Dynamic simulation of solar-powered desalination with integrated photovoltaic/thermal collectors and membrane distillation

This study describes a computational model that simulates the behaviour of a solar-powered desalination system. The model incorporates photovoltaic/thermal (PVT) collectors and direct contact membrane distillation (DCMD). A novel DCMD unit model was established and verified using existing data from the literature and the model was incorporated into the TRNSYS library. The effect of feed water mass flow rate and temperature on production was investigated through a parametric analysis. The PVT-DCMD system was modeled, analyzed, and dynamically simulated for the month of June in Algeria using TRNSYS software. Results show that the PVT collector's outlet solar fluid temperature ranges from 20 °C to 85 °C, providing 5000 kJ/hr of useful energy for seawater desalination through a heat exchanger. Meanwhile, the auxiliary heater utilizes around 10,000 kJ/hr of solar energy. The simulation demonstrates the feasibility and effectiveness of using PVT collectors with a DCMD system for seawater desalination, achieving a distillate production rate of approximately 12 L/hr.m2 of membrane.