SCR脱硝技术在广州恒运热电厂300 MW机组上的应用

SCR De-NO_x technologies applied in the 300 MW units of Hengyun Power Plant

近年来国家环保总局已批复20个左右的电厂要求安装烟气脱硝装置,采用的工艺有SCR、SNCR和SNCR+SCR组合,但使用较多的还是SCR工艺。结合广州恒运热电厂的SCR脱硝项目,介绍了SCR工艺的原理、流程、技术特点和运行成本分析等,阐述了SCR工艺具有技术成熟、运行易于控制、安全可靠、脱硝率高、运行成本比较低等优点,针对SCR工艺存在的空气预热器积盐堵塞提出了预防措施:(1)降低氨气逃逸量,严格控制在3×10-6以下;(2)采用低SO2/SO3转化率的脱硝催化剂;(3)降低飞灰含碳量;(4)选择合适的空气预热器和吹灰系统;(5)采用低过量空气燃烧方式。

In recent years, the State Environment Protection Administration of China has approved about twenty power plants to construct flue gas De-NOx equipment. The De-NOx technologies applied covers SCR,SNCR,SNCR ＋SCR, most of which adopt SCR technology. Based on the De-NOx projects in Hengyun Thermal Power Plant, this paper introduced the principle, process, technical performance and operation cost of SCR and pointed out its strong points as well, such as mature technology, easy control, safe and reliable operation, high efficiency and low cost etc. In addition, several measures were put forward to prevent the salt blockage in the air preheater, such as reducing the ammonia escapement to be no more than 3×10^-6; using catalyst with low transform rate of SO2/SO3; cutting down the carbon content in fly ash; selecting suitable air preheater and soot blowing system; burning with low excess air.