伞罩型除尘脱硫塔内气固二相流数值模拟分析

Numerical simulation and analysis for gas-solid two-phase flow in dedusting and desulphurization tower with umbrella type plates

利用FLUENT软件对新型的伞罩型湿法除尘脱硫塔内的三维二相流场进行数值模拟,气相采用κ-ε湍流模型,颗粒相采用离散相模型(DPM)和欧拉模型,选择SIMPLEC算法进行计算。分析塔内x=0截面的气固二相的浓度,体积分数、速度矢量和压力等参数的分布。结果表明,伞形罩使烟气在塔体内分布得更均匀,延长了气体在塔内停留时间,从而实现高效净化气体的目的;在入口粉尘浓度很低的情况下,DPM更适合气固二相流。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。

κ-ε turbulence model, Eulerian model and discrete phase model （DPM） were used in the simulation of three-dimensional two-phase flow in the new type wet dedusting and desulphurization tower with umbrella type plates by using FLUENT package, and SIMPLE algorithm was used in the calculation. The distributions of the gassolid volume fractions and fly-ash concentration, velocity and pressure at cross section of x = 0 were analyzed. The simulation results show that the umbrella type plates can make gas distribute more even and residence time longer in the tower, so that the dust gas can be purified with high efficiency. DPM is more suitable for the gas-solid simulation when fly-ash concentration is very low. Furthermore, the simulation results are of major significance for the optimization design and practical tower operation.