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NUMERICAL STUDY OF HYDRODYNAMICS AND THERMAL CHARACTERISTICS OF HEAT EXCHANGERS WITH DELTA WINGLETS

ABSTRACT
The comprehensive performance of heat exchangers is represented by the maximum thermal transfer, the minimum pressure loss, and the smallest pumping power. In recent years, the application of longitudinal vortex generators is developed as an effective technique and important research topic, which could increase the heat transfer enhancement of compact heat exchangers. A 3-D CFD numerical simulation is successfully carried out on thermohydraulic characteristics of the fin-and-tube compact heat exchanger with new types of vortex generators. The effects of six different arrangement of delta winglets are studied, which are front-up-rear-down, front-down-rear-up, common-flow-up, and common-flow-down. In addition, there are also different direction of hole position in the same delta winglets arrangement. The investigation of thermal-hydraulic performance is conducted for Reynolds number in the range of 204-2034. The overall and local performance comparisons among the fin with delta winglets and the wavy fin are performed. Then, the comprehensive performance evaluation diagram was adopted to analyze the combined index point of thermal and flow. This study shows that the flow distinction between different fins has a profound influence on the thermal-hydrodynamic performance. The results reveal that the fin with delta winglets can considerably strengthen the thermal efficiency with a moderate pressure loss penalty. The computational results indicate that the average j-factor for the fin with delta wing-lets can be increased up to 41.9% over the baseline case and the corresponding f-factor decreased up to 19.5%. The combination property of front-up-rear-down are better the others at lower Reynolds number, and that of front-down-rear-up are better at higher Reynolds number. Compare with the traditional arrangement (common-flow-up and common-flow-down), The newly designed fin has great effectiveness and uniform performance in the local region.
KEYWORDS
PAPER SUBMITTED: 2018-03-30
PAPER REVISED: 2018-08-22
PAPER ACCEPTED: 2018-08-24
PUBLISHED ONLINE: 2018-09-30
DOI REFERENCE: https://doi.org/10.2298/TSCI180330254W
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2020, VOLUME 24, ISSUE Issue 1, PAGES [325 - 338]
REFERENCES
  1. Bergles A.E., Handbook of heat transfer applications, McGraw-Hill, New York, 1985.
  2. Bergles A.E., ExHFT for fourth generation heat transfer technology, Experimental Thermal and Fluid Science, 26(2002), pp. 335-344.
  3. Jacobi A.M., Shah R.K., Heat transfer surface enhancement through the use of longitudinal vortices: A review of recent progress, xperimental Thermal and Fluid Science, 11(1995), pp. 295-309.
  4. Fiebig M., Embedded vortices in internal flow-heat-transfer and pressure loss enhancement, International Journal of Heat and Fluid Flow, 16(1995), pp. 376-388.
  5. Johnson T.R., Joubert P.N., The influence of vortex generators on drag and heat transfer from a circular cylinder normal to an airstream, Journal of Heat Transfer-Transactions of the ASME, 91(1969), pp. 91-99.
  6. Biswas G., Mitra N.K., Fiebig M., Heat transfer enhancement in fin-tube heat exchangers by winglet type vortex generators, International Journal of Heat and Mass Transfer, 37(1994), pp. 283-291.
  7. Torii K., Kwak K.M., Nishino K., Heat transfer enhancement accompanying pressure-loss reduction with winglet-type vortex generators for fin-tube heat exchangers, International Journal of Heat and Mass Transfer, 45(2002), pp. 3795-3801.
  8. Jain A., Biswas G., Maurya D., Winglet-type vortex generators with common-flow-up configuration for fin-tube heat exchangers, Numerical Heat Transfer Part a-Applications, 43(2003), pp. 201-219.
  9. O'Brien J.E., Sohal M.S., Heat transfer enhancement for finned-tube heat exchangers with winglets, Journal of Heat Transfer-Transactions of the ASME, 127(2005), pp. 171-178.
  10. Pesteei S.M., Subbarao P.M.V., Agarwal R.S., Experimental study of the effect of winglet location on heat transfer enhancement and pressure drop in fin-tube heat exchangers, Applied Thermal Engineering, 25(2005), pp. 1684-696.
  11. Joardar A., Jacobi A.M., A numerical study of flow and heat transfer enhancement using an array of delta-winglet vortex generators in a fin-and-tube heat exchanger, Journal of Heat Transfer-Transactions of the ASME, 129(2007), pp. 1156-1167.
  12. Joardar A., Jacobi A.M., Heat transfer enhancement by winglet-type vortex generator arrays in compact plain-fin-and-tube heat exchangers, International Journal of Refrigeration-Revue Internationale Du Froid, 31(2008), pp. 87-97.
  13. Tian L.T., He Y.L., Lei Y.G., Tao W.Q., Numerical study of fluid flow and heat transfer in a flat-plate channel with longitudinal vortex generators by applying field synergy principle analysis, International Communications in Heat and Mass Transfer, 36(2009), p. 111-120.
  14. Lei Y.G., He Y.L., Tian L.T., Chu P., Tao W.Q., Hydrodynamics and heat transfer characteristics of a novel heat exchanger with delta-winglet vortex generators, Chemical Engineering Science, 65(2010) pp. 1551-1562.
  15. Chu P., He Y.L., Tao W.Q., Three-Dimensional Numerical Study of Flow and Heat Transfer Enhancement Using Vortex Generators in Fin-and-Tube Heat Exchangers, Journal of Heat Transfer-Transactions of the ASME, 131(2009), pp. 091903.
  16. Chu P., He Y.L., Lei Y.G., Tian L.T., Li R., Three-dimensional numerical study on fin-and-oval-tube heat exchanger with longitudinal vortex generators, Applied Thermal Engineering, 292009), pp. 859-876.
  17. Tang L.H., Zeng M., Wang Q.W., 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), pp. 818-827.
  18. Wu J.M., Tao W.Q., Impact of delta winglet vortex generators on the performance of a novel fin-tube surfaces with two rows of tubes in different diameters, Energy Conversion and Management, 52(2011), pp. 2895-2901.
  19. Wu J.M., Zhang H., Yan C.H., Wang Y., Experimental study on the performance of a novel fin-tube air heat exchanger with punched longitudinal vortex generator, Energy Conversion and Management, 57(2012), pp. 42-48.
  20. Du X.P., Yin Y.T., Zeng M., et.al, An experimental investigation on air-side performances of finned tube heat exchangers for indirect air-cooling tower, Thermal Science, 18(2014), pp. 863-874.
  21. Gholami A.A., Wahid M. A., Mohammed H.A., Heat transfer enhancement and pressure drop for fin-and-tube compact heat exchangers with wavy rectangular winglet-type vortex generators, International Communications in Heat and Mass Transfer, 54(2014), pp. 132-140.
  22. Lotfi B., Sundén B., Wang Q.W., An investigation of the thermo-hydraulic performance of the smooth wavy fin-and-elliptical tube heat exchangers utilizing new type vortex generators, Applied Energy, 126(2016), pp. 1282-1302.
  23. Bhuiyan A.A., Islam A.K.M., Thermal and hydraulic performance of finned-tube heat exchangers under different flow ranges: A review on modeling and experiment, International Journal of Heat and Mass Transfer, 101(2016), pp. 38-59.
  24. Deng J., Qian Z.Q., Simplified analysis of thermal contact resistance on arc-slotted fin core, Applied Thermal Engineering, 125(2017), pp. 266-284.
  25. Sarangi S.K., Mishra D.P., Effect of winglet location on heat transfer of a fin-and-tube heat exchanger, Applied Thermal Engineering, 116(2017), pp. 528-540.
  26. Gholami A., Wahid M.A., Mohammed H.A., Thermal-hydraulic performance of fin-and-oval tube compact heat exchangers with innovative design of corrugated fin patterns, International Journal of Heat and Mass Transfer, 106(2017), pp. 573-592.
  27. Välikangas T., Singh S., Sørensen K., Condra T., Fin-and-tube heat exchanger enhancement with a combined herringbone and vortex generator design, International Journal of Heat and Mass Transfer, 118(2018), pp. 602-616.
  28. Tao W.Q., Numerical Heat Transfer, Xi'an, China: Xi'an Jiaotong University Press, 2001.
  29. Fan J.F., Ding W.K., Zhang J.F., He Y.L., Tao W.Q., A performance evaluation plot of enhanced heat transfer techniques oriented for energy-saving, International Journal of Heat and Mass Transfer, 52(2009), pp. 33-44.

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