1000MW机组烟气脱硝系统烟道流场优化

摘要

In this study,the numerical simulation of the flue flow field in the selective catalytic reduction(SCR)reactor of a 1 000 MW boiler is carried out and the ammonia injection system is optimized.By using the Computational Fluid Dynamics module for fluid numerical simulation,the airflow distribution of the denitration system is analyzed and studied.Using partition type vortex ammonia injection optimized device,on the basis of the original denitration system,the flue section has realized the control of the ammonia injection by setting the double row eddy mixing device.This can significantly improve the uneven distribution of ammonia gas and the controllability of ammonia injection control so as to improve the denitration efficiency and reduce the ammonia escape.The optimization results show that the distribution deviation of NOx concentration at the export of SCR reactor is greatly reduced,which verifies the effectiveness of the optimization scheme.%对某1 000 MW机组锅炉选择性催化还原(SCR)烟气脱硝系统反应器内烟气流场进行数值模拟,并对氨喷射系统进行优化.利用CFD(computational fluid dynamics)模块进行流体数值模拟,对脱硝系统的气流分布状况进行分析研究,采用分区式驻涡喷氨优化装置,在原脱硝系统的基础上,通过设置双排涡流混合装置,对烟道截面实现分区域的喷氨控制,可显著改善氨气分布不均现象,提高喷氨控制调节性,从而提高脱硝效率,降低氨逃逸量.结果表明,优化后SCR反应器出口NOx分布偏差大幅降低,验证了该优化方案的有效性.