In this paper,the Peng-Robinson equation of state with dynamic boundary conditions is discussed,which considers the interactions with solid walls.At first,the model is introduced and the regularization method on the n...In this paper,the Peng-Robinson equation of state with dynamic boundary conditions is discussed,which considers the interactions with solid walls.At first,the model is introduced and the regularization method on the nonlinear term is adopted.Next,The scalar auxiliary variable(SAV)method in temporal and finite element method in spatial are used to handle the Peng-Robinson equation of state.Then,the energy dissipation law of the numerical method is obtained.Also,we acquire the convergence of the discrete SAV finite element method(FEM).Finally,a numerical example is provided to confirm the theoretical result.展开更多
当气体在管道中流动时,遇到阀门、孔板等节流元件,由于压力显著降低形成节流现象,需要通过焦耳-汤姆逊系数预测温度的变化。对具有代表性的立方型状态方程,即Re dlich-Kw ong (RK)、 Soave-Re dlich-Kw ong (SRK)、 Pe ng-Robins on (PR...当气体在管道中流动时,遇到阀门、孔板等节流元件,由于压力显著降低形成节流现象,需要通过焦耳-汤姆逊系数预测温度的变化。对具有代表性的立方型状态方程,即Re dlich-Kw ong (RK)、 Soave-Re dlich-Kw ong (SRK)、 Pe ng-Robins on (PR)状态方程,以及多参数状态方程即Be ne dict-We bb-Rubin-Starling (BWRS)状态方程和对比态原理状态方程即Le e-Ke s le r-Plocke r (LKP)状态方程进行了焦耳-汤姆逊系数相关偏导数的推导,并给出了计算过程中涉及到的温度的一阶导数da/d T和Tda/d T公式及其单组分计算公式和多组分的混合规则。由具有代表性的状态方程推导出焦耳-汤姆逊系数公式,便于工程设计计算中使用。展开更多
Cubic equations of state(EOSs) are simple and easy at calculation. One way of improving the accuracy of a cubic EOS is through the modification of temperature-dependent energy parameter by using alpha-function.The ind...Cubic equations of state(EOSs) are simple and easy at calculation. One way of improving the accuracy of a cubic EOS is through the modification of temperature-dependent energy parameter by using alpha-function.The industrial applications of natural gas are very wide and as a result, prediction of thermodynamic properties and phase behavior of natural gas is an important part of design for such processes. In this work we develop a newα-function for the Peng-Robinson(PR) EOS with the parameters optimized especially for natural gas components.The parameters are generalized as a linear function of acentric factor. The results are compared to the predictions from original PR EOS and other α-functions in literature. It is shown that the new α-function presents a good accuracy with the average deviation of 1.42% for natural gas components.展开更多
This research proposes a modified two-dimensional Peng-Robinson equation model to predict adsorption isotherm in adsorbate-adsorbent systems. The parameters of the proposed model are calculated by using the optimizati...This research proposes a modified two-dimensional Peng-Robinson equation model to predict adsorption isotherm in adsorbate-adsorbent systems. The parameters of the proposed model are calculated by using the optimization of experimental data for the different single gas adsorption systems at various temperatures. The experimental adsorption equilibrium data of adsorbate-adsorbent systems was compared with the calculated results in our proposed model and the two-dimensional Hill-deBoer equation model. The proposed model as indicated in the results shows a better prediction of the experimental results compared with two others.展开更多
Solubility data of carbon dioxide （CO2） （1） in methanol （2）, 1-octyl-3-methylimidazolium bis（trifluoro- methylsulfonyl）imide （[omim]＋[TfzN]-） （3）, and their mixtures （w3 = 0.2, 0.5, and 0.8） at temperat...Solubility data of carbon dioxide （CO2） （1） in methanol （2）, 1-octyl-3-methylimidazolium bis（trifluoro- methylsulfonyl）imide （[omim]＋[TfzN]-） （3）, and their mixtures （w3 = 0.2, 0.5, and 0.8） at temperatures 313.2 and 333.2 K and pressures up to 7.0 MPa were measured by a high-pressure view-cell technique. The solubility of CO2 in methanol （w3 = 0）, [omim]＋[Tf2N]- （w3 = 1.0） and their mixtures follows the order of （w3 = 0）〈（w3 = 0.2）〈 （w3 = 0.5）〈（w3 = 0.8）〈（w3 = 1.0） at the same temperature and pressure, while the magnitude of Henry＇s constants follows the reverse order at a given temperature, which is consistent with the COSMO-RS （conductor-like screen- ing for real solvents） calculation. The solubility data of CO2 in methanol and [omim]~[Tf2N]- are correlated with the Peng-Robinson equation of state, and the solubility of CO2 in the mixtures of methanol and [omim]＋[TfzN] can be well predicted based on the mole fraction average of methanol and [omim]＋[Tf2N] over the solubility of CO2 in pure methanol and [omim]＋[Tf2N] . The mixtures of methanol and [omim]＋[Tf2N]- may be used as physical solvents for capturing CO2 with high partial pressures since they combine the advantages of organic solvents and ionic liquids.展开更多
Based on the surface chemical potential and Peng-Robinson equation of state,a newmodel is proposed to predict and correlate the surface tensions of binary and ternary liquid mix-tures.Using this method,the surface ten...Based on the surface chemical potential and Peng-Robinson equation of state,a newmodel is proposed to predict and correlate the surface tensions of binary and ternary liquid mix-tures.Using this method,the surface tensions of 73 binary and 8 ternary systems are calculatedwith average relative deviations 1.35% and 3.52% respectively.The proposed model is simple, re-liable and accurate.展开更多
The Peng-Robison equation of state,one of the most extensively applied equations of state in the petroleum industry and chemical engineering,has an excel-lent appearance in predicting the thermodynamic properties of a...The Peng-Robison equation of state,one of the most extensively applied equations of state in the petroleum industry and chemical engineering,has an excel-lent appearance in predicting the thermodynamic properties of a wide variety of ma-terials.It has been a great challenge on how to design numerical schemes with preser-vation of mass conservation and energy dissipation law.Based on the exponential time difference combined with the stabilizing technique and added Lagrange multi-plier enforcing the mass conservation,we develop the efficientfirst-and second-order numerical schemes with preservation of maximum bound principle(MBP)to solve the single-component two-phase diffuse interface model with Peng-Robison equation of state.Convergence analyses as well as energy stability are also proven.Several two-dimensional and three-dimensional experiments are performed to verify these theo-retical results.展开更多
基金the National Natural Science Foundation of China(No.11871441).
文摘In this paper,the Peng-Robinson equation of state with dynamic boundary conditions is discussed,which considers the interactions with solid walls.At first,the model is introduced and the regularization method on the nonlinear term is adopted.Next,The scalar auxiliary variable(SAV)method in temporal and finite element method in spatial are used to handle the Peng-Robinson equation of state.Then,the energy dissipation law of the numerical method is obtained.Also,we acquire the convergence of the discrete SAV finite element method(FEM).Finally,a numerical example is provided to confirm the theoretical result.
文摘当气体在管道中流动时,遇到阀门、孔板等节流元件,由于压力显著降低形成节流现象,需要通过焦耳-汤姆逊系数预测温度的变化。对具有代表性的立方型状态方程,即Re dlich-Kw ong (RK)、 Soave-Re dlich-Kw ong (SRK)、 Pe ng-Robins on (PR)状态方程,以及多参数状态方程即Be ne dict-We bb-Rubin-Starling (BWRS)状态方程和对比态原理状态方程即Le e-Ke s le r-Plocke r (LKP)状态方程进行了焦耳-汤姆逊系数相关偏导数的推导,并给出了计算过程中涉及到的温度的一阶导数da/d T和Tda/d T公式及其单组分计算公式和多组分的混合规则。由具有代表性的状态方程推导出焦耳-汤姆逊系数公式,便于工程设计计算中使用。
文摘Cubic equations of state(EOSs) are simple and easy at calculation. One way of improving the accuracy of a cubic EOS is through the modification of temperature-dependent energy parameter by using alpha-function.The industrial applications of natural gas are very wide and as a result, prediction of thermodynamic properties and phase behavior of natural gas is an important part of design for such processes. In this work we develop a newα-function for the Peng-Robinson(PR) EOS with the parameters optimized especially for natural gas components.The parameters are generalized as a linear function of acentric factor. The results are compared to the predictions from original PR EOS and other α-functions in literature. It is shown that the new α-function presents a good accuracy with the average deviation of 1.42% for natural gas components.
文摘This research proposes a modified two-dimensional Peng-Robinson equation model to predict adsorption isotherm in adsorbate-adsorbent systems. The parameters of the proposed model are calculated by using the optimization of experimental data for the different single gas adsorption systems at various temperatures. The experimental adsorption equilibrium data of adsorbate-adsorbent systems was compared with the calculated results in our proposed model and the two-dimensional Hill-deBoer equation model. The proposed model as indicated in the results shows a better prediction of the experimental results compared with two others.
基金Supported by the National Natural Science Foundation of China （21121064, 21076008）, and the Projects in the National Sci ence ＆ Technology Pillar Program During the Twelfth Five-Year Plan Period （2011BAC06B04）.
文摘Solubility data of carbon dioxide （CO2） （1） in methanol （2）, 1-octyl-3-methylimidazolium bis（trifluoro- methylsulfonyl）imide （[omim]＋[TfzN]-） （3）, and their mixtures （w3 = 0.2, 0.5, and 0.8） at temperatures 313.2 and 333.2 K and pressures up to 7.0 MPa were measured by a high-pressure view-cell technique. The solubility of CO2 in methanol （w3 = 0）, [omim]＋[Tf2N]- （w3 = 1.0） and their mixtures follows the order of （w3 = 0）〈（w3 = 0.2）〈 （w3 = 0.5）〈（w3 = 0.8）〈（w3 = 1.0） at the same temperature and pressure, while the magnitude of Henry＇s constants follows the reverse order at a given temperature, which is consistent with the COSMO-RS （conductor-like screen- ing for real solvents） calculation. The solubility data of CO2 in methanol and [omim]~[Tf2N]- are correlated with the Peng-Robinson equation of state, and the solubility of CO2 in the mixtures of methanol and [omim]＋[TfzN] can be well predicted based on the mole fraction average of methanol and [omim]＋[Tf2N] over the solubility of CO2 in pure methanol and [omim]＋[Tf2N] . The mixtures of methanol and [omim]＋[Tf2N]- may be used as physical solvents for capturing CO2 with high partial pressures since they combine the advantages of organic solvents and ionic liquids.
基金Project 29676020 supported by the National Nature Science Foundation of China.
文摘Based on the surface chemical potential and Peng-Robinson equation of state,a newmodel is proposed to predict and correlate the surface tensions of binary and ternary liquid mix-tures.Using this method,the surface tensions of 73 binary and 8 ternary systems are calculatedwith average relative deviations 1.35% and 3.52% respectively.The proposed model is simple, re-liable and accurate.
基金supported by National Natural Science Foundation of China under grant number No.11971047supported by National Natural Science Foundation of China under grant number No.61962056.
文摘The Peng-Robison equation of state,one of the most extensively applied equations of state in the petroleum industry and chemical engineering,has an excel-lent appearance in predicting the thermodynamic properties of a wide variety of ma-terials.It has been a great challenge on how to design numerical schemes with preser-vation of mass conservation and energy dissipation law.Based on the exponential time difference combined with the stabilizing technique and added Lagrange multi-plier enforcing the mass conservation,we develop the efficientfirst-and second-order numerical schemes with preservation of maximum bound principle(MBP)to solve the single-component two-phase diffuse interface model with Peng-Robison equation of state.Convergence analyses as well as energy stability are also proven.Several two-dimensional and three-dimensional experiments are performed to verify these theo-retical results.
