عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In this paper, the effects of swirling air and primary aeration on NOx production are numerically investigated. In this regard, a combustion chamber with two-dimensional axisymmetric geometry and non-premixed combustion is considered. The k–e Realizable model is adopted as a turbulence closure model. Also, the Presumed PDF and EDM models with Zeldovich mechanism are considered for combustion modeling. Comparisons of numerical results with available experimental data show that the PDF model is capable of predicting the combustion characteristics. Results show that for every swirl number a specific aeration exists that consequences the minimum NO emissions. As the result, the increase of swirl number in without aeration will lead first to an increase and then a slight decrease of combustion temperature and NO at the exit. The effect of aeration in constant stoichiometric ratio shows that, swirl number of 0.48 and 2.5% aeration, leads to the complete combustion and minimum NO emissions.
 S. R Turns, S. J. Mantel, an Introduction to Combustion, 2nd Edition, New York, McGraw Hill, 2000.
 Sh. Hashemi, M. FarzaneGord, A. Ershadi, Investigation on NOX reduction 2D modeling Electric Arc Furnace (EAF), Proceedings of the Fourth International Exergy, Energy and Environment Symposium, pp. 18-23, 2009.
 M. Zaki, M. Rajabi-Zargarabadi, Numerical analysis of effects of primary aeration on NOX production in a model gas turbine combustion chamber, Modares Mechanical Engineering, Vol. 14, No. 10, pp. 101-109, 2014, (In Persian فارسی).
 C. S. Cooper, N. M. Laurendeau, Parametric study of NO production via quantitative laser-induced fluorescence in high-pressure, swirl stabilization spray flames, Proc Combust Inst, Vol. 28, pp. 287–293, 2000.
 M. Ilbas, The effect of thermal radiation and radiation models on hydrogen–hydrocarbon combustion modeling, International Journal of Hydrogen Energy, Vol. 30, Issue 10, pp 1113-1126, 2005.
 S. Mahdizadeh, S. Tabe’jamaa’t, NOx Reduction Analysis in Fuel Gas Combustion Chamber using Water Injection, Mechanic and airspace Journal of Imam Hossein university, Vol. 1, No. 1, 2006 (In Persian فارسی).
 R. Ebrahimi, S. Agha Najafi, Reburn effective method for NOx reduction, 12th International Conference on Mechanical Engineering, Tarbiat Modares university, 2005 (In Persian فارسی).
 S. M. Javadi, M. Moghiman, Experimental Study of Natural Gas Temperature Effects on the Flame Luminosity and NO Emission in a 120 kW Boiler, Vol. 4, pp. 15-24, 2011 (In Persian فارسی).
 M. E. Feyz, J. A. Esfahani, I. Pishbin, S. M. Modarres Razavi, Effect of recess length on the flame parameters and combustion performance of a low swirl burner, Applied Thermal Engineering, Vol. 89, pp. 609-617, 2015.
 Y. A. Eldrainy, Kh. M. Saqr, H. S. Aly, M. Nazri Mohd Jaafar, CFD insight of the flow dynamics in a novel swirler for gas turbine combustors, International Communications in Heat and Mass Transfer, Vol. 36, pp. 936–941, 2009.
 Sh. Ti, Zh. Chen, Zh. Li, Y. Xie, Y. Shao, Q. Zong, Q. Zhang, Influence of different swirl vane angles of over fire air on flow and combustion characteristics and NOx emissions in a 600 MWe utility boiler, Energy, Vol. 74, pp. 775-787, 2014.
 Y. A. Eldrainy, Kh. M. Saqr, H. S. Aly, Th. M. Lazim, M. Nazri-Mohd-Jaafar, Large eddy simulation and preliminary modeling of the flow downstream a variable geometry swirler for gas turbine combustors, International communications in Heat and Mass Transfer, Vol. 38, pp. 1104–1109, 2011.
 Y. Wu, C. Carlsson, R. Szasz, L. Peng, L. Fuchs, X. S. Bai, Effect of geometrical contraction on vortex breakdown of swirling turbulent flow in a model combustor, Fuel, Vol. 170, pp. 210–225, 2016.
 Y. Li, R. Li, D. Li, J. Bao, P. Zhang, Combustion characteristics of a slotted swirl combustor: An experimental test and numerical validation, International Communications in Heat and Mass Transfer, vol. 66, pp 140–147, 2015.
 L. X. Zhou, X. L. Chen, Studies on the effect of swirl on NO formation in methan/air turbulent combustion, Proceedings of the Combustion Institute, Vol. 29, pp. 2235–2242, 2002.
 W. Fang, X. Xiang, Effect of turbulence on NO formation in swirling combustor, Chinese Journal of Aeronautics, Vol. 27, No. 4, pp 797–804, 2014.
 M. Arabnejad, M. Shahsavari-Farshchi, A Numerical Study of the Effect of Swirl Number on Premixed Low Swirl Combustion, Vol. 8, pp. 1-12, 2015 (In Persian فارسی).
 M. Ilbas, S. Karyeyen, I. Yilmaz, Effect of swirl number on combustion characteristics of hydrogen-containing fuels in a combustor, Int. J. of hydrogen energy, vol. xxx, pp. 1-7, 2016.
 FLUENT 6.3., Tutorial Guide Fluent 6.3. Inc., 2006.
 S. Chouaieb, W. Kriaa, H. Mhiri, Ph. Bournot, Presumed PDF modeling of microjet assisted CH4–H2/air turbulent flames, Energy Conversion and Management, Vol. 120, pp. 412–421, 2016.