مرضیه بابایی ربیعی

This study investigates three configurations of power and freshwater cogeneration systems, addressing the urgent energy and freshwater availability challenges. The configurations consist of open Brayton, steam Rankine, and organic Rankine cycles. A water-heated humidification-dehumidification system with a closed-air open-water cycle is employed for water desalination. In parallel arrangement (first cycle), the exhaust gases from the heat recovery boiler enter a vapor generator. In series arrangement (second and third cycles), the organic Rankine cycle is connected to the steam Rankine cycle and utilizes the rejected heat from the steam Rankine cycle’s condenser. The thermodynamic analysis, conducted based on parallel or series arrangements of the open Brayton, steam Rankine, and organic Rankine cycles and also different locations of the humidification-dehumidification system reveals that the first configuration exhibits the best performance with 7.2% and 8.9% improvement in energy efficiency compared to the second and third cycles, respectively. It has 9.5 and 2.1 times the freshwater production capacity of the second and third configurations, respectively. Moreover, a heliostat field and solar tower are integrated into the first cycle with an open Brayton cycle’s power capacity of 1 MWe. The results demonstrate that the cycle can generate an impressive 1985 kW of electric power and 1.74 kg/s of freshwater, with energy and exergy efficiencies of 39.6% and 35.8%, respectively. The solar system reduces fuel consumption by 67.9%, while the flow rate ratio of freshwater to fuel touches the amazing value of 41.8, signifying a substantial leap forward from current solar cogeneration models.