300 MW贫煤锅炉低氮燃烧系统改造及性能优化

APPLICATION AND PERFORMANCE OPTIMIZATION OF LOWNITROGEN COMBUSTION SYSTEM RETROFIT FOR 300 MW LEAN COAL-FIRED BOILER

针对300 MW贫煤锅炉,进行了低NOx燃烧系统改造和性能优化实验,研究了低氮燃烧器组合深度空气分级低氮燃烧技术对贫煤燃烧锅炉NOx排放的影响规律和控制效果.结果表明,锅炉采用新型低氮燃烧器、全炉膛深度分级燃烧改造后,锅炉SCR脱硝系统入口NOx浓度可由改造前约1 100mg/m3(干态,6%氧量)下降至改造后的460mg/m3(干态,6%氧量)左右,氮氧化物排放浓度平均降幅达到50%以上.改造方案及实验结果可为贫煤燃烧锅炉低NOx燃烧改造和运行优化提供借鉴.

This paper introduces the application and performance optimization of low- nitrogen combustion technology in nitro oxides（NOx） emissions control for a lean-coal fired 300 MW tangentially fired boiler. Effects of the combination of low-nitrogen burner, air-staged com- bustion technology and tertiary air down-operating technology on the control of NOt emissions are studied. The experimental results indicate that after the retrofit on the combustion system by the application of new tyl^e low-nitrogen burner together with air-staged combustion and tertiary air down-operating, the NOx emission concentration at the entry of SCR-denitration system can be lowed to around 460 mg/m3（O2=6% O2, dry） from 1 100 mg/m3（O2=6% 02, dry）. The NOx emission concentration drops by more than 50% averagely, which proves that the retrofit is effective. The retrofit solution and experimental results can be taken as a reference for the low NOx retrofit and performance optimization of lean coal-fired boilers.