Float glass tin bath protective gas flow direction intelligent regulation and control system and method thereof

Abstract

The invention discloses a float glass tin bath protective gas flow direction intelligent regulation and control system and a method thereof, the system comprises a sensing system, a central control system and an execution system, the central control system is respectively in control connection with the sensing system and the execution system; the sensing system comprises a plurality of groups of laser sheet light sources, a high-definition industrial camera and a data acquisition module, the data acquisition module can generate an air flow direction and flow velocity cloud picture through a PIV principle, and the sensing system can communicate with the DCS system to obtain process parameters; the central control system comprises an industrial computer and an AI intelligent control model, the AI intelligent control model has a deep reinforcement learning algorithm, the execution system comprises at least two groups of adjustable air curtain generators, and the float glass tin bath protective gas flow direction intelligent regulation and control system based on a simple multi-stage adjustable air curtain and the modulation method thereof are realized. The device adapts to abnormal working conditions of the tin bath and can effectively stabilize the flow direction of protective gas.

Description

Technical Field

[0001] This invention belongs to the field of float glass manufacturing technology, specifically relating to an intelligent control system and method for the flow direction of protective gas in the tin bath of float glass. It is applicable to all glass production scenarios that use tin bath forming, including ordinary float glass, ultra-thin electronic glass, high-alumina glass, and lithium aluminum silicon glass. Background Technology

[0002] In float glass production, the tin bath is a core forming device. To prevent oxidation of the molten tin, a high-purity nitrogen-hydrogen protective gas must be continuously introduced into the tin bath. Ideally, the protective gas should flow smoothly from the inlet to the outlet, forming a stable slightly positive pressure environment. However, in actual production, there is a huge temperature difference of 1000°C to 600°C within the tin bath, which causes natural convection due to differences in gas density. Leakage points are easily formed at openings such as the slag box, observation hole, and edge puller, disrupting the pressure balance and creating a chimney effect, causing backflow of external air. At the same time, the traditional air inlet and distribution system is simply designed and cannot dynamically adapt to changes in operating conditions, making it difficult to form an effective directional airflow barrier, ultimately leading to turbulent flow of the protective gas.

[0003] Currently, the industry lacks effective direct monitoring of the flow direction of protective gas inside the tin bath. Control methods mostly rely on manual experience to adjust the total air intake or zone pressure, resulting in slow response and inability to precisely control the flow direction. Although there are air curtains on the production line, they are not integrated with real-time flow field sensing data to form intelligent control, making it difficult to meet the high requirements of glass production for airflow stability control. If precise intelligent control is required, the glass float tin bath would be large, with a complex structure and high cost. Summary of the Invention

[0004] This invention proposes an intelligent control system for the protective gas flow direction of float glass tin bath based on an adjustable air curtain, and an intelligent control method based on the system.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A smart control system for the flow direction of protective gas in a float glass tin bath, comprising a sensing system, a central control system, and an execution system, wherein the central control system controls the sensing system and the execution system respectively.

[0007] The sensing system is used to collect real-time flow field data and process parameters within the tin bath. It includes multiple sets of laser sheet light sources, a high-definition industrial camera, and a data acquisition module. The laser sheet light sources and high-definition industrial cameras are respectively located at the end of the high-temperature zone, the transition zone, and the inlet of the slag box on the top and sidewalls of the tin bath. The laser sheet light sources project a laser plane onto the cross-section, which can make the naturally occurring tin ash particles suspended in the gas visible using the particle image velocimetry (PIV) principle. The high-definition industrial camera captures the particle trajectory, and the data acquisition module can generate airflow direction and velocity cloud maps by realizing velocity vectors at multiple points on the cross-section. The sensing system can communicate with the tin bath DCS system to synchronously acquire parameters such as temperature, total gas flow rate, and pressure in each zone.

[0008] The central control system includes an industrial computer and an AI intelligent control model. The industrial computer is located at the edge, running the AI ​​intelligent control model and communicating in real time with the sensing system and the execution system. The AI ​​intelligent control model has a deep reinforcement learning algorithm DDPG or SAC, and its input feature vector includes the average reverse flow velocity in the slag box direction, the location and intensity of the vortex core area, the temperature of each zone of the tin bath, the total inlet pressure, and the inlet and throat pressure of each air curtain generator. The AI ​​intelligent control model has situation diagnosis, prediction and early warning, and control decision-making functions. It can identify abnormal flow fields such as reverse flow and vortices, predict the evolution trend of the flow field, and calculate the optimal control parameters of each execution unit.

[0009] The execution system includes at least two sets of dynamically adjustable air curtain generators, respectively located at the front of the tin bath transition zone and the front of the slag box inlet. Each air curtain generator is a dynamically adjustable Venturi air curtain generator, specifically a Venturi air curtain generator made of 310S stainless steel, with an adjustable guide vane assembly at the air outlet. This type of air curtain generator is commonly used and its structure is not detailed here. The two sets of air curtain generators are fixed at the front of the tin bath transition zone and the front of the slag box inlet, forming a main directional air curtain F1 and a blocking air curtain F2. The main directional air curtain F1 has a preset angle of +20°, and the blocking air curtain F2 has a preset angle of 0°. The air curtain generators are connected to the main protective gas pipeline via pipes and are also equipped with solenoid valves connected to the main protective gas pipeline to ensure a controllable and stable gas flow.

[0010] The laser sheet light source is a semiconductor laser, the high-definition industrial camera is a near-infrared light-sensitive high frame rate camera, a high-temperature resistant optical window is opened at the corresponding installation position of the tin bath and a positive pressure purging system is configured; the air curtain generator is made of high-temperature resistant and corrosion-resistant 310S stainless steel; the central control system includes a visual monitoring interface for displaying flow field cloud map, early warning information and air curtain operating parameters.

[0011] A method for intelligently controlling the flow direction of protective gas in the tin bath of float glass based on the above system includes the following:

[0012] S1 flow field data acquisition: The laser sheet light source projects a laser plane, and a high-definition industrial camera captures the movement trajectory of tin ash particles at a frequency of 1 time per second. The data acquisition module generates a flow velocity cloud map; the process parameters of the DCS system are acquired simultaneously and transmitted to the central control system.

[0013] The S2 flow field diagnosis and decision-making process uses an AI intelligent control model to analyze real-time data. When the average reverse flow velocity in the slag box direction is ≤0.1m / s and there are no obvious eddies, it is determined to be a normal flow field, and the current control parameters are maintained. When the reverse flow velocity is >0.1m / s or the eddy intensity exceeds the standard, it is determined to be an abnormal flow field. The model predicts the flow field evolution trend and calculates the opening degree of the solenoid valves of each air curtain generator (0-1000 steps) and the angle of the guide vanes (-15° to +45°).

[0014] S3 air curtain control execution: The main air curtain F1 sprays airflow according to control parameters to enhance the directional flow of the main airflow field; the blocking air curtain F2 forms an airflow barrier to block the backflow of reverse airflow and external air; the protective gas is stably ejected after pressure stabilization, filtration, flow regulation, acceleration, angle adjustment and rectification;

[0015] S4 Control: After the air curtain control is executed, there is a 2-3 second delay. The sensing system collects flow field data again, and the central control system compares the parameters before and after the control. If the abnormal flow field is not eliminated, the AI ​​model recalculates the control parameters and repeats the control steps until the flow field returns to normal, and then enters the continuous monitoring state.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] This paper presents an intelligent control system and method for the protective gas flow direction in a float glass tin bath based on a multi-level adjustable air curtain. Utilizing PIV technology combined with natural tin ash particles as tracers, it achieves real-time visual monitoring of the flow field, adapting to industrial tin bath scenarios. The AI ​​intelligent control model integrates flow field data and process parameters, enabling integrated anomaly diagnosis, trend prediction, and decision-making. This enhances its adaptability to complex operating conditions, achieving intelligent control of perception, decision-making, execution, and feedback. It can automatically maintain optimal airflow organization 24 / 7, effectively blocking reverse airflow and external air backflow, improving glass surface quality, and reducing protective gas consumption, thus achieving energy saving and efficiency improvement. In terms of execution and control, the system employs an angle adjustment motor for the air curtain generator and control of the solenoid valve opening, achieving multi-level effective control of the protective gas's pressure stabilization, acceleration, angle adjustment, and rectification, effectively improving its control accuracy and stability. Attached Figure Description

[0018] Figure 1 is a schematic diagram of the working principle of the system of the present invention;

[0019] Figure 2 is a flowchart of the overall architecture of the present invention;

[0020] Figure 3 is a side view of the installation layout of the air curtain system in the tin bath of the present invention; Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0022] As shown in Figure 1-3, a smart control system for the flow direction of protective gas in a float glass tin bath is provided. The system includes a sensing system, a central control system, and an execution system. The central control system controls the sensing system and the execution system respectively.

[0023] The sensing system includes multiple sets of laser sheet light sources, high-definition industrial cameras, and data acquisition modules. One set of semiconductor laser sheet light sources and a near-infrared high-frame-rate high-definition industrial camera are installed at each of the three sections of the tin bath during glass forming: the end of the high-temperature zone, the transition zone, and the inlet of the slag box. High-temperature resistant optical windows are provided at corresponding positions in the tin bath, and a positive pressure purging system is configured to prevent window contamination. The data acquisition module is connected to both the cameras and the DCS system to ensure real-time data transmission.

[0024] The execution system includes at least two sets of air curtain generators. Each air curtain generator is a dynamically adjustable Venturi air curtain generator made of 310S stainless steel, and has a motor-adjustable guide vane assembly at the air outlet. This type of air curtain generator is commonly used and its structure is not detailed here. The two sets of air curtain generators are fixed at the front of the tin bath transition zone and the front of the slag box inlet, respectively, forming a main directional air curtain F1 and a blocking air curtain F2. The main directional air curtain F1 has a preset angle of +20°, and the blocking air curtain F2 has a preset angle of 0°. The air curtain generators are connected to the main protective gas pipeline via pipes and are also equipped with solenoid valves connected to the main protective gas pipeline to ensure a controllable and stable gas flow.

[0025] A filter screen is installed at the air outlet of the main protective gas pipeline to filter out tin ash.

[0026] The central control system deploys an industrial computer at the edge of the production line, installs an AI intelligent control model trained with the DDPG algorithm, and communicates with the sensing system and execution system respectively. It also debugs the visual monitoring interface to ensure that the flow field cloud map and parameter data are displayed in real time.

[0027] A method for intelligent control of the protective gas flow direction in the tin bath of float glass based on the above system.

[0028] S1 flow field data acquisition: The laser sheet light source projects a laser plane onto each cross section, and a high-definition industrial camera captures one frame of tin ash particle motion image per second. The data acquisition module processes the data to generate a flow velocity cloud map. Simultaneously, parameters such as temperature (600-1000°C), total pressure at the tin bath inlet (0.05-0.15MPa), and air curtain inlet pressure of each zone of the DCS system are acquired.

[0029] S2 Flow Field Diagnosis and Decision-Making: After receiving and analyzing the data, the AI ​​intelligent control model detects an abnormal flow field when the reverse flow velocity in the slag box direction is 0.18 m / s (exceeding the threshold of 0.1 m / s) and vortices exist in the transition zone. The model predicts that this abnormality will affect the airflow in the glass forming zone within 6 seconds and calculates the control parameters: F1 solenoid valve opening 850 steps, blade angle +28°; F2 solenoid valve opening 800 steps, blade angle -4°.

[0030] S3 air curtain control execution: The central control system issues control commands to synchronously activate the solenoid valves and stepper motors of the two air curtain generators, adjust the flow rate and blade angle, and stabilize the protective gas in the cavity to 0.12MPa. After the guide vanes adjust the angle, the gas is ejected from the directional injection outlet to form a stable air curtain.

[0031] S4 Control: After 3 seconds of control execution, the sensing system collects flow field data again, detects that the reverse flow velocity has dropped to 0.07 m / s, the eddies have disappeared, and the flow field has returned to normal; the system maintains the current control parameters and enters continuous monitoring state. If any abnormality occurs later, the above control process will be automatically repeated.

[0032] The aforementioned system employs PIV technology combined with natural tin ash particles as tracer particles to achieve real-time visual monitoring of the flow field, making it suitable for tin bath industrial scenarios. Furthermore, its AI intelligent control model integrates flow field data and process parameters, enabling integrated anomaly diagnosis, trend prediction, and decision-making. This enhances its adaptability to complex operating conditions, allowing for intelligent control of perception, decision-making, execution, and feedback. It can automatically maintain optimal airflow organization 24 / 7, effectively blocking reverse airflow and external air backflow, improving glass surface quality, and reducing protective gas consumption, thus achieving energy saving and efficiency improvement. In terms of execution and control, it utilizes an angle adjustment motor for the air curtain generator and control of the solenoid valve opening, achieving multi-level effective control of protective gas pressure stabilization, acceleration, angle adjustment, and rectification, effectively improving its control accuracy and stability.

[0033] The above system realizes an intelligent control system for the protective gas flow direction of float glass tin bath based on a simple multi-level adjustable air curtain. It also realizes intelligent control of the protective gas flow direction of float glass tin bath based on a simple system structure. Moreover, the structure of this system is adapted to abnormal working conditions of the tin bath, the control method and steps are clear and easy to operate, and it can effectively stabilize the protective gas flow direction. It is suitable for various glass production scenarios that use tin bath forming, and it is of great significance for improving product quality and reducing production costs.

[0034] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A float glass tin bath protective gas flow intelligent control system, characterized in that, The system comprises a sensing system, a central control system and an execution system, the central control system is connected with the sensing system and the execution system for control respectively; the sensing system comprises multiple groups of laser sheet light sources, high-definition industrial cameras and data acquisition modules, the laser sheet light sources and the high-definition industrial cameras are correspondingly arranged at the end of the high-temperature zone of the top and the side wall of the tin bath, the transition zone and the front of the slag box inlet, the data acquisition module is a kind of cloud chart capable of generating airflow direction and flow rate by PIV principle, the sensing system can communicate with the DCS system to obtain process parameters; the central control system comprises an industrial computer and an AI intelligent control model, the AI intelligent control model has a deep reinforcement learning algorithm, can input flow field characteristic parameters and process parameters, and can output control instructions; the execution system comprises at least two groups of adjustable air curtain generators arranged in front of the transition zone of the float glass tin bath and in front of the slag box inlet.

2. The system of claim 1, wherein, The air curtain generator is a dynamic adjustable Venturi air curtain generator, and is a Venturi air curtain generator made of 310S stainless steel, and a motor-adjustable guide vane group is arranged at the air outlet, the air curtain generator is connected with the main pipeline of the protective gas through a pipeline and is connected with the main pipeline of the protective gas through an electromagnetic valve.

3. The system of claim 2, wherein, The laser sheet light source is a semiconductor laser, the high-definition industrial camera is a near-infrared light-sensitive high-frame-rate camera, a high-temperature-resistant optical window is arranged at the installation position of the tin bath, and a positive pressure purging system is arranged.

4. The system of claim 3, wherein, The input feature vector of the AI intelligent control model comprises the average reverse flow rate in the direction of the slag box, the position and intensity of the vortex core zone, the temperature of each zone of the tin bath, the total pressure at the inlet and the inlet and throat pressure of each air curtain generator, and the output parameters comprise the electromagnetic valve opening (0-1000 steps) and the guide vane angle (-15° to +45°).

5. The system of claim 2, wherein, The preset injection angle of the air curtain in front of the transition zone is +10° to +30°, and the preset injection angle of the air curtain in front of the slag box inlet is -5° to +10°.

6. A method for intelligent control of flow of protective gas in a float glass tin bath, implemented based on the system of any one of claims 1-5, characterized in that, The method comprises the following steps: S1 flow field data acquisition: the sensing system collects flow field data and DCS process parameters at a frequency of 1 time per second, and transmits the data to the central control system; S2 flow field diagnosis and decision: the AI intelligent control model analyzes the data, determines whether the flow field is normal, and calculates the control parameters of each air curtain generator when the flow field is abnormal; S3 air curtain regulation and execution: the Venturi air curtain generator adjusts the airflow parameters according to the control parameters, the main directional air curtain strengthens the main flow field, and the blocking air curtain intercepts the reverse airflow; S4 regulation: after a delay of 2-3 seconds, the flow field data is collected again, the regulation effect is compared, and steps (2)-(3) are repeated until the flow field is stable.

7. The method of claim 6, wherein, The determination standard of the normal flow field in step (2) is that the average reverse flow rate in the direction of the slag box is ≤0.1 m / s and there is no obvious vortex.

Images