精馏型自复叠天然气液化流程绝热混合效应研究

Study on the Adiabatic Mixing Effects in an Auto-Cascade Natural Gas Liquefaction Cycle with a Rectifier

本文采用改进型PT方程,对影响新型精馏型天然气液化循环中多元混合制冷剂绝热混合效应的各项关键参数进行了深入的分析研究。结果表明,混合效应随混合压力变化有峰值存在,混合前混合制冷剂的两相状态可以产生较大的混合效应;混合效应随混合前流量比变化的峰值出现在混合后混合工质干度接近于1时;混合效应随混合前温度变化也有峰值存在,当混合后的流体干度小于1时,可以有较大的混合效应;混合前两股混合制冷剂的成分均对混合效应有明显影响。在循环设计时,要对这些关键参数加以综合考量。

Based on the improved Patel-Teja equation of state,the influence of key parameters on the adiabatic mixing effect in an auto-cascade liquefaction cycle with a rectifier for liquefying natural gas was studied in the paper.The results show that there is a maximum mixing effect with the variation of the pressure and the two phase state of refrigerant can lead a large mixing effect.When the flow ratio of the two mixing streams varies,the maximum mixing effects occur when the quality of the mixed streams approaches to 1.A maximum mixing effect can also be found when the temperatures of the two mixing streams vary and the relatively large mixing effects usually occur when the qualities of mixed streams are less than 1.The composition of two refrigerant streams before mixing also has a noticeable influence on the mixing effect.All the above key parameters should be considered in the design of the auto-cascade natural gas liquefaction cycle.