Abstract Supersonic swirl separation technology has been widely used in natural gas processing and has achieved good results. However, there are few studies on the application of supersonic separation technology to the removal of CO2 from natural gas, and the condensation rule of CO2 under supersonic swirling flow condition is still unclear. In order to study the supersonic swirling condensation characteristics of CO2 in Laval nozzle, the Euler mathematical model of the condensation flow of CO2-CH4 two-component mixed gas was established, and the feasibility of CO2 removal by supersonic separation technology was verified by numerical simulation. The results show that, in the process of axial flow and swirling flow, the variation trend of CO2 condensation parameters is basically the same along the axial direction of the nozzle, but the distribution of parameters is significantly different along the radial direction. The increase of swirl intensity will increase the nozzle’s liquefaction efficiency and reduce the working flow of the nozzle. The inlet temperature and inlet pressure had a significant influence on the liquefaction efficiency of the nozzle, while the inlet CO2 content had little influence on the liquefaction efficiency.

中文翻译：

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拉瓦尔喷管内CO2超音速旋流凝结特性研究

摘要 超音速旋流分离技术在天然气加工中得到了广泛的应用并取得了良好的效果。然而，应用超音速分离技术去除天然气中CO2的研究较少，超音速旋流条件下CO2的凝结规律尚不清楚。为研究CO2在Laval喷管中超音速旋流凝结特性，建立了CO2-CH4双组分混合气体凝结流的欧拉数学模型，并通过数值模拟验证了超音速分离技术去除CO2的可行性. 结果表明，在轴流和旋流过程中，CO2冷凝参数沿喷嘴轴向的变化趋势基本一致，但参数分布沿径向有显着差异。涡流强度的增加会提高喷嘴的液化效率，降低喷嘴的工作流量。进口温度和进口压力对喷嘴的液化效率有显着影响，而进口CO2含量对液化效率影响不大。