Experimental device for studying the deposition and resuspension of particles in a pebble bed structure

Abstract

The application discloses a kind of experimental device for studying particle deposition resuspension in pebble bed structure, comprising: circulation pipeline, circulation pipeline is equipped with atmospheric vent;Gas source;Compressor;Circulating fan;Pebble bed simulation device, pebble bed simulation device includes shell, graphite ball friction mechanism, simulated pebble bed and heating element, heating cavity is in shell, shell is equipped with air inlet and air outlet, graphite ball friction mechanism is arranged in heating cavity and is suitable for making graphite ball friction to produce dust particle;First cooling device;Second cooling device;Third cooling device;Vacuum pump;Vacuum tank;First dust detection device;Second dust detection device.According to the pebble bed structure of the embodiment of the application experimental device for studying particle deposition resuspension can simulate the generation, deposition and resuspension process of dust particle under high temperature and high pressure environment, with experimental result real and accurate, strong reliability and the like advantages.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of nuclear reactor engineering, and particularly relates to a research experimental device for particle deposition and resuspension in a pebble bed structure. BACKGROUND

[0002] A pebble bed high temperature gas cooled reactor is composed of a large number of graphite pebbles to form a moving core. During loading and unloading operation, dust particles will be generated due to impact and wear. The generated dust particles will move in the pebble bed and then deposit on the surface of the pebble bed. Part of the dust particles will leave the pebble bed core and enter the loop. Under the condition of pressure loss accident, part of the dust particles deposited in the pebble bed may also resuspend and separate from the pebble bed core, which may cause the risk of radioactive diffusion.

[0003] The dust particles deposited on the surface of the pebble bed in a high temperature and high pressure environment will sinter over time, which will cause the particles to adhere more tightly to the surface of the pebble bed and reduce the resuspension fraction.

[0004] The graphite dust movement experiment in the related art can only simulate the movement of graphite dust at normal temperature, and lacks an integrated experimental platform for simulating the generation of graphite ball wear dust, the deposition of dust particles in the pebble bed, and the resuspension of dust particles in the pebble bed under high temperature and high pressure. Moreover, the high temperature and high pressure environment will cause the related measuring instruments and operating equipment to be difficult to operate normally, which increases the experimental difficulty. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a research experimental device for particle deposition and resuspension in a pebble bed structure, which can simulate the generation, deposition and resuspension process of dust particles under high temperature and high pressure environment, and has the advantages of true and accurate experimental results, strong reliability and the like.

[0006] To achieve the above-mentioned purpose, according to an embodiment of the present invention, an experimental device for studying the deposition and resuspension of particles in a ball bed structure is proposed, the experimental device for studying the deposition and resuspension of particles in a ball bed structure comprising: a circulation pipeline, the circulation pipeline being provided with an atmospheric exhaust port; an air source, the air source being connected to the circulation pipeline through an air source pipeline; a compressor, the compressor being connected to the air source pipeline; a circulation fan, the circulation fan being connected to the circulation pipeline; a ball bed simulation device, the ball bed simulation device comprising a shell, a graphite ball friction mechanism, a simulated ball bed and a heating element, the shell having a heating chamber, an air inlet and an air outlet being provided on the shell, the shell being connected to the circulation pipeline through the air inlet and the air outlet, the graphite ball friction mechanism being provided in the heating chamber and being suitable for causing graphite balls to rub against each other to generate dust particles, the simulated ball bed being provided at the bottom of the shell, the heating element being provided on the shell and being suitable for heating the heating chamber; a first cooling device, the first cooling device being connected to the circulation pipeline and being located between the air outlet of the ball bed simulation device and the circulation fan; a second cooling device The second cooling device is connected to the circulation pipeline and is located between the first cooling device and the circulation fan; a vacuum pump, the vacuum pump is connected to the circulation pipeline through a vacuum pipeline, and the connection between the vacuum pipeline and the circulation pipeline is located between the first cooling device and the air outlet of the ball bed simulation device; a vacuum tank, the vacuum tank is connected to the vacuum pipeline; a third cooling device, the third cooling device is connected to the vacuum pipeline and is located between the circulation pipeline and the vacuum tank; a first dust detection device, the first dust detection device is provided on the ball bed simulation device and is suitable for detecting the concentration and particle size of dust particles in the heating chamber; a second dust detection device, the second dust detection device is connected to the circulation pipeline and the vacuum pipeline respectively and is suitable for detecting the concentration and particle size of dust particles in the circulation pipeline and the vacuum pipeline, the connection between the second dust detection device and the circulation pipeline is located between the first cooling device and the second cooling device, and the connection between the second dust detection device and the vacuum pipeline is located between the third cooling device and the vacuum tank.

[0007] The experimental device for studying particle deposition and resuspension in a pebble bed structure according to an embodiment of the present invention can simulate the generation, deposition and resuspension process of dust particles under a high temperature and high pressure environment, and has the advantages of true and accurate experimental results and strong reliability.

[0008] In addition, the experimental device for studying particle deposition and resuspension in a pebble bed structure according to the above embodiment of the present invention may also have the following additional technical features:

[0009] According to one embodiment of the present invention, the graphite ball friction mechanism includes: a rotating shaft, which is rotatably provided on the shell and oriented in the up and down directions; a plurality of rotating graphite balls, which are all connected to the rotating shaft and arranged at circumferential intervals along the rotating shaft, and the plurality of rotating graphite balls rotate together with the rotating shaft, and an openable and closable graphite ball delivery port is provided on the top wall of the shell, and the graphite ball delivery port is suitable for delivering sample graphite balls, and the plurality of rotating graphite balls are constructed to be suitable for keeping the sample graphite balls entering the heating chamber through the sample graphite ball delivery port above the plurality of rotating graphite balls and for causing the sample graphite balls to rub against the rotating graphite balls.

[0010] According to one embodiment of the present invention, the first cooling device and the third cooling device both include: an outer tube, the outer peripheral surface of the outer tube is provided with a cooling air inlet, the cooling air inlet is connected to the circulation pipeline through a return pipeline, and the connection between the return pipeline and the circulation pipeline is located between the second cooling device and the circulation fan; an inner tube, the inner tube is connected to the circulation pipeline, the inner tube is provided on the radial inner side of the outer tube and a cooling air cavity is formed between the inner tube and the outer tube, and a plurality of air film holes are provided on the peripheral wall of the inner tube for connecting the cooling air cavity and the inner side of the inner tube.

[0011] According to one embodiment of the present invention, the reflux pipeline is connected to a booster air pump, a buffer tank and a reflux regulating valve.

[0012] According to one embodiment of the present invention, the experimental device for studying the deposition and resuspension of particles in the pebble bed structure further includes a heat recovery device, and the heat recovery device includes a first heat exchange channel and a second heat exchange channel suitable for exchanging heat with each other, the first heat exchange channel being connected to the circulation pipeline and being located between the circulation fan and the air inlet of the pebble bed simulation device, and the two ends of the second heat exchange channel being respectively connected to the circulation pipeline and the connection being located between the first cooling device and the second cooling device.

[0013] According to one embodiment of the present invention, the experimental device for studying the deposition and resuspension of particles in the pebble bed structure further includes a dust removal device, which is connected to the circulation pipeline. The dust removal device includes: an aerosol charger, which is located between the second cooling device and the circulation fan and is suitable for charging the dust particles in the circulation pipeline; and an electrostatic precipitator, which is located between the aerosol charger and the circulation fan and is suitable for collecting the charged dust particles.

[0014] According to one embodiment of the present invention, the atmospheric exhaust port is connected to an exhaust on-off valve, the gas source pipeline is connected to an gas source on-off valve, the circulation pipeline is connected to a circulation on-off valve, and the circulation on-off valve is located between the atmospheric exhaust port and the gas source pipeline; the vacuum pipeline is connected to a vacuum on-off valve, and the vacuum on-off valve is located between the vacuum tank and the circulation pipeline.

[0015] According to one embodiment of the present invention, the experimental device for studying the deposition and resuspension of particles in the pebble bed structure further includes: a first temperature sensor, which is arranged at the air outlet of the pebble bed simulation device; a second temperature sensor, which is connected to the circulation pipeline and is located between the first cooling device and the second cooling device; a third temperature sensor, which is connected to the circulation pipeline and is located between the second cooling device and the circulation fan; and a fourth temperature sensor, which is connected to the vacuum pipeline and is located between the third cooling device and the vacuum tank.

[0016] According to one embodiment of the present invention, the housing of the ball bed simulation device includes a main body and a bottom cover, and the bottom cover is detachably mounted on the main body.

[0017] According to one embodiment of the present invention, the gas source includes a nitrogen storage tank and a helium storage tank.

[0018] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0020] Figure 1 3 is a schematic structural diagram of an experimental device for studying particle deposition and resuspension in a pebble bed structure according to an embodiment of the present invention.

[0021] Figure 2 2 is a schematic structural diagram of a pebble bed simulation device according to an experimental device for studying particle deposition and resuspension in a pebble bed structure according to an embodiment of the present invention.

[0022] Figure 3 2 is a schematic structural diagram of a pebble bed simulation device according to an experimental device for studying particle deposition and resuspension in a pebble bed structure according to an embodiment of the present invention.

[0023] Figure 4 3 is a schematic structural diagram of a first cooling device of an experimental device for studying particle deposition and resuspension in a pebble bed structure according to an embodiment of the present invention.

[0024] Fig. 1 is a schematic diagram of an experimental device for studying the deposition and resuspension of particles in a pebble bed structure; 10, circulating pipeline; 11, atmospheric exhaust port; 12, gas source pipeline; 13, vacuum pipeline; 14, backflow pipeline; 15, bypass pipeline; 16, first heat recovery section; 17, second heat recovery section; 20, gas source; 21, nitrogen storage tank; 22, helium storage tank; 30, compressor; 40, circulating fan; 50, pebble bed simulation device; 51, shell; 511, gas inlet; 512, gas outlet; 513, main body; 514, top cover; 515, bottom cover; 52, graphite ball friction mechanism; 521, rotating shaft; 522, rotating graphite ball; 53, simulated pebble bed; 54, heating element; 55, graphite ball feeding port; 56, sample graphite ball; 60, first cooling device; 61, outer tube; 611, cooling gas inlet; 62, inner tube; 621, gas film hole; 70, second cooling device; 80, vacuum pump; 90, vacuum tank; 100, first dust detection device; 110, second dust detection device; 120, booster gas pump; 130, buffer tank; 140, backflow regulating valve; 150, heat recovery device; 151, first heat exchange flow channel; 152, second heat exchange flow channel; 160, dust removal device; 161, aerosol charger; 162, electrostatic precipitator; 171, exhaust on-off valve; 172, gas source on-off valve; 173, circulating on-off valve; 174, vacuum on-off valve; 175, heat recovery on-off valve; 176, heat recovery regulating valve; 177, first fan on-off valve; 178, second fan on-off valve; 179, third fan on-off valve; 181, first temperature sensor; 182, second temperature sensor; 183, third temperature sensor; 184, third temperature sensor; 191, first flow meter; 192, second flow meter; 193, third flow meter; 200, pressure gauge; 210, filter; 220, third cooling device. DETAILED DESCRIPTION

[0025] The present application is based on the discovery and realization of the inventors of the following facts and problems:

[0026] The present application is based on the discovery and realization of the inventors of the following facts and problems:

[0027] The present application is based on the discovery and realization of the inventors of the following facts and problems:

[0028] The graphite dust movement experiment in the related art can only simulate the movement of graphite dust at room temperature, lacks an integrated experimental platform for simulating the generation of graphite ball wear dust, the deposition of dust particles in the pebble bed, and the resuspension of dust particles in the pebble bed under high temperature and high pressure, and the high temperature and high pressure environment can cause the related measuring instruments and operating equipment to be difficult to operate normally, increasing the experimental difficulty.

[0029] In order to complete the closed loop and data collection, the airflow heated in the pebble bed simulation device needs to be cooled. However, if a conventional heat exchanger is used for cooling, the high temperature gradient on the heat exchange surface will cause small-scale dust particles to deposit, affecting the accuracy of sampling.

[0030] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0032] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0033] The following describes an experimental device 1 for studying the deposition and resuspension of particles in a pebble bed structure according to an embodiment of the present invention with reference to the accompanying drawings.

[0034] like Figures 1-4 As shown, the experimental device 1 for studying the deposition and resuspension of particles in a pebble bed structure according to an embodiment of the present invention includes a circulation pipeline 10, an air source 20, a compressor 30, a circulation fan 40, a pebble bed simulation device 50, a first cooling device 60, a second cooling device 70, a third cooling device 220, a vacuum pump 80, a vacuum tank 90, a first dust detection device 100 and a second dust detection device 110.

[0035] The circulation pipeline 10 is provided with an atmospheric exhaust port 11. The air source 20 is connected to the circulation pipeline 10 through the air source pipeline 12. The compressor 30 is connected to the air source pipeline 12. The circulation fan 40 is connected to the circulation pipeline 10.

[0036] The ball bed simulation device 50 includes a shell 51, a graphite ball friction mechanism 52, a simulated ball bed 53 and a heating element 54. The shell 51 has a heating chamber, and the shell 51 is provided with an air inlet 511 and an air outlet 512. The shell 51 is connected to the circulation pipeline 10 through the air inlet 511 and the air outlet 512. The graphite ball friction mechanism 52 is arranged in the heating chamber and is suitable for making the graphite balls rub against each other to generate dust particles. The simulated ball bed 53 is arranged at the bottom of the shell 51, and the heating element 54 is arranged on the shell 51 and is suitable for heating the heating chamber.

[0037] The first cooling device 60 is connected to the circulation pipeline 10 and is located between the air outlet 512 of the pebble bed simulator 50 and the circulation fan 40. The second cooling device 70 is connected to the circulation pipeline 10 and is located between the first cooling device 60 and the circulation fan 40. The third cooling device 220 is connected to the vacuum pipeline 13 and is located between the circulation pipeline 10 and the vacuum tank 90.

[0038] The vacuum pump 80 is connected to the circulation pipeline 10 via the vacuum pipeline 13 . The connection between the vacuum pipeline 13 and the circulation pipeline 10 is located between the first cooling device 60 and the air outlet 512 of the pebble bed simulation device 50 . The vacuum tank 90 is connected to the vacuum pipeline 13 .

[0039] The first dust detection device 100 is mounted on the pebble bed simulator 50 and is adapted to detect the concentration and size of dust particles within the heating chamber. The second dust detection device 110 is connected to the circulation pipeline 10 and the vacuum pipeline 13, respectively, and is adapted to detect the concentration and size of dust particles within the circulation pipeline 10 and the vacuum pipeline 13. The connection between the second dust detection device 110 and the circulation pipeline 10 is located between the first cooling device 60 and the second cooling device 70, and the connection between the second dust detection device 110 and the vacuum pipeline 13 is located between the third cooling device 220 and the vacuum tank 90.

[0040] Specifically, the first dust detection device 100 and the second dust detection device 110 can both be aerosol particle size spectrometers, so as to detect the concentration and particle size of dust particles and improve the experimental accuracy.

[0041] First, the gas in circulation pipeline 10 must be replaced with the gas required for the experiment: Open the atmospheric vent 11 and start the vacuum pump 80 to extract the air from circulation pipeline 10 to prevent it from affecting subsequent experiments. Then, open the gas source 20 and start the compressor 30. The air from source 20 then enters circulation pipeline 10. After a predetermined period of time, the vacuum pump 80 is turned off, and the air flows through the entire circulation pipeline 10 and is discharged into the atmosphere through the atmospheric vent 11.

[0042] After that, the circulation pipeline 10 needs to be pressurized: the atmospheric exhaust port 11 is closed, the gas at the gas source 20 is continuously filled into the circulation pipeline 10 through the compressor 30, and after the pressure of the circulation pipeline 10 changes to the predetermined pressure, the gas source 20 is closed.

[0043] Then, the gas in the circulation pipeline 10 needs to be circulated and heated so that the gas in the circulation pipeline 10 reaches a predetermined flow rate and a predetermined experimental temperature:

[0044] The circulation fan 40 is turned on to allow the air flow in the circulation pipeline 10 to flow driven by the circulation fan 40 , and the circulation pipeline 10 is tested to see whether it reaches a predetermined flow rate.

[0045] The airflow is cooled by the first cooling device 60 and the second cooling device 70, the heating element 54 in the pebble bed simulation device 50 is turned on, and the power of the heating element 54 is adjusted so that the pebble bed simulation device 50 reaches the specified temperature; the operating state of the second cooling device 70 is adjusted so that the airflow temperature remains within the operating temperature range of the circulating fan 40; the operating state of the first cooling device 60 is adjusted so that the airflow temperature remains within the operating temperature range of the second dust detection device 110.

[0046] The closed loop within the current circulation fan 40 requires cooling the airflow heated by the heater 54 within the pebble bed simulator 50 to prevent overheating and damage to downstream components. The airflow heated by the heater 54 first passes through the first cooling device 60 to reduce the temperature and prevent overheating of the second dust detection device 110. It then passes through the second cooling device 70 to reduce the temperature and prevent overheating of the circulation fan 40. After passing through the circulation fan 40, the airflow returns to the pebble bed simulator 50 to complete the cycle.

[0047] After that, you can formally conduct the experiment:

[0048] Dust particles must first be generated: the graphite ball friction mechanism 52 in the pebble bed simulation device 50 operates, causing the graphite balls to rub against each other, generating dust particles. The airflow in the circulation pipeline 10 enters the pebble bed simulation device 50 through the air inlet 511, carrying dust particles with it. The first dust detection device 100 is used to measure the number and particle size of dust particles generated by wear. Subsequently, the dust particles generated by friction under the action of airflow and gravity enter the simulated pebble bed 53. The pebble bed height of the simulated pebble bed 53 can be adjusted according to actual needs, thereby studying the effect of the pebble bed stacking height on deposition. After passing through the simulated pebble bed 53, the airflow returns to the circulation pipeline 10 through the air outlet 512.

[0049] If a deposition experiment is required: the airflow carrying dust particles coming out of the pebble bed simulation device 50 is cooled by the first cooling device 60, and then passes through the second dust detection device 110 to measure the concentration and particle size of the dust particles in the circulation pipeline 10. By comparing with the detection values ​​of the first dust detection device 100, the deposition proportion of the dust particles after passing through the pebble beds with different stacking heights and the deposition characteristics of dust particles with different particle sizes are obtained.

[0050] If a resuspension experiment is required, vacuum line 13 is closed and vacuum pump 80 is turned on to achieve a negative pressure environment within vacuum tank 90. ​​Subsequently, while maintaining the high-pressure airflow in circulation line 10, vacuum line 13 is opened. Due to the high pressure in circulation line 10 and the negative pressure in vacuum tank 90, the airflow discharge effect during a rupture accident is simulated. The second dust detection device 110 is used to observe the changes in dust particle size between the two circuits, thereby calculating the number of particles resuspended within the pebble bed structure during a rupture accident.

[0051] According to the experimental device 1 for studying the deposition and resuspension of particles in a ball bed structure according to an embodiment of the present invention, a circulation pipeline 10, an air source 20, a compressor 30, a circulation fan 40, and a ball bed simulation device 50 are set. The air source 20 is connected to the circulation pipeline 10 through the air source pipeline 12, the compressor 30 is connected to the air source pipeline 12, and the circulation fan 40 is connected to the circulation pipeline 10. The gas at the air source 20 can be continuously filled into the circulation pipeline 10 through the compressor 30, so that a high-pressure environment is simulated in the circulation pipeline 10 and the ball bed simulation device 50.

[0052] By setting up the ball bed simulation device 50, the graphite ball friction mechanism 52 of the ball bed simulation device 50 can make the graphite balls rub against each other to generate dust particles, the simulated ball bed 53 of the ball bed simulation device 50 can simulate the stacked ball bed, and the heating element 54 can heat the airflow in the ball bed simulation device 50 to simulate a high temperature environment.

[0053] By providing a first dust detection device 100 and a second dust detection device 110, the first dust detection device 100 is installed on the pebble bed simulator 50 and is suitable for detecting the concentration and particle size of dust particles in the heating chamber. The second dust detection device 110 is connected to the circulation pipeline 10 and the vacuum pipeline 13, respectively, and is suitable for detecting the concentration and particle size of dust particles in the circulation pipeline 10 and the vacuum pipeline 13. The second dust detection device 110 and the first dust detection device 100 can be used to detect the concentration and particle size of dust particles, facilitating the detection and quantification of dust particle deposition and resuspension, providing a numerical basis for the experiment.

[0054] By setting a first cooling device 60, a second cooling device 70 and a third cooling device 70, the first cooling device 60 is connected to the circulation pipeline 10 and is located between the air outlet 512 of the ball bed simulation device 50 and the circulation fan 40, the second cooling device 70 is connected to the circulation pipeline 10 and is located between the first cooling device 60 and the circulation fan 40, the third cooling device 220 is connected to the vacuum pipeline 13 and is located between the circulation pipeline 10 and the vacuum tank 90, the connection point of the second dust detection device 110 and the circulation pipeline 10 is located between the first cooling device 60 and the second cooling device 70, and the second dust detection device 110 and the vacuum pipeline 13 are connected. The connection between the second dust detection device 110 and the circulation pipeline 10 is located between the third cooling device 220 and the vacuum tank 90. ​​The first cooling device 60, the second cooling device 70, and the third cooling device 70 can be used to cool the heated airflow in the pebble bed simulator 50. The connection between the second dust detection device 110 and the circulation pipeline 10 is located downstream of the first cooling device 60, and the connection between the second dust detection device 110 and the vacuum pipeline 13 is located downstream of the third cooling device 70. This prevents overheating of the connection between the second dust detection device 110 and the circulation pipeline 10 and the connection between the second dust detection device 110 and the vacuum pipeline 13, which would affect the normal operation of the second dust detection device 110. By providing a vacuum pump 80, not only can the vacuum pump 80 be used to extract air from the circulation pipeline 10 during the experimental preparation stage to prevent air from affecting the experimental process, but the vacuum tank 90 can also be provided to generate a negative pressure inside the vacuum tank 90. ​​During the resuspension experiment, the negative pressure vacuum tank 90 is connected to the circulation pipeline 10 to simulate the effect of air discharge during a rupture accident.

[0055] That is to say, the experimental device 1 for studying particle deposition and resuspension in a ball bed structure can simulate the generation and deposition process of dust particles, and can also simulate the resuspension process of dust particles in a breach accident. Moreover, the source of the dust particles in the resuspension process is the movement and deposition of dust in the simulated ball bed 53, which is closer to the actual situation, and the experimental results are more accurate and reliable.

[0056] In addition, the experimental device 1 for studying the deposition and resuspension of particles in a ball bed structure can provide a high-temperature and high-pressure experimental environment, simulating the influence of the sintering phenomenon under high temperature and high pressure on the deposition and resuspension process of dust particles. Moreover, the first cooling device 60 and the second cooling device 70 ensure that the detection and circulation equipment circulates within the working temperature range, thereby improving the reliability of the operation of the experimental device 1 for studying the deposition and resuspension of particles in a ball bed structure.

[0057] Therefore, the experimental device 1 for studying particle deposition and resuspension in a pebble bed structure according to an embodiment of the present invention can simulate the generation, deposition and resuspension process of dust particles under a high temperature and high pressure environment, and has the advantages of true and accurate experimental results and strong reliability.

[0058] The following describes an experimental device 1 for studying the deposition and resuspension of particles in a pebble bed structure according to a specific embodiment of the present invention with reference to the accompanying drawings.

[0059] In some specific embodiments of the present invention, Figures 1-4 As shown, the experimental device 1 for studying the deposition and resuspension of particles in a pebble bed structure according to an embodiment of the present invention includes a circulation pipeline 10, an air source 20, a compressor 30, a circulation fan 40, a pebble bed simulation device 50, a first cooling device 60, a second cooling device 70, a third cooling device 220, a vacuum pump 80, a vacuum tank 90, a first dust detection device 100 and a second dust detection device 110.

[0060] Specifically, if Figure 1-Figure 3 As shown, the graphite ball friction mechanism 52 includes a rotating shaft 521 and a plurality of rotating graphite balls 522. The rotating shaft 521 is rotatably provided on the housing 51 and oriented in the up-down direction (the up-down direction is indicated by the arrow in the figure). The plurality of rotating graphite balls 522 are all connected to the rotating shaft 521 and are arranged at intervals along the circumference of the rotating shaft 521. The plurality of rotating graphite balls 522 rotate together with the rotating shaft 521. An openable and closable graphite ball delivery port 55 is provided on the top wall of the housing 51. The graphite ball delivery port 55 is suitable for delivering sample graphite balls 56. The plurality of rotating graphite balls 522 are configured to be suitable for keeping the sample graphite balls 56 entering the heating chamber through the graphite ball delivery port 55 above the plurality of rotating graphite balls 522 and for causing the sample graphite balls 56 to rub against the rotating graphite balls 522. Specifically, there are three rotating graphite balls 522 and they are arranged at equal intervals. By adjusting the rotation speed of the rotating shaft 521, the wear rate between the graphite balls can be adjusted. In this way, the rotation of the rotating shaft 521 can cause the rotating graphite balls 522 and the sample graphite balls 56 introduced through the graphite ball introduction port 55 to rub against each other, thereby generating dust particles.

[0061] More specifically, if Figure 2 and Figure 3As shown, the housing 51 of the ball bed simulator 50 includes a main body 513 and a bottom cover 515, which is detachably mounted on the main body 513. Specifically, the housing 51 also includes a top cover 514, on which a graphite ball inlet 55 is located. This allows for easy adjustment of the height of the simulated ball bed 53 after removing the bottom cover 515.

[0062] Advantageously, as Figure 1 and Figure 4 As shown, both the first cooling device 60 and the third cooling device 220 include an outer tube 61 and an inner tube 62. A cooling air inlet 611 is provided on the outer circumference of the outer tube 61. The cooling air inlet 611 is connected to the circulation pipeline 10 via the return pipeline 14. The connection between the return pipeline 14 and the circulation pipeline 10 is located between the second cooling device 70 and the circulation fan 40. The inner tube 62 is connected to the circulation pipeline 10. The inner tube 62 is provided radially inward of the outer tube 61 and forms a cooling air cavity with the outer tube 61. The circumferential wall of the inner tube 62 is provided with a plurality of air film holes 621 that connect the cooling air cavity with the inner side of the inner tube 62.

[0063] After extensive research, the inventors of this application discovered that the temperature of the air flow carrying dust particles coming out of the pebble bed simulation device 50 is relatively high, making it difficult to directly measure the concentration of the dust particles therein. If a conventional heat exchanger is used for cooling, the high temperature gradient on the heat exchange surface will cause small-scale dust particles to settle, affecting the accuracy of sampling.

[0064] By installing the first cooling device 60 and the third cooling device 220, the low-temperature gas cooled downstream by the second cooling device 70 is injected into the cooling air cavity between the inner tube 62 and the outer tube 61 through the return line 14. The high-temperature gas in the circulation line 10 flows within the inner tube 62, and the cooling air flow from the return line 14 enters the cooling air cavity between the outer tube 61 and the inner tube 62 through the cooling air inlet 611. It is then injected into the inner tube 62 through the air film holes 621, mixing with the high-temperature air flow in the circuit, thereby achieving the effect of reducing the temperature.

[0065] Compared with the method of using a conventional heat exchanger, this method can not only allow high-temperature gas and low-temperature gas to be directly mixed for cooling, reducing the deposition of dust particles caused by temperature gradients, but also form an air film on the inner wall of the inner tube 62 through the air film holes 621, thereby further reducing the deposition of dust particles on the wall and improving the sampling accuracy.

[0066] More advantageously, if Figure 1As shown, the return line 14 is connected to a booster air pump 120, a buffer tank 130 and a return regulating valve 140. Specifically, the low-temperature gas cooled by the second cooling device 70 downstream is injected into the buffer tank 130 through the return line 14 and the booster air pump 120. The cooling airflow in the buffer tank 130 enters the cooling air cavity between the outer tube 61 and the inner tube 62 through the cooling air inlet 611 of the first cooling device 60 and the third cooling device 220 respectively. In this way, the airflow cooled by the second cooling device 70 can be driven by the booster air pump 120 to flow back to the first cooling device 60 and the third cooling device 220 through the return line 14, ensuring that the pressure on the outside of the inner tube 62 is greater than the pressure on the inside, so that the cooling airflow can enter the inside from the outside of the inner tube 62. The buffer tank 130 can store and buffer the cooling airflow, thereby improving the stability of the airflow. By adjusting the opening of the reflux regulating valve 140, the operating status of the first cooling device 60 and the third cooling device 220 can be adjusted, and the cooling capacity of the first cooling device 60 and the third cooling device 220 can be adjusted, thereby adjusting the temperature of the air flow discharged from the first cooling device 60 and the third cooling device 220, so as to ensure that the connection between the second dust detection device 110 and the circulation pipeline 10 and the connection between the second dust detection device 110 and the vacuum pipeline 13 are within the operating temperature range.

[0067] Further, if Figure 1 As shown, the experimental apparatus 1 for studying particle deposition and resuspension in a pebble bed structure further includes a heat recovery device 150, which includes a first heat exchange channel 151 and a second heat exchange channel 152 adapted for exchanging heat with each other. The first heat exchange channel 151 is connected to the circulation pipeline 10 and is located between the circulation fan 40 and the air inlet 511 of the pebble bed simulator 50. The second heat exchange channel 152 is connected to the circulation pipeline 10 at both ends, and the connection is located between the first cooling device 60 and the second cooling device 70. In this way, the airflow, which still has a certain amount of heat after preliminary cooling by the first cooling device 60, can pass through the second heat exchange channel 152, while the airflow, which has been thoroughly cooled after passing through the first cooling device 60, the second cooling device 70, and the circulation fan 40, can pass through the first heat exchange channel 151. The two heat exchange processes occur within the heat recovery device 150, causing the airflow in the first heat exchange channel 151 to heat up while the airflow in the second heat exchange channel 152 to cool down. In this way, the gas after passing through the circulating fan 40 can first be heated up by the heat recovery device 150 and the first cooling device 60 after preliminary cooling, and then enter the pebble bed simulation device 50. At the same time, the air flow after preliminary cooling by the first cooling device 60 is further cooled down to realize heat energy recovery, improve the utilization rate of heat energy, and reduce energy consumption.

[0068] Specifically, the two ends of the second heat exchange channel 152 are connected to the circulation pipeline 10 through the first heat regeneration section 16 and the second heat regeneration section 17, respectively. The connection points between the first heat regeneration section 16 and the second heat regeneration section 17 and the circulation pipeline 10 are both located between the first cooling device 60 and the second cooling device 70. A heat recovery on-off valve 175 is connected to the first heat regeneration section 16, and a heat recovery regulating valve 176 is connected to the circulation pipeline 10. The heat recovery regulating valve 176 is located between the first heat regeneration section 16 and the second heat regeneration section 17. In this way, the operating state of the heat recovery device 150 can be controlled by opening or closing the heat recovery on-off valve 175, and the heat recovery efficiency of the heat recovery device 150 can be adjusted by adjusting the heat recovery regulating valve 176, thereby adjusting the airflow temperature within the circulation pipeline 10.

[0069] Figure 1 The following is an experimental device 1 for studying the sedimentation and resuspension of particles in a pebble bed structure according to some examples of the present invention. Figure 1 As shown, the experimental apparatus 1 for studying particle deposition and resuspension within a pebble bed structure also includes a dust removal device 160, which is connected to the circulation pipeline 10 and includes an aerosol charger 161 and an electrostatic precipitator 162. The aerosol charger 161 is located between the second cooling device 70 and the circulation fan 40 and is suitable for charging dust particles within the circulation pipeline 10. The electrostatic precipitator 162 is located between the aerosol charger 161 and the circulation fan 40 and is suitable for collecting the charged dust particles. Due to the limited head of the circulation fan 40, the aerosol charger 161 is used to charge the dust particles within the circulation pipeline 10, and then the electrostatic precipitator 162 is used to collect the dust particles and remove them from the airflow. This can efficiently remove dust particles before entering the circulation fan 40 with low pressure loss, preventing dust particles from affecting the operation of the circulation fan 40.

[0070] Specifically, if Figure 1 As shown, the atmospheric discharge port 11 is connected to an exhaust on-off valve 171, the gas source pipeline 12 is connected to an exhaust on-off valve 172, the circulation pipeline 10 is connected to a circulation on-off valve 173, and the circulation on-off valve 173 is located between the atmospheric discharge port 11 and the gas source pipeline 12. The vacuum on-off valve 174 is connected to the vacuum pipeline 13, and the vacuum on-off valve 174 is located between the vacuum tank 90 and the circulation pipeline 10. In this way, the exhaust on-off valve 171 can be used to control the opening and closing of the atmospheric discharge port 11, the gas source on-off valve 172 can be used to control the on-off of the gas source pipeline 12, the circulation on-off valve 173 can be used to control the on-off of the circulation pipeline 10, and the vacuum on-off valve 174 can be used to control the on-off of the vacuum pipeline 13, thereby facilitating the switching of functions such as gas supply, atmospheric discharge, pipeline circulation, and vacuuming, and facilitating the control of the experimental device 1 for studying particle deposition and resuspension in a pebble bed structure.

[0071] Advantageously, as Figure 1As shown, the experimental device 1 for studying particle deposition and resuspension in a pebble bed structure further includes a first temperature sensor 181, a second temperature sensor 182, a third temperature sensor 183, and a fourth temperature sensor 184. The first temperature sensor 181 is located at the air outlet 512 of the pebble bed simulation device 50. The second temperature sensor 182 is connected to the circulation pipeline 10 and is located between the first cooling device 60 and the second cooling device 70. The third temperature sensor 183 is connected to the circulation pipeline 10 and is located between the second cooling device 70 and the circulation fan 40. The fourth temperature sensor 184 is connected to the vacuum pipeline 13 and is located between the third cooling device 220 and the vacuum tank 90. ​​Specifically, the second temperature sensor 182 is connected to the circulation pipeline 10 and is located between the first cooling device 60 and the second dust detection device 110. The fourth temperature sensor 184 is connected to the vacuum pipeline 13 and is located between the third cooling device 220 and the probe of the second dust detection device 110. This makes it easy to detect the air flow temperature at the air outlet 512, the air flow temperature between the first cooling device 60 and the second cooling device 70, and the air flow temperature between the second cooling device 70 and the circulating fan 40, so as to ensure that the pebble bed simulation device 50 reaches the required experimental temperature and avoid overheating of the second dust detection device 110 and the circulating fan 40.

[0072] Specifically, if Figure 1 As shown, the gas source 20 includes a nitrogen storage tank 21 and a helium storage tank 22. In this way, different gas sources can be selected to be introduced into the circulation pipeline 10 according to experimental needs, thereby improving the flexibility and applicability of the experiment.

[0073] Specifically, the circulation pipeline 10 is connected to a bypass pipeline 15, which is connected in parallel with the circulation fan 40. A first fan on-off valve 177 is connected to the bypass pipeline 15. A second fan on-off valve 178 and a third fan on-off valve 179 are also connected to the circulation pipeline 10. The second fan on-off valve 178 is located between the outlet of the circulation fan 40 and the bypass pipeline 15, and the third fan on-off valve 179 is located between the inlet of the circulation fan 40 and the bypass pipeline 15. In this way, by controlling the first fan on-off valve 177, the second fan on-off valve 178, and the third fan on-off valve 179, the airflow is switched between the bypass pipeline 15 and the circulation fan 40, thereby controlling whether the airflow in the circulation pipeline 10 passes through the circulation fan 40, and preventing the fan blades from reversing during commissioning and discharge during a breach accident.

[0074] The circulation line 10 is also connected to a first flowmeter 191, a second flowmeter 192, and a pressure gauge 200. The pressure gauge 200 is located between the pebble bed simulator 50 and the heat recovery device 150. The first flowmeter 191 is located between the atmospheric exhaust port 11 and the circulation fan 40, and the second flowmeter 192 is located between the electrostatic precipitator 162 and the return line 14. This allows the first and second flowmeters 191, 192 to detect the airflow rate within the circulation line 10, while the pressure gauge 200 to detect the gas pressure within the circulation line 10. This facilitates confirmation that the predetermined flow rate and pressure within the circulation line 10 have been reached, ensuring the accuracy of the experimental conditions. A third flowmeter 193 is also connected to the end of the vacuum line 13 away from the circulation line 10 to monitor the airflow rate during a simulated breach event.

[0075] A filter 210 is provided between the compressor 30 and the circulation pipeline 10. The filter 210 can be used to filter out impurities that may be present in the gas source 20 and the compressor 30, making the gas purer when it enters the circulation pipeline 10, thereby preventing impurities from affecting the experimental results and improving the accuracy of the experimental results.

[0076] Reference below Figures 1-4 The working process of the experimental device 1 for studying the deposition and resuspension of particles in a pebble bed structure according to a specific embodiment of the present invention is described.

[0077] First, the gas in the circulation pipeline 10 needs to be replaced with the gas required for the experiment: open the gas source on-off valve 172, the heat recovery on-off valve 175, the heat recovery regulating valve 176, the first fan on-off valve 177, the reflux regulating valve 140, and the vacuum on-off valve 174, close the circulation on-off valve 173, the discharge on-off valve 171, the second fan on-off valve 178, and the third fan on-off valve 179, and start the vacuum pump 80 to extract the air in the circulation pipeline 10 to prevent the air from affecting subsequent experiments. Subsequently, according to the gas environment required for the experiment, open the nitrogen storage tank 21 or the helium storage tank 22, start the compressor 30, and then the air flow at the gas source 20 passes through the filter 210 for filtration, enters the circulation pipeline 10 through the gas source on-off valve 172, and after a predetermined time, close the vacuum pump 80 and the vacuum on-off valve 174. After passing through the entire circulation pipeline 10, the air flow is discharged to the atmosphere through the discharge on-off valve 171.

[0078] After that, the circulation pipeline 10 needs to be pressurized: close the discharge on-off valve 171, open the circulation on-off valve 173, and use the compressor 30 to continuously fill the gas at the gas source 20 into the circulation pipeline 10 through the filter 210. After monitoring the pressure change of the circulation pipeline 10 to the predetermined pressure through the pressure gauge 200, close the gas source on-off valve 172.

[0079] Then, the gas in the circulation pipeline 10 needs to be circulated and heated so that the gas in the circulation pipeline 10 reaches a predetermined flow rate and a predetermined experimental temperature:

[0080] Open the second fan on-off valve 17, the third fan on-off valve 179 and the circulation fan 40, close the first fan on-off valve 177, let the air flow in the circulation pipeline 10 flow driven by the circulation fan 40, and observe whether the first flow meter 191 reaches the predetermined flow.

[0081] Reduce the opening of heat recovery control valve 176, open heat recovery on-off valve 175 and reflux control valve 140. Turn on second cooling device 70, turn on heater 54 in pebble bed simulator 50, adjust heater 54 power, and observe whether first temperature sensor 181 reaches the specified temperature. Observe whether third temperature sensor 183 is within the operating temperature range of circulation fan 40. If it is outside the temperature range, increase the power of second cooling device 70. Observe whether second temperature sensor 182 is within the operating temperature range of second dust detection device 110. If it is outside the temperature range, increase the opening of reflux control valve 140.

[0082] The closed loop within the current circulating fan 40 requires cooling the airflow heated by the heater 54 within the pebble bed simulator 50 to prevent overheating and damage to downstream components due to heat accumulation. The airflow heated by the heater 54 first passes through the first cooling device 60 to reduce the temperature and prevent overheating of the second dust detection device 110. It then passes through the heat recovery device 150 and the second cooling device 70 to reduce the temperature and prevent overheating of the circulating fan 40. After passing through the circulating fan 40, it is heated by the heat recovery device 150 and then returns to the pebble bed simulator 50 to complete the cycle.

[0083] Since the head of the circulating fan 40 is limited, in order to remove the dust particles before entering the flow channel of the circulating fan 40 efficiently and with low pressure loss, an aerosol charger 161 is used to charge the dust particles in the circulating fan 40, and then an electrostatic precipitator 162 is used to collect the charged dust particles, so that the dust particles are removed from the circulating airflow, thereby preventing the dust particles from affecting the operation of the circulating fan 40.

[0084] After that, you can formally conduct the experiment:

[0085] It is necessary to generate dust particles first: drive the rotating shaft 521 in the ball bed simulation device 50 to rotate, and the three rotating graphite balls 522 rotate under the drive of the rotating shaft 521. Open the graphite ball delivery port 55, and put the sample graphite ball 56 into the ball bed simulation device 50. The rotating graphite ball 522 and the sample graphite ball 56 are constantly rubbed to generate dust particles. The airflow in the circulation pipeline 10 enters the ball bed simulation device 50 through the air inlet 511, carrying dust particles, and the first dust detection device 100 is used to measure the number and particle size of dust particles generated by wear. Subsequently, the dust particles generated by friction under the action of airflow and gravity enter the simulated ball bed 53. The ball bed height of the simulated ball bed 53 can be adjusted according to actual needs after the bottom cover 515 is removed, and then the influence of the ball bed stacking height on deposition is studied. After passing through the simulated ball bed 53, the airflow returns to the circulation pipeline 10 through the air outlet 512.

[0086] If a deposition experiment is required: the airflow carrying dust particles coming out of the pebble bed simulation device 50 is cooled by the first cooling device 60, and then passes through the second dust detection device 110 to measure the concentration and particle size of the dust particles in the circulation pipeline 10. By comparing with the detection values ​​of the first dust detection device 100, the deposition proportion of the dust particles after passing through the pebble beds with different stacking heights and the deposition characteristics of dust particles with different particle sizes are obtained.

[0087] If a resuspension experiment is required, the vacuum pump 80 is turned on to achieve a negative pressure environment within the vacuum tank 90. ​​Subsequently, while maintaining the high-pressure airflow in the circulation pipeline 10, the vacuum on-off valve 174 is opened. Due to the high pressure within the circulation pipeline 10 and the negative pressure in the vacuum tank 90, the airflow discharge effect during a rupture event is simulated. The high-temperature gas from the outlet 512 of the pebble bed simulation device 50 is cooled by the third cooling device 220. The gas is then connected to the vacuum pipeline 13 through the second dust detection device 110. The changes in dust particle size in the two circuits are observed, thereby calculating the number of particles resuspended within the pebble bed structure during a rupture event.

[0088] That is to say, the experimental device 1 for studying the deposition and resuspension of particles in a pebble bed structure according to an embodiment of the present invention can simulate the generation, deposition and resuspension process of dust particles in a high-temperature and high-pressure environment, can control the influence of variables such as pressure, atmosphere, and temperature, and provide operating conditions that are closer to reactor rupture accidents. Compared with existing experimental devices, it has the advantages of true and accurate experimental results and strong reliability.

[0089] Other structures and operations of the experimental device 1 for studying the deposition and resuspension of particles in a pebble bed structure according to an embodiment of the present invention are well known to those skilled in the art and will not be described in detail here.

[0090] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0091] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. An experimental device for studying particle deposition and resuspension in a pebble bed structure, characterized in that: include: A circulation pipeline, wherein the circulation pipeline is provided with an atmospheric discharge port; an air source, the air source being connected to the circulation pipeline via an air source pipeline; a compressor connected to the gas source pipeline; a circulation fan connected to the circulation pipeline; A ball bed simulation device, comprising a housing, a graphite ball friction mechanism, a simulated ball bed, and a heating element. The housing has a heating chamber therein and is provided with an air inlet and an air outlet. The housing is connected to the circulation pipeline via the air inlet and the air outlet. The graphite ball friction mechanism is disposed within the heating chamber and is adapted to cause graphite balls to rub against each other to generate dust particles. The simulated ball bed is disposed at the bottom of the housing. The heating element is disposed on the housing and is adapted to heat the heating chamber. a first cooling device connected to the circulation pipeline and located between the air outlet of the pebble bed simulation device and the circulation fan; a second cooling device connected to the circulation pipeline and located between the first cooling device and the circulation fan; a vacuum pump, the vacuum pump being in communication with the circulation pipeline via a vacuum pipeline, wherein a connection between the vacuum pipeline and the circulation pipeline is located between the first cooling device and an air outlet of the pebble bed simulation device; a vacuum tank connected to the vacuum pipeline; a third cooling device connected to the vacuum pipeline and located between the circulation pipeline and the vacuum tank; a first dust detection device, the first dust detection device being provided on the pebble bed simulation device and being adapted to detect the concentration and particle size of dust particles in the heating chamber; A second dust detection device, the second dust detection device is respectively connected to the circulation pipeline and the vacuum pipeline and is suitable for detecting the concentration and particle size of dust particles in the circulation pipeline and the vacuum pipeline, the connection between the second dust detection device and the circulation pipeline is located between the first cooling device and the second cooling device, and the connection between the second dust detection device and the vacuum pipeline is located between the third cooling device and the vacuum tank.

2. The experimental device for studying particle deposition and resuspension in a pebble bed structure according to claim 1, characterized in that: The graphite ball friction mechanism comprises: a rotating shaft rotatably disposed on the housing and oriented in an up-down direction; Multiple rotating graphite balls are connected to the rotating shaft and are arranged at intervals along the circumference of the rotating shaft. The multiple rotating graphite balls rotate together with the rotating shaft. An openable and closable graphite ball delivery port is provided on the top wall of the shell. The graphite ball delivery port is suitable for delivering sample graphite balls. The multiple rotating graphite balls are constructed to be suitable for keeping the sample graphite balls entering the heating chamber through the graphite ball delivery port above the multiple rotating graphite balls and for causing the sample graphite balls to rub against the rotating graphite balls.

3. The experimental device for studying particle deposition and resuspension in a pebble bed structure according to claim 1, characterized in that: The first cooling device and the third cooling device both include: An outer tube, wherein the outer circumferential surface of the outer tube is provided with a cooling air inlet, the cooling air inlet is connected to the circulation pipeline through a return pipeline, and the connection between the return pipeline and the circulation pipeline is located between the second cooling device and the circulation fan; An inner tube is connected to the circulation pipeline, the inner tube is arranged on the radial inner side of the outer tube and a cooling air cavity is formed between the inner tube and the outer tube, and a plurality of air film holes are provided on the peripheral wall of the inner tube to connect the cooling air cavity and the inner side of the inner tube.

4. The experimental device for studying particle deposition and resuspension in a pebble bed structure according to claim 3, characterized in that: The reflux pipeline is connected with a booster air pump, a buffer tank and a reflux regulating valve.

5. The experimental device for studying particle deposition and resuspension in a pebble bed structure according to claim 1, characterized in that: It also includes a heat recovery device, which includes a first heat exchange channel and a second heat exchange channel suitable for exchanging heat with each other. The first heat exchange channel is connected to the circulation pipeline and is located between the circulation fan and the air inlet of the ball bed simulation device. The two ends of the second heat exchange channel are respectively connected to the circulation pipeline and the connection is located between the first cooling device and the second cooling device.

6. The experimental device for studying particle deposition and resuspension in a pebble bed structure according to claim 1, characterized in that: It also includes a dust removal device, which is connected to the circulation pipeline and includes: an aerosol charger, located between the second cooling device and the circulating fan and adapted to charge dust particles in the circulating pipeline; An electrostatic precipitator is located between the aerosol charger and the circulating fan and is suitable for collecting charged dust particles.

7. The experimental device for studying particle deposition and resuspension in a pebble bed structure according to claim 1, characterized in that: The atmospheric exhaust port is connected to an exhaust on-off valve, the gas source pipeline is connected to an gas source on-off valve, the circulation pipeline is connected to a circulation on-off valve, and the circulation on-off valve is located between the atmospheric exhaust port and the gas source pipeline. The vacuum pipeline is connected to a vacuum on-off valve, and the vacuum on-off valve is located between the vacuum tank and the circulation pipeline.

8. The experimental device for studying particle deposition and resuspension in a pebble bed structure according to claim 1, characterized in that: Also includes: a first temperature sensor, the first temperature sensor being disposed at the air outlet of the pebble bed simulation device; a second temperature sensor connected to the circulation pipeline and located between the first cooling device and the second cooling device; a third temperature sensor connected to the circulation pipeline and located between the second cooling device and the circulation fan; A fourth temperature sensor is connected to the vacuum pipeline and is located between the third cooling device and the vacuum pump.

9. The experimental device for studying particle deposition and resuspension in a pebble bed structure according to claim 1, characterized in that: The shell of the ball bed simulation device includes a main body and a bottom cover, and the bottom cover is detachably mounted on the main body.

10. The experimental device for studying particle deposition and resuspension in a pebble bed structure according to claim 1, characterized in that: The gas source includes a nitrogen storage tank and a helium storage tank.

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