• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.1
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• pp.91-99
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• 1999

Vapor-liquid equilibrium apparatus is designed and set up. The equilibrium data of two binary systems, HFC-32/143a and HFC-143a/134a, are measured. Fifteen equilibrium data for HFC-32/143a and HFC-143a/134a systems are measured over the temperature range 263.15~283.15K at 10K interval and the composition range 0.10~0.80, respectively. And vapor-liquid equilibrium data are calculated using equation of state and correlation of activity coefficient and compared with the present data. Equation of state is used CSD and RKS equations and correlation of activity coefficient is used Margules' and Van Ness and Abbott's correlations. Real behavior of HFC-32/143a system has very large deviation with Raoult's rule which is ideal behavior. But real behavior of HFC-143a/134a system is similar to ideal behavior. The calculated data from CSD equation are compared with the data in the open literatures and the calculated data from REFPROP. In the results for REFPROP, the relative deviations of bubble point pressure for HFC-32/143a system are within -2.16~0.84% for CSD equation and within -0.20~1.10% for RKS equation. And the relative deviations of bubble point pressure for HFC-143a/134a system are within -0.45~0.12% and -0.20~2.8% for CSD and RKS equations, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.2055-2061
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• 2013

Recently, an understanding of new sources of liquid hydrocarbons such as bio-ethanol is economically very important. Successful design of distillation columns in a separation process depend on the availability of accurate vapor-liquid equilibrium data. For the binary system of Ethanol/3-methyl-l-butanol mixture, isothermal Vapor-liquid equilibrium data were measured at temperature of 50, 55, 60, 65, 70, 75 and $80^{\circ}C$. An empirical relation to predict Vapor-liquid equilibrium data was obtained from the above measured data. The predicted values are compared with the measured ones to be in a good agreement within accuracy of ${\pm}0.0005$, ${\pm}0.0022$.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.5 no.3
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• pp.217-225
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• 1993

Nonflammable mixtures of flammable and nonflammable refrigerants are possible as substitute refrigerants for use in domestic heat pumps and refrigerators. Refrigerant leakage from such a system is of paramount concern since it is possible that the resulting mixture composition remaining in system will reside in the flammable range. This paper presents a simulation of a leakage process of refrigerant mixtures. Idealized cases of isothermal leakage process are considered in this study representing a slow leak. Simulation is performed for selected composition of binary and ternary refrigerant mixture; R-32/134a and R-32/125/134a. Mixture compositions with respect to percentage leak of original charge are presented. In isothermal leakage process, both vapor and liquid compositions of more volatile refrigerant decrease during vapor and liquid leak, but the total composition of this component decreases during vapor leak and increases during liquid leak. Vapor and liquid compositions are determined depending on the vapor-liquid equilibrium relation of the refrigerant mixture. The refrigerant mixture left in the system can go to a nonflammable direction relying on which component in the mixture is flammable.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.39-44
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• 2016

Suitable design and operation of distillation process is very dependent on vapor-liquid equilibrium calculation. The usual calculation method is use binary interaction parameter. Flash points of n-propanol+n-butanol and 2-butanol+n-butanol were measured by Seta-flash closed cup tester. Experimental Flash points were compared with those calculated by the method based on Raoult's law and the optimization method using Wilson equation. The binary interaction parameters obtained by the optimization method are then used to calculate the bubble points of n-propanol+n-butanol and 2-butanol+n-butanol.

• Journal of the Korean Society of Industry Convergence
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• v.8 no.1
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• pp.37-45
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• 2005

Adsorption equilibrium data of pure solvent vapors (n-Hexane, Toluene, MEK) as well as their binary mixtures on activated carbon (sorbonorit $B_4$) were experimentally determined in the range of 293.2~323.2 K and beyond saturated vapor pressure corresponding to experimental temperature. Langmuir, Freundlich, LRC, W-VSM, FH-VSM were estimated for the predication of single component as well as binary mixtuer systems. The isosteric heat of adsorption at infinite dilution of pure n-hexane, toluene, MEK on activated carbon were 45.18, 25.85, 34.62 Kcal/mol, respectively, also, n-hexane-toluene binary adsorption of activated carbon formed an azeotrope at 293.2 K and total pressure 5.1~10.3 mmHg.

• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.663-670
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• 2009

Performing random number simulations, we obtained an approximate distribution of the number of ways arranging molecules in a binary lattice solution of nonrandom mixing with a specific interaction. From the distribution an approximate equation of excess Gibbs energy for a binary lattice solution was derived. Using the equation, liquid-vapor equilibrium at constant pressure for 15 binary solutions were calculated and compared with the result from Wilson equation, Van Laar equation and Redlich-Kister equation.

• 한국가스학회:학술대회논문집
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• 1998.09a
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• pp.139-142
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• 1998

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.10
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• pp.844-853
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• 2002

A dynamic model which simulates the coupled heat and mass transfer within a vertical tube absorber was developed. The liquid film is a binary mixture of two components, and both of these components are present in the vapor phase. The pressure, concentration, temperature and mass flow rate of the vapor are obtained by assuming that the pressure is uniform within an absorber. The model was applied to an absorber for an ammonia/water absorption refrigerator. The transient behaviors of the pressure, the outlet temperature and the concentration of the solution and the cooling water outlet temperature on a step change at the absorber inlet of the cooling water temperature, the vapor mass flow rate and the concentration of the solution were shown.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1196-1197
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• 2006

FePt binary-alloy nanopowder has been successfully synthesized by chemical vapor condensation process with two metal organic precursors, i.e., iron pentacarbonyl and platinum acetylacetonate. Average particle size of the powder was less than 50 nm with very narrow size distribution, revealing high dispersion capability. Characteristics of the powder could be controlled by changing process parameters such as reaction temperature, chamber pressure, as well as gas flow rate. Magnetic properties of the synthesized FePt nanopowder were investigated and analyzed in terms of the powder characteristics.

• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.302-308
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• 2015

Isothermal vapor liquid equilibria for the binary system of 3-methylpentane with ethylene glycol monopropyl ether ($C_3E_1$) and ethylene glycol isopropyl ether ($iC_3E_1$) were measured at 303.15, 318.15, and 333.15K. In our previous work, phase equilibria for the binary system of $C_3E_1$ mixtures were investigated according to the chain length of alkane, alcohol or those isomer. But in this study, we discussed the different effect of $C_3E_1$ and its isomer, $iC_3E_1$, on the phase equilibria. The measured systems were correlated with a Peng-Robinson equation of state (PR EOS) combined with Wong-Sandler mixing rule for the vapor phase, and NRTL, UNIQUAC, and Wilson activity coefficient models for the liquid phase. All the measured systems showed good agreement with the correlation results. And it was found that the phase equilibria showed very little difference between the $iC_3E_1$ mixture system and the $C_3E_1$ mixture system.