Integrated optical fiber electrode and self-calibration collaborative control system and glass melting furnace

Abstract

The application provides an integrated optical fiber electrode, a self-calibration cooperative control system and a glass melting furnace.The integrated optical fiber electrode comprises an electrode body, a multi-core optical fiber and an optical fiber coupler.The self-calibration cooperative control system comprises the integrated optical fiber electrode, a signal processing module, a self-calibration module and a control module.The glass melting furnace comprises a melting furnace body and the integrated optical fiber electrode.The application realizes the spatial unification of the temperature measuring point and the electrode heating point, eliminates the spatial distance between the measuring point and the heating point in the traditional separated layout, and effectively improves the real-time performance and control accuracy of the temperature feedback.

Description

Technical Field

[0001] This invention relates to the field of electro-assisted melting technology, specifically to an integrated optical fiber electrode and a self-calibrating collaborative control system, and a glass melting furnace. Background Technology

[0002] In electric melting systems for glass melting furnaces, the electrodes, as the core heating elements, directly affect the temperature distribution and glass melting quality within the furnace. In traditional electric melting systems, the temperature measuring device and the electrodes are typically separated. The temperature sensor is installed on the furnace wall or bottom, while the electrode is inserted into the furnace from another location. This arrangement results in a significant spatial distance between the temperature measuring point and the electrode heating point, creating an inherent spatial positioning error. When the control system adjusts the electrode power based on the temperature data collected by the separate sensors, the spatial misalignment between the actual heating position and the temperature feedback position causes inherent control lag, making precise local temperature regulation difficult.

[0003] To address the aforementioned issues, existing technologies attempt to improve temperature field monitoring accuracy by increasing the density of sensor deployment or employing distributed fiber optic temperature measurement networks. However, these improvements only increase the number of temperature measurement points and do not change the fundamental structure of separating temperature measurement from heating execution; the spatial misalignment problem between temperature measurement points and heating points still exists. Summary of the Invention

[0004] To address the technical problems existing in the background art, this invention proposes an integrated optical fiber electrode and a self-calibration collaborative control system, as well as a glass melting furnace.

[0005] This invention proposes an integrated optical fiber electrode, comprising: an electrode body, a multi-core optical fiber, and an optical fiber coupler, wherein: The electrode body has an axially penetrating channel inside; A multi-core optical fiber is disposed in the channel of the electrode body. The multi-core optical fiber includes at least a temperature sensing fiber core for measuring the temperature distribution on the surface of the electrode body and a current sensing fiber core for measuring the current distribution of the electrode body itself. Fiber optic couplers connect to multi-core optical fibers and are used for optical signal input / output of the multi-core optical fibers.

[0006] Preferably, the multi-core optical fiber also includes a strain-sensing core for measuring the thermal expansion deformation of the electrode body.

[0007] Preferably, multiple temperature sensing fiber cores, current sensing fiber cores, and strain sensing fiber cores are provided, wherein: the current sensing fiber core is located in the central area of ​​the multi-core cable, and the temperature sensing fiber core and strain sensing fiber core are located on the periphery of the multi-core optical fiber, and the grating area of ​​the temperature sensing fiber core faces the outer wall of the electrode body.

[0008] Preferably, the current sensing fiber core is made of magneto-optical fiber; the strain sensing fiber core is made of fiber Bragg grating structure.

[0009] Preferably, the outer wall of the electrode body is provided with an axially spirally arranged spiral groove and an auxiliary temperature measuring optical fiber embedded in the spiral groove.

[0010] Preferably, the spiral groove is axially divided into a lower spiral segment and an upper spiral segment along the lower end to the upper end of the electrode body, and the pitch of the lower spiral segment is smaller than the pitch of the upper spiral segment.

[0011] Preferably, the pitch of the lower helical section is 10-20 mm, and the pitch of the upper helical section is 30-50 mm.

[0012] The self-calibration collaborative control system proposed in this invention includes the integrated fiber optic electrode described above, and further includes a signal processing module, a self-calibration module, and a control module, wherein: The signal processing module is connected to the fiber optic coupler to demodulate the optical signals of the temperature sensing fiber core and the current sensing fiber core, and to calculate the temperature gradient vector field on the surface of the electrode body and the current density vector field inside the electrode body. The self-calibration module is connected to the signal processing module to establish the electrode resistance-temperature relationship curve and correct the zero-point drift of the temperature sensing fiber core. The control module is connected to the signal processing module, the self-calibration module, and the power supply of the electrode body. It is used to adjust the current phase and amplitude of the electrode body according to the temperature gradient vector field and the current density vector field.

[0013] Preferably, the control module adopts a two-layer collaborative control architecture, wherein: The first layer is a single-electrode closed-loop control, which aims to minimize the temperature gradient vector field on the electrode surface and independently adjusts the current phase and amplitude of each electrode. The second layer is a multi-electrode collaborative control system, in which adjacent electrodes exchange temperature distribution and current parameters and collaboratively adjust the phase combination to ensure that Joule heat is evenly distributed between the electrodes.

[0014] Preferably, the multi-electrode collaborative control employs a distributed optimization algorithm, aiming to maximize the global temperature uniformity index, and iteratively solves for the optimal phase combination of each electrode.

[0015] Preferably, the self-calibration module is configured to perform the following operations: The theoretical electrode resistance is calculated based on the resistivity-temperature characteristics of the electrode body material. Calculate the actual electrode resistance based on the total current measured by the current sensing fiber core and the actual voltage measured at both ends of the electrode body. The actual electrode resistance is compared with the theoretical electrode resistance, and the deviation rate between the two is calculated. When the deviation rate exceeds the preset threshold, it is determined that there is a drift in the temperature sensing fiber core, and the calibration mode is automatically entered to adjust the wavelength-temperature relationship curve coefficient of the temperature sensing fiber core so that the average temperature of all temperature measurement points is consistent with the reference temperature.

[0016] The present invention proposes a glass melting furnace, comprising: a melting furnace body; and an integrated optical fiber electrode as described above, wherein the integrated optical fiber electrode is inserted inside the melting furnace body.

[0017] This invention integrates an axially continuous channel within the electrode body, embedding a multi-core optical fiber within this channel. This creates a unified structure between the temperature sensing core and the current sensing core, achieving spatial unification between the temperature measurement point and the electrode heating point. This eliminates the spatial distance between the measurement and heating points in traditional separate layouts, reducing spatial positioning errors from hundreds of millimeters to the millimeter level. Consequently, it effectively improves the real-time performance and control accuracy of temperature feedback. Simultaneously, it reduces the number of openings in the melting furnace, lowering the safety risk of molten glass leakage. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of an integrated optical fiber electrode proposed in this invention; Figure 2 This is a structural block diagram of a self-calibration cooperative control system proposed in this invention. Detailed Implementation

[0019] Example 1: Integrated Fiber Optic Electrode Reference Figure 1 The present invention proposes an integrated optical fiber electrode, comprising: an electrode body 1, a multi-core optical fiber 2, and an optical fiber coupler.

[0020] The electrode body 1 is made of molybdenum or a molybdenum alloy. An axially penetrating channel is provided inside the electrode body 1 to accommodate a multi-core optical fiber 2. The outer wall of the electrode body 1 is machined with a spiral groove and an auxiliary temperature-sensing optical fiber 3 embedded within the spiral groove. The spiral groove is axially divided into a lower spiral section and an upper spiral section from the lower end of the electrode body 1 towards its upper end: the lower spiral section corresponds to the lower region where the electrode is inserted deeper into the molten glass; the upper spiral section corresponds to the upper region of the electrode, and the pitch of the lower spiral section is smaller than that of the upper spiral section. This variable pitch design allows for a denser concentration of temperature measurement points in the lower region of the electrode body 1 with a larger temperature gradient, and a sparser concentration in the upper region with a smaller temperature gradient, ensuring measurement accuracy in critical areas while reducing the cost of optical fiber deployment.

[0021] As a further preferred embodiment, the pitch of the lower helical section is 10-20mm, and the pitch of the upper helical section is 30-50mm.

[0022] As a further preferred option in this embodiment, the auxiliary temperature measuring fiber 3 is a single-mode fiber and is fixed to the bottom of the spiral groove with high-temperature adhesive. The surface of the spiral groove is covered with a zirconium oxide protective layer to prevent glass melt corrosion.

[0023] A multi-core optical fiber 2 is disposed within the central channel of the electrode body 1 and fixed to the inner wall of the channel with high-temperature ceramic adhesive. A seven-core optical fiber structure is adopted, specifically distributed as follows: from the center outwards, two current-sensing fiber cores are placed in the central area, and three temperature-sensing fiber cores and two strain-sensing fiber cores are placed on the periphery. Specifically, the grating positions of each temperature-sensing fiber core are staggered along the axial direction, and the grating area of ​​the temperature-sensing fiber core is aligned with the outer wall of the electrode to ensure minimal distance (approximately 10 mm) between the temperature measurement point and the electrode surface, thereby accurately measuring the temperature distribution on the electrode surface. The current-sensing fiber cores use magneto-optical fiber, which operates based on the Faraday effect. When current passes through the electrode, the magnetic field generated causes the polarization plane of the light transmitted in the fiber to rotate, and the rotation angle is proportional to the current intensity. By measuring the rotation angle, the current distribution inside the electrode can be inverted. The strain-sensing fiber cores use a fiber Bragg grating structure. When the electrode expands due to heat, the period of the grating changes, causing a drift in the reflected wavelength. By measuring the wavelength drift, the axial strain can be calculated.

[0024] The fiber optic coupler is encapsulated in high-temperature resistant ceramic material and integrates a multi-core fiber 2 fan-out structure, which separates the seven cores of the multi-core fiber 2 into independent single-core fibers for easy connection to the temperature demodulator, current demodulator and strain demodulator respectively.

[0025] Example 2: Self-calibration Cooperative Control System Reference Figure 2 This embodiment provides a self-calibration collaborative control system, which includes the integrated fiber optic electrode described in Embodiment 1, and also includes a signal processing module, a self-calibration module and a control module.

[0026] The signal processing module is connected to the fiber optic coupler and is used to demodulate the optical signals of the temperature sensing fiber core and the current sensing fiber core, and to calculate the temperature gradient vector field on the surface of electrode body 1 and the current density vector field inside electrode body 1. Specifically, it can adopt the following structural design: The signal processing module includes an optical signal demodulator and a data processing unit. The optical signal demodulator contains three independent channels: a temperature demodulation channel for demodulating the grating wavelength signals of the temperature sensing fiber core and the auxiliary temperature measurement fiber 3; a current demodulation channel for measuring the Faraday rotation angle of the current sensing fiber core; and a strain demodulation channel for demodulating the wavelength signal of the strain sensing fiber core. The data processing unit adopts an FPGA plus ARM dual-core architecture. The FPGA is responsible for high-speed data acquisition and preprocessing, while the ARM is responsible for complex algorithm calculations. The data processing unit calculates the following parameters in real time: ①Electrode surface temperature distribution: Based on the wavelength data of the temperature sensing fiber core and the auxiliary temperature measuring fiber 3, combined with the spatial position encoding of each grating, the three-dimensional temperature distribution of the electrode surface is reconstructed using an interpolation algorithm, including temperature information in two dimensions: axial coordinate and circumferential angle.

[0027] ②Electrode surface temperature gradient: Based on the reconstructed temperature distribution, calculate the rate of temperature change in the axial and circumferential directions, and synthesize the temperature gradient vector field.

[0028] ③ Current distribution inside the electrode: Based on the Faraday rotation angle data of the current sensing fiber core and combined with the geometric parameters of the electrode, the distribution of current density along the axial direction and the total current value are inverted.

[0029] ④ Electrode thermal expansion: The axial strain at each measuring point is calculated based on the wavelength change of the strain sensing fiber core, and the total expansion is obtained by integrating along the axial direction.

[0030] The self-calibration module is connected to the signal processing module and is used to establish the electrode resistance-temperature relationship curve and correct the zero-point drift of the temperature sensing fiber core. The self-calibration module runs the following program: First, the theoretical electrode resistance is calculated based on the resistivity-temperature characteristics of the electrode body 1 material. Specifically, the resistivity of the electrode body 1 material increases with increasing temperature; the theoretical resistance value is obtained by integrating the ratio of resistivity to cross-sectional area along the electrode axis.

[0031] Secondly, the actual electrode resistance is calculated based on the total current measured by the current sensing fiber core and the measured voltage across electrode body 1. Specifically, the actual resistance is equal to the ratio of voltage to current.

[0032] Then, the actual electrode resistance is compared with the theoretical electrode resistance, and the deviation rate between the two is calculated. When the deviation rate exceeds a preset threshold (5% in this embodiment), it is determined that the temperature sensing fiber core has drifted, and the system automatically enters calibration mode.

[0033] The self-calibration module operates on the following principle: In calibration mode, the average temperature of electrode body 1 is calculated using thermal expansion data measured by the strain sensing fiber core. Based on this calculated average temperature, the wavelength-temperature relationship curve coefficient of the temperature sensing fiber core is adjusted to ensure the average temperature at all measurement points matches the reference temperature, thus completing the calibration process. Specifically, since the thermal expansion coefficient of electrode body 1 is known, the average temperature of the electrode can be deduced by measuring the total expansion of the electrode.

[0034] After calibration is complete, the system will automatically exit calibration mode. The self-calibration program will execute automatically at regular intervals or be triggered when the deviation rate exceeds a threshold.

[0035] The control module is connected to the signal processing module, the self-calibration module, and the power supply of electrode body 1. It is used to adjust the current phase and amplitude of electrode body 1 based on the temperature gradient vector field and the current density vector field. The control module adopts a two-layer collaborative control architecture, wherein: The first layer is a single-electrode closed-loop control: aiming to minimize the temperature gradient vector field on the electrode surface, it independently adjusts the current phase and amplitude of each electrode. Specifically, each electrode is equipped with an independent controller. The controller's input is the magnitude of the temperature gradient vector field on the electrode surface, and its output is the current phase adjustment. The control objective is to minimize the temperature gradient on the electrode surface, making the temperature at all points on the electrode surface tend to be uniform. The controller uses a proportional-integral-derivative (PID) control algorithm, gradually reducing the temperature gradient by adjusting the current phase.

[0036] The second layer is multi-electrode collaborative control: adjacent electrodes exchange temperature distribution and current parameters, and collaboratively adjust phase combinations to ensure a uniform distribution of Joule heat among the electrodes. Specifically, adjacent electrodes form a collaborative group, exchanging their respective temperature distribution and current parameters via a communication bus. Within the collaborative group, a distributed optimization algorithm is used to iteratively solve for the optimal phase combination of each electrode, aiming to maximize the global temperature uniformity index. The global temperature uniformity index is defined as the ratio of the reciprocal of the temperature standard deviation to the average temperature; a larger index indicates more uniform temperature. Through multiple iterations, the distributed optimization algorithm allows each electrode controller to gradually adjust its phase setpoint based on local temperature information and boundary temperature information transmitted from adjacent electrodes, ultimately making the temperature distribution within the collaborative group's coverage area tend towards uniformity.

[0037] In actual operation, when a temperature gradient appears on the surface of an electrode, the single-electrode closed-loop control responds first, independently adjusting the current phase of that electrode to eliminate the local gradient. When there is temperature unevenness between adjacent electrodes, multi-electrode collaborative control is activated. By coordinating the phase combination of each electrode, Joule heat is evenly distributed between the electrodes, achieving global temperature balance.

[0038] Example 3: Glass Melting Furnace This embodiment provides a glass melting furnace, including a furnace body, an electrode mounting base disposed on the furnace body, and the integrated optical fiber electrode described in the foregoing embodiment. The integrated optical fiber electrode is inserted into the furnace through the electrode mounting base, the power supply cable of the electrode is connected through a terminal block at the tail of the electrode, and the optical fiber coupler is connected to a signal processing module in the control room through an optical cable.

[0039] As a further preferred embodiment, a metal bellows compensation structure is provided between the fiber optic coupler and the furnace wall. The metal bellows compensation structure absorbs the axial displacement of the electrodes caused by thermal expansion during heating. A ceramic heat-insulating gasket is provided between the metal bellows compensation structure and the fiber optic coupler to reduce heat conduction into the coupler and protect the optical components within the fiber optic coupler.

[0040] During normal production, the signal processing module collects temperature and current data from each electrode in real time, the self-calibration module executes a self-calibration program periodically, and the control module dynamically adjusts the current phase and amplitude of each electrode based on the temperature gradient vector field and the current density vector field. When a temperature gradient increases in a certain area, the single-electrode closed-loop control responds first to the local adjustment of that electrode; when there is temperature unevenness between adjacent electrodes, the multi-electrode collaborative control coordinates the phase combination of each electrode through a distributed optimization algorithm to ensure that Joule heat is evenly distributed between the electrodes.

[0041] The above description is only a preferred embodiment 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. An integrated optical fiber electrode, characterized in that, include: Electrode body (1), multi-core optical fiber (2), and optical fiber coupler, wherein: The electrode body (1) has an axially penetrating channel inside; A multi-core optical fiber (2) is disposed in the channel of the electrode body (1). The multi-core optical fiber (2) includes at least a temperature sensing fiber core for measuring the surface temperature distribution of the electrode body (1) and a current sensing fiber core for measuring the current distribution of the electrode body (1) itself. The fiber optic coupler is connected to the multi-core fiber (2) for optical signal input / output of the multi-core fiber (2).

2. The integrated optical fiber electrode according to claim 1, characterized in that, The multi-core optical fiber (2) also includes a strain-sensing core for measuring the thermal expansion deformation of the electrode body (1).

3. The integrated optical fiber electrode according to claim 2, characterized in that, Multiple temperature sensing fiber cores, current sensing fiber cores and strain sensing fiber cores are provided. Among them, the current sensing fiber core is located in the central area of ​​the multi-core cable, and the temperature sensing fiber core and strain sensing fiber core are located on the periphery of the multi-core optical fiber (2). The grating area of ​​the temperature sensing fiber core faces the outer wall of the electrode body (1). Preferably, the current sensing fiber core is made of magneto-optical fiber; the strain sensing fiber core is made of fiber Bragg grating structure.

4. The integrated optical fiber electrode according to claim 1, characterized in that, The outer wall of the electrode body (1) is provided with an axially spiral groove and an auxiliary temperature measuring fiber (3) embedded in the spiral groove.

5. The integrated optical fiber electrode according to claim 4, characterized in that, The spiral groove is divided into a lower spiral section and an upper spiral section along the lower end of the electrode body (1) and its upper end, and the pitch of the lower spiral section is smaller than that of the upper spiral section.

6. A self-calibrating cooperative control system, comprising: The integrated fiber optic electrode according to any one of claims 1-5 further includes a signal processing module, a self-calibration module, and a control module, wherein: The signal processing module is connected to the fiber optic coupler to demodulate the optical signals of the temperature sensing fiber core and the current sensing fiber core, and to calculate the temperature gradient vector field on the surface of the electrode body (1) and the current density vector field inside the electrode body (1). The self-calibration module is connected to the signal processing module to establish the electrode resistance-temperature relationship curve and correct the zero-point drift of the temperature sensing fiber core. The control module is connected to the signal processing module, the self-calibration module, and the power supply of the electrode body (1) to adjust the current phase and amplitude of the electrode body (1) according to the temperature gradient vector field and the current density vector field.

7. The self-calibration and cooperative control system according to claim 6, characterized in that, The control module adopts a two-layer collaborative control architecture, in which: The first layer is a single-electrode closed-loop control, which aims to minimize the temperature gradient vector field on the electrode surface and independently adjusts the current phase and amplitude of each electrode. The second layer is a multi-electrode collaborative control system, in which adjacent electrodes exchange temperature distribution and current parameters and collaboratively adjust the phase combination to ensure that Joule heat is evenly distributed between the electrodes.

8. The self-calibration and collaborative control system according to claim 7, characterized in that, The multi-electrode collaborative control employs a distributed optimization algorithm, aiming to maximize the global temperature uniformity index, and iteratively solves for the optimal phase combination of each electrode.

9. The self-calibration and collaborative control system according to claim 6, characterized in that, The self-calibration module is configured to perform the following operations: The theoretical electrode resistance is calculated based on the resistivity-temperature characteristics of the electrode body material (1). The actual electrode resistance is calculated based on the total current measured by the current sensing fiber core and the actual voltage measured at both ends of the electrode body (1). The actual electrode resistance is compared with the theoretical electrode resistance, and the deviation rate between the two is calculated. When the deviation rate exceeds the preset threshold, it is determined that there is a drift in the temperature sensing fiber core, and the calibration mode is automatically entered to adjust the wavelength-temperature relationship curve coefficient of the temperature sensing fiber core so that the average temperature of all temperature measurement points is consistent with the reference temperature.

10. A glass melting furnace, comprising: The furnace body is characterized in that it further includes the integrated optical fiber electrode as described in any one of claims 1-5, wherein the integrated optical fiber electrode is inserted inside the furnace body.

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