A comparison of advanced heat recovery power cycles in a combined cycle for large ships

Ulrik Larsen, Oskar Sigthorsson, Fredrik Haglind

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Abstract

Strong motivation exists within the marine sector to reduce fuel expenses and to comply with ever stricter emission regulations. Heat recovery can address both of these issues. The ORC (organic Rankine cycle), the Kalina cycle and the steam Rankine cycle have received the majority of the focus in the literature. In the present work we compare these cycles in a combined cycle application with a large marine two-stroke diesel engine. We present an evaluation of the efficiency and the environmental impact, safety concerns and practical aspects of each of the cycles. A previously validated numerical engine model is combined with a turbocharger model and bottoming cycle models written in Matlab. Genetic algorithm optimisation results suggest that the Kalina cycle possess no significant advantages compared to the ORC or the steam cycle. While contributing to very high efficiencies, the organic working fluids possess high global warming potentials and hazard levels. It is concluded that the ORC has the greatest potential for increasing the fuel efficiency, and the combined cycle offers very high thermal efficiency. While being less efficient, the steam cycle has the advantages of being well proven, harmless to the environment as well as being less hazardous in comparison.
Original languageEnglish
JournalEnergy
Volume74
Pages (from-to)260–268
ISSN0360-5442
DOIs
Publication statusPublished - 2014
Event26th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems - Guilin, China
Duration: 16 Jul 201319 Jul 2013
Conference number: 26

Conference

Conference26th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems
Number26
CountryChina
CityGuilin
Period16/07/201319/07/2013

Keywords

  • Ship propulsion
  • Heat recovery
  • Organic Rankine cycle
  • Kalina cycle
  • Steam Rankine cycle

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