SCR脱硝装置喷氨优化调整试验研究

Research for Optimized Adjustment Tests of Ammonia Injection in SCR Denitrification System

选择性催化还原脱硝装置的区域喷氨量与烟气中NO_(x)的分布如果出现不一致,会导致脱硝出口NO_(x)分布均匀性变差,以及氨逃逸过高等问题,严重影响脱硝效率.对山东某电厂2号机组进行摸底试验的测试,结果表明:在305MW、250MW、170MW3个负荷工况下,脱硝入口NO_(x)分布都非常均匀,但是出口NO_(x)分布均匀度却非常差,不均匀度最大值达到了64.8%,均值为53.0%,NO_(x)质量浓度偏差最大达到了73 mg/m^(3),氨逃逸质量浓度均值分别为2.10mg/m^(3)、2.24mg/m^(3)、2.40mg/m^(3).经过喷氨优化调整之后,出口NO_(x)分布不均匀度大幅度下降,不均匀度最大值为18.9%,均值为18.5%,NO_(x)质量浓度偏差最大值下降至24mg/m^(3),氨逃逸质量浓度均值分别下降为155mg/m^(3)、1.61mg/m^(3)、1.80mg/m^(3),优化效果明显.

There were some problems such as uneven NO_(x) distribution of SCR outlet and excessive ammonia escape which were caused by the disaccord between regional ammonia injection and NO_(x) distribution in flue gas in SCR denitrification system, seriously affecting the SCR efficiency. The data of thorough test for No.2 unit of a power plant in Shandong indicated that the NO_(x) in SCR inlet was well-distributed under 3 load conditions of 305 MW, 250 MW and 170 MW, but the NO_(x) distribution in SCR outlet represented poor uniformity. The maximum unevenness reached 64.8%, the average was 53.0%, and the maximum deviation of NO_(x) concentration was 73 mg/m^(3), the average values of ammonia escape were 2.10 mg/m^(3), 2.24 mg/m^(3), 2.40 mg/m^(3). After optimization and adjustment of ammonia injection, the unevenness of NO_(x) distribution in SCR outlet was significantly lower, the maximum unevenness was 18.9%,the average was 18.5%, and the maximum deviation of NO_(x) concentration was 24 mg/m^(3), the average values of ammonia escape were 1.55 mg/m^(3), 1.61 mg/m^(3), 1.80 mg/m^(3), the effect of optimization was appreciable.