| The energy crises caused by the rapidly increasing population density around the world and the economic, environmental and health threats, that have reached significant dimensions, emphasize the importance of the concept of sustainable energy more and more every day. For this reason, to ensure the sustainability of energy, not only sustainable energy sources, but also optimum system designs are developed, which can be integrated with these sources and where waste heat recovery mechanisms are effective. At this point, Rankine cycle systems (RCSs) are an extremely good opportunity to close this gap due to their structural features. In this study, we grouped the RCSs existing in the literature and made a comprehensive evaluation of these systems from broad perspectives, such as exergo-economics, exergoenvironment, optimization, and system design, results and effects. The potential system designs revealed by compiling studies in the literature for the system type in question, through the novel general system description figures, were drawn with a completely original approach. For comparing the system designs in the studies examined with each other more easily and seeing the possible effects, the systems considered were originally and completely drawn by the authors of this paper, based on the principle of standardization. We summarized the examined study in terms of system design, the applied energy, exergy, economic analyzes and optimization processes, the obtained general results, input and output parameters affecting the system and their interaction with system components in a single table with novel flow chart tables. We presented an effective, easy-to-understand comparison method based on a strong visualization principle and expect that in this way one can inspire potential studies and understand easily the gaps in the literature. Also, we prepared a novel comprehensive comparison table for all types of RCSs in terms of techno-economic and environmental considerations. The main findings indicated that the maximum power, heating and cooling output rates, thermal and exergy efficiency values, mean total production cost rate, payback period and greenhouse gas emission ranges were 1040–329750 kW, 15.2–2500 kW, 567–22500 kW, 12.8–73.8%, 51.6–75.5%, 85.39 $/h, 3.6 years and 0.098 t/MWh, respectively, for cogeneration RCSs. The mean greenhouse gas emission, total production cost rate and payback period values were lower compared to other RCS types with higher exergy efficiencies and production outputs. It may be concluded that in terms of exergoeconomic and environmental perspectives, cogeneration RCSs form a better optimum configuration for many cases with utilization of influent waste heat recovery opportunities compared to other choices. |
Arş. Gör. Aslı TİKTAŞ
Hüseyin Günerhan
