Improving multi-stage solar desalination efficiency through vibration-induced frequencies and grooved condenser technology

Abstract

Nowadays, multi-stage solar desalination systems have attracted considerable interest because of their passive and efficient nature, compared to traditional solar desalination. The most important advancement in these systems involves minimizing energy loss from evaporation to condensation by reducing the distance between the evaporator and condenser, along with using the heat released during condensation in the previous stage to raise the evaporator's temperature in the next stage. We propose enhancing the efficiency of multi-stage solar desalination systems integrated with photovoltaic (PV) panels by incorporating water-collecting grooves (12, 24, 36 grooves at angles of 30°, 45°, 55°, 65°) in the condenser and applying vibrations across five frequencies (0–49.63 Hz). Our results reveal that adding grooves to the condensers in each stage, with 36 grooves at a 65-degree angle, led to a 31% improvement in freshwater production over the baseline system. The effect of the frequency induced by the cooling fan's vibration also shows that adding a fan and cooling generate a frequency of 63.49 Hz at 3200 rpm, improving freshwater production by 87.5% compared to a simple 4-stage system. The exergy efficiency of the system also improves from 27.9% for the reference system to 40% for the best system (grooves/fan/vibration).