Prediction of the Heat of Vaporization from the Heat of Vaporization at Normal Boiling Point

Abstract

A generalized enthalpy-temperature correlation for a group of liquid compounds has been developed to represent the data for a wide range of temperatures. Detailed analysis shows that the proposed correlation fits the experimental measurements of enthalpy of liquid with the calculated values with an overall absolute error of 3.7% for 79 data points.

Vaporization Enthalpy of Pure Refrigerants: Comparative Study of Eighteen Correlations

“…The following 3C model studied here is that proposed recently by Al-Shorachi and Hashim (A-SH): Δ h / Δ h b n = m ( 1 − t ) λ Originally they fixed the values of the parameters as m = 45.129353, n = 1.06402, λ = 0.3913. We tried to reproduce their results, but found that the dimensions used for the enthalpy could possibly be incorrect, so that the values of these parameters should be taken with caution.…”

“…[10][11][12][13][14] Some of them include coefficients that must be calculated for each substance, [15][16][17][18][19][20][21][22][23][24] or the value of the enthalpy at a given temperature. [25][26][27][28][29][30][31][32][33][34] The choice of a specific equation depends on several factors, mainly, the available number of experimental data, the temperature range over which one wants to apply the correlation, and the set of substances chosen for testing the equation. These factors and the desired or expected accuracy of the predicted values will also determine the number of adjustable parameters or coefficients in the correlation under consideration.…”

“…The proposal of Park reduced the MAAD to only 0.05%. Nevertheless, the Park study does not consider some other recent interesting proposals, such as those of Chen et al, 28 Roma ´n et al, 31 Velasco et al, 32 and Al-Shorachi and Hashim, 33 and that used in the DIPPR database, 37 which is due to the work of Chueh and Swanson. 38 Also recently, Jovanovic and Grozdanic 24 have tested 27 correlations, including a new one proposed by them, using 1958 data for 162 compounds.…”

“…A plethora of correlations have been proposed in order to fit the enthalpy of vaporization of pure fluids as a function of the temperature. − Some of them include coefficients that must be calculated for each substance, − or the value of the enthalpy at a given temperature. − …”

“…The proposal of Park reduced the MAAD to only 0.05%. Nevertheless, the Park study does not consider some other recent interesting proposals, such as those of Chen et al, Román et al, Velasco et al, and Al-Shorachi and Hashim, and that used in the DIPPR database, which is due to the work of Chueh and Swanson …”