烟煤层燃炉颗粒物的生成特征与管理控制

以95台中小型燃烟煤层燃炉(≤70MW)的燃料特性分析数据和颗粒物(PM)排放实测数据为基础,利用统计分析方法,研究了锅炉出力、过量空气系数、燃煤灰分含量对燃烧过程中PM初始排放浓度的影响,分析了燃煤锅炉PM排放现状,讨论了我国中小型燃煤锅炉PM排放管理控制的潜力和可行性。结果表明,在锅炉运行负荷≥80%的条件下,PM初始排放浓度随过量空气系数和燃煤灰分含量的增加略有增大,而与锅炉出力无关;在用烟煤层燃炉PM排放浓度基本上能够满足国家现行污染物排放标准规定的排放限值要求;有96%的锅炉所采用的除尘装置的除尘效率大于80%;与其他国家相比,目前我国对于中小型燃煤锅炉PM的排放控制还处于中等水平,建议在国家层面上适时提高燃煤锅炉颗粒物的排放限制。

Generation Characteristics and Regulatory Control of PM from Layer Burning Boilers Firing Soft Coal

Influences of boiler output, excess air coefficient, coal ash content on PM initial emission concentration in coal combustion were investigated by statistical analysis using PM field data and coal analysis data from 95 medium and small layer burning boilers firing soft coal with actual capacity of boilers less than 70MW. The emission of PM from coal-fired boilers was analyzed and possibility and feasibility of regulatory control of PM emission of medium and small coal-fired boilers in China were also discussed. Results indicated that PM initial emission concentrations increase slightly with excess air coefficient and coal ash content increasing and are not related with boiler output under the condition of boiler load more than 80%. PM emission concentrations of layer burning boilers firing soft coal in use basically can meet the emission limits prescribed by existing national emission standard. There are 96% of boilers which the dust collection efficiencies of dust catchers installed are more than 80%. Compared with other countries, the regulatory control of PM emitted from medium and small coal-fired boilers in China is at a medium level. Enhancing particulate matter emission limitation for coal-fired boilers at the national level timely is suggested as well.