Multi-objective optimizations and exergoeconomic analyses of a high-efficient bi-evaporator multigeneration system with freshwater unit

• Published in: Renewable energy 2022-05, Vol.191, p.699-714
• Main Authors: Cao, Yan, Dhahad, Hayder A., Alsharif, Sameer, Sharma, Kamal, El.Shafy, Asem Saleh, Farhang, Babak, Mohammed, Adil Hussein
• Format: Article
• Language: English
• Subjects: Bi-evaporator systems; Exergoeconomic analyses; NSGA-II; Solar-geothermal energy; Two-objective optimizations
• ISSN: 0960-1481
• DOI: 10.1016/j.renene.2022.04.030

Due to the ubiquitous, cost-effective, and environmentally friendly characteristics of renewable energies, employing renewable energy sources has become an inevitable part of new-designed energy systems. In this regard, the present study proposes a multi-generation system with the potential of power, cooling, and freshwater production by utilizing geothermal and solar energies at the same time. The proposed system consists of two evaporators operating at above and below zero temperatures and a humidification and dehumidification desalination system for freshwater production. Along with the parametric evaluations based on thermodynamic and exergoeconomic perspectives, two-objective optimizations are conducted by employing the NSGA-II method. The results show that cooling capacity and energy efficiency increase by an increment of the temperature of the flashing separator, evaporator 1 and 2. Besides, increasing the temperature of evaporator 2 leads to lower hydrogen and net electricity production. The results indicate that the exergy-cost case of optimization correspondingly leads to exergy efficiency and overall unit cost of products of 20.82% and 0.144 $/kWh. Also, the maximum value of cooling is produced in the energy-cost optimization, when the objective function is the energy efficiency, which is equal to 848.9 kW with a 48.16% improvement compared to the base state. •Using solar-geothermal energy to produce power, cooling, and freshwater.•Evaluation of the proposed system by parametric study and two-objective optimizations.•Outputs at the base case are 548.4 kW electricity, 569.1 kW cooling, and 3.436 m3/day freshwater.•Based on energy-cost optimization, the overall unit cost of products is obtained 0.146 $/kWh.•Based on exergy-cost optimization, energy and exergy efficiencies are obtained 21.91% and 20.82%.