scholarly journals Predictions of the vapor-liquid equilibrium data for low-GWP Hydrofluorocarbons + polyethylene-glycol dimethylether solvents by modified UNIFAC model

2021 ◽  
Vol 267 ◽  
pp. 02052
Author(s):  
Xiao Zhang ◽  
Liang Cai ◽  
Jingyi Qiao
Keyword(s):  
Experimental Data ◽  
Polyethylene Glycol ◽  
Large Deviations ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Liquid Equilibrium ◽  
Unifac Model ◽  
Equilibrium Data ◽  
Vle Data ◽  
Absorption Refrigeration System

The working fluids are crucial for developing the absorption refrigeration system. Our previous work has proposed three novel working pairs, which uses the low-GWP HFCs (R32, R152a and R161) as the refrigerants and the polyethylene-glycol dimethylether solvent DMETEG as the absorbent. To explore the VLE behaviors of HFCs in other longer chain structures of polyethylene-glycol dimethylether solvents, the modified UNIFAC (Dortmund) model was applied for prediction. The previous binary parameters showed large deviations from the experimental data. Then the new binary parameters were obtained by regression. For R32+DMEDEG and R152a/R161+DMETrEG, the prediction ARAD results were reduced from 17.13%, 24.06% and 12.48% to 3.71%, 2.61% and 6.86%, respectively. Finally, the VLE data of R161 + PGDE at the temperatures of 293.15-343.15K were predicted.

Isobaric Vapor-Liquid Equilibria of Hexamethyl Disiloxane + Ethyl Acetate System at Normal Pressure

2011 ◽  
Vol 396-398 ◽  
pp. 968-972
Author(s):  
Wen Lin Zhang ◽  
Nan Meng ◽  
Ru Yi Sun ◽  
Chun Li Li
Keyword(s):  
Experimental Data ◽  
Ethyl Acetate ◽  
Normal Pressure ◽  
Liquid Equilibrium ◽  
Vapor Liquid Equilibrium ◽  
Equilibrium Data ◽  
Vle Data ◽  
Vapor Liquid Equilibria ◽  
Ethyl Acetate System ◽  
Vapor Liquid

Vapor-liquid equilibrium data of hexamethyl disiloxane + ethyl acetate system at 101.3kPa were measured by using double circulating vapor-liquid equilibrium still. The thermodynamic consistency of the VLE data was examined by Herrington method. Experimental data was correlated by NRTL and UNIQUAC parameter models. Both of the models satisfactorily correlated with the VLE data. The result showed that the NRTL model was the most suitable one to represent experimental data satisfactorily and the system had a minimum temperature azeotrope at 350.31 K and the mole azeotropic composition was 0.0330.

scholarly journals Simulation research on absorption refrigeration system based on NH3-H2O-LiBr vapor-liquid equilibrium calculation model

2021 ◽  
pp. 201-201
Author(s):  
Shan Wang ◽  
Shuhong Li ◽  
Mengkai Xu ◽  
Zhenghao Jin ◽  
Chengcheng Xu
Keyword(s):  
Liquid Phase ◽  
Lithium Bromide ◽  
Calculation Model ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Liquid Equilibrium ◽  
Equilibrium Calculation ◽  
Vapor Liquid Equilibrium ◽  
Temperature Range ◽  
Absorption Refrigeration System

In order to investigate the ammonia + water + lithium bromide absorption refrigeration cycle process and to simulate it accurately, a vapor-liquid equilibrium calculation model was proposed to obtain thermodynamic characteristic data of the ternary mixtures. The calculation of parameters of liquid phase is based on Wilson?s equation and NRTL equation. The vapor phase, assumed to consist of ammonia and water only, is described by The Redlich-Kwong Equation of State. The data of the equilibrium vapor pressure and the ammonia concentration in liquid phase calculated by this model was compared with the experimental data, the difference is between 0.5% to 9.6% within the temperature range from303 K to 425 K. The COP obtained by the simulation matches with that obtained by experiment and the absolute deviation is less than 0.02. Therefore, this calculation model can be used for simulation to extend the temperature range and pressure range of the system, so as to determine the design parameters of the absorption refrigeration system. The simulation results indicates that under different working conditions, the optimal generator temperature and concentration of adding lithium bromide can be selected, to which the theoretical explanations were given in this paper.

scholarly journals Use of the SSF equations in the Kojima-Moon-Ochi thermodynamic consistency test of isothermal vapour-liquid equilibrium data

2000 ◽  
Vol 65 (12) ◽  
pp. 877-889
Author(s):  
Jelena Jelic ◽  
Aleksandar Tasic ◽  
Bojan Djordjevic ◽  
Slobodan Serbanovic
Keyword(s):  
Experimental Data ◽  
Binary Systems ◽  
Thermodynamic Consistency ◽  
Data Sets ◽  
Liquid Equilibrium ◽  
Consistency Test ◽  
Equilibrium Data ◽  
Vle Data ◽  
Kister Equation

The Kojima-Moon-Ochi (KMO) thermodynamic consistency test of vapour-liquid equilibrium (VLE) measurements for 32 isothermal data sets of binary systems of various complexity was applied using two fitting equations: the Redlich-Kister equation and the Sum of Symmetrical Functions. It was shown that the enhanced reliability of the fitting of the experimental data can change the conclusions drawn on their thermodynamic consistency in those cases of VLE data sets that are estimated to be near the border of consistency.

Vapour-phase non-ideality in low-pressure vapour-liquid equilibrium data correlation

1980 ◽  
Vol 45 (11) ◽  
pp. 3057-3062 ◽  
Author(s):  
Jan Linek
Keyword(s):  
Experimental Data ◽  
Phase Composition ◽  
Liquid Phase ◽  
Low Pressure ◽  
Vapour Phase ◽  
Liquid Equilibrium ◽  
Ideal Behavior ◽  
Equilibrium Data ◽  
Vle Data ◽  
Volumetric Behavior

The effect of vapour-phase imperfections and the volumetric behavior of liquid phase on the low-pressure VLE data reduction was investigated. The errors in the vapour-phase composition due to processing experimental data assuming ideal behavior of the vapour phase were evaluated.

scholarly journals Theoretical Formulation of the Thermodynamic Properties of Ammonia-Water and Ammonia-Water-Lithium Bromide Solutions

2020 ◽  
Vol 9 (2) ◽  
pp. 683-687
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Lithium Bromide ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Theoretical Formulation ◽  
Ammonia Water ◽  
Absorption Refrigeration System ◽  
Bromide Solutions ◽  
Good Agreement

System of Ammonia-Water-Lithium Bromide overcomes the disadvantage of Ammonia-Water absorption refrigeration system. Addition of lithium bromide reduces the formation of water vapour thus presents its entry into the condenser. A set of computational formulations of thermodynamic and Thermophysical properties of Ammonia-Water, Water-Lithium bromide and Ammonia-Water-Lithium Bromide solutions at different pressures and temperatures are presented in the paper. Obtained results are validated with the experimental data which were available in the literature. It is found to be in good agreement with those values of the literature..

Modeling and Simulation of the Absorber of an Absorption Refrigeration System

2018 ◽  
Author(s):  
Leonardo Cavalheiro Martinez ◽  
Wellington Balmant ◽  
Iago Costa ◽  
Matias Nicolas Muñoz ◽  
Luiz Rigatti ◽  
...  
Keyword(s):  
Modeling And Simulation ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Absorption Refrigeration System

Isothermal and isobaric vapour-liquid equilibrium data in the tetrachloromethane-sec-butyl alcohol system

1983 ◽  
Vol 48 (9) ◽  
pp. 2446-2453 ◽  
Author(s):  
Jan Linek
Keyword(s):  
Experimental Data ◽  
Boiling Point ◽  
Butyl Alcohol ◽  
Correlation Equations ◽  
Wilson Equation ◽  
Liquid Equilibrium ◽  
Raoult’S Law ◽  
System A ◽  
Equilibrium Data ◽  
Alcohol System

Isothermal vapour-liquid equilibrium data at 65, 73 and 80 °C and isobaric ones at 101.3 kPa were measured in the tetrachloromethane-sec-butyl alcohol system. A modified circulation still of the Gillespie type was used for the measurements. Under the conditions of measurement, the system exhibits positive deviations from Raoult's law and minimum boiling-point azeotropes. The experimental data were fitted to a number of correlation equations, the most suitable being the Wilson equation.

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