Experimental device for deposition of corrosion products of lead-bismuth fast reactor fuel assembly

Abstract

The invention provides an experimental device for deposition of corrosion products of a lead-bismuth fast reactor fuel assembly, and relates to the technical field of research on thermal-hydraulic characteristics of reactor cores. The experimental device comprises a storage tank, an experimental section and a glove box, wherein the experiment section and the glove box are connected end to end through a second pipeline to form a closed loop; an electric heating simulation fuel assembly comprising a cladding tube is arranged in an inner cavity of the experiment section; the storage tank is connected with the second pipeline through the first pipeline and located at the liquid inlet end of the experiment section. And the glove box is used for releasing particles into the liquid lead bismuth in the experimental device. Compared with the prior art, the experimental device is simple in structure, the experimental cost of corrosion product deposition of the lead-bismuth fast reactor fuel assembly can be reduced, and the experimental time can be shortened.

Description

Technical Field

[0001] The invention relates to the technical field of core thermal hydraulic characteristics research, and in particular to an experimental device for the deposition of corrosion products of a lead-bismuth fast reactor fuel assembly. Background Art

[0002] When the core fuel assemblies of lead-bismuth fast reactors operate under long-term high temperature and strong radiation environment, a deposition layer will form on the cladding surface. The existence of the deposition layer will seriously affect the heat transfer characteristics between the fuel assemblies and the coolant, causing local heat transfer deterioration and local corrosion, and even leading to damage and other hazards, posing a great safety hazard to the safe operation of the nuclear reactor.

[0003] In the existing related technologies, the research on the impact of the deposited layer in the lead-bismuth fast reactor on the safety of reactor operation mainly focuses on computational simulation and theoretical model prediction. It is impossible to accurately simulate the relationship between the deposition thickness and particle concentration of the fuel assembly after the corrosion product is deposited in the actual lead-bismuth fast reactor environment, and thus cannot meet the safety operation assessment requirements of the fuel assembly in the reactor environment. If the deposition layer is simulated according to the actual operation time of the lead-bismuth fast reactor, it will be time-consuming and costly because the deposition of corrosion products on the surface of the fuel cladding is a long solute migration process.

[0004] In addition, there are many technologies in the prior art that simulate the corrosion product deposition phenomenon of pressurized water reactors. However, the coolant media used in lead-bismuth fast reactors and pressurized water reactors are different. The difference in the thermophysical properties of the coolant will lead to essential differences in the corrosion product deposition phenomenon. Therefore, the existing technology applicable to the corrosion product deposition phenomenon of pressurized water reactors is not suitable for the study of corrosion product deposition of lead-bismuth fast reactor fuel assemblies.

[0005] Based on this, the present application intends to propose an experimental device suitable for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies to at least solve one or more of the problems mentioned above. Summary of the invention

[0006] 1. Technical issues to be resolved In view of the shortcomings of the prior art, the present invention provides an experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies, which at least solves the problem that the existing experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies is time-consuming and costly.

[0007] (II) Technical solution To achieve the above objectives, the present invention is implemented through the following technical solutions: An experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies, the experimental device comprising: Storage tanks, experimental sections, and glove boxes; The experimental section and the glove box are connected end to end through a second pipeline to form a closed loop; An electrically heated simulated fuel assembly including a cladding tube is disposed in the internal cavity of the experimental section; the storage tank is connected to a second pipeline through a first pipeline and is located at the liquid inlet end of the experimental section; The glove box is used to release particles into liquid lead bismuth in the experimental apparatus.

[0008] In one embodiment, the material of the first pipe includes 304 stainless steel, and the material of the second pipe includes 316L stainless steel.

[0009] In one embodiment, the electrically heated simulated fuel assembly further includes: an electric heating rod and a thermocouple; the electric heating rod is covered by a cladding tube, and an insulating material is used to evenly fill the gap between the electric heating rod and the cladding tube; the thermocouple is arranged on the inner wall surface of the cladding tube.

[0010] Preferably, the cavity wall material of the experimental section is T91 stainless steel, the cladding tube material is T91 stainless steel, and the electric heating rod material is Cr20Ni80 nickel-chromium alloy.

[0011] More preferably, the insulating material comprises magnesium oxide.

[0012] In one embodiment, the experimental device further comprises: an electric heater, wherein the electric heater is disposed on the second pipe between the storage tank and the experimental section.

[0013] In one embodiment, the experimental device further includes: an electromagnetic pump and a flow meter; the electromagnetic pump is arranged on the second pipeline between the glove box and the experimental section; the flow meter is arranged on the second pipeline between the glove box and the electric heater.

[0014] In one embodiment, the experimental device further includes: a filter, which is disposed on the flow pipeline between the electromagnetic pump and the flow meter and is connected in parallel with the glove box.

[0015] In one embodiment, the experimental device also includes: an oxygen control box and a liquid level meter; the oxygen control box is arranged on the second pipeline between the electromagnetic pump and the experimental section; the liquid level meter is used to detect the liquid lead bismuth level height in the oxygen control box.

[0016] In one embodiment, the experimental device further includes: a heat exchanger, and the heat exchanger is arranged on the second pipeline between the electromagnetic pump and the oxygen control box.

[0017] Preferably, the heat exchanger is a shell-and-tube heat exchanger, the flow medium on the tube side is liquid lead-bismuth, and the flow medium on the shell side is high-temperature heat transfer oil.

[0018] In one embodiment, the structure of the cladding tube includes: a structure in which the cladding and spiral grooves are combined, or a structure in which the cladding and trapezoidal ribs are combined.

[0019] Preferably, the spiral groove includes but is not limited to a single spiral groove, a double spiral groove and a quadruple spiral groove; the trapezoidal ribs include but are not limited to a single trapezoidal rib, a double trapezoidal rib and a quadruple trapezoidal rib.

[0020] In one embodiment, the experimental device further includes: a melting tank, wherein the melting tank is connected to the storage tank through the first pipeline.

[0021] In one embodiment, the experimental device further includes: a high-pressure argon gas cylinder; the high-pressure argon gas cylinder is connected to the storage tank, the oxygen control box and the glove box respectively through a third pipeline.

[0022] In one embodiment, the experimental device further includes: a heating system, a temperature measuring thermocouple, and a temperature controlling thermocouple; wherein the electric heating wire of the heating system is arranged in all areas through which lead and bismuth flow in the experimental device, and the temperature measuring thermocouple and the temperature controlling thermocouple are both arranged in all areas through which lead and bismuth flow in the experimental device.

[0023] In one embodiment, the experimental device further includes: a vacuum pump, wherein the vacuum pump is connected to the oxygen control box through a third pipeline.

[0024] (III) Beneficial effects The present invention provides an experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies. Compared with the prior art, the device has the following beneficial effects: The experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies proposed in this application adds an additional glove box to the experimental pipeline, which can effectively shorten the experimental time of generating particles from lead-bismuth corrosion of structural materials and simulating the deposition of dirt on the surface of lead-bismuth fast reactor fuel. Compared with the prior art, the experimental device has a simple structure, which can not only reduce the experimental cost, but also reduce the experimental time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 This is a schematic diagram of the structure of an experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies in an embodiment of the present application; Figure 2This is a schematic diagram of the structure of the electrically heated simulated fuel assembly in the embodiment of the present application, wherein: Figure 2 (a) is a schematic diagram of the structure of the electrically heated simulated fuel assembly from one perspective; Figure 2 (b) is the effect of the electrically heated simulated fuel assembly from another perspective; Figure 3 This is a schematic diagram of the location of the thermocouple in the embodiment of the present application; Figure 4 This is a schematic diagram of the structure of the cladding structure 1 in the embodiment of the present application; Figure 5 This is a rendering of the cladding structure 1 in the embodiment of the present application; Figure 6 This is a schematic diagram of the structure of the second cladding structure in the embodiment of the present application; Figure 7 This is a rendering of the second cladding structure in the embodiment of the present application; In the figure: 1-melting tank; 2-storage tank; 3-electric heater; 4-experimental section; 5-electrically heated simulated fuel assembly; 6-electric heating rod; 7-cladding tube; 8-thermocouple; 9-oxygen control box; 10-heat exchanger; 11-electromagnetic pump; 12-glove box; 13-filter; 14-flow meter; 15-high-pressure argon bottle; 16-vacuum pump; 17-heating system; 18-first high-temperature electric liquid valve; 19-second high-temperature electric liquid valve; 20-third high-temperature electric liquid valve; 21-fourth high-temperature electric liquid valve; 22-fifth high-temperature electric liquid valve; 23-sixth high-temperature electric liquid valve; 24-first electric gas valve; 25-second electric gas valve; 26-third electric gas valve; 27-first pipeline; 28-second pipeline; 29-third pipeline; 30-liquid level meter; 31-temperature measuring thermocouple; 32-temperature controlling thermocouple. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] When the core fuel assembly of the lead-bismuth fast reactor is operated in a long-term high temperature and strong radiation environment, a deposit layer will form on the surface of the cladding. The existence of the deposit layer will seriously affect the heat transfer characteristics of the fuel assembly and the coolant, causing local heat transfer deterioration and local corrosion, and even leading to damage and other hazards, posing a great safety hazard to the safe operation of the nuclear reactor.

[0029] In the particle corrosion deposition phenomenon at the core of the lead-bismuth fast reactor, the sources of particles are diverse. For example, metal dissolution in the high-temperature section (core) crystallizes and precipitates particles in the low-temperature section (heat exchanger), or liquid lead-bismuth impacts the oxide film, causing the oxide film to peel off. At the same time, the particle formation time in the reactor's particle corrosion deposition process is relatively long. For example, particles formed by liquid lead-bismuth impacting the oxide film must first form an oxide film on the surface of the material through oxidative corrosion, and then the liquid lead-bismuth impacts the oxide film to form particles, or they are formed through crystallization experiments. Specifically, the particles formed by impacting the oxide film are Fe 3 O 4 The oxide film has a three-layer structure, the outermost layer is Fe 3 O 4 Easy to peel off, the high temperature section structural material metal Fe dissolves to form Fe 2+ or Fe 3+ , in the low temperature range Fe 2+ or Fe 3+ With oxygen, forming Fe 3 O 4 , Fe is precipitated in the form of crystals 3 O 4 ; In the low-temperature section, the lead in liquid lead bismuth combines with oxygen to form PbO, which precipitates in the form of crystals.

[0030] The above particles will have different deposition behaviors in different areas. For example, after coming out of the low-temperature section (heat exchanger), they enter the high-temperature section (core). Since the oxygen concentration in the core area is high (oxidative corrosion only occurs in the high-temperature area, the oxygen concentration in the core area needs to be maintained at a high level to form an oxide film to protect the cladding from corrosion and reduce the dissolution of structural materials), the particles formed in the low-temperature section are not easy to dissolve. In addition, due to the force of the fluid on the particles, a deposition layer will form on the surface of the core cladding.

[0031] In the existing related technologies, the research on the impact of the deposited layer in the lead-bismuth fast reactor on the safety of reactor operation mainly focuses on computational simulation and theoretical model prediction. It is unable to accurately simulate the relationship between the deposition thickness and particle concentration and other parameters after the corrosion product deposition of the fuel assembly in the actual lead-bismuth fast reactor environment, and cannot meet the safety operation assessment requirements of the fuel assembly in the reactor environment. If the deposition layer is simulated according to the actual operation time of the lead-bismuth fast reactor, it will be time-consuming and costly. This is because the deposition of corrosion products on the surface of the fuel cladding is a long solute migration process, which requires precise control of solute conditions, long-term heat transfer, mass transfer and deposition, and the impact of the core oxidation corrosion product deposition layer on the core safety must be assessed, which requires a lot of time and consumables.

[0032] In addition, there are different strategies in the prior art to simulate the deposition phenomenon of corrosion products in pressurized water reactors. For example, some technologies construct a WALT experimental system, control the water chemical conditions of the WALT experimental system, and run it continuously for thousands of hours to obtain the deposition of oxidation corrosion products on the cladding of pressurized water reactor fuel rods; there are also technologies that disclose experimental devices that simulate dirt deposition and boron precipitation on the surface of pressurized water reactor fuel. By controlling the electric heating rods of the condenser and the reactor, the experimental device can be quickly cooled down to shorten the simulation experiment time; there are also technologies that disclose a method for reproducing the deposition layer of oxidation corrosion products in the core of a pressurized water reactor, in which a wet gel formed by nickel salt and iron salt is applied to the surface of the alloy, and a dense intermediate layer is obtained after heating, and nickel ferrite powder, adhesive, and pore-forming agent are mixed and ground into a paste; the paste is applied to the intermediate layer, and an oxidation corrosion product deposition layer is obtained after heating, and so on.

[0033] However, the coolant medium used in the lead-bismuth fast reactor is different from that used in the pressurized water reactor. The difference in the thermophysical properties of the coolant will lead to essentially different corrosion product deposition phenomena. For example, liquid lead-bismuth corrodes structural materials more severely, and the corrosion deposition effects produced are more diverse, including not only soluble corrosion deposition, but also particle corrosion deposition. Liquid lead-bismuth has a higher density, and compared to water, particles in liquid lead-bismuth tend to move in the opposite direction of gravity due to buoyancy.

[0034] Based on this, the present application proposes an experimental device suitable for the deposition of corrosion products in lead-bismuth fast reactor fuel assemblies, so as to realize the analysis of the deposition of corrosion products and the analysis of the influence of the deposition of corrosion products on flow heat transfer, core neutron physics and reactor safety.

[0035] The embodiment of the present application provides an experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies, which at least solves the problem that the existing experimental devices for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies are time-consuming and costly, thereby achieving the purpose of low-cost and efficient experiments.

[0036] The technical solution in the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows: In order to solve one or more technical problems existing in the above-mentioned prior art, the experimental device proposed in this application is designed with two pipelines. On the one hand, the pipeline where the glove box is located can realize the uniform distribution of particles in the liquid lead bismuth through circulating flow, and the particle concentration in the liquid lead bismuth can be increased online in real time through the glove box, which effectively shortens the experimental time of particles generated by lead bismuth corrosion structural materials; on the other hand, the pipeline where the filter is located can filter impurities in lead bismuth after the experiment, which is convenient for experiments with other concentrations. In addition, considering that one experimental device cannot complete the multiple tasks described above, the existing experiments can be verified by simulation calculations to predict the approximate particle diameter, and then the device can directly use the particle size predicted by simulation calculations to adjust different particle types and particle sizes, which can be used to quickly conduct particle corrosion deposition experiments and save experimental time. At the same time, by designing different cladding tube wall structures, the deposition phenomenon of different fuel assembly structures in the lead-bismuth fast reactor can be studied, and the experimental cost is low.

[0037] In order to better understand the above technical solution, the above technical solution will be described in detail below in combination with the description of the drawings, the structure and function of the specific components in the drawings, and the specific implementation methods.

[0038] The following describes in detail the implementation process of an embodiment of the present invention and its preferred embodiment in conjunction with the accompanying drawings and explanations of the specific structure.

[0039] See also Figure 1 , an experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies, comprising: a storage tank 2, an experimental section 4, and a glove box 12. Among them, the experimental section 4 and the glove box 12 are connected end to end through a second pipe 28 to form a closed loop. The storage tank 2 is used to store liquid lead-bismuth, and the storage tank 2 is connected to the second pipe 28 through a first pipe 27, and is located at the liquid inlet end of the experimental section 4. The experimental section 4 contains a cavity, and the interior of the cavity is configured to accommodate an electrically heated simulated fuel assembly 5, and the electrically heated simulated fuel assembly 5 includes a cladding tube 7. After the particles are evenly mixed, the electrically heated simulated fuel assembly 5 is started to heat the liquid lead-bismuth in the cavity of the experimental section 4 with a certain power. Under the action of thermophoretic force, Saffman force, drag force and buoyancy, the particles in the liquid lead-bismuth will be deposited on the outer wall surface of the cladding tube 7 and the cavity wall of the experimental section 4. The glove box 12 is used to store particles, and to release and deliver particles in a timely and multiple times according to experimental needs, so as to adjust the particle concentration in the liquid lead-bismuth, effectively shortening the experimental time for generating particles caused by lead-bismuth corrosion of structural materials and simulating dirt deposition on the surface of lead-bismuth fast reactor fuel.

[0040] The first pipeline 27 and the second pipeline 28 are both liquid pipelines through which liquid lead and bismuth flow. However, considering the temperature difference of the liquid lead and bismuth flowing through the pipelines, in a preferred embodiment, 316L stainless steel is used for the second pipeline 28 and 304 stainless steel is used for the first pipeline 27. This is because the temperature of the liquid lead and bismuth flowing through the experimental section 4 is not higher than 450°C. Under this temperature limit, the degree of dissolution and corrosion of 316L stainless steel is low, so 316L stainless steel is used for the second pipeline 28; while the temperature of the liquid lead and bismuth at the liquid inlet end of the experimental section 4 is not higher than 350°C. Under this temperature limit, the degree of dissolution and corrosion of 304 stainless steel is low, so 304 stainless steel is used for the first pipeline 27.

[0041] In one embodiment, the electrically heated simulated fuel assembly 5 includes, in addition to the cladding tube 7, an electric heating rod 6 and a thermocouple 8, as shown in FIG. Figure 2-3 The electric heating rod 6 is covered by the cladding tube 7, and the insulating material magnesium oxide is used to uniformly fill the gap between the electric heating rod 6 and the cladding tube 7; the insulating material adjacent to the inner wall of the cladding tube 7 is grooved, and multiple thermocouples 8 are set in multiple grooves adjacent to the inner wall of the cladding tube 7 for measuring the cladding temperature, as shown in FIG. Figure 3 shown.

[0042] In a preferred embodiment, the cavity wall material of the experimental section 4 is T91 stainless steel, the cladding tube 7 is T91 stainless steel, and the electric heating rod 6 is made of Cr20Ni80 nickel-chromium alloy.

[0043] It should be noted that the particles are affected by the force of the fluid and form a deposition layer on the surface of the core cladding. The structural form of the cladding will affect the flow channel structure, thereby affecting the force on the particles. Therefore, different cladding structures are considered to be designed to study the particle corrosion and deposition phenomenon under different cladding structures.

[0044] The experimental section of the existing experimental bench basically adopts the combination of cladding and spiral wire winding. The wire winding is fixed on the surface of the cladding by spot welding. The wire winding can enhance fluid mixing and heat transfer, but there are problems such as wire winding shedding and local overtemperature at the welding point. If there is corrosion particle deposition, the problem of local overtemperature will be further aggravated.

[0045] In order to solve the above problems existing in the prior art, the cladding structure proposed in the embodiment of the present application is a combination of a cladding and a spiral groove. The structure diagram of this method is as follows: Figure 4-5 As shown. A spiral groove is machined on the surface of the cladding. Preferably, a combination of the cladding and a single spiral groove, a double spiral groove and a quadruple spiral groove can be considered. The cladding structure 2 proposed in the embodiment of the present application is a combination of the cladding and trapezoidal ribs. The structure diagram of this method is shown in FIG. Figure 6-7As shown. Trapezoidal ribs are processed on the surface of the cladding. Preferably, a combination of the cladding and single trapezoidal ribs, double trapezoidal ribs and quadruple trapezoidal ribs can be considered. The above two cladding structures can also achieve the functions of enhancing fluid mixing and heat exchange, and there is no problem of shedding, local over-temperature and other problems.

[0046] In one embodiment, the second pipeline 28 between the storage tank 2 and the experimental section 4 is further provided with an electric heater 3, a second high-temperature electric hydraulic valve 19, and a sixth high-temperature electric hydraulic valve 23. The electric heater 3 is used to heat the lead and bismuth entering the experimental section 4.

[0047] Preferably, the second high-temperature electric hydraulic valve 19 and the sixth high-temperature electric hydraulic valve 23 are respectively arranged on both sides of the electric heater 3, wherein the second high-temperature electric hydraulic valve 19 is located on the side of the electric heater 3 close to the storage tank 2, and the sixth high-temperature electric hydraulic valve 23 is located on the side of the electric heater 3 close to the experimental section 4.

[0048] In one embodiment, the above device further comprises: an electromagnetic pump 11. The electromagnetic pump 11 is arranged on the second pipeline 28 between the glove box 12 and the experimental section 4. The electromagnetic pump 11 provides a pressure head for the lead-bismuth circulation in the entire experimental device.

[0049] In one embodiment, the above device further comprises: a flow meter 14. The flow meter 14 is disposed on the second pipeline 28 and is located between the glove box 12 and the electric heater 3. The flow meter 14 is used to measure the flow in the circuit.

[0050] In one embodiment, the device further includes: a filter 13, which is used to filter impurities in the experimental device. The filter 13 is located on the circulation pipeline 2 formed between the electromagnetic pump 11 and the flow meter 14, and the circulation pipeline 2 is connected in parallel with the circulation pipeline 1 (the circulation pipeline 1 refers to the pipeline including the glove box 12 and the third high-temperature electric hydraulic valve 20).

[0051] Preferably, a fourth high-temperature electric hydraulic valve 21 and a fifth high-temperature electric hydraulic valve 22 are respectively provided on the circulation pipeline 2 and at both ends of the inlet and outlet of the filter 13 .

[0052] In one embodiment, an oxygen control box 9 is provided on the second pipeline 28 between the electromagnetic pump 11 and the experimental section 4. The oxygen control box 9 can control the oxygen concentration in the liquid lead and bismuth in the loop, thereby forming an oxide film on the surface of the experimental device to reduce the corrosion of the liquid lead and bismuth to the experimental device; at the same time, the oxygen control box 9 can also serve as an expansion box to accommodate the increased volume of the liquid lead and bismuth due to thermal expansion caused by the increase in temperature.

[0053] Preferably, a liquid level meter 30 is provided on the oxygen control box 9 to detect the liquid level height of the liquid lead and bismuth in the oxygen control box 9 .

[0054] In one embodiment, a heat exchanger 10 is further provided on the second pipe 28 between the electromagnetic pump 11 and the oxygen control box 9. The heat exchanger 10 cools down the high-temperature liquid lead and bismuth flowing out of the oxygen control box.

[0055] Preferably, the heat exchanger 10 is a shell-and-tube heat exchanger, the flow medium on the tube side is liquid lead-bismuth, and the flow medium on the shell side is high-temperature heat transfer oil.

[0056] In one embodiment, the above device further includes: a melting tank 1. The melting tank 1 is used to dissolve the solid lead bismuth added initially into liquid lead bismuth. The melting tank 1 is generally arranged at a high position of the storage tank 2, and the melting tank 1 and the storage tank 2 are connected through a first pipe 27 and a first high-temperature electric liquid valve 18. When the solid lead bismuth is melted into liquid lead bismuth and the state is suitable, the first high-temperature electric liquid valve 18 and the first pipe 27 are used to flow the liquid lead bismuth into the storage tank 2 for storage.

[0057] In one embodiment, the above device further includes: a high-pressure argon gas cylinder 15. The high-pressure argon gas cylinder 15 is connected to the storage tank 2, the oxygen control box 9 and the glove box 12 respectively through the third pipeline 29 (the third pipeline 29 is a gas pipeline). Specifically, the high-pressure argon gas cylinder 15 is connected to the oxygen control box 9 through the second electric gas valve 25, and at the same time, the high-pressure argon gas cylinder 15 is connected to the storage tank 2 through the first electric gas valve 24, and the high-pressure argon gas is filled into the storage tank 2, so that the liquid lead and bismuth are filled into the experimental device from the storage tank 2 through the second high-temperature electric liquid valve 19, the sixth high-temperature electric liquid valve 23, and the third high-temperature electric liquid valve 20, until the liquid level meter 30 shows a signal, and then the first high-temperature electric liquid valve 18, the second high-temperature electric liquid valve 19 and the first electric gas valve 24 are closed. The high-pressure argon cylinder 15 is connected to the glove box 12 through the third electric gas valve 26. If it is necessary to maintain a slight positive pressure in the glove box 12, a gas line needs to be connected to the upper end of the glove box 12, and the glove box 12 should also be placed at a high position to prevent lead and bismuth from spilling out when the sealing cover of the glove box 12 is subsequently opened. Among them, the second high-temperature electric liquid valve 19 is arranged on the first pipeline 27 and is located between the electric heater 3 and the storage tank 2. The sixth high-temperature electric liquid valve 23 is located on the second pipeline 28 and is located between the electric heater 3 and the experimental section 4.

[0058] In one embodiment, the device further comprises: a heating system 17, which is a device for maintaining the temperature of pipes, equipment, etc. In this embodiment, the heating system 17 heats the liquid lead-bismuth in the storage tank 2 to a specified temperature. The electric heating wire of the heating system 17 is arranged in all areas where the lead-bismuth flows through the experimental device.

[0059] In one embodiment, the above device further includes: a temperature measuring thermocouple 31 and a temperature controlling thermocouple 32. Preferably, the temperature measuring thermocouple 31 and the temperature controlling thermocouple 32 are both arranged in all areas through which the lead and bismuth flow in the above experimental device, and the heating system 17 realizes zone control of the temperature of the liquid lead and bismuth in different areas of the experimental device through the temperature measuring thermocouple 31 and the temperature controlling thermocouple 32. The electric heater 3 cooperates with the heating system 17 to heat the liquid lead and bismuth entering the experimental section 4. However, in specific implementation, the heating system 17 and the above electric heater 3 are zoned controlled, the heating system 17 monitors the global temperature, and the electric heater 3 only heats the liquid lead and bismuth at the entrance of the experimental section 4.

[0060] In one embodiment, the device further comprises: a vacuum pump 16. The vacuum pump 16 is used to evacuate the pipelines involved in the experimental device. Specifically, the vacuum pump 16 is connected to the oxygen control box 9 through a third pipeline 29.

[0061] The working principle and working process of the experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies proposed in the above embodiment of the present application are as follows: After assembling the experimental device for corrosion product deposition of lead-bismuth fast reactor fuel assembly proposed in this embodiment according to the components involved in the above embodiments and preferred embodiments and the connection relationship between the components, start the electromagnetic pump 11, adjust the flow of the experimental device, and when the flow meter 14 reading reaches the experimental requirements, maintain the current of the electromagnetic pump 11 unchanged. Open the sealing flange connecting the glove box 12 and the experimental device, put the particles on the platform of the glove box 12 into the experimental device, and then close the sealing flange. After a period of circulation, ensure that the particles are evenly mixed in the liquid lead-bismuth, and conduct the experiment of corrosion product deposition of lead-bismuth fast reactor fuel assembly.

[0062] During the experiment, multiple particle delivery is performed through the glove box 12 to achieve the purpose of adjusting the particle concentration, thereby effectively shortening the experimental time for generating particles by lead-bismuth corrosion of structural materials.

[0063] After completing the designed test conditions, close the third high-temperature electric liquid valve 20, open the fourth high-temperature electric liquid valve 21 and the fifth high-temperature electric liquid valve 22, so that the liquid lead and bismuth of the experimental device flow to the pipeline where the filter 13 is located. After a period of time, close the electric heating simulated fuel assembly 5, the secondary side of the heat exchanger 10 and the electromagnetic pump 11 in turn, open the second high-temperature electric liquid valve 19, and discharge all the liquid lead and bismuth into the storage tank 2. Then open the second electric gas valve 25, use the high-pressure argon bottle 15 to purge impurities from the experimental device, and then open the vacuum pump 16 to evacuate the vacuum. After the vacuuming work is completed, close the fourth high-temperature electric liquid valve 21, the fifth high-temperature electric liquid valve 22, the sixth high-temperature electric liquid valve 23, the second high-temperature electric liquid valve 19 and the second electric gas valve 25 in turn, and finally shut down the heating system 17.

[0064] In summary, compared with the prior art, the present invention has the following beneficial effects: 1. The experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies proposed in this application, by adding an additional glove box to the experimental pipeline, can effectively shorten the experimental time of generating particles from lead-bismuth corrosion of structural materials and simulating the deposition of dirt on the surface of lead-bismuth fast reactor fuel. Compared with the prior art, the experimental device has a simple structure, which can not only reduce the experimental cost, but also reduce the experimental time.

[0065] 2. The experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies proposed in the present application is designed with two flow pipelines. The pipeline where the glove box is located can release and increase the particle concentration in the circulating liquid lead-bismuth in real time online through the glove box, and allow the particles to be evenly distributed in the liquid lead-bismuth, effectively shortening the experimental time for particles generated by lead-bismuth corrosion of structural materials and simulating the dirt deposition on the surface of lead-bismuth fast reactor fuel under different particle concentrations; and the pipeline where the filter is located can filter impurities in the lead-bismuth after the experiment, facilitating experiments at other concentrations.

[0066] 3. The experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies proposed in this application can study the deposition phenomenon of different fuel assembly structures in lead-bismuth fast reactors by designing different cladding tube wall structures, and the experimental cost is low. It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0067] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An experimental device for the deposition of corrosion products of lead-bismuth fast reactor fuel assemblies, characterized in that: The experimental device includes: storage tank (2), experimental section (4), and glove box (12); The experimental section (4) and the glove box (12) are connected end to end via a second pipeline (28) to form a closed loop; An electrically heated simulated fuel assembly (5) including a cladding tube (7) is arranged in the internal cavity of the experimental section (4); the storage tank (2) is connected to the second pipe (28) via a first pipe (27) and is located at the liquid inlet end of the experimental section (4); The glove box (12) is used to release particles into the liquid lead bismuth in the experimental device.

2. The experimental device according to claim 1, characterized in that: The electrically heated simulated fuel assembly (5) further comprises: an electrically heated rod (6) and a thermocouple (8); the electrically heated rod (6) is coated by the cladding tube (7), and an insulating material is used to uniformly fill the gap between the electrically heated rod (6) and the cladding tube (7); and the thermocouple (8) is arranged on the inner wall surface of the cladding tube (7).

3. The experimental device according to claim 2, characterized in that: The experimental device further comprises: an electric heater (3), wherein the electric heater (3) is arranged on the second pipe (28) between the storage tank (2) and the experimental section (4).

4. The experimental device according to claim 1, characterized in that: The experimental device further comprises: an electromagnetic pump (11) and a flow meter (14); the electromagnetic pump (11) is arranged on the second pipeline (28) between the glove box (12) and the experimental section (4); and the flow meter (14) is arranged on the second pipeline (28) between the glove box (12) and the electric heater (3).

5. The experimental device according to claim 4, characterized in that: The experimental device further comprises: a filter (13), wherein the filter (13) is arranged on the flow pipeline between the electromagnetic pump (11) and the flow meter (14), and is connected in parallel with the glove box (12).

6. The experimental device according to claim 4, characterized in that: The experimental device further comprises: an oxygen control box (9) and a liquid level meter (30); the oxygen control box (9) is arranged on the second pipeline (28) between the electromagnetic pump (11) and the experimental section (4); the liquid level meter (30) is used to detect the liquid level height of liquid lead and bismuth in the oxygen control box (9).

7. The experimental device according to claim 6, characterized in that: The experimental device further comprises: a heat exchanger (10), wherein the heat exchanger (10) is arranged on the second pipeline (28) between the electromagnetic pump (11) and the oxygen control box (9).

8. The experimental device according to any one of claims 1 to 7, characterized in that: The structure of the cladding tube (7) includes: a structure in which the cladding and spiral grooves are combined, or a structure in which the cladding and trapezoidal ribs are combined.

9. The experimental device according to claim 8, characterized in that: The experimental device further comprises: a high-pressure argon gas cylinder (15); the high-pressure argon gas cylinder (15) is respectively connected to the storage tank (2), the oxygen control box (9) and the glove box (12) via a third pipeline (29).

10. The experimental device according to claim 8, characterized in that: The experimental device further comprises: a heating system (17), a temperature measuring thermocouple (31), and a temperature controlling thermocouple (32); wherein the heating system (17), the temperature measuring thermocouple (31), and the temperature controlling thermocouple (32) are arranged in all areas of the experimental device through which lead and bismuth flow.

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