Heat Transfer Simulation Of Aggregate Dryer Using Coupled CFD And DEM Methods

The heat transfer process of drying apparatus is accompanied by complicated particle motion,so it can't be accurately described by the heat transfer model which is established on the basis of two-dimensional plane.With the development of numerical simulation technology and the improvement of computer hardware level,finite element and discrete element technology have gradually developed maturely,and at the same time they are successfully applied to the simulation in the process of industrial production.At present,digital analysis technology based on CFD-DEM coupling has successfully simulated the process of gas-solid two-phase flow,and this breakthrough can provide new ideas to research the process of internal heat transfer of drying apparatus.This paper firstly analyzed Chinese energy situation and the significance of drying apparatus energy saving,and it also introduced the research progress of CFD-DEM gas-solid two-phase flow.Of course the paper expounded it's the purpose and significance to research including its research methods.For influencing factors in heat transfer process of drying apparatus,this paper has made systematical analysis in terms of rotational speed,installation inclination,leaf structure,leaf quantity and so on.According to the features of heat transfer process of drying apparatus,this paper introduced the fundamental principle of CFD-DEM coupling numerical simulation with the example of Fluent and EDEM,and this paper also analyzed the Euler-euler numerical analysis method which applied to dense gas-solid two phase system,the energy control equation between particle and gas and solution method of energy control equation's kernel parameter named Nusselt number.By the finite element analysis software EDEM,the paper simulated aggregate's movement in the material curtain area,then analyzed the times aggregate particles were lifted and dropped and their retention time.Finally,on the basis of CFD-DEM coupling numerical simulation method,the paper simulates the heat transfer process of drying apparatus in the material curtain area.in term of particle' temperature variation,this paper mainly analyzed drying apparatus exit temperature variation trend with time going by and the axial particle' temperature variation trend when the drying apparatus were in the steady state.As for the gas temperature,this paper mainly analyzed temperature variation trend of longitudinal center of surface temperature and gas exit of surface temperature.