A SATURATED LIQUID DENSITY CORRELATION FOR PURE REFRIGERANTS AND OTHER SUBSTANCES

2012 ◽  
Vol 20 (02) ◽  
pp. 1250004 ◽  
Author(s):  
KYOUNG KUHN PARK

A modification is proposed of the Chouaieb–Ghazouani–Bellagi (CGB) correlation for the saturated liquid density. After we examined the values of the critical exponent, which is a nonlinear parameter for the CGB correlation, we assumed that the exponent deviates by a small amount from the theoretical value of 0.325. Then, a Taylor-series expansion was conducted for the CGB correlation in order to develop a new correlation with two linear adjustable parameters. Data on the saturated liquid density for 70 pure fluids including 43 refrigerants from the NIST Chemistry WebBook in the whole vapor-liquid saturation range were fitted to the new and existing correlations. The results show that the new correlation yields better performance for substances of which reduced triple point temperature is higher than 0.4. Excellent performance (i.e., AAD < 0.1%) can be achieved with the modified CGB for 14 fluids but only for four fluids with the modified Guggenheim model.

1973 ◽  
Vol 9 (5) ◽  
pp. 591-594
Author(s):  
Edgar Watson ◽  
Robert E. Stronski

2019 ◽  
Author(s):  
zhiren he

<p>A new four-parameter cubic equation of state (EoS) is generated by incorporating the critical compressibility factor (Z<sub>c</sub>) apart from the critical pressure (P<sub>c</sub>) and temperature (T<sub>c</sub>). One free parameter in the denominator of the attractive term and two parameters in the alpha function are adjusted using the experimental data of saturated liquid density, vapor pressure, and isobaric liquid heat capacity of 48 components including hydrocarbons and non-hydrocarbons. Applying this equation of state, saturated liquid density, saturated vapor density, and vapor pressure of pure components are accurately reproduced compared with experimental values. Furthermore, the predicted properties including derivatives of alpha function, such as enthalpy of vaporization, entropy of vaporization and isobaric heat capacity of liquid, also have decent accuracy. The global average absolute relative deviation (AAD) of saturated liquid density, saturated vapor density, saturated vapor pressure, enthalpy of vaporization, entropy of vaporization, and isobaric heat capacity of liquid in a wide reduced temperature (Tr) range of subcritical region reproduced by this work are 4.33%, 4.18%, 3.19%, 2.26%, 2.27%, and 5.82%, respectively. Substantial improvement has been achieved for the isobaric liquid heat capacity calculation.</p>


1999 ◽  
Vol 166 (2) ◽  
pp. 163-181 ◽  
Author(s):  
Kh. Nasrifar ◽  
Sh. Ayatollahi ◽  
M. Moshfeghian

2019 ◽  
Author(s):  
zhiren he

<p>A new four-parameter cubic equation of state (EoS) is generated by incorporating the critical compressibility factor (Z<sub>c</sub>) apart from the critical pressure (P<sub>c</sub>) and temperature (T<sub>c</sub>). One free parameter in the denominator of the attractive term and two parameters in the alpha function are adjusted using the experimental data of saturated liquid density, vapor pressure, and isobaric liquid heat capacity of 48 components including hydrocarbons and non-hydrocarbons. Applying this equation of state, saturated liquid density, saturated vapor density, and vapor pressure of pure components are accurately reproduced compared with experimental values. Furthermore, the predicted properties including derivatives of alpha function, such as enthalpy of vaporization, entropy of vaporization and isobaric heat capacity of liquid, also have decent accuracy. The global average absolute relative deviation (AAD) of saturated liquid density, saturated vapor density, saturated vapor pressure, enthalpy of vaporization, entropy of vaporization, and isobaric heat capacity of liquid in a wide reduced temperature (Tr) range of subcritical region reproduced by this work are 4.33%, 4.18%, 3.19%, 2.26%, 2.27%, and 5.82%, respectively. Substantial improvement has been achieved for the isobaric liquid heat capacity calculation.</p>


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