Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
권호 표지
DOI QR코드

DOI QR Code

Wet Surface Air-Side Performance of Fin-and-Tube Heat Exchangers Having Sine Wave Fins and Oval Tubes

사인 웨이브 핀과 타원관으로 구성된 핀-관 열교환기의 공기측 습표면 성능

  • Kim, Nae-Hyun (Department of Mechanical System Engineering, University of Incheon)
  • 김내현 (인천대학교 기계시스템공학과)
  • Received : 2014.10.27
  • Accepted : 2015.04.09
  • Published : 2015.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

Experiments were conducted on sine wave fin-and-tube heat exchangers having oval tubes under wet condition. Oval tubes having an aspect ratio of 0.6 were made, by deforming 12.7mm round tubes. Twelve samples, having different fin pitch and tube row, were tested. Results showed that, for oval tube samples, the effect of fin pitch on j and f factor was not significant. As for the effect of tube row, the lowest j factor was obtained for one row configuration(81% of two row configuration), which is clear contrast to round tube samples, where the highest j factor was obtained for one row configuration. Possible reasoning is provided considering the flow and heat transfer characteristics of sine wave channel combined with connecting oval tubes. Comparison of $j/f^{1/3}$ with plain fin-and-tube heat exchanger having 15.9mm O.D. round tube reveals that present oval fin-and-tube heat exchanger shows superior thermal performance except for one row configuration. In other words, $j/f^{1/3}$ of the two row oval tube heat exchanger was 1.6~2.5 times larger than those of round tube heat exchanger, 1.4~2.4 times larger for three row configuration and 1.2~2.8 times for four row configuration.

본 논문은 12.7mm 원관을 변형하여 만든 세장비 0.6(짧은 직경 10.0mm, 긴 직경 16.5mm)의 타원관이 적용된 사인 웨이브 핀-관 열교환기의 습표면 공기측 성능실험에 관한 것이다. 핀 핏치와 열 수를 변화시켜 총 12개의 시료에 대하여 실험을 수행하였다. 타원관에서 핀 핏치 변화에 따른 j, f 인자의 영향은 미미 하였으나, 열수에 따라서는 1row에서 j인자가 가장 낮았다 (가장 높은 2row의 81%). 하지만 원관에서는 1row에서 가장 높게 나타나는 차이점을 보였다. 이는 타원관에 적용된 사인 웨이브 채널의 유동 특성에 기인한 것으로 판단된다. 원관 열교환기와 $j/f^{1/3}$값을 비교한 결과 1열을 제외하고는 타원관 열교환기의 전열성능이 우수함을 알 수 있다. 즉, 타원관 열교환기의 $j/f^{1/3}$값이 원관의 값보다 2열에서 1.6~2.5 배, 3열에서 1.4~2.4 배, 4열에서 1.2~1.8배 크게 나타났다.

Keywords

References

  1. D. R. Mirth, S. Ramadhyani, "Prediction of cooling coil performance under condensing conditions", Int. J. Heat Fluid Flow, Vol. 14, PP. 391-400, 1993. DOI: http://dx.doi.org/10.1016/0142-727X(93)90013-D
  2. R. L. Webb, N. H. Kim, "Principles of Enhanced Heat Transfer", 2nd Edition, Taylor and Francis Pub, 2005.
  3. C. C. Wang, "Recent advances in fin-and-tube heat exchangers", Int. J. Air-Cond. Refrig, 19 ,PP. 291-301, 2011. DOI: http://dx.doi.org/10.1142/S2010132511000624
  4. W. Pirompugd, C. C. Wang and S. Wongwises, "A review on reduction method for heat and mass transfer characteristics of fin-and-tube heat exchangers under dehumidifying conditions", Int. J. Heat Mass Trans, Vol. 52, pp. 2370-2378, 2009. DOI: http://dx.doi.org/10.1016/j.ijheatmasstransfer.2008.10.019
  5. C. C. Wang, C. T. Chang, "Heat and mass transfer for plate fin-and-tube heat exchangers, with and without hydrophilic coating", Int. J. Heat Mass Trans, Vol. 41, pp. 3109-3120, 1998. DOI: http://dx.doi.org/10.1016/S0017-9310(98)00060-X
  6. C. C. Wang, W. S. Lee, W. T. Sheu and Y. T. Chang, "A comparison of the airside performance of fin-and-tube heat exchangers in wet conditions; with and without hydrophilic coating", Applied Thermal Eng, Vol. 22, pp. 267-278, 2002. DOI: http://dx.doi.org/10.1016/S1359-4311(01)00090-4
  7. J. Min, X. Wu, L. Shen and F. Gao, "Hydrophilic treatment and performance evaluation of copper finned tube evaporator", Applied Thermal Eng, Vol. 31, pp. 2936-2942, 2011. DOI: http://dx.doi.org/10.1016/j.applthermaleng.2011.05.024
  8. C. C. Wang, J. S. Liaw and B. C. Yang, "Airside performance of herringbone wavy fin-and-tube heat exchangers - Data with larger diameter tube", Int. J. Heat Mass Trans, Vol. 54, pp. 1024-1029, 2011. DOI: http://dx.doi.org/10.1016/j.ijheatmasstransfer.2010.11.038
  9. Y. C. Liu, S. Wongwises, W. J. Chang and C. C. Wang, "Air-side performance of fin-and-tube heat exchangers in dehumidifying conditions - Data with larger diameter", Int. J. Heat Mass Trans, Vol. 53, pp. 1603-1608, 2010. DOI: http://dx.doi.org/10.1016/j.ijheatmasstransfer.2009.12.015
  10. S. M. Saboya and F. E. M. Saboya, "Experiments on elliptic sections in one- and two-row arrangements of plate fin and tube heat exchangers", Exp. Thermal Fluis Sci, Vol. 24, pp. 65-75, 2001. DOI: http://dx.doi.org/10.1615/JEnhHeatTransf.v11.i1.50
  11. J. C. Min and R. L. Webb, "Numerical analyses of effects of tube shape on performance of a finned tube heat exchanger", J. Enhanced Heat Trans, Vol. 11, No. 1, pp. 61-73, 2004. DOI: http://dx.doi.org/10.1615/JEnhHeatTransf.v11.i1.50
  12. J. S. Leu, M. S. Liu, J. S. Liaw and C. C. Wang, "A numerical investigation of louvered fin-and-tube heat exchangers having circular and oval tube configurations", Int. J. Heat Mass Trans, Vol. 44, pp. 4235-4243, 2001. DOI: http://dx.doi.org/10.1016/S0017-9310(01)00081-3
  13. J. V. Simo Tala, D. Bougeard, S. Ruesseil, and J. L. Harion, "Tube pattern effect on thermal hydraulic characteristics in a two-row finned tube heat exchanger", Int. J. Thermal Sci, Vol. 60, pp. 225-235, 2012. DOI: http://dx.doi.org/10.1016/j.ijthermalsci.2012.05.015
  14. ASHRAE Standard 41.1, "Standard method for temperature measurement", ASHRAE, 1986.
  15. ASHRAE Standard 41.2, "Standard method for laboratory air-flow measurement", ASHRAE, 1987.
  16. ASHRAE Standard 41.5, "Standard measurement guide, engineering analysis and experimental data", 1975.
  17. ESDU 98005, "Design and performance evaluation of heat exchangers: the effectiveness and NTU method", Engineering and Sciences Data Unit 98005 with Amendment A, London ESDU International plc, pp. 122-129, 1998.
  18. V. Gnielinski, "New equations for heat and mass transfer in turbulent pipe flows", Int. Chem. Eng, Vol. 16, pp.359-368, 1976.
  19. J. C. Min, T. Tao and X. F. Peng, "Efficiency of fins used in a finned oval tube heat exchanger", J. Enhanced Heat Transfer, Vol. 10, No. 3, pp. 323-334, 2003. DOI: http://dx.doi.org/10.1615/JEnhHeatTransf.v10.i3.70
  20. R.L. Webb, A. Iyengar, "Oval finned tube condenser and design pressure limits", J. Enhanced Heat Trans, Vol. 8, pp. 147-158, 2001. DOI: http://dx.doi.org/10.1615/JEnhHeatTransf.v8.i3.20
  21. K. Torikoshi, G. N. Xi, Y. Nakazawa, and H. Asano, "Flow and heat transfer performance of a plate fin and tube heat exchanger(first report: effect of fin pitch)", Heat Transfer 1994, Proceedings of the 0th Int. Heat Transfer Conf, Vol. 4, pp. 411-416, 1994.
  22. D. G. Rich, "The effect of fin spacing on the heat transfer and friction performance of multi-row plate fin-and-tube heat exchangers", ASHRAE Trans. 79(2), pp. 137-145, 1973.
  23. C. C. Wang, and W. L. Fu and C. T. Chang, "Heat transfer and friction characteristics of typical wavy fin-and-tube heat exchangers", Exp. Thermal Fluid Sci, Vol. 14, pp. 174-186, 1997. DOI: http://dx.doi.org/10.1016/S0894-1777(96)00056-8
  24. Y. C. Liu, S. Wongwises, W.J. Chang, C.C. Wang, "Airside performance of fin-and-tube heat exchangers in dehumidifying conditions - Data with larger diameter", Int. J. Heat Mass Trans, Vol. 53, pp. 1603-1608, 2010. DOI: http://dx.doi.org/10.1016/j.ijheatmasstransfer.2009.12.015
  25. D. G. Rich, "The effect of the number of tube rows on heat transfer performance of smooth plate fin-and-tube heat exchangers", ASHRAE Trans, 81(1), pp. 307-317, 1975.
  26. T. A. Rush, T. A. Newell and A. M. Jacobi, "An experimental stludy of flow and heat transfer in sinusoidal wavy passages", Int. J. Heat Mass Transfer, Vol. 42, pp. 1541-1553, 1999. DOI: http://dx.doi.org/10.1016/S0017-9310(98)00264-6