O_2/CO_2煤粉燃烧对矿物质成灰行为的影响

Impacts of O_2/CO_2 Pulverized Coal Combustion on Ash Formation Behaviors of Mineral Matter

通过乌兰木伦煤在高温沉降炉中的燃烧实验,研究了O2/CO2燃烧时煤中矿物质的成灰行为.通过对所生成灰样的详细分析,并和O2/N2气氛下煤灰特性比较,研究了O2/CO2燃烧对矿物质成灰行为的影响.结果表明,与O2/N2燃烧相比,O2/CO2燃烧对灰样中生成的主要矿物质物相未产生显著影响,但改变了它们的相对含量;煤粉在O2和CO2体积比R为1∶4条件下燃烧时,亚微米颗粒的生成量在较空气燃烧时减少,而当O2和CO2体积比R为2∶3时,亚微米颗粒的生成量较相同氧浓度的O2/N2燃烧时大幅度增加;燃烧气氛还显著地影响亚微米颗粒的元素组成.

Combustion experiments were performed by burning Wulanmulun coal in a drop tube furnace to study ash formation behaviors during O2/CO2 pulverized coal combustion. The ash samples collected were analyzed in detail and extensive comparisons were made between O2/CO2 combustion and O2/N2 combustion to probe the impacts of O2/CO2 combustion on ash formation behaviors. It was found that, in comparison with O2/N2 combustion, O2/CO2 combustion did not have a significant effect on crystalline phases formed. However, it did affect their relative amounts in ashes. Pulverized coal combustion in volumetric ratio of O2 to CO2 R = 1：4 generated less submicron ash than in air combustion, while combustion in volumetric ratio of O2 to CO2 R=2：3 increased more significantly submicron ash compared with that in O2/N2 with the same O2 concentration. Moreover, combustion atmosphere was found to significantly affect the elemental composition of submicron ash particles.