Open Access Peer-reviewed

Calculation of Radiant Section Temperatures in Fired Process Heaters

Hassan Al-Haj Ibrahim1,, M. Mourhaf Al-Qassimi1

1Department of Chemical Engineering, Al-Baath University, Homs, Syria

Chemical Engineering and Science. 2013, 1(4), 55-61. DOI: 10.12691/ces-1-4-2
Published online: August 25, 2017


Flame and effective gas temperatures are key variables that need to be accurately determined before analysis of heat transfer in the radiant section of fired heaters can be meaningfully undertaken. To facilitate the calculation of these temperatures, appropriate equations were derived using two Computer Matlab programmes specially written for the purpose. A third programme was also written for the solution of the derived equations using the Newton-Raphson method. The whole calculation procedure was illustrated by an example worked out for an actual process heater used in a crude oil topping unit.


effective gas temperature, flame temperature, radiation section, fired heater, tubular heater
[1]  P. Wuithier (ed), Raffinage et génie chimique, L'institut français du pétrole, Paris, 1972, Tome 1.
[2]  Nelson, W. L., Petroleum Refinery Engineering, 4th ed. McGraw-Hill, New York, 1958.
[3]  Al-Haj Ibrahim, H., Fired process heaters, Ch. 16, pp. 327-364, in: Matlab, Modelling, programming and simulations, Ed. E. P. Leite, Sciyo, 2010.
[4]  Stehlik, P., et al., Furnace integration into process justified by detailed calculation using a simple mathematical model, Chemical Engineering and Processing, 34, pp. 9-23, 1995.View Article
[5]  Fired Heaters: A Guide to Performance Evaluation, Prepared by Equipment Testing Procedures Committee, AIChI Equipment Testing Procedure, 1989.
[6]  Al-Haj Ibrahim, H., Al-Qassimi, M.; Matlab program computes thermal efficiency of fired heater, Periodica Polytechnica, Chemical Engineering, Vol. 52, No. 2, pp. 61-69, 2008.
[7]  Effective gas temperature in firebox, Available at:
[8]  Lobo, W. E, Evans, J. E.; Heat Transfer in Radiant Section of Petroleum Heaters, Trans. Am. Inst. Chem. Engrs. 35, pp. 748-778, 1939.
[9]  Cross, A., Evaluate Temperature Gradients in Fired Heaters, Chemical Engineering Progress, Vol. 98, No.6, pp. 42-46, 2002.
[10]  Heat Balance in the Radiant Section, Available at:
[11]  Walas, S. M., Fired heaters, Chemical Process Equipment, Selection and Design, Butterworth-Heinmann, 1990.
[12]  Chapra Steven C., Applied Numerical Methods with MATLAB for Engineers and Scientists, 1st edition, McGraw-Hill Companies, Inc, 2005.
[13]  Vacini, C. A., Program calculates flame temperature, Chemical Engineering, pp.133-136, March 22, 1982.
[14]  Flame Temperature Calculator, Available at:
[15]  Perry, R. H., Green, D. W.; Perry's Chemical Engineers' Handbook, 8th Edition, McGraw-Hill Publishing, 2008.