Developing an infrared-assisted solar drying system using a vertical solar air heater with perforated baffles and nano-enhanced black paint

Abstract

In the present study, it is aimed to improve the performance of a solar drying system (SDS) utilizing ZnO nano-enhanced absorber coating and infrared heating system. In the first stage of this work, different geometrical configurations of the main heating system of the SDS which is a vertical solar air heater (VSH) have been numerically analyzed. According to the numerical findings, VSH with perforated type baffles gave the best performance results. Then, the determined configuration has been manufactured and combined with a drying chamber. Moreover, two other modifications have been applied to the system including an infrared heater and nano-enhanced black paint. In other words, the experimental part of this research contains three SDS types including a conventional SDS, a SDS with infrared heater and a SDS with infrared heater and ZnO nano-enhanced absorber coating (combined usage of two modifications). The mean thermal and exergetic efficiencies of the VSH analyzed within the scope of this work were attained between 53.54–65.12% and 9.94–14.32%, respectively. Moreover, combined use of infrared heater and nano-enhanced absorber coating material in the VSH decreased the drying time period as 43.75% when compared to the unmodified SDS.