Liquid lead-bismuth alloy thermal stripe oscillation experiment device and liquid lead-bismuth alloy thermal stripe oscillation experiment method

Abstract

The invention relates to the technical field of lead-bismuth reactors, and particularly discloses a liquid lead-bismuth alloy thermal stripe oscillation experiment device and method. The device comprises an experiment loop, a gas protection loop, a data acquisition device and an integrated control module. According to the experimental loop, a magnetic pump is used for driving lead-bismuth fluid and an air cooler to realize cooling through a cold and hot double-loop structure, lead-bismuth jet flow with temperature difference is formed, and the lead-bismuth jet flow is mixed in a three-inlet experimental section to simulate a hot stripe oscillation phenomenon. The method comprises the steps of gas replacement, preheating, loop filling, temperature and flow rate regulation and control, data acquisition and the like. The device can truly simulate a lead bismuth alloy thermal stripe oscillation process, effectively prevents high-temperature oxidation, has a modular experimental section structure, can research thermal stress responses under different structures, and provides reliable experimental data for reactor safety design.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of alloy thermal striping oscillation, and particularly relates to a liquid lead-bismuth alloy thermal striping oscillation experimental device and method. BACKGROUND

[0002] In engineering applications, when LBE with different temperatures mixes at the outlet, a mixed zone with a temperature field that fluctuates continuously is formed, which is called thermal striping. Thermal striping can cause periodic changes in thermal stress on the surface of adjacent solid structures, and long-term effects can cause fatigue damage to the structure material, thereby threatening the long-term safe operation of the engineering equipment. Current research on thermal striping mainly uses numerical simulation methods, which is mainly due to the multiple technical challenges faced by experimental research on lead-bismuth eutectic alloy (LBE):

[0003] (1) Phase state maintenance problem: The experimental system needs to maintain a temperature field of > 125℃ throughout the process to ensure that lead bismuth is in a molten state; any local temperature drop caused by solidification will cause pipe blockage and equipment damage;

[0004] (2) High-temperature oxidation control: At a typical working temperature range of 350-450℃, the chemical reaction rate of LBE with oxygen increases exponentially;

[0005] (3) Material compatibility problem: The high density (10.5g / cm 3 ) of LBE causes erosion effects at high flow rates.

[0006] (4) Measurement technology limitations: The opacity of LBE excludes the application of visualization techniques such as particle image velocimetry (PIV) and laser-induced fluorescence (LIF). Using a Venturi flowmeter to measure the flow of lead bismuth cannot completely remove the air in the pressure pipe, and the differential pressure transmitter and lead bismuth do not closely contact, which will cause inaccurate measurement results.

[0007] Therefore, the existing experimental devices for studying thermal striping mostly use water as the working medium, which is a liquid at room temperature, and temperature control is simple, and there is no need to consider oxidation, erosion and other problems, and safety is higher. However, using water as the working medium cannot truly simulate the flow and heat transfer of liquid lead bismuth, and the existing high-temperature lead bismuth experimental devices cannot create lead bismuth fluid with temperature difference to conduct thermal striping experiments. SUMMARY

[0008] In view of the problem of the prior art in the study of lead-bismuth alloy thermal stripe oscillation, the application designs and builds a high-temperature lead-bismuth thermal stripe oscillation experimental device. The experimental device is composed of two cold and hot circuits, and the two lead-bismuth circuits with temperature difference meet at the inlet of the experimental section and are stirred and mixed in the experimental section. Temperature measuring points and strain measuring points are arranged on the experimental section to monitor temperature and strain data. The temperature distribution of lead-bismuth alloy thermal stripe oscillation and the stress data generated in the structure can be obtained. The application solves the problem of the prior art in the study of lead-bismuth alloy thermal stripe oscillation.

[0009] The technical scheme of the liquid lead-bismuth alloy thermal stripe oscillation experimental device and method of the application is as follows:

[0010] A liquid lead-bismuth alloy thermal stripe oscillation experimental device comprises:

[0011] An experimental circuit is used to circulate liquid lead-bismuth alloy.

[0012] A gas protection circuit is used to provide gas protection and control the oxygen content.

[0013] A data acquisition device is used to acquire temperature, flow and strain data.

[0014] An integrated control module is used to control the operation of each component.

[0015] The experimental circuit comprises a lead-bismuth storage tank, a cold circuit magnetic drive pump, a hot circuit magnetic drive pump, an air cooler, a three-inlet experimental section and a heating system, and is connected by pipelines to form a closed circuit.

[0016] Further, two outlets are arranged on the lead-bismuth storage tank and are connected with the cold circuit magnetic drive pump and the hot circuit magnetic drive pump respectively, and the air cooler is connected with the cold circuit magnetic drive pump; a fan is connected outside the air cooler.

[0017] Further, the gas protection circuit comprises a gas protection device and a vacuum pump; the gas protection device and the vacuum pump are connected to the experimental circuit by pipelines to perform vacuum pumping and protective gas filling treatment on the experimental circuit and maintain an oxygen-free environment.

[0018] Further, the data acquisition device comprises a cold circuit flow meter, a hot circuit left side flow meter, a hot circuit right side flow meter, a high-temperature strain gauge and a thermocouple.

[0019] A liquid outlet is arranged laterally on the air cooler, and the cold circuit flow meter is connected with the air cooler through the liquid outlet; one of the inlets of the three-inlet experimental section is connected with the cold circuit flow meter; the hot circuit magnetic drive pump is connected with the hot circuit left side flow meter and the hot circuit right side flow meter respectively; the other two inlets of the three-inlet experimental section are connected with the hot circuit left side flow meter and the hot circuit right side flow meter respectively.

[0020] Further, the three-inlet experimental section is modularly designed for studying thermal strip oscillation phenomenon under different structural forms.

[0021] Further, the heating system comprises heating belts and heating rods, which are used for heating the equipment and pipelines in each experimental loop, melting the solid lead-bismuth alloy, facilitating its flow in the experimental loop, and providing the required temperature conditions for the experiment.

[0022] Further, the air cooler and the fan are used for cooling the fluid in the loop where the cold loop magnetic pump is located.

[0023] An experimental method based on a liquid lead-bismuth alloy thermal strip oscillation experimental device, comprising the following steps:

[0024] Step 1: Gas displacement; start the vacuum pump to perform vacuumizing treatment on the lead-bismuth storage tank and the experimental loop, control the gas protection device to start by the integrated control module, inject argon into the experimental loop to form protection.

[0025] Step 2: Device preheating; start the heating system, the heating rods heat the lead-bismuth storage tank until the solid lead-bismuth alloy is completely melted and the temperature is raised to the working temperature; the heating belts preheat the entire experimental loop to ensure uniform temperature.

[0026] Step 3: Loop filling and fluid circulation; use the gas protection device and the vacuum pump to pressurize the lead-bismuth storage tank, press the molten lead-bismuth alloy fluid into the experimental loop until it is completely filled, start the cold loop magnetic pump and the hot loop magnetic pump to make the molten lead-bismuth alloy fluid circulate, monitor the flow condition in real time and adjust it to establish a stable flow rate working condition.

[0027] Step 4: Temperature regulation; start the fan to accurately cool the lead-bismuth alloy fluid in the loop where the cold loop magnetic pump is located, cooperate with the heating system to realize gradient control of the temperature; through the temperature monitoring feedback of the data acquisition device, use the integrated control module to adjust the system power to establish a temperature working condition that meets the experimental requirements.

[0028] Step 5: Flow rate regulation; use the integrated control module to control the rotational speed of the cold loop magnetic pump and the hot loop magnetic pump to make the lead-bismuth alloy fluid in different branches move at a specific flow rate to achieve a flow rate working condition that meets the experimental requirements.

[0029] Step 6: Data acquisition and analysis; arrange a sensor array at a specified position of the three-inlet experimental section, collect temperature data and strain data according to the sensor array, monitor and record the dynamic evolution process of the thermal strip oscillation phenomenon, analyze the data, and correct the simulation model according to the analysis results.

[0030] Further, the sensor array of step 6 includes a plurality of thermocouples and a plurality of high-temperature strain gauges.

[0031] Compared with the prior art, the present application has the following advantages:

[0032] Liquid lead bismuth is used as fluid working medium, which completely simulates the real working condition of thermal stripe oscillation in actual engineering, so that the key parameters can be more accurately reflected, which is superior to the traditional experimental device using water as working medium; the cold loop and the hot loop are respectively driven by double magnetic pumps, and the air cooler is arranged in the cold loop to realize rapid cooling of liquid lead bismuth, so that lead bismuth jet with temperature difference is formed, and ideal mixing effect in the experimental section is ensured; at the same time, the gas composition in the argon protection system and the vacuum pump control device is controlled, the oxygen content is effectively inhibited, the oxidation of high-temperature lead bismuth and the damage to the equipment are prevented, and the accuracy of the experimental results is ensured; the replaceable experimental section structure design is adopted, which facilitates the research on the influence of thermal stripe oscillation on different structures, greatly reduces the reform workload and material consumption, and improves the experimental efficiency; the main structure can not only promote the generation of expected thermal cracks, but also has excellent liquid lead bismuth erosion resistance at the experimental temperature, so that the reliability of the experiment is comprehensively ensured. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 The prefix tree index structure of the present application is shown in the figure.

[0034] Figure 2 The data collected in the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0035] The following will be described in conjunction with the accompanying Figure 1 The present application is further described.

[0036] A liquid lead bismuth alloy thermal stripe oscillation experimental device includes:

[0037] An experimental loop is used to circulate liquid lead bismuth alloy.

[0038] An argon loop is used to provide gas protection and control the oxygen content.

[0039] A data acquisition device 13 is used to acquire temperature, flow and strain data.

[0040] An integrated control module 14 is used to control the operation of each component.

[0041] The experimental loop includes a lead bismuth storage tank 1, a cold loop magnetic pump 2, a hot loop magnetic pump 3, an air cooler 4, a three-inlet experimental section 9 and a heating system 10, and is connected by pipes to form a closed loop.

[0042] As preferred, two outlets are arranged on the lead-bismuth storage tank 1, which are connected with the cold loop magnetic pump 2 and the hot loop magnetic pump 3 respectively, the air cooler 4 is connected with the cold loop magnetic pump 2, and the air cooler 4 is externally connected with the fan 5.

[0043] As preferred, the argon gas loop comprises an argon gas protection device and a vacuum pump 12; the argon gas protection device and the vacuum pump 12 are connected to the experimental loop through pipelines, for vacuumizing and protection gas filling treatment of the experimental loop, to maintain an oxygen-free environment.

[0044] As preferred, the data acquisition device 13 comprises a cold loop Venturi flowmeter, a hot loop left side Venturi flowmeter, a hot loop right side Venturi flowmeter, a high-temperature strain gauge 15 and a thermocouple 16.

[0045] The air cooler 4 is laterally provided with a liquid outlet, the cold loop flowmeter is connected with the air cooler 4 through the liquid outlet; one of the three inlets of the three-inlet experimental section 9 is connected with the cold loop Venturi flowmeter; the hot loop magnetic pump 3 is respectively connected with the hot loop left side Venturi flowmeter and the hot loop right side Venturi flowmeter; the other two inlets of the three-inlet experimental section 9 are respectively connected with the hot loop left side Venturi flowmeter and the hot loop right side Venturi flowmeter.

[0046] As preferred, the flowmeter can be a Venturi flowmeter, an exhaust pipe is arranged at the position of the differential pressure transmitter, the opening is upward, the exhaust valve is opened before the experiment, the gas at the end of the pilot pipe is exhausted, the differential pressure transmitter is ensured to be in full contact with the liquid lead-bismuth, and the flow measurement precision is improved.

[0047] This improvement is only used to improve the measurement precision of the Venturi flowmeter, to provide guarantee for accurately obtaining the flow velocity data of the lead-bismuth experimental section inlet; if other flowmeters are selected, the improvement is not needed.

[0048] As preferred, the three-inlet experimental section 9 is modularized designed, for studying the thermal stripe oscillation phenomenon under different structural forms.

[0049] As preferred, the heating system 10 comprises heating belts and heating rods; for heating the equipment and pipelines in each experimental loop, melting the solid lead-bismuth alloy, facilitating the flow of the lead-bismuth alloy in the experimental loop, and providing required temperature conditions for the experiment.

[0050] As preferred, the air cooler 4 and the fan 5 are used for cooling the fluid in the loop where the cold loop magnetic pump 2 is located.

[0051] When starting the experiment, gas replacement: start the vacuum pump 12 to vacuumize the lead-bismuth storage tank 1 and the experimental circuit, and establish an oxygen-free environment with a vacuum degree of 80%; open the valve of the argon protection system, inject high-purity argon into the system to form a protective atmosphere; ensure that the liquid lead-bismuth is completely isolated from oxygen during subsequent operations to prevent oxidation.

[0052] System preheating: start the heating system 10 to heat the lead-bismuth storage tank 1; heat the solid lead-bismuth to a completely melted state and raise the temperature to the experimental operating temperature of 450°C; simultaneously preheat the entire experimental device circuit to ensure temperature uniformity.

[0053] Circuit filling and circulation establishment: use the argon protection system to apply pressure to the storage tank; press the molten lead-bismuth into the experimental circuit until it is completely filled; start the magnetic pumps 2, 3 to drive the lead-bismuth circulation; establish a stable flow rate operating condition through real-time monitoring and adjustment.

[0054] Temperature field regulation: start the fan 5 to accurately cool the lead-bismuth in the cold circuit; cooperate with the heating system 10 to achieve temperature gradient control; adjust the system power through temperature monitoring and feedback of the three-inlet experimental section 9; establish a temperature operating condition that meets the experimental requirements.

[0055] Flow rate regulation: control the speed of the magnetic pumps 2, 3 to make the liquid lead-bismuth in different branches move at a specific flow rate to achieve a flow rate operating condition that meets the experimental requirements.

[0056] Data acquisition and analysis: arrange a sensor array at key positions in the three-inlet experimental section 9 according to actual conditions; real-time acquisition of temperature field and strain field data, as shown in FIG. 6, the temperature measuring points arranged in the experimental section and each temperature monitoring area, the data measured are displayed in real time on the monitoring equipment, in addition, the data of the flow meter and the strain data can also be displayed and saved on the same monitoring equipment; monitor and record the dynamic evolution process of the thermal stripe oscillation phenomenon; provide complete and reliable experimental data for subsequent analysis. Figure 2

[0057] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.​

Claims

1. A liquid lead-bismuth alloy hot streak oscillation experiment device, characterized by, The application relates to a lead-bismuth eutectic loop experimental device. The experimental loop is used for circulating liquid lead-bismuth alloy; the gas protection loop is used for providing gas protection and controlling oxygen content; the data acquisition device (13) is used for acquiring temperature, flow and strain data; the integrated control module (14) is used for controlling the operation of various components; the experimental loop comprises a lead-bismuth storage tank (1), a cold loop magnetic pump (2), a hot loop magnetic pump (3), an air cooler (4), a three-inlet experimental section (9) and a heating system (10) and is connected by pipelines to form a closed loop. The lead-bismuth storage tank (1) is provided with two outlets which are connected with the cold loop magnetic pump (2) and the hot loop magnetic pump (3) respectively, and the air cooler (4) is connected with the cold loop magnetic pump (2); the air cooler (4) is externally connected with a fan (5). The gas protection loop comprises a gas protection device (11) and a vacuum pump (12); the gas protection device (11) and the vacuum pump (12) are connected to the experimental loop by pipelines and are used for vacuumizing the experimental loop and processing the experimental loop by filling protective gas to maintain an oxygen-free environment. The data acquisition device (13) comprises a cold loop flowmeter (6), a left side hot loop flowmeter (7), a right side hot loop flowmeter (8), a high-temperature strain gauge (15) and a thermocouple (16); The air cooler (4) is provided with a liquid outlet on the side, the cold loop flowmeter (6) is connected with the air cooler (4) through the liquid outlet, one inlet of the three-inlet experimental section (9) is connected with the cold loop flowmeter (6), the hot loop magnetic pump (3) is connected with the left side hot loop flowmeter (7) and the right side hot loop flowmeter (8) respectively, and the other two inlets of the three-inlet experimental section (9) are connected with the left side hot loop flowmeter (7) and the right side hot loop flowmeter (8) respectively.

2. The liquid lead-bismuth alloy thermal strip oscillation experimental device according to claim 1, characterized in that: The three-inlet experimental section (9) is modularized and is used for studying thermal stripe oscillation phenomena under different structural forms.

3. The liquid lead-bismuth alloy thermal strip oscillation experimental device according to claim 1, characterized in that: The heating system (10) comprises heating belts and heating rods and is used for heating equipment and pipelines in the experimental loop, melting solid lead-bismuth alloy, facilitating the flow of the lead-bismuth alloy in the experimental loop and providing required temperature conditions for experiments.

4. The liquid lead-bismuth alloy thermal strip oscillation experimental device according to claim 1, characterized in that: The air cooler (4) and the fan (5) are used for cooling the fluid in the loop where the cold loop magnetic pump (2) is located. The application further discloses a lead-bismuth eutectic loop experimental device and a lead-bismuth eutectic loop experimental method.

5. The liquid lead-bismuth alloy thermal strip oscillation experimental device according to claim 1, characterized in that: Step 1: gas replacement; the vacuum pump (12) is started to vacuumize the lead-bismuth storage tank (1) and the experimental loop, the integrated control module (14) controls the gas protection device (11) to start and inject protective gas into the experimental loop to form protection; 6. The liquid lead-bismuth alloy thermal strip oscillation experimental device according to claim 1, characterized in that: Step 2: device preheating; the heating system (10) is started, the heating rods heat the lead-bismuth storage tank (1) until the solid lead-bismuth alloy is completely melted and the temperature is increased to a working temperature; the heating belts preheat the whole experimental loop to ensure uniform temperature; 7. The liquid lead-bismuth alloy thermal strip oscillation experimental device according to claim 1, characterized in that: ​ 8. An experimental method based on a liquid lead-bismuth alloy thermal stripe oscillation experimental device, characterized by, ​ ​ ​ Step 3: Loop filling and fluid circulation; the lead-bismuth storage tank (1) is pressurized by the gas protection device (11) and the vacuum pump (12) to press the molten lead-bismuth alloy fluid into the experimental loop until it is completely filled, the cold loop magnetic pump (2) and the hot loop magnetic pump (3) are started to make the molten lead-bismuth alloy fluid circulate, the flow condition is monitored and adjusted in real time, and a stable flow rate working condition is established; Step 4: Temperature regulation; the fan (5) is started to accurately cool the lead-bismuth alloy fluid in the loop where the cold loop magnetic pump (2) is located, and the heating system (10) is used to realize gradient control of the temperature; through the temperature monitoring feedback of the data acquisition device (13), the integrated control module (14) is used for system power regulation to establish a temperature working condition meeting the experimental requirements; Step 5: Flow rate regulation; the integrated control module (14) is used to control the rotating speed of the cold loop magnetic pump (2) and the hot loop magnetic pump (3) to make the lead-bismuth alloy fluid in different branches move at a specific flow rate to meet the flow rate working condition required by the experiment; Step 6: Data acquisition and analysis; a sensor array is arranged at a specified position of the three-inlet experimental section (9), temperature data and strain data are collected according to the sensor array, the dynamic evolution process of the thermal stripe oscillation phenomenon is monitored and recorded, and the simulation model is corrected according to the analysis results.

9. The experimental method based on the liquid lead-bismuth alloy thermal stripe oscillation experimental device according to claim 8, characterized in that: The sensor array of step 6 comprises a plurality of thermocouples (16) and a plurality of high-temperature strain gauges (15).

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