Particle radiation has a spectral dependence and is closely related to the chemical composition of the material. Iron oxide, one of the main components of fly ash, observably affects the complex index of refraction of the particles. In this study, following the theory of the spectrum k-distribution based weighted sum of gray particles model (Guo et al. [4,13]), a non-gray fly ash radiative property model involving the chemical composition was developed. First, four typical fly ash particles with different iron oxide contents were selected, and the corresponding particle radiative parameters were obtained using the Mie theory. Then, the absorption efficiency and weighting factors of the non-gray model were directly obtained from the Gaussian integral points of the k-distribution. The scattering efficiency of the particles was obtained from the Planck mean. The accuracy of the newly developed model was evaluated in a one-dimensional plane-parallel slab system through comparison with the line-by-line (LBL) model and two commonly used gray radiative property models. The results show that the new non-gray model agrees well with the LBL solution and becomes more accurate as the iron oxide content increases. When the iron oxide content of the fly ash increased from 5.47% to 30.50%, the maximum relative error of the radiative heat flux and the radiative source term decreased from 12.50% to 5.68% and from 20.97% to 12.62%, respectively. The new model can improve the prediction accuracy of radiative heat transfer in pulverized coal-fired furnaces.

粒子辐射具有光谱依赖性，并且与材料的化学组成密切相关。氧化铁，粉煤灰的主要成分之一，可观察到影响颗粒的复杂折射率。在这项研究中，根据基于光谱k分布的灰色颗粒加权总和模型的理论（Guo等人[4,13]），建立了涉及化学成分的非灰色粉煤灰辐射特性模型。首先，选择了四个典型的具有不同氧化铁含量的粉煤灰颗粒，并使用米氏理论获得了相应的颗粒辐射参数。然后，直接从k的高斯积分点获得非灰色模型的吸收效率和加权因子。-分配。从普朗克平均值获得颗粒的散射效率。通过与逐行（LBL）模型和两个常用的灰色辐射特性模型进行比较，在一维平面平行平板系统中评估了新开发模型的准确性。结果表明，新的非灰色模型与LBL解决方案非常吻合，并且随着氧化铁含量的增加而变得更加准确。当粉煤灰中的氧化铁含量从5.47％增加到30.50％时，辐射热通量和辐射源项的最大相对误差分别从12.50％降低到5.68％和从20.97％降低到12.62％。该模型可以提高煤粉炉辐射热传递的预测精度。