Authors

1 Research scholar, Mechanical Engineering Department, NIT Jamshedpur, Jharkhand, India

2 Mechanical Engineering Department, NIT Jamshedpur, Jharkhand, India

Abstract

This paper represented theoretically investigation of energy and exergy performance of an offset finned solar air heater. Parametric study was done to investigate the effect of variation of offset fin parameters i.e. fins spacing (1 to 5cm) and fins height (1.8 to 5.8cm) at different mass flow rates (0.01388 to 0.0833kg/s) on the energy and exergy efficiency. The results indicated that attaching offset finned below the absorber plate at low mass flow rates can lead to noticeable enhancement of exergy efficiency. The results revealed that the trend of variation of the energy and exergy efficiencies are not the same and the exergy efficiency is the chief criterion for performance evaluation. Decreasing the fins height, reducing the fins spacing are effective at low mass flow rates, but at high mass flow rates the inverse trend is observable, such that exergy efficiency reduces sharply. The efficiencies of offset finned solar collector were compared with conventional flat-plate collectors and longitudinal fins collector.

Keywords

1.   Ho-Ming, Y., 1992. Theory of baffled solar air heaters. Energy, 17(7): 697-702.
2.   Yeh, H.-M., 1994. Energy balances for upward-type baffled solar air heaters. Energy, 19(9): 919-924.
3.   Lalji, M.K., R. Sarviya and J. Bhagoria, 2012. Exergy evaluation of packed bed solar air heater. Renewable and Sustainable Energy Reviews, 16(8): 6262-6267.
4.   Ramadan, M., A. El-Sebaii, S. Aboul-Enein and E. El-Bialy, 2007. Thermal performance of a packed bed double-pass solar air heater. Energy, 32(8): 1524-1535.
5.   Dović, D. and M. Andrassy, 2012. Numerically assisted analysis of flat and corrugated plate solar collectors thermal performances. Solar energy, 86(9): 2416-2431.
6.   El-Sebaii, A., S. Aboul-Enein, M. Ramadan, S. Shalaby and B. Moharram, 2011. Investigation of thermal performance of-double pass-flat and v-corrugated plate solar air heaters. Energy, 36(2): 1076-1086.
7.   Ho,  C.,  C.  Yeh  and  S.  Hsieh,  2005.  Improvement  in  device performance of multi-pass flat-plate solar air heaters with external recycle. Renewable Energy, 30(10): 1601-1621.
8.   Ho, C., H. Yeh and R. Wang, 2005. Heat-transfer enhancement in double-pass  flat-plate  solar  air  heaters  with  recycle.  Energy, 30(15): 2796-2817.
9.   Gupta, M. and S. Kaushik, 2009. Performance evaluation of solar air heater for various artificial roughness geometries based on energy,  effective  and  exergy  efficiencies.  Renewable  Energy, 34(3): 465-476.
10. Lior, N., W. Sarmiento-Darkin and H.S. Al-Sharqawi, 2006. The exergy fields in transport processes: their calculation and use. Energy, 31(5): 553-578.
11. Gupta,  M.   and   S.   Kaushik,   2008.   Exergetic   performance evaluation and parametric studies of solar air heater. Energy, 33(11): 1691-1702.
12. Singh, S., S. Chander and J. Saini, 2012. Exergy based analysis of solar air heater having discrete V-down rib roughness on absorber plate. Energy, 37(1): 749-758.
13. Alta, D., E. Bilgili, C. Ertekin and O. Yaldiz, 2010. Experimental investigation  of  three  different  solar  air  heaters:  Energy  and exergy analyses. Applied Energy, 87(10): 2953-2973.
14. Manglik, R.M. and A.E. Bergles, 1995. Heat transfer and pressure drop correlations for the rectangular offset strip fin compact heat exchanger. Experimental Thermal and Fluid Science, 10(2): 171-180.
15. Duffie, J.A. and W.A. Beckman, Solar engineering of thermal processes. Vol. 3. 1980: Wiley New York etc.
16. Karim, M.A. and M. Hawlader, 2006. Performance investigation of flat plate, v-corrugated and finned air collectors. Energy, 31(4):452-470.