Numerical Simulation and Optimal Control in the Continuous Casting of Billets

A two-dimensional heat-transfer model for transient simulation and control of a continuous steel billet caster was developed. Billet temperature and solidification were computed by the model as a function of casting speed, secondary spray cooling water flow rates and temperature, shell thickness, steel chemistry, and pouring and ambient temperatures. Typically, the solidification path, temperature-solid fraction relationship, was prescribed. Results of several simulations are given to demonstrate the effects of changing casting conditions on the billet thermal profile, end of liquid pool, and solidification end point. A control methodology and algorithm suitable for control of a continuous casting machine is described, and the ability to control the surface temperature profile by dynamically adjusting secondary spray cooling flow rates is demonstrated by simulation. Results from a preliminary version of the model show that is capable of using in realistic caster.