Water recovery of drying waste using a thermoelectric cooler and PV/T assisted.

Abstract

Energy, food, and water are the most essential demands for the human community. In this study, a novel hybrid solar photovoltaic/thermal (PV/T) solar dryer integrated with a water recovery unit is designed, developed, and experimentally evaluated for drying agricultural products. The system combines a PV/T air collector that simultaneously generates electricity and hot air with a thermoelectric cooling (TEC) unit that condenses water vapor from the drying exhaust. This theoretical research aims to develop a new concept for drying systems based on thermoelectric coolers, using PV/T as a solar collector and an electric supplier. The scientific innovation lies in utilizing the waste heat from the hot side of the TEC units and introducing it into the drying chamber to enhance the evaporation rate. Meanwhile, the water vapor expelled through the cold side of the units is condensed, transforming the drying-to-drinking (D2D) process without energy or mass loss. Furthermore, drying 1 kg of tomato leads to two sources of condensed water (tomato moisture + atmospheric water). While an airflow rate of 0.05 kg/s corresponds to an inlet of atmospheric air at 1440 kg during 8 h, the water recovery unit produced nearly 3.9 L of water during an 8-hour drying cycle. Thus, addressing the dual challenge of food preservation and water scarcity.