关键词: 天然气液化, Aspen Plus, 能量分析, 有效能损失

Abstract: This paper presented a simulation of liquefied natural gas process of the mixed refrigerant cycle using Aspen Plus software，and calculated the exergy losses of each unit. The results showed that the exergy loss of compression process was 63.8% of all energy loss，heat transfer process accounted for 19% of the energy loss，but was the key point to reduce the exergy loss in the entire process. On the basis of the process simulation，the pressure and temperature of high-pressure refrigerant，low-pressure refrigerant，and the molar content of methane and n-pentane in the mixed refrigerants were selected as the variables in the detailed analysis of the impacts on the exergy losses. Suggestions were proposed to reduce the system effective loss. The analysis results showed that improving the high-pressure refrigerant pressure，low-pressure refrigerant pressure and temperature，and the molar content of the n-pentane in the mixed refrigerants could help reduce the exergy loss of the entire process. Reducing the high-pressure refrigerant temperature and the molar content of the methane in the mixed refrigerant process had similar effects.

Key words: liquefied natural gas (LNG), Aspen Plus, energy analysis, exergy loss