Second Law Analysis of Spectral Radiative Transfer and Calculation in One-Dimensional Furnace Cases

Abstract

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.

A novel flame energy grading conversion system: Preliminary experiment and thermodynamic parametric analysis

“…The coal combustion is complete at temperatures above 800°C; thus, the characteristics of the spectral radiation during combustion are basically similar for the three coals at high temperatures. Moreover, it is believed that the radiative energy with a shorter wavelength is more useful since its higher exergy; thus, increasing the radiation ratio in shorter wavelength band is meaningful to new proposed system.…”

“…Researchers have pointed out the difference between radiative energy and thermal energy; furthermore, radiative exergy has been investigated, and it was theoretically proved that the blackbody radiative exergy is different from thermal exergy. Recently, we proposed the theory of spectral radiative exergy, and the equation of monochromatic radiative exergy efficiency has been established through the infinite staged Carnot heat engine model based on the concept of equivalent temperature: where T λ is the equivalent temperature, it has the dimension of temperature and could characterize the doing‐work ability of spectral radiation . Spectral radiation with different frequencies has different exergy values, and T λ is associated with the wavelength and the radiative temperature: …”

“…Previous studies indicated that at a certain radiative temperature, the shorter the wavelength, the higher the spectral equivalent temperature is, and the larger the corresponding spectral radiative exergy is. This is in agreement with the actual process, that is, high‐frequency radiation causes a photoelectric effect, even photosynthesis, but this does not occur for low‐frequency infrared radiation.…”

“…29 Researchers have pointed out the difference between radiative energy and thermal energy; 30,31 furthermore, radiative exergy has been investigated, 32 and it was theoretically proved that the blackbody radiative exergy is different from thermal exergy. Recently, we proposed the theory of spectral radiative exergy, 33,34 and the equation of monochromatic radiative exergy efficiency has been established through the infinite staged Carnot heat engine model based on the concept of equivalent temperature 33 :…”

The Energy and Exergy of Light with Application to Societal Exergy Analysis

“…Recent advances in the thermodynamics of radiation community enable converting the energy of EM radiation (Ė EM ) into the exergy of EM radiation (Ẋ EM ) [43]. The exergy-to-energy ratio of EM radiation (φ EM , called the "radiative exergy-energy coefficient" in that community) is most commonly given by Petela's Equation [43][44][45]:…”