The dual mixed-refrigeration process makes it possible to achieve higher liquefaction of natural gas with the advancement in both the refrigeration cycles and refrigerant combinations of components. This is made possible by the fact that the process uses multiple mixed refrigerants. This has a significant impact on the overall improved performance of natural gas liquefaction by having a negative influence on the quantity of energy that is consumed. This study proposes a methodology for selecting the MR components based on their thermodynamic behavior in both warm and cold refrigerant streams. As a result, eighteen alternative scenarios are simulated for this study, each based on (i) fixing the warm loop components or (ii) fixing the cold loop components. The procedure was investigated from the point of view of process engineering, with the 3E model of energy, exergy, and economics serving as the decision-making factor. The findings indicate that increasing the number of components for pre-cooling and subcooling cycles from three to five results in specific energy consumption of 0.49 kW.kg, which seems to be a reduction of 54% in terms of the amount of energy that is consumed in comparison to the process that is based on three components. The irreversibilities of the process were uncovered by doing an exergy analysis. It identified the cases based on five refrigerant components providing reduced exergy destruction of 3505.02 kW with 59% exergy efficiency. The viability of the proposed process is assessed even further through economic analysis. It was observed that five MR-based processes save 22.93% of the total capital cost, 43.56% of the overall operating cost, and 33.61 %of the total annualized cost.

中文翻译：

---

双混合制冷剂 NG 液化过程中混合制冷剂选择相对于 3E（能源、火能、经济）的热力学评估

双混合制冷工艺通过制冷循环和制冷剂组合的进步，使得天然气的更高液化成为可能。这是因为该过程使用多种混合制冷剂。这对消耗的能量产生负面影响，从而对天然气液化的整体性能改善产生重大影响。本研究提出了一种根据 MR 组件在热制冷剂流和冷制冷剂流中的热力学行为来选择 MR 组件的方法。因此，本研究模拟了十八种替代场景，每种场景都基于 (i) 修复热环路组件或 (ii) 修复冷环路组件。该过程从过程工程的角度进行研究，以能源、火用和经济的3E模型作为决策因素。研究结果表明，将预冷和过冷循环的部件数量从 3 个增加到 5 个，单位能耗为 0.49 kW.kg，从消耗的能源量来看，这似乎减少了 54%与基于三个组件的过程相比。通过火用分析揭示了该过程的不可逆性。它根据五种制冷剂组件确定了案例，可将火用破坏减少到 3505.02 kW，火用效率为 59%。通过经济分析进一步评估所提出工艺的可行性。据观察，五种基于 MR 的流程可节省总资本成本 22.93%、总运营成本 43.56% 和总年化成本 33.61%。