화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.49, No.10, 5018-5026, 2010
Vaporization Enthalpy of Pure Refrigerants: Comparative Study of Eighteen Correlations
In this work, the performance and accuracy of 18 correlations for the vaporization enthalpy of 48 pure substances is studied. Forty-six of these substances are refrigerants, and two (hexane and heptane) could be used in refrigerant mixtures. Seven of the correlations include 2 adjustable coefficients for every fluid, whereas the other 11 have three coefficients. Some of these correlations are classical expressions, but others have been proposed recently or have been slightly modified or extended for this study. In all the cases, we consider the normal boiling point as a constraint, and then the input parameters are the critical temperature, and the temperature and vaporization enthalpy at the normal boiling point. The data and input properties were taken from both the DIPPR (1968 data) and the NIST databases (10 650 data). Thus, as a first step, we have studied the possible differences between these data. The results showed that the correlation recently proposed by Park gives the lowest mean average percentage deviations for both two-coefficient and three-coefficient models.