Flexible Fuel Operation of a Dry-Low-NOx Micromix Combustor with Variable Hydrogen Methane Mixtures

The role of hydrogen (H 2 ) as a carbon-free energy carrier is discussed since decades for reducing greenhouse gas emissions. As bridge technology towards a hydrogen-based energy supply, fuel mixtures of natural gas or methane (CH 4 ) and hydrogen are possible. The paper presents the first test results of a low-emission Micromix combustor designed for flexible-fuel operation with variable H 2 /CH 4 mixtures. The numerical and experimental approach for considering variable fuel mixtures instead of recently investigated pure hydrogen is described. In the experimental studies, a first generation FuelFlex Micromix combustor geometry is tested at atmospheric pressure at gas turbine operating conditions corresponding to part- and full-load. The H 2 /CH 4 fuel mixture composition is varied between 57 and 100 vol.% hydrogen content. Despite the challenges flexible-fuel operation poses onto the design of a combustion system, the evaluated FuelFlex Micromix prototype shows a significant low NO x performance and high combustion efficiency over a wide fuel range.