Total gaseous radiation modeling for natural gas combustion with full-range hydrogen blending ratios based on line by line method

Hydrogen-blended combustion is recognized as a crucial pathway for hydrogen utilization and is suitable for gas turbines and boilers. Under such conditions, the H_2{O} / CO_2 molar ratio in the flue gas varies significantly, resulting in changes to thermal radiative properties. Accurate heat transfer calculations require new reference data and updated computational methods, especially for high-temperature and high-pressure condition. This study proposes a novel total radiation model based on the weighted-sum-of-gray gases (WSGG) principle, tailored for natural gas combustion with full-range hydrogen blending ratios (0-100%), introducing an innovative weighting coefficient formulation to account for pressure (1-40 atm), temperature (400-2500 K), and H_2{O} / CO_2 molar ratio effects on radiative properties. The model, benchmarked against the HITEMP 2010 based line by line (LBL) method, covers the partial pressure path lengths from 0.001 to 60 atm?m. The accuracy of the new WSGG model was validated through emissivity calculations and one- and two-dimensional radiative heat transfer simulations, while the impacts of pressure, gas composition, and path length on radiative heat transfer were investigated. The average heat source error does not exceed 4.18% under full working conditions. The developed model provides a critical foundation for designing hydrogen-blended natural gas combustors and CFD-based calculations.