Crystallizer breakout prediction method based on logical judgment

Abstract

The invention belongs to the field of control of metallurgical continuous-casting production techniques, and relates to a crystallizer breakout prediction method based on logical judgment. The crystallizer breakout prediction method based on logical judgment comprises the following steps that firstly, logical judgment rule parameters are read; secondly, data are acquired and processed; thirdly, temperature rise of thermocouples is detected; fourthly, the temperature rise rate of the thermocouples which meet the temperature rise judgment condition is detected; fifthly, temperature change delay of the three thermocouples around the thermocouple TC (i, j) with abnormal temperature rise is detected; sixthly, the seven steps is conducted after detection of continuous temperature fall of the thermocouple TC (i, j) or detection of the temperature change delay of the thermocouples around the thermocouple TC (m, n); seventhly, temperature inverted detection of the thermocouples is conducted; and eighthly, whether a sticking breakout alarm needs to be given out or not is judged according to the alarm shielding condition. By adoption of the crystallizer breakout prediction method based on logical judgment, timely and accurate prediction of sticking breakout is achieved, smooth proceeding of continuous-casting production is ensured, and the quality of cast blanks is improved.

Description

technical field [0001] The invention belongs to the field of metallurgical continuous casting production process control, and more specifically relates to a method for predicting mold breakout based on logic judgment. Background technique [0002] The rapid development of modern high-efficiency continuous casting technology requires not only high-quality continuous casting slabs, but also high casting speed. Bonded breakouts have always been an important problem restricting high-speed continuous casting. Solving the impact of bonded breakouts on continuous casting production It is of great significance to go forward and produce high-quality slabs. At present, in addition to improving the process conditions that induce slab shell bonding, the main means is to develop a mold breakout prediction system with high prediction accuracy, low false alarm rate, and fast response. The mold breakout prediction system commonly used at home and abroad is mainly to embed a certain number o...

AI Technical Summary

Problems solved by technology

Although the prediction control method improves the accuracy of steel breakout prediction to a certain extent and reduces the number of false alarms, it does not take into account the response time and timeliness of the bonding alarm, especially when the temperature amplitude inspection is used. The identification and alarm time of a single thermocouple bonding temperature waveform is late, which may not be able to report the bonding behavior in time. If the alarm is late, even if the machine is shut down directly, it cannot guarantee the repair of the bonding crack without steel leakage. If it is earlier The alarm can be maintained at a low shell healing rate to repair the bonded crack without stopping the machine or stopping pouring, which increases unnecessary operation time, reduces production efficiency and increases equipment loss.

[0005] Patent document CN102825234A discloses a method for judging and alarming bonded breakouts. The method for judging and alarming is based on the time-lag of the temperature of multiple rows of thermocouples in space and the characteristics of temperature curve crossing (ie, temperature inversion). The typical temperature change waveform mode or the theoretical temperature change waveform mode is designed, but in the actual production process, not all bonding temperature change waveform modes will show the "temperature inversion" phenomenon, and the actual production is due to the liquid steel level fluctuations, Influenced by factors such as mold flux performance, molten steel flow, and thermocouple failure, temperature inversion of the upper and lower thermocouples on the copper plate of the mold often occurs, or in non-bonding conditions such as unsteady casting and thermocouple failure, there are often relatively high Large thermocouple temperature fluctuations are also prone to temperature inversion, so the design of this method undoubtedly increases the probability of false positives and negative negatives

[0006] A comprehensive investigation of the current domestic and foreign breakout forecasting systems and logical judgment forecasting methods found that the main problems are as follows: (1) The failure of the thermocouple itself caused abnormal changes in the measured temperature, which affected the breakout forecasting algorithm and system judgment

For example: due to the quality problem of the thermocouple itself, the performance is unstable or the thermocouple loses its thermoelectric characteristics, and the temperature curve fluctuates too much; the thermocouple is assembled in the wrong way or the seal is not good, resulting in a large deviation between the measured temperature and the actual temperature after oil or cooling water enters, Make the temperature curve fluctuate; distortion occurs during the transmission of the thermocouple signal, making the temperature curve fluctuate

(2) Under unsteady casting conditions such as start of pouring, tundish replacement, and final pouring, the temperature of the thermocouple will be greatly affected, and false alarms of the algorithm will also increase; The temperature waveform of the thermocouple in the junction process can reduce false alarms, but in the actual process, sometimes the temperature change of the thermocouple under unsteady conditions is very close to the temperature waveform of the bonding process, which increases the difficulty of the design of the breakout prediction model

(3) Some important parameters of the logic judgment algorithm depend on the specific process and equipment conditions. With the change of casting conditions such as equipment loss, material replacement, steel type and mold slag, the algorithm becomes more and more inaccurate

(4) Although the characteristics of single thermocouple temperature change with time during bonding and the "time lag" and "temperature inversion" characteristics of the temperature change of multiple rows and rows of thermocouples in space have become consensus, they are the basis for the design of breakout prediction logic algorithm , although the logic judgment algorithms designed according to these characteristics are different, but the comprehensive consideration of forecast accuracy and alarm time is insufficient

[0007] In summary, how to overcome the shortcomings of the continuous casting breakout prediction method and device in the prior art in terms of prediction accuracy and alarm timeliness is a technical problem that needs to be solved urgently in the prior art

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