Abstract
This paper presents laser diagnostic experiments and large-eddy simulations (LES) of low-swirl lean premixed methane/air flames in a multi-nozzle combustor including five nozzles with the same structure. OH planar laser-induced fluorescence is used to observe flame shapes and identify main reaction zones. NOx and CO emissions are also recorded during the experiment. The flows and flames are studied at different equivalence ratios ranging from 0.5 to 0.8, while the bulk inlet velocity is fixed at 6.2 m/s. Results show that the neighboring swirling flows interact with each other, generating a highly turbulent interacting zone where intensive reactions take place. The flame is stabilized above the nozzle rim, and its liftoff height decreases with increasing equivalence ratio. The center flow is confined and distorted by the neighboring flows, resulting in instabilities of the center flame. Mean OH radical images reveal that the center nozzle flame is extinguished when equivalence ratio is equals to 0.5, which is successfully predicted by LES. In addition, NOx emissions show log-linear dependency on the adiabatic flame temperature, while the CO emissions remain lower than 10 ppm. NOx emissions for multi-nozzle flame are less sensitive to the flame temperature than that for single nozzle. These results demonstrate that the low-swirl multi-nozzle concept is a promising solution to achieve stable combustion with ultra-low emissions in gas turbines.
Similar content being viewed by others
References
Biagioli F, Güthe F, Schuermans B (2008) Combustion dynamics linked to flame behaviour in a partially premixed swirled industrial burner. Exp Therm Fluid Sci 32:1344–1353
Boehm B, Dreizler A, Gnirss M, Tropea C, Findeisen J, Schiffer H (2007) Experimental investigation of turbulence structure in a three-nozzle combustor. In: ASME Turbo Expo 2007, GT2007-27111
Cai J, Jeng SM, Tacina R (2001) Multi-swirler aerodynamics experimental measurements. In: 37th AIAA/ASME/SAE/ASEE joint propulsion conference and exhibit, AIAA 2001-3574
Cai J, Jeng SM, Tacina R (2002) Multi-swirler aerodynamics: comparison of different configurations. In: Proceedings of ASME Turbo Expo, GT2002-30464
Chan CK, Lau KS, Chin WK, Cheng RK (1992) Freely propagating open premixed turbulent flames stabilized by swirl. Proc Combust Inst 24:511–518
Cheng RK (1995) Velocity scalar characteristics of premixed turbulent flames stabilized by weak swirl. Combust Flame 101:1–14
Cheng RK (2006) Low swirl combustion the gas turbine hand book. http://prod75-inter1.netl.doe.gov/technologies/coalpower/turbines/refshelf/handbook/3.2.1.4.2.pdf
Cheng RK, Fable SA, Schmidt D, Arellano L, Smith KO (2001) Development of a low swirl injector concept for gas turbines. In: International joint power conference, IJPGC2001/FACT-19055
Cheng RK, Littlejohn D, Nazeer WA, Smith KO (2006) Laboratory studies of the flow field characteristics of low-swirl injectors for adaptation to fuel-flexible turbines. In: ASME Turbo Expo, GT2006-90878
Cheng RK, Littlejohn D, Strakey PA, Sidwell T (2009) Laboratory investigations of a low-swirl injector with H2 and CH4 at gas turbine conditions. Proc Combust Inst 32:3001–3009
Day M, Tachibana S, Bell J, Lijewski M, Beckner V, Cheng RK (2012) A combined computational and experimental characterization of lean premixed turbulent low swirl laboratory flames I. Methane flames. Combust Flame 159:275–290
Erlebacher G, Hussani MY, Speziale CG, Zang TA (1992) Toward the large eddy simulation of compressible turbulent flows. J Fluid Mech 238:155–158
Johnson MR, Littlejohn D, Nazeer WA, Smith KO, Cheng RK (2005) A comparison of the flowfields and emissions of high-swirl injectors and low-swirl injectors for lean premixed gas turbines. Proc Combust Inst 30:2867–2874
Kim J, Yoo K, Sung H, Zhang LW, Yang V (2010) A numerical study of flow dynamics in an annular combustor with multiple swirl injectors. In: 48th AIAA aerospace sciences meeting, AIAA 2010-583
Lannetti A, Tacina R, Cai J, Jeng SM (2001) Multi-swirler aerodynamics—CFD predictions. In: 37th AIAA/ASME/SAE/ASEE joint propulsion conference and exhibit, AIAA 2001-3575
Littlejohn D, Cheng RK, Noble DR, Lieuwen T (2010) Laboratory investigations of low-swirl injectors operating with syngases. J Eng Gas Turb Power 132:011502-1–011502-8
Nazeer W, Smith K, Sheppard P, Cheng RK, Littlejohn D (2006) Full scale testing of a low swirl fuel injector concept for ultra-low NOx gas turbine combustion systems. In: ASME Turbo Expo, GT2006-90150
Nogenmyr K-J, Fureby C, Bai XS, Petersson P, Collin R, Linne M (2009) Large eddy simulation and laser diagnostic studies on a low swirl stratified premixed flame. Combust Flame 156:25–36
Petersson P, Collin R, Lantz A, Aldén M (2011) Simultaneous PIV, OH-and fuel-PLIF measurements in a low-swirl stratified turbulent lean premixed flame. In: Proceedings of the European combustion meeting, pp 1–6
Smith KO, Therkelsen PL, Littlejohn D, Ali S, Cheng RK (2010) Conceptual studies of a fuel-flexible low-swirl combustion system for the gas turbine in power plants. In: Proceedings of the ASME Turbo Expo, GT2010-23506
Szedlmayer MT, Quay BD, Samarasinghe J, Rosa AD, Lee JG, Santavicca DA (2011) Forced flame response of a lean premixed multi-nozzle can combustor. In: ASME Turbo Expo 2011, GT2011-46080
Villalva R (2013) Emissions and operability of a muli-point low NOx staged combustor at intermediate pressures. In: ASME Turbo Expo, GT2013-95135
Worth NA, Dawson JR (2012) Cinematographic OH-PLIF measurements of two interacting turbulent premixed flames with and without acoustic forcing. Combust Flame 159:1109–1126
Acknowledgments
This work was supported by the National Natural Science Foundation of China (Grant No. 51206109).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Liu, W.J., Ge, B., Tian, Y.S. et al. Experimental investigations and large-eddy simulation of low-swirl combustion in a lean premixed multi-nozzle combustor. Exp Fluids 56, 34 (2015). https://doi.org/10.1007/s00348-015-1899-5
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/s00348-015-1899-5