| 摘要 |
<p>PURPOSE:To restrain the fluctuation of BOG liquefying pressure without controlling a flowrate of BOG and LNG fed to a heat exchanger by providing a liquefied BOG storage drum above the heat exchanger, and forming and retaining the liquid level of the liquefied BOG in the heat exchanger. CONSTITUTION:BOG generated in an LNG storage tank 1 is raised in pressure with a BOG compressor 2 and, then, fed to a plate fin type heat exchanger 3. Also, the BOG in the heat exchanger 3 exchanges heat with LNG discharged from the tank l and raised in pressure with an LNG pump 6. Thereafter, the BOG is stored in a liquefied BOG drum 4 laid above the heat exchanger 3. Furthermore, a bypass line 22 is led from a BOG feed line 21 to the drum 4, and a pressure control valve 10 fitted to the bypass line 22 is controlled by measuring the fluctuation of the BOG in the line 21 with a pressure controller 9. Also, the liquefied BOG in the drum 4 is raised in pressure with a liquefied BOG pump 7. Thereafter, the liquefied BOG as pressurized is made to flow together with LNG from the heat exchanger 3, and fed to an LNG vaporizer 5.</p> |
