Master's work
ABOUT WAYS OF RISE OF EFFICIENCY OF WORK OF MACHINES OF CONTINUOUS CASTING OF PURVEYANCES
Today technology of steel continuous casting is well develops. But still in this area there are same problems. They are usually associated with necessity of casting speed increase, with starting of new steel grates casting or with laves quality improvement. For decision of listed above tasks the method of optimization, based on application of mathematical model, is most effective.
Development of mathematical model of processes of the continuous pouring of steel
For description of processes of crystallization and cooling of metal it is accepted to use differential equalization of unstationary heat conductivity with the internal sources of heat (consideration of crystallization hear is carried out due to introduction of effective heat capacity of concept:
where ρ - metal density, kg/m3;
– temperature substancial derivative;
where tl, ts – temperatures of liquidus and solidus correspondingly 0Ń;
qkr – heat of crystallization, Dg/kg;
Initial conditions
Initial conditions set distributing of physical values in the studies region in the initial moment of time. In the given work the task to initial set conditions is it is necessary determine to field of temperature in the «zero moment» of time (on a meniscus). It is assumed thus, that the temperature of liquid metal at the initial moment of tine is set by following expressia:
Boundary conditions
Heat exchange between coolant and bar surface is described with boundary conditions of the 3-s type:
