O_2/N_2与O_2/CO_2条件下燃煤颗粒物的生成特性研究

EMISSION AND PROPERTIES OF PARTICULATE MATTER GENERATED DURING COAL COMBUSTION UNDER O_2/N_2 AND O_2/CO_2 CONDITIONS

将煤粉在O_2/N_2与O_2/CO_2条件下进行沉降炉燃烧实验,研究了燃煤颗粒物的质量粒径分布、生成浓度以及元素组成特性。研究结果表明,燃煤颗粒物均呈三模态粒径分布,气氛的改变不影响各模态的分布趋势。相同O_2含量条件下,与O_2/N_2气氛相比,O_2/CO_2气氛中PM_(10)和PM_1的生成浓度均降低,PM_1中易挥发元素Na、K、S的含量升高,而难熔元素Si、Al、Mg、Ca、Fe的含量降低。随着O_2浓度的增加,O_2/N_2燃烧气氛下PM_(10)和PM_1的生成浓度逐渐增加,O_2/CO_2燃烧气氛下PM_(10)的生成浓度增加,而PM_1的生成浓度先减小后增加。

Combustion experiments of a pulverized coal were conducted in a laboratory drop tube furnace （DTF） under O2/N2 and O2/CO2 conditions. The mass size distribution, concentration and elemental composition of generated particulate matter （PM） were investigated. The results showed that coal-derived PM was trimodally distributed with respect to particle size, which was not influenced by combustion conditions. Compared with the O2/N2 condition, under the O2/CO2 condition, both the inhalable particulate matter （PM10） and submicron particles （PM1） production decreased. PM1 contained higher concentrations of Na, K, S while lower concentrations of Si, Al, Mg, Ca and Fe. Under the O2/N2 condition, the PM10 and PM1 production increased with increasing O2 concentration. Under the O2/CO2 condition, with the increase of the O2 concentration, the PM10 production increased while the PM1 production decreased first and then increased.