• Title/Summary/Keyword: Peng-Robinson equation of state

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An Experimental Study on Vapor-Liquid Equilibria of HFC and HC Refrigerant Mixtures (탄화수소 및 불화탄화수소 혼합냉매의 기상-액상 평형에 관한 실험적 연구)

  • 강병복;김민수;김영일
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.11
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    • pp.1031-1037
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    • 2000
  • Isothermal vapor-liquid equilibrium(VLE) data have been obtained for the systems of propane(R290)+1,1,1,2-tetrafluoroethane(R134a) and 1,1,1,2-tetrafluoroethane(R134a)+isobutane(R60A) in the temperature range of 253.15 to 323.15K. Experiments were performed in a circulation type apparatus by injecting vapor through liquid pool using a magnetic pump. Both systems form azeotropes in the temperature range of this study. The experimental results were estimated with the Peng-Robinson equation of state. When the temperature-dependent binary interaction parameter was used in the Peng-Robinson equation of state, the absolute average deviation of the measured bubble point pressures from the values correlated by the Peng-Robinson equation was 0.65% and 0.78% for R290+R134a and R134a+600a, respectively. Azeotropic compositions for both systems were presented.

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Comparative Study on the Properties Estimation of the Constituents of the Natural Gas and Refrigerant Mixtures Between GERG-2004 Model and Peng-Robinson Equation of State (GERG-2004 모델식과 Peng-Robinson 상태방정식을 이용한 천연가스 및 냉매 구성성분들의 물성 비교연구)

  • Kim, Mi-Jin;Rho, Jae-Hyun;Kim, Dong-Sun;Cho, Jung-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.2
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    • pp.906-918
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    • 2012
  • In this study, we compared with results simulated by EOS(Equation of State) using Peng-Robinson model and GERG-2004 model for estimating vapor pressure, latent heat of vaporation, liquid density, and binary isotherm vapor-liquid equilibrium on pure components composing natural gases. We obtained the simulated results that while EOS using GERG-2004 model is more accurate than EOS using Peng-Robinson model for estimating liquid density, but rather it is less accurate for estimating binary isotherm vapor-liquid equilibrium. On the other hand, the use of Costald model in EOS using Peng-Robinson model for increasing more accuracy to calculate liquid density is almost same as EOS using GERG-2004 model within the error of 1 % compared with experimental data. Also, we confirmed that on the estimation of binary isotherm vapor-liquid equilibrium, EOS using GERG-2004 model is more accurate than EOS using Peng-Robinson model, but they are almost same.

Prediction of partial molar volumes of solutes in supercritical CO2 using the Peng-Robinson equation of state with various mixing rules and Kirkwood-Buff solution theory (3차 상태방정식과 여러 혼합법칙 및 Kirkwood-Buff용액이론을 이용한 초임계유체내에서의 용질의 무한희석 부분몰부피의 계산)

  • Jeon, Young-Pyo;Park, Jong-Seon;Kwon, Yong-Jung
    • Journal of Industrial Technology
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    • v.19
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    • pp.253-260
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    • 1999
  • Two thermodynamic models were used to predict the partial molar volumes of solutes in supercritical carbon dioxide at infinite dilution: (1) the Peng-Robinson equation of state with various mixing rules including those based on $EOS/G^E$ (2) the Kirkwood Buff fluctuation integral with the hard sphere expansion (HSE) method. The Kirkwood-Buff fluctuation integral method, in which an equation of state for pure component and molecular parameters are required, produced better results especially near the critical point than the Peng-Robinson equation of state with the several mixing rules based an $EOS/G^E$. When the $EOS/G^E$ mixing rules were used, poorer results were obtained compared with the classical mixing rule and Kirkwood-Buff model.

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Density Measurement of Liquid Mixture and Estimation of Excess Molar Volume by A Cubic Equation of State (액체혼합물의 밀도 측정과 3차 상태방정식에 의한 과잉 몰부피의 예측)

  • Kim, Jung-Min;Bae, Hyo-Kwang
    • Korean Chemical Engineering Research
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    • v.43 no.5
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    • pp.637-640
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    • 2005
  • The density of polar-nonpolar liquid mixtures composed of methyl tert-butyl ether(MTBE) and 2,2,4-trimethylpentane, and methyl ethyl ketone (MEK) and 2,2,4-trimethylpentane, and the density of polar-polar liquid mixture of MTBE and MEK were measured by densitometer at 278.15 K, 288.15 K and 298.15 K, respectively. The excess molar volume of the binary systems calculated from the measured density was shown good agreement with the calculated one by the cubic Peng-Robinson- Stryjek-Vera (PRSV) equation of state together with Huron-Vidal mixing rule and it confirmed that the cubic PRSV equation of state could be used in the molar volume calculation of polar mixture.

Vapor-Liquid Equilibria of Carbon Dioxide and Propane Mixtures (이산화탄소와 프로판 혼합냉매의 기상-액상 평형)

  • Kim, Ju-Hyok;Kim, Min-Soo;Kim, Man-Hoe
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.11
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    • pp.859-866
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    • 2006
  • This paper presents the vapor-liquid equilibrium (VLE) data measured for carbon dioxide and propane mixtures. Their mixtures were considered as promising alternative refrigerants due to good thermophysical properties and negligible environmental impact. The isothermal VLE data were measured at eight temperatures ranging from 253.15 to 323.15 K in the circulation type equipment with a view cell. The binary system was found to be a zeotropic mixture in the tested temperature range and could be correlated with sufficient accuracy by using the Peng-Robinson equation of state (PR EoS) with the van der Waals one fluid mixing rule. A comparison with published experimental VLE data has been carried out by means of the PR equation of state. In addition, the phase behaviors of carbon dioxide and propane mixtures were analyzed based on the measured VLE data.

A Study on the Simulation of LPG Refrigeration Cylcle Using Pure Propane Refrigerant (순수한 프로판 냉매를 사용한 액화석유가스 냉동사이클의 모사에 관한 연구)

  • Cho Jung-Ho
    • Journal of the Korean Institute of Gas
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    • v.10 no.1 s.30
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    • pp.38-42
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    • 2006
  • In this study, a simulation technology for refrigeration cycle which can liquefy and store liquified petroleum gas (LPG) using pure propane as a refrigerant has been introduced. Cooling water as the second cooling medium was used for the liquefaction of propane. Peng-Robinson equation of state was used for the entire refrigeration cycle. A new alpha formulation proposed by Twu et al. was used for the more accurate prediction of vapor pressures of pure propane component and LPG constituents. API method for the accurate estimation of liquid densities of propane and LPG was used instead of using Peng-Robinson equation of state. PRO/II with PROVISION release 7.1, a general purpose chemical process simulator was used for the simulation of the overall refrigeration system. Through this work, we can successfully simulate the real propane refrigeration plant operating at domestic site.

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Measurement and Modeling of Bubble Points for Binary Mixtures of Carbon Dioxide and N,N-Dimethylformamide (이산화탄소와 디메틸포름아마이드 혼합물의 기포점 측정 및 모델링)

  • Jung, Joon-Young;Lee, Byung-Chul
    • Clean Technology
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    • v.17 no.1
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    • pp.19-24
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    • 2011
  • The bubble point pressures of binary mixtures of carbon dioxide ($CO_2$) and N,N-dimethylformamide (DMF) were measured by using a high-pressure experimental apparatus equipped with a variable-volume view cell, at various $CO_2$ compositions in the range of temperatures above the critical temperature of $CO_2$ and below the critical temperature of DMF. The experimental bubble point pressure data were correlated with the Peng-Robinson equation of state (PR-EOS) to estimate the corresponding dew point compositions at equilibrium with the bubble point compositions. The experimentally measured bubble point pressures gave good agreement with those calculated by the PR-EOS. The variable-volume view cell equipment was verified to be an easy and quick way to measure the bubble point pressures of high-pressure compressible fluid mixtures.

Sensitivity of EOS in Analyzing the High-Pressure Vaporization Characteristics (고압 상태의 증발 특성 해석결과에 미치는 상태방정식의 영향)

  • You, Y.W.;Kim, Y.M.
    • Journal of ILASS-Korea
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    • v.2 no.3
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    • pp.32-43
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    • 1997
  • A comparison of predicted molar volume, vapor - liquid equilibrium, enthalpy of vaporization, droplet size history. and vaporization rates with several forms of equation of state has been made. The equation of state (EOS) investigated in this study includes the EOS given by Redlich - Kwong, the Soave - Redlich - Kwong, and the Peng - Robinson. Numerical results indicate that the Peng - Robinson EOS yields more accurate predictions of vapor - liquid equilibrium under a broader range of temperature and pressure conditions, especially at high pressures and near the critical point.

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A Study on the Computer Simulation for the Complete Combustion Reaction of PCBs in Supercritical Water (초임계수 내에서 PCBs 완전산화반응의 전산모사에 관한 연구)

  • Cho, Jungho;Kim, Kyeongsook;Son, Soon Hwan;Kim, Yeong-Cheol
    • Korean Chemical Engineering Research
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    • v.45 no.1
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    • pp.46-51
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    • 2007
  • In this study, computer simulations have been performed for the removal of the transformer oil contaminated with polychlorinated biphenyls (PCBs) in supercritical water through complete combustion reaction. We regarded n-decane as a main material of transformer oil, and it is assumed to be 3.0 wt% of transformer oil in supercritical water. We used Peng-Robinson equation of state to estimate the physical properties of components in supercritical water. Throughout the computer simulation done in this work, we could explain the solubilities of 3.0 wt% of transformer oil and excess oxygen in supercritical water.

Investigation of Thermophysical Properties of the Kerosene Using the Surrogate Model Fuel at Supercritical Conditions (초임계 영역에서 대체 모델 연료를 이용한 케로신의 열역학적 상태량 연구)

  • Kim, Kuk-Jin;Heo, Jun-Young;Sung, Hong-Gye
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.8
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    • pp.823-833
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    • 2010
  • For the study of thermophysical properties of kerosene for the liquid rocket and aviation fuels, the surrogate models are investigated. The density distributions based on the real gas equations of state(Soave modification of Redlich-Kwong and Peng-Robinson equation of state) and NIST SUPERTRAPP(extended corresponding state principle) are compared with the previous experimental results at supercritical conditions. The error range of thermophysical properties analyzed for the surrogate models as well. Peng-Robinson equation of state and extended corresponding state principle are especially accurate for the hydrocarbon fuels but the appropriate surrogate models need to be chosen to the operation conditions such as pressure and temperature.