液化天然气取样单元性能评价方法及应用研究  

Performance evaluation method and application research of LNG sampling unit

作　　者：刘冰[1] 田靖 邢楠[1] LIU Bing;TIAN Jing;XING Nan(CNOOC Gas and Power Group,Beijing 10002&China)

机构地区：[1]中海石油气电集团有限责任公司,北京100028

出　　处：《天然气化工—C1化学与化工》2021年第1期34-37,89,共5页Natural Gas Chemical Industry

摘　　要：进口液化天然气(LNG)的船运交接涉及近亿元人民币的贸易结算。由于尚无贸易级别的分析仪器直接计算交接能量,需要对LNG进行取样预处理,再分析气态样品的组成和能量。而针对LNG的超低温特性,任何温度压力的变化都易导致其提前气化,进而影响交接精度。分析了取样预处理单元易发生失效的关键技术环节,提出了评估取样预处理单元性能的方法,总结了LNG接收站日常开展数据比对评估的方法,并通过计算实例介绍了评价过程和评价指标。结果表明:持续保冷、确保气化完全、监控调节是三个关键技术要素;气化器的出/入口、加热温度及气化器出口流量是侧面反映预处理单元可靠性能的关键指标;实验室离线分析数据与货源地的数据比对、在线实时数据的不确定度评价方法,均可作为评价预处理单元性能的有效方法。该方法不仅适用于LNG接收站,在LNG运输船、液化工厂、加注站等多种LNG能量分析场合都具有参考价值。The delivery of imported liquefied natural gas(LNG)involves nearly 100 million yuan of trade settlement.Since there is no trade grade analytical instrument to directly calculate the transfer energy,it is necessary to sample and pretreat LNG,and then analyze the composition and energy of gaseous samples.In view of the ultra-low temperature characteristics of LNG,any change of temperature and pressure will easily lead to its early gasification,which will affect the handover accuracy.This paper analyzed the key technical links of the sampling pretreatment unit that is prone to failure,put forward the methods of evaluating the performance of the sampling pretreatment unit,summarized the methods of daily data comparison and evaluation in the LNG terminal,and introduced the evaluation process and evaluation indicators through calculation examples.The results show that continuous cold insulation,ensuring complete gasification and monitoring regulation are the three key technical elements.The inlet/outlet,heating temperature and outlet flow of gasifier are the key indicators reflecting the reliability of pretreatment unit.The comparison of laboratory off-line analysis data and source data and the uncertainty evaluation method of on-line real-time data can be used as effective methods to evaluate the performance of pretreatment unit.This method is not only suitable for LNG terminal,but also has reference value in many LNG energy analysis occasions such as LNG carrier,liquefaction plant and filling station.

关 键 词：液化天然气 取样预处理 性能评价 色谱分析 不确定度 

分 类 号：TE81[石油与天然气工程—油气储运工程] TE83