Hot Numerical Simulation Of Cyclone Pre-heater's Fluent

Cyclone pre-heater is an important thermal equipment in the new cement production. It takes full advantage of the high temperature exhaust gas from the back-end calciner or the bottom of the combustion to preheat the raw material, then the lower raw material will be collected into the kiln, improving the thermal efficiency and reducing heat consumption, raising cement production. Cyclone pre-heater system is the main gas-solid reaction unit. The separation efficiency, system pressure drop and the thermal transform efficiency are important indicator to measure a Cyclone pre-heater's performance. Maximum heat transfer and material collecting, the minimum flow resistance are the basic requirement of pre-heater. Simulation of the pre-heater is an important method to study the performance of the pre-heater, but now the cyclone pre-heater simulation study mainly concentrated in the cold state of collecting and pressure losses. One can imagine that the cold state can not simulate the pre-heater 'efficiency of the heat transfer. Therefore, this study is the thermal state and is a better study of pre-heater's heat transfer.In this paper, CFD software FLUENT be used to research the cyclone pre-heater's internal thermal flow field of new dry cement-kiln system. Mainly simulating its internal gas-solid flow and heat transfer. on the basic understanding of the preheat system'structure and internal single-phase flow field, simulating the gas-solid flow field, particle trajectory, and the separation efficiency, pressure drop under many states. In addition, the user defined functions is used in the simulation study.Based on the simulation study, first of all, gain some method of the preheater's thermal simulation, that is using Reynolds stress model, discrete phase model and heat transfer model to simulate and study. Firstly, use the RNG model to single-phase model simulation, when the convergence is steady add discrete phase and heat transfer model, and change the RNG model to Reynolds stress model, This is beneficial for the Solution's convergence. Secondly carry out a series of comparison research in hot and cold state. And then, gain some conclusions: the performance of preheater under wind speed, Discrete concentration, diameter of the inner tube, depth of the inner tube and when join the UDF function, such as viscosity. Finally carrying on the system's elementary thermal state research, including the model choosing, the boundary establishment, and draws some conclusions. For example, the system's efficiency of receiving the dust, heat transfer efficiency and pressure losing.The conclusions we gets from this simulation, can be used by engineering design. Like the preliminary appraisal of pre-heater monomer's performance, the size reasonable choice of pre-heater's certain structure, the choice of pre-heater's work wind speed as well as system's performance computation, appraisal and so on.