Solar-driven mechanical vapor compression desalination equipped with organic Rankine cycle to supply domestic distilled water and power – Thermodynamic and exergoeconomic implications

Abstract

Abstract The world will need the utilization of renewables as fossils are phased out. In this between, solar energy has gained much attention. A Mechanical Vapor Compression desalination system, driven by a concentrated photovoltaic/thermal is proposed. The proposed co-generation system is analyzed using thermodynamic and economic principles. Absorbed heat from panels is utilized to run an organic Rankine cycle. Produced power by the organic Rankine cycle and panels is supplied as the electricity demand of a hypothesized neighborhood and surplus power is utilized to generate freshwater by desalination unit. On the other hand, to generalize the obtained results, a sensitivity analysis is carried out for both summer and winter conditions to analyze the effect of solar radiation on the system’s performance. Under the base condition and considering solar radiation of 500 W/m2, the produced electricity by the solar panels and organic Rankine cycle are found to be 43.43 kW and 33.27 kW, respectively. Also, 38.7 kW overproduced electricity is utilized to produce 141 m3/d distilled water. Furthermore, it is revealed that the highest investment cost belongs to the evaporator/condenser unit of the desalination unit followed by the employed compressor with 24.1% and 22% of the total capital investment cost, respectively. Moreover, a total exergoeconomic factor of 20.1% is obtained for the entire system indicating that 79.9% of total costs are related to the exergy destruction.