SYSTEM FOR TREATING BOIL-OFF GAS FOR A SHIP

摘要

The present invention relates to a system for treating boil-off gas for a ship in which the boil-off gas that is discharged from a storage tank is pressurized and then most of the pressurized boil-off gas is used as the fuel of a high-pressure natural gas injection engine of the ship and the rest is returned to the storage tank through liquefaction with the cold heat of boil-off gas which is newly discharged from the storage tank so that the boil-off gas can be used efficiently. According to the system of the present invention for treating boil-off gas for a ship, which is provided with the storage tank storing liquefied natural gas and the engine using the liquefied natural gas stored in the storage tanks as the fuel, includes a first stream of the boil-off gas that is discharged from the storage tank after generation from the liquefied natural gas in the storage tank; a second stream of the boil-off gas that branches from the first stream and is supplied to the engine as the fuel when the amount of the first stream is greater than the amount of the fuel required by the engine; and a third stream of the boil-off gas that is a part of the first stream which is not supplied to the engine. The third stream is liquefied in a heat exchanger through heat exchange with the first stream, and thus the boil-off gas can be treated without having to use a re-liquefaction device having an additional refrigeration cycle.