超低排放脱硝运行状态及稳定性评估  

Evaluation on operation state and stability for denitrification of ultra low emission

作　　者：李清毅 孟炜 吴国潮 张军[3] 朱松强 胡达清 郑成航[3] 高翔[3] 王汝能 刘海蛟 

机构地区：[1]浙江天地环保科技有限公司,浙江杭州310003 [2]浙江省能源集团有限公司,浙江杭州310007 [3]浙江大学能源清洁利用国家重点实验室,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2016年第12期2303-2311,共9页Journal of Zhejiang University：Engineering Science

基　　金：国家杰出青年科学基金资助项目(51125025);浙江省重点科技创新团队资助项目(2011R50017);浙江省重大科技专项重点社会发展资助项目(2013C03022;2014C03018)

摘　　要：以超低排放改造后的某1 000 MW燃煤机组为例,建立该机组脱硝装置的性能评估体系,对脱硝装置的运行状态、可靠性和稳定性进行评估.得到的结论如下:按照该机组选择性催化还原(SCR)入口NOx浓度、SCR出口NOx浓度、脱硝效率、氨逃逸和压力损失分别为300mg/m3、50mg/m3、85%、3×10-6和600Pa的评估标准,对应的达标率分别为90.45%、92.34%、78.98%、98.32%和100.00%;不达标状态一般出现在机组变负荷和低负荷运行状态下,主要是喷氨量信号的响应速度过慢、炉膛内氧量难以控制和SCR入口温度较低等原因所致;超低排放改造后的机组SCR出口NOx平均浓度明显降低,小于30mg/m3,改造效果显著;机组总排口NOx排放浓度稳定可靠,达标率为98.74%,高于超低排放设计目标.The evaluation system for the performance of denitrification device was established by taking the1 000 MW coal-fired unit after ultra low emission transformation as an example.The operation,reliability and stability of denitrification device was evaluated in detail.Results show that the qualified rates of selective catalytic reduction（SCR）inlet NOxconcentration,SCR outlet NOxconcentration,denitrification efficiency,ammonia escape and pressure loss are 90.45%,92.34%,78.98%,92.34% and 100.00%,respectively,while the corresponding evaluation standards are 300 mg/m^3、50 mg/m^3、85%、3×10^6 and600 Pa,respectively.Substandard working conditions occurs at the operation state of variable and low load.The main reasons are that the response rate of spray ammonia signal is too slow,that the oxygen content in the furnace is difficult to control and that the SCR inlet temperature is too also low.The average NOxconcentration at SCR outlet after reformation decreases significantly,even lower than 30mg/m^3.TheNOxconcentration at the outlet of the chimney is stable and reliable with the qualified rate of 98.74%,which is even higher than the designed value.

关 键 词：超低排放 选择性催化还原(SCR) 脱硝效率 达标率 稳定性 

分 类 号：X511[环境科学与工程—环境工程]