低氮燃烧器改造及运行调整方法探讨

介绍了NOx生成机理及双尺度低NOx燃烧技术,指出低NOx燃烧器改造后运行的核心是控制炉内局部区域的空燃比和炉内燃烧的最高温度。介绍了1台300 MW机组锅炉进行双尺度低NOx燃烧器改造的方案,改造后NOx的排放值能大幅降低。探讨了低NOx燃烧器改造后锅炉的优化控制以及对锅炉经济性的影响。运行氧量降低能够有效降低NOx的生成,然而却会导致飞灰含碳量的增加。同样地,加大燃尽风量也能减少NOx,但飞灰含碳量也会相应增加。在不同的煤质、机组负荷、磨煤机组合的情况下,NOx的排放也会有所区别。本文可为国内燃煤锅炉低NOx燃烧器的改造及优化运行提供借鉴。

Study of Low NOx Burner Retrofit and Operation Adjustment

This paper introduces the formation mechanism of NOx and the low NOx technology with the double-scale. It shows that the core of operation is controlling the ratio of air to coal and the highest temperature in the furnace for the low NOx burner. The low NOx burners with the double-scale are adopted for the 300 MW unit in a power plant and the reconstruction scheme is introduced in detail. The optimized controlling mode is studied for the boiler with the low NOx burners and the impact of the mode on the economy is analyzed. The NOx will decrease while the un- burned carbon in the flue gas will increase when increasing the air during the combusting process. Similarly, the NOx will also decrease while the unburned carbon in the flue dust increases when increasing the proportion of the overfire air. The emission of NOx could be influenced by the various combination of coals, unit loads and the pulverizers. The present study could be reference for the domestic power plants in the retrofit and optimized operation of Low NOx burner.