Solubility measurements of R134a in nanolubricant

In the last years, the employment of hydrofluorocarbons (HFCs) in Heating, Ventilating, Air Conditioning and Refrigeration (HVACR) applications has gained a big increase, due to the necessity to substitute the old chlorinated refrigerants. However, HFCs are not compatible with the mineral oils (MO), widely used in the past. They show a good solubility in polyolester oil (POE), that are hydroscopic and hydrophilic, causing many problems in their management, and show poorer lubrication capability respect to MO. In the last years, nanolubricants, i.e. solutions of solid nanoparticles in oils, have been proposed to overcome the problems with compatibility of refrigerants and MO [1-4]. In this study, the solubility of 1,1,1,2-tetrafluoroethane (R134a) in MO and in the same oil added with titanium oxide (TiO2) nanoparticles (nano-MO) is presented. From these measurements, it is evident that no differences are noticeable between the solubility of R134a in MO or in nano-MO. [1] Fan, Z., Wang, R., Zheng, M., MNHMT2009-18432, Proc. ASME 2009 2nd Micro/Nanoscale Heat & Mass Transfer International Conference MNHMT2009, December 18-21, 2009, Shanghai, China. [2] Saidur, R., Kazi, S.N., Hossain, M.S., Rahman, M.M., Mohammed, H.A., Renew. Sust. Energ. Rev. 2011, 15, 310-323 [3] Wang, R., Wu, Q., Wu, Y. Energ. Buildings 2010, 42, 2111-2117. [4] Bi, S., Shi, L., Zhang, L. Appl. Therm. Eng. 2008, 28, 1834-1843.