Method and apparatus for handling a boil-off gas stream

摘要

A boil-off gas (BOG) stream (15) from a liquefied hydrocarbon storage tank is split into a BOG heat exchanger feed stream (25) and a BOG bypass stream (35). The BOG heat exchanger feed stream (25) is heat exchanged in a BOG heat exchanger (40) against a process stream (135), thereby providing a warmed BOG stream (45) and a cooled process stream (195). The warmed BOG stream (45) is combined with the BOG bypass stream (35) to provide a temperature controlled BOG stream (55). Herein, the mass flow of the process stream (135) is controlled in response to a measured first temperature of at least one of (i) the warmed BOG stream (45) and (ii) the cooled process stream (195) to move the measured first temperature towards a first set point temperature; and the mass flow of one or both of the BOG heat exchanger feed stream (25) and the BOG bypass stream (35) are controlled in response to a measured second temperature of the temperature controlled BOG stream (55), to move the measured second temperature towards a second set point temperature.