APPARATUS AND METHOD FOR RELIQUEFYING BOIL-OFF GAS CAPABLE OF STABILIZING OPERATION START-UP

摘要

A method for reliquefying boil-off gas capable of stabilizing operation start-up is provided to maintain stable operation of a compressor and boil-off gas reliquefying equipment by preventing rapid flow rate variation of the boil-off gas when opening inlet valve of an ultra low heat exchanger. A method for reliquefying boil-off gas capable of stabilizing operation start-up comprises the steps of: compressing boil-off gas generated inside an LNG storage tank(1) in a compressor; overcooling and reliquefying the compressed boil-off gas through an ultra low heat exchanger(20); returning the compressed boil-off gas to the LNG storage tank through a gas-liquid separator(30) installed in an end of the ultra low heat exchanger; and allowing nitrogen gas to be supplied to the gas-liquid separator installed in the end of the ultra low heat exchanger so that pressure of the gas-liquid separator is equal to pressure of an end of the compressor before starting boil-off gas reliquefying operation.