Evaluation of radiative entropy generation in a high temperature system including H2O, CO2 and soot with non-gray wall

Abstract

In this paper, radiative entropy generation in a high temperature parallel plate system containing H2O, CO2 and soot with non-gray wall was investigated. Based on Discrete Ordinates method and Narrow Band k-distribution model, the spectral radiative entropy generation rate and radiative entropy generation rate due to different physical processes were given. The effects of CO2, H2O, soot, spectral emissivity of wall, as well as medium temperature on radiative entropy generation were evaluated. Some conclusions were obtained as below. The irreversibility of emission and reflection process on wall has main contribution on radiative entropy generation rate of system. The radiative entropy generation rate increases with the mole fraction of gas and volume fraction of soot. CO2 has less effect on total radiative entropy generation rate, but H2O and soot particle have more effect on total radiative entropy generation rate. The radiative entropy generation rate increases with the increase of total hemispherical absorptance of wall. The radiative entropy generation rate and dimensionless radiative entropy generation increase with the increase of non-uniformity of medium temperature distribution and difference of gas temperature and soot temperature.