Influence of particle shape and internal thermal gradients of biomass particles on pulverised coal/biomass co-fired flames
Influence of particle shape and internal thermal gradients of biomass particles on pulverised coal/biomass co-fired flames
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DOI：
10.1016/j.fuproc.2011.07.003
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发表时间：
2011-11
影响因子：
7.5
通讯作者：
S. Gubba;Lin Ma;M. Pourkashanian;A. Williams
中科院分区：
文献类型：
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作者：
S. Gubba;Lin Ma;M. Pourkashanian;A. Williams
在发电厂中采用粉煤/生物质共燃的实践逐渐增加。这主要是因为减少基于煤炭的二氧化碳和基于生物质的硫氧化物和氮氧化物排放所带来的好处。然而，生物质由于其纤维质地而难以研磨，这导致存在影响燃烧特性的不同形状的大颗粒。现有的计算流体动力学（CFD）模型往往忽略了颗粒内的热梯度，这导致燃烧过程建模的不准确性。在本文中，大颗粒内的传热的CFD子模型的开发。该模型是有效的加热，水分释放和挥发的单一木材颗粒的测量，可在文献中。在工业燃烧试验装置上，研究了燃料颗粒尺寸对混合燃料着火、脱挥发分和焦炭燃烧特性的影响。的预测，同时考虑内部的热梯度与颗粒尺寸和形状分布，被确定为与测量数据非常吻合。当与ANSYS FLUENT耦合时，代码运行良好，并且计算的额外时间可以忽略不计。
The practice of employing pulverised coal/biomass co-firing in power plants is gradually increasing. This is mainly because of the benefits associated in reducing the coal based CO2and biomass based SOxand NOxemissions. However, biomass is difficult to mill due to its fibrous texture and this results in the presence of large particles of different shapes which influence the combustion characteristics. Existing computational fluid dynamics (CFD) models often ignore thermal gradients within the particles and this leads to inaccuracy in the combustion process modelling. In this paper, a CFD sub-model for the heat transfer within large particles is developed. The model is validated for the heating up, moisture release and devolatilisation of single wood particle measurements that are available in the literature. The impact of fuel particle sizes on the combustion characteristics has been investigated in terms of ignition, devolatilisation and char combustion in a co-firing case of an industrial combustion test facility. The predictions, while considering the internal thermal gradients with particle size and shape distribution, were identified to be in excellent agreement with measured data. The code was worked well when coupled with ANSYS FLUENT and with a negligible amount of extra time for the computations.