Experimental Characterization and Emission Analysis of Hydrogen-Enriched Fuel Blends in Gas Turbine Applications

The gas turbine industry is actively exploring lean premixed combustion with hydrogen (H2)-enriched fuel blends to decrease greenhouse gas and Nitrogen Oxides (NOx) emissions. Hydrogen enrichment is a crucial area for investigation, aiming to enhance combustion processes and reduce emissions. This study explores the potential of hydrogen-enriched blends to improve energy efficiency and mitigate greenhouse gas emissions. Two flame configurations-lean and rich-are investigated at constant thermal power outputs. In rich condition and pure CH4 a lifted flame is established. Scenarios with incremental H2 additions to air/methane mixtures are examined using chemiluminescence techniques and spectral filtering for OH species. Proper Orthogonal Decomposition (POD) and Spectral Proper Orthogonal Decomposition (SPOD) methods identify coherent structures and frequency ranges of flame fluctuations. Acoustic microphone analysis provides insights into flame fluctuations, and Power Spectral Density (PSD) evaluation is performed. Measurements of exhaust temperature and emissions (NOx, CO2) further contribute to understanding hydrogen's role in cleaner and more efficient combustion.