HYDROGEN-ENRICHED METHANE COMBUSTION DILUTED WITH EXHAUST GAS AND STEAM: FUNDAMENTAL INVESTIGATION ON LAMINAR FLAMES AND NO_X EMISSIONS

摘要

Hydrogen utilization in conventional power plants can offer a possibility to cover the residual load of volatile renewable energies while at the same time reducing the carbon footprint of power production. The challenge here is the high reactivity of hydrogen posing a risk of flashback, whereas increased flame temperature may result in higher NO_x emissions. A promising approach to overcome this challenges is the dilution of combustion mixtures by exhaust gas recirculation or by steam injection. The present paper provides experimental laminar burning velocities of hydrogen-enriched methane/air mixtures diluted with major components of exhaust gas and with steam. The corresponding numerical study based on a fictive species approach is used to quantify the chemical and physical effects of dilution on laminar burning velocities. The influence of hydrogen-enrichment and dilution on NO_x formation is studied numerically. The results demonstrate high potential of dilution with steam or exhaust gas to ensure stable operation even for hydrogen-rich mixtures while maintaining low NO_x emissions.