摘要
从多个角度分析了空分装置中应用液化天然气(LNG)冷量的优势,针对不同的场合提出了2种引进LNG冷量的液体空分流程新方案。方案1适用于投资建设新设备的场合,方案2适用于现有流程的改造生产液体的场合,2种方案有一个共同点即使用LNG冷量冷却循环氮气制冷。采用Aspen P lus软件对2个方案进行了模拟计算,结果表明:引进LNG冷量之后,所需循环氮气量明显减少,系统最高运行压力降低由传统流程的4.2—5.0 MPa降低到2.1—2.6 MPa,液态产品的单位能耗从约0.5 kW.h/kg降低到0.327—0.338 kW.h/kg,节能效果明显。LNG气化过程中换热压力的提高对冷量回收影响较小,而采用液泵加压节省能耗,将气化过程安排在升压过程之后有利于能源的合理利用。
The advantages of air separation unit employing liquefied natural gas （LNG） cold energy were analyzed from different points. Two new liquid - product air separation systems by using cold energy of LNG for precooling the cycle nitrogen were introduced for two different occasions. The first one was for the building of a new system, the second one was for the rebuilding of an old system. Two new systems were simulated by Aspen Plus software. Compared with the conventional system without LNG, the simulation results show that the total quality of cycle nitrogen decreases obviously, the highest pressure of the new systems decreases from 4.2-5.0 MPa to 2. 1-2.6 MPa, and the consumed electric energy per-kilogram liquid product decreases from about 0.5 kW · h/kg to 0. 327-0.338 kW · h/kg after using cold energy of LNG. The effect of the LNG pressure during heat exchanging process is less. If pump is used to pressurize before its regasification, the energy would be saved a lot.
出处
《化学工程》
EI
CAS
CSCD
北大核心
2007年第9期58-61,共4页
Chemical Engineering(China)
关键词
空分流程
液化天然气
冷量回收
air separation unit
liquefied natural gas
cold energy recovering
