Flameless combustion conditions and efficiency improvement of single- and multi-burner-FLOX furnaces in relation to changes in fuel and oxidizer composition

 

Flameless combustion is a clean combustion concept leading to strongly reduced pollutant emissions compared to traditional combustion processes. To reach the flameless combustion regime the air (and/or fuel) streams are diluted with hot combustion products with a temperature sufficiently high for the combustion process to be stable and occurring in a distributed reaction zone. In furnace applications it leads to a higher efficiency because of the more extensive use of air preheat, and is called High Efficiency Combustion (HEC). To widen the range of applicability of the HEC technology, the impact of changes in fuel and oxidizer composition on the combustion process in a furnace operated using flameless combustion is investigated. Natural gas being the base-line fuel, also the combustion of biogas and several low calorific gas mixtures of relevance for the iron and steel making and the petrochemical industry, is investigated. By combining detailed measurements and CFD modeling, in single- and multiburner furnaces insight is gained in the flame structure, heat transfer enhancement and emission reduction. 
 
In the single-burner studies the relevant turbulent reactive mixing processes are examined using laser diagnostic methods (LDA, CARS, LIV, PIV and their combinations) and computed using detailed and reduced chemical models and using statistical models for turbulence and turbulence-chemistry interaction. New computational models are developed for the reliable prediction of flameless combustion, extending or replacing existing models for traditional combustion.
 
The multi-burner furnace studies are made in the MEEC furnace operating at full load (three pairs of regenerative burner of each 100kW) or at partial load with two burner pairs. Sensitivity of efficiency and emissions to burner arrangement and firing mode is investigated. Local measurements using probes and laser diagnostics are made. Using CFD the observed trends are explained. Throughout the research work special attention is paid to the measurement and simulation of NOx.
 
After successful validation the CFD models formulated in the project are applied to predict heat flux patterns and emission levels in industrial furnaces. The industrial partners Tata Steel, Shell, WS GmbH, NUMECA Int. and TNO are actively involved in the project.

PUBLICATIONS REPORTING ON THE RESULTS OF THE PROJECT

Journal Publications

E.-S. Cho,  D. Shin, J. Lu,  W. de Jong and D.J.E.M. Roekaerts, Configuration effects of natural gas fired multi-pair regenerative burners in a flameless oxidation furnace on efficiency and emissions, Applied Energy, 107 (2013) 25-32 
http://dx.doi.org/10.1016/j.apenergy.2013.01.035

G. Sarras, Y. Mahmoudi, L.D. Arteaga Mendez, E.H. van Veen, M.J. Tummers, and D.J.E.M. Roekaerts, Modeling of Turbulent Natural Gas and Biogas Flames of the Delft Jet-in-Hot-Coflow Burner: Effects of Coflow Temperature, Fuel Temperature and Fuel Composition on the Flame Lift-Off Height,Flow, Turbulence and Combustion,93 (2014)4,607-635
http://dx.doi.org/10.1007/s10494-014-9555-3

L.D. Arteaga Mendez, E.H. van Veen, M.J. Tummers and D.J.E.M. Roekaerts, Effect of hydrogen addition on the structure of natural-gas jet-in-hot-coflow flames, Proceedings of the Combustion Institute, 35 (2015) 3557–3564,
http://dx.doi.org/10.1016/j.proci.2014.06.146

 

Conference papers

E.-S. Cho, J. Lu, W. de Jong and D. Roekaerts, Emission characteristics of a flameless oxidation furnace with various multi-burner configurations, European Combustion Meeting, Cardiff, June 29- July 1, 2011, T. Griffiths (Ed.), Cardiff, UK,  paper 212, 1-6

M.A. Etaati, D. Roekaerts, G. Sarras and M. Stoellinger, Modeling of the Delft jet-in-hot-coflow burner as a non-adiabatic three stream problem, European Combustion Meeting, Cardiff, June 29- July 1, 2011, T. Griffiths (Ed.), Cardiff, UK, paper 293, 1-6

G. Sarras, M.K. Stoellinger and D.J.E.M. Roekaerts, Transported PDF simulations of the Delft-jet-in-hot-coflow, burner based on 3D FGM tabulated chemistry, In: Book of Extended Abstracts, Turbulence, Heat and Mass Transfer 7, K.Hanjalic, Y.Nagano, D.Borello, S.Jakirlic (Eds.), Begell House, Inc., 2012, pp 729 – 732

G. Sarras, M.K. Stoellinger and D.J.E.M. Roekaerts, Transported PDF simulations of the Delft-jet-in-hot-coflow, burner based on 3D FGM tabulated chemistry, In: Proceedings Turbulence, Heat and Mass Transfer 7, K.Hanjalic, Y.Nagano, D.Borello, S.Jakirlic (Eds.), 2012, 10 pages

L.D. Arteaga Mendez, M.J. Tummers, D.J.E.M. Roekaerts, Effect of Hydrogen on the Stabilization Mechanism of Natural Gas jet-in-hot-coflow Flames, European Combustion Meeting – 2013, June 25-28, 2013, Lund, Sweden, Paper P1-16, 1-4

G.Sarras, M.K.Stoellinger, D.J.E.M. Roekaerts, Transported PDF simulations of the Delft Jet-in-Hot-Coflow burner based on 4D-FGM tabulated chemistry,  European Combustion Meeting – 2013, June 25-28, 2013, Lund, Sweden, Paper P1-80, 1-6, ISBN 978-91-637-2151-9.

Y. Mahmoudi, G. Sarras, L.D. Arteaga Mendez, M. Çelik, M.J. Tummers, and D.J.E.M. Roekaerts, Flame structure and stabilization mechanism of biogas flame in a jet-in-hot-coflow burner, 8th Mediterranean Combustion Symposium, September 8-13, 2013, Çeşme, Izmir, Turkey, Paper TC-16, 1-12, Editors: Nevin Selcuk, Federico Beretta, Mohy S. Mansour, and Andrea d’Anna.Publisher: International Centre For Heat and Mass Transfer, METU, Ankara, Turkey.

Abstracts of poster presentations at international conferences

G. Sarras, M.K. Stöllinger and D.J.E.M. Roekaerts, Simulation of the Delft-jet-in-hot-coflow burner using transported PDF methods and FGM tabulated chemistry, In: A. Dreizler, A. Kemp land R. Barlow (Eds.), Book of abstracts of TNF11 “Eleventh International Workshop on Measurement and Computation of Turbulent Flames”, July 26–28, 2012, Darmstadt, Germany, pp 14-15

L.D. Arteaga Mendez, M.J. Tummers and D.J.E.M. Roekaerts, Effect of fuel and oxidizer composition on jet-in-coflow flames, In: A. Dreizler, A. Kemp land R. Barlow (Eds.), Book of abstracts of TNF11 “Eleventh International Workshop on Measurement and Computation of Turbulent Flames”, July 26–28, 2012, Darmstadt, Germany, pp 54-55

Gerasimos Sarras, Michael Stoellinger and Dirk Roekaerts, Simulation of the Delft-jet-in-hot-coflow burner using transported PDF method and FGM tabulated chemistry, Abstract of Work-in-Progress poster, Thirthy-Fourth International Symposium on Combustion, Warsaw, 2012, poster W4P100

Jie Lu, Eun-Seong Cho, Eric van Veen, Wiebren de Jong and Dirk Roekaerts, Coherent anti-Stokes Raman spectroscopy measurement in a regenerative multi-burner flameless oxidation furnace, Abstract of Work-in-Progress poster, Thirthy-Fourth International Symposium on Combustion, Warsaw, 2012, poster W5P035

G. Sarras, L.D. Arteaga Mendez, S.Y. Mahmoudi Larimi, M.J. Tummers, D.J.E.M. Roekaerts, Flame structure and lift-off height of biogas combustion in jet-in-hot coflow flame, Abstract of Work-in-Progress Poster, Int. Conf. Dynamics of Explosive and Reactive Systems (ICDERS), Taipei, July 28, August 2, 2013,  poster #269, p. 120