A FUEL GAS SUPPLY SYSTEM OF LIQUEFIED NATURAL GAS AND METHOD FOR REFUELING LIQUEFIED NATURAL GAS

摘要

The present invention relates to an LNG fuel supply system and an LNG refueling method. The LNG fuel supply system of the present invention includes: an LNG storage tank which stores LNG which is supplied to an engine; a pump part which pressurizes LNG which is discharged from the LNG storage tank; a heat exchanger which heats the LNG which is pressurized by the pump part and supplies the heated LNG to the engine; and LNG refueling equipment which is installed by being connected to the LNG storage tank and is combined with an LNG refueling tank. The LNG refueling equipment includes: an LNG refueling valve part which is combined with the LNG refueling tank at one end and is installed in an LNG refueling line part which is connected to the upper and lower parts of the LNG storage tank at the other end; and an outlet valve which is automatically closed by sensing an LNG refueling state if the LNG refueling valve part is opened and is installed in a fuel supply line by being connected to the lower part of the LNG storage tank at one end and being connected to the pump part at the other end. The LNG fuel supply system and the LNG refueling method according to the present invention are able to smoothly refuel the LNG storage tank with LNG while maintaining a pressure difference between the LNG refueling tank and the LNG storage tank by: lowering an internal pressure of the LNG storage tank during the LNG refueling by using a second LNG refueling valve and a pressure control valve connected and installed in the upper part of the LNG storage tank; and including the LNG refueling equipment which prevents an automatic LNG discharge during the LNG refueling in the LNG storage tank by using the outlet valve which is connected and installed in the lower part of the LNG storage tank.