Generalized constructal optimization for solidification heat transfer process of slab continuous casting based on heat loss rate

Based on constructal theory, generalized constructal optimization of a solidification heat transfer process of slab continuous casting is carried out by taking a complex function as optimization objective. The complex function is composed of the functions of the heat loss rate and surface temperature gradient of the slab subjected to the constraints of shell thickness, surface temperature and liquid core length of the slab. For the specified total water flow rate, the “optimal construct” of the water distribution in the secondary cooling zone is obtained. Comparing the optimal results with the initial ones, it is shown that the complex function, the functions of the heat loss rate and the surface temperature gradient after optimization are decreased by 35.04%, 2.14% and 59.48%, respectively. Therefore, the scheme of the “optimal construct” of the water distribution reduces the heat loss rate and surface temperature gradient of the slab simultaneously, that is, improves its energy retention and quality simultaneously. The optimization results obtained in this paper can provide some guidelines for parameter designs and dynamic operations of the solidification heat transfer process of slab continuous casting.