Computational Analysis of Gas Phase Mixing in a Co-Fired Burner with Two Different Designs

J. Iqbal, S. Gao^*

Department of Engineering, University of Leicester, Leicester, UK.

DOI: 10.4236/jpee.2015.34025                

Abstract

The study of swirling jet combustor for biomass coal co-firing is of great interest for energy industry. The biomass co-firing can serve as a NO_x reduction method as well as the better use of renewable energy source. Large eddy simulation (LES) and RANS modelling have been performed with two different burner designs. Usually pulverized coal-biomass mixture enters the furnace along with primary air through primary pipe, and the secondary pipe provides necessary air and mixing for combustion. The improved model has three passages including primary, secondary and middle passage for swirling. The simulations on two geometries have been compared, and the aim is to design a better and improved burner model for better pre-combustion mixing in the biomass co- fired furnace. The results from two-way and three-way geometry have been compared with each other as well as with the results from the furnace model used by Apte and Mahesh [8].

Keywords

Swirling Jet, Co-Firing, Biomass, Turbulence, LES

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Aroussi, A., Iqbal, J., et al. (2008) Solid Fuel Biomass Co Firing with Coal. The 4th International Symposium on Hydrocarbon and Chemistry, Ghardaia, Algeria
[2]	Glenn Research Centre (2009) Dynamic Pressure. www.grc.nasa.gov/WWW/K-12/airplane/dynpress.html
[3]	Splithoff, H., Hein, K.R.G. (1998) Effect of Co-Combustion of Biomass on Emission in Pulverized Fuel Furnaces. Fuel Processing Technology, 54, 189-205. http://dx.doi.org/10.1016/S0378-3820(97)00069-6
[4]	Sele, L., et al. (2004) Compressible Large Eddy Simulation of Turbulent Combustion in Complex Geometery on Unstructured Meshes. Combustion and Flame, 137, 489-505. http://dx.doi.org/10.1016/j.combustflame.2004.03.008
[5]	Slack, M.D., et al. (2000) Advances in Cyclone Modelling Using Unstructured Grids. Trans IChemE, 78.
[6]	Garc?a, M., et al. (2006) LES of a Free Annular Swirling Jet-Dependence of Coherent Structure on a Pilot Jet and the Level of Swirl. International Journal of Heat and Fluid Flow, 27, 911-923. http://dx.doi.org/10.1016/j.ijheatfluidflow.2006.03.015
[7]	Ahmed, S., et al. (2004) Experimental Investigation of Rectangular Slot Burner in the Presence of Cross Flow for Different Jet Velocity Ratios. 15th Australia Fluid Mechanics Centre Conferene, Sydney.
[8]	Apte, S.V., Mahesh, K., et al. (2003) Large Eddy Simulation of Swirling Particle-Laden Flows in a Coaxial-Jet Combustor. Multiphase Flow, 1311-1331.
[9]	Sommerfeld, M. and Qiu, H.H. (1991) Detailed Measurements in a Swirling Particulate Two-Phase Flow by a Phase- Doppler Anemometer. Int. J. Heat and Fluid Flow, 12, 20-28. http://dx.doi.org/10.1016/j.ijheatfluidflow.2006.03.015