The Numerical Simulation Of Gas Solid Flow In A Circulating Fluidized Bed

During quite some time for the future, coal will still be the main source of energy. With advantages of fuel adaptability, high combustion efficiency, high desulfurization efficiency and low emission of NOx, CFB boiler has been used widely. As a technique of clean coal combustion technology, CFB technique will get more attention both at home and abroad.Due to the complex mechanisms of CFB technique, guiding engineering practice largely depends on traditional experience and limited data from laboratories, therefore, with computing ability being enhanced and development of pulverized coal combustion model, the numerical simulation become an important tool to cover the shortages of traditional experiments.Because the Euler two fluid model treats the discrete phase as non-individual body and solves the average value of the discrete phase by the numbers, much time cost is cut.This paper used Euler two fluid model to catch on 2-D cold simulations of the fluidized bed and the circulating fluidized bed, used the Gidaspow drag model to explain the interactionforce between the gas and solid phases, got idea partical distribution which is called "core-annular" structure,it shows that particles in the central zone rise quickly and drop near the wall and concentration of the solid phase is high in the lower zone while low in the higher zone. Researches on influencements of single parameter's variations were catched on by using different diameter of particle, restitution coefficient, inlet velocity to, and observed distributions of solid volume fraction and pressure in order to provide some references to engineering.