THERMAL SCIENCE

International Scientific Journal

EFFECT OF WORKING FLUIDS AND INTERNAL DIAMETERS ON THERMAL PERFORMANCE OF VERTICAL AND HORIZONTAL CLOSED-LOOP PULSATING HEAT PIPES WITH MULTIPLE HEAT SOURCES

ABSTRACT
Some electrical applications have a number of heat sources. The closed-loop pulsating heat pipe (CLPHP) is applied to transfer heat from these devices. Since the CLPHP primarily transfers heat by means of the working fluid’s phase change in a capillary tube, the thermal performance of the CLPHP significantly depends on the working fluid type and the tube’s internal diameter. In order to provide the fundamental information for manufacturers of heat exchangers, this study on the effect of working fluids and internal diameters has been conducted. Three electrical plate heaters were installed on the CLPHP as the heat sources. The experiments were conducted by varying the working fluid to be R123, ethanol, and water, and the internal diameter to be 1.0 mm, 1.5 mm, and 2.0 mm. For each set of the same working fluid and internal diameter, the input heat fluxes of the heat sources were also made to vary within six different patterns. It can be concluded that when the latent heat of evaporation increases - in the case of vertical CLPHP - and when the dynamic viscosity of the liquid increases - in the case of horizontal CLPHP - the thermal performance decreases. Moreover, when the internal diameter increases, the thermal performance increases for both of vertical and horizontal CLPHPs.
KEYWORDS
PAPER SUBMITTED: 2014-09-04
PAPER REVISED: 2014-11-04
PAPER ACCEPTED: 2014-11-14
PUBLISHED ONLINE: 2014-12-14
DOI REFERENCE: https://doi.org/10.2298/TSCI140904141K
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2016, VOLUME 20, ISSUE Issue 1, PAGES [77 - 87]
REFERENCES
  1. Akachi, H. et al., Pulsating Heat Pipes, Proceedings, 5th Intl. Heat Pipe Symp., Melbourne, Australia, 1996, pp. 208-217.
  2. Maezawa, S. et al., Thermal Performance of Capillary Tube Thermosyphon, Proceedings, 9th Intl. Heat Pipe Conf., Albuquerque, USA, 1995, pp. 791-795.
  3. Xu, J. L. et al., High Speed Flow Visualization of a Closed Loop Pulsating Heat Pipe, Heat Mass Transfer, 48 (2005), pp. 3338-3351.
  4. Soponpongpipat, N. et al., Investigation of the Startup Condition of a Closed Loop Oscillating Heat Pipe, Heat Transfer Eng., 30 (2009), 8, pp. 626-642.
  5. Charoensawan, P. et al., Closed Loop Pulsating Heat Pipes - Part A: Parametric Experimental Investigations, Appl. Therm. Eng., 23 (2003), 16, pp. 2009-2020.
  6. Khandekar, S. et al., Closed Loop Pulsating Heat Pipes - Part B: Visualization and Semi-Empirical Modeling, Appl. Therm. Eng., 23 (2003), 16, pp. 2021-2033. ]7
  7. Dmitrin, V. I., Maidanik, Yu. F., Experimental Investigations of a Closed-Loop Oscillating Heat Pipe, High Temp., 45 (2007), 5, pp. 703-707.
  8. Charoensawan, P., Terdtoon, P., Thermal Performance of Horizontal Closed-Loop Oscillating Heat Pipe, Appl. Therm. Eng., 28 (2008), 5-6, pp. 460-466.
  9. Wang, S. et al., Experimental Study on Pulsating Heat Pipe with Functional Thermal Fluids, Heat Mass Transfer, 52 (2009), 21-22, pp. 5276-5279.
  10. Kammuang-lue, N. et al., Thermal Performance of a Closed-Loop Pulsating Heat Pipe with Multiple Heat Sources, Heat Transfer Eng., 35 (2014), 13, pp. 1161-1172.
  11. Kammuang-lue, N. et al., Correlation to Predict the Maximum Heat Flux of a Vertical Closed-Loop Pulsating Heat Pipe, Heat Transfer Eng., 30 (2009), 12, pp. 961-972.
  12. Karthikeyan, V. K. et al., Infrared Thermography of a Pulsating Heat Pipe: Flow Regimes and Multiple Steady States, Appl. Therm. Eng., 62 (2014), 2, pp. 470-480.
  13. Tong, B. Y. et al., Closed-Loop Pulsating Heat Pipe, Appl. Therm. Eng., 21 (2001), 18, pp. 1845-1862.
  14. Charoensawan, P. et al., Effect of Inclination Angles, Filling Ratios and Total Lengths on Heat Transfer Characteristics of a Closed-Loop Oscillating Heat Pipe, Proceedings, 6th Intl. Heat Pipe Symp., Chiang Mai, Thailand, 2000, pp. 421-430.
  15. Kammuang-lue, N. et al., Effect of Numbers of Turns and Internal Diameters on Internal Flow Pattern of a Horizontal Closed-Loop Pulsating Heat Pipe at Maximum Heat Flux State, Proceedings, 9th Intl. Heat Pipe Symp., Kuala Lumpur, Malaysia, 2008, pp. 159-165.
  16. Zhang, Y., Faghri, A., Advances and Unsolved Issues in Pulsating Heat Pipes, Heat Transfer Eng., 29 (2007), 1, pp. 20-44.
  17. Yang, H. et al., Operational Limit of Closed Loop Pulsating Heat Pipes, Applied Thermal Engineering, Appl. Therm. Eng., 28 (2008), 1, pp. 49-59.
  18. Kammuang-lue, N. et al., Establishment, Verification and Application of a Correlation to Predict the Maximum Heat Flux of a Horizontal Closed-Loop Pulsating Heat Pipe, Energy Res. J., 1 (2010), 2, pp. 96-103.

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence