data in real time through oxide film thickness and stress sensors, and combined with the analysis module, provides comprehensive support, laying the foundation for optimizing material selection and anti-corrosion measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings of the embodiments of the present invention. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Among them:

[0018] Figure 1 Shows a diagram of a dynamic simulation system for metal corrosion in a complex steam environment;

[0019] Figure 2 shows the connection diagram of the monitoring system;

[0020] Figure 3 Shows the S304H heat-resistant steel water vapor oxidation test diagram at 650°C;

[0021] Figure 4 Shown Figure 3 Backscattered electron image of 3D sample;

[0022] Figure 5 Shows the XRD patterns of S304H heat-resistant steel in water vapor at 650℃ for different oxidation times;

[0023] Figure 6 A schematic diagram of the oxidation mechanism of S304H heat-resistant steel is shown. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below with reference to specific embodiments and the accompanying drawings.

[0025] The terms used in the present invention are those commonly used in the art in view of the functions of the present invention, but these terms may vary according to the intentions of those skilled in the art, precedents, or new technologies in the art. In addition, specific terms may be selected by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but rather as the meanings of the terms and the overall description of the present invention.

[0026] Reference Figure 1 This embodiment provides a dynamic simulation system for metal corrosion in a complex steam environment, including a steam generating unit 1, which is responsible for generating high-temperature and high-pressure steam to ensure the continuity and stability of the experimental medium, a pressure regulating unit 2 and a simulation generator 3. The pressure regulating unit 2 meets the experimental requirements for a high-temperature and high-pressure environment by increasing the steam pressure and flow rate; the simulation generator 3 can realize an integrated dynamic simulation of oxidation and spalling, and truly restore the actual operating environment of the power plant pipeline; the steam generating unit 1 generates high-temperature and high-pressure steam and, after adjusting the pressure and flow rate through the pressure regulating unit 2, transports it to the simulation generator 3, and dynamically simulates the oxidation and spalling behavior of the metal material under a high-temperature and high-pressure environment.

[0027] As an optional embodiment, the steam generating unit 1 includes a deoxygenation water tank 11, which can remove dissolved oxygen in the water to ensure the purity of the generated steam, reduce the interference of dissolved oxygen on the experimental results, and provide a stable water source to ensure the continuous operation of the steam generator; two or more steam generators 12 are connected in parallel, and the steam generators 12 can generate high-temperature and high-pressure steam to provide the required high-temperature and high-pressure environment for the experiment. The dual parallel design ensures the continuity of the gas supply. When one steam generator needs to be added with water or maintained, the other steam generator can continue to work to ensure the continuity of the experiment.

[0028] As an optional embodiment, the water outlet of the deoxygenated water storage tank 11 is connected to the water inlet of each steam generator 12 through a water supply pipe 111. The water supply pipe 111 evenly distributes the deoxygenated water to multiple parallel steam generators 12 to achieve the coordinated operation of dual steam generators or multiple steam generators.

[0029] As an optional embodiment, the steam generating unit 1 also includes a gas flow meter 13, which can measure the flow of high-temperature and high-pressure steam flowing out of the steam generator 12, ensuring that the steam flow entering the gas booster component 2 is stable and meets the precise flow rate requirements of the experiment; the air outlet of each steam generator 12 is connected to the water inlet of the gas flow meter 13 through the first steam pipe 121.

[0030] As an optional embodiment, the pressure control unit 2 includes a gas booster pump 21, which boosts the high-temperature and high-pressure steam delivered from the steam generating assembly 1 to increase its pressure and flow rate. A second steam pipe 22 is provided between the inlet of the gas booster pump 21 and the water outlet of the gas flow meter 13. The second steam pipe 22 can deliver the steam regulated by the gas flow meter 13 to the gas booster pump 21.

[0031] As an optional embodiment, a valve 23 is provided on the outer wall of the second steam pipe 22, and the valve 23 is used to dynamically adjust the amount of steam entering the gas booster pump 21; according to experimental requirements, the pressure and flow rate of the steam can be flexibly adjusted by controlling the opening of the valve 23 and the working state of the gas booster pump 21; the pressure control unit 2 also includes an air compressor 24, which provides a power source for the air-driven gas booster pump 21 and outputs stable high-pressure gas to ensure that the gas booster pump 21 can operate normally.

[0032] As an optional embodiment, the air compressor 24 is connected to the gas booster pump 21 via a driving gas pipeline 25 , and the driving gas pipeline 25 delivers the high-pressure gas generated by the air compressor 24 to the driving gas interface of the gas booster pump 21 .

[0033] As an optional embodiment, the water outlet of the gas booster pump 21 is connected to the simulation generator 3 through a third steam pipe 26. The third steam pipe 26 connects the gas booster pump 21 and the simulation generator 3 to ensure smooth transmission of the pressurized steam and avoid leakage or pressure loss; the simulation generator 3 is composed of a stainless steel tube sample and a tubular furnace. The tubular furnace heats the outer wall of the stainless steel tube sample to truly restore the high-temperature operating conditions of the power plant boiler tube.

[0034] When in use, the deoxygenated water storage tank 11 is started to remove dissolved oxygen in the water. The deoxygenated water flows into two or more parallel steam generators 12 through the water supply pipe 111. Each steam generator 12 works independently to heat the deoxygenated water and convert it into high-temperature and high-pressure steam. The generated high-temperature and high-pressure steam enters the gas flow meter 13 through the first steam pipe 121. The gas flow meter 13 measures the steam flow flowing out of the steam generator 12 and adjusts the steam flow according to the experimental requirements. The adjusted steam enters the gas booster pump 21 through the second steam pipe 22, and the air compressor 2 4 provides power for the air-driven gas booster pump 21, which boosts the steam and increases its pressure and flow rate to achieve the high-temperature and high-pressure conditions required for the experiment. The boosted high-temperature and high-pressure steam is transported to the simulation generator 3 through the third steam pipe 26. The stainless steel pipe sample in the simulation generator 3 is used as the tested material and is directly exposed to the high-temperature and high-pressure steam environment. It is heated to 500-1100°C in the tube furnace. The high-temperature steam introduced into the inner wall and the high-temperature environment of the outer wall act together to simulate the oxidation and spalling process of the metal material in the actual power plant pipeline.

[0035] Reference Figures 1 and 2 This embodiment provides a monitoring system, including an acquisition module 4, a data processing module 5, a control unit 6, and a display and analysis module 7; the acquisition module 4 is responsible for acquiring data from the simulation generator in real time, the data processing module 5 analyzes and preprocesses the acquired data, the control unit 6 generates control instructions based on the processed data and coordinates system operation, and the display and analysis module 7 visualizes the results and provides in-depth analysis.

[0036] As an optional embodiment, the acquisition module 4 includes an oxide film thickness sensor 41 and a stress sensor 42 provided on the simulation generator. The oxide film thickness sensor 41 and the stress sensor 42 are both provided on the stainless steel pipe sample in the simulation generator 3 .

[0037] When in use, the oxide film thickness sensor 41 monitors the growth of the oxide film in real time, the stress sensor 42 monitors the stress distribution of the oxide film in real time, the data processing module 5 analyzes and preprocesses the data obtained by the acquisition module 4, extracts key information, and the control unit 6 generates control instructions based on the processed data, dynamically adjusts parameters such as steam flow and pressure to ensure that the experimental conditions meet the requirements, and the display and analysis module 7 visualizes the results to facilitate researchers to monitor the experimental process in real time, provide in-depth analysis support, and provide a scientific basis for the selection of metal materials and the design of anti-corrosion measures.

[0038] Oxidation test of S304H heat-resistant steel in 650℃ steam environment:

[0039] The oxidation time was selected as 5h, 6h, 7h and 8h respectively. The oxidation results were as follows: Figure 3As shown in Figure 1, the oxide film on S304H heat-resistant steel exhibits a typical double-layer structure, with the interface between the inner and outer oxide layers being the original surface of the substrate. The oxidation morphologies of samples B and D show that the inner oxide film is denser, while the outer oxide film is looser.

[0040] The interface between the inner oxide film and the substrate is highly uneven, with the internal oxide exhibiting a nodular structure that grows into the steel substrate. A band-like structure is present at the tip of the nodule (marked in the image). Research has shown that this layer possesses self-healing properties and is very dense, effectively blocking the outward diffusion of atoms from the metal matrix, thereby slowing metal oxidation. The outer oxide film has a loose structure and is characterized by numerous pores.

[0041] like Figure 3 As shown, sample D was selected for backscattering analysis ( Figure 3 a), it was found that O element only exists in the oxide layer, according to ( Figure 3 b) It can be seen that the oxide layer in this sample is a gray area, which is divided into two layers, and the outer layer is relatively loose. Figure 3 c) Cr is primarily distributed in the inner oxide layer and matrix, with a certain amount also present in the outer oxide layer. Similarly, the outer oxide layer and matrix contain a high Fe content, while the inner oxide layer contains a relatively low Fe content. The oxides in the inner oxide film are rich in Cr, with certain amounts of Fe, Ni, and a small amount of Cu, while the outer oxide layer is rich in Fe.

[0042] like Figure 4 As shown in the figure, the oxide phases observed in the oxide film are Fe2O3, Fe3O4, Cr2O3 and NiO. Combined with the cross-sectional EDS results, it can be seen that the outer oxide is mainly Fe2O3 and Fe3O4, and the inner oxide is Cr2O3 and NiO. At the same time, there is a certain amount of Fe2O3 in the inner layer. By analyzing the structure and composition of the oxide film cross section of the sample oxidized at 600℃ for 5h, 6h, 7h and 8h, combined with the XRD phase detection results ( Figure 5 ), and we get the following conclusions.

[0043] After oxidation in a 600℃ steam environment for 5 hours, the oxide film is a double-layer structure, and the interface between the inner and outer layers is the original surface of the original sample. The inner oxide film grows in a tumor-like manner toward the inside of the substrate, and a dense banded Cr2O3 oxide layer is formed at its tip. There are oxides of (Cr, Fe, Ni) between the Cr2O3 film and the inner and outer interfaces, and the outer oxide film is composed of Fe2O3 and Fe3O4. When heat-resistant steel is oxidized in water vapor, O atoms are first adsorbed on the metal surface, and metal oxides nucleate. After nucleation, NiO begins to grow first, and the dissolved oxygen in the formed NiO film layer provides the required O for the growth of Cr2O3. After a certain period of time, Fe atoms diffuse outward and react with O at the interface to generate Fe2O3 and an outer oxide film of FeO ( Figure 6 ).

[0044] Based on the above phase and image analysis results, the oxide film growth mechanism of Super304H in high-temperature water vapor oxidation can be obtained. First, Cr and Ni oxides nucleate, and NiO nuclei grow first to form columnar crystals; then Cr2O3 begins to grow and slowly covers NiO. The dense film formed will prevent O from diffusing into the interior, hindering the continued growth of NiO; at the same time, a large amount of Fe in the matrix begins to nucleate, forming FeO nuclei. Some of the nuclei inside interact with Cr and H2O to form spinel-structured FeCr2O4; finally, after the inner oxide film is formed, a large amount of iron will combine with the oxygen on the surface to form FeO nuclei. As the oxidation time increases and the oxide film thickens, the O entering the reaction will be insufficient, so Fe2O3 will be converted into more stable Fe3O4.

[0045] Finally, it should be pointed out that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways without departing from the scope of the present invention.

Claims

1. A dynamic simulation system for metal corrosion in a complex steam environment, characterized by: include, A steam generating unit (1), a pressure regulating unit (2) and a simulation generator (3); The steam generation unit (1) generates high-temperature and high-pressure steam, and after the pressure and flow rate are adjusted by the pressure control unit (2), the steam is transported to the simulation generator (3) to dynamically simulate the oxidation and spalling behavior of the metal material under a high-temperature and high-pressure environment.

2. The complex steam environment metal corrosion dynamic simulation system according to claim 1 is characterized by: The steam generation unit (1) comprises a deoxygenated water storage tank (11) and two or more steam generators (12) connected in parallel.

3. The dynamic simulation system for metal corrosion in a complex steam environment according to claim 2 is characterized by: The water outlet of the deoxygenated water storage tank (11) is connected to the water inlet of each steam generator (12) through a water supply pipe (111).

4. The dynamic simulation system for metal corrosion in a complex steam environment according to claim 3 is characterized by: The steam generating unit (1) further comprises a gas flow meter (13), and the water outlet of the steam generator (12) is connected to the water inlet of the gas flow meter (13) via a first steam pipe (121).

5. The complex steam environment metal corrosion dynamic simulation system according to claim 4 is characterized by: The pressure regulating unit (2) comprises a gas booster pump (21), and a second steam pipe (22) is provided between the inlet of the gas booster pump (21) and the water outlet of the gas flow meter (13).

6. The complex steam environment metal corrosion dynamic simulation system according to claim 5 is characterized by: A valve (23) is provided on the outer wall of the second steam pipe (22), and the pressure regulating unit (2) further comprises an air compressor (24).

7. The complex steam environment metal corrosion dynamic simulation system according to claim 6 is characterized by: The air compressor (24) is connected to the gas booster pump (21) via a driving air pipeline (25).

8. The complex steam environment metal corrosion dynamic simulation system according to claim 7 is characterized by: The water outlet of the gas booster pump (21) is connected to the simulation generator (3) through a third steam pipe (26).

9. A monitoring system, characterized in that: The system comprises a dynamic simulation system for metal corrosion in a complex steam environment as claimed in any one of claims 1 to 8, further comprising: Acquisition module (4), data processing module (5), control unit (6) and display and analysis module (7); The acquisition module (4) is responsible for acquiring data from the simulation generator in real time, the data processing module (5) analyzes and pre-processes the acquired data, the control unit (6) generates control instructions based on the processed data and coordinates system operation, and the display and analysis module (7) visualizes the results and provides in-depth analysis.

10. The monitoring system according to claim 9, characterized in that: The acquisition module (4) comprises an oxide film thickness sensor (41) and a stress sensor (42) arranged on the simulation generator.

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