Abstract:

In this study,a new small scale auto-cascade natural gas liquefier using a rectifying column was presented,and the system performance was simulated and optimized by HYSYS^®.The influence of the concentrations of the refrigerant mixture and system pressures on the system performance was analyzed in detail.The results showed that,for different concentrations of refrigerant mixtures,when the inlet pressure arose,the variation trends of the quantity of LNG were divided into two types,the upward convex type and a little change type,and the corresponding variation trends of the energy consumption for the liquefaction of per unit LNG presented the downward concave type and a straight reduction type,while the compressor power and discharge temperature both decreased.Finally,the optimal concentration of the refrigerant mixtures and working condition were obtained aimed at the energy consumption for the liquefaction of per unit LNG.

Key words: mixed refrigerant, rectifying column, auto-cascade, LNG, optimization

摘要：

本文提出了一种新型精馏型自复叠小型天然气液化系统,并采用HYSYS^®软件对其进行了性能模拟计算和优化分析,详细分析了组分配比和系统压力位对系统性能的影响规律。研究结果表明:对于不同组分配比的混合制冷剂,当吸气压力上升时,天然气液化量的变化趋势则可分为向下凹和变化不大两种类型,其对应的系统单位液化功的变化趋势可分为向上凸和单调减少两种类型,压缩机功率和排气温度则基本上呈单调降低趋势,并以系统单位液化功为目标优化,得到了最佳配比和最佳工况。

关键词: 混合制冷剂, 精馏, 自复叠, 天然气液化, 优化