Energy and exergoeconomic assessments of a renewable hybrid ERC/ORC integrated with solar dryer unit, PEM electrolyzer, and RO desalination subsystem

Abstract

In this investigation, a zero-dimensional model of a renewable generation system encompassing a solar-geothermal driven Proton Exchange Membrane (PEM) electrolyzer integrated with Organic Rankine Cycle (ORC), Ejector Refrigeration Cycle (ERC) and Reverse osmosis (RO) unit is expressed with respect to energetic, exergetic, economic, and exergoeconomic points of view. Cooling and heating energies, electricity, distilled water, Hydrogen (H2), Oxygen (O2) are the key products of the mentioned system. In order to acquire the influences of the solar collector numbers, area ratio, and pressure drop of the ejector and working fluid of solar collectors on the efficiency of the hybrid unit, a set of equations were coded in MATLAB and Engineering Equation Solver (EES). The exergy destruction rate, exergy efficiency, and exergy destruction ratio of each subsystem and exergy flow diagram of all subsystems were evaluated in this study. Afterward, the results of the sensitivity analysis were used for multi-criteria optimization in three various layouts that the LINMAP as well as the fuzzy TOPSIS decision makings and Gray Wolf Optimizer (GWO), are considered to get the optimal result. The results have indicated that the main variables analyzed are more affected by the variation in the number of the flat plate solar collector. Besides, in the second optimization scenario, the TOPSIS selects the optimal solution of exergy efficiency and unit exergy cost of the product of 3% and 19.77 $/Gj, while the LINMAP selects 3.001% and 19.80 $/Gj point.