Axial staging in premixed gas turbine combustors is a promising option for the increase of firing temperature without NOx-penalty and for the improvement of turndown ratio, which is limited by the onset of CO-emissions. The configuration of greatest interest is the combination of state of the art premixed combustion in the primary stage with secondary injectors near the turbine inlet, which feed additional jets of premixed combustible mixture into the hot cross flow. Regarding NOx this configuration is particularly beneficial (1) if the overall mixing quality in the first stage is limited, (2) if the difference between primary zone flame temperature and turbine inlet temperature due to air addition along the combustor is large and (3) if a high degree of mixing in the second stage is achieved. The potential of this promising combustion concept was investigated in a large scale atmospheric test rig. For the study presented below scaling of the second stage according to Karlovitz number similarity was chosen. This leads to smaller jet diameters and higher injection velocities compared to scaling based on Damköhler number applied in an earlier study. The impact of the higher velocities at the injector outlet on the flow field, on the lift-off height of the flame and on NOx-formation is analyzed. A chemical network model is presented, which illustrates the effects of pre-flame and post-flame mixing on NOx-formation under atmospheric and high pressure conditions. In addition this model is used to study the interactions of chemistry with mixing between the reacting jet and cross flow. On the basis of atmospheric testing and reactor modeling, predictions for engine pressure are made assuming similar lift-off as well as pre- and post-flame mixing. These results are further analyzed regarding the NOx-reduction potential at different equivalence ratios and residence times. Finally, it is discussed under which conditions the investigated configuration can be beneficially applied to reduce NOx-emissions of real engines.
Skip Nav Destination
ASME Turbo Expo 2015: Turbine Technical Conference and Exposition
June 15–19, 2015
Montreal, Quebec, Canada
Conference Sponsors:
- International Gas Turbine Institute
ISBN:
978-0-7918-5668-0
PROCEEDINGS PAPER
Influence of Pre-Flame and Post-Flame Mixing on NOx-Formation in a Reacting Premixed Jet in Hot Cross Flow Available to Purchase
Denise Ahrens,
Denise Ahrens
Technische Universität München, Garching, Germany
Search for other works by this author on:
Michael Kolb,
Michael Kolb
Technische Universität München, Garching, Germany
Search for other works by this author on:
Christoph Hirsch,
Christoph Hirsch
Technische Universität München, Garching, Germany
Search for other works by this author on:
Thomas Sattelmayer
Thomas Sattelmayer
Technische Universität München, Garching, Germany
Search for other works by this author on:
Denise Ahrens
Technische Universität München, Garching, Germany
Michael Kolb
Technische Universität München, Garching, Germany
Christoph Hirsch
Technische Universität München, Garching, Germany
Thomas Sattelmayer
Technische Universität München, Garching, Germany
Paper No:
GT2015-42224, V04AT04A022; 14 pages
Published Online:
August 12, 2015
Citation
Ahrens, D, Kolb, M, Hirsch, C, & Sattelmayer, T. "Influence of Pre-Flame and Post-Flame Mixing on NOx-Formation in a Reacting Premixed Jet in Hot Cross Flow." Proceedings of the ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. Volume 4A: Combustion, Fuels and Emissions. Montreal, Quebec, Canada. June 15–19, 2015. V04AT04A022. ASME. https://doi.org/10.1115/GT2015-42224
Download citation file:
36
Views
Related Proceedings Papers
Related Articles
Advanced Catalytic Pilot for Low NO x Industrial Gas Turbines
J. Eng. Gas Turbines Power (October,2003)
NO x -Abatement Potential of Lean-Premixed GT Combustors
J. Eng. Gas Turbines Power (January,1998)
Analysis of NO X Formation in an Axially Staged Combustion System at Elevated Pressure Conditions
J. Eng. Gas Turbines Power (March,2012)
Related Chapters
Outlook
Closed-Cycle Gas Turbines: Operating Experience and Future Potential
Combined Cycle Power Plant
Energy and Power Generation Handbook: Established and Emerging Technologies
Performance Testing of Combined Cycle Power Plant
Handbook for Cogeneration and Combined Cycle Power Plants, Second Edition