Effect of Re-burn Fuel Stream Location on NO Reduction in a Model Pulverized Coal Combustor

Document Type : Original Research Paper

Authors

School of Mechanical Engineering, KIIT Deemed to be University, Patia, P.O. Box 75102, Bhubaneswar, India

Abstract

I is missing this work, a computational simulation has been performed to investigate the positional effect of reburn fuel injection on NO-reburn. Reburn fuel methane is injected across the coal injection plane at different axial positions of the combustor. Various major NO source mechanisms are considered for NO formation and NO reburn mechanism is used for NO depletion. Temperature profile, species concentration are also investigated, as both NO formation and depletion rate depends on these parameters. It has been observed that, a high temperature flame exists near coal inlet, when the reburn fuel injection plane is closer to coal inlet. On the other hand, the temperature of the flame near the coal inlet decreases when the reburn fuel injection position is far away from coal inlet region.  Moreover, NO sources are observed near coal inlet region, when the reburn fuel is injected closer to coal inlet. On the other hand, only Fuel-NO is observed near coal inlet, when the reburn fuel is injected away from the coal inlet. Maximum NO reduction efficiency is observed at outlet plane when reburn fuel is injected closer to inlet, whereas a relatively lower NO reduction efficiency has been observed at outlet plane when reburn fuel is injected far away from coal inlet region.

Keywords


Abbas, T., Costen, P., Hassan, M. A. and Lockwood, F. C. (1993). The Effect of the Near Burner Aerodynamics on Pollution, Stability and Combustion in a PF-Fired Furnace. Combustion Science and Technology, 93(1); 73–90.
ANSYS FLUENT 14.0 Theory guide, 2011.
Backreedy, R. I., Fletcher, L. M., Jones, J. M., Ma, L., Pourkashanian, M. and Williams, A. (2005). Co-firing pulverised coal and biomass: a modeling approach. Proceedings of the Combustion Institute, 30(2); 2955–2964.
Backreedy, R.I., Fletcher, L.M., Ma, L., pourkashanian, A. and williams, A. (2006). modelling pulverised coal combustion using a detailed coal combustion model. Combustion Science and Technology, 178(4); 763–787.
Bowman C.T., (1991). Chemistry of gaseous pollutant formation and destruction. U S Department of Energy, Office of Scientific and Technical information, New York. 250.
Choi, C. R. and Kim, C. N. (2009). Numerical investigation on the flow, combustion and NOx emission characteristics in a 500MWe tangentially fired pulverized-coal boiler. Fuel, 88(9); 1720–1731.
De S. and SOETE G. DE (1974). Overall reaction rates of NO and N2 formation from fuel nitrogen.
FIVELAND, W.A. (1988). Three-dimensional radiative heat-transfer solutions by the discrete-ordinates method. Journal of Thermo physics and Heat Transfer, 2(4); 309–316.
Franchetti, B. M., Cavallo Marincola, F., Navarro-Martinez, S. and Kempf, A. M. (2013). “Large Eddy simulation of a pulverised coal jet flame. Proceedings of the Combustion Institute, 34(2); 2419–2426.
Ghose, P., Patra, J., Datta, A. and Mukhopadhyay, A. (2016). Prediction of soot and thermal radiation in a model gas turbine combustor burning kerosene fuel spray at different swirl levels. Combustion Theory and Modelling, 20(3); 457–485.
Gorenflo, R., Mainardi, F., Moretti, D., Pagnini, G. and Paradisi, P. (2002). Discrete random walk models for space–time fractional diffusion. Chemical Physic, 284(1-2); 521–541.
Gu M, Zhang M, Fan W, Wang L, Tian F . (2005). The effect of the mixing characters of primary and secondary air on NO formation in a swirling pulverized coal flame. Fuel, 84(16); 2093–2101.
Han, X., Wei, X., Schnell, U. and Hein, K. R. G. (2003). Detailed modelling of hybrid reburn /SNCR processes for NOX reduction in coal-fired furnaces. Combustion and Flame, 132(3); 374–386.
Hashimoto, N., Kurose, R., Hwang, S.-M., Tsuji, H. and Shirai, H. (2012). A numerical simulation of pulverized coal combustion employing a tabulated-devolatilization-process model (TDP model). Combustion and Flame, 159(1); 353–366.
HWANG, S.M., KUROSE, R., AKAMATSU, F., TSUJI, H., MAKINO, H. and KATSUKI, M. (2006). Observation of Detailed Structure of Turbulent Pulverized-Coal Flame by Optical Measurement. JSME International Journal Series B, 49(4); 1316–1327.
LAUNDER, B. E. and SPALDING, D. B. (1983). The numerical computation of turbulent flows. Turbulence and Combustion, 96–116.
Leung, K. M. and Lindstedt, R. P. (1995).Detailed kinetic modelling of C1 — C3 alkane diffusion flames. Combustion and Flame, 102(1-2); 129–160.
Magnussen, B. F., & Hjertager, B. H. (1977). On mathematical modelling of turbulent combustion with special emphasis on soot formation and combustion. Symposium (International) on Combustion, 16(1); 719–729.
Morsi, S. A. and Alexander, A. J. (1972). An investigation of particle trajectories in two-phase flow systems. Journal of Fluid Mechanics, 55(02); 193-208.
Muto, M., Watanabe, H., Kurose, R., Komori, S., Balusamy, S. and Hochgreb, S. (2015). Large-eddy simulation of pulverized coal jet flame – Effect of oxygen concentration on NOx formation.  Fuel, 142, 152–163.
Ranz, W.E. and Marshall, W.R.(1952). Evaporation from drops. Chemical Engineering progress, 48(3);141-146.
Saffari Pour, M., & Weihong, Y. (2014). Performance of pulverized coal combustion under high temperature air diluted by steam. International Scholarly Research Notices, 2014.
Sahu, A.K. and Ghose, P. (2020). Computational modelling on pulverized coal combustion in a 5 kW burner to study NO reduction through Co-flow methane used as secondary fuel. Computational Thermal Sciences, An International Journal. 12(6); 555–578.
Su, S., Xiang, J., Sun, L., Zhang, Z., Sun, X. and Zheng, C. (2007). Numerical simulation of nitric oxide destruction by gaseous fuel reburning in a single-burner furnace. Proceedings of the Combustion Institute, 31(2); 2795–2803.
Su, S., Xiang, J., Sun, X., Zhang, Z., Zheng, C. and Xu, M. (2006). Mathematical Modeling of Nitric Oxide Destruction by Reburning.  Energy & Fuels, 20(4); 1434–1443.
Wen, X., Jin, H., Stein, O. T., Fan, J. and Luo, K. (2015). Large Eddy Simulation of piloted pulverized coal combustion using the velocity-scalar joint filtered density function model. Fuel, 158, 494–502.
Wu, K.-T., Lee, H. T., Juch, C. I., Wan, H. P., Shim, H. S., Adams, B. R. and Chen, S. L. (2004). Study of syngas co-firing and reburning in a coal fired boiler. Fuel, 83(14-15); 1991–2000.
YU, M. J., BAEK, S. W. and KANG, S. J. (2001). Modelling of Pulverized Coal Combustion with Non-Gray Gas Radiation Effects. Combustion Science and Technology, 166(1); 151–174.
Zarnitz, R., & Pisupati, S. V. (2007). Evaluation of the use of coal volatiles as reburning fuel for NOx reduction. Fuel, 86(4); 554–559.
Zhang, X., Zhou, J., Sun, S., Sun, R., & Qin, M. (2015). Numerical investigation of low NOx combustion strategies in tangentially-fired coal boilers. Fuel, 142; 215–221.