ESP对燃煤电站锅炉颗粒汞形态及热稳定性的影响  

ESP Effects on Particulate Mercury Speciation and Thermal Stability in Coal-fired Utility Boiler

作　　者：高正阳[1] 吕少昆 陈嵩涛 杨朋飞[1] 郑双清[1] 殷立宝[2] 陈传敏[3] 

机构地区：[1]华北电力大学能源动力与机械工程学院,河北保定071003 [2]广东电网公司电力科学研究院,广东广州510000 [3]华北电力大学环境科学与工程学院,河北保定071003

出　　处：《华北电力大学学报（自然科学版）》2015年第1期63-68,共6页Journal of North China Electric Power University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51076045)

摘　　要：分析飞灰颗粒中Hg的形态对揭示烟气中Hg反应机理,确定飞灰颗粒中Hg的稳定性具有重要意义。在2个不同负荷下,采集了一台300 MW机组锅炉的各个电场的飞灰样品,将采集的飞灰进行了粒径分析,利用XRF分析以及扫描电镜分析,测定了各飞灰样品的含碳量;对各飞灰样品进行2种加热方式的热处理,利用LUMEX全自动测汞仪测定了处理前后各飞灰样品的汞含量。根据飞灰中汞随温度的释放规律确定了飞灰中汞的形态,对加热过程颗粒Hg释放动力学参数进行了计算。测试与分析结果表明:飞灰含碳量与飞灰汞含量呈明显正相关关系;飞灰对汞的吸附既与粒径大小有关,又与粒径分布有关,还与颗粒的堆积状态有关;飞灰对汞的吸附主要受物理吸附影响,飞灰化学成分对汞的吸附有影响,但是与物理吸附相比影响较小;原煤Cl含量是影响飞灰Hg Cl2含量的关键因素,原煤Cl含量越高,飞灰Hg Cl2含量越高;灰颗粒所含Hg释放的活化能与Hg Cl2所占比例有显著的相关性。Hg Cl2所占比例越大,灰颗粒Hg释放的活化能就越小。Morphological analysis of Hg is important to reveal the reaction mechanism of Hg in the flue gas,and determines the stability of Hg in fly ash particles. Fly ash samples of each electric field were collected from a 300 MW unit boiler with two different loads. To determine the carbon content of fly ash samples through particle size analysis,XRF analysis and scanning electron microscopy analysis were done on the collected fly ash samples. The fly ash samples were subjected to heat treatment in two heating methods,using LUMEX automated mercury analyzer to measure the mercury levels of the fly ash samples before and after treatment. In accordance with the law of the release of mercury in the fly ash with temperature to determine the speciation of mercury in fly ash,and the Hgprelease kinetics parameters in the heating process were calculated. Test and analysis results show that： the carbon content of fly ash and the mercury level obviously had a positive correlation; fly ash adsorption of mercury is related to fly ash particle size,particle size distribution,particle accumulation state; fly ash adsorption of mercury is mainly influenced by physical adsorption,and fly ash chemical composition also has an influence on the adsorption of mercury,but the impact is small compared with the physical absorption; Cl content of raw coal is the key factor influencing the fly ash content of HgCl2,and the higher Cl content in raw coal,the higher the HgCl2 content of fly ash; the Hg release of activation energy in ash particles has a significant correlation with the proportion of HgCl2. On the whole,the larger proportion of HgCl2,the smaller activation energy of Hg release in ash particles.

关 键 词：ESP 燃煤电站 锅炉 飞灰 颗粒汞 

分 类 号：TM611[电气工程—电力系统及自动化]