LNG船舶气试工艺及方案实施要点

Analysis on LNG Vessel Gas Test and Its Implement Key Points

以LNG船舶"闽榕"号、"闽鹭"号的气试过程为例,介绍了LNG船舶气试的基本流程,分析了气试作业过程的关键点及优化措施,主要包括LNG船舶状态、系统隔离、储罐降压、BOG置换等;发现在LNG码头气试流程已经确定情况下,"闽鹭"号气试时间仅为29.6 h,消耗LNG为1 020 m^3。实践表明,在气试流程已经优化的条件下,保持LNG船舶货舱CO_2的体积分数在0.1%左右、N_2体积分数在98%以上,对提高气试作业的安全和效率有明显效果。

Gas test is a key process before LNG carrier transportation, with complex procedure and strict safety requirements. Thus, it is necessary to analyze and optimize the gas test procedure. This paper, by taking Fujian LNG terminal gas test experience as an example, in-troduces the basic process of LNG carrier gas test, and analyzes its key points and optimization measures, including LNG carrier status, sys-tem isolation, tank depress, BOG replacement. In Apr.2009 and Jan.2010 respectively, 16 ten thousand cdm GTT LNG carrier “Minron” “Minlu” gas test were carried out in given condition . In this gas test , “ Minlu” time - consuming was only 2 9 .6 hours and the LNG amount used was only 1 020 m3 . Practice shows that the gas test efficiency and safety could significantly improve when the content of C02 is sufficiently reduced and the volume fraction of N2 is above 98 % .