Thermodynamic Performance Assessment of a Combined Micro Humid Air Turbine and Organic Rankine Cycle System for Maritime Application

For centuries, maritime transport has remained among the most vital means of connecting the world. The shipping industry is currently under great pressure to reduce its environmental impact. One method of reducing carbon emissions are highly efficient power generation systems. Interest in ensuring reliable power, and controlling energy costs, has led to advanced power generation technologies on land. Large ships are considered as an ideal entry point to the offshore market for these technologies. This study proposes a novel power generation system for installation in seagoing vessels either as the main prime mover or as an auxiliary power unit system. The proposed plant includes a 1 MW micro humid air turbine system fed by liquefied natural gas (LNG) combined with organic Rankine cycle (ORC) system for recovering waste exhaust heat from the turbine and converting it to useful power. The findings of this study show that the proposed plant for marine vessels can achieve an electrical efficiency of 54.95 % where both liquefied natural gas and required make-up water for inlet air humidification are available. It was also found that integration of the ORC system leads to 5 % increase in the net electrical efficiency of the baseline humid air turbine system.