Investigation of Boiling Heat Transfer Characteristics of Two-Phase Closed Thermosyphons with Various Internal Grooves

  • Han, Ku-Il (School of Mechanical Engineering, Pukyong National University) ;
  • Cho, Dong-Hyun (Department of Mechanical Design Engineering, Daejin University) ;
  • Park, Jong-Un (Department of Education, Pukyong National University)
  • Published : 2003.11.01

Abstract

The boiling heat transfer characteristics of two-phase closed thermosyphons with internal grooves are studied experimentally and a simple mathematical model is developed to predict the performance of such thermosyphons. The study focuses on the boiling heat transfer characteristics of a two-phase closed thermosyphons with copper tubes having 50, 60, 70, 80, 90 internal grooves. A two-phase closed thermosyphon with plain copper tube having the same inner and outer diameter as those of grooved tube is also tested for comparison. Methanol is used as working fluid. The effects of the number of grooves, the operating temperature, the heat flux are investigated experimentally. From these experimental results, a simple mathematical model is developed. In the present model, boiling of liquid pool in the evaporator is considered for the heat transfer mechanism of the thermosyphon. And also the effects of the number of grooves, the operating temperature, the heat flux are brought into consideration. A good agreement between the boiling heat transfer coefficient of the thermosyphon estimated from experimental results and the predictions from the present mathematical model is obtained. The experimental results show that the number of grooves and the amount of the working fluid are very important factors for the operation of thermosyphons. The two-phase closed thermosyphon with copper tubes having 60 internal grooves shows the best boiling heat transfer performance.

Keywords

References

  1. Andros, F. E., 1980, 'Heat Transfer Characteristics of the Two-Phase Closed Thermosyphon (Wickless Heat Pipe) Including Direct Flow Observation,' Ph. D. Thesis, Arizona State University
  2. Cohen, H. and Bayley, F. J., 1955, 'Heat Transfer Problem of Liquid Cooled Gas Turbine Blades,' Proc. Inst. Mech. Eng., 169-20, pp. 1063-1080
  3. Gaugler, R. S., 1942, 'Heat Transfer Device,' US Patent No. 2350348, US Patent Application. Dec. 21
  4. Hashimoto, H., Kaminaga, F. and Matsumura, K., 1999, 'Study on Condensation Heat Transfer Characteristics in a Thermosyphon with Non-Condensable Gas Effect,' 11th IHPC, Vol. 1, pp. 121-126
  5. Hong, J., Boo, J. and Jung, Y., 1988, 'Experimentson the Thermal Performance of a Thermosyphon in Inner Grooved Copper Tube,' Proc. SAREK Summer Conf, pp. 313-317
  6. Imura, H., Kusuda, H., Ogata, J. I., Miyaz, T. and Sakamoto, N., 1977, 'Heat Transfer in TwoPhase Closed-Type Thermosyphons,' Trans. of Japan Soc. of Mech. Engrs., pp. 485-493
  7. Kim, W. T., Song, K. S. and Lee, Y., 1998, 'Design of a Two-Phase Loop Thermosyphon for Telecommunication System (I)-Experimentals and Visualization-,' KSME Int. J., Vol. 12, No. 5, pp. 926-941 https://doi.org/10.1007/BF02945560
  8. Kim, W. T., Song, K. S. and Lee, Y., 1998, 'Design of a Two-Phase Loop Thermosyphon for Telecommunication System (II)-Experimentals and Visualization-,' KSME Int. J., Vol. 12, No. 5, pp. 942-955 https://doi.org/10.1007/BF02945561
  9. Kline, S. J. and McClintock, F. A., 1953, Describing Uncertainties in Single-Sample Experiments, Mechanical Engineering, Vol. 75, pp. 3-8
  10. Larkin, B. S., 1971, 'A Experimental Study of the Two Phase Thermosyphon Tube,' Trans. Canda. Soc. Mech. Engrg., 14-B6, pp. 1-8
  11. Lee, B. I. and Lee, S. H., 2001, 'Manufacturing and Temperature Measurements of a Sodium Heat Pipe,' KSME Int. J., Vol. 15, No. 11, pp. 1533-1540 https://doi.org/10.1007/BF03185743
  12. Lee, Y. and Mital, U., 1972, 'A Two-Phase Closed Thermosyphon,' Int. J. of Heat and Mass Transfer, 15-9, pp. 1695-1707
  13. Peterson, G. P. and Ma, H. B., 1996, 'Experimental Investigation of the Maximum Heat Transport in Triangular Groove,' ASME J. of Heat Transfer, Vol. 35, No. 3, pp. 740-746
  14. Stret'stov, A. I., 1975, 'Theoretical and Experimental Investigation of Optimum Filling for Heat Pipes,' Heat Transfer, Soviet Research, Vol. 7, No. 1, pp. 23-27