12th Global Conference on Global Warming (GCGW-2024), 16 - 19 Mayıs 2024, ss.531-534
This study aims to thermodynamically analyze a novel organic Rankine cycle system design working under
vacuum conditions for a marine vessel propelled by liquified natural gas (LNG)-powered main engines. While
the main engines are fed by LNG fuel, the cold waste heat of the LNG is utilized in the condenser of the
analyzed vacuum ORC system. The waste heat sources of jacket cooling water and exhaust gas were utilized.
The condenser was cooled by LNG fuel. A parametric study was carried out for main engine MCR loads of
50% and 100%, and condensation tank pressure was set to 55 kPa. The results showed that the highest
energy efficiencies for all organic fluids were achieved with 50% MCR engine load and 7 kg/s high-pressure
pump mass flow rate. The best performance was yielded with R600 with 16.00% thermal efficiency for 800
kPa evaporation pressure. It is obtained that low-pressure waste heat recovery with an ORC system can be
feasible by utilizing mostly used ORC working fluid for marine vessels using LNG as fuel.