مشخصات پژوهش

The increasing global demand for food drying operations has intensified research on energy-efficient solar drying technologies. Conventional Open Sun Drying (OSD) suffers from inconsistent heating, contamination, and poor product quality, necessitating the development of improved solar drying arrangements. In this research, an experimental investigation was conducted on an Indirect Solar Dryer (ISD) coupled with a Phase Change Material (PCM) enhanced solar air collector, employing paraffin wax embedded with aluminium fins to increase thermal behaviour. Two absorber plate configurations, corrugated and sinusoidal, were evaluated to compare their drying, energy, and environmental performance. The systems, designated as ISDC (corrugated) and ISDS (sinusoidal), were tested for drying bitter gourd slices from the moisture content of 94% to 12% w.b. The total drying duration was reduced to 12 hours for ISDC and 11 hours for ISDS, compared to 16 hours in OSD. The PCM-integrated solar collector achieved a mean useful heat gain of 468.52W for the ISDC and 485.14W for the ISDS. An average thermal efficiency of the solar collectors and ISD systems was 24.07% and 19.11% for ISDC, and 25.28% and 19.21% for ISDS, respectively. The Energy Payback Time (EPT) was 1.61years for ISDC and 1.60 years for ISDS. Ove a 40-year operational lifespan, the systems achieved CO₂ mitigation of 21.78 tonnes and 21.91 tonnes, translating to carbon credit gains of $ 435.60 and $ 438.21, respectively. Overall, the ISDS exhibited marginally superior performance, demonstrating that integrating PCM with sinusoidal absorber geometry can enhance the thermal and environmental sustainability of ISD systems.