Experimental Investigation on Hydrodynamic and Thermal Performance of a Gas-Liquid Thermosyphon Heat Exchanger in a Pilot Plant

Document Type: Research Article


1 Department of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, I.R. IRAN

2 Department of Chemical Engineering, Ferdowsi University of Mashhad, Mashhad, I.R. IRAN


Waste heat recovery is very important, because not only it reduces the expenditure of heat generation, but also it is of high priority in environmental consideration, such as reduction in greenhouse gases. One of the devices is used in waste heat recovery is heat pipe heat exchanger.Anexperimental research has been carried out to investigate the hydrodynamic and thermal performance of a gas- liquid thermosyphon heat exchanger “THE” in a pilot plant. The ε-NTU method has been used. The pressure drop has been calculated across tube bundle of the thermosyphon heat exchanger. It's module is composed of 6 “rows” and 15 “columns” copper pipes with aluminum plate fins with dimensions of 130 cm “height”, 47 cm “width” and  20 cm “depth” . The tubes have been filled by water with filling ratio of 30 %, 50 % and 70 %. The density and thickness of fins are 300 fin/m and 0.4 mm, respectively. The configuration of tubes is in-line with 30 mm pitch. The results show that as the ratio of Ce/Cc raises the amount of heat transfer increases. The effectiveness of heat pipe heat exchanger remains constant as the temperature of hot stream rises, but the amount of heat transfer increases. Filling ratio in normal region (30-70 %) has no effects on experimental results. A new correlation for thermosyphon heat exchanger with individual finned tubes and in-line geometry has been proposed for calculating pressure drop across tube bank of a “THE”. The error in pressure drop for 40 experimental points in the new correlation is less than 15 %. This indicates that the new correlation possesses an acceptable accuracy predicting pressure drop.


Main Subjects

[1] Vasiliev, Leonard L., Heat Pipes in Modern Heat Exchangers, Applied Thermal Engineering, 25, p.1 (2005).

[2] Azad, E., Geoola, F., A Design Procedure for Gravity-Assisted Heat Pipe Heat Exchanger, Heat Recovery Sys., Elsevier Science, p. 101 (1984).

[3] Zhonglliang Liu, Zengyi Wang, and Chongfang Ma, Experimental Study on Heat Transfer Characteristics of Heat Pipe Heat Exchanger with Latent Heat Storage, Part І: Charging only and Discharging only Modes, Energy Conversion and Management, (2005).

[4] Zhonglliang Liu, Zengyi Wang, and Chongfang Ma, Experimental Study on Heat Transfer Characteristics of Heat Pipe Heat Exchanger with Latent Heat Storage, Part ІІ: Simultaneous Charging/Discharging Modes, Energy Conversion and Management, (2005).

[5] Shah, R.K., Giovannell, A.D., “Heat Pipe Heat Exchanger Design Theory”, Hemisphere, WashingtonD.C., (1987).

[6] Tan, J.O., Liu, C.Y. and Wang, Y.W., Heat Pipe Heat Exchanger Optimization, Heat Recovery Sys. & CHP, 11(4), p. 313 (1991).

[7] Wadowski, T., Akbarzadeh, A., and Johnson, P., Characteristics of a Gravity-Assisted Heat Pipe - Based Heat Exchanger, Heat Recovery Sys. & CHP, 11(1), p. 69 (1991).

[8] Yang, F., Yuan, X. and Lin, G., Waste Heat Recovery Using Heat Pipe Heat Exchanger for Heating Automobile using Exhaust Gas , Applied Thermal Engineering, Elsevier Science, 23, p. 367 (2003).

[9] Noie, S. H., Majideian, G. R. , Waste Heat Recovery using Heat Pipe Heat Exchanger (HPHE) for Surgery Rooms in Hospitals, Applied Thermal Engineering, Elsevier Science, 20, p. 1271 (2000).

[10] Noie, S.H., Investigation of Thermal Performance of Air-to-Air Thermosyphon Heat Exchanger using
ε-NTU Method, Applied Thermal Engineering, 26, p. 1073 (2005).

[11] Lin, S., Broadbent, J., and McGlan, R., Numerical Study of Heat Pipe Application in Heat Recovery Systems, Applied Thermal Engineering, 25, p. 127 (2005).

[12] Kays,  W. M.,  London, A. L., “Compact  Heat Exchangers”, 3rd Ed. McGraw-Hill, New York, (1984).

[13] Rohsenow, W. M., “Handbook  of  Heat  Transfer Applications”, McGraw-Hill, New York, (1985).

[14] Tan, J.O., Liu, C.Y., Predicting the Performance of a Heat Pipe Heat Exchanger using the Effectiveness NTU Method, Int. J. Heat Fluid Flow, 11(4), p. 376 (1990).

[15] Haung, B.J., Tsuei, J.T., A Method of Analysis for Heat Pipe Heat Exchangers, Int. J. Heat Mass Transfer, 28(3), p. 553 (1985).

[16] Faghri, A., “Heat pipe Science and Technology”, Taylor & Francis, USA, (1995).

[17] Incropera, F. P., DeWitt, D. P., “Fundamentals of Heat and Mass Transfer”, 5th Ed., John Wiley and Sons, New York, p. 640 (2002).

[18] Perez, R.,  Bendescu, J.,  the Influence of the Heat Pipe Heat Exchanger's Geometry on Its Heat Transfer Effectiveness, Heat Recovery Sys. & CHP, (1983).

[19] Robinson, K. K., Briggs, D. E., Pressure Drop of Air Flowing Across Triangular Pitch Bank of Finned Tubes, Chem. Eng. Prog. Symp. Series, 62(64), p. 177(1996).

[20] Zukauskas, A., “Convective Heat Transfer in Cross Flow”, John Wiley, New York, (2000).