A New Surface Tension Equation for Refrigerants

This study presents a new formula for the surface tension prediction of refrigerants. As a first step, an analysis of the available experimental surface tension data for refrigerants was performed. The experimental data were collected, after a careful literature survey, for the following pure fluids: R11, R12, R13, R13B1, R14, R21, R22, R23, R32, R113, R114, R115, R123, R124, R125, R134, R134a, R141b, R143a, R152a, R218, R227ea, R236ea, R236fa, R245ca, R245fa, R365mfc, and R1234yf. Then, the experimental data were regressed with the most reliable semi-empirical correlating methods based on the corresponding-states theory existing in the literature. As a final step, to minimize the deviation between the predicted data and the experimental data and to find the optimal equation for experimental data regression, a (μ + λ)-evolution strategy was adopted. After a careful statistical analysis of the results, a new formula based on the corresponding-states principle with improved representation of the experimental results was found and proposed.