An on-line monitoring device and method for the surface layer oxide of the internal material of a high-temperature and high-pressure reaction kettle

Abstract

The application discloses an on-line monitoring device and method for surface layer oxides of internal materials of a high-temperature and high-pressure reaction kettle. The device comprises a monitoring window assembly and a Raman spectrum monitor. A window opening is arranged on a reaction kettle body of the high-temperature and high-pressure reaction kettle, and the monitoring window assembly is of a detachable structure. The monitoring window assembly comprises a window penetrating assembly, a window fixing flange and bolts. The window penetrating assembly is fixed on the window opening through the window fixing flange and the bolts. The Raman spectrum monitor is arranged outside the reaction kettle body. The on-line monitoring device for surface layer oxides of internal materials of the high-temperature and high-pressure reaction kettle simplifies the overall structure, reduces equipment cost and maintenance difficulty, and is suitable for long-term high-temperature and high-pressure test requirements. The overall design of the device focuses on on-line monitoring of the surface layer oxides of the materials, and internal dynamics can be observed in time. Meanwhile, the monitoring window assembly is of a detachable structure, replacement and maintenance of the window penetrating and sealing components are facilitated, and the practicality and service life of the device are further improved.

Description

Technical Field

[0001] This invention relates to the field of high-temperature and high-pressure corrosion testing and monitoring technology, and in particular to an online monitoring device and method for surface oxides of materials inside a high-temperature and high-pressure reactor. Background Technology

[0002] In high-temperature and high-pressure corrosion tests on fusion reactor water-cooled blankets and nuclear power equipment, oxides are generated on the surface of materials inside the reactor. The composition, thickness, and growth rate of these oxides directly reflect the degree of corrosion and are the core basis for studying material corrosion mechanisms and optimizing corrosion protection schemes. Raman spectroscopy, based on the principle of molecular vibration, can accurately characterize the composition, crystal structure, and stress state of oxides. It also has the advantages of being non-destructive, having high detection accuracy, and requiring no contact with the material, making it an ideal method for characterizing oxides on the material surface.

[0003] Currently, when using Raman spectroscopy for online monitoring of surface oxides in materials within high-temperature and high-pressure reactors, a monitoring window needs to be installed on the reactor for receiving both incident and scattered laser light. This places extremely high demands on the overall performance of the monitoring device. However, existing monitoring devices still have many unresolved defects that seriously affect monitoring effectiveness and experimental safety: First, the material of the monitoring window is difficult to simultaneously achieve high temperature resistance, high pressure resistance, high light transmittance, and corrosion resistance. Under high-temperature and high-pressure conditions, it is prone to cracking and attenuation of light transmittance, leading to obstructed laser propagation, signal distortion, and reduced monitoring accuracy. Second, the monitoring window structure design is unreasonable, resulting in thermal stress concentration problems. It is prone to optical distortion due to temperature changes, further aggravating monitoring errors. Third, the sealing structure design of the monitoring device is imperfect. A single sealing structure cannot achieve zero-leakage sealing under high-temperature and high-pressure conditions. Leakage of the medium inside the reactor not only threatens experimental safety but also damages the monitoring environment, leading to unreliable monitoring data.

[0004] Therefore, there is an urgent need to design a high-temperature and high-pressure reactor monitoring device and method with reliable sealing performance and adaptable to online monitoring of surface oxides of materials, to overcome the shortcomings of existing technologies, meet the monitoring needs of high-temperature and high-pressure corrosion tests such as fusion water-cooled cladding, and further expand the engineering application scenarios of such monitoring devices. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an online monitoring device and method for surface oxides on materials inside a high-temperature, high-pressure reactor. It is particularly suitable for real-time, accurate online monitoring of oxide growth on the surface of materials inside the reactor under high-temperature, high-pressure corrosive environments such as fusion water-cooled cladding, providing technical support for research on material corrosion mechanisms.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An online monitoring device for surface oxides of materials inside a high-temperature and high-pressure reactor, comprising a monitoring window assembly and a Raman spectroscopy monitor;

[0008] The high-temperature and high-pressure reactor has a window opening on its vessel body, and the monitoring window assembly is a detachable structure. The monitoring window assembly includes a window component, a window fixing flange, and bolts. The window component is fixed to the window opening by the window fixing flange and bolts. The Raman spectrometer is located on the outside of the reactor body.

[0009] The Raman incident laser emitted by the Raman spectrometer passes through the monitoring window assembly and irradiates the surface of the material to be monitored. The Raman scattered laser generated by the oxide on the surface of the material to be monitored passes through the monitoring window assembly and is received by the Raman spectrometer, thereby realizing online monitoring of the oxide on the surface of the material inside the high-temperature and high-pressure reactor.

[0010] The window fixing flange includes a flange body, a sealing groove, and a bolt opening. The sealing groove is located at the connection position between the flange body and the window assembly. The bolt opening corresponds to the bolt groove of the reactor body. The bolt passes through the bolt opening and is fastened in the bolt groove, which is located on the outside of the reactor body.

[0011] The window assembly includes a window body, a soft filler, and a flange gasket. The soft filler is used to fill the installation gap between the window body and the window opening, and the flange gasket is located in the sealing groove.

[0012] The reactor vessel body has a chamfered window that matches the transparent window body. The transparent window body is embedded in the chamfered window body, and an adhesive is placed between the chamfered window body and the transparent window body. The adhesive, soft filler and flange gasket constitute a triple sealing structure.

[0013] The transparent window body includes a pressure-bearing layer and a light-transmitting layer, wherein the light-transmitting layer is coated on the surface of the pressure-bearing layer.

[0014] The bolt includes a bolt post, a bolt main bearing washer, and a bolt copper ring washer. The bolt post passes through the bolt main bearing washer, the bolt copper ring washer, and the bolt opening of the window fixing flange in sequence and is fastened to the bolt groove.

[0015] The window fixing flange is made of high-temperature resistant alloy material, the pressure-bearing layer of the window body is made of ceramic material, and the bolts are made of high-temperature resistant and high-strength alloy material.

[0016] An online monitoring method for surface oxides of materials inside a high-temperature, high-pressure reactor, employing the aforementioned online monitoring device for surface oxides of materials inside a high-temperature, high-pressure reactor, includes the following steps:

[0017] S1: Place the material to be monitored inside a high-temperature and high-pressure reactor;

[0018] S2: Align the laser emitter and signal receiver of the Raman spectrometer with the outer plane of the window body of the high-temperature and high-pressure reactor, adjust the incident angle of the Raman incident laser, focus on the surface of the material to be monitored, and set the detection parameters of the Raman spectrometer.

[0019] S3: Start the high-temperature and high-pressure reactor, adjust the internal conditions of the high-temperature and high-pressure reactor to the preset parameters, simulate the actual corrosion environment such as the fusion water-cooled blanket, and start the corrosion test. Oxides are gradually generated on the surface of the material to be monitored.

[0020] S4: During the experiment, the Raman spectral signal of the oxide on the surface of the material to be monitored is collected in real time by a Raman spectrometer. The Raman incident laser is incident on the oxide on the surface of the material to be monitored, and the Raman scattered laser of the oxide returns along the original path and is output to the Raman spectrometer.

[0021] S5. Analyze the collected Raman spectral signals, identify the characteristic Raman peaks of the oxides, calculate the peak position, peak width and peak area of ​​the characteristic peaks, and obtain the composition, thickness and growth rate of the oxides in real time to realize online monitoring of oxide growth on the surface of the material to be monitored.

[0022] S6. After the test, close the high-temperature and high-pressure reactor. After the temperature and pressure inside the reactor drop to normal temperature and pressure, take out the material to be monitored.

[0023] In step S5, the oxide thickness is calculated by the change in the peak area of ​​the characteristic peak. The peak area and the oxide thickness are linearly positively correlated, with a linear correlation coefficient R²≥0.98 and a monitoring error ≤5%. The stress state of the oxide is analyzed by the peak position shift of the characteristic peak. A red shift of the peak position indicates that the oxide has compressive stress, and a blue shift of the peak position indicates that the oxide has tensile stress.

[0024] In step S1, the surface of the material to be monitored corresponds to the inner convex surface of the window body, and the distance between the surface of the material to be monitored and the inner end face of the window body is controlled at 5-10mm.

[0025] The beneficial effects of this invention are as follows:

[0026] (1) Simple and reliable structure: The online monitoring device for surface oxides of materials inside the high temperature and high pressure reactor of the present invention simplifies the overall structure, reduces equipment cost and maintenance difficulty, and is suitable for long-term high temperature and high pressure test requirements; the overall design of the device focuses on online monitoring of surface oxides of materials, and can observe internal dynamics in a timely manner; at the same time, the monitoring window assembly is a detachable structure, which facilitates the replacement and maintenance of the window and sealing components, further improving the practicality and service life of the device.

[0027] (2) Excellent optical and mechanical properties: The online monitoring device for surface oxides of materials inside the high-temperature and high-pressure reactor of the present invention has a composite window structure. The window body adopts a composite structure of pressure-bearing layer and light-transmitting layer. The pressure-bearing layer is made of high-strength ceramic material such as sapphire, which has excellent high temperature resistance, high pressure resistance and corrosion resistance. It can withstand the stress under high pressure conditions of 300-400℃, avoiding window breakage. The light-transmitting layer adopts a multi-coating structure, which is adapted to the Raman spectroscopy detection wavelength, with high light transmittance and small optical distortion, ensuring stable transmission of laser and scattering signals and effectively improving the monitoring accuracy of oxides.

[0028] (3) Reliable sealing performance: The online monitoring device for surface oxides of materials inside the high temperature and high pressure reactor of the present invention has a triple sealing design. It adopts a triple sealing structure composed of "adhesive-soft filler-flange gasket" to form a sealing redundancy, realize zero leakage sealing between the window and the reactor, and can stably adapt to the fusion water-cooled blanket simulation working conditions of 330℃ and 16MPa, eliminate the leakage of the medium inside the reactor, ensure the safety of the test, and at the same time avoid the interference of the medium leakage on the monitoring environment, ensure the reliability of the monitoring data, and provide a guarantee for the long-term stable operation of the device.

[0029] (4) High monitoring accuracy: The online monitoring device and method of the present invention accurately match the advantages of Raman spectroscopy in characterizing solid oxides, avoiding its unsuitability for ion concentration detection. It can capture the composition, thickness and growth rate of oxides on the surface of materials in real time, and is a non-destructive detection that does not affect the corrosion process of materials. It is compatible with commonly used materials for fusion water-cooled cladding and can monitor the growth process of common oxides such as Fe3O4 and Cr2O3. It is not only suitable for corrosion tests of fusion reactor water-cooled cladding, but also for online monitoring of oxides on the surface of materials in other high-temperature and high-pressure corrosion tests such as nuclear power and chemical industry.

[0030] (5) Easy assembly and low maintenance cost: The monitoring window assembly of the present invention adopts a bolt connection method, which makes assembly and disassembly convenient. Combined with the detachable design, it is easy to replace and maintain the window and sealing components, and has strong repeatability. The materials of each component of the triple sealing device are suitable for high temperature and high pressure corrosion conditions, with no aging or leaching, and excellent compatibility with the window and vessel body. It can alleviate thermal stress and mechanical stress, not only ensuring the reliability of the seal, but also protecting the window from damage, extending the service life of the window, reducing maintenance costs, and facilitating promotion and application. Attached Figure Description

[0031] Figure 1 This is an overall schematic diagram of the online monitoring device for surface oxides of materials inside the high-temperature and high-pressure reactor of the present invention;

[0032] Figure 2 This is a schematic diagram of the internal structure of the online monitoring device for surface oxides of materials inside the high-temperature and high-pressure reactor of the present invention.

[0033] The attached figures are labeled as follows: 1-High temperature and high pressure reactor; 10-Reactor body; 11-Bolt groove; 12-Window chamfer; 13-Window opening; 2-Monitoring window assembly; 20-Window fixing flange; 200-Sealing groove; 201-Bolt opening; 21-Window body; 210-Light-transmitting layer; 211-Adhesive; 212-Soft filler; 213-Flange gasket; 22-Bolt; 220-Bolt post; 221-Bolt main load-bearing gasket; 222-Bolt copper ring gasket; 3-Raman spectrometer; 30-Raman spectrometer probe; 301-Raman incident laser; 302-Raman scattering laser; 4-Material to be monitored; 40-Surface layer of material to be monitored. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0035] See Figure 1 The present invention provides an online monitoring device for the surface oxides of the internal material of a high-temperature and high-pressure reactor 1, which includes a monitoring window assembly 2 and a Raman spectrometer 3.

[0036] The reactor vessel body 10 serves as the mounting base for the entire monitoring device and must be made of materials resistant to high temperatures, high pressures, and corrosion. Bolt grooves 11 are provided on the outer side of the reactor vessel body 10 to secure the monitoring window assembly with bolts. A window opening 13 is located in the middle of the reactor vessel body 10, serving as a channel for laser incident and scattered light exit, while also providing installation space for the monitoring window assembly 2. A chamfered edge 12 is provided on the inner side of the reactor vessel body 10, which cooperates with the window body 21 to achieve precise positioning of the window, while dispersing the thermal stress and pressure on the window, preventing breakage due to stress concentration, and ensuring the long-term stable operation of the monitoring device.

[0037] The monitoring window assembly 2, fixed to the window opening 13, is the core component for achieving sealing and light transmission. It is a detachable structure, comprising a window assembly, a window fixing flange 20, and bolts 22. These components work together to ensure sealing and optical performance under high temperature and high pressure conditions, providing a stable optical path for oxide monitoring. The bolts 22 allow for the complete disassembly of the monitoring window assembly 2, facilitating the replacement and maintenance of the window body 21 and sealing components. The window assembly is fixed to the window opening 13 via the window fixing flange 20 and bolts 22.

[0038] The Raman spectrometer 3 is set outside the reactor vessel body 10 and outside the window body 21 of the window assembly; the material to be monitored 4 is set inside the reactor vessel body 10 and inside the window body 21 of the window assembly. The material to be monitored 4 is a commonly used material for fusion water-cooled cladding. The surface 40 of the material to be monitored 4 corresponds to the inner convex surface of the window body 21 to ensure that the laser can accurately irradiate the surface of the material, capture the Raman signal of the surface oxide, and realize the accurate monitoring of the oxide.

[0039] The Raman incident laser 301 emitted by the Raman spectrometer probe 30 of the Raman spectrometer 3 passes through the transparent window body 21 of the monitoring window assembly 2 and irradiates the surface layer 40 of the material to be monitored 4. The Raman scattered laser 302 generated by the oxide of the surface layer 40 of the material to be monitored passes through the transparent window body 21 of the monitoring window assembly 2 and is received by the Raman spectrometer probe 30, thereby realizing the online monitoring of the oxide of the surface layer of the material inside the high temperature and high pressure reactor 1.

[0040] Further, see Figure 2 The window fixing flange 20 includes a flange body, a sealing groove 200, and a bolt opening 201. The sealing groove 200 is located at the connection between the flange body and the window assembly. The bolt opening 201 corresponds to the bolt groove 11 of the reactor body 10. The bolt 22 passes through the bolt opening 201 and is fastened in the bolt groove 11, which is located on the outside of the reactor body 10. The window fixing flange 20 is made of a high-temperature resistant alloy material that matches the reactor body material. The sealing groove 200 is used to place the flange gasket 213 to form a sealing structure. The bolt opening 201 allows the bolt 22 to pass through, achieving a tight connection between the window fixing flange 20 and the reactor body 10, ensuring connection strength and sealing performance, and preventing leakage of the medium inside the reactor.

[0041] See Figure 2 The transparent window assembly includes a transparent window body 21, a flexible filler 212, and a flange gasket 213. The flexible filler 212 is used to fill the installation gap between the transparent window body 21 and the window opening 13, and the flange gasket 213 is located within the sealing groove 200. A chamfered window 12 that mates with the transparent window body 21 is provided on the inner side of the reactor vessel body 10. The transparent window body 21 is embedded within the chamfered window 12, and an adhesive 211 is provided between the chamfered window 12 and the transparent window body 21. The adhesive 211, the flexible filler 212, and the flange gasket 213 constitute a triple sealing structure. The transparent window body 21 includes a pressure-bearing layer and a light-transmitting layer 210, wherein the light-transmitting layer 210 is coated on the surface of the pressure-bearing layer.

[0042] Specifically, the pressure-bearing layer of the transparent window body 21 is made of ceramic material (including but not limited to sapphire and magnesium aluminum spinel ceramic), which has the characteristics of high temperature resistance, high pressure resistance, high light transmittance and corrosion resistance, and is compatible with Raman spectroscopy detection wavelength (200nm-2500nm), which can reduce laser attenuation and signal interference; the light-transmitting layer 210 is coated on the surface of the pressure-bearing layer to further improve the light transmittance and reduce laser scattering; the transparent window body 21 is embedded in the chamfered corner 12 of the window, and the middle is filled with adhesive 211 to achieve the initial sealing and positioning of the transparent window body 21 and the reactor vessel body 10; the soft filler 212 is placed between the transparent window body 21 and the window opening 13 to fill the gap between the two, further improve the sealing performance, and at the same time buffer thermal stress; the flange gasket 213 is placed in the sealing groove 200, and with the clamping force of the fixed flange, a third seal is formed; the adhesive 211, the soft filler 212 and the flange gasket 213 constitute a triple sealing structure to achieve zero leakage sealing under high temperature and high pressure conditions and ensure the stability of the monitoring environment.

[0043] Further, see Figure 2 Bolt 22 includes bolt post 220, bolt main bearing washer 221, and bolt copper ring washer 222. Bolt post 220 passes sequentially through bolt main bearing washer 221, bolt copper ring washer 222, and bolt opening 201 of window fixing flange 20 and is fastened to bolt groove 11. Bolt main bearing washer 221 is used to distribute the clamping force of bolt 22 and avoid uneven force on window fixing flange 20; bolt copper ring washer 222 further improves the fastening performance of bolt connection, prevents uneven force on fixing flange, ensures sealing reliability, and thus ensures the overall stability of monitoring device. At the same time, it facilitates the disassembly of bolt 22, realizing the detachable function of monitoring window assembly 2.

[0044] In this embodiment, the window fixing flange 20 is made of high-temperature resistant alloy material, the pressure-bearing layer of the window body 21 is made of ceramic material, and the bolt 22 is made of high-temperature resistant and high-strength alloy material.

[0045] An online monitoring method for surface oxides of materials inside a high-temperature, high-pressure reactor, comprising the following steps:

[0046] S1: Material installation and positioning: Place the material to be monitored 4 inside the high temperature and high pressure reactor 1, ensuring that the surface layer 40 of the material to be monitored corresponds to the inner convex surface of the window body 21, and the distance between the surface layer 40 of the material to be monitored and the inner end face of the window body 21 is controlled at 5-10mm. This distance is within the effective range of Raman laser confocal (<20mm), which can effectively avoid signal attenuation during laser propagation, ensure the strength and clarity of the Raman signal, and lay the foundation for accurate monitoring.

[0047] S2: Monitoring Component Debugging: Align the laser emitter and signal receiver of the Raman spectrometer probe 30 with the outer plane of the window body 21 of the high-temperature and high-pressure reactor 1. Adjust the incident angle of the Raman incident laser 301 to 0-15°. This angle can reduce the reflection loss of the laser on the window surface and ensure that the laser can stably penetrate the window. Focus the Raman incident laser 301 on the surface layer 40 of the material to be monitored. Set the detection parameters of the Raman spectroscopy monitoring component according to the monitoring requirements: laser power of 50-200mW, exposure time of 30-100s, and spectral resolution of 2-5cm. -1 The detection wavelength is selected as 532nm. This parameter combination can balance monitoring accuracy and material safety, and avoid damage to the material surface caused by excessive laser power.

[0048] S3: Start-up of test conditions: Start the high-temperature and high-pressure reactor 1, adjust the internal conditions of the high-temperature and high-pressure reactor to the preset parameters, simulate the actual corrosion environment such as the fusion water-cooled cladding, and start the corrosion test. Oxides will gradually form on the surface of the material to be monitored 40. During the test, the temperature and pressure inside the reactor are monitored in real time to ensure stable conditions (temperature fluctuation ≤ ±2℃, pressure fluctuation ≤ ±0.1MPa), providing stable environmental conditions for the growth of oxides on the material surface and Raman monitoring.

[0049] S4: Real-time acquisition of oxide signals: During the experiment, the Raman spectral signal of the oxide on the surface layer 40 of the material to be monitored is acquired in real time by the Raman spectrometer 3; the Raman incident laser 301 is incident on the oxide on the surface layer 40 of the material to be monitored through the outer plane of the window body 21; the Raman scattered laser 302 of the oxide returns along the original path and is output to the Raman spectrometer 3 through the window body 21; the triple sealing device maintains a sealed state throughout the process to prevent leakage of the medium inside the reactor and ensure experimental safety and monitoring accuracy;

[0050] S5: Signal Analysis and Monitoring: Analyze the acquired Raman spectral signals by identifying the characteristic Raman peaks of oxides (such as Fe3O4, Cr2O3, etc.). (The characteristic peak of Fe3O4 is located at 670 cm⁻¹.) -1 Nearby, the characteristic peak of Cr2O3 is located at 540 cm⁻¹. -1 (Nearby), calculate the peak position, peak width and peak area of ​​characteristic peaks, obtain the composition, thickness and growth rate of oxides in real time, and realize online monitoring of oxide growth on the surface of materials;

[0051] S6: End of Experiment and Accuracy Verification: After the experiment, close the high-temperature and high-pressure reactor 1. After the temperature and pressure inside the reactor drop to room temperature and pressure, take out the material to be monitored 4. Use offline detection methods (such as scanning electron microscopy, X-ray diffraction) to detect the composition and thickness of the oxide layer on the surface of the material. Compare the Raman online monitoring data with the offline detection data of the oxide layer on the surface of the material to verify the monitoring accuracy and ensure the reliability and practicality of the monitoring method of this invention. If the window body is worn, the light transmission performance decreases, or the sealing components age, the monitoring window assembly 2 can be removed by disassembling bolt 22, the damaged parts can be replaced, and the assembly can be reassembled and tightened before it can be put into use again.

[0052] Preferably, in step S5, the oxide thickness is calculated by the change in the peak area of ​​the characteristic peaks. The peak area and the oxide thickness are linearly positively correlated, with a linear correlation coefficient R²≥0.98 and a monitoring error ≤5%. The stress state of the oxide is analyzed by the peak position shift of the characteristic peaks. A red shift of the peak position indicates that the oxide has compressive stress, and a blue shift of the peak position indicates that the oxide has tensile stress.

[0053] Preferably, in step S1, the surface layer 40 of the material to be monitored corresponds to the inner convex surface of the window body 21, and the distance between the surface layer 40 of the material to be monitored and the inner end face of the window body 21 is controlled at 5-10mm.

[0054] Preferably, the material to be monitored 4 is a commonly used material for fusion water-cooled cladding, and the oxides to be monitored are oxides such as Fe3O4 and Cr2O3 generated by the corrosion of the material to be monitored 4 in a high-temperature and high-pressure water environment. The Raman spectroscopy monitoring component can capture the compositional changes and thickness growth patterns of the oxides in real time during the growth process.

[0055] The following uses a corrosion test of fusion water-cooled cladding material as an application scenario, simulating a high-temperature and high-pressure water environment of 330℃ and 16MPa. The online monitoring device and method for surface oxides of materials inside the high-temperature and high-pressure reactor of this invention are used to achieve online monitoring of the growth of surface oxides on CLF-1 steel. The specific implementation steps are as follows:

[0056] I. Preparation of Materials and Equipment

[0057] (1) Preparation of the window body 21: The pressure-bearing layer is made of sapphire material with a diameter of 25 mm, a thickness of 5 mm, and a Mohs hardness of 9.2. After polishing, the surface is free of scratches. The light-transmitting layer 210 is prepared by multiple coating processes with a thickness of 220 nm. It is attached to the inner side of the pressure-bearing layer and annealed at 400℃ for 2 h. The light transmittance at 532 nm wavelength is 96.3%, the reflectance is 0.3%, the salt water resistance (5% NaCl salt spray test for 72 h) shows no peeling, and the moisture resistance (60℃, 95% humidity) is stable for 1000 h without abnormalities. The window is processed into an arc structure with a curvature radius of 65 mm on the inner convex surface and a rounded corner radius of 2.5 mm on the edge of the convex surface. The inner surface of the light-transmitting layer is polished to Ra=0.03 μm to ensure stable laser transmission and meet the requirements of oxide monitoring.

[0058] (2) Preparation of sealing components: The soft filler 212 of the triple sealing device is made of high-purity gold wire with a purity of 99.995% and a wire diameter of 0.3mm. It is annealed at 300℃ and has a hardness of HV=28. The flange gasket 213 is made of OFHC oxygen-free copper (Cu=99.96%) with a thickness of 0.2mm. It is vacuum annealed at 400℃ for 2h and has a hardness of HV=75. The adhesive 211 is made of Cr2O3 / ZrO2 nanopowder modified aluminum phosphate-based inorganic high-temperature adhesive with a solid content of 96% and a curing temperature of 200℃. The shear strength of the adhesive with sapphire is 17MPa and the shear strength of the adhesive with the metal vessel is 22MPa. After curing, the density is 99.2% and the porosity is 0.4%, which ensures the reliability of the triple sealing structure.

[0059] (3) Bolt 22 and gasket preparation: Bolt 22 is made of Inconel 718 material, and the main bearing gasket 221 of the bolt is made of Inconel 718 nickel-based high temperature alloy gasket with a thickness of 0.8mm. It is subjected to solution and aging heat treatment (solution at 1050℃ for 1h, aging at 720℃ for 8h), with a hardness of HRC=35 and a surface roughness of Ra=1.2μm. The potential difference between the bolt 22 and the flange body and bolt 22 is ≤5mV, with no risk of galvanic corrosion. The bolt copper ring gasket 222 is made of OFHC oxygen-free copper gasket with a thickness of 0.4mm. It is subjected to vacuum annealing at 400℃ for 2h and has a hardness of HV=78. This ensures the tightness and sealing of the bolt 22 connection, and at the same time facilitates the disassembly of bolt 22, which is compatible with the detachable function of the monitoring window assembly 2.

[0060] (4) Equipment and material preparation: 1 high-temperature and high-pressure reactor (volume 1000mL, temperature resistance 400℃, pressure resistance 25MPa), 3 Raman spectrometers (detection wavelength 532nm, laser power range 0-500mW, spectral resolution 2cm). -1The equipment used included a scanning electron microscope (SEM, 10,000x magnification) and an energy dispersive spectroscopy (EDS). The material to be monitored, 4, was CLF-1 steel, processed into a sheet of 10mm×10mm×3mm. The surface was ground and polished to Ra=0.02μm, cleaned and dried before use to ensure that the surface of the material was free of impurities and would not affect the oxide monitoring.

[0061] II. Assembly of monitoring devices.

[0062] (1) First, clean the window mounting groove of the reactor body 10 of the high temperature and high pressure reactor 1 to ensure that there are no impurities or scratches. Apply the adhesive 211 evenly to the window mounting groove of the reactor body with a thickness of 0.5 mm. Then, embed the prepared window body 21 into the mounting groove, ensuring that the arc-shaped bottom surface of the window body 21 is tightly attached to the adhesive 211. Then, place it in a 200℃ oven for 2 hours to cure and complete the bottom bonding and sealing, laying the foundation for the sealing performance of the monitoring device.

[0063] (2) Place the soft filler 212 around the side edge of the window body 21 and the radial gap between the window chamfer 12 of the reactor body 10, and gently press to make the soft filler 212, i.e. the gold wire coil, completely fill the gap to achieve radial sealing; then place the flange gasket 213 on the outer end face of the window to ensure that the flange gasket 213 fits tightly with the window and the window fixing flange 20 to further improve the sealing performance.

[0064] (3) Cover the outside of the window body 21 with the window fixing flange 20, and install the bolt main bearing gasket 221 and bolt copper ring gasket 222 in sequence. Tighten the bolts 22 evenly in the bolt groove 11 of the reactor body 10. The pre-tightening force is controlled at 800N to ensure that the sealing surface is subjected to uniform force and avoid stress concentration in the window. The assembly of the entire monitoring window assembly 2 and the sealing device is completed. At this time, the adhesive 211, soft filler 212 and flange gasket 213 form a triple sealing structure to achieve zero leakage sealing. Finally, install the Raman spectrometer 3 and align the Raman spectrometer probe 30 with the outer plane of the window body 21 to complete the assembly of the entire monitoring device. The assembly process is simple and convenient, and the monitoring window assembly can be disassembled and maintained by removing the bolts.

[0065] III. Monitoring Methods and Operations

[0066] (1) Material placement: Place the material to be monitored 4 in the high temperature and high pressure reactor 1, adjust the material position so that the surface layer 40 of the material to be monitored corresponds to the inner convex surface of the window body 21, and control the distance between the surface layer 40 of the material to be monitored and the inner end face of the window body 21 to 8 mm. After fixing the material, inject deionized water (simulating the water-cooled coating environment of fusion) into the high temperature and high pressure reactor 1, and remove the air in the reactor to avoid the air from interfering with the corrosion test and Raman monitoring, and ensure the stability of the oxide generation environment.

[0067] (2) Equipment debugging: Align the laser emitter and signal receiver of Raman spectrometer 3 with the outer plane of the window, adjust the laser incident angle to 8°, focus on the surface of the material to be monitored at 40°, and set the detection parameters: laser power 100mW, exposure time 60s, spectral resolution 2cm -1 The detection wavelength is 532nm. The instrument is preheated for 30 minutes to ensure stable operation. The laser can stably penetrate the transparent window body 21, and the scattered signal can be effectively received.

[0068] (3) Test start-up: Start the high temperature and high pressure reactor 1, turn on the heating system, and heat up to 330℃ at a rate of 5℃ / min. At the same time, pressurize to 16MPa. After the working conditions are stable, start the corrosion test. The test cycle is 720h. During the test, monitor the temperature and pressure inside the reactor in real time to ensure that the temperature fluctuation is ≤±2℃ and the pressure fluctuation is ≤±0.1MPa. The triple sealing device is leak-free throughout the process to ensure the safety of the test and the stability of the monitoring environment.

[0069] (4) Signal acquisition: During the experiment, the Raman spectrum signal of the oxide on the surface layer 40 of the material to be monitored was acquired every 24 hours by the Raman spectrometer 3. Three sets of data were collected each time and the average value was taken. After the Raman incident laser 301 was incident through the window body 21, it passed through the pressure layer and the light-transmitting layer 210 in sequence and irradiated the oxide on the surface layer 40 of the material to be monitored. The Raman scattered laser 302 returned to the Raman spectrometer 3 along the original path. The acquired spectral signal was clear and there was no obvious stray light interference, which ensured the accuracy of the monitoring data.

[0070] (5) Data analysis: The collected Raman spectral signals were analyzed, and the characteristic peak of Fe3O4 (670 cm⁻¹) was identified. -1 The characteristic peaks of Cr2O3 (near) and Cr2O3 (540 cm⁻¹) -1 Near the target area, the oxide thickness and growth rate were obtained in real time by calculating the peak area and combining it with a standard curve (linear correlation coefficient R² = 0.985). In the initial stage of the experiment (0-240h), the oxide grew rapidly, with the thickness increasing from 0 to 1.2μm, and the growth rate was 5×10⁻⁶. -3 μm / h; in the later stages (240-720h), oxide growth tended to plateau, eventually reaching a thickness of 2.8 μm, and the growth rate decreased to 2.2 × 10⁻⁶. -3 μm / h; Peak shift analysis showed that the characteristic peak of Fe3O4 was red-shifted by 2 cm. -1 This indicates that the oxide exhibits slight compressive stress, providing crucial data for the study of material corrosion mechanisms.

[0071] (6) Accuracy verification: After the test, the high temperature and high pressure reactor 1 was closed and cooled to room temperature at a rate of 3℃ / min. The pressure was slowly released to normal pressure, and the material to be monitored 4 was taken out. The surface oxide morphology of the material was observed by SEM and the oxide composition was detected by EDS. The results showed that the main oxide components were Fe3O4 and Cr2O3, and the measured thickness was 2.75μm. The error between the measured thickness and the Raman online monitoring data (2.8μm) was 1.8%, which was less than 5%, thus verifying the accuracy and reliability of the monitoring device and method of the present invention. After the test, if it is necessary to maintain the window or sealing component, the bolt 22 can be removed, the monitoring window assembly 2 can be taken off, the component can be replaced and then reassembled. The operation is convenient.

[0072] In this embodiment, the pressure-bearing layer of the transparent window body 21 can also be made of magnesium aluminum spinel ceramic material, the flange gasket 213 can be made of metal C-ring, the bolt 22 can be made of Hastelloy material, and the parameters of the Raman spectrometer 3 can be adjusted according to actual monitoring needs, all of which do not affect the implementation effect of the present invention.

[0073] This invention optimizes the overall structure of the monitoring device, the material and installation method of the monitoring window, and combines a triple sealing device to achieve zero-leakage sealing under high temperature and high pressure conditions. It enables accurate and stable online monitoring of the growth of oxides on the surface of materials inside the reactor, expands the protection range of the device, and is designed as a detachable structure for easy maintenance and replacement. It provides a reliable monitoring method for high temperature and high pressure corrosion tests such as fusion water-cooled blankets.

[0074] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention. The above embodiments are provided only for the purpose of describing the present invention and are not intended to limit the present invention. Parts not described in detail in this specification are well-known in the art and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims. All equivalent substitutions and modifications made without departing from the spirit and principle of the present invention should be covered within the scope of the present invention.

Claims

1. An online monitoring device for surface oxides of materials inside a high-temperature, high-pressure reactor, characterized in that, Including the monitoring window assembly and the Raman spectroscopy monitor; The high-temperature and high-pressure reactor has a window opening on its vessel body, and the monitoring window assembly is a detachable structure. The monitoring window assembly includes a window component, a window fixing flange, and bolts. The window component is fixed to the window opening by the window fixing flange and bolts. The Raman spectrometer is located on the outside of the reactor body. The Raman incident laser emitted by the Raman spectrometer passes through the monitoring window assembly and irradiates the surface of the material to be monitored. The Raman scattered laser generated by the oxide on the surface of the material to be monitored passes through the monitoring window assembly and is received by the Raman spectrometer, thereby realizing online monitoring of the oxide on the surface of the material inside the high-temperature and high-pressure reactor.

2. The online monitoring device for surface oxides of materials inside a high-temperature and high-pressure reactor according to claim 1, characterized in that, The window fixing flange includes a flange body, a sealing groove, and a bolt opening. The sealing groove is located at the connection position between the flange body and the window assembly. The bolt opening corresponds to the bolt groove of the reactor body. The bolt passes through the bolt opening and is fastened in the bolt groove, which is located on the outside of the reactor body.

3. The online monitoring device for surface oxides of materials inside a high-temperature and high-pressure reactor according to claim 2, characterized in that, The window assembly includes a window body, a flexible filler, and a flange gasket. The flexible filler is used to fill the installation gap between the window body and the window opening, and the flange gasket is located in the sealing groove.

4. The online monitoring device for surface oxides of materials inside a high-temperature and high-pressure reactor according to claim 3, characterized in that, A chamfered window is provided on the inner side of the reactor body to match the window body. The window body is embedded in the chamfered window, and an adhesive is provided between the chamfered window and the window body. The adhesive, soft filler and flange gasket constitute a triple sealing structure.

5. The online monitoring device for surface oxides of materials inside a high-temperature and high-pressure reactor according to claim 4, characterized in that, The transparent window body includes a pressure-bearing layer and a light-transmitting layer, wherein the light-transmitting layer is coated on the surface of the pressure-bearing layer.

6. The online monitoring device for surface oxides of materials inside a high-temperature and high-pressure reactor according to claim 5, characterized in that, The bolt consists of a bolt post, a bolt main bearing washer, and a bolt copper ring washer. The bolt post passes through the bolt main bearing washer, the bolt copper ring washer, and the bolt opening of the window fixing flange in sequence and is fastened to the bolt groove.

7. The online monitoring device for surface oxides of materials inside a high-temperature and high-pressure reactor according to claim 6, characterized in that, The window fixing flange is made of high-temperature resistant alloy material, the pressure-bearing layer of the window body is made of ceramic material, and the bolts are made of high-temperature resistant and high-strength alloy material.

8. A method for online monitoring of surface oxides on materials inside a high-temperature, high-pressure reactor, characterized in that, The online monitoring device for surface oxides of materials inside a high-temperature and high-pressure reactor as described in any one of claims 1 to 7 comprises the following steps: S1: Place the material to be monitored inside a high-temperature and high-pressure reactor; S2: Align the laser emitter and signal receiver of the Raman spectrometer with the outer plane of the window body of the high-temperature and high-pressure reactor, adjust the incident angle of the Raman incident laser, focus on the surface of the material to be monitored, and set the detection parameters of the Raman spectrometer. S3: Start the high-temperature and high-pressure reactor, adjust the internal conditions of the high-temperature and high-pressure reactor to the preset parameters, simulate the actual corrosion environment such as the fusion water-cooled blanket, and start the corrosion test. Oxides are gradually generated on the surface of the material to be monitored. S4: During the experiment, the Raman spectral signal of the oxide on the surface of the material to be monitored is collected in real time by a Raman spectrometer. The Raman incident laser is incident on the oxide on the surface of the material to be monitored, and the Raman scattered laser of the oxide returns along the original path and is output to the Raman spectrometer. S5: Analyze the collected Raman spectral signals, identify the characteristic Raman peaks of the oxides, calculate the peak position, peak width and peak area of ​​the characteristic peaks, and obtain the composition, thickness and growth rate of the oxides in real time to realize online monitoring of oxide growth on the surface of the material to be monitored. S6: After the test, close the high-temperature and high-pressure reactor. After the temperature and pressure inside the reactor drop to normal temperature and pressure, take out the material to be monitored.

9. The method for online monitoring of surface oxides of materials inside a high-temperature and high-pressure reactor according to claim 8, characterized in that, In step S5, the oxide thickness is calculated by the change in the peak area of ​​the characteristic peak. The peak area and the oxide thickness are linearly positively correlated, with a linear correlation coefficient R²≥0.98 and a monitoring error ≤5%. The stress state of the oxide is analyzed by the peak position shift of the characteristic peak. A red shift of the peak position indicates that the oxide has compressive stress, and a blue shift of the peak position indicates that the oxide has tensile stress.

10. The method for online monitoring of surface oxides of materials inside a high-temperature and high-pressure reactor according to claim 8, characterized in that, In step S1, the surface of the material to be monitored corresponds to the inner convex surface of the window body, and the distance between the surface of the material to be monitored and the inner end face of the window body is controlled at 5-10mm.

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