220MW热电联产锅炉中痕量元素的迁移及分布特性

发布时间：2018-05-25 04:19

本文选题：煤燃烧 + 热电联产锅炉　；参考：《化工学报》2014年09期

【摘要】：本实验在北京某220 MW热电联产锅炉上进行。采用承重撞击器系统对该锅炉选择性催化还原(SCR)前、电子除尘(ESP)前以及烟气脱硫(FGD)前的颗粒物进行采集,研究了痕量元素在烟道沿程上的迁移特性,另外,还给出了痕量元素在各固体燃烧产物中的分布。结果表明:ESP前的颗粒物上As、Cd、Cr和Pb的浓度明显高于SCR前的浓度;在从SCR到ESP的过程中,As、Cd、Cr、Pb从气态迁移到固态的质量分别占到了原煤中总质量的26%、16%、12%和11%;从ESP到FGD的过程中,颗粒物上As与Cd的浓度有略微增加,而Cr和Pb的浓度几乎不变;Mn在3个采样点的浓度几乎一致;大部分痕量元素存在于ESP捕获的飞灰中,在ESP出口处,As、Cd、Cr、Pb在10μm的4个粒径段上的质量随着粒径的减小而增大,而Mn的质量分布与颗粒物质量分布类似。
[Abstract]:The experiment was carried out on a 220 MW cogeneration boiler in Beijing. The particulate matter of the boiler before selective catalytic reduction (SCR), electronic dust removal (ESP) and flue gas desulfurization (FGD) were collected by a load-bearing impactor system. The migration characteristics of trace elements along the flue were studied. The distribution of trace elements in various solid combustion products was also given. The results showed that the concentrations of aspergine, cdcr and Pb on the particles before ESP were significantly higher than those before SCR, and the migration from gas to solid accounted for 26% and 11% of the total mass of raw coal in the process of moving from SCR to ESP, respectively, and in the process from ESP to FGD, the concentration of Cr and Pb was significantly higher than that before ESP, the results showed that the contents of Cr and Pb were significantly higher than those before SCR, and the mass of Cr-Pb migrated from gas to ESP accounted for 26% of the total mass of raw coal. The concentrations of as and CD in particulate matter increased slightly, while the concentrations of Cr and Pb were almost the same in the three sampling sites. Most trace elements were found in the fly ash captured by ESP. At the exit of ESP, the mass of Cr-Pb at 10 渭 m increases with the decrease of particle size, but the mass distribution of mn is similar to that of particulate matter.
【作者单位】：华中科技大学煤燃烧国家重点实验室;
【基金】：国家自然科学基金项目(51276072) 国家重点基础研究发展计划项目(2013CB228501) 煤炭联合基金重点项目(U1261204)~~
【分类号】：X773

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