Application of Combustion Hot Spot Analysis to Process Furnace with Arbor Coils

Document Type: Research Paper

Authors

1 Faculty of Caspian, College of Engineering, University of Tehran, Guilan, I. R. Iran

2 School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, I. R. Iran

3 Farayand Sabz Engineering Company, No.117, Somaye Street, Tehran, I. R. Iran

Abstract

Hot spots are among the most serious operational issues in furnaces as they may result in the destruction of tubes. Hence, it is essential to locate such hot spots precisely on the tube surfaces inside the industrial furnaces in order to secure a safe design and operation. In the current study, we have extended the model proposed by Talmor in order to precisely locate the combustion hot spots on the surface of the tubes inside process furnaces with arbor coils. These furnaces are mostly used in catalytic reforming units. The Talmor model is one of the best models for analyzing combustion hot spots on the tube surfaces of industrial furnaces. This model is developed by considering the furnace geometry and arrangement (tube arrangements and burner positions). In the current paper, we have derived and extended the equations formulated by Talmor for furnaces with arbor coil. As the second step, a specific furnace already installed in a catalytic conversion unit of a refinery has been selected for the sake of modeling. The modeling of the preceding furnace was completed using the code prepared for this purpose. The results have been used not only for analyzing the hot spots but also to model the heat flux profile inside the furnace. Upon modeling the furnace, the location of the hot spot on the 20th coil was predicted which was consistent with the experimental results.

Keywords


[1] Hottel, H.C. and Sarofim, A.F. (1967). "Radiative Heat Transfer." Mc Graw –Hill Pub. Co., New York.

[2] Hottel, H.C. and Cohen, H.S. (1958). "Radiant Heat Exchange in a gas filled enclosure Allowance  for nonuniformity of gas temp." A.I.Ch.E. Journal, Vol. 4, No. 1, pp. 3-14.

[3] Nobel, J.M. (1975). "The zone method: Explicit matrix relations for total exchange areas."  Journal of Heat and Mass Transfer, Vol. 18, No. 2, pp. 261-269.

[4] Yuen, W. W. and Takara, E. E. (1994). "Development of a generalized zonal method for analysis of radiative transfer in absorbing an anisotropically scattering media." Numerical Heat Transfer, Vol. 25, No. 1, pp. 75-96.

[5] Marino, P. (2000). "Numerical Modeling of Steel Tube Reheating in Walking Beam Furnaces." Proceedings of The 5th European Conference on Industrial Furnaces and Boilers, Porto, Portugal, pp. 11- 14.

[6] Mechi, R., Habib, F. and Said, R. (2007). "Improved zonal method predictions in a rectangular furnace by smoothing the exchange areas." Turkish J. Eng. Env. Sci., Vol. 31, No. 6, pp. 333- 343.

[7] Ebrahimi, H., Zamaniyan, A., Soltan Mohammadzadeh, J.S., Khalili, A.A. (2013). "Zonal modeling of radiative heat transfer in industrial furnaces using simplified model for exchange area calculation." Applied Mathematical Modelling, Vol. 37, No. 16-17, pp. 8004- 8015.

[8] Tan, C.K., Jenkins, J., Ward, J., Broughton, J. and Heeley, A. (2013). "Zone modelling of the thermal performances of a large-scale bloom reheating furnace." Applied Thermal Engineering, Vol. 50, No. 1, pp. 1111-1118.

[9] Fleck Jr., J.A. and Canfield, E.H., (1984). "A random walk procedure for improving the computational efficiency of the implicit Monte Carlo method for nonlinear radiation transport." Journal of Computational Physics., Vol. 54, No. 3, pp. 508–523.

[10] Howell, J. R. and Pelmutter, M. (1964). "Monte Carlo Solution of thermal transfer through radiant media between gray walls." ASME Journal of Heat Transfer., Vol. 86, No. 1, pp. 116-122.

[11] Howell, J. R. and Pelmutter, M. (1964). "Radiant heat transfer through gray gas between concentric cylinders using Monte Carlo." ASME Journal of Heat Transfer, Vol. 86, No. 2, pp. 169- 179.

[12] Steward, F.R. and Cannon, P. (1971). "The calculation of radiative heat flux in a cylindrical furnace using the Monte Carlo method." International Journal of Heat and Mass Transfer., Vol. 14, No. 2, pp. 245-262.

[13] Abed, A. Al. and Sacadura, J. F. (1983). "A Monte Carlo finite difference method for coupled radiation  conduction heat transfer in semi transparent media." ASME Journal of Heat Transfer, Vol. 105, No. 4, pp. 931- 933.

[14] Tiwari, S. N. and Liu, J. (1992). "Investigation of radiative interaction in laminar flows of nongray gases using Monte Carlo simulation." In Proceeding of the National Heat Transfer Conference, San Diego, CA, USA, pp. 187-195.

[15] Farmer, J.T. and  Howell, J.R. (1994). "Monte Carlo prediction of radiative heat transfer in inhomogeneous, anisotropic, nongray media." Journal of Thermophysics and Heat Transfer, Vol. 8, No. 1, pp. 133- 139.

[16] Mishara, S.C. and Blank, D.A. (1995). "High to low optical thickness Monte Carlo solutions of the radiative heat transfer problems in 2-D rectangular enclosures with absorbing- emitting- isotropic scattering." In Proceeding of the International Conference on Advance in Mechanical Engineering,  I.I.Sc. Bangalore, India, pp. 1657- 1668.

[17] Zhou, Y.H., Shen, Y. J. , Zhang, Z. M., Tsai, B.K. and DeWitt, D.P. (2002). "A Monte Carlo model for predicting the effective emissivity of the silicon wafer in rapid thermal processing furnaces." International Journal of Heat and Mass Transfer, Vol. 45, No.9, pp. 1945- 1949.

[18] Soroka, B., Zgurskyy, V. and Pyanykh, K. (2003). "Development of the Monte-Carlo method to predict radiative heat transfer within the boilers and furnaces." 13th Intern. Conference on Thermal Engineering and Thermogrammetry, Budapest, Hungary, pp. 18-20.

[19] Maurente, A., Bayer, P. O. and Franca, F. H. R. (2008). "A Monte Carlo Implementation to Solve Radiation Heat Transfer in Non-Uniform Media with Spectrally Dependent Properties." Journal of Quantitative  Spectroscopy & Radiative Transfer, Vol. 108, No. 2, pp. 295-307.

[20] Kovtanyuk, A.E., Botkin, N.D. and Hoffmann, K.H. (2012). "Numerical simulations of a coupled radiative – conductive heat transfer model using a modified Monte Carlo method." International Journal of Heat and Mass Transfer, Vol. 55, No. 4, pp. 649- 654.

[21] Razzaque, M.M., Klein, D.E. and Howell, j.R. (1983). "Finite element solution of radiative heat transfer in a two- dimensional rectangular enclosures with gray participating media." Journal of Heat Transfer, Vol. 105, No. 4, pp. 933- 936.

[22] Razzaque, M.M., Howell, J.R. and Klein, D.E. (1984). "Coupled radiative and conductive heat transfer in two- dimensional enclosure with gray participating media using finite elements." Journal of Heat Transfer, Vol. 106, No. 3, pp. 613- 619.

[23] Chung, T.J. and Kim, J.Y. Two-Dimensional, (1984). "Combined-Mode Heat Transfer by Conduction, Convection, and Radiation in Emitting, Absorbing, and Scattering Media-Solution by Finite Elements." Journal of Heat Transfer, Vol. 106, No. 2, pp. 448- 452.

[24] Fernandes, R., Francis, J. and Reddy, J. (1980). "A finite element approach to combined conductive and radiative heat transfer in a planar medium." 15th Thermophysics Conference, Snowmass,CO,U.S.A.

[25] Fernandes, R. and Francis, J. (1982). "Combined Conductive and Radiative Heat Transfer in an Absorbing, Emitting, and Scattering Cylindrical Medium." Journal of Heat Transfer, Vol. 104, No. 4, pp. 594-601.

[26] Harish, J. and Dutta, P. (2005). "Heat transfer analysis of pusher type reheat furnace." Ironmaking and Steelmaking , Vol. 32, No. 2, pp. 151–158.

[27] Kim, M. Y. (2007). "A heat transfer model for the analysis of transient heating of the slab in a direct–fired walking beam type reheating furnace." International Journal of Heat and Mass Transfer, Vol. 50, No. 19-20, pp. 3740–3748.

[28] Hachem, E., Jannoun, G., Veysset, J., Henri, M., Pierrot, R., Poitrault, I., Massoni, E. and Coupes, T.(2013). "Modeling of heat transfer and turbulent flow inside industrial furnaces." Simulation ModelingPractice and Theory, Vol. 30, pp. 35- 53.

[29] Talmor, E. (1982). "Combustion Hot Spot Analysis for Fired Process Heaters." Gulf PublishingCo.,Houston, Texas.

[30] Prasanna, D. and Aung, K. (2006). "Combustion Hot Spot Analysis for Single-Side-Fired Tubes In a FloorFired Box Furnace." ASME International Mechanical Engineering Congress and Exposition, Chicago, Illinois, USA.