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用SRK方程与PR方程求算双组分混合气体热力学性质 总被引:1,自引:0,他引:1
流体热力学性质的计算是化工热力学中的一类重要计算,立方型方程经常用于这类计算中。SRK方程与PR方程是在RK方程基础上发展而来的,具有比RK方程更好的计算精度。但现有教材中没有给出PR方程和SRK方程的剩余焓、剩余熵的计算公式,缺失了流体热力学性质计算的系统性。本文通过立方型状态方程的一般形式推导出PR方程和SRK方程的剩余焓、剩余熵的计算公式,利用Excel电子表格计算双组分混合气体的热力学性质。计算过程简捷明了,利于学生更好地理解混合物热力学性质的计算过程。 相似文献
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本文对计算孔径分布的Broekhoff方程做了简化,得到一组近似方程,实例计算结果证明它和原方程等效.近似方程的优点在于能制成专用机与吸附仪联用,加快数据处理.近似方程的适用范围为:10(?)—300(?) 相似文献
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<正>液体混合物的汽液平衡数据和粘度数据都是基本的物性数据,人们很早就开始了对它们的研究,并取得了不小的进展.对于汽液平衡的研究,人们提出了许多溶液理论和活度系数方程,例如Flory-Huggins方程,Van Laar方程,Margules方程,Wilson方程和其修正方程,NRTL方程以及UNIQUAC方程等;对于液体混合物的粘度,人们也提出了许多流体粘度理论,其中最著名的是Eyring反应速率理论.作者曾应用这一理论建立了一个新的液体混合物粘度方程,用于关联二元体系的粘度数据和推算多元体系的粘度数据,结果令人满意. 相似文献
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为获得正确的浮子流量计流量方程,对现有习用浮子流量计流量方程在理论推导过程中存在的问题进行讨论,针对习用流量方程中物理概念混淆、忽略浮子高度和选用非典型浮子模型的问题进行了修正,推导出新浮子流量计流量方程:Q=αAR2g特征曲线。新浮子流量计流量方程相对于原有流量方程能够更合理的描述浮子流量计的工作机理。 相似文献
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利用分子动力学(MD)模拟验证了含醇溶液的无限稀释扩散系数模型和不同浓度溶液的扩散系数模型.选用的溶质分别为甲醇、乙醇、丙醇、异丙醇、正丁醇和甘油,温度为293.15K,压力为0.1MPa.计算结果表明:Dullien和Asfour方程适用于计算甲醇和乙醇溶液的扩散系数DAB;而对于其它醇溶液的扩散系数,Leffler和Cullinan方程较适用. 相似文献
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This naver analvzes the surface emission coefficient corresponding to anv diffusion coefficient expressed as an exponential function of the concentration diffusing substance in capillary porous solids. Theoretical equations for surface emission coefficient for both sorption and desorption are presented. Procedures to derive the diffusion coefficient and to verify the corresponding surface emission coefficient are made using experimental sorption data of aspen (Populur sp.) wood. It is of interest to note that the theoretical models for diffusion and surface emission coefficients can be established and/or evaluated using the same set of experimental dara. 相似文献
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ABSTRACT This naver analvzes the surface emission coefficient corresponding to anv diffusion coefficient expressed as an exponential function of the concentration diffusing substance in capillary porous solids. Theoretical equations for surface emission coefficient for both sorption and desorption are presented. Procedures to derive the diffusion coefficient and to verify the corresponding surface emission coefficient are made using experimental sorption data of aspen (Populur sp.) wood. It is of interest to note that the theoretical models for diffusion and surface emission coefficients can be established and/or evaluated using the same set of experimental dara. 相似文献
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《分离科学与技术》2012,47(12-13):1799-1811
Abstract The Stefan-Maxwell multicomponent diffusion equations were used to characterize albumin transport in ultrafiltration membranes in both an unstirred batch filtration device and a well-stirred diffusion cell. We developed a theoretical model for ultrafiltrate flux and concentration in the filtration device that explicitly incorporates the effects of protein polarization, protein osmotic pressure, and a flux-dependent sieving coefficient. Experimental data were in good agreement with model predictions, providing quantitative evidence for the predicted dependence of the apparent sieving coefficient on flux. Experimental data in the diffusion cell indicate that the effective albumin diffusivity in the 50,000 molecular weight cut-off membranes was four orders of magnitude less than the Brownian motion value. The Stefan-Maxwell diffusivities evaluated independently in the two experimental systems were in excellent agreement, indicating the general applicability of the Stefan-Maxwell approach to protein transport in ultrafiltration membranes. 相似文献
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The relationship between osmotic pressure difference across the membrane and mass transfer coefficient is developed in this paper. On the basis of this relationship, a method for measuring mass transfer coefficient by using experimental data on reverse osmosis is established. Pitzer's equations are used to calculate osmotic pressure differences in order to assure accuracy of results. Under the conditions of constant operating pressure and bulk flow, mass transfer coefficient is scarcely affected by membrane structure, but decreases slightly with increasing feed concentration. The solute concentration in the polarization layer is calculated by using the measured values of mass transfer coefficient. Polarization layer concentration increases with augmentation in bulk concentration. However, their difference increases with increasing bulk concentration until a maximum difference is reached, and then decreases. Mass transfer coefficient increases with higher velocity of bulk flow. If mass transfer coefficient is so large that the ratio(PwΔπσ/k)becomes very small, polarization could be neglected. 相似文献
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The model of structural relaxation by Narayanaswamy deals only with the constant temperature coefficients of the glass property, p. The assumption is seldom valid for real glasses. In this work, equations are obtained for the fictive temperature of glass if the temperature coefficient, dp/dT, is a linear function of T or of 1 /T2 . The temperature dependence of p has no significant influence on the calculated fictive temperatures. 相似文献
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Osmotic coefficient data for aqueous sodium polyanetholesulfonic acid, sodium polyacrylate and polydiallyl dimethylammonium chloride solutions were determined at 298 K by employing the isopiestic method. The measured osmotic coefficients increase with increasing concentration in the experimental concentration range (0.1-1.5 m). A molecular thermodynamic model developed previously for polyelectrolyte solutions has been used to fit the experimental data. The concentration dependence of the osmotic coefficients can be described satisfactorily. 相似文献
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The drop volume technique has been used to measure the equilibrium and dynamic interfacial tension at the liquid/liquid interfaces of selected hydroxyoximes, as examples of chelating type hydrophobic metal ion extractants. The measurements for the kinetics of adsorption enable the calculation of diffusion coefficients. In this paper, new methods for the estimation of the diffusion coefficient by Fick's and the Maxwell‐Stefan equations are presented. The calculated values of the diffusion coefficient were compared with the values obtained from the short and long time approximation models of the Ward‐Tordai equation. The influence of the organic phase and the addition of non‐organic electrolyte to the aqueous phase on the estimated values of the diffusion coefficients were investigated. 相似文献
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The stoichiometric matrix of a simplified metabolic network in Bacillus Subtillis was contructed from the flux balance equations, which were used for reconciliation of the measured rates and determination of the inner metabolic rates. Thus more reliable results of the true and empirical maintenance coefficients were obtained. The true maintenance coefficient is linearly related to the specific growth rate and changes with the P/O ratiol. The neasured biomass yield of adenosine triphosphate (ATP) is also linearly related to the P/O ratio. 相似文献