在蒸汽压缩循环中，压缩机内部需要润滑油。一小部分油与制冷剂一起在整个系统部件中循环，在热交换器中，过量的润滑剂会破坏热传递并增加压力损失:这两种影响都是不希望的，但却是不可避免的。纳米润滑剂——即精细分散在润滑剂中的高导电固体纳米颗粒——是一种潜在的成本中性技术，用于提高暖通空调和空调应用中热交换器的传热性能。本文介绍了一项表征纳米润滑剂基本热物理性质的实验研究，并显示了管内流动沸腾的传热增强潜力。研究了三种类型的Al2O3纳米润滑剂，它们都有标称直径约为40 nm的颗粒，但使用了不同的表面活性剂来稳定纳米颗粒。 纳米润滑剂的溶解度似乎略低于R-410A，但实际上，纳米颗粒并没有真正干扰POE油的溶解度特性。高粘度悬浮液有望稳定纳米粒子并避免聚集。这一点在目前的工作中得到了验证，本文中的数据显示了表面活性剂的最佳组合，从而实现了稳定和均匀的纳米润滑剂。表面活性剂对纳米润滑剂的热导率、比热、粘度和溶解度性能影响较小，并用本文的新数据验证了几种纳米流体模型对这些性能的影响。最后，本文对纳米润滑剂和制冷剂R的管内两相流沸腾传热进行了初步的实验室实验- 410A混合物和分散在液相中的纳米颗粒增加了制冷剂和润滑剂混合物（不含任何纳米颗粒）的两相传热系数。引用:ASHRAE论文:2015年ASHRAE年会，伊利诺伊州芝加哥

In vapor compression cycles, lubricating oil is needed inside the compressors. A small portion of the oil circulates with the refrigerant throughout the system components and, in the heat exchangers, the lubricant in excess penalizes the heat transfer and increases the pressure losses: both effects are undesired but yet unavoidable. Nanolubricants - that is high conductive solid nanoparticles finely dispersed in the lubricant - are a potential cost-neutral technology to increase the heat transfer performance of heat exchangers in HVAC&R applications. This paper presents an experimental study that characterizes the basic thermophysical properties of nanolubricants and that shows the heat transfer enhancement potentials for in-tube flow boiling. Three types of Al2O3 nanolubricants were investigated and all had particles with nominal diameter of approximately 40 nm but used different surfactants to stabilize the nanoparticles. The nanolubricants appeared to have slightly lower solubility than that of R-410A but actually the nanoparticles did not really interfere with the POE oil solubility characteristics. High viscosity suspensions are expected to stabilize the nanoparticles and avoid clustering. This aspect was verified in the present work and the data in this paper showed optimum combinations of surfactants that achieved stable and uniform nanolubricants. The surfactants affected slightly the thermal conductivity, specific heat, viscosity, and solubility properties of the nanolubricants and several nanofluids models for these properties were verified with the new data of the present paper. Finally this paper presents preliminary laboratory experiments for in-tube two-phase flow boiling heat transfer of nanolubricants and refrigerant R- 410A mixture and the nanoparticles dispersed in the liquid phase increased the two-phase heat transfer coefficient with respect to the case of refrigerant and lubricant mixture without any nanoparticles.