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Mitigating Climate Change Through Ammonia-Hydrogen Premixed Turbulent Combustion

Jacqueline H. Chen, Sandia National Laboratories

Martin Rieth, Sandia National Laboratories

Andrea Gruber, SINTEF

Forman Williams, University of California, San Diego

Mitigating climate change while providing our nation’s transportation and power generation needs are key to energy and environmental security. New e-fuels and hydrogen rich fuels provide a near zero-carbon alternative to fossil fuels for gas turbine engines for power generation and for compression ignition engines for marine shipping. A potential shift to hydrogen as a clean energy carrier is one of the most promising strategies to significantly reduce carbon dioxide emissions in the face of increasing energy demand. This is particularly relevant for large-scale power generation combined with pre-combustion carbon sequestration and large-scale energy-storage schemes, both relying on hydrogen obtained from fossil or renewable sources. The use of ammonia as a fuel for gas turbines is attractive due to its advantages over hydrogen from the perspective of transport and storage and has been explored in the past but was supplanted by conventional hydrocarbons due to its poor reactivity. However, recent studies with rich-lean fuel staging have shown some promising results. In principle gas turbines are fuel flexible; however in reality, burner design becomes tuned to specific fuels, methane being the most common. Here, we consider mixtures of ammonia and hydrogen, as a carbon free fuel blend for gas turbines and marine shipping applications. Direct numerical simulation (DNS) results will be presented illustrating the crucial role of fast hydrogen diffusion in ammonia blends in highly turbulent flames in the enhancement of the combustion rate and in the prevention of extinction and blowout relative to methane.  More recently, DNS results also demonstrate the surprising robustness of combustion with ammonia/hydrogen blends at elevated pressure, again due to the intrinsic thermo-diffusive instability of hydrogen. The DNS simulations were performed with S3D-Regent on the 200 Pflop Summit supercomputer at the Oakridge Leadership Computing Facility leveraging a dynamic task-based programming system, Legion/Regent, developed for heterogeneous architectures.

Biography

Jacqueline H. Chen is a Senior Scientist at the Combustion Research Facility at Sandia National Laboratories.  She has contributed broadly to research in turbulent combustion elucidating turbulence-chemistry interactions in combustion through direct numerical simulations. To achieve scalable performance of DNS on heterogeneous computer architectures she leads an interdisciplinary team of computer scientists, applied mathematicians and computational scientists  to develop an exascale direct numerical simulation capability for turbulent combustion with complex chemistry and multi-physics. She is a member of the National Academy of Engineering and a Fellow of the Combustion Institute and the Americal Physical Society. She is an Associate Fellow of the AIAA.  She received the Combustion Institute’s Bernard Lewis Gold Medal Award in 2018, the Society of Women Engineers Achievement Award in 2018, the Department of Energy Office of Science Distinguished Scientists Fellow Award in 2020, and the R&D100 Award for the Legion Programming System in 2020.