A temperature strain measuring device during solidification of liquid metal

Abstract

The present application belongs to the technical field of liquid metal cooled nuclear reactor measurement, and relates to a temperature and strain measurement device in the solidification process of liquid metal, which can measure the temperature and strain data change rule in the solidification process of liquid metal by measuring the deformation of the cavity inner wall of different materials under temperature change, and the main structure comprises a first cavity, a second cavity, a third cavity, a first capillary and a second capillary, the bottom of the measurement instrument body is composed of two hemispherical cavities closely attached together, the first capillary and the second capillary are respectively connected above the first and second cavities, the instrument container contains liquid metal, the test sample is immersed in the liquid metal, and in the solidification process of the liquid metal, the outer wall of the third cavity absorbs the shrinkage deformation in the solidification process of the liquid metal, so that the temperature strain change value in the solidification process of the liquid metal can be accurately measured; the overall structure is scientific and reasonable, easy to use, has good high-temperature resistance effect, high measurement precision and long service life.

Description

Technical fields:

[0001] This invention belongs to the field of temperature measurement technology in liquid metal cooled nuclear reactors, and relates to a device that uses different cavities and cavity inner walls made of different materials to measure the temperature and strain data changes during the solidification process of liquid metal by measuring the deformation under temperature changes. In particular, it relates to a temperature and strain measurement device during the solidification process of liquid metal. Background Technology

[0002] Nuclear energy, as a clean energy source, has broad development prospects. Developed countries such as Russia and the United States have begun to develop fourth-generation nuclear reactor systems, and the construction technology of fast neutron reactors using liquid metal cooling is receiving much attention from the industry. Liquid metal-cooled reactors have advantages such as compact reactor design and small size, good thermal conductivity, high thermal efficiency, high power, natural circulation, and low noise. In the application of liquid metal-cooled nuclear reactors, the reactor coolant must be kept in a liquid state and cannot solidify during normal operation. If the liquid metal solidifies, the reactor core cannot be cooled, ultimately leading to the reactor core meltdown. Therefore, accurately measuring the temperature and strain data changes during the solidification process of liquid metal is crucial for evaluating the integrity of liquid metal-cooled nuclear reactors. Currently, the commonly used strain measurement device is the strain gauge. Ordinary waterproof strain gauges use waterproof adhesives, epoxy resins, etc., as waterproof coatings. During the solidification process of liquid metal, the waterproof coating is not resistant to high temperatures. The strain gauge itself and its connecting wires are affected by the high-temperature liquid metal, and their deformation state and electrical insulation properties are severely damaged, making it impossible to accurately measure the strain state during the solidification process of liquid metal.

[0003] In the prior art, Chinese patent CN201110350598.3 discloses a pressure sensor for a liquid sodium experimental circuit, including a sodium inlet pipe, an elastic strain gauge, a sodium-sodium-potassium alloy pressure sensing box, a sodium-potassium alloy-air pressure sensor, and a pressure gauge. The sodium inlet pipe is connected to the main pipeline, allowing liquid sodium to enter the sodium-sodium-potassium alloy pressure sensing box. An elastic strain gauge is located in the center of the pressure sensing box, with liquid sodium and liquid sodium-potassium alloy on either side. The liquid sodium-potassium alloy enters the sodium-potassium alloy-air pressure sensor through a pipeline, where the pressure signal is converted into an electrical signal. The converted electrical signal is displayed by the pressure gauge. This technology employs a two-stage sensing system. The bridge circuit of the sodium-potassium alloy-air pressure sensor uses a temperature compensation circuit to prevent sodium from coming into contact with air, making it suitable for measurements in small- to medium-scale liquid sodium experiments.

[0004] Chinese patent CN201710060210.3 discloses a fatigue strain measurement device and system suitable for high-temperature liquid metal media. This device is applicable to measuring test samples in high-temperature liquid metal media. Its key feature is that the fatigue strain measurement device includes a first crossbeam support and a second crossbeam support separately and fixedly connected between the gauge lengths of the test sample; a mounting frame fixedly installed on the first crossbeam support; a displacement sensor fixedly installed on the mounting frame; and an extension rod with one end connected to the displacement sensor and the other end fixedly connected to the second crossbeam support. The deformation displacement of the test sample is directly transmitted to the displacement sensor through the first and second crossbeam supports, thus directly obtaining the measurement data without the need for multiple tedious calibrations.

[0005] Chinese patent CN202111003477.1 discloses a dual-modal flexible sensor for measuring temperature and strain, and its fabrication method. The sensor includes two flexible substrates on the outermost side, with strain-sensitive materials attached to their outer surfaces and electrodes covering their inner surfaces. A dielectric material layer is sandwiched between the electrodes. The flexible substrates are flexible thin films and are non-conductive. This dual-modal flexible sensor utilizes the change in resistance of the strain-sensitive material with strain and the changes in the dielectric constant ε and thickness d of the dielectric material with temperature to achieve dual-modal measurement of temperature and strain. Furthermore, this dual-modal flexible sensor has a simple structure, is easy and efficient to fabricate and use, has a wide temperature range (20–200℃) and a strain range (0–2000 με), and high measurement accuracy (temperature measurement error approximately 4.44% and strain measurement error approximately 6.5%). It can be applied to the detection of tire pressure and temperature in automobiles.

[0006] However, the aforementioned methods for measuring the strain of liquid metal all suffer from high-temperature intolerance, severely damaging the structural deformation state and electrical insulation properties, and failing to accurately measure the strain state during the solidification process of liquid metal. Therefore, it is necessary to design a device that can withstand high temperatures and uses different cavities and cavity inner walls made of different materials to measure the temperature and strain data changes during the solidification process of liquid metal by measuring the deformation under temperature variations. This device can overcome the shortcomings of existing technologies, accurately measure the temperature and strain data of liquid metal during the solidification process, and improve the feasibility of application. Summary of the Invention:

[0007] The purpose of this invention is to overcome the shortcomings of existing technologies. Based on improvements to existing devices for measuring the temperature and strain of liquid metal during the smelting process, this invention designs a device that can withstand high temperatures and uses different cavities and cavity inner walls made of different materials to measure the temperature and strain data changes during the solidification process of liquid metal by measuring the deformation data under temperature variations. This solves the problems of existing liquid metal strain measurement techniques, which are not heat-resistant, severely damage the deformation state and electrical insulation properties of the structure, and cannot accurately measure the strain state during the solidification process of liquid metal.

[0008] To achieve the above objectives, the present invention relates to a temperature strain measuring device during the solidification process of liquid metal. Its main structure includes a first cavity, a second cavity, a third cavity, a first capillary tube, and a second capillary tube. The bottom of the measuring device body consists of two hemispherical cavities of identical size and shape, tightly fitted together. The left hemispherical cavity is the first cavity, and the right hemispherical cavity is the second cavity. A contact surface separates the first and second cavities. The first and second cavities are respectively connected to the first capillary tube and the second capillary tube in an upward, parallel direction to the contact surface. The capillaries have equal inner diameters and are tightly attached to each other. Their contact surfaces are on the same plane as the contact surfaces between the first and second cavities and are connected to each other to form a contact surface structure. The contact surface structure is made of a low-expansion metal material. The hemispherical outer wall of the first cavity is made of an elastic metal material, and the hemispherical outer wall of the second cavity is made of a hollow low-expansion metal material. The lower parts of the first and second capillaries are made of hollow low-expansion metal material, and the upper parts are made of optical high-temperature resistant glass material that facilitates liquid level observation. The surface of the optical high-temperature resistant glass material is marked with graduations for accurate counting. The hollow part of the outer wall of the second cavity is connected to the hollow part of the outer wall of the second capillary to form a third cavity.

[0009] The temperature strain measuring device involved in the solidification process of liquid metal of the present invention has a first cavity and a second cavity fixed at the bottom with the same volume, which are filled with an equal amount of high temperature resistant liquid medium. The third cavity is in a vacuum state or is not completely filled with high temperature resistant liquid medium.

[0010] The temperature strain measuring device involved in the solidification process of liquid metal of this invention includes a container, liquid metal, device body, camera, support, and test sample. The measurement process is as follows: first, liquid metal is placed in the container; then, the test sample is immersed in the liquid metal; next, the device body of the temperature strain measuring device is placed inside the test sample; the camera is fixedly placed on one side of the container and fixedly mounted on the top of the support; as the liquid metal solidifies, the outer wall of the third cavity absorbs the shrinkage deformation during solidification, while the second cavity is filled with a high-temperature resistant liquid medium, preventing shrinkage and compression during solidification. It accurately reflects the expansion or contraction of the liquid medium caused by temperature changes in liquid metal. The slight thermal expansion or contraction of the high-temperature resistant liquid medium causes a significant change in the liquid level in the upper part of the hollow section of the second capillary. It can accurately measure the temperature change value during the solidification process of liquid metal, and the temperature change value can be read through the scale. The first cavity is filled with a high-temperature resistant liquid medium. Under the combined action of the compression of the liquid metal solidification contraction and thermal expansion and contraction, the liquid level in the upper part of the first capillary will be higher than the liquid level in the second capillary in the second cavity. The difference between the liquid levels in the first capillary and the second capillary can accurately reflect the temperature strain state of the liquid metal during the solidification process, realizing the measurement of temperature strain.

[0011] Compared with existing technologies, this invention has the following advantages: it employs three types of cavities and cavity walls made of different materials, using the deformation differences of different materials under temperature changes to reflect the temperature and strain patterns during the solidification process of liquid metal; the materials are heat-resistant; during the gradual cooling and solidification of the liquid metal, the temperature change and strain state changes of the liquid metal during solidification can be accurately measured by visually observing the changes in the capillary liquid level within the measuring device itself. Its structural design is scientifically sound, its operation is simple, its temperature and strain response is sensitive, its detection method is safe, its detection accuracy is high, and its application environment is friendly. Attached image description:

[0012] Figure 1 This is a schematic diagram of the structural principle of the temperature strain measurement device during the solidification process of liquid metal involved in this invention.

[0013] Figure 2 This is a schematic diagram of the measurement principle of the temperature strain measuring device during the solidification process of liquid metal, which is involved in this invention.

[0014] Figure 3 This is a schematic diagram illustrating the structural principle of the support system involved in this invention. Detailed implementation method:

[0015] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0016] Example 1:

[0017] This embodiment relates to a temperature strain measuring device during the solidification process of liquid metal. The overall structure of the device is a device body 3. The main structure of the device body 3 includes a first cavity 7, a second cavity 8, a third cavity 9, a first capillary tube 10, a second capillary tube 11, a hollow portion 12 of the second capillary tube, and a scale 13. The bottom of the device body 3 consists of two hemispherical cavities of the same size and shape that are tightly attached together. The left hemispherical cavity is the first cavity 7, and the right hemispherical cavity is the second cavity 8. There is a tightly attached surface separating the first cavity 7 and the second cavity 8. The first cavity 7 and the second cavity 8 are respectively connected to the first capillary tube 10 and the second capillary tube in a direction parallel to the tightly attached surface. 11 is connected to it. The inner diameters of the first capillary 10 and the second capillary 11 are equal and they are in close contact with each other. Their contact surfaces are on the same plane as the contact surfaces between the first cavity 7 and the second cavity 8, and they are connected to each other to form a contact surface structure. The contact surfaces are made of low-expansion metal. The hemispherical outer wall of the first cavity 7 is made of elastic metal. The hemispherical outer wall of the second cavity 8 is made of hollow low-expansion metal. The lower part of the first capillary 10 and the second capillary 11 is made of hollow low-expansion metal, and the upper part is made of optical glass material that is convenient for liquid level observation. The surface of the optical glass material is marked with a scale 13 for accurate counting. The cavity formed by the connection and combination of the hollow part of the outer wall of the second cavity 8 and the hollow part 12 of the outer wall of the second capillary 11 is the third cavity 9.

[0018] The temperature strain measuring device involved in the solidification process of liquid metal in this embodiment has the same volume in the first cavity 7 and the second cavity 8 at the bottom of the device body 3. The cavity is filled with an equal amount of mercury or high-temperature oil-based high-temperature resistant liquid medium. The third cavity 9 is in a vacuum state or is not completely filled with mercury or high-temperature oil-based high-temperature resistant liquid medium.

[0019] The working process of the temperature strain measuring device involved in this embodiment is as follows: During the solidification process of liquid metal, the outer wall of the third cavity 9 can absorb the shrinkage deformation of the liquid metal during solidification. The second cavity 8 is filled with a high-temperature resistant liquid medium, which avoids the shrinkage and compression of the liquid metal during solidification. It can accurately reflect the expansion or contraction of the liquid medium caused by temperature changes in the liquid metal. The slight thermal expansion or contraction of the high-temperature resistant liquid medium causes a significant change in the liquid level in the upper part of the hollow part 12 of the second capillary 11. The temperature change value during the solidification process of the liquid metal can be accurately measured, and the value can be read through the scale 13. The first cavity 7 is filled with a high-temperature resistant liquid medium. Under the combined action of the compression of the liquid metal solidification contraction and thermal expansion and contraction, the liquid level in the upper part of the first capillary 10 will be higher than the liquid level in the second capillary. The difference between the liquid levels in the first capillary 10 and the second capillary 11 can accurately reflect the strain state of the liquid metal during solidification. The outer wall of the first cavity 7 is made of elastic metal, while the outer walls of the second cavity 8 and the third cavity 9 are made of hollow, low-expansion metal. This improves the ability of the first cavity 7, the second cavity 8, and the third cavity 9 to withstand the contraction and compression during the solidification of liquid metal, ensuring that the measuring device can obtain accurate results. The first cavity 7, the second cavity 8, and the third cavity 9 are filled with a high-temperature resistant liquid medium, ensuring that the first cavity 7, the second cavity 8, and the third cavity 9 can work normally, ensuring the accuracy of the liquid level in the first capillary tube 10 and the second capillary tube 11, and obtaining accurate data on the strain state. The second cavity 8 is filled with a high-temperature resistant liquid medium, ensuring the accurate measurement of the temperature change during the solidification process of liquid metal.

[0020] The first capillary 10, the second capillary 11, and the hollow portion 12 of the second capillary involved in this embodiment have the same diameter. The specific structure of the first capillary 10, the second capillary 11, and the hollow portion 12 of the second capillary can be designed and changed according to the actual situation of the measurement site, or the capillary can be bent into a special shape and size to measure the strain state of complex components. Its specific structure includes L-shaped, arc-shaped and Z-shaped, which makes the operation more flexible.

[0021] Example 2:

[0022] This embodiment relates to an application example of a temperature strain measuring device during the solidification process of liquid metal, such as... Figure 2 As shown, the equipment or components used in the measurement include a container 1, liquid metal 2, device body 3, (charge-coupled device) camera 4, bracket 5, and test sample 6. During the measurement, liquid metal 2 is first placed in the container 1, and then the test sample 6 is immersed in the liquid metal 2. Then, the device body 3 of the temperature strain measuring device is placed in the test sample 6, the camera 4 is fixedly placed on one side of the container 1, and the camera 4 is fixedly installed on the top of the bracket 5.

[0023] The container 1 involved in this embodiment has a transparent and high-temperature resistant structure and materials. The test sample 6 is immersed in liquid metal 2, and several device bodies 3 are arranged around the test sample 6. During the gradual cooling and solidification of liquid metal 2, the change of capillary liquid level can be visually observed through the device body 3, thereby measuring the temperature change and strain state change of liquid metal 2 during the solidification process. Multiple CCD-type cameras 4 are arranged around the container 1 to record the measurement process of the device body 3, and also have a scale recognition function, realizing intelligent measurement of temperature and strain changes of liquid metal during solidification.

[0024] Example 3:

[0025] like Figure 3 As shown, the bracket 5 involved in this embodiment has the function of automatically adjusting the height according to the change of liquid level. The specific structure of the bracket 5 includes a controller 13, a motor 14, a gear 15, a moving rod 16, a fixed rod 17, and a toothed rack 18. The bracket 5 is composed of two halves, the upper half being the moving rod 16 and the lower half being the fixed rod 17. The fixed rod 17 is sleeved with the moving rod 16. The outer wall of the moving rod 16 has a toothed rack 18, which meshes with the gear 15. The gear 15 is connected to the motor 14 through a transmission rod. The controller 13 is integrated on the motor 14, and the controller 13 is wirelessly connected to the camera 4.

[0026] The working process of the bracket 5 and camera 4 in this embodiment is as follows: The CCD camera 4 acquires a real-time image of the optical glass tube containing a high-temperature resistant liquid medium, acquires the liquid area in the real-time image and generates a liquid area image of the liquid area. When the position of the liquid area image changes, the camera 4 acquires the image information of the changed position and transmits a movement command to the controller. When the controller receives the movement command, it controls the motor 14 at the bottom of the bracket 5 to rotate, which drives the moving rod 16 to move upward through the gear 15, thereby moving the camera 4. The motor 14 realizes the automatic movement of the moving rod 16, which can realize the optimal angle for the camera 4 to capture the liquid level, thus helping to obtain accurate results of temperature and strain changes of the liquid metal.

Claims

1. A temperature strain measuring device during the solidification process of liquid metal, characterized in that: The main structure includes a first cavity, a second cavity, a third cavity, a first capillary tube, and a second capillary tube. The bottom of the measuring device body consists of two cavities tightly attached together. The cavity on the left is the first cavity, and the cavity on the right is the second cavity. A contact surface is provided between the first and second cavities to separate them. The first and second cavities are hemispherical in shape and size. The outer wall of the hemispherical cavity of the first cavity is made of elastic metal, and the outer wall of the hemispherical cavity of the second cavity is made of hollow, low-expansion metal. The contact surface is made of low-expansion metal. The first and second cavities are connected upwards in a direction parallel to the contact surface. The structure is composed of a first capillary and a second capillary, which have equal inner diameters and are tightly fitted together. Their mating surfaces are on the same plane as the mating surfaces between the first and second cavities, and are connected to each other to form a mating surface structure. The lower part of the first and second capillary is made of hollow, low-expansion metal, while the upper part is made of optical high-temperature resistant glass for easy liquid level observation. The hollow portion of the outer wall of the second cavity is connected to the hollow portion of the outer wall of the second capillary to form a third cavity. The first and second cavities have the same volume and are filled with equal amounts of high-temperature resistant liquid medium, while the third cavity is either in a vacuum state or partially filled with high-temperature resistant liquid medium.

2. The temperature and strain measuring device during the solidification process of liquid metal according to claim 1, characterized in that: The surface of the optical high-temperature resistant glass material is marked with graduations for easy counting.

3. The temperature strain measuring device during the solidification process of liquid metal according to claim 1 or 2, characterized in that: During measurement, the equipment or components used include a container, liquid metal, device body, camera, bracket, and test sample. First, liquid metal is filled in the container, then the test sample is immersed in the liquid metal. The temperature strain measurement device body is embedded in the test sample, then the camera is fixedly placed on one side of the container, and finally the camera is fixedly mounted on the top of the bracket.

4. The temperature and strain measuring device during the solidification process of liquid metal according to claim 3, characterized in that: The container is made of transparent and high-temperature resistant materials.

5. The temperature strain measuring device during the solidification process of liquid metal according to claim 3, characterized in that: The camera mentioned is a CCD camera.

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