Optimizing solar-driven multi-generation systems: A cascade heat recovery approach for power, cooling, and freshwater production

The pursuit of an optimal solution for performance is essential in ensuring that a solar-driven multi-generation system functions efficiently. Due to the vast amount of solar power received by such systems, the production of significant waste heat ensues. Therefore, this study aims to propose and optimize a new cascade heat recovery method for a solar system that generates power, cooling, and freshwater. The designed configuration encompasses a parabolic trough solar collector to supply the required input energy of integration of a dual-pressure organic Rankine cycle with an ejector refrigeration cycle and an integration of a steam power cycle with a thermal vapor compression- multi-effect desalination. Employing both thermodynamic and economic assessments leads to attaining the performance indexes, which are involved in the optimization procedure. The outcomes of the simulation reveal that the net power, cooling, and freshwater productions are attainted at about 12.56 MW, 2.01 MW, and 138.3 kg/s. Also, the mass fraction 0.5-0.5 is an ideal composition for the highest values of net power and exergy efficiency, and these indexes are highly sensitive to changes in the temperature of vapor generator 3. The optimal operation mode provides an exergy efficiency of 14.76 % and a payback period of 5.49 years. In conclusion, the proposed cascade heat recovery method not only enhances the overall efficiency of the solar-driven multi-generation system but also demonstrates economic viability with a reasonable payback period.