烟气再循环对350 MW CFB锅炉深调运行特性影响  

Influence of flue gas recirculation on deep peak regulationoperation characteristics of 350 MW CFB boiler

作　　者：王家兴 彭建升[1] 李凡 贺建平 杨天亮 董永胜 王帅 WANG Jiaxing;PENG Jiansheng;LI Fan;HE Jianping;YANG Tianliang;DONG Yongsheng;WANG Shuai(Yantai Longyuan Power Technology Co.,Ltd.,Yantai 264006,China;School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150006,China;Shenhua Shendong Electric Power Shanxi Hequ Power Generation Co.,Ltd.,Xinzhou 036501,China)

机构地区：[1]烟台龙源电力技术股份有限公司,山东烟台264006 [2]哈尔滨工业大学能源科学与工程学院,黑龙江哈尔滨150006 [3]神华神东电力山西河曲发电有限公司,山西忻州036501

出　　处：《洁净煤技术》2024年第9期68-76,共9页Clean Coal Technology

基　　金：国家重点研发计划资助项目(2022YFB4100302)。

摘　　要：为解决超临界CFB锅炉超低负荷时流化安全性及NO_(x)超低排放,引入烟气再循环技术,以某电厂超临界350 MW CFB锅炉为研究对象,搭建了循环半干法脱硫后烟气的再循环辅助调峰系统,基于运行实测数据,研究该锅炉在30%~60%负荷率下烟气再循环对平均床温、分离器入口温度、排烟温度、炉膛出口烟气NO_(x)、CO质量浓度、飞灰及底渣可燃物含量、汽水参数等运行参数的影响,试验结果表明:烟气再循环协同下,30%~60%负荷SNCR脱硝后NO_(x)最终排放小于50 mg/m^(3),30%负荷实现锅炉原始NO_(x)超低排放;床温降低15~22℃,炉膛出口烟温提高10~13℃,主再热汽温在558℃以上;随锅炉负荷降低,飞灰及底渣含碳量升高,CO质量浓度未见大幅增加;40%负荷炉膛二次风SNCR脱硝NO_(x)降幅约15 mg/m^(3);负荷上升/下降变化最小速率1.23%Pe;30%负荷及以上保持干态运行,水冷壁壁温最大偏差55℃,屏过及屏再最大壁温差分别55、47℃,均未出现壁温超温。To solve the problems of fluidization safety and ultra-low NO_(x)emission of supercritical CFB boiler under ultra-low load,flue gas recirculation technology was introduced.Taking a supercritical 350 MW CFB boiler as the research object,a flue gas recirculation auxiliary peak-shaving system after semi-dry desulfurization was built.Based on the data of field operation,the effects of operating parameters such as the average bed temperature,separator inlet temperature,exhaust temperature,NO_(x),CO mass concentration of outlet flue gas,combustible content of fly ash and bottom ash,steam-water parameter at 30%-60%load were studied under the flue gas recirculation.The results show that under the coordination of flue gas recirculation,the final emission of NO_(x)at 30%-60%load is less than 50 mg/m^(3)after SNCR,the original NO_(x)emission is less than 50 mg/m^(3)at 30%load;the bed temperature is reduced by 15-22℃,the boiler exit flue temperature increases 10-13℃,and the primary and reheat steam temperature is above 558℃.With the decrease of boiler load,the carbon content of fly ash and bottom slag increases,and the mass concentration of CO does not increase significantly.The NO_(x)is reduced about 15 mg/m^(3)by SNCR arranged at secondary air;the minimum change rate of load rise/fall is 1.23%Pe;the boiler keeps dry operation above 30%load,the maximum deviation of water wall temperature is 55℃at 30%load,the maximum deviation of overheated and reheated heating surfaces is 55 and 47℃respectively,and no over-temperature appears.

关 键 词：超临界 循环流化床锅炉 深度调峰 烟气再循环 NO_(x)超低排放 锅炉运行特性 

分 类 号：TK09[动力工程及工程热物理] X511[环境科学与工程—环境工程]