Document Type : Full article


CFD Research Centre, Department of Chemical Engineering, Razi University, Kermanshah, Iran


"> Despite numerous studies of shell and helically coiled tube heat exchangers, a few investigations on the heat transfer and flow characteristic consider the geometrical effects like coil pitch. Moreover, this scarcity is highlighted for the shell side of this type of heat exchangers. This study reports experimental and Computational Fluid Dynamics (CFD) investigations on heat transfer and flow characteristics of a shell and helically coiled tube heat exchanger. The experiments were carried out using a helically coiled tube, which was placed in a cylindrical shell. Hot and cold water were used as the process fluids on the tube and shell side, respectively. The CFD modeling technique was employed to describe the experimental results, fluid flow pattern, and temperature profiles as well as dead zones in the heat exchanger. Quantitative predicted results of CFD modeling show a good agreement with the experimental data for temperature. The effect of the coil pitch on heat transfer rate was numerically studied and it was found that the heat transfer coefficient intensifies with an increase in coil pitch. The average turbulent kinetic energy (k) for the old coil tube and twice coil pitch heat exchanger was computed as 2.9×10-3 and 3.3×10-3 m 2 /s2, respectively. This indicates an increase of about 14% in flow turbulent kinetic energy. Nusselt numbers were compared with those estimated using published correlation and a mean relative error (MRE) of 14.5% was found between the experimental and predicted data. However, a good agreement was obtained in lower shell Reynolds numbers (lower than Re=200).


Main Subjects

[1]  Zhou, Y., Yu, J. and Chen, X., "Thermodynamic optimization analysis of a tube-in-tube helically coiled heat exchanger for Joule–Thomson refrigerators", Int. J. Therm. Sci., 58, 151 (2012).
[2]  Yi, J., Liu, Z. H. and Wang, J., "Heat transfer characteristics of the evaporator section using small helical coiled pipe in a looped heat pipe", Appl. Therm. Eng., 23 (1), 89 (2003).
[3]  Wongwises, S. and Polsongkram, M., "Evaporation heat transfer and pressure drop of HFC-134a in a helically coiled concentric tube-in-tube heat exchanger", Int. J. Heat Mass Transf., 49 (3-4), 658 (2006).
[4]  Guo, L. J., Feng, Z. P., Chen, X. J., "Pressure drop oscillation of steam–water two-phase flow in a helically coiled tube", Int. J. Heat Mass Transf., 44 (8) 1555 (2001).
[5]  Vashisth, S., Kumar, V. and Nigam, K. D. P., "A review on the potential applications of curved geometries in process industry", Ind. Eng. Chem. Res., 47 (10), 3291 (2008).
[6]  Naphon, P. and Wongwises, S., "A review of flow and heat transfer characteristics in curved tubes", Renew. Sust. Energ. Rev., 10 (5), 463 (2006).
[7]  Ebrahimnia-Bajestan, E. and Niazmand, H., "Convective heat transfer of nanofluids flows through an isothermally heated curved pipe", J. Chem. Eng., 8 (2), 81 (2011).
[8]  Beigzadeh, R., Rahimi, M. and Parvizi, M., "Experimental study and genetic algorithm-based multi-objective optimization of thermal and flow characteristics in helically coiled tubes", Heat. Mass. Transfer., 49, 1307 (2013).
[9]  Beigzadeh, R. and Rahimi, M., "Prediction of heat transfer and flow characteristics in helically coiled tubes using artificial neural networks", Int. Commun., Heat. Mass. Transfer., 39 (8), 1279 (2012).
[10]      Beigzadeh. R., Rahimi, M., "Prediction of thermal and fluid flow characteristics in helically coiled tubes using ANFIS and GA based correlations", Int. Commun. Heat. Mass. Transfer., 39 (10), 1647 (2012).
[11]      Salimpour, M. R., "Heat transfer coefficients of shell and coiled tube heat exchangers", Exp. Therm. Fluid. Sci., 33 (2), 203 (2009).
[12]      Salimpour, M. R., "Heat transfer characteristics of a temperature-dependent-property fluid in shell and coiled tube heat exchangers", Int. Commun. Heat. Mass. Transfer., 35 (9), 1190 (2008).
[13]      Eiamsaard, S., Wongcharee, K. and Sripattanapipat, S., "3-D Numerical simulation of swirling flow and convective heat transfer in a circular tube induced by means of loose-fit twisted tapes", Int. Commun. Heat. Mass. Transfer., 36 (9), 947 (2009).
[14]      Moradi, M., Etemad, S. Gh. and Moheb A., "laminar flow heat transfer of a pseudoplastic fluid through a double pipe heat exchanger", Iran. J. Chem. Eng., 3 (2), 13 (2006).
[15]      Wang, Y., Liu, Z., Huang, S., Liu, W. and Li, W., "Experimental investigation of shell-and-tube heat exchanger with a new type of baffles", Heat. Mass. Transfer., 47, 833 (2011).
[16]      Chen, G. D., Zeng, M. and Wang, Q., "Experimental and numerical studies on shell-side performance of three different shell-and-tube heat exchangers with helical baffles", J. Enhanced Heat Trans., 18 (5), 449 (2011).
[17]      Conté, I., Peng, X. F. and Wang, B. X., "Numerical investigation of forced fluid flow and heat transfer from conically coiled pipes", Numer. Heat. Tr. A-Appl., 53 (9), 945 (2008).
[18]      Piazza, I. D. and Ciofalo, M., "Numerical prediction of turbulent flow and heat transferin helically coiled pipes", Int. J. Therm. Sci., 49 (4), 653 (2010).
[19]      Jayakumar, J. S., Mahajani, S. M., Mandal, J. C., Vijayan, P. K. and Rohidas, B., "Experimental and CFD estimation of heat transfer in helically coiled heat exchangers", Chem. Eng. Res. Des., 86 (3), 221 (2008).
[20]      Jayakumar, J. S., Mahajani, S. M., Mandal, J. C., Iyer K. N. and Vijayan, P. K., "CFD analysis of single-phase flows inside helically coiled tubes", Comput. Chem. Eng., 34 (4), 430 (2010).
[21]      Shokouhmand, H., Salimpour, M. R. and Akhavan-Behabadi, M. A., "Experimental investigation of shell and coiled tube heat exchangers using wilson plots", Int. Commun. Heat Mass Transfer., 35 (1), 84 (2008).
[22]      Fluent 6.2®, Fluent Inc, Lebanon, NH, USA, 2005.
[23]      Launder, B. E. and Spalding, D. B., "The numerical computation of turbulent flows", Comput. Meth. Appl. Mech. Eng., 3 (2), 269 (1974).