BOG reliquefaction process in LNG filling station

In order to reduce the environmental pollution and energy dissipation caused by direct BOG venting in LNG filling station, taking the 1×10⁴ m³/d capacity of LNG filling station as an example, the BOG volume per day is calculated. BOG reliquefaction process applied in this LNG filling station is simulated by HYSYS, and refrigeration grid is optimized step by step. Then, the required LNG flowrate for BOG reliquefaction in this station is calculated. For the LNG filling station, the BOG reliquefaction can be realized with the addition of one set of BOG reliquefaction plant (including 1 BOG compressor, 1 BOG buffer tank, 1 recondenser and 1 pressure regulating valve). After parameters at each node of the process are adjusted, when the LNG flowrate reaches 90 kg/h, BOG is condensated completely. The BOG is condensated in this process by using LNG cold quantity, and reinjected into the LNG tank. In this way, the BOG recovery is improved so as to realize its circulation in the LNG filling station and accordingly ensure the tank temperature and pressure within a certain range, and the LNG cold energy waste can be effectively reduced.