Experimental investigation of nanomaterial doped in black paint coating on absorber for energy conversion applications

Abstract

In the present study, the absorber plate of the triangular solar air heater system is coated with graphene nanomaterial doped in black paint. This is done to analyze the performance based on various mass flow rate of air and solar intensity. The different percentages of graphene nanomaterial (0.1%, 0.2%, & 0.3%) are doped in black paint which increases the absorption of heat. The Reynolds number is varied for the fixed selective coating on absorber plate and mass flow rate. Also the heat transfer of air and absorption rate on the absorber plate is increased . The thermal efficiency, exergy efficiency and improvement potential are also enhanced. In addition, the effects of entropy generation are examined with respect to solar radiation and ambient temperature. The results are presented for constant mass flow rate ranging from 0.0036 to 0.0181 kg/s. The experimental result gives the average thermal efficiency enhancement of 4.91% for BP-II. Entropy generation varies 0.1571 to 0.7189 W/K. Entropy generation is maximum for BP-I and minimum for BP-II. It concludes that the entropy generation increases with increase in mass flow rate. Exergy efficiency for BP-II is found to be 4.27% higher as compared to BP-I.