含油金刚石纳米制冷剂的核态池沸腾换热特性

Nucleate Pool Boiling Heat Transfer Characteristics of Refrigerant/Oil Mixture with Diamond Nanoparticles

研究了含油金刚石纳米制冷剂(即由制冷剂R113、润滑油VG68和金刚石纳米颗粒组成的纳米流体)的核态池沸腾换热特性,分析了金刚石纳米颗粒对含油制冷剂核态池沸腾换热的影响.实验中饱和压力为101.3 kPa;热流密度为10～80 kW/m2;纳米油(纳米颗粒和润滑油的混合物)的质量分数为0～5%;在纳米油中金刚石纳米颗粒的质量分数为0～15%.实验结果表明:金刚石纳米颗粒增强了含油制冷剂的池沸腾换热,在测试工况下换热系数最大可增加63.4%,并且增加幅度随纳米油中纳米颗粒质量分数的增加而增加,随纳米油质量分数的降低而增加.开发了含油纳米制冷剂池沸腾换热关联式,关联式预测值与94%的实验数据偏差在±20%以内.

Nucleate pool boiling heat transfer characteristics of refrigerant/oil mixture with diamond nanoparticles were investigated experimentally.The refrigerant is R113 and the oil is VG68.The experimental conditions include a saturation pressure of 101.3 kPa,heat fluxes from 10 to 80 kW·m-2,nanoparticles concentrations in the nanoparticles/oil suspension from 0 to 15 %,and nanoparticles/oil suspension concentrations from 0 to 5 %.The experimental results indicate that the nucleate pool boiling heat transfer coefficient of R113/oil mixture with diamond nanoparticles is larger than that of R113/oil mixture by maximum of 63.4% under the present experimental conditions,and the enhancement increases with the increase of nanoparticles concentration in the nanoparticles/oil suspension and decreases with the increase of nanoparticles/oil suspension concentration.A correlation for predicting the nucleate pool boiling heat transfer coefficient of refrigerant/oil mixture with nanoparticles was proposed.The predicted values of the new correlation can agree with 94% of the experimental data of R113/oil mixture with diamond nanoparticles in the present study within the deviation of ±20%.