Abstract
In light of the global commitment to decarbonize industrial processes, Carbon Capture and Storage (CCS) is crucial for mitigating carbon footprint from Gas Turbine (GT) power generation. Efficient GT-CCS coupling requires high percentages of Exhaust Gas Recirculation (EGR) to maximize CO2 content at the CCS inlet. However, the resulting reduced oxygen concentration limits engine operability, posing challenges for conventional combustion systems. Addressing this requires innovative solutions to extend the combustor operability at high EGR rates. Computational Fluid Dynamics (CFD) simulations are essential to identify the flame stability limits across various EGR levels and burner designs, aiming for high accuracy while minimizing computational costs.
This study focuses on comparing enhanced versions of the Flamelet Generated Manifolds (FGM) and Artificially Thickened Flame (ATF) models through a Large Eddy Simulation (LES) based CFD analysis. The investigation is performed on an industrial lean premixed burner by Baker Hughes, operating with Natural Gas and CO2-diluted air at atmospheric pressure. While the Extended-FGM has been previously studied under standard air conditions, the current work aims to extend its application to critical oxygen-depleted conditions, where near-blow-out phenomena may become significant. Validation involves comparing computed heat-release profiles, representing flame topology, with experimental OH* chemiluminescence data from tests conducted at the University of Florence's THT Lab. Experimental data serves as the primary benchmark for assessing the models's effectiveness in capturing the main dynamics and addressing any disparities in aero-thermal fields at the burner exit between the two models.
