Capillary-Constant Correlations for Some New Refrigerants

This paper presents a method of evaluating the capillary constant of some new refrigerants, namely HFCs 32, 125, 134, 134a, 143a, and 152a; HCFCs 123, 123a, 124, 141b, and 142b in the liquid-vapor coexistence regions except within 2K from the critical point. The correlation is of the form a2 = a20( 1 - Tr)0.92 where a20 is obtained through the saturated-liquid density data. The calculated results show that the correlation is able to predict experimental data within 4% with a maximum absolute deviation less than 9%. A procedure to calculate the surface tension without the saturated vapor density data is also preseInted