Model of heterogeneous combustion of small particles
Model of heterogeneous combustion of small particles
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DOI：
10.1016/j.combustflame.2013.06.018
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发表时间：
2013-12-01
影响因子：
4.4
通讯作者：
Dreizin, Edward L.
中科院分区：
文献类型：
--
作者：
Ermoline, Alexandre;Yildiz, Deniz;Dreizin, Edward L.
建立了过渡传热传质过程中球形颗粒非均相燃烧的稳态模型。该模型假定凝聚产物的形成和反应速率受氧化剂向颗粒表面的传输控制。该模型基于Fuchs的极限球法。对不同尺寸的锆粉的燃烧进行了计算。计算了温度和氧气浓度分布，并与连续介质传输模型预测的结果进行了比较。将预测结果与已有的实验数据进行了比较。对于粗颗粒，当假设反应生成的是锆氧溶液而不是化学计量比的氧化锆时，预测的燃烧温度和燃烧速率都与各自的实验数据相匹配。对于较小的颗粒，预测了颗粒大小对其燃烧时间的较弱影响，这与最近的实验定性一致。然而，该模型低估了燃烧时间，高估了小颗粒的燃烧温度。这种差异很可能与粒子表面的有限反应动力学有关，这一点必须在未来的工作中得到解释。(C)2013年，燃烧研究所。爱思唯尔公司出版，版权所有。
A steady model of heterogeneous combustion for a spherical particle in the transition heat and mass transfer regime is developed. The model assumes formation of condensed products and reaction rate controlled by the transport of oxidizer to the particle surface. The model is based on the Fuchs' limiting sphere approach. Calculations are performed for combustion of zirconium particles of different sizes. Temperature and oxygen concentration profiles are calculated and compared to those predicted by the continuous medium transfer model. The predictions are compared with available experimental data. For coarse particles, both predicted combustion temperatures and burn rates match respective experimental data when the reaction is assumed to produce zirconium-oxygen solution rather than stoichiometric ZrO2. A weaker effect of particle size on their burn time is predicted for smaller particles, in qualitative agreement with recent experiments. However, the model underestimates the burn times and overestimates the combustion temperatures for small particles. This discrepancy is likely associated with the finite reaction kinetics at the particle surface that must be accounted for in the future work. (C) 2013 The Combustion Institute. Published by Elsevier Inc. All rights reserved.