Investigation of an Offset Finned Solar Air Heater Based on Energy and ExergyPerformance

his paper represented theoretically investigation of energy and exergy performance of an offsetfinned solar air heater. Parametric study was done to investigate the effect of variation of offset finparameters 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 offsetfinned below the absorber plate at low mass flow rates can lead to noticeable enhancement of exergyefficiency. The results revealed that the trend of variation of the energy and exergy efficiencies are notthe same and the exergy efficiency is the chief criterion for performance evaluation. Decreasing thefins height, reducing the fins spacing are effective at low mass flow rates, but at high mass flow ratesthe inverse trend is observable, such that exergy efficiency reduces sharply. The efficiencies of offsetfinned solar collector were compared with conventional flat-plate collectors and longitudinal finscollector

Keywords:

Plane solar air collector , Exergy efficiency , Thermal efficiency , Parametric study , Offset-fins ,