Numerical Simulation And Optimization Of Both Temperature Field Of Fused Magnesia Furnace And Morphology Of Magnesia In Cooling Process

Fused magnesia as advanced refractory materials,the larger the size,the higher the purity,the better the performance,the greater the value.In the production process of fused magnesia using fused magnesia furnace,the formative stage of molten pool in smelting process and the crystallization stage in cooling process are the main stages determine the morphology and size of fused magnesia,and the crystallization stage in cooling process directly affects the yield and quality of large size crystals.In this paper,the cooling process is studied,the temperature field model and the crystal nucleation and growth model are established,and the numerical simulation of temperature field and crystal morphology is also carried out.Analyze the relationship between temperature field and crystal morphology,to provide a theoretical basis for the optimization of the production process.The main research contents are:(1)According to the heat transfer theory,three dimensional unsteady heat conduction equation of the cooling process of fused magnesium furnace is established,considering the influence of phase field change on temperature field,the latent heat of phase change is treated as internal heat source,and numerical simulation is carried out by using the finite element method,to obtain the distribution of dynamic temperature field in the furnace.(2)By crystallography theory,study the nucleation and growth principle to obtain the nucleation and growth equations of Magnesium Oxide crystal in the fused magnesium furnace,and in order to conduct a unified simulate macroscopic temperature field and the microscopic crystal morphology,the growth of crystal microstructure is simulated by cellular automaton.(3)Analyze the influence factors of the crystal growth and some methods of controlling the crystal growth in the fused magnesium furnace,determine the boundary conditions and initial conditions of the fused magnesium furnace in the cooling process,and process the thermal physical parameters of the materials.The microstructure model of the crystal is simulated by using PROCAST software.Based on the simulation results,analyze the influence of the degree of cooling on the formation of crystal morphology.(4)In order to increase the yield of large size crystals with better fire resistance,propose control model of multi-objective optimization.Using multi-objective particle swarm optimization method to optimize the model,obtain the optimal control strategy,provide guidance and advice for the optimization of production process.