Techno-economical analysis of single pressure exhaust gas waste heat recovery systems in marine propulsion plants

摘要

In this article, the waste heat recovery (WHR) installations used for the production of saturated steam and electric power for the cases of a two-stroke and a four-stroke engine propulsion plant of a typical merchant ship are investigated. The examined WHR system is considered to be of the single steam pressure type with an external heat exchanger for the heating of feed water entering into the boiler drum. The option of using the engine air cooler for heating the feed water was also examined. The WHR installation was modeled under steady-state conditions, and the derived WHR installation parameters for various engine loads are presented and analyzed. Furthermore, using the simulation results, the improvement of Energy Efficiency Design Index (EEDI) of the examined ship is calculated, and the impact of the WHR on the ship EEDI is discussed. In addition, following the technical evaluation of the alternative options for the ship propulsion plant, an economic study was performed for a typical ship voyage. The derived results were presented and discussed leading to conclusions for the most techno-economical propulsion system configuration.