DOI QR코드

DOI QR Code

슬림형 루버 핀이 장착된 알루미늄 열교환기의 공기측 전열 성능에 대한 실험적 연구

Experimental Study on the Airside Performance of Aluminum Heat Exchangers Having Slim Louver Fins

  • Kim, Nae-Hyun (Dept. of Mechanical Engineering, Incheon Nat'l Univ.) ;
  • Cho, Honggi (Home Appliance Div., Samsung Electronics)
  • 투고 : 2017.03.07
  • 심사 : 2017.06.11
  • 발행 : 2017.09.01

초록

최근 들어 공조기가 슬림화 되고 따라서 열교환기의 깊이를 줄일 필요가 있다. 본 연구에서는 슬림형 알루미늄 열교환기에 적절한 루버 핀 형상을 도출하였다. 또한 도출된 루버 핀이 적용된 알루미늄 열교환기 시료를 제작하고 성능 시험을 수행하였다. 비교를 위하여 기존 열교환기에 대해서도 실험을 수행하였다. 도출된 형상의 핀 깊이($F_d$)는 10.0 mm, 루버 핏치($L_p$)는 0.9 mm, 루버 각(${\theta}$)은 $35^{\circ}$이다. 기존 시료에 비하여 신규 슬림 시료의 j 인자는 36%, f 인자는 2.3% 크게 나타났다. 따라서 열교환기 체적은 슬림 시료에서 26% 줄어들게 된다. 또한 동일 소비 동력에서의 전열량을 의미하는 $j/f^{1/3}$은 슬림 시료에서 55% 크다. 실험 데이터를 기존 상관식의 예측치와 비교하였다.

Recent trends in slim air conditioners require heat exchangers of reduced flow depth. In this study, slim louver fin geometry was obtained using predictive correlations. The deduced geometry yielded 10 mm flow depth, 0.9 mm louver pitch, and $35^{\circ}$ louver angle. Samples were made and tests were conducted. The new slim sample yielded 36% higher j factor and 2.3% higher f factor compared with those of the standard sample. This implies that 26% reduction of heat exchanger volume was possible by reducing the flow depth. In addition, the $j/f^{1/3}$ of the slim sample was 55% larger than that of the standard sample. Furthermore, the results are compared with predictions made using existing correlations.

키워드

참고문헌

  1. Webb, R. L. and Jung, S.-H., 1992, "Air-side Performance of Enhanced Brazed Aluminum Heat Exchangers," ASHRAE Trans., Vol. 98, No. 2, pp. 391-410.
  2. Webb, R. L. and Lee, H., 2001, "Brazed Aluminum Heat Exchangers for Residential Air-conditioning," J. Enhanced Heat Transfer, Vol. 8, pp. 1-14. https://doi.org/10.1615/JEnhHeatTransf.v8.i1.10
  3. Davenport, C. J., 1980, Heat Transfer and Fluid Flow in Louvered Triangular Ducts, PhD Thesis, Lanchester Polytechnic, U. K.
  4. Davenport, C. J., 1983, "Correlation of Heat Transfer and Flow Friction Characteristics of Louvered Fin," AIChE Symp. Ser., Vol. 79, pp. 19-27.
  5. Achaichia, A. and Cowell, T. A., 1998, "Heat Transfer and Pressure drop Characteristics of Flat Tube and Louvered Plate Fin Surfaces," Exp. Thermal Fluid Science, Vol. 1, pp. 147-157.
  6. Sunden, B. and Svantessen, J., 1992, "Correlation of j and f Factors for Multi-louvered Heat Transfer Surfaces," Proceedings of Third UK National Heat Transfer Conference, pp. 805-811.
  7. Chang, Y.-J. and Wang, C.-C., 1996, "Air-side Performance of Brazed Aluminum Heat Exchangers," J. Enhanced Heat Transfer, Vol. 3, No. 1, pp. 15-28. https://doi.org/10.1615/JEnhHeatTransf.v3.i1.20
  8. Kim, M.-H. and Bullard, C. W., 2002, "Air-side Thermal Hydraulic Performance of Multi-louvered Flat Aluminum Heat Exchangers," Int. J. Refrig., Vol. 25, pp. 390-400. https://doi.org/10.1016/S0140-7007(01)00025-1
  9. Kang, H. C. and Jun, G. W., 2011, "Heat Transfer and Friction Resistance Characteristics of Louver Fin Geometry for Automobile Applications," J. Heat Trans., Vol. 133, 101802. https://doi.org/10.1115/1.4004169
  10. Dogan, B., Altun, O., Ugurlubilek, N., Tosun, M. and Saricay, T., 2015, "An Experimental Comparison of Two Multi-louvered Fin Heat Exchangers with Different Number of Fin Rows," Applied Therm. Eng., Vol. 91, pp. 270-278. https://doi.org/10.1016/j.applthermaleng.2015.07.059
  11. Sahnoun, A. and Webb, R. L., 1992, "Prediction of Heat Transfer and Friction for the Louver Fin Geometry," J. Heat Transfer, Vo. 114, pp. 893-900. https://doi.org/10.1115/1.2911898
  12. Achaichia, A. and Cowell, T. A., 1988, "A Finite Difference Analysis of Fully Developed Periodic Laminar Flow in Inclined Louvered Arrays," Proceedings of Second UK National Heat Transfer Conference, Glasgow, pp. 883-888.
  13. Hiramatsu, M. Ishimaru, T. and atsuzaki, K. 1990, "Research on Fins for Air-conditioning Heat Exchangers (First Report, Numerical Analysis of Heat Transfer on Louvered Fins)," JSME International Journal, Series II, Vol. 33, No. 4, Paper No. 88-1254A.
  14. Suga, K., Aoki, H. and Shingawa, T., 1990, "Numerical Analysis on Two Dimensional Flow and Heat Transfer on Louvered Fins using Overlaid Grids," JSME International Journal, Vol. 33, pp. 122-127.
  15. Achaichia, A., Heikal, M. R., Sulaimna, Y. and Cowell, T. A., 1994, "Numerical Investigation of Flow and Friction in Louver Fin Arrays," Proceedings of the Tenth International Heat Transfer Conference, Vol. 4, pp. 333-338.
  16. Tafti, D. K., Wang, G. and Lin, W., 2000, "Flow Transition in a Multi-louvered Fin Array," Int. J. Heat Mass Transfer, Vol. 43, pp. 901-919. https://doi.org/10.1016/S0017-9310(99)00190-8
  17. Tafti, D. K. and Cui, J., 2003, "Fin-tube Junction Effects on Flow and Heat Transfer in Flat Tube Multilouvered Heat Exchangers," Int. J. Heat Mass Transfer, Vol. 46, pp. 2027-2038. https://doi.org/10.1016/S0017-9310(02)00509-4
  18. Lee, K. S., Jeon, C. D. and Lee, J. H., 1994, "Study of Flow Structure and Pressure Drop Characteristics in Louvered-fin Type Heat Exchanger," J. SAREK, Vol. 6, No. 2, pp. 140-154.
  19. Carija, Z., Frankovic, B., Percic, M. and Cavrak, M., 2014, "Heat Transfer Analysis of Fin-and-tube Heat Exchangers with Flat and Louvered Fin Geometries," Int. J. Refrig., Vol. 45, pp. 160-167. https://doi.org/10.1016/j.ijrefrig.2014.05.026
  20. Ryu, K. and Lee, K.-S., 2015, "Generalized Heat Transfer and Fluid Flow Correlations for Corrugated Louvered Fins," Int. J. Heat Mass Trans., Vol. 83, pp. 604-612. https://doi.org/10.1016/j.ijheatmasstransfer.2014.12.044
  21. Chang, Y.-J. and Wang, C.-C., 1997, "A Generalized Heat Transfer Correlation for Louver Fin Geometry," Int. J. Heat Mass Trans., Vol. 40, No. 3, pp. 533-544. https://doi.org/10.1016/0017-9310(96)00116-0
  22. Chang, Y.-J., Hsu, K.-C., Lin, Y.-T. and Wang, C.-C., 2000, "A Generalized Friction Correlation for Louver Fin Geometry," Int. J. Heat Mass Trans., Vol. 43, pp. 2237-2243. https://doi.org/10.1016/S0017-9310(99)00289-6
  23. Dong, J., Chen, J., Chen, Z., Zhang, W. and Zhou, Y., 2007, "Heat Transfer and Pressure Drop Correlations for the Multi-louvered Fin Compact Heat Exchangers," Energy Conv. Manage., Vol. 48, pp. 1506-1515. https://doi.org/10.1016/j.enconman.2006.11.023
  24. Park, Y.-G. and Jacobi, A. M., 2009, "Air-side Heat Transfer and Friction Correlations for Flat-tube Louver-fin Heat Exchangers," J. Heat Trans., Vol. 131, 021801. https://doi.org/10.1115/1.3000609
  25. Webb, R. L. and Trauger, P. E., 1991, "The Flow Structure in the Louver Fin Heat Exchanger Geometry," Exp. Thermal Fluid Sci., Vol. 4, pp. 205-217. https://doi.org/10.1016/0894-1777(91)90065-Y
  26. ASHRAE Standard 41.1, 1986, Standard Method for Temperature Measurement, ASHRAE.
  27. ASHRAE Standard 41.2, 1987, Standard Method for Laboratory Air-flow Measurement, ASHRAE.
  28. ASHRAE Standard 41.5, 1975, Standard Measurement Guide, Engineering Analysis of Experimental data, ASHRAE.
  29. ESDU 98005, 1998, 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.
  30. Gnielinski, V., 1976, "New Equations for Heat and Mass Transfer in Turbulent Pipe and Channel Flow," Int. Chem. Eng., Vol. 16, pp. 359-368.
  31. Schmidt, T. E., 1949, "Heat Transfer Calculations for Extended Surfaces," J. of ASRE, Refrigeration Engineering, Vol. 4, pp. 351-357.
  32. Webb, R. L. and Kim, N.-H., 2005, Principles of Enhanced Heat Transfer, 2nd ed., Taylor and Francis Pub.