300MW级燃煤机组SCR烟气脱硝超低排放性能评估

Evaluation on Ultra-Low Emission Performance of SCR Flue Gas Denitrification Device for 300-MW Class Coal-Fired Units

对脱硝超低排放机组进行性能评估与分析,可为超低排放形势下燃煤机组选择性催化还原法(SCR)烟气脱硝装置的稳定、高效、经济运行提供借鉴及指导。某3台300 MW级燃煤机组SCR脱硝装置已实现NOx超低排放,以此为例,对其脱硝装置的脱硝效率、进出口NOx浓度分布、出口速度分布、氨逃逸率、SO2/SO3转化率、系统阻力等运行参数进行了评估,掌握了此类机组脱硝装置主要性能。试验结果表明,3台300 MW级燃煤机组脱硝装置整体性能良好,但存在流场不均、飞灰堵塞、氨逃逸超标等问题,为此提出了避免此类问题的方法和建议。

The evaluation and analysis on the ultra-low emission performance of SCR denitrification device can provide reference and guideline for its stable, efficient and economic operation. Taking the SCR denitrification device of three 300 MW coal-fired units with ultra-low emissions for example, the operation parameters are evaluated, such as the denitrification efficiency, the inlet/outlet NO~ concentration distribution, the outlet flue gas velocity distribution, the ammonia escape rate, the conversion rate of SO2 into SO3, and the system resistance. Thusthe major properties of the device are obtained. The test results show that the overall performance of the device is good, but there still exist some problems such as flow field imbalance, fly ash clogging and excess ammonia escape. Therefore, the methods and recommendations are proposed to solve such problems.