The Numerical Simulation Researches On The Two-Phases Flow Of Preheated Cyclone

Two-phase flow in a preheater cyclone with three core volute structure was simulated by CFD software in this paper. On the base of deeply understanding of preheater cyclone, dose the research for the flow of gas, moving tracks of particles, pressure drop and separated efficiency in many different conditions. Many of models for the research had been made, from the preparation that defined the appropriate model and method to complete of this research.For the following works on this thesis: First, through compared three models of turbulence, as well as several format of pressure interpolation and difference scheme, the method of numerical computation for simulating preheater cyclone has been confirmed; at the same time, the appropriate model of two-phase flow for preheater cyclone has been confirmed also. Second, the flow behavior of preheater cyclone has been analyzed. Third, the relation between the parameter of structure and operation and working performance has been analyzed. Fourth, basis on the result of numerical simulation, a new type preheater cyclone with the structure of eccentric inner cylinder and oblique top was designed, and gave some corresponding researches.Basis on the result of research, there were come to some conclusions: First, in order to get the more ideal results, we must adopt Reynolds Stress Model based on anisotropy, QUICK format and PRESTO format on the premise of good mesh for the simulation of the complex flow field in preheater cyclone. Second, the main flow in preheater cyclone is double vortex, with the boundary of LZVV, outside of which is the revolved flow downwards, center of which is the revolved flow upwards, and their revolved direction is the same; on the side, the movement of particles in the preheater cyclone is very complex and much more random, especially the small particles, their moving tracks are different, even if they are the same particles and their original locations are the same. Third, with the accretion of the inlet velocity, the separated efficiency is much higher, but the pressure drop is also much higher; the exhaust duct inserted depth has the same effect, with the accretion of exhaust duct inserted depth, the pressure drop is much higher, but separated efficiency is also much higher. Fourth, this type structure design has the significance to improve the operating performance of preheater cyclone,...