Energy and exergy based performance evaluation of an innovative PV-assisted solar dryer with and without modified absorber

Abstract

The advancement of clean and sustainable energy technologies is necessary to fulfill the world's growing energy demand. Food preservation must consider the usage of PV-assisted solar dryers to eliminate the traditional energy-intensive drying systems. However, there is a significant technology gap in the drying system to effectively utilize solar energy. Some modifications can be done through the absorber surface by adding obstacles for the selection of an effective design that increases the heat transmission to the fluid flowing inside the solar collector and dryer. The primary objective of this research was to improve the PV-assisted solar dryer performance by modifying the absorber through the incorporation of square obstacles equipped with threaded pin fins. The investigations were carried out in plain absorber (Model-I) and modified absorber (Model-II) to compare the performance at 0.0024, 0.0072, and 0.012 kg/s airflow rates. The reduction in moisture content of green papaya and green banana was 71.42 % and 49.27 % more using Model-II instead of drying outside the dryer. The maximum drying efficiency was 29.55 % and 29.80 % in Model-II for crops A and B, respectively at 0.0072 kg/s. The thermal energy and thermal exergy efficiency were 33.43 % and 27.17 % higher, respectively in Model-II than compared to Model-I. The lower payback of 1.51 yr and higher CO2 mitigation of 46.17 tons were attained. The quality analysis findings recommended that the proposed design can be applied in numerous food drying applications and is a promising solution for further advancing absorber design for solar collectors and dryers.