0
Research Papers: Gas Turbines: Combustion, Fuels, and Emissions

Increasing Flashback Resistance in Lean Premixed Swirl-Stabilized Hydrogen Combustion by Axial Air Injection

[+] Author and Article Information
Thoralf G. Reichel

Chair of Fluid Dynamics,
Hermann-Föttinger-Institut,
Technische Universität Berlin,
Müller-Breslau-Str. 8,
Berlin 10623, Germany
e-mail: thoralf.reichel@tu-berlin.de

Steffen Terhaar, Oliver Paschereit

Chair of Fluid Dynamics,
Hermann-Föttinger-Institut,
Technische Universität Berlin,
Müller-Breslau-Str. 8,
Berlin 10623, Germany

1Corresponding author.

Contributed by the Combustion and Fuels Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received September 1, 2014; final manuscript received October 30, 2014; published online December 23, 2014. Editor: David Wisler.

J. Eng. Gas Turbines Power 137(7), 071503 (Jul 01, 2015) (9 pages) Paper No: GTP-14-1522; doi: 10.1115/1.4029119 History: Received September 01, 2014; Revised October 30, 2014; Online December 23, 2014

Since lean premixed combustion allows for fuel-efficiency and low emissions, it is nowadays state of the art in stationary gas turbines. In the long term, it is also a promising approach for aero engines, when safety issues like lean blowout (LBO) and flame flashback in the premixer can be overcome. While for the use of hydrogen the LBO limits are extended, the flashback propensity is increased. Thus, axial air injection is applied in order to eliminate flashback in a swirl-stabilized combustor burning premixed hydrogen. Axial injection constitutes a nonswirling jet on the central axis of the radial swirl generator which influences the vortex breakdown (VB) position. In the present work, changes in the flow field and their impact on flashback limits of a model combustor are evaluated. First, a parametric study is conducted under isothermal test conditions in a water tunnel employing particle image velocimetry (PIV). The varied parameters are the amount of axially injected air and swirl number. Subsequently, flashback safety is evaluated in the presence of axial air injection in an atmospheric combustor test rig and a stability map is recorded. The flame structure is measured using high-speed OH* chemiluminescence imaging. Simultaneous high-speed PIV measurements of the reacting flow provide insight in the time-resolved reacting flow field and indicate the flame location by evaluating the Mie scattering of the raw PIV images by means of the qualitative light sheet (QLS) technique. The isothermal tests identify the potential of axial air injection to overcome the axial velocity deficits at the nozzle outlet, which is considered crucial in order to provide flashback safety. This effect of axial air injection is shown to prevail in the presence of a flame. Generally, flashback safety is shown to benefit from an elevated amount of axial air injection and a lower swirl number. Note that the latter also leads to increased NOx emissions, while axial air injection does not. Additionally, fuel momentum is indicated to positively influence flashback resistance, although based on a different mechanism, an explanation of which is suggested. In summary, flashback-proof operation of the burner with a high amount of axial air injection is achieved on the whole operating range of the test rig at inlet temperatures of 620 K and up to stoichiometric conditions while maintaining single digit NOx emissions below a flame temperature of 2000 K.

FIGURES IN THIS ARTICLE
<>
Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Brand, J., Sampath, S., and Shum, F., 2003, “Potential Use of Hydrogen in Air Propulsion,” AIAA Paper No. 2003–2879. [CrossRef]
Corchero, G., and Montañés, J. L., 2005, “An Approach to the Use of Hydrogen for Commercial Aircraft Engines,” Proc. Inst. Mech. Eng., Part G., 219(1), pp. 35–44. [CrossRef]
Haglind, F., and Singh, R., 2006, “Design of Aero Gas Turbines Using Hydrogen,” ASME J. Eng. Gas Turbines Power, 128(4), pp. 754–764. [CrossRef]
Yin, F., Rao, A. G., and van Buijtenen, J., 2013, “Performance Cycle Analysis for a Multi-Fuel Hybrid Engine,” ASME Paper No. GT2013-94601. [CrossRef]
Levy, Y., Sherbaum, V., and Arfi, P., 2004, “Basic Thermodynamics of FLOXCOM, the Low-NOx Gas Turbines Adiabatic Combustor,” Appl. Therm. Eng., 24(11), pp. 1593–1605. [CrossRef]
Boerner, S., Funke, H. H.-W., Hendrick, P., Recker, E., and Elsing, R., 2011, “Development and Integration of a Scalable Low NOx Combustion Chamber for a Hydrogen-Fueled Aerogas Turbine,” Prog. Propuls. Phys., 4, pp. 357–372. [CrossRef]
Lefebvre, A. H., and Ballal, D. R., 2010, Gas Turbine Combustion: Alternative Fuels and Emissions, 3rd ed., Taylor & Francis, Boca Raton, FL.
Ziemann, J., 1998, “Low-NOx Combustors for Hydrogen Fueled Aero Engine,” Int. J. Hydrogen Energy, 23(4), pp. 281–288. [CrossRef]
Beerer, D., McDonnell, V., Therkelsen, P. L., and Cheng, R. K., 2012, “Flashback, Blow Out, Emissions and Turbulent Displacement Flame Speed Measurements in a Hydrogen and Methane Fired Low-Swirl Injector at Elevated Temperatures and Pressures,” ASME Paper No. GT2012-68216. [CrossRef]
Döbbeling, K., and Hellat, J., 2007, “25 Years of BBC/ABB/Alstom Lean Premix Combustion Technologies,” ASME J. Eng. Gas Turbines Power, 129(1), pp. 2–12. [CrossRef]
Gupta, A. K., Lilley, D. G., and Syred, N., 1984, Swirl Flows, Abacus, Tunbridge Wells and Kent, UK.
Burmberger, S., Hirsch, C., and Sattelmayer, T., 2006, “Designing a Radial Swirler Vortex Breakdown Burner,” ASME Paper No. GT2006-90497. [CrossRef]
Burmberger, S., and Sattelmayer, T., 2011, “Optimization of the Aerodynamic Flame Stabilization for Fuel Flexible Gas Turbine Premix Burners,” ASME J. Eng. Gas Turbines Power, 133(10), p. 101501. [CrossRef]
Burmberger, S., Hirsch, C., and Sattelmayer, T., “Design Rules for the Velocity Field of Vortex Breakdown Swirl Burners,” ASME Paper No. GT2006-90495. [CrossRef]
Jochmann, P., Sinigersky, A., Koch, R., and Bauer, H.-J., “URANS Prediction of Flow Instabilities of a Novel Atomizer Combustor Configuration,” ASME Paper No. GT2006-90495. [CrossRef]
Spencer, A., McGuirk, J. J., and Midgley, K., 2008, “Vortex Breakdown in Swirling Fuel Injector Flows,” ASME J. Eng. Gas Turbines Power, 130(2), p. 021503. [CrossRef]
Midgley, K., Spencer, A., and McGuirk, J. J., 2005, “Unsteady Flow Structures in Radial Swirler Fed Fuel Injectors,” ASME J. Eng. Gas Turbines Power, 127(4), pp. 755–764. [CrossRef]
Terhaar, S., Reichel, T. G., Schrödinger, C., Rukes, L., Paschereit, C. O., and Oberleitner, K., 2013, “Vortex Breakdown and Global Modes in Swirling Combustor Flows With Axial Air Injection,” AIAA Paper No. 0748-4658. [CrossRef]
Galley, D., Ducruix, S., Lacas, F., and Veynante, D., 2011, “Mixing and Stabilization Study of a Partially Premixed Swirling Flame Using Laser Induced Fluorescence,” Combust. Flame, 158(1), pp. 155–171. [CrossRef]
Reichel, T. G., Terhaar, S., and Paschereit, C. O., 2013, “Flow Field Manipulation by Axial Air Injection to Achieve Flashback Resistance and Its Impact on Mixing Quality,” AIAA Paper No. 2013-2603. [CrossRef]
Billant, P., Chomaz, J.-M., and Huerre, P., 1998, “Experimental Study of Vortex Breakdown in Swirling Jets,” J. Fluid Mech., 376, pp. 183–219. [CrossRef]
Mayer, C., Sangl, J., Sattelmayer, T., Lachaux, T., and Bernero, S., 2012, “Study on the Operational Window of a Swirl Stabilized Syngas Burner Under Atmospheric and High Pressure Conditions,” ASME J. Eng. Gas Turbines Power, 134(3), p. 031506. [CrossRef]
Sangl, J., Mayer, C., and Sattelmayer, T., “Dynamic Adaptation of Aerodynamic Flame Stabilization of a Premix Swirl Burner to Fuel Reactivity Using Fuel Momentum,” ASME Paper No. GT2010-22340. [CrossRef]
Lieuwen, T., McDonell, V., Petersen, E., and Santavicca, D., 2008, “Fuel Flexibility Influences on Premixed Combustor Blowout, Flashback, Autoignition, and Stability,” ASME J. Eng. Gas Turbines Power, 130(1), p. 011506. [CrossRef]
Kröner, M., Fritz, J., and Sattelmayer, T., 2003, “Flashback Limits for Combustion Induced Vortex Breakdown in a Swirl Burner,” ASME J. Eng. Gas Turbines Power, 125(3), pp. 693–700. [CrossRef]
Beerer, D. J., and McDonell, V. G., 2008, “Autoignition of Hydrogen and Air Inside a Continuous Flow Reactor With Application to Lean Premixed Combustion,” ASME J. Eng. Gas Turbines Power, 130(5), p. 051507. [CrossRef]
Lacarelle, A., and Paschereit, C. O., 2012, “Increasing the Passive Scalar Mixing Quality of Jets in Crossflow With Fluidics Actuators,” ASME J. Eng. Gas Turbines Power, 134(2), p. 021503. [CrossRef]
Roehle, I., Schodl, R., Voigt, P., and Willert, C., 2000, “Recent Developments and Applications of Quantitative Laser Light Sheet Measuring Techniques in Turbomachinery Components,” Meas. Sci. Technol., 11(7), pp. 1023–1035. [CrossRef]
Terhaar, S., and Paschereit, C., 2012, “High-Speed PIV Investigation of Coherent Structures in a Swirl-Stabilized Combustor Operating at Dry and Steam-Diluted Conditions,” 16th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, Portugal, July 9–12, pp. 37–48.

Figures

Grahic Jump Location
Fig. 1

Increase of both, (a) bulk outlet velocity u0(φ) and (b) momentum ratio J, with equivalence ratio strongly depends on ratio of inlet air to fuel temperature (Tin/Tfuel)

Grahic Jump Location
Fig. 2

Schematic of burner model, indicating different volume flow pathways through swirl generator or axial injection

Grahic Jump Location
Fig. 3

Experimental setup for simultaneous PIV and OH* measurements in atmospheric combustion test rig

Grahic Jump Location
Fig. 4

Velocity vectors superimposed on normalized mean axial velocity of the isothermal flow field in the (a) absence (Dor = 0 mm) and (b) presence of a medium (Dor = 8.0 mm), and (c) high (Dor = 8.8 mm) amount of axial air injection (long mixing tube; S = 0.9), solid lines indicating zero axial velocity

Grahic Jump Location
Fig. 5

Histogram of axial velocity at (x/D = 0.1, r/D = 0) for isothermal conditions in the absence (Dor = 0 mm) and presence of a medium (Dor = 8.0 mm) and high (Dor = 8.8 mm) amount of axial air injection (Re = 68,000)

Grahic Jump Location
Fig. 6

Stability limits for varied air mass flows at two inlet temperatures; configurations 1–4 operated at stoichiometric conditions without flashback (symbol ×, not tested above stoichiometric). Hence, only the lower stability limits are displayed for each configuration.

Grahic Jump Location
Fig. 7

Impact of increased equivalence ratio for the reacting flow (m· = 180 kg/h, tin = 450 k) for a high ((a)–(c), φ=0, 0.4, and 0.8) and medium ((d)–(f), φ=0, 0.4, and 0.6) amount of axial air injection. Solid lines indicate zero axial velocity.

Grahic Jump Location
Fig. 8

Histogram of axial velocity at (x/D = 0.1, r/D = 0) revealing impact of fuel momentum in the presence of high (Dor = 8.8 mm) amount of axial air injection (Re = 75,000)

Grahic Jump Location
Fig. 9

Observed VB types during PIV measurements of configurations 3 and 4 transferred to schematic in Ref. [18], in order to explain difference in character of axial air injection (χ ↑) and fuel momentum (φ↑)

Grahic Jump Location
Fig. 10

Flame probability indicating the likelihood of the flame to appear in a certain region, hence, allowing to determine the upstream flame shape (Re = 75,000)

Grahic Jump Location
Fig. 11

ABEL-deconvoluted OH* images normalized to the maximum intensity of the image at φ=0.8 (Re = 75,000)

Grahic Jump Location
Fig. 12

NOx emissions (dry) over calculated adiabatic flame temperature for high axial air injection

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In