中文摘要：

该文建立了撞击流吸收器湿法同时脱硫脱硝化学反应与气液两相流动的三维数学模型。数值模拟采用双欧拉法对吸收器中气液两相流的流动特性进行描述，并通过双膜理论耦合了相关的化学反应。模拟计算发现：气相流场呈“镜像”对称分布；撞击面两侧存在4个烟气流线密集且对称反向螺旋上升的旋流柱；撞击区范围内存在很大的压力梯度和速度梯度，撞击中心处气相的静压力达到最大值；（NH4）2SO3，在加速管内的流动过程中迅速生成，而部分接近液相主流区的（NH4）2S03逐渐被氧化成（NH4）2S04，脱硫效率达96．8％；同时发现，加速管内NO的浓度则几乎不变。SO2和NO浓度在撞击区内迅速降低，NO吸收反应（包括与NH4）2SO3，的协同反应）大部分发生在撞击区内，尿素对HN02具有明显还原分解作用。反应器内氮氧化物中氮元素在脱硝后的主要赋存形态是NO3-，无添加剂条件下脱硝效率达49．2％。

英文摘要：

A 3-D numerical model was used to investigate the effect of simultaneous desulfurization and denitrification by wet process in an impinging stream absorber. The numerical model was based on the Euler-Euler method, and the two-film theory was introduced to couple the chemical absorption reactions of SO2 and NOx. It is found that gas flow shows ＂mirror＂ distribution and there are four dense symmetric reverse spiral cyclone columns on both sides of impinging surface. It also shows that the gas flow has large static pressure gradient and x-axial velocity gradient in the impinging area, and the static pressure reaches its maximum value in the centre of the impinging area. In the accelerating tube, （NH4）2803 generates immediately, and part of it close to the main liquid flow is gradually oxidized to （NH4）2SO4. The efficiency of desulfurization reaches 96.8%. The concentration of NO remains nearly unchanged in the accelerating tube. The concentration of both SO2 and NO drops sharply, and denitrification reaction （including the reaction with （NH4）2SO3） takes place mainly in the impinging area. Urea exhibits an enhanced effect on reducing HNO2. The nitrogen element from NOx mainly turns into NO3- in liquid phase after the denitrification process. The simulation result shows that the efficiency of denitrification reaches 49.2% without catalyzer,