Abstract: After the low-NOx reformation of a 90 t/h natural circulation gas boiler burner in a refinery, the operation adjustment is always unsatisfactory. Under 40%～90% load conditions, the temperature differences of furnace chamber, high temperature/low temperature section of superheater and flue gas on both sides of coal saver are large, the NOx content and the oxygen content are high, and the emission concentration of particulate matter is high. After analysis, the main cause of these problems is the uneven air distribution of the four burners. In response to this problem, the air distribution of the four burners is optimized and adjusted. After optimization, the temperature difference of flue gas on the α/β side of the boiler coal saver is reduced by 30 ℃, the temperature difference of the two sides inside the furnace chamber is reduced by 9 ℃, the temperature difference of the high temperature sections of the superheater is reduced by 40 ℃/30 ℃, and the temperature at each measuring point changes greatly on the α side and slightly on the β side. The content of NOx decreased by nearly 100 mg/m3, the concentration of particulate matter is reduced from 16.3 mg/m3 to 5.8 mg/m3, which effectively solves the problems of partial combustion on both sides of the boiler, uneven distribution of O₂, high content of NOx, and high emission concentration of particulate matter.

Key words: boiler, air distribution method, oxygen distribution, particle concentration, optimization adjustment, experimental study

摘要： 某炼油厂90 t/h自然循环燃气锅炉燃烧器低氮改造后，运行调整总是不太理想。在40%～90%负荷工况下，出现炉膛和过热器的高温/低温段、省煤器两侧烟气温度(烟温)偏差大，NOx、氧含量及颗粒物排放浓度较高的问题。经过分析，造成该现象的主要原因是4个燃烧器配风不均。针对此问题，对4个燃烧器配风进行了优化调整，优化后的锅炉省煤器α/β侧烟气温差较原来减少30 ℃，炉膛内部两侧温差较原来减少9 ℃，过热器高温/低温段温差较原来减少40 ℃/30 ℃，各侧点温度α侧变化较大，β侧变化较小。NOx平均质量浓度下降了近100 mg/m3;颗粒物质量浓度由16.3 mg/m3降低到5.8 mg/m3。有效地解决了锅炉两侧燃烧偏烧和氧气分布不均匀及NOx、颗粒物排放浓度较高的问题。

关键词: 锅炉, 配风方式, 氧分布, 颗粒物浓度, 优化调整, 试验研究