摘要
为提高某660MW机组选择性催化还原(selective catalytic reduction,SCR)脱硝系统出口NOx浓度分布均匀性,基于性能试验的实测烟气数据作为模拟入口边界条件,对烟气的湍流流动、多组分扩散和化学反应进行CFD数值计算。模拟分析了100%、75%和50%这3个典型工况下的烟气流场规律,得到5个分区及42个喷嘴喷氨对催化剂入口截面18个区域氨浓度分布影响因子,建立并求解最优喷氨量的矩阵方程。对优化后的喷氨量进行模拟得到3个工况出口NOx浓度的相对标准偏差分别为13.7%、15.3%和17.6%,出口均匀性显著提高。结果表明采用影响因子定量计算最优喷氨量的方法适用于不同工况,且计算效率高,为实际喷氨优化调整试验和运行提供理论参考。
In order to improve the uniformity of the NOx concentration distribution at the outlet of the selective catalytic reduction(SCR) DeNOx system of a 660 MW unit, the measured flue gas data based on the performance test was used as the simulated inlet boundary condition. The turbulent flow, multi-component diffusion and chemical reaction of the flue gas were calculated by CFD numerical simulation. The flue gas flow fields under three typical loads(i.e., 100%, 75% and 50%) were simulated and the patterns were analyzed.The influential factors of 5 zones and 42 nozzles on ammonia concentration distribution in 18 zones of catalyst inlet section were obtained, and the matrix equation of optimal ammonia amount was established and solved. The simulation of the optimal ammonia amount shows that the relative standard deviations of the outlet NOx concentration of the three working conditions are 13.7%, 15.3% and 17.6% respectively, and the outlet uniformity is significantly improved. The results show that the method of quantitatively calculating the optimal ammonia injection amount by using the influential factor is suitable for different working conditions, and the calculation efficiency is high, which provides a theoretical reference for the actual ammonia injection optimization adjustment test and operation.
作者
卢志民
李文庆
廖永进
姚顺春
成明涛
吴康洛
LU Zhimin;LI Wenqing;LIAO Yongjin;YAO Shunchun;CHENG Mingtao;WU Kangluo(School of Electric Power,South China University of Technology,Guangzhou 510640,Guangdong Province,China;Guangdong Electric Power Research Institute Energy Technology Co,Ltd,Guangzhou 510030,Guangdong Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2021年第14期4923-4930,共8页
Proceedings of the CSEE
基金
国家自然科学基金(51876068)
广东省自然科学基金(2018A030313800)。
关键词
喷氨优化
数值模拟
选择性催化还原脱硝反应
影响因子
NOx浓度场
ammonia spraying optimization
numerical simulation
selective catalytic reduction(SCR)DeNOx reaction
influential factors
NOx concentration field
