Experimental and numerical analysis of industrial-type low-swirl combustion of hydrogen enriched natural gas including OH* chemiluminescence imaging

Abstract

The utilization of hydrogen (H2) instead of natural gas (NG) in high-temperature industries has the potential to significantly reduce global greenhouse gas emissions. To obtain detailed information on the combustion characteristics in a semi-industrial air–fuel setup, comprehensive experiments and 3D CFD simulations are performed on a low-swirl burner inside a combustion chamber. The H2 enrichment in NG of 0–100 vol% is analyzed at burner powers of 75–120 kW and temperatures of 900–1400 °C. The process efficiency increases by up to 10 percentage points due to higher temperatures and enhanced heat transfer. Furthermore, up to 20% lower NOx emissions are observed, which is attributed to a significant change in the flow and flame characteristics. For the first time, OH* chemiluminescence imaging is successfully applied to validate RANS simulations of an industrial turbulent flame. Further research should be directed toward evaluating OH* reaction kinetics in both laminar and turbulent NG/H2 combustion setups.