AN EXPERIMENTAL INVESTIGATION ON AIR-SIDE PERFORMANCES OF FINNED TUBE HEAT EXCHANGERS FOR INDIRECT AIR-COOLING TOWER

Abstract

A tremendous quantity of water can be saved if the air cooling system is used, comparing with the ordinary water-cooling technology. In this study, two kinds of finned tube heat exchangers in an indirect air-cooling tower are experimentally studied, which are a plain finned oval-tube heat exchanger and a wavy-finned flat-tube heat exchanger in a cross flow of air. Four different air inlet angles (90°, 60 °, 45°, and 30°) are tested separately to obtain the heat transfer and resistance performance. Then the air-side experimental correlations of the Nusselt number and friction factor are acquired. The comprehensive heat transfer performances for two finned tube heat exchangers under four air inlet angles are compared. For the plain finned oval-tube heat exchanger, the vertical angle (90°) has the worst performance while 45° and 30° has the best performance at small ReDc and at large ReDc, respectively. For the wavy-finned flat-tube heat exchanger, the worst performance occurred at 60°, while the best performance occurred at 45° and 90° at small ReDc and at large ReDc, respectively. From the comparative results, it can be found that the air inlet angle has completely different effects on the comprehensive heat transfer performance for the heat exchangers with different structures.

Keywords

Dates

  • Submission Date2013-12-18
  • Revision Date2014-01-24
  • Acceptance Date2014-03-06
  • Online Date2014-09-06

DOI Reference

10.2298/TSCI1403863D

References

  1. Kroger, D. G., Air-Cooled Heat Exchangers and Cooling Towers, Vol. I, PennWell Corporation,Tulsa, Okla., USA, 2004
  2. Pistochini, T., Modera, M., Water-use Efficiency for Alternative Cooling Technologies in Arid Climates, Energy and Buildings, 43 (2011), 2-3, pp. 631-638
  3. Meyer, C. J., Kroger, D. G., Air-Cooled Heat Exchanger Inlet Flow Losses, Applied Thermal Engineering, 21 (2001), 7, pp. 771-786
  4. Pooranachandran, K., et al., Experimental and Numerical Investigation of a Louvered Fin and Elliptical Tube Compact Heat Exchanger, Thermal Science, On line first list, DOI: 10.2298/TSCI120220146P
  5. Dong, J. Q., et al., Experimental Study on Thermal-Hydraulic Performance of a Wavy Fin-and-Flat Tube Aluminum Heat Exchanger, Applied Thermal Engineering, 51 (2013), 1-2, pp. 32-39
  6. Du, X. Z., et al., Experimental Study on Heat Transfer Enhancement of Wavy Finned Flat Tube With Longitudinal Vortex Generators, Applied Thermal Engineering, 50 (2013), 1, pp. 55-62
  7. Xie, G. N., et al., Parametric Study and Multiple Correlations on Air-Side Heat Transfer And Friction Characteristics of Fin-And-Tube Heat Exchangers with Large Number of Large-Diameter Tube Rows, Applied Thermal Engineering, 29 (2009), 1, pp. 1-16
  8. Zeng, M., et al., Optimization of Heat Exchangers with Vortex-Generator Fin by Taguchi Method, Applied Thermal Engineering, 30 (2010), 13, pp. 1775-1783
  9. Tang, L. H., et al., Experimental and Numerical Investigation on Air-Side Performance of Fin-and-Tube Heat Exchangers with Various Fin Patterns, Experimental Thermal and Fluid Science, 33 (2009), 5, pp. 818-827
  10. Xie, G. N., et al., Application of a Genetic Algorithm for Thermal Design of Fin-and-Tube Heat Exchangers, Heat Transfer Engineering, 29 (2008), 7, pp. 597 - 607
  11. Meyer, C. J., Kroger, D. G., Numerical Investigation of the Effect of Fan Performance on Forced Draught Air-Cooled Heat Exchanger Plenum Chamber Aerodynamic Behaviour, Applied Thermal Engineering, 24 (2004), 2-3, pp. 359-371
  12. Kennedy, I. J., et al., Investigation of Heat Exchanger Inclination in Forced-Draught Air-Cooled Heat Exchangers, Applied Thermal Engineering, 54 (2013), 2, pp. 413-421
  13. Yang, L. J., et al., Effects of Ambient Winds on the Thermo-Flow Performances of Indirect Dry Cooling System in a Power Plant, International Journal of Thermal Sciences, 64 (2013), Feb., pp. 178-187
  14. Alinia Kashani, A. H., et al., Thermal-Economic Optimization of an Air-Cooled Heat Exchanger Unit, Applied Thermal Engineering, 54 (2013), 1, pp. 43-55
  15. Du, X. P., et al., Experimental Study of the Effect of Air Inlet Angle on the Air-Side Performance for Cross-Flow Finned Oval-Tube Heat Exchangers, Experimental Thermal and Fluid Science, 52 (2014), Jan., pp. 146-155
  16. Du, X. P., et al., Experimental Investigation of Heat Transfer and Resistance Characteristics of a Finned Oval-Tube Heat Exchanger with Different Air Inlet Angles, Heat Transfer Engineering, 35 (2014), 6-8, pp. 703-710
  17. Wang, C. C., Heat Exchanger Design (in Chinese), Wunan Press, Taipei, China, 2003
  18. Kim, N. H., et al., Experimental Investigation on the Airside Performance of Fin-and-Tube Heat Exchangers Having Herringbone Wave Fins and Proposal of a New Heat Transfer and Pressure Drop Correlation, Journal of Mechanical Science and Technology, 22 (2008), 3, pp. 545-555
  19. Wang, C. C., et al., Heat Transfer and Friction Characteristics of Plain Fin-and-Tube Heat Exchangers, part II: Correlation, International Journal of Heat and Mass Transfer, 43 (2000), 15, pp. 2693-2700
  20. Kline, S. J., McClintock, F.A., Describing Uncertainties in Single-Sample Experiments, Mechanical Engineering, 75 (1953), 1, pp. 3-8
  21. Wang, Q. W., et al., Experimental study of Heat Transfer Enhancement in Narrow Rectangular Channel With Longitudinal Vortex Generators, Nuclear Engineering and Design, 237 (2007), 7, pp. 686-693
  22. Guo, L., et al., Influence of Geometrical Factors and Pressing Mould Wear on Thermal-Hydraulic Characteristics for Steel Offset Strip Fins at Low Reynolds Number, International Journal of Thermal Sciences, 46 (2007), 12, pp. 1285-1296
Volume 18, Issue 3, Pages863 -874