喷嘴角度对循环流化床脱硫工艺塔内流动特性影响的数值模拟

摘要

The CFB-FGD process is a semi-dry flue gas desulfurization technology used at the end of the boiler. Considering multiple complex chemical reactions in the desulfurization tower,the mixing level of the gas-liquid-solid in the desulfurization tower would be one of the dominant factors of the reactions. Considering the high cost to build the desulfurization test bench,this paper presented a numerical simulation for flow field of desulfurization reactor using a pseudo-homogeneous fluid model in order to improve the flow field in the circulating fluidized bed desulfurization reactor with nonuniformity generated by its nozzle angle. The influencing mechanism of nozzle angle (-30°,0° and 30°) on the gas-liquid-solid flow field in the desulfurization tower was discussed. The results showed that at nozzle angle of -30°,the nonuniformity of the flow field was reduced in the circulating fluidized bed the volume fraction distribution of the desulfurizer particles had better uniformity and the mixing of the gas-liquid-solid three phase was better,resulting in a better efficiency of desulphurization.%循环流化床脱硫工艺（CFB-FGD）是一种国际上新兴起的用于锅炉尾部烟气、先进的半干法烟气脱硫技术，由于建立脱硫实验台成本较高，为了改进循环流化床脱硫塔内喷嘴布置角度所造成的脱硫塔内区域不均匀气流场，本文采用拟均相模型对脱硫塔内的流场进行了数值模拟计算，讨论了喷嘴布置角度（-30°、0°和30°）对脱硫塔内气液固三相流场的影响机理，结果表明：3种喷嘴布置角度下，喷嘴呈-30°布置时，脱硫塔内的流场不均匀性降低，脱硫剂颗粒体积分数分布较均匀，有利于气液固三相的混合，有利于脱硫塔内化学反应的进行。