为解决现有的乙烷回收工艺系统中深度制冷的外部冷源供应问题,同时有效地回收利用LNG气化工程中释放的高品位冷能,设计了一种耦合LNG冷能进行乙烷回收的新工艺系统(以下简称新工艺)。利用Aspen HYSYS软件进行新工艺建模,选取3组不同气质的富气,采用单因素敏感性分析法筛选出新工艺系统的最佳LNG流量分别为8.05×10⁴、8.53×10⁴、9.15×10⁴ kg/h,脱甲烷塔压力的最优值区间为2.2~2.3 MPa。并对乙烷回收新工艺和RSV工艺进行对比分析,结果表明,保证乙烷收率不低于95%,乙烷回收新工艺比常规RSV工艺的总压缩功率及综合能耗大幅度下降,且气质越富,新工艺的节能效果越明显。

In order to address the issue of external cold source supply for deep cooling in the existing ethane recovery process system,and to effectively recover and utilize the high-quality cold energy released in LNG vaporization projects,a new process system coupling LNG cold energy with ethane recovery is designed.Aspen HYSYS software is utilized to establish model for the new process.Three groups of rich gas with different gas compositions are selected.A single factor sensitivity analysis method is employed to determine the optimal LNG flow rates for the new process system,which are 8.05×10⁴ kg/h,8.53×10⁴ kg/h,and 9.15×10⁴ kg/h,respectively.The optimal pressure range for the de-methanizer is identified as 2.2-2.3 MPa.A comparative analysis is conducted on the new process and the RSV process.Study results indicate that under the premise of ensuring that the ethane yield is not less than 95%,the new ethane recovery process can significantly reduce the total compression power and comprehensive energy consumption compared to the conventional RSV process.Furthermore,the richer the gas composition,the more pronounced the energy-saving effect of the new process.