Thermal-hydraulic performance of novel louvered fin using flat tube cross-flow heat exchanger

Abstract

Experimental studies were conducted to investigate the air-side heat transfer and pressure drop characteristics of a novel louvered fins and flat tube heat exchangers. A series of tests were conducted for 9 heat exchangers with different fin space and fin length, at a constant tube-side water flow rate of 2.8 m³/h. The air side thermal performance data were analyzed using the effectiveness-NTU method. Results were presented as plot of Colburn j factor and friction factor f against the Reynolds number in the range of 500–6500. The characteristics of the heat transfer and pressure drop of different fin space and fin length were analyzed and compared. In addition, the curves of the heat transfer coefficients vs. pumping power per unit heat transfer area were plotted. Finally, the area optimization factor was used to evaluate the thermal hydraulic performance of the louvered fins with differential geometries. The results showed that the j and f factors increase with the decrease of the fin space and fin length, and the fin space has more obvious effect on the thermal hydraulic characteristics of the novel louvered fins.

References

1. Sahnoun A Webb R L Prediction of heat transferand friction for the louver fin geometryASME. J. Heat Transfer 1992 114(4)893900
2. Chang Y J Wang C C Chang W J Heat transfer and flow characteristics of automobile brazedaluminum heat exchangersASHRAE Trans 1994 100(2)643652
3. Kim S Y Paek J W Kang B H Flow and heat transfer correlation for porous fin in aplate-fin heat exchangerASME. J. Heat Transfer 2000 122572578
4. Chang Y J Wang C C Air side performance of brazedaluminum heat exchangersJournal of EnhancedHeat Transfer 1996 3(1)1528
5. Dong J Chen J Chen Z et al.Air-side thermal hydraulic performance of offsetstrip fin aluminum heat exchangersAppliedThermal Engineering 2007 27306313
6. Chang Y J Wang C C A Generalized heat transfercorrelation for louver fin geometryInternationalJournal of Heat and Mass Transfer 1997 40(3)533544
7. Kim M H BullardC W. Air-side thermal hydraulic performance of multi-louvered finaluminum heat exchangersInternational Journalof Refrigeration 2002 25(3)390400
8. Chang Y J Hsu K C Generalized friction correlationfor louver fin geometryInternational Journalof Heat and Mass Transfer 2000 43(12)22372243
9. Dong J Chen J Chen Z et al.Heat transfer and pressure drop correlations forthe wavy fin andflat tube heat exchangersApplied Thermal Engineering 2007 2720662073
10. Zhang J Kundu J Manglik R M Effect of fin waviness and spacing on the lateral vortexstructure and laminar heat transfer in wavy-plate-fin coresInt. J. Heat Mass Transfer 2004 4717191730
11. Manglik R M Bergles A E Heat transfer and pressuredrop correlations for the rectangular offset strip fin compact heatexchangerJ. Experimental Thermal and FluidScience 1995 10(2)171180
12. Muzychka Y S Yovanovich M M Modeling the F and J characteristicsfor transverse flow through an offset strip fin at low Reynolds numberASME. J. Heat transfer 1999 364(1)7990
13. Shin S H Lavin A S Heat transfer investigationof an offset strip fin using liquid crystalsASME heat transfer 2000 365(1)111118
14. Wang C C Webb R L Data reduction for air-sideperformance of fin-and-tube heat exchangersJ. Experimental Thermal and Fluid Science 2000 21(4)218226
15. Gnielinski V Newequation for heat and mass transfer in turbulent pipe and channelflowJ. Int Chem Eng 1976 16359368
16. Yang S M Tao W Q Heat Transfer, 3rdBeijingHigherEducation Press 1998
17. Kays W M London A L Compact Heat Exchangers, 3rdNew YorkMcGraw-HillPress 1984
18. Mofft R J Describingthe uncertainties in experiment resultsExperimental Thermal and Fluid Science 1988 (1)317
19. Wang J Hirs G G Rollmann P The performance of a new gas to gas heat exchanger withstrip finEnergy Conversion and Management 1999 40743751
20. Yan W M Sheen P J Heat transfer and frictioncharacteristics of fin-and-tube heat exchangersInternational Journal of Heat Mass Transfer 2000 4316291651