华南理工大学学报(自然科学版) ›› 2016, Vol. 44 ›› Issue (8): 1-7.doi: 10.3969/j.issn.1000-565X.2016.08.001

• 动力与电气工程 •    下一篇

微细通道内纳米制冷剂的流动沸腾传热特性

罗小平1 吴迪1 冯振飞1,2 涂华营1   

  1. 1. 华南理工大学 机械与汽车工程学院,广东 广州 510640; 2. 广西大学 化学化工学院,广西 南宁 530004
  • 收稿日期:2016-01-04 修回日期:2016-03-22 出版日期:2016-08-25 发布日期:2016-07-04
  • 通信作者: 罗小平( 1967-) ,男,教授,博士生导师,主要从事微尺度相变强化传热机理以及微尺度热物理系统的拓扑学、分子动力学模拟等的研究 E-mail:mmxpluo@scut.edu.cn
  • 作者简介:罗小平( 1967-) ,男,教授,博士生导师,主要从事微尺度相变强化传热机理以及微尺度热物理系统的拓扑学、分子动力学模拟等的研究
  • 基金资助:
    国家自然科学基金资助项目( 21276090)

Heat Transfer Characteristics of Flow Boiling Nano-Refrigerant in Rectangular Microchannel

LUO Xiao-ping1 WU Di1 FENG Zhen-fei1,2 TU Hua-ying1   

  1. 1.School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China; 2.School of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,Guangxi,China
  • Received:2016-01-04 Revised:2016-03-22 Online:2016-08-25 Published:2016-07-04
  • Contact: 罗小平( 1967-) ,男,教授,博士生导师,主要从事微尺度相变强化传热机理以及微尺度热物理系统的拓扑学、分子动力学模拟等的研究 E-mail:mmxpluo@scut.edu.cn
  • About author:罗小平( 1967-) ,男,教授,博士生导师,主要从事微尺度相变强化传热机理以及微尺度热物理系统的拓扑学、分子动力学模拟等的研究
  • Supported by:
    Supported by the National Natural Science Foundation of China( 21276090)

摘要: 分别以0、0. 031%、0. 062%、0. 155%、0. 248% 浓度的Al2O3-R141b 纳米制冷剂为工质,在水力直径为1. 33mm 的矩形铝基微细通道内进行了流动沸腾实验,研究了不同浓度纳米制冷剂实验后槽道表面能的变化情况. 结果表明: 加入少量纳米颗粒后,壁面形成大量的活化核心,使得沸腾起始点ONB 提前,强化了传热; 浓度为0. 062% 纳米制冷剂的强化传热效果最好,传热系数比纯制冷剂最大可提高48. 1% ; 当纳米颗粒浓度超过最佳浓度而继续增大时,颗粒在表面沉积现象越来越严重,使槽道表面能增大,换热热阻也随之增大,强化传热效果反而依次降低. 浓度为0. 031%、0. 062%、0. 155%、0. 248% 纳米制冷剂实验后的槽道表面能,比槽道原始表面能分别增长了0. 47、1. 39、1. 89、2. 14 倍.

关键词: 微细通道, 纳米制冷剂, 强化传热, 表面能

Abstract: The nano-refrigerants respectively of 0,0. 031%,0. 062%,0. 155% and 0. 248% ( volume fraction) Al2O3-R141b particles,were taken as the working fluids to perform flow boiling experiments in the aluminum-based rectangular microchannels of a hydraulic diameter of 1. 33mm,so as to reveal the influence of the nanoparticle concentrations on the surface energy of the microchannels after the experiments.The results show that ( 1) after adding a small amount of nanoparticles,a massive amount of activation nucleuses form on the wall surface,which brings forward the onset of nucleation boiling ( ONB) and then enhances the heat transfer; ( 2) the nanorefrigerant of 0. 062% Al2O3-R141b achieves the best effect in enhancing the heat transfer,and its heat transfer coefficient can be increased by a maximum of 48. 1% in comparison with that of pure R141b refrigerant; ( 3) when the nanoparticle concentration is greater than the optimal concentration of 0. 062%,the particle deposition on the surface becomes serious with the increase of the nanoparticle concentration,which causes the surface energy and heat flow resistance of microchannels to increase,but with a decrease in the heat transfer enhancement; and ( 4) the surface energy of the microchannels treated with the nano-refrigerants respectively of 0. 031%,0. 062%,0. 155%,0. 248% Al2O3-R141b particles,increases respectively by 0. 47,1. 39,1. 89 and 2. 14 times,in comparison with that of the original microchannels before the experiments.

Key words: microchannels, nano-refrigerant, heat transfer enhancement, surface energy

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