A liquid lead-bismuth high-speed erosion and corrosion device and method with controllable flow rate

Abstract

The invention belongs to the technical field of material corrosion resistance testing, and discloses a liquid lead-bismuth high-speed erosion-corrosion device and method with controllable flow rate, comprising a liquid lead-bismuth environment module, an air supply module, a control module and a loading module; a liftable liquid-cooled sealing section is constructed by a KF flange water-cooled sealing lower connecting pipe and a KF flange water-cooled sealing upper connecting pipe, and a method combining a ferrule connection and a KF vacuum seal is used to achieve a telescopic lifting effect of the water-cooled section; in conjunction with a lifting platform, the accuracy of the erosion-corrosion test results can be guaranteed to the maximum extent, and the static oxidation corrosion influence of the liquid metal on the sample during the oxygen reduction process in the early stage of the test can be prevented; at the same time, a baffle plate is added to the inner wall of the test kettle to limit the relative flow caused by the viscosity of the liquid metal during the rotation of the re-corrosion test stand, thereby greatly reducing the error between the erosion speed calculated by the motor speed and the actual erosion speed.

Description

Technical Field

[0001] The invention belongs to the technical field of material corrosion resistance testing, and in particular relates to an erosion corrosion testing device and a testing method. Background Art

[0002] With the continuous growth of global energy demand, the sustainable development of society is facing severe challenges, which has accelerated the exploration and research of new energy sources. Nuclear energy has attracted much attention due to its many advantages such as cleanliness, high energy density, low cost and reliability, but the special environment of nuclear reactors has put forward higher requirements for structural materials, such as resistance to radiation damage, liquid metal corrosion and embrittlement. In order to meet this challenge, countries around the world have conducted systematic research on candidate structural materials such as ferrite / martensite, austenite, ODS, etc. Among them, the erosion corrosion test in the lead-bismuth environment is crucial for evaluating the performance of structural materials in the nuclear reactor environment. As an important development direction of future nuclear energy technology, the operating environment and conditions of the lead-bismuth fast reactor have put forward extremely high requirements on the corrosion resistance and erosion resistance of structural materials. By simulating the environment in the actual reactor, the erosion corrosion test can deeply understand the corrosion behavior and performance of the material in the lead-bismuth melt, and provide a scientific basis for the material selection and structural design of the reactor. This test not only helps to ensure the safety and reliability of the reactor and reduce the operating risk, but also optimizes the performance of the reactor and improves the energy utilization efficiency. In addition, the results of the erosion corrosion test are also of great guiding significance for the maintenance and overhaul of the reactor, which can reduce maintenance costs and extend the service life of the reactor. Therefore, the erosion corrosion test in the lead-bismuth environment is an indispensable part of the research and development and application of nuclear reactor technology.

[0003] At present, the erosion corrosion test devices in the lead-bismuth environment all drive the corrosion platform to rotate through the rotating shaft, and use complex fluid simulation to calculate the relative speed of the sample. However, this calculation method idealizes the fluidity of lead-bismuth and has large errors; it mainly focuses on the saturated oxygen liquid lead-bismuth environment, and cannot achieve the oxygen concentration control of lead-bismuth, which makes it difficult to study the environmental damage of materials under the actual service conditions of nuclear power plants; and most of them are double-reactor structures of test reactors and oxygen control reactors. When used, the liquid metal in the oxygen control reactor must be controlled to the target oxygen concentration before the lead-bismuth is transported to the test reactor through the lead-bismuth pump, vacuum pump and delivery pipeline, which makes the entire device structure more complicated, the test operation more difficult, the manufacturing cost higher, and will cause huge fluctuations in oxygen concentration during the process; there are also some single-reactor structures that can achieve oxygen control, but when used, the sample must first be placed in liquid metal with saturated oxygen concentration, and then the oxygen concentration in the test reactor must be controlled to be reduced, but oxygen control takes a long time, so it will cause obvious oxidation corrosion of the sample during the oxygen control process, which will affect the final test results of oxygen control corrosion. Therefore, in order to establish a more accurate corrosion failure model of structural materials in a lead-bismuth environment, test their various corrosion performance parameters in a liquid lead-bismuth environment, and reduce the cost, structural complexity and operation difficulty of the test equipment, it is necessary to develop a set of liquid lead-bismuth high-speed erosion corrosion technology with controllable flow rate in a lead-bismuth environment. Summary of the invention

[0004] The present invention focuses on solving the problem of oxidative corrosion in the oxygen reduction process of a single-pot corrosion device under a high-speed lead-bismuth environment, as well as the relative flow problem between liquid metal and the test bench during the test process. A liquid lead-bismuth high-speed scouring corrosion device and method with controllable flow rate are provided, which can accurately obtain corrosion results and easily obtain a relatively accurate scouring speed while simplifying the equipment structure and optimizing the test process, making the processing of subsequent test data more reliable and true, and facilitating obtaining a better mechanical model to guide engineering applications.

[0005] In order to achieve the above-mentioned object of the invention, the present invention is implemented by the following technical solutions:

[0006] According to one aspect of the present invention, there is provided a liquid lead-bismuth high-speed erosion and corrosion device with controllable flow rate, comprising a test kettle, a heating cavity is arranged outside the test kettle, and the test kettle is sealed and connected to a test kettle upper cover;

[0007] The upper cover of the test kettle is connected with an air inlet pipeline and an air outlet pipeline, and is connected with an oxygen concentration control module and a temperature control module; a KF flange pipe is arranged at the center of the upper cover of the test kettle, and a KF flange water-cooled sealed lower connecting pipe and a KF flange water-cooled sealed upper connecting pipe are sequentially connected to the KF flange pipe; the KF flange water-cooled sealed lower connecting pipe forms a KF sealed connection with the KF flange pipe; the KF flange water-cooled sealed lower connecting pipe has a double-layer tube wall, an annular cavity is provided between the double-layer tube walls, and an annular opening is formed on the top surface of the double-layer tube wall; the KF flange water-cooled sealed upper connecting pipe has a single-layer tube wall, which can The water-cooled seal of the KF flange can be inserted between the double-layer tube walls of the lower connecting tube of the KF flange water-cooled seal through the annular opening; and the lower part of the single-layer tube wall of the upper connecting tube of the KF flange water-cooled seal is covered with a rubber sealing sleeve; the upper connecting tube of the KF flange water-cooled seal can slide axially relative to the lower connecting tube of the KF flange water-cooled seal, and can form a dynamic seal through the rubber sealing sleeve; the lower outer side of the double-layer tube wall of the lower connecting tube of the KF flange water-cooled seal is provided with a cooling liquid inlet and the upper outer side is provided with a cooling liquid outlet. When in use, a cooling medium is introduced from the cooling liquid inlet and discharged from the cooling liquid outlet to form a sleeve-type cooling sealing cavity;

[0008] A sealing rotation mechanism is arranged on the upper connecting pipe of the KF flange water-cooled seal, and the sealing rotation mechanism comprises a bearing seat, the lower part of the bearing seat forms a KF sealing connection with the upper connecting pipe of the KF flange water-cooled seal, and the upper part of the bearing seat is sealed and connected with the servo loading system; a roller bearing is arranged inside the bearing seat, and the roller bearing supports a power output shaft, the top of the power output shaft is connected with the output shaft of the servo loading system, and the bottom of the power output shaft is connected with the stand support rotating shaft, and the power output shaft and the stand support rotating shaft are connected and pass through the lower connecting pipe of the KF flange water-cooled seal, the upper connecting pipe of the KF flange water-cooled seal and the KF flange connecting pipe in sequence; the rotating sealing medium is arranged between the bearing seat and the power output shaft, and the rotating sealing medium is used to form a dynamic seal for the rotation of the power output shaft;

[0009] The servo loading system is connected to a lifting platform, and the lifting platform is used to support the servo loading system and drive the servo loading system to move up and down; the servo motor and reducer of the servo loading system are used to provide power to the power output shaft and adjust the speed;

[0010] A plurality of corrosion stands are installed at the lower part of the stand support shaft, and the corrosion stands are used to install samples; the corrosion stands can realize the use of samples with the lifting and lowering of the stand support shaft, and the rotation of the stand support shaft can realize the flushing of samples;

[0011] The inner wall of the test kettle is installed with multiple layers of baffles, which are spaced apart in the axial direction of the test kettle, and the multiple baffles in each layer are evenly spaced apart in the circumferential direction of the inner wall of the test kettle, and each baffle is arranged axially and extends radially along the test kettle; the spacing between two adjacent layers of baffles should be designed to avoid interference with the corrosion test bench.

[0012] Furthermore, the heating cavity is sleeved on the outside of the test kettle, and can heat the test kettle from the bottom and the surrounding side.

[0013] Furthermore, the test kettle is connected to the test kettle upper cover by bolts via a flange connection end at the top thereof, and a graphite gasket is used to seal the connection.

[0014] Furthermore, the upper cover of the test kettle is provided with a CF flange connecting pipe, and the CF flange connecting pipe and the air inlet pipeline form a CF flange vacuum seal; the upper cover of the test kettle is welded with an air outlet pipeline, and the air outlet pipeline is externally connected to a one-way valve.

[0015] Furthermore, the oxygen concentration control module includes a CF welding flange arranged on the upper cover of the test kettle, and the CF welding flange is used to form a CF flange vacuum seal with the oxygen concentration sensor; the oxygen concentration sensor is used to monitor the oxygen concentration in the test kettle and transmit the oxygen concentration to the PLC, and the PLC controls the air intake pipeline to stabilize the oxygen concentration in the test kettle at a set value; the temperature control module includes a thermocouple KF flange pipe arranged on the upper cover of the test kettle, and the thermocouple KF flange pipe is used to form a KF vacuum seal with the KF thermocouple; the KF thermocouple is used to feed back the temperature in the test kettle to the temperature controller, and the temperature controller stabilizes the temperature in the test kettle at a set value by controlling the heating cavity.

[0016] Furthermore, multiple layers of the corrosion racks are spaced apart at the bottom of the rack support shaft, and each layer is provided with at least one corrosion rack.

[0017] Furthermore, the corrosion stand adopts a metal cylinder with an external thread on one end, and the external thread is used to be fixed to the internal threaded hole provided on the stand support shaft through a threaded connection; the metal cylinder of the corrosion stand has a plurality of through holes spaced apart along its axial direction, and the through holes can be used to fix the sample by binding with metal wire.

[0018] Furthermore, a T-shaped groove is provided on the inner wall of the test kettle, and a T-shaped protrusion is correspondingly provided on the baffle plate, and the baffle plate is fixed to the test kettle by a concave-convex mortise and tenon structure.

[0019] Furthermore, the thickness of the baffle plate gradually decreases from the inner wall of the test kettle toward the axial direction.

[0020] According to another aspect of the present invention, a liquid lead-bismuth high-speed erosion and corrosion method with controllable flow rate based on the above device is provided, comprising:

[0021] Before the test begins, the KF flange water-cooled seal upper connecting pipe is connected and assembled with the KF flange water-cooled seal lower connecting pipe, the cooling liquid inlet is connected with the water cooler outlet, and the cooling liquid outlet is connected with the water cooler inlet to ensure the circulation of the coolant; and the baffle is installed on the inner wall of the test kettle, and the corrosion stand is installed at the lower part of the stand support shaft;

[0022] After the lead-bismuth alloy inside the test kettle is melted, the test kettle and the test kettle upper cover are sealed and assembled, and the corrosion bench is raised to the upper limit position by the lifting platform to ensure that the sample does not contact with the liquid metal;

[0023] After the internal temperature and oxygen concentration of the test kettle are stabilized at the set values, the corrosion stand is lowered to the lower limit position by the lifting platform to ensure that the sample is completely immersed in the liquid metal.

[0024] The beneficial effects of the present invention are:

[0025] (I) The present invention constructs a liftable liquid-cooled sealing section through a KF flange water-cooled sealing lower connecting pipe and a KF flange water-cooled sealing upper connecting pipe, and uses a combination of a ferrule connection and a KF vacuum seal to achieve a telescopic lifting effect of the water-cooled section; in conjunction with a lifting platform, the accuracy of the erosion-corrosion test results can be guaranteed to the maximum extent, and the static oxidation corrosion of the sample by the liquid metal during the oxygen reduction process in the early stage of the test can be prevented, and the complexity of the liquid lead-bismuth high-speed erosion-corrosion device with a controllable flow rate can be greatly reduced. The target effect can be achieved without adopting a double-kettle connection, and the corrosion test requirements of iron / horsepower, ODS, austenitic steel and other alloys can be met.

[0026] (ii) The present invention increases the baffle plate on the inner wall of the test kettle to limit the relative flow caused by the viscosity of the liquid metal (related to temperature) during the rotation of the corrosion test bench, thereby greatly reducing the error between the scouring speed calculated by the motor speed and the actual scouring speed. The specially designed corrosion test bench can be used to perform high-throughput corrosion tests. Compared with the lead-bismuth environment test machines on the market, it has a light structure, high adaptability, and simple operation. At the same time, the baffle plate can be changed in shape or adjusted in distribution to adapt to corrosion samples of various shapes, which can realize complex corrosion conditions of the samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the structure of a liquid lead-bismuth high-speed erosion and corrosion device provided in an embodiment of the present invention;

[0028] Figure 2 for Figure 1 A schematic cross-sectional view of the connection between the middle upper water-cooling sealing pipe and the lower water-cooling sealing pipe;

[0029] Figure 3 for Figure 1 Schematic diagram of the suspended state of the medium corrosion test bench;

[0030] Figure 4 for Figure 1 Schematic diagram of the immersion state of the medium corrosion test bench;

[0031] Figure 5 for Figure 1 A schematic diagram of the axial structure of the middle baffle;

[0032] Figure 6 for Figure 1 A schematic cross-sectional view of the middle seal rotating mechanism;

[0033] Figure 7 This is a comparison chart of the fluid flow velocity simulation in the test kettle without and with baffles.

[0034] In the above figure: 1-servo loading system, 2-lifting platform, 3-thermocouple, 4-check valve, 5-KF flange pipe, 6-air outlet pipe, 7-thermocouple KF flange pipe, 8-heating chamber, 9-test kettle, 10-test kettle cover, 11-CF welding flange, 12-oxygen sensor, 13-CF flange pipe, 14-air inlet pipe, 15-KF flange water-cooled seal lower connecting pipe, 1501-cooling inlet, 1502-KF flange with hole, 1503-cooling outlet, 16-KF flange water-cooled seal upper connecting pipe, 1601-rubber sealing sleeve, 17-sealed rotating mechanism, 1701-ball bearing, 1702-rotating sealing medium, 1703-power output shaft, 1704-bearing seat, 18-test bench support shaft, 19-corrosion test bench, 20-baffle. DETAILED DESCRIPTION

[0035] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:

[0036] like Figure 1 As shown, this embodiment provides a liquid lead-bismuth high-speed erosion and corrosion device with controllable flow rate, which includes: a liquid lead-bismuth environment module, a gas supply module, a control module and a loading module.

[0037] The liquid lead-bismuth environment module includes a heating chamber 8, a test kettle 9, a test kettle upper cover 10, a KF flange connecting pipe 5, a lower KF flange water-cooling sealing pipe 15, an upper KF flange water-cooling sealing pipe 16, and a baffle 20, which can ensure good sealing and stably realize a liquid metal environment.

[0038] The heating chamber 8 is a cylindrical structure that is sleeved on the outside of the test kettle 9, and can heat the test kettle 9 from the bottom and the surrounding side, making the heating faster and more stable, and achieving a better heating effect. The heating chamber 8 can adjust the internal temperature of the test kettle 9 within the range of 30-600°C.

[0039] The top of the test kettle 9 has a flange connection end, and its flange connection end is provided with circumferentially evenly distributed and axially penetrating through holes, which are used to connect with the through holes provided on the upper cover 10 of the test kettle through bolts. In addition, the surface of the flange connection end of the test kettle 9 has a groove, and the groove is used to place a graphite gasket to achieve sealing at the connection between the test kettle 9 and the upper cover 10 of the test kettle. The test kettle 9 and the upper cover 10 of the sample kettle are both made of corrosion-resistant 410 stainless steel material, and their sizes are customized according to the number of tests required. Various environmental accessories can be set inside the test kettle 9, including but not limited to corrosive environment, high temperature environment, inert gas environment, hydrogen environment, etc.

[0040] A KF flange pipe 5 is provided at the center of the test kettle upper cover 10, and the KF flange pipe 5 is used to pass through the stand support shaft 18. The KF flange pipe 5 is sequentially connected with a KF flange water-cooled seal lower connecting pipe 15 and a KF flange water-cooled seal upper connecting pipe 16, and a sealing rotating mechanism 17 is provided on the KF flange water-cooled seal upper connecting pipe 16.

[0041] Combination Figure 2 As shown, the bottom end of the KF flange water-cooled seal lower connecting pipe 15 is provided with a vacuum-welded KF flange, which is used to connect with the KF flange pipe 5 and cooperate with the KF sealing assembly to form a KF sealing connection. The top end of the KF flange water-cooled seal upper connecting pipe 16 is provided with a vacuum-welded KF flange, which is used to connect with the vacuum-welded KF flange provided at the lower end of the sealing rotating mechanism 17 and cooperate with the KF sealing assembly to form a KF sealing connection.

[0042] The KF flange water-cooled seal lower connecting pipe 15 has a double-layer pipe wall, an annular cavity is provided between the double-layer pipe walls, and an annular opening is formed on the top surface of the double-layer pipe wall. The KF flange water-cooled seal upper connecting pipe 16 has a single-layer pipe wall, which can be inserted between the double-layer pipe walls of the KF flange water-cooled seal lower connecting pipe 15 through the annular opening, and there is a distance between the double-layer pipe walls of the KF flange water-cooled seal lower connecting pipe 15, so that the KF flange water-cooled seal upper connecting pipe 16 can slide axially relative to the KF flange water-cooled seal lower connecting pipe 15. At the same time, a rubber sealing sleeve 1601 is sleeved on the lower part of the single-layer tube wall of the KF flange water-cooled seal upper connecting tube 16. By utilizing the deformation characteristics of the rubber sealing sleeve 1601, after the KF flange water-cooled seal lower connecting tube 15 and the KF flange water-cooled seal upper connecting tube 16 are nested and connected, the rubber sealing sleeve 1601 can form an interference fit with the annular cavity between the double-layer tube wall of the KF flange water-cooled seal lower connecting tube 15, thereby achieving a sealing effect.

[0043] The lower outer side of the double-layer tube wall of the KF flange water-cooled seal lower connecting tube 15 is provided with a cooling liquid inlet 1501 and the upper outer side is provided with a cooling liquid outlet 1503. When in use, the cooling medium is introduced from the cooling liquid inlet 1501 and discharged from the cooling liquid outlet 1503 to form a sleeve-type cooling seal cavity. The cooling liquid in the sleeve-type cooling seal cavity also has the function of forming a liquid seal, which can prevent the internal gas of the test kettle 9 from overflowing through the annular cavity of the KF flange water-cooled seal lower connecting tube 15.

[0044] It can be seen that the whole after the KF flange water-cooled seal lower connecting pipe 15 and the KF flange water-cooled seal upper connecting pipe 16 are connected is used to pass through the bench support shaft 18 and the power output shaft 1703, which can not only provide an effective water cooling effect, but also realize axial telescopic lifting and lowering, and at the same time form a liquid seal to ensure sealing, thereby achieving a more accurate corrosion test effect. In this way, through the dynamic sealing effect of the KF flange water-cooled seal lower connecting pipe 15 and the KF flange water-cooled seal upper connecting pipe 16, the axial movement of the bench support shaft 18 in a sealed state can be realized. Compared with the previous design of using double kettles to connect and control the liquid metal immersion sample, it can also achieve the effect of avoiding the static corrosion effect of the liquid metal on the sample during the oxygen reduction process in the early stage of the test. Therefore, the complexity of the liquid lead-bismuth scouring corrosion device on the domestic market is greatly reduced, and the oxidation corrosion problem caused by the oxygen reduction process of the liquid lead-bismuth environment on the market is solved, so that the corrosion results can be accurately obtained, and the water cooling effect of the sealing section can be achieved, thereby reducing the severity of the seal.

[0045] like Figure 3 and Figure 4As shown, a plurality of baffles 20 are installed on the inner wall of the test kettle 9. The plurality of baffles 20 are spaced apart axially along the test kettle 9. The plurality of baffles 20 in each layer are evenly spaced apart circumferentially on the inner wall of the test kettle 9. Each baffle 20 is axially arranged and radially extends along the test kettle 9. The baffles 20 are used to prevent relative flow between the liquid and the corrosion test bench 19 to ensure uniformity of liquid flow.

[0046] As a preferred embodiment, the multi-layer baffles 20 are spaced 60 mm apart along the axial direction of the test kettle 9, and the angle between adjacent baffles 20 of each layer is 60°.

[0047] As a preferred embodiment, a T-shaped groove is provided on the inner wall of the test kettle 9, and a T-shaped protrusion is also provided on the baffle plate 20. The baffle plate 20 is fixed with a concave-convex mortise and tenon structure to facilitate disassembly and replacement.

[0048] By adding a baffle 20 in the test kettle 9, the flow of liquid metal caused by the rotation of the corrosion bench 19 during the test can be avoided, so that only the corrosion bench 19 rotates while the liquid metal is close to a stationary state. Then, the motor speed can be calculated through the laws of mechanical physics to obtain a more accurate scouring speed; that is, by applying simple physical formulas, the scouring speed can be calculated more accurately, which greatly simplifies the complexity of scouring corrosion data processing, makes the processing of subsequent test data more reliable and realistic, and facilitates obtaining a better mechanical model to guide engineering applications.

[0049] like Figure 5 As shown, this embodiment provides a preferred shape design of the baffle plate 20 , and the thickness of the baffle plate 20 gradually decreases from the inner wall of the test kettle 9 toward the axial direction, thereby achieving the purpose of improving the baffle effect of the baffle plate 20 .

[0050] The gas supply module includes an air inlet pipeline 14, an air outlet pipeline 6, a one-way valve 4 and corresponding sealing components to provide a suitable and safe gas environment for realizing an oxygen-controlled liquid lead-bismuth environment. The air inlet pipeline 14 is used to introduce argon, oxygen or argon / hydrogen mixed gas into the test kettle 9, while the air outlet pipeline 6 is used to discharge and collect the mixed gas in the test kettle 9. Both the air inlet pipeline 14 and the air outlet pipeline 6 are made of corrosion-resistant stainless steel pipes. In order to maximize the retention time of the gas in the cavity and better control the oxygen concentration in the test kettle 9, the air inlet pipeline 14 and the air outlet pipeline 6 are preferably connected to the central point of the sample kettle cover 10 at an angle of 90°, and are as close to the inner wall of the test kettle 9 as possible without affecting the assembly. The air outlet pipeline 6 is welded and fixed to the test kettle cover 10, and the air outlet pipeline 6 is externally connected to the one-way valve 4 to prevent gas reflux from affecting the gas concentration in the test kettle 9. After the air inlet pipe 14 is vacuum welded with the CF vacuum flange, it forms a CF flange vacuum seal with the CF flange pipe 13 installed on the test kettle upper cover 10, and the two are connected by flange threads. The length of the air inlet pipe 14 is set to a depth of 2 / 3 that can fully enter the test kettle 9, so that the oxygen concentration of the liquid metal near the sample position can change first, thereby reducing the impact of gas diffusion lag.

[0051] The control module includes an oxygen concentration sensor 12, a PLC, a KF thermocouple 3, and a temperature controller, which are used to realize the oxygen concentration control and temperature control of the lead-bismuth environment. The lower end of the oxygen concentration sensor 12 is provided with a CF vacuum flange, which cooperates with the CF welding flange 11 welded on the upper cover 10 of the test kettle to form a vacuum seal. The position of the oxygen concentration sensor 12 is as close as possible to the inner wall of the test kettle 9 to ensure that it will not interfere with other moving structures inside the test kettle 9. The oxygen concentration sensor 12 is used to monitor the oxygen concentration in the test kettle 9 and transmit the data to the PLC. The PLC controls the switch of the solenoid valve on the intake pipe 14 through a preset program to stabilize the oxygen concentration in the test kettle 9 at a set value. The KF thermocouple 3 is connected to the thermocouple KF flange pipe 7 welded on the upper cover 10 of the test kettle to form a KF vacuum seal. The KF thermocouple 3 feeds back the temperature in the test kettle 9 to the temperature controller, and the temperature controller stabilizes the temperature at a set value by controlling the switch of the heating cavity 8.

[0052] The loading module includes a servo loading system 1, a lifting platform 2, a sealing rotating mechanism 17, a stand support shaft 18, a corrosion stand 19, etc., which are used to realize high-speed erosion corrosion testing in a high-temperature lead-bismuth environment. The lifting platform 2 can be set on a plane near the test kettle 9, and is mainly used to support the servo loading system 1 composed of a servo motor and a reducer, and can also drive the servo loading system 1 to rise and fall. The servo loading system 1 includes a servo motor and a reducer, which are used to provide power to the power output shaft 1703 of the sealing rotating mechanism 17 and adjust the speed.

[0053] Combination Figure 5 As shown, the sealing rotating mechanism 17 includes a ball bearing 1701, a rotating sealing medium 1702, a power output shaft 1703, and a bearing seat 1704, which can ensure good rotating sealing performance while ensuring the normal operation of the power output shaft 1703. A roller bearing 1701 is arranged inside the bearing seat 1704, and the roller bearing 1701 is used to support the power output shaft 1703. The top of the power output shaft 1703 is connected to the output shaft of the servo loading system 1 through a coupling, and the bottom is connected to the stand support shaft 18. The rotating sealing medium 1702 preferably adopts a graphite packing, which is arranged between the power output shaft 1703 and the bearing seat 1704, and is located below the bearing seat 1704. The upper end of the bearing seat 1704 is threadedly connected to the servo loading system 1 through a thread and a sealing ring to form a seal, and the lower end of the bearing seat 1704 forms a KF seal with the upper connecting pipe 16 of the KF flange water-cooled seal. Through the filling method of the ball bearing 1701 and the rotating sealing medium 1702, combined with the sealing connection at both ends of the bearing seat 1704, a good axial and rotating sealing effect can be ensured, which is suitable for high-temperature lead-bismuth test environment.

[0054] The top of the stand support shaft 18 is connected to the lower part of the power output shaft 1703 through a coupling. On the one hand, it can be lifted and lowered along with the power output shaft 1703 and the servo loading system 1 under the action of the lifting platform 2, and on the other hand, it can be rotated along with the power output shaft 1703 under the action of the servo loading system.

[0055] Several corrosion stands 19 are installed at the bottom of the stand support shaft 18. The lifting and lowering of the corrosion stands 19 can realize the access of the sample, and the rotation of the corrosion stands 19 can realize the flushing of the sample at a speed of 0-12m / s. Multiple layers of corrosion stands 19 can be arranged at intervals at the bottom of the stand support shaft 18, and the distance between two adjacent layers of corrosion stands 19 is set to avoid interference with the baffle 20. The distance between the corrosion platforms 19 and the thickness of the baffle 20 can be increased or decreased according to different test requirements, so that multiple corrosion can be carried out simultaneously.

[0056] As a preferred embodiment, the corrosion stand 19 adopts a metal cylinder with a length of about 150 mm. One end of the metal cylinder is provided with an external thread for being fixed to the internal threaded hole provided on the stand support shaft 18 through a threaded connection. The metal cylinder of the corrosion stand 19 is provided with a plurality of through holes at intervals of 30 mm, and the through holes can be used to bind and fix the specimens by means of metal wires. In addition, the corrosion stand 19 can be replaced with platforms of other shapes and lengths to adapt to structures of different shapes and sizes. In this way, the device can not only carry out batch tests at the same time, but also obtain scour tests within a wider speed band by setting different gyration radii, thereby making the entire device more adaptable.

[0057] It can be seen that the present invention provides a liquid lead-bismuth high-speed erosion-corrosion device with controllable flow rate, which controls the gas flow rate around PLC and the test oxygen concentration around the high-temperature sealed test kettle, and makes the corrosion bench 19 rotate at different speeds around the servo loading system 1 to test the erosion corrosion under different flow rates, and achieves the effect of sealing and lifting the corrosion platform 19 around the KF flange water-cooled sealed lower connecting pipe 15 and the KF flange water-cooled sealed upper connecting pipe 16, and greatly reduces the oxidative corrosion of the sample during the oxygen reduction process in the early stage of the test, and limits the movement between the liquid metal and the corrosion bench 19 during the experiment around the baffle 20 to ensure the accuracy of the flow rate.

[0058] Based on the above-mentioned liquid lead-bismuth high-speed scouring and corrosion device with controllable flow rate, the present invention also provides a liquid lead-bismuth high-speed scouring and corrosion device method with controllable flow rate, including the following process:

[0059] (1) The servo loading system 1 is connected to the lifting platform 2 by bolts, the output end of the servo motor is sealed to the upper end of the sealed rotating mechanism 17, and the power output shaft 1703 is connected to the stand support shaft 18 by a coupling to complete the assembly of the power transmission path.

[0060] (2) The rubber sealing sleeve 1601 is nested and connected with the lower end of the KF flange water-cooled seal upper connecting pipe 16, and then the KF flange water-cooled seal lower connecting pipe 15 and the KF flange water-cooled seal upper connecting pipe 16 are connected and assembled to complete the assembly of the sealed water-cooled section; and the KF flange at the lower end of the KF flange water-cooled seal lower connecting pipe 15 and the KF flange connecting pipe 5 are matched with the KF assembly to form a KF seal, and the KF flange at the upper end of the KF flange water-cooled seal upper connecting pipe 16 and the KF flange at the lower end of the sealing rotating mechanism 17 are matched with the KF assembly to form a KF seal.

[0061] (3) Assemble and match the thermocouple 3, the air intake pipe 14, the oxygen sensor 12, etc. with the corresponding sealing positions of the test kettle cover 10 to ensure the sealing of the gas path, and complete the assembly of the test kettle cover 10.

[0062] (4) The baffle plate 20 is installed on the inner wall of the test kettle 9 through a T-shaped mortise and tenon connection, and the corrosion test bench 19 is connected to the test bench support shaft 18 through internal and external threads to complete the assembly of the test kettle 9.

[0063] (5) Fix the corrosion sample in the through hole set in the corrosion stand 19 by iron wire or other metal wire-like objects to ensure the stability of the fixation and complete the sample setting.

[0064] (6) Connect the cooling liquid inlet 1501 to the outlet of the water cooler, and connect the cooling liquid outlet 1503 to the inlet of the water cooler to ensure the circulation of the coolant.

[0065] (5) Turn on the temperature controller to control the heating chamber 8 to heat up to 180°C, place a small piece of lead-bismuth eutectic alloy into the test kettle 9, wait for it to be completely melted, and then seal the test kettle 9 with the test kettle cover 10. At the same time, raise the corrosion test bench 19 to the upper limit position through the lifting platform 2 to ensure that the sample does not come into contact with the liquid metal.

[0066] (6) Before starting the experiment, argon gas is introduced into the test kettle 9 through the air inlet pipe 14 for about 5-10 hours for gas washing. The argon air inlet pipe is closed and the argon / hydrogen mixer air inlet pipe is started. The target temperature is adjusted by the temperature controller. At the same time, the temperature in the test kettle 9 is measured by the thermocouple 3, and its signal is fed back to the temperature controller. By controlling the intermittent heating of the heating chamber 8, the temperature value is automatically adjusted to stabilize at the set value (30-600°C). At the same time, the oxygen sensor 12 feeds back the oxygen concentration in the test kettle 9 to the electrical signal collector and PLC in real time. The PLC automatically controls the switches of the argon, argon / hydrogen mixed gas and oxygen gas line solenoid valves through the set program until the displayed voltage values ​​reach the required oxygen concentration.

[0067] (7) After the oxygen concentration and temperature in the test kettle 9 stabilize to the target values, the lifting platform 2 lowers the corrosion bench 19 to the lower limit position. At this time, it can be ensured that the sample is completely immersed. This treatment method can ensure that the sample does not undergo the deoxygenation process of the liquid metal during the entire corrosion process, thereby ensuring the rigor of the test results.

[0068] During the test, once the gas concentration detection device on the outer wall of the test kettle detects abnormal gas, the heating power is immediately cut off, the argon / hydrogen mixture and oxygen inlet valves are closed, and a large amount of argon is introduced into the test kettle 9 to ensure safety.

[0069] like Figure 7 As shown, the experimental effect of the present invention is demonstrated through a simulation example of 700K 10m / s. After 100 iterations, it can be clearly observed that the baffle 20 provided by the present invention can control the fluid flow rate within the range of 0-3m / s, while the fluid flow rate in the existing liquid metal erosion and corrosion device is within the range of 7-10m / s. It can be concluded that the baffle provided by the present invention can reduce the fluid flow rate by 70-100%, so there is a significant baffle effect.

[0070] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms of specific changes without departing from the scope of protection of the invention and the claims, all of which fall within the scope of protection of the present invention.

Claims

1. A liquid lead-bismuth high-speed erosion and corrosion device with controllable flow rate, comprising a test kettle, a heating cavity is arranged outside the test kettle, and the test kettle is sealed and connected to a test kettle upper cover; characterized in that: The upper cover of the test kettle is connected with an air inlet pipeline and an air outlet pipeline, and is connected with an oxygen concentration control module and a temperature control module; a KF flange pipe is arranged at the center of the upper cover of the test kettle, and a KF flange water-cooled sealed lower connecting pipe and a KF flange water-cooled sealed upper connecting pipe are sequentially connected to the KF flange pipe; the KF flange water-cooled sealed lower connecting pipe forms a KF sealed connection with the KF flange pipe; the KF flange water-cooled sealed lower connecting pipe has a double-layer tube wall, an annular cavity is provided between the double-layer tube walls, and an annular opening is formed on the top surface of the double-layer tube wall; the KF flange water-cooled sealed upper connecting pipe has a single-layer tube wall, which can The water-cooled seal of the KF flange can be inserted between the double-layer tube walls of the lower connecting tube of the KF flange water-cooled seal through the annular opening; and the lower part of the single-layer tube wall of the upper connecting tube of the KF flange water-cooled seal is covered with a rubber sealing sleeve; the upper connecting tube of the KF flange water-cooled seal can slide axially relative to the lower connecting tube of the KF flange water-cooled seal, and can form a dynamic seal through the rubber sealing sleeve; the lower outer side of the double-layer tube wall of the lower connecting tube of the KF flange water-cooled seal is provided with a cooling liquid inlet and the upper outer side is provided with a cooling liquid outlet. When in use, a cooling medium is introduced from the cooling liquid inlet and discharged from the cooling liquid outlet to form a sleeve-type cooling sealing cavity; A sealing rotation mechanism is arranged on the upper connecting pipe of the KF flange water-cooled seal, and the sealing rotation mechanism comprises a bearing seat, the lower part of the bearing seat forms a KF sealing connection with the upper connecting pipe of the KF flange water-cooled seal, and the upper part of the bearing seat is sealed and connected with the servo loading system; a roller bearing is arranged inside the bearing seat, and the roller bearing supports a power output shaft, the top of the power output shaft is connected with the output shaft of the servo loading system, and the bottom of the power output shaft is connected with the stand support shaft, and the power output shaft and the stand support shaft are connected and pass through the upper connecting pipe of the KF flange water-cooled seal, the lower connecting pipe of the KF flange water-cooled seal and the KF flange connecting pipe in sequence; a rotating sealing medium is arranged between the bearing seat and the power output shaft, and the rotating sealing medium is used to form a dynamic seal for the rotation of the power output shaft; The servo loading system is connected to a lifting platform, and the lifting platform is used to support the servo loading system and drive the servo loading system to move up and down; the servo motor and reducer of the servo loading system are used to provide power to the power output shaft and adjust the speed; A plurality of corrosion stands are installed at the lower part of the stand support shaft, and the corrosion stands are used to install samples; the corrosion stands can realize the use of samples as the stand support shaft is raised and lowered, and the corrosion stands can realize the flushing of samples as the stand support shaft is rotated; The inner wall of the test kettle is installed with multiple layers of baffles, which are spaced apart in the axial direction of the test kettle, and the multiple baffles in each layer are evenly spaced apart in the circumferential direction of the inner wall of the test kettle, and each baffle is arranged axially and extends radially along the test kettle, and the thickness of the baffle gradually decreases from the inner wall of the test kettle to the axial direction; the spacing between the baffles of two adjacent layers should be designed to avoid interference with the corrosion test bench.

2. The liquid lead-bismuth high-speed erosion and corrosion device with controllable flow rate according to claim 1 is characterized in that: The heating cavity is sleeved outside the test kettle and can heat the test kettle from the bottom and the surrounding side.

3. The liquid lead-bismuth high-speed erosion and corrosion device with controllable flow rate according to claim 1 is characterized in that: The test kettle is connected to the test kettle upper cover by bolts through the flange connection end at the top thereof, and the connection is sealed by a graphite gasket.

4. The liquid lead-bismuth high-speed erosion and corrosion device with controllable flow rate according to claim 1 is characterized in that: The upper cover of the test kettle is provided with a CF flange connecting pipe, and the CF flange connecting pipe and the air inlet pipeline form a CF flange vacuum seal; the upper cover of the test kettle is welded with an air outlet pipeline, and the air outlet pipeline is externally connected to a one-way valve.

5. The liquid lead-bismuth high-speed erosion and corrosion device with controllable flow rate according to claim 1 is characterized in that: The oxygen concentration control module includes a CF welding flange arranged on the upper cover of the test kettle, and the CF welding flange is used to form a CF flange vacuum seal with the oxygen concentration sensor; the oxygen concentration sensor is used to monitor the oxygen concentration in the test kettle and transmit the oxygen concentration to the PLC, and the PLC controls the air intake pipeline to stabilize the oxygen concentration in the test kettle at a set value; the temperature control module includes a thermocouple KF flange pipe arranged on the upper cover of the test kettle, and the thermocouple KF flange pipe is used to form a KF vacuum seal with the KF thermocouple; the KF thermocouple is used to feed back the temperature in the test kettle to the temperature controller, and the temperature controller stabilizes the temperature in the test kettle at a set value by controlling the heating cavity.

6. The liquid lead-bismuth high-speed erosion and corrosion device with controllable flow rate according to claim 1 is characterized in that: The multiple layers of corrosion racks are arranged at intervals below the rack support shaft, and each layer is provided with at least one corrosion rack.

7. The liquid lead-bismuth high-speed erosion and corrosion device with controllable flow rate according to claim 1 is characterized in that: The corrosion stand adopts a metal cylinder with an external thread on one end, and the external thread is used to be fixed to the internal thread hole provided on the stand support shaft through a threaded connection; the metal cylinder of the corrosion stand has a plurality of through holes distributed at intervals along its axial direction, and the through holes can be used to bind and fix the sample by metal wire.

8. The liquid lead-bismuth high-speed erosion and corrosion device with controllable flow rate according to claim 1 is characterized in that: The inner wall of the test kettle is provided with a T-shaped groove, and the baffle plate is correspondingly provided with a T-shaped protrusion, and the baffle plate is fixed to the test kettle through a concave-convex mortise and tenon structure.

9. A liquid lead-bismuth high-speed erosion and corrosion method based on a controllable flow rate device as claimed in any one of claims 1 to 8, characterized in that: include: Before the test begins, the KF flange water-cooled seal upper connecting pipe is connected and assembled with the KF flange water-cooled seal lower connecting pipe, the cooling liquid inlet is connected with the water cooler outlet, and the cooling liquid outlet is connected with the water cooler inlet to ensure the circulation of the coolant; and the baffle is installed on the inner wall of the test kettle, and the corrosion stand is installed at the lower part of the stand support shaft; After the lead-bismuth alloy inside the test kettle is melted, the test kettle and the test kettle upper cover are sealed and assembled, and the corrosion bench is raised to the upper limit position by the lifting platform to ensure that the sample does not contact with the liquid metal; After the internal temperature and oxygen concentration of the test kettle are stabilized at the set values, the corrosion stand is lowered to the lower limit position by the lifting platform to ensure that the sample is completely immersed in the liquid metal.

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