Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Forced Convective Boiling of Pure Refrigerants in a Bundle of Enhanced Tubes

전열촉진관군의 순수냉매 강제대류비등

  • 김내현 (인천대학교 기계공학과) ;
  • 정호종 (인천대학교 대학원 기계공학과) ;
  • 조진표 (인천대학교 대학원 기계공학과) ;
  • 최국광 (인천대학교 기계공학과)
  • Published : 2001.12.01
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Abstract

In this study, convective boiling tests were conducted for enhanced tube bundles. The surface geometry consists of pores and connecting gaps. Tubes with three different pore sizes (d$_{p}$ = 0.20, 0.23 and 0.27 mm) were tested using R-123 and R-l34a for the following range: 8 kg/m$^2$s G 26 kg/m$^2$s, 10 kW/m$^2$ q0 40 kW/m$^2$and 0.1 $\chi$ 0.9. The convective boiling heat transfer coefficients were strongly dependent on heat flux with negligible dependency on mass flux or quality. For the present enhanced geometry (pores and gaps), the convective effect was apparent. The gaps of the present tubes may have served routes for the passage of two-phase mixtures, and enhanced the boiling heat transfer. The convective effect was more pronounced at a higher saturation temperature. More bubbles will be generated at a higher saturation temperature, which will lead to enhanced convective contribution. The pore size where the maximum heat transfer coefficient was obtained was larger for R-l34a (d$_{p}$ = 0.27 mm) compared with that for R-123 (d$_{p}$ = 0.23 mm). This trend was consistent with the previous pool boiling results. For the enhanced tube bundles, the convective effect was more pronounced for R-134a than for R-123. This trend was reversed for the smooth tube bundle. Possible reasoning is provided based on the bubble behavior on the tube wall. Both the modified Chen and the asymptotic model predicted the present data reasonably well. The RMSEs were 14.3% for the modified Chen model and 12.7% for the asymptotic model.model.

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References

  1. Roser, R, Thonon, B. and Mercier, P., 1999, 'Experimental Investigation on Boiling of n-Pentane Across a Horizontal Tube Bundle: Two-Phase Flow and Heat Transfer Characteristics,' Int. J. Refrig., Vol 22. pp 536-547 https://doi.org/10.1016/S0140-7007(99)00021-3
  2. Marto, P. J. and Anderson, C. L., 1992, 'Nucleate Boiling Characteristics of R-113 in a Small Tube Bundle,' J. Heat Transfer, Vol 114. pp 425-433
  3. Hwang, T. H. and Yao, S. C; 1986, 'Forced Convective Boiling in Horizontal Tube Bundles,' Int. J. Heat and Mass Transfer, Vol 29. pp 785-795 https://doi.org/10.1016/0017-9310(86)90130-4
  4. Li, Z.-X. and Hahne, E., 1995, 'Boiling Heat Transfer on Finned Tube Bundle with Low Tubes Heated with Constant Heat Flux,' Experimental Thermal and Fluid Science, Vol. 11. pp 174-180 https://doi.org/10.1016/0894-1777(95)00009-B
  5. Hahne, E. and Muller, J., 1983, 'Boiling on a Finned Tube and a Finned Tube Bundle,' Int. J. Heat and Mass Transfer, Vol 26. pp 849-859
  6. Gupte, N. S. and Webb, R. L., 1995, 'Convective Vaporization Data for Pure Refrigerants in Tube Banks,' HVAC&R Research, Vol 1. pp 48-60
  7. Memory, S. B., Akcasayar, N., Eraydin, H. and Marto, P. J., 1995, 'Nucleate Pool Boiling of R-114 and R-1l4-oil Mixtures from Smooth and Enhance Surfaces - II. Tube Bundles,' Int. J. Heat and Mass Transfer, Vol 38. pp 1363-1376 https://doi.org/10.1016/0017-9310(94)00264-V
  8. Fujita, Y, Ohta, H., Hidaka, S. and Nishikawa, K, 1986, 'Nucleate Boiling Heat Transfer on Horizontal Tubes in Bundles,' Proceedings of the 8th International Heat Transfer Conference, San Francisco, CA, Vol 5. pp 2131-2136
  9. Kim, N.-H. and Choi, K-K, 2001, 'Nucleate Pool Boiling on Structured Enhanced Tubes Having Pores with Connecting Gaps,' Int. J. Heat and Mass Transfer, Vol 44. pp 17-28 https://doi.org/10.1016/S0017-9310(00)00096-X
  10. 김종원, 김정오, 김내현, 2001, '평활관군의 R-134a 흐름비등에 관한 연구,' 설비공학 논문집, Vol 13. pp 9-17
  11. Kline, S. J. and McClintock, F. A., 1953, 'The Description of Uncertainties in Single Sample Experiments,' Mechanical Engineering, Vol 75. pp 3-9
  12. Webb, R. L. and Pais, C., 1992, 'Nucleate Pool Boiling Data for Five Refrigerants on Plain, IntegralFin and Enhanced Tube Geometries,' Int. J. Heat and Mass Transfer, Vol 35. pp 893-1904 https://doi.org/10.1016/0017-9310(92)90192-U
  13. Ulbrich, R. and Mewes, D., 1994, 'Vertical, Upward Gas-Liquid Two-Phase Flow Across a Tube Bundle,' Int. J. Multiphase Flow, Vol 20. pp 249-272 https://doi.org/10.1016/0301-9322(94)90081-7
  14. Jensen, M. K., Trewin, R. R. and Bergles, A. E., 1992, 'Cross Flow Boiling in Enhanced Tube Bundles,' in: S. Kakac et al. (Eds.) Two-phase Flow in Energy Systems, ASME HTD, Vol. 220. pp 11-17
  15. Chien, L.-H. and Webb, R. L., 1998, 'Measurement of Bubble Dynamics on an Enhanced Boiling Surface,' Experimental Thermal and Fluid Science, Vol 16. pp 177-186 https://doi.org/10.1016/S0894-1777(97)10017-6
  16. Zukauskas, A., Skrinska, A., Zingzda, J. and Gnielinski, V., 1998, 'Banks of Plain and Finned Tubes,' in: G. F. Hewitt (ed.), Heat Exchanger Design Handbook, Begell House Inc., New York, Part II, Section 2.5.3
  17. Bennet, L. and Chen, J. C, 1980, 'Forced Convective Boiling in Vertical Tubes for Saturated Pure Components and Binary Mixtures,' J. AIChE, Vol 26. pp 454--461 https://doi.org/10.1002/aic.690260317
  18. Ishihara, K., Palen, J. W. and Taborek, J., 1980, 'Critical Review of Correlations for Predicting TwoPhase Flow Pressure Drop Across Tube Banks,' Heat Transfer Engineering, Vol 1. pp 23-32 https://doi.org/10.1080/01457638008939560
  19. Webb, R. L. and Chien, L.-H., 1994, Correlation of Convective Vaporization on Banks of Plain Tubes Using Refrigerants,' Heat Transfer Engineering, Vol 15. pp 57-69 https://doi.org/10.1080/01457639408939831
  20. Bennet, L., Davies, M. W. and Hertzler, B. L., 1980, 'The Suppression of Saturated Nucleate Boiling by Forced Convective Flow,' AIChE symposium series, Vol 76. pp 91-100