Performance and Routes of Nitrogen Oxide Formation of MILD Forward-Flow Furnace with Reflector
Publication: Journal of Energy Engineering
Volume 143, Issue 4
Abstract
High-momentum jets, which are the key parameter to achieve moderate or intense low-oxygen dilution (MILD) combustion may lead to insufficient residence time and high CO emissions, especially for furnaces with a forward-flow configuration. A reflector for application in the furnace was proposed by two-dimensional numerical simulations to reduce the CO emissions and maintain low emissions. The prediction showed a remarkable agreement with measurements. The effects of the reflector height , the excess air factor (changes in the inlet methane-mass flow rate), and the hydrogen content in the blended gas were investigated. The numerical results indicate that the reflector blocks the reactant’s flow, intensifies the combustion before it, and prolongs the residence time of flue gases both before and behind it. The added hydrogen in methane can intensify combustion, increase reaction temperature and NO emissions, and reduce CO emissions. The reaction rates of thermal, prompt, NNH, and -intermediate routes increase with the decrease of . The addition of hydrogen decreases the rate of the prompt route, but the rates of NNH and thermal routes increase. MILD combustion is achieved under the reflector conditions, considering the nearly uniform temperature distribution and the low pollutants.
Get full access to this article
View all available purchase options and get full access to this article.
References
Afarin, Y., and Tabejamaat, S. (2013). “Effect of hydrogen on flame structure of MILD combustion using the LES method.” Int. J. Hydrogen Energy, 38(8), 3447–3458.
Aminian, J., Galletti, C., Shahhosseini, S., and Tognotti, L. (2012). “Numerical investigation of a MILD combustion burner: Analysis of mixing field, chemical kinetics and turbulence-chemistry interaction.” Flow Turbul. Combust., 88(4), 597–623.
Arghode, V. K., and Gupta, A. K. (2011a). “Investigation of forward flow distributed combustion for gas turbine application.” Appl. Energy, 88(1), 29–40.
Arghode, V. K., and Gupta, A. K. (2011b). “Investigation of reverse flow distributed combustion for gas turbine application.” Appl. Energy, 88(4), 1096–1104.
Arghode, V. K., Gupta, A. K., and Bryden, K. M. (2012). “High intensity colorless distributed combustion for ultra low emissions and enhanced performance.” Appl. Energy, 92, 822–830.
Ayoub, M., Rottier, C., Carpentier, S., Villermaux, C., Boukhalfa, A. M., and Honoré, D. (2012). “An experimental study of mild flameless combustion of methane/hydrogen mixtures.” Int. J. Hydrogen Energy, 37(8), 6912–6921.
Bowman, C. T., et al. (2016). “GRI-Mech 2.11.” ⟨http://www.me.berkeley.edu/gri_mech⟩ (Sep. 30, 2016).
Cao, S., Zou, C., Han, Q., Liu, Y., Wu, D., and Zheng, C. (2015). “Numerical and experimental studies of NO formation mechanisms under methane moderate or intense low-oxygen dilution (MILD) combustion without heated air.” Energy Fuels, 29(3), 1987–1996.
Castela, M., Veríssimo, A. S., Rocha, A. M. A., and Costa, M. (2012). “Experimental study of the combustion regimes occurring in a laboratory combustor.” Combust. Sci. Technol., 184(2), 243–258.
Cavaliere, A., and de Joannon, M. (2004). “Mild combustion.” Prog. Energy Combust., 30(4), 329–366.
Christo, F. C., and Dally, B. B. (2005). “Modeling turbulent reacting jets issuing into a hot and diluted coflow.” Combust. Flame, 142(1–2), 117–129.
Dally, B. B., Karpetis, A. N., and Barlow, R. S. (2002). “Structure of turbulent non-premixed jet flames in a diluted hot coflow.” Proc. Combust. Inst., 29(1), 1147–1154.
Dally, B. B., Shim, S. H., Craig, R. A., Ashman, P. J., and Szegö, G. G. (2010). “On the burning of sawdust in a MILD combustion furnace.” Energy Fuels, 24(6), 3462–3470.
FLUENT v6.3. [Computer software]. FLUENT, Lebanon, NH.
Galletti, C., Ferrarotti, M., Parente, A., and Tognotti, L. (2015). “Reduced NO formation models for CFD simulations of MILD combustion.” Int. J. Hydrogen Energy, 40(14), 4884–4897.
Kosmadakis, G., and Rakopoulos, C. (2015). “Computational fluid dynamics study of alternative nitric-oxide emission mechanisms in a spark-ignition engine fueled with hydrogen and operating in a wide range of exhaust gas recirculation rates for load control.” J. Energy Eng., .
Kulkarni, R. M., and Polifke, W. (2013). “LES of delft-jet-in-hot-coflow (DJHC) with tabulated chemistry and stochastic fields combustion model.” Fuel Process. Technol., 107, 138–146.
Kumar, S., Paul, P. J., and Mukunda, H. S. (2002). “Studies on a new high-intensity low-emission burner.” Proc. Combust. Inst., 29(1), 1131–1137.
Lee, C. L., and Jou, C. J. G. (2016). “Influence of the hydrogen-rich on the furnace thermal efficiency.” Appl. Therm. Eng., 93, 556–560.
Li, P., et al. (2011). “Progress and recent trend in MILD combustion.” Sci. China Technol. Sci., 54(2), 255–269.
Luo, R., et al. (2016). “Effect of the adjustable inner secondary air-flaring angle of swirl burner on coal-opposed combustion.” J. Energy Eng., 142(1), .
Mardani, A., and Tabejamaat, S. (2012). “NOx formation in blended flame under MILD conditions.” Combust. Sci. Technol., 184(7–8), 995–1010.
Mardani, A., Tabejamaat, S., and Ghamari, M. (2010). “Numerical study of influence of molecular diffusion in the MILD combustion regime.” Combust. Theor. Model., 14(5), 747–774.
Nikolopoulos, A., Malgarinos, I., Nikolopoulos, N., Grammelis, P., Karellas, S., and Kakaras, E. (2014). “A decoupled approach for 3-D CFD modeling in CFB plants.” Fuel, 115, 401–415.
Oldenhof, E., Tummers, M. J., van Veen, E. H., and Roekaerts, D. J. E. M. (2012). “Transient response of the Delft jet-in-hot coflow flames.” Combust. Flame, 159(2), 697–706.
Panagiotis, D., Athanasios, N., Nikolaos, N., Aristeidis, N., Dimitrios, R., and Emmanouil, K. (2016). “Numerical investigation of NOx emissions for a flexible Greek lignite-fired power plant.” J. Energy Eng., 142(2), .
Pope, S. B. (1997). “Computationally efficient implementation of combustion chemistry using in situ adaptive tabulation.” Combust. Theory Model., 1(1), 41–63.
Rebola, A., Coelho, P. J., and Costa, M. (2013a). “Assessment of the performance of several turbulence and combustion models in the numerical simulation of a flameless combustor.” Combust. Sci. Technol., 185(4), 600–626.
Rebola, A., Costa, M., and Coelho, P. J. (2013b). “Experimental evaluation of the performance of a flameless combustor.” Appl. Therm. Eng., 50(1), 805–815.
Sepman, A. V., Abtahizadeh, S. E., Mokhov, A. V., van Oijen, J. A., Levinsky, H. B., and de Goey, L. P. H. (2013). “Numerical and experimental studies of the NO formation in laminar coflow diffusion flames on their transition to MILD combustion regime.” Combust. Flame, 160(8), 1364–1372.
Shabanian, S. R., Medwell, P. R., Rahimi, M., Frassoldati, A., and Cuoci, A. (2013). “Kinetic and fluid dynamic modeling of ethylene jet flames in diluted and heated oxidant stream combustion conditions.” Appl. Therm. Eng., 52(2), 538–554.
Sofianopoulos, A., Assanis, D., and Mamalis, S. (2016). “Effects of hydrogen addition on automotive lean-burn natural gas engines: Critical review.” J. Energy Eng., 142(2), .
Souflas, K., Paterakis, G., and Koutmos, P. (2016). “Investigation of disk-stabilized propane flames operated under stratified and vitiated inlet mixture conditions.” J. Energy Eng., 142(2), .
Tu, Y., et al. (2015a). “Numerical study of addition effects on pulverized coal oxy-MILD combustion.” Fuel Process. Technol., 138, 252–262.
Tu, Y., Liu, H., Chen, S., Liu, Z., Zhao, H., and Zheng, C. (2015b). “Effects of furnace chamber shape on the MILD combustion of natural gas.” Appl. Therm. Eng., 76, 64–75.
Veríssimo, A. S., Rocha, A. M. A., Coelho, P. J., and Costa, M. (2015). “Experimental and numerical investigation of the influence of the air preheating temperature on the performance of a small-scale mild combustor.” Combust. Sci. Technol., 187(11), 1724–1741.
Veríssimo, A. S., Rocha, A. M. A., and Costa, M. (2011). “Operational, combustion, and emission characteristics of a small-scale combustor.” Energy Fuels, 25(6), 2469–2480.
Veríssimo, A. S., Rocha, A. M. A., and Costa, M. (2013). “Experimental study on the influence of the thermal input on the reaction zone under flameless oxidation conditions.” Fuel Process. Technol., 106, 423–428.
Wang, F., Li, P., Zhang, J., Mei, Z., Mi, J., and Wang, J. (2015). “Routes of formation and destruction of nitrogen oxides in jet flames in a hot coflow.” Int. J. Hydrogen Energy, 40(18), 6228–6242.
Wünning, J. A., and Wünning, J. G. (1997). “Flameless oxidation to reduce thermal NO-formation.” Prog. Energy Combust., 23(1), 81–94.
Information & Authors
Information
Published In
Journal of Energy Engineering
Volume 143 • Issue 4 • August 2017
Copyright
©2016 American Society of Civil Engineers.
History
Received: Jun 2, 2016
Accepted: Sep 6, 2016
Published online: Oct 27, 2016
Discussion open until: Mar 27, 2017
Published in print: Aug 1, 2017
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.