摘要
针对某600 MW燃煤机组SCR脱硝系统投运后出现喷氨量不均、CEMS表计偏差大、氨逃逸报警等问题,通过喷氨优化调整,改善了脱硝装置入口氨氮摩尔比分布情况,消除了脱硝效率过高和过低的区域,使A、B侧SCR反应器出口截面NO_(x)浓度分布趋于均匀,相对标准偏差CV值分别从133%、81%减小至31%、32%,平均氨逃逸浓度分别从4.20μL/L、3.01μL/L降低至1.31μL/L、1.32μL/L,局部氨逃逸浓度峰值分别从7.05μL/L、5.38μL/L降低至1.78μL/L、1.73μL/L。SCR出口NO_(x)浓度分布均匀性得到明显改善,CEMS取样测量代表性提高,不同区域脱硝效率波动减小,局部氨逃逸浓度峰值显著降低。经统计,喷氨优化调整后,机组600 MW负荷下,总喷氨流量由206 kg/h减小至171 kg/h,降低比例约17.0%;机组450 MW负荷下,总喷氨流量由171 kg/h减小至119 kg/h,降低比例约30.4%,不同工况下总喷氨流量均大幅下降,每年可减少液氨费用约73.95万元,不仅为电厂节省了生产维护成本,还减小了空预器及下游设备的ABS堵塞风险,保障了机组长周期安全稳定运行,为同类型火电机组提供了良好的实践经验。
After the denitrification system of a 600 MW coal-fired power plant is operated,the problems arise inculding uneven ammonia injecting,large deviation of CEMS meter,and the alarm of ammonia escape.Through the ammonia-injection optimization and adjustment,the distribution of ammonia nitrogen molar ratio at the inlet of denitrification unit is improved,moreover the areas where the denitration efficiency is too high and too low were eliminated.The NO_(x) concentration distribution at the outlet section of SCR reactor on sides A and B tend to be uniform,and the relative standard deviations CV was reduced from 133%and 81%to 31%and 32%,respectively.Average ammonia escape concentrations decreases from 4.20μL/L and 3.01μL/L to 1.31μL/L and 1.32μL/L,respectively.Loacl peak ammonia escape concentrations decreased from 7.05μL/L and 5.38μL/L to 1.78μL/L and 1.73μL/L,respectively.The NO_(x) concentration distribution uniformity of SCR export was improved significantly.The CEMS sampling measurement is more representative.The denitration efficiency fluctuation of different regions and the partial ammonia escape peak concentration are reduced.According to statistics,after optimizing and adjusting the ammonia injection,total ammonia injection flow decreases from 206 kg/h to 171 kg/h under 600 MW load of the unit,with a reduction ratio of about 17.0%.Under 450 MW load of the unit,the total ammonia injection flow decreases from 171 kg/h to 119 kg/h,with a reduction ratio of about 30.4%.Under different working conditions,total ammonia injection flow decreases rapidly,and the annual liquid ammonia cost is reduced by about 739,500 yuan,which not only saved the power plant production and maintenance costs.Also,it reduces the ABS congestion risk of air preheater and downstream equipments to ensure the unit safe and stable operation for a long period of time and to provide a good practical experience for the same type thermal power unit.
作者
郭磊
刘艇安
王靓
崔强
艾峰
GUO Lei;LIU Ting'an;WANG Liang;CUI Qiang;AI Feng(China Power Hua Chuang(Suzhou)Electricity Technology Research Co.,Ltd.,Suzhou 215123,China;Pingdingshan Yaomeng Power Generation Co.,Ltd.,Pingdingshan 467033,China;Wuhu Power Generation Co.,Ltd.,Wuhu 241009,China)
出处
《电力科技与环保》
2022年第1期49-55,共7页
Electric Power Technology and Environmental Protection
基金
中国电力国际发展有限公司科技项目(2020-010-ZGDL-KJ-X)。
关键词
燃煤机组
烟气脱硝
氨逃逸
喷氨优化调整
coal-fired power units
denitration of flue gas
ammonia escape
ammonia injection optimization adjustment
