Radiative Heat Transfer Properties of Coal Char and Ash Particles Cloudin Gasification Processes

摘要

The thermal radiation properties are studied for a cloud of coal char and ash particles. Thernmonochromatic absorption of the sample particles dispersed in liquid paraffin wax isrnmeasured spectroscopically at an atmospheric state by using FT-IR. The effect of thernparticles number density in the cloud and the thickness of the dispersion layer on thernspectrum of absorption could be expressed in the property of the extinction efficiency. Thernspectral distribution of the extinction efficiency is dependent of wavelength in the nearrninfrared region of 0.8 to 2.2 micrometers. The extinction efficiency is influencedrnsignificantly so as to rise with increasing the carbon content in the char, and is correlated byrna 2nd order polynomial function of the content. The contribution of scattering by ashrnparticles can be ignored, or the forward scattering dominates the particle scattering in thernradiative heat transfer in the cloud.