This study combines the radiation transfer process with the thermodynamic second law to achieve more accurate results for the energy quality and its variability in the spectral radiation transfer process. First, the core ideas of the monochromatic photon exergy theory based on the equivalent temperature and the infinite-staged Carnot model are reviewed and discussed. Next, this theory is combined with the radiation transfer equation and thus the spectral radiative entropy and the radiative exergy transfer equations are established and verified based on the second law of thermodynamics. Finally, one-dimensional furnace case calculations are performed to determine the applicability to engineering applications. It is found that the distribution and variability of the spectral radiative exergy flux in the radiation transfer process can be obtained using numerical calculations and the scatter media could slightly improve the proportion of short-wavelength radiative exergy during the radiation transfer process. This has application value for research on flame energy spectrum-splitting conversion systems.
Keywords: entropy; exergy; spectral radiation transfer; thermodynamics second law.