Accurate heating control method, device and system for platinum heating body in cover plate and substrate glass manufacturing

Abstract

The invention provides a precise heating control method, device and system for a platinum heating body in cover plate and substrate glass manufacturing, and is characterized in that the control system is provided with a cascade PI controller, a temperature given slope, an output slope, an output limiter, a temperature detection unit, a current detection unit, an electric control regulator and a heating body, the cascade PI control controller is divided into a temperature PI controller, a current PI controller and an external temperature PI controller. The device is suitable for heating control of platinum heating bodies in the field of special glass industry, especially platinum material bowls.

Description

Technical Field

[0001] This invention relates to the field of special glass production technology, and more specifically, to a method, apparatus and system for controlling the heating of molten glass discharge using platinum as a heating carrier. Background Technology

[0002] In the specialty electronic glass industry, precise heating and temperature control of glass are used to achieve certain performance characteristics, making glass products easier to form and process. Alternatively, precise temperature control can be used to control the flow rate of molten glass, ensuring a constant output.

[0003] The inherent lag in temperature feedback control is a challenge for precise temperature control. Furthermore, the rapid cooling of the outer insulation layer and fluctuations in ambient temperature are detrimental to glass processing and glass flow control. Therefore, precise temperature control is of great importance to glass forming and processing.

[0004] To address the aforementioned issues, a method, apparatus, and system for precise heating control of platinum heating elements in the manufacture of cover glass and substrate glass are proposed. Summary of the Invention

[0005] In view of the defects and deficiencies of the existing technology, the present invention proposes a method, device and system for precise heating control of platinum heating element in the manufacturing of cover plate and substrate glass, which achieves precise temperature control through cascaded controllers.

[0006] The specific technical solution adopted is as follows: A method, apparatus, and system for precise heating control of a platinum heating element in the manufacture of cover glass and substrate glass are characterized by: a cascade PI controller, a temperature setpoint ramp, an output ramp, an output limiter, a temperature detection unit, a current detection unit, an electronic control regulator, and a heating carrier. The cascade PI controller is divided into a temperature PI controller, a current PI controller, and an external temperature PI controller.

[0007] The temperature PI controller uses a ramp-based temperature setting method, where the target temperature value is gradually given to the input of the temperature PI controller in a ramp manner, and the ramp is adjustable.

[0008] The temperature PI controller is connected to the temperature detection unit of the heating circuit; the current PI controller is connected to the current detection unit of the heating circuit. The external temperature PI controller is connected to the temperature detection unit of the external insulation layer.

[0009] The current loop output is configured with an output ramp and an output limiter. During control operation, both the slope of the output ramp and the output limiter value can be adjusted.

[0010] It is equipped with an electronic control regulator that acts directly on the heating medium, and the current of the heating medium is adjusted by regulating the voltage.

[0011] Temperature PI control and current PI control are cascaded, with temperature PI control as the outer loop and current PI control as the inner loop; the output of temperature PI control is used as the input of current PI control.

[0012] The temperature PI control deviation of the insulation layer is used as the input of the temperature PI control. The weighted output value of the temperature of multiple measuring points in the platinum heating body represents the temperature control point of the platinum heating body. The control deviation of the temperature control point is used as the input of the temperature PI controller of the insulation layer.

[0013] The weighted average of the temperatures at multiple measuring points within the platinum heating element is obtained from the thermal model and corrected using actual values. The correction coefficients can be manually input into the system.

[0014] The temperature PI controller calculates the control output based on the given value and the deviation value of the temperature detection unit. The calculated output value is then linearly converted and given to the input value of the current PI controller. The current PI controller calculates the output to the ramp calculation block based on the input value and the deviation value of the current detection unit.

[0015] The current loop output is given to the input of the output ramp block. The output ramp block gradually adjusts the rise and fall of the output value according to the set slope. The output value of the output ramp is given to the input value of the output limit. The output limit is judged according to the input value. If the input value is greater than the limit setting value, the output limit setting value is given to the electronic control regulator as the output value of the output limit. If the input value is less than or equal to the limit setting value, the input value is given as the output value of the limit output.

[0016] When the temperature PI controller is saturated, the input value of the current PI controller reaches its maximum value. By setting the output limit value, the current can be maintained, preventing the current output value from changing abruptly when the current sensing element is damaged. The adjustable limit output is also a protection measure for the heating medium. The output ramp function realizes the gradual adjustment of the output value. Fluctuations of external sensing elements do not affect the input of the electronic controller, thus achieving stable operation of the electronic controller. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the device composition according to an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Specific implementation examples are given below.

[0020] To make the features and advantages of this patent more apparent and understandable, specific examples are provided below for detailed explanation: Figure 1 This is a simplified on-site schematic diagram of the present invention, wherein 1 is a temperature setpoint ramp generator, 2 is a temperature PI controller, 3 is a current PI controller, 4 is a current loop output ramp generator, 5 is an output limiting controller, 6 is an electronic control regulator, 7 is a temperature detection element, 8 is a current detection element, 9 is a thermal insulation layer temperature detection element, and 10 is a steel structure layer temperature detection element.

[0021] In this embodiment, a platinum heating element is used as the heating carrier to control the flow rate of molten glass. The core of the flow rate control method is to control the temperature.

[0022] Preferably, the setpoint for the temperature PI control is given by a ramp, with a preset ramp rate of 0.015℃ / s. The ramp rate can be set according to the target temperature and the heating time. The actual temperature value of the temperature detection unit is fed back to the temperature PI control, and the temperature PI control calculates the control output.

[0023] Preferably, the output of the temperature PI control is linearized and then given to the input of the current PI control. The actual current value of the current detection unit is fed back to the current PI control, and the current PI control calculates the control output. Preferably, the output of the current PI control is given to an output ramp block with a ramp rate set to 0.01% / s. As the control continues, the output ramp gradually adjusts to the output limit. The inventors discovered that, under sufficient heating capacity, an excessively fast ramp output can rapidly raise the temperature, but this can cause the platinum current density to exceed the design value, and even lead to platinum wire breakage. To solve this problem, this system adds a ramp-based output given a ramp rate, while simultaneously superimposing a current saturation limit, ensuring safe and stable current control under sufficient heating capacity.

[0024] Preferably, the output value of the output ramp is given to the output limit, the output limit value is set to 80%, and the output limit is judged based on the set value and the input value. If the input value is greater than the output limit value, the output limit will output the set value to the electronic control regulator. If the input value is less than or equal to the output limit value, the output limit will output the input value to the electronic control regulator. Preferably, the electronic control regulator adjusts the current value of the heating circuit carrier according to the input value to raise the temperature.

[0025] Preferably, the temperature ramp generator operates continuously, with the set temperature value gradually adjusted. Temperature PI control and current PI control continuously provide outputs, and the output ramp adjusts the set value of the electronic controller according to the slope setting to slowly increase or decrease the current of the heating medium. As the temperature of the heating medium gradually rises to the set temperature value, the temperature control PI control and current PI control gradually decrease their outputs, and the output ramp gradually decreases the value of the electronic controller according to the slope setting, avoiding a sudden drop in the current of the heating medium and thus preventing temperature fluctuations.

[0026] Preferably, the output ramp is adjusted according to the slope setting value during the control process, so that sudden changes in the temperature detection unit and current detection unit during the control process cannot immediately affect the electronic control regulator.

[0027] Preferably, the output limiting is used to limit the value of the given electronic control regulator according to the output limiting setting value during the control process, so as to effectively control the current of the current heating carrier and protect the carrier of the heating circuit.

[0028] Based on the above design, the problem of temperature fluctuation during the heating process is solved, and precise temperature control is achieved. The slope of the current loop output ramp generator can be set according to the actual working conditions.

[0029] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method, apparatus, and system for precise heating control of a platinum heating element in the manufacture of cover glass and substrate glass, characterized in that, include: The secondary current of the platinum heating element and the body temperature at multiple measuring points within the heating element are obtained; the control point temperature is represented by the weighted average of the body temperatures at multiple measuring points. A platinum heating element temperature cascade controller, comprising a temperature PI controller and a current PI controller; an auxiliary electric heating device for the insulation layer; temperature detection of the insulation layer and the outer metal structure; and a method and strategy for cascade control of mixed inner and outer layer temperatures.

2. The method, apparatus, and system for precise heating control of a platinum heating element in the manufacture of cover glass and substrate glass according to claim 1, characterized in that: The temperature PI controller uses a ramp-based temperature setting method, where the target temperature value is gradually given to the input of the temperature PI controller in a ramp manner, and the ramp is adjustable. It is designed to prevent system disturbances caused by sudden changes in set values ​​and strain damage caused by sudden temperature rises or falls in the body.

3. The method, apparatus, and system for precise heating control of a platinum heating element in the manufacture of cover glass and substrate glass according to claim 1, characterized in that: The temperature PI controller is connected to the temperature detection unit of the heating circuit; the current PI controller is connected to the current detection unit of the heating circuit.

4. The method, apparatus, and system for precise heating control of a platinum heating element in the manufacture of cover glass and substrate glass according to claim 1, characterized in that: The current loop output is configured with an output ramp and an output limiter. During control operation, both the slope of the output ramp and the output limiter value can be adjusted.

5. The method, apparatus, and system for precise heating control of a platinum heating element in the manufacture of cover glass and substrate glass according to claim 1, characterized in that: It is equipped with a thyristor regulator that acts directly on the heating medium.

6. The method, apparatus, and system for precise heating control of a platinum heating element in the manufacture of cover glass and substrate glass according to claim 1, characterized in that: Temperature PI control and current PI control are cascaded, with temperature PI control as the outer loop and current PI control as the inner loop; the output of temperature PI control is used as the input of current PI control.

7. The method, apparatus, and system for precise heating control of a platinum heating element in the manufacture of cover glass and substrate glass according to claim 6, characterized in that: The temperature PI controller calculates the control output based on the given value and the deviation value of the temperature detection unit. The calculated output value is then linearly converted and given to the input value of the current PI controller. The current PI controller calculates the output and outputs it to the output ramp based on the input value and the deviation value of the current detection unit.

8. A method, apparatus, and system for precise heating control of a platinum heating element in the manufacture of cover glass and substrate glass according to any one of claims 1-7, characterized in that: The current loop output is given to the input of the output ramp. The output ramp gradually adjusts the rise and fall of the output value according to the set slope. The output value of the output ramp is given to the input value of the output limit. The output limit is judged according to the input value. If the input value is greater than the limit setting value, the output limit setting value is used as the output value of the output limit and given to the electronic control regulator. If the input value is less than or equal to the limit setting value, the input value is used as the output value of the limit output.

9. A method, apparatus, and system for precise heating control of a platinum heating element in the manufacture of cover glass and substrate glass according to any one of claims 1-8, characterized in that: When the temperature PI controller is saturated, the input value of the current PI controller reaches its maximum value. By setting the output limit value, the current can be maintained, preventing the current output value from changing abruptly when the current sensing element is damaged. The adjustable limit output is also a protection measure for the heating medium. The output ramp function realizes the gradual adjustment of the output value. Fluctuations of external sensing elements do not affect the input of the electronic controller, thus achieving stable operation of the electronic controller.

10. The method, apparatus, and system for precise heating control of a platinum heating element in the manufacture of cover glass and substrate glass according to claim 1, characterized in that: The temperature of the outer steel structure and the insulation layer of the platinum heating element participate in the system temperature control. The deviation of the external temperature is used as the setpoint of the temperature PI controller as described in claim 6 to eliminate the influence of external temperature changes on the temperature of the platinum heating element.

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