W火焰锅炉低氮燃烧器改造问题与解决方案

Problem and Solution of Low NOx Burner Modification in W Shaped Flame Boiler

＂W＂火焰锅炉为了燃烧难燃无烟煤,通常采取高煤粉浓度、高温、高氧量集中送风、高停留时间方式组织燃烧,而高氧量集中送风是造成锅炉NOx排放浓度高达1 200-2 000 mg/m^3的主要原因。某电厂300 MW机组采用＂W火焰＂燃烧方式,NOx排放浓度约600-1 300 mg/m^3。为了能够节能减排,通过燃烧器、分级配风、卫燃带这三个方面进行了低氮燃烧改造。改造后NOx排放浓度达到了预期改造效果,将脱硝入口NOx排放浓度降低到800 mg/m^3以下。针对改造后产生的锅炉严重结渣问题,采用卫燃带改造的方法进行解决。

In order to combust hard anthracite,pulverized coal with high concentration,high temperature,central air supply with high oxygen content,high resident time to organize combustion were utilized in W shaped flame boiler. However,central air supply with high oxygen content is the main reason why boiler＇s NOx emission concentration reaches 1 200 - 2 000 mg / m^3. A power plant with 300 MW unit used ＂W shaped flame＂combustion mode and NOx emission content was about 600 - 1 300 mg / m^3. In response to national policy of energy saving and emission reduction,low-nitrogen retrofit was conducted through burner,staged air distribution and refractory belt.The results show that NOx emission content reached expected goal and it was lower than 800 mg / m^3 at the entrance of denitration facility after retrofit. And serious problem of slag bonding after retrofit was solved by refractory belt reconstruction.