Thermal design and zeotropic working fluids mixture selection optimization for a solar waste heat driven combined cooling and power system

• Published in: Chemosphere (Oxford) 2023-09, Vol.335, p.139036-139036, Article 139036
• Main Authors: Kheimi, Marwan, K. Salamah, Sultan, A. Maddah, Hisham, Mustafa Al Bakri Abdullah, Mohd
• Format: Article
• Language: English
• Subjects: Combined cooling and power system; Economic analysis; Exergy efficiency; Multiobjective optimization; Solar flat plate collector; Zeotropic mixture
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2023.139036

Considering the limitation of fossil fuel resources and their environmental effects, the use of renewable energies is increasing. In the current research, a combined cooling and power production (CCPP) system is investigated, the energy source of which is solar energy. Solar energy absorbs by solar flat plate collectors (SFPC). The system produces power with the help of an organic Rankine cycle (ORC). An ejector refrigeration cycle (ERC) system is considered to provide cooling capacity. The motive flow is supplied from the expander extraction in the ERC system. Various working fluids have been applied so far for the ORC-ERC cogeneration system. This research investigates the effect of using two working fluids R-11 and R-2545fa, and the zeotropic mixtures obtained by mixing these two fluids. A multiobjective optimization process is considered to select the appropriate working fluid. In the optimization design process, the goal is to minimize the total cost rate (TCR) and maximize the exergy efficiency of the system. The design variables are the quantity of SFPC, heat recovery vapor generator (HRVG) pressure, ejector motive flow pressure, evaporator pressure, condenser pressure, and entertainment ratio. Finally, it is observed that using zeotropic mixtures obtained from these two refrigerants has a better result than using pure refrigerants. Finally, it is observed that the best performance is achieved when R-11 and R245fa are mixed with a ratio of 80 to 20%, respectively and led to 8.5% improvement in exergy efficiency, while the increase in TCR is only 1.5%. [Display omitted] •A thermoeconomic study of a solar based multi-generation system is done.•A zeotropic mixture selection study is done to find the best working from exergy efficiency and total cost rate point of view.•A parametric study is conducted and the effect of design parameters on exergy efficiency and total cost rate is considered.•A multiobjective optimization is conducted and the Pareto front is drawn.