烧成系统中CO对SNCR系统运行效率的影响及应对措施

Influence of CO on SNCR system operating efficiency in firing system and the countermeasures

分析了当烧成系统煤燃烧不完全对SNCR系统运行效率的影响,结果表明:煤燃烧不完全使得窑尾烟气中CO浓度上升,会明显降低SNCR系统的脱硝效率,必须通过大幅提高SNCR系统的氨氮比从而满足环保排放要求(320mg/m^3,标况下),这样不仅大幅提高了系统运行成本,而且造成烟囱氨逃逸增加。通过调节雾化压力、调整喷枪布置、脱硝反应区温度等措施来降低系统运行氨水耗量。结果表明:雾化压力、喷枪布置对系统氨水耗量几乎没有影响,降低反应区温度可显著减小系统氨氮比,同时保持排放满足环保要求,说明反应区CO的存在会拉低SNCR系统的最佳温度窗口。

The effect of incomplete combustion of coal in clinker burning system to the efficiency of Selective Non-Catalytic Reduction （SNCR） De-NOx system has been analyzed. The result shows： carbon monoxide （CO） concentration rises with incomplete combustion of coal, which reduced the efficiency of SNCR system. To meet the environmental requirement with NO, emission level below 320 mg/m3, increasing mole ration of NH3 to NO （NSR） of SNCR system sharply is necessary. But the measure resulted in increased cost of SNCR system and ammonia escape. Adjusting the atomizing air pressure, spraying ejectors distribution and changing the temperature of De-NO,, reaction region are taken to reduce the consumption of ammonia. The result reveals that reducing the temperature of reaction region is an effective way to decrease the NSR of SNCR system, while changing the atomizing air pressure and the spray ejectors distribution are not relate to the ammonia consumption. It means that the high concentration of CO in reaction region lead the optimal temperature range of De-NO, reaction descending.