Higher performance solar air dryer functioned with palmitic acid phase change material and hybrid nanofluid: Thermal performance evaluation

Abstract

The significance of solar renewable energy is familiar for air dryer applications, and solar-operated air dryer is found to have uneven temperature distribution, lack of heat transfer rate, and variation in dryer performance due to climate conditions and thermal loss. This research overcomes the disputes and enriches the functional behaviour/dryer performance of solar air dryers featuring flat plate collectors, which are operated by using graphene: alumina hybrid nanofluid as the ratios of 1:3 and fatty acids (palmitic acid) phase change material. During the investigation, the hybrid nanofluid maintained a 7 L/min flow rate with different concentrations (0.5, 1, and 1.5 percentages in volume). Influences of hybrid nanofluid concentration along with phase change material on functional properties of solar dryer featured with flat plate solar collector setup are investigated, and its outcome results are related to ethylene glycol/ palmitic acid phase change material operated solar dryer system. The excellence of hybrid nanofluid with 1.5 vol% concentration and phase change material influences superior thermal and dryer performance like better thermal conductivity (0.75 W/mK), improved heat transfer rate property (345.5 W), reduced heat loss (58.7 W), improved thermal/exergy efficiency (62.5 %/20.7 %), and improved dryer efficiency of 46.8 %, which are superior to solar dryer operated with ethylene glycol/ palmitic acid phase change material.