On-line control method of continuous casting blank temperature based on memory recognition mode

Abstract

The invention provides a method for controlling the temperature of continuous casting blanks on line based on a memory recognition mode, wherein a computer control system aiming at the characteristics of the continuous process applies a feedback and feedforward complementary control model algorithm based on the memory recognition mode to perform real-time complementary control on a water distributing system in the whole secondary cooling region of a continuous casting machine, so that the surface temperature of a casting blank on a set temperature measurement control point is kept within a target temperature range to ensure the quality of the casting blank and the smooth operation of continuous casting production; and the method traces and analyzes disturbance factors to the temperature of the casting blank in the continuous casting process, considers the pulling speed and the history accumulative effect of water quantity changes, adopts an complementary mode of feedback control and feedforward control before and after a temperature measurement point, dually controls the hot state of the continuous casting blank in the whole secondary cooling region, solves the problem that the feedback control of the temperature is hysteretic so that the temperature feedback control algorithm can truly reflect the cooling process and the current hot state of the continuous casting blank, and introduces two control adjusting regions including an optimal temperature region and a fine adjustment temperature region to perform effective and reasonable control.

Description

technical field [0001] The invention relates to the field of continuous casting of iron and steel materials and other metal materials in the metallurgical process, and is suitable for various types of metallurgical continuous casting machines. Background technique [0002] (1) Research status of on-line control technology for continuous casting slab temperature [0003] As an important process of iron and steel production, the continuous casting process is a key link in the quality control of solidification and forming of iron and steel products. Uneven cooling or improper cooling intensity will cause quality defects of continuous casting slabs. Therefore, it is very necessary to study the secondary cooling of the continuous casting process and master the control of the cooling and solidification state of the continuous casting slab. [0004] Continuous casting slab temperature is the most intuitive reflection of the strength of continuous casting secondary cooling, and is...

AI Technical Summary

Problems solved by technology

Due to the requirement of online control time and the limitations of mathematical model establishment and solution, usually the dynamic heat transfer model will make a lot of simplified assumptions, and the boundary conditions of the heat transfer model are difficult to fully meet the actual boundary conditions of continuous casting machine production

[0009] The above three restrictive technical problems of the dynamic control of the secondary cooling are the important reasons for the poor application effect of the dynamic control system of the secondary cooling and the dynamic light reduction system of the secondary cooling in the continuous casting machines of many iron and steel enterprises.

Such a simple control cannot consider the influence of casting speed and secondary cooling water volume change history on the slab temperature during the control process, and cannot effectively control according to the actual cooling effect of the slab, and the control cannot be stable.

Even when the process operating parameters are relatively stable, it will lead to repeated fluctuations in the control of the secondary cooling water

[0012] ② Only the feedback control effect of the secondary cooling zone before the temperature measurement point is considered, and the secondary cooling zone after the temperature measurement point does not take compensation control

This is not conducive to controlling the cooling and solidification state of the continuous casting slab in the entire secondary cooling zone

[0013] ③Due to the serious water mist, water vapor, dust, oil pollution, etc. in the secondary cooling zone during the continuous casting process, and there are iron oxide scales, water films, residues, etc. on the surface of the continuous casting slab, there are many factors that interfere with the actual temperature measurement , the temperature measurement environment is harsh, and it is impossible to accurately measure the billet temperature online

For example, ZL200510110014.X "a continuous casting slab surface target temperature monitoring and analysis method and its device", but the invention uses an infrared thermometer to detect the actual temperature of the slab during the production process, and analyzes and stores the data. The main content is Regarding the online detection and data analysis and processing of the continuous casting slab temperature, there is no online feedback control of the continuous casting secondary cooling based on the measured data

The rest of the patents do not involve the online control of continuous casting slab temperature

[0017] (3) Current status of online control of continuous casting slab temperature

This method has been studied in relevant literature, but it is only a simple coefficient multiplied by the control effect of temperature difference, regardless of the hysteresis of temperature feedback control and the history of casting speed and water volume changes, and basically cannot reflect the cooling experience of continuous casting slabs according to actual conditions. The slab temperature cannot be stably controlled to the target value, which has been confirmed in our test analysis

[0019] The continuous casting slab secondary cooling dynamic control system can control and adjust the continuous casting slab temperature, but it does not use the actual measurement of the slab temperature, but only calculates the slab temperature through the heat transfer model and performs open-loop control, which cannot be accurately grasped and react the actual thermal state of the continuous casting slab, especially the thermal state of the slab under the abnormal casting state, so the control effect is also limited by the accuracy of the heat transfer model.

[0020] Due to the limitations of the above problems, the continuous casting slab temperature line control is not yet well applied in industrial production.

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