| Title |
Prediction of Density and Viscosity for CO2-PEC9 Mixture at Low Oil Concentration |
| Keywords |
이산화탄소-오일 혼합물 ; 밀도 ; 점성계수 ; 상태방정식 CO2-oil mixture ; Density ; Viscosity ; EoS |
| Abstract |
Due to environmental concerns CO2 has been reintroduced as a potential candidate to replace HFCs in refrigeration systems. Oils are always required in a vapor- compression cycle, and thus it is necessary to precisely estimate the thermodynamic mixture properties of CO2-lubricant oil. In the present study, the density and the viscosity of the mixture was calculated by the Redlich and Kwong type EoS and the modified Peng and Robinson type viscosity EoS, respectively. The viscosity model was based on the similarity between P-v-T and T-μ-P relationships. The predicted results were compared with the experimental data of Pensado et al. whose test conditions were 100～650 bar of pressure and 303K～353K of temperature with the CO2-POEs mixtures under 92.2wt.% and 83.3wt.% of CO2 concentration. The mean deviations of the mixture density were 7.93% and 8.32% for 92.2wt.% and 83.3wt.% of CO2 concentration, respectively. Concerning the viscosity, the mean deviations were 4% and 10% for 92.2wt.% and 83.3wt.% of CO2 concentration under the Pensado et al.’s test conditions. |