A method of controlling transverse temperature differences in a forming zone of a float glass tin bath

Abstract

The application discloses a control method for reducing transverse temperature difference in a forming area of a float glass tin bath, which comprises the following steps: collecting temperature data of the forming area of the tin bath along the width direction of a glass ribbon, dividing an edge area, a sub-edge area and a middle area, and adopting a partitioned air nozzle cooling mode according to the thermal load difference of each area, so that the cooling intensity gradually increases from the edge area to the middle area; meanwhile, the temperature field of the forming area of the tin bath is closed-loop and cooperatively adjusted by combining edge side wall and breast wall composite insulation, linear motor driven tin liquid flow state adjustment, barrier suppression of edge tin liquid backflow and edge control of a pulling machine. Through calculation of the transverse temperature difference, the glass ribbon offset and the temperature asymmetry parameters, the cooling intensity and the operation parameters are dynamically adjusted, so that the temperature distribution along the width direction of the glass ribbon is more uniform, the transverse temperature difference in the forming area of the tin bath is reduced, and the glass plate quality and the production stability are improved.

Description

Technical Field

[0001] This invention relates to the field of float glass production technology, and specifically to a method for controlling the transverse temperature difference in the tin bath forming zone of float glass. Background Technology

[0002] In the float glass production process, molten glass enters the tin bath and floats on the surface of the molten tin, where it undergoes leveling, polishing, and shaping within the tin bath forming zone. The lateral temperature uniformity of the tin bath forming zone directly affects the thickness uniformity, surface flatness, optical quality, and yield of the glass ribbon. In actual production, the side walls, bottom edges, and breast walls of the tin bath forming zone are more prone to heat loss, with heat loss at the edges typically exceeding that in the center. This can easily lead to a lateral temperature difference where the edges are cooler and the center is warmer. When this lateral temperature difference is large, the viscosity, fluidity, and cooling contraction of the glass ribbon are inconsistent along its width, potentially resulting in quality problems such as excessive thickness at the edges, thinner thickness in the center, surface deformation, and optical distortion.

[0003] Currently, the bottom cooling of the solder bath forming area mostly adopts a relatively fixed cooling arrangement, with some production lines using uniformly sized nozzles or a fixed cooling intensity. Since the edge areas naturally dissipate more heat, while the central area has a relatively concentrated heat, if the edges and center use the same or similar cooling methods, it easily leads to overcooling at the edges and insufficient cooling in the center, making it difficult to maintain a balanced lateral temperature distribution. Simultaneously, the molten solder in the solder bath exhibits natural convection, edge backflow, and local dead zones. Low-temperature molten solder easily flows back from the edge areas to the forming area, continuously cooling the edges and adjacent areas, further widening the lateral temperature difference. Relying solely on heating or cooling adjustments is insufficient to promptly improve the molten solder flow and stably suppress the backflow of cold molten solder from the edges. Furthermore, if the glass ribbon deviates from the centerline of the solder bath during operation, it will cause asymmetry in heat dissipation, cooling, and edge pulling on both sides, increasing the temperature difference on one side and affecting the stability of the glass ribbon's shape and thickness. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for controlling the transverse temperature difference in the tin bath forming area that can simultaneously take into account bottom zone cooling, edge heat preservation, molten tin flow regulation, edge backflow suppression, and glass strip centering control, so as to improve the uniformity of the temperature field in the tin bath forming area and the stability of glass strip forming.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for controlling the transverse temperature difference in the tin bath forming zone of float glass, wherein the tin bath forming zone is the area between the tin bath inlet side and the forming stable section, the control method includes the following steps: S1. Collect the temperature values ​​of multiple temperature measuring points arranged along the width direction of the glass strip in the tin bath forming area, and obtain the offset of the glass strip centerline relative to the tin bath centerline. S2. Divide the tin bath forming area along the width direction into the left side area, the left secondary side area, the middle area, the right secondary side area, and the right side area; S3. A partitioned air nozzle cooling structure is set on the outer side of the bottom shell of the tin bath forming area, so that the left side area and the right side area are equipped with air nozzles with the first effective flow diameter, the left secondary side area and the right secondary side area are equipped with air nozzles with the second effective flow diameter, and the middle area is equipped with air nozzles with the third effective flow diameter. The first effective flow diameter is smaller than the second effective flow diameter, and the second effective flow diameter is smaller than the third effective flow diameter, so as to form a partitioned cooling method of the bottom of the tank with increasing cooling intensity from the edge to the middle. S4. Strengthen the insulation of the side wall of the tin bath forming area and set a high temperature resistant composite insulation structure in the breast wall of the tin bath to reduce heat loss at the edge. S5. Linear motors are installed at the corresponding positions of the pair of edge-pulling machines located at the downstream end along the glass belt running direction. By adjusting the current, frequency, pole pitch, height of the working head from the molten tin surface, and distance between the working head and the side wall of the molten tin bath of the linear motor, the molten tin is driven in a directional manner to suppress the backflow of cold molten tin at the edge to the center of the forming area. S6. A baffle structure is set at the edge of the solder bath forming area to slow down the backflow of low-temperature solder liquid at the edge and weaken the dead zone of solder liquid. S7. Adjust the position, speed or angle of the left and right edge pulling machines to keep the center line of the glass strip near the center line of the tin bath. S8. Based on the temperature value and the offset, the cooling intensity of the partitioned air nozzle, the operating parameters of the linear motor, the configuration parameters of the retaining wall, and the parameters of the edge pulling machine are adjusted in a closed loop to reduce the lateral temperature difference in the tin bath forming area to the target range.

[0006] Preferably, the lateral temperature difference ΔT in the tin bath forming zone is calculated according to the following formula: ; in, The temperature values ​​are the n temperature measuring points arranged along the width of the glass strip; when ΔT is greater than the preset transverse temperature difference threshold ΔT0, the closed-loop coordinated adjustment in step S8 is executed.

[0007] Preferably, in step S3, the first effective flow orifice diameter d1, the second effective flow orifice diameter d2, and the third effective flow orifice diameter d3 satisfy the following relationship: ; ; ; And it satisfies: ; This results in the cooling intensity of the edge region being lower than that of the sub-edge region, and the cooling intensity of the sub-edge region being lower than that of the central region.

[0008] Preferably, the first effective flow orifice diameter d1, the second effective flow orifice diameter d2, and the third effective flow orifice diameter d3 further satisfy the following orifice diameter ratio relationship: ; Furthermore, the partitioned air nozzle cooling structure includes replaceable air nozzles, adjustable opening air nozzles, or air nozzles with throttling orifice plates; by replacing the air nozzles, adjusting the air nozzle opening, or adjusting the flow area of ​​the throttling orifice plate, the effective flow diameter and cooling air volume of the corresponding partition can be changed.

[0009] Preferably, in step S3, the effective flow aperture of each zone's air nozzle is determined according to the following relationship for different plate widths or different production capacity conditions: ; in, The effective flow orifice diameter selected for the i-th partition. Let i be the temperature of the i-th partition. The lowest temperature in each zone. Where D represents the highest temperature in each zone, and D is the set of available effective flow orifice diameters. This indicates that the orifice diameter closest to the calculated value is selected from the set of selectable effective flow orifices; the zone with higher temperature is configured with a larger effective flow orifice diameter, and the zone with lower temperature is configured with a smaller effective flow orifice diameter.

[0010] Preferably, in step S4, the high-temperature resistant composite insulation structure includes one or more of the following: a sillimanite material layer, a mullite material layer, and a sillimanite-mullite composite material layer; the reinforced insulation of the sidewalls and the cooling structure of the trough bottom partitioned air nozzles work together to reduce heat loss in the side area and enhance the cooling capacity of the middle area.

[0011] Preferably, in step S5, the current adjustment range of the linear motor is 70A to 160A, and the frequency adjustment range is 5Hz to 60Hz; when the temperature of the edge area is lower than that of the middle area and the lateral temperature difference is greater than the preset lateral temperature difference threshold, the current or frequency of the linear motor is increased to enhance the directional drive of the molten solder and increase the temperature of the edge area.

[0012] Preferably, in step S6, the baffle structure includes submerged baffles and handle-type baffles. There are 6 to 16 pairs of submerged baffles and 1 to 6 pairs of handle-type baffles. The submerged baffles and the handle-type baffles are arranged alternately or in segments along the edge of the tin bath forming area, so as to jointly suppress the backflow of cold tin liquid at the edge with the directional drive of tin liquid generated by the linear motor.

[0013] Preferably, in step S7, the offset of the glass strip centerline... Calculate using the following formula: ; in, This is the position of the center line of the glass strip. The position of the center line of the solder bath; when When the offset exceeds the preset allowable amount, adjust the position, speed or angle of the left and right edge-pulling machines to control the difference in position between the left and right edge-pulling machines within the range of 30mm to 120mm per edge-pulling machine, and reduce the lateral temperature difference between the left and right sides of the tin bath forming area.

[0014] Preferably, in step S8, the closed-loop coordinated regulation includes calculating the mid-edge temperature difference evaluation value B, the left-right asymmetry evaluation value A, and the control objective function J, wherein: ; ; ; In the formula, Temperature in the central region, This represents the combined temperature of the left-side edge region and the left-side sub-edge region. The combined temperature of the right-side edge region and the right-side sub-edge region is given by ΔT, where ΔT is the lateral temperature difference and ΔT0 is the target lateral temperature difference. R represents the offset of the glass strip centerline, R represents the intensity of the cold solder reflux at the edge, and Q represents the cooling energy consumption or airflow deviation per unit time. The weighting coefficient is used to determine the adjustment direction of the cooling intensity of the partitioned air nozzle, the current of the linear motor, the frequency of the linear motor, and the parameters of the edge-pulling machine by reducing J, so that the lateral temperature difference of the tin bath forming area is reduced to within 3℃ or to within the preset lateral temperature difference threshold.

[0015] The present invention has the following beneficial effects: 1. Through the synergistic effect of bottom zoned air nozzle cooling, edge heat preservation, linear motor regulation of molten tin flow, backflow suppression by baffles, and centering control of the glass strip, the temperature distribution in the molten tin bath forming area along the width of the glass strip is made more uniform, effectively reducing the lateral temperature difference between the edge and the center. 2. Based on the heat dissipation differences between the edge, sub-edge and center, the present invention adopts a zoned cooling method with increasing cooling intensity from the edge to the center, and is combined with the insulation structure of the edge sidewall and breast wall to reduce the problems of excessive cooling at the edge and insufficient cooling in the center. 3. By using a linear motor to drive the molten solder in a directional manner, and in conjunction with immersion baffles and knife handle baffles to slow down the backflow of cold molten solder at the edges, dead zones and backflow disturbances in the molten solder can be reduced, thereby improving the flow stability of the molten solder in the forming zone. 4. With the reduction of transverse temperature difference, the viscosity, fluidity and cooling contraction state of the glass strip are more consistent in the width direction, which can reduce defects such as thickness difference, plate deformation and optical distortion, and improve the glass yield and appearance quality. 5. This invention allows for the adjustment of nozzle aperture, linear motor parameters, baffle configuration, and edge-pulling machine parameters according to different board widths, production capacities, and solder bath conditions, making it easy to implement on existing production lines. At the same time, it can reduce ineffective heat dissipation and excessive cooling, reduce energy consumption, and improve the stability of continuous production. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall structure of the transverse temperature difference control system for the tin bath forming area of ​​float glass according to the present invention; Figure 2 This is a schematic diagram of the arrangement of temperature measuring points in the width direction of the tin bath forming area according to the present invention. Figure 3 This is a schematic diagram showing the relationship between the cooling intensity of the zoned nozzle orifice of the present invention; Figure 4 This is a flowchart of the closed-loop collaborative control of the present invention; Figure 5 This is a schematic diagram of the thermal insulation structure of the present invention; Figure 6 This is a schematic diagram of the glass strip centering control of the present invention; Figure 7 This is a flowchart of the overall control method of the present invention. Detailed Implementation

[0017] Example 1: Zoned Air Nozzle Cooling Control Example like Figure 1 , Figure 2 , Figure 3 and Figure 7 As shown, this embodiment provides a method for controlling the lateral temperature difference in the tin bath forming area based on bottom-partitioned air nozzle cooling; The solder bath forming area is divided into a left side section, a left secondary side section, a central section, a right secondary side section, and a right side section along the width of the glass strip. Temperature measuring points are set up in each section to collect the temperature values ​​of the corresponding area. These temperature measuring points can be thermocouples, infrared thermometers, or other temperature detection devices suitable for the high-temperature environment of the solder bath. The control system collects real-time temperature values ​​from each temperature measuring point and calculates the lateral temperature difference in the solder bath forming area. ; in, The temperature values ​​are the values ​​of n temperature measuring points arranged along the width of the glass strip; when the transverse temperature difference ΔT is greater than the preset transverse temperature difference threshold, the system starts the zoned cooling adjustment. like Figure 3 As shown, the cooling nozzles at the bottom of the tank are arranged with increasing cooling intensity from the edges to the center. The edge zone uses nozzles with smaller effective flow orifice diameters, the secondary edge zone uses nozzles with medium effective flow orifice diameters, and the central zone uses nozzles with larger effective flow orifice diameters. This method reduces overcooling in the edge zone and provides stronger cooling in the central zone, thus improving the problem of lower temperatures at the edges and higher temperatures in the central zone. In one embodiment, the effective flow orifice diameter of the edge zone nozzle is 8mm to 30mm, the effective flow orifice diameter of the secondary edge zone nozzle is 18mm to 45mm, and the effective flow orifice diameter of the central zone nozzle is 35mm to 80mm, and satisfies the following: ; in, These represent the effective flow apertures of the nozzles in the edge zone, sub-edge zone, and central zone, respectively. In another implementation, the zoned air nozzles can be replaceable nozzles, adjustable-opening nozzles, or nozzles with orifice plates. The system can change the effective flow diameter and cooling air volume of the corresponding zone by replacing the nozzles, adjusting the nozzle opening, or adjusting the flow area of ​​the orifice plate. In this embodiment, Figure 1 Used to represent the overall relationship of the transverse temperature difference control system in the tin bath forming area; Figure 2 Used to indicate the width-direction partitions and the arrangement of temperature measuring points; Figure 3 Used to indicate the correspondence between nozzle orifice diameter and cooling intensity; Figure 7 Used to represent the execution flow of the overall control method; The control method of this embodiment can make the cooling distribution at the bottom of the tin bath more consistent with the heat load difference between the edge and the middle without significantly changing the main structure of the tin bath, thereby reducing the lateral temperature difference in the tin bath forming area.

[0018] Example 2: Composite Insulation and Tin Molten Flow Regulation Example: like Figure 1 , Figure 4 , Figure 5 and Figure 7 As shown, this embodiment, based on embodiment one, further incorporates edge composite insulation, linear motor active drive of molten solder flow, and baffle to suppress the backflow of cold molten solder at the edges; like Figure 5 As shown, the sidewalls of the tin bath forming area are equipped with reinforced insulation structures, and the breast wall is equipped with a high-temperature resistant composite insulation structure. The composite insulation structure may include a sillimanite material layer, a mullite material layer, or a sillimanite-mullite composite material layer. Through the combined insulation of the sidewalls and the breast wall, heat loss at the edges of the tin bath forming area can be reduced, mitigating the phenomenon of low edge temperatures. Linear motors are installed at corresponding positions on the pair of edge-pulling machines located at the downstream end along the glass belt running direction. The working position of the linear motor maintains an adjustable distance from the molten solder surface and the side wall of the molten solder bath. The control system directionally drives the molten solder by adjusting the current, frequency, pole pitch, height of the working head from the molten solder surface, and distance between the working head and the side wall of the molten solder bath of the linear motor. In one embodiment, the linear motor has a current adjustment range of 70A to 160A and a frequency adjustment range of 5Hz to 60Hz. When the temperature of the edge area is lower than that of the middle area and the lateral temperature difference exceeds a preset lateral temperature difference threshold, the control system increases the current or frequency of the linear motor to enhance the directional driving capability of the molten solder and reduce the backflow of cold molten solder at the edge. The edge of the solder bath forming area is also provided with submersible baffles and knife-handle baffles. The submersible baffles and knife-handle baffles can be arranged alternately or in sections along the edge of the solder bath forming area to block, slow down or change the backflow path of the low-temperature solder liquid at the edge; in one embodiment, 6 to 16 pairs of submersible baffles and 1 to 6 pairs of knife-handle baffles are provided; like Figure 4 As shown, the control system performs closed-loop coordinated adjustment of the cooling intensity of the partitioned air nozzles, the operating parameters of the linear motor, and the parameters of the edge-pulling machine based on the lateral temperature difference, the degree of temperature asymmetry between the left and right sides, the offset of the glass strip center, and the backflow status of the cold tin liquid at the edge. In this embodiment, Figure 4 Used to represent closed-loop collaborative control processes; Figure 5 Used to indicate the composite insulation structure at the side walls and breast walls; Figure 7 Used to represent the logical relationships between various control steps in an overall control method; The control method in this embodiment can simultaneously improve the low temperature problem at the edge from two aspects: "reducing heat dissipation at the edge" and "suppressing the backflow of cold solder at the edge", making the temperature field of the solder bath forming area more stable.

[0019] Example 3: Composite Insulation and Tin Molten Flow Regulation Example: like Figure 2 , Figure 4 , Figure 6 and Figure 7 As shown, this embodiment provides a closed-loop collaborative control method that combines glass strip centering control; like Figure 6 As shown, when the glass ribbon is running in the solder bath, the control system detects the offset of the glass ribbon's centerline relative to the solder bath's centerline. The glass ribbon's center offset is calculated using the following formula: ; in, This is the position of the center line of the glass strip. The position of the center line of the solder bath; when When the offset exceeds the preset allowable amount, adjust the position, speed or angle of the left and right edge pulling machines so that the center line of the glass strip gradually approaches the center line of the tin bath. In one implementation, the difference in the positioning of the edge-pulling machines on the left and right sides is controlled within the range of 30mm to 120mm per edge-pulling machine. By controlling the centering of the glass strip, the asymmetry of heat dissipation distance and cooling conditions on the left and right sides can be reduced, thereby reducing lateral temperature fluctuations on one side. like Figure 4 As shown, during the closed-loop coordinated control process, the control system calculates the evaluation values ​​of the temperature difference between the middle and the edges and the left-right asymmetry: ; ; in, Temperature in the central region, This represents the combined temperature of the left-side edge region and the left-side sub-edge region. The combined temperature of the right-side edge region and the right-side sub-edge region; When B is greater than 0 and the lateral temperature difference exceeds the preset threshold, it indicates that the temperature in the middle is higher than that at the edge. The control system increases the cooling intensity of the corresponding air nozzle in the middle area and decreases or maintains the cooling intensity of the corresponding air nozzle in the edge area. When the absolute value of A is greater than the preset asymmetry threshold, it indicates that the temperature distribution on the left and right sides is asymmetrical. The control system prioritizes adjusting the glass strip alignment parameters and adjusts the drive parameters of the corresponding linear motor as needed. In a preferred embodiment, the closed-loop control objective function is: ; Where J is the control objective function, ΔT is the lateral temperature difference, ΔT0 is the target lateral temperature difference, and A is the left-right asymmetry evaluation value. R represents the offset of the glass ribbon center, R represents the intensity of the cold solder reflux at the edge, and Q represents the cooling energy consumption or airflow deviation per unit time. These are the weighting coefficients; The control system determines the adjustment direction of the zoned air nozzle cooling intensity, linear motor current, linear motor frequency, edge-pulling machine position, edge-pulling machine speed, or edge-pulling machine angle by reducing the control objective function J. In this embodiment, Figure 2 Used to indicate the arrangement of temperature measuring points and temperature zones in the width direction; Figure 4 Used to represent closed-loop collaborative control logic; Figure 6 Used to indicate the offset between the center line of the glass strip and the center line of the tin bath, and to adjust the centering; Figure 7 Used to represent the overall control method flow; The control method in this embodiment can simultaneously consider lateral temperature difference, left-right asymmetry, glass strip offset, molten solder reflux state, and cooling energy consumption, making the control results more stable and applicable to production conditions with different board widths, different production capacities, and different molten solder bath thermal states.

[0020] Example 4: Adaptive Adjustment Example under Different Board Width Conditions like Figure 2 , Figure 3 , Figure 4 and Figure 7 As shown, this embodiment provides an adaptive adjustment method applicable to different board widths or different production capacity conditions; When the width of the glass plate, the width of the tin bath, or the production drawing amount changes, the heat load and heat dissipation conditions of each zone change accordingly. The control system adaptively adjusts the effective flow diameter or air volume of the air nozzles in each zone based on the temperature values ​​collected from the temperature measuring points in each zone. In one implementation, the effective flow aperture of each zone's air nozzle is determined according to the following relationship: ; in, The effective flow orifice diameter selected for the i-th partition. Let i be the temperature of the i-th partition. The lowest temperature in each zone. Where D represents the highest temperature in each zone, and D is the set of available effective flow orifice diameters. This indicates that the orifice diameter closest to the calculated value is selected from the set of available effective flow orifice diameters; Higher temperature zones are configured with larger effective flow orifices or larger cooling air volumes, while lower temperature zones are configured with smaller effective flow orifices or smaller cooling air volumes. This ensures that the basic control logic of increasing cooling intensity from the edges to the center is maintained under different board widths and production capacity conditions. When the lateral temperature difference decreases to the target range, the control system maintains the current cooling intensity of the zone air nozzles, the operating parameters of the linear motor, and the control parameters of the edge-pulling machine; when the lateral temperature difference exceeds the preset threshold again, the closed-loop coordinated adjustment is re-executed. In this embodiment, Figure 3 Used to represent the relationship between the effective flow passage diameter of different air nozzles and the cooling intensity; Figure 4 Used to represent the closed-loop control logic corresponding to adaptive adjustment; Figure 7 Used to represent the cyclic execution process of a global method; Through the adaptive adjustment method of this embodiment, the present invention can adapt to different production specifications, avoid temperature field imbalance caused by fixed cooling structure or fixed control parameters, and improve the flexibility and stability of production line operation.

Claims

1. A method for controlling the transverse temperature difference in the tin bath forming zone of float glass, characterized in that, The solder bath forming zone is the area between the solder bath inlet side and the forming stable section. This control method includes the following steps: S1. Collect the temperature values ​​of multiple temperature measuring points arranged along the width direction of the glass strip in the tin bath forming area, and obtain the offset of the glass strip centerline relative to the tin bath centerline. S2. Divide the tin bath forming area along the width direction into the left side area, the left secondary side area, the middle area, the right secondary side area, and the right side area; S3. A partitioned air nozzle cooling structure is set on the outer side of the bottom shell of the tin bath forming area, so that the left side area and the right side area are equipped with air nozzles with the first effective flow diameter, the left secondary side area and the right secondary side area are equipped with air nozzles with the second effective flow diameter, and the middle area is equipped with air nozzles with the third effective flow diameter. The first effective flow diameter is smaller than the second effective flow diameter, and the second effective flow diameter is smaller than the third effective flow diameter, so as to form a partitioned cooling method of the bottom of the tank with increasing cooling intensity from the edge to the middle. S4. Strengthen the insulation of the side walls of the tin bath forming area and set a high-temperature resistant composite insulation structure in the breast wall of the tin bath to reduce heat loss at the edge. S5. Linear motors are installed at the corresponding positions of the pair of edge-pulling machines located at the downstream end along the glass belt running direction. By adjusting the current, frequency, pole pitch, height of the working head from the molten tin surface, and distance between the working head and the side wall of the molten tin bath of the linear motor, the molten tin is driven in a directional manner to suppress the backflow of cold molten tin at the edge to the center of the forming area. S6. A baffle structure is set at the edge of the solder bath forming area to slow down the backflow of low-temperature solder liquid at the edge and weaken the dead zone of solder liquid. S7. Adjust the position, speed or angle of the left and right edge pulling machines to keep the center line of the glass strip near the center line of the tin bath. S8. Based on the temperature value and the offset, the cooling intensity of the partitioned air nozzle, the operating parameters of the linear motor, the configuration parameters of the retaining wall, and the parameters of the edge pulling machine are adjusted in a closed loop to reduce the lateral temperature difference in the tin bath forming area to the target range.

2. The method for controlling the transverse temperature difference in the tin bath forming zone of float glass according to claim 1, characterized in that, The transverse temperature difference ΔT in the solder bath forming zone is calculated using the following formula: ； in, The temperature values ​​are the n temperature measuring points arranged along the width of the glass strip; when ΔT is greater than the preset transverse temperature difference threshold ΔT0, the closed-loop coordinated adjustment in step S8 is executed.

3. The method for controlling the transverse temperature difference in the tin bath forming zone of float glass according to claim 1, characterized in that, In step S3, the first effective flow orifice diameter d1, the second effective flow orifice diameter d2, and the third effective flow orifice diameter d3 satisfy the following relationship: ； ； ； And it satisfies: ; This results in the cooling intensity of the edge region being lower than that of the sub-edge region, and the cooling intensity of the sub-edge region being lower than that of the central region.

4. The method for controlling the transverse temperature difference in the tin bath forming zone of float glass according to claim 3, characterized in that, The first effective flow orifice diameter d1, the second effective flow orifice diameter d2, and the third effective flow orifice diameter d3 further satisfy the following orifice diameter ratio relationship: ； Furthermore, the partitioned air nozzle cooling structure includes replaceable air nozzles, adjustable opening air nozzles, or air nozzles with throttling orifice plates; by replacing the air nozzles, adjusting the air nozzle opening, or adjusting the flow area of ​​the throttling orifice plate, the effective flow diameter and cooling air volume of the corresponding partition can be changed.

5. The method for controlling the transverse temperature difference in the tin bath forming zone of float glass according to claim 1, characterized in that, In step S3, the effective flow aperture of each zone's air nozzle is determined according to the following relationship for different plate widths or different production capacity conditions: ； in, The effective flow orifice diameter selected for the i-th partition. Let i be the temperature of the i-th partition. The lowest temperature in each zone. Where D represents the highest temperature in each zone, and D is the set of available effective flow orifice diameters. This indicates that the orifice diameter closest to the calculated value is selected from the set of optional effective flow orifices; the zone with higher temperature is configured with a larger effective flow orifice diameter, and the zone with lower temperature is configured with a smaller effective flow orifice diameter; dmin is the smallest orifice diameter in the set of optional effective flow orifices D, and dmax is the largest orifice diameter in the set of optional effective flow orifices D.

6. The method for controlling the transverse temperature difference in the tin bath forming zone of float glass according to claim 1, characterized in that, In step S4, the high-temperature resistant composite insulation structure includes one or more of the following: sillimanite material layer, mullite material layer, and sillimanite-mullite composite material layer; the reinforced insulation of the side walls and the cooling structure of the trough bottom partitioned air nozzles work together to reduce heat loss in the side area and enhance the cooling capacity of the middle area.

7. The method for controlling the transverse temperature difference in the tin bath forming zone of float glass according to claim 1, characterized in that, In step S5, the current adjustment range of the linear motor is 70A to 160A, and the frequency adjustment range is 5Hz to 60Hz. When the temperature of the edge area is lower than that of the middle area and the lateral temperature difference is greater than the preset lateral temperature difference threshold, the current or frequency of the linear motor is increased to enhance the directional drive of the molten solder and increase the temperature of the edge area.

8. The method for controlling the transverse temperature difference in the tin bath forming zone of float glass according to claim 1, characterized in that, In step S6, the retaining structure includes submerged retaining structures and knife-handle retaining structures. There are 6 to 16 pairs of submerged retaining structures and 1 to 6 pairs of knife-handle retaining structures. The submerged retaining structures and the knife-handle retaining structures are arranged alternately or in segments along the edge of the tin bath forming area, so as to jointly suppress the backflow of cold tin liquid at the edge with the directional drive of molten tin generated by the linear motor.

9. The method for controlling the transverse temperature difference in the tin bath forming zone of float glass according to claim 1, characterized in that, In step S7, the offset of the glass strip centerline Calculate using the following formula: ； in, This is the position of the center line of the glass strip. The position of the center line of the solder bath; when When the offset exceeds the preset allowable amount, adjust the position, speed or angle of the left and right edge-pulling machines to control the difference in position between the left and right edge-pulling machines within the range of 30mm to 120mm per edge-pulling machine, and reduce the lateral temperature difference between the left and right sides of the tin bath forming area.

10. The method for controlling the transverse temperature difference in the tin bath forming zone of float glass according to claim 1, characterized in that, In step S8, closed-loop coordinated regulation includes calculating the evaluation value B of the temperature difference between the middle and the edge, the evaluation value A of the left and right asymmetry, and the control objective function J, where: ； ； ； In the formula, Temperature in the central region, This represents the combined temperature of the left-side edge region and the left-side sub-edge region. The combined temperature of the right-side edge region and the right-side sub-edge region is given by ΔT, where ΔT is the lateral temperature difference and ΔT0 is the target lateral temperature difference. R represents the offset of the glass strip centerline, R represents the intensity of the cold solder reflux at the edge, and Q represents the cooling energy consumption or airflow deviation per unit time. The weighting coefficient is used to determine the adjustment direction of the cooling intensity of the partitioned air nozzle, the current of the linear motor, the frequency of the linear motor, and the parameters of the edge-pulling machine by reducing J, so that the lateral temperature difference of the tin bath forming area is reduced to within 3℃ or to within the preset lateral temperature difference threshold.

Images