SCR脱硝系统烟道内流场优化

Optimization of flow field in the SCR denitrification system

为了改善选择性催化还原法(SCR)催化剂上游烟气的流场、温度场和浓度场分布,基于CFD仿真分析技术,建立了整个脱硝系统三维模型,并通过优化导流板及整流格栅,使得速度标准偏差、浓度标准偏差、温度偏差、速度偏转角以及压降等性能指标都满足设计要求,在满足脱硝效率和氨逃逸率前提下,大大降低了烟气对催化剂层的冲刷,保证催化剂的使用寿命。最后,为了合理布置吹灰器,对优化结构下粉尘颗粒在烟道内的运动情况进行了仿真分析研究,为设计提供了依据。

In order to improve the distribution of flow,temperature and the concentration at the first layer of the upstream catalyst in the selective catalytic reduction(SCR) system,a three-dimensional model of the entire denitration systems was established based on CFD simulation technology.Then,by optimizing the guide plate and rectifier grilles,performance indicators including the standard deviation of velocity,standard deviation of concentration,temperature deviation,velocity deviation angle and pressure drop and so on,meet the design requirements.At the same time,under meeting the denitration efficiency and ammonia slip rate conditions,the optimized structure greatly reduces the gas erosion on the catalyst layer to ensure the catalyst durable life.Finally,under optimized conditions,we also simulated the dust particles motion,providing the basis for a better arrangement of soot blowers.