Development of a Three-Layer Hybrid Solar Dryer with a Solar Collector for Thermal Performance Improvement

Abstract

This research aims to develop a three-tier hybrid solar dryer integrated with a solar collector to enhance thermal performance and prolong the drying period. The system employs water as a heat transfer fluid, circulating from the solar collector to the drying chamber via copper pipes installed beneath the product trays on all three tiers. The experimental methodology involved continuous temperature monitoring and comparative thermal performance analysis against a conventional solar dryer. Namwa bananas, precisely controlled at an initial weight of 500 grams (10-12 pieces) per batch, served as the test material to evaluate moisture reduction via weight loss percentage across 10 independent trials. Results indicated that the hybrid system's thermal performance was significantly superior, achieving a peak internal chamber temperature of 80°C, compared to 70°C in the conventional counterpart. Consequently, the hybrid configuration facilitated a more rapid drying process. On the initial day, the hybrid system achieved a weight loss of 44.20%, substantially outperforming the conventional system's 14.60%, thereby demonstrating a superior moisture removal capacity. Furthermore, the application of water for thermal energy storage stabilized internal temperatures, allowing the system to continuously radiate effective drying heat for approximately two additional hours compared to the conventional baseline. In conclusion, the integration of a solar collector provides a cost-effective mechanism to extend operational drying time and elevate thermal efficiency. This innovation is highly viable for agricultural drying processes demanding robust thermal performance, such as bananas, tea leaves, and bagasse.