Concentrated photovoltaic and thermal system application for fresh water production

Abstract

This study was conducted to investigate the performance of Concentrated Photovoltaic/Thermal system (CPV/T) coupled with direct contact membrane distillation (DCMD) for saline water desalination. A numerical heat and mass flux model was constructed to investigate the feasibility of freshwater production. The average electrical efficiency was found to be about 18%, while thermal efficiency increased to an average of 25% and the total efficiency reached an average of 71%. The CPV/T efficiency with the cooling loop reached 19.26% at the peak time of the process. Eventually, the DCMD produced 3 kg/m2/h of fresh water and consumed thermal energy of about 9200 kJ/kg water. Moreover, the water mass flux decreased from 3 L/m2/h to 1.8 L/m2/h in a nonlinear manner. When the gain output ratio (GOR) of the system reaches 2.6 efficiency value or greater, the water outlet temperature from the CPV/T can increase along with the water permeate flux produced by the coupled system. In contrast, if the temperature of the outlet water from the CPV/T system is low, the feed water temperature in the heat exchanger also decreases. As a result, a significant decrease is observed in the feed inlet temperature of the DCMD module.