新型工业煤粉锅炉运行及排放特性试验研究

Performance and Emission Characteristics of a New Industrial Pulverized Coal Boiler

为了改善工业煤粉锅炉的NO_x排放特性并保证其燃烧效率,对某新型空气分级燃烧器进行了现场试验.通过改变煤种、过量空气系数及三次风开度,分析了锅炉NO_x及CO排放质量浓度的变化规律,同时采用反平衡法对锅炉的热效率进行了测算.试验结果表明,工业煤粉锅炉能达到较高的热效率;煤中氮含量及挥发分含量与NO_x的生成具有一定的相关性,氮含量越高,NO_x排放质量浓度越高,挥发分含量越低,NO_x排放质量浓度越高;过量空气系数和三次风开度不仅影响锅炉燃烧效率,而且对NO_x排放的影响也较为显著.研究发现,试验锅炉的排烟氧含量(质量分数)应控制在2.5%~2.6%之间较为合理,三次风开度为39%时NO_x排放质量浓度最低.

To improve the nitrogen oxides （NOx） emission characteristics of industrial pulverized coal boiler and guarantee its combustion efficiency, field test was carried out on a model of air staged burner newly developed by a company in Shanghai. The emission characteristics of NOx and carbon monoxide （CO） were analyzed by changing the coal type,excess air coefficient and opening of the tertiary air. At the same time, Thermal efficiency of the boiler was calculated by anti-balance method. Experimental results showed that high thermal efficiency of this industrial boiler could be achieved. The nitrogen content and volatile content in the coal samples had some correlations with NOx generation. The higher the nitrogen content, the higher the NOx emission was. The lower the volatile content, the higher the NOx emission was. The excess air coefficient and opening of the tertiary air not only had influences on the combustion efficiency of the boiler, but also had significant influence on the NOx emission. It was reasonable to control oxygen content in the flue gas between 2.5% and 2.6%. The lowest NOx emission was achieved when the opening of the tertiary air was 39%.