Exergy loss-based efficiency optimization of a double-pass/glazed v-corrugated plate solar air heater

•A double-pass/glazed v-corrugated plate solar air heater was exegetically optimized.•Results of simulation show good agreements with those of experiment in literature.•An optimum exergy efficiency of 6.27% is found for the present air heater.•Exergy loss due to sun-absorber temperature difference is the most destructive term.

The main objective of the present study is to perform an in-depth exergetic analysis of a double-pass/glazed v-corrugated plate solar air heater based on exergy loss terms. Consequently, the detailed thermal modeling of the given air heater is carried out and validated with literature which shows good agreements. Through an exergy analysis performed with regard to internal/external exergy losses, the exergetic efficiency is optimized considering four independent variables of distance between the two adjacent glazings, height of v-corrugations, area of the heater and the total mass flow rate. Based on the simulation results, the maximum exergy efficiency of the given air heater was gained 6.27% corresponding to distance of 0.0023 m between glazings, corrugation height of 0.0122 m, heater area of 1.79 m2 and total air rate of 0.005 kg/s. Moreover, as an important conclusion, it was found that the internal exergy loss term originating from temperature difference between sun and absorber surface can be interpreted as the most destructive term in comparison to four other terms which accounted for 63.57% of the whole exergy losses at the point corresponding to maximum exergy efficiency.