Abstract Supersonic gas separator is proposed for methane purification. One-dimensional analysis is performed to examine the design aspects associated with the converging-diverging nozzle and the liquid separation chamber. The results indicate that at low swirl intensities, the separation chamber length is about 100 times of the nozzle throat. Increasing the swirl intensity would lower this length sharply and it will be less than 10 for swirl intensity of unity which is equivalent to a swirl angle of 45°. In addition, a sensitivity analysis of the separator performance to the inlet conditions like the temperature, pressure, and composition of the mixture is carried out. It is observed that increasing the inlet temperature will reduce the condensation rate and separation performance, while an increase in the inlet pressure and methane mole fraction will boost the flow condensation rate. Further, changes in the inlet condition will affect the critical droplets diameter and required separation length. In this regard, the separation length will increase with decreasing inlet temperature and increasing inlet pressure and methane mole fraction. The results reveal that the operation envelope of the supersonic separator is more sensitive to the variations in the inlet flow temperature where high swirl intensity is required at low inlet temperature in order to maintain the separation chamber length. Finally, the results support that, for a fixed geometry of the supersonic gas separator, in order to maintain the performance, single or combined variations in the inlet conditions can be compensated by changing the swirl intensity within a reasonable envelope.

中文翻译：

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涡流强度作为超音速气体分离器中甲烷净化的控制机制

摘要 提出了用于甲烷净化的超音速气体分离器。进行一维分析以检查与收敛-发散喷嘴和液体分离室相关的设计方面。结果表明，在低涡流强度下，分离室长度约为喷嘴喉部的 100 倍。增加涡流强度会显着降低该长度，对于等于 45° 的涡流角的统一涡流强度，它将小于 10。此外，还进行了分离器性能对入口条件（如温度、压力和混合物组成）的敏感性分析。据观察，提高入口温度会降低冷凝速率和分离性能，而入口压力和甲烷摩尔分数的增加将提高流动冷凝率。此外，入口条件的变化将影响临界液滴直径和所需的分离长度。在这方面，分离长度将随着入口温度的降低和入口压力和甲烷摩尔分数的增加而增加。结果表明，超音速分离器的运行范围对入口流动温度的变化更敏感，在低入口温度下需要高涡流强度以保持分离室长度。最后，结果支持，对于固定几何形状的超音速气体分离器，为了保持性能，