含油纳米制冷剂沸腾中碳纳米管相间迁移机制,是评估纳米制冷剂沸腾传热效果和制冷系统中碳纳米管循环能力的基础。本文基于颗粒捕集理论和气浮理论,提出了各因素对碳纳米管相间迁移的影响机制;即碳纳米管迁移率随其长度或直径的增大而增大,制冷剂动力学黏度越小、密度越大,其完全蒸发时碳纳米管迁移率越大,碳纳米管迁移率随润滑油浓度的增大而减小、随热流密度的增大而减小、随初始液位高度的增加而增大。同时通过实验验证了理论分析结果的准确性.
Migration mechanism of carbon nanotubes from liquid phase to vapor phase in the boiling of refrigerant/nanolubricant mixture is fundamental to the evaluation of nanorefrigerant boiling heat transfer and carbon nanotubes circulation in refrigeration systems.Based on the particles trapping theory and notation theory,the influence mechanism of different factors on the migration of carbon nanotubes is proposed.The results showed that the migration ratio of carbon nanotubes increases with the increase of the diameter or length of carbon nanotubes.When the refrigerant is completely evaporated,the smaller dynamic viscosity or larger density of refrigerant causes the larger migration ratio of carbon nanotubes.The migration ratio of carbon nanotubes decreases with the increase of lubricating oil concentration or heat flux,while increases with the increase of initial liquid-level height.The accuracy of the theoretical analysis results is verified by the experimental results.