旋转喷雾塔Ca(OH)_2/NaClO_2联合脱硫脱硝数值模拟

Numerical simulation of simultaneous desulfurization and denitration using Ca( OH)_2/NaClO_2 in rotary spray tower

针对开发低温烟气联合脱硫脱硝技术的需求,采用欧拉-拉格朗日方法,建立了旋转喷雾塔气固流动与脱硫脱硝反应耦合的三维数理模型.气相场采用k-ε湍流模型,SO2,NOx的吸收采用双膜理论模型.以2个180 m2烧结烟气的旋转喷雾塔为模拟对象,采用Ca(OH)2/NaClO2浆液作为吸收剂,考察了NaClO2/Ca(OH)2摩尔比、烟气流速、烟气温度、SO2和NO的浓度等对烟气二氧化硫和氮氧化物脱除效率的影响.研究结果表明:随着溶液中NaClO2/Ca(OH)2摩尔比的增加,氮氧化物的脱除效率显著提高,二氧化硫的脱除效率无明显变化;随烟气流速、温度的增大,二氧化硫以及氮氧化物脱除效率均有所降低;氮氧化物的脱除效率随SO2浓度的增大无显著变化,而二氧化硫的脱除效率明显降低;随NO浓度的增加,氮氧化物脱除效率明显降低,二氧化硫脱除效率无显著变化.

A three-dimensional numerical model of a rotating spray tower gas-solid flow coupling with simultaneous desulfurization and denitration reaction was set up on the Euler-Lagrange approach for the demand of the development of low temperature flue gas desulfurization and denitration technology.The k-εturbulence model was used for the gas phase,and the two-film theory absorption model for the absorption of SO2,NOx.The investigation of the influence of NaClO2/Ca（OH）2 molar ratio,gas velocity,gas temperature,SO2 and NO concentration on the removal efficiency of sulfur dioxide and nitrogen oxides using Ca（OH）2/NaClO2 slurry as the absorbent was carried out on a model of 2 ×1 80 m^2 sintering gas rotating spray tower.Research results show that with the increase of NaClO2/Ca（OH）2 molar ratio,the removal efficiency of nitrogen oxides increases significantly, while the removal efficiency of sulfur dioxide has no obvious change.With the increase of gas velocity and temperature,both the removal efficiency of sulfur dioxide and nitrogen oxides decrease.The removal efficiency of nitrogen oxides has no significant change with the increase of SO2 concentration,while the removal efficiency of sulfur dioxide decreases obviously.With the increase of NO concentration,the removal efficiency of nitrogen oxides decreases obviously,while the removal efficiency of sulfur dioxide has no significant change.