Radiative heat transfer in H<sub>2</sub>O and CO<sub>2</sub> mixtures

Abstract

In this work, an approximate solution is presented to evaluate the heat exchange by radiation through a gaseous participating medium composed of and , which is valid for values of the product of the total pressure and the mean beam length (PL) from 0.06 to and temperatures (T) from 300 K to 2100 K. To approximate the exact solutions, the Spence root weighting method is used. For each set of PL; T values, the values of exact spectral emissivity and absorptivity and for the gas mixture are calculated using the analytical solution (AS) and the values of the emissivity and absorptivity of the mixture and , using the Hottel graphical method (HGM) and the proposed approximate solution. The weaker correlation fit corresponds to the HGM, with mean errors of ±15 % and ±20% for 54.2% and 75.3 % of the data evaluated, respectively, while the proposed method provides the best fit, with mean errors of ±10% and ±15% for 79.4% and 98.6 % of the data evaluated, respectively. In all cases, the agreement of the proposed model with the available experimental data is good enough to be considered satisfactory for practical design.