LNB+SCR联合脱硝技术在贫煤锅炉上的应用

LNB+SCR Combined Technology Used in Lean Pulverized Coal Boiler

介绍了LNB+SCR联合脱硝技术原理及工艺流程,阐述了综合脱硝技术在220 t/h贫煤炉上的工程应用以及SCR在设计安装过程中的关键技术措施。通过对燃烧器进行低氮燃烧器改造,并在三次风上增加燃尽风,在启动低氮模式运行后,炉膛出口NO_x浓度由改造前的840 mg/m^3(标准状态,以下同)降至600 mg/m^3以内;在高温预热器和低温省煤器间将烟气引出,在锅炉烟道背后新增SCR装置,烟气通过SCR装置反应后,NO_x排放浓度由入口的600 mg/m^3降至100 mg/m^3以内,SCR装置出口各类指标完全达标,取得了很好的环保效益。

LNB and SCR are the most mature and widely used denitration technology in the world at present. This thesis mainly introduces the principles and technological process of denitration technology. It also elaborates on the project application of comprehensive denitration technology on the 220 t/h pulverized coal boiler and the key technical measures of designing and installing SCR. Through LNB retrofitting, adding SOFA wind to the third air and starting low-nitrogen operation mode, the furnace exit NOx of the 220 t/h pulverized coal boiler has been reduced from 840 mg/m3 to below 600 rag/m3; The second step is extracting the flue gas between high-temperature preheater and low-temperature economizer, and adding SCR device behind boiler. The NOx concentration is reduced from 600 mg/m3 in the inlet to 100 mg/m3 in the emission, and all kinds of indicators like the content of nitrogen oxides in gas meet standards, achieving good environmental benefits.