Parametric Study of a Two-Phase Closed Thermosyphon Loop

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Akram Amer Thieb
Wail Sami Sarsam


A theoretical and experimental investigation was carried out to study the behavior of a two-phase closed thermosyphon loop (TPCTL) during steady-state operation using different working fluids. Three working fluids were investigated, i.e., distilled water, methanol, and ethanol. The TPCTL was constructed from an evaporator, condenser, and two pipelines (riser and downcomer). The driving force is the difference in pressure between the evaporator and condenser sections and the fluid returns to the heating section by gravity. In this study, the significant parameters used in the experiments were filling ratios (FR%) of 50%, 75%, and 100% and heat-input range at the evaporator section of 215-860.2 W. When the loop reached to the steady-state, the wall-temperature was recorded at various positions along the thermosyphon loop. Results showed that the thermal performance with water was better than methanol and ethanol with same condition. The experimental values of the heat transfer coefficient at the evaporator section were measured for the three working fluids. The results were estimated with the nucleate boiling correlation using engineering equation solver (ESS) program. In addition, a comparison between the experimental ( ) and theoretical ( values of heat transfer coefficient in the evaporator section showed good agreement with a maximum difference of 16%.


Article Details

How to Cite
“Parametric Study of a Two-Phase Closed Thermosyphon Loop” (2022) Journal of Engineering, 28(5), pp. 92–118. doi:10.31026/j.eng.2022.05.06.

How to Cite

“Parametric Study of a Two-Phase Closed Thermosyphon Loop” (2022) Journal of Engineering, 28(5), pp. 92–118. doi:10.31026/j.eng.2022.05.06.

Publication Dates


• Adeeb, A. et al. (2021). Experimental study of closed‐loop thermosyphon with a different evaporator geometry. Heat Transfer, 50(1), 466-486.

• Cole-Parmer Company “Temperature and Thermocouple instruments” Cole-Parmer Engineering, Inc 2001/2002

• David, A. and Peter, A. "Heat Pipes Theory, Design and Applications", International Journal of New York, Fifth Edition, (2006).

• David, A. et al. 2014, Heat Pipes: Theory, Design and Applications, sixth ed., Butterworth-Heinemann.

• Eidan, A. et al. (2017). An experimental and a numerical investigation of HVAC system using thermosyphon heat exchangers for sub-tropical climates. Applied Thermal Engineering, 114, 693-703.‏

• Ezzat, A. W. and Ghashim, S. L. (2019) “Investigation of Optimum Heat Flux Profile Based on the Boiling Safety Factor”, Journal of Engineering, 25(4), pp. 139–154. doi: 10.31026/j.eng.2019.04.10.

• Filippeschi, S., On periodic two-phase thermosyphons operating against gravity. International Journal of Thermal Sciences, 2006. 45(2): p. 124-137.

• Franco, A. and Filippeschi S. (2013). Experimental analysis of closed loop two phase thermosyphon (CLTPT) for energy systems. Experimental thermal and fluid science, 51, 302-311.

• Jiao, B. et al. (2008). Investigation on the effect of filling ratio on the steady-state heat transfer performance of a vertical two-phase closed thermosyphon. Applied Thermal Engineering, 28(11-12), 1417-1426.‏

• Holman, J. p(2001)"experimental methods for engineers"", 7th editions, New York.

• Haider, S. et al. 2002, A natural circulation model of the closed loop, two-phase thermosyphon for electronics cooling. J. Heat Transfer. 124(5): p. 881-890.

• Hamad, A. J., & Yasser, Z. K. (2019). Investigation of R134a Flow Boiling Heat Transfer and Pressure Drop in the Evaporator Test Section of Refrigeration System. Journal of Engineering, 25(1), 13-31.‏

• Kannan, M. et al. (2014). Thermal performance of a two phase closed thermosyphon charged with different working fluids. Daffodil International University Journal of Science And Technology, 9(1).

• Kang, S. et al. (2010). Thermal performance of a loop thermosyphon. Journal of Applied Science and Engineering, 13(3), 281-288.

• Salem, M. A. M. (2010). Experimental study for transient response of a double-tube thermosyphon (DTTH).‏

• Shabgard, H., Xiao, B., Faghri, A., Gupta, R., & Weissman, W. (2014). Thermal characteristics of a closed thermosyphon under various filling conditions. International Journal of Heat and Mass Transfer, 70, 91-102.‏‏

• Rao, N. et al. (2006). Steady-state performance of a two-phase natural circulation loop. International communications in heat and mass transfer, 33(8), 1042-1052.‏

• Zhang, P. et al. (2015). Experimental investigation on two-phase thermosyphon loop with partially liquid-filled downcomer. Applied energy, 160, 10-17.