基于数值模拟的660 MW塔式锅炉SCR脱硝流场优化研究

Research on Flow Field Optimization of SCR Denitration in a 660 MW Tower Type Boiler Based on Numerical Simulation

针对某电厂660 MW塔式锅炉SCR脱硝系统出口氨逃逸率大、流场不均等问题,利用流体分析软件对SCR脱硝反应器烟道流场进行数值模拟,并对SCR入口导流板进行优化研究。结果表明,SCR反应器入口NO_(x)质量浓度不均匀度为4.73%,烟气流速不均匀度为12.76%,均达到设计要求,SCR反应器出口氨逃逸分布不均,氨逃逸平均值为3.61 mg/Nm^(3),测孔2位置氨逃逸超标严重,达到7 mg/Nm^(3)。

In order to solve the problem of large ammonia escape rate and uneven flow field at the outlet of SCR denitrification system in a 660 MW tower type boiler power plant,the flow field in flue of SCR denitrification reactor is numerically simulated by using fluid analysis software,and the optimization of inlet guide plate is studied.The results show that the non-uniformity of NO_(x) concentration at the inlet of SCR reactor is 4.73%,and the non-uniformity of flue gas velocity is 12.76%,which all meet the design requirements.The ammonia escape distribution at the outlet of SCR reactor is uneven,and the average value of ammonia escape is 3.61 mg/Nm^(3).The ammonia escaping from the 2 test-hole is seriously over the standard,which reaches 7 mg/Nm^(3).