Abstract For two-phase refrigerant flow, the maldistribution at the entrance of plate-fin heat exchangers (PFHEs) is a severe issue which tends to make the thermal performance of heat exchangers worse. Especially when PFHEs are applied in the field of liquefied natural gas (LNG), the non-uniformity restricts the natural gas liquefaction efficiency of PFHEs. To improve the thermal performance and liquefaction efficiency, a distributor named liquid injected seal is added at the entrance of PFHEs and its maldistribution is analyzed numerically by ANSYS FLUENT. Firstly, a numerical model of liquid injected seal is built and verified by the experimental data. Then, the effects of gas and liquid velocity of refrigerant on the flow uniformity are analyzed. It indicates that the velocity of gas phase is more effective on the distribution characteristic of the distributor than that of liquid phase. In addition, the pressure drop of the distributor is also studied under varied gas and liquid velocities. It is found that the liquid pressure drop is larger than gas pressure drop under the same condition. Further, an empirical correlation for maldistribution is obtained to predict the maldistribution of gas-liquid refrigerants, and empirical correlations for pressure drop in liquid injected seal in PFHEs are proposed. This investigation provides support for the improvement of efficiency of LNG.

中文翻译：

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LNG板翅式换热器入口气液流动分布特性数值研究

摘要 对于两相制冷剂流动，板翅式换热器（PFHE）入口处分布不均是一个严重的问题，往往会使换热器的热性能变差。尤其是PFHEs在液化天然气（LNG）领域的应用时，其不均匀性限制了PFHEs的天然气液化效率。为了提高热性能和液化效率，在PFHEs的入口处增加了一个名为注液密封的分配器，并通过ANSYS FLUENT对其分布不均进行了数值分析。首先，建立了注液密封的数值模型，并通过实验数据进行了验证。然后，分析了制冷剂的气液速度对流动均匀性的影响。这表明气相速度比液相速度对分布器的分布特性更有效。此外，还研究了在不同的气体和液体速度下分布器的压降。发现在相同条件下，液体压降大于气体压降。此外，获得了分布不均的经验相关性以预测气液制冷剂的分布不均，并提出了 PFHE 中注液密封压降的经验相关性。本研究为提高LNG的效率提供了支持。发现在相同条件下，液体压降大于气体压降。此外，获得了分布不均的经验相关性以预测气液制冷剂的分布不均，并提出了 PFHE 中注液密封压降的经验相关性。本研究为提高LNG的效率提供了支持。发现在相同条件下，液体压降大于气体压降。此外，获得了分布不均的经验相关性来预测气液制冷剂的分布不均，并提出了 PFHE 中注液密封压降的经验相关性。本研究为提高LNG的效率提供了支持。