LNG加气站槽车BOG压缩液化回收研究

近年来,在LNG加气站快速发展的同时,LNG车辆发展相对缓慢,导致LNG加气站蒸发气(boil-off gas,简称BOG)量较大,特别是LNG槽车卸车后残余压力为0.2～0.4 MPa的BOG,给LNG加气站带来了较大的经济损失和安全隐患。提出了基于BOG压缩机的BOG压缩液化工艺和装置,利用LNG冷量回收BOG,实现加气站BOG零排放。在此基础上,搭建了实验装置,并采用液氮和LNG开展了BOG回收实验。实验数据表明,当BOG和LNG质量比为3%时,该工艺BOG液化回收率在90%左右。由此可知,该工艺可以实现槽车的BOG快速高效回收。

Research on BOG compression and re-liquefaction of LNG cargo at LNG filling station

In recent years, with the rapid development of LNG filling station, the amount of boil-off gas(BOG) is very large because of the relatively slow development of LNG vehicles. Especially after LNG unloading for the LNG tanker, the pressure of BOG is 0.2 to 0.4 MPa. The BOG process related to energy consumption and safe operation is one of the critical issues that should be considered at LNG filling station. A set of BOG compression and re-liquefaction process and equipment is established by using the LNG cold energy to recover BOG to avoid energy dissipation and environmental pollution caused by BOG direct discharge. A BOG recovery experimental setup is built and some experiments are carried out with liquid nitrogen and LNG. The results show that the ratio of BOG recovery is 90% when the ratio of BOG and LNG is 3%. Accordingly, the process of BOG compression and re-liquefaction is an effective way for BOG recovery.