摘要
LNG储罐是各类LNG工厂和LNG站必不可少的重要设备,由于LNG温度远低于环境温度,尽管对储罐采取绝热措施,但蒸发仍是不可避免的,LNG蒸发使储罐内压力和温度升高,对储罐产生不利影响。为了减少LNG储罐内低温蒸发气(BOG)直接放空或燃烧造成的污染与浪费,在以往BOG再液化工艺基础上进行优化,设计出适用于LNG站储罐内BOG再液化工艺。该工艺利用LNG站对外供气过程中输出的LNG自身冷能,在压缩机、冷凝器等设备的作用下将LNG储罐内BOG再液化,并以60方LNG储罐为例,用Aspen Plus软件对工艺参数进行优化。研究结果表明:该工艺利用对外供气过程中输出的LNG自身冷能不仅可提高BOG的回收率,使BOG在LNG储罐中循环利用,同时可有效减少LNG冷能浪费;60方LNG储罐,输出LNG流量达到110kg/h即可满足BOG冷凝要求;具有设备少、投资小、能耗低、操作简单的优点,为各类LNG站储罐内BOG再液化处理均有应用价值。
In various LNG plants and LNG stations,the LNG storage tank is the indispensable important equipment. Because the LNG storage temperature is far lower than the environment temperature,so although the storage tank heat insulation measure is taken,but the evaporation is still inevitable. LNG vaporization causes the increasing of storage tank pressure and temperature and brings adverse effect to the storage tank. In order to reduce the pollution and waste caused by the direct vent and burning of the LNG storage tank cryogenic boil-off gas（ BOG）,on the basis of the previous BOG reliquefaction process,the BOG process was optimized and the BOG reliquefaction process that was suitable for the LNG storage tank in LNG station was designed. In this process the cold energy of LNG used for gas supply and export was utilized,and the BOG in LNG storage tank was reliquefacted under the actions of compressor,condenser and other equipments,meanwhile the 60m3 LNG storage tank is set as an example and based on the Aspen Plus software the process parameter was optimized. The research result shows that by taking advantage of the cold energy of LNG used for gas supply and export,this process not only improves the BOG recovery rate,makes the BOG cyclic utilization in LNG storage tank,but effectively reduces the waste of LNG cold energy; for 60m3 LNG storage tank,the110 kg / h LNG output flow can meet the BOG condensation requirement; this process has the advantages of less equipment,small investment,low energy consumption,simple operation and has application value to the storage tank BOG reliquefaction process in all kinds of LNG stations.
出处
《低温与超导》
CAS
北大核心
2015年第3期24-27,41,共5页
Cryogenics and Superconductivity
基金
甘肃省科技支撑计划(1204GKCA004)资助
