Research device and test method for deposition test of particles in high-temperature liquid lead bismuth

Abstract

The invention discloses an experimental research device and an experimental method for deposition of particles in high-temperature liquid lead bismuth, and belongs to the technical field of lead-based reactor thermotechnical waterpower. The device comprises a lead-bismuth liquid storage tank, a main loop, a test section, a sampling branch, a filtering branch, a heat exchange branch and a pipeline, the test section comprises a rod bundle structure with a winding wire, a rectangular channel with a visual window and a rectangular channel with a temperature measuring point; through the design of the test section of the device, the device can well test the influence of factors such as thermophoresis, gravity and buoyancy on particle deposition in a lead-bismuth medium, and can simulate the deposition of particles in liquid lead-bismuth on a pipeline wall surface and a reactor core rod bundle structure so as to analyze the deposition behavior of the particles in lead-bismuth; and meanwhile, basic experimental data is provided for numerical calculation in the field.

Description

Technical Field

[0001] The present invention relates to the technical field of lead-based reactor thermal-hydraulics, and particularly relates to an experimental research device and method for particle deposition in high-temperature liquid lead-bismuth. Background Art

[0002] Lead-cooled fast reactors use liquid metal lead-bismuth as the coolant of the nuclear reactor, which has the advantages of strong natural circulation ability, stable chemical properties, high inherent safety, etc., and occupies an important position in the research and development of small nuclear reactors. During the operation of the reactor, some in-core material debris particles or foreign particles may enter the coolant; at the same time, liquid lead-bismuth, as a highly corrosive substance, will cause dissolution corrosion and intergranular corrosion to the reactor structural materials, and its high-density characteristic will further exacerbate the corrosion and generate impurity particles in the loop. During the process of these particles flowing and spreading to various parts of the loop with lead-bismuth, they will deposit on the pipe wall and in-core components, and the particle deposition will affect the normal operation of the reactor and even lead to reactor accidents.

[0003] At present, due to the characteristics of liquid metal such as opacity, high temperature and high corrosiveness, it is difficult and costly to carry out relevant thermal-hydraulic experiments on liquid metal. Due to its opaque characteristic, there is a lack of direct observation means for the particle deposition process in lead-bismuth medium, and it is difficult to obtain detailed information on the deposition process. Usually, numerical calculations are used to carry out research, lacking experimental research data. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides an experimental device and method for studying the particle deposition characteristics in liquid lead-bismuth, which can simulate the deposition of particles in liquid lead-bismuth on the pipe wall and the rod bundle structure of the reactor core, so as to analyze the behavior of particle deposition in lead-bismuth, and at the same time provide basic experimental data for numerical calculations in this field.

[0005] The present invention provides an experimental research device for particle deposition in high-temperature liquid lead-bismuth, including a lead-bismuth storage tank, a main loop, a test section, a sampling branch 1, a sampling branch 2, a filtering branch, a heat exchange branch, and pipes;

[0006] On the pipeline of the main loop, a main loop regulating valve, a main loop flowmeter, a main loop electromagnetic pump, a main loop pressure sensor 1, a main loop temperature sensor 1, a test section, a main loop temperature sensor 2, a main loop pressure sensor 2, and a filtering stop valve are sequentially installed from the main loop inlet section to the main loop outlet section;

[0007] The top of the lead-bismuth storage tank is provided with an opening into which a heating rod is inserted, and the opening is sealed after the heating rod is inserted; the surface of the lead-bismuth storage tank is provided with a temperature sensor 3 and a pressure sensor 3; the top of the lead-bismuth storage tank is connected to the pipeline of the main loop outlet section, and the bottom is connected to the pipeline of the main loop inlet section; the lead-bismuth storage tank is connected to a particle addition branch, and the particle addition branch is provided with a particle addition branch stop valve and a particle addition device connected to an argon gas cylinder 1; the surface of the particle addition device is provided with a screw pusher;

[0008] On the pipeline of the main loop, a test section front stop valve and a test section rear stop valve are respectively installed at the front and rear ends of the test section; the test section front stop valve is located between the test section and the sampling branch 1, and the test section rear stop valve is located between the test section and the sampling branch 2; the front end of the sampling branch 1 and the rear end of the sampling branch 2 are connected in parallel to a pressurization branch; the surface of the test section is provided with a heat exchanger, and the two ends of the heat exchanger are connected to the heat exchange branch pipeline;

[0009] The filtration branch is connected to both ends of a filtration stop valve, and two groups of stop valves and filters are installed on the filtration branch. One group includes a filtration branch stop valve 1 and a filter 1, and the other group includes a filtration branch stop valve 2 and a filter 2; each group of stop valves and filters are connected in series first, and then the two groups are connected in parallel. When in use, the two filters are used alternately.

[0010] Further, the test section is one of a rod bundle structure test section with wire winding, a rectangular channel test section with a visualization window, and a rectangular channel test section with temperature measurement points. The outside of the test section is wrapped with heat insulation cotton; in the channel of the rod bundle structure test section with wire winding, the rod bundle structure can be heated with a constant heat flux, and the rod bundle structure is connected to external equipment through wires, and temperature measurement points are arranged at equal distances on the outer wall of the test section to monitor the temperature.

[0011] Further, the rectangular channel test section with a visualization window includes a test section main body and a toughened glass window embedded in the middle of the test section main body; a graphite gasket and a toughened glass cover plate are sequentially installed on the surface of the toughened glass window; epoxy resin sealant, high-temperature resistant glue or high-temperature resistant glass is applied between the test section main body, the graphite gasket and the toughened glass cover plate; a high-speed camera is arranged perpendicular to the flow direction outside the toughened glass window; in the rectangular channel test section with temperature measurement points, a constant heat flux heating method is adopted at one side wall surface, and temperature measurement points are arranged at equal distances on the heating side wall surface to monitor the change of the wall surface temperature.

[0012] Further, a vacuum pump branch is provided at the front end of the main loop temperature sensor 2, and the vacuum pump branch is a vacuum pump controlled by a vacuum pump branch stop valve; on the pipeline of the heat exchange branch, a heat exchange branch water tank, a heat exchange branch regulating valve and a heat exchange branch circulation pump are sequentially installed to control the cooling water circulation and the magnitude of the heat exchange amount.

[0013] Further, a flowmeter, a regulating valve, a ball valve, and a sample container of the sampling branch 1 are sequentially installed on the pipeline of the sampling branch 1; a flowmeter, a regulating valve, a ball valve, and a sample container of the sampling branch 2 are sequentially installed on the pipeline of the sampling branch 2; the regulating valves of the sampling branch 1 and the sampling branch 2 are used to adjust the flow rates of the sampling branch 1 and the sampling branch 2 to be consistent with the main circuit, and the ball valves of the sampling branch 1 and the sampling branch 2 are used to control the start and end of sampling.

[0014] Further, the test section is horizontally arranged on the pipeline of the main circuit or vertically arranged on the rising section pipeline of the main circuit; heat insulation cotton is wound on the outer sides of the pipelines of the main circuit, the sampling branch 1, the sampling branch 2, the filtering branch, the heat exchange branch, the particle addition branch, the pressurization branch, and the vacuum pump branch, and a heat tracing tape is wound on the pipeline of the main circuit.

[0015] The present invention further provides a test method for a test device for particle deposition in high-temperature liquid lead-bismuth, including the following steps:

[0016] Step 1: Heat the lead-bismuth through a heating rod in the lead-bismuth storage tank, and at the same time, energize the heat tracing tape wound on the pipeline of the main circuit to preheat the pipeline; turn on the vacuum pump, evacuate the pipeline of the main circuit, and then turn off the vacuum pump.

[0017] Step 2: Monitor the temperature of the lead-bismuth storage tank. After the lead-bismuth is completely melted, inject particles into the particle addition device, and push and tighten them through the screw pusher of the particle addition device; after tightening, turn on the argon gas cylinder 1, inject high-purity argon gas into the particle addition device to increase the pressure, and press the particles into the bottom of the lead-bismuth storage tank through the particle addition branch through the pressure difference for preliminary mixing with the lead-bismuth, and then turn off the argon gas cylinder 1.

[0018] Step 3: Check whether the temperatures at all parts of the test circuit meet the requirements. After meeting the requirements, open the regulating valve of the main circuit and the stop valve of the particle addition branch, turn on the argon gas cylinder 1, gradually increase the pressure in the pipeline, and then maintain it at a safe pressure that can press the lead-bismuth onto the circuit, turn off the argon gas cylinder 1, and turn off the stop valve of the particle addition branch.

[0019] Step 4: Start the main circuit electromagnetic pump to make the lead-bismuth circulate in the main circuit; open the sampling branch 1 ball valve and the sampling branch 2 ball valve, adjust the sampling branch 1 regulating valve and the sampling branch 2 regulating valve, and convert the flow rates of the sampling branch 1 and the sampling branch 2 through the sampling branch 1 flowmeter and the sampling branch 2 flowmeter, so that the lead-bismuth flow rates of the sampling branch 1 and the sampling branch 2 are consistent with that of the main circuit. Then close the sampling branch 1 ball valve and the sampling branch 2 ball valve, and replace the sample containers of the sampling branch 1 and the sampling branch 2; at different moments during the test, open the sampling branch 1 ball valve and the sampling branch 2 ball valve simultaneously, take samples within the same time period, close the sampling branch 1 ball valve and the sampling branch 2 ball valve after sampling, replace the new sample containers of the sampling branch 1 and the sampling branch 2, and record the samples at different moments for subsequent sample analysis;

[0020] Step 5: After the lead-bismuth starts to circulate in the main circuit, turn on the heating tape to heat the parts that need to be heated in the test section with a constant heat flux density. Continuously observe the temperature changes of the measuring points in the test section from the official start of the test. When the temperature of the measuring point stabilizes at a certain temperature and no longer changes, it indicates that the particle deposition at this point has reached equilibrium. Record this moment and other test data at this moment; open the heat exchange branch regulating valve and the heat exchange branch circulation pump, and change the amount of heat exchange according to the requirements of each test condition setting to evaluate the influence of thermophoresis on particle deposition;

[0021] Step 6: After the test is completed, close the filter stop valve to make the lead-bismuth flow into the filter branch. Alternately open the stop valve 1 of the filter branch and the stop valve 2 of the filter branch to make the lead-bismuth flow through the filter 1 and the filter 2 for filtration; when the filter 1 reaches the maximum filtration capacity, close the stop valve 1 of the filter branch, and at the same time open the stop valve 2 of the filter branch to replace it with the filter 2, and the two groups are alternately replaced; after no more particulate impurities are filtered out from the lead-bismuth, open the filter stop valve;

[0022] Close the heat exchange branch regulating valve, the heat exchange branch circulation pump and the main circuit electromagnetic pump, close the front stop valve and the rear stop valve of the test section; open the stop valve 1 of the pressurization branch, the stop valve 2 of the pressurization branch and the argon cylinder 2 of the pressurization branch, inject high-purity argon into the main circuit pipeline, and appropriately open the pressure relief branch regulating valve to relieve the pressure of the lead-bismuth storage tank so that the pressure can press the lead-bismuth back into the lead-bismuth storage tank; close the argon cylinder 2, close the stop valve 1 of the pressurization branch and the stop valve 2 of the pressurization branch on the pressurization branch, and close the pressure relief branch regulating valve;

[0023] Turn off the pipeline heating tape and the heating rod, close the main circuit regulating valve, and wait for the lead-bismuth in the lead-bismuth storage tank and the lead-bismuth in the test section to cool naturally; cut out the test section and slice the test section for subsequent analysis.

[0024] Further, before the start of the experiment, open the stop valve at the front section of the test section and the stop valve at the rear section of the test section to ensure that the pressure and temperature of all pipelines and devices in the loop are consistent with the external environment when in the non-test state.

[0025] Further, the test section with the wire-wound rod bundle structure is used to simulate the deposition of particles on the fuel rods in the reactor core. The time when the particle deposition reaches the equilibrium state and the influence on heat exchange can be measured through the temperature change of the temperature measurement points. At the same time, the subsequent slicing can study the particle distribution law; the main function of the visual rectangular channel test section is to study the deposition behavior of particles at the wall surface. A high-speed camera is used to photograph the behavior of particles migrating and depositing in the test section and conduct subsequent analysis; when conducting experiments using the visual test section, when lead-bismuth flows through the visual window, a high-speed camera is used to take pictures to collect the development images of the deposition distribution of particles in the wall surface in the lead-bismuth medium, conduct data analysis and calculation, and combined with the visual test of particle deposition in the vertical narrow rectangular channel, the movement and deposition law of particles in the high-temperature lead-bismuth medium and the influencing factors of the particle migration and deposition law in the lead-bismuth fluid can be obtained; by using the rectangular channel test section with temperature measurement points, the time when the particle deposition on the wall surface of the rectangular channel reaches the equilibrium state and the influence on heat exchange can be measured.

[0026] Further, the influence of gravity on deposition can be obtained by comparing the particle deposition analysis in the horizontal or vertical state of the test section.

[0027] The beneficial effects of the present invention are as follows:

[0028] 1. The device of the present invention can simulate the phenomenon of lead-bismuth carrying particles and depositing during the normal flow process in the channel.

[0029] 2. The particle adding device of the device of the present invention can make the replacement process of different particles more convenient. Cooperating with the filtering section, the switching of particle types in the test loop can be realized without replacing the new lead-bismuth.

[0030] 3. The design of the test section of the device of the present invention enables the device to well conduct experiments on the influence of factors such as thermophoresis, gravity, and buoyancy on the particle deposition in the lead-bismuth medium. At the same time, it can realize the visual research on the formation process of particle deposition on the wall surface in the lead-bismuth medium, the research on the deposition characteristics of particles on the surface of the rod bundle in the lead-bismuth medium, and other multi-purpose test researches. Information such as the thermophoretic movement, deposition thickness, deposition distribution, and deposition morphology of particles can be obtained, and the obtained test data is used to study the migration and deposition mechanism of particles in the lead-bismuth alloy fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the particle deposition test loop of the horizontal test section of the device of the present invention;

[0032] Figure 2Schematic diagram of the particle deposition test loop for the vertical test section of the device of the present invention;

[0033] Figure 3 Schematic diagram of the rod bundle structure test section with wire winding for the device of the present invention;

[0034] Figure 4 Schematic diagram of the rectangular channel test section with a visualization window for the device of the present invention;

[0035] Figure 5 Schematic diagram of the rectangular channel test section with temperature measurement points for the device of the present invention;

[0036] Figure 6 Schematic diagram of the overall layout design of the rectangular test section with a visualization window for the device of the present invention.

[0037] In the figure: 1. Argon gas cylinder 1; 2. Particle addition device; 3. Screw rod pusher; 4. Particle addition branch pipeline; 5. Particle addition branch stop valve; 6. Lead-bismuth liquid storage tank; 7. Heating rod; 8. Liquid storage tank pressure sensor; 9. Liquid storage tank temperature sensor; 10. Main loop inlet section pipeline; 11. Main loop regulating valve; 12. Main loop flowmeter; 13. Main loop electromagnetic pump; 14. Main loop pressure sensor 1; 15. Main loop temperature sensor 1; 16. Sampling branch 1 flowmeter; 17. Sampling branch 1 regulating valve; 18. Sampling branch 1 ball valve; 19. Sampling branch 1 sample container; 20. Test section front end stop valve; 21. Pressurization branch stop valve 1; 22. Pressurization branch stop valve 2; 23. Argon gas cylinder 2; 24. Test section; 25. Heat exchange branch water tank; 26. Heat exchange branch regulating valve; 27. Heat exchange branch circulation pump; 28. Heat exchanger; 29. Test section rear end stop valve; 30. Sampling branch 2 flowmeter; 31. Sampling branch 2 regulating valve; 32. Sampling branch 2 ball valve; 33. Sampling branch 2 sample container; 34. Vacuum pump branch stop valve; 35. Vacuum pump; 36. Main loop temperature sensor 2; 37. Main loop pressure sensor 2; 38. Filter stop valve; 39. Filter branch stop valve 1; 40. Filter 1; 41. Filter branch stop valve 2; 42. Filter 2; 43. Main loop outlet section pipeline; 44. Pressure relief branch regulating valve; 45. Heating equipment; 46. Test section temperature sensor; 47. Rod bundle structure with wire winding; 48. Visualization window; 49. High-speed camera; 50. Main body of the rectangular channel test section with a visualization window; 51. Graphite gasket; 52. Tempered glass partition. Detailed implementation manners

[0038] The present invention will be further described below in conjunction with the specific implementation manners with reference to the attached drawings.

[0039] Example 1

[0040] As Figure 1As shown in the figure, the present invention provides a test research device for particle deposition in high-temperature liquid lead-bismuth, which includes a main circuit, a test section, a particle addition branch, a lead-bismuth storage tank, a circulating electromagnetic pump, a sampling branch, a filtration branch, a heat exchange branch, as well as pipelines and instruments.

[0041] On the main circuit, there are installed instrument devices such as a main circuit regulating valve, a main circuit flowmeter, a main circuit electromagnetic pump, a main circuit temperature sensor 1, a main circuit pressure sensor 1, a test section, a main circuit temperature sensor 2, a main circuit pressure sensor 2, a filtration stop valve, etc.; among them, the test section is horizontally placed on the pipeline of the main circuit.

[0042] The outer sides of the main circuit and each branch are wrapped with heat-insulating cotton for heat preservation to prevent the lead-bismuth from solidifying due to temperature reduction during the flowing process.

[0043] The main circuit regulating valve is installed between the outlet of the lead-bismuth storage tank and the main circuit flowmeter for regulating the flow of the main circuit.

[0044] There are three types of the test sections, namely a rod bundle structure with wire windings, a rectangular channel with a visualization window, and a rectangular channel with temperature measurement points. A single-side / full-surface heat exchanger is provided on the outside of the test section, and the outside of the test section is not completely wrapped with heat-insulating cotton.

[0045] At both ends of the main circuit of the test section, a front-end stop valve and a rear-end stop valve of the test section are respectively provided, which are used to close before the lead-bismuth refluxes at the end of the test to ensure that the lead-bismuth can be stored in the test section for subsequent slicing or replacement of the test section.

[0046] The side of the test section without heat-insulating cotton is in contact with the heat exchanger to cool the side wall surface to enhance the thermophoretic effect. The branch where the heat exchanger exists is the heat exchange branch, and a heat exchange branch circulating pump, a heat exchange branch water tank, and a heat exchange branch regulating valve are set to control the cooling water circulation and the magnitude of the heat exchange amount.

[0047] The test section with a rod bundle structure with wire windings, as Figure 3 shown, the rod bundle structure in the channel can be heated to ensure a constant heat flux. The rod bundle structure is connected to external equipment through wires, and temperature measurement points are equidistantly arranged on the outer wall of the test section and connected to external equipment through wires along the same direction as the heating wires to monitor the temperature of the temperature measurement points. The arrangement of the wires and the temperature measurement points ensures the minimum influence on the internal flow field.

[0048] The test section with a rectangular channel with a visualization window, as Figure 4 、 6As shown in the figure, it is divided into the main body of the test section, graphite gaskets, tempered glass covers, and several bolts. Epoxy resin sealant is applied between the main body of the test section, graphite gaskets, and tempered glass covers. A high-speed camera is arranged facing the flow direction of the tempered glass window of the test section to photograph the process of particle deposition distribution during the test. To ensure that the upper and lower dimensions of the rectangular channel of the test section are consistent and sealed, the test section is not fixed by welding. Instead, a support plus pouring of high-temperature resistant epoxy resin or high-temperature resistant glue, glass, etc. is used for sealing to achieve the purpose of sealing;

[0049] The rectangular channel test section with temperature measurement points, as Figure 5 shown, a constant heat flux heating method is adopted on one side wall surface, and temperature measurement points are arranged at equal distances on the heating side wall surface to monitor the change of wall temperature;

[0050] The particle addition branch includes an argon gas cylinder 1, a particle addition device, and pipelines. The argon gas cylinder 1 is connected to a section of stainless steel pipeline through a flexible hose, and the airtightness is ensured at the interface between the two. The stainless steel pipeline is connected above the particle addition device, and a stainless steel pipeline is connected below the particle addition device and extends to the bottom of the lead-bismuth storage tank; The upper part of the particle addition device is open, and a screw pusher is used in a supporting manner. When particles need to be added, the required particles are added at the opening. While the particles are pushed into the addition device by the screw pusher, the sealing effect is achieved, and the particle concentration in the particle mass control loop is controlled;

[0051] The lead-bismuth storage tank is used to store lead-bismuth. An opening is made above the lead-bismuth storage tank and a heating rod is inserted to heat and melt the lead-bismuth. After the heating rod is inserted, the opening is sealed. The lead-bismuth storage tank is equipped with a pressure sensor and a temperature sensor to monitor the state of lead-bismuth in the storage tank. The upper end of the storage tank is connected to the outlet section of the main loop, and the lower end is connected to the inlet section of the main loop. A pipeline leading to the external environment is arranged above the storage tank, and a regulating valve is set to release the internal pressure of the storage tank;

[0052] The main loop electromagnetic pump is used to drive the circulation of lead-bismuth in the loop;

[0053] There are two sampling branches, located in front of the stop valve at the front end of the test section and behind the stop valve at the rear end of the test section; A flow meter, a regulating valve, a ball valve, and a sample container are installed on the sampling branch. The regulating valve and the ball valve are in series. The flow rate of the sampling branch calculated from the reading of the flow meter on the sampling branch is kept consistent with the flow rate of lead-bismuth in the main loop. The regulating valve is used to adjust the sampling flow rate, the ball valve is used to control the start or end of sampling, and the sample container is used to receive the taken lead-bismuth sample;

[0054] Two identical stop valves and filters are installed on the filtering section. Each group of stop valves and filters is connected in series first, and then the two groups are connected in parallel to filter out particulate impurities in the liquid lead-bismuth during the non-test state. After the test is completed, the lead-bismuth fluid is filtered to remove the particles mixed in the lead-bismuth fluid, so as to avoid affecting the next test. When in use, the two filters are used alternately. After one filter reaches its maximum load capacity, another filter can be opened, this filter can be closed and a new filter can be replaced to achieve the function of online replacement.

[0055] Embodiment 2

[0056] As Figure 2 shown, the present invention further provides a device for experimental study on particle deposition in high-temperature liquid lead-bismuth. The experimental loop is basically the same as that in Embodiment 1, and the only difference is that the test section changes from a horizontal state to a vertical state and is placed in the rising section of the main loop. The comparison of the results of the two experimental loops can be used to compare the influence of gravity on particle deposition.

[0057] Embodiment 3

[0058] Before the experiment starts using the experimental research method of the device for experimental study on particle deposition in high-temperature liquid lead-bismuth in Embodiment 1, except for the stop valve at the front end of the test section, the stop valve at the rear end of the test section, and the filtering stop valve being opened, all the other valves are in a closed state.

[0059] 1. Preheating stage:

[0060] When the pressure and temperature of all the pipelines and devices in the loop are consistent with the external environment during the non-test state. At the beginning of the experiment, first, the lead-bismuth is heated by the heating rod in the lead-bismuth storage tank, and at the same time, the heating tape wound around the loop pipeline is powered on to preheat the pipeline. Both the heating rod and the heating tape are controlled at a constant temperature by an automatic control system. The vacuum pump is turned on to evacuate the loop pipeline, and then the vacuum pump is turned off.

[0061] Monitor the temperature of the lead-bismuth storage tank. After the lead-bismuth is completely melted, inject enough particles into the particle addition device, push them in through the spiral pusher and tighten. After tightening, open the argon gas cylinder 1, inject high-purity argon gas into the particle addition device to increase the pressure, and through the pressure difference, the particles are pressed into the bottom of the lead-bismuth storage tank through the particle addition branch to be preliminarily mixed with the lead-bismuth, and then close the argon gas cylinder 1.

[0062] 2. Lead-bismuth upward flushing stage:

[0063] Check whether the temperature at each part of the experimental loop meets the requirements. After meeting the requirements, open the main loop regulating valve and the particle addition branch stop valve, open the argon gas cylinder 1, gradually increase the pressure in the pipeline, and then maintain it at a safe pressure that can press the lead-bismuth onto the loop. Then close the argon gas cylinder 1 and the stop valve on the particle addition branch.

[0064] 3. Test Phase:

[0065] Turn on the electromagnetic pump to make the lead-bismuth circulate in the loop. At the same time, open the ball valves of the two sampling branches, adjust the regulating valves of the two sampling branches, and convert the flow velocity of the sampling branches through the flow meters of the sampling branches so that the lead-bismuth flow velocity of the sampling branches is the same as that of the main loop. Then close the ball valves and replace the sampling containers of each sampling branch. At different moments during the test, open the ball valves of the two sampling branches simultaneously, take samples within the same time period, close the ball valves after sampling, replace the new sample containers and make records for subsequent sample analysis.

[0066] After the lead-bismuth starts to circulate in the loop, turn on the heating equipment to perform isothermal heat flux heating on the parts of the test section that need to be heated. Continuously observe the temperature changes of the measuring points in the test section from the official start of the test. When the temperature of the measuring point stabilizes at a certain temperature and no longer changes, it indicates that the particle deposition at this point has reached equilibrium. Record this moment and other test data at this moment.

[0067] Open the regulating valve of the heat exchange branch and the circulating pump of the heat exchange branch, and change the amount of heat exchange according to the requirements of each test condition to evaluate the influence of thermophoresis on particle deposition.

[0068] 4. Filtration Phase:

[0069] After the test is completed, close the filtration stop valve, alternately open the stop valve 1 of the filtration branch and the stop valve 2 of the filtration branch to make the lead-bismuth flow through filter 1 and filter 2 for filtration. When one of the filters reaches the maximum filtration capacity, close the stop valve corresponding to this filter, and at the same time open the stop valve corresponding to the other filter to replace the filter that has reached the maximum filtration capacity. After no more particle impurities are filtered out from the lead-bismuth, open the filtration stop valve.

[0070] 5. Reflux Phase:

[0071] Close the regulating valve of the heat branch, the circulating pump of the heat exchange branch and the electromagnetic pump of the main loop, and close the front stop valve and the rear stop valve of the test section. Open the two stop valves of the pressurization branch where argon cylinder 2 is located, open argon cylinder 2, inject high-purity argon into the upper pipeline of the main loop, and appropriately open the regulating valve of the pressure relief branch to relieve the pressure of the liquid storage tank so that the pressure can press the lead-bismuth back into the lead-bismuth liquid storage tank. Then close argon cylinder 2, close the two stop valves on the pressurization branch, and close the regulating valve of the pressure relief branch.

[0072] 6. End of Test:

[0073] Turn off the pipe tracing and heating rods, close the regulating valve of the main loop, and wait for the lead-bismuth in the liquid storage tank and the test section to cool naturally. Cut out the test section and slice the test section for subsequent analysis.

[0074] 7. Data Analysis:

[0075] As Figure 1 shown, the sample obtained by sampling on the sampling branch 1 is defined as the upstream sample, and the sample obtained by sampling on the sampling branch 2 is defined as the downstream sample. After the test, the upstream and downstream lead-bismuth samples sampled in the same time period are analyzed, and the particle concentrations in them are measured by the conductivity measurement method. The particle concentration in the upstream sample is C up , and the particle concentration in the downstream sample is C down . Thus, the particle deposition efficiency η in a certain time period of the test section is obtained as follows:

[0076]

[0077] In the formula: C up is the particle concentration in the upstream sample, g / m 3 ;

[0078] C down is the particle concentration in the downstream sample, g / m 3 ;

[0079] According to the test requirements, the particle deposition efficiencies under different test conditions can be obtained.

[0080] At the same time, the particle deposition velocity can be obtained:

[0081]

[0082] Appendix Figure 3 , 4 , 5 are different test sections. Appendix Figure 3 is a test section with a wire-wound rod bundle structure used to simulate the deposition of particles on the fuel rods in the reactor core. The time when the particle deposition reaches the equilibrium state and the influence on heat exchange can be measured by the temperature change of the temperature measurement points. At the same time, the subsequent slices can study the particle distribution law; Appendix Figure 4 The test section in it is a visual rectangular channel, and its main function is to study the deposition behavior of particles at the wall surface. A high-speed camera and an electron scanning microscope are used to photograph the migration and deposition behavior of particles in the test section and conduct subsequent analysis; Appendix Figure 5 is a rectangular channel test section with temperature measurement points, which can measure the time when the particle deposition on the wall surface of the rectangular channel reaches the equilibrium state and the influence on heat exchange.

[0083] In the visualization test stage, turn on the heat exchanger branch equipment and the electromagnetic pump to make the lead-bismuth circulate in the loop. Open the sampling branch ball valve, adjust the sampling branch regulating valve, and convert the sampling branch flow rate through the sampling branch flowmeter so that the lead-bismuth flow rate in the sampling branch is the same as that in the main loop. Then close the ball valve and replace the sampling container. In addition, when the lead-bismuth flows through the visualization window, high-speed cameras can be used to capture the development images of the deposition distribution of particulate matter on the wall surface in the lead-bismuth medium. Through data analysis and calculation, combined with the visualization test of particulate deposition in a vertical narrow rectangular channel, the movement and deposition law of particulate matter in the high-temperature lead-bismuth medium and the influencing factors of the particulate migration and deposition law in the lead-bismuth fluid can be obtained.

[0084] The vertical state of the test section in Example 2 is the same as the specific implementation in Example 3 in the stages of test preheating, charging, filtering, reflux, and end, which will not be elaborated here.

[0085] The above are only the embodiments of the present invention, and do not limit the protection scope of the present invention. Any equivalent structural transformation made by using the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A high-temperature liquid lead-bismuth particle deposition test research device, characterized in that: It comprises a lead-bismuth liquid storage tank (6), a main circuit, a test section, a sampling branch 1, a sampling branch 2, a filtering branch, a heat exchange branch, and a pipeline; The pipeline of the main circuit is provided with a main circuit regulating valve (11), a main circuit flow meter (12), a main circuit electromagnetic pump (13), a main circuit pressure sensor 1 (14), a main circuit temperature sensor 1 (15), a test section (24), a main circuit temperature sensor 2 (36), a main circuit pressure sensor 2 (37), and a filter stop valve (38) in sequence from the main circuit inlet section pipeline (10) to the main circuit outlet section pipeline (43); The top of the lead-bismuth liquid storage tank (6) is provided with an opening and a heating rod (7) is inserted therein, and the opening is sealed after the heating rod (7) is inserted therein; a temperature sensor 3 (8) and a pressure sensor 3 (9) are provided on the surface of the lead-bismuth liquid storage tank (6); the top of the lead-bismuth liquid storage tank (6) is connected to the main circuit outlet section pipeline (43), and the bottom of the lead-bismuth liquid storage tank (6) is connected to the main circuit inlet section pipeline (10); the lead-bismuth liquid storage tank (6) is connected to a particle addition branch, and the particle addition branch is provided with a particle addition branch stop valve (5) and a particle addition device (2) connected to an argon gas cylinder 1 (1); a screw rod pusher (3) is provided on the surface of the particle addition device (2); A test section front end stop valve (20) and a test section rear end stop valve (29) are respectively installed at the front and rear ends of the test section (24) on the pipeline of the main loop; the test section front end stop valve (20) is located between the test section (24) and the sampling branch 1, and the test section rear end stop valve (29) is located between the test section (24) and the sampling branch 2; the front end of the sampling branch 1 and the rear end of the sampling branch 2 are connected in parallel with the pressurized branch; a heat exchanger (28) is provided on the surface of the test section (24), and both ends of the heat exchanger (28) are connected to the heat exchange branch pipeline; The filter branch is connected to both ends of the filter stop valve (38). Two groups of stop valves and filters are installed on the filter branch, one group includes a filter branch stop valve 1 (39) and a filter 1 (40), and the other group includes a filter branch stop valve 2 (41) and a filter 2 (42). Each group of stop valves and filters is first connected in series, and then the two groups are connected in parallel. When in use, the two groups of filters are used alternately.

2. The high-temperature liquid lead-bismuth particle deposition test and research device according to claim 1 is characterized in that: The test section (24) is one of a rod bundle structure test section with wire winding, a rectangular channel test section with a visualization window, and a rectangular channel test section with temperature measuring points, and the test section is wrapped with thermal insulation cotton; the rod bundle structure in the channel of the rod bundle structure test section with wire winding can be heated by a constant heat flow, the rod bundle structure is connected to an external device through a wire, and temperature measuring points are arranged at equal distances on the outer wall of the test section (24) to monitor the temperature.

3. The high-temperature liquid lead-bismuth particle deposition test and research device according to claim 2 is characterized in that: The rectangular channel test section with a visualization window includes a test section body and a tempered glass window embedded in the middle of the test section body; a graphite gasket and a tempered glass cover are installed on the surface of the tempered glass window in sequence; epoxy resin sealant, high-temperature resistant glue or high-temperature resistant glass is coated between the test section body, the graphite gasket and the tempered glass cover; a high-speed camera is arranged perpendicular to the flow direction on the outside of the tempered glass window; the rectangular channel test section with temperature measuring points adopts a constant heat flow heating method on one side wall, and temperature measuring points are arranged at equal distances on the heated side wall to monitor changes in wall temperature.

4. The high-temperature liquid lead-bismuth particle deposition test and research device according to claim 1 is characterized in that: A vacuum pump branch is provided at the front end of the main circuit temperature sensor 2 (36), and the vacuum pump branch is a vacuum pump (35) controlled by a vacuum pump branch stop valve (34); a heat exchange branch water tank (25), a heat exchange branch regulating valve (26), and a heat exchange branch circulation pump (27) are installed in sequence on the pipeline of the heat exchange branch to control the circulation of cooling water and the amount of heat exchange.

5. The high-temperature liquid lead-bismuth particle deposition test and research device according to claim 1 is characterized in that: The pipeline of the sampling branch 1 is installed with a flow meter (16) for the sampling branch 1, a regulating valve (17) for the sampling branch 1, a ball valve (18) for the sampling branch 1, and a sample container (19) for the sampling branch 1 in sequence; the pipeline of the sampling branch 2 is installed with a flow meter (30) for the sampling branch 2, a regulating valve (31) for the sampling branch 2, a ball valve (32) for the sampling branch 2, and a sample container (33) for the sampling branch 2 in sequence; the regulating valve (17) for the sampling branch 1 and the regulating valve (31) for the sampling branch 2 are used to regulate the flow rates of the sampling branch 1 and the sampling branch 2 to be consistent with the main circuit (I); the ball valve (18) for the sampling branch 1 and the ball valve (32) for the sampling branch 2 are used to control the start and end of sampling.

6. The high-temperature liquid lead-bismuth particle deposition test and research device according to claim 1 is characterized in that: The test section (24) is placed horizontally on the pipeline of the main circuit or vertically on the rising section pipeline of the main circuit; the outer sides of the pipelines of the main circuit, sampling branch 1, sampling branch 2, filtering branch, heat exchange branch, particle adding branch, pressurizing branch, and vacuum pump branch are all wrapped with thermal insulation cotton, and the heating tape is wrapped around the pipeline of the main circuit.

7. A test method for the particle deposition test research device in high temperature liquid lead and bismuth as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: heating the lead-bismuth by a heating rod (7) in a lead-bismuth liquid storage tank (6), and simultaneously energizing a heating tape wound around a main loop pipeline to preheat the pipeline; turning on a vacuum pump (35), evacuating the main loop pipeline, and turning off the vacuum pump (35); Step 2: monitor the temperature of the lead-bismuth liquid storage tank (6), and after the lead-bismuth is completely dissolved, inject particles into the particle adding device (2), push them in through the screw pusher (3) of the particle adding device (2) and tighten them; after tightening, open the argon gas cylinder 1 (1), inject high-purity argon gas into the particle adding device (2) to increase the pressure, and at the same time, press the particles into the bottom of the lead-bismuth liquid storage tank (6) through the particle adding branch through the pressure difference, and preliminarily mix them with the lead-bismuth, and then close the argon gas cylinder 1 (1); Step 3: Check whether the temperature at each location in the test loop meets the requirements. If the requirements are met, open the main loop regulating valve (11) and the particle addition branch stop valve (5), open the argon gas cylinder 1 (1), gradually increase the pressure in the pipeline, maintain it at a safe pressure that can press the lead and bismuth into the loop, close the argon gas cylinder 1 (1), and close the particle addition branch stop valve (5); Step 4: Start the main circuit electromagnetic pump (13) to allow the lead and bismuth to circulate in the main circuit; open the sampling branch 1 ball valve (18) and the sampling branch 2 ball valve (32), adjust the sampling branch 1 regulating valve (17) and the sampling branch 2 regulating valve (31), convert the flow rates of the sampling branch 1 and the sampling branch 2 through the sampling branch 1 flow meter (16) and the sampling branch 2 flow meter (30), so that the lead and bismuth flow rates of the sampling branch 1 and the sampling branch 2 are consistent with those of the main circuit, close the sampling branch 1 ball valve (18) and the sampling branch 2 ball valve (31), and adjust the sampling branch 1 regulating valve (17) and the sampling branch 2 regulating valve (31). The ball valve (32) of branch 2 is opened, and the sample container (19) of sampling branch 1 and the sample container (33) of sampling branch 2 are replaced; at different times of the test, the ball valve (18) of sampling branch 1 and the ball valve (32) of sampling branch 2 are opened at the same time, and samples are taken in the same time period. After the sampling is completed, the ball valve (18) of sampling branch 1 and the ball valve (32) of sampling branch 2 are closed, and new sample containers (19) of sampling branch 1 and sample containers (33) of sampling branch 2 are replaced, and samples at different times are recorded for subsequent sample analysis; Step 5: After lead and bismuth begin to circulate in the main loop, the heating tape is turned on to heat the part of the test section (24) that needs to be heated with equal heat flux density. The temperature change of the test section measuring point is continuously observed from the formal start of the test. When the temperature of the measuring point stabilizes at a certain temperature and does not change, it means that the particle deposition at this point has reached equilibrium. The time and other test data at this time are recorded; the heat exchange branch regulating valve (26) and the heat exchange branch circulation pump (27) are turned on, and the heat exchange amount is changed according to the setting requirements of each test condition to evaluate the influence of thermophoresis on particle deposition; Step 6: After the test is completed, close the filter stop valve (38) to allow the lead and bismuth to flow into the filter branch, and alternately open the filter branch stop valve 1 (39) and the filter branch stop valve 2 (41) to allow the lead and bismuth to flow through the filter 1 (40) and the filter 2 (42) for filtration; when the filter 1 (40) reaches the maximum filtration carrying capacity, close the filter branch stop valve 1 (39), open the filter branch stop valve 2 (41) at the same time, and replace it with the filter 2 (42), and the two groups are replaced alternately; when no more particulate impurities are filtered out of the lead and bismuth, open the filter stop valve (38); Close the heat exchange branch regulating valve (26), the heat exchange branch circulation pump (27) and the main circuit electromagnetic pump (13), and close the test section front end stop valve (21) and the test section rear end stop valve (29); open the pressurization branch stop valve 1 (21), the pressurization branch stop valve 2 (22) and the argon gas bottle 2 (2) of the pressurization branch, inject high-purity argon gas into the main circuit pipeline, and appropriately open the pressure relief branch regulating valve (44) to relieve the pressure of the lead-bismuth storage tank (6), so that the pressure can press the lead-bismuth back into the lead-bismuth storage tank (6); close the argon gas bottle 2 (23), close the pressurization branch stop valve 1 (21) and the pressurization branch stop valve 2 (22) on the pressurization branch, and close the pressure relief branch regulating valve (44); The pipeline heating belt and the heating rod (7) are turned off, the main circuit regulating valve (11) is turned off, and the lead-bismuth in the lead-bismuth storage tank (6) and the lead-bismuth in the test section are allowed to cool naturally; the test section (24) is cut out, and the test section (24) is sliced ​​for subsequent analysis.

8. The test method of the high-temperature liquid lead-bismuth particle deposition test research device according to claim 7 is characterized in that: Before the test begins, open the stop valve (20) at the front end of the test section and the stop valve (29) at the rear end of the test section to ensure that the pressure and temperature of all pipes and devices in the loop are consistent with the external environment when not in the test state.

9. The test method of the high-temperature liquid lead-bismuth particle deposition test research device according to claim 7 is characterized in that: The rod bundle structure test section with winding wire is used to simulate the deposition of particles on the fuel rods in the reactor core. The time for the particle deposition to reach the equilibrium state and the influence on the heat exchange can be measured by the temperature change of the temperature measuring point, and the subsequent slicing can be used to study the particle distribution law; the visualization rectangular channel test section is mainly used to study the deposition behavior of particles at the wall surface, and a high-speed camera is used to shoot the migration and deposition behavior of particles in the test section and conduct subsequent analysis; when the visualization test section is used for testing, when lead and bismuth flow through the visualization window, a high-speed camera can be used to capture the deposition distribution development image of particles in the lead-bismuth medium at the wall surface, and data analysis and calculation are performed. Combined with the vertical narrow rectangular channel particle deposition visualization test, the particle movement and deposition law in the high-temperature lead-bismuth medium and the influencing factors of the particle migration and deposition law in the lead-bismuth fluid can be obtained; the rectangular channel test section with temperature measuring points can be used to measure the time for the particle deposition on the rectangular channel wall to reach the equilibrium state and the influence on the heat exchange.

10. The test method of the high temperature liquid lead bismuth particle deposition test research device according to claim 7 is characterized in that: By comparing the particle deposition analysis of the test section (24) in a horizontal state or a vertical state, the effect of gravity on the deposition can be obtained.

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