期刊名称：International Journal of Energy and Environment
印刷版ISSN：2076-2895
电子版ISSN：2076-2909
出版年度：2010
卷号：1
期号：5
页码：897-910
出版社：International Energy and Environment Foundation (IEEF)
摘要：The use of an artificial roughness on a surface is an effective technique to enhance the rate of heat transfer to fluid flow in the duct of a solar air heater. This paper presents a comparison of exergetic performance of solar air heaters having different types of geometry of roughness elements (continuous ribs) on the absorber plate. The exergy efficiency has been computed by using the correlations for heat transfer and friction factor developed by various investigators within the investigated range of operating and system parameters. The exergy efficiency based criterion shows the better results at lower value of Re. There is not a single roughness geometry which gives best exergetic performance for whole range of Reynolds number. Solar air heater having rib-grooved and arc shaped wire as artificial roughness is found to have better exergy efficiency in the lower range of Reynolds number. However, smooth duct is found suitable in the higher range of Reynolds number.
