负荷随动烟气选择性催化还原脱硝控制策略优化研究及工程应用

Study on optimization and engineering application of selective catalyst reduction denitrification control strategy for loading fluctuation

为实现对锅炉负荷随动时喷氨量自动控制的优化,减少选择性催化还原(SCR)系统尿素过量使用和避免氨逃逸,以尿素热解喷氨系统为研究对象,采用模糊算法和前馈反馈控制方法,以NO_x浓度、锅炉负荷以及氨逃逸为控制参数,提出尿素热解控制的优化方案,实现对SCR出口NOx浓度的自动控制。在实际工程项目中应用该控制策略对喷氨量进行控制,结果表明,在锅炉负荷变动较大时能够实现出口NO_x稳定达标排放,氨逃逸小于2.5mg/m^3。

Urea pyrolysis ammonia injection system was investigated as the research object.It was used to optimize the automatic control of ammonia injection when the boiler loading fluctuated.And it could reduce the overuse of urea in the selective catalyst reduction(SCR)system and avoid ammonia leak.Fuzzy algorithm and feed forward feedback control method were utilized,and NO x concentration,boiler loading and ammonia leak were chosen as the control parameters.The optimal solution of urea pyrolysis control was proposed to control NO x concentration of SCR automatically.The control strategy was applied to control the ammonia spray rate for the project.The results showed that the NO x emission could be achieved steadily,and the ammonia leak was lower than 2.5 mg/m 3 when the boiler loading fluctuated greatly.