Experiment-based feasibility study of LNG equipment-embedded fuel gas supply system for vessels

Abstract

This study introduces and validates an innovative Liquefied Natural Gas (LNG) Equipment-Embedded Fuel Gas Supply System (LEEF) designed for small LNG-fueled vessels. These ships face significant challenges in implementing LNG Fuel Gas Supply Systems (FGSS) owing to limited space and stringent regulatory requirements to reduce Greenhouse Gas (GHG) emissions. The LEEF system addresses these challenges by replacing the external Pressure Build-up Unit (PBU) with an integrated in-tank Electric PBU (EPBU) and vaporizer, enhancing spatial efficiency and safety while reducing LNG leakage risks. The experimental results indicate that the Pressure Rise Rate (PRR) accelerates with higher tank levels and increases the EPBU power. The PRR doubled at higher liquid levels and improved by 30–44 % with increased EPBU power at a constant liquid level. The EPBU effectively maintained the tank pressure against flow variations, achieving pressure control with minimal power. A review of international regulations and codes confirms that the EPBU satisfies explosion-proof standards and ensures stable operation. The LEEF system demonstrated substantial potential for application in small LNG-fueled ships by combining improved spatial efficiency and enhanced safety. This study contributes to the development of the FGSS solution that is more compact and safer compared to conventional systems, encouraging sustainable marine propulsion.