Radiation online purging device, control system and control method

Abstract

The present application belongs to the technical field of radiation purging, and discloses a radiation online purging device, a control system and a control method. In combination with the modification requirements of a radiation online measuring device, the influence of the flow guide area parameters and the flow area structure on the purging system performance is analyzed by using the knowledge of computational fluid dynamics and the numerical simulation method. The input parameters of the flow guide area include the purging gas velocity, and the structural parameters include the gas rotating pipe diameter, the gas rotating pipe length, the vertical rectifier area height and the horizontal rectifier area width. The influencing factors of the flow area structure include the sealing plate diameter, the sealing plate interlayer thickness, the relative position of the overflow pipe and the gas outlet pipe, and the distance between the overflow pipe and the sealing plate. By optimizing the input parameters and the structural parameters of the purging system, the present application ensures that the aerosol concentration in the cross section along the flow cell axis direction within the range of 80mm below the sealing plate detection area is less than 10ppm. The aerosol concentration distribution below the sealing plate detection area is greatly improved, and the reliability of the radiation online measuring device is significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of radiation purging technology, and particularly relates to an online radiation purging device, control system and control method. Background Technology

[0002] Currently, the principle of gas shielding technology is to form a protective gas layer around the protected object, thereby isolating it from external substances. Different gas media can be used depending on the physicochemical properties of the protected object. Commonly used protective gas media include reducing gases (such as hydrogen and nitrogen), inert gases (such as helium and argon), and oxidizing gases (such as carbon dioxide). At present, thanks to extensive experimental research by numerous scholars both domestically and internationally, gas shielding technology can be used in various environmental conditions, and its isolation effect can well meet the requirements. It is mainly applied in welding, smelting and casting, food industry, and dust-generating industries.

[0003] In welding, gas shielding technology is used to isolate the molten pool from the external environment to prevent cavitation and compounds from forming due to reactions between molten metal and air components. Studies by Mohanavel et al. have shown that a reasonable shielding gas flow rate can improve the impact strength of welded joints. In smelting and casting, the protected material is usually large and generally operates under high temperature and pressure, making the use of gas as a shielding medium highly advantageous. You et al. invented an online gas shielding device for magnesium alloy molten pools. This device uses a mixture of SO2, CO2, and N2 as the shielding gas, effectively isolating the magnesium molten pool from oxygen during actual operation, offering advantages such as good protection, low pollution, and low loss. In the food industry, gas shielding technology is used to isolate food from the external environment, slowing down enzymatic browning and oxidation reactions, and extending shelf life. Ding Juan et al. studied the changes in easily oxidized components in lychee wine using nitrogen as the shielding gas, finding that the decrease rates of organic acids and SO2 content were lower than under conditions without gas shielding. In the dust industry, dust particles, due to their small size, fine particle size, and susceptibility to oxidation, are prone to spontaneous combustion or even explosion during generation, storage, and transportation. Gas protection technology is used to isolate dust from the external oxidizing environment to suppress spontaneous combustion or explosion. Zhang et al. studied the inhibitory effect of inert gas on aluminum dust explosions and found that as the volume fraction of inert gas increases, the oxidation reaction intermediates are consumed more quickly, thus inhibiting the process and suppressing aluminum dust explosions.

[0004] To ensure the measurement accuracy of the online radiation measurement device, the purge gas curtain should be uniformly distributed along the cross-section of the flow cell and possess a certain rigidity and thickness. The flow of the aerosol and the parameters of the purge system both affect the effectiveness of the gas curtain. Furthermore, the device has many components and is difficult to disassemble. Experimentally modifying the device structure to optimize the gas curtain effect would be costly and time-consuming. Therefore, using numerical simulation to study the flow characteristics of the purge gas within the system is of great significance.

[0005] Currently, numerous domestic and international scholars employ numerical simulation to study the flow characteristics of shielding gases. In the welding field, Fan Ding et al. used the commercial software Phoenics to study the influence of welding torch structural parameters on welding protection. Their results showed that when the shielding gas flow rate remains constant, as the welding torch diameter increases, the laminar flow of the gas gradually improves, and the protection range gradually increases, but the flow velocity gradually decreases, and the stiffness gradually decreases, leading to a deterioration in the protection effect. The optimal diameter range for the sleeve is 8–12 mm, which is consistent with the results calculated using empirical formulas. Wang et al. used Fluent to analyze the influence of shielding gas on the welding effect during laser deep melting of titanium alloys, finding that as the nozzle tilt angle decreases and the shielding gas flow rate increases, the effective protection area gradually increases. Dmitry et al. used numerical simulation to analyze the influence of wind speed on the movement of shielding gas using CO2 as the medium, finding that compared to the traditional single-nozzle gas protection method, welding with a dual-nozzle gas protection method results in increased shielding gas stiffness, reduced wind speed influence, and improved protection effect.

[0006] In the fields of smelting and casting, Ying Fuqiang et al. used the computational fluid dynamics software Fluent to study the flow of protective gas SF6 in a magnesium furnace. Their results showed that as the gas flow velocity increased, the distribution of SF6 on the surface of the molten magnesium gradually became uneven, and the protective effect on the surface of the molten magnesium gradually deteriorated. As the concentration of SF6 at the inlet increased, the concentration of SF6 on the surface of the molten magnesium gradually increased, but the distribution law of the density difference did not change significantly. Zhang Xihe et al. used computational fluid dynamics principles and dynamic mesh technology to study the flow field characteristics of protective gas using hydrogen as the medium in a bell-type furnace. Their research found that the flow rate of the protective gas was linearly related to the rotational speed of the circulating fan; as the height of the protective gas rising along the inner wall of the bell-type furnace increased, the flow velocity of the protective gas gradually decreased. Li Weiyi et al. analyzed the velocity field distribution law of the protective gas in a glass tin bath and found that as the amount of protective gas in the tin bath increased, only the front end of the tin bath showed annular flow.

[0007] The above brief introduction to the current research status of gas protection technology shows that by using reasonable structural and input parameters, protective gas can effectively isolate the protected object from the external environment, and numerical simulation can accurately predict the flow characteristics of the protective gas.

[0008] Based on the above analysis, the problems and defects of the existing technology are as follows: the flow and purging system parameters of the existing aerosols will affect the effect of the air curtain, and the device has many parts, unreasonable structure, and inconvenient disassembly; if the structure of the device is modified experimentally to optimize the effect of the air curtain, the cost will be high and the cycle will be long. Summary of the Invention

[0009] To address the problems existing in the prior art, the present invention provides an online radiation purging device, a control system, and a control method.

[0010] This invention is implemented as follows: a control method for an online radiation purging device, the control method comprising:

[0011] Based on the requirements for the modification of the radiation online measurement device, and using relevant knowledge of computational fluid dynamics, numerical simulation methods were employed to analyze the impact of the parameters of the guide zone and the structure of the flow zone on the performance of the purging system.

[0012] Furthermore, the input parameters for the flow guiding zone are the purge gas velocity and the structural parameters include the diameter of the gas rotating pipe, the length of the gas rotating pipe, the height of the vertical rectification zone, and the width of the horizontal rectification zone. The influencing factors of the flow zone structure include the diameter of the sealing plate, the thickness of the sealing plate interlayer, the relative position of the overflow pipe and the gas outlet pipe, and the distance between the overflow pipe and the sealing plate.

[0013] Furthermore, the control method for the online radiation purging device includes the following steps:

[0014] Step 1: Using computer numerical simulation, the effects of purge gas velocity, rotating pipe diameter, rotating pipe length, vertical rectification zone height, and horizontal rectification zone width on the purge system are analyzed by examining the internal flow field and aerosol concentration distribution in the longitudinal section of the flow cell.

[0015] Step two involves using computer numerical simulation, combined with the requirements for modifying the online radiation measurement device, to analyze the internal flow field of the purging system and the aerosol concentration distribution in the longitudinal section of the flow pool. The effects of the sealing plate diameter, sealing plate interlayer thickness, relative position of the overflow pipe and the gas outlet pipe, and distance between the overflow pipe and the sealing plate on the performance of the purging system are analyzed, ultimately resulting in a purging system that meets the requirements.

[0016] Furthermore, the analysis of the effects of the purge gas velocity, rotating pipe diameter, rotating pipe length, vertical rectification zone height, and horizontal rectification zone width on the purge system in step one includes:

[0017] (1) Analyze the influence of the purge gas velocity and determine that the purge gas velocity of 2m / s is the optimal working condition;

[0018] (2) Analyze the influence of the gas rotating pipe diameter and determine that a gas rotating pipe diameter of 9mm is the optimal working condition;

[0019] (3) Analyze the influence of the length of the gas rotating pipe and determine that the optimal working condition is a gas rotating pipe length of 410 mm.

[0020] (4) Analyze the influence of the height of the vertical rectification zone of the gas and determine that the optimal working condition is a height of 7mm in the vertical rectification zone of the gas.

[0021] (5) Analyze the influence of the width of the horizontal rectification zone of the gas and determine that the width of the horizontal rectification zone is 80mm as the optimal working condition.

[0022] Furthermore, the analysis in step two regarding the effects of the sealing plate diameter, sealing plate interlayer thickness, relative position of the overflow pipe and gas outlet pipe, and distance between the overflow pipe and the sealing plate on the purging system performance includes:

[0023] (1) Analyze the influence of the sealing plate diameter and determine that the sealing plate diameter is 70mm as the original working condition of the modification plan;

[0024] (2) Analyze the influence of the thickness of the sealing plate interlayer and determine that the thickness of the sealing plate interlayer is 1.5mm as the optimal working condition.

[0025] Another object of the present invention is to provide a control system for an online radiation purging device that implements the control method of the aforementioned online radiation purging device, the control system of the online radiation purging device comprising:

[0026] The flow guide zone parameter influence analysis module is used to analyze the influence of purge gas velocity, rotation zone height, rotation zone radius, vertical rectification zone height, and airflow width on the purge system by analyzing the internal flow field and aerosol concentration distribution law of the flow pool longitudinal section through computer numerical simulation.

[0027] The circulation zone structure impact analysis module is used to analyze the impact of the internal flow field and aerosol concentration distribution of the circulation pool section on the purging system by using computer numerical simulation methods and combining the requirements of the online radiation measurement device modification. It analyzes the impact of the sealing plate diameter, sealing plate interlayer thickness, relative position of the overflow pipe and gas outlet pipe, and distance between the overflow pipe and the sealing plate on the performance of the purging system, and finally obtains a purging system that meets the requirements.

[0028] Another object of the present invention is to provide a radiation online purging device for implementing the control method of the aforementioned radiation online purging device, the radiation online purging device comprising a guide zone and a flow zone.

[0029] The flow guiding zone includes a gas inlet pipe, a gas rotating pipe, a vertical rectification zone, a horizontal rectification zone, and a flow limiting zone; wherein, the length of the gas rotating pipe along the axial and radial directions of the gas inlet pipe is distributed in a 1:2 ratio, and the diameter remains consistent; the widths of the vertical rectification zone, the horizontal rectification zone, and the flow limiting zone are consistent.

[0030] The circulation zone includes a gas outlet pipe, an overflow pipe, a sealing plate, and a circulation pool; the sealing plate consists of a sealing plate detection area on the top wall of the circulation pool and a sealing plate interlayer, and the upper wall of the sealing plate interlayer and the sealing plate detection area are on the same plane; a radiation detector is placed above the sealing plate detection area, and the mixture of aerosol and purge gas is below it; the diameter of the sealing plate refers to the outer diameter of the arc-shaped area of ​​the sealing plate interlayer; the gas outlet pipe is arranged in a horizontal direction, and the overflow pipe has an angle of 45° with the horizontal plane.

[0031] Another object of the present invention is to provide a computer device including a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the control method steps of the radiation online purging device.

[0032] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the control method for the radiation online purging device.

[0033] Another object of the present invention is to provide an information data processing terminal for implementing the aforementioned online radiation purging device.

[0034] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0035] This invention employs computer numerical simulation to analyze the internal flow field and aerosol concentration distribution in the longitudinal section of the flow cell within the purging system. It further analyzes the influence of purging gas velocity, rotation zone height, rotation zone radius, vertical rectifying zone height, and airflow width on the purging system, drawing the following conclusions:

[0036] (1) As the purge gas velocity increases, the downward stroke of the gas along the wall of the flow cell increases, the pressure difference between the gas outlet side and the overflow pipe side increases, and the swirling effect inside the flow cell intensifies, thus increasing the amount of aerosol flowing into the sealing plate detection area. After comprehensive consideration, a purge gas velocity of 2 m / s is selected as the optimal operating condition.

[0037] (2) As the diameter of the gas rotating pipe increases, the velocity of the airflow entering the vertical rectification zone decreases, the vortex weakens, and the collision between the airflow and the wall weakens. The energy consumed by the purging gas decreases, the velocity of the gas ejected horizontally from the sealing plate interlayer increases, the difference in pressure on the aerosol on the gas outlet pipe side and the overflow pipe side increases, and the aerosol concentration distribution deteriorates. After comprehensive consideration, a gas rotating pipe diameter of 9 mm was selected as the original operating condition for the next step of analysis.

[0038] (3) As the length of the gas rotating pipe increases, the downward stroke of the gas along the wall of the flow pool increases, the difference in pressure on the aerosol on the gas outlet side and the overflow pipe side increases, and the aerosol concentration increases. After comprehensive consideration, a gas rotating pipe length of 410 mm is selected as the optimal operating condition.

[0039] (4) When the height of the vertical rectification zone increases from 0 mm to 7 mm, the velocity distribution of the purge gas in the horizontal rectification zone becomes more uniform, the uniformity of the air curtain increases, and the aerosol concentration decreases. As the height continues to increase, although the uniformity of the air curtain increases, the velocity of the purge gas ejected horizontally forward from the sealing plate interlayer decreases, the rigidity of the air curtain decreases, and therefore the aerosol concentration increases. Considering all factors, a vertical rectification zone height of 7 mm is selected as the optimal operating condition.

[0040] (5) When the width of the horizontal rectifying zone increases from 50mm to 80mm, the coverage area of ​​the air curtain increases, and the velocity direction of the aerosol flowing towards the detection area of ​​the sealing plate tends to be horizontal, resulting in a better aerosol concentration distribution. When the width continues to increase, the velocity of the purge gas ejected horizontally forward from the sealing plate interlayer decreases, the rigidity of the air curtain decreases, and at the same time, the local high-speed zone below the sealing plate increases, the uniformity of the air curtain deteriorates, and therefore the aerosol concentration distribution worsens. After comprehensive consideration, an airflow width of 80mm is selected as the optimal operating condition.

[0041] (6) By comparing the effects of the flow guide parameters on aerosol distribution, it was found that the width of the horizontal flow restriction zone had the most significant impact, followed by the purge gas velocity. By optimizing the flow guide parameters, the aerosol concentration distribution was greatly improved. At this point, the aerosol concentration in the flow cell section within 80 mm below the sealing plate detection area ranged from a minimum of 17 ppm to a maximum of 362 ppm.

[0042] This invention employs computer numerical simulation, combined with the requirements for modifying an online radiation measurement device. By analyzing the internal flow field of the purging system and the aerosol concentration distribution across the longitudinal section of the flow cell, it delves into the effects of the sealing plate diameter, sealing plate interlayer thickness, the relative positions of the overflow pipe and gas outlet pipe, and the distance between the overflow pipe and the sealing plate on the purging system performance, ultimately obtaining a purging system that meets the requirements. The conclusions of this invention are as follows: 1) When the sealing plate diameter increases from 50mm to 55mm, the amount of purging gas flowing from the sealing plate interlayer to the center of the flow cell increases, the air curtain thickness increases but rigidity is insufficient, and the aerosol concentration increases. When the diameter continues to increase, the air curtain coverage area increases and the amount of purging gas flowing to the center of the flow cell further increases, both the air curtain thickness and rigidity increase, and the aerosol concentration decreases. After comprehensive consideration, a sealing plate diameter of 70mm is selected as the optimal operating condition. 2) When the thickness of the sealing plate interlayer increases from 1 mm to 1.5 mm, the velocity at the end of the flow-limiting zone decreases, the pressure difference between the gas outlet side and the overflow pipe side decreases, and the swirling effect inside the flow pool weakens, leading to an increase in the low-concentration aerosol zone. When the thickness further increases, the non-uniformity of the air curtain increases and the coverage area decreases, further reducing the low-concentration aerosol zone. Considering all factors, a sealing plate interlayer thickness of 1.5 mm is selected as the optimal operating condition.

[0043] This invention optimizes the input and structural parameters of the purging system to ensure that the aerosol concentration in the cross-section along the flow cell axis within 80 mm below the sealing plate detection area is less than 10 ppm. Through analysis of the impact of the flow guide parameters on the performance of the purging system, this invention significantly improves the aerosol concentration distribution below the sealing plate detection area, thereby significantly enhancing the reliability of the online radiation measurement device.

[0044] Does the technical solution of this invention solve a long-standing technical problem that people have long desired to solve but have never been able to successfully address? By employing gas purging and a non-direct contact method, the impact of aerosols on the structure below the detection area of ​​the sealing plate is minimized, thus optimizing the structure and protective effect of the air curtain. Automatic cleaning of aerosol contamination is achieved. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a flowchart of the control method for the radiation online purging device provided in an embodiment of the present invention;

[0047] Figure 2The diagram shows the longitudinal cross-sectional flow field vector diagram of the flow tank provided in this embodiment of the invention; Figure (a) is 2 m / s, Figure (b) is 2.5 m / s, Figure (c) is 3 m / s, Figure (d) is 3.5 m / s, and Figure (e) is 4 m / s.

[0048] Figure 3 The following is a cloud map showing the aerosol concentration distribution in the longitudinal section of the flow cell provided in this embodiment of the invention: (a) is 2 m / s, (b) is 2.5 m / s, (c) is 3 m / s, (d) is 3.5 m / s, and (e) is 4 m / s.

[0049] Figure 4 This is a graph showing the change in aerosol concentration along the axis of the flow cell, provided in an embodiment of the present invention.

[0050] Figure 5 These are the horizontal and vertical rectifying zone cross-sectional flow field vector diagrams provided in the embodiments of the present invention; (a) is 9mm, (b) is 10.5mm, (c) is 12mm, (d) is 13.5mm, and (e) is 15mm.

[0051] Figure 6 The following is a cloud map showing the aerosol concentration distribution in the longitudinal section of the flow cell provided in this embodiment of the invention: (a) is 9 mm, (b) is 10.5 mm, (c) is 12 mm, (d) is 13.5 mm, and (e) is 15 mm.

[0052] Figure 7 This is a graph showing the change in aerosol concentration provided in an embodiment of the present invention;

[0053] Figure 8 The vector diagram of the flow field at a cross-section 4mm below the detection area of ​​the sealing plate provided in the embodiment of the present invention is shown in (a) 410mm, (b) 470mm, (c) 530mm, (d) 590mm, and (e) 650mm.

[0054] Figure 9 The cloud map of aerosol concentration distribution in the longitudinal section of the flow cell provided in the embodiment of the present invention is shown; (a) is 410 mm, (b) is 470 mm, (c) is 530 mm, (d) is 590 mm, and (e) is 650 mm.

[0055] Figure 10 This is a graph showing the change in aerosol concentration provided in an embodiment of the present invention;

[0056] Figure 11 These are vector diagrams of the horizontal and vertical rectifying zone cross sections provided in this embodiment of the invention; (a) is 0 mm, (b) is 3.5 mm, (c) is 7 mm, (d) is 10.5 mm, and (e) is 14 mm.

[0057] Figure 12The vector diagram of the horizontal rectification zone provided in this embodiment of the invention is shown below; (a) is 0 mm, (b) is 3.5 mm, (c) is 7 mm, (d) is 10.5 mm, and (e) is 14 mm.

[0058] Figure 13 The following are aerosol concentration distribution cloud maps provided in the embodiments of the present invention: (a) is 0 mm, (b) is 3.5 mm, (c) is 7 mm, (d) is 10.5 mm, and (e) is 14 mm.

[0059] Figure 14 This is a graph showing the change in aerosol concentration provided in an embodiment of the present invention;

[0060] Figure 15 The diagram shows the longitudinal cross-sectional flow field vector diagram of the flow tank provided in this embodiment of the invention; (a) is 50mm, (b) is 60mm, (c) is 80mm, (d) is 100mm, and (e) is 120mm.

[0061] Figure 16 This is a vector diagram of the flow field on the wall of the flow pool below the sealing plate provided in an embodiment of the present invention; (a) is 50mm, (b) is 60mm, (c) is 80mm, (d) is 100mm, and (e) is 120mm.

[0062] Figure 17 The cloud map of aerosol concentration distribution in the longitudinal section of the flow cell provided in the embodiment of the present invention is shown; (a) is 50 mm, (b) is 60 mm, (c) is 80 mm, (d) is 100 mm, and (e) is 120 mm.

[0063] Figure 18 This is a graph showing the change in aerosol concentration provided in an embodiment of the present invention;

[0064] Figure 19 These are velocity cloud diagrams and streamline diagrams of a section 0.5mm below the upper sealing plate provided in the embodiments of the present invention; (a) is 50mm, (b) is 55mm, (c) is 60mm, (d) is 65mm, and (e) is 70mm.

[0065] Figure 20 The cloud map of aerosol concentration distribution in the longitudinal section of the flow cell provided in the embodiment of the present invention is shown; (a) is 50 mm, (b) is 55 mm, (c) is 60 mm, (d) is 65 mm, and (e) is 70 mm.

[0066] Figure 21 This is a graph showing the change in aerosol concentration provided in an embodiment of the present invention;

[0067] Figure 22These are velocity cloud diagrams and streamline diagrams of a section 0.5mm below the upper sealing plate provided in this embodiment of the invention; (a) is 1mm, (b) is 1.5mm, (c) is 2mm, (d) is 2.5mm, and (e) is 3mm.

[0068] Figure 23 The following is a cloud map showing the aerosol concentration distribution in the longitudinal section of the flow cell provided in this embodiment of the invention: (a) is 1 mm, (b) is 1.5 mm, (c) is 2 mm, (d) is 2.5 mm, and (e) is 3 mm.

[0069] Figure 24 This is a graph showing the change in aerosol concentration provided in an embodiment of the present invention;

[0070] Figure 25 This is a schematic diagram of the flow guiding area provided in an embodiment of the present invention;

[0071] Figure 26 This is a schematic diagram of the main dimensions of the current-limiting zone provided in an embodiment of the present invention;

[0072] Figure 27 This is a schematic diagram of the circulation area provided in an embodiment of the present invention. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0074] To address the problems existing in the prior art, the present invention provides an online radiation purging device, a control system, and a control method. The present invention will now be described in detail with reference to the accompanying drawings.

[0075] To enable those skilled in the art to fully understand how the present invention is specifically implemented, this section provides an explanatory description of the embodiments that expand upon the technical solutions of the claims.

[0076] The control method for the radiation online purging device provided in this embodiment of the invention includes:

[0077] Based on the requirements for the modification of the radiation online measurement device, and using relevant knowledge of computational fluid dynamics, numerical simulation methods were employed to analyze the impact of the parameters of the guide zone and the structure of the flow zone on the performance of the purging system.

[0078] The input parameters for the flow guiding zone are the purge gas velocity and the structural parameters include the diameter of the gas rotating pipe, the length of the gas rotating pipe, the height of the vertical rectification zone, and the width of the horizontal rectification zone. The influencing factors of the flow zone structure include the diameter of the sealing plate, the thickness of the sealing plate interlayer, the relative position of the overflow pipe and the gas outlet pipe, and the distance between the overflow pipe and the sealing plate.

[0079] like Figure 1 As shown, the control method of the radiation online purging device provided in this embodiment of the invention includes the following steps:

[0080] S101 uses computer numerical simulation to analyze the internal flow field and aerosol concentration distribution in the longitudinal section of the flow cell of the purging system, and analyzes the effects of purging gas velocity, gas rotating pipe diameter, gas rotating pipe length, vertical rectification zone height and horizontal rectification zone width on the purging system.

[0081] S102, using computer numerical simulation and combined with the requirements for the modification of the radiation online measurement device, analyzes the internal flow field and aerosol concentration distribution law of the flow pool longitudinal section of the purging system, and analyzes the influence of the sealing plate diameter, sealing plate interlayer thickness, relative position of the overflow pipe and gas outlet pipe and distance between the overflow pipe and the sealing plate on the performance of the purging system, and finally obtains a purging system that meets the requirements.

[0082] The analysis of the effects of purge gas velocity, rotation zone height, rotation zone radius, vertical rectification zone height, and airflow width on the purge system in step S101 of the embodiment of the present invention includes:

[0083] (1) Analyze the influence of the purge gas velocity and determine that the purge gas velocity of 2m / s is the optimal working condition;

[0084] (2) Analyze the influence of the gas rotating pipe diameter and determine that a gas rotating pipe diameter of 9mm is the optimal working condition;

[0085] (3) Analyze the influence of the length of the gas rotating pipe and determine that the optimal working condition is a gas rotating pipe length of 410 mm.

[0086] (4) Analyze the influence of the height of the vertical rectification zone of the gas and determine that the optimal working condition is a height of 7mm in the vertical rectification zone of the gas.

[0087] (5) Analyze the influence of the width of the gas horizontal rectification zone and determine that the optimal working condition is 80mm.

[0088] The analysis of the effects of the sealing plate diameter, sealing plate interlayer thickness, relative position of the overflow pipe and gas outlet pipe, and distance between the overflow pipe and the sealing plate on the purging system performance in step S102 of this embodiment of the invention includes:

[0089] (1) Analyze the influence of the sealing plate diameter and determine that the sealing plate diameter is 70mm as the original working condition of the modification plan;

[0090] (2) Analyze the influence of the thickness of the sealing plate interlayer and determine that the thickness of the sealing plate interlayer is 1.5mm as the optimal working condition.

[0091] The control system of the radiation online purging device provided in this embodiment of the invention includes:

[0092] The flow guide zone parameter influence analysis module is used to analyze the influence of the purge gas velocity, gas rotating pipe diameter, gas rotating pipe length, vertical rectification zone height and horizontal rectification zone width on the purge system by analyzing the internal flow field and aerosol concentration distribution law of the flow pool longitudinal section of the purge system using computer numerical simulation.

[0093] The circulation zone structure impact analysis module is used to analyze the impact of the internal flow field and aerosol concentration distribution of the circulation pool section on the purging system by using computer numerical simulation methods and combining the requirements of the online radiation measurement device modification. It analyzes the impact of the sealing plate diameter, sealing plate interlayer thickness, relative position of the overflow pipe and gas outlet pipe, and distance between the overflow pipe and the sealing plate on the performance of the purging system, and finally obtains a purging system that meets the requirements.

[0094] The radiation online purging device provided in this embodiment of the invention includes a flow guiding zone and a flow circulation zone.

[0095] Figure 25 This is a schematic diagram of the flow guiding zone. The main structures of the flow guiding zone include a gas inlet pipe, a gas rotating pipe, a vertical rectification zone, a horizontal rectification zone, and a flow limiting zone. The width of the flow limiting zone is shown below. Figure 26 As shown, the widths of the vertical rectification zone, horizontal rectification zone, and current limiting zone are consistent.

[0096] Figure 27 This is a schematic diagram of the flow zone. The main structures of the flow zone include a gas outlet pipe, an overflow pipe, a sealing plate, and a flow pool. The sealing plate consists of a sealing plate detection area (the top wall of the flow pool) and a sealing plate interlayer, with the upper wall of the interlayer and the detection area on the same plane. A radiation detector is placed above the detection area, and the mixture of aerosol and purge gas is below it. The sealing plate diameter refers to the outer diameter of the arc-shaped area of ​​the interlayer. The gas outlet pipe is arranged horizontally, and the overflow pipe forms a 45° angle with the horizontal plane.

[0097] The embodiments of the present invention have achieved some positive results during the research and development or use process, and have indeed great advantages compared with the prior art. The following content describes them in conjunction with the data, charts and other information of the experimental process.

[0098] 1. The impact of guide zone parameters on the performance of the purging system

[0099] The guide zone is mainly used to optimize the flow state of the purge gas and has a significant impact on the formation of the air curtain. This embodiment of the invention, combined with the modification requirements of the online radiation measurement device, utilizes computational fluid dynamics and numerical simulation methods to analyze the influence of guide zone parameters on the performance of the purge system. The input parameters for the guide zone analyzed in this embodiment are the purge gas velocity, and the structural parameters include the diameter of the gas-gas rotating pipe, the length of the gas-gas rotating pipe, the height of the vertical rectifying zone, and the width of the horizontal rectifying zone.

[0100] 1.1 Effect of purge gas velocity

[0101] The purging system suppresses rising aerosols by introducing inert gas through the gas inlet to form an air curtain in the flow cell. If the purging gas velocity is too low, the system lacks rigidity, allowing aerosols to penetrate the air curtain and contaminate the flow cell sealing plate. Conversely, if the gas velocity is too high, the impact is too strong, and the aerosols are subjected to excessive suppression, potentially causing the area below the sealing plate to become filled with aerosols. Therefore, this invention will analyze in detail the impact of purging gas velocity on the purging system. The purging gas velocity in the original operating condition is 3 m / s, and the velocities for the four modified operating conditions are 2 m / s, 2.5 m / s, 3.5 m / s, and 4 m / s, respectively, while other parameters remain consistent with the original operating condition.

[0102] Figure 2 The vector diagram shows the flow field in the longitudinal section of the flow cell. It can be seen that the flow fields under the five operating conditions exhibit similar distribution patterns. After the purge gas is ejected horizontally forward from the sealing plate interlayer, it flows downward along the wall due to the obstruction of the flow cell wall. Approximately 110 mm below the sealing plate detection area, it flows towards the overflow pipe. Upon reaching the overflow pipe, a portion of the mixture of purge gas and aerosol flows towards the sealing plate. As the purge gas velocity increases, the downward stroke along the flow cell wall increases, and the gas lags behind at the turning point below the gas outlet pipe, enhancing the local interaction with the aerosol. This leads to an increase in the amount of aerosol flowing towards the overflow pipe. Furthermore, the mixture of purge gas and aerosol forms three vortices in the flow cell. The first vortex is located below the sealing plate detection area near the gas outlet pipe. As the purge velocity increases, the vortex rotation intensity gradually increases, while the size remains relatively unchanged. This enhances the aerosol entrainment capacity at this location, increasing the aerosol concentration within 80 mm below the sealing plate detection area. The second vortex is located approximately 20 mm below the detection area of ​​the sealing plate. As the gas velocity increases, the rotational intensity and range of the vortex gradually increase, thus entraining more aerosol into the detection area of ​​the sealing plate. The third vortex is located approximately 90 mm below the sealing plate. As the purge velocity increases, the rotational intensity and range of the vortex gradually decrease. This is because, with the increase in velocity, a large amount of the mixture of purge gas and aerosol flows past this point and then flows towards the sealing plate, disrupting the conditions for vortex formation.

[0103] Figure 3 The image shows the aerosol concentration distribution cloud map of the longitudinal section of the flow cell. It can be observed that the aerosol concentration field distribution pattern remains similar as the purge gas velocity increases from 2 m / s to 3 m / s. Near the sealing plate detection area, the gas flows horizontally forward close to the sealing plate, and the impact force generated by the flow prevents a large amount of rising aerosol from approaching the sealing plate. Compared with the overflow pipe side, the aerosol concentration on the gas outlet pipe side is significantly lower. Figure 2Flow field vector diagram analysis shows that this is because the impact force generated by the purge gas flow blows the aerosol along the path to the overflow pipe side, and the amount of aerosol discharged by the overflow pipe per unit time is limited. The difference between the three operating conditions is that as the gas velocity increases, the aerosol concentration in the 80mm range below the sealing plate detection area gradually increases, combined with... Figure 2 Analysis of the flow field vector diagram reveals two main reasons for this phenomenon: First, the increased gas velocity leads to greater suppression of the aerosol on the gas outlet pipe side, causing more aerosol to flow towards the overflow pipe side and be forced to flow towards the sealing plate instead of being completely discharged. Second, the increased intensity and range of the vortex below the sealing plate detection area enhances the entrainment effect. When the velocity increases to 3.5 m / s, the difference in suppression force between the aerosol on the gas outlet side and the overflow pipe side further increases, and the swirling effect inside the flow cell significantly intensifies. Except for the area near the sealing plate detection area, the flow cell is almost completely filled with aerosol. When the velocity continues to increase to 4 m / s, the flow cell is completely filled with aerosol. Therefore, as the purge gas velocity increases, the aerosol concentration increases, and the reliability of the online radiation measurement device decreases.

[0104] Figure 4 The graph shows the aerosol concentration variation along the axis of the flow cell. It can be observed that the aerosol concentration gradually increases with increasing purge gas velocity, which is consistent with the analysis above that high speed is detrimental to purging. As the distance between the flow cell cross-section and the detection area of ​​the sealing plate increases, the influence of gas velocity on aerosol concentration gradually strengthens. This is presumably because the air curtain's suppression effect deteriorates downwards along the flow cell axis, while the upward impact force of the aerosols increases. Therefore, a purge gas velocity of 2 m / s is selected as the optimal operating condition.

[0105] 1.2 Influence of Gas Rotation Pipe Diameter

[0106] By reducing the purge gas velocity, the lowest aerosol concentration in the flow cell section within 80 mm below the detection zone of the sealing plate decreased from 4750 ppm to 772 ppm, and the highest decreased from 12518 ppm to 2827 ppm, thus improving the aerosol concentration field distribution. However, further reducing the velocity will have negative effects: First, the rigidity of the air curtain decreases. When the aerosol content from nuclear waste volatilization increases, the upward impact force of the aerosols strengthens, potentially penetrating the air curtain and contaminating the sealing plate. Second, the gas output from the overflow pipe decreases, and insufficient gas development inside leads to backflow of external air, affecting aerosol discharge. Therefore, the optimal purge gas velocity of 2 m / s is selected to analyze the impact of the guide zone structural parameters on the purge system. The gas enters the rotating zone and is divided into two parts, then merges in the vertical rectification zone. Considering that changing the diameter of the gas rotating pipe will change the contact area and collision velocity when the two gas flows merge, this invention analyzes in detail the impact of the gas rotating pipe diameter on the purge system. The height of the gas rotation zone in the original operating condition is 9mm. The diameters of the four modified operating conditions are 10.5mm, 12mm, 13.5mm and 15mm, respectively, while other parameters remain the same as the original operating condition.

[0107] Figure 5 The diagram shows the flow field vectors for the horizontal and vertical rectifying sections. As can be seen from the diagram, the flow fields exhibit similar distribution patterns under the five operating conditions. The two airflows entering the vertical rectifying section from the rotating section do not collide directly, but rather collide with the lower wall at a certain angle. Vortices form between the two airflows and on both sides of the vertical rectifying section. As the height of the rotating section increases, due to the constant total gas flow rate but increased cross-sectional area, the velocity of the airflow entering the vertical rectifying section gradually decreases. This leads to a gradual weakening of the vortex intensity formed between the two airflows and on both sides of the vertical rectifying section, and also weakens the collision between the airflow and the wall. Therefore, the energy consumed by the purge gas here decreases, and the velocity of the purge gas ejected horizontally at the end of the flow-limiting section increases, thereby increasing the velocity of the purge gas ejected horizontally from the sealing plate interlayer.

[0108] Figure 6 This is a cloud map showing the aerosol concentration distribution along the longitudinal section of the flow cell. The cloud map reveals similar aerosol concentration field distribution patterns for gas rotating pipe diameters of 9 mm and 10.5 mm. When the diameter increases to 12 mm, the aerosol concentration on the gas outlet pipe side increases. Figure 5 Analysis of the flow field vector diagram reveals that this is due to the increased velocity of the purge gas horizontally ejected from the sealing plate interlayer. The gas flows downwards along the wall of the flow tank at an increased velocity, causing a large amount of aerosol that cannot be completely discharged from the overflow pipe and is forced to flow towards the sealing plate. This situation is consistent with high-speed purging. When the height continues to increase from 12 mm, the aerosol concentration distribution does not change significantly. This may be because the airflow velocity decreases, the energy loss is reduced, and the magnitude of the purge gas velocity horizontally ejected from the sealing plate interlayer does not differ significantly.

[0109] Figure 7 The graph shows the aerosol concentration variation. As the diameter of the gas rotating pipe increases, the aerosol concentration gradually increases. Considering all factors, a gas rotating pipe diameter of 9 mm is selected as the optimal operating condition.

[0110] 1.3 Influence of Gas Rotation Pipe Length

[0111] Analysis revealed that aerosol distribution improved with decreasing gas rotation pipe diameter. However, further reduction in the gas rotation pipe diameter was limited by the 8mm gas inlet pipe diameter, and its impact on the purging system was relatively small compared to the purge gas velocity. Therefore, increasing the gas rotation pipe diameter could not significantly optimize aerosol concentration distribution. This invention selected an optimal gas rotation pipe diameter of 9mm and analyzed the influence of the gas rotation pipe length on the purging system. The radius of the gas rotation zone in the original operating condition was 410mm, and the radii for the four modified operating conditions were 470mm, 530mm, 590mm, and 650mm, respectively, while other parameters remained consistent with the original operating condition.

[0112] Figure 8 This is a vector diagram of the flow field at a cross-section of the flow cell 4mm below the detection area of ​​the sealing plate. The diagram shows that, within the length and radius of the gas rotating pipe, the flow field distribution patterns are similar for the five operating conditions. Combined with... Figure 2 Flow field vector diagram analysis shows that the purge gas is ejected horizontally forward from the sealing plate interlayer. Due to the obstruction of the flow cell wall, part of the gas flows downwards along the flow cell wall, while the other part flows horizontally circumferentially along the flow cell wall. This portion of the purge gas forms two symmetrical vortices with the high-speed gas in the center of the flow cell cross-section. When the length of the gas rotating pipe increases from 410 mm to 470 mm, the high-speed region expands and the vortices intensify, indicating an increase in the downward velocity of the gas along the flow cell wall. When the pipe length further increases, the high-speed region and vortices do not change significantly, possibly because the gas develops more fully within the pipe, and the internal flow field of the purge system tends to stabilize.

[0113] Figure 9 This is a cloud map showing the aerosol concentration distribution across the longitudinal section of the flow cell. It can be seen that as the length of the gas rotating pipe increases from 410 mm to 650 mm, the aerosol concentration on the gas outlet pipe side gradually increases. Figure 8 The flow field vector diagram shows that this is because the increased length of the gas rotating pipe leads to an increased velocity of the gas flowing downwards along the wall of the flow tank. This increases the pressure difference between the gas outlet side and the overflow pipe side, resulting in more aerosol flowing towards the sealing plate detection area, a situation consistent with high-speed purging. Furthermore, when the length of the gas rotating pipe increases from 410 mm to 470 mm, the increase in aerosol concentration on the gas outlet pipe side is the largest, likely due to the significant increase in the velocity of the gas flowing downwards along the wall of the flow tank.

[0114] Figure 10 The graph shows the aerosol concentration variation. It can be seen that the aerosol concentration gradually increases with the increase of the gas rotating pipe length, which is consistent with... Figure 9 The aerosol concentration cloud map distribution patterns are consistent. Taking all factors into consideration, a gas-gas rotating pipe length of 410 mm is selected as the optimal operating condition.

[0115] 1.4 Influence of the height of the vertical rectification zone of gas

[0116] Analysis of Section 1.3 reveals that the radius of the gas rotation zone has a limited impact on the purging system. Under these conditions, the aerosol concentration within 80 mm below the detection zone of the sealing plate ranges from a minimum of 641 ppm to a maximum of 2491 ppm in the flow cell cross-section. Combined with the analysis in Section 1.2, it is known that the purging gas forms vortices in the vertical rectification zone. As the height of the vertical rectification zone changes, the range and intensity of the vortices change, affecting the velocity of the purging gas at the end of the flow-limiting zone, thus altering the aerosol concentration distribution. Therefore, the optimal operating condition gas rotation pipe length of 410 mm is selected to analyze the impact of the height of the gas vertical rectification zone on the purging system. The height of the gas vertical rectification zone in the original operating condition is 7 mm. The heights in the four modified operating conditions are 0 mm, 3.5 mm, 10.5 mm, and 14 mm, respectively, while other parameters remain consistent with the original operating condition.

[0117] Figure 11 The vector diagrams show the flow field at the horizontal and vertical rectifying sections. As the height of the vertical rectifying section increases, the intensity and range of the vortices formed on both sides of the rectifying section gradually increase. The two airflows gradually approach each other, and the collision intensifies. At the same time, since the flow velocities of the two airflows do not change significantly, the vortices between the airflows do not change significantly. Therefore, the energy consumed by the gas at this point increases, and the velocity of the purge gas ejected horizontally forward from the sealing plate interlayer decreases.

[0118] Figure 12 This is a vector diagram of the flow field in the horizontal rectification region. As can be seen from the diagram, with the increase of the height of the vertical rectification region, the collision points of the two airflows with the wall gradually approach each other, and the angle between their velocity directions decreases. This reduces the high-speed zone generated during merging, resulting in a more uniform velocity distribution, which leads to increased uniformity of the air curtain. This is mainly because the flow paths of the two airflows increase in the vertical rectification region, allowing for more complete development. The diagram also shows that with increasing height, the collision velocities of the two airflows with the wall gradually decrease, combined with… Figure 11 Analysis shows that this is partly because the airflow consumes more energy and decreases in speed in the vertical rectification region, and partly because the airflow develops more fully in the vertical rectification region, resulting in a reduction in the local high-speed zone.

[0119] Figure 13This is a cloud map showing the aerosol concentration distribution. It can be observed that as the height of the vertical rectifying zone increases from 0 mm to 7 mm, the low-concentration aerosol area near the gas outlet gradually increases. Combined with... Figure 12 Analysis of the flow field vector diagram in the horizontal rectification region reveals that this is mainly due to the gradual uniformity of the purge gas velocity distribution in the horizontal rectification region, leading to increased uniformity of the air curtain. As the height continues to increase, the low-concentration aerosol region gradually decreases, combined with... Figure 11 and Figure 12 Flow field vector diagram analysis shows that although the uniformity of the air curtain increases, the velocity of the gas ejected horizontally forward from the sealing plate interlayer decreases, the rigidity of the air curtain decreases, and the aerosol penetrates the air curtain and flows to the sealing plate. When the height of the vertical rectification zone is 7mm, the low concentration area of ​​aerosols reaches its maximum value, which may be because the uniformity and rigidity of the air curtain are both relatively good at this time.

[0120] Figure 14 The graph shows the aerosol concentration variation. As can be seen from the graph, with the increase of the vertical rectification zone height, the aerosol concentration exhibits a trend of first decreasing and then increasing, which is consistent with... Figure 13 The aerosol concentration cloud map distribution patterns are consistent. When the height increases from 10.5 mm to 14 mm, the aerosol concentration change is very small, indicating that the aerosol concentration distribution is less affected by height at this point. This may be because the internal flow field of the purging system tends to stabilize. Taking all factors into consideration, a height of 7 mm in the vertical rectification zone of the gas is selected as the optimal operating condition.

[0121] 1.5 Influence of the width of the gas horizontal rectification region

[0122] In this invention, the widths of the horizontal and vertical rectification zones are the same as the width of the flow-limiting zone. To maintain the consistency of the structures of the vertical, horizontal, and flow-limiting zones and reduce the difficulty of device fabrication, the widths of all three are varied simultaneously during the analysis of the influence of the horizontal rectification zone width. As analyzed in Section 1.2, the gases initially converge in the vertical rectification zone, and changes in the vertical rectification zone width may affect the merging process of the two gas streams. The width of the horizontal rectification zone affects the cross-sectional area of ​​the gas flow direction, while the flow-limiting zone width may directly affect the coverage area and rigidity of the air curtain. Therefore, the optimal operating condition of a 7mm vertical rectification zone height is selected, and the influence of the horizontal rectification zone width on the purging system is analyzed in detail. The original horizontal rectification zone width is 60mm, and the widths of the horizontal rectification zones for the four modified operating conditions are 50mm, 80mm, 100mm, and 120mm, respectively, with other parameters remaining consistent with the original operating condition.

[0123] Figure 15The diagram shows the flow field vector of the longitudinal section of the flow cell. It can be seen that as the width of the horizontal gas rectification zone increases, the velocity of the purge gas ejected horizontally forward from the sealing plate interlayer decreases due to the increased flow cross-sectional area of ​​the purge gas, leading to a decrease in the rigidity of the air curtain. Furthermore, as the width of the horizontal gas rectification zone increases, the velocity vector direction of the aerosol flowing towards the sealing plate detection area gradually becomes horizontal, which helps reduce the aerosol concentration. Simultaneously, the local high-speed zone of the purge gas increases at a position 15 mm below the sealing plate detection area, which reduces the uniformity of the air curtain and increases the aerosol concentration.

[0124] Figure 16 This is a vector diagram of the flow field on the wall of the flow tank below the sealing plate. It can be observed that as the width of the horizontal gas rectification zone increases, the five operating conditions exhibit similar flow field distribution patterns. The purge gas is ejected horizontally forward from the sealing plate interlayer. Due to the obstruction of the flow tank wall, part of it flows downwards along the wall, while the other part flows circumferentially along the wall. As the width of the horizontal gas rectification zone increases, the amount of gas flowing circumferentially along the wall gradually increases, indicating an increase in the air curtain coverage area.

[0125] Figure 17 This is a cloud map showing the aerosol concentration distribution across the longitudinal section of the flow cell. The cloud map shows that the aerosol concentration gradually decreases as the width of the horizontal rectifier zone increases from 50 mm to 80 mm. Figure 15 and Figure 16 Flow field analysis revealed two main reasons for this phenomenon: First, the upward aerosol velocity tends to be horizontal, making it easier for the purge gas to carry it to the overflow pipe for discharge; second, the width of the rectifying zone has increased to the same as the diameter of the flow cell, leading to an increase in the air curtain coverage area and enhanced air curtain uniformity. As the width continues to increase, the low-concentration aerosol zone gradually decreases, combined with... Figure 15 Flow field analysis shows that this is due to two factors: firstly, the reduced velocity of the purge gas ejected horizontally forward from the sealing plate interlayer, resulting in decreased air curtain rigidity; and secondly, the increased local high-speed zone of the purge gas 15mm below the sealing plate, leading to poorer uniformity of the air curtain.

[0126] Figure 18 The graph shows the aerosol concentration variation. It can be seen that as the width of the horizontal rectification zone increases, the aerosol concentration first decreases and then increases, which is consistent with... Figure 17The aerosol concentration cloud map distribution patterns are consistent. The graphs also show that when the width of the horizontal rectifier zone increases from 50mm to 80mm, the decrease in aerosol concentration is significantly greater than the increase when the width increases from 80mm to 120mm. Furthermore, the differences in aerosol concentration curves are small when the width of the horizontal rectifier zone is 80mm, 100mm, and 120mm, indicating that the aerosol concentration distribution is less affected when the width of the horizontal rectifier zone is greater than 80mm. This is because the diameter of the flow cell is 80mm. When the width of the horizontal rectifier zone is not less than 80mm, the coverage area of ​​the air curtain formed by the purge gas in the horizontal direction is close to the cross-sectional area of ​​the flow cell along the axis, resulting in a more uniform pressure on the aerosols, which is beneficial for the aerosols to be discharged through the overflow pipe. Based on the above analysis, an airflow width of 80mm is selected as the initial operating condition for the next stage of the modification plan.

[0127] 1.6 Summary

[0128] This invention employs computer numerical simulation to analyze the internal flow field of the purging system and the aerosol concentration distribution in the longitudinal section of the flow cell. It further analyzes the effects of purging gas velocity, rotating pipe diameter, rotating pipe length, vertical rectifying zone height, and horizontal rectifying zone width on the purging system, drawing the following conclusions:

[0129] (1) As the purge gas velocity increases, the downward stroke of the gas along the wall of the flow cell increases, the pressure difference between the gas outlet side and the overflow pipe side increases, and the swirling effect inside the flow cell intensifies, thus increasing the amount of aerosol flowing into the sealing plate detection area. After comprehensive consideration, a purge gas velocity of 2 m / s is selected as the optimal operating condition.

[0130] (2) As the diameter of the gas rotating pipe increases, the velocity of the airflow entering the vertical rectification zone decreases, the vortex weakens, and the collision between the airflow and the wall weakens. The energy consumed by the purging gas decreases, the velocity of the gas ejected horizontally from the sealing plate interlayer increases, the difference in pressure on the aerosols on the gas outlet pipe side and the overflow pipe side increases, and the aerosol concentration distribution deteriorates. After comprehensive consideration, a gas rotating pipe diameter of 9mm was selected as the original operating condition for the next step of analysis.

[0131] (3) As the length of the gas rotating pipe increases, the downward stroke of the gas along the wall of the flow pool increases, the difference in pressure on the aerosol on the gas outlet side and the overflow pipe side increases, and the aerosol concentration increases. After comprehensive consideration, a gas rotating pipe length of 410 mm is selected as the optimal operating condition.

[0132] (4) When the height of the vertical rectification zone increases from 0 mm to 7 mm, the velocity distribution of the purge gas in the horizontal rectification zone becomes more uniform, the uniformity of the air curtain increases, and the aerosol concentration decreases. As the height continues to increase, although the uniformity of the air curtain increases, the velocity of the purge gas ejected horizontally forward from the sealing plate interlayer decreases, the rigidity of the air curtain decreases, and therefore the aerosol concentration increases. Considering all factors, a vertical rectification zone height of 7 mm is selected as the optimal operating condition.

[0133] (5) When the width of the horizontal gas rectification zone increases from 50mm to 80mm, the coverage area of ​​the air curtain increases, and the velocity direction of the aerosol flowing towards the detection area of ​​the sealing plate tends to be horizontal, resulting in a better aerosol concentration distribution. When the width continues to increase, the velocity of the purge gas ejected horizontally forward from the sealing plate interlayer decreases, the rigidity of the air curtain decreases, and the local high-speed zone below the sealing plate increases, leading to a worse uniformity of the air curtain and thus a worse aerosol concentration distribution. After comprehensive consideration, an airflow width of 80mm is selected as the optimal operating condition.

[0134] (6) By comparing the effects of the flow guide parameters on aerosol distribution, it was found that the width of the horizontal gas rectification zone had the most significant impact, followed by the purge gas velocity. By optimizing the flow guide parameters, the aerosol concentration distribution was greatly improved. At this point, the aerosol concentration in the flow cell section within 80 mm below the sealing plate detection zone ranged from a minimum of 17 ppm to a maximum of 362 ppm.

[0135] 2. The impact of the flow zone structure on the performance of the purging system

[0136] This invention, in conjunction with the modification requirements of the online radiation measurement device, analyzes the impact of the flow zone structure on the performance of the purging system in order to further reduce the aerosol concentration. The influencing factors include the diameter of the sealing plate, the thickness of the sealing plate interlayer, the relative position of the overflow pipe and the gas outlet pipe, and the distance between the overflow pipe and the sealing plate.

[0137] 2.1 Influence of sealing plate diameter

[0138] This invention selects the optimal operating condition airflow width of 80mm from Section 1.5 and analyzes in detail the influence of the sealing plate diameter on the purging system. The sealing plate diameter in the original operating condition is 60mm, and the diameters for the four modified operating conditions are 50mm, 55mm, 65mm and 70mm respectively, while other parameters remain the same as the original operating condition.

[0139] Figure 19 The diagram shows the velocity contour and streamline of a section located 0.5 mm below the upper sealing plate. It can be seen that as the diameter of the sealing plate increases, the proportion of the high-speed zone inside the interlayer increases due to the increased flow of high-speed purge gas into the sealing plate interlayer, and the gas flow path also widens. This is beneficial for increasing the coverage area of ​​the air curtain and reducing the velocity of the gas flowing downwards along the wall of the flow pool. This, in turn, reduces the pressure difference between the gas outlet side and the overflow pipe side, thus lowering the aerosol concentration.

[0140] Figure 19 The diagram shows the velocity contour and streamline of a section located 0.5 mm below the upper sealing plate. It can be seen that as the diameter of the sealing plate increases, the proportion of the high-speed zone inside the interlayer increases due to the increased flow of high-speed purge gas into the sealing plate interlayer, and the gas flow path also widens. This is beneficial for increasing the coverage area of ​​the air curtain and reducing the velocity of the gas flowing downwards along the wall of the flow pool. This, in turn, reduces the pressure difference between the gas outlet side and the overflow pipe side, thus lowering the aerosol concentration.

[0141] Figure 20 The image shows the aerosol concentration distribution cloud map of the longitudinal section of the flow cell. It can be observed that when the diameter of the sealing plate increases from 50mm to 55mm, aerosols move simultaneously towards both the gas outlet pipe side and the sealing plate. The aerosol concentration increases significantly approximately 30mm below the sealing plate detection area. This is likely due to an increase in purge gas flowing from the sealing plate interlayer to the center of the flow cell, and the increased thickness of the air curtain but insufficient rigidity, which pushes more aerosols from the overflow pipe side towards the area approximately 30mm below the sealing plate detection area. When the diameter increases to 60mm, the aerosol concentration decreases. This is mainly due to a further increase in purge gas flowing from the sealing plate interlayer to the center of the flow cell, and an increase in both the thickness and rigidity of the air curtain, which pushes the aerosols towards the gas outlet side, where they are then carried by the purge gas flowing downwards along the flow cell wall to the overflow pipe for discharge. When the diameter continues to increase from 60mm, the aerosol concentration decreases further. (Combined with...) Figure 19 Flow field analysis shows that this is due to improvements in the coverage area, thickness, and rigidity of the air curtain.

[0142] Figure 21 The graph shows the aerosol concentration variation. It can be seen from the graph that as the diameter of the sealing plate increases, the aerosol concentration first increases and then decreases, which is consistent with... Figure 20 The trends shown in the aerosol concentration cloud maps are consistent. Notably, when the diameter is 50mm, the increase in aerosol concentration slows significantly in the 40-80mm range below the sealing plate detection area, indicating that the suppression effect of the air curtain in this area is essentially eliminated, and the air curtain thickness is insufficient. When the diameter increases to 55mm, the inflection point of the aerosol concentration growth rate lags slightly, indicating that the thickness has increased. When the diameter continues to increase, the growth rate trend of aerosol concentration along the height of the flow cell remains basically consistent, indicating that the air curtain thickness has been further improved, confirming the hypothesis of increased air curtain thickness. Taking all factors into consideration, a sealing plate diameter of 70mm is selected as the initial operating condition for the next stage of the modification plan.

[0143] 2.2 Influence of the thickness of the sealing plate interlayer

[0144] After the purge gas enters the sealing plate interlayer from the flow-limiting zone, part of the gas flows horizontally forward into the flow pool, while the other part first flows along the sealing plate interlayer and then enters the flow pool. The thickness of the sealing plate interlayer may affect the flow path of the purge gas within the interlayer, thus affecting the coverage area of ​​the air curtain. Therefore, this section selects the optimal operating condition with a sealing plate diameter of 70mm and analyzes in detail the impact of the sealing plate interlayer thickness on the purge system. However, reducing the interlayer thickness is detrimental to the cleaning process of the sealing plate; therefore, this section only increases the sealing plate interlayer thickness. To reduce the manufacturing difficulty of the device, when changing the sealing plate interlayer thickness, the upper wall surface of the horizontal rectification zone, the upper wall surface of the flow-limiting zone, and the upper wall surface of the sealing plate are kept on the same plane. The sealing plate interlayer thickness in the original operating condition is 1mm, and the thicknesses for the four modified operating conditions are 1.5mm, 2mm, 2.5mm, and 3mm, respectively, while other parameters remain consistent with the original operating condition.

[0145] Figure 22 The diagram shows the velocity contour and streamline of a section 0.5 mm below the upper sealing plate. It can be seen that as the thickness of the sealing plate interlayer increases, the proportion of the high-speed zone inside the interlayer decreases, while the gas flow rate decreases, which reduces the coverage area of ​​the air curtain. Due to the increased cross-sectional area of ​​the purge gas flow and the decreased velocity in the flow-limiting zone, the gas flow velocity downwards along the flow tank wall decreases, thus reducing the aerosol concentration. Figure 22 It can also be seen that in the horizontal rectification zone, as the thickness increases, the two airflows gradually approach each other, the distance to the impact point with the lower wall decreases, and the non-uniformity of the streamlines increases, which will lead to a decrease in the uniformity of the air curtain.

[0146] Figure 23 This is a cloud map showing the aerosol concentration distribution along the longitudinal section of the flow cell. The cloud map reveals that when the thickness of the sealing plate interlayer increases from 1 mm to 1.5 mm, the low-concentration aerosol region slightly increases. This is because the velocity at the end of the flow-limiting zone decreases, the pressure difference between the gas outlet side and the overflow pipe side decreases, and the swirling effect inside the flow cell weakens. When the thickness further increases, more aerosol flows towards the sealing plate, and the low-concentration aerosol region decreases. Figure 22 Flow field analysis shows that this is due to the increased velocity non-uniformity in the horizontal rectification region and the reduced coverage area of ​​the air curtain, resulting in poorer uniformity of the air curtain.

[0147] Figure 24 The graph shows the aerosol concentration variation. As the thickness of the sealing plate interlayer increases, the aerosol concentration initially decreases and then increases, which is consistent with the distribution pattern of the aerosol concentration cloud map. Notably, when the thickness increases from 2.5 mm to 3 mm, the aerosol concentration decreases in the range of approximately 48–80 mm below the sealing plate detection area, leading to a smaller difference in aerosol distribution along the height of the flow cell. Combined with… Figure 23Analysis of the aerosol concentration cloud map revealed that this was because while the uniformity of the air curtain deteriorated, the overall suppression effect on aerosols did not change significantly. Aerosols flowed from areas with poor air curtain uniformity to the sealing plate detection area, while the aerosol discharge rate from the overflow pipe remained largely unchanged. Taking all factors into consideration, a sealing plate interlayer thickness of 1.5 mm was selected as the optimal operating condition.

[0148] 2.3 Summary

[0149] This invention employs computer numerical simulation, combined with the requirements for modifying an online radiation measurement device. By analyzing the internal flow field and aerosol concentration distribution in the longitudinal section of the flow cell within the purging system, it delves into the effects of the sealing plate diameter, sealing plate interlayer thickness, the relative positions of the overflow pipe and gas outlet pipe, and the distance between the overflow pipe and the sealing plate on the purging system performance. Ultimately, a purging system meeting the requirements is obtained. The conclusions of this invention are as follows:

[0150] (1) When the diameter of the sealing plate increases from 50mm to 55mm, the amount of purge gas flowing from the sealing plate interlayer to the center of the flow cell increases, the thickness of the air curtain increases but its rigidity is insufficient, and the aerosol concentration increases. When the diameter continues to increase, the coverage area of ​​the air curtain increases and the amount of purge gas flowing to the center of the flow cell further increases, both the thickness and rigidity of the air curtain increase, and the aerosol concentration decreases. After comprehensive consideration, a sealing plate diameter of 70mm is selected as the optimal working condition.

[0151] (2) When the thickness of the sealing plate interlayer increases from 1 mm to 1.5 mm, the velocity at the end of the flow-limiting zone decreases, the pressure difference between the gas outlet side and the overflow pipe side decreases, and the swirling effect inside the flow pool weakens, leading to an increase in the low-concentration aerosol zone. When the thickness further increases, the non-uniformity of the air curtain increases and the coverage area decreases, further reducing the low-concentration aerosol zone. Considering all factors, a sealing plate interlayer thickness of 1.5 mm is selected as the optimal operating condition.

[0152] It should be noted that embodiments of the present invention can be implemented in hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution system, such as a microprocessor or dedicated-design hardware. Those skilled in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuitry such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., or by software executed by various types of processors, or by a combination of the above-described hardware circuitry and software, such as firmware.

[0153] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A control method of a radiation on-line purging device, characterized by, The control method for the online radiation purging device includes: Based on the requirements for the modification of the online radiation measurement device, and using relevant knowledge of computational fluid dynamics, numerical simulation methods are employed to analyze the impact of the parameters of the guide zone and the structure of the flow zone on the performance of the purging system. The input parameter for the flow guiding zone is the purge gas velocity, and the structural parameters include the height of the gas rotation zone, the radius of the gas rotation zone, the height of the vertical rectification zone, and the airflow width. The influencing factors of the flow zone structure include the diameter of the sealing plate, the thickness of the sealing plate interlayer, the relative position of the overflow pipe and the gas outlet pipe, and the distance between the overflow pipe and the sealing plate. The control method for the radiation online purging device includes the following steps: Step 1: Using computer numerical simulation, the effects of purge gas velocity, rotation zone height, rotation zone radius, vertical rectification zone height, and airflow width on the purge system are analyzed by examining the internal flow field and aerosol concentration distribution in the longitudinal section of the flow cell. Step two involves using computer numerical simulation, combined with the requirements for modifying the online radiation measurement device, to analyze the internal flow field of the purging system and the aerosol concentration distribution in the longitudinal section of the flow pool. The effects of the sealing plate diameter, sealing plate interlayer thickness, relative position of the overflow pipe and the gas outlet pipe, and distance between the overflow pipe and the sealing plate on the performance of the purging system are analyzed, ultimately resulting in a purging system that meets the requirements.

2. The control method of the radiation online purge apparatus according to claim 1, characterized by, The analysis of the effects of purge gas velocity, rotation zone height, rotation zone radius, vertical rectification zone height, and airflow width on the purge system in step one includes: (1) Analyze the influence of the purge gas velocity and determine that the purge gas velocity of 2m / s is the optimal working condition; (2) Analyze the influence of the height of the gas rotating zone and determine that a gas rotating zone height of 9mm is the optimal working condition; (3) Analyze the influence of the gas rotation zone radius and determine that the gas rotation zone radius of 157.5 mm is the optimal working condition; (4) Analyze the influence of the height of the vertical rectification zone of the gas and determine that the optimal working condition is a height of 7mm in the vertical rectification zone of the gas. (5) Analyze the influence of airflow width and determine that an airflow width of 80mm is the optimal working condition.

3. The control method of the radiation online purge apparatus according to claim 1, characterized by, The analysis of the effects of the sealing plate diameter, sealing plate interlayer thickness, relative position of the overflow pipe and gas outlet pipe, and distance between the overflow pipe and the sealing plate on the purging system performance in step two includes: (1) Analyze the influence of the sealing plate diameter and determine that the sealing plate diameter is 70mm as the original working condition of the modification plan; (2) Analyze the influence of the thickness of the sealing plate interlayer and determine that the thickness of the sealing plate interlayer is 1.5mm as the optimal working condition.

4. A control system of a radiation online purge device which implements a control method of the radiation online purge device according to any one of claims 1 to 3, characterized by The control system of the radiation online purging device includes: The flow guide zone parameter influence analysis module is used to analyze the influence of purge gas velocity, rotation zone height, rotation zone radius, vertical rectification zone height, and airflow width on the purge system by analyzing the internal flow field and aerosol concentration distribution law of the flow pool longitudinal section through computer numerical simulation. The circulation zone structure impact analysis module is used to analyze the impact of the internal flow field and aerosol concentration distribution of the circulation pool section on the purging system by using computer numerical simulation methods and combining the requirements of the online radiation measurement device modification. It analyzes the impact of the sealing plate diameter, sealing plate interlayer thickness, relative position of the overflow pipe and gas outlet pipe, and distance between the overflow pipe and the sealing plate on the performance of the purging system, and finally obtains a purging system that meets the requirements.

5. A radiation on-line purge apparatus embodying a control method of the radiation on-line purge apparatus as claimed in any one of claims 1 to 3, characterized by The radiation online purging device includes a flow guiding zone and a flow circulation zone; The flow guiding zone includes a gas inlet pipe, a gas rotation zone, a vertical rectification zone, a horizontal rectification zone, and a flow restriction zone; wherein, the radius of the gas rotation zone refers to the inner diameter of the arc-shaped area, and the height of the gas rotation zone and the height of the vertical rectification zone refer to the dimensions along the axis of the flow pool; the width of the vertical rectification zone, the width of the horizontal rectification zone, and the width of the flow restriction zone are consistent; The circulation zone includes a gas outlet pipe, an overflow pipe, a sealing plate, and a circulation pool; the sealing plate consists of a sealing plate detection area on the top wall of the circulation pool and a sealing plate interlayer, and the upper wall of the sealing plate interlayer and the sealing plate detection area are on the same plane; a radiation detector is placed above the sealing plate detection area, and the mixture of aerosol and purge gas is below it; the diameter of the sealing plate refers to the outer diameter of the arc-shaped area of ​​the sealing plate interlayer; the gas outlet pipe is arranged in a horizontal direction, and the overflow pipe has an angle of 45° with the horizontal plane.

6. A computer device, comprising: The computer device includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the control method steps of the radiation online purging device as described in any one of claims 1 to 3.

7. A computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the control method for the radiation online purging device as described in any one of claims 1 to 3.

8. An information data processing terminal, characterized by The information data processing terminal is used to implement the online radiation purging device as described in claim 5.

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