Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
Analysis of the effect of high pressure levels on the radiative heat transfer of participating gases
Submission Author:
Francis França , RS , Brazil
Co-Authors:
Felipe Ramos Coelho, Roberta Juliana Collet da Fonseca
Presenter: Felipe Ramos Coelho
doi://10.26678/ABCM.ENCIT2016.CIT2016-0364
Abstract
Thermal radiation is a dominant heat transfer mechanism in high pressure combustion processes such as oxy-fuel combustion. The solution of radiation in participating media is complex due to the integro-differential governing equation and the highly irregular spectral behavior of the absorption coefficient. Thus the radiative transfer equation (RTE) is usually solved using spectral models to determine the radiative quantities. The weighted-sum-of-gray-gases (WSGG) model replaces the spectral integration of the RTE by bands of uniform absorption coefficients, and has recently received considerable attention mainly because of its simplicity and overall great performance. However, this model is based on the assumption that the emittance of the participating gas is only a function of the temperature and the pressure-pathlength. This paper checks the validity of this assumption by studying the effect of different pressure values on the emittance of a participating gas composed by water vapor and carbon while keeping the pressure-pathlength constant. For the emittance calculation the RTE is solved by the line-by-line (LBL) method using the HITEMP 2010 spectral emissivity database for the spectral integration and the discrete ordinates method (DOM) for the angular integration.
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