半干法压力旋流式喷嘴雾化性能数值模拟

Numerical simulation on atomizing performance of pressure swirl nozzle for semi-drying FGD

摘要:

对压力旋流式脱硫雾化喷嘴雾化特性进行了数值模拟研究,分析了各因素对雾化液滴粒径的影响,得到了喷嘴下游流场内液滴粒径和速度空间分布.计算结果表明:雾化液滴粒径与雾化压力和喷嘴直径成正比,与雾化介质黏度和表面张力成反比;液滴速度沿轴向方向急剧衰减,在距喷嘴200mm处几乎不发生变化,而在径向方向上呈中心低,边缘高的分布;在破碎和聚合的作用下,液滴粒径沿轴向方向呈先减小、后增加的趋势,大颗粒主要集中在雾炬外围.试验结果与计算值基本吻合.

Abstract:

The numerical simulation on spray characteristic of pressure swirl nozzle was carried out,and the main factors effecting the atomizing performance of the nozzle were studied.The distributions of velocity and diameter of droplets were obtained at different special sections.Simulation results were compared with the experimental results.The simulation results indicate that the droplet size is proportional to pressure and nozzle diameter,and inversely proportional to viscosity and surface tension of liquid.Along the spray axis,droplet velocity decreases acutely,and keeps steady at the downstream of 200 mm.Along the radial direction,the axial velocity of droplet in the center is lower than that on the edge,where the droplet size is maximum.Due to droplet collision and breakup,the droplet size decreases first,and then slowly increases.The simulation results are in good agreement with experimental results.