TY - JOUR
T1 - Non-gray chemical composition based radiative property model of fly ash particles
AU - Wan, Jiawei
AU - Guo, Junjun
AU - Li, Pengfei
AU - Liu, Zhaohui
N1 - KAUST Repository Item: Exported on 2021-11-24
Acknowledgements: This study is financially supported by the National Natural Science Foundation of China (51906075, 91641122), the National Key Research and Development Program of China (2018YFB0605301), and the China Postdoctoral Science Foundation funded project (2018M612837). The authors also thank the Hubei Postdoctoral Science and Technology Program (G33) (2020T130218).
PY - 2020/10/18
Y1 - 2020/10/18
N2 - 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.
AB - 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.
UR - http://hdl.handle.net/10754/666505
UR - https://linkinghub.elsevier.com/retrieve/pii/S1540748920304193
UR - http://www.scopus.com/inward/record.url?scp=85097368739&partnerID=8YFLogxK
U2 - 10.1016/j.proci.2020.06.326
DO - 10.1016/j.proci.2020.06.326
M3 - Article
SN - 1540-7489
VL - 38
SP - 4281
EP - 4290
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
IS - 3
ER -