Operation-dependent exergetic sustainability assessment and environmental analysis on a large tanker ship utilizing Organic Rankine cycle system

This study focuses on the novel perspective of marine ORC systems with a detailed marine diesel generator plant simulation integrated with an ORC system model to evaluate environmental impacts and energy efficiency increments by reducing the number or the load of generators by using the ORC system support during operation. It is aimed to analyze the fuel-saving potential and sustainability performance of the power generation plant of a tanker ship when an ORC is integrated. The thermodynamic system simulation determined the fuel consumption of the plant within two years regarding six operation modes. The results show that the optimum working fluid is R1336mzz (Z) for the evaporation pressure of 16 bar. Organic Rankine cycle system integration provided a total fuel-saving of 15% from diesel generators and the total fuel consumption of the vessel was reduced by 5.16%. The sustainability performance of the system was ensured with a novel operation-dependent approach that enhances the exergetic sustainability assessment by considering the operation modes of the vessel and the time spent on these operations for a certain time. The load reduction in the generators resulted in better sustainability performance and the operation-dependent indicators were affected by operations having more working hours.