采用FLUENT软件对SCX型脱硫除尘器内部气固两相流场进行数值模拟。气相采用Realizable k-ε湍流模型,颗粒相采用离散相模型(DPM),压力-速度耦合算法选择SIMPLE进行计算。分析了装置内z=0截面上气相压力和速度的分布,并对不同粒径颗粒的浓度和运动轨迹进行计算,还在考虑重力及不考虑重力2种情况下分析了颗粒的浓度分布。结果表明:装置内压降最大处为改性文丘里管下部的导流板,其压降超过1 000 Pa;改性文丘里管内烟气的旋转程度较小,锥体中存在多处不同程度的回流;重力对离散相颗粒浓度的分布影响较小,锥体下部的颗粒浓度非常大,达0.01 kg/m3。模拟结果对设备的优化设计和实际运行有一定的指导作用。
Realizable k-ε turbulence model,discrete phase model(DPM) were used in the simulation of three-dimensional gas-solid flow in the SCX dedusting and desulphurization scrubber by using FLUENT package.The SIMPLE which is one type of pressure-velocity coupling algorithm was used in the calculation.The distributions of gas pressure and velocity at cross-section of z=0 in the scrubber were analyzed deeply,the concentration distribution of different size particles and the particle trajectories were computed as well.The concentration distribution of particles with and without the influence of gravity were also researched.The simulation results show that there is the maximum pressure drop on the gas deflector,over 1 000 Pa.In inner-pipe,the vortex of gas is weak,and some backflows phenomenon are observed in the cone shell.The gravity barely influences the distribution of the fly-ash and the particle concentration in the lower part of cone shell in which there is the highest concentration is up to 0.01 kg/m^3.Furthermore,the simulation results are of major significance for the optimization design and practical operation.