多组分颗粒轨道模型氨法脱硫过程仿真研究  

A Multicomponent Droplet Model in Simulating Mass Transfer of the Ammonia-based Spray Process

作　　者：李立清[1] 张纯[1] 黄贵杰[1] 刘铮[1] 马卫武[1] 

机构地区：[1]中南大学能源科学与工程学院,湖南省长沙市410083

出　　处：《中国电机工程学报》2014年第32期5741-5749,共9页Proceedings of the CSEE

基　　金：国家自然科学基金项目(20976200);湖南省节能减排重大专项(08SK1003)~~

摘　　要：将双膜理论、亨利定律、NH3与SO2间的化学反应通过自定义函数（UDF）的方法导入Fluent多组分液滴模型,计算氨法脱硫塔喷淋过程的脱硫效率。旋流烟气采用RNG k-ε模型,喷淋液滴采用颗粒轨道模型（discrete Particle model,DPM）,应用PISO算法对传质、流动过程进行压力-速度耦合的非稳定计算。计算结果显示：脱硫效率计算值与实验值误差在10%以内;随喷淋液气比增大、喷淋液温度及入口烟气中SO2浓度的降低,脱硫效率升高;喷淋液初始温度从40升高至50℃时,脱硫效率从91%迅速降至80%;在脱硫塔液气比较低时,增大液气比（0.5～1.8 L/m^3）能明显提高脱硫效率（65%～93%）;当进口SO2浓度从1 208升高到4 832 mg/m^3时,在塔高平面上,壁面与外塔中间区域的浓度差（300～1 050 mg/m^3）增大,不均匀性增强。Fluent传质反应模型能综合反映不同工况下脱硫塔运行状况,指导设备的优化设计。A mass-heat transfer and instantaneous chemical reaction model was built and analyzed by incorporating dual-film theory,Henry＇s law and various appropriate empirical and semi-empirical correlations of mass-heat transfer into the computational fluid dynamics（CFD） software package through User Defined Functions.Trajectories were calculated by discrete particle model（DPM）; the flow pattern of flue gases was described by the local averaged Navier-Stokes equation closed via the RNG k-ε model.PISO algorithm was adopted to calculate the pressure-velocity coupled unsteady flow.The experimental results are in good agreement with the calculation with relative error of around 10%,which proves the rationality of the mathematical model.Results show that the desulfurization efficiency（η） decreases with the increase of the slurry temperature and the initial concentration of SO2,or with the decrease of liquid-gas ratio.Since NH4HSO3 decomposes at around 50 ℃,η decreases significantly from 91% to 80% as the slurry temperature varied from 40 to 50 ℃.η is improved from 65% to 93% with the increase of liquid-gas ratio from 0.5to 1.8 L/m^3.With the increase of initial SO2 concentration from 1 208 to 4 832 mg/m^3,the heterogeneous of distribution of SO2 concentration increases.The distribution of absorbent and species can be directly displayed by the mass-transfer model,which offers instructions for operation and optimization.

关 键 词：氨法脱硫 Euler-Lagrange坐标系 多组分传质液滴模型 环栅喷淋泡沫塔 流体计算 

分 类 号：TK121[动力工程及工程热物理—工程热物理]