The dual fuel engine and generator can meet the requirements of International Maritime Organization (IMO) for the emission of nitrogen oxides and sulfide, and can reduce the emission of carbon dioxide and particulate matter, when using the liquefied natural gas (LNG), a clean energy source, as fuel. The objective of the current study on the application of the fuel gas supply system is how to ensure the safe use of LNG as fuel, which is also the main requirement of the International Code of the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk(IGC Code). This paper introduces the design of a set of fuel gas supply systems for a LNG bunker vessel with one main engine and two generators. The main gas valve design, ventilation flow calculation and dangerous region setting that are required in the IGC Code are calculated, studied and analyzed. The design requirements of one main valve for several devices in the fuel gas supply system that meets the IGC Code is summarized. The optimized system design can meet the requirements of the ICG Code for the safe use of LNG fuel.

Floating production storage and offloading (FPSO) unit is an offshore oil and gas processing unit that integrates the ship hull system, topside oil and gas processing system, mooring system and export system. The system of FPSO is very complex and easy to cause serious accidents in case of oil and gas leakage. The firefighting system is the important subsystem of FPSO ship system and the important guarantee for personnel and production. The fire situation in the fire compartment has been analyzed to configure the reasonable extinguishing methods aiming at the rationality of the firefighting system design and the equipment selection for the internal turret moored FPSO. A calculation method for the firefighting system of the internal turret FPSO is then proposed based on the relevant rules and regulations. It can improve the safety and reliability of the firefighting system design and ensure the safety of the FPSO production and the crew safety. This firefighting system calculation method is critical to the design of the firefighting system and the equipment selection. It can provide reference for the design of the FPSO firefighting system.