LAMINAR CONVECTIVE HEAT TRANSFER FOR IN-PLANE SPIRAL COILS OF NONCIRCULAR CROSS SECTIONS DUCTS: A COMPUTATIONAL FLUID DYNAMICS STUDY

Abstract

The objective of this study was to carry out a parametric study of laminar flow and heat transfer characteristics of coils made of tubes of several different cross-sections e.g. square, rectangular, half-circle, rectangular and trapezoidal. For the purpose of ease of comparison, numerical experiments were carried out base on a square-tube Reynolds number of 1000 and a fixed fluid flow rate while length of the tube used to make coils of different diameter and pitch was held constant. A figure of merit was defined to compare the heat transfer performance of different geometry coils; essentially it is defined as total heat transferred from the wall to the surroundings per unit pumping power required. Simulations were carried out for the case of constant wall temperature as well as constant heat flux. In order to allow reasonable comparison between the two different boundary conditions - constant wall temperature and constant wall heat flux - are tested; the uniform heat flux boundary condition was computed by averaging the heat transferred per unit area of the tube for the corresponding constant wall temperature case. Results are presented and discussed in the light of the geometric effects which have a significant effect on heat transfer performance of coils.

Dates

  • Submission Date2010-06-27
  • Revision Date2011-01-05
  • Acceptance Date2011-02-21

DOI Reference

10.2298/TSCI100627014K

References

  1. Egner, M. W., Burmeister L. C., Heat Transfer for Laminar Flow in Spiral Ducts of Rectangular Cross Section. ASME J. Heat Transfer., 127 (2005), pp. 352-356
  2. Dean, W. R., Note on the motion of fluid in a curved pipe. Philos. Mag., 4 (1927), 20, pp. 208-223
  3. Dean, W. R., The stream-line Motion of fluid in a curved pipe. Philos. Mag., 5 (1927), 7, pp. 208-223
  4. Naphon, P., Suwagrai J., Effect of curvature ratios on the heat transfer and flow developments in the horizontal spirally coiled tubes. Int. J. Heat Mass Transfer, 50 (2007), pp. 444-451
  5. Saravanan, K., Rajavel R., An Experimental investigation of heat transfer coefficients for spiral plate heat exchanger. Modern Appl. Sci., 2 (2008), 5, pp. 14-20
  6. Ramachandran, S., Kalaichelvi, P., Sundaram, S., Heat transfer in a spiral plate heat exchanger for water-palm oil two phase systems. Braz. J. Chem. Eng., 25 (2008), 3, pp. 483-490
  7. Rajavel, R., Saravanan, K., An experimental study of spiral plate heat exchanger for electrolyte. J. Univ. Chem. Tech. Metal., 43 (2008), 2, pp. 255-260
  8. Balakrishnan, R., Santhappan, J. S., Dhasan, M. L., Heat transfer correlation for a refrigerant mixture in a vertical helical coil evaporator. Therm. Sci., 13 (2009), 4, pp. 197-206
  9. Rajavel, R., Saravanan, K., Heat transfer studies on spiral plate heat exchanger. Therm. Sci., 12 (2008), 3, pp. 85-90
  10. Vijayan, R., Srinivasan, P., Experimental evaluation of internal heat exchanger influence on R-22 window air conditioner retrofitted with R-407C. Therm. Sci., 14 (2010), 1, pp. 85-90
  11. Nakayama, A., Kokubo, N., Ishida, T., Kuwahara, F., Conjugate numerical model for cooling a fluid flowing through a spiral coil immersed in a chilled water container. Numer. Heat Transfer, Part A, 17 (2000), pp. 155-165
  12. Naphon, P., Wongwises, S., An experimental study on the in-tube heat transfer coefficient in a spiral coil heat exchanger. Int. Commun. Heat Mass Transfer, 29 (2002), pp. 797-809
  13. Ho, J. C., Wijeysundera, N. E., An unmixed-air flow model of a spiral cooling dehumidifying unit. Appl. Therm. Eng., 19 (1999), pp. 865-883
  14. Alammar, K. N., Turbulent flow and heat transfer characteristics in u-tubes: a numerical study. Therm. Sci., 13 (2009), 4, pp. 175-181
  15. Kurnia, J. C., Sasmito, A. P., Mujumdar, A. S., Evaluation of the heat transfer performance of helical coils of non-circular tubes. J. Zhejiang Univ-Sci. A (Appl. Phys. & Eng.), 12 (2011), 1, pp.63-70
  16. Kurnia, J. C., Sasmito, A. P., Mujumdar, A. S., Numerical investigation of laminar heat transfer performance of various cooling channel design. Appl. Therm. Eng. (2011), doi:10.1016/j.applthermaleng.2010.12.036
  17. Kays, W., Crawford, M., Weigand, B., Convective Heat and Mass Transport 4th Ed, MacGraw Hill, Singapore, 2005
  18. Vasith, S., Kumar, V., Nigam, K. D. P., A Review on the Potential Applications of Curved Geometries in Process Industry. Ind. Eng. Chem. Res., 47 (2008), pp. 3291-3337
Volume 16, Issue 1, Pages109 -118