Continuous casting tundish temperature monitoring and erosion early warning method
By using a fiber optic Raman distributed temperature measurement system and a temperature-erosion rate dynamic model, the internal detection problem of temperature monitoring in continuous casting tundish was solved, enabling real-time monitoring and erosion early warning, and improving safety and automation management.
Patent Information
- Application Number
- CN202511123549.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-12
- Publication Date
- 2025-11-14
AI Technical Summary
In existing technologies, steel plants face problems in continuous casting tundish temperature monitoring, such as the inability to detect the internal structural temperature, increased labor intensity and safety hazards due to manual operation, and large measurement errors.
A fiber optic Raman distributed temperature measurement system is used for temperature monitoring. Combined with a temperature-erosion rate dynamic model, and through the laying of double-layer sensing optical fibers and real-time data analysis, real-time monitoring and erosion early warning of the intermediate tundish temperature are achieved.
It enables real-time monitoring of intermediate batch temperature, reduces the occurrence of batch penetration accidents, improves the level of automated management, reduces false alarm rate, and provides safe and reliable production assurance.
Smart Images
Figure CN120940600A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of metallurgical technology, and in particular relates to a method for monitoring temperature and providing early warning of corrosion in a continuous casting tundish. Background Technology
[0002] In recent years, with continuous technological advancements, the level of industrial production in human society has been greatly improved. However, as temperature safety issues in production and daily life have become increasingly prominent, people's concern about safety has also grown daily. In this process, high temperature, as an important physical quantity, plays a crucial role not only in daily life but also in scientific research and industrial production. Monitoring the temperature of the inner wall of the tundish in continuous casting of molten steel is of paramount importance in steel metallurgical sites. Currently, the most common temperature measurement methods used in steel plants are infrared thermal imaging or handheld infrared thermometers.
[0003] Infrared thermometers work by converting the infrared radiation emitted by an object into an electrical signal. The magnitude of the infrared radiation corresponds to the object's temperature. The temperature can be determined by the magnitude of the converted electrical signal. Because it doesn't require contact with the object, it doesn't interfere with the measured temperature field. Furthermore, it offers advantages such as a wide measurement range and high sensitivity. However, its disadvantages include its applicability only to surface measurements and its inability to detect the temperature of internal structures. Additionally, environmental interference (dust in the air) and complex background noise are limiting factors for accurate temperature measurement.
[0004] The handheld infrared thermometer is a manual operation, requiring periodic measurement of the walls and bottom of the tundish and manual recording of temperature data. The data cannot be effectively traced back. The disadvantages are: firstly, manual operation increases labor intensity; secondly, it is close to the high-temperature molten steel in the tundish, posing a safety hazard; and thirdly, manual measurement is prone to errors and cannot effectively guide safe production. Summary of the Invention
[0005] The purpose of this invention is to provide a method for monitoring temperature and providing early warning of erosion in continuous casting tundishes, so as to solve the problems existing in the prior art.
[0006] The technical solution adopted by this invention to solve its technical problem is:
[0007] A method for monitoring temperature and providing early warning of erosion in a continuous casting tundish includes the following steps:
[0008] (1) Temperature measurement system installation: Install a fiber optic Raman distributed temperature measurement system in the intermediate package to detect real-time temperature data at each monitoring point in the intermediate package;
[0009] (2) Erosion rate calculation: The erosion rate ER of each monitoring point is calculated based on the temperature-erosion rate dynamic model according to real-time temperature data.
[0010] (3) Risk assessment: When the temperature change rate at the monitoring point If ER>K and this condition persists for time t1, it is marked as a high penetration risk and an alert is triggered.
[0011] when If the penetration risk persists for a period of time t2, it is marked as medium penetration risk;
[0012] when At that time, it was marked as low penetration risk.
[0013] Furthermore, the fiber optic Raman distributed temperature measurement system includes, but is not limited to, a pulsed laser, a wavelength division multiplexer, a photodetector, a data acquisition card, a sensing fiber, a host computer, and a protection box. The protection box is fixed to the outer wall of the tundish. The pulsed laser, wavelength division multiplexer, photodetector, and data acquisition card are installed inside the protection box. The sensing fiber is laid on the inner wall of the steel shell of the tundish. The sensing fiber is led out from a circular hole near the slag line of the steel shell and connected to the wavelength division multiplexer. The wavelength division multiplexer is connected to the pulsed laser and the photodetector. The pulsed laser and the photodetector are connected to the data acquisition card. The data acquisition card is wirelessly connected to the host computer, which is located in the monitoring room.
[0014] Furthermore, the sensing optical fiber is selected from polyimide-coated optical fiber or gold-coated optical fiber. The sensing optical fiber is laid before the fire-resistant lining is installed in the tundish. During the laying, the sensing optical fiber is first encapsulated with a 4mm steel pipe, and then the steel pipe is fixed to the inner wall and bottom of the tundish steel shell with pipe clamps. After the laying is completed, the tundish lining is installed.
[0015] Furthermore, the sensing optical fiber is laid in two layers. One layer of sensing optical fiber is located in the inner layer of the working layer of the tundish lining, i.e., the inner layer optical fiber, and the other layer of sensing optical fiber is located in the outer layer of the working layer of the tundish lining, i.e., the outer layer optical fiber.
[0016] Furthermore, the temperature-erosion rate dynamic model is as follows:
[0017]
[0018] Where: ER(t) is the erosion rate at the detection point at time t. The monitoring point represents the rate of temperature change, where T is the temperature value detected by the inner fiber optic cable at the monitoring point, and t is the time variable. ΔT represents the intensity of temperature fluctuation at the detection point, ΔT is the temperature difference between the outer and inner optical fibers at the detection point, and α, β, and γ are all weighting coefficients.
[0019] Furthermore, in the risk assessment step, A, B, and K are all set values, which are set based on historical data.
[0020] The present invention has the following beneficial effects:
[0021] 1. This invention uses a fiber optic Raman distributed temperature measurement system to monitor the temperature of the tundish in real time, identify the location of temperature anomalies throughout the tundish, provide early warnings, minimize the occurrence of tundish penetration accidents, improve the automation management level of the entire tundish, and provide reliable technical support for the operational safety of the entire steel plant.
[0022] 2. By establishing a dynamic model of temperature-erosion rate and laying double-layer sensing optical fibers, the intermediate package can be monitored for temperature and erosion warning in real time, shortening the warning response time, increasing the warning lead time, and reducing the false alarm rate, thereby more accurately assisting production.
[0023] 3. The residual thickness can be calculated and output in real time using the temperature-erosion rate dynamic model.
[0024] 4. Compared to point thermometers such as thermocouples, resistance temperature detectors (RTDs), and fiber optic gratings, fiber optic Raman distributed temperature sensors can achieve distributed measurement, and any temperature change along the fiber optic cable can be reflected in the change of temperature profile.
[0025] 5. The sensing fiber serves as both a sensor and a transmission medium, transmitting optical signals internally. It is corrosion-resistant and resistant to electromagnetic interference, making it more suitable for extreme working conditions compared to electronic sensors such as thermocouples. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the fiber optic Raman distributed temperature measurement system of the present invention.
[0027] Figure 2 This is a schematic diagram of the steel tube packaging structure for the sensing optical fiber of the present invention.
[0028] Figure 3 This is a flowchart of the risk assessment process for this invention.
[0029] The components include: 1. Pulsed laser; 2. Wavelength division multiplexer; 3. Photodetector; 4. Data acquisition card; 5. Sensor fiber optic cable; 6. Host computer; 7. Protection box; 8. Steel pipe. Detailed Implementation
[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0031] like Figure 1-3 As shown, a method for monitoring temperature and providing early warning of erosion in a continuous casting tundish includes the following steps:
[0032] (1) Temperature Measurement System Installation: A fiber optic Raman distributed temperature measurement system is installed in the intermediate package to detect real-time temperature data at each monitoring point of the intermediate package. The fiber optic Raman distributed temperature measurement system includes, but is not limited to, a pulsed laser 1, a wavelength division multiplexer 2, a photodetector 3, a data acquisition card 4, a sensing fiber optic cable 5, a host computer 6, and a protection box 7. The protection box 7 is fixed to the outer wall of the intermediate package. The pulsed laser 1, wavelength division multiplexer 2, photodetector 3, and data acquisition card 4 are installed inside the protection box 7. The sensing fiber optic cable 5 is laid on the inner wall of the steel shell of the intermediate package. The sensing fiber optic cable 5 is led out from the round hole near the slag line of the steel shell and connected to the wavelength division multiplexer 2. The wavelength division multiplexer 2 is connected to the pulsed laser 1 and the photodetector 3. The pulsed laser 1 and the photodetector 3 are connected to the data acquisition card 4. The data acquisition card 4 is wirelessly connected to the host computer 6, which is located in the monitoring room.
[0033] The sensing fiber 5 is made of polyimide-coated fiber or gold-coated fiber. The sensing fiber 5 is laid before the fire-resistant lining is installed in the tundish. During the laying, the sensing fiber 5 is first encapsulated with a 4mm steel pipe 8, and then the steel pipe 8 is fixed to the inner wall and bottom of the tundish steel shell with pipe clamps. After the laying is completed, the tundish lining is installed.
[0034] The sensing fiber 5 is laid in two layers. One layer of sensing fiber 5 is located in the inner layer of the working layer of the tundish lining, i.e., the inner fiber 5, and the other layer of sensing fiber 5 is located in the outer layer of the working layer of the tundish lining, i.e., the outer fiber 5.
[0035] When the fiber optic Raman distributed temperature measurement system starts working, the data acquisition card 4 sends a trigger pulse to the pulsed laser 1, driving the pulsed laser 1 to emit light pulses at a certain repetition frequency. The pulsed light is coupled into the sensing fiber 5 via the wavelength division multiplexer 2, where a scattering effect occurs. The wavelength division multiplexer 2 filters out the Stokes light and anti-Stokes light in the backscattered Raman light that is reflected back along the fiber, according to the different wavelengths. After photoelectric conversion by the photodetector 3, the voltage value is acquired by the data acquisition card 4 and transmitted to the host computer 6 software for temperature demodulation.
[0036] (2) Erosion rate calculation: Based on real-time temperature data, the erosion rate ER at each monitoring point is calculated according to the temperature-erosion rate dynamic model. The temperature-erosion rate dynamic model is as follows:
[0037]
[0038] Where: ER(t) is the erosion rate at the detection point at time t. The monitoring point represents the rate of temperature change, where T is the temperature value detected by the inner fiber optic cable at the monitoring point, and t is the time variable. ΔT represents the intensity of temperature fluctuation at the detection point, ΔT is the temperature difference between the outer and inner optical fibers at the detection point, and α, β, and γ are all weighting coefficients.
[0039] The values of α, β, and γ are related to the number of heats used in the tundish, i.e., α = a(1 + 0.05N), β = b, γ = c(1 + 0.03N), where a, b, and c are basic weights. The values of a, b, and c are related to the steel grade (which can be obtained by analyzing historical data of different steel grades). For example, when the steel grade is high manganese steel, a = 0.6, b = 0.3, and c = 0.1; when the steel grade is ordinary steel, a = 0.4, b = 0.4, and c = 0.2. N is the number of heats used, which can be substituted to calculate the values of α, β, and γ.
[0040] (3) Risk assessment:
[0041] When the temperature change rate at the monitoring point If ER>K and this condition persists for time t1, it is marked as a high penetration risk and an alert is triggered.
[0042] when If the penetration risk persists for a period of time t2, it is marked as medium penetration risk;
[0043] when At that time, it was marked as low penetration risk.
[0044] A, B, and K are all set values, determined based on historical data or actual conditions (such as lining thickness, material, etc.). First, the calculated... The value of is compared with A, if If ER > K and this condition persists for time t1, a high penetration risk is identified and an alert is triggered; otherwise, the comparison continues. And continue for time t2, if it is determined to be of medium penetration risk, otherwise continue the comparison; if At that time, it was determined to be of low penetration risk.
[0045] By integrating the ER(t) calculated by the temperature-erosion rate dynamic model, the residual thickness of the working layer can be further calculated. The formula is: H=H0-∫ER(t)dt, where H is the real-time residual thickness and H0 is the initial residual thickness.
[0046] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the design concept of the present invention should fall within the protection scope of the present invention.
[0047] The technologies, shapes, and structures not described in detail in this invention are all known technologies.
Claims
1. A method for monitoring temperature and providing early warning of erosion in a continuous casting tundish, characterized in that, Includes the following steps: (1) Temperature measurement system installation: Install a fiber optic Raman distributed temperature measurement system in the intermediate package to detect real-time temperature data at each monitoring point in the intermediate package; (2) Erosion rate calculation: The erosion rate ER of each monitoring point is calculated based on the temperature-erosion rate dynamic model according to real-time temperature data. (3) Risk assessment: When the temperature change rate at the monitoring point If ER>K and this condition persists for time t1, it is marked as a high penetration risk and an alert is triggered. when If the penetration risk persists for a period of time t2, it is marked as medium penetration risk; when At that time, it was marked as low penetration risk.
2. The method for monitoring temperature and providing early warning of erosion in continuous casting tundish according to claim 1, characterized in that, The fiber optic Raman distributed temperature measurement system includes, but is not limited to, a pulsed laser, a wavelength division multiplexer, a photodetector, a data acquisition card, a sensing fiber, a host computer, and a protection box. The protection box is fixed to the outer wall of the intermediate tundish. The pulsed laser, wavelength division multiplexer, photodetector, and data acquisition card are installed inside the protection box. The sensing fiber is laid on the inner wall of the steel shell of the intermediate tundish. The sensing fiber is led out from a circular hole near the slag line of the steel shell and connected to the wavelength division multiplexer. The wavelength division multiplexer is connected to the pulsed laser and the photodetector. The pulsed laser and the photodetector are connected to the data acquisition card. The data acquisition card is wirelessly connected to the host computer, which is located in the monitoring room.
3. The method for monitoring temperature and providing early warning of erosion in continuous casting tundish according to claim 2, characterized in that, The sensing optical fiber is selected from polyimide-coated optical fiber or gold-coated optical fiber. The sensing optical fiber is laid before the fire-resistant lining is installed in the tundish. During the laying, the sensing optical fiber is first encapsulated with a 4mm steel pipe, and then the steel pipe is fixed to the inner wall and bottom of the tundish steel shell with pipe clamps. The tundish lining is installed after the laying is completed.
4. The method for monitoring temperature and providing early warning of erosion in continuous casting tundish according to claim 3, characterized in that, The sensing optical fiber is laid in two layers. One layer of sensing optical fiber is located in the inner layer of the working layer of the intermediate liner, i.e., the inner layer optical fiber, and the other layer of sensing optical fiber is located in the outer layer of the working layer of the intermediate liner, i.e., the outer layer optical fiber.
5. The method for monitoring temperature and providing early warning of erosion in a continuous casting tundish according to claim 4, characterized in that, The temperature-erosion rate dynamic model is as follows: Where: ER(t) is the erosion rate at the detection point at time t. The monitoring point represents the rate of temperature change, where T is the temperature value detected by the inner fiber optic cable at the monitoring point, and t is the time variable. ΔT represents the intensity of temperature fluctuation at the detection point, ΔT is the temperature difference between the outer and inner optical fibers at the detection point, and α, β, and γ are all weighting coefficients.
6. The method for monitoring temperature and providing early warning of erosion in a continuous casting tundish according to claim 5, characterized in that, In the risk assessment step, A, B, and K are all set values, which are set based on historical data.