Abstract An experimental investigation of single-phase and two-phase (evaporation and condensation) heat transfer and pressure drop characteristics is performed for five micro-fin tubes with various geometries using refrigerant R22 as the working fluid. The mass flux is in the range of 130–550 kg/m2s. Evaporation tests are conducted at 6 °C saturation temperature, 0.1 inlet quality and 0.9 outlet quality, while condensation tests are carried out at 45 °C saturation temperature, 0.8 inlet quality and 0.1 outlet quality. The results suggest that the micro-fin tubes single-phase heat transfer coefficients increased by 46.3%–63.6% compared to smooth tubes. Tube geometries that have the best evaporation or condensation heat transfer performance are identified. A new evaporation heat transfer correlation that takes the micro-fin effects and heat transfer mechanisms into consideration is developed, which predicts the experimental data within 15% error compared with the previously reported correlations which show prediction errors beyond 30%. The new model is applied to intermittent and annular flow patterns in micro-fin tubes. As for condensation, the Choi et al. correlation well predicts the pressure drop within 20% error, and the Yu and Koyama correlation provides the best heat transfer predictions within 25% error.

中文翻译：

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微型翅片管中的两相流传热

摘要 使用制冷剂 R22 作为工作流体，对具有各种几何形状的五个微翅片管进行了单相和两相（蒸发和冷凝）传热和压降特性的实验研究。质量通量在 130–550 kg/m2s 的范围内。蒸发试验在6℃饱和温度、0.1入口质量和0.9出口质量下进行，而冷凝试验在45℃饱和温度、0.8入口质量和0.1出口质量下进行。结果表明，与光滑管相比，微翅片管单相传热系数提高了 46.3%~63.6%。确定具有最佳蒸发或冷凝传热性能的管几何形状。开发了一种新的考虑了微翅片效应和传热机制的蒸发传热关联式，与之前报道的关联式预测误差超过 30% 相比，该关联式预测实验数据误差在 15% 以内。新模型应用于微翅片管中的间歇和环形流动模式。至于冷凝，Choi 等人。相关性很好地预测了 20% 误差内的压降，Yu 和 Koyama 相关性提供了 25% 误差内的最佳传热预测。至于冷凝，Choi 等人。相关性很好地预测了 20% 误差内的压降，Yu 和 Koyama 相关性提供了 25% 误差内的最佳传热预测。至于冷凝，Choi 等人。相关性很好地预测了 20% 误差内的压降，Yu 和 Koyama 相关性提供了 25% 误差内的最佳传热预测。