Advertisement

Applied Solar Energy

, Volume 54, Issue 1, pp 23–31 | Cite as

Effect of Buoyancy on the Perfomance of Solar Air Collectors with Different Structures

  • Shuilian Li
  • Xiangrui Meng
  • Weixinli
Solar Power Plants and Their Application
  • 16 Downloads

Abstract

In order to study the effect of buoyancy on the performance of solar air collector, the theoretical analysis and experimental tests of four solar air collectors with different structures under natural convection and mixed convection are carried out. The results show that the air temperature rise of the protrusion-corrugated plate air collector is the highest in the natural convection, which is 9.17 Chigher than that of the flat plate collector, and the air outlet velocity is 0.19 m/s, increasing by 16.88% than that of the flat plate collector. Observing the effects on the heat transfer performance of mixed convection, it can be found, in addition to the protrusion-corrugated plate air collector, the buoyancy plays a positive role on the other three solar air collectors in the upward flow, while the buoyancy plays a negative role on the other three solar air collectors in the downward flow, and the enhanced degree of the buoyancy to the corrugated plate air collector is the largest, while the enhancement degree of the flat plate collector is the least.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Yan, W.M. and Li, H.Y., Radiation effects on mixed convection heat transfer in a vertical squareduct, Heat Mass Transfer, 2001, vol. 44, pp. 1401–1410.CrossRefzbMATHGoogle Scholar
  2. 2.
    Krishnan, A.S., Premachandran, B., Balaji, C., and Venkateshan, S.P., Combined experimental and numerical approaches to multi-mode heat transfer between vertical parallel plates, Exp. Thermal Fluid Sci., 2004, vol. 29, pp. 75–86.CrossRefGoogle Scholar
  3. 3.
    Jackson, J.D. and Hall, W.B., Influences of buoyancy on heat transfer to fluids flowing in vertical tubes under turbulent conditions, in Proceedings of the Conference on Turbulent Forced Convection in Channels and Bundles, Hemisphere, 1979, pp. 613–640.Google Scholar
  4. 4.
    Polyakov, A.F. and Shindin, S.A., Development of heat transfer along vertical tubes in the presence of mixed air convection, Heat Mass Transfer, 1988, vol. 31, pp. 987–992.CrossRefGoogle Scholar
  5. 5.
    Wang, J.L., Li, J.K., and Jackson, J.D., A study of the influence of buoyancy on turbulent flow in a vertical plane passage, Int. J. Heat Fluid Flow, 2004, vol. 25, pp. 420–430.CrossRefGoogle Scholar
  6. 6.
    Jackson, J.D., Cotton, M.A., Axcell, B.P., Studies of mixed convection in vertical tubes, Int. J. Heat Fluid Flow, 1989, vol. 10, pp. 2–15.CrossRefGoogle Scholar
  7. 7.
    Kim Moin, P. and Moser, R.D., Turbulence statistics in fully developed channel flow at low Reynolds number, J. Fluid Mech., 1987, vol. 177, pp. 133–166.CrossRefzbMATHGoogle Scholar
  8. 8.
    Wamotor, I.K., Database of fully developed channel flow, THTLAB Internal Report ILR-0201, Tokyo, Japan, 2003.Google Scholar
  9. 9.
    Cheng, X. and Mueller, U., Turbulent natural convection coupled with thermal radiation in large vertical channels with asymmetric heating, Int. J. Heat Mass Transfer, 1998, vol. 41, no. 12, pp. 1681–1692.CrossRefzbMATHGoogle Scholar
  10. 10.
    Xie Zhengrui, Yang Yanhua, and Gu Hanyang, Numerical analysis of turbulent mixed convection heat transfer in a rectangular channel, Nucl. Power Eng., 2009, vol. 30, no. 1, pp. 50–55.Google Scholar
  11. 11.
    Liu Minghou, Chen, T. L., and Chen Yiliang, Buoyancy effect on the flow and heat transfer characteristics of mixed convection, 2004, vol. 36, pp. 336–340.Google Scholar
  12. 12.
    Kalidasan, K., Velkennedy, R., Rajesh Kanna, P., Buoyancy enhanced natural convection inside the ventilated square enclosure with a partition and an overhanging transverse baffle, Int. Commun. Heat Mass Transfer, 2014, vol. 56, pp. 121–132.CrossRefGoogle Scholar
  13. 13.
    Pourya Forooghi and Kamel Hooman, Effect of buoyancy on turbulent convection heat transfer in corrugated channels -a numerical study, Int. J. Heat Mass Transfer, 2013, vol. 64, pp. 850–862.CrossRefGoogle Scholar
  14. 14.
    Bazdidi-Tehrani, F. and Nezamabadi, M., Effect of Gr/Re on mixed convection and combined mixed convection-radiation heat transfer within a vertical channel with variable wall temperature, 2005, vol. 12, pp. 178–189.Google Scholar
  15. 15.
    Ingham, D.B., Keen, D.J., and Heggs, P.J., Flows in vertical channels with asymmetric wall temperatures and including situations where reverse flow occurs, ASME J. Heat Transfer, 1999, vol. 110, pp. 910–917.CrossRefGoogle Scholar
  16. 16.
    Gau, C., Yih, K.A., and Aung, W., Reversal flow structure and heat transfer measurement for buoyancyassisted convection in a heated vertical duct, ASME J. Heat Transfer, 1992, vol. 114, pp. 928–935.CrossRefGoogle Scholar
  17. 17.
    Jeng, Y.N., Chen, J.L., and Aung, W., On the Reynolds-number independence of mixed convection in a vertical channel subjected to asymmetric wall temperature with and with outflow reversal, Int. J. Heat Fluid Flow, 1992, vol. 13, pp. 329–339.CrossRefGoogle Scholar
  18. 18.
    Lin, T.F., Chang, T.S., and Chen, Y.F., Development of oscillatory asymmetric recirculating flow in transient laminar opposing mixed convection in symmetrically heated vertical channel, ASME J. Heat Transfer, 1993, vol. 105, pp. 342–352.CrossRefGoogle Scholar
  19. 19.
    Hegg, P.J., Ingham, D.B., and Keen, D.J., The effects of heated conduction in the wall on the development of recirculating combined convection flows in vertical tubes, Int. J. Heat Mass Transfer, 1990, vol. 33, pp. 517–528.CrossRefGoogle Scholar
  20. 20.
    Wang, M., Tsuji, T., and Nagano, Y., Mixed convection with flow reversal in the thermal entrance region of horizontal and vertical pipes, Int. J. Heat Mass Transfer, 1994, vol. 37, pp. 2305–2319.CrossRefzbMATHGoogle Scholar
  21. 21.
    Hesreddin, H., Galanis, N., and Nguyen, C.T., Effects of axial diffusion on laminar heat transfer with low Peclet numbers in the entrance region of thin vertical tubes, Numer. Heat Transfer, Part A, 1998, vol. 33, pp. 247–266.CrossRefGoogle Scholar
  22. 22.
    Avezov, R.R. and Abdukhamidov, D.U., On determining the solar radiation absorption factor for translucent coatings of flat solar plants, Appl. Sol. Energy, 2015, vol. 51, no. 3, pp. 232–234.CrossRefGoogle Scholar
  23. 23.
    Holman, J.P., Experimental Methods for Engineers, McGraw-Hill Series in Mechanical Engineering, New York: McGraw-Hill, 1994.Google Scholar
  24. 24.
    Chiu, H. and Yan, W., Mixed convection heat transfer in inclined rectangular ducts with radiation effects, Int. J. Heat Mass Transfer, 2008, vol. 51, pp. 1085–1094.CrossRefzbMATHGoogle Scholar
  25. 25.
    Esposito, A., Fluid Mechanics with Applications, Upper Saddle River, NJ: Prentice-Hall, 1998.Google Scholar
  26. 26.
    Tonui, J.K. and Tripanagnostopoulos, Y., Performance improvement of PV/T solar collectors with natural air flow operation, Solar Energy, 2008, vol. 82, pp. 1–12.CrossRefGoogle Scholar
  27. 27.
    Hirunlabh, J., Kongduang, W., Namprakai, P., and Khedari, J., Study of natural ventilation of houses by a metallic solar wall under tropical climate, Renewable Energy, 1999, vol. 18, pp. 109–119.CrossRefGoogle Scholar
  28. 28.
    Saini, R.P. and Verma, J., Heat transfer and friction factor correlations for a duct having dimple-shape artificial roughness for solar air heaters, Energy, 2008, vol. 33, pp. 1277–1287.CrossRefGoogle Scholar

Copyright information

© Allerton Press, Inc. 2018

Authors and Affiliations

  1. 1.Zhengzhou Technical CollegeZhengzhouChina
  2. 2.Engineering Center of Energy Saving Technology and EquipmentZhengzhouChina
  3. 3.Zhengzhou UniversityZhengzhouChina

Personalised recommendations