Design and application of dynamic control system for secondary cooling of billet continuous casting

The continuous casting process is used for the solidification of molten steel into semi-finished shapes. The technology of secondary cooling is extremely important for output of the casting machine and quality of the strand. In the paper, a dynamic control system is presented, including solidification model in the secondary cooling, feedforward control based on continuous temperature measurement in tundish and feedback control based on surface temperature measurement. The mathematical model of solidification process is developed according to the principle of solidification, and the model is verified by measuring billet shell thickness through nail shooting and sulfur printing. Primary water distribution is calculated by solidification model according to procedure parameters. And it is adjusted by the other two control strategies on line. The control system has been applied on some caster and billet quality is obviously improved, indicating that the dynamic control system is better than the conventional open-loop system.