Gray gas emissivities for H2O-CO2-CO-N2 mixtures
Abstract
Gray gas emissivities of water vapor, carbon dioxide, and carbon monoxide are needed in many engineering calculations to determine radiative heat fluxes in high-temperature processes. In this work we provide (a) an EXCEL program (see Supplementary Material) that predicts total gas emissivities for H2O-CO2-CO-N2 mixtures and (b) a set of graphs for calculations by hand (see Appendix). The EXCEL program uses pre-calculated emissivity charts and overlap correction charts to interpolate the total emissivity for given compositions, temperatures, and pressures. The interpolated emissivities differ by - 0.15 % ± 0.73 % on average if compared to spectral line-by-line calculations using HITEMP-2010 spectroscopic database. Differences in case of the well-known Hottel's emissivity charts are larger than 200%, particularly at high pressures. Emissivities calculated using Leckner's polynomials may differ from the line-by-line calculated values by -90%-180%.
- Publication:
-
Journal of Quantitative Spectroscopy and Radiative Transfer
- Pub Date:
- November 2018
- DOI:
- 10.1016/j.jqsrt.2018.08.008
- Bibcode:
- 2018JQSRT.219..274A
- Keywords:
-
- Total emissivity;
- Hottel's charts;
- Line-by-line;
- HITEMP