作　　者： ; ; ;

机构地区： 北京工业大学环境与能源工程学院

出　　处： 《热科学与技术》 2013年第4期360-367,共8页

摘　　要： 为提高热虹吸管的传热效率,以低沸点制冷剂工质R410A为基准流体,通过添加不同比例的碳纳米管(CNTs)颗粒,经混合震荡,制备出不同质量分数的碳纳米管流体。将其用于热虹吸管强化传热,搭建了相应的试验平台,通过试验研究了不同质量分数的碳纳米管对热虹吸管传热性能以及管壁温度、管内压力等方面的影响。结果发现,碳纳米管颗粒的添加能够有效地改善热虹吸管的传热性能,等效对流传热系数平均提高40%以上,冷凝段顶端管壁温度升高9.9%以上,蒸发段与冷凝段管壁温差降低13.9%以上,冷凝段管内压力提高8%以上。建议在低温度工况下添加碳纳米管,且其质量分数不宜超过0.005%,以便获得较好的传热性能。 The themosyphon is a high effectiveness heat transfer unit, and is widely applied in many fields, especially in cooling telecommunication and electric equipment with high heat flux. In order to improve the thermosyphon and increase the heat transfer coefficient, a new working fluid was developed and adopted. In the new working fluid, different mass fraction carbon nano tubes （CNTs） were added based on the low boiling-point refrigerant R410A, and different mass fractions carbon nano tubes working fluids were obtained through mixing and vibration for thermosyphon heat transfer enhancement. The dispersant was poly ethylene glycol （PEG） 400. The thermosyphon experimental system was set up. And the effect on thermosyphon heat transfer performance, wall temperature and inner pressure of different proportion carbon nano tubes working fluid was investigated experimentally. It is found that the added carbon nano tubes can improve the thermosyphon heat transfer performance effectively. The equivalent convective heat transfer coefficient increases by over 40%. The condenser section wall temperature rises by more than 9.9%. The wall temperature difference between evaporator section and condenser section decreases by above 13.9 %. And the inner pressure increases by over 8%. The dispersant PEG 400 does not affect the thermal performance of the base working fluid R410A significantly. The enhancement of CNTs working fluid at 28 degrees is more than that at 55 degrees. It is suggested that carbon nano tubes be added under low temperature working conditions and the mass fraction be less than 0.005% for good heat transfer performance.

关 键 词： 碳纳米管 热虹吸管 制冷剂 热工特性

领　　域： [动力工程及工程热物理]