W火焰锅炉低氮燃烧器改造问题与解决方案

摘要

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 con⁃centration reaches 1 200 ~2 000 mg/m3 . A power plant with 300MW unit used “W shaped flame” combustion mode and NOx emission content was about 600~1 300 mg/m3 . 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 800mg/m3at the entrance of denitration facility after retrofit. And serious problem of slag bonding after retrofit was solved by refractory belt reconstruction.%“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1200～2000 mg／m3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600～1300 mg／m3。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／m3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。