A method and device for inverting divertor heat flow based on laser speckle image

Abstract

The present invention provides a method and device for inverting the heat flow of a divertor based on laser speckle images, and belongs to the technical field of thermal hydraulic testing of nuclear fusion engineering. The device includes a fusion reactor high heat flow simulation loading system, a laser speckle effect testing system, a divertor water cooling simulation system, and a test database system. By adjusting the cooling water flow conditions of the divertor specimen, performing a series of high heat flow loading on the divertor, and measuring the divertor using laser speckle digital correlation technology, a database corresponding to the heat flow of the divertor target plate and the strain of the loading surface is established. In actual reactor applications, the surface strain of the same component in the reactor is measured by laser speckle technology, and the loading heat flow inversion is realized by corresponding query database. The present invention adopts the above-mentioned method and device for inverting the heat flow of a divertor based on laser speckle images, realizes the quantitative inversion of the divertor loading heat flow in the actual fusion reactor service environment, and improves the safety of the operation of the nuclear fusion reaction device.

Description

Technical Field

[0001] The invention relates to the technical field of thermal hydraulic testing of nuclear fusion engineering, and in particular to a method and a device for inverting divertor heat flow based on laser speckle images. Background Art

[0002] In a nuclear fusion reactor, the divertor is a crucial component that is responsible for discharging high-energy particles and heat generated by the reaction to protect the rest of the reaction chamber from damage. In order to accurately understand the distribution of the loading heat flux of the divertor during operation, researchers need to develop a loading heat flux inversion method.

[0003] The actual environment of fusion reactors is extremely complex, and the experimental cost is high. It is difficult to directly measure the actual heat flux loading on the divertor by discharge. The existing divertor loading heat flux test method mainly relies on infrared measurement technology, and the loading heat flux is inferred by measuring the temperature data on the divertor surface. However, this method has significant defects and shortcomings. First, the accuracy of infrared temperature measurement is affected by many factors, such as the emissivity of the object surface, the observation angle, the ambient temperature, and the transmittance of the optical system. Changes in these factors may cause large errors in the infrared temperature measurement results, thereby reducing the accuracy of the loading heat flux calculation. In addition, the infrared temperature measurement method is also difficult to cope with some special working environments, such as extreme conditions such as high temperature, high pressure or strong radiation. Under these environments, the performance and stability of the infrared temperature measurement equipment may be seriously affected, making the measurement results even more unreliable. Therefore, developing a more accurate, reliable and adaptable divertor loading heat flux inversion method is of great significance to improving the safety and efficiency of nuclear fusion reaction devices. Summary of the invention

[0004] The purpose of the present invention is to propose a method and device for inverting the heat flow of a divertor based on laser speckle images. The basic principle is that for a divertor of a certain structure, under similar environmental conditions, there is a corresponding relationship between its surface deformation and the loaded heat flow. By simulating the loading platform in a high heat flow environment in service, the corresponding surface strain data within the service water flow pressure, temperature, and flow rate range are generated, and the relationship between the surface strain and the corresponding heat flow is established through a database. Under actual reactor environmental conditions, the actual measured strain data is used as input, and the loaded heat flow is inverted by the relationship between the surface strain and the corresponding heat flow. The technology of the present invention realizes the accurate inversion of the loaded heat flow of the divertor, thereby improving the safety and efficiency of the nuclear fusion reaction device.

[0005] To achieve the above object, the present invention provides a method for inverting divertor heat flow based on laser speckle image, comprising the following steps:

[0006] Step S1, fixing the divertor specimen on the loading platform of the fusion reactor high heat flux simulation loading system so that the divertor specimen is located in the heat flux loading scanning area;

[0007] Step S2, starting the heat exchanger, adjusting the cooling water flow inside the divertor specimen to reach the service temperature range of the divertor, such as room temperature to 120° C., then starting the magnetic pump, and again adjusting the cooling water flow velocity inside the divertor specimen to reach the service condition range, such as 5 to 10 m / s. At the same time, it is also necessary to adjust the pressure of the cooling water flow to reach the pressure range of the divertor when it is in service, such as 1 to 4 MPa;

[0008] Step S3, adjusting the angle between the laser and the horizontal surface of the loading platform, then irradiating the divertor specimen, and obtaining a laser speckle cloud image through a camera;

[0009] Step S4: subjecting the surface of the divertor specimen to periodic high heat flux loading of different intensities, such as 0.5-20 MW / m 2 ;

[0010] The precise loading heat flux can be obtained by two methods: one is to arrange thermocouples inside the divertor specimen for measurement; the other is to calibrate the surface absorption coefficient and then calculate it based on the electron beam output power and scanning area.

[0011] Step S5, using DIC software to calculate and process the laser speckle cloud image to obtain a series of cooling water temperature, flow rate, pressure and strain data under the condition of loading heat flow;

[0012] Step S6, extracting data and establishing a strain database of the divertor target plate loading surface of the divertor specimen under different cooling water temperatures, flow rates, pressures, and different loading heat flows;

[0013] Step S7, fitting the strain database of the divertor target plate loading surface to obtain the relationship between the loading heat flow and the strain under a series of cooling water temperature, flow rate, pressure, and loading cycle (considering fatigue effect), and integrating it into the test software algorithm;

[0014] Step S8, for the actual fusion reactor service environment, considering the actual service conditions with known cooling water temperature, flow rate, pressure, loading cycle and unknown loading heat flux, repeat step S5 to obtain the current strain data, and obtain the radiation loading heat flux on the current divertor surface by searching the divertor target plate loading surface strain database and using multi-dimensional interpolation calculation.

[0015] Preferably, the laser is a single-mode laser with an operating wavelength of 355-780 nm.

[0016] Preferably, the camera is equipped with an ultra-narrow band filter.

[0017] Preferably, the angle between the laser and the horizontal surface of the loading platform is 30-60°.

[0018] The present invention also provides a device for implementing the above-mentioned method of inverting divertor heat flow based on laser speckle image, comprising a laser speckle effect test system, a fusion reactor high heat flow simulation loading system, a divertor water cooling simulation system and a test database system;

[0019] Among them, the fusion reactor high heat flux simulation loading system is used to generate the actual service heat flux environment;

[0020] The laser speckle effect test system is used to adjust the relative position and angle of the laser, camera and loading platform;

[0021] The divertor water cooling simulation system is used to monitor and adjust the cooling water flow temperature, flow rate and pressure inside the divertor specimen in real time;

[0022] The test database system is used to preprocess, extract features and analyze data of laser speckle images to obtain strain data of divertor specimens under different conditions and establish a corresponding database.

[0023] Preferably, the laser speckle effect testing system comprises a camera and a laser arranged on both sides of the electron gun, the laser irradiates the divertor test piece through one observation window, and the camera receives the laser speckle cloud image through another observation window.

[0024] Therefore, the present invention adopts the above-mentioned method and device for inverting the heat flow of the divertor based on the laser speckle image, and the beneficial technical effects are as follows:

[0025] The actual environment of a fusion reactor is extremely complex and the experimental cost is high. It is difficult to directly measure the actual heat flow loading on the divertor by discharge. The existing infrared measurement technology has large errors and can only obtain the surface temperature, and cannot directly measure the heat flow. Ordinary digital correlation technology is difficult to deal with the problem of spotting under extreme conditions, and cannot directly measure the surface strain of the divertor, so it is impossible to invert the heat flow of the divertor components. The technology of the present invention can achieve accurate inversion of the heat flow loaded on the divertor, thereby improving the safety and efficiency of the nuclear fusion reaction device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of a device for a method of inverting divertor heat flow based on laser speckle image according to the present invention;

[0027] Figure 2 Schematic diagram of the heat flow calibration specimen structure and thermocouple position.

[0028] Reference numerals

[0029] 1. Magnetic pump; 2. Heat exchanger; 3. Vortex flowmeter; 4. Inlet valve; 5. Inlet thermometer; 6. Inlet pressure gauge; 7. Outlet pressure gauge; 8. Outlet thermometer; 9. Outlet valve; 10. Camera; 11. Computer; 12. Observation window; 13. Electron gun; 14. Laser; 15. Divertor specimen; 16. Loading platform; 17. Mechanical pump three; 18. Molecular pump two; 19. Water reservoir; 20. Vacuum box cooling pipe; 21. Lead room; 22. Electron beam; 23. Vacuum box; 24. Mechanical pump two; 25. Pulley; 26. Horizontal platform surface; 27. Clamping arm; 28. Molecular pump one; 29. ​​Mechanical pump one; 30. Thermocouple. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0031] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0032] Embodiment 1

[0033] like Figure 1 As shown, a device for a method of inverting divertor heat flow based on laser speckle images of the present invention includes a laser speckle effect test system, a fusion reactor high heat flow simulation loading system, a divertor water cooling simulation system and a test database system.

[0034] The laser speckle effect testing system is used to adjust the relative position and angle of the laser 14 , the camera 10 and the loading platform 16 .

[0035] The laser speckle effect test system is the core part of the device, which is mainly composed of a camera 10 and a laser 14. The laser 14 accurately illuminates the divertor specimen 15 through an observation window 12 on one side, while the camera 10 captures the cloud pattern formed by the laser speckle through the observation window 12 on the other side.

[0036] The fusion reactor high heat flux simulation loading system is used to generate the actual service heat flux environment. The system includes an electron gun 13, which is responsible for emitting an electron beam 22 to provide high heat flux loading. To ensure the purity of the test environment, the system is also equipped with a molecular pump 28 and a mechanical pump 29 for vacuuming. The vacuum box 23 is the main part of the test environment, and a loading platform 16 is arranged inside it to carry the divertor specimen 15. The loading platform 16 is not only stable and reliable, but also equipped with a pulley 25 for easy movement and adjustment, while two clamping arms 27 ensure that the specimen is firmly fixed. In addition, the vacuum box 23 also achieves more efficient vacuuming through a molecular pump 2 18 and a mechanical pump 3 17 to ensure the extremely low air pressure conditions of the test environment.

[0037] The divertor water cooling simulation system is used to monitor and adjust the cooling water flow temperature, flow rate and pressure inside the divertor specimen in real time.

[0038] The water circulation system of the divertor water cooling simulation system is responsible for regulating the cooling water flow inside the divertor specimen 15 to ensure temperature control during the test. The water reservoir 19 is connected to the vacuum box 23 through the vacuum box cooling pipe 20, and the mechanical pump 24 is responsible for the vacuum pumping of the pipe. At the other end of the cooling water circulation system, a vortex flowmeter 3, an inlet valve 4, an inlet thermometer 5, and an inlet pressure gauge 6 are arranged in sequence between the heat exchanger 2 and the inlet of the divertor specimen 15, and a magnetic pump 1, an outlet valve 9, an outlet thermometer 8, and an outlet pressure gauge 7 are arranged in sequence between the heat exchanger 2 and the outlet of the divertor specimen 15.

[0039] The test database system is used to preprocess, extract features and analyze data of laser speckle images to obtain strain data of divertor specimens under different conditions and establish a corresponding database.

[0040] The test database system is provided with a computer 11, which is connected to the camera 10 to realize real-time data transmission and processing. In addition, the system is also equipped with background processing software and a strain database of the divertor target plate loading surface for storing and analyzing test data, thereby obtaining strain data of the divertor specimen under different conditions.

[0041] Embodiment 2

[0042] The present invention provides a method for inverting divertor heat flow based on laser speckle images, the method comprising the following steps:

[0043] Step S1, fixing the divertor specimen 15 on the loading platform 16 of the fusion reactor high heat flux simulation loading system, so that the divertor specimen 15 is located in the heat flux loading scanning area;

[0044] Step S2, starting the heat exchanger, adjusting the cooling water flow inside the divertor specimen 15 to reach the service temperature range of the divertor, such as room temperature to 120° C., then starting the magnetic pump 1, and again adjusting the cooling water flow velocity inside the divertor specimen 15 to reach the service condition range, such as 5 to 10 m / s. At the same time, it is also necessary to adjust the pressure of the cooling water flow to reach the pressure range of the divertor when it is in service, such as 1 to 4 MPa;

[0045] Step S3, adjusting the angle between the laser 14 and the horizontal surface of the loading platform 16, then irradiating the divertor specimen 15, and obtaining the laser speckle cloud image through the camera 10;

[0046] Step S4: subjecting the surface of the divertor specimen to periodic high heat flux loading of different intensities, such as 0.5-20 MW / m 2 ;

[0047] Step S5, using DIC software to calculate and process the laser speckle cloud image to obtain a series of cooling water temperature, flow rate, pressure and strain data under the condition of loading heat flow;

[0048] Step S6, extracting data and establishing a strain database of the divertor target plate loading surface of the divertor specimen 15 under different cooling water temperatures, flow rates, pressures, and different loading heat flows;

[0049] Step S7, fitting the strain database of the divertor target plate loading surface to obtain the relationship between the loading heat flow and the strain under a series of cooling water temperature, flow rate, pressure, and periodic loading (considering fatigue effect) conditions, and integrating it into the test software algorithm;

[0050] Step S8, for the actual fusion reactor service environment, considering the actual service conditions with known cooling water temperature, flow rate, pressure, loading cycle and unknown loading heat flux, repeat step S5 to obtain the current strain data, and obtain the radiation loading heat flux on the current divertor surface by searching the divertor target plate loading surface strain database and using multi-dimensional interpolation calculation.

[0051] Since different materials have different absorption rates to the electron beam 22, in order to determine the absorption coefficient of the specimen to the electron beam 22, a calibration experiment should be carried out on the specimen before the formal experiment, so as to obtain the relationship between the internal heat flow of the specimen and the loaded heat flow, to ensure that the specimen will not be damaged due to excessive loaded heat flow during the formal experiment.

[0052] The schematic diagram of the calibration specimen is as follows: Figure 2 As shown, the aperture of the thermocouple 30 is 0.6 mm, and the distance between the two thermocouples is , the depth of the thermocouple 30 inserted into the specimen is half of the specimen thickness, that is, , is the thickness of the specimen. The heat flow calculation formula inside the specimen is:

[0053] ;

[0054] in, , are the temperatures of the upper and lower thermocouples, is the distance between the two thermocouples, is the thermal conductivity of the specimen.

[0055] Absorption coefficient The calculation formula is:

[0056] ;

[0057] in, is the accelerating voltage; is the loading current; is the specimen absorption rate; is the loading area.

[0058] In formal experiments, Determine the internal heat flow of the specimen to avoid damage to the specimen. is the input current;

[0059] .

[0060] It is worth noting that the contents not elaborated in detail in the present invention are all prior art and are well known to those skilled in the art.

[0061] Therefore, the present invention adopts the above-mentioned method and device for inverting the divertor heat flow based on laser speckle image, which solves the problem that the existing infrared measurement technology has large errors and is difficult to cope with extreme conditions. Through this technology, accurate inversion of the heat flow inside the divertor can be achieved, thereby improving the safety and efficiency of the nuclear fusion reaction device.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for inverting divertor heat flow based on laser speckle image, characterized in that: The following steps are involved: Step S1, fixing the divertor specimen on the loading platform of the fusion reactor high heat flux simulation loading system so that the divertor specimen is located in the heat flux loading scanning area; Step S2, starting the heat exchanger, adjusting the cooling water flow inside the divertor specimen to reach the divertor service temperature range, then starting the magnetic pump, again adjusting the cooling water flow rate inside the divertor specimen to reach the service condition range, and at the same time adjusting the pressure inside the divertor specimen to reach the divertor service pressure range; Step S3, adjusting the angle between the laser and the horizontal surface of the loading platform, then irradiating the divertor specimen, and obtaining a laser speckle cloud image through a camera; Step S4, performing high heat flux periodic loading of different intensities on the surface of the divertor specimen; Step S5, using DIC software to calculate and process the laser speckle cloud image to obtain a series of cooling water temperature, flow rate, pressure and strain data under the condition of loading heat flow; Step S6, extracting data and establishing a strain database of the divertor target plate loading surface of the divertor specimen under different cooling water temperatures, flow rates, pressures, and different loading heat flows; Step S7, fitting the strain database of the divertor target plate loading surface to obtain the relationship between the loading heat flow and the strain under a series of cooling water temperature, flow rate, pressure, and loading cycle conditions; Step S8, for the actual fusion reactor service environment, considering the actual service conditions with known cooling water temperature, flow rate, pressure, loading cycle and unknown loading heat flux, repeat step S5 to obtain the current strain data, and obtain the radiation loading heat flux on the current divertor surface by searching the divertor target plate loading surface strain database and using multi-dimensional interpolation calculation.

2. The method for inverting divertor heat flow based on laser speckle image according to claim 1, characterized in that: The laser is a single-mode laser with an operating wavelength of 355~780nm.

3. The method for inverting divertor heat flow based on laser speckle image according to claim 1, characterized in that: The camera is equipped with an ultra-narrow band filter.

4. The method for inverting divertor heat flow based on laser speckle image according to claim 1, characterized in that: The angle between the laser and the horizontal surface of the loading platform is 30~60°.

5. A device for implementing the method for inverting divertor heat flow based on laser speckle image according to any one of claims 1 to 4, characterized in that: Including laser speckle effect test system, fusion reactor high heat flux simulation loading system, divertor water cooling simulation system and test database system; Among them, the fusion reactor high heat flux simulation loading system is used to generate the actual service heat flux environment; The laser speckle effect test system is used to adjust the relative position and angle of the laser, camera and loading platform; The divertor water cooling simulation system is used to monitor and adjust the cooling water flow temperature, flow rate and pressure inside the divertor specimen in real time; The test database system is used to preprocess, extract features and analyze data of laser speckle images to obtain strain data of divertor specimens under different conditions and establish a corresponding database.

6. The device for inverting divertor heat flow based on laser speckle image according to claim 5, characterized in that: The laser speckle effect test system includes a camera and a laser arranged on both sides of the electron gun. The laser irradiates the divertor specimen through an observation window, and the camera receives the laser speckle cloud image through another observation window.

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