Multi-physics Coupling Simulation And Process Parameter Optimization Of Large Vertical Mills

Large-scale vertical mill is the core equipment in the production of cement industry.Its operation process involves the complex coupling of multi-source physical fields such as fluid,large-scale solid particles and heat transfer.The internal flow field of the vertical mill is a strongly coupled fluid-particle multiphase flow.In the process of energy-saving control,there is a problem that the correlation mechanism between key operating parameters and multi-physics morphology is not clear,and it is difficult for experimental research methods to accurately describe the correspondence between these operating parameters and mass characteristics.In order to explore the working mechanism of multi-physics coupling in the working process of large vertical mill,the multiphase flow coupling simulation technology is used to simulate and analyze the vertical mill.On the basis of numerical simulation,a set of multi-objective optimization design method for operating parameters of large vertical mill based on the agent model is proposed,which provides decision basis for intelligent control of operating parameters of large vertical grinding.In this paper,the LGM vertical mill was taken as the research object to establish a large particle-fluid coupling numerical calculation model.Based on the theory of computational fluid dynamics,the discrete phase model(DPM)was used to simulate the particle motion trajectory in the chamber.The influence of the key operating parameters of vertical mill on the flow field distribution,particle classification and fineness of finished powder was studied by analyzing the motion characteristics of particles in the flow field.In Fluent,discrete samples were generated to calculate the particle size distribution in different intervals,so as to compare the effect of the two main influencing parameters of the system air volume and the speed of the powder separator on the particle size distribution.The Rosin-Rammler distribution function was used to mathematically describe the distribution characteristics of particle size.The analytical solution of the powder specific surface area was obtained by the functional expression.On this foundation,the effect of particle size distribution on the specific surface area of powder was discussed.Aiming at the problems of large vertical mill with multiple optimization objectives and large consumption of objective function computing resources,this paper performed multi-objective optimization based on the agent model for the main operating parameters of the vertical mill.With the goal of improving the production capacity and product quality of the vertical mill,numerical simulation was carried out on the basis of experimental design.Based on the simulation results,the response value of the sample points was obtained and used to construct the agent model.The multi-objective optimization algorithm was used to optimize the design.The feasibility of the optimization method was verified by numerical calculation based on the optimization results.Through the Insight engineering design optimization software,the optimization design of large vertical grinding operating parameters was realized,which provides theoretical and methodological support for quantitative analysis and optimization decision-making in the operation and maintenance process of complex equipment.