Advanced exergoeconomic analysis of organic Rankine cycle waste heat recovery system of a marine power plant

Exergoeconomic analysis is based on conventional exergy analysis of a system that reveals exergy destruction costs in components. However, it lacks of evaluating the true destruction cost avoiding potential of each component and the overall system. Advanced exergoeconomic analysis is developed not only to eliminate these issues but also to show avoidable part of investment costs. In this paper, superheated and saturated vapor ORCs as waste heat recovery system of a marine power plant are investigated. First, a parametric study with different organic fluids has been carried out by applying conventional exergy and exergoeconomic analyses to the system in order to identify the best possible operating conditions and also to evaluate outcomes of conventional exergy-based analyses. Then, advanced exergy and exergoeconomic analyses have been performed on ORCs by splitting exergy destruction rates, exergy destruction costs and investment costs of components and overall system to identify avoidable parts of costs and exergy destructions. Finally, conclusions are drawn to provide more information and decision criteria on the selection of more appropriate system depending on the results of the analysis.