基于团聚理论的纳米制冷剂导热系数预测方法

A PREDICTION METHOD FOR NANOREFRIGERANTS'THERMAL CONDUCTIVITIES BASED ON AGGREGATION THEORY

纳米流体中纳米颗粒以团聚体的形式存在.为预测纳米流体的导热系数,模拟了流体中纳米颗粒团聚体的三维空间结构并用热阻网络法计算了团聚体的导热系数。在得到团聚体的导热系数与考虑液体分子吸附层后团聚体的体积分数后,预测纳米流体的导热系数.用实验数据验证了该预测方法并运用该方法预测了铜-R22纳米制冷剂的导热系数.

Nanoparticles in nanofluids are in the form of nanoparticle clusters caused by aggregation. In order to predict the thermal conductivities of the nanofluids, the three-dimensional space structure of the nanoparticle cluster in the fluid was simulated, and then the thermal conductivities of the clusters were calculated with the resistance network method. The thermal conductivities of the nanofluids were calculated based on the simulated thermal conductivities of nanoparticle clusters, the volume fraction of nanoparticle clusters to the nanofluids as well as the liquid molecule adsorption layer of the nanoparticle. The simulation method was validated by experimental data. The conductivities of copper-R22 nanorefrigerants are calculated by the method.