Analysis of an infrared-assisted triple-flow prototype solar drying system with nano-embedded absorber coating: An experimental and numerical study

In this study, the impact of combined usage of infrared heater and nano-improved absorber coating in the triple-flow solar dryer (TFSD) has been analyzed. In the first stage of the study, a newly developed baffle configuration in the triple-flow solar air collector (SAC) has been numerically analyzed utilizing computational fluid dynamics. The new configuration was compared numerically with the conventional collector. Considering the numerical results, a triple-flow SAC with perforated baffles was manufactured and coupled with a drying room. In the experimental part, a conventional TFSD, an infrared-assisted TFSD and an infrared-assisted TFSD with iron (Fe) nano-embedded absorber coating (industrial matt black paint) have been examined. According to the experimentally obtained findings, combined usage of infrared heater and nano-improved paint decreased the drying period by 40% compared to the conventional TFSD. Thermal and exergetic efficiencies of the triple-flow collector were upgraded in the ranges of 14.62–16.94% and 31.19–37.72%, respectively using nano-coating. The mean specific energy consumption values were gained in the range of 4.18–4.53 kWh/kg. Moreover, energy efficiency values of the dryer were attained between 32.18 and 40.84% for the tested three configurations. It must be stated that the mean difference between experimental and numerical outlet air temperatures of the SAC was found as 6.2%.