Co-Firing Hydrogen With Natural Gas for 9 MW Siemens Energy Dry Low Emissions Combustor: Part II – Large Eddy Simulations

Abstract To demonstrate Siemens Energy’s industrial gas turbine engines’ (SEITL) 30% hydrogen (H2) capability (by volume), a 9 MW Dry Low Emissions (DLE) combustion system of an SGT-300-2S engine was tested at the Siemens Energy Clean Energy Center in Berlin. The fuel blend used contained up to 40% H2 by volume. The test results were reported in Part I of the paper. Part II presents the numerical simulation results. Reacting flow simulations for fuels containing H2 present a challenge with existing combustion models and chemical mechanisms. This paper aims to numerically validate the effect of H2 on combustion performance. The Simcenter STAR-CCM+® solver was used to conduct numerical simulations of the DLE combustor in the high-pressure rig configuration. Large Eddy Simulations (LES) with a Flamelet Generated Manifold (FGM) combustion model and Thickened Flame Model (TFM) were employed. The ARM22 chemical mechanism was used to generate flamelet manifolds for each configuration of varied H2 concentration. Simulations for natural gas were performed first to provide reference, then natural gas blended with 30% and 40% H2 by volume were carried out. The effect of pilot fuel schedule was also investigated to provide physical insight. Flame structure, NOx emission, and combustor exit profiles were investigated at ISO full load engine condition for these fuels and compared with natural gas. Results from the numerical study were compared with those from the high-pressure rig test.