Radiative property model for non-gray particle based on dependent scattering

Abstract

The radiative heat transfer of the particles has been investigated based on the gray body and the independent scattering. However, the radiative properties of the particles are strongly wavelength dependent and interact with each other with the increase of particle concentration. In order to indicate the radiative heat transfer under the high particle volume fraction, the radiation heat transfer model of non-gray particle is developed in this paper, which is based on the ideology of the weighted sum of gray gases (WSGG) model and the full-spectrum correlated k-distribution (FSCK) model, and the dependent scattering of particles is considered. For a one-dimensional plane-parallel slab system, the WSCK (the Weighted Sum of Gray Particles based on the full-Spectrum Correlated k-distribution) model is verified. Compared with the modified LBL model based on Mie theory and dependent scattering theory, the maximum errors of the dependent scattering WSCK (WSCKD) model are about 3.3% for the radiative heat flux and 11.5% for the radiative source term under non-isothermal and inhomogeneous conditions. The radiative heat flux and radiative source term by the WSCKD model and the independent scattering WSCK (WSCKI) model are almost identical for the low particle volume fraction and the calculation accuracy is higher by the WSCKD model on the industrial scale. For the high particle volume fraction, the WSCKD model is more accurate, especially for particle systems with a large percentage of small particles or a relatively high-volume fraction. In addition, the radiative heat transfers of gases, particles and gas-particle mixtures at different one-dimensional scales are examined, highlighting the crucial role of particle radiative property model in large furnaces.