Numerical study of the flow and heat transfer due to the changing of the burner angle in a П-type boiler

Document Type : Mechanics article

Authors

1 Department of mechanical Engineering, Arak university of Technology, Arak, Iran

2 Department of Mechanical Engineering, Islamic Azad University Kashan branch, Kashan, Iran

Abstract

This research was carried out to optimize energy consumption in Isfahan Steel P-type boilers by numerical modeling of heat transfer in combustion chamber at different angles of natural gas fuel burner. Using the Ansys-Fluent combustion chamber modeling software, four natural gas burners, 187 firefighting tubes and its refractory walls were used. The results show that changing the angle of the burner is a good way to control the flame. By decreasing the angle of the burner, the heat flux on the firebox tubes the temperature and fluid velocity inside the combustion chamber increases and thus improves the boiler efficiency. However, reducing the angle of the burners results in an increase in the surface temperature of the fire pipes and can even pierce and damage the equipment. The results also showed that with constant amount of gas consumed, the ratio of radiation heat transfer to total heat transfer of firewall tubes at different angles is 90% on average. Also the agreement between numerical and experimental results including the existing boiler condition in which the burner at 30 ° angle confirms the modeling accuracy.

Keywords


[1] J.W. Stokes, L. Holly and K.H. Mayer, "The boiler and pressure vessel code", Non-Destructive Testing, Vol. 7, No. 3, June 1974, pp. 145-151.
[2] R. D. Bell, N.W. Rees, and K.B. Lee, "Models of Large Boiler-Turbine Plant", IFAC Proceedings Volumes, Vol. 10, No. 1, 1977, pp. 469-474.
[3] Z. Li, J. Jing, G. Liu, Z. Chen and C. Liu, "Measurement of Gas Species, Temperatures, Char Burnout, and Wall Heat Fluxes In A 200-MweLignite-Fired Boiler at Different Loads", Applied Energy, Vol. 87, No. 4, 2010, pp. 1217-1230.
[4] M. Rahimi, S. M. Shariati and A. Khoshhal, "Investigation of Combustion and Transport Phenomena in Bistoun Power Plant Using CFD", 10th Congress of Chemical Engineering, Sistan and Baluchestan University, Sistan and Baluchestan, 2005,
[5] B. Danon, E.-S.Cho, W.de.Jong and D.J.E.M Roekaerts. "Numerical investigation of burner positioning effects in a multi-burner flameless combustion furnace", Applied Thermal Engineering, Vol. 31, No. 17, 2011, pp. 3885-3895.
[6] Audai Hussein Al-Abbas, Jamal Naser and David Dodds. "CFD modeling of air-fired and oxy-fuel combustion in a large scale furnace at Loy Yang a brown coal power station", Fuel, Vol. 102, 2012, pp.646-665.
[7] Moghari M., and Hosseini S. "A numerical study on thermal behavior of a D-type water-cooled steam boiler", Applied Thermal Engineering, Vol. 37, 2012, pp. 360-372.
]9[ سید­محمد­حسین مدرسی، مهرداد کاشفی و جلیل وحدتی ،"شبیه­سازی اثر پارامتر­های کاری کوره و پارامتر­های محیطی بر عملیات سطحی کربوراسیون گازی"، نشریه­مدل­‌سازی در مهندسی، دوره 4، شماره 18، پاییز 1388، صفحه 51- 58
[10] G. D. Rago, G. Rossiello, R. Dadduzio, T. Giani and V. Panebianco, "CFD analysis of a swirl stabilized coal combustion burner", Energy Procedia, Vol. 148, 2018, pp 703-711.
[12] J. Hart, A. Bhuiyan and J.Naser, "Aerodynamics of burner jet in a tangentially-fired boiler: A CFD modelling and experiment", International Journal of Thermal Sciences, Vol. 129, July 2018, pp. 238-253.
[13] A.M. Eaton, L.D. Smoot,  S.C. Hill, and C.N. Eatough , "Components, formulations, solutions, evaluation, and application of comprehensive combustion models", Progress in Energy and Combustion Science, Vol. 25, No. 4, August 1999, pp. 387-436.
 [14] Yin C. "Refined weighted sum of gray gas model for air fuel combustion and its impacts", Energy and Fuels, Vol. 27, No. 10, 2013, pp. 6287-6294.
[15] Pope S.B. "PDF Methods for turbulent reactive fluids", Energy and Combustion Science, Vol. 11, No. 2, 1985, 119-192.