气化站回收利用LNG槽车BOG工艺方案研究

Study on process scheme for LNG tanker BOG recycling in gasification station

目的以LNG作为气源供应的气化站或加气站,由于当前LNG卸车工艺原因,在LNG槽车卸车后,其储罐内仍残存一定量已付费却无法利用的BOG气体。针对此普遍问题,研究回收BOG的有效办法。方法以某气化站为研究实例,通过计算LNG槽车储罐内可回收BOG量,结合回收BOG状态参数、气化站卸车和运行工艺流程,制定出相应的工艺改造方案。结果模拟拟选主要设备运行工况,绘制出单级及两级压缩机排气量、功率随时间变化的状态图,以及槽车储罐内BOG压力、余量随时间变化的状态图,直观地比对出拟选型设备的功效。结论在气化站回收LNG槽车BOG的工艺改造方案中,选用两级低温压缩机可有效减排和降低槽车卸车损耗,其更具优势。

Objective For the gasification station or gas filling station that uses LNG as the gas source,due to the current LNG unloading process,after the unloading of LNG tanker,there is still a certain amount of paid but unusable BOG in storage tank.In view of this common problem,an effective method for recovering BOG is studied.Methods Taking a gasification station as an example,by calculating the recoverable BOG amount in the LNG tanker storage tank,combined with the recovered BOG state parameters,the unloading and operation process flow of the gasification station,the corresponding process transformation scheme is formulated.Results The operation conditions of the main equipment to be selected are simulated.The state diagram of the exhaust capacity and power changing of the single-stage and two-stage compressors with time,and the state diagram of the BOG pressure and margin changing in the tanker with time are drawn.The efficiency of the equipment to be selected is compared visually.Conclusions In the transformation scheme of LNG tanker BOG recovering process in the gasification station,the selection of two-stage low-temperature compressor can reduce the emission and the unloading loss of tanker effectively,which has more advantages.