某电厂选择性催化还原脱硝系统运行案例分析

Case study of selective catalytic reduction for denitrification system of a certain power plant

以某200 MW超高压中间再热供热式汽轮发电机组选择性催化还原(SCR)脱硝系统为例,结合运行中出现的脱硝效率不达标、氨逃逸率不稳定、空气预热器堵塞等突出问题,分析其原因为脱硝系统长期脱离设计值运行、部分空气预热器堵塞等。提出了解决措施,设计脱硝系统最低安全运行温度,确保实际运行时反应器内催化剂入口烟气分布均匀,定期检测催化剂物性指标,为电站锅炉SCR脱硝系统安全、高效、稳定运行提供指导。

Take SCR reheat heating type in 200 MW ultrahigh pressure steam turbine generator unit as an example,and combined with the problem of unsatisfied of denitration efficiency,unstable ammonia escapement ratio and blocking air preheater,this paper analyzed that the reason is because denitrification system was running away from the design value for a long time and several air preheater was blocking. In the end,this paper put forward countermeasures for above problems and set up the lowest temperature of safe operation to make sure flue gas is homogeneous distribution at the catalyst inlet of the reactor during actual operation. This proposal provides a security,high efficiency and stability guidance for SCR denitrification system.