摘 要：针对国内某百万千瓦机组塔式炉选择性催化还原（Selective Catalytic Reduction，SCR）烟气脱硝装置两侧反应器喷氨量无法独立调节而造成喷氨不均的问题，结合现场测试数据，采用计算流体动力学（Computational Fluid Dynamics，CFD）数值模拟方法进行双母管供氨优化改造方案的设计及校核。结果表明：相同出口NOx排放浓度时，两侧反应器脱硝效率偏差由改造前的19.0%下降到2.9%，平均氨逃逸浓度由3.7 mg/m3 降低到2.3 mg/ m3，局部氨逃逸浓度由6.2 mg/ m3 降低到2.6 mg/ m3 ，两侧反应器出口NOx 浓度均值偏差得到消除。供氨系统优化改造不仅提升了脱硝装置整体性能，还降低了局部氨逃逸浓度峰值，减轻了空气预热器硫酸氢铵（Ammoniu Bisulfate，ABS）堵塞风险。

Abstract: For a domestic 1 000 MW unit,the ammonia supply system cannot adjust independently for each side of the SCR equipment，resulting in nonuniform ammonia injection.To solve this problem,an ammonia supply system was designed from single pipe to double pipes for SCR by means of CFD method.The field performance test was conducted before and after the retrofitting.The results showed that after the retrofitting,under the same NOx emission condition，the denitration efficiency deviation of the SCR reactors was reduced from 19.0% to 2.9%,the average NH3 slip was decreased from 3.7 mg/ m3 to 2.3 mg/ m3,and the local NH3 slip was decreased from 6.2 mg/ m3 to 2.6 mg/ m3.The deviation of the average NOx concentration at SCR outlet duct was eliminated.The potential performance of each reactor of the SCR equipment was fully utilized and the peak of the local NH3 slip was reduced,alleviating the risk of air pre-heater ABS block.

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