Performance evaluation of innovative sensible energy storage material integration as an obstacle in solar collectors for drying applications

Abstract

This research paper presents an innovative approach to enhance the performance of solar collectors in drying processes by integrating a sensible energy storage material within the airflow passage as an obstacle. The study involves a real-time comparative analysis of different collector configurations, under identical meteorological conditions, including flat collector, finned collector and rock integrated collector. The experimental results demonstrate that at high flow rate the collector equipped with fins achieves higher outlet temperatures, with a maximum of 59.8 °C, compared to 58.2 °C for the collector without fins. Additionally, for low and intermediate flow rates, the collector utilizing rocks as the energy storage material exhibits a maximum outlet temperature of 70.2 °C, while the collector with fins reaches 76.8 °C. Notably, the collector with rocks demonstrates a temperature gain of 13.6 °C during the night period. The drying efficiency of both solar dryers is evaluated, and they achieve a final moisture content of 6 % from an initial moisture content of 88 % (kg water/kg wet basis) in 1452 and 1722 min in solar dryer with fins and rocks, respectively. The drying rate is observed to be higher in the solar dryer with fins compared to the one with rocks. Midilli-Kucuk model provided the best agreements between experimental and predicted moisture ratios. Furthermore, the average effective moisture diffusivity is found to be higher in the solar dryer with fins (6.39485E-10 m2/s) compared to the one with rocks (1.33512E-10 m2/s).