BOG (boil-off gas) treatment process and device under normal operation condition of LNG (liquefied natural gas) receiving station

The invention discloses a BOG (boil-off gas) treatment process and device under normal operation condition of an LNG (liquefied natural gas) receiving station. The treatment process includes the steps: conveying BOG from an LNG storage tank into a low-pressure BOG compressor, pressurizing the BOG to reach 0.5-0.8MPaG, reaching the outlet temperature of 0-5 DEG C and then enabling the BOG to enter an LNG/BOG heat exchanger; conveying LNG into the LNG/BOG heat exchanger by a low-pressure LNG pipeline from an LNG low-pressure pump, exchanging heat with the BOG at an outlet of the low-pressure BOG compressor and finally condensing the BOG into liquid; enabling condensed BOG condensate to a BOG condensate buffer tank; arranging a nitrogen pipeline on the BOG condensate buffer tank and maintaining the pressure of the buffer tank at 0.6MPaG; enabling the condensate from the BOG condensate buffer tank to enter a pressurizing pump, pressurizing the condensate to reach 1.0MPaG, conveying the condensate to an LNG tank car for loading, and treating the BOG. The treatment process has the advantages of reasonable design, simplicity in control, easiness in operation, convenience in mounting and the like, a horizontal LNG/BOG shell-and-tube or shell-and-plate heat exchanger replaces a previous overhead re-condenser, construction difficulty is greatly reduced, and safety can be improved.