奈米冷凍機油的合成、特性分析、最佳化與碳氫冷媒冷凍空調系統應用研究

The nanolubricants of refrigeration (NLUB) were produced by two-step synthesis method that used to disperse the alumina (Al2O3) and titania (TiO2) nanoparticles in the polyolester (NPOE) and mineral (NMIL) refrigeration lubricant with oleic as a dispersant. The experiments in this study were conducted to evaluate the suspension performance, viscosity, specific heat, and tribological performance of the NPOE and NMIL using a static position/centrifuged method, rheometer, differential scanning calorimeter (DSC), and rotary tribology testing machine (pin-on-disk apparatus) with samples of various nanoparticles concentrations. The experimental results showed that the suspension performance of NLUB with TiO2 nanoparticles is very poor; therefore, we eliminate TiO2-NLUB in follow-up experiments. NPOE and NMIs had excellent suspension performance with the ratio of Al2O3 nanoparticles/oleic was 1.6/0.1 and 1.6/1.6. The differences in specific heat of NLUB and base lubricant are small. Adding Al2O3 nanoparticles to refrigeration lubricant will increase the viscosity of refrigeration lubricant, but added oleic into NLUB will decrease viscosity of NLUB. NLUBs had higher tribological performance to compare with base lubricant in the most expermental parameters. Experimental results in tribological test with NPOE and NMIL, NPOE and NMIL with Al2O3 concentration of 0.4/0.8 and 0.2 wt.% had the lowest wear weight loss and could decrease the wear loss reached 49.44% and 51.02% to compare with base lubricant. We suggested that the added concentration of Al2O3 nanoparticles should be less than 0.4 wt% with proportion of Al2O3 nanoparticles and oleic acid for NPOE and NMIL were 16:1 and 1:1 base on the results of rheological experiments, tribological experiments and long-term static position test.