Gas-solid two-phase flow model and its applicationin vibrated fluidized bed of fine coal

In order to understand the microstructure of vibrated fluidized bed and to simulate,predict and optimize the control of gas-solid two-phase flow and heat transfer behavior,based on the analysis of the spatio-temporal heterogeneous structure characteristics of the bed,the types,characteristics,advantages,disadvantages and application status of gas-solid two-phase flow models widely used in vibrated fluidized bed simulation are reviewed and analyzed,and the future development is prospected.The results show that:the simulation results of the pseudo-fluid model are close to the engineering practice,the discrete particle model can track the particle trajectory,the pseudo-particle model can reveal the non-uniform structure of the bed and solve the complex flow field problems，there is no unified model to describe gas-solid flow in a comprehensive way.The two-fluid model and the discrete particle model can well simulate the porosity,solid particle concentration and velocity,particle distribution uniformity and pressure stability of the bed.The choice of model and parameters is very important,and it is difficult to solve the basic equation,so there is still a gap with the engineering practice.The introduction of non-linear theory to characterize the multi-flow regime and the non-uniform structure of the bed,and the study of the energy transfer behavior and the control mechanism of segregation and mixing modes in the vibrated fluidized bed are the future development directions.