• 설비공학논문집
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• 제10권2호
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• pp.238-250
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• 1998

Vapor-liquid equilibrium apparatus is designed and set up. The vapor-liquid equilibrium data of the binary system HFC125/134a are measured in the range between 268.15 and 283.15K at five compositions. Twenty-five equilibrium data are obtained. To verify consistency of these data, they are tested for thermodynamic consistency. Based upon the present data, the binary interaction parameter for CSD and RKS equation of state is calculated at five isotherms and comparison with the data in the open literatures is made. Results of Nagel and Bier are in very good agreements with those from this study within 0.32∼1.11% for bubble point pressure and －0.66∼0.18% for vapor mole fraction.

• 설비공학논문집
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• 제15권7호
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• pp.563-571
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• 2003

The forty vapor-liquid equilibrium data of the binary system, HFC125＋Propane, were measured between 273.15 and 313.15 K at 10 K interval and the composition range 0.2∼0.75, respectively. Experiments were performed in a circulation type apparatus in which the vapor phase was forced through the liquid phase. The composition at equilibrium were mea-sured by gas chromatography, and its response was calibrated using gravimetrically prepared mixtures. Vapor-liquid equilibrium data were calculated by using CSD equation of state and compared with the experimental data.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.418-425
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• 2004

Characteristics of a liquid-vapor interface where a nonequilibrium condensation flow exists are considered based on molecular dynamics simulations, The condensation coefficient, the velocity distributions of the reflected and evaporated molecules and the number flux of the evaporated molecules are compared with those under the liquid-vapor equilibrium. The comparison shows that the condensation coefficient under the nonequilibrium condensation is slightly larger and the number flux of the evaporated molecules is considerably smaller than those under the liquid-vapor equilibrium. The net condensation flux under the nonequilibrium condensation is underestimated if it is evaluated from the condensation coefficient and the number flux of the evaporated molecules under the liquid-vapor equilibrium. However the underestimation is relatively small.

• 설비공학논문집
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• 제9권4호
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• pp.527-535
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• 1997

Vapor-liquid equilibrium apparatus is designed and set up. The vapor-liquid equilibrium data of the binary system HFC32/134a are measured in the range between 258.15 and 283.15K at compositions of 0.2, 0.4, 0.6 and 0.8 mole fraction of HFC32. Twenty-two equilibrium data are obtained. Based upon the present data, the binary interaction parameter for Carnahan-Starling-De Santis equation of state is calculated. Temperature range of data is extended to 313.04K using the data in the open literatures. Interaction parameters are determined at nine isotherms.

• 한국산학기술학회논문지
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• 제14권4호
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• pp.2055-2061
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• 2013

청정대체 에너지로 관심이 고조되고 있는 바이오 에탄올의 경제적 생산은 고유가 시대에 있어 매우 중요하다. 분리공정에서 성공적인 정류탑의 설계에는 정확한 기-액 평형치가 이용된다. 2성분 Ethanol/3-methyl-1-butanol 계에 대하여 정온하 즉 50, 55, 60, 65, 70, 75 및 $80^{\circ}C$에서 2성분 기-액평형측정치를 측정하고, 그 측정치를 이용하여 기액평형치를 추산하는 추산식을 이끌어 내었다. 측정치와 추산치를 비교 검토한 결과 ${\pm}0.0005$, ${\pm}0.0022$의 범위 내에서 잘 일치함을 확인하였다.

• 한국가스학회지
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• 제14권2호
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• pp.22-26
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• 2010

본 연구에서는 PC-SAFT 모델식을 활용하여 메탄과 에탄의 온도에 따른 증기압과 기상 및 액상에서의 밀도를 추산하였으며, 그 결과를 PR 상태방정식과 비교하였다. 기상의 밀도에 대해서는 두 모델이 모두 실험 데이터를 잘 추산하였으며, 액상의 밀도에 대해서는 PR 상태방정식보다 PC-SAFT 모델식이 좀 더 정확함을 알 수 있었다. 한편 메탄과 에탄 이성분계에 대한 기-액 상평형 실험 데이터에 대해서 두 모델식을 이용하여 추산하였는데 PC-SAFT 모델식이 PR 상태방정식보다 좀 더 우수함을 알 수 있었다.

• 설비공학논문집
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• 제12권6호
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• pp.589-598
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• 2000

The vapor-liquid equilibrium and miscibility measurement apparatus was developed and used to obtain data for refrigerant/oil mixture. The vapor-liquid equilibrium and miscibility data for R-410a/POE32 and R-410A/POE46 oil mixtures are obtained over the temperature range from -20 to $60^{\circ}C\;with\;10^{\circ}C$ intervals and the oil concentration range from 0 to 90 wt%. Using the experimental data, an empirical model is developed to predict the temperature-pressure-concentration relations for R-410A/POE oil mixtures at equilibrium. In the R-410A/POE32 oil mixture, the average root-mean-square deviation between measured data and calculated results from the empirical model is 2.00% and in the R-410a/POE46 oil mixture, that is 3.69%. Flory-Huggins theory is also used to predict refrigerant/oil mixture behavior. Miscibility for R-410A/POE32 oil mixture was observed all over the experimental conditions. Immiscibility for R-410A/POE46 oil mixture was observed at the low oil concentrations(10~30 wt%).

• 한국산업융합학회 논문집
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• 제7권1호
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• pp.97-105
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• 2004

The Vapor-liquid equilibrium data for the binary system of 2-methyl-2-propanol-2-butanone are measured at subatmospheric pressure of 100, 200, 300, 400, 500, 600, 700 and 760 torr. This study shows that the relations between logarithmic values of relative valatility(log ${\alpha}$)and liquid phase composition(${\chi}$) in the above binary systems are expressed as a linear function. When the linear relationships of between logarithmic values of relative volatilities and liquid phase compositions in the binary systems of various pressure intersect at a point, this empirical equation can be applied to the systems of this kind. From these relations the vapor-liquid equilibrium data are estimated and compared with the measured values to be in a good agreement with in accuracy ${\pm}0.0021$ for the various pressure.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.25.1-25.1
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• 2005

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1584-1589
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• 2003

This work applies the equilibrium molecular dynamics simulation method to study a Lennard-Jones liquid thin film suspended in the vapor and calculates diffusion coefficients by Green-Kubo equation derived from Einstein relationship. As a preliminary test, the diffusion coefficients of the pure argon fluid are calculated by equilibrium molecular dynamics simulation. It is found that the diffusion coefficients increase with decreasing the density and increasing the temperature. When both argon liquid and vapor phases are present, the effects of the system temperature on the diffusion coefficient are investigated. It can be seen that the diffusion coefficient significantly increases with the temperature of the system.