With the increasing emphasis of the international community on low-carbon and emission reduction, LNG fuel, as the most important transitional clean energy, has received more attention. Some shipowners have begun to retrofit their fleets with clean fuel power, but there are some difficulties in the retrofitting of fuel power systems for large ships. The LNG power retrofitting of a 15 000 TEU large container ship has been examined to analyze and study several design methods for the retrofitting of the new fuel system by focusing on the LNG fuel tank, main engine, generator and boiler, gas supply system, filling system and auxiliary system. This study can provide a design method as a reference for the ship retrofitting of the new fuel power system.

Liquefied natural gas (LNG) becomes widely used in ship industry as it is a kind of green fuel. The thermal and physical parameters of the different LNG components are compared and calculated based on the design of a 210 000 ton dual fuel bulk carrier, such as their boiling point, density, heating value of evaporation, enthalpy, composition of evaporation gas, low heating value and methane number. The value and deviation range of the boil-off rate of the marine LNG fuel tank and the critical gas supply parameter of the dual fuel engine are quantitatively analyzed and calculated corresponding to the different LNG fuel compositions. Some reasonable suggestions are provided for the practical application of LNG as marine fuel.