A review of waste heat recovery technologies for maritime applications

• Major waste heat sources available on ships have been reviewed.
• A review of suitable waste heat recovery systems was conducted for marine vessels.
• Technologies have been compared for their potential and suitability for marine use.
• Kalina cycle offers the highest potential for marine waste heat recovery.
• Turbo compound system most suitable for recovering diesel exhaust pressure energy.

A waste heat recovery system produces power by utilizing the heat energy lost to the surroundings from thermal processes, at no additional fuel input. For marine vessels, about 50 percent of the total fuel energy supplied to diesel power-plant aboard is lost to the surroundings. While the total amount of wasted energy is considerable, the quality of this energy is quite low due to its low temperature and has limited potential for power production. Effective waste heat recovery systems use the available low temperature waste heat to produce mechanical/electrical power with high efficiency value. In this study a review of different waste heat recovery systems has been conducted, to lay out the potential recovery efficiencies and suitability for marine applications. This work helps in identifying the most suitable heat recovery technologies for maritime use depending on the properties of shipboard waste heat and achievable recovery efficiencies, whilst discussing the features of each type of system.