Session: 04-30 Emissions - hydrogen/ammonia III

Paper Number: 129248

129248 - Large-Eddy Simulation of a Non-Premixed Ammonia-Hydrogen Flame: NOx Emission and Flame Characteristics Validation 

Despite the rising interest in ammonia and ammonia-hydrogen blends as fuels for gas turbine applications, many aspects still remain to be solved to ensure a safe and stable combustion of such gases. Above all, the reduced margin against flame extinction and high NOx emission related to the fuel-bound pathway can strongly limit the operability of the combustor.

A promising technical solution to overcome these drawbacks is represented by the rich-quench-lean architecture that allows the combustor to operate at the optimal equivalence ratio in the primary zone and consequently to contain the NOx, ensuring the highest flame stability at the same time. In this context, the investigation of non-premixed burner configurations plays a pivotal role in the definition and the optimization of a specific design.

In this work, a computational fluid dynamic investigation of a generic swirler burner fed with a blend of 75% H₂ – 25% NH₃ (% vol.) and operated in fully non-premixed conditions will be presented. The validation of the model, performed on a test condition at atmospheric pressure, will be based on the experimental test campaign executed at the Gas Turbine Research Center of the Cardiff University[1]. Specifically, attention will be focused on the prediction of NOx emission and to the extremely elongated flame position, leveraging the OH* chemiluminescence. The novelty of the simulation is represented by an extended version of the thickened flame model to properly describe the diffusive combustion regime.

[1] Pugh, D et al. "Influence of Variable Swirl on Emissions in a Non-Premixed Fuel-Flexible Burner At Elevated Ambient Conditions." ASME. J. Eng. Gas Turbines Power.

https://doi.org/10.1115/1.4063786

Presenting Author: Dr. Naseem Ansari Ansys Inc

Presenting Author Biography: Naseem Ansari is a Principal Engineer at Ansys Inc in the Fluids Division.
Naseem Ansari has over 20 years of experience in the area of turbulence and combustion
modeling in gas turbine combustors. He holds a Ph.D from the University of Pittsburgh, USA
in Mechanical Engineering.

Authors:

Dr. Naseem Ansari Ansys Inc
Stefano Orsino Ansys Inc
Roberto Meloni Baker Hughes
Egidio Pucci Baker Hughes
Simone Castellani University of Florence
Antonio Andreini University of Florence
A. Valera-Medina Cardiff University School of Engineering