绝热毛细管内制冷剂流动的非平衡性

On Non-Equilibrium Characteristics of Refrigerants Through Adiabatic Capillary Tubes

建立了制冷剂在绝热毛细管内流动的两流体模型,模型中考虑了气液两相间的速度滑移和温度滑移.采用6种制冷剂的流量实验数据验证该模型,结果表明,90%的预测值与实验值偏差在±10%以内,并且能合理预测压力的沿程分布.应用该模型研究了制冷剂在绝热毛细管内自蒸发过程的非平衡特性.结果显示:气液两相间的速度滑移和温度滑移在整个两相区一直存在,但在绝大部分区域内,这种非平衡性并不显著;与不考虑非平衡性的平衡均相流模型相比,本文模型计算的毛细管流量平均偏高7.3%.

A two-fluid model (TFM) for two-phase flow of refrigerant in adiabatic capillary tube was developed. Both inter-phase velocity slip and temperature slip are taken into account in the model. The experimental results show that the deviations of 90% model prediction are within ±10%. And this model can give reasonable pressure distribution along the tube length. Non-equilibrium characteristics in the process of refrigerant self-evaporation in the adiabatic capillary tube were studied. The results show that both the inter-phase velocity slip and temperature slip always exist in the whole two-phase region, but are not obvious. Compared with the homogeneous equilibrium model (HEM), the results of the two-fluid model on mass flow rate are 7.3% higher.