A comprehensive review on organic Rankine cycle systems used as waste heat recovery technologies for marine applications

ABSTRACT

In the field of marine engineering, there is a strong motivation to increase the propulsion system efficiency, mainly due to rising fuel prices and the new environmental and technological regulations concerning worldwide shipping. In this regard, organic Rankine cycle (ORC) has been considered and adapted as a promising waste heat recovery technology to convert the main waste heat sources on marine applications into useful power. This study aims at presenting a comprehensive review of the marine ORC systems and the potential waste heat recovery options on marine vessels from the marine engineering point of view. The selection criteria of ORC equipment and working fluid type for any power range of marine applications are discussed. This review shows that ORC system configurations for marine vessels proposed in the literature have conversion efficiencies less than 20%, while LNG waste heat utilization might boost it up to 35.6%, and combined cycle arrangements with ORC could recover up to 58.4% of the delivered waste heat. The latest marine ORC demonstration project reports indicate that marine vessels could save at least 3% of their fuel consumption with the utilization of marine ORC systems. The payback time of these investments is stated to be around 4 years. As a result of the synthesis of the results and discussion found in the reviewed papers, this study shows that these systems propose many possibilities for reducing the environmental effects of marine vessels while increasing their energy efficiency and sustainability level; however, there are also several technical and economical challenges with the use of marine ORC systems.

KEYWORDS:

• Organic Rankine cycle
• waste heat recovery
• energy
• marine engineering
• ship

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Acknowledgments

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Disclosure statement

No potential conflict of interest was reported by the author(s).