循环流化床烟气脱硫气固两相流动特性的试验研究

Experimental Research on Gas-Solid Two-phase Flow Characteristic for Flue Gas Desulfurization in Circulating Fluidized Bed

采用三准则相似理论设计了循环流化床烟气脱硫气固两相流动试验台.通过对循环流化床脱硫反应器试验装置内沿高度方向阻力分布和不同高度截面上局部颗粒质量通量的测量,详细地研究了脱硫反应器内气固两相流动规律和内循环特性.结果表明:脱硫反应器阻力主要集中在文丘里管段,而且随着循环物料量和气体流量的增加,系统阻力显著增加;脱硫反应器内气固两相流动呈典型的环核流动结构,边壁下降流颗粒浓度高,中心区域上升流颗粒浓度低,且固体质量回流比率随着脱硫反应器高度的上升而下降.研究结果为循环流化床烟气脱硫系统的设计与放大提供了依据.

Gas-solid two-phase flow test rig for flue gas desulfurization in circulating fluidized bed was designed by use of similitude with three criterions. The gas-solid two-phase flow law and internal circulating characteristics in desulfurizing reactor were studied in detail by measurement for the resistance distribution along the height and local mass flow rate of the particles across the section at different altitude of the desulfurizing test device of circulating fluidized bed. Results show that the resistance of the desulfurizing reactor mainly lies in the Venturi tube section and increases significantly with the circulating solid flow rate and gas flow rate. The gas-solid two-phase flow in desulfurizing reactor is a typical core-annulus flow pattern. The particle concentration of upward flow in central zone is low, while the particle concentration of downward flow near the wall is high. Moreover, the solid mass backflow ratio decreases along the height of the desulfurizing reactor. The studied results will give reference to the design and scale-up of the flue gas desulfurizing system in circulating fluidized bed.