Full-spectrum k-distribution weighted sum of gray gases model for air and oxyfuel combustion of hydrogen-hydrocarbon blends at atmospheric pressure

As a result of work carried out within HYINHEAT, we are pleased to share the peer-reviewed publication “Full-spectrum k-distribution weighted sum of gray gases model for air and oxyfuel combustion of hydrogen-hydrocarbon blends at atmospheric pressure”, published in the journal Thermal Science and Engineering Progress.

Abstract

The decarbonisation of industrial heating processes requires the introduction of alternative fuels such as hydrogen, ammonia and biogas to replace conventional fossil fuels such as natural gas.

However, changes in fuel composition also modify the composition of the flue gases, particularly the concentrations of water vapour and carbon dioxide, making accurate modelling of radiative heat transfer increasingly important.
This study develops two new sets of coefficients for a five-gray-gas Weighted Sum of Gray Gases (WSGG) model, specifically calibrated for air and oxyfuel combustion of hydrogen-hydrocarbon blends at atmospheric pressure. The models cover a broad range of H₂O-to-CO₂ molar ratios and temperatures, allowing their application to combustion systems with varying hydrogen contents. The coefficients are derived from detailed spectroscopic calculations and are assessed through predictions of total emissivity, radiative heat flux and radiative source terms.

The results show that the proposed models provide significantly improved predictions compared with recent WSGG models, offering a more flexible and accurate approach for modelling radiative heat transfer under the wide range of gas compositions expected as industrial combustion systems transition towards hydrogen and other alternative fuels.