Lng / lpg Combine line reliquefaction system and a fuel supply method

The invention LNG / LPG Combine relates to a re-liquefying system and the fuel supply line method, LNG storage LNG boil-off gas circulation line for circulating the gas in the evaporation tank to the outside; The evaporated LNG is installed on the gas circulation line LNG gas-liquid separator to separate the mutually LNG boil-off gas and LNG liquid fuel; LNG boil-off gas compressor in which the LNG gas-liquid separator installed in the rear side LNG boil-off gas circulation line; Engine fuel supply line which is branched from the LNG boil-off gas circulation line supplying a portion of the boil-off gas discharged from the LNG boil-off gas compressor to the engine; LNG boil-off gas jaeaek weapon installed in the LNG boil-off gas circulation line; LPG boil-off gas circulation line for circulating the evaporated gas in the LPG storage tank to the outside; LPG boil-off gas compressor installed in the LPG boil-off gas circulation line; And LPG boil-off gas jaeaek firearms which are mounted to the LPG boil-off gas circulation line;, suctioning the liquid fuel in the LNG storage tank to the outside of the LPG boil-off gas jaeaek fire, after passing through the LNG gas-liquid separator in order again LNG storage tank comprising a including LNG liquid fuel supply means to return to is characterized in that configured. In this way, not only to cool the LPG boil-off gas in a more efficient, even if the first loading operation the fuel stored in the LNG storage tank is effective to perform the operation of the re-liquefied boil-off gas LPG reliably.