New coefficients of the weighted-sum-of-gray-gases model for gas radiation characteristics of hydrogen/natural gas blends combustion

Abstract

To achieve carbon neutrality, hydrogen/natural gas blends are gaining momentum as a clean low-carbon fuel for the future. In order to accurately carry out the CFD numerical simulation of hydrogen/natural gas blends combustion, it is imperative to establish a precise model for gas radiation characteristics. The existing weighted-sum-of-gray-gases model (WSGGM) is not suitable for high hydrogen content fuels, such as hydrogen/natural gas blends. Hence, new coefficients of WSGGM is formulated specifically for the combustion of hydrogen/natural gas blends, drawing upon the groundwork established by the statistical narrow-band model (SNB model). This model is specifically designed to be applicable within the ambient pressures, encompassing the temperature regime of 400–2500 K, a path-length range of 0.001–60 m, and a hydrogen blending ratio of 20%–70%. The radiative heat transfer characteristics of the sum of the molar fraction of H2O and CO2 at 0.9, 0.6, and 0.3 were studied according to application conditions. The WSGGM is implemented to compute the radiative heat transfer in non-isothermal and non-homogeneous gas mixtures. When compared to the benchmark model, the deviation of the wall heat flux does not surpass 5.20%. The results demonstrate the excellent adaptability of the WSGG coefficients in simulating the radiative heat transfer during hydrogen/natural gas blends combustion.