| Based on the product enhanced quality technical transformation project after rolling cooling system engineering project of Hunan Valin Steel Co. Ltd. The Ultra Fast Cooling system after rolling is studied, and then the Ultra Fast Cooling system platform is built for comparing. The research concludes the controlling system, temperature distribution water-cooled models and so on. The main contents and results are as follows:(1) To meet the needs of the after rolling cooling system and contraposes the characteristics of the Hot Strip Rolling, the basic automation system and the process controlling system platform are built. The basic automation contents the strip head and tail tracking, precision regulation of medium flow rate, accurate sample tracking, the related characterization parameters calculation and the monitoring function. The process control system is mainly contents the sets up of processing parameter, calculation of strip temperature distribution and open and close of the associated cooling tubes. And achieved the high-precision controlling of intermediate temperature and coiling temperature.(2) According to the characteristic of Hot Strip line, the high speed, short distance Ultra Fast cooling device and intensive cooling capability, according to the use of Fuzzy PID control and the coupling controlled of cooling medium method. Applied to the field, the actual flux is precisely controlled within±3.5m3/min beyond the target value, and the pressure is within±0.03MPa beyond the target are indicated. In the normal production, the suddenly opened and closed of the pipe often caused the large fluctuation of the pressure and enlarged the regulated time,however, under the control of the developed Ultra Fast cooling system, coupled with the coupling control method, the accreted flow and pressure are quickly achieved within the allowed deviation.(3) To meet the Ultra Fast cooling process, the cooling control model of the cooling precess is established. Combined with the actual temperature data and the cooling process of 2250,lysteel, inverse heat conduction method is used for calculating the average heat transfer coefficienct of the cooling process. And lay a foundation for the research on the temperature distribution of different thickness and the set up of parameter during the cooling process.(4) Aim at the cooling process of the Hot Strip Steel process, the temperature distribution under different cooling path based on the Ultra Fasting Cooling are systematically analyses And the thickness of the steel over9.7mm have the reddish obviously is indicated. Based on the actual data of the field and the calculated heat transfer coefficient,the temperature distribution under different cooling path are simulated separately. And lays a guiding role for anaphase debugging.(5) The developed Ultra Fast Cooling controlled system applied to the process, the actual controlled effect indicated that the Ultra Fast Cooling temperature precision is±20℃and the coiling temperature precision is±18℃. The high precision temperature controlling system for the actual need of the field is achieved. In additional, based on the controlled system, the continuous and stable production of the Q345B upgraded from Q235B, the trial of dual phase steel DP600is successfully achieved, thus bring significant economic benefits for the lysteel. |
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