Journal of Mechanical Science and Technology

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지

Heat Transfer Enhancement for Fin-Tube Heat Exchanger Using Vortex Generators

  • Yoo, Seong-Yeon (Department of Mechanical Design Engineering, Chungnam National University, Taejon 305-715) ;
  • Park, Dong-Seong (Department of Mechanical Design Engineering, Chungnam National University, Taejon 305-715) ;
  • Chung, Min-Ho (Department of Mechanical Design Engineering, Chungnam National University, Taejon 305-715)
  • Published : 2002.01.01
Download PDF
⟨ Previous Next ⟩

Abstract

Vortex generators are fabricated on the fin surface of a fin-tube heat exchanger to augment the convective heat transfer. In addition to horseshoe vortices formed naturally around the tube of the fin-tube heat exchanger, longitudinal vortices are artificially created on the fin surface by vortex generators. The purpose of this study is to investigate the local heat transfer phenomena in the fin-tube heat exchangers with and without vortex generators, and to evaluate the effect of vortices on the heat transfer enhancement. Naphthalene sublimation technique is employed to measure local mass transfer coefficients, then analogy equation between heat and mass transfer is used to calculate heat transfer coefficients. Experiments are performed for the model of fin -circular tube heat exchangers with and without vortex generators, and of fin-flat tube heat exchangers with and without vortex generators. Average heat transfer coefficients of finn-flat tube heat exchanger without vertex generator are much lower than those of fin-circular tube heat exchanger. On the other hand, fin-flat tube heat exchanger with vortex generators has much higher heat transfer value than conventional fin-circular tube heat exchanger At the same time, pressure losses for four types of heat exchanger is measured and compared.

Keywords

References

  1. Ambrose, D., Lawrenson, I. J., Sparke, C. H. S., 1975, 'The Vapor Pressure of Naphthalene,' J. of Chemical Thermodynamics, Vol. 7, pp. 1173-1176 https://doi.org/10.1016/0021-9614(75)90038-5
  2. Cho, K., 1989, 'Measurement of Diffusion Coefficient of Naphthalene into Air,' Ph. D Thesis, State University of New York
  3. Fiebig, M. and Chen, Y., 1998, 'Heat Transfer Enhancement by Wing-type Longitudinal Vortex Generators and Their Application to Finned Oval Tube Heat Exchanger Elements,' Proc. of the NATO Advanced Study Institute on Heat Transfer Enhancement of Heat Exchangers, pp. 79-105
  4. Goldstein, R. J., Yoo, S. Y. and Chung, M. K., 1990, 'Convective Mass Transfer from a Square Cylinder and Its Base Plate,' Int. J. of Heat and Mass Transfer, Vol. 33, pp. 9-18 https://doi.org/10.1016/0017-9310(94)00177-W
  5. Yoo, S. Y., 1997, 'Development of High Efficiency Fin-Flat Tube Heat Exchanger Using Vortex Generators,' MOTI Report, 95-P-10-2
  6. Zhu, J. X., Fiebig, M. and Mitra, N. K., 1995, 'Numerical Investigation of Turbulent Flows and Heat Transfer in a Rib-Roughened Channel with Longitudinal Vortex Generators,' Int. J. Heat Mass Transfer, Vol. 38, No. 3, pp. 495-501 https://doi.org/10.1016/0017-9310(94)00177-W