煤燃烧超细颗粒物的粒径分布及数浓度排放特征试验

利用快速迁移率粒径谱仪(fast mobility particle sizer,FMPS)对煤燃烧排放的超细颗粒物粒径分布特征进行测量研究,并对单位质量煤粉燃烧产生的超细颗粒物数量排放因子进行分析.结果表明,煤燃烧超细颗粒物数浓度粒径谱呈对数双峰分布,颗粒几何平均粒径(the geometry mean diameter,GMD)约为23.1 nm.在燃烧阶段,煤燃烧超细颗粒物数浓度随时间呈指数增长,各模态颗粒物数浓度与煤粉量呈线性相关关系,单位质量煤粉燃烧产生的核模态颗粒物数量排放因子为(1.50±0.64)×1010个·mg-1,爱根核模态颗粒为(1.18±0.56)×1010个·mg-1,积聚模态颗粒物为(0.19±0.06)×1010个·mg-1,总颗粒物为(2.87±1.09)×1010个·mg-1.在扩散过程中,颗粒粒径随时间呈线性增长,粒径增长速率与煤粉量呈线性相关关系.单位质量煤粉燃烧排放的颗粒粒径平均增长速率为7.5 nm·h-1·mg-1.

Size distribution and number emission characteristics of ultrafine particles from coal combustion

Particle size distributions of ultrafine particles (UFPs) from coal combustion were measured with fast mobility particle sizer (FMPS), and the emission characteristics of number concentration of coal UFPs were analyzed. Results showed that the number concentration of UFPs was logarithmic bi-modal distribution, and its geometry mean diameter (GMD) was about 23.1 nm. During the burning process, the number concentration of UFPs increased exponentially with time, and the particles of different modes demonstrated a linear relationship with the amount of coal. The number emission factor of nucleation mode particles, Aitken mode particles, accumulation mode particles and total particles by per unit mass of coal were (1.50±0.64)×10¹⁰, (1.18±0.56)×10¹⁰, (0.19±0.06)×10¹⁰ and (2.87±1.09)×10¹⁰ units · mg^-1 respectively. After completely burned, the particle size grew linearly with time, and the growth rate of particle size increased linearly with the amount of combustion coal. The average growth rate of GMD was 7.5 nm · h^-1 · mg^-1.