摘要
针对某650 MW机组W炉SCR系统静态混合器在非均匀来流条件下的布置及喷氨优化进行了数值模拟研究。通过分析常规导流板设计下SCR系统内流场,提出利用静态混合器对SCR系统进行分区流场优化。大范围混合器布置在脱硝入口烟道,分区混合器布置在喷氨格栅下游并将烟道划分为3个分区。经分区流场优化后,SCR系统内流速、温度和NOx浓度分布均有明显改善,首层催化剂入口氨氮摩尔比峰值从1.50降至1.06,但系统阻力增加了177 Pa。为了进一步改善SCR系统内氨氮匹配性,提出分区喷氨优化方案。经分区喷氨优化后,首层催化剂入口的氨氮摩尔比峰值从1.06降至0.98。在非均匀来流边界条件下,分区流场优化结合分区喷氨优化是改善SCR系统内部流场并降低氨逃逸率的最优方案。
The numerical simulation study on the static mixer layout and ammonia injection optimization of the SCR system in a 650 MW W-flame boiler under non-uniform intake flow conditions was carried out.Under the non-uniform intake flow conditions, the flow field of the SCR system with the normal guide plates was analyzed, and then the static mixers were proposed for the partitioned flow field optimization.The wide range mixers were installed in the inlet flue duct of the SCR system.The zonal mixers were installed in the downstream of the ammonia injection grid(AIG),and the flue dust was divided into 3 sections.After the partitioned flow field optimization, the distributions of velocity, temperature and NOx concentration of the SCR system were improved dramatically, and the NH3/NOx peek molar ratio at the entrance of the first catalyst layer was reduced from 1.50 to 1.06,but the system resistance was increased by 177 Pa.The partitioned ammonia injection optimization was proposed to further improve the ammonia nitrogen matching in the SCR system.After the partitioned ammonia injection optimization, the NH3/NOx peek molar ratio at the entrance of the first catalyst layer was reduced from 1.06 to 0.98.For the improvement of the SCR flow field and the reduction of the ammonia escape, the optimum solution was to combine the partitioned flow field optimization with the partitioned ammonia injection optimization.
作者
李源
毛睿
任利明
岑可法
LI Yuan;MAO Rui;REN Li-ming;CEN Ke-fa(Rundian Energy Science and Technology Co.,Ltd.,Zhengzhou,China,450052;State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou,China,310027)
出处
《热能动力工程》
CAS
CSCD
北大核心
2021年第6期78-85,共8页
Journal of Engineering for Thermal Energy and Power
基金
国家自然科学基金创新研究群体项目(51621005)。
关键词
SCR
非均匀来流
静态混合器
分区喷氨
数值模拟
SCR
non-uniform intake flow
static mixer
partitioned ammonia injection
numerical simulation
