Test equipment and test method for interaction of melt and nuclear power special material

Abstract

The invention discloses test equipment and a test method for interaction of a melt and a nuclear power special material. The test equipment comprises a smelting chamber, a smelting container assembly, an electromagnetic and shielding control system, a gas control system, a temperature measurement system and a remote operation system, the smelting container assembly is located in the smelting chamber, the smelting container assembly is used for containing test materials including melts and nuclear power special materials, and at least part of the electromagnetic and shielding control system is located in the smelting chamber and wraps the outer side of the smelting container assembly so as to conduct electromagnetic induction heating on the melts; nuclear power special materials are shielded from electromagnetic interference; the gas control system is used for providing a gas environment for the interior of the smelting container assembly and extracting gas for filtering, discharging, collecting or analyzing, the temperature measuring system is used for measuring the temperature in the molten pool and the temperature of the nuclear power special material, and the remote operation system is used for remotely controlling the test equipment to complete test operation.

Description

Technical Field

[0001] The present invention relates to the technical field of interaction between melts and special nuclear power materials, and in particular to a test device and a test method for the interaction between melts and special nuclear power materials. Background Art

[0002] After a severe accident in a pressurized water reactor (PWR), a large area of ​​the core melts, forming a high-temperature molten material. During different severe accident sequences, the molten material may react with structural materials and fall onto the lower head of the pressure vessel, forming a high-temperature molten pool. If the pressure vessel is penetrated, the molten material may fall into the reactor pit and react with the concrete floor, resulting in MCCI (Molten-Core-Concrete Interaction). By adopting an off-core melt retention strategy and placing a core catcher within the reactor cavity, the molten material may react with the sacrificial material placed within the catcher. During this process, the molten material will undergo corrosion reactions with various materials. Studying the corrosion characteristics of the molten material with various specialty materials, including corrosion rate, gas production rate, and stratification, is crucial for the development of new nuclear power specialty materials, such as new sacrificial materials and new concrete materials, as well as for conducting research on in- and out-of-core melt retention strategies and verifying the safety performance of nuclear power plants.

[0003] Conducting experimental research on high-temperature melts and specialized nuclear power materials first requires designing a heating method to ensure smooth melting of the melt. The melting point of the prototype material can reach 2800°C. When the high-temperature melt comes into contact with the specialized nuclear power materials, the materials should be at room temperature. Therefore, a zoned heating method is required to protect the specialized nuclear power materials from the effects of heating. During the reaction, an inert gas environment must be maintained to prevent oxidation of the metal components in the melt and specialized nuclear power materials. Finally, the study aims to determine the melt erosion rate, melt temperature, gas production during the reaction, and the elemental and phase distribution after the reaction. However, existing experimental bench designs are unable to simultaneously meet all of these requirements.

[0004] For example, the sacrificial concrete ablation experimental devices designed by patents CN104101621A, CN104568724A and CN104713905A are too simple and are only suitable for simple measurements of the erosion rate of the simulating working fluid. Patents CN116130126A, CN111562282A and CN113012830A are used to focus on the interaction between the melt and the metal, using a water-cooled crucible and an induction coil to heat the melt, and an electromagnetic shielding ring to prevent the metal from being inductively heated. However, the process of adding metal to these experimental devices uses a feeding box on the top of the stand for secondary feeding, which does not conform to the actual scenario of the reaction between the melt and nuclear power special materials. Patent CN107393607A simulates the reaction process of pouring the melt into concrete, but its related design can only realize molten iron as a reaction simulant.

[0005] In view of the above technical problems, the present invention is specially introduced. Summary of the Invention

[0006] The main purpose of the present invention is to provide a test equipment and test method for the interaction between molten materials and nuclear power special materials, which is used to simulate the process of mutual contact and reaction between real prototype materials and nuclear power special materials, and to achieve the purposes of prototype molten pool temperature measurement, nuclear power special material corrosion rate measurement, reaction process gas production analysis and corrosion result detection.

[0007] To achieve the above-mentioned object, according to one aspect of the present invention, a test device for the interaction between melt and special nuclear power materials is provided, comprising a melting chamber, a melting vessel assembly, an electromagnetic and shielding control system, a gas control system, a temperature measurement system, and a remote operation system;

[0008] The smelting vessel assembly is located inside the smelting chamber and is used to accommodate test materials, including molten material and nuclear power special materials. At least a portion of the electromagnetic and shielding control system is located in the smelting chamber and wrapped around the outside of the smelting vessel assembly to perform electromagnetic induction heating on the molten material and shield the nuclear power special materials from electromagnetic interference.

[0009] The gas control system is used to provide a gas environment to the inside of the smelting vessel components and extract gas for filtration, discharge, collection or analysis. The temperature measurement system is used to measure the temperature inside the molten pool and nuclear power special materials. The remote operation system is used to remotely control the test equipment to complete the test operation.

[0010] Furthermore, the smelting container assembly includes a cold crucible, which is arranged on the inner bottom wall of the smelting chamber shell of the smelting chamber. The cold crucible includes a circumferential crucible wall and a crucible cover and a crucible bottom located at the upper and lower ends. The upper and lower parts of the crucible wall respectively contain the melt and nuclear power special materials.

[0011] Furthermore, the electromagnetic and shielding control system includes a coil assembly, a shielding ring assembly and a power supply assembly. The coil assembly includes an induction coil, which is installed around the outer circumference of the upper part of the crucible wall. The shielding ring assembly is installed around the outer circumference of the lower part of the crucible wall. The power supply assembly supplies power to the induction coil.

[0012] Furthermore, the coil assembly also includes an electrode shaft connected to the induction coil, the electrode shaft is connected to the power supply assembly outside the smelting chamber, and the movement of the electrode shaft can drive the induction coil to move in the vertical direction.

[0013] Furthermore, the power supply assembly includes a power cabinet, an inverter cabinet and a lifting platform which are connected in sequence outside the smelting chamber. The electrode shaft passes through the bottom wall of the smelting chamber shell in a sealed manner and is connected to the lifting platform. The remote operating system can control the lifting platform.

[0014] Furthermore, the power frequency in the power cabinet can be adjusted within the range of 100 to 150 kHz according to the change of oxide resistivity with temperature and the change of melt composition.

[0015] Furthermore, the shielding ring assembly is connected to a lifting device, which passes through the bottom wall of the smelting chamber shell in a sealed manner. The remote operating system can drive the shielding ring assembly to move in a vertical direction by controlling the lifting device.

[0016] Furthermore, the diameter of the induction coil is 10% to 15% larger than the outer diameter of the crucible wall, and the diameter of the shielding ring assembly is smaller than the diameter of the induction coil.

[0017] Furthermore, the number of turns of the induction coil is 2 to 5, the total height of the shielding ring assembly is 5 to 10 cm greater than the laying height of the nuclear power special material, and the shielding ring assembly can be completely moved out of the crucible wall area.

[0018] Furthermore, the temperature measurement system includes an infrared temperature measurement component and a thermocouple temperature measurement component. The infrared temperature measurement component includes an infrared thermometer and a hollow tungsten tube. The hollow tungsten tube is used to break the shell on the upper surface of the molten pool, and serves as a temperature measurement channel of the infrared thermometer and a flow channel for inert gas in the gas control system; the thermocouple temperature measurement component includes a thermocouple pre-buried at the location of nuclear power special materials and a thermocouple data acquisition system.

[0019] Furthermore, a coaxial infrared thermometer is arranged at the top of the hollow tungsten tube, and the bottom end is sealed through the melting chamber shell and the crucible cover. An air inlet is left on the side of the hollow tungsten tube and is connected to the argon filling subsystem. The remote operating system can drive the infrared temperature measurement component to move in the vertical direction so that the hollow tungsten tube is immersed in the molten pool to measure the temperature.

[0020] Furthermore, a plurality of through holes for installing thermocouples are provided on the bottom of the crucible, and the plurality of thermocouples are sealed through the plurality of through holes and are respectively located at different depths of the nuclear power special material.

[0021] Furthermore, a first crucible exhaust port is provided on the crucible cover, and the gas control system includes a smoke dust filtering subsystem, which is connected to the first crucible exhaust port. The smoke dust filtering subsystem can extract smoke and harmful substances generated in the melting chamber and the cold crucible, and filter, discharge or collect them.

[0022] Furthermore, the gas control system includes a gas analysis subsystem, which is connected to the exhaust port of the first crucible. The gas analysis subsystem includes a gas analyzer and a vacuum pump for collecting gases generated during the reaction for analysis. Valves and flow meters are installed on the smoke filtration subsystem and the gas analysis subsystem pipelines. The two pipelines are connected by a tee pipe and sealed through the smelting chamber shell.

[0023] Furthermore, a second crucible exhaust port is provided on the crucible cover, and the gas control system includes a vacuum subsystem connected to the second crucible exhaust port, and the vacuum subsystem can evacuate the cold crucible.

[0024] Furthermore, the test equipment also includes a water cooling system, which includes a forced cooling system and a normal temperature water cooling system. The water cooling system is used to provide circulating cooling water to the melting chamber, melting vessel components, electromagnetic and shielding control systems and vacuum subsystems.

[0025] Furthermore, the cold crucible also includes a crucible water jacket, which is located between the crucible wall and the crucible cover, and the crucible water jacket collects multiple cooling water pipes of the strong cooling system.

[0026] Furthermore, the crucible wall is composed of a copper tube bundle evenly fixed on the crucible water jacket along the circumference, and can be disassembled into two identical semicircular walls.

[0027] To achieve the above object, according to another aspect of the present invention, a test method for the interaction between a melt and a special nuclear power material is provided, using the above test equipment and comprising the following steps:

[0028] Pre-test preparation steps include preparing a heat-resistant layer on the inner surface of the melting vessel assembly, loading the melt and nuclear power special materials into the melting vessel assembly, and moving the electromagnetic and shielding control systems to the starting position;

[0029] The test operation steps include starting the water cooling system, providing a gas environment to the interior of the melting chamber through the gas control system, performing electromagnetic induction heating on the melt through the electromagnetic and shielding control system, and shielding the nuclear power special materials from electromagnetic interference, measuring the temperature of the interior of the molten pool and the nuclear power special materials through the temperature measurement system, and moving the electromagnetic and shielding control system until the melt is completely melted and then in contact with the nuclear power special materials to react;

[0030] The post-test processing steps are to disassemble the melting vessel components after they have cooled, observe and record the reaction between the melt and the nuclear power special materials, and sample the materials in different areas for elemental and phase analysis.

[0031] Furthermore, the pre-test preparation step includes a sub-step of pre-embedding thermocouples, in which multiple thermocouples are inserted from the bottom of the crucible into the nuclear power special material at different depths and records are kept; in the test operation step, the power supply is turned off in time after the thermocouple at the lowest point is damaged; in the post-test processing step, a data analysis sub-step is included, in which the corrosion rate is calculated based on the thermocouple insertion depth and damage time.

[0032] Furthermore, the pre-test preparation step includes a sub-step of moving the electromagnetic and shielding control system, moving the induction coil until the center of the coil is flush with the upper edge of the melt, and moving the shielding ring assembly until the upper edge of the shielding ring assembly is flush with the upper edge of the nuclear power special material;

[0033] The experimental operation steps include a sub-step of the reaction of the molten material and the nuclear power special materials. After the liquid level of the molten pool drops, the induction coil is moved downward according to the coil width. The power is increased or decreased according to the melting and material splashing conditions. The current is always kept within the limit during the movement and heating process. The above operations are repeated until the lower edge of the coil is flush with the upper edge of the shielding ring assembly. After a period of stability, the shielding ring assembly is moved downward to start the reaction, so that all the molten melt contacts and reacts with the nuclear power special materials.

[0034] Furthermore, the experimental operation steps include a molten pool temperature measurement sub-step. According to the charging height, the hollow tungsten tube is first lowered to the surface of the melt. While descending, inert gas is introduced into the hollow tungsten tube to drive the hollow tungsten tube to knock downward until the hard shell is broken. The hollow tungsten tube is immersed in the molten pool for 2 to 3 minutes, and the reading of the infrared thermometer is recorded. After the measurement is completed, the hollow tungsten tube is reset in time.

[0035] Furthermore, the pre-test preparation steps include a material loading sub-step, in which materials are loaded into a cold crucible. If powder materials are loaded, the powder is compacted using a tool after loading. If block materials are loaded, the gaps are filled with powder after loading. If the melts are all non-conductive solid substances, a melting starter metal is pre-embedded in the upper layer of the melt. The loading height of the nuclear power special materials and the melt is recorded.

[0036] Furthermore, the test operation steps include a melt start-up sub-step, in which the power supply assembly is started to preheat the melt, the power is gradually increased to 20-40 kW, the smoke filter sub-system is turned on according to the smoke production conditions, the current begins to decrease after the melt is partially melted, and the power is gradually increased until the melt in the induction coil is completely melted. The melt pool is observed during the heating process, and the power is reduced if there is severe material splashing.

[0037] It also includes a reaction gas analysis sub-step. If the gas generated by the reaction needs to be analyzed, the gas analysis subsystem is turned on after the melt and the nuclear power special material begin to react, and at the same time, inert gas is introduced into the hollow tungsten tube to ensure stable pressure in the melting chamber.

[0038] The application of the technical solution of the present invention achieves at least the following beneficial effects:

[0039] 1. The test equipment of the present invention, combined with the corresponding test method, can realize the interaction experiment between liquid simulated melt or prototype melt of tens to hundreds of kilograms and nuclear power special materials, measure the temperature inside the molten pool, analyze the melting rate and post-reaction stratification, and perform sample testing after the test.

[0040] 2. The test equipment of the present invention can realize zoned heating of the melt and nuclear power special materials by arranging an induction coil and a shielding ring assembly that can be raised and lowered, and can control the start and progress of the experiment.

[0041] 3. The test equipment of the present invention is equipped with a two-color infrared thermometer and a liftable hollow tungsten tube. It can purge the smoke and dust generated during the test process by passing inert gas into the hollow tungsten tube, break the hard crust on the surface of the molten pool, and accurately measure the temperature inside the molten pool.

[0042] 4. The test equipment of the present invention embeds thermocouples in nuclear power special materials. The test progress can be judged by the insertion position and damage time of the thermocouples, and the corrosion rate can be calculated.

[0043] 5. The test equipment of the present invention is equipped with a smoke filtration subsystem and a crucible exhaust port, which can extract smoke or harmful substances generated in the melting chamber and the cold crucible, filter and discharge or collect them, thereby preventing smoke generated during the material heating process from obstructing the view through the observation window. By providing a gas analysis subsystem, the gases generated by the reaction are collected and analyzed during the test, thereby calculating and analyzing the reaction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0045] Figure 1 A schematic diagram of the test equipment of the present invention is shown.

[0046] The above drawings include the following reference numerals:

[0047] 100. Melting chamber; 01. Melting chamber shell; 02. Solenoid valve; 03. Monitoring;

[0048] 10. Melting vessel assembly; 11. Crucible wall; 12. Crucible cover; 13. Crucible bottom; 14. Crucible support; 15. First crucible exhaust port; 16. Second crucible exhaust port; 17. Observation window;

[0049] 20. Test materials; 21. Melts; 22. Melting metals; 23. Special materials for nuclear power;

[0050] 30. Electromagnetic and shielding control system; 31. Induction coil; 32. Electrode shaft; 33. Power supply cabinet; 34. Inverter cabinet; 35. Lifting platform; 36. Shielding ring assembly;

[0051] 40. Gas control system; 41. Vacuum subsystem; 42. Argon filling subsystem; 43. Hollow tungsten tube; 44. Gas analysis subsystem; 45. Soot filtration subsystem;

[0052] 50. Temperature measurement system; 51. Infrared thermometer; 52. Thermocouple. DETAILED DESCRIPTION

[0053] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0054] The present invention is described in further detail below with reference to specific embodiments. These embodiments are not to be construed as limiting the scope of protection claimed by the present invention. The term "including" when used indicates the presence of a feature, but does not exclude the presence or addition of one or more other features; the terms "lateral", "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for ease of description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be construed as limiting the present invention; in addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance.

[0055] In this description, it should be noted that, unless otherwise specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention. Furthermore, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0056] Example:

[0057] The present invention proposes a test device for the interaction between melt and nuclear power special materials. Figure 1 As shown, it includes a smelting chamber 100, a smelting container assembly 10, an electromagnetic and shielding control system 30, a gas control system 40, a temperature measurement system 50, a water cooling system and a remote operation system.

[0058] The special nuclear power materials mentioned in this application include not only sacrificial materials in the nuclear power field, but also concrete materials, etc., thereby expanding the application scope of the test equipment of this application, so that this equipment can be used to study the interaction between melts and various materials that require measurement of melting rate and temperature.

[0059] The smelting vessel assembly 10 is located within a smelting chamber 100, which also houses necessary connectors and provides a vacuum or inert gas environment. The smelting vessel assembly 10 houses test material 20, which includes a melt 21 and specialized nuclear power materials 23. At least a portion of an electromagnetic and shielding control system 30 is located within the smelting chamber 100 and surrounds the outside of the smelting vessel assembly 10. This system provides electromagnetic induction heating for the melt 21 and shields the specialized nuclear power materials 23 from electromagnetic interference.

[0060] The gas control system 40 is used to provide a gas environment to the interior of the smelting vessel assembly 10 and extract gas for filtering, discharge, collection or analysis. The temperature measurement system 50 is used to measure the temperature inside the molten pool and the nuclear power special material 23. The remote operation system is used to remotely control the test equipment to complete the test operation.

[0061] Specifically, the smelting vessel assembly 10 adopts a cold crucible, which is arranged on the inner bottom wall of the smelting chamber shell 01 of the smelting chamber 100. The cold crucible includes a circumferential crucible wall 11 and a crucible cover 12 and a crucible bottom 13 located at the upper and lower ends. The upper and lower parts of the crucible wall 11 respectively contain the melt 21 and the nuclear power special material 23.

[0062] The electromagnetic and shielding control system 30 includes a coil assembly, a shielding ring assembly 36, and a power supply assembly. The coil assembly includes an induction coil 31 and an electrode shaft 32 connected to the induction coil 31. The electrode shaft 32 is connected to the power supply assembly outside the smelting chamber 100. Movement of the electrode shaft 32 drives the induction coil 31 in the vertical direction. The induction coil 31 is mounted around the upper circumference of the crucible wall 11, and the shielding ring assembly 36 is mounted around the lower circumference of the crucible wall 11. The power supply assembly provides power to the induction coil 31.

[0063] Preferably, the power supply assembly includes a power supply cabinet 33, an inverter cabinet 34, and a lift platform 35, which are located outside the smelting chamber 100 and connected in sequence. The electrode shaft 32 is sealed through the bottom wall of the smelting chamber shell 01 and connected to the lift platform 35. The remote operating system can control the lifting and lowering of the lift platform 35. Furthermore, preferably, the power supply cabinet assembly can provide a high-power, high-frequency power supply of tens to hundreds of kilowatts. The power supply frequency in the power supply cabinet 33 can be adjusted within a range of 100 to 150 kHz based on the temperature-dependent changes in the oxide resistivity and the composition of the melt 21.

[0064] Furthermore, the shielding ring assembly 36 is connected to a lifting mechanism that sealably passes through the bottom wall of the smelting chamber housing 01. A remote operating system controls the lifting mechanism to vertically move the shielding ring assembly 36. Preferably, the diameter of the induction coil 31 is 10% to 15% larger than the outer diameter of the crucible wall 11, while the diameter of the shielding ring assembly 36 is smaller than that of the induction coil 31. This effectively protects the nuclear power specialty material 23 from electromagnetic interference.

[0065] Preferably, the number of turns of the induction coil 31 is 2 to 5, and the turn pitch is designed so that the induction coil can be moved 2 to 3 times to achieve uniform heating of the entire material. The total height of the shielding ring assembly 36 is 5 to 10 cm greater than the height of the nuclear power special material, and the shielding ring assembly 36 can be completely removed from the crucible wall 11 area.

[0066] Preferably, the induction coil 31 , the electrode shaft 32 and the shielding ring assembly 36 are all made of copper. The number of turns, height and diameter of the induction coil 31 are designed so that the power loaded by the coil on the melt 21 is flattened.

[0067] In the present invention, the temperature measurement system 50 includes an infrared temperature measurement assembly and a thermocouple temperature measurement assembly. The infrared temperature measurement assembly includes an infrared thermometer 51 and a hollow tungsten tube 43. The hollow tungsten tube 43 is used to break the crust on the upper surface of the molten pool and serves as a temperature measurement channel for the infrared thermometer 51 and a flow channel for the inert gas in the gas control system 40. The thermocouple temperature measurement assembly includes a thermocouple 52 pre-buried at the location of the nuclear power special material 23 and a thermocouple data acquisition system. The infrared thermometer 51 is a two-color infrared thermometer.

[0068] Specifically, a coaxial infrared thermometer is positioned at the top of the hollow tungsten tube 43, while its bottom end is sealed through the top wall of the smelting chamber shell 01 and the crucible lid 12. A gas inlet is provided on the side of the hollow tungsten tube 43 and is connected to the argon filling subsystem 42, allowing inert gas to be introduced into the hollow tungsten tube 43 through the inlet. A remote operating system drives the infrared temperature measurement assembly vertically, bringing the bottom of the hollow tungsten tube close to the upper surface of the molten pool. A pneumatic device then drives the hollow tungsten tube 43 downward, breaking through the upper shell of the molten pool and allowing the hollow tungsten tube 43 to penetrate the interior of the molten pool for temperature measurement. This method provides a closer approximation to the actual molten pool temperature than directly measuring the hard shell temperature with an infrared thermometer.

[0069] Preferably, the crucible bottom 13 is provided with multiple through-holes for installing thermocouples 52. Multiple thermocouples 52 are sealed through these through-holes and positioned at different depths within the nuclear power specialty material 23. During installation, the thermocouples are inserted through the crucible bottom 13 and embedded within the nuclear power specialty material 23. Extension cables are then sealed through the bottom wall of the smelting chamber shell 01 and connected to a thermocouple data acquisition system. During the experiment, the temperature of the nuclear power specialty material can be displayed in real time, allowing for assessment of the ablation progress and calculation of the ablation rate.

[0070] Preferably, the smelting chamber shell 01 includes an arc-shaped furnace body and a rotatable furnace door, both of which preferably adopt a double-layer stainless steel water-cooled structure. The furnace door can be rotated to open, and a window and a camera are provided on the furnace door, so that the remote operating system can observe or record the movement of the coil assembly and the shielding ring assembly 36.

[0071] More preferably, a monitor 03 is provided on the top wall of the smelting chamber shell 01 and an observation window 17 is provided on the crucible cover 12, so that the remote operating system can observe or record the situation in the cold crucible.

[0072] In addition, automatic and manual solenoid valves 02 are installed on the side of the furnace to relieve pressure when the internal pressure exceeds atmospheric pressure. The side of the furnace also has necessary water inlet and outlet connections for the water cooling system, air inlet and outlet connections for the gas control system, a penetration port for the infrared temperature measurement component, and a pressure gauge.

[0073] The gas control system 40 includes a vacuum subsystem 41 and an argon filling subsystem 42. The vacuum subsystem 41 includes a slide valve pump and a Roots pump, which can evacuate the melting chamber 100 to an ultimate vacuum of 0.1 Pa to 0.01 Pa. The argon filling subsystem 42 includes an air compressor and an argon gas cylinder, which can introduce inert gas into the hollow tungsten tube 43.

[0074] Furthermore, a first crucible exhaust port 15 is provided on the crucible cover 12. The gas control system 40 includes a smoke dust filtering subsystem 45. The smoke dust filtering subsystem 45 is connected to the first crucible exhaust port 15. The smoke dust filtering subsystem 45 can extract smoke and harmful substances generated in the melting chamber 100 and the cold crucible, filter and discharge or collect them, so as to prevent smoke generated during the heating process from obstructing the view through the observation window.

[0075] Gas control system 40 includes a gas analysis subsystem 44, which is also connected to first crucible exhaust port 15. This subsystem includes a gas analyzer and a vacuum pump, and is used to collect gases generated during the reaction for testing and analysis. Valves and flow meters are installed on the pipelines connecting fume filtration subsystem 45 and gas analysis subsystem 44. The two pipelines are connected by a T-junction pipe and sealed through the melting chamber shell 01.

[0076] The crucible cover 12 is further provided with a second crucible exhaust port 16 , to which a vacuum subsystem 41 is connected. The vacuum subsystem 41 can evacuate the interior of the cold crucible.

[0077] Preferably, the water cooling system includes a forced cooling system and a normal-temperature water cooling system. The water cooling system is used to provide circulating cooling water to the melting chamber 100, the melting vessel assembly 10, and the electromagnetic and shielding control system 30. The forced cooling system consists of a water tank, a chiller, necessary piping, a water pump, and valves, and is used to cool the crucible wall 11, the crucible bottom 13, the crucible lid 12, the induction coil 31, and the shielding ring assembly 36. The normal-temperature water cooling system, consisting of a water tank, necessary piping, a water pump, and valves, is used to cool the power supply cabinet 33, the inverter cabinet 34, the melting chamber 100, and the vacuum subsystem 41.

[0078] The cold crucible preferably also includes a crucible water jacket, located between the crucible wall 11 and the crucible lid 12. This jacket collects the multiple cooling water pipes of the forced cooling system. Preferably, the crucible wall 11 is composed of a bundle of copper tubes uniformly fixed to the crucible water jacket along its circumference and can be disassembled into two identical semicircular walls to facilitate material removal after the experiment. The crucible lid 12 and crucible bottom 13 are made of stainless steel, and the crucible bottom 13 is secured to the bottom of the crucible wall with removable bolts. The smelting vessel assembly also includes a stainless steel crucible support 14, fixed to the bottom plate of the smelting chamber shell 01, to support the cold crucible.

[0079] In summary, the remote operating system can control the start and stop of the water cooling system and the gas control system 40; control the position and lifting of the induction coil 31 and the shielding ring assembly 36; control the lifting and lifting of the infrared temperature measurement assembly and the ramming of the hollow tungsten tube 43; and can monitor and record the various water channels, air pressure and power supply signals in real time; and can monitor and record the monitoring or camera images in real time.

[0080] The present invention further proposes a test method for the interaction between a melt and a special nuclear power material, using a sacrificial material as a special nuclear power material as an implementation case, using the test equipment described above, and comprising the following steps:

[0081] In the pre-test preparation step S1, a heat-resistant layer is prepared on the inner surface of the smelting vessel assembly 10, the melt 21 and the nuclear power special material 23 are loaded into the smelting vessel assembly 10, and the electromagnetic and shielding control system 30 is moved to the starting position.

[0082] In the experimental operation step S2, the water cooling system is started, a gas environment is provided to the interior of the smelting chamber 100 through the gas control system 40, the melt 21 is subjected to electromagnetic induction heating through the electromagnetic and shielding control system 30, and the nuclear power special material 23 is shielded from electromagnetic interference, the temperature inside the molten pool and the nuclear power special material 23 is measured through the temperature measurement system 50, and the electromagnetic and shielding control system 30 is moved until the melt 21 is completely melted and contacts and reacts with the nuclear power special material 23.

[0083] In the post-test processing step S3, the smelting vessel assembly 10 is disassembled after cooling, the reaction between the melt 21 and the nuclear power special material 23 is observed and recorded, and the materials in different areas are sampled and subjected to elemental and phase analysis.

[0084] Specifically, the pre-test preparation step S1 includes the following sub-steps:

[0085] Crucible Preparation Sub-Step S1-1: Clean any residual material from the inner surface of the crucible wall 11. Zirconium dioxide is then applied to the cold crucible in a paste form and evenly applied to the inner surface. Allow to dry to form a heat-resistant layer. The cold crucible is then installed in the desired location and connected to the water and gas lines. In this embodiment, the smelting chamber has an inner diameter of 1.5 m and an inner height of 1.8 m. The inner and outer walls are constructed of 10 mm thick 304 stainless steel. The crucible wall has an inner diameter of 16 cm and a height of 60 cm, capable of holding 20 kg of liquid material.

[0086] In the material loading sub-step S1-2, the cold crucible is filled with material. If powdered material is used, the powder is compacted using a tool after loading. If bulk material is used, the powder is used to fill gaps after loading. If the melt 21 is entirely non-conductive solid, iron particles or zirconium rings, or other conductive metals, are embedded in the melt 21 as a starter metal 22. The filling heights of the nuclear power specialty material 23 and the melt 21 are recorded. In this embodiment, zirconium oxide powder is used as a melt simulant to interact with the sintered nuclear power specialty material blocks. The filling height of the nuclear power specialty material is approximately 20 cm, and the filling height of the zirconium oxide powder is approximately 20 cm. A certain amount of iron particles is embedded in the upper layer of the zirconium oxide powder as a starter metal.

[0087] The electromagnetic and shielding control system performs movement sub-step S1-3, moving the induction coil 31 until the center of the coil is flush with the upper edge of the melt 21, and moving the shielding ring assembly 36 until the upper edge of the shielding ring assembly 36 is flush with the upper edge of the nuclear power specialty material 23. In this embodiment, the center of the moving induction coil is approximately 40 cm high, and the upper edge of the shielding ring assembly is approximately 20 cm high.

[0088] In the thermocouple embedding sub-step S1-4, multiple K / C type thermocouples 52 are inserted from the crucible bottom 13 into the nuclear power specialty material 23 at different depths and recorded. In this embodiment, four K type thermocouples are inserted at the center of the nuclear power specialty material at 2 cm, 6 cm, 10 cm, and 14 cm from the top edge. Two K type thermocouples are inserted at 4 cm from the center on both sides of the bottom surface and at 2 cm and 7 cm from the top edge.

[0089] The test operation step S2 includes the following sub-steps:

[0090] Cooling water circulation sub-step S2-1, start the water cooling system, so that the cooling water flow, pressure, and temperature of each channel are stable within the normal range. In this embodiment, the cooling water flow rate is 15~20m 3 / h, pressure is 0.25~0.3MPa, and temperature is 15~25℃.

[0091] In the atmosphere control sub-step S2-2, the vacuum subsystem 41 is activated to evacuate the cold crucible to a predetermined pressure, and then the argon filling subsystem 42 is used to fill the cold crucible with clean argon gas to a predetermined pressure. In this embodiment, the vacuum subsystem 41 evacuates the cold crucible to a pressure of 0.1 Pa, and the argon filling subsystem 42 fills the cold crucible with clean argon gas until the pressure is slightly above atmospheric pressure.

[0092] In the melt starting sub-step S2-3, the power supply component is started to preheat the melt 21, and the power is gradually increased to 20-40 kW. The smoke filtering subsystem 45 is turned on according to the smoke production conditions. After part of the melt 21 is melted, the current begins to decrease, and the power is continued to be gradually increased until all the melt 21 in the induction coil 31 is melted. The condition of the molten pool is observed during the heating process. If the material splashes seriously, the power is appropriately reduced.

[0093] In the molten pool temperature measurement sub-step S2-4, hollow tungsten tube 43 is first lowered to the surface of melt 21, depending on the charge height. Clean argon gas is simultaneously introduced through the hollow tungsten tube to purge the molten pool surface. Hollow tungsten tube 43 is then driven downward to break through the hard shell. Hollow tungsten tube 43 is then submerged in the molten pool to a certain depth for 2-3 minutes. The reading from infrared thermometer 51 is recorded. After the measurement is completed, hollow tungsten tube 43 is promptly reset to prevent damage due to overheating.

[0094] In this embodiment, hollow tungsten tube 43 is first lowered to a height of approximately 40 cm. It is then driven downward to strike the hard crust. If the hard crust is not struck, hollow tungsten tube 43 is driven downward an additional 5 cm until the hard crust is broken. The hollow tungsten tube 43 is then immersed in the molten pool at a depth of 5 cm for 2 minutes, and the infrared thermometer reading is recorded.

[0095] In sub-step S2-5 of the melt nuclear power special material reaction, a renewed increase in current indicates a drop in the melt pool level and a lack of material at the coil position. After the melt pool level drops, the induction coil 31 is moved downward according to the coil width. The power is increased or decreased based on the melting and material splashing conditions. During movement and heating, the current is maintained constant, and the above steps are repeated until the lower edge of the coil is flush with the upper edge of the shielding ring assembly 36. After a period of stabilization, the shielding ring assembly 36 is moved downward to initiate the reaction, allowing all molten melt 21 to contact and react with the nuclear power special material 23. The values ​​of each thermocouple 52 are observed. If the thermocouple 52 at the lowest point is damaged, the power is immediately turned off to prevent damage to the crucible.

[0096] In this embodiment, the coil is moved downward approximately 5 cm when the current is increased again. The power is increased or decreased based on the melting and material splashing conditions. The current is maintained within the 450A limit during the movement and heating process. This process is repeated until the bottom edge of the coil is approximately 20 cm away. Once the thermocouple value exceeds 100°C, the shielding ring assembly 36 is moved downward to initiate the reaction. Once the lowest thermocouple exceeds 1300°C and is damaged, the power is immediately turned off.

[0097] In the reaction gas analysis sub-step S2-6, if the gas generated by the reaction needs to be analyzed, after the melt 21 and the nuclear power special material 23 start to react, the gas analysis subsystem is turned on, and at the same time, an inert gas is introduced into the hollow tungsten tube 43 to ensure that the pressure in the smelting chamber 100 is stable.

[0098] The post-test processing step S3 includes the following sub-steps:

[0099] In step S3-1 of removing the material, after the crucible has completely cooled, remove the thermocouple 52, disassemble the crucible into two halves, observe and record the stratification of the molten pool, and slowly tap the gap between the material and the crucible with a tool until the material completely falls off.

[0100] In the sample detection sub-step S3-2, elemental analysis is performed on samples from different regions using XRF or SEM / EDS.

[0101] In the data analysis sub-step S3-3, the ablation rate is calculated based on the insertion depth of the thermocouple 52 and the damage time.

[0102] In summary, from the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0103] 1. The test equipment of the present invention, combined with the corresponding test method, can realize the interaction experiment between liquid simulated melt or prototype melt of tens to hundreds of kilograms and nuclear power special materials, measure the temperature inside the molten pool, analyze the melting rate and post-reaction stratification, and perform sample testing after the test.

[0104] 2. The test equipment of the present invention can realize zoned heating of the melt and nuclear power special materials by arranging an induction coil and a shielding ring assembly that can be raised and lowered, and can control the start and progress of the experiment.

[0105] 3. The test equipment of the present invention is equipped with a two-color infrared thermometer and a liftable hollow tungsten tube. It can purge the smoke and dust generated during the test process by passing inert gas into the hollow tungsten tube, break the hard crust on the surface of the molten pool, and accurately measure the temperature inside the molten pool.

[0106] 4. The test equipment of the present invention embeds thermocouples in nuclear power special materials. The test progress can be judged by the insertion position and damage time of the thermocouples, and the corrosion rate can be calculated.

[0107] 5. The test equipment of the present invention is equipped with a smoke filtration subsystem and a crucible exhaust port, which can extract smoke or harmful substances generated in the melting chamber and the cold crucible, filter and discharge or collect them, thereby preventing smoke generated during the material heating process from obstructing the view through the observation window. By providing a gas analysis subsystem, the gases generated by the reaction are collected and analyzed during the test, thereby calculating and analyzing the reaction process.

[0108] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A test device for the interaction between melt and nuclear power special materials, characterized in that: The invention comprises a smelting chamber (100), a smelting container assembly (10), an electromagnetic and shielding control system (30), a gas control system (40), a temperature measurement system (50) and a remote operation system; The smelting vessel assembly (10) is located inside the smelting chamber (100), and the smelting vessel assembly (10) is used to accommodate test materials (20), including a melt (21) and a nuclear power special material (23). At least a portion of the electromagnetic and shielding control system (30) is located in the smelting chamber (100) and wrapped around the outside of the smelting vessel assembly (10) to perform electromagnetic induction heating on the melt (21) and shield the nuclear power special material (23) from electromagnetic interference. The gas control system (40) is used to provide a gas environment to the interior of the smelting vessel assembly (10) and extract gas for filtering, discharge, collection or analysis. The temperature measurement system (50) is used to measure the temperature inside the molten pool and the nuclear power special material (23). The remote operation system is used to remotely control the test equipment to complete the test operation.

2. The test equipment according to claim 1, characterized in that: The smelting container assembly (10) includes a cold crucible, which is arranged on the inner bottom wall of the smelting chamber shell (01) of the smelting chamber (100). The cold crucible includes a circumferential crucible wall (11) and a crucible cover (12) and a crucible bottom (13) located at upper and lower ends. The upper and lower parts of the crucible wall (11) respectively accommodate the melt (21) and the nuclear power special material (23).

3. The test equipment according to claim 2, characterized in that: The electromagnetic and shielding control system (30) comprises a coil assembly, a shielding ring assembly (36) and a power supply assembly, wherein the coil assembly comprises an induction coil (31), the induction coil (31) is mounted around the outer circumference of the upper portion of the crucible wall (11), the shielding ring assembly (36) is mounted around the outer circumference of the lower portion of the crucible wall (11), and the power supply assembly supplies power to the induction coil (31).

4. The test equipment according to claim 3, characterized in that: The coil assembly further includes an electrode shaft (32) connected to the induction coil (31), wherein the electrode shaft (32) is connected to the power supply assembly outside the smelting chamber (100), and movement of the electrode shaft (32) can drive the induction coil (31) to move in a vertical direction.

5. The test equipment according to claim 4, characterized in that: The power supply assembly includes a power supply cabinet (33), an inverter cabinet (34) and a lifting platform (35) which are connected in sequence outside the smelting chamber (100); the electrode shaft (32) passes through the bottom wall of the smelting chamber shell (01) in a sealed manner and is connected to the lifting platform (35); and the remote operating system can control the lifting platform (35).

6. The test equipment according to claim 5, characterized in that: The power frequency in the power cabinet (33) can be adjusted within the range of 100 to 150 kHz according to the change of the resistivity of the melt (21) with temperature and the change of the components of the melt (21).

7. The test equipment according to claim 3, characterized in that: The shielding ring assembly (36) is connected to a lifting device, which passes through the bottom wall of the smelting chamber shell (01) in a sealed manner. The remote operating system can drive the shielding ring assembly (36) to move in a vertical direction by controlling the lifting device.

8. The test device according to any one of claims 3 to 7, characterized in that: The diameter of the induction coil (31) is 10% to 15% larger than the outer diameter of the crucible wall (11), and the diameter of the shielding ring assembly (36) is smaller than the diameter of the induction coil (31).

9. The test device according to claim 8, characterized in that: The number of turns of the induction coil (31) is 2 to 5, the total height of the shielding ring assembly (36) is 5 to 10 cm greater than the laying height of the nuclear power special material (23), and the shielding ring assembly (36) can be completely moved out of the crucible wall (11) area.

10. The test equipment according to claim 2, characterized in that: The temperature measurement system (50) includes an infrared temperature measurement component and a thermocouple temperature measurement component. The infrared temperature measurement component includes an infrared thermometer (51) and a hollow tungsten tube (43). The hollow tungsten tube (43) is used to break the shell layer on the upper surface of the molten pool and serves as a temperature measurement channel of the infrared thermometer (51) and a flow channel for the inert gas in the gas control system (40). The thermocouple temperature measurement component includes a thermocouple (52) pre-buried at the position of the nuclear power special material (23) and a thermocouple data acquisition system.

11. The test device according to claim 10, characterized in that: A coaxial infrared thermometer is arranged at the top of the hollow tungsten tube (43), and the bottom end is sealed through the smelting chamber shell (01) and the crucible cover (12). An air inlet is left on the side of the hollow tungsten tube (43) and is connected to the argon filling subsystem (42). The remote operation system can drive the infrared temperature measurement component to move in the vertical direction so that the hollow tungsten tube (43) is immersed in the inside of the molten pool to measure the temperature.

12. The test device according to claim 10, characterized in that: The crucible bottom (13) is provided with a plurality of through holes for installing the thermocouples (52), and the plurality of thermocouples (52) pass through the plurality of through holes in a sealed manner and are respectively located at different depths of the nuclear power special material (23).

13. The test device according to claim 2, characterized in that: A first crucible exhaust port (15) is provided on the crucible cover (12), and the gas control system (40) includes a smoke filter subsystem (45). The smoke filter subsystem (45) is connected to the first crucible exhaust port (15). The smoke filter subsystem (45) can extract smoke and harmful substances generated in the smelting chamber (100) and the cold crucible, and filter, discharge or collect them.

14. The test device according to claim 13, characterized in that: The gas control system (40) includes a gas analysis subsystem (44), which is connected to the first crucible exhaust port (15). The gas analysis subsystem (44) includes a gas analyzer and a vacuum pump for collecting gases generated during the reaction process for analysis. Valves and flow meters are installed on the pipelines of the smoke filtering subsystem (45) and the gas analysis subsystem (44). The two pipelines are connected by a tee pipe and pass through the smelting chamber shell (01) in a sealed manner.

15. The test device according to claim 13, characterized in that: The crucible cover (12) is also provided with a second crucible exhaust port (16), and the gas control system (40) includes a vacuum subsystem (41). The vacuum subsystem (41) is connected to the second crucible exhaust port (16), and the vacuum subsystem (41) can evacuate the cold crucible.

16. A test method for the interaction between melt and nuclear power special materials, characterized in that: Use the test device according to any one of claims 1 to 15, and comprising the following steps: Pre-test preparation step S1, preparing a heat-resistant layer on the inner surface of the smelting container assembly (10), loading the melt (21) and the nuclear power special material (23) into the smelting container assembly (10), and moving the electromagnetic and shielding control system (30) to the starting position; test operation step S2, starting the water cooling system, providing a gas environment to the inside of the smelting chamber (100) through the gas control system (40), performing electromagnetic induction heating on the melt (21) through the electromagnetic and shielding control system (30), and shielding the nuclear power special material (23) from electromagnetic interference, measuring the temperature inside the molten pool and the nuclear power special material (23) through the temperature measurement system (50), and moving the electromagnetic and shielding control system (30) until the melt (21) is completely melted and then contacts and reacts with the nuclear power special material (23); In the post-test processing step S3, the smelting vessel assembly (10) is disassembled after cooling, the reaction between the molten material (21) and the nuclear power special material (23) is observed and recorded, and materials in different areas are sampled and subjected to elemental and phase analysis.

17. The test method according to claim 16, characterized in that: The pre-test preparation step S1 includes a pre-embedded thermocouple sub-step S1-4, wherein a plurality of thermocouples (52) are inserted from the bottom of the crucible (13) into the nuclear power special material (23) at different depths and records are kept; in the test operation step S2, the power supply is promptly turned off after the thermocouple (52) located at the lowest point is damaged; and in the post-test processing step S3, a data analysis sub-step S3-3 is included, wherein the ablation rate is calculated according to the insertion depth and damage time of the thermocouple (52).

18. The test method according to claim 16, characterized in that: The pre-test preparation step S1 includes an electromagnetic and shielding control system moving sub-step S1-3, moving the induction coil (31) to the coil center and flush with the upper edge of the molten material (21), and moving the shielding ring assembly (36) to the upper edge of the shielding ring assembly (36) and flush with the upper edge of the nuclear power special material (23); the test operation step S2 includes a molten nuclear power special material reaction sub-step S2-5, after the molten pool liquid level drops, the induction coil (31) is moved downward according to the coil width, the power is increased or decreased according to the melting and material splashing conditions, and the current is always kept within the limit during the movement and heating process, and the above operation is repeated until the lower edge of the coil is flush with the upper edge of the shielding ring assembly (36). After stabilization for a period of time, the shielding ring assembly (36) is moved downward to start the reaction, so that all the melted molten material (21) contacts and reacts with the nuclear power special material (23).

19. The test method according to claim 16, characterized in that: In the test operation step S2, a molten pool temperature measurement sub-step S2-4 is included. According to the charging height, the hollow tungsten tube (43) is first lowered to the surface of the molten material (21). While lowering, an inert gas is introduced into the hollow tungsten tube (43). The hollow tungsten tube (43) is driven to knock downward until the hard shell is broken. The hollow tungsten tube (43) is immersed in the molten pool for 2 to 3 minutes. The reading of the infrared thermometer (51) is recorded. After the measurement is completed, the hollow tungsten tube (43) is reset in time.

20. The test method according to claim 16, characterized in that: The pre-test preparation step S1 includes a material loading sub-step S1-2, wherein the material is loaded into the cold crucible. If powder material is loaded, the powder is compacted using a tool after loading. If block material is loaded, the gap is filled with powder after loading. If the melt (21) is a non-conductive solid substance, a melting starter metal (22) is pre-buried on the upper layer of the melt (21); and the loading heights of the nuclear power special material (23) and the melt (21) are recorded.

21. The test method according to claim 18, characterized in that: In the test operation step S2, including the melt starting sub-step S2-3, the power supply component is started to preheat the melt (21), the power is gradually increased to 20-40kW, the smoke filter subsystem (45) is turned on according to the smoke production condition, the current begins to decrease after part of the melt (21) is melted, and the power is gradually increased until the melt (21) in the induction coil (31) is completely melted. During the heating process, the molten pool is observed, and if the material splashes seriously, the power is reduced; The method further includes a reaction gas analysis sub-step S2-6. If it is necessary to analyze the gas generated by the reaction, after the melt (21) and the nuclear power special material (23) begin to react, the gas analysis subsystem (44) is turned on, and at the same time, an inert gas is introduced into the hollow tungsten tube (43) to ensure that the pressure in the smelting chamber (100) is stable.

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