Miroshnichenko V. Improvement of control systems for water-air cooling of continuously cast slabs and heavy plates

Purpose of the work – to increase and stabilize the quality of Water-Air Cooled Continuously Cast Slabs and Heavy Plates by means of a physically grounded analytic model together with novel predictive controlling system development both providing the cooling regimes stabilizing. Investigation object – thermal exchanging processes between steel products and air-water coolant Subject matter of the research - Water-Air Cooling effects on the quality characteristics of Continuously Cast Slabs and Heavy Plates Investigation techniques: contact and distant metal billets temperature measurements; balanced approach of the thermal exchange theory; computer Monte-Carlo simulations; standard heavy plates mechanical characterizations; multiple computer regression; computer JavaScript software development; jQuery and jQuery charts libraries aided computer visualizing; computer numerical modeling. An actual scientific-technological problem of increasing and stabilizing the quality of Water-Air Cooled Continuously Cast Slabs (SSC) and Heavy Plates (HP) is solved in the thesis by means of improvements of their Water-Air cooling control systems A novel theoretical approach is proposed and a new analytic model for Water-Air Cooling is developed providing absence of the components turbulent flow. A novel analytic predictive control system was developed. Regression models were obtained to describe the cooling parameter effects on the heavy plate mechanical properties. A new hierarchical method for modeling the control objects with vector objective functions was proposed to improve the dynamic control effectiveness. By industry verified experiments considerable decreasing the cooling water consumption – over three times; CCS metal temperature – from 27 ºС to 15 ºС was shown due to the obtained results application with final decrease of the defect slab overall percentage from 11 % to 5 %.