微细通道内纳米制冷剂的流动沸腾传热特性

发布时间：2018-06-12 18:54

本文选题：微细通道 + 纳米制冷剂　；参考：《华南理工大学学报(自然科学版)》2016年08期

【摘要】：分别以0、0.031%、0.062%、0.155%、0.248%浓度的Al_2O_3-R141b纳米制冷剂为工质,在水力直径为1.33 mm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.
[Abstract]:A flow boiling experiment was carried out in a rectangular aluminum-base microchannel with a hydraulic diameter of 1.33 mm with 0.155% Al2O3-R141b nano-refrigerant as working medium. The surface energy of the channel was studied after the experiment of different concentrations of nano-refrigerant. The results show that a large number of activated cores are formed on the wall after adding a small amount of nano-particles, which makes the boiling start point onb advance and enhances the heat transfer, and the concentration of 0.062% nano-refrigerant has the best effect on heat transfer enhancement. The maximum heat transfer coefficient can be increased by 48.1 than that of pure refrigerant. When the concentration of nanoparticles exceeds the optimum concentration, the deposition of particles on the surface becomes more and more serious, which increases the energy on the surface of the channel and the heat transfer resistance. On the contrary, the heat transfer enhancement effect decreases in turn. The surface energy of the channel after the experiment of 0.031 / 0.062 / 0.155% nanometer refrigerant is 0.47 / 1.39 / 1.89/ 2.14 times higher than that of the original channel's surface, respectively.
【作者单位】：华南理工大学机械与汽车工程学院;广西大学化学化工学院;
【基金】：国家自然科学基金资助项目(21276090)~~
【分类号】：TK124

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