Numerical Re-Design of a Heavy Duty Gas Turbine Hydrogen-Fired Combustion Chamber

The present work describes the numerical methodology followed to characterize and study modifications to a silo-type diffusive combustion chamber installed on a GE10, a 10 MW class heavy-duty gas turbine manufactured by GE Oil & Gas. The goal of the work was to investigate modifications to the combustion chamber to allow operation with 100% hydrogen fuel at reduced NO_x production in dry conditions. The investigation focused mainly on the burner; the liner was not substantially changed. The swirler and the fuel injection holes were redesigned to achieve better fuel-air mixing and a higher airflow rate in the primary zone of the combustor, maintaining a diffusion flame scheme. The proposed modifications were analyzed using a 3D CFD RANS reactive procedure based on commercial codes. The method was previously validated by comparison with the experimental data from the full scale tests performed at the Enel Facility at Sesta, Italy. In-house codes were developed for the post-processing of the results. The numerical analysis has shown that the modified version can provide a NO_x reduction up to 40%. The results are discussed focusing on the effect of fuel injection scheme on mixing quality and NO_x emission containment.