基于深冷技术的液化天然气蒸发气提氦流程优化分析  

Optimization analysis of helium extraction process from LNG-BOG using cryogenic technology

作　　者：张丽萍 巨永林[1] Zhang Liping;Ju Yonglin(Institute of Refrigeration and Cryogenics,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学制冷与低温工程研究所,上海200240

出　　处：《低温工程》2023年第2期97-106,共10页Cryogenics

摘　　要：针对中国宁夏银川某一提氦工厂液化天然气蒸发气(LNG-BOG)提氦液化流程,采用Aspen Hysys构建BOG提氦气系统和氦气液化系统的流程模型,首先分析了BOG提氦气流程中关键参数对能耗设备的影响情况。之后采用遗传算法,以系统单位能耗为目标函数,分别对BOG提氦气系统和氦气液化系统中关键能耗参数进行优化。同时采用[火用]分析方法,分析优化前后氦气液化系统的[火用]效率以及[火用]损失情况。结果表明,BOG提氦气系统和氦气液化系统经优化后系统单位能耗分别为8.3515 kWh/Nm^(3)和0.7519 kWh/Nm^(3),相比优化前分别下降7.09%和14.71%,且氦气液化系统[火用]效率较优化前提高了18.54%,[火用]损失下降12.79%,换热器换热总量约上升2.54%。因此整个系统在优化后单位能耗有所降低,系统运行经济性得到提高。A process model for the helium extraction process from the boil-off gas of liquefied natural gas(LNG-BOG)in a helium extraction plant located in Yinchuan of China was built and simulated by Aspen Hysys.The process was divided into the helium extraction system from LNGBOG and the helium liquefaction system.Influences of the energy consumption parameters for key equipment in the BOG helium extraction process were analyzed,then the GA(Genetic Algorithm)was used to optimize the key energy consumption parameters of the BOG helium extraction system and the helium liquefaction system respectively,taking unit energy consumption of the system as the objective function.Exergy efficiency and exergy loss of the helium liquefaction system before and after the optimization were analyzed by the exergy analysis method.The results show that the unit energy consumption of the BOG helium extraction system and the helium liquefaction system after the optimization are 8.3515 kWh/Nm^(3)and 0.7519 kWh/Nm^(3),respectively,which decreased by 7.09%and 14.71%,compared with that before the optimization.The exergy efficiency of the helium liquefaction system increased by 18.54%compared with before optimization,the exergy loss decreased by 12.79%and the total amount of heat transfer increased by 2.54%.As a result,the energy consumption of the whole system was reduced after the optimization,and the operation economy of the system was improved.

关 键 词：液化天然气蒸发气 氦气 遗传算法 优化 [火用]分析 

分 类 号：TB662[一般工业技术—制冷工程]