Impact of combustion conditions on physical and morphological properties of biomass burning aerosol
Impact of combustion conditions on physical and morphological properties of biomass burning aerosol
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DOI：
10.1080/02786826.2020.1822512
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发表时间：
2020-10
影响因子：
5.2
通讯作者：
R. Pokhrel;Janica Gordon;M. Fiddler;S. Bililign
中科院分区：
文献类型：
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作者：
R. Pokhrel;Janica Gordon;M. Fiddler;S. Bililign
摘要生物质燃烧颗粒密度的研究提供了老化、新颗粒形成、传输特性等方面的信息，是气溶胶影响模拟中的一个重要参数。密度用于质量闭合技术，以估计颗粒质量浓度的时间分辨率。然而，作为燃烧条件的函数的BB颗粒密度的研究仍然是有限的。实验室测量六个撒哈拉以南非洲生物质燃料燃烧的条件范围内，从纯阴燃到纯燃烧条件下，提出。阴燃主导的燃烧（修正燃烧效率（MCE）0.95）颗粒显示出所有六种不同燃料的尺寸依赖性。在这种情况下，平均值和标准差随着尺寸的增加而降低，从迁移率直径为80 nm时的（0.94 ± 0.21）g cm−3降低到迁移率直径为400 nm时的（0.31 ± 0.07）g cm −3。火焰主导的气溶胶的尺寸依赖性表明了新排放的颗粒的分形性质。之间的关系和MCE表现出三个不同的形态制度，我们定义为球形颗粒，过渡，和分形制度。我们提出的与MCE的关系可以作为一种工具，以评估米氏理论的适用性，在没有粒子形态信息的光学闭合计算。
Abstract The study of biomass burning particle density provides information on aging, new particle formation, transport properties, and is an important parameter in aerosol impacts modeling. Density is used in mass closure techniques to estimate the temporal resolution of particulate mass concentrations. However, the study of BB particle density as a function of burning conditions is still limited. Laboratory measurement of six sub-Saharan African biomass fuels burned under a range of conditions, from pure smoldering to pure flaming conditions, is presented. Smoldering-dominated burning (modified combustion efficiency (MCE) 0.95) particles, show a size dependent for all six different fuels. In this case, the mean and standard deviation of the decreased with increasing size, from (0.94 ± 0.21) g cm−3 at a mobility diameter of 80 nm to (0.31 ± 0.07) g cm−3 at a mobility diameter of 400 nm. The size-dependent of flaming-dominated aerosol suggests the fractal nature of freshly emitted particles. The relationship between and the MCE shows three distinct morphology regimes, which we define as the spherical particle, the transition, and the fractal regime. Our proposed relationship of with the MCE can be used as a tool to assess the applicability of Mie theory for optical closure calculations in the absence of particle morphological information.