zbMATH — the first resource for mathematics

Simulations of the PC boiler equipped with complex swirling burners. (English) Zbl 1356.80045
Summary: Purpose
- The purpose of this paper is to show possible approaches which can be used for modeling complex flow phenomena caused by swirl burners combined with simulating coal combustion process using air- and oxy-combustion technologies. Additionally, the response of exist boiler working parameter on changing the oxidizer composition from air to a mixture of the oxygen and recirculated flue gases is investigated. Moreover, the heat transfer in the superheaters section of the boiler was taken into account by modeling of the heat exchange process between continuum phase and three stages of the steam superheaters.
- An accurate solution of the flow field is required in order to predict combustion phenomena correctly for numerical simulations of the industrial pulverized coal (PC) boilers. Nevertheless, it is a very demanding task due to the complicated swirl burner construction and complex character of the flow. The presented simulations were performed using the discrete phase model for tracking particles and combustion phenomena in a dispersed phase, whereas the Eulerian approach was applied for the volatile combustion process modeling in a gaseous phase.
- Applying the air- to oxy-combustion technology the temperature in the combustion chamber, decreased for investigated oxidizer compositions. This was caused by the higher heat capacity of flue gases which also influences on the level of the heat flux at the boiler walls. Simulations shows that increasing the \(O_{2}\) concentration to 30 percent of volume base in the oxidizer mixture provided the similar combustion conditions as those for the conventional air firing. Moreover, the evaluated results give a good overview of differences between approaches used for complex swirl burners simulations.
Practical implications
- Nowadays, the numerical techniques such as computational fluid dynamic (CFD) can be seen as an useful engineering tool for design and processes optimization purposes. The application of the CFD gives a possibility to predict the combustion phenomena in a large industrial PC boiler and investigate the impact of changing the combustion technology from a conventional air firing to oxy-fuel combustion.
- This paper gives good overview on existing technique, approaches used for modeling PC boiler equipped with complex swirl burners. Additionally, the novelty of this work is application of the heat exchanger model for predicting heat loses in convective section of the boiler. This usually is not taken into account during simulations. The reader can also find basic concept of oxy-combustion technology, and their impact on boiler working conditions.

80M10 Finite element, Galerkin and related methods applied to problems in thermodynamics and heat transfer
80A25 Combustion
Full Text: DOI
[1] ANSYS Inc (2012), ”ANSYS fluent”, available at: , Released 14.5 October.
[2] Baum, M.M. and Street, P.J. (1971), ”Predicting the combustion behavior of coal particles”, Com-bustion Science Technology, Vol. 3 No. 5, pp. 231-243. , · Zbl 1356.80045 · doi:10.1108/HFF-02-2013-0067
[3] Cengel, Y.A. and Ghajar, A.J. (2011), Heat and Mass Transfer, Fundamentals and Applications, McGraw Hill, New York, NY.
[4] Chen, L. , Zheng, S. and Ghoniem, A.F. (2012), ”Oxy-fuel combustion of pulverized coal: characterization, fundamentals, stabilization and CFD modeling”, Progress in Energy and Combustion Science, Vol. 38 No. 2, pp. 156-214. , · Zbl 1356.80045 · doi:10.1108/HFF-02-2013-0067
[5] Cremer, M. , Adams, B. , Valentine, J. , Letcavits, J. and Vierstra, S. (2002), ”Use of CFD modeling to guide design and implementation of overfire air for NOx control in coal-fired boilers”, Proceedings of Nineteenth Annual International Pittsburgh Coal Conference, Pittsburgh, PA, September 23-27.
[6] Crowe, C.T. , Schwarzkopf, J.D. , Sommerfeld, M. and Tsuji, Y. (2012), Multiphase Flows with Droplets and Particles, CRC Press, Taylor & Francis Group, Boca Raton, FL.
[7] Dudek, S.A. , Chen, Z. and Sayre, A.N. (2008), ”COMO: a computational fluid dynamics model for predicting boiler flow and combustion”, 33rd International Technical Conference on Coal Utilization and Fuel Systems, Clearwater, FL, June 1-5.
[8] Edge, P. , Gharebaghi, M. , Irons, R. , Porter, R. , Porter, R.T.J. , Pourkashanian, M. , Smith, D. , Stephenson, P. and Williams, A. (2011), ”Combustion modeling opportunities and challenges for oxy-coal carbon capture technology”, Chemical Engineering Research and Design, Vol. 89, pp. 1470-1493. , · Zbl 1356.80045 · doi:10.1108/HFF-02-2013-0067
[9] Jonovic, R. , Milewska, A. , Swiatkowski, B. , Goanta, A. and Spliethoff, H. (2011), ”Numerical investigation of influence of homogeneous/heterogeneous ignition/combustion mechanisms on ignition point position during pulverized coal combustion in oxygen enriched and recycled flue gases atmosphere”, International Journal of Heat and Mass Transfer, Vol. 54 No. 4, pp. 921-931. , · Zbl 1209.80038 · doi:10.1108/HFF-02-2013-0067
[10] Launder, B.E. and Spalding, D.B. (1974), ”The numerical computation of turbulent flows”, Computer Methods in Applied Mechanics and Engineering, Vol. 3 No. 2, pp. 269-289. · Zbl 0277.76049 · doi:10.1108/HFF-02-2013-0067
[11] Magnussen, B.F. and Hjertager, B.H. (1977), ”On mathematical models of turbulent combustion with special emphasis on soot formation and combustion”, Symposium (International) on Combustion, Vol. 16 No. 1, pp. 719-729. · Zbl 1356.80045 · doi:10.1108/HFF-02-2013-0067
[12] Murphy, J.J. and Shaddix, C.R. (2006), ”Combustion kinetics of coal chars in oxygen-enriched environments”, Combustion and Flame, Vol. 144 No. 4, pp. 710-729. , · Zbl 1356.80045 · doi:10.1108/HFF-02-2013-0067
[13] Smith, T.F. , Shen, Z.F. and Friedman, J.N. (1982), ”Evaluation of coefficients for the weighted sum of gray gases model”, Journal of Heat Transfer, Vol. 104 No. 4, pp. 602-608. , · Zbl 1356.80045 · doi:10.1108/HFF-02-2013-0067
[14] Toporov, D. , Bocian, P. , Heil, P. , Kellermann, A. , Stadler, H. , Tschunko, S. , Forster, M. and Kneer, R. (2008), ”Combustion kinetics of coal chars in oxygen-enriched environments”, Combustion and Flame, Vol. 155 No. 4, pp. 605-618. , · Zbl 1356.80045 · doi:10.1108/HFF-02-2013-0067
[15] Wall, T. , Liu, Y. , Spero, C. , Elliott, L. , Khare, S. , Rathnam, R. , Zeenathal, F. , Moghtaderi, B. , Buhre, B. , Sheng, C. , Gupta, R. , Yamada, T. , Makino, K. and Yu, J. (2009), ”An overview on oxy-fuel coal combustion: state of the art research and technology development”, Chemical Engineering Research and Design, Vol. 87 No. 8, pp. 1003-1016. , · Zbl 1356.80045 · doi:10.1108/HFF-02-2013-0067
[16] Wall, T.F. (2007), ”Combustion processes carbon capture”, Proceedings of the Combustion Institute, Vol. 31, pp. 31-47. , · Zbl 1356.80045 · doi:10.1108/HFF-02-2013-0067
[17] Wang, W. , Lawal, A. , Stephenson, P. , Sidders, J. and Ramshaw, C. (2011), ”Post-combustion CO_2 capture with chemical absorption: a state-of-the-art review”, Chemical Engineering Research and Design, Vol. 89 No. 9, pp. 1609-1624. , · Zbl 1356.80045 · doi:10.1108/HFF-02-2013-0067
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.