Radiant energy exchange through participating media composed of arbitrary concentrations of H₂O, CO₂, and CO

Abstract

In this work, an approximate analytical solution (AS) is presented to evaluate the radiative thermal exchange through a gaseous participating medium composed of H2O, CO2, and CO, which is valid for the product values of pressure path‐length (PL) from 0.06 to 20 atm m and temperatures (T) from 300 K to 2100 K. The Spence root weighting method is used to approximate the exact solutions. For each set of , the value of exact spectral emissivity and absorptivity and for the gas mixture is calculated using the AS, the Hottel graphical method (HGM) and the proposed approximate solution. The weaker adjustment was achieved in the modeling of the HGM, with a mean deviation obtained of ±15% and ±20% for 43.8% and 56.3% of the data evaluated, respectively, while the best indices were obtained in the estimation of the proposed method, with a mean deviation obtained of ±10% and ±15% for 81.3% and 98.1% of the available data, 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.

Gas emissivities and absorptivities for H2O–CO2–CO mixtures

“…The partial pressure P x of the gas is the key point for determining the emissivity of the gas mixture, being determined by the following relationship 30 :…”

“…The results obtained agree with previous reports by other authors. 30 For Equation (41), Figure 14 shows the best fit in the correlation with analytical data, with a mean deviation of ±15% and ±10% for 89.8% and 74.1% of the analytical points evaluated, respectively. The best fit is obtained for PL = 5, with a mean error of ±15% and ±10% for 98.8% and 83.2% of the testing data, respectively, while the weaker fit is obtained for PL = 0.6, with a mean error of ±15% and ±10% for 90.2% and 71.1% of the available data, respectively.…”

“…The results obtained agree with previous reports by other authors. 30 For the absorptivity, a range of temperature ≤ ≤ T 300K…”