Simulations of saturated vapor pressures of single refrigerants by COSMO-RS

摘要

Based on the theory of Conductor like Screening Model for Realistic Solvents (COSMO-RS), thegas-liquid phase equilibrium thermal properties of single refrigerants were simulated. COSMO-RScan predict the thermophysical properties of the fluids only needing the structural information of asingle molecule. It is the most effective way of connecting the quantum mechanics andthermodynamics at present. But the relative errors are larger, reaching 10-20% when it is applied forcalculations of refrigerants. For this reason, the influences of various parameters on the saturatedvapor pressure are studied. The results show that the scale factor of surface area can improve theaccuracy of calculation. Under the optimum scale factor of surface area, the simulated values areconsistent with the experimental data provided by NIST. The relative error are within ±2%. On thisbasis, the relation of the size factor with type of refrigerant is analyzed. Finally, the Antoine equationsof saturated vapor pressure for various types of refrigerants are fitted.