Numerical Simulation Of The Spatial Disstribution Of Energy Dissipation And Its Influencing Factors On Cyclone Separators

Due to the advantages of simple structure,convenient operation,low operation and maintenance cost,and high dust removal efficiency,cyclone separators have been widely used in industry.The main working principle of the cyclone is that the centrifugal force generated by the strong rotating flow separates from gas.However,due to the high rotation speed of the gas flow in the separator and the limitation of the separator structure,the friction between the gas flow and the wall and the kinetic energy dissipation will cause the large pressure drop of the cyclone separator.At present,the researches on the optimization of cyclone separators mainly focus on reducing the pressure drop of the separator while maintaining or improving the separation efficiency by means of structural optimization design,but there are few studies on the mechanism of pressure drop generation,composition and spatial distribution.On the basis of previous studies,the energy dissipation model of cyclone separator was established with numerical simulation as the main method and experiment as the auxiliary method,and the composition,proportion and spatial distribution of energy dissipation were studied to explore the influence rules of turbulence and wall roughness.Firstly,the Reynolds stress model was selected as the turbulence model,the standard wall functions and the non-equilibrium wall functions were used as the near wall treatment method of the circular tube and the cyclone separator respectively,and the numerical simulation methods of each part of the energy dissipation were established.Secondly,the reliability of the model was verified by comparing the simulation data with the empirical data of pressure drop in the tube and the experimental data of the cyclone separator.Finally,the numerical simulation method was used to analyze the changes of flow field and energy dissipation under different turbulence and wall roughness,focusing on the different effects of different wall roughness on the circular tube and cyclone separator,and exploring the influence of turbulence and wall roughness on the composition and spatial distribution of energy dissipation.The main conclusions are as follows:(1)The energy dissipation of cyclone separator is mainly composed of viscous dissipation,turbulent energy generation and turbulent diffusion,and the proportions of viscous dissipation and turbulent energy generation are both about 50%;(2)From the perspective of spatial distribution,the energy dissipation of cyclone separator is mainly concentrated in the near wall region and the region from the vortex finder to the middle part of the cylinder;(3)With the increase of turbulence,the total energy dissipation of the cyclone increases,the turbulent energy generation of the cyclone gradually dominates,as for the spatial distribution,the energy dissipation area of the separator also extends to the lower end of the he vortex finder and the middle part of the cylinder;(4)With the increase of wall roughness,the energy dissipation of the cyclone decreases,and the turbulent energy generation gradually becomes the dominant factor.The spatial distribution of cyclone separators is more concentrated on the wall.The research results improve the theory of energy dissipation in cyclone separators and provide guidance for the optimal design of the separators.